| blob | f5bd842df0eb4f78dfdcc105cd42ae463c605de7 |
1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2014 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
4 Rewritten by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Known bugs or deficiencies include:
24 all methods must be provided in header files; can't use a source
25 file that contains only the method templates and "just win". */
50 /* The type of functions taking a tree, and some additional data, and
51 returning an int. */
54 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
55 instantiations have been deferred, either because their definitions
56 were not yet available, or because we were putting off doing the work. */
60 };
75 /* Live only within one (recursive) call to tsubst_expr. We use
76 this to pass the statement expression node from the STMT_EXPR
77 to the EXPR_STMT that is its result. */
80 /* True if we've recursed into fn_type_unification too many times. */
84 {
85 tree tmpl;
86 tree args;
87 tree spec;
88 };
91 {
94 };
100 /* Contains canonical template parameter types. The vector is indexed by
101 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
102 TREE_LIST, whose TREE_VALUEs contain the canonical template
103 parameters of various types and levels. */
106 #define UNIFY_ALLOW_NONE 0
107 #define UNIFY_ALLOW_MORE_CV_QUAL 1
108 #define UNIFY_ALLOW_LESS_CV_QUAL 2
109 #define UNIFY_ALLOW_DERIVED 4
110 #define UNIFY_ALLOW_INTEGER 8
111 #define UNIFY_ALLOW_OUTER_LEVEL 16
112 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
113 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
116 tbr_incomplete_type,
117 tbr_ambiguous_baseclass,
118 tbr_success
119 };
142 tree);
204 location_t);
212 /* Make the current scope suitable for access checking when we are
213 processing T. T can be FUNCTION_DECL for instantiated function
214 template, VAR_DECL for static member variable, or TYPE_DECL for
215 alias template (needed by instantiate_decl). */
217 static void
219 {
227 else
231 {
232 saved_access_scope = tree_cons
235 }
236 }
238 /* Restore the scope set up by push_access_scope. T is the node we
239 are processing. */
241 static void
243 {
245 {
248 }
252 else
254 }
256 /* Do any processing required when DECL (a member template
257 declaration) is finished. Returns the TEMPLATE_DECL corresponding
258 to DECL, unless it is a specialization, in which case the DECL
259 itself is returned. */
261 tree
263 {
270 {
271 tree type;
279 {
283 }
285 }
289 {
291 {
294 }
295 else
297 }
298 else
302 }
304 /* Create a template info node. */
306 tree
308 {
313 }
315 /* Return the template info node corresponding to T, whatever T is. */
317 tree
319 {
340 }
342 /* Returns the template nesting level of the indicated class TYPE.
344 For example, in:
345 template <class T>
346 struct A
347 {
348 template <class U>
349 struct B {};
350 };
352 A<T>::B<U> has depth two, while A<T> has depth one.
353 Both A<T>::B<int> and A<int>::B<U> have depth one, if
354 they are instantiations, not specializations.
356 This function is guaranteed to return 0 if passed NULL_TREE so
357 that, for example, `template_class_depth (current_class_type)' is
358 always safe. */
360 int
362 {
369 {
375 }
378 }
380 /* Subroutine of maybe_begin_member_template_processing.
381 Returns true if processing DECL needs us to push template parms. */
383 static bool
385 {
391 }
393 /* Subroutine of maybe_begin_member_template_processing.
394 Push the template parms in PARMS, starting from LEVELS steps into the
395 chain, and ending at the beginning, since template parms are listed
396 innermost first. */
398 static void
400 {
408 current_template_parms
414 NULL);
416 {
425 {
432 {
433 /* Make a CONST_DECL as is done in process_template_parm.
434 It is ugly that we recreate this here; the original
435 version built in process_template_parm is no longer
436 available. */
446 }
451 }
452 }
453 }
455 /* Restore the template parameter context for a member template, a
456 friend template defined in a class definition, or a non-template
457 member of template class. */
459 void
461 {
462 tree parms;
467 {
470 /* Disregard full specializations (c++/60999). */
473 }
476 {
481 {
484 }
487 }
489 /* Remember how many levels of template parameters we pushed so that
490 we can pop them later. */
492 }
494 /* Undo the effects of maybe_begin_member_template_processing. */
496 void
498 {
507 {
511 }
512 }
514 /* Return a new template argument vector which contains all of ARGS,
515 but has as its innermost set of arguments the EXTRA_ARGS. */
517 static tree
519 {
520 tree new_args;
538 }
540 /* Like add_to_template_args, but only the outermost ARGS are added to
541 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
542 (EXTRA_ARGS) levels are added. This function is used to combine
543 the template arguments from a partial instantiation with the
544 template arguments used to attain the full instantiation from the
545 partial instantiation. */
547 static tree
549 {
550 tree new_args;
552 /* If there are more levels of EXTRA_ARGS than there are ARGS,
553 something very fishy is going on. */
556 /* If *all* the new arguments will be the EXTRA_ARGS, just return
557 them. */
561 /* For the moment, we make ARGS look like it contains fewer levels. */
566 /* Now, we restore ARGS to its full dimensions. */
570 }
572 /* Return the N levels of innermost template arguments from the ARGS. */
574 tree
576 {
577 tree new_args;
583 /* If N is 1, just return the innermost set of template arguments. */
587 /* If we're not removing anything, just return the arguments we were
588 given. */
594 /* Make a new set of arguments, not containing the outer arguments. */
601 }
603 /* The inverse of get_innermost_template_args: Return all but the innermost
604 EXTRA_LEVELS levels of template arguments from the ARGS. */
606 static tree
608 {
609 tree new_args;
615 /* If N is 1, just return the outermost set of template arguments. */
619 /* If we're not removing anything, just return the arguments we were
620 given. */
625 /* Make a new set of arguments, not containing the inner arguments. */
632 }
634 /* We've got a template header coming up; push to a new level for storing
635 the parms. */
637 void
639 {
640 /* We use a non-tag-transparent scope here, which causes pushtag to
641 put tags in this scope, rather than in the enclosing class or
642 namespace scope. This is the right thing, since we want
643 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
644 global template class, push_template_decl handles putting the
645 TEMPLATE_DECL into top-level scope. For a nested template class,
646 e.g.:
648 template <class T> struct S1 {
649 template <class T> struct S2 {};
650 };
652 pushtag contains special code to call pushdecl_with_scope on the
653 TEMPLATE_DECL for S2. */
658 }
660 /* This routine is called when a specialization is declared. If it is
661 invalid to declare a specialization here, an error is reported and
662 false is returned, otherwise this routine will return true. */
664 static bool
666 {
669 /* [temp.expl.spec]
671 An explicit specialization shall be declared in the namespace of
672 which the template is a member, or, for member templates, in the
673 namespace of which the enclosing class or enclosing class
674 template is a member. An explicit specialization of a member
675 function, member class or static data member of a class template
676 shall be declared in the namespace of which the class template
677 is a member. */
679 {
682 }
684 /* [temp.expl.spec]
686 In an explicit specialization declaration for a member of a class
687 template or a member template that appears in namespace scope,
688 the member template and some of its enclosing class templates may
689 remain unspecialized, except that the declaration shall not
690 explicitly specialize a class member template if its enclosing
691 class templates are not explicitly specialized as well. */
693 {
696 }
699 }
701 /* We've just seen template <>. */
703 bool
705 {
709 }
711 /* Called at then end of processing a declaration preceded by
712 template<>. */
714 void
716 {
719 }
721 /* Any template <>'s that we have seen thus far are not referring to a
722 function specialization. */
724 void
726 {
729 }
731 /* We've just seen a template header. If SPECIALIZATION is nonzero,
732 it was of the form template <>. */
734 static void
736 {
738 template_header_count++;
739 }
741 /* We're beginning an explicit instantiation. */
743 void
745 {
748 }
751 void
753 {
756 }
758 /* An explicit specialization or partial specialization of TMPL is being
759 declared. Check that the namespace in which the specialization is
760 occurring is permissible. Returns false iff it is invalid to
761 specialize TMPL in the current namespace. */
763 static bool
765 {
768 /* [tmpl.expl.spec]
770 An explicit specialization shall be declared in the namespace of
771 which the template is a member, or, for member templates, in the
772 namespace of which the enclosing class or enclosing class
773 template is a member. An explicit specialization of a member
774 function, member class or static data member of a class template
775 shall be declared in the namespace of which the class template is
776 a member. */
779 {
782 }
784 /* Same or super-using namespace. */
786 else
787 {
791 }
792 }
794 /* SPEC is an explicit instantiation. Check that it is valid to
795 perform this explicit instantiation in the current namespace. */
797 static void
799 {
800 tree ns;
802 /* DR 275: An explicit instantiation shall appear in an enclosing
803 namespace of its template. */
809 }
811 /* The TYPE is being declared. If it is a template type, that means it
812 is a partial specialization. Do appropriate error-checking. */
814 tree
816 {
817 tree context;
822 /* A lambda that appears in specialization context is not itself a
823 specialization. */
828 {
832 }
837 {
842 else
845 }
847 {
848 /* This is for ordinary explicit specialization and partial
849 specialization of a template class such as:
851 template <> class C<int>;
853 or:
855 template <class T> class C<T*>;
857 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
861 {
868 {
872 }
873 }
879 /* Trying to define a specialization either without a template<> header
880 or in an inappropriate place. We've already given an error, so just
881 bail now so we don't actually define the specialization. */
883 }
889 {
890 /* This is for an explicit specialization of member class
891 template according to [temp.expl.spec/18]:
893 template <> template <class U> class C<int>::D;
895 The context `C<int>' must be an implicit instantiation.
896 Otherwise this is just a member class template declared
897 earlier like:
899 template <> class C<int> { template <class U> class D; };
900 template <> template <class U> class C<int>::D;
902 In the first case, `C<int>::D' is a specialization of `C<T>::D'
903 while in the second case, `C<int>::D' is a primary template
904 and `C<T>::D' may not exist. */
908 {
909 tree t;
914 {
917 }
919 /* Check for invalid specialization after instantiation:
921 template <> template <> class C<int>::D<int>;
922 template <> template <class U> class C<int>::D; */
926 {
930 {
931 /* We already have a full specialization of this partial
932 instantiation, or a full specialization has been
933 looked up but not instantiated. Reassign it to the
934 new member specialization template. */
935 spec_entry elt;
947 spec_entry **slot
952 }
953 else
954 /* But if we've had an implicit instantiation, that's a
955 problem ([temp.expl.spec]/6). */
958 }
960 /* Mark TYPE as a specialization. And as a result, we only
961 have one level of template argument for the innermost
962 class template. */
967 }
968 }
970 {
971 /* Someday C++0x may allow for enum template specialization. */
976 else
977 {
980 }
981 }
984 }
986 /* Returns nonzero if we can optimize the retrieval of specializations
987 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
988 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
992 {
995 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
996 parameter. */
998 /* The optimized lookup depends on the fact that the
999 template arguments for the member function template apply
1000 purely to the containing class, which is not true if the
1001 containing class is an explicit or partial
1002 specialization. */
1006 /* It is possible to have a template that is not a member
1007 template and is not a member of a template class:
1009 template <typename T>
1010 struct S { friend A::f(); };
1012 Here, the friend function is a template, but the context does
1013 not have template information. The optimized lookup relies
1014 on having ARGS be the template arguments for both the class
1015 and the function template. */
1017 }
1019 /* Retrieve the specialization (in the sense of [temp.spec] - a
1020 specialization is either an instantiation or an explicit
1021 specialization) of TMPL for the given template ARGS. If there is
1022 no such specialization, return NULL_TREE. The ARGS are a vector of
1023 arguments, or a vector of vectors of arguments, in the case of
1024 templates with more than one level of parameters.
1026 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1027 then we search for a partial specialization matching ARGS. This
1028 parameter is ignored if TMPL is not a class template.
1030 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1031 result is a NONTYPE_ARGUMENT_PACK. */
1033 static tree
1035 {
1045 /* There should be as many levels of arguments as there are
1046 levels of parameters. */
1053 {
1054 tree class_template;
1055 tree class_specialization;
1057 tree fns;
1060 /* The template arguments actually apply to the containing
1061 class. Find the class specialization with those
1062 arguments. */
1064 class_specialization
1068 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1069 for the specialization. */
1073 /* Iterate through the methods with the indicated name, looking
1074 for the one that has an instance of TMPL. */
1077 {
1080 /* using-declarations can add base methods to the method vec,
1081 and we don't want those here. */
1084 }
1086 }
1087 else
1088 {
1090 spec_entry elt;
1099 else
1107 }
1110 }
1112 /* Like retrieve_specialization, but for local declarations. */
1114 static tree
1116 {
1122 }
1124 /* Returns nonzero iff DECL is a specialization of TMPL. */
1126 int
1128 {
1129 tree t;
1132 {
1138 }
1139 else
1140 {
1149 }
1152 }
1154 /* Returns nonzero iff DECL is a specialization of friend declaration
1155 FRIEND_DECL according to [temp.friend]. */
1157 bool
1159 {
1166 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1167 of a template class, we want to check if DECL is a specialization
1168 if this. */
1172 {
1173 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1176 }
1181 /* There is nothing to do if this is not a template friend. */
1188 /* [temp.friend/6]
1189 A member of a class template may be declared to be a friend of a
1190 non-template class. In this case, the corresponding member of
1191 every specialization of the class template is a friend of the
1192 class granting friendship.
1194 For example, given a template friend declaration
1196 template <class T> friend void A<T>::f();
1198 the member function below is considered a friend
1200 template <> struct A<int> {
1201 void f();
1202 };
1204 For this type of template friend, TEMPLATE_DEPTH below will be
1205 nonzero. To determine if DECL is a friend of FRIEND, we first
1206 check if the enclosing class is a specialization of another. */
1213 {
1214 /* Next, we check the members themselves. In order to handle
1215 a few tricky cases, such as when FRIEND_DECL's are
1217 template <class T> friend void A<T>::g(T t);
1218 template <class T> template <T t> friend void A<T>::h();
1220 and DECL's are
1222 void A<int>::g(int);
1223 template <int> void A<int>::h();
1225 we need to figure out ARGS, the template arguments from
1226 the context of DECL. This is required for template substitution
1227 of `T' in the function parameter of `g' and template parameter
1228 of `h' in the above examples. Here ARGS corresponds to `int'. */
1235 {
1237 {
1240 else
1242 current_depth++;
1243 }
1245 }
1248 {
1250 tree friend_type;
1251 tree decl_type;
1252 tree friend_args_type;
1253 tree decl_args_type;
1255 /* Make sure that both DECL and FRIEND_DECL are templates or
1256 non-templates. */
1262 {
1263 /* If both are templates, check template parameter list. */
1264 tree friend_parms
1269 friend_parms))
1273 }
1274 else
1282 /* Check if return types match. */
1286 /* Check if function parameter types match, ignoring the
1287 `this' parameter. */
1296 }
1297 else
1298 {
1299 /* DECL is a TYPE_DECL */
1303 /* Make sure that both DECL and FRIEND_DECL are templates or
1304 non-templates. */
1305 is_template
1312 {
1313 tree friend_parms;
1314 /* If both are templates, check the name of the two
1315 TEMPLATE_DECL's first because is_friend didn't. */
1320 /* Now check template parameter list. */
1321 friend_parms
1324 return comp_template_parms
1326 friend_parms);
1327 }
1328 else
1331 }
1332 }
1334 }
1336 /* Register the specialization SPEC as a specialization of TMPL with
1337 the indicated ARGS. IS_FRIEND indicates whether the specialization
1338 is actually just a friend declaration. Returns SPEC, or an
1339 equivalent prior declaration, if available.
1341 We also store instantiations of field packs in the hash table, even
1342 though they are not themselves templates, to make lookup easier. */
1344 static tree
1346 hashval_t hash)
1347 {
1348 tree fn;
1350 spec_entry elt;
1358 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1359 register it; we want the corresponding TEMPLATE_DECL instead.
1360 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1361 the more obvious `uses_template_parms (spec)' to avoid problems
1362 with default function arguments. In particular, given
1363 something like this:
1365 template <class T> void f(T t1, T t = T())
1367 the default argument expression is not substituted for in an
1368 instantiation unless and until it is actually needed. */
1372 /* We don't put these specializations in the hash table, but we might
1373 want to give an error about a mismatch. */
1375 else
1376 {
1384 slot =
1388 else
1390 }
1392 /* We can sometimes try to re-register a specialization that we've
1393 already got. In particular, regenerate_decl_from_template calls
1394 duplicate_decls which will update the specialization list. But,
1395 we'll still get called again here anyhow. It's more convenient
1396 to simply allow this than to try to prevent it. */
1400 {
1402 {
1405 {
1407 fn);
1409 }
1410 else
1411 {
1412 tree clone;
1413 /* This situation should occur only if the first
1414 specialization is an implicit instantiation, the
1415 second is an explicit specialization, and the
1416 implicit instantiation has not yet been used. That
1417 situation can occur if we have implicitly
1418 instantiated a member function and then specialized
1419 it later.
1421 We can also wind up here if a friend declaration that
1422 looked like an instantiation turns out to be a
1423 specialization:
1425 template <class T> void foo(T);
1426 class S { friend void foo<>(int) };
1427 template <> void foo(int);
1429 We transform the existing DECL in place so that any
1430 pointers to it become pointers to the updated
1431 declaration.
1433 If there was a definition for the template, but not
1434 for the specialization, we want this to look as if
1435 there were no definition, and vice versa. */
1438 /* The call to duplicate_decls will have applied
1439 [temp.expl.spec]:
1441 An explicit specialization of a function template
1442 is inline only if it is explicitly declared to be,
1443 and independently of whether its function template
1444 is.
1446 to the primary function; now copy the inline bits to
1447 the various clones. */
1449 {
1456 }
1460 }
1461 }
1463 {
1465 /* Dup decl failed, but this is a new definition. Set the
1466 line number so any errors match this new
1467 definition. */
1471 }
1472 }
1476 /* A specialization must be declared in the same namespace as the
1477 template it is specializing. */
1483 {
1492 /* If TMPL is a forward declaration of a template function, keep a list
1493 of all specializations in case we need to reassign them to a friend
1494 template later in tsubst_friend_function.
1496 Also keep a list of all variable template instantiations so that
1497 process_partial_specialization can check whether a later partial
1498 specialization would have used it. */
1501 }
1504 }
1506 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1507 TMPL and ARGS members, ignores SPEC. */
1511 bool
1513 {
1522 }
1524 /* Returns a hash for a template TMPL and template arguments ARGS. */
1526 static hashval_t
1528 {
1531 }
1533 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1534 ignoring SPEC. */
1536 hashval_t
1538 {
1540 }
1542 /* Recursively calculate a hash value for a template argument ARG, for use
1543 in the hash tables of template specializations. */
1545 hashval_t
1547 {
1559 /* We can get one of these when re-hashing a previous entry in the middle
1560 of substituting into a pack expansion. Just look through it. */
1569 {
1577 {
1582 }
1604 {
1608 {
1611 }
1613 }
1617 {
1620 }
1631 val = iterative_hash_template_arg
1643 val);
1645 val);
1654 /* A lambda can't appear in a template arg, but don't crash on
1655 erroneous input. */
1667 /* Now hash operands as usual. */
1672 }
1675 {
1678 {
1679 // We want an alias specialization that survived strip_typedefs
1680 // to hash differently from its TYPE_CANONICAL, to avoid hash
1681 // collisions that compare as different in template_args_equal.
1682 // These could be dependent specializations that strip_typedefs
1683 // left alone, or untouched specializations because
1684 // coerce_template_parms returns the unconverted template
1685 // arguments if it sees incomplete argument packs.
1688 }
1691 val);
1694 /* Otherwise just compare the types during lookup. */
1703 {
1708 }
1709 }
1712 }
1714 /* Unregister the specialization SPEC as a specialization of TMPL.
1715 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1716 if the SPEC was listed as a specialization of TMPL.
1718 Note that SPEC has been ggc_freed, so we can't look inside it. */
1720 bool
1722 {
1724 spec_entry elt;
1732 {
1737 }
1740 }
1742 /* Like register_specialization, but for local declarations. We are
1743 registering SPEC, an instantiation of TMPL. */
1745 static void
1747 {
1749 }
1751 /* TYPE is a class type. Returns true if TYPE is an explicitly
1752 specialized class. */
1754 bool
1756 {
1760 }
1762 /* Print the list of functions at FNS, going through all the overloads
1763 for each element of the list. Alternatively, FNS can not be a
1764 TREE_LIST, in which case it will be printed together with all the
1765 overloads.
1767 MORE and *STR should respectively be FALSE and NULL when the function
1768 is called from the outside. They are used internally on recursive
1769 calls. print_candidates manages the two parameters and leaves NULL
1770 in *STR when it ends. */
1772 static void
1774 {
1780 {
1784 }
1785 else
1786 {
1789 {
1790 /* Pick the prefix string. */
1792 {
1796 }
1800 }
1803 }
1806 {
1809 }
1810 }
1812 /* Print the list of candidate FNS in an error message. FNS can also
1813 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1815 void
1817 {
1821 }
1823 /* Returns the template (one of the functions given by TEMPLATE_ID)
1824 which can be specialized to match the indicated DECL with the
1825 explicit template args given in TEMPLATE_ID. The DECL may be
1826 NULL_TREE if none is available. In that case, the functions in
1827 TEMPLATE_ID are non-members.
1829 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1830 specialization of a member template.
1832 The TEMPLATE_COUNT is the number of references to qualifying
1833 template classes that appeared in the name of the function. See
1834 check_explicit_specialization for a more accurate description.
1836 TSK indicates what kind of template declaration (if any) is being
1837 declared. TSK_TEMPLATE indicates that the declaration given by
1838 DECL, though a FUNCTION_DECL, has template parameters, and is
1839 therefore a template function.
1841 The template args (those explicitly specified and those deduced)
1842 are output in a newly created vector *TARGS_OUT.
1844 If it is impossible to determine the result, an error message is
1845 issued. The error_mark_node is returned to indicate failure. */
1847 static tree
1849 tree decl,
1853 tmpl_spec_kind tsk)
1854 {
1855 tree fns;
1856 tree targs;
1857 tree explicit_targs;
1859 /* A TREE_LIST of templates of which DECL may be a specialization.
1860 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1861 corresponding TREE_PURPOSE is the set of template arguments that,
1862 when used to instantiate the template, would produce a function
1863 with the signature of DECL. */
1873 /* We shouldn't be specializing a member template of an
1874 unspecialized class template; we already gave an error in
1875 check_specialization_scope, now avoid crashing. */
1878 {
1881 }
1889 /* Check for baselinks. */
1894 {
1897 }
1899 {
1902 }
1904 /* Count the number of template headers specified for this
1905 specialization. */
1915 {
1919 {
1920 tree decl_arg_types;
1921 tree fn_arg_types;
1922 tree insttype;
1924 /* In case of explicit specialization, we need to check if
1925 the number of template headers appearing in the specialization
1926 is correct. This is usually done in check_explicit_specialization,
1927 but the check done there cannot be exhaustive when specializing
1928 member functions. Consider the following code:
1930 template <> void A<int>::f(int);
1931 template <> template <> void A<int>::f(int);
1933 Assuming that A<int> is not itself an explicit specialization
1934 already, the first line specializes "f" which is a non-template
1935 member function, whilst the second line specializes "f" which
1936 is a template member function. So both lines are syntactically
1937 correct, and check_explicit_specialization does not reject
1938 them.
1940 Here, we can do better, as we are matching the specialization
1941 against the declarations. We count the number of template
1942 headers, and we check if they match TEMPLATE_COUNT + 1
1943 (TEMPLATE_COUNT is the number of qualifying template classes,
1944 plus there must be another header for the member template
1945 itself).
1947 Notice that if header_count is zero, this is not a
1948 specialization but rather a template instantiation, so there
1949 is no check we can perform here. */
1953 /* Check that the number of template arguments at the
1954 innermost level for DECL is the same as for FN. */
1962 /* DECL might be a specialization of FN. */
1966 /* For a non-static member function, we need to make sure
1967 that the const qualification is the same. Since
1968 get_bindings does not try to merge the "this" parameter,
1969 we must do the comparison explicitly. */
1975 /* Skip the "this" parameter and, for constructors of
1976 classes with virtual bases, the VTT parameter. A
1977 full specialization of a constructor will have a VTT
1978 parameter, but a template never will. */
1979 decl_arg_types
1981 fn_arg_types
1984 /* Function templates cannot be specializations; there are
1985 no partial specializations of functions. Therefore, if
1986 the type of DECL does not match FN, there is no
1987 match. */
1989 {
1993 }
1995 /* See whether this function might be a specialization of this
1996 template. Suppress access control because we might be trying
1997 to make this specialization a friend, and we have already done
1998 access control for the declaration of the specialization. */
2004 /* We cannot deduce template arguments that when used to
2005 specialize TMPL will produce DECL. */
2008 /* Make sure that the deduced arguments actually work. */
2012 fn_arg_types
2017 /* Save this template, and the arguments deduced. */
2019 }
2021 /* FN is an ordinary member function, and we need a
2022 specialization of a member template. */
2023 ;
2025 /* We can get IDENTIFIER_NODEs here in certain erroneous
2026 cases. */
2027 ;
2029 /* This is just an ordinary non-member function. Nothing can
2030 be a specialization of that. */
2031 ;
2033 /* Cannot specialize functions that are created implicitly. */
2034 ;
2035 else
2036 {
2037 tree decl_arg_types;
2039 /* This is an ordinary member function. However, since
2040 we're here, we can assume its enclosing class is a
2041 template class. For example,
2043 template <typename T> struct S { void f(); };
2044 template <> void S<int>::f() {}
2046 Here, S<int>::f is a non-template, but S<int> is a
2047 template class. If FN has the same type as DECL, we
2048 might be in business. */
2051 /* Its enclosing class is an explicit specialization
2052 of a template class. This is not a candidate. */
2057 /* The return types differ. */
2060 /* Adjust the type of DECL in case FN is a static member. */
2067 decl_arg_types))
2068 /* They match! */
2070 }
2071 }
2074 {
2075 /* We have:
2077 [temp.expl.spec]
2079 It is possible for a specialization with a given function
2080 signature to be instantiated from more than one function
2081 template. In such cases, explicit specification of the
2082 template arguments must be used to uniquely identify the
2083 function template specialization being specialized.
2085 Note that here, there's no suggestion that we're supposed to
2086 determine which of the candidate templates is most
2087 specialized. However, we, also have:
2089 [temp.func.order]
2091 Partial ordering of overloaded function template
2092 declarations is used in the following contexts to select
2093 the function template to which a function template
2094 specialization refers:
2096 -- when an explicit specialization refers to a function
2097 template.
2099 So, we do use the partial ordering rules, at least for now.
2100 This extension can only serve to make invalid programs valid,
2101 so it's safe. And, there is strong anecdotal evidence that
2102 the committee intended the partial ordering rules to apply;
2103 the EDG front end has that behavior, and John Spicer claims
2104 that the committee simply forgot to delete the wording in
2105 [temp.expl.spec]. */
2108 {
2111 }
2112 }
2115 {
2123 }
2127 {
2133 }
2135 /* We have one, and exactly one, match. */
2137 {
2140 /* DECL is a re-declaration or partial instantiation of a template
2141 function. */
2144 /* It was a specialization of an ordinary member function in a
2145 template class. */
2147 }
2149 /* It was a specialization of a template. */
2152 {
2157 }
2158 else
2161 }
2163 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2164 but with the default argument values filled in from those in the
2165 TMPL_TYPES. */
2167 static tree
2169 tree tmpl_types)
2170 {
2171 tree new_spec_types;
2179 /* Substitute into the rest of the list. */
2180 new_spec_types =
2184 /* Add the default argument for this parameter. */
2187 new_spec_types);
2188 }
2190 /* DECL is an explicit specialization. Replicate default arguments
2191 from the template it specializes. (That way, code like:
2193 template <class T> void f(T = 3);
2194 template <> void f(double);
2195 void g () { f (); }
2197 works, as required.) An alternative approach would be to look up
2198 the correct default arguments at the call-site, but this approach
2199 is consistent with how implicit instantiations are handled. */
2201 static void
2203 {
2204 tree tmpl;
2205 tree spec_types;
2206 tree tmpl_types;
2207 tree new_spec_types;
2208 tree old_type;
2209 tree new_type;
2210 tree t;
2215 /* See if there's anything we need to do. */
2228 {
2229 /* Remove the this pointer, but remember the object's type for
2230 CV quals. */
2236 {
2237 /* DECL may contain more parameters than TMPL due to the extra
2238 in-charge parameter in constructors and destructors. */
2241 }
2243 {
2246 }
2247 }
2249 /* Compute the merged default arguments. */
2250 new_spec_types =
2253 /* Compute the new FUNCTION_TYPE. */
2255 {
2259 new_spec_types);
2262 /* Put the in-charge parameter back. */
2265 new_spec_types);
2269 new_spec_types);
2270 }
2271 else
2273 new_spec_types);
2283 }
2285 /* Return the number of template headers we expect to see for a definition
2286 or specialization of CTYPE or one of its non-template members. */
2288 int
2290 {
2294 {
2295 /* You're supposed to have one `template <...>' for every
2296 template class, but you don't need one for a full
2297 specialization. For example:
2299 template <class T> struct S{};
2300 template <> struct S<int> { void f(); };
2301 void S<int>::f () {}
2303 is correct; there shouldn't be a `template <>' for the
2304 definition of `S<int>::f'. */
2306 /* If CTYPE does not have template information of any
2307 kind, then it is not a template, nor is it nested
2308 within a template. */
2316 }
2319 }
2321 /* Do a simple sanity check on the template headers that precede the
2322 variable declaration DECL. */
2324 void
2326 {
2331 {
2334 "variable templates only available with "
2337 // Namespace-scope variable templates should have a template header.
2339 }
2341 {
2348 "members of an explicitly specialized class are defined "
2350 }
2351 }
2353 /* Check to see if the function just declared, as indicated in
2354 DECLARATOR, and in DECL, is a specialization of a function
2355 template. We may also discover that the declaration is an explicit
2356 instantiation at this point.
2358 Returns DECL, or an equivalent declaration that should be used
2359 instead if all goes well. Issues an error message if something is
2360 amiss. Returns error_mark_node if the error is not easily
2361 recoverable.
2363 FLAGS is a bitmask consisting of the following flags:
2365 2: The function has a definition.
2366 4: The function is a friend.
2368 The TEMPLATE_COUNT is the number of references to qualifying
2369 template classes that appeared in the name of the function. For
2370 example, in
2372 template <class T> struct S { void f(); };
2373 void S<int>::f();
2375 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2376 classes are not counted in the TEMPLATE_COUNT, so that in
2378 template <class T> struct S {};
2379 template <> struct S<int> { void f(); }
2380 template <> void S<int>::f();
2382 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2383 invalid; there should be no template <>.)
2385 If the function is a specialization, it is marked as such via
2386 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2387 is set up correctly, and it is added to the list of specializations
2388 for that template. */
2390 tree
2392 tree decl,
2395 {
2403 tmpl_spec_kind tsk;
2406 {
2409 else
2411 }
2412 else
2416 {
2419 {
2422 }
2424 {
2426 /* This could be something like:
2428 template <class T> void f(T);
2429 class S { friend void f<>(int); } */
2431 else
2432 {
2433 /* This case handles bogus declarations like template <>
2434 template <class T> void f<int>(); */
2437 declarator);
2439 }
2440 }
2444 /* The error has already been reported in
2445 check_specialization_scope. */
2451 /* Fall through. */
2464 decl);
2467 else
2471 /* Fall through. */
2474 /* In cases like template<> constexpr bool v = true;
2475 We'll give an error in check_template_variable. */
2481 else
2487 {
2488 /* This case handles bogus declarations like template <>
2489 template <class T> void f<int>(); */
2493 declarator);
2495 {
2496 /* Partial specialization of variable template. */
2500 }
2504 else
2508 ok:;
2509 }
2512 /* This is a specialization of a member template, without
2513 specialization the containing class. Something like:
2515 template <class T> struct S {
2516 template <class U> void f (U);
2517 };
2518 template <> template <class U> void S<int>::f(U) {}
2520 That's a specialization -- but of the entire template. */
2526 }
2529 /* This doesn't apply to variable templates. */
2532 {
2536 {
2540 }
2541 }
2544 {
2549 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2551 {
2552 tree fns;
2557 else
2558 {
2559 /* If there is no class context, the explicit instantiation
2560 must be at namespace scope. */
2563 /* Find the namespace binding, using the declaration
2564 context. */
2568 {
2571 }
2572 else
2573 {
2579 }
2580 }
2583 }
2589 {
2591 /* A specialization in class scope. This is invalid,
2592 but the error will already have been flagged by
2593 check_specialization_scope. */
2595 else
2596 {
2597 /* It's not valid to write an explicit instantiation in
2598 class scope, e.g.:
2600 class C { template void f(); }
2602 This case is caught by the parser. However, on
2603 something like:
2605 template class C { void f(); };
2607 (which is invalid) we can get here. The error will be
2608 issued later. */
2609 ;
2610 }
2613 }
2616 {
2617 // We'll match variable templates in start_decl.
2621 /* Find the list of functions in ctype that have the same
2622 name as the declared function. */
2628 {
2633 {
2634 /* From [temp.expl.spec]:
2636 If such an explicit specialization for the member
2637 of a class template names an implicitly-declared
2638 special member function (clause _special_), the
2639 program is ill-formed.
2641 Similar language is found in [temp.explicit]. */
2644 }
2647 }
2650 {
2654 }
2655 else
2656 {
2658 tree ovl;
2660 /* For a type-conversion operator, we cannot do a
2661 name-based lookup. We might be looking for `operator
2662 int' which will be a specialization of `operator T'.
2663 So, we find *all* the conversion operators, and then
2664 select from them. */
2672 {
2674 /* There are no more conversion functions. */
2677 /* Glue all these conversion functions together
2678 with those we already have. */
2681 }
2682 }
2685 {
2688 }
2689 else
2691 }
2693 /* Figure out what exactly is being specialized at this point.
2694 Note that for an explicit instantiation, even one for a
2695 member function, we cannot tell apriori whether the
2696 instantiation is for a member template, or just a member
2697 function of a template class. Even if a member template is
2698 being instantiated, the member template arguments may be
2699 elided if they can be deduced from the rest of the
2700 declaration. */
2703 member_specialization,
2704 template_count,
2705 tsk);
2708 /* We couldn't figure out what this declaration was
2709 specializing. */
2711 else
2712 {
2716 {
2717 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2718 is done by do_decl_instantiation later. */
2724 {
2725 /* If TMPL is not the most general template (for
2726 example, if TMPL is a friend template that is
2727 injected into namespace scope), then there will
2728 be too many levels of TARGS. Remove some of them
2729 here. */
2731 tree new_targs;
2738 }
2741 }
2743 /* If we thought that the DECL was a member function, but it
2744 turns out to be specializing a static member function,
2745 make DECL a static member function as well. */
2751 /* If this is a specialization of a member template of a
2752 template class, we want to return the TEMPLATE_DECL, not
2753 the specialization of it. */
2755 {
2760 {
2761 tree parm;
2765 /* We want to use the argument list specified in the
2766 definition, not in the original declaration. */
2771 }
2774 }
2776 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2782 /* Inherit default function arguments from the template
2783 DECL is specializing. */
2787 /* This specialization has the same protection as the
2788 template it specializes. */
2792 /* 7.1.1-1 [dcl.stc]
2794 A storage-class-specifier shall not be specified in an
2795 explicit specialization...
2797 The parser rejects these, so unless action is taken here,
2798 explicit function specializations will always appear with
2799 global linkage.
2801 The action recommended by the C++ CWG in response to C++
2802 defect report 605 is to make the storage class and linkage
2803 of the explicit specialization match the templated function:
2805 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2806 */
2808 {
2812 /* This specialization has the same linkage and visibility as
2813 the function template it specializes. */
2816 {
2819 }
2822 {
2825 }
2826 }
2828 /* If DECL is a friend declaration, declared using an
2829 unqualified name, the namespace associated with DECL may
2830 have been set incorrectly. For example, in:
2832 template <typename T> void f(T);
2833 namespace N {
2834 struct S { friend void f<int>(int); }
2835 }
2837 we will have set the DECL_CONTEXT for the friend
2838 declaration to N, rather than to the global namespace. */
2843 /* This is not really a declaration of a specialization.
2844 It's just the name of an instantiation. But, it's not
2845 a request for an instantiation, either. */
2848 /* A specialization is not necessarily COMDAT. */
2854 /* Register this specialization so that we can find it
2855 again. */
2858 /* A 'structor should already have clones. */
2864 }
2865 }
2868 }
2870 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2871 parameters. These are represented in the same format used for
2872 DECL_TEMPLATE_PARMS. */
2874 int
2876 {
2877 const_tree p1;
2878 const_tree p2;
2886 {
2898 {
2902 /* If either of the template parameters are invalid, assume
2903 they match for the sake of error recovery. */
2916 }
2917 }
2920 /* One set of parameters has more parameters lists than the
2921 other. */
2925 }
2927 /* Determine whether PARM is a parameter pack. */
2929 bool
2931 {
2932 /* Determine if we have a non-type template parameter pack. */
2939 /* If this is a list of template parameters, we could get a
2940 TYPE_DECL or a TEMPLATE_DECL. */
2944 /* Otherwise it must be a type template parameter. */
2948 }
2950 /* Determine if T is a function parameter pack. */
2952 bool
2954 {
2958 }
2960 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2961 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2963 tree
2965 {
2972 }
2974 /* Return true iff the function parameter PARAM_DECL was expanded
2975 from the function parameter pack PACK. */
2977 bool
2979 {
2984 /* The parameter pack and its pack arguments have the same
2985 DECL_PARM_INDEX. */
2987 }
2989 /* Determine whether ARGS describes a variadic template args list,
2990 i.e., one that is terminated by a template argument pack. */
2992 static bool
2994 {
2996 tree last_parm;
3010 }
3012 /* Generate a new name for the parameter pack name NAME (an
3013 IDENTIFIER_NODE) that incorporates its */
3015 static tree
3017 {
3018 /* Munge the name to include the parameter index. */
3019 #define NUMBUF_LEN 128
3033 }
3035 /* Return true if T is a primary function, class or alias template
3036 instantiation. */
3038 bool
3040 {
3054 }
3056 /* Return true if PARM is a template template parameter. */
3058 bool
3060 {
3062 }
3064 /* Return true iff PARM is a DECL representing a type template
3065 parameter. */
3067 bool
3069 {
3074 }
3076 /* Return the template parameters of T if T is a
3077 primary template instantiation, NULL otherwise. */
3079 tree
3081 {
3086 parms = INNERMOST_TEMPLATE_PARMS
3090 }
3092 /* Return the template parameters of the LEVELth level from the full list
3093 of template parameters PARMS. */
3095 tree
3097 {
3098 tree p;
3109 }
3111 /* Returns the template arguments of T if T is a template instantiation,
3112 NULL otherwise. */
3114 tree
3116 {
3124 }
3126 /* Return the argument pack elements of T if T is a template argument pack,
3127 NULL otherwise. */
3129 tree
3131 {
3137 }
3139 /* Structure used to track the progress of find_parameter_packs_r. */
3140 struct find_parameter_pack_data
3141 {
3142 /* TREE_LIST that will contain all of the parameter packs found by
3143 the traversal. */
3146 /* Set of AST nodes that have been visited by the traversal. */
3148 };
3150 /* Identifies all of the argument packs that occur in a template
3151 argument and appends them to the TREE_LIST inside DATA, which is a
3152 find_parameter_pack_data structure. This is a subroutine of
3153 make_pack_expansion and uses_parameter_packs. */
3154 static tree
3156 {
3162 /* Handle type aliases/typedefs. */
3164 {
3171 }
3173 /* Identify whether this is a parameter pack or not. */
3175 {
3191 {
3192 /* We don't want to walk into the type of a PARM_DECL,
3193 because we don't want to see the type parameter pack. */
3196 }
3199 /* Look through a lambda capture proxy to the field pack. */
3202 {
3208 }
3215 /* Not a parameter pack. */
3217 }
3220 {
3221 /* Add this parameter pack to the list. */
3223 }
3229 /* This switch statement will return immediately if we don't find a
3230 parameter pack. */
3232 {
3237 /* Check the template itself. */
3240 /* Check the template arguments. */
3256 /* Fall through. */
3298 }
3301 }
3303 /* Determines if the expression or type T uses any parameter packs. */
3304 bool
3306 {
3314 }
3316 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3317 representation a base-class initializer into a parameter pack
3318 expansion. If all goes well, the resulting node will be an
3319 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3320 respectively. */
3321 tree
3323 {
3324 tree result;
3333 {
3334 /* The only time we will see a TREE_LIST here is for a base
3335 class initializer. In this case, the TREE_PURPOSE will be a
3336 _TYPE node (representing the base class expansion we're
3337 initializing) and the TREE_VALUE will be a TREE_LIST
3338 containing the initialization arguments.
3340 The resulting expansion looks somewhat different from most
3341 expansions. Rather than returning just one _EXPANSION, we
3342 return a TREE_LIST whose TREE_PURPOSE is a
3343 TYPE_PACK_EXPANSION containing the bases that will be
3344 initialized. The TREE_VALUE will be identical to the
3345 original TREE_VALUE, which is a list of arguments that will
3346 be passed to each base. We do not introduce any new pack
3347 expansion nodes into the TREE_VALUE (although it is possible
3348 that some already exist), because the TREE_PURPOSE and
3349 TREE_VALUE all need to be expanded together with the same
3350 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3351 resulting TREE_PURPOSE will mention the parameter packs in
3352 both the bases and the arguments to the bases. */
3353 tree purpose;
3354 tree value;
3357 /* Determine which parameter packs will be used by the base
3358 class expansion. */
3365 {
3369 }
3372 {
3373 /* Collect the sets of parameter packs used in each of the
3374 initialization arguments. */
3376 {
3377 /* Determine which parameter packs will be expanded in this
3378 argument. */
3381 }
3382 }
3386 /* Create the pack expansion type for the base type. */
3391 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3392 they will rarely be compared to anything. */
3396 }
3401 /* Build the PACK_EXPANSION_* node. */
3402 result = for_types
3407 {
3408 /* Propagate type and const-expression information. */
3411 }
3412 else
3413 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3414 they will rarely be compared to anything. */
3417 /* Determine which parameter packs will be expanded. */
3423 /* Make sure we found some parameter packs. */
3425 {
3428 else
3431 }
3437 }
3439 /* Checks T for any "bare" parameter packs, which have not yet been
3440 expanded, and issues an error if any are found. This operation can
3441 only be done on full expressions or types (e.g., an expression
3442 statement, "if" condition, etc.), because we could have expressions like:
3444 foo(f(g(h(args)))...)
3446 where "args" is a parameter pack. check_for_bare_parameter_packs
3447 should not be called for the subexpressions args, h(args),
3448 g(h(args)), or f(g(h(args))), because we would produce erroneous
3449 error messages.
3451 Returns TRUE and emits an error if there were bare parameter packs,
3452 returns FALSE otherwise. */
3453 bool
3455 {
3471 {
3474 {
3483 else
3488 else
3492 }
3495 }
3498 }
3500 /* Expand any parameter packs that occur in the template arguments in
3501 ARGS. */
3502 tree
3504 {
3510 /* First, determine if we need to expand anything, and the number of
3511 slots we'll need. */
3513 {
3518 {
3522 else
3524 }
3525 else
3526 {
3528 num_result_args++;
3529 }
3530 }
3532 /* If no expansion is necessary, we're done. */
3536 /* Expand arguments. */
3539 non_default_args_count =
3542 {
3545 {
3552 }
3553 else
3554 {
3557 }
3558 }
3562 }
3564 /* Checks if DECL shadows a template parameter.
3566 [temp.local]: A template-parameter shall not be redeclared within its
3567 scope (including nested scopes).
3569 Emits an error and returns TRUE if the DECL shadows a parameter,
3570 returns FALSE otherwise. */
3572 bool
3574 {
3575 tree olddecl;
3577 /* If we're not in a template, we can't possibly shadow a template
3578 parameter. */
3582 /* Figure out what we're shadowing. */
3587 /* If there's no previous binding for this name, we're not shadowing
3588 anything, let alone a template parameter. */
3592 /* If we're not shadowing a template parameter, we're done. Note
3593 that OLDDECL might be an OVERLOAD (or perhaps even an
3594 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3595 node. */
3599 /* We check for decl != olddecl to avoid bogus errors for using a
3600 name inside a class. We check TPFI to avoid duplicate errors for
3601 inline member templates. */
3607 /* Don't complain about the injected class name, as we've already
3608 complained about the class itself. */
3615 }
3617 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3618 ORIG_LEVEL, DECL, and TYPE. */
3620 static tree
3624 tree decl,
3625 tree type)
3626 {
3637 }
3639 /* Find the canonical type parameter for the given template type
3640 parameter. Returns the canonical type parameter, which may be TYPE
3641 if no such parameter existed. */
3643 static tree
3645 {
3646 tree list;
3660 else
3661 {
3666 }
3667 }
3669 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3670 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3671 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3672 new one is created. */
3674 static tree
3676 tsubst_flags_t complain)
3677 {
3682 {
3701 /* Template template parameters need this. */
3706 }
3709 }
3711 /* Process information from new template parameter PARM and append it
3712 to the LIST being built. This new parameter is a non-type
3713 parameter iff IS_NON_TYPE is true. This new parameter is a
3714 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3715 is in PARM_LOC. */
3717 tree
3720 {
3722 tree defval;
3729 {
3733 {
3737 else
3739 }
3742 }
3745 {
3751 {
3752 /* [temp.param]
3754 The top-level cv-qualifiers on the template-parameter are
3755 ignored when determining its type. */
3760 && !is_parameter_pack
3761 /* If we're in a nested template parameter list, the template
3762 template parameter could be a parameter pack. */
3764 {
3765 /* This template parameter is not a parameter pack, but it
3766 should be. Complain about "bare" parameter packs. */
3769 /* Recover by calling this a parameter pack. */
3771 }
3772 }
3774 /* A template parameter is not modifiable. */
3783 processing_template_decl,
3788 }
3789 else
3790 {
3791 tree t;
3795 {
3797 /* This is for distinguishing between real templates and template
3798 template parameters */
3802 }
3803 else
3804 {
3806 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3809 }
3816 processing_template_decl,
3820 }
3826 }
3828 /* The end of a template parameter list has been reached. Process the
3829 tree list into a parameter vector, converting each parameter into a more
3830 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3831 as PARM_DECLs. */
3833 tree
3835 {
3840 current_template_parms
3845 {
3849 }
3854 }
3856 /* end_template_decl is called after a template declaration is seen. */
3858 void
3860 {
3866 /* This matches the pushlevel in begin_template_parm_list. */
3871 }
3873 /* Takes a TREE_LIST representing a template parameter and convert it
3874 into an argument suitable to be passed to the type substitution
3875 functions. Note that If the TREE_LIST contains an error_mark
3876 node, the returned argument is error_mark_node. */
3878 static tree
3880 {
3893 {
3897 {
3898 /* Turn this argument into a TYPE_ARGUMENT_PACK
3899 with a single element, which expands T. */
3901 #ifdef ENABLE_CHECKING
3902 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3904 #endif
3909 }
3910 }
3911 else
3912 {
3916 {
3917 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3918 with a single element, which expands T. */
3921 #ifdef ENABLE_CHECKING
3922 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3924 #endif
3931 }
3932 else
3934 }
3936 }
3938 /* Given a set of template parameters, return them as a set of template
3939 arguments. The template parameters are represented as a TREE_VEC, in
3940 the form documented in cp-tree.h for template arguments. */
3942 static tree
3944 {
3945 tree header;
3950 /* If there is only one level of template parameters, we do not
3951 create a TREE_VEC of TREE_VECs. Instead, we return a single
3952 TREE_VEC containing the arguments. */
3957 {
3965 #ifdef ENABLE_CHECKING
3967 #endif
3971 else
3973 }
3976 /* This can happen for template parms of a template template
3977 parameter, e.g:
3979 template<template<class T, class U> class TT> struct S;
3981 Consider the level of the parms of TT; T and U both have
3982 level 2; TT has no template parm of level 1. So in this case
3983 the first element of full_template_args is NULL_TREE. If we
3984 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
3985 of 2. This will make tsubst wrongly consider that T and U
3986 have level 1. Instead, let's create a dummy vector as the
3987 first element of full_template_args so that TMPL_ARGS_DEPTH
3988 returns the correct depth for args. */
3991 }
3993 /* Within the declaration of a template, return the currently active
3994 template parameters as an argument TREE_VEC. */
3996 static tree
3998 {
4000 }
4002 /* Update the declared TYPE by doing any lookups which were thought to be
4003 dependent, but are not now that we know the SCOPE of the declarator. */
4005 tree
4007 {
4018 /* Don't bother building up the args in this case. */
4020 {
4021 /* tsubst in the args corresponding to the template parameters,
4022 including auto if present. Most things will be unchanged, but
4023 make_typename_type and tsubst_qualified_id will resolve
4024 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4027 tree pushed;
4029 {
4033 }
4038 }
4044 {
4047 else
4049 }
4051 }
4053 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4054 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4055 a member template. Used by push_template_decl below. */
4057 static tree
4059 {
4067 }
4069 struct template_parm_data
4070 {
4071 /* The level of the template parameters we are currently
4072 processing. */
4075 /* The index of the specialization argument we are currently
4076 processing. */
4079 /* An array whose size is the number of template parameters. The
4080 elements are nonzero if the parameter has been used in any one
4081 of the arguments processed so far. */
4084 /* An array whose size is the number of template arguments. The
4085 elements are nonzero if the argument makes use of template
4086 parameters of this level. */
4088 };
4090 /* Subroutine of push_template_decl used to see if each template
4091 parameter in a partial specialization is used in the explicit
4092 argument list. If T is of the LEVEL given in DATA (which is
4093 treated as a template_parm_data*), then DATA->PARMS is marked
4094 appropriately. */
4096 static int
4098 {
4106 {
4109 }
4111 /* Return zero so that for_each_template_parm will continue the
4112 traversal of the tree; we want to mark *every* template parm. */
4114 }
4116 /* Process the partial specialization DECL. */
4118 static tree
4120 {
4127 tree inner_parms;
4128 tree inst;
4141 /* We check that each of the template parameters given in the
4142 partial specialization is used in the argument list to the
4143 specialization. For example:
4145 template <class T> struct S;
4146 template <class T> struct S<T*>;
4148 The second declaration is OK because `T*' uses the template
4149 parameter T, whereas
4151 template <class T> struct S<int>;
4153 is no good. Even trickier is:
4155 template <class T>
4156 struct S1
4157 {
4158 template <class U>
4159 struct S2;
4160 template <class U>
4161 struct S2<T>;
4162 };
4164 The S2<T> declaration is actually invalid; it is a
4165 full-specialization. Of course,
4167 template <class U>
4168 struct S2<T (*)(U)>;
4170 or some such would have been OK. */
4178 {
4183 NULL,
4185 }
4188 {
4189 /* One of the template parms was not used in a deduced context in the
4190 specialization. */
4192 {
4196 }
4200 }
4205 /* [temp.class.spec]
4207 The argument list of the specialization shall not be identical to
4208 the implicit argument list of the primary template. */
4209 tree main_args
4215 /* A partial specialization that replaces multiple parameters of the
4216 primary template with a pack expansion is less specialized for those
4217 parameters. */
4219 {
4221 "primary template because it replaces multiple parameters "
4225 }
4227 /* [temp.class.spec]
4229 A partially specialized non-type argument expression shall not
4230 involve template parameters of the partial specialization except
4231 when the argument expression is a simple identifier.
4233 The type of a template parameter corresponding to a specialized
4234 non-type argument shall not be dependent on a parameter of the
4235 specialization.
4237 Also, we verify that pack expansions only occur at the
4238 end of the argument list. */
4242 {
4249 {
4250 /* Extract the arguments from the argument pack. We'll be
4251 iterating over these in the following loop. */
4254 }
4257 {
4259 /* Get the Jth argument in the parameter pack. */
4263 {
4264 /* Pack expansions must come at the end of the
4265 argument list. */
4268 {
4272 else
4275 }
4276 }
4279 /* We only care about the pattern. */
4285 /* This next two lines are the `argument expression is not just a
4286 simple identifier' condition and also the `specialized
4287 non-type argument' bit. */
4291 {
4295 arg);
4296 else
4297 {
4298 /* Look at the corresponding template parameter,
4299 marking which template parameters its type depends
4300 upon. */
4304 {
4305 /* We haven't yet initialized TPD2. Do so now. */
4307 /* The number of parameters here is the number in the
4308 main template, which, as checked in the assertion
4309 above, is NARGS. */
4313 }
4315 /* Mark the template parameters. But this time, we're
4316 looking for the template parameters of the main
4317 template, not in the specialization. */
4324 NULL,
4328 {
4329 /* The type depended on some template parameters.
4330 If they are fully specialized in the
4331 specialization, that's OK. */
4340 "type %qT of template argument %qE depends "
4342 "type %qT of template argument %qE depends "
4344 type,
4345 arg);
4346 }
4347 }
4348 }
4349 }
4350 }
4352 /* We should only get here once. */
4371 {
4377 {
4380 {
4384 "partial specialization of %qD after instantiation "
4386 }
4387 }
4388 }
4391 }
4393 /* PARM is a template parameter of some form; return the corresponding
4394 TEMPLATE_PARM_INDEX. */
4396 static tree
4398 {
4410 }
4412 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4413 parameter packs used by the template parameter PARM. */
4415 static void
4417 {
4418 /* A type parm can't refer to another parm. */
4422 {
4426 }
4433 }
4435 /* PARM is a template parameter pack. Return any parameter packs used in
4436 its type or the type of any of its template parameters. If there are
4437 any such packs, it will be instantiated into a fixed template parameter
4438 list by partial instantiation rather than be fully deduced. */
4440 tree
4442 {
4443 /* This can only be true in a member template. */
4446 /* This can only be true for a parameter pack. */
4449 /* A type parm can't refer to another parm. */
4462 }
4464 /* Check that a template declaration's use of default arguments and
4465 parameter packs is not invalid. Here, PARMS are the template
4466 parameters. IS_PRIMARY is true if DECL is the thing declared by
4467 a primary template. IS_PARTIAL is true if DECL is a partial
4468 specialization.
4470 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4471 declaration (but not a definition); 1 indicates a declaration, 2
4472 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4473 emitted for extraneous default arguments.
4475 Returns TRUE if there were no errors found, FALSE otherwise. */
4477 bool
4480 {
4483 tree parm_level;
4486 /* [temp.param]
4488 A default template-argument shall not be specified in a
4489 function template declaration or a function template definition, nor
4490 in the template-parameter-list of the definition of a member of a
4491 class template. */
4495 /* You can't have a function template declaration in a local
4496 scope, nor you can you define a member of a class template in a
4497 local scope. */
4505 /* A lambda doesn't have an explicit declaration; don't complain
4506 about the parms of the enclosing class. */
4513 /* If this is either a friend defined in the scope of the class
4514 or a member function. */
4520 /* And, if it was a member function, it really was defined in
4521 the scope of the class. */
4524 /* We already checked these parameters when the template was
4525 declared, so there's no need to do it again now. This function
4526 was defined in class scope, but we're processing its body now
4527 that the class is complete. */
4530 /* Core issue 226 (C++0x only): the following only applies to class
4531 templates. */
4534 {
4535 /* [temp.param]
4537 If a template-parameter has a default template-argument, all
4538 subsequent template-parameters shall have a default
4539 template-argument supplied. */
4541 {
4548 {
4558 {
4560 /* For better subsequent error-recovery, we indicate that
4561 there should have been a default argument. */
4564 }
4566 && !is_friend_decl
4567 /* Don't complain about an enclosing partial
4568 specialization. */
4573 /* A fixed parameter pack will be partially
4574 instantiated into a fixed length list. */
4576 {
4577 /* A primary class template can only have one
4578 parameter pack, at the end of the template
4579 parameter list. */
4584 else
4592 }
4593 }
4594 }
4595 }
4598 || is_partial
4599 || !is_primary
4601 /* For an ordinary class template, default template arguments are
4602 allowed at the innermost level, e.g.:
4603 template <class T = int>
4604 struct S {};
4605 but, in a partial specialization, they're not allowed even
4606 there, as we have in [temp.class.spec]:
4608 The template parameter list of a specialization shall not
4609 contain default template argument values.
4611 So, for a partial specialization, or for a function template
4612 (in C++98/C++03), we look at all of them. */
4613 ;
4614 else
4615 /* But, for a primary class template that is not a partial
4616 specialization we look at all template parameters except the
4617 innermost ones. */
4620 /* Figure out what error message to issue. */
4633 else
4637 /* If we're inside a class definition, there's no need to
4638 examine the parameters to the class itself. On the one
4639 hand, they will be checked when the class is defined, and,
4640 on the other, default arguments are valid in things like:
4641 template <class T = double>
4642 struct S { template <class U> void f(U); };
4643 Here the default argument for `S' has no bearing on the
4644 declaration of `f'. */
4646 else
4647 /* Check everything. */
4653 {
4660 {
4665 {
4667 {
4674 }
4676 /* Clear out the default argument so that we are not
4677 confused later. */
4679 }
4680 }
4682 /* At this point, if we're still interested in issuing messages,
4683 they must apply to classes surrounding the object declared. */
4687 }
4690 }
4692 /* Worker for push_template_decl_real, called via
4693 for_each_template_parm. DATA is really an int, indicating the
4694 level of the parameters we are interested in. If T is a template
4695 parameter of that level, return nonzero. */
4697 static int
4699 {
4705 else
4708 }
4710 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4711 parameters given by current_template_args, or reuses a
4712 previously existing one, if appropriate. Returns the DECL, or an
4713 equivalent one, if it is replaced via a call to duplicate_decls.
4715 If IS_FRIEND is true, DECL is a friend declaration. */
4717 tree
4719 {
4720 tree tmpl;
4721 tree args;
4722 tree info;
4723 tree ctx;
4727 /* True if the template is a member template, in the sense of
4728 [temp.mem]. */
4734 /* See if this is a partial specialization. */
4747 /* For a friend, we want the context of the friend function, not
4748 the type of which it is a friend. */
4752 /* In the case of a virtual function, we want the class in which
4753 it is defined. */
4755 else
4756 /* Otherwise, if we're currently defining some class, the DECL
4757 is assumed to be a member of the class. */
4766 /* See if this is a primary template. */
4769 /* A friend template that specifies a class context, i.e.
4770 template <typename T> friend void A<T>::f();
4771 is not primary. */
4776 else
4780 {
4785 {
4788 }
4790 {
4792 {
4795 }
4797 {
4798 /* [temp.mem]
4800 A destructor shall not be a member template. */
4803 }
4810 {
4811 /* [basic.stc.dynamic.allocation]
4813 An allocation function can be a function
4814 template. ... Template allocation functions shall
4815 have two or more parameters. */
4818 }
4819 }
4825 /* alias-declaration */
4829 else
4830 {
4833 }
4834 }
4836 /* Check to see that the rules regarding the use of default
4837 arguments are not being violated. */
4841 /* Ensure that there are no parameter packs in the type of this
4842 declaration that have not been expanded. */
4844 {
4845 /* Check each of the arguments individually to see if there are
4846 any bare parameter packs. */
4852 {
4855 {
4856 /* This is a PARM_DECL that contains unexpanded parameter
4857 packs. We have already complained about this in the
4858 check_for_bare_parameter_packs call, so just replace
4859 these types with ERROR_MARK_NODE. */
4862 }
4866 }
4868 /* Check for bare parameter packs in the return type and the
4869 exception specifiers. */
4871 /* Errors were already issued, set return type to int
4872 as the frontend doesn't expect error_mark_node as
4873 the return type. */
4877 }
4882 {
4885 }
4898 {
4903 /* If DECL is a TYPE_DECL for a class-template, then there won't
4904 be DECL_LANG_SPECIFIC. The information equivalent to
4905 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4909 {
4910 /* Since a template declaration already existed for this
4911 class-type, we must be redeclaring it here. Make sure
4912 that the redeclaration is valid. */
4914 current_template_parms);
4915 /* We don't need to create a new TEMPLATE_DECL; just use the
4916 one we already had. */
4918 }
4919 else
4920 {
4922 member_template_p);
4927 {
4928 /* A specialization of a member template of a template
4929 class. */
4933 }
4934 }
4935 }
4936 else
4937 {
4943 {
4946 }
4954 {
4955 tree new_tmpl;
4957 /* The declaration is a specialization of a member
4958 template, declared outside the class. Therefore, the
4959 innermost template arguments will be NULL, so we
4960 replace them with the arguments determined by the
4961 earlier call to check_explicit_specialization. */
4964 new_tmpl
4966 member_template_p);
4976 args,
4979 }
4981 /* Make sure the template headers we got make sense. */
4986 {
4991 }
4992 else
4994 {
4999 {
5003 else
5007 /* Avoid crash in import_export_decl. */
5010 }
5015 /* Can happen in erroneous input. */
5017 else
5019 }
5021 /* Check that the parms are used in the appropriate qualifying scopes
5022 in the declarator. */
5026 {
5032 /* Avoid crash in import_export_decl. */
5035 }
5036 }
5041 /* Push template declarations for global functions and types. Note
5042 that we do not try to push a global template friend declared in a
5043 template class; such a thing may well depend on the template
5044 parameters of the class. */
5047 {
5052 /* Hide template friend classes that haven't been declared yet. */
5054 {
5057 }
5058 }
5061 {
5067 {
5070 /* It is a conversion operator. See if the type converted to
5071 depends on innermost template operands. */
5074 depth))
5076 }
5078 /* Give template template parms a DECL_CONTEXT of the template
5079 for which they are a parameter. */
5082 {
5086 }
5087 }
5089 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5090 back to its most general template. If TMPL is a specialization,
5091 ARGS may only have the innermost set of arguments. Add the missing
5092 argument levels if necessary. */
5100 else
5101 {
5106 }
5109 && !is_friend
5112 /* Set DECL_COMDAT on template instantiations; if we force
5113 them to be emitted by explicit instantiation or -frepo,
5114 mark_needed will tell cgraph to do the right thing. */
5118 }
5120 tree
5122 {
5124 }
5126 /* FN is an inheriting constructor that inherits from the constructor
5127 template INHERITED; turn FN into a constructor template with a matching
5128 template header. */
5130 tree
5132 {
5133 tree inner_parms
5136 tree parms
5147 }
5149 /* Called when a class template TYPE is redeclared with the indicated
5150 template PARMS, e.g.:
5152 template <class T> struct S;
5153 template <class T> struct S {}; */
5155 bool
5157 {
5158 tree tmpl;
5159 tree tmpl_parms;
5163 {
5166 }
5170 /* The type is nested in some template class. Nothing to worry
5171 about here; there are no new template parameters for the nested
5172 type. */
5176 {
5178 tmpl);
5180 }
5186 {
5196 }
5199 {
5200 tree tmpl_parm;
5201 tree parm;
5202 tree tmpl_default;
5203 tree parm_default;
5217 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5218 TEMPLATE_DECL. */
5228 {
5232 }
5235 {
5236 /* We have in [temp.param]:
5238 A template-parameter may not be given default arguments
5239 by two different declarations in the same scope. */
5244 }
5247 /* Update the previous template parameters (which are the ones
5248 that will really count) with the new default value. */
5251 /* Update the new parameters, too; they'll be used as the
5252 parameters for any members. */
5254 }
5257 }
5259 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5260 to be used when the caller has already checked
5261 (processing_template_decl
5262 && !instantiation_dependent_expression_p (expr)
5263 && potential_constant_expression (expr))
5264 and cleared processing_template_decl. */
5266 tree
5268 {
5271 complain,
5275 }
5277 /* Simplify EXPR if it is a non-dependent expression. Returns the
5278 (possibly simplified) expression. */
5280 tree
5282 {
5286 /* If we're in a template, but EXPR isn't value dependent, simplify
5287 it. We're supposed to treat:
5289 template <typename T> void f(T[1 + 1]);
5290 template <typename T> void f(T[2]);
5292 as two declarations of the same function, for example. */
5296 {
5297 processing_template_decl_sentinel s;
5299 }
5301 }
5303 tree
5305 {
5307 }
5309 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5310 template declaration, or a TYPE_DECL for an alias declaration. */
5312 bool
5314 {
5322 }
5324 /* Return TRUE iff T is a specialization of an alias template. */
5326 bool
5328 {
5329 /* It's an alias template specialization if it's an alias and its
5330 TYPE_NAME is a specialization of a primary template. */
5332 {
5336 {
5339 }
5340 }
5342 }
5344 /* Return TRUE iff T is a specialization of an alias template with
5345 dependent template-arguments. */
5347 bool
5349 {
5351 && (any_dependent_template_arguments_p
5353 }
5355 /* Return the number of innermost template parameters in TMPL. */
5357 static int
5359 {
5362 }
5364 /* Return either TMPL or another template that it is equivalent to under DR
5365 1286: An alias that just changes the name of a template is equivalent to
5366 the other template. */
5368 static tree
5370 {
5373 {
5376 {
5381 {
5382 tree alias_args = INNERMOST_TEMPLATE_ARGS
5386 /* The alias type is equivalent to the pattern of the
5387 underlying template, so strip the alias. */
5390 }
5391 }
5393 }
5395 }
5397 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5398 must be a function or a pointer-to-function type, as specified
5399 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5400 and check that the resulting function has external linkage. */
5402 static tree
5404 tsubst_flags_t complain)
5405 {
5408 linkage_kind linkage;
5420 /* [temp.arg.nontype]/1
5422 A template-argument for a non-type, non-template template-parameter
5423 shall be one of:
5424 [...]
5425 -- the address of an object or function with external [C++11: or
5426 internal] linkage. */
5429 {
5431 {
5437 else
5440 }
5442 }
5446 {
5448 {
5453 else
5457 }
5459 }
5462 }
5464 /* Subroutine of convert_nontype_argument.
5465 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5466 Emit an error otherwise. */
5468 static bool
5470 tsubst_flags_t complain)
5471 {
5482 {
5486 }
5488 }
5490 /* Returns TRUE iff the address of OP is value-dependent.
5492 14.6.2.4 [temp.dep.temp]:
5493 A non-integral non-type template-argument is dependent if its type is
5494 dependent or it has either of the following forms
5495 qualified-id
5496 & qualified-id
5497 and contains a nested-name-specifier which specifies a class-name that
5498 names a dependent type.
5500 We generalize this to just say that the address of a member of a
5501 dependent class is value-dependent; the above doesn't cover the
5502 address of a static data member named with an unqualified-id. */
5504 static bool
5506 {
5507 /* We could use get_inner_reference here, but there's no need;
5508 this is only relevant for template non-type arguments, which
5509 can only be expressed as &id-expression. */
5511 {
5515 }
5518 }
5520 /* The next set of functions are used for providing helpful explanatory
5521 diagnostics for failed overload resolution. Their messages should be
5522 indented by two spaces for consistency with the messages in
5523 call.c */
5525 static int
5527 {
5529 }
5531 static int
5533 {
5538 }
5540 static int
5542 {
5544 }
5546 static int
5548 {
5554 }
5556 static int
5558 {
5562 }
5564 static int
5566 {
5569 " template parameter %qD is not a parameter pack, but "
5573 }
5575 static int
5577 {
5580 " template argument %qE does not match "
5584 }
5586 static int
5588 {
5592 }
5594 static int
5596 {
5602 }
5604 static int
5606 {
5608 {
5613 else
5615 " deduced conflicting values for non-type parameter "
5617 }
5619 }
5621 static int
5623 {
5626 " variable-sized array type %qT is not "
5628 arg);
5630 }
5632 static int
5634 {
5638 arg);
5640 }
5642 static int
5644 {
5646 {
5652 else
5657 }
5659 }
5661 static int
5663 {
5665 }
5667 static int
5670 {
5672 }
5674 static int
5677 {
5683 }
5685 static int
5688 {
5691 {
5699 }
5701 }
5703 static int
5705 {
5708 " template parameters of a template template argument are "
5711 }
5713 static int
5715 {
5721 }
5723 static int
5725 {
5730 }
5732 static int
5734 {
5738 arg);
5740 }
5742 /* Attempt to convert the non-type template parameter EXPR to the
5743 indicated TYPE. If the conversion is successful, return the
5744 converted value. If the conversion is unsuccessful, return
5745 NULL_TREE if we issued an error message, or error_mark_node if we
5746 did not. We issue error messages for out-and-out bad template
5747 parameters, but not simply because the conversion failed, since we
5748 might be just trying to do argument deduction. Both TYPE and EXPR
5749 must be non-dependent.
5751 The conversion follows the special rules described in
5752 [temp.arg.nontype], and it is much more strict than an implicit
5753 conversion.
5755 This function is called twice for each template argument (see
5756 lookup_template_class for a more accurate description of this
5757 problem). This means that we need to handle expressions which
5758 are not valid in a C++ source, but can be created from the
5759 first call (for instance, casts to perform conversions). These
5760 hacks can go away after we fix the double coercion problem. */
5762 static tree
5764 {
5765 tree expr_type;
5767 /* Detect immediately string literals as invalid non-type argument.
5768 This special-case is not needed for correctness (we would easily
5769 catch this later), but only to provide better diagnostic for this
5770 common user mistake. As suggested by DR 100, we do not mention
5771 linkage issues in the diagnostic as this is not the point. */
5772 /* FIXME we're making this OK. */
5774 {
5780 }
5782 /* Add the ADDR_EXPR now for the benefit of
5783 value_dependent_expression_p. */
5786 {
5790 }
5792 /* If we are in a template, EXPR may be non-dependent, but still
5793 have a syntactic, rather than semantic, form. For example, EXPR
5794 might be a SCOPE_REF, rather than the VAR_DECL to which the
5795 SCOPE_REF refers. Preserving the qualifying scope is necessary
5796 so that access checking can be performed when the template is
5797 instantiated -- but here we need the resolved form so that we can
5798 convert the argument. */
5804 && processing_template_decl
5813 else
5816 /* If the argument is non-dependent, perform any conversions in
5817 non-dependent context as well. */
5822 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5823 to a non-type argument of "nullptr". */
5827 /* In C++11, integral or enumeration non-type template arguments can be
5828 arbitrary constant expressions. Pointer and pointer to
5829 member arguments can be general constant expressions that evaluate
5830 to a null value, but otherwise still need to be of a specific form. */
5832 {
5834 /* A PTRMEM_CST is already constant, and a valid template
5835 argument for a parameter of pointer to member type, we just want
5836 to leave it in that form rather than lower it to a
5841 {
5846 }
5847 }
5849 /* HACK: Due to double coercion, we can get a
5850 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5851 which is the tree that we built on the first call (see
5852 below when coercing to reference to object or to reference to
5853 function). We just strip everything and get to the arg.
5854 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5855 for examples. */
5857 {
5863 {
5864 /* ??? Maybe we could use convert_from_reference here, but we
5865 would need to relax its constraints because the NOP_EXPR
5866 could actually change the type to something more cv-qualified,
5867 and this is not folded by convert_from_reference. */
5872 && (same_type_ignoring_top_level_qualifiers_p
5875 {
5878 }
5879 }
5880 }
5882 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5883 parameter is a pointer to object, through decay and
5884 qualification conversion. Let's strip everything. */
5886 {
5891 {
5892 /* Skip the ADDR_EXPR only if it is part of the decay for
5893 an array. Otherwise, it is part of the original argument
5894 in the source code. */
5899 }
5900 }
5902 /* [temp.arg.nontype]/5, bullet 1
5904 For a non-type template-parameter of integral or enumeration type,
5905 integral promotions (_conv.prom_) and integral conversions
5906 (_conv.integral_) are applied. */
5908 {
5917 /* Notice that there are constant expressions like '4 % 0' which
5918 do not fold into integer constants. */
5920 {
5922 {
5933 /* else cxx_constant_value complained but gave us
5934 a real constant, so go ahead. */
5936 }
5937 else
5939 }
5941 /* Avoid typedef problems. */
5944 }
5945 /* [temp.arg.nontype]/5, bullet 2
5947 For a non-type template-parameter of type pointer to object,
5948 qualification conversions (_conv.qual_) and the array-to-pointer
5949 conversion (_conv.array_) are applied. */
5951 {
5952 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5954 A template-argument for a non-type, non-template template-parameter
5955 shall be one of: [...]
5957 -- the name of a non-type template-parameter;
5958 -- the address of an object or function with external linkage, [...]
5959 expressed as "& id-expression" where the & is optional if the name
5960 refers to a function or array, or if the corresponding
5961 template-parameter is a reference.
5963 Here, we do not care about functions, as they are invalid anyway
5964 for a parameter of type pointer-to-object. */
5967 /* Non-type template parameters are OK. */
5968 ;
5973 {
5975 {
5978 "because %qD is a variable, not the address of "
5981 }
5983 {
5989 }
5990 /* Other values, like integer constants, might be valid
5991 non-type arguments of some other type. */
5993 }
5994 else
5995 {
5996 tree decl;
6001 {
6006 }
6008 {
6014 }
6016 {
6021 }
6022 }
6031 }
6032 /* [temp.arg.nontype]/5, bullet 3
6034 For a non-type template-parameter of type reference to object, no
6035 conversions apply. The type referred to by the reference may be more
6036 cv-qualified than the (otherwise identical) type of the
6037 template-argument. The template-parameter is bound directly to the
6038 template-argument, which must be an lvalue. */
6040 {
6042 expr_type))
6046 {
6051 }
6054 {
6059 }
6061 /* [temp.arg.nontype]/1
6063 A template-argument for a non-type, non-template template-parameter
6064 shall be one of: [...]
6066 -- the address of an object or function with external linkage. */
6069 {
6072 {
6075 "because a reference variable does not have a constant "
6078 }
6079 }
6082 {
6088 }
6091 {
6097 }
6100 }
6101 /* [temp.arg.nontype]/5, bullet 4
6103 For a non-type template-parameter of type pointer to function, only
6104 the function-to-pointer conversion (_conv.func_) is applied. If the
6105 template-argument represents a set of overloaded functions (or a
6106 pointer to such), the matching function is selected from the set
6107 (_over.over_). */
6109 {
6110 /* If the argument is a template-id, we might not have enough
6111 context information to decay the pointer. */
6113 {
6117 }
6120 /* Null pointer values are OK in C++11. */
6126 }
6127 /* [temp.arg.nontype]/5, bullet 5
6129 For a non-type template-parameter of type reference to function, no
6130 conversions apply. If the template-argument represents a set of
6131 overloaded functions, the matching function is selected from the set
6132 (_over.over_). */
6134 {
6136 {
6138 {
6143 }
6145 }
6152 }
6153 /* [temp.arg.nontype]/5, bullet 6
6155 For a non-type template-parameter of type pointer to member function,
6156 no conversions apply. If the template-argument represents a set of
6157 overloaded member functions, the matching member function is selected
6158 from the set (_over.over_). */
6160 {
6165 /* [temp.arg.nontype] bullet 1 says the pointer to member
6166 expression must be a pointer-to-member constant. */
6170 /* There is no way to disable standard conversions in
6171 resolve_address_of_overloaded_function (called by
6172 instantiate_type). It is possible that the call succeeded by
6173 converting &B::I to &D::I (where B is a base of D), so we need
6174 to reject this conversion here.
6176 Actually, even if there was a way to disable standard conversions,
6177 it would still be better to reject them here so that we can
6178 provide a superior diagnostic. */
6180 {
6182 {
6186 /* If we are just one standard conversion off, explain. */
6190 }
6192 }
6193 }
6194 /* [temp.arg.nontype]/5, bullet 7
6196 For a non-type template-parameter of type pointer to data member,
6197 qualification conversions (_conv.qual_) are applied. */
6199 {
6200 /* [temp.arg.nontype] bullet 1 says the pointer to member
6201 expression must be a pointer-to-member constant. */
6208 }
6210 {
6212 {
6217 }
6219 }
6220 /* A template non-type parameter must be one of the above. */
6221 else
6224 /* Sanity check: did we actually convert the argument to the
6225 right type? */
6229 }
6231 /* Subroutine of coerce_template_template_parms, which returns 1 if
6232 PARM_PARM and ARG_PARM match using the rule for the template
6233 parameters of template template parameters. Both PARM and ARG are
6234 template parameters; the rest of the arguments are the same as for
6235 coerce_template_template_parms.
6236 */
6237 static int
6239 tree arg,
6240 tsubst_flags_t complain,
6241 tree in_decl,
6242 tree outer_args)
6243 {
6252 {
6254 /* We encounter instantiations of templates like
6255 template <template <template <class> class> class TT>
6256 class C; */
6257 {
6264 }
6265 /* Fall through. */
6270 /* Argument is a parameter pack but parameter is not. */
6275 /* The tsubst call is used to handle cases such as
6277 template <int> class C {};
6278 template <class T, template <T> class TT> class D {};
6279 D<int, C> d;
6281 i.e. the parameter list of TT depends on earlier parameters. */
6283 && !same_type_p
6290 /* Argument is a parameter pack but parameter is not. */
6297 }
6300 }
6303 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6304 template template parameters. Both PARM_PARMS and ARG_PARMS are
6305 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6306 or PARM_DECL.
6308 Consider the example:
6309 template <class T> class A;
6310 template<template <class U> class TT> class B;
6312 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6313 the parameters to A, and OUTER_ARGS contains A. */
6315 static int
6317 tree arg_parms,
6318 tsubst_flags_t complain,
6319 tree in_decl,
6320 tree outer_args)
6321 {
6332 /* Determine whether we have a parameter pack at the end of the
6333 template template parameter's template parameter list. */
6335 {
6342 {
6356 }
6357 }
6363 /* Check all of the template parameters except the parameter pack at
6364 the end (if any). */
6366 {
6375 outer_args))
6378 }
6381 {
6382 /* Check each of the template parameters in the template
6383 argument against the template parameter pack at the end of
6384 the template template parameter. */
6391 {
6398 outer_args))
6400 }
6401 }
6404 }
6406 /* Verifies that the deduced template arguments (in TARGS) for the
6407 template template parameters (in TPARMS) represent valid bindings,
6408 by comparing the template parameter list of each template argument
6409 to the template parameter list of its corresponding template
6410 template parameter, in accordance with DR150. This
6411 routine can only be called after all template arguments have been
6412 deduced. It will return TRUE if all of the template template
6413 parameter bindings are okay, FALSE otherwise. */
6414 bool
6416 {
6420 /* We're dealing with template parms in this process. */
6426 {
6431 {
6436 {
6437 /* Look inside the argument pack. */
6440 }
6443 {
6447 /* Extract the next argument from the argument
6448 pack. */
6452 /* Look at the pattern of the pack expansion. */
6455 /* Extract the template parameters from the template
6456 argument. */
6462 /* Verify that we can coerce the template template
6463 parameters from the template argument to the template
6464 parameter. This requires an exact match. */
6466 && !coerce_template_template_parms
6468 targ_parms,
6469 tf_none,
6470 tparm,
6471 targs))
6472 {
6475 }
6476 }
6477 }
6478 }
6480 out:
6484 }
6486 /* Since type attributes aren't mangled, we need to strip them from
6487 template type arguments. */
6489 static tree
6491 {
6492 tree mv;
6499 {
6504 }
6506 }
6508 /* Convert the indicated template ARG as necessary to match the
6509 indicated template PARM. Returns the converted ARG, or
6510 error_mark_node if the conversion was unsuccessful. Error and
6511 warning messages are issued under control of COMPLAIN. This
6512 conversion is for the Ith parameter in the parameter list. ARGS is
6513 the full set of template arguments deduced so far. */
6515 static tree
6517 tree arg,
6518 tree args,
6519 tsubst_flags_t complain,
6521 tree in_decl)
6522 {
6523 tree orig_arg;
6524 tree val;
6529 {
6530 /* The template argument was the name of some
6531 member function. That's usually
6532 invalid, but static members are OK. In any
6533 case, grab the underlying fields/functions
6534 and issue an error later if required. */
6537 }
6545 /* When determining whether an argument pack expansion is a template,
6546 look at the pattern. */
6550 /* Deal with an injected-class-name used as a template template arg. */
6552 {
6555 {
6565 }
6566 }
6568 is_tmpl_type =
6584 {
6586 {
6590 }
6593 "to refer to a type member of a template parameter, "
6598 typename_type,
6599 complain);
6602 }
6604 {
6606 {
6608 {
6620 else
6623 }
6624 }
6626 }
6628 {
6630 {
6637 else
6640 }
6642 }
6645 {
6647 {
6651 /* The number of argument required is not known yet.
6652 Just accept it for now. */
6654 else
6655 {
6657 tree argparm;
6659 /* Strip alias templates that are equivalent to another
6660 template. */
6666 args))
6667 {
6670 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6671 TEMPLATE_DECL. */
6673 {
6678 }
6679 }
6680 else
6681 {
6683 {
6690 }
6693 }
6694 }
6695 }
6696 else
6698 /* We only form one instance of each template specialization.
6699 Therefore, if we use a non-canonical variant (i.e., a
6700 typedef), any future messages referring to the type will use
6701 the typedef, which is confusing if those future uses do not
6702 themselves also use the typedef. */
6705 }
6706 else
6707 {
6714 {
6717 else
6718 {
6719 /* Not sure if this is reachable, but it doesn't hurt
6720 to be robust. */
6723 }
6724 }
6727 /* We used to call digest_init here. However, digest_init
6728 will report errors, which we don't want when complain
6729 is zero. More importantly, digest_init will try too
6730 hard to convert things: for example, `0' should not be
6731 converted to pointer type at this point according to
6732 the standard. Accepting this is not merely an
6733 extension, since deciding whether or not these
6734 conversions can occur is part of determining which
6735 function template to call, or whether a given explicit
6736 argument specification is valid. */
6738 else
6747 {
6748 /* Strip typedefs from the SCOPE_REF. */
6751 complain);
6754 }
6755 }
6758 }
6760 /* Coerces the remaining template arguments in INNER_ARGS (from
6761 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6762 Returns the coerced argument pack. PARM_IDX is the position of this
6763 parameter in the template parameter list. ARGS is the original
6764 template argument list. */
6765 static tree
6768 tree args,
6769 tree inner_args,
6771 tree new_args,
6773 tree in_decl,
6774 tsubst_flags_t complain)
6775 {
6778 tree packed_args;
6779 tree argument_pack;
6786 {
6787 /* When the template parameter is a non-type template parameter pack
6788 or template template parameter pack whose type or template
6789 parameters use parameter packs, we know exactly how many arguments
6790 we are looking for. Build a vector of the instantiated decls for
6791 these template parameters in PACKED_PARMS. */
6792 /* We can't use make_pack_expansion here because it would interpret a
6793 _DECL as a use rather than a declaration. */
6807 /* If we're doing a partial instantiation of a member template,
6808 verify that all of the types used for the non-type
6809 template parameter pack are, in fact, valid for non-type
6810 template parameters. */
6813 {
6816 {
6820 }
6821 }
6824 }
6825 else
6828 /* Convert the remaining arguments, which will be a part of the
6829 parameter pack "parm". */
6831 {
6837 {
6838 /* Once we've packed as many args as we have types, stop. */
6842 /* We don't know how many args we have yet, just
6843 use the unconverted ones for now. */
6845 else
6847 }
6850 {
6853 }
6854 else
6857 in_decl);
6861 }
6865 {
6870 }
6875 else
6876 {
6881 }
6884 #ifdef ENABLE_CHECKING
6887 #endif
6889 }
6891 /* Returns the number of pack expansions in the template argument vector
6892 ARGS. */
6894 static int
6896 {
6901 {
6905 }
6907 }
6909 /* Convert all template arguments to their appropriate types, and
6910 return a vector containing the innermost resulting template
6911 arguments. If any error occurs, return error_mark_node. Error and
6912 warning messages are issued under control of COMPLAIN.
6914 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6915 for arguments not specified in ARGS. Otherwise, if
6916 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6917 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6918 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6919 ARGS. */
6921 static tree
6923 tree args,
6924 tree in_decl,
6925 tsubst_flags_t complain,
6928 {
6930 tree orig_inner_args;
6931 tree inner_args;
6932 tree new_args;
6933 tree new_inner_args;
6937 /* When used as a boolean value, indicates whether this is a
6938 variadic template parameter list. Since it's an int, we can also
6939 subtract it from nparms to get the number of non-variadic
6940 parameters. */
6945 /* Likewise for parameters with default arguments. */
6953 /* Determine if there are any parameter packs or default arguments. */
6955 {
6963 }
6966 /* If there are no parameters that follow a parameter pack, we need to
6967 expand any argument packs so that we can deduce a parameter pack from
6968 some non-packed args followed by an argument pack, as in variadic85.C.
6969 If there are such parameters, we need to leave argument packs intact
6970 so the arguments are assigned properly. This can happen when dealing
6971 with a nested class inside a partial specialization of a class
6972 template, as in variadic92.C, or when deducing a template parameter pack
6973 from a sub-declarator, as in variadic114.C. */
6977 /* Count any pack expansion args. */
6983 && require_all_args
6984 && !variadic_args_p
6985 && (!use_default_args
6988 {
6990 {
6992 {
6996 }
6997 else
7003 }
7006 }
7007 /* We can't pass a pack expansion to a non-pack parameter of an alias
7008 template (DR 1430). */
7010 && variadic_args_p
7012 {
7014 {
7016 {
7022 {
7027 }
7028 }
7030 found:;
7031 }
7033 }
7035 /* We need to evaluate the template arguments, even though this
7036 template-id may be nested within a "sizeof". */
7045 {
7046 tree arg;
7047 tree parm;
7049 /* Get the Ith template parameter. */
7053 {
7056 }
7058 /* Calculate the next argument. */
7061 else
7066 {
7067 /* Some arguments will be placed in the
7068 template parameter pack PARM. */
7075 {
7076 /* We don't know how many args we have yet, just use the
7077 unconverted (and still packed) ones for now. */
7081 }
7085 /* Store this argument. */
7087 {
7088 lost++;
7089 /* We are done with all of the arguments. */
7091 }
7092 else
7093 {
7096 }
7099 }
7101 {
7103 {
7104 /* "If every valid specialization of a variadic template
7105 requires an empty template parameter pack, the template is
7106 ill-formed, no diagnostic required." So check that the
7107 pattern works with this parameter. */
7112 in_decl);
7114 {
7118 }
7120 /* Recover from missing typename. */
7124 /* We don't know how many args we have yet, just
7125 use the unconverted ones for now. */
7129 }
7130 }
7132 {
7133 /* There must be a default arg in this case. */
7136 /* The position of the first default template argument,
7137 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
7138 Record that. */
7142 }
7143 else
7147 {
7150 }
7152 /* This only occurs if there was an error in the template
7153 parameter list itself (which we would already have
7154 reported) that we are trying to recover from, e.g., a class
7155 template with a parameter list such as
7156 template<typename..., typename>. */
7158 else
7164 lost++;
7166 }
7171 {
7173 {
7178 }
7180 }
7185 #ifdef ENABLE_CHECKING
7189 #endif
7192 }
7194 /* Like coerce_template_parms. If PARMS represents all template
7195 parameters levels, this function returns a vector of vectors
7196 representing all the resulting argument levels. Note that in this
7197 case, only the innermost arguments are coerced because the
7198 outermost ones are supposed to have been coerced already.
7200 Otherwise, if PARMS represents only (the innermost) vector of
7201 parameters, this function returns a vector containing just the
7202 innermost resulting arguments. */
7204 static tree
7206 tree args,
7207 tree in_decl,
7208 tsubst_flags_t complain,
7211 {
7214 tree coerced_args;
7217 {
7219 tree level;
7225 {
7226 tree l;
7230 require_all_args,
7231 use_default_args);
7232 else
7239 }
7240 }
7241 else
7244 require_all_args,
7245 use_default_args);
7247 }
7249 /* Returns 1 if template args OT and NT are equivalent. */
7251 static int
7253 {
7260 /* For member templates */
7269 {
7286 }
7288 {
7289 /* We get here probably because we are in the middle of substituting
7290 into the pattern of a pack expansion. In that case the
7291 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
7292 interested in. So we want to use the initial pack argument for
7293 the comparison. */
7298 }
7300 {
7303 /* Don't treat an alias template specialization with dependent
7304 arguments as equivalent to its underlying type when used as a
7305 template argument; we need them to be distinct so that we
7306 substitute into the specialization arguments at instantiation
7307 time. And aliases can't be equivalent without being ==, so
7308 we don't need to look any deeper. */
7311 else
7313 }
7316 else
7318 }
7320 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7321 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7322 NEWARG_PTR with the offending arguments if they are non-NULL. */
7324 static int
7327 {
7340 {
7345 {
7351 }
7352 }
7354 }
7356 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7357 of template arguments. Returns 0 otherwise. */
7359 int
7361 {
7363 }
7365 static void
7367 {
7377 /* We are called both from instantiate_decl, where we've already had a
7378 tinst_level pushed, and instantiate_template, where we haven't.
7379 Compensate. */
7390 else
7399 }
7402 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7403 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7404 documentation for TEMPLATE_ID_EXPR. */
7406 tree
7408 {
7409 tree type;
7417 {
7420 }
7423 {
7425 unknown_type_node,
7427 arglist);
7429 }
7436 }
7438 /* Within the scope of a template class S<T>, the name S gets bound
7439 (in build_self_reference) to a TYPE_DECL for the class, not a
7440 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7441 or one of its enclosing classes, and that type is a template,
7442 return the associated TEMPLATE_DECL. Otherwise, the original
7443 DECL is returned.
7445 Also handle the case when DECL is a TREE_LIST of ambiguous
7446 injected-class-names from different bases. */
7448 tree
7450 {
7454 /* DR 176: A lookup that finds an injected-class-name (10.2
7455 [class.member.lookup]) can result in an ambiguity in certain cases
7456 (for example, if it is found in more than one base class). If all of
7457 the injected-class-names that are found refer to specializations of
7458 the same class template, and if the name is followed by a
7459 template-argument-list, the reference refers to the class template
7460 itself and not a specialization thereof, and is not ambiguous. */
7462 {
7465 {
7471 }
7474 else
7476 }
7482 }
7484 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
7485 parameters, find the desired type.
7487 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7489 IN_DECL, if non-NULL, is the template declaration we are trying to
7490 instantiate.
7492 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7493 the class we are looking up.
7495 Issue error and warning messages under control of COMPLAIN.
7497 If the template class is really a local class in a template
7498 function, then the FUNCTION_CONTEXT is the function in which it is
7499 being instantiated.
7501 ??? Note that this function is currently called *twice* for each
7502 template-id: the first time from the parser, while creating the
7503 incomplete type (finish_template_type), and the second type during the
7504 real instantiation (instantiate_template_class). This is surely something
7505 that we want to avoid. It also causes some problems with argument
7506 coercion (see convert_nontype_argument for more information on this). */
7508 static tree
7511 {
7513 tree t;
7516 spec_entry elt;
7517 hashval_t hash;
7520 {
7524 else
7525 {
7532 }
7535 }
7537 {
7540 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7541 an implicit typename for the second A. Deal with it. */
7546 {
7549 }
7550 }
7553 {
7556 }
7558 {
7562 }
7564 {
7567 }
7569 /* Issue an error message if we didn't find a template. */
7571 {
7575 }
7578 /* Make sure it's a user visible template, if it was named by
7579 the user. */
7582 {
7584 {
7588 }
7590 }
7594 /* An alias that just changes the name of a template is equivalent to the
7595 other template, so if any of the arguments are pack expansions, strip
7596 the alias to avoid problems with a pack expansion passed to a non-pack
7597 alias template parameter (DR 1430). */
7602 {
7603 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7604 template arguments */
7606 tree parm;
7607 tree arglist2;
7608 tree outer;
7612 /* Consider an example where a template template parameter declared as
7614 template <class T, class U = std::allocator<T> > class TT
7616 The template parameter level of T and U are one level larger than
7617 of TT. To proper process the default argument of U, say when an
7618 instantiation `TT<int>' is seen, we need to build the full
7619 arguments containing {int} as the innermost level. Outer levels,
7620 available when not appearing as default template argument, can be
7621 obtained from the arguments of the enclosing template.
7623 Suppose that TT is later substituted with std::vector. The above
7624 instantiation is `TT<int, std::allocator<T> >' with TT at
7625 level 1, and T at level 2, while the template arguments at level 1
7626 becomes {std::vector} and the inner level 2 is {int}. */
7632 /* This is an argument of the current template, so we haven't set
7633 DECL_CONTEXT yet. */
7640 complain,
7650 }
7651 else
7652 {
7654 tree gen_tmpl;
7655 tree type_decl;
7663 /* An error occurred while building the template TEMPL, and a
7664 diagnostic has most certainly been emitted for that
7665 already. Let's propagate that error. */
7674 {
7675 /* We've been given an incomplete set of template arguments.
7676 For example, given:
7678 template <class T> struct S1 {
7679 template <class U> struct S2 {};
7680 template <class U> struct S2<U*> {};
7681 };
7683 we will be called with an ARGLIST of `U*', but the
7684 TEMPLATE will be `template <class T> template
7685 <class U> struct S1<T>::S2'. We must fill in the missing
7686 arguments. */
7687 arglist
7689 arglist);
7691 }
7693 /* Now we should have enough arguments. */
7696 /* From here on, we're only interested in the most general
7697 template. */
7699 /* Calculate the BOUND_ARGS. These will be the args that are
7700 actually tsubst'd into the definition to create the
7701 instantiation. */
7703 {
7704 /* We have multiple levels of arguments to coerce, at once. */
7714 {
7715 tree a;
7719 complain,
7722 else
7723 /* Outer levels should have already been coerced. */
7726 /* Don't process further if one of the levels fails. */
7728 {
7729 /* Restore the ARGLIST to its full size. */
7732 }
7736 /* We temporarily reduce the length of the ARGLIST so
7737 that coerce_template_parms will see only the arguments
7738 corresponding to the template parameters it is
7739 examining. */
7741 }
7743 /* Restore the ARGLIST to its full size. */
7747 }
7748 else
7749 arglist
7752 gen_tmpl,
7753 complain,
7758 /* We were unable to bind the arguments. */
7761 /* In the scope of a template class, explicit references to the
7762 template class refer to the type of the template, not any
7763 instantiation of it. For example, in:
7765 template <class T> class C { void f(C<T>); }
7767 the `C<T>' is just the same as `C'. Outside of the
7768 class, however, such a reference is an instantiation. */
7772 /* comp_template_args is expensive, check it last. */
7774 arglist))
7777 /* If we already have this specialization, return it. */
7788 /* If the deduced arguments are invalid, then the binding
7789 failed. */
7793 complain))
7800 {
7805 }
7815 /* Create the type. */
7817 {
7818 /* The user referred to a specialization of an alias
7819 template represented by GEN_TMPL.
7821 [temp.alias]/2 says:
7823 When a template-id refers to the specialization of an
7824 alias template, it is equivalent to the associated
7825 type obtained by substitution of its
7826 template-arguments for the template-parameters in the
7827 type-id of the alias template. */
7830 /* Note that the call above (by indirectly calling
7831 register_specialization in tsubst_decl) registers the
7832 TYPE_DECL representing the specialization of the alias
7833 template. So next time someone substitutes ARGLIST for
7834 the template parms into the alias template (GEN_TMPL),
7835 she'll get that TYPE_DECL back. */
7839 }
7841 {
7843 {
7852 }
7853 else
7854 {
7855 /* We don't want to call start_enum for this type, since
7856 the values for the enumeration constants may involve
7857 template parameters. And, no one should be interested
7858 in the enumeration constants for such a type. */
7861 }
7865 }
7867 {
7874 /* A local class. Make sure the decl gets registered properly. */
7879 /* This instantiation is another name for the primary
7880 template type. Set the TYPE_CANONICAL field
7881 appropriately. */
7884 /* Some of the template arguments require structural
7885 equality testing, so this template class requires
7886 structural equality testing. */
7888 }
7889 else
7892 /* If we called start_enum or pushtag above, this information
7893 will already be set up. */
7895 {
7902 }
7903 else
7907 {
7913 {
7916 }
7917 }
7921 {
7924 {
7927 else
7931 }
7932 }
7934 /* Let's consider the explicit specialization of a member
7935 of a class template specialization that is implicitly instantiated,
7936 e.g.:
7937 template<class T>
7938 struct S
7939 {
7940 template<class U> struct M {}; //#0
7941 };
7943 template<>
7944 template<>
7945 struct S<int>::M<char> //#1
7946 {
7947 int i;
7948 };
7949 [temp.expl.spec]/4 says this is valid.
7951 In this case, when we write:
7952 S<int>::M<char> m;
7954 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7955 the one of #0.
7957 When we encounter #1, we want to store the partial instantiation
7958 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
7960 For all cases other than this "explicit specialization of member of a
7961 class template", we just want to store the most general template into
7962 the CLASSTYPE_TI_TEMPLATE of M.
7964 This case of "explicit specialization of member of a class template"
7965 only happens when:
7966 1/ the enclosing class is an instantiation of, and therefore not
7967 the same as, the context of the most general template, and
7968 2/ we aren't looking at the partial instantiation itself, i.e.
7969 the innermost arguments are not the same as the innermost parms of
7970 the most general template.
7972 So it's only when 1/ and 2/ happens that we want to use the partial
7973 instantiation of the member template in lieu of its most general
7974 template. */
7978 /* the enclosing class must be an instantiation... */
7981 {
7982 tree partial_inst_args;
7985 partial_inst_args =
7991 use_partial_inst_tmpl =
7992 /*...and we must not be looking at the partial instantiation
7993 itself. */
7995 partial_inst_args);
7996 }
7999 /* This case is easy; there are no member templates involved. */
8001 else
8002 {
8003 /* This is a full instantiation of a member template. Find
8004 the partial instantiation of which this is an instance. */
8006 /* Temporarily reduce by one the number of levels in the ARGLIST
8007 so as to avoid comparing the last set of arguments. */
8011 /* FOUND is either a proper class type, or an alias
8012 template specialization. In the later case, it's a
8013 TYPE_DECL, resulting from the substituting of arguments
8014 for parameters in the TYPE_DECL of the alias template
8015 done earlier. So be careful while getting the template
8016 of FOUND. */
8020 }
8030 /* Note this use of the partial instantiation so we can check it
8031 later in maybe_process_partial_specialization. */
8038 /* Now that the type has been registered on the instantiations
8039 list, we set up the enumerators. Because the enumeration
8040 constants may involve the enumeration type itself, we make
8041 sure to register the type first, and then create the
8042 constants. That way, doing tsubst_expr for the enumeration
8043 constants won't result in recursive calls here; we'll find
8044 the instantiation and exit above. */
8048 /* If the type makes use of template parameters, the
8049 code that generates debugging information will crash. */
8052 /* Possibly limit visibility based on template args. */
8059 }
8060 }
8062 /* Wrapper for lookup_template_class_1. */
8064 tree
8067 {
8068 tree ret;
8074 }
8076 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST.
8077 The type of the expression is the unknown_type_node since the
8078 template-id could refer to an explicit or partial specialization. */
8080 tree
8082 {
8089 }
8091 \f
8092 struct pair_fn_data
8093 {
8094 tree_fn_t fn;
8096 /* True when we should also visit template parameters that occur in
8097 non-deduced contexts. */
8100 };
8102 /* Called from for_each_template_parm via walk_tree. */
8104 static tree
8106 {
8119 {
8123 /* Fall through. */
8146 /* Since we're not going to walk subtrees, we have to do this
8147 explicitly here. */
8151 /* Fall through. */
8154 /* Check the return type. */
8159 /* Check the parameter types. Since default arguments are not
8160 instantiated until they are needed, the TYPE_ARG_TYPES may
8161 contain expressions that involve template parameters. But,
8162 no-one should be looking at them yet. And, once they're
8163 instantiated, they don't contain template parameters, so
8164 there's no point in looking at them then, either. */
8165 {
8166 tree parm;
8173 /* Since we've already handled the TYPE_ARG_TYPES, we don't
8174 want walk_tree walking into them itself. */
8176 }
8194 /* Fall through. */
8210 /* Record template parameters such as `T' inside `TT<T>'. */
8214 /* Fall through. */
8226 /* A template template parameter is encountered. */
8232 /* Already substituted template template parameter */
8255 /* If there's no type, then this thing must be some expression
8256 involving template parameters. */
8278 }
8280 /* We didn't find any template parameters we liked. */
8282 }
8284 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
8285 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
8286 call FN with the parameter and the DATA.
8287 If FN returns nonzero, the iteration is terminated, and
8288 for_each_template_parm returns 1. Otherwise, the iteration
8289 continues. If FN never returns a nonzero value, the value
8290 returned by for_each_template_parm is 0. If FN is NULL, it is
8291 considered to be the function which always returns 1.
8293 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
8294 parameters that occur in non-deduced contexts. When false, only
8295 visits those template parameters that can be deduced. */
8297 static int
8301 {
8305 /* Set up. */
8310 /* Walk the tree. (Conceptually, we would like to walk without
8311 duplicates, but for_each_template_parm_r recursively calls
8312 for_each_template_parm, so we would need to reorganize a fair
8313 bit to use walk_tree_without_duplicates, so we keep our own
8314 visited list.) */
8317 else
8320 for_each_template_parm_r,
8324 /* Clean up. */
8326 {
8329 }
8332 }
8334 /* Returns true if T depends on any template parameter. */
8336 int
8338 {
8368 else
8369 {
8372 }
8377 }
8379 /* Returns true iff current_function_decl is an incompletely instantiated
8380 template. Useful instead of processing_template_decl because the latter
8381 is set to 0 during instantiate_non_dependent_expr. */
8383 bool
8385 {
8394 }
8396 /* Returns true if T depends on any template parameter with level LEVEL. */
8398 int
8400 {
8403 }
8405 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8406 ill-formed translation unit, i.e. a variable or function that isn't
8407 usable in a constant expression. */
8411 {
8415 }
8417 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8418 neglectable and instantiated from within an erroneous instantiation. */
8420 static bool
8422 {
8433 }
8441 /* We're starting to instantiate D; record the template instantiation context
8442 for diagnostics and to restore it later. */
8444 bool
8446 {
8448 }
8450 /* We're starting to instantiate D; record the template instantiation context
8451 at LOC for diagnostics and to restore it later. */
8453 bool
8455 {
8459 {
8462 max_tinst_depth);
8464 }
8466 /* If the current instantiation caused problems, don't let it instantiate
8467 anything else. Do allow deduction substitution and decls usable in
8468 constant expressions. */
8485 }
8487 /* We're done instantiating this template; return to the instantiation
8488 context. */
8490 void
8492 {
8493 /* Restore the filename and line number stashed away when we started
8494 this instantiation. */
8498 }
8500 /* We're instantiating a deferred template; restore the template
8501 instantiation context in which the instantiation was requested, which
8502 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8504 static tree
8506 {
8518 }
8520 /* Returns the TINST_LEVEL which gives the original instantiation
8521 context. */
8525 {
8531 }
8533 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8534 vector of template arguments, as for tsubst.
8536 Returns an appropriate tsubst'd friend declaration. */
8538 static tree
8540 {
8541 tree new_friend;
8546 /* This was a friend declared with an explicit template
8547 argument list, e.g.:
8549 friend void f<>(T);
8551 to indicate that f was a template instantiation, not a new
8552 function declaration. Now, we have to figure out what
8553 instantiation of what template. */
8554 {
8556 tree new_args;
8557 tree tmpl;
8560 /* Friend functions are looked up in the containing namespace scope.
8561 We must enter that scope, to avoid finding member functions of the
8562 current class with same name. */
8577 tsk_none);
8579 }
8583 /* The NEW_FRIEND will look like an instantiation, to the
8584 compiler, but is not an instantiation from the point of view of
8585 the language. For example, we might have had:
8587 template <class T> struct S {
8588 template <class U> friend void f(T, U);
8589 };
8591 Then, in S<int>, template <class U> void f(int, U) is not an
8592 instantiation of anything. */
8598 {
8602 }
8604 /* The mangled name for the NEW_FRIEND is incorrect. The function
8605 is not a template instantiation and should not be mangled like
8606 one. Therefore, we forget the mangling here; we'll recompute it
8607 later if we need it. */
8609 {
8612 }
8615 {
8616 tree old_decl;
8617 tree new_friend_template_info;
8618 tree new_friend_result_template_info;
8619 tree ns;
8622 /* We must save some information from NEW_FRIEND before calling
8623 duplicate decls since that function will free NEW_FRIEND if
8624 possible. */
8626 new_friend_is_defn =
8631 {
8632 /* This declaration is a `primary' template. */
8635 new_friend_result_template_info
8637 }
8638 else
8641 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8645 /* Inside pushdecl_namespace_level, we will push into the
8646 current namespace. However, the friend function should go
8647 into the namespace of the template. */
8657 {
8658 /* This new friend declaration matched an existing
8659 declaration. For example, given:
8661 template <class T> void f(T);
8662 template <class U> class C {
8663 template <class T> friend void f(T) {}
8664 };
8666 the friend declaration actually provides the definition
8667 of `f', once C has been instantiated for some type. So,
8668 old_decl will be the out-of-class template declaration,
8669 while new_friend is the in-class definition.
8671 But, if `f' was called before this point, the
8672 instantiation of `f' will have DECL_TI_ARGS corresponding
8673 to `T' but not to `U', references to which might appear
8674 in the definition of `f'. Previously, the most general
8675 template for an instantiation of `f' was the out-of-class
8676 version; now it is the in-class version. Therefore, we
8677 run through all specialization of `f', adding to their
8678 DECL_TI_ARGS appropriately. In particular, they need a
8679 new set of outer arguments, corresponding to the
8680 arguments for this class instantiation.
8682 The same situation can arise with something like this:
8684 friend void f(int);
8685 template <class T> class C {
8686 friend void f(T) {}
8687 };
8689 when `C<int>' is instantiated. Now, `f(int)' is defined
8690 in the class. */
8693 /* On the other hand, if the in-class declaration does
8694 *not* provide a definition, then we don't want to alter
8695 existing definitions. We can just leave everything
8696 alone. */
8697 ;
8698 else
8699 {
8703 /* Overwrite whatever template info was there before, if
8704 any, with the new template information pertaining to
8705 the declaration. */
8709 {
8710 /* We should have called reregister_specialization in
8711 duplicate_decls. */
8716 /* Instantiate it if the global has already been used. */
8720 }
8721 else
8722 {
8723 tree t;
8725 /* Indicate that the old function template is a partial
8726 instantiation. */
8734 /* Reassign any specializations already in the hash table
8735 to the new more general template, and add the
8736 additional template args. */
8740 {
8742 spec_entry elt;
8754 register_specialization
8757 }
8759 }
8760 }
8762 /* The information from NEW_FRIEND has been merged into OLD_DECL
8763 by duplicate_decls. */
8765 }
8766 }
8767 else
8768 {
8772 /* In the code
8773 template <class T> class C {
8774 template <class U> friend void C1<U>::f (); // case 1
8775 friend void C2<T>::f (); // case 2
8776 };
8777 we only need to make sure CONTEXT is a complete type for
8778 case 2. To distinguish between the two cases, we note that
8779 CONTEXT of case 1 remains dependent type after tsubst while
8780 this isn't true for case 2. */
8790 {
8792 /* do_friend adds the TEMPLATE_DECL for any member friend
8793 template even if it isn't a member template, i.e.
8794 template <class T> friend A<T>::f();
8795 Look through it in that case. */
8799 /* Check to see that the declaration is really present, and,
8800 possibly obtain an improved declaration. */
8805 }
8806 }
8809 }
8811 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8812 template arguments, as for tsubst.
8814 Returns an appropriate tsubst'd friend type or error_mark_node on
8815 failure. */
8817 static tree
8819 {
8820 tree friend_type;
8821 tree tmpl;
8822 tree context;
8825 {
8828 }
8833 {
8836 else
8838 }
8840 /* Look for a class template declaration. We look for hidden names
8841 because two friend declarations of the same template are the
8842 same. For example, in:
8844 struct A {
8845 template <typename> friend class F;
8846 };
8847 template <typename> struct B {
8848 template <typename> friend class F;
8849 };
8851 both F templates are the same. */
8855 /* But, if we don't find one, it might be because we're in a
8856 situation like this:
8858 template <class T>
8859 struct S {
8860 template <class U>
8861 friend struct S;
8862 };
8864 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8865 for `S<int>', not the TEMPLATE_DECL. */
8867 {
8870 }
8873 {
8874 /* The friend template has already been declared. Just
8875 check to see that the declarations match, and install any new
8876 default parameters. We must tsubst the default parameters,
8877 of course. We only need the innermost template parameters
8878 because that is all that redeclare_class_template will look
8879 at. */
8882 {
8883 tree parms;
8884 location_t saved_input_location;
8893 }
8896 }
8897 else
8898 {
8899 /* The friend template has not already been declared. In this
8900 case, the instantiation of the template class will cause the
8901 injection of this template into the global scope. */
8906 /* The new TMPL is not an instantiation of anything, so we
8907 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8908 the new type because that is supposed to be the corresponding
8909 template decl, i.e., TMPL. */
8916 /* Inject this template into the global scope. */
8918 }
8921 {
8924 else
8926 }
8929 }
8931 /* Returns zero if TYPE cannot be completed later due to circularity.
8932 Otherwise returns one. */
8934 static int
8936 {
8946 else
8948 }
8952 /* Apply any attributes which had to be deferred until instantiation
8953 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8954 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8956 static void
8959 {
8961 tree t;
8966 {
8970 }
8973 {
8977 }
8978 else
8982 {
8987 {
8990 {
8997 {
9004 clauses
9008 else
9010 }
9011 /* If the first attribute argument is an identifier, don't
9012 pass it through tsubst. Attributes like mode, format,
9013 cleanup and several target specific attributes expect it
9014 unmodified. */
9017 {
9018 tree chain
9020 in_decl,
9025 chain);
9026 }
9027 else
9033 }
9034 else
9036 }
9039 }
9040 }
9042 /* Perform (or defer) access check for typedefs that were referenced
9043 from within the template TMPL code.
9044 This is a subroutine of instantiate_decl and instantiate_class_template.
9045 TMPL is the template to consider and TARGS is the list of arguments of
9046 that template. */
9048 static void
9050 {
9051 location_t saved_location;
9062 {
9074 /* Make access check error messages point to the location
9075 of the use of the typedef. */
9079 tf_warning_or_error);
9080 }
9082 }
9084 static tree
9086 {
9088 tree typedecl;
9089 tree pbinfo;
9090 tree base_list;
9092 tree fn_context;
9101 /* Figure out which template is being instantiated. */
9105 /* Determine what specialization of the original template to
9106 instantiate. */
9109 {
9112 }
9114 {
9115 /* This TYPE is actually an instantiation of a partial
9116 specialization. We replace the innermost set of ARGS with
9117 the arguments appropriate for substitution. For example,
9118 given:
9120 template <class T> struct S {};
9121 template <class T> struct S<T*> {};
9123 and supposing that we are instantiating S<int*>, ARGS will
9124 presently be {int*} -- but we need {int}. */
9127 }
9128 else
9129 {
9132 }
9134 /* If the template we're instantiating is incomplete, then clearly
9135 there's nothing we can do. */
9139 /* If we've recursively instantiated too many templates, stop. */
9143 /* Now we're really doing the instantiation. Mark the type as in
9144 the process of being defined. */
9147 /* We may be in the middle of deferred access check. Disable
9148 it now. */
9152 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
9157 /* Use #pragma pack from the template context. */
9163 /* Set the input location to the most specialized template definition.
9164 This is needed if tsubsting causes an error. */
9176 {
9179 /* Adjust visibility for template arguments. */
9181 }
9187 /* We should never instantiate a nested class before its enclosing
9188 class; we need to look up the nested class by name before we can
9189 instantiate it, and that lookup should instantiate the enclosing
9190 class. */
9196 {
9197 tree pbase_binfo;
9198 tree pushed_scope;
9201 /* We must enter the scope containing the type, as that is where
9202 the accessibility of types named in dependent bases are
9203 looked up from. */
9206 /* Substitute into each of the bases to determine the actual
9207 basetypes. */
9209 {
9210 tree base;
9216 {
9217 expanded_bases =
9224 }
9227 {
9229 /* Extract the already-expanded base class. */
9231 else
9232 /* Substitute to figure out the base class. */
9234 NULL_TREE);
9242 }
9243 }
9245 /* The list is now in reverse order; correct that. */
9250 }
9251 /* Now call xref_basetypes to set up all the base-class
9252 information. */
9260 /* Now that our base classes are set up, enter the scope of the
9261 class, so that name lookups into base classes, etc. will work
9262 correctly. This is precisely analogous to what we do in
9263 begin_class_definition when defining an ordinary non-template
9264 class, except we also need to push the enclosing classes. */
9267 /* Now members are processed in the order of declaration. */
9270 {
9274 {
9276 {
9277 /* Build new CLASSTYPE_NESTED_UTDS. */
9279 tree newtag;
9285 /* If the member is a class template, then -- even after
9286 substitution -- there may be dependent types in the
9287 template argument list for the class. We increment
9288 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
9289 that function will assume that no types are dependent
9290 when outside of a template. */
9300 {
9304 /* Unfortunately, lookup_template_class sets
9305 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
9306 instantiation (i.e., for the type of a member
9307 template class nested within a template class.)
9308 This behavior is required for
9309 maybe_process_partial_specialization to work
9310 correctly, but is not accurate in this case;
9311 the TAG is not an instantiation of anything.
9312 (The corresponding TEMPLATE_DECL is an
9313 instantiation, but the TYPE is not.) */
9316 /* Now, we call pushtag to put this NEWTAG into the scope of
9317 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
9318 pushtag calling push_template_decl. We don't have to do
9319 this for enums because it will already have been done in
9320 tsubst_enum. */
9324 }
9325 }
9327 {
9328 /* Build new TYPE_METHODS. */
9329 tree r;
9338 /* Instantiate members marked with attribute used. */
9344 }
9347 /* A closure type for a lambda in a default argument for a
9348 member template. Ignore it; it will be instantiated with
9350 else
9351 {
9352 /* Build new TYPE_FIELDS. */
9354 {
9355 tree condition;
9358 condition =
9368 }
9370 {
9371 tree r;
9375 /* The file and line for this declaration, to
9376 assist in error message reporting. Since we
9377 called push_tinst_level above, we don't need to
9378 restore these. */
9388 {
9389 /* A capture pack became multiple fields. */
9392 }
9395 {
9399 {
9400 /* In [temp.inst]:
9402 [t]he initialization (and any associated
9403 side-effects) of a static data member does
9404 not occur unless the static data member is
9405 itself used in a way that requires the
9406 definition of the static data member to
9407 exist.
9409 Therefore, we do not substitute into the
9410 initialized for the static data member here. */
9411 finish_static_data_member_decl
9417 /* Instantiate members marked with attribute used. */
9420 }
9422 {
9423 /* Determine whether R has a valid type and can be
9424 completed later. If R is invalid, then its type
9425 is replaced by error_mark_node. */
9431 {
9434 }
9435 }
9437 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9438 such a thing will already have been added to the field
9439 list by tsubst_enum in finish_member_declaration in the
9440 CLASSTYPE_NESTED_UTDS case above. */
9444 {
9447 }
9448 }
9449 }
9450 }
9451 }
9452 else
9453 {
9456 {
9457 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9463 {
9464 /* template <class T> friend class C; */
9467 }
9469 {
9470 /* template <class T> friend class C::D; */
9476 }
9479 {
9480 /* This could be either
9482 friend class T::C;
9484 when dependent_type_p is false or
9486 template <class U> friend class T::C;
9488 otherwise. */
9491 /* Bump processing_template_decl for correct
9492 dependent_type_p calculation. */
9497 }
9500 {
9501 /* friend class C;
9503 where C hasn't been declared yet. Let's lookup name
9504 from namespace scope directly, bypassing any name that
9505 come from dependent base class. */
9508 /* The call to xref_tag_from_type does injection for friend
9509 classes. */
9511 friend_type =
9515 }
9517 /* friend class C<T>; */
9520 /* Otherwise it's
9522 friend class C;
9524 where C is already declared or
9526 friend class C<int>;
9528 We don't have to do anything in these cases. */
9531 /* Trick make_friend_class into realizing that the friend
9532 we're adding is a template, not an ordinary class. It's
9533 important that we use make_friend_class since it will
9534 perform some error-checking and output cross-reference
9535 information. */
9543 }
9544 else
9545 {
9546 /* Build new DECL_FRIENDLIST. */
9547 tree r;
9549 /* The file and line for this declaration, to
9550 assist in error message reporting. Since we
9551 called push_tinst_level above, we don't need to
9552 restore these. */
9556 {
9559 }
9564 {
9567 }
9568 }
9569 }
9570 }
9573 {
9576 {
9581 /* We need to instantiate the capture list from the template
9582 after we've instantiated the closure members, but before we
9583 consider adding the conversion op. Also keep any captures
9584 that may have been added during instantiation of the op(). */
9586 tree tmpl_cap
9595 }
9596 else
9598 }
9600 /* Set the file and line number information to whatever is given for
9601 the class itself. This puts error messages involving generated
9602 implicit functions at a predictable point, and the same point
9603 that would be used for non-template classes. */
9610 /* We don't instantiate default arguments for member functions. 14.7.1:
9612 The implicit instantiation of a class template specialization causes
9613 the implicit instantiation of the declarations, but not of the
9614 definitions or default arguments, of the class member functions,
9615 member classes, static data members and member templates.... */
9617 /* Some typedefs referenced from within the template code need to be access
9618 checked at template instantiation time, i.e now. These types were
9619 added to the template at parsing time. Let's get those and perform
9620 the access checks then. */
9630 /* The vtable for a template class can be emitted in any translation
9631 unit in which the class is instantiated. When there is no key
9632 method, however, finish_struct_1 will already have added TYPE to
9633 the keyed_classes list. */
9638 }
9640 /* Wrapper for instantiate_class_template_1. */
9642 tree
9644 {
9645 tree ret;
9650 }
9652 static tree
9654 {
9655 tree r;
9661 else
9662 {
9669 }
9671 }
9673 /* Given a function parameter pack TMPL_PARM and some function parameters
9674 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9675 and set *SPEC_P to point at the next point in the list. */
9677 static tree
9679 {
9680 /* Collect all of the extra "packed" parameters into an
9681 argument pack. */
9682 tree parmvec;
9683 tree parmtypevec;
9694 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9699 {
9702 }
9704 /* Build the argument packs. */
9711 }
9713 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9714 NONTYPE_ARGUMENT_PACK. */
9716 static tree
9718 {
9720 }
9722 /* Return true iff the Ith element of the argument pack ARG_PACK is a
9723 pack expansion. */
9725 static bool
9727 {
9732 }
9735 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9737 static tree
9739 {
9746 }
9748 /* This is a subroutine of tsubst_pack_expansion.
9750 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9751 mechanism to store the (non complete list of) arguments of the
9752 substitution and return a non substituted pack expansion, in order
9753 to wait for when we have enough arguments to really perform the
9754 substitution. */
9756 static bool
9760 {
9761 /* If one pack has an expansion and another pack has a normal
9762 argument or if one pack has an empty argument and an another
9763 one hasn't then tsubst_pack_expansion cannot perform the
9764 substitution and need to fall back on the
9765 PACK_EXPANSION_EXTRA mechanism. */
9773 {
9776 parm_pack;
9778 {
9783 else
9785 }
9789 }
9791 }
9793 /* [temp.variadic]/6 says that:
9795 The instantiation of a pack expansion [...]
9796 produces a list E1,E2, ..., En, where N is the number of elements
9797 in the pack expansion parameters.
9799 This subroutine of tsubst_pack_expansion produces one of these Ei.
9801 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9802 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9803 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9804 INDEX is the index 'i' of the element Ei to produce. ARGS,
9805 COMPLAIN, and IN_DECL are the same parameters as for the
9806 tsubst_pack_expansion function.
9808 The function returns the resulting Ei upon successful completion,
9809 or error_mark_node.
9811 Note that this function possibly modifies the ARGS parameter, so
9812 it's the responsibility of the caller to restore it. */
9814 static tree
9816 tree parm_packs,
9818 tree args /* This parm gets
9820 tsubst_flags_t complain,
9821 tree in_decl)
9822 {
9823 tree t;
9826 /* For each parameter pack, change the substitution of the parameter
9827 pack to the ith argument in its argument pack, then expand the
9828 pattern. */
9830 {
9835 ith_elem_is_expansion |=
9838 /* Select the Ith argument from the pack. */
9841 {
9843 {
9847 }
9848 else
9850 }
9851 else
9852 {
9857 {
9859 /* Update the corresponding argument. */
9861 }
9862 else
9863 /* Re-use the ARGUMENT_PACK_SELECT. */
9865 }
9867 }
9869 /* Substitute into the PATTERN with the (possibly altered)
9870 arguments. */
9872 /* Expanding a fixed parameter pack from
9873 coerce_template_parameter_pack. */
9878 else
9881 /* If the Ith argument pack element is a pack expansion, then
9882 the Ith element resulting from the substituting is going to
9883 be a pack expansion as well. */
9888 }
9890 /* Substitute ARGS into T, which is an pack expansion
9891 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9892 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9893 (if only a partial substitution could be performed) or
9894 ERROR_MARK_NODE if there was an error. */
9895 tree
9897 tree in_decl)
9898 {
9899 tree pattern;
9903 tree result;
9911 /* Add in any args remembered from an earlier partial instantiation. */
9916 /* Determine the argument packs that will instantiate the parameter
9917 packs used in the expansion expression. While we're at it,
9918 compute the number of arguments to be expanded and make sure it
9919 is consistent. */
9922 {
9929 {
9933 else
9936 }
9938 {
9941 else
9942 {
9943 /* We can't rely on local_specializations for a parameter
9944 name used later in a function declaration (such as in a
9945 late-specified return type). Even if it exists, it might
9946 have the wrong value for a recursive call. Just make a
9947 dummy decl, since it's only used for its type. */
9950 /* Partial instantiation of the parm_pack, we can't build
9951 up an argument pack yet. */
9953 else
9956 }
9957 }
9960 else
9961 {
9967 }
9974 /* This can only happen if we forget to expand an argument
9975 pack somewhere else. Just return an error, silently. */
9976 {
9980 }
9983 {
9987 /* Don't bother trying to do a partial substitution with
9988 incomplete packs; we'll try again after deduction. */
9995 {
10001 pattern);
10002 else
10005 pattern);
10007 }
10009 /* Keep track of the parameter packs and their corresponding
10010 argument packs. */
10013 }
10014 else
10015 {
10016 /* We can't substitute for this parameter pack. We use a flag as
10017 well as the missing_level counter because function parameter
10018 packs don't have a level. */
10020 }
10021 }
10023 /* If the expansion is just T..., return the matching argument pack. */
10026 {
10031 /* Otherwise use the normal path so we get convert_from_reference. */
10032 }
10034 /* We cannot expand this expansion expression, because we don't have
10035 all of the argument packs we need. */
10037 {
10038 /* We got some full packs, but we can't substitute them in until we
10039 have values for all the packs. So remember these until then. */
10044 }
10046 {
10047 /* There were no real arguments, we're just replacing a parameter
10048 pack with another version of itself. Substitute into the
10049 pattern and return a PACK_EXPANSION_*. The caller will need to
10050 deal with that. */
10054 else
10058 }
10063 {
10064 /* We're in a late-specified return type, so create our own local
10065 specializations map; the current map is either NULL or (in the
10066 case of recursive unification) might have bindings that we don't
10067 want to use or alter. */
10070 }
10072 /* For each argument in each argument pack, substitute into the
10073 pattern. */
10076 {
10078 i,
10080 in_decl);
10083 {
10086 }
10087 }
10089 /* Update ARGS to restore the substitution from parameter packs to
10090 their argument packs. */
10092 {
10098 else
10099 {
10107 /* Update the corresponding argument. */
10111 else
10113 }
10114 }
10117 {
10120 }
10123 }
10125 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
10126 TMPL. We do this using DECL_PARM_INDEX, which should work even with
10127 parameter packs; all parms generated from a function parameter pack will
10128 have the same DECL_PARM_INDEX. */
10130 tree
10132 {
10134 tree patparm;
10137 {
10143 }
10144 else
10145 {
10150 }
10153 }
10155 /* Substitute ARGS into the vector or list of template arguments T. */
10157 static tree
10159 {
10171 {
10173 tree new_arg;
10178 {
10179 /* Substitute into an expansion expression. */
10183 /* Add to the expanded length adjustment the number of
10184 expanded arguments. We subtract one from this
10185 measurement, because the argument pack expression
10186 itself is already counted as 1 in
10187 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
10188 the argument pack is empty. */
10190 }
10192 {
10193 /* Substitute into each of the arguments. */
10199 new_arg,
10213 }
10214 }
10215 else
10224 }
10229 /* Make space for the expanded arguments coming from template
10230 argument packs. */
10232 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
10233 arguments for a member template.
10234 In that case each TREE_VEC in ORIG_T represents a level of template
10235 arguments, and ORIG_T won't carry any non defaulted argument count.
10236 It will rather be the nested TREE_VECs that will carry one.
10237 In other words, ORIG_T carries a non defaulted argument count only
10238 if it doesn't contain any nested TREE_VEC. */
10240 {
10244 }
10246 {
10250 {
10253 /* Now expand the template argument pack "in place". */
10256 }
10257 else
10258 {
10260 out++;
10261 }
10262 }
10265 }
10267 /* Return the result of substituting ARGS into the template parameters
10268 given by PARMS. If there are m levels of ARGS and m + n levels of
10269 PARMS, then the result will contain n levels of PARMS. For
10270 example, if PARMS is `template <class T> template <class U>
10271 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
10272 result will be `template <int*, double, class V>'. */
10274 static tree
10276 {
10280 /* When substituting into a template, we must set
10281 PROCESSING_TEMPLATE_DECL as the template parameters may be
10282 dependent if they are based on one-another, and the dependency
10283 predicates are short-circuit outside of templates. */
10290 {
10291 tree new_vec =
10296 {
10297 tree tuple;
10309 }
10315 }
10320 }
10322 /* Return the result of substituting ARGS into one template parameter
10323 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
10324 parameter and which TREE_PURPOSE is the default argument of the
10325 template parameter. */
10327 static tree
10329 {
10350 }
10352 /* Substitute the ARGS into the indicated aggregate (or enumeration)
10353 type T. If T is not an aggregate or enumeration type, it is
10354 handled as if by tsubst. IN_DECL is as for tsubst. If
10355 ENTERING_SCOPE is nonzero, T is the context for a template which
10356 we are presently tsubst'ing. Return the substituted value. */
10358 static tree
10360 tree args,
10361 tsubst_flags_t complain,
10362 tree in_decl,
10364 {
10369 {
10374 /* Else fall through. */
10378 {
10379 tree argvec;
10380 tree context;
10381 tree r;
10385 /* In "sizeof(X<I>)" we need to evaluate "I". */
10391 /* First, determine the context for the type we are looking
10392 up. */
10395 {
10398 /* If context is a nested class inside a class template,
10399 it may still need to be instantiated (c++/33959). */
10401 }
10403 /* Then, figure out what arguments are appropriate for the
10404 type we are trying to find. For example, given:
10406 template <class T> struct S;
10407 template <class T, class U> void f(T, U) { S<U> su; }
10409 and supposing that we are instantiating f<int, double>,
10410 then our ARGS will be {int, double}, but, when looking up
10411 S we only want {double}. */
10416 else
10417 {
10421 }
10427 }
10428 else
10429 /* This is not a template type, so there's nothing to do. */
10434 }
10435 }
10437 /* Substitute into the default argument ARG (a default argument for
10438 FN), which has the indicated TYPE. */
10440 tree
10442 {
10447 /* This can happen in invalid code. */
10451 /* This default argument came from a template. Instantiate the
10452 default argument here, not in tsubst. In the case of
10453 something like:
10455 template <class T>
10456 struct S {
10457 static T t();
10458 void f(T = t());
10459 };
10461 we must be careful to do name lookup in the scope of S<T>,
10462 rather than in the current class. */
10464 /* The "this" pointer is not valid in a default argument. */
10466 {
10471 }
10474 /* The default argument expression may cause implicitly defined
10475 member functions to be synthesized, which will result in garbage
10476 collection. We must treat this situation as if we were within
10477 the body of function so as to avoid collecting live data on the
10478 stack. */
10486 /* Restore the "this" pointer. */
10488 {
10491 }
10498 /* Make sure the default argument is reasonable. */
10504 }
10506 /* Substitute into all the default arguments for FN. */
10508 static void
10510 {
10511 tree arg;
10512 tree tmpl_args;
10516 /* If this function is not yet instantiated, we certainly don't need
10517 its default arguments. */
10520 /* Don't do this again for clones. */
10525 arg;
10531 complain);
10532 }
10534 /* Substitute the ARGS into the T, which is a _DECL. Return the
10535 result of the substitution. Issue error and warning messages under
10536 control of COMPLAIN. */
10538 static tree
10540 {
10541 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10542 location_t saved_loc;
10547 /* Set the filename and linenumber to improve error-reporting. */
10552 {
10554 {
10555 /* We can get here when processing a member function template,
10556 member class template, or template template parameter. */
10558 tree spec;
10559 tree tmpl_args;
10560 tree full_args;
10563 {
10564 /* Template template parameter is treated here. */
10568 /* If we get a real template back, return it. This can happen in
10569 the context of most_specialized_partial_spec. */
10581 complain);
10584 }
10586 /* We might already have an instance of this template.
10587 The ARGS are for the surrounding class type, so the
10588 full args contain the tsubst'd args for the context,
10589 plus the innermost args from the template decl. */
10593 /* Because this is a template, the arguments will still be
10594 dependent, even after substitution. If
10595 PROCESSING_TEMPLATE_DECL is not set, the dependency
10596 predicates will short-circuit. */
10604 /* If this is a default template template argument,
10605 tsubst might not have changed anything. */
10612 {
10615 }
10617 /* Make a new template decl. It will be similar to the
10618 original, but will record the current template arguments.
10619 We also create a new function declaration, which is just
10620 like the old one, but points to this new template, rather
10621 than the old one. */
10630 {
10631 tree new_type;
10639 /* For a partial specialization, we need to keep pointing to
10640 the primary template. */
10646 }
10647 else
10648 {
10649 tree new_decl;
10661 }
10667 /* The template parameters for this new template are all the
10668 template parameters for the old template, except the
10669 outermost level of parameters. */
10672 complain);
10678 /* Record this non-type partial instantiation. */
10682 }
10686 {
10687 tree ctx;
10690 tree gen_tmpl;
10691 tree type;
10696 /* Nobody should be tsubst'ing into non-template functions. */
10700 {
10701 tree spec;
10704 /* If T is not dependent, just return it. We have to
10705 increment PROCESSING_TEMPLATE_DECL because
10706 value_dependent_expression_p assumes that nothing is
10707 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10714 /* Calculate the most general template of which R is a
10715 specialization, and the complete set of arguments used to
10716 specialize R. */
10719 (DECL_TEMPLATE_RESULT
10725 /* Check to see if we already have this specialization. */
10730 {
10733 }
10735 /* We can see more levels of arguments than parameters if
10736 there was a specialization of a member template, like
10737 this:
10739 template <class T> struct S { template <class U> void f(); }
10740 template <> template <class U> void S<int>::f(U);
10742 Here, we'll be substituting into the specialization,
10743 because that's where we can find the code we actually
10744 want to generate, but we'll have enough arguments for
10745 the most general template.
10747 We also deal with the peculiar case:
10749 template <class T> struct S {
10750 template <class U> friend void f();
10751 };
10752 template <class U> void f() {}
10753 template S<int>;
10754 template void f<double>();
10756 Here, the ARGS for the instantiation of will be {int,
10757 double}. But, we only need as many ARGS as there are
10758 levels of template parameters in CODE_PATTERN. We are
10759 careful not to get fooled into reducing the ARGS in
10760 situations like:
10762 template <class T> struct S { template <class U> void f(U); }
10763 template <class T> template <> void S<T>::f(int) {}
10765 which we can spot because the pattern will be a
10766 specialization in this case. */
10768 parms_depth =
10773 }
10774 else
10775 {
10776 /* This special case arises when we have something like this:
10778 template <class T> struct S {
10779 friend void f<int>(int, double);
10780 };
10782 Here, the DECL_TI_TEMPLATE for the friend declaration
10783 will be an IDENTIFIER_NODE. We are being called from
10784 tsubst_friend_function, and we want only to create a
10785 new decl (R) with appropriate types so that we can call
10786 determine_specialization. */
10788 }
10791 {
10794 else
10798 }
10799 else
10800 {
10803 }
10808 /* If we hit excessive deduction depth, the type is bogus even if
10809 it isn't error_mark_node, so don't build a decl. */
10813 /* We do NOT check for matching decls pushed separately at this
10814 point, as they may not represent instantiations of this
10815 template, and in any case are considered separate under the
10816 discrete model. */
10820 /* Clear out the mangled name and RTL for the instantiation. */
10823 /* Leave DECL_INITIAL set on deleted instantiations. */
10828 /* OpenMP UDRs have the only argument a reference to the declared
10829 type. We want to diagnose if the declared type is a reference,
10830 which is invalid, but as references to references are usually
10831 quietly merged, diagnose it here. */
10833 {
10834 tree argtype
10839 "reference type %qT in "
10843 argtype);
10844 }
10847 /* Type-conversion operator. Reconstruct the name, in
10848 case it's the name of one of the template's parameters. */
10858 /* If this is an instantiation of a function with internal
10859 linkage, we already know what object file linkage will be
10860 assigned to the instantiation. */
10869 /* We'll re-clone as appropriate in instantiate_template. */
10872 /* If we aren't complaining now, return on error before we register
10873 the specialization so that we'll complain eventually. */
10879 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10880 this in the special friend case mentioned above where
10881 GEN_TMPL is NULL. */
10883 {
10888 tree new_r
10891 /* We instantiated this while substituting into
10892 the type earlier (template/friend54.C). */
10895 /* We're not supposed to instantiate default arguments
10896 until they are called, for a template. But, for a
10897 declaration like:
10899 template <class T> void f ()
10900 { extern void g(int i = T()); }
10902 we should do the substitution when the template is
10903 instantiated. We handle the member function case in
10904 instantiate_class_template since the default arguments
10905 might refer to other members of the class. */
10910 }
10911 else
10914 /* Copy the list of befriending classes. */
10918 {
10922 in_decl);
10923 }
10926 {
10932 /* If this is an instantiation of a member template, clone it.
10933 If it isn't, that'll be handled by
10934 clone_constructors_and_destructors. */
10937 }
10948 /* Possibly limit visibility based on template args. */
10951 {
10955 }
10963 }
10967 {
10975 {
10976 /* If there is a local specialization that isn't a
10977 parameter pack, it means that we're doing a "simple"
10978 substitution from inside tsubst_pack_expansion. Just
10979 return the local specialization (which will be a single
10980 parm). */
10987 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10988 the parameters in this function parameter pack. */
10992 {
10995 /* Zero-length parameter packs are boring. Just substitute
10996 into the chain. */
11000 }
11001 else
11002 {
11003 /* All we did was update the type. Make a note of that. */
11006 }
11007 }
11009 /* Loop through all of the parameters we'll build. When T is
11010 a function parameter pack, LEN is the number of expanded
11011 types in EXPANDED_TYPES; otherwise, LEN is 1. */
11014 {
11021 /* We're on the Ith parameter of the function parameter
11022 pack. */
11023 {
11024 /* Get the Ith type. */
11027 /* Rename the parameter to include the index. */
11030 }
11032 /* We're dealing with a normal parameter. */
11040 {
11043 else
11046 }
11056 /* Keep track of the first new parameter we
11057 generate. That's what will be returned to the
11058 caller. */
11062 /* Build a proper chain of parameters when substituting
11063 into a function parameter pack. */
11066 }
11068 /* If cp_unevaluated_operand is set, we're just looking for a
11069 single dummy parameter, so don't keep going. */
11074 /* FIRST_R contains the start of the chain we've built. */
11076 }
11080 {
11087 {
11088 /* This field is a lambda capture pack. Return a TREE_VEC of
11089 the expanded fields to instantiate_class_template_1 and
11090 store them in the specializations hash table as a
11091 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
11095 {
11098 }
11099 else
11100 {
11101 /* All we did was update the type. Make a note of that. */
11104 }
11105 }
11108 {
11111 {
11115 }
11125 /* For bit-fields, DECL_INITIAL gives the number of bits. For
11126 non-bit-fields DECL_INITIAL is a non-static data member
11127 initializer, which gets deferred instantiation. */
11133 {
11134 /* Set up DECL_TEMPLATE_INFO so that we can get at the
11135 NSDMI in perform_member_init. Still set DECL_INITIAL
11136 so that we know there is one. */
11141 }
11142 /* We don't have to set DECL_CONTEXT here; it is set by
11143 finish_member_declaration. */
11151 }
11154 {
11162 }
11163 }
11167 /* We reach here only for member using decls. We also need to check
11168 uses_template_parms because DECL_DEPENDENT_P is not set for a
11169 using-declaration that designates a member of the current
11170 instantiation (c++/53549). */
11173 {
11180 else
11181 {
11184 }
11185 }
11186 else
11187 {
11190 }
11195 {
11198 tree spec;
11200 tree ctx;
11209 {
11210 /* If this is the canonical decl, we don't have to
11211 mess with instantiations, and often we can't (for
11212 typename, template type parms and such). Note that
11213 TYPE_NAME is not correct for the above test if
11214 we've copied the type for a typedef. */
11220 }
11222 /* Check to see if we already have the specialization we
11223 need. */
11226 {
11227 /* T is a static data member or namespace-scope entity.
11228 We have to substitute into namespace-scope variables
11229 (even though such entities are never templates) because
11230 of cases like:
11232 template <class T> void f() { extern T t; }
11234 where the entity referenced is not known until
11235 instantiation time. */
11239 {
11241 complain,
11243 /* If CTX is unchanged, then T is in fact the
11244 specialization we want. That situation occurs when
11245 referencing a static data member within in its own
11246 class. We can use pointer equality, rather than
11247 same_type_p, because DECL_CONTEXT is always
11248 canonical... */
11250 /* ... unless T is a member template; in which
11251 case our caller can be willing to create a
11252 specialization of that template represented
11253 by T. */
11257 }
11260 {
11268 }
11269 }
11270 else
11271 {
11272 /* A local variable. */
11274 /* Subsequent calls to pushdecl will fill this in. */
11277 }
11278 /* If we already have the specialization we need, there is
11279 nothing more to do. */
11281 {
11284 }
11286 /* Create a new node for the specialization we need. */
11289 {
11292 else
11299 }
11301 {
11302 /* Even if the original location is out of scope, the
11303 newly substituted one is not. */
11310 {
11311 /* It may seem that this case cannot occur, since:
11313 typedef void f();
11314 void g() { f x; }
11316 declares a function, not a variable. However:
11318 typedef void f();
11319 template <typename T> void g() { T t; }
11320 template void g<f>();
11322 is an attempt to declare a variable with function
11323 type. */
11325 /* R is not yet sufficiently initialized, so we
11326 just use its name. */
11329 }
11331 /* Wait until cp_finish_decl to set this again, to handle
11332 circular dependency (template/instantiate6.C). */
11337 {
11342 {
11345 }
11347 }
11350 }
11356 /* Clear out the mangled name and RTL for the instantiation. */
11360 /* The initializer must not be expanded until it is required;
11361 see [temp.inst]. */
11367 {
11368 /* Possibly limit visibility based on template args. */
11371 {
11375 }
11377 }
11380 {
11381 /* A static data member declaration is always marked
11382 external when it is declared in-class, even if an
11383 initializer is present. We mimic the non-template
11384 processing here. */
11390 }
11400 /* Preserve a typedef that names a type. */
11402 {
11405 }
11408 }
11413 }
11414 #undef RETURN
11416 out:
11417 /* Restore the file and line information. */
11421 }
11423 /* Substitute into the ARG_TYPES of a function type.
11424 If END is a TREE_CHAIN, leave it and any following types
11425 un-substituted. */
11427 static tree
11429 tree args,
11430 tree end,
11431 tsubst_flags_t complain,
11432 tree in_decl)
11433 {
11434 tree remaining_arg_types;
11438 tree default_arg;
11449 {
11450 /* For a pack expansion, perform substitution on the
11451 entire expression. Later on, we'll handle the arguments
11452 one-by-one. */
11457 /* So that we'll spin through the parameters, one by one. */
11459 else
11460 {
11461 /* We only partially substituted into the parameter
11462 pack. Our type is TYPE_PACK_EXPANSION. */
11465 }
11466 }
11479 {
11481 {
11485 }
11487 }
11488 /* DR 657. */
11492 /* Do array-to-pointer, function-to-pointer conversion, and ignore
11493 top-level qualifiers as required. */
11496 /* We do not substitute into default arguments here. The standard
11497 mandates that they be instantiated only when needed, which is
11498 done in build_over_call. */
11502 {
11503 /* We've instantiated a template before its default arguments
11504 have been parsed. This can happen for a nested template
11505 class, and is not an error unless we require the default
11506 argument in a call of this function. */
11507 remaining_arg_types =
11510 }
11511 else
11512 remaining_arg_types =
11514 }
11517 }
11519 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
11520 *not* handle the exception-specification for FNTYPE, because the
11521 initial substitution of explicitly provided template parameters
11522 during argument deduction forbids substitution into the
11523 exception-specification:
11525 [temp.deduct]
11527 All references in the function type of the function template to the
11528 corresponding template parameters are replaced by the specified tem-
11529 plate argument values. If a substitution in a template parameter or
11530 in the function type of the function template results in an invalid
11531 type, type deduction fails. [Note: The equivalent substitution in
11532 exception specifications is done only when the function is instanti-
11533 ated, at which point a program is ill-formed if the substitution
11534 results in an invalid type.] */
11536 static tree
11538 tree args,
11539 tsubst_flags_t complain,
11540 tree in_decl)
11541 {
11542 tree return_type;
11544 tree fntype;
11546 /* The TYPE_CONTEXT is not used for function/method types. */
11549 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
11550 failure. */
11554 {
11555 /* Substitute the argument types. */
11567 {
11568 /* DR 1207: 'this' is in scope in the trailing return type. */
11570 }
11572 /* Substitute the return type. */
11576 {
11579 }
11580 }
11581 else
11582 /* Substitute the return type. */
11587 /* DR 486 clarifies that creation of a function type with an
11588 invalid return type is a deduction failure. */
11591 {
11593 {
11596 else
11598 }
11600 }
11601 /* And DR 657. */
11606 {
11607 /* Substitute the argument types. */
11612 }
11614 /* Construct a new type node and return it. */
11616 {
11621 }
11622 else
11623 {
11625 /* Don't pick up extra function qualifiers from the basetype. */
11628 {
11629 /* [temp.deduct]
11631 Type deduction may fail for any of the following
11632 reasons:
11634 -- Attempting to create "pointer to member of T" when T
11635 is not a class type. */
11638 r);
11640 }
11645 }
11652 }
11654 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11655 ARGS into that specification, and return the substituted
11656 specification. If there is no specification, return NULL_TREE. */
11658 static tree
11660 tree args,
11661 tsubst_flags_t complain,
11662 tree in_decl,
11664 {
11665 tree specs;
11666 tree new_specs;
11671 {
11672 /* A noexcept-specifier. */
11677 {
11678 /* Defer instantiation of noexcept-specifiers to avoid
11679 excessive instantiations (c++/49107). */
11682 {
11683 /* We already partially instantiated this member template,
11684 so combine the new args with the old. */
11689 }
11690 else
11691 {
11694 }
11695 }
11696 else
11697 new_specs = tsubst_copy_and_build
11701 }
11703 {
11706 else
11708 {
11709 tree spec;
11714 {
11715 /* Expand the pack expansion type. */
11718 in_decl);
11724 else
11725 {
11726 /* We're substituting into a member template, so
11727 we got a TYPE_PACK_EXPANSION back. Add that
11728 expansion and move on. */
11732 expanded_specs,
11733 complain);
11736 }
11737 }
11740 {
11743 else
11748 complain);
11749 }
11752 }
11753 }
11755 }
11757 /* Take the tree structure T and replace template parameters used
11758 therein with the argument vector ARGS. IN_DECL is an associated
11759 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11760 Issue error and warning messages under control of COMPLAIN. Note
11761 that we must be relatively non-tolerant of extensions here, in
11762 order to preserve conformance; if we allow substitutions that
11763 should not be allowed, we may allow argument deductions that should
11764 not succeed, and therefore report ambiguous overload situations
11765 where there are none. In theory, we could allow the substitution,
11766 but indicate that it should have failed, and allow our caller to
11767 make sure that the right thing happens, but we don't try to do this
11768 yet.
11770 This function is used for dealing with types, decls and the like;
11771 for expressions, use tsubst_expr or tsubst_copy. */
11773 tree
11775 {
11798 else
11803 /* Reuse typedefs. We need to do this to handle dependent attributes,
11804 such as attribute aligned. */
11807 {
11811 {
11812 /* DECL represents an alias template and we want to
11813 instantiate it. */
11817 }
11821 {
11825 }
11830 else
11831 /* The typedef is from a non-template context. */
11835 {
11837 r = cp_build_qualified_type_real
11841 }
11842 else
11843 {
11844 /* We don't have an instantiation yet, so drop the typedef. */
11849 }
11850 }
11863 {
11889 {
11895 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11896 needed. */
11902 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11903 with TREE_SIDE_EFFECTS that indicates this is not an integral
11904 constant expression. */
11907 {
11910 }
11913 }
11919 {
11932 {
11936 {
11937 /* See through ARGUMENT_PACK_SELECT arguments. */
11939 /* If the selected argument is an expansion E, that most
11940 likely means we were called from
11941 gen_elem_of_pack_expansion_instantiation during the
11942 substituting of pack an argument pack (which Ith
11943 element is a pack expansion, where I is
11944 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
11945 In this case, the Ith element resulting from this
11946 substituting is going to be a pack expansion, which
11947 pattern is the pattern of E. Let's return the
11948 pattern of E, and
11949 gen_elem_of_pack_expansion_instantiation will
11950 build the resulting pack expansion from it. */
11952 {
11953 /* Make sure we aren't throwing away arg info. */
11956 }
11957 }
11958 }
11963 {
11965 /* If ARG is an argument pack, we don't actually want to
11966 perform a substitution here, because substitutions
11967 for argument packs are only done
11968 element-by-element. We can get to this point when
11969 substituting the type of a non-type template
11970 parameter pack, when that type actually contains
11971 template parameter packs from an outer template, e.g.,
11973 template<typename... Types> struct A {
11974 template<Types... Values> struct B { };
11975 }; */
11979 {
11985 return cp_build_qualified_type_real
11987 }
11989 {
11990 /* We are processing a type constructed from a
11991 template template parameter. */
12002 /* Consider this code:
12004 template <template <class> class Template>
12005 struct Internal {
12006 template <class Arg> using Bind = Template<Arg>;
12007 };
12009 template <template <class> class Template, class Arg>
12010 using Instantiate = Template<Arg>; //#0
12012 template <template <class> class Template,
12013 class Argument>
12014 using Bind =
12015 Instantiate<Internal<Template>::template Bind,
12016 Argument>; //#1
12018 When #1 is parsed, the
12019 BOUND_TEMPLATE_TEMPLATE_PARM representing the
12020 parameter `Template' in #0 matches the
12021 UNBOUND_CLASS_TEMPLATE representing the argument
12022 `Internal<Template>::template Bind'; We then want
12023 to assemble the type `Bind<Argument>' that can't
12024 be fully created right now, because
12025 `Internal<Template>' not being complete, the Bind
12026 template cannot be looked up in that context. So
12027 we need to "store" `Bind<Argument>' for later
12028 when the context of Bind becomes complete. Let's
12029 store that in a TYPENAME_TYPE. */
12033 argvec),
12034 typename_type,
12035 complain);
12037 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
12038 are resolving nested-types in the signature of a
12039 member function templates. Otherwise ARG is a
12040 TEMPLATE_DECL and is the real template to be
12041 instantiated. */
12049 complain);
12050 return cp_build_qualified_type_real
12052 }
12053 else
12054 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
12056 }
12059 /* This can happen during the attempted tsubst'ing in
12060 unify. This means that we don't yet have any information
12061 about the template parameter in question. */
12064 /* Early in template argument deduction substitution, we don't
12065 want to reduce the level of 'auto', or it will be confused
12066 with a normal template parm in subsequent deduction. */
12070 /* If we get here, we must have been looking at a parm for a
12071 more deeply nested template. Make a new version of this
12072 template parameter, but with a lower level. */
12074 {
12079 {
12081 r = cp_build_qualified_type_real
12085 }
12086 else
12087 {
12098 /* We have reduced the level of the template
12099 template parameter, but not the levels of its
12100 template parameters, so canonical_type_parameter
12101 will not be able to find the canonical template
12102 template parameter for this level. Thus, we
12103 require structural equality checking to compare
12104 TEMPLATE_TEMPLATE_PARMs. */
12108 else
12112 {
12120 }
12121 }
12130 }
12133 }
12136 {
12144 {
12148 }
12151 {
12155 }
12158 {
12162 }
12168 }
12171 /* We should never be tsubsting a binfo. */
12175 /* A vector of template arguments. */
12181 {
12185 /* [temp.deduct]
12187 Type deduction may fail for any of the following
12188 reasons:
12190 -- Attempting to create a pointer to reference type.
12191 -- Attempting to create a reference to a reference type or
12192 a reference to void.
12194 Core issue 106 says that creating a reference to a reference
12195 during instantiation is no longer a cause for failure. We
12196 only enforce this check in strict C++98 mode. */
12200 {
12203 /* We keep track of the last time we issued this error
12204 message to avoid spewing a ton of messages during a
12205 single bad template instantiation. */
12208 {
12213 else
12216 }
12219 }
12223 {
12225 {
12228 type);
12229 else
12231 type);
12232 }
12234 }
12236 {
12240 }
12242 /* In C++0x, during template argument substitution, when there is an
12243 attempt to create a reference to a reference type, reference
12244 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
12246 "If a template-argument for a template-parameter T names a type
12247 that is a reference to a type A, an attempt to create the type
12248 'lvalue reference to cv T' creates the type 'lvalue reference to
12249 A,' while an attempt to create the type type rvalue reference to
12250 cv T' creates the type T"
12251 */
12252 r = cp_build_reference_type
12255 else
12260 /* Will this ever be needed for TYPE_..._TO values? */
12264 }
12266 {
12269 {
12270 /* [temp.deduct]
12272 Type deduction may fail for any of the following
12273 reasons:
12275 -- Attempting to create "pointer to member of T" when T
12276 is not a class type. */
12280 }
12282 {
12286 }
12288 {
12292 }
12295 {
12296 /* The type of the implicit object parameter gets its
12297 cv-qualifiers from the FUNCTION_TYPE. */
12298 tree memptr;
12299 tree method_type
12304 complain);
12305 }
12306 else
12309 complain);
12310 }
12313 {
12314 tree fntype;
12315 tree specs;
12320 /* Substitute the exception specification. */
12328 }
12330 {
12335 /* As an optimization, we avoid regenerating the array type if
12336 it will obviously be the same as T. */
12340 /* These checks should match the ones in create_array_type_for_decl.
12342 [temp.deduct]
12344 The deduction may fail for any of the following reasons:
12346 -- Attempting to create an array with an element type that
12347 is void, a function type, or a reference type, or [DR337]
12348 an abstract class type. */
12354 {
12358 }
12366 {
12369 }
12372 }
12375 {
12385 {
12389 }
12391 {
12392 /* Normally, make_typename_type does not require that the CTX
12393 have complete type in order to allow things like:
12395 template <class T> struct S { typename S<T>::X Y; };
12397 But, such constructs have already been resolved by this
12398 point, so here CTX really should have complete type, unless
12399 it's a partial instantiation. */
12402 {
12406 }
12407 }
12414 {
12417 }
12420 {
12422 {
12426 else
12428 }
12430 {
12434 else
12436 }
12437 }
12439 return cp_build_qualified_type_real
12441 }
12444 {
12456 }
12459 {
12460 tree type;
12476 complain);
12477 }
12480 {
12481 tree type;
12499 else
12500 {
12504 /* In a template ~id could be either a complement expression
12505 or an unqualified-id naming a destructor; if instantiating
12506 it produces an expression, it's not an id-expression or
12507 member access. */
12510 }
12515 }
12518 {
12522 }
12526 {
12528 tree packed_out =
12530 args,
12531 complain,
12532 in_decl);
12535 /* For template nontype argument packs, also substitute into
12536 the type. */
12541 }
12557 /* We should use one of the expression tsubsts for these codes. */
12563 }
12564 }
12566 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
12567 type of the expression on the left-hand side of the "." or "->"
12568 operator. */
12570 static tree
12573 {
12574 tree name;
12575 tree qualifying_scope;
12576 tree fns;
12577 tree optype;
12582 /* A baselink indicates a function from a base class. Both the
12583 BASELINK_ACCESS_BINFO and the base class referenced may
12584 indicate bases of the template class, rather than the
12585 instantiated class. In addition, lookups that were not
12586 ambiguous before may be ambiguous now. Therefore, we perform
12587 the lookup again. */
12594 {
12601 }
12609 /* If lookup found a single function, mark it as used at this
12610 point. (If it lookup found multiple functions the one selected
12611 later by overload resolution will be marked as used at that
12612 point.) */
12618 /* Add back the template arguments, if present. */
12623 template_args);
12624 /* Update the conversion operator type. */
12632 qualifying_scope,
12633 object_type);
12635 }
12637 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
12638 true if the qualified-id will be a postfix-expression in-and-of
12639 itself; false if more of the postfix-expression follows the
12640 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
12641 of "&". */
12643 static tree
12647 {
12648 tree expr;
12649 tree scope;
12650 tree name;
12652 tree template_args;
12657 /* Figure out what name to look up. */
12660 {
12668 }
12669 else
12670 {
12673 }
12675 /* Substitute into the qualifying scope. When there are no ARGS, we
12676 are just trying to simplify a non-dependent expression. In that
12677 case the qualifying scope may be dependent, and, in any case,
12678 substituting will not help. */
12681 {
12684 }
12685 else
12689 {
12694 }
12697 {
12699 {
12700 /* A BIT_NOT_EXPR is used to represent a destructor. */
12702 {
12706 }
12707 else
12710 }
12711 else
12715 {
12717 {
12721 }
12723 }
12724 }
12727 {
12729 scope);
12730 /* Remember that there was a reference to this entity. */
12732 }
12735 {
12741 }
12750 {
12751 expr = (adjust_result_of_qualified_name_lookup
12753 expr = (finish_qualified_id_expr
12757 }
12759 /* Expressions do not generally have reference type. */
12761 /* However, if we're about to form a pointer-to-member, we just
12762 want the referenced member referenced. */
12767 }
12769 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
12770 initializer, DECL is the substituted VAR_DECL. Other arguments are as
12771 for tsubst. */
12773 static tree
12776 {
12783 {
12784 /* If we had an initializer but it
12785 instantiated to nothing,
12786 value-initialize the object. This will
12787 only occur when the initializer was a
12788 pack expansion where the parameter packs
12789 used in that expansion were of length
12790 zero. */
12792 complain);
12795 }
12798 }
12800 /* Like tsubst, but deals with expressions. This function just replaces
12801 template parms; to finish processing the resultant expression, use
12802 tsubst_copy_and_build or tsubst_expr. */
12804 static tree
12806 {
12808 tree r;
12816 {
12821 {
12822 /* We get here for a use of 'this' in an NSDMI. */
12824 && current_function_decl
12828 /* This can happen for a parameter name used later in a function
12829 declaration (such as in a late-specified return type). Just
12830 make a dummy decl, since it's only used for its type. */
12833 /* Give it the template pattern as its context; its true context
12834 hasn't been instantiated yet and this is good enough for
12835 mangling. */
12837 }
12845 {
12846 tree enum_type;
12847 tree v;
12851 /* There is no need to substitute into namespace-scope
12852 enumerators. */
12855 /* If ARGS is NULL, then T is known to be non-dependent. */
12859 /* Unfortunately, we cannot just call lookup_name here.
12860 Consider:
12862 template <int I> int f() {
12863 enum E { a = I };
12864 struct S { void g() { E e = a; } };
12865 };
12867 When we instantiate f<7>::S::g(), say, lookup_name is not
12868 clever enough to find f<7>::a. */
12869 enum_type
12879 /* We didn't find the name. That should never happen; if
12880 name-lookup found it during preliminary parsing, we
12881 should find it again here during instantiation. */
12883 }
12888 {
12889 /* Check for a local specialization set up by
12890 tsubst_pack_expansion. */
12892 {
12896 }
12898 /* When retrieving a capture pack from a generic lambda, remove the
12899 lambda call op's own template argument list from ARGS. Only the
12900 template arguments active for the closure type should be used to
12901 retrieve the pack specialization. */
12907 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
12908 tsubst_decl put in the hash table. */
12910 }
12913 {
12914 tree ctx;
12919 {
12922 {
12926 }
12928 }
12929 }
12938 {
12941 {
12942 /* First try name lookup to find the instantiation. */
12945 {
12946 /* Make sure that the one we found is the one we want. */
12951 }
12955 else
12956 {
12957 /* This can happen for a variable used in a
12958 late-specified return type of a local lambda, or for a
12959 local static or constant. Building a new VAR_DECL
12960 should be OK in all those cases. */
12963 {
12964 /* We can't call cp_finish_decl, so handle the
12965 initializer by hand. */
12976 }
12981 {
12984 at_eof);
12986 /* A use of a local constant decays to its value.
12987 FIXME update for core DR 696. */
12989 }
12990 }
12991 /* Remember this for subsequent uses. */
12994 }
12995 }
12996 else
13005 /* An OVERLOAD will always be a non-dependent overload set; an
13006 overload set from function scope will just be represented with an
13007 IDENTIFIER_NODE, and from class scope with a BASELINK. */
13023 {
13024 /* Template template argument like the following example need
13025 special treatment:
13027 template <template <class> class TT> struct C {};
13028 template <class T> struct D {
13029 template <class U> struct E {};
13030 C<E> c; // #1
13031 };
13032 D<int> d; // #2
13034 We are processing the template argument `E' in #1 for
13035 the template instantiation #2. Originally, `E' is a
13036 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
13037 have to substitute this with one having context `D<int>'. */
13041 }
13042 else
13043 /* Ordinary template template argument. */
13054 {
13058 }
13062 {
13072 /* We only want to compute the number of arguments. */
13086 {
13093 else
13096 }
13097 else
13099 }
13101 {
13109 }
13110 /* Fall through */
13126 {
13130 }
13133 {
13134 tree object;
13135 tree name;
13140 {
13144 }
13147 {
13157 }
13162 in_decl);
13163 else
13166 }
13204 {
13208 }
13211 {
13216 }
13219 {
13223 }
13226 {
13234 }
13240 {
13247 }
13250 {
13257 }
13260 {
13267 }
13270 {
13271 /* Substituted template arguments */
13280 }
13283 {
13303 }
13328 /* Fall through. */
13331 {
13334 }
13335 else
13339 /* This is handled by tsubst_copy_and_build. */
13343 {
13347 }
13350 /* We shouldn't have built any of these during initial template
13351 generation. Instead, they should be built during instantiation
13352 in response to the saved STMT_IS_FULL_EXPR_P setting. */
13356 {
13364 }
13382 {
13383 /* Instantiate any typedefs in the type. */
13388 }
13391 /* These can sometimes show up in a partial instantiation, but never
13392 involve template parms. */
13397 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
13400 }
13401 }
13403 /* Like tsubst_copy, but specifically for OpenMP clauses. */
13405 static tree
13408 {
13412 {
13418 {
13421 {
13427 }
13428 /* FALLTHRU */
13456 {
13459 {
13466 }
13467 else
13469 }
13499 }
13500 }
13506 }
13508 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
13510 static tree
13512 tree in_decl)
13513 {
13514 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
13534 {
13537 else
13538 {
13542 }
13543 }
13548 #undef RECUR
13549 }
13551 /* Substitute one OMP_FOR iterator. */
13553 static void
13558 {
13559 #define RECUR(NODE) \
13560 tsubst_expr ((NODE), args, complain, in_decl, \
13561 integral_constant_expression_p)
13570 {
13571 /* We need to jump through some hoops to handle declarations in the
13572 for-init-statement, since we might need to handle auto deduction,
13573 but we need to keep control of initialization. */
13577 }
13578 else
13590 {
13592 {
13593 /* Declare the variable, but don't let that initialize it. */
13598 }
13603 {
13608 }
13609 else
13616 }
13619 {
13620 /* Declare and initialize the variable. */
13623 }
13625 {
13626 tree c;
13628 {
13639 }
13641 {
13646 {
13649 }
13650 }
13651 }
13654 {
13658 }
13659 else
13663 {
13674 {
13682 }
13683 else
13689 {
13695 }
13699 {
13707 }
13708 else
13714 }
13720 #undef RECUR
13721 }
13723 /* Like tsubst_copy for expressions, etc. but also does semantic
13724 processing. */
13726 static tree
13729 {
13730 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13731 #define RECUR(NODE) \
13732 tsubst_expr ((NODE), args, complain, in_decl, \
13733 integral_constant_expression_p)
13736 tree r;
13737 location_t loc;
13749 {
13751 {
13752 tree_stmt_iterator i;
13756 }
13771 else
13780 {
13782 tree init;
13788 {
13791 tree decl;
13799 else
13801 }
13803 {
13804 /* Don't build up decls for a variadic capture proxy, we'll
13805 instantiate the elements directly as needed. */
13807 }
13808 else
13809 {
13813 {
13814 /* By marking the declaration as instantiated, we avoid
13815 trying to instantiate it. Since instantiate_decl can't
13816 handle local variables, and since we've already done
13817 all that needs to be done, that's the right thing to
13818 do. */
13823 /* Anonymous aggregates are a special case. */
13826 {
13829 {
13833 }
13835 }
13841 {
13846 }
13847 else
13848 {
13853 {
13854 /* For __PRETTY_FUNCTION__ we have to adjust the
13855 initializer. */
13859 }
13860 else
13864 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
13867 }
13868 }
13869 }
13872 }
13887 {
13897 }
13924 {
13928 }
13936 else
13944 else
13965 {
13969 }
13973 {
13975 tree label;
13980 }
13986 /* Computed goto's must be tsubst'd into. On the other hand,
13987 non-computed gotos must not be; the identifier in question
13988 will have no binding. */
13990 else
13996 {
14012 }
14017 {
14022 }
14023 else
14024 {
14029 else
14036 else
14042 else
14044 }
14048 {
14052 {
14054 /* Prevent instantiate_decl from trying to instantiate
14055 this variable. We've already done all that needs to be
14056 done. */
14059 }
14064 }
14070 {
14071 /* Local classes are not independent templates; they are
14072 instantiated along with their containing function. And this
14073 way we don't have to deal with pushing out of one local class
14074 to instantiate a member of another local class. */
14075 tree fn;
14076 /* Closures are handled by the LAMBDA_EXPR. */
14082 }
14086 {
14087 tree condition;
14090 condition =
14092 args,
14101 }
14126 {
14135 {
14140 }
14152 integral_constant_expression_p);
14161 else
14162 {
14170 }
14173 }
14232 {
14237 {
14240 }
14246 }
14247 else
14248 {
14255 {
14258 }
14261 {
14266 {
14269 }
14275 }
14276 else
14277 {
14281 }
14284 }
14288 {
14294 {
14298 {
14303 }
14307 }
14308 else
14309 {
14314 }
14315 }
14319 {
14323 }
14343 /* If the first operand was a statement, we're done with it. */
14347 complain));
14359 integral_constant_expression_p));
14360 }
14363 out:
14366 #undef RECUR
14367 #undef RETURN
14368 }
14370 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
14371 function. For description of the body see comment above
14372 cp_parser_omp_declare_reduction_exprs. */
14374 static void
14376 {
14382 tree_stmt_iterator tsi;
14393 {
14412 }
14414 {
14434 }
14435 }
14437 /* T is a postfix-expression that is not being used in a function
14438 call. Return the substituted version of T. */
14440 static tree
14442 tsubst_flags_t complain,
14443 tree in_decl)
14444 {
14448 else
14454 }
14456 /* Like tsubst but deals with expressions and performs semantic
14457 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
14459 tree
14461 tree args,
14462 tsubst_flags_t complain,
14463 tree in_decl,
14466 {
14467 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
14468 #define RECUR(NODE) \
14469 tsubst_copy_and_build (NODE, args, complain, in_decl, \
14471 integral_constant_expression_p)
14474 location_t loc;
14483 /* N3276 decltype magic only applies to calls at the top level or on the
14484 right side of a comma. */
14489 {
14492 /* Fall through. */
14494 {
14495 tree decl;
14496 cp_id_kind idk;
14501 {
14504 }
14506 /* Look up the name. */
14509 /* By convention, expressions use ERROR_MARK_NODE to indicate
14510 failure, not NULL_TREE. */
14516 integral_constant_expression_p,
14524 input_location);
14528 {
14532 }
14534 }
14537 {
14538 tree object;
14546 {
14549 }
14550 else
14557 else
14559 }
14562 {
14566 {
14567 /* A type conversion to reference type will be enclosed in
14568 such an indirect ref, but the substitution of the cast
14569 will have also added such an indirect ref. */
14572 }
14573 else
14577 }
14580 {
14584 }
14587 {
14594 flags));
14595 }
14598 {
14602 }
14609 {
14610 tree type;
14616 {
14621 }
14627 {
14645 }
14648 }
14682 else
14684 in_decl);
14719 {
14724 tree r = build_x_binary_op
14726 op0,
14728 ? ERROR_MARK
14730 op1,
14732 ? ERROR_MARK
14740 }
14743 {
14747 }
14760 {
14769 }
14773 /* Fall through */
14776 {
14777 tree r;
14783 {
14784 /* When there are no ARGS, we are trying to evaluate a
14785 non-dependent expression from the parser. Trying to do
14786 the substitutions may not work. */
14789 }
14790 else
14791 {
14796 else
14799 /*integral_constant_expression_p=*/
14803 }
14807 else
14811 {
14813 {
14815 {
14819 }
14820 else
14824 }
14826 }
14828 }
14831 {
14841 }
14857 {
14861 tree r = build_x_modify_expr
14864 /* TREE_NO_WARNING must be set if either the expression was
14865 parenthesized or it uses an operator such as >>= rather
14866 than plain assignment. In the former case, it was already
14867 set and must be copied. In the latter case,
14868 build_x_modify_expr sets it and it must not be reset
14869 here. */
14874 }
14879 /* Remember that there was a reference to this entity. */
14885 {
14890 tree ret;
14894 else
14895 {
14899 }
14901 /* If there was an initializer in the original tree, but it
14902 instantiated to an empty list, then we should pass a
14903 non-NULL empty vector to tell build_new that it was an
14904 empty initializer() rather than no initializer. This can
14905 only happen when the initializer is a pack expansion whose
14906 parameter packs are of length zero. */
14909 else
14910 {
14914 else
14915 {
14918 }
14919 }
14925 complain);
14933 }
14936 {
14942 complain));
14943 }
14946 {
14950 integral_constant_expression_p);
14952 op0,
14955 }
14958 {
14959 tree function;
14964 tree ret;
14967 /* When we parsed the expression, we determined whether or
14968 not Koenig lookup should be performed. */
14971 {
14976 }
14978 {
14979 /* Do nothing; calling tsubst_copy_and_build on an identifier
14980 would incorrectly perform unqualified lookup again.
14982 Note that we can also have an IDENTIFIER_NODE if the earlier
14983 unqualified lookup found a member function; in that case
14984 koenig_p will be false and we do want to do the lookup
14985 again to find the instantiated member function.
14987 FIXME but doing that causes c++/15272, so we need to stop
14988 using IDENTIFIER_NODE in that situation. */
14990 }
14991 else
14992 {
14994 {
15000 }
15001 else
15006 /* Avoid error about taking the address of a constructor. */
15010 in_decl,
15012 integral_constant_expression_p);
15016 }
15021 {
15026 else
15027 {
15028 /* Expand the pack expansion and push each entry onto
15029 CALL_ARGS. */
15032 {
15037 {
15042 }
15043 }
15044 else
15045 {
15046 /* A partial substitution. Add one entry. */
15048 }
15049 }
15050 }
15052 /* We do not perform argument-dependent lookup if normal
15053 lookup finds a non-function, in accordance with the
15054 expected resolution of DR 218. */
15057 /* If lookup found a member function, the Koenig lookup is
15058 not appropriate, even if an unqualified-name was used
15059 to denote the function. */
15062 /* Only do this when substitution turns a dependent call
15063 into a non-dependent call. */
15070 {
15072 {
15073 /* For backwards compatibility and good diagnostics, try
15074 the unqualified lookup again if we aren't in SFINAE
15075 context. */
15076 tree unq = (tsubst_copy_and_build
15078 integral_constant_expression_p));
15083 {
15092 "%qD was not declared in this scope, "
15093 "and no declarations were found by "
15094 "argument-dependent lookup at the point "
15096 {
15100 {
15102 input_location);
15104 "declarations in dependent base %qT are "
15110 else
15114 }
15115 else
15118 }
15120 }
15121 }
15123 {
15128 }
15129 }
15131 /* Remember that there was a reference to this entity. */
15135 /* Put back tf_decltype for the actual call. */
15140 complain);
15142 {
15157 complain);
15158 else
15159 ret = (build_new_method_call
15164 complain));
15165 }
15166 else
15169 koenig_p,
15170 complain);
15175 }
15178 {
15184 {
15186 {
15191 }
15192 else
15193 {
15198 }
15200 }
15201 else
15202 {
15205 }
15209 }
15212 {
15217 input_location));
15218 }
15221 {
15229 {
15230 /* We have pack expansions, so expand those and
15231 create a new list out of it. */
15234 tree chain;
15237 /* Expand the argument expressions. */
15245 /* Build the rest of the list. */
15250 /* Determine the number of arguments. */
15252 {
15255 }
15258 else
15259 {
15260 /* Since we only performed a partial substitution into
15261 the argument pack, we only RETURN (a single list
15262 node. */
15269 }
15271 /* Convert the argument vectors into a TREE_LIST */
15274 {
15275 /* Grab the Ith values. */
15276 i--;
15279 value
15283 /* Build the list (backwards). */
15285 }
15288 }
15304 }
15307 {
15308 tree object;
15309 tree object_type;
15310 tree member;
15311 tree r;
15315 /* Remember that there was a reference to this entity. */
15325 else
15333 {
15335 {
15340 {
15343 }
15345 {
15350 }
15351 }
15352 }
15355 {
15356 /* Lookup the template functions now that we know what the
15357 scope is. */
15365 {
15368 args);
15369 member = (adjust_result_of_qualified_name_lookup
15371 object_type));
15372 }
15373 else
15374 {
15376 input_location);
15378 }
15379 }
15383 {
15385 {
15389 else
15392 }
15394 }
15396 {
15401 }
15405 complain);
15409 }
15416 {
15424 tree r;
15429 /* digest_init will do the wrong thing if we let it. */
15433 /* We do not want to process the index of aggregate
15434 initializers as they are identifier nodes which will be
15435 looked up by digest_init. */
15441 {
15443 /* An identifier index is looked up in the type
15444 being initialized, not the current scope. */
15449 {
15450 /* Substitute into the pack expansion. */
15452 in_decl);
15456 ;
15458 /* Just move the argument into place. */
15460 else
15461 {
15462 /* Update the length of the final CONSTRUCTOR
15463 arguments vector, and note that we will need to
15464 copy.*/
15467 }
15468 }
15469 else
15471 }
15474 {
15479 {
15481 {
15486 }
15487 else
15489 }
15490 }
15500 }
15503 {
15506 {
15509 }
15510 else
15511 {
15514 }
15515 }
15521 {
15522 /* We don't build decls for an instantiation of a
15523 variadic capture proxy, we instantiate the elements
15524 when needed. */
15527 }
15528 /* Fall through */
15531 {
15533 /* ??? We're doing a subset of finish_id_expression here. */
15535 && !processing_template_decl
15536 && !cp_unevaluated_operand
15539 {
15541 /* Replace an evaluated use of the thread_local variable with
15542 a call to its wrapper. */
15544 }
15549 /* If the original type was a reference, we'll be wrapped in
15550 the appropriate INDIRECT_REF. */
15553 }
15556 {
15560 }
15567 {
15578 }
15581 {
15587 integral_constant_expression_p);
15591 /* If the resulting list of expression statement is empty,
15592 fold it further into void_node. */
15597 }
15600 {
15614 /* For a function scope, we want to use tsubst so that we don't
15615 complain about referring to an auto function before its return
15616 type has been deduced. Otherwise, we want to use tsubst_copy so
15617 that we look up the existing field/parameter/variable rather
15618 than build a new one. */
15623 {
15624 /* Look up the parameter we want directly, as tsubst_copy
15625 doesn't do what we need. */
15631 /* FIXME Work around the parm not having DECL_CONTEXT set. */
15634 }
15635 else
15644 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
15646 /* Now that we know visibility, instantiate the type so we have a
15647 declaration of the op() for later calls to lambda_function. */
15653 }
15656 /* We can get here for a constant initializer of non-dependent type.
15657 FIXME stop folding in cp_parser_initializer_clause. */
15658 {
15660 complain);
15662 }
15666 integral_constant_expression_p));
15672 {
15677 complain));
15678 }
15681 /* Handle Objective-C++ constructs, if appropriate. */
15682 {
15683 tree subst
15688 }
15690 }
15692 #undef RECUR
15693 #undef RETURN
15694 out:
15697 }
15699 /* Verify that the instantiated ARGS are valid. For type arguments,
15700 make sure that the type's linkage is ok. For non-type arguments,
15701 make sure they are constants if they are integral or enumerations.
15702 Emit an error under control of COMPLAIN, and return TRUE on error. */
15704 static bool
15706 {
15710 {
15720 }
15722 {
15723 /* [basic.link]: A name with no linkage (notably, the name
15724 of a class or enumeration declared in a local scope)
15725 shall not be used to declare an entity with linkage.
15726 This implies that names with no linkage cannot be used as
15727 template arguments
15729 DR 757 relaxes this restriction for C++0x. */
15734 {
15735 /* DR 488 makes use of a type with no linkage cause
15736 type deduction to fail. */
15738 {
15741 else
15744 }
15746 }
15747 /* In order to avoid all sorts of complications, we do not
15748 allow variably-modified types as template arguments. */
15750 {
15754 }
15755 }
15756 /* Class template and alias template arguments should be OK. */
15758 ;
15759 /* A non-type argument of integral or enumerated type must be a
15760 constant. */
15765 {
15769 }
15771 }
15773 static bool
15775 {
15780 {
15783 }
15787 }
15789 /* We're out of SFINAE context now, so generate diagnostics for the access
15790 errors we saw earlier when instantiating D from TMPL and ARGS. */
15792 static void
15794 {
15806 }
15808 /* Instantiate the indicated variable, function, or alias template TMPL with
15809 the template arguments in TARG_PTR. */
15811 static tree
15813 {
15815 tree fndecl;
15816 tree gen_tmpl;
15817 tree spec;
15825 /* If this function is a clone, handle it specially. */
15827 {
15828 tree spec;
15829 tree clone;
15831 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
15832 DECL_CLONED_FUNCTION. */
15838 /* Look for the clone. */
15842 /* We should always have found the clone by now. */
15845 }
15850 /* Check to see if we already have this specialization. */
15853 /* The TMPL is a partial instantiation. To get a full set of
15854 arguments we must add the arguments used to perform the
15855 partial instantiation. */
15857 targ_ptr);
15859 /* It would be nice to avoid hashing here and then again in tsubst_decl,
15860 but it doesn't seem to be on the hot path. */
15869 {
15871 {
15875 }
15877 }
15880 complain))
15883 /* We are building a FUNCTION_DECL, during which the access of its
15884 parameters and return types have to be checked. However this
15885 FUNCTION_DECL which is the desired context for access checking
15886 is not built yet. We solve this chicken-and-egg problem by
15887 deferring all checks until we have the FUNCTION_DECL. */
15890 /* Instantiation of the function happens in the context of the function
15891 template, not the context of the overload resolution we're doing. */
15893 /* If there are dependent arguments, e.g. because we're doing partial
15894 ordering, make sure processing_template_decl stays set. */
15898 {
15902 }
15907 {
15908 /* We need to determine if we're using a partial or explicit
15909 specialization now, because the type of the variable could be
15910 different. */
15916 {
15920 }
15921 }
15923 /* Substitute template parameters to obtain the specialization. */
15930 {
15933 }
15935 /* The DECL_TI_TEMPLATE should always be the immediate parent
15936 template, not the most general template. */
15939 /* Now we know the specialization, compute access previously
15940 deferred. */
15947 /* If we've just instantiated the main entry point for a function,
15948 instantiate all the alternate entry points as well. We do this
15949 by cloning the instantiation of the main entry point, not by
15950 instantiating the template clones. */
15955 {
15957 {
15958 /* Remember to reinstantiate when we're out of SFINAE so the user
15959 can see the errors. */
15961 }
15963 }
15965 }
15967 /* Wrapper for instantiate_template_1. */
15969 tree
15971 {
15972 tree ret;
15977 }
15979 /* Instantiate the alias template TMPL with ARGS. Also push a template
15980 instantiation level, which instantiate_template doesn't do because
15981 functions and variables have sufficient context established by the
15982 callers. */
15984 static tree
15986 {
15993 {
15996 }
15998 args =
16006 /* We can't free this if a pending_template entry or last_error_tinst_level
16007 is pointing at it. */
16013 }
16015 /* PARM is a template parameter pack for FN. Returns true iff
16016 PARM is used in a deducible way in the argument list of FN. */
16018 static bool
16020 {
16023 {
16025 tree packs;
16031 {
16032 /* The template parameter pack is used in a function parameter
16033 pack. If this is the end of the parameter list, the
16034 template parameter pack is deducible. */
16037 else
16038 /* Otherwise, not. Well, it could be deduced from
16039 a non-pack parameter, but doing so would end up with
16040 a deduction mismatch, so don't bother. */
16042 }
16043 }
16044 /* The template parameter pack isn't used in any function parameter
16045 packs, but it might be used deeper, e.g. tuple<Args...>. */
16047 }
16049 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
16050 NARGS elements of the arguments that are being used when calling
16051 it. TARGS is a vector into which the deduced template arguments
16052 are placed.
16054 Returns either a FUNCTION_DECL for the matching specialization of FN or
16055 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
16056 true, diagnostics will be printed to explain why it failed.
16058 If FN is a conversion operator, or we are trying to produce a specific
16059 specialization, RETURN_TYPE is the return type desired.
16061 The EXPLICIT_TARGS are explicit template arguments provided via a
16062 template-id.
16064 The parameter STRICT is one of:
16066 DEDUCE_CALL:
16067 We are deducing arguments for a function call, as in
16068 [temp.deduct.call].
16070 DEDUCE_CONV:
16071 We are deducing arguments for a conversion function, as in
16072 [temp.deduct.conv].
16074 DEDUCE_EXACT:
16075 We are deducing arguments when doing an explicit instantiation
16076 as in [temp.explicit], when determining an explicit specialization
16077 as in [temp.expl.spec], or when taking the address of a function
16078 template, as in [temp.deduct.funcaddr]. */
16080 tree
16082 tree explicit_targs,
16083 tree targs,
16086 tree return_type,
16087 unification_kind_t strict,
16091 {
16092 tree parms;
16093 tree fntype;
16101 tree tinst;
16107 /* In C++0x, it's possible to have a function template whose type depends
16108 on itself recursively. This is most obvious with decltype, but can also
16109 occur with enumeration scope (c++/48969). So we need to catch infinite
16110 recursion and reject the substitution at deduction time; this function
16111 will return error_mark_node for any repeated substitution.
16113 This also catches excessive recursion such as when f<N> depends on
16114 f<N-1> across all integers, and returns error_mark_node for all the
16115 substitutions back up to the initial one.
16117 This is, of course, not reentrant. */
16127 {
16128 /* [temp.deduct]
16130 The specified template arguments must match the template
16131 parameters in kind (i.e., type, nontype, template), and there
16132 must not be more arguments than there are parameters;
16133 otherwise type deduction fails.
16135 Nontype arguments must match the types of the corresponding
16136 nontype template parameters, or must be convertible to the
16137 types of the corresponding nontype parameters as specified in
16138 _temp.arg.nontype_, otherwise type deduction fails.
16140 All references in the function type of the function template
16141 to the corresponding template parameters are replaced by the
16142 specified template argument values. If a substitution in a
16143 template parameter or in the function type of the function
16144 template results in an invalid type, type deduction fails. */
16149 /* Adjust any explicit template arguments before entering the
16150 substitution context. */
16151 explicit_targs
16153 complain,
16159 /* Substitute the explicit args into the function type. This is
16160 necessary so that, for instance, explicitly declared function
16161 arguments can match null pointed constants. If we were given
16162 an incomplete set of explicit args, we must not do semantic
16163 processing during substitution as we could create partial
16164 instantiations. */
16166 {
16171 /* Dig out the actual parm. */
16174 {
16177 }
16179 {
16182 }
16185 /* No explicit argument for this template parameter. */
16189 {
16190 /* Mark the argument pack as "incomplete". We could
16191 still deduce more arguments during unification.
16192 We remove this mark in type_unification_real. */
16194 {
16198 }
16200 /* We have some incomplete argument packs. */
16202 }
16203 }
16207 {
16210 }
16213 /* Ignore any access checks; we'll see them again in
16214 instantiate_template and they might have the wrong
16215 access path at this point. */
16227 /* Place the explicitly specified arguments in TARGS. */
16230 }
16232 /* Never do unification on the 'this' parameter. */
16236 {
16245 }
16247 /* We allow incomplete unification without an error message here
16248 because the standard doesn't seem to explicitly prohibit it. Our
16249 callers must be ready to deal with unification failures in any
16250 event. */
16253 /* If we aren't explaining yet, push tinst context so we can see where
16254 any errors (e.g. from class instantiations triggered by instantiation
16255 of default template arguments) come from. If we are explaining, this
16256 context is redundant. */
16258 {
16261 }
16263 /* type_unification_real will pass back any access checks from default
16264 template argument substitution. */
16276 /* Now that we have bindings for all of the template arguments,
16277 ensure that the arguments deduced for the template template
16278 parameters have compatible template parameter lists. We cannot
16279 check this property before we have deduced all template
16280 arguments, because the template parameter types of a template
16281 template parameter might depend on prior template parameters
16282 deduced after the template template parameter. The following
16283 ill-formed example illustrates this issue:
16285 template<typename T, template<T> class C> void f(C<5>, T);
16287 template<int N> struct X {};
16289 void g() {
16290 f(X<5>(), 5l); // error: template argument deduction fails
16291 }
16293 The template parameter list of 'C' depends on the template type
16294 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
16295 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
16296 time that we deduce 'C'. */
16299 {
16302 }
16304 /* All is well so far. Now, check:
16306 [temp.deduct]
16308 When all template arguments have been deduced, all uses of
16309 template parameters in nondeduced contexts are replaced with
16310 the corresponding deduced argument values. If the
16311 substitution results in an invalid type, as described above,
16312 type deduction fails. */
16315 {
16318 }
16320 /* Also collect access checks from the instantiation. */
16333 /* Now perform any access checks encountered during substitution. */
16340 /* If we're looking for an exact match, check that what we got
16341 is indeed an exact match. It might not be if some template
16342 parameters are used in non-deduced contexts. But don't check
16343 for an exact match if we have dependent template arguments;
16344 in that case we're doing partial ordering, and we already know
16345 that we have two candidates that will provide the actual type. */
16347 {
16351 tree sarg
16357 {
16361 }
16362 }
16366 fail:
16369 {
16371 /* Reset once we're all the way out. */
16373 }
16375 /* We can't free this if a pending_template entry or last_error_tinst_level
16376 is pointing at it. */
16382 }
16384 /* Adjust types before performing type deduction, as described in
16385 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
16386 sections are symmetric. PARM is the type of a function parameter
16387 or the return type of the conversion function. ARG is the type of
16388 the argument passed to the call, or the type of the value
16389 initialized with the result of the conversion function.
16390 ARG_EXPR is the original argument expression, which may be null. */
16392 static int
16396 tree arg_expr)
16397 {
16401 {
16406 {
16407 /* Swap PARM and ARG throughout the remainder of this
16408 function; the handling is precisely symmetric since PARM
16409 will initialize ARG rather than vice versa. */
16414 }
16417 /* Core issue #873: Do the DR606 thing (see below) for these cases,
16418 too, but here handle it by stripping the reference from PARM
16419 rather than by adding it to ARG. */
16427 /* Nothing else to do in this case. */
16432 }
16435 {
16436 /* [temp.deduct.call]
16438 If P is not a reference type:
16440 --If A is an array type, the pointer type produced by the
16441 array-to-pointer standard conversion (_conv.array_) is
16442 used in place of A for type deduction; otherwise,
16444 --If A is a function type, the pointer type produced by
16445 the function-to-pointer standard conversion
16446 (_conv.func_) is used in place of A for type deduction;
16447 otherwise,
16449 --If A is a cv-qualified type, the top level
16450 cv-qualifiers of A's type are ignored for type
16451 deduction. */
16456 else
16458 }
16460 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
16461 of the form T&&, where T is a template parameter, and the argument
16462 is an lvalue, T is deduced as A& */
16468 /* try_one_overload doesn't provide an arg_expr, but
16469 functions are always lvalues. */
16473 /* [temp.deduct.call]
16475 If P is a cv-qualified type, the top level cv-qualifiers
16476 of P's type are ignored for type deduction. If P is a
16477 reference type, the type referred to by P is used for
16478 type deduction. */
16481 {
16484 }
16486 /* DR 322. For conversion deduction, remove a reference type on parm
16487 too (which has been swapped into ARG). */
16492 }
16494 /* Subroutine of unify_one_argument. PARM is a function parameter of a
16495 template which does contain any deducible template parameters; check if
16496 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
16497 unify_one_argument. */
16499 static int
16502 {
16503 tree type;
16507 else
16514 {
16518 }
16520 {
16525 }
16529 else
16531 }
16535 /* Returns true iff the expression EXPR is one from which a template
16536 argument can be deduced. In other words, if it's an undecorated
16537 use of a template non-type parameter. */
16539 static bool
16541 {
16543 }
16545 /* Returns true iff the array domain DOMAIN uses a template parameter in a
16546 deducible way; that is, if it has a max value of <PARM> - 1. */
16548 static bool
16550 {
16559 }
16561 /* Returns true iff the template arguments ARGS use a template parameter
16562 in a deducible way. */
16564 static bool
16566 {
16568 {
16573 else
16574 {
16581 else
16583 }
16586 }
16588 }
16590 /* Returns true iff TYPE contains any deducible references to template
16591 parameters, as per 14.8.2.5. */
16593 static bool
16595 {
16599 /* T
16600 cv-list T
16601 TT<T>
16602 TT<i>
16603 TT<> */
16608 /* T*
16609 T&
16610 T&& */
16614 /* T[integer-constant ]
16615 type [i] */
16620 /* T type ::*
16621 type T::*
16622 T T::*
16623 T (type ::*)()
16624 type (T::*)()
16625 type (type ::*)(T)
16626 type (T::*)(T)
16627 T (type ::*)(T)
16628 T (T::*)()
16629 T (T::*)(T) */
16632 || (uses_deducible_template_parms
16635 /* template-name <T> (where template-name refers to a class template)
16636 template-name <i> (where template-name refers to a class template) */
16643 /* type (T)
16644 T()
16645 T(T) */
16648 {
16657 }
16660 }
16662 /* Subroutine of type_unification_real and unify_pack_expansion to
16663 handle unification of a single P/A pair. Parameters are as
16664 for those functions. */
16666 static int
16670 {
16677 /* We can't deduce anything from this, but we might get all the
16678 template args from other function args. */
16681 /* Implicit conversions (Clause 4) will be performed on a function
16682 argument to convert it to the type of the corresponding function
16683 parameter if the parameter type contains no template-parameters that
16684 participate in template argument deduction. */
16686 /* For function parameters that contain no template-parameters at all,
16687 we have historically checked for convertibility in order to shortcut
16688 consideration of this candidate. */
16690 explain_p);
16693 /* For function parameters with only non-deducible template parameters,
16694 just return. */
16698 {
16700 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
16701 | UNIFY_ALLOW_MORE_CV_QUAL
16715 }
16717 /* We only do these transformations if this is the top-level
16718 parameter_type_list in a call or declaration matching; in other
16719 situations (nested function declarators, template argument lists) we
16720 won't be comparing a type to an expression, and we don't do any type
16721 adjustments. */
16723 {
16725 {
16728 {
16729 /* [temp.deduct.type] A template-argument can be
16730 deduced from a pointer to function or pointer
16731 to member function argument if the set of
16732 overloaded functions does not contain function
16733 templates and at most one of a set of
16734 overloaded functions provides a unique
16735 match. */
16742 }
16748 }
16750 arg_strict |=
16752 }
16753 else
16758 /* For deduction from an init-list we need the actual list. */
16762 }
16764 /* Most parms like fn_type_unification.
16766 If SUBR is 1, we're being called recursively (to unify the
16767 arguments of a function or method parameter of a function
16768 template).
16770 CHECKS is a pointer to a vector of access checks encountered while
16771 substituting default template arguments. */
16773 static int
16775 tree targs,
16776 tree xparms,
16780 unification_kind_t strict,
16784 {
16789 tree parms;
16798 /* Reset the number of non-defaulted template arguments contained
16799 in TARGS. */
16802 again:
16810 {
16815 /* For a function parameter pack that occurs at the end of the
16816 parameter-declaration-list, the type A of each remaining
16817 argument of the call is compared with the type P of the
16818 declarator-id of the function parameter pack. */
16824 /* For a function parameter pack that does not occur at the
16825 end of the parameter-declaration-list, the type of the
16826 parameter pack is a non-deduced context. */
16835 }
16840 {
16841 /* Unify the remaining arguments with the pack expansion type. */
16842 tree argvec;
16845 /* Allocate a TREE_VEC and copy in all of the arguments */
16850 /* Copy the parameter into parmvec. */
16856 /* Advance to the end of the list of parameters. */
16858 }
16860 /* Fail if we've reached the end of the parm list, and more args
16861 are present, and the parm list isn't variadic. */
16864 /* Fail if parms are left and they don't have default values and
16865 they aren't all deduced as empty packs (c++/57397). This is
16866 consistent with sufficient_parms_p. */
16869 {
16873 do
16874 {
16877 count++;
16879 }
16883 type_pack_p);
16884 }
16887 {
16888 tsubst_flags_t complain = (explain_p
16889 ? tf_warning_or_error
16893 {
16897 /* Clear the "incomplete" flags on all argument packs now so that
16898 substituting them into later default arguments works. */
16900 {
16903 }
16909 /* If this is an undeduced nontype parameter that depends on
16910 a type parameter, try another pass; its type may have been
16911 deduced from a later argument than the one from which
16912 this parameter can be deduced. */
16918 /* Core issue #226 (C++0x) [temp.deduct]:
16920 If a template argument has not been deduced, its
16921 default template argument, if any, is used.
16923 When we are in C++98 mode, TREE_PURPOSE will either
16924 be NULL_TREE or ERROR_MARK_NODE, so we do not need
16925 to explicitly check cxx_dialect here. */
16927 {
16942 else
16943 {
16945 /* The position of the first default template argument,
16946 is also the number of non-defaulted arguments in TARGS.
16947 Record that. */
16951 }
16952 }
16954 /* If the type parameter is a parameter pack, then it will
16955 be deduced to an empty parameter pack. */
16957 {
16958 tree arg;
16961 {
16965 }
16966 else
16973 }
16976 }
16977 }
16978 #ifdef ENABLE_CHECKING
16981 #endif
16984 }
16986 /* Subroutine of type_unification_real. Args are like the variables
16987 at the call site. ARG is an overloaded function (or template-id);
16988 we try deducing template args from each of the overloads, and if
16989 only one succeeds, we go with that. Modifies TARGS and returns
16990 true on success. */
16992 static bool
16994 tree targs,
16995 tree parm,
16996 tree arg,
16997 unification_kind_t strict,
17000 {
17007 {
17010 }
17011 else
17015 /* Handle `&x' where `x' is some static or non-static member
17016 function name. */
17022 /* Strip baselink information. */
17027 {
17028 /* If we got some explicit template args, we need to plug them into
17029 the affected templates before we try to unify, in case the
17030 explicit args will completely resolve the templates in question. */
17037 {
17050 {
17055 {
17058 }
17059 }
17062 }
17063 /* If no templates (or more than one) are fully resolved by the
17064 explicit arguments, this template-id is a non-deduced context; it
17065 could still be OK if we deduce all template arguments for the
17066 enclosing call through other arguments. */
17069 }
17072 /* If ARG is, for example, "(0, &f)" then its type will be unknown
17073 -- but the deduction does not succeed because the expression is
17074 not just the function on its own. */
17076 else
17082 {
17085 }
17087 /* [temp.deduct.type] A template-argument can be deduced from a pointer
17088 to function or pointer to member function argument if the set of
17089 overloaded functions does not contain function templates and at most
17090 one of a set of overloaded functions provides a unique match.
17092 So if we found multiple possibilities, we return success but don't
17093 deduce anything. */
17096 {
17100 {
17105 /* Don't forget explicit template arguments in a pack. */
17109 }
17110 }
17115 }
17117 /* Core DR 115: In contexts where deduction is done and fails, or in
17118 contexts where deduction is not done, if a template argument list is
17119 specified and it, along with any default template arguments, identifies
17120 a single function template specialization, then the template-id is an
17121 lvalue for the function template specialization. */
17123 tree
17125 {
17138 {
17141 }
17143 {
17146 }
17148 {
17151 }
17154 {
17158 /* If we got some explicit template args, we need to plug them into
17159 the affected templates before we try to unify, in case the
17160 explicit args will completely resolve the templates in question. */
17168 {
17181 {
17184 {
17187 }
17189 {
17192 }
17193 }
17194 }
17196 {
17204 {
17205 tree base
17208 }
17212 }
17214 /* There were no good options and at least one bad one, so let the
17215 user know what the problem is. */
17217 }
17219 }
17221 /* Subroutine of resolve_overloaded_unification; does deduction for a single
17222 overload. Fills TARGS with any deduced arguments, or error_mark_node if
17223 different overloads deduce different arguments for a given parm.
17224 ADDR_P is true if the expression for which deduction is being
17225 performed was of the form "& fn" rather than simply "fn".
17227 Returns 1 on success. */
17229 static int
17231 tree orig_targs,
17232 tree targs,
17233 tree parm,
17234 tree arg,
17235 unification_kind_t strict,
17239 {
17241 tree tempargs;
17247 /* [temp.deduct.type] A template-argument can be deduced from a pointer
17248 to function or pointer to member function argument if the set of
17249 overloaded functions does not contain function templates and at most
17250 one of a set of overloaded functions provides a unique match.
17252 So if this is a template, just return success. */
17264 /* We don't copy orig_targs for this because if we have already deduced
17265 some template args from previous args, unify would complain when we
17266 try to deduce a template parameter for the same argument, even though
17267 there isn't really a conflict. */
17274 /* First make sure we didn't deduce anything that conflicts with
17275 explicitly specified args. */
17277 {
17284 /* Since we're unifying against ourselves, we will fill in
17285 template args used in the function parm list with our own
17286 template parms. Discard them. */
17290 }
17293 {
17298 }
17301 }
17303 /* PARM is a template class (perhaps with unbound template
17304 parameters). ARG is a fully instantiated type. If ARG can be
17305 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
17306 TARGS are as for unify. */
17308 static tree
17311 {
17312 tree copy_of_targs;
17319 /* We need to make a new template argument vector for the call to
17320 unify. If we used TARGS, we'd clutter it up with the result of
17321 the attempted unification, even if this class didn't work out.
17322 We also don't want to commit ourselves to all the unifications
17323 we've already done, since unification is supposed to be done on
17324 an argument-by-argument basis. In other words, consider the
17325 following pathological case:
17327 template <int I, int J, int K>
17328 struct S {};
17330 template <int I, int J>
17331 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
17333 template <int I, int J, int K>
17334 void f(S<I, J, K>, S<I, I, I>);
17336 void g() {
17337 S<0, 0, 0> s0;
17338 S<0, 1, 2> s2;
17340 f(s0, s2);
17341 }
17343 Now, by the time we consider the unification involving `s2', we
17344 already know that we must have `f<0, 0, 0>'. But, even though
17345 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
17346 because there are two ways to unify base classes of S<0, 1, 2>
17347 with S<I, I, I>. If we kept the already deduced knowledge, we
17348 would reject the possibility I=1. */
17351 /* If unification failed, we're done. */
17357 }
17359 /* Given a template type PARM and a class type ARG, find the unique
17360 base type in ARG that is an instance of PARM. We do not examine
17361 ARG itself; only its base-classes. If there is not exactly one
17362 appropriate base class, return NULL_TREE. PARM may be the type of
17363 a partial specialization, as well as a plain template type. Used
17364 by unify. */
17366 static enum template_base_result
17369 {
17371 tree binfo;
17377 {
17378 /* The type could not be completed. */
17381 }
17383 /* Walk in inheritance graph order. The search order is not
17384 important, and this avoids multiple walks of virtual bases. */
17386 {
17391 {
17392 /* If there is more than one satisfactory baseclass, then:
17394 [temp.deduct.call]
17396 If they yield more than one possible deduced A, the type
17397 deduction fails.
17399 applies. */
17401 {
17404 }
17407 }
17408 }
17412 }
17414 /* Returns the level of DECL, which declares a template parameter. */
17416 static int
17418 {
17420 {
17430 }
17432 }
17434 /* Decide whether ARG can be unified with PARM, considering only the
17435 cv-qualifiers of each type, given STRICT as documented for unify.
17436 Returns nonzero iff the unification is OK on that basis. */
17438 static int
17440 {
17446 {
17447 /* Although a CVR qualifier is ignored when being applied to a
17448 substituted template parameter ([8.3.2]/1 for example), that
17449 does not allow us to unify "const T" with "int&" because both
17450 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
17451 It is ok when we're allowing additional CV qualifiers
17452 at the outer level [14.8.2.1]/3,1st bullet. */
17462 }
17473 }
17475 /* Determines the LEVEL and INDEX for the template parameter PARM. */
17476 void
17478 {
17482 {
17485 }
17486 else
17487 {
17490 }
17491 }
17493 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
17494 do { \
17495 if (unify (TP, TA, P, A, S, EP)) \
17496 return 1; \
17497 } while (0);
17499 /* Unifies the remaining arguments in PACKED_ARGS with the pack
17500 expansion at the end of PACKED_PARMS. Returns 0 if the type
17501 deduction succeeds, 1 otherwise. STRICT is the same as in
17502 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
17503 call argument list. We'll need to adjust the arguments to make them
17504 types. SUBR tells us if this is from a recursive call to
17505 type_unification_real, or for comparing two template argument
17506 lists. */
17508 static int
17512 {
17513 tree parm
17523 /* Determine the parameter packs we will be deducing from the
17524 pattern, and record their current deductions. */
17527 {
17531 /* Determine the index and level of this parameter pack. */
17534 /* Keep track of the parameter packs and their corresponding
17535 argument packs. */
17538 }
17540 /* Loop through all of the arguments that have not yet been
17541 unified and unify each with the pattern. */
17543 {
17544 tree parm;
17548 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
17549 or the element of its argument pack at the current index if
17550 this argument was explicitly specified. */
17552 {
17561 {
17564 }
17566 }
17568 /* If we had explicit template arguments, substitute them into the
17569 pattern before deduction. */
17571 {
17572 /* Some arguments might still be unspecified or dependent. */
17580 NULL_TREE);
17585 }
17586 else
17589 /* Unify the pattern with the current argument. */
17594 /* For each parameter pack, collect the deduced value. */
17596 {
17602 }
17603 }
17605 /* Verify that the results of unification with the parameter packs
17606 produce results consistent with what we've seen before, and make
17607 the deduced argument packs available. */
17609 {
17616 /* By default keep the original deduced argument pack.
17617 If necessary, more specific code is going to update the
17618 resulting deduced argument later down in this function. */
17622 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
17623 actually deduce anything. */
17631 {
17632 /* If we had fewer function args than explicit template args,
17633 just use the explicits. */
17638 }
17641 {
17642 tree result;
17643 /* Build the deduced *_ARGUMENT_PACK. */
17645 {
17650 }
17651 else
17656 /* Note the deduced argument packs for this parameter
17657 pack. */
17659 }
17663 {
17664 /* We only had the explicitly-provided arguments before, but
17665 now we have a complete set of arguments. */
17671 }
17672 else
17673 {
17679 /* Inconsistent unification of this parameter pack. */
17681 bad_old_arg,
17682 bad_new_arg);
17683 }
17684 }
17687 }
17689 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
17690 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
17691 parameters and return value are as for unify. */
17693 static int
17697 {
17698 tree parm_max;
17699 tree arg_max;
17703 /* Our representation of array types uses "N - 1" as the
17704 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
17705 not an integer constant. We cannot unify arbitrarily
17706 complex expressions, so we eliminate the MINUS_EXPRs
17707 here. */
17711 {
17714 }
17718 {
17719 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
17720 trying to unify the type of a variable with the type
17721 of a template parameter. For example:
17723 template <unsigned int N>
17724 void f (char (&) [N]);
17725 int g();
17726 void h(int i) {
17727 char a[g(i)];
17728 f(a);
17729 }
17731 Here, the type of the ARG will be "int [g(i)]", and
17732 may be a SAVE_EXPR, etc. */
17736 }
17738 /* If only one of the bounds used a MINUS_EXPR, compensate
17739 by adding one to the other bound. */
17742 integer_type_node,
17743 parm_max,
17744 integer_one_node);
17747 integer_type_node,
17748 arg_max,
17749 integer_one_node);
17753 }
17755 /* Deduce the value of template parameters. TPARMS is the (innermost)
17756 set of template parameters to a template. TARGS is the bindings
17757 for those template parameters, as determined thus far; TARGS may
17758 include template arguments for outer levels of template parameters
17759 as well. PARM is a parameter to a template function, or a
17760 subcomponent of that parameter; ARG is the corresponding argument.
17761 This function attempts to match PARM with ARG in a manner
17762 consistent with the existing assignments in TARGS. If more values
17763 are deduced, then TARGS is updated.
17765 Returns 0 if the type deduction succeeds, 1 otherwise. The
17766 parameter STRICT is a bitwise or of the following flags:
17768 UNIFY_ALLOW_NONE:
17769 Require an exact match between PARM and ARG.
17770 UNIFY_ALLOW_MORE_CV_QUAL:
17771 Allow the deduced ARG to be more cv-qualified (by qualification
17772 conversion) than ARG.
17773 UNIFY_ALLOW_LESS_CV_QUAL:
17774 Allow the deduced ARG to be less cv-qualified than ARG.
17775 UNIFY_ALLOW_DERIVED:
17776 Allow the deduced ARG to be a template base class of ARG,
17777 or a pointer to a template base class of the type pointed to by
17778 ARG.
17779 UNIFY_ALLOW_INTEGER:
17780 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
17781 case for more information.
17782 UNIFY_ALLOW_OUTER_LEVEL:
17783 This is the outermost level of a deduction. Used to determine validity
17784 of qualification conversions. A valid qualification conversion must
17785 have const qualified pointers leading up to the inner type which
17786 requires additional CV quals, except at the outer level, where const
17787 is not required [conv.qual]. It would be normal to set this flag in
17788 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
17789 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
17790 This is the outermost level of a deduction, and PARM can be more CV
17791 qualified at this point.
17792 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
17793 This is the outermost level of a deduction, and PARM can be less CV
17794 qualified at this point. */
17796 static int
17799 {
17801 tree targ;
17802 tree tparm;
17805 /* I don't think this will do the right thing with respect to types.
17806 But the only case I've seen it in so far has been array bounds, where
17807 signedness is the only information lost, and I think that will be
17808 okay. */
17816 /* We can't deduce anything from this, but we might get all the
17817 template args from other function args. */
17820 /* If PARM uses template parameters, then we can't bail out here,
17821 even if ARG == PARM, since we won't record unifications for the
17822 template parameters. We might need them if we're trying to
17823 figure out which of two things is more specialized. */
17827 /* Handle init lists early, so the rest of the function can assume
17828 we're dealing with a type. */
17830 {
17835 /* Replace T with std::initializer_list<T> for deduction. */
17842 /* We can only deduce from an initializer list argument if the
17843 parameter is std::initializer_list or an array; otherwise this
17844 is a non-deduced context. */
17849 else
17853 {
17860 {
17862 /* It should only be possible to get here for a call. */
17864 elt_strict |= maybe_adjust_types_for_deduction
17867 }
17870 explain_p);
17871 }
17875 {
17876 /* Also deduce from the length of the initializer list. */
17883 }
17885 /* If the std::initializer_list<T> deduction worked, replace the
17886 deduced A with std::initializer_list<A>. */
17888 {
17893 }
17895 }
17897 /* Immediately reject some pairs that won't unify because of
17898 cv-qualification mismatches. */
17901 /* It is the elements of the array which hold the cv quals of an array
17902 type, and the elements might be template type parms. We'll check
17903 when we recurse. */
17905 /* We check the cv-qualifiers when unifying with template type
17906 parameters below. We want to allow ARG `const T' to unify with
17907 PARM `T' for example, when computing which of two templates
17908 is more specialized, for example. */
17922 {
17926 /* In a type which contains a nested-name-specifier, template
17927 argument values cannot be deduced for template parameters used
17928 within the nested-name-specifier. */
17940 /* The PARM is not one we're trying to unify. Just check
17941 to see if it matches ARG. */
17942 {
17947 else
17949 }
17956 /* Check for mixed types and values. */
17964 {
17965 /* ARG must be constructed from a template class or a template
17966 template parameter. */
17970 {
17972 /* An alias template name is never deduced. */
17977 tree parm_parms
17978 = DECL_INNERMOST_TEMPLATE_PARMS
17983 /* The resolution to DR150 makes clear that default
17984 arguments for an N-argument may not be used to bind T
17985 to a template template parameter with fewer than N
17986 parameters. It is not safe to permit the binding of
17987 default arguments as an extension, as that may change
17988 the meaning of a conforming program. Consider:
17990 struct Dense { static const unsigned int dim = 1; };
17992 template <template <typename> class View,
17993 typename Block>
17994 void operator+(float, View<Block> const&);
17996 template <typename Block,
17997 unsigned int Dim = Block::dim>
17998 struct Lvalue_proxy { operator float() const; };
18000 void
18001 test_1d (void) {
18002 Lvalue_proxy<Dense> p;
18003 float b;
18004 b + p;
18005 }
18007 Here, if Lvalue_proxy is permitted to bind to View, then
18008 the global operator+ will be used; if they are not, the
18009 Lvalue_proxy will be converted to float. */
18011 full_argvec,
18013 (explain_p
18014 ? tf_warning_or_error
18021 /* Deduce arguments T, i from TT<T> or TT<i>.
18022 We check each element of PARMVEC and ARGVEC individually
18023 rather than the whole TREE_VEC since they can have
18024 different number of elements. */
18031 /* Check if the parameters end in a pack, making them
18032 variadic. */
18038 /* If the template argument list of P contains a pack
18039 expansion that is not the last template argument, the
18040 entire template argument list is a non-deduced
18041 context. */
18050 {
18055 }
18060 DEDUCE_EXACT,
18063 }
18066 /* Fall through to deduce template name. */
18067 }
18071 {
18072 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
18074 /* Simple cases: Value already set, does match or doesn't. */
18079 }
18080 else
18081 {
18082 /* If PARM is `const T' and ARG is only `int', we don't have
18083 a match unless we are allowing additional qualification.
18084 If ARG is `const int' and PARM is just `T' that's OK;
18085 that binds `const int' to `T'. */
18090 /* Consider the case where ARG is `const volatile int' and
18091 PARM is `const T'. Then, T should be `volatile int'. */
18092 arg = cp_build_qualified_type_real
18097 /* Simple cases: Value already set, does match or doesn't. */
18103 /* Make sure that ARG is not a variable-sized array. (Note
18104 that were talking about variable-sized arrays (like
18105 `int[n]'), rather than arrays of unknown size (like
18106 `int[]').) We'll get very confused by such a type since
18107 the bound of the array is not constant, and therefore
18108 not mangleable. Besides, such types are not allowed in
18109 ISO C++, so we can do as we please here. We do allow
18110 them for 'auto' deduction, since that isn't ABI-exposed. */
18114 /* Strip typedefs as in convert_template_argument. */
18116 }
18118 /* If ARG is a parameter pack or an expansion, we cannot unify
18119 against it unless PARM is also a parameter pack. */
18124 /* If the argument deduction results is a METHOD_TYPE,
18125 then there is a problem.
18126 METHOD_TYPE doesn't map to any real C++ type the result of
18127 the deduction can not be of that type. */
18141 {
18142 /* The PARM is not one we're trying to unify. Just check
18143 to see if it matches ARG. */
18149 }
18155 {
18160 }
18162 /* [temp.deduct.type] If, in the declaration of a function template
18163 with a non-type template-parameter, the non-type
18164 template-parameter is used in an expression in the function
18165 parameter-list and, if the corresponding template-argument is
18166 deduced, the template-argument type shall match the type of the
18167 template-parameter exactly, except that a template-argument
18168 deduced from an array bound may be of any integral type.
18169 The non-type parameter might use already deduced type parameters. */
18172 /* Template-parameter dependent expression. Just accept it for now.
18173 It will later be processed in convert_template_argument. */
18174 ;
18179 /* Convert the ARG to the type of PARM; the deduced non-type
18180 template argument must exactly match the types of the
18181 corresponding parameter. */
18184 /* We haven't deduced the type of this parameter yet. Try again
18185 later. */
18187 else
18190 /* If ARG is a parameter pack or an expansion, we cannot unify
18191 against it unless PARM is also a parameter pack. */
18201 {
18202 /* A pointer-to-member constant can be unified only with
18203 another constant. */
18207 /* Just unify the class member. It would be useless (and possibly
18208 wrong, depending on the strict flags) to unify also
18209 PTRMEM_CST_CLASS, because we want to be sure that both parm and
18210 arg refer to the same variable, even if through different
18211 classes. For instance:
18213 struct A { int x; };
18214 struct B : A { };
18216 Unification of &A::x and &B::x must succeed. */
18219 }
18222 {
18226 /* [temp.deduct.call]
18228 A can be another pointer or pointer to member type that can
18229 be converted to the deduced A via a qualification
18230 conversion (_conv.qual_).
18232 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
18233 This will allow for additional cv-qualification of the
18234 pointed-to types if appropriate. */
18237 /* The derived-to-base conversion only persists through one
18238 level of pointers. */
18243 }
18275 /* We have already checked cv-qualification at the top of the
18276 function. */
18280 /* As far as unification is concerned, this wins. Later checks
18281 will invalidate it if necessary. */
18284 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
18285 /* Type INTEGER_CST can come from ordinary constant template args. */
18297 {
18307 /* Check for pack expansions in the parameters. */
18309 {
18311 {
18313 /* We can unify against something with a trailing
18314 parameter pack. */
18316 else
18317 /* [temp.deduct.type]/9: If the template argument list of
18318 P contains a pack expansion that is not the last
18319 template argument, the entire template argument list
18320 is a non-deduced context. */
18322 }
18323 }
18325 /* If we don't have enough arguments to satisfy the parameters
18326 (not counting the pack expression at the end), or we have
18327 too many arguments for a parameter list that doesn't end in
18328 a pack expression, we can't unify. */
18334 /* Unify all of the parameters that precede the (optional)
18335 pack expression. */
18337 {
18342 }
18345 DEDUCE_EXACT,
18348 }
18356 {
18364 }
18369 {
18373 {
18374 /* First, we try to unify the PARM and ARG directly. */
18379 {
18380 /* Fallback to the special case allowed in
18381 [temp.deduct.call]:
18383 If P is a class, and P has the form
18384 template-id, then A can be a derived class of
18385 the deduced A. Likewise, if P is a pointer to
18386 a class of the form template-id, A can be a
18387 pointer to a derived class pointed to by the
18388 deduced A. */
18395 }
18396 }
18400 /* Perhaps PARM is something like S<U> and ARG is S<int>.
18401 Then, we should unify `int' and `U'. */
18403 else
18404 /* There's no chance of unification succeeding. */
18409 }
18416 {
18419 tree a;
18425 /* CV qualifications for methods can never be deduced, they must
18426 match exactly. We need to check them explicitly here,
18427 because type_unification_real treats them as any other
18428 cv-qualified parameter. */
18430 && (!check_cv_quals_for_unify
18450 }
18453 /* Unify a pointer to member with a pointer to member function, which
18454 deduces the type of the member as a function type. */
18456 {
18457 /* Check top-level cv qualifiers */
18465 /* Determine the type of the function we are unifying against. */
18469 }
18488 /* Matched cases are handled by the ARG == PARM test above. */
18492 /* A non-type template parameter that is a variable should be a
18493 an integral constant, in which case, it whould have been
18494 folded into its (constant) value. So we should not be getting
18495 a variable here. */
18506 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
18507 or UNDERLYING_TYPE nodes. */
18511 /* Unification fails if we hit an error node. */
18516 {
18521 }
18522 /* FALLTHRU */
18525 /* An unresolved overload is a nondeduced context. */
18530 /* We must be looking at an expression. This can happen with
18531 something like:
18533 template <int I>
18534 void foo(S<I>, S<I + 2>);
18536 This is a "nondeduced context":
18538 [deduct.type]
18540 The nondeduced contexts are:
18542 --A type that is a template-id in which one or more of
18543 the template-arguments is an expression that references
18544 a template-parameter.
18546 In these cases, we assume deduction succeeded, but don't
18547 actually infer any unifications. */
18552 else
18554 }
18555 }
18556 #undef RECUR_AND_CHECK_FAILURE
18557 \f
18558 /* Note that DECL can be defined in this translation unit, if
18559 required. */
18561 static void
18563 {
18564 tree clone;
18568 }
18570 /* Called if RESULT is explicitly instantiated, or is a member of an
18571 explicitly instantiated class. */
18573 void
18575 {
18578 /* If this entity has already been written out, it's too late to
18579 make any modifications. */
18583 /* For anonymous namespace we don't need to do anything. */
18585 {
18588 }
18591 /* The TREE_PUBLIC flag for function declarations will have been
18592 set correctly by tsubst. */
18595 /* This might have been set by an earlier implicit instantiation. */
18600 else
18601 {
18604 /* Always make artificials weak. */
18607 /* For WIN32 we also want to put explicit instantiations in
18608 linkonce sections. */
18611 }
18613 /* If EXTERN_P, then this function will not be emitted -- unless
18614 followed by an explicit instantiation, at which point its linkage
18615 will be adjusted. If !EXTERN_P, then this function will be
18616 emitted here. In neither circumstance do we want
18617 import_export_decl to adjust the linkage. */
18619 }
18621 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
18622 important template arguments. If any are missing, we check whether
18623 they're important by using error_mark_node for substituting into any
18624 args that were used for partial ordering (the ones between ARGS and END)
18625 and seeing if it bubbles up. */
18627 static bool
18629 {
18634 {
18637 }
18639 {
18643 }
18645 }
18647 /* Given two function templates PAT1 and PAT2, return:
18649 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
18650 -1 if PAT2 is more specialized than PAT1.
18651 0 if neither is more specialized.
18653 LEN indicates the number of parameters we should consider
18654 (defaulted parameters should not be considered).
18656 The 1998 std underspecified function template partial ordering, and
18657 DR214 addresses the issue. We take pairs of arguments, one from
18658 each of the templates, and deduce them against each other. One of
18659 the templates will be more specialized if all the *other*
18660 template's arguments deduce against its arguments and at least one
18661 of its arguments *does* *not* deduce against the other template's
18662 corresponding argument. Deduction is done as for class templates.
18663 The arguments used in deduction have reference and top level cv
18664 qualifiers removed. Iff both arguments were originally reference
18665 types *and* deduction succeeds in both directions, an lvalue reference
18666 wins against an rvalue reference and otherwise the template
18667 with the more cv-qualified argument wins for that pairing (if
18668 neither is more cv-qualified, they both are equal). Unlike regular
18669 deduction, after all the arguments have been deduced in this way,
18670 we do *not* verify the deduced template argument values can be
18671 substituted into non-deduced contexts.
18673 The logic can be a bit confusing here, because we look at deduce1 and
18674 targs1 to see if pat2 is at least as specialized, and vice versa; if we
18675 can find template arguments for pat1 to make arg1 look like arg2, that
18676 means that arg2 is at least as specialized as arg1. */
18678 int
18680 {
18693 /* Remove the this parameter from non-static member functions. If
18694 one is a non-static member function and the other is not a static
18695 member function, remove the first parameter from that function
18696 also. This situation occurs for operator functions where we
18697 locate both a member function (with this pointer) and non-member
18698 operator (with explicit first operand). */
18700 {
18705 }
18707 {
18710 {
18711 len--;
18713 }
18714 }
18716 /* If only one is a conversion operator, they are unordered. */
18720 /* Consider the return type for a conversion function */
18722 {
18725 len++;
18726 }
18728 processing_template_decl++;
18734 /* Stop when an ellipsis is seen. */
18736 {
18747 {
18748 /* When both arguments are pack expansions, we need only
18749 unify the patterns themselves. */
18753 /* This is the last comparison we need to do. */
18755 }
18758 {
18762 }
18765 {
18769 }
18775 {
18781 /* Setup the parameter vector, which contains only ARG1. */
18784 /* Setup the argument vector, which contains the remaining
18785 arguments. */
18794 /* We cannot deduce in the other direction, because ARG1 is
18795 a pack expansion but ARG2 is not. */
18797 }
18799 {
18805 /* Setup the parameter vector, which contains only ARG1. */
18808 /* Setup the argument vector, which contains the remaining
18809 arguments. */
18818 /* We cannot deduce in the other direction, because ARG2 is
18819 a pack expansion but ARG1 is not.*/
18821 }
18823 else
18824 {
18825 /* The normal case, where neither argument is a pack
18826 expansion. */
18833 }
18835 /* If we couldn't deduce arguments for tparms1 to make arg1 match
18836 arg2, then arg2 is not as specialized as arg1. */
18842 /* "If, for a given type, deduction succeeds in both directions
18843 (i.e., the types are identical after the transformations above)
18844 and both P and A were reference types (before being replaced with
18845 the type referred to above):
18846 - if the type from the argument template was an lvalue reference and
18847 the type from the parameter template was not, the argument type is
18848 considered to be more specialized than the other; otherwise,
18849 - if the type from the argument template is more cv-qualified
18850 than the type from the parameter template (as described above),
18851 the argument type is considered to be more specialized than the other;
18852 otherwise,
18853 - neither type is more specialized than the other." */
18856 {
18858 {
18861 else
18863 }
18865 {
18870 }
18871 }
18874 /* We've failed to deduce something in either direction.
18875 These must be unordered. */
18880 /* We have already processed all of the arguments in our
18881 handing of the pack expansion type. */
18886 }
18888 /* "In most cases, all template parameters must have values in order for
18889 deduction to succeed, but for partial ordering purposes a template
18890 parameter may remain without a value provided it is not used in the
18891 types being used for partial ordering."
18893 Thus, if we are missing any of the targs1 we need to substitute into
18894 origs1, then pat2 is not as specialized as pat1. This can happen when
18895 there is a nondeduced context. */
18901 processing_template_decl--;
18903 /* All things being equal, if the next argument is a pack expansion
18904 for one function but not for the other, prefer the
18905 non-variadic function. FIXME this is bogus; see c++/41958. */
18909 {
18912 }
18918 else
18920 }
18922 /* Determine which of two partial specializations of TMPL is more
18923 specialized.
18925 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
18926 to the first partial specialization. The TREE_PURPOSE is the
18927 innermost set of template parameters for the partial
18928 specialization. PAT2 is similar, but for the second template.
18930 Return 1 if the first partial specialization is more specialized;
18931 -1 if the second is more specialized; 0 if neither is more
18932 specialized.
18934 See [temp.class.order] for information about determining which of
18935 two templates is more specialized. */
18937 static int
18939 {
18940 tree targs;
18951 /* Just like what happens for functions, if we are ordering between
18952 different template specializations, we may encounter dependent
18953 types in the arguments, and we need our dependency check functions
18954 to behave correctly. */
18958 {
18961 }
18965 {
18968 }
18971 /* In the case of a tie where at least one of the templates
18972 has a parameter pack at the end, the template with the most
18973 non-packed parameters wins. */
18975 && any_deductions
18978 {
18984 /* We don't count the pack expansion at the end. */
18994 }
18997 }
18999 /* Return the template arguments that will produce the function signature
19000 DECL from the function template FN, with the explicit template
19001 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
19002 also match. Return NULL_TREE if no satisfactory arguments could be
19003 found. */
19005 static tree
19007 {
19011 tree decl_arg_types;
19014 tree arg;
19018 /* Never do unification on the 'this' parameter. */
19039 }
19041 /* Return the innermost template arguments that, when applied to a partial
19042 specialization of TMPL whose innermost template parameters are
19043 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
19044 ARGS.
19046 For example, suppose we have:
19048 template <class T, class U> struct S {};
19049 template <class T> struct S<T*, int> {};
19051 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
19052 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
19053 int}. The resulting vector will be {double}, indicating that `T'
19054 is bound to `double'. */
19056 static tree
19058 {
19060 tree deduced_args;
19061 tree innermost_deduced_args;
19065 {
19069 innermost_deduced_args);
19070 }
19071 else
19084 /* Verify that nondeduced template arguments agree with the type
19085 obtained from argument deduction.
19087 For example:
19089 struct A { typedef int X; };
19090 template <class T, class U> struct C {};
19091 template <class T> struct C<T, typename T::X> {};
19093 Then with the instantiation `C<A, int>', we can deduce that
19094 `T' is `A' but unify () does not check whether `typename T::X'
19095 is `int'. */
19101 /* We only need to check the innermost arguments; the other
19102 arguments will always agree. */
19107 /* Now that we have bindings for all of the template arguments,
19108 ensure that the arguments deduced for the template template
19109 parameters have compatible template parameter lists. See the use
19110 of template_template_parm_bindings_ok_p in fn_type_unification
19111 for more information. */
19116 }
19118 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
19119 Return the TREE_LIST node with the most specialized template, if
19120 any. If there is no most specialized template, the error_mark_node
19121 is returned.
19123 Note that this function does not look at, or modify, the
19124 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
19125 returned is one of the elements of INSTANTIATIONS, callers may
19126 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
19127 and retrieve it from the value returned. */
19129 tree
19131 {
19138 {
19144 fate--;
19149 fate++;
19154 {
19155 /* Equally specialized, move to next function. If there
19156 is no next function, nothing's most specialized. */
19161 }
19162 }
19165 /* Now verify that champ is better than everything earlier in the
19166 instantiation list. */
19174 {
19177 }
19179 processing_template_decl--;
19185 }
19187 /* If DECL is a specialization of some template, return the most
19188 general such template. Otherwise, returns NULL_TREE.
19190 For example, given:
19192 template <class T> struct S { template <class U> void f(U); };
19194 if TMPL is `template <class U> void S<int>::f(U)' this will return
19195 the full template. This function will not trace past partial
19196 specializations, however. For example, given in addition:
19198 template <class T> struct S<T*> { template <class U> void f(U); };
19200 if TMPL is `template <class U> void S<int*>::f(U)' this will return
19201 `template <class T> template <class U> S<T*>::f(U)'. */
19203 tree
19205 {
19207 {
19210 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
19211 template friend, or a FIELD_DECL for a capture pack. */
19214 }
19216 /* Look for more and more general templates. */
19218 {
19219 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
19220 (See cp-tree.h for details.) */
19229 /* Stop if we run into an explicitly specialized class template. */
19236 }
19239 }
19241 /* Return the most specialized of the template partial specializations
19242 which can produce TARGET, a specialization of some class or variable
19243 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
19244 a TEMPLATE_DECL node corresponding to the partial specialization, while
19245 the TREE_PURPOSE is the set of template arguments that must be
19246 substituted into the template pattern in order to generate TARGET.
19248 If the choice of partial specialization is ambiguous, a diagnostic
19249 is issued, and the error_mark_node is returned. If there are no
19250 partial specializations matching TARGET, then NULL_TREE is
19251 returned, indicating that the primary template should be used. */
19253 static tree
19255 {
19257 tree t;
19258 tree champ;
19265 {
19269 }
19271 {
19274 }
19276 {
19280 }
19281 else
19286 /* For determining which partial specialization to use, only the
19287 innermost args are interesting. */
19289 {
19292 }
19295 {
19296 tree partial_spec_args;
19297 tree spec_args;
19305 {
19306 /* Discard the outer levels of args, and then substitute in the
19307 template args from the enclosing class. */
19309 partial_spec_args = tsubst_template_args
19312 /* And the same for the partial specialization TEMPLATE_DECL. */
19314 }
19316 partial_spec_args =
19318 partial_spec_args,
19332 partial_spec_args,
19333 args);
19335 {
19340 }
19341 }
19351 {
19354 ;
19355 else
19356 {
19358 {
19361 {
19364 }
19365 }
19367 }
19368 }
19372 {
19375 {
19378 }
19379 }
19382 {
19389 else
19393 {
19398 }
19401 }
19404 }
19406 /* Explicitly instantiate DECL. */
19408 void
19410 {
19415 /* An error occurred, for which grokdeclarator has already issued
19416 an appropriate message. */
19419 {
19422 }
19428 {
19429 /* There is an asymmetry here in the way VAR_DECLs and
19430 FUNCTION_DECLs are handled by grokdeclarator. In the case of
19431 the latter, the DECL we get back will be marked as a
19432 template instantiation, and the appropriate
19433 DECL_TEMPLATE_INFO will be set up. This does not happen for
19434 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
19435 should handle VAR_DECLs as it currently handles
19436 FUNCTION_DECLs. */
19438 {
19441 }
19444 {
19447 }
19449 {
19454 }
19455 }
19457 {
19460 }
19461 else
19464 /* Check for various error cases. Note that if the explicit
19465 instantiation is valid the RESULT will currently be marked as an
19466 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
19467 until we get here. */
19470 {
19471 /* DR 259 [temp.spec].
19473 Both an explicit instantiation and a declaration of an explicit
19474 specialization shall not appear in a program unless the explicit
19475 instantiation follows a declaration of the explicit specialization.
19477 For a given set of template parameters, if an explicit
19478 instantiation of a template appears after a declaration of an
19479 explicit specialization for that template, the explicit
19480 instantiation has no effect. */
19482 }
19484 {
19485 /* [temp.spec]
19487 No program shall explicitly instantiate any template more
19488 than once.
19490 We check DECL_NOT_REALLY_EXTERN so as not to complain when
19491 the first instantiation was `extern' and the second is not,
19492 and EXTERN_P for the opposite case. */
19495 /* If an "extern" explicit instantiation follows an ordinary
19496 explicit instantiation, the template is instantiated. */
19499 }
19501 {
19504 }
19506 {
19509 }
19512 ;
19514 {
19517 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
19520 }
19521 else
19529 }
19531 static void
19533 {
19539 {
19542 }
19543 }
19545 /* Called from do_type_instantiation through binding_table_foreach to
19546 do recursive instantiation for the type bound in ENTRY. */
19547 static void
19549 {
19555 }
19557 /* Called from do_type_instantiation to instantiate a member
19558 (a member function or a static member variable) of an
19559 explicitly instantiated class template. */
19560 static void
19562 {
19567 }
19569 /* Perform an explicit instantiation of template class T. STORAGE, if
19570 non-null, is the RID for extern, inline or static. COMPLAIN is
19571 nonzero if this is called from the parser, zero if called recursively,
19572 since the standard is unclear (as detailed below). */
19574 void
19576 {
19586 {
19587 tree tmpl =
19591 else
19594 }
19599 {
19602 t);
19604 }
19607 {
19609 {
19611 {
19614 "ISO C++ 1998 forbids the use of %<extern%> on "
19616 }
19617 else
19619 "ISO C++ forbids the use of %qE"
19621 }
19629 else
19630 {
19632 storage);
19634 }
19635 }
19638 {
19639 /* DR 259 [temp.spec].
19641 Both an explicit instantiation and a declaration of an explicit
19642 specialization shall not appear in a program unless the explicit
19643 instantiation follows a declaration of the explicit specialization.
19645 For a given set of template parameters, if an explicit
19646 instantiation of a template appears after a declaration of an
19647 explicit specialization for that template, the explicit
19648 instantiation has no effect. */
19650 }
19652 {
19653 /* [temp.spec]
19655 No program shall explicitly instantiate any template more
19656 than once.
19658 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
19659 instantiation was `extern'. If EXTERN_P then the second is.
19660 These cases are OK. */
19667 /* If we've already instantiated the template, just return now. */
19670 }
19678 {
19679 tree tmp;
19681 /* In contrast to implicit instantiation, where only the
19682 declarations, and not the definitions, of members are
19683 instantiated, we have here:
19685 [temp.explicit]
19687 The explicit instantiation of a class template specialization
19688 implies the instantiation of all of its members not
19689 previously explicitly specialized in the translation unit
19690 containing the explicit instantiation.
19692 Of course, we can't instantiate member template classes, since
19693 we don't have any arguments for them. Note that the standard
19694 is unclear on whether the instantiation of the members are
19695 *explicit* instantiations or not. However, the most natural
19696 interpretation is that it should be an explicit instantiation. */
19711 }
19712 }
19714 /* Given a function DECL, which is a specialization of TMPL, modify
19715 DECL to be a re-instantiation of TMPL with the same template
19716 arguments. TMPL should be the template into which tsubst'ing
19717 should occur for DECL, not the most general template.
19719 One reason for doing this is a scenario like this:
19721 template <class T>
19722 void f(const T&, int i);
19724 void g() { f(3, 7); }
19726 template <class T>
19727 void f(const T& t, const int i) { }
19729 Note that when the template is first instantiated, with
19730 instantiate_template, the resulting DECL will have no name for the
19731 first parameter, and the wrong type for the second. So, when we go
19732 to instantiate the DECL, we regenerate it. */
19734 static void
19736 {
19737 /* The arguments used to instantiate DECL, from the most general
19738 template. */
19739 tree args;
19740 tree code_pattern;
19745 /* Make sure that we can see identifiers, and compute access
19746 correctly. */
19750 {
19751 tree decl_parm;
19752 tree pattern_parm;
19753 tree specs;
19767 specs);
19769 /* Merge parameter declarations. */
19772 pattern_parm
19776 {
19777 tree parm_type;
19778 tree attributes;
19783 NULL_TREE);
19789 {
19792 }
19795 }
19796 /* Merge any parameters that match with the function parameter
19797 pack. */
19799 {
19801 tree expanded_types;
19802 /* Expand the TYPE_PACK_EXPANSION that provides the types for
19803 the parameters in this function parameter pack. */
19808 {
19809 tree parm_type;
19810 tree attributes;
19813 /* Rename the parameter to include the index. */
19822 {
19825 }
19827 }
19828 }
19829 /* Merge additional specifiers from the CODE_PATTERN. */
19833 }
19835 {
19843 }
19844 else
19848 }
19850 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
19851 substituted to get DECL. */
19853 tree
19855 {
19858 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
19859 for the instantiation. This is not always the most general
19860 template. Consider, for example:
19862 template <class T>
19863 struct S { template <class U> void f();
19864 template <> void f<int>(); };
19866 and an instantiation of S<double>::f<int>. We want TD to be the
19867 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
19869 more general template. */
19871 /* We must also deal with friend templates. Given:
19873 template <class T> struct S {
19874 template <class U> friend void f() {};
19875 };
19877 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
19878 so far as the language is concerned, but that's still
19879 where we get the pattern for the instantiation from. On
19880 other hand, if the definition comes outside the class, say:
19882 template <class T> struct S {
19883 template <class U> friend void f();
19884 };
19885 template <class U> friend void f() {}
19887 we don't need to look any further. That's what the check for
19888 DECL_INITIAL is for. */
19892 {
19893 /* The present template, TD, should not be a definition. If it
19894 were a definition, we should be using it! Note that we
19895 cannot restructure the loop to just keep going until we find
19896 a template with a definition, since that might go too far if
19897 a specialization was declared, but not defined. */
19899 /* Fetch the more general template. */
19901 }
19904 }
19906 /* Returns true if we need to instantiate this template instance even if we
19907 know we aren't going to emit it.. */
19909 bool
19911 {
19912 /* We always instantiate inline functions so that we can inline them. An
19913 explicit instantiation declaration prohibits implicit instantiation of
19914 non-inline functions. With high levels of optimization, we would
19915 normally inline non-inline functions -- but we're not allowed to do
19916 that for "extern template" functions. Therefore, we check
19917 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
19921 /* And we need to instantiate static data members so that
19922 their initializers are available in integral constant
19923 expressions. */
19926 }
19928 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
19929 instantiate it now, modifying TREE_TYPE (fn). */
19931 void
19933 {
19936 /* Don't instantiate a noexcept-specification from template context. */
19951 {
19955 {
19970 }
19971 else
19975 }
19978 {
19981 else
19983 }
19984 }
19986 /* Produce the definition of D, a _DECL generated from a template. If
19987 DEFER_OK is nonzero, then we don't have to actually do the
19988 instantiation now; we just have to do it sometime. Normally it is
19989 an error if this is an explicit instantiation but D is undefined.
19990 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
19991 explicitly instantiated class template. */
19993 tree
19996 {
19998 tree gen_args;
19999 tree args;
20000 tree td;
20001 tree code_pattern;
20002 tree spec;
20003 tree gen_tmpl;
20010 tree fn_context;
20013 /* This function should only be used to instantiate templates for
20014 functions and static member variables. */
20017 /* Variables are never deferred; if instantiation is required, they
20018 are instantiated right away. That allows for better code in the
20019 case that an expression refers to the value of the variable --
20020 if the variable has a constant value the referring expression can
20021 take advantage of that fact. */
20026 /* Don't instantiate cloned functions. Instead, instantiate the
20027 functions they cloned. */
20035 /* D has already been instantiated or explicitly specialized, so
20036 there's nothing for us to do here.
20038 It might seem reasonable to check whether or not D is an explicit
20039 instantiation, and, if so, stop here. But when an explicit
20040 instantiation is deferred until the end of the compilation,
20041 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
20042 the instantiation. */
20045 /* Check to see whether we know that this template will be
20046 instantiated in some other file, as with "extern template"
20047 extension. */
20050 /* In general, we do not instantiate such templates. */
20058 /* We should already have the extra args. */
20061 /* And what's in the hash table should match D. */
20065 /* This needs to happen before any tsubsting. */
20071 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
20072 for the instantiation. */
20076 /* We should never be trying to instantiate a member of a class
20077 template or partial specialization. */
20082 /* In the case of a friend template whose definition is provided
20083 outside the class, we may have too many arguments. Drop the
20084 ones we don't need. The same is true for specializations. */
20085 args = get_innermost_template_args
20087 else
20091 {
20096 }
20097 else
20098 {
20101 }
20103 /* We may be in the middle of deferred access check. Disable it now. */
20106 /* Unless an explicit instantiation directive has already determined
20107 the linkage of D, remember that a definition is available for
20108 this entity. */
20118 /* If D is a member of an explicitly instantiated class template,
20119 and no definition is available, treat it like an implicit
20120 instantiation. */
20123 {
20124 /* Leave linkage flags alone on instantiations with anonymous
20125 visibility. */
20127 {
20130 }
20132 }
20134 /* Defer all other templates, unless we have been explicitly
20135 forbidden from doing so. */
20137 template. */
20138 ! pattern_defined
20139 /* If it's OK to postpone instantiation, do so. */
20140 || defer_ok
20141 /* If this is a static data member that will be defined
20142 elsewhere, we don't want to instantiate the entire data
20143 member, but we do want to instantiate the initializer so that
20144 we can substitute that elsewhere. */
20146 /* Handle here a deleted function too, avoid generating
20147 its body (c++/61080). */
20149 {
20150 /* The definition of the static data member is now required so
20151 we must substitute the initializer. */
20155 {
20156 tree ns;
20157 tree init;
20166 args,
20169 /* If instantiating the initializer involved instantiating this
20170 again, don't call cp_finish_decl twice. */
20172 {
20173 /* Make sure the initializer is still constant, in case of
20174 circular dependency (template/instantiate6.C). */
20175 const_init
20179 LOOKUP_ONLYCONVERTING);
20180 }
20184 }
20186 /* We restore the source position here because it's used by
20187 add_pending_template. */
20193 /* [temp.explicit]
20195 The definition of a non-exported function template, a
20196 non-exported member function template, or a non-exported
20197 member function or static data member of a class template
20198 shall be present in every translation unit in which it is
20199 explicitly instantiated. */
20203 /* If we're in unevaluated context, we just wanted to get the
20204 constant value; this isn't an odr use, so don't queue
20205 a full instantiation. */
20208 /* ??? Historically, we have instantiated inline functions, even
20209 when marked as "extern template". */
20213 }
20214 /* Tell the repository that D is available in this translation unit
20215 -- and see if it is supposed to be instantiated here. */
20217 {
20218 /* In a PCH file, despite the fact that the repository hasn't
20219 requested instantiation in the PCH it is still possible that
20220 an instantiation will be required in a file that includes the
20221 PCH. */
20224 /* Instantiate inline functions so that the inliner can do its
20225 job, even though we'll not be emitting a copy of this
20226 function. */
20229 }
20235 else
20236 {
20241 }
20243 /* Mark D as instantiated so that recursive calls to
20244 instantiate_decl do not try to instantiate it again. */
20247 /* Regenerate the declaration in case the template has been modified
20248 by a subsequent redeclaration. */
20251 /* We already set the file and line above. Reset them now in case
20252 they changed as a result of calling regenerate_decl_from_template. */
20256 {
20257 tree init;
20260 /* Clear out DECL_RTL; whatever was there before may not be right
20261 since we've reset the type of the declaration. */
20265 /* The initializer is placed in DECL_INITIAL by
20266 regenerate_decl_from_template so we don't need to
20267 push/pop_access_scope again here. Pull it out so that
20268 cp_finish_decl can process it. */
20273 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
20274 initializer. That function will defer actual emission until
20275 we have a chance to determine linkage. */
20278 /* Enter the scope of D so that access-checking works correctly. */
20291 }
20295 {
20297 tree subst_decl;
20298 tree tmpl_parm;
20299 tree spec_parm;
20302 /* Save away the current list, in case we are instantiating one
20303 template from within the body of another. */
20306 /* Set up the list of local specializations. */
20309 /* Set up context. */
20313 else
20316 /* Some typedefs referenced from within the template code need to be
20317 access checked at template instantiation time, i.e now. These
20318 types were added to the template at parsing time. Let's get those
20319 and perform the access checks then. */
20321 gen_args);
20323 /* Create substitution entries for the parameters. */
20328 {
20332 }
20334 {
20336 {
20339 }
20340 else
20341 {
20342 /* Register the (value) argument pack as a specialization of
20343 TMPL_PARM, then move on. */
20346 }
20347 }
20350 /* Substitute into the body of the function. */
20354 else
20355 {
20360 /* Set the current input_location to the end of the function
20361 so that finish_function knows where we are. */
20362 input_location
20365 /* Remember if we saw an infinite loop in the template. */
20366 current_function_infinite_loop
20368 }
20370 /* We don't need the local specializations any more. */
20374 /* Finish the function. */
20378 else
20379 {
20382 }
20386 }
20388 /* We're not deferring instantiation any more. */
20396 out:
20406 }
20408 /* Run through the list of templates that we wish we could
20409 instantiate, and instantiate any we can. RETRIES is the
20410 number of times we retry pending template instantiation. */
20412 void
20414 {
20418 /* Instantiating templates may trigger vtable generation. This in turn
20419 may require further template instantiations. We place a limit here
20420 to avoid infinite loop. */
20422 {
20426 " instantiating %q+D, possibly from virtual table generation"
20430 /* Pretend that we defined it. */
20433 }
20435 do
20436 {
20441 {
20446 {
20447 tree fn;
20450 {
20454 fn;
20462 }
20465 }
20466 else
20467 {
20470 {
20471 instantiation
20477 }
20481 }
20484 /* If INSTANTIATION has been instantiated, then we don't
20485 need to consider it again in the future. */
20487 else
20488 {
20491 }
20494 }
20496 }
20500 }
20502 /* Substitute ARGVEC into T, which is a list of initializers for
20503 either base class or a non-static data member. The TREE_PURPOSEs
20504 are DECLs, and the TREE_VALUEs are the initializer values. Used by
20505 instantiate_decl. */
20507 static tree
20509 {
20513 {
20514 tree decl;
20515 tree init;
20521 {
20522 tree expr;
20523 tree arg;
20525 /* Expand the base class expansion type into separate base
20526 classes. */
20528 tf_warning_or_error,
20529 NULL_TREE);
20533 /* We'll be building separate TREE_LISTs of arguments for
20534 each base. */
20540 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
20541 expand each argument in the TREE_VALUE of t. */
20548 /* VOID_TYPE_NODE is used to indicate
20549 value-initialization. */
20550 {
20553 }
20554 else
20555 {
20556 /* Substitute parameter packs into each argument in the
20557 TREE_LIST. */
20560 {
20561 tree expanded_exprs;
20563 /* Expand the argument. */
20565 expanded_exprs
20567 tf_warning_or_error,
20568 NULL_TREE);
20572 /* Prepend each of the expanded expressions to the
20573 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
20575 {
20580 }
20581 }
20584 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
20585 since we built them backwards. */
20587 {
20590 }
20591 }
20592 }
20595 {
20597 {
20601 }
20602 else
20603 {
20604 tree tmp;
20619 /* If we had an initializer but it instantiated to nothing,
20620 value-initialize the object. This will only occur when
20621 the initializer was a pack expansion where the parameter
20622 packs used in that expansion were of length zero. */
20625 }
20628 {
20632 }
20633 }
20634 }
20636 }
20638 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
20640 static void
20642 {
20647 else
20649 }
20651 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
20652 is the instantiation (which should have been created with
20653 start_enum) and ARGS are the template arguments to use. */
20655 static void
20657 {
20658 tree e;
20664 {
20665 tree value;
20666 tree decl;
20669 /* Note that in a template enum, the TREE_VALUE is the
20670 CONST_DECL, not the corresponding INTEGER_CST. */
20675 /* Give this enumeration constant the correct access. */
20678 /* Actually build the enumerator itself. */
20679 build_enumerator
20681 }
20691 }
20693 /* DECL is a FUNCTION_DECL that is a template specialization. Return
20694 its type -- but without substituting the innermost set of template
20695 arguments. So, innermost set of template parameters will appear in
20696 the type. */
20698 tree
20700 {
20701 tree fn_type;
20702 tree tmpl;
20703 tree targs;
20704 tree tparms;
20712 /* There should be as many levels of arguments as there are levels
20713 of parameters. */
20719 /* No substitution is necessary. */
20720 ;
20721 else
20722 {
20724 tree partial_args;
20726 /* Replace the innermost level of the TARGS with NULL_TREEs to
20727 let tsubst know not to substitute for those parameters. */
20736 /* Make sure that we can see identifiers, and compute access
20737 correctly. */
20741 /* Now, do the (partial) substitution to figure out the
20742 appropriate function type. */
20746 /* Substitute into the template parameters to obtain the real
20747 innermost set of parameters. This step is important if the
20748 innermost set of template parameters contains value
20749 parameters whose types depend on outer template parameters. */
20754 }
20757 }
20759 /* Return truthvalue if we're processing a template different from
20760 the last one involved in diagnostics. */
20761 bool
20763 {
20765 }
20767 /* Remember current template involved in diagnostics. */
20768 void
20770 {
20772 }
20776 {
20778 }
20780 /* [temp.param] Check that template non-type parm TYPE is of an allowable
20781 type. Return zero for ok, nonzero for disallowed. Issue error and
20782 warning messages under control of COMPLAIN. */
20784 static int
20786 {
20803 {
20806 else
20808 type);
20809 }
20811 }
20813 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
20814 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
20816 static bool
20818 {
20819 tree scope;
20821 /* [temp.dep.type]
20823 A type is dependent if it is:
20825 -- a template parameter. Template template parameters are types
20826 for us (since TYPE_P holds true for them) so we handle
20827 them here. */
20831 /* -- a qualified-id with a nested-name-specifier which contains a
20832 class-name that names a dependent type or whose unqualified-id
20833 names a dependent type. */
20836 /* -- a cv-qualified type where the cv-unqualified type is
20837 dependent.
20838 No code is necessary for this bullet; the code below handles
20839 cv-qualified types, and we don't want to strip aliases with
20840 TYPE_MAIN_VARIANT because of DR 1558. */
20841 /* -- a compound type constructed from any dependent type. */
20851 {
20852 tree arg_type;
20857 arg_type;
20862 }
20863 /* -- an array type constructed from any dependent type or whose
20864 size is specified by a constant expression that is
20865 value-dependent.
20867 We checked for type- and value-dependence of the bounds in
20868 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
20870 {
20875 }
20877 /* -- a template-id in which either the template name is a template
20878 parameter ... */
20881 /* ... or any of the template arguments is a dependent type or
20882 an expression that is type-dependent or value-dependent. */
20884 && (any_dependent_template_arguments_p
20888 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
20889 dependent; if the argument of the `typeof' expression is not
20890 type-dependent, then it should already been have resolved. */
20896 /* A template argument pack is dependent if any of its packed
20897 arguments are. */
20899 {
20905 }
20907 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
20908 be template parameters. */
20912 /* The standard does not specifically mention types that are local
20913 to template functions or local classes, but they should be
20914 considered dependent too. For example:
20916 template <int I> void f() {
20917 enum E { a = I };
20918 S<sizeof (E)> s;
20919 }
20921 The size of `E' cannot be known until the value of `I' has been
20922 determined. Therefore, `E' must be considered dependent. */
20926 /* Don't use type_dependent_expression_p here, as it can lead
20927 to infinite recursion trying to determine whether a lambda
20928 nested in a lambda is dependent (c++/47687). */
20932 && (any_dependent_template_arguments_p
20936 /* Other types are non-dependent. */
20938 }
20940 /* Returns TRUE if TYPE is dependent, in the sense of
20941 [temp.dep.type]. Note that a NULL type is considered dependent. */
20943 bool
20945 {
20946 /* If there are no template parameters in scope, then there can't be
20947 any dependent types. */
20949 {
20950 /* If we are not processing a template, then nobody should be
20951 providing us with a dependent type. */
20955 }
20957 /* If the type is NULL, we have not computed a type for the entity
20958 in question; in that case, the type is dependent. */
20962 /* Erroneous types can be considered non-dependent. */
20966 /* If we have not already computed the appropriate value for TYPE,
20967 do so now. */
20969 {
20972 }
20975 }
20977 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
20978 lookup. In other words, a dependent type that is not the current
20979 instantiation. */
20981 bool
20983 {
20986 }
20988 /* T is a SCOPE_REF; return whether we need to consider it
20989 instantiation-dependent so that we can check access at instantiation
20990 time even though we know which member it resolves to. */
20992 static bool
20994 {
21000 else
21002 }
21004 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
21005 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
21006 expression. */
21008 /* Note that this predicate is not appropriate for general expressions;
21009 only constant expressions (that satisfy potential_constant_expression)
21010 can be tested for value dependence. */
21012 bool
21014 {
21018 /* A name declared with a dependent type. */
21023 {
21025 /* A name that has not been looked up -- must be dependent. */
21029 /* A non-type template parm. */
21033 /* A non-type template parm. */
21039 /* A constant with literal type and is initialized
21040 with an expression that is value-dependent.
21042 Note that a non-dependent parenthesized initializer will have
21043 already been replaced with its constant value, so if we see
21044 a TREE_LIST it must be dependent. */
21048 /* cp_finish_decl doesn't fold reference initializers. */
21059 /* These expressions are value-dependent if the type to which
21060 the cast occurs is dependent or the expression being casted
21061 is value-dependent. */
21062 {
21068 /* A functional cast has a list of operands. */
21071 {
21072 /* If there are no operands, it must be an expression such
21073 as "int()". This should not happen for aggregate types
21074 because it would form non-constant expressions. */
21079 }
21085 }
21090 /* FALLTHRU */
21093 /* A `sizeof' expression is value-dependent if the operand is
21094 type-dependent or is a pack expansion. */
21103 /* An 'encode' expression is value-dependent if the operand is
21104 type-dependent. */
21113 /* All instantiation-dependent expressions should also be considered
21114 value-dependent. */
21122 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
21123 is value-dependent. */
21124 {
21133 }
21136 {
21140 }
21151 {
21155 }
21158 {
21165 {
21167 /* In a call to a constexpr member function, look through the
21168 implicit ADDR_EXPR on the object argument so that it doesn't
21169 cause the call to be considered value-dependent. We also
21170 look through it in potential_constant_expression. */
21177 }
21179 }
21182 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
21183 type-dependent. */
21187 {
21189 tree val;
21196 }
21199 /* Treat a GNU statement expression as dependent to avoid crashing
21200 under instantiate_non_dependent_expr; it can't be constant. */
21204 /* A constant expression is value-dependent if any subexpression is
21205 value-dependent. */
21207 {
21214 {
21218 {
21221 /* In some cases, some of the operands may be missing.l
21222 (For example, in the case of PREDECREMENT_EXPR, the
21223 amount to increment by may be missing.) That doesn't
21224 make the expression dependent. */
21227 }
21228 }
21232 }
21234 }
21236 /* The expression is not value-dependent. */
21238 }
21240 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
21241 [temp.dep.expr]. Note that an expression with no type is
21242 considered dependent. Other parts of the compiler arrange for an
21243 expression with type-dependent subexpressions to have no type, so
21244 this function doesn't have to be fully recursive. */
21246 bool
21248 {
21255 /* An unresolved name is always dependent. */
21259 /* Some expression forms are never type-dependent. */
21272 /* The types of these expressions depends only on the type to which
21273 the cast occurs. */
21282 /* The types of these expressions depends only on the type created
21283 by the expression. */
21286 {
21287 /* For NEW_EXPR tree nodes created inside a template, either
21288 the object type itself or a TREE_LIST may appear as the
21289 operand 1. */
21292 /* This is an array type. We need to check array dimensions
21293 as well. */
21295 || value_dependent_expression_p
21297 else
21299 }
21302 {
21306 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
21307 contains an identifier associated by name lookup with one or more
21308 declarations declared with a dependent type, or...a
21309 nested-name-specifier or qualified-id that names a member of an
21310 unknown specialization. */
21313 }
21318 && (any_dependent_template_arguments_p
21330 {
21331 tree elt;
21335 {
21338 }
21340 }
21342 /* A static data member of the current instantiation with incomplete
21343 array type is type-dependent, as the definition and specializations
21344 can have different bounds. */
21351 /* An array of unknown bound depending on a variadic parameter, eg:
21353 template<typename... Args>
21354 void foo (Args... args)
21355 {
21356 int arr[] = { args... };
21357 }
21359 template<int... vals>
21360 void bar ()
21361 {
21362 int arr[] = { vals... };
21363 }
21365 If the array has no length and has an initializer, it must be that
21366 we couldn't determine its length in cp_complete_array_type because
21367 it is dependent. */
21375 {
21380 {
21386 }
21387 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
21391 /* Always dependent, on the number of arguments if nothing else. */
21396 {
21401 }
21404 {
21409 }
21414 {
21418 }
21420 }
21425 }
21427 /* walk_tree callback function for instantiation_dependent_expression_p,
21428 below. Returns non-zero if a dependent subexpression is found. */
21430 static tree
21433 {
21435 {
21436 /* We don't have to worry about decltype currently because decltype
21437 of an instantiation-dependent expr is a dependent type. This
21438 might change depending on the resolution of DR 1172. */
21441 }
21444 {
21445 /* Don't treat an argument list as dependent just because it has no
21446 TREE_TYPE. */
21453 /* A constant with a dependent initializer is dependent. */
21461 /* Handle expressions with type operands. */
21466 {
21471 {
21474 else
21475 {
21478 }
21479 }
21481 }
21493 /* In a template, finish_class_member_access_expr creates a
21494 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
21495 type-dependent, so that we can check access control at
21496 instantiation time (PR 42277). See also Core issue 1273. */
21503 else
21506 /* Treat statement-expressions as dependent. */
21512 }
21516 else
21518 }
21520 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
21521 sense defined by the ABI:
21523 "An expression is instantiation-dependent if it is type-dependent
21524 or value-dependent, or it has a subexpression that is type-dependent
21525 or value-dependent." */
21527 bool
21529 {
21530 tree result;
21541 }
21543 /* Like type_dependent_expression_p, but it also works while not processing
21544 a template definition, i.e. during substitution or mangling. */
21546 bool
21548 {
21554 }
21556 /* Returns TRUE if ARGS contains a type-dependent expression. */
21558 bool
21560 {
21562 tree arg;
21565 {
21568 }
21570 }
21572 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21573 expressions) contains any type-dependent expressions. */
21575 bool
21577 {
21583 }
21585 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21586 expressions) contains any value-dependent expressions. */
21588 bool
21590 {
21596 }
21598 /* Returns TRUE if the ARG (a template argument) is dependent. */
21600 bool
21602 {
21606 /* Assume a template argument that was wrongly written by the user
21607 is dependent. This is consistent with what
21608 any_dependent_template_arguments_p [that calls this function]
21609 does. */
21620 {
21624 {
21627 }
21630 }
21633 else
21636 }
21638 /* Returns true if ARGS (a collection of template arguments) contains
21639 any types that require structural equality testing. */
21641 bool
21643 {
21653 {
21656 {
21662 {
21663 /* Look inside the argument pack. */
21666 }
21669 {
21682 }
21683 }
21684 }
21687 }
21689 /* Returns true if ARGS (a collection of template arguments) contains
21690 any dependent arguments. */
21692 bool
21694 {
21704 {
21709 }
21712 }
21714 /* Returns TRUE if the template TMPL is dependent. */
21716 bool
21718 {
21720 {
21722 {
21726 }
21728 }
21730 /* Template template parameters are dependent. */
21734 /* So are names that have not been looked up. */
21737 /* So are member templates of dependent classes. */
21741 }
21743 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
21745 bool
21747 {
21750 }
21752 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
21753 is dependent. */
21755 bool
21757 {
21764 {
21785 {
21789 }
21793 {
21797 {
21802 }
21803 }
21804 }
21807 }
21809 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
21810 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
21811 no such TYPE can be found. Note that this function peers inside
21812 uninstantiated templates and therefore should be used only in
21813 extremely limited situations. ONLY_CURRENT_P restricts this
21814 peering to the currently open classes hierarchy (which is required
21815 when comparing types). */
21817 tree
21819 {
21820 tree scope;
21821 tree name;
21822 tree decl;
21824 tree pushed_scope;
21825 tree result;
21830 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
21831 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
21832 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
21833 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
21834 identifier of the TYPENAME_TYPE anymore.
21835 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
21836 TYPENAME_TYPE instead, we avoid messing up with a possible
21837 typedef variant case. */
21840 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
21841 it first before we can figure out what NAME refers to. */
21843 {
21845 /* Given a class template A with a dependent base with nested type C,
21846 typedef typename A::C::C C will land us here, as trying to resolve
21847 the initial A::C leads to the local C typedef, which leads back to
21848 A::C::C. So we break the recursion now. */
21850 else
21852 }
21853 /* If we don't know what SCOPE refers to, then we cannot resolve the
21854 TYPENAME_TYPE. */
21857 /* If the SCOPE is a template type parameter, we have no way of
21858 resolving the name. */
21861 /* If the SCOPE is not the current instantiation, there's no reason
21862 to look inside it. */
21865 /* If this is a typedef, we don't want to look inside (c++/11987). */
21868 /* If SCOPE isn't the template itself, it will not have a valid
21869 TYPE_FIELDS list. */
21871 /* scope is either the template itself or a compatible instantiation
21872 like X<T>, so look up the name in the original template. */
21874 else
21875 /* scope is a partial instantiation, so we can't do the lookup or we
21876 will lose the template arguments. */
21878 /* Enter the SCOPE so that name lookup will be resolved as if we
21879 were in the class definition. In particular, SCOPE will no
21880 longer be considered a dependent type. */
21882 /* Look up the declaration. */
21884 tf_warning_or_error);
21888 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
21889 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
21894 {
21898 }
21901 {
21902 tree tmpl;
21903 tree args;
21904 /* Obtain the template and the arguments. */
21907 /* Instantiate the template. */
21913 }
21915 /* Leave the SCOPE. */
21919 /* If we failed to resolve it, return the original typename. */
21923 /* If lookup found a typename type, resolve that too. */
21925 {
21926 /* Ill-formed programs can cause infinite recursion here, so we
21927 must catch that. */
21931 }
21933 /* Qualify the resulting type. */
21939 }
21941 /* EXPR is an expression which is not type-dependent. Return a proxy
21942 for EXPR that can be used to compute the types of larger
21943 expressions containing EXPR. */
21945 tree
21947 {
21948 tree inner_expr;
21950 #ifdef ENABLE_CHECKING
21951 /* Try to get a constant value for all non-dependent expressions in
21952 order to expose bugs in *_dependent_expression_p and constexpr. */
21955 #endif
21957 /* Preserve OVERLOADs; the functions must be available to resolve
21958 types. */
21969 /* There is no need to return a proxy for a variable. */
21972 /* Preserve string constants; conversions from string constants to
21973 "char *" are allowed, even though normally a "const char *"
21974 cannot be used to initialize a "char *". */
21977 /* Preserve void and arithmetic constants, as an optimization -- there is no
21978 reason to create a new node. */
21983 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
21984 There is at least one place where we want to know that a
21985 particular expression is a throw-expression: when checking a ?:
21986 expression, there are special rules if the second or third
21987 argument is a throw-expression. */
21991 /* Don't wrap an initializer list, we need to be able to look inside. */
21995 /* Don't wrap a dummy object, we need to be able to test for it. */
22014 /* If the type is unknown, it can't really be non-dependent */
22017 /* Otherwise, build a NON_DEPENDENT_EXPR. */
22019 }
22021 /* ARGS is a vector of expressions as arguments to a function call.
22022 Replace the arguments with equivalent non-dependent expressions.
22023 This modifies ARGS in place. */
22025 void
22027 {
22029 tree arg;
22032 {
22036 }
22037 }
22039 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
22040 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
22041 parms. */
22043 static tree
22045 {
22058 }
22060 tree
22062 {
22064 }
22066 tree
22068 {
22070 }
22072 /* Given type ARG, return std::initializer_list<ARG>. */
22074 static tree
22076 {
22077 tree std_init_list = namespace_binding
22079 tree argvec;
22081 {
22085 }
22090 }
22092 /* Replace auto in TYPE with std::initializer_list<auto>. */
22094 static tree
22096 {
22103 }
22105 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
22106 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
22108 tree
22110 {
22111 tree targs;
22117 /* Defining a subset of type-dependent expressions that we can deduce
22118 from ahead of time isn't worth the trouble. */
22121 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
22122 with either a new invented type template parameter U or, if the
22123 initializer is a braced-init-list (8.5.4), with
22124 std::initializer_list<U>. */
22126 {
22131 else
22132 {
22136 "for deduction to %<std::initializer_list%>, use copy-"
22139 }
22140 }
22146 {
22152 {
22155 }
22156 }
22157 else
22158 {
22169 {
22171 /* Try again at instantiation time. */
22174 /* If type is error_mark_node a diagnostic must have been
22175 emitted by now. Also, having a mention to '<type error>'
22176 in the diagnostic is not really useful to the user. */
22177 {
22181 else
22183 }
22185 }
22186 }
22188 /* If the list of declarators contains more than one declarator, the type
22189 of each declared variable is determined as described above. If the
22190 type deduced for the template parameter U is not the same in each
22191 deduction, the program is ill-formed. */
22194 {
22200 else
22204 }
22210 }
22212 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
22213 result. */
22215 tree
22217 {
22218 tree argvec;
22225 /* For a late-specified return type in a template type-parameter, we
22226 need to add a dummy argument level for its parmlist. */
22227 argvec = add_to_template_args
22232 }
22234 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
22235 'decltype(auto)'. */
22237 bool
22239 {
22244 else
22246 }
22248 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
22249 a use of `auto'. Returns NULL_TREE otherwise. */
22251 tree
22253 {
22255 }
22257 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
22258 'decltype(auto)' or a concept. */
22260 bool
22262 {
22264 }
22266 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
22267 a concept identifier) iff TYPE contains a use of a generic type. Returns
22268 NULL_TREE otherwise. */
22270 tree
22272 {
22274 }
22277 /* For a given template T, return the vector of typedefs referenced
22278 in T for which access check is needed at T instantiation time.
22279 T is either a FUNCTION_DECL or a RECORD_TYPE.
22280 Those typedefs were added to T by the function
22281 append_type_to_template_for_access_check. */
22285 {
22286 tree ti;
22297 {
22302 }
22305 }
22307 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
22308 tied to T. That list of typedefs will be access checked at
22309 T instantiation time.
22310 T is either a FUNCTION_DECL or a RECORD_TYPE.
22311 TYPE_DECL is a TYPE_DECL node representing a typedef.
22312 SCOPE is the scope through which TYPE_DECL is accessed.
22313 LOCATION is the location of the usage point of TYPE_DECL.
22315 This function is a subroutine of
22316 append_type_to_template_for_access_check. */
22318 static void
22320 tree type_decl,
22321 tree scope,
22322 location_t location)
22323 {
22324 qualified_typedef_usage_t typedef_usage;
22325 tree ti;
22332 && type_decl
22346 }
22348 /* Append TYPE_DECL to the template TEMPL.
22349 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
22350 At TEMPL instanciation time, TYPE_DECL will be checked to see
22351 if it can be accessed through SCOPE.
22352 LOCATION is the location of the usage point of TYPE_DECL.
22354 e.g. consider the following code snippet:
22356 class C
22357 {
22358 typedef int myint;
22359 };
22361 template<class U> struct S
22362 {
22363 C::myint mi; // <-- usage point of the typedef C::myint
22364 };
22366 S<char> s;
22368 At S<char> instantiation time, we need to check the access of C::myint
22369 In other words, we need to check the access of the myint typedef through
22370 the C scope. For that purpose, this function will add the myint typedef
22371 and the scope C through which its being accessed to a list of typedefs
22372 tied to the template S. That list will be walked at template instantiation
22373 time and access check performed on each typedefs it contains.
22374 Note that this particular code snippet should yield an error because
22375 myint is private to C. */
22377 void
22379 tree type_decl,
22380 tree scope,
22381 location_t location)
22382 {
22388 /* Make sure we don't append the type to the template twice. */
22395 }
22397 /* Convert the generic type parameters in PARM that match the types given in the
22398 range [START_IDX, END_IDX) from the current_template_parms into generic type
22399 packs. */
22401 tree
22403 {
22414 {
22415 /* Create a distinct parameter pack type from the current parm and add it
22416 to the replacement args to tsubst below into the generic function
22417 parameter. */
22432 }
22438 /* If there are more levels then build up the replacement with the outer
22439 template parms. */
22443 replacement);
22446 }
22449 /* Set up the hash tables for template instantiations. */
22451 void
22453 {
22456 }
22458 /* Print stats about the template hash tables for -fstats. */
22460 void
22462 {
22471 }