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1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2014 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
4 Rewritten by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Known bugs or deficiencies include:
24 all methods must be provided in header files; can't use a source
25 file that contains only the method templates and "just win". */
53 /* The type of functions taking a tree, and some additional data, and
54 returning an int. */
57 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
58 instantiations have been deferred, either because their definitions
59 were not yet available, or because we were putting off doing the work. */
63 };
68 void
70 {
73 }
85 /* Live only within one (recursive) call to tsubst_expr. We use
86 this to pass the statement expression node from the STMT_EXPR
87 to the EXPR_STMT that is its result. */
90 /* True if we've recursed into fn_type_unification too many times. */
94 {
95 tree tmpl;
96 tree args;
97 tree spec;
101 htab_t decl_specializations;
104 htab_t type_specializations;
106 /* Contains canonical template parameter types. The vector is indexed by
107 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
108 TREE_LIST, whose TREE_VALUEs contain the canonical template
109 parameters of various types and levels. */
112 #define UNIFY_ALLOW_NONE 0
113 #define UNIFY_ALLOW_MORE_CV_QUAL 1
114 #define UNIFY_ALLOW_LESS_CV_QUAL 2
115 #define UNIFY_ALLOW_DERIVED 4
116 #define UNIFY_ALLOW_INTEGER 8
117 #define UNIFY_ALLOW_OUTER_LEVEL 16
118 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
119 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
122 tbr_incomplete_type,
123 tbr_ambiguous_baseclass,
124 tbr_success
125 };
148 tree);
211 location_t);
219 /* Make the current scope suitable for access checking when we are
220 processing T. T can be FUNCTION_DECL for instantiated function
221 template, VAR_DECL for static member variable, or TYPE_DECL for
222 alias template (needed by instantiate_decl). */
224 static void
226 {
234 else
238 {
239 saved_access_scope = tree_cons
242 }
243 }
245 /* Restore the scope set up by push_access_scope. T is the node we
246 are processing. */
248 static void
250 {
252 {
255 }
259 else
261 }
263 /* Do any processing required when DECL (a member template
264 declaration) is finished. Returns the TEMPLATE_DECL corresponding
265 to DECL, unless it is a specialization, in which case the DECL
266 itself is returned. */
268 tree
270 {
277 {
278 tree type;
286 {
290 }
292 }
296 {
298 {
301 }
302 else
304 }
305 else
309 }
311 /* Create a template info node. */
313 tree
315 {
320 }
322 /* Return the template info node corresponding to T, whatever T is. */
324 tree
326 {
344 }
346 /* Returns the template nesting level of the indicated class TYPE.
348 For example, in:
349 template <class T>
350 struct A
351 {
352 template <class U>
353 struct B {};
354 };
356 A<T>::B<U> has depth two, while A<T> has depth one.
357 Both A<T>::B<int> and A<int>::B<U> have depth one, if
358 they are instantiations, not specializations.
360 This function is guaranteed to return 0 if passed NULL_TREE so
361 that, for example, `template_class_depth (current_class_type)' is
362 always safe. */
364 int
366 {
373 {
379 }
382 }
384 /* Subroutine of maybe_begin_member_template_processing.
385 Returns true if processing DECL needs us to push template parms. */
387 static bool
389 {
395 }
397 /* Subroutine of maybe_begin_member_template_processing.
398 Push the template parms in PARMS, starting from LEVELS steps into the
399 chain, and ending at the beginning, since template parms are listed
400 innermost first. */
402 static void
404 {
412 current_template_parms
418 NULL);
420 {
429 {
436 {
437 /* Make a CONST_DECL as is done in process_template_parm.
438 It is ugly that we recreate this here; the original
439 version built in process_template_parm is no longer
440 available. */
450 }
455 }
456 }
457 }
459 /* Restore the template parameter context for a member template, a
460 friend template defined in a class definition, or a non-template
461 member of template class. */
463 void
465 {
466 tree parms;
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;
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;
1091 htab_t specializations;
1099 else
1107 }
1110 }
1112 /* Like retrieve_specialization, but for local declarations. */
1114 static tree
1116 {
1124 }
1126 /* Returns nonzero iff DECL is a specialization of TMPL. */
1128 int
1130 {
1131 tree t;
1134 {
1140 }
1141 else
1142 {
1151 }
1154 }
1156 /* Returns nonzero iff DECL is a specialization of friend declaration
1157 FRIEND_DECL according to [temp.friend]. */
1159 bool
1161 {
1168 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1169 of a template class, we want to check if DECL is a specialization
1170 if this. */
1174 {
1175 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1178 }
1183 /* There is nothing to do if this is not a template friend. */
1190 /* [temp.friend/6]
1191 A member of a class template may be declared to be a friend of a
1192 non-template class. In this case, the corresponding member of
1193 every specialization of the class template is a friend of the
1194 class granting friendship.
1196 For example, given a template friend declaration
1198 template <class T> friend void A<T>::f();
1200 the member function below is considered a friend
1202 template <> struct A<int> {
1203 void f();
1204 };
1206 For this type of template friend, TEMPLATE_DEPTH below will be
1207 nonzero. To determine if DECL is a friend of FRIEND, we first
1208 check if the enclosing class is a specialization of another. */
1215 {
1216 /* Next, we check the members themselves. In order to handle
1217 a few tricky cases, such as when FRIEND_DECL's are
1219 template <class T> friend void A<T>::g(T t);
1220 template <class T> template <T t> friend void A<T>::h();
1222 and DECL's are
1224 void A<int>::g(int);
1225 template <int> void A<int>::h();
1227 we need to figure out ARGS, the template arguments from
1228 the context of DECL. This is required for template substitution
1229 of `T' in the function parameter of `g' and template parameter
1230 of `h' in the above examples. Here ARGS corresponds to `int'. */
1237 {
1239 {
1242 else
1244 current_depth++;
1245 }
1247 }
1250 {
1252 tree friend_type;
1253 tree decl_type;
1254 tree friend_args_type;
1255 tree decl_args_type;
1257 /* Make sure that both DECL and FRIEND_DECL are templates or
1258 non-templates. */
1264 {
1265 /* If both are templates, check template parameter list. */
1266 tree friend_parms
1271 friend_parms))
1275 }
1276 else
1284 /* Check if return types match. */
1288 /* Check if function parameter types match, ignoring the
1289 `this' parameter. */
1298 }
1299 else
1300 {
1301 /* DECL is a TYPE_DECL */
1305 /* Make sure that both DECL and FRIEND_DECL are templates or
1306 non-templates. */
1307 is_template
1314 {
1315 tree friend_parms;
1316 /* If both are templates, check the name of the two
1317 TEMPLATE_DECL's first because is_friend didn't. */
1322 /* Now check template parameter list. */
1323 friend_parms
1326 return comp_template_parms
1328 friend_parms);
1329 }
1330 else
1333 }
1334 }
1336 }
1338 /* Register the specialization SPEC as a specialization of TMPL with
1339 the indicated ARGS. IS_FRIEND indicates whether the specialization
1340 is actually just a friend declaration. Returns SPEC, or an
1341 equivalent prior declaration, if available.
1343 We also store instantiations of field packs in the hash table, even
1344 though they are not themselves templates, to make lookup easier. */
1346 static tree
1348 hashval_t hash)
1349 {
1350 tree fn;
1352 spec_entry elt;
1360 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1361 register it; we want the corresponding TEMPLATE_DECL instead.
1362 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1363 the more obvious `uses_template_parms (spec)' to avoid problems
1364 with default function arguments. In particular, given
1365 something like this:
1367 template <class T> void f(T t1, T t = T())
1369 the default argument expression is not substituted for in an
1370 instantiation unless and until it is actually needed. */
1374 /* We don't put these specializations in the hash table, but we might
1375 want to give an error about a mismatch. */
1377 else
1378 {
1386 slot =
1390 else
1392 }
1394 /* We can sometimes try to re-register a specialization that we've
1395 already got. In particular, regenerate_decl_from_template calls
1396 duplicate_decls which will update the specialization list. But,
1397 we'll still get called again here anyhow. It's more convenient
1398 to simply allow this than to try to prevent it. */
1402 {
1404 {
1407 {
1409 fn);
1411 }
1412 else
1413 {
1414 tree clone;
1415 /* This situation should occur only if the first
1416 specialization is an implicit instantiation, the
1417 second is an explicit specialization, and the
1418 implicit instantiation has not yet been used. That
1419 situation can occur if we have implicitly
1420 instantiated a member function and then specialized
1421 it later.
1423 We can also wind up here if a friend declaration that
1424 looked like an instantiation turns out to be a
1425 specialization:
1427 template <class T> void foo(T);
1428 class S { friend void foo<>(int) };
1429 template <> void foo(int);
1431 We transform the existing DECL in place so that any
1432 pointers to it become pointers to the updated
1433 declaration.
1435 If there was a definition for the template, but not
1436 for the specialization, we want this to look as if
1437 there were no definition, and vice versa. */
1440 /* The call to duplicate_decls will have applied
1441 [temp.expl.spec]:
1443 An explicit specialization of a function template
1444 is inline only if it is explicitly declared to be,
1445 and independently of whether its function template
1446 is.
1448 to the primary function; now copy the inline bits to
1449 the various clones. */
1451 {
1458 }
1462 }
1463 }
1465 {
1467 /* Dup decl failed, but this is a new definition. Set the
1468 line number so any errors match this new
1469 definition. */
1473 }
1474 }
1478 /* A specialization must be declared in the same namespace as the
1479 template it is specializing. */
1485 {
1493 /* TMPL is a forward declaration of a template function; keep a list
1494 of all specializations in case we need to reassign them to a friend
1495 template later in tsubst_friend_function. */
1498 }
1501 }
1503 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1504 TMPL and ARGS members, ignores SPEC. */
1508 static int
1510 {
1521 }
1523 /* Returns a hash for a template TMPL and template arguments ARGS. */
1525 static hashval_t
1527 {
1530 }
1532 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1533 ignoring SPEC. */
1535 static hashval_t
1537 {
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 {
1607 {
1610 }
1612 }
1616 {
1619 }
1630 val = iterative_hash_template_arg
1642 val);
1644 val);
1653 /* A lambda can't appear in a template arg, but don't crash on
1654 erroneous input. */
1666 /* Now hash operands as usual. */
1671 }
1674 {
1678 val);
1681 /* Otherwise just compare the types during lookup. */
1690 {
1695 }
1696 }
1699 }
1701 /* Unregister the specialization SPEC as a specialization of TMPL.
1702 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1703 if the SPEC was listed as a specialization of TMPL.
1705 Note that SPEC has been ggc_freed, so we can't look inside it. */
1707 bool
1709 {
1711 spec_entry elt;
1719 {
1724 }
1727 }
1729 /* Like register_specialization, but for local declarations. We are
1730 registering SPEC, an instantiation of TMPL. */
1732 static void
1734 {
1739 }
1741 /* TYPE is a class type. Returns true if TYPE is an explicitly
1742 specialized class. */
1744 bool
1746 {
1750 }
1752 /* Print the list of functions at FNS, going through all the overloads
1753 for each element of the list. Alternatively, FNS can not be a
1754 TREE_LIST, in which case it will be printed together with all the
1755 overloads.
1757 MORE and *STR should respectively be FALSE and NULL when the function
1758 is called from the outside. They are used internally on recursive
1759 calls. print_candidates manages the two parameters and leaves NULL
1760 in *STR when it ends. */
1762 static void
1764 {
1770 {
1774 }
1775 else
1776 {
1779 {
1780 /* Pick the prefix string. */
1782 {
1786 }
1790 }
1793 }
1796 {
1799 }
1800 }
1802 /* Print the list of candidate FNS in an error message. FNS can also
1803 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1805 void
1807 {
1811 }
1813 /* Returns the template (one of the functions given by TEMPLATE_ID)
1814 which can be specialized to match the indicated DECL with the
1815 explicit template args given in TEMPLATE_ID. The DECL may be
1816 NULL_TREE if none is available. In that case, the functions in
1817 TEMPLATE_ID are non-members.
1819 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1820 specialization of a member template.
1822 The TEMPLATE_COUNT is the number of references to qualifying
1823 template classes that appeared in the name of the function. See
1824 check_explicit_specialization for a more accurate description.
1826 TSK indicates what kind of template declaration (if any) is being
1827 declared. TSK_TEMPLATE indicates that the declaration given by
1828 DECL, though a FUNCTION_DECL, has template parameters, and is
1829 therefore a template function.
1831 The template args (those explicitly specified and those deduced)
1832 are output in a newly created vector *TARGS_OUT.
1834 If it is impossible to determine the result, an error message is
1835 issued. The error_mark_node is returned to indicate failure. */
1837 static tree
1839 tree decl,
1843 tmpl_spec_kind tsk)
1844 {
1845 tree fns;
1846 tree targs;
1847 tree explicit_targs;
1849 /* A TREE_LIST of templates of which DECL may be a specialization.
1850 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1851 corresponding TREE_PURPOSE is the set of template arguments that,
1852 when used to instantiate the template, would produce a function
1853 with the signature of DECL. */
1863 /* We shouldn't be specializing a member template of an
1864 unspecialized class template; we already gave an error in
1865 check_specialization_scope, now avoid crashing. */
1868 {
1871 }
1879 /* Check for baselinks. */
1884 {
1887 }
1889 /* Count the number of template headers specified for this
1890 specialization. */
1898 {
1902 {
1903 tree decl_arg_types;
1904 tree fn_arg_types;
1905 tree insttype;
1907 /* In case of explicit specialization, we need to check if
1908 the number of template headers appearing in the specialization
1909 is correct. This is usually done in check_explicit_specialization,
1910 but the check done there cannot be exhaustive when specializing
1911 member functions. Consider the following code:
1913 template <> void A<int>::f(int);
1914 template <> template <> void A<int>::f(int);
1916 Assuming that A<int> is not itself an explicit specialization
1917 already, the first line specializes "f" which is a non-template
1918 member function, whilst the second line specializes "f" which
1919 is a template member function. So both lines are syntactically
1920 correct, and check_explicit_specialization does not reject
1921 them.
1923 Here, we can do better, as we are matching the specialization
1924 against the declarations. We count the number of template
1925 headers, and we check if they match TEMPLATE_COUNT + 1
1926 (TEMPLATE_COUNT is the number of qualifying template classes,
1927 plus there must be another header for the member template
1928 itself).
1930 Notice that if header_count is zero, this is not a
1931 specialization but rather a template instantiation, so there
1932 is no check we can perform here. */
1936 /* Check that the number of template arguments at the
1937 innermost level for DECL is the same as for FN. */
1945 /* DECL might be a specialization of FN. */
1949 /* For a non-static member function, we need to make sure
1950 that the const qualification is the same. Since
1951 get_bindings does not try to merge the "this" parameter,
1952 we must do the comparison explicitly. */
1958 /* Skip the "this" parameter and, for constructors of
1959 classes with virtual bases, the VTT parameter. A
1960 full specialization of a constructor will have a VTT
1961 parameter, but a template never will. */
1962 decl_arg_types
1964 fn_arg_types
1967 /* Function templates cannot be specializations; there are
1968 no partial specializations of functions. Therefore, if
1969 the type of DECL does not match FN, there is no
1970 match. */
1972 {
1976 }
1978 /* See whether this function might be a specialization of this
1979 template. Suppress access control because we might be trying
1980 to make this specialization a friend, and we have already done
1981 access control for the declaration of the specialization. */
1987 /* We cannot deduce template arguments that when used to
1988 specialize TMPL will produce DECL. */
1991 /* Make sure that the deduced arguments actually work. */
1995 fn_arg_types
2000 /* Save this template, and the arguments deduced. */
2002 }
2004 /* FN is an ordinary member function, and we need a
2005 specialization of a member template. */
2006 ;
2008 /* We can get IDENTIFIER_NODEs here in certain erroneous
2009 cases. */
2010 ;
2012 /* This is just an ordinary non-member function. Nothing can
2013 be a specialization of that. */
2014 ;
2016 /* Cannot specialize functions that are created implicitly. */
2017 ;
2018 else
2019 {
2020 tree decl_arg_types;
2022 /* This is an ordinary member function. However, since
2023 we're here, we can assume its enclosing class is a
2024 template class. For example,
2026 template <typename T> struct S { void f(); };
2027 template <> void S<int>::f() {}
2029 Here, S<int>::f is a non-template, but S<int> is a
2030 template class. If FN has the same type as DECL, we
2031 might be in business. */
2034 /* Its enclosing class is an explicit specialization
2035 of a template class. This is not a candidate. */
2040 /* The return types differ. */
2043 /* Adjust the type of DECL in case FN is a static member. */
2050 decl_arg_types))
2051 /* They match! */
2053 }
2054 }
2057 {
2058 /* We have:
2060 [temp.expl.spec]
2062 It is possible for a specialization with a given function
2063 signature to be instantiated from more than one function
2064 template. In such cases, explicit specification of the
2065 template arguments must be used to uniquely identify the
2066 function template specialization being specialized.
2068 Note that here, there's no suggestion that we're supposed to
2069 determine which of the candidate templates is most
2070 specialized. However, we, also have:
2072 [temp.func.order]
2074 Partial ordering of overloaded function template
2075 declarations is used in the following contexts to select
2076 the function template to which a function template
2077 specialization refers:
2079 -- when an explicit specialization refers to a function
2080 template.
2082 So, we do use the partial ordering rules, at least for now.
2083 This extension can only serve to make invalid programs valid,
2084 so it's safe. And, there is strong anecdotal evidence that
2085 the committee intended the partial ordering rules to apply;
2086 the EDG front end has that behavior, and John Spicer claims
2087 that the committee simply forgot to delete the wording in
2088 [temp.expl.spec]. */
2091 {
2094 }
2095 }
2098 {
2106 }
2110 {
2116 }
2118 /* We have one, and exactly one, match. */
2120 {
2123 /* DECL is a re-declaration or partial instantiation of a template
2124 function. */
2127 /* It was a specialization of an ordinary member function in a
2128 template class. */
2130 }
2132 /* It was a specialization of a template. */
2135 {
2140 }
2141 else
2144 }
2146 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2147 but with the default argument values filled in from those in the
2148 TMPL_TYPES. */
2150 static tree
2152 tree tmpl_types)
2153 {
2154 tree new_spec_types;
2162 /* Substitute into the rest of the list. */
2163 new_spec_types =
2167 /* Add the default argument for this parameter. */
2170 new_spec_types);
2171 }
2173 /* DECL is an explicit specialization. Replicate default arguments
2174 from the template it specializes. (That way, code like:
2176 template <class T> void f(T = 3);
2177 template <> void f(double);
2178 void g () { f (); }
2180 works, as required.) An alternative approach would be to look up
2181 the correct default arguments at the call-site, but this approach
2182 is consistent with how implicit instantiations are handled. */
2184 static void
2186 {
2187 tree tmpl;
2188 tree spec_types;
2189 tree tmpl_types;
2190 tree new_spec_types;
2191 tree old_type;
2192 tree new_type;
2193 tree t;
2198 /* See if there's anything we need to do. */
2211 {
2212 /* Remove the this pointer, but remember the object's type for
2213 CV quals. */
2219 {
2220 /* DECL may contain more parameters than TMPL due to the extra
2221 in-charge parameter in constructors and destructors. */
2224 }
2226 {
2229 }
2230 }
2232 /* Compute the merged default arguments. */
2233 new_spec_types =
2236 /* Compute the new FUNCTION_TYPE. */
2238 {
2242 new_spec_types);
2245 /* Put the in-charge parameter back. */
2248 new_spec_types);
2252 new_spec_types);
2253 }
2254 else
2256 new_spec_types);
2262 }
2264 /* Return the number of template headers we expect to see for a definition
2265 or specialization of CTYPE or one of its non-template members. */
2267 int
2269 {
2273 {
2274 /* You're supposed to have one `template <...>' for every
2275 template class, but you don't need one for a full
2276 specialization. For example:
2278 template <class T> struct S{};
2279 template <> struct S<int> { void f(); };
2280 void S<int>::f () {}
2282 is correct; there shouldn't be a `template <>' for the
2283 definition of `S<int>::f'. */
2285 /* If CTYPE does not have template information of any
2286 kind, then it is not a template, nor is it nested
2287 within a template. */
2295 }
2298 }
2300 /* Do a simple sanity check on the template headers that precede the
2301 variable declaration DECL. */
2303 void
2305 {
2312 {
2318 "members of an explicitly specialized class are defined "
2320 }
2321 }
2323 /* Check to see if the function just declared, as indicated in
2324 DECLARATOR, and in DECL, is a specialization of a function
2325 template. We may also discover that the declaration is an explicit
2326 instantiation at this point.
2328 Returns DECL, or an equivalent declaration that should be used
2329 instead if all goes well. Issues an error message if something is
2330 amiss. Returns error_mark_node if the error is not easily
2331 recoverable.
2333 FLAGS is a bitmask consisting of the following flags:
2335 2: The function has a definition.
2336 4: The function is a friend.
2338 The TEMPLATE_COUNT is the number of references to qualifying
2339 template classes that appeared in the name of the function. For
2340 example, in
2342 template <class T> struct S { void f(); };
2343 void S<int>::f();
2345 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2346 classes are not counted in the TEMPLATE_COUNT, so that in
2348 template <class T> struct S {};
2349 template <> struct S<int> { void f(); }
2350 template <> void S<int>::f();
2352 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2353 invalid; there should be no template <>.)
2355 If the function is a specialization, it is marked as such via
2356 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2357 is set up correctly, and it is added to the list of specializations
2358 for that template. */
2360 tree
2362 tree decl,
2365 {
2373 tmpl_spec_kind tsk;
2376 {
2379 else
2381 }
2382 else
2386 {
2389 {
2392 }
2394 {
2396 /* This could be something like:
2398 template <class T> void f(T);
2399 class S { friend void f<>(int); } */
2401 else
2402 {
2403 /* This case handles bogus declarations like template <>
2404 template <class T> void f<int>(); */
2407 declarator);
2409 }
2410 }
2414 /* The error has already been reported in
2415 check_specialization_scope. */
2421 /* Fall through. */
2434 decl);
2437 else
2441 /* Fall through. */
2446 else
2452 {
2453 /* This case handles bogus declarations like template <>
2454 template <class T> void f<int>(); */
2459 else
2461 declarator);
2463 }
2466 /* This is a specialization of a member template, without
2467 specialization the containing class. Something like:
2469 template <class T> struct S {
2470 template <class U> void f (U);
2471 };
2472 template <> template <class U> void S<int>::f(U) {}
2474 That's a specialization -- but of the entire template. */
2480 }
2483 {
2487 {
2491 }
2492 }
2495 {
2499 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2501 {
2502 tree fns;
2507 else
2508 {
2509 /* If there is no class context, the explicit instantiation
2510 must be at namespace scope. */
2513 /* Find the namespace binding, using the declaration
2514 context. */
2518 {
2521 }
2522 else
2523 {
2529 }
2530 }
2533 }
2539 {
2541 /* A specialization in class scope. This is invalid,
2542 but the error will already have been flagged by
2543 check_specialization_scope. */
2545 else
2546 {
2547 /* It's not valid to write an explicit instantiation in
2548 class scope, e.g.:
2550 class C { template void f(); }
2552 This case is caught by the parser. However, on
2553 something like:
2555 template class C { void f(); };
2557 (which is invalid) we can get here. The error will be
2558 issued later. */
2559 ;
2560 }
2563 }
2566 {
2567 /* Find the list of functions in ctype that have the same
2568 name as the declared function. */
2574 {
2579 {
2580 /* From [temp.expl.spec]:
2582 If such an explicit specialization for the member
2583 of a class template names an implicitly-declared
2584 special member function (clause _special_), the
2585 program is ill-formed.
2587 Similar language is found in [temp.explicit]. */
2590 }
2593 }
2596 {
2600 }
2601 else
2602 {
2604 tree ovl;
2606 /* For a type-conversion operator, we cannot do a
2607 name-based lookup. We might be looking for `operator
2608 int' which will be a specialization of `operator T'.
2609 So, we find *all* the conversion operators, and then
2610 select from them. */
2618 {
2620 /* There are no more conversion functions. */
2623 /* Glue all these conversion functions together
2624 with those we already have. */
2627 }
2628 }
2631 {
2634 }
2635 else
2637 }
2639 /* Figure out what exactly is being specialized at this point.
2640 Note that for an explicit instantiation, even one for a
2641 member function, we cannot tell apriori whether the
2642 instantiation is for a member template, or just a member
2643 function of a template class. Even if a member template is
2644 being instantiated, the member template arguments may be
2645 elided if they can be deduced from the rest of the
2646 declaration. */
2649 member_specialization,
2650 template_count,
2651 tsk);
2654 /* We couldn't figure out what this declaration was
2655 specializing. */
2657 else
2658 {
2662 {
2663 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2664 is done by do_decl_instantiation later. */
2670 {
2671 /* If TMPL is not the most general template (for
2672 example, if TMPL is a friend template that is
2673 injected into namespace scope), then there will
2674 be too many levels of TARGS. Remove some of them
2675 here. */
2677 tree new_targs;
2684 }
2687 }
2689 /* If we thought that the DECL was a member function, but it
2690 turns out to be specializing a static member function,
2691 make DECL a static member function as well. */
2696 /* If this is a specialization of a member template of a
2697 template class, we want to return the TEMPLATE_DECL, not
2698 the specialization of it. */
2700 {
2705 {
2706 tree parm;
2710 /* We want to use the argument list specified in the
2711 definition, not in the original declaration. */
2716 }
2719 }
2721 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2724 /* Inherit default function arguments from the template
2725 DECL is specializing. */
2728 /* This specialization has the same protection as the
2729 template it specializes. */
2733 /* 7.1.1-1 [dcl.stc]
2735 A storage-class-specifier shall not be specified in an
2736 explicit specialization...
2738 The parser rejects these, so unless action is taken here,
2739 explicit function specializations will always appear with
2740 global linkage.
2742 The action recommended by the C++ CWG in response to C++
2743 defect report 605 is to make the storage class and linkage
2744 of the explicit specialization match the templated function:
2746 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2747 */
2749 {
2753 /* This specialization has the same linkage and visibility as
2754 the function template it specializes. */
2757 {
2760 }
2763 {
2766 }
2767 }
2769 /* If DECL is a friend declaration, declared using an
2770 unqualified name, the namespace associated with DECL may
2771 have been set incorrectly. For example, in:
2773 template <typename T> void f(T);
2774 namespace N {
2775 struct S { friend void f<int>(int); }
2776 }
2778 we will have set the DECL_CONTEXT for the friend
2779 declaration to N, rather than to the global namespace. */
2784 /* This is not really a declaration of a specialization.
2785 It's just the name of an instantiation. But, it's not
2786 a request for an instantiation, either. */
2789 /* Register this specialization so that we can find it
2790 again. */
2793 /* A 'structor should already have clones. */
2798 }
2799 }
2802 }
2804 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2805 parameters. These are represented in the same format used for
2806 DECL_TEMPLATE_PARMS. */
2808 int
2810 {
2811 const_tree p1;
2812 const_tree p2;
2820 {
2832 {
2836 /* If either of the template parameters are invalid, assume
2837 they match for the sake of error recovery. */
2850 }
2851 }
2854 /* One set of parameters has more parameters lists than the
2855 other. */
2859 }
2861 /* Determine whether PARM is a parameter pack. */
2863 bool
2865 {
2866 /* Determine if we have a non-type template parameter pack. */
2873 /* If this is a list of template parameters, we could get a
2874 TYPE_DECL or a TEMPLATE_DECL. */
2878 /* Otherwise it must be a type template parameter. */
2882 }
2884 /* Determine if T is a function parameter pack. */
2886 bool
2888 {
2892 }
2894 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2895 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2897 tree
2899 {
2906 }
2908 /* Return true iff the function parameter PARAM_DECL was expanded
2909 from the function parameter pack PACK. */
2911 bool
2913 {
2918 /* The parameter pack and its pack arguments have the same
2919 DECL_PARM_INDEX. */
2921 }
2923 /* Determine whether ARGS describes a variadic template args list,
2924 i.e., one that is terminated by a template argument pack. */
2926 static bool
2928 {
2930 tree last_parm;
2944 }
2946 /* Generate a new name for the parameter pack name NAME (an
2947 IDENTIFIER_NODE) that incorporates its */
2949 static tree
2951 {
2952 /* Munge the name to include the parameter index. */
2953 #define NUMBUF_LEN 128
2967 }
2969 /* Return true if T is a primary function, class or alias template
2970 instantiation. */
2972 bool
2974 {
2988 }
2990 /* Return true if PARM is a template template parameter. */
2992 bool
2994 {
2996 }
2998 /* Return true iff PARM is a DECL representing a type template
2999 parameter. */
3001 bool
3003 {
3008 }
3010 /* Return the template parameters of T if T is a
3011 primary template instantiation, NULL otherwise. */
3013 tree
3015 {
3020 parms = INNERMOST_TEMPLATE_PARMS
3024 }
3026 /* Return the template parameters of the LEVELth level from the full list
3027 of template parameters PARMS. */
3029 tree
3031 {
3032 tree p;
3043 }
3045 /* Returns the template arguments of T if T is a template instantiation,
3046 NULL otherwise. */
3048 tree
3050 {
3058 }
3060 /* Return the argument pack elements of T if T is a template argument pack,
3061 NULL otherwise. */
3063 tree
3065 {
3071 }
3073 /* Structure used to track the progress of find_parameter_packs_r. */
3074 struct find_parameter_pack_data
3075 {
3076 /* TREE_LIST that will contain all of the parameter packs found by
3077 the traversal. */
3080 /* Set of AST nodes that have been visited by the traversal. */
3082 };
3084 /* Identifies all of the argument packs that occur in a template
3085 argument and appends them to the TREE_LIST inside DATA, which is a
3086 find_parameter_pack_data structure. This is a subroutine of
3087 make_pack_expansion and uses_parameter_packs. */
3088 static tree
3090 {
3096 /* Handle type aliases/typedefs. */
3098 {
3105 }
3107 /* Identify whether this is a parameter pack or not. */
3109 {
3125 {
3126 /* We don't want to walk into the type of a PARM_DECL,
3127 because we don't want to see the type parameter pack. */
3130 }
3133 /* Look through a lambda capture proxy to the field pack. */
3136 {
3142 }
3149 /* Not a parameter pack. */
3151 }
3154 {
3155 /* Add this parameter pack to the list. */
3157 }
3163 /* This switch statement will return immediately if we don't find a
3164 parameter pack. */
3166 {
3171 /* Check the template itself. */
3174 /* Check the template arguments. */
3190 /* Fall through. */
3232 }
3235 }
3237 /* Determines if the expression or type T uses any parameter packs. */
3238 bool
3240 {
3248 }
3250 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3251 representation a base-class initializer into a parameter pack
3252 expansion. If all goes well, the resulting node will be an
3253 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3254 respectively. */
3255 tree
3257 {
3258 tree result;
3267 {
3268 /* The only time we will see a TREE_LIST here is for a base
3269 class initializer. In this case, the TREE_PURPOSE will be a
3270 _TYPE node (representing the base class expansion we're
3271 initializing) and the TREE_VALUE will be a TREE_LIST
3272 containing the initialization arguments.
3274 The resulting expansion looks somewhat different from most
3275 expansions. Rather than returning just one _EXPANSION, we
3276 return a TREE_LIST whose TREE_PURPOSE is a
3277 TYPE_PACK_EXPANSION containing the bases that will be
3278 initialized. The TREE_VALUE will be identical to the
3279 original TREE_VALUE, which is a list of arguments that will
3280 be passed to each base. We do not introduce any new pack
3281 expansion nodes into the TREE_VALUE (although it is possible
3282 that some already exist), because the TREE_PURPOSE and
3283 TREE_VALUE all need to be expanded together with the same
3284 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3285 resulting TREE_PURPOSE will mention the parameter packs in
3286 both the bases and the arguments to the bases. */
3287 tree purpose;
3288 tree value;
3291 /* Determine which parameter packs will be used by the base
3292 class expansion. */
3299 {
3303 }
3306 {
3307 /* Collect the sets of parameter packs used in each of the
3308 initialization arguments. */
3310 {
3311 /* Determine which parameter packs will be expanded in this
3312 argument. */
3315 }
3316 }
3320 /* Create the pack expansion type for the base type. */
3325 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3326 they will rarely be compared to anything. */
3330 }
3335 /* Build the PACK_EXPANSION_* node. */
3336 result = for_types
3341 {
3342 /* Propagate type and const-expression information. */
3345 }
3346 else
3347 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3348 they will rarely be compared to anything. */
3351 /* Determine which parameter packs will be expanded. */
3357 /* Make sure we found some parameter packs. */
3359 {
3362 else
3365 }
3371 }
3373 /* Checks T for any "bare" parameter packs, which have not yet been
3374 expanded, and issues an error if any are found. This operation can
3375 only be done on full expressions or types (e.g., an expression
3376 statement, "if" condition, etc.), because we could have expressions like:
3378 foo(f(g(h(args)))...)
3380 where "args" is a parameter pack. check_for_bare_parameter_packs
3381 should not be called for the subexpressions args, h(args),
3382 g(h(args)), or f(g(h(args))), because we would produce erroneous
3383 error messages.
3385 Returns TRUE and emits an error if there were bare parameter packs,
3386 returns FALSE otherwise. */
3387 bool
3389 {
3405 {
3408 {
3417 else
3422 else
3426 }
3429 }
3432 }
3434 /* Expand any parameter packs that occur in the template arguments in
3435 ARGS. */
3436 tree
3438 {
3444 /* First, determine if we need to expand anything, and the number of
3445 slots we'll need. */
3447 {
3452 {
3456 else
3458 }
3459 else
3460 {
3462 num_result_args++;
3463 }
3464 }
3466 /* If no expansion is necessary, we're done. */
3470 /* Expand arguments. */
3473 non_default_args_count =
3476 {
3479 {
3486 }
3487 else
3488 {
3491 }
3492 }
3496 }
3498 /* Checks if DECL shadows a template parameter.
3500 [temp.local]: A template-parameter shall not be redeclared within its
3501 scope (including nested scopes).
3503 Emits an error and returns TRUE if the DECL shadows a parameter,
3504 returns FALSE otherwise. */
3506 bool
3508 {
3509 tree olddecl;
3511 /* If we're not in a template, we can't possibly shadow a template
3512 parameter. */
3516 /* Figure out what we're shadowing. */
3521 /* If there's no previous binding for this name, we're not shadowing
3522 anything, let alone a template parameter. */
3526 /* If we're not shadowing a template parameter, we're done. Note
3527 that OLDDECL might be an OVERLOAD (or perhaps even an
3528 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3529 node. */
3533 /* We check for decl != olddecl to avoid bogus errors for using a
3534 name inside a class. We check TPFI to avoid duplicate errors for
3535 inline member templates. */
3541 /* Don't complain about the injected class name, as we've already
3542 complained about the class itself. */
3549 }
3551 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3552 ORIG_LEVEL, DECL, and TYPE. */
3554 static tree
3558 tree decl,
3559 tree type)
3560 {
3571 }
3573 /* Find the canonical type parameter for the given template type
3574 parameter. Returns the canonical type parameter, which may be TYPE
3575 if no such parameter existed. */
3577 static tree
3579 {
3580 tree list;
3594 else
3595 {
3600 }
3601 }
3603 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3604 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3605 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3606 new one is created. */
3608 static tree
3610 tsubst_flags_t complain)
3611 {
3616 {
3635 /* Template template parameters need this. */
3640 }
3643 }
3645 /* Process information from new template parameter PARM and append it
3646 to the LIST being built. This new parameter is a non-type
3647 parameter iff IS_NON_TYPE is true. This new parameter is a
3648 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3649 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3650 parameter list PARM belongs to. This is used used to create a
3651 proper canonical type for the type of PARM that is to be created,
3652 iff PARM is a type. If the size is not known, this parameter shall
3653 be set to 0. */
3655 tree
3658 {
3660 tree defval;
3661 tree err_parm_list;
3668 {
3672 {
3676 else
3678 }
3681 }
3682 else
3686 {
3692 {
3696 }
3697 else
3698 {
3699 /* [temp.param]
3701 The top-level cv-qualifiers on the template-parameter are
3702 ignored when determining its type. */
3705 {
3709 }
3712 /* If we're in a nested template parameter list, the template
3713 template parameter could be a parameter pack. */
3715 {
3716 /* This template parameter is not a parameter pack, but it
3717 should be. Complain about "bare" parameter packs. */
3720 /* Recover by calling this a parameter pack. */
3722 }
3723 }
3725 /* A template parameter is not modifiable. */
3734 processing_template_decl,
3739 }
3740 else
3741 {
3742 tree t;
3746 {
3748 /* This is for distinguishing between real templates and template
3749 template parameters */
3753 }
3754 else
3755 {
3757 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3760 }
3767 processing_template_decl,
3771 }
3777 }
3779 /* The end of a template parameter list has been reached. Process the
3780 tree list into a parameter vector, converting each parameter into a more
3781 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3782 as PARM_DECLs. */
3784 tree
3786 {
3791 current_template_parms
3796 {
3800 }
3805 }
3807 /* end_template_decl is called after a template declaration is seen. */
3809 void
3811 {
3817 /* This matches the pushlevel in begin_template_parm_list. */
3822 }
3824 /* Takes a TREE_LIST representing a template parameter and convert it
3825 into an argument suitable to be passed to the type substitution
3826 functions. Note that If the TREE_LIST contains an error_mark
3827 node, the returned argument is error_mark_node. */
3829 static tree
3831 {
3844 {
3848 {
3849 /* Turn this argument into a TYPE_ARGUMENT_PACK
3850 with a single element, which expands T. */
3852 #ifdef ENABLE_CHECKING
3853 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3855 #endif
3860 }
3861 }
3862 else
3863 {
3867 {
3868 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3869 with a single element, which expands T. */
3872 #ifdef ENABLE_CHECKING
3873 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3875 #endif
3882 }
3883 else
3885 }
3887 }
3889 /* Given a set of template parameters, return them as a set of template
3890 arguments. The template parameters are represented as a TREE_VEC, in
3891 the form documented in cp-tree.h for template arguments. */
3893 static tree
3895 {
3896 tree header;
3901 /* If there is only one level of template parameters, we do not
3902 create a TREE_VEC of TREE_VECs. Instead, we return a single
3903 TREE_VEC containing the arguments. */
3908 {
3916 #ifdef ENABLE_CHECKING
3918 #endif
3922 else
3924 }
3927 /* This can happen for template parms of a template template
3928 parameter, e.g:
3930 template<template<class T, class U> class TT> struct S;
3932 Consider the level of the parms of TT; T and U both have
3933 level 2; TT has no template parm of level 1. So in this case
3934 the first element of full_template_args is NULL_TREE. If we
3935 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
3936 of 2. This will make tsubst wrongly consider that T and U
3937 have level 1. Instead, let's create a dummy vector as the
3938 first element of full_template_args so that TMPL_ARGS_DEPTH
3939 returns the correct depth for args. */
3942 }
3944 /* Within the declaration of a template, return the currently active
3945 template parameters as an argument TREE_VEC. */
3947 static tree
3949 {
3951 }
3953 /* Update the declared TYPE by doing any lookups which were thought to be
3954 dependent, but are not now that we know the SCOPE of the declarator. */
3956 tree
3958 {
3969 /* Don't bother building up the args in this case. */
3971 {
3972 /* tsubst in the args corresponding to the template parameters,
3973 including auto if present. Most things will be unchanged, but
3974 make_typename_type and tsubst_qualified_id will resolve
3975 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3978 tree pushed;
3980 {
3984 }
3989 }
3995 {
3998 else
4000 }
4002 }
4004 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4005 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4006 a member template. Used by push_template_decl below. */
4008 static tree
4010 {
4018 }
4020 struct template_parm_data
4021 {
4022 /* The level of the template parameters we are currently
4023 processing. */
4026 /* The index of the specialization argument we are currently
4027 processing. */
4030 /* An array whose size is the number of template parameters. The
4031 elements are nonzero if the parameter has been used in any one
4032 of the arguments processed so far. */
4035 /* An array whose size is the number of template arguments. The
4036 elements are nonzero if the argument makes use of template
4037 parameters of this level. */
4039 };
4041 /* Subroutine of push_template_decl used to see if each template
4042 parameter in a partial specialization is used in the explicit
4043 argument list. If T is of the LEVEL given in DATA (which is
4044 treated as a template_parm_data*), then DATA->PARMS is marked
4045 appropriately. */
4047 static int
4049 {
4055 {
4058 }
4059 else
4060 {
4063 }
4066 {
4069 }
4071 /* Return zero so that for_each_template_parm will continue the
4072 traversal of the tree; we want to mark *every* template parm. */
4074 }
4076 /* Process the partial specialization DECL. */
4078 static tree
4080 {
4086 tree inner_parms;
4087 tree inst;
4100 /* We check that each of the template parameters given in the
4101 partial specialization is used in the argument list to the
4102 specialization. For example:
4104 template <class T> struct S;
4105 template <class T> struct S<T*>;
4107 The second declaration is OK because `T*' uses the template
4108 parameter T, whereas
4110 template <class T> struct S<int>;
4112 is no good. Even trickier is:
4114 template <class T>
4115 struct S1
4116 {
4117 template <class U>
4118 struct S2;
4119 template <class U>
4120 struct S2<T>;
4121 };
4123 The S2<T> declaration is actually invalid; it is a
4124 full-specialization. Of course,
4126 template <class U>
4127 struct S2<T (*)(U)>;
4129 or some such would have been OK. */
4137 {
4142 NULL,
4144 }
4147 {
4148 /* One of the template parms was not used in the
4149 specialization. */
4151 {
4154 }
4157 }
4162 /* [temp.class.spec]
4164 The argument list of the specialization shall not be identical to
4165 the implicit argument list of the primary template. */
4172 /* A partial specialization that replaces multiple parameters of the
4173 primary template with a pack expansion is less specialized for those
4174 parameters. */
4176 {
4178 "primary template because it replaces multiple parameters "
4182 }
4184 /* [temp.class.spec]
4186 A partially specialized non-type argument expression shall not
4187 involve template parameters of the partial specialization except
4188 when the argument expression is a simple identifier.
4190 The type of a template parameter corresponding to a specialized
4191 non-type argument shall not be dependent on a parameter of the
4192 specialization.
4194 Also, we verify that pack expansions only occur at the
4195 end of the argument list. */
4199 {
4206 {
4207 /* Extract the arguments from the argument pack. We'll be
4208 iterating over these in the following loop. */
4211 }
4214 {
4216 /* Get the Jth argument in the parameter pack. */
4220 {
4221 /* Pack expansions must come at the end of the
4222 argument list. */
4225 {
4229 else
4232 }
4233 }
4236 /* We only care about the pattern. */
4242 /* This next two lines are the `argument expression is not just a
4243 simple identifier' condition and also the `specialized
4244 non-type argument' bit. */
4248 {
4252 arg);
4253 else
4254 {
4255 /* Look at the corresponding template parameter,
4256 marking which template parameters its type depends
4257 upon. */
4261 {
4262 /* We haven't yet initialized TPD2. Do so now. */
4264 /* The number of parameters here is the number in the
4265 main template, which, as checked in the assertion
4266 above, is NARGS. */
4270 }
4272 /* Mark the template parameters. But this time, we're
4273 looking for the template parameters of the main
4274 template, not in the specialization. */
4281 NULL,
4285 {
4286 /* The type depended on some template parameters.
4287 If they are fully specialized in the
4288 specialization, that's OK. */
4297 "type %qT of template argument %qE depends "
4299 "type %qT of template argument %qE depends "
4301 type,
4302 arg);
4303 }
4304 }
4305 }
4306 }
4307 }
4309 /* We should only get here once. */
4327 {
4331 {
4335 "partial specialization of %qT after instantiation "
4337 }
4338 }
4341 }
4343 /* PARM is a template parameter of some form; return the corresponding
4344 TEMPLATE_PARM_INDEX. */
4346 static tree
4348 {
4360 }
4362 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4363 parameter packs used by the template parameter PARM. */
4365 static void
4367 {
4368 /* A type parm can't refer to another parm. */
4372 {
4376 }
4383 }
4385 /* PARM is a template parameter pack. Return any parameter packs used in
4386 its type or the type of any of its template parameters. If there are
4387 any such packs, it will be instantiated into a fixed template parameter
4388 list by partial instantiation rather than be fully deduced. */
4390 tree
4392 {
4393 /* This can only be true in a member template. */
4396 /* This can only be true for a parameter pack. */
4399 /* A type parm can't refer to another parm. */
4412 }
4414 /* Check that a template declaration's use of default arguments and
4415 parameter packs is not invalid. Here, PARMS are the template
4416 parameters. IS_PRIMARY is true if DECL is the thing declared by
4417 a primary template. IS_PARTIAL is true if DECL is a partial
4418 specialization.
4420 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4421 declaration (but not a definition); 1 indicates a declaration, 2
4422 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4423 emitted for extraneous default arguments.
4425 Returns TRUE if there were no errors found, FALSE otherwise. */
4427 bool
4430 {
4433 tree parm_level;
4436 /* [temp.param]
4438 A default template-argument shall not be specified in a
4439 function template declaration or a function template definition, nor
4440 in the template-parameter-list of the definition of a member of a
4441 class template. */
4444 /* You can't have a function template declaration in a local
4445 scope, nor you can you define a member of a class template in a
4446 local scope. */
4452 /* A lambda doesn't have an explicit declaration; don't complain
4453 about the parms of the enclosing class. */
4460 /* If this is either a friend defined in the scope of the class
4461 or a member function. */
4467 /* And, if it was a member function, it really was defined in
4468 the scope of the class. */
4471 /* We already checked these parameters when the template was
4472 declared, so there's no need to do it again now. This function
4473 was defined in class scope, but we're processing its body now
4474 that the class is complete. */
4477 /* Core issue 226 (C++0x only): the following only applies to class
4478 templates. */
4481 {
4482 /* [temp.param]
4484 If a template-parameter has a default template-argument, all
4485 subsequent template-parameters shall have a default
4486 template-argument supplied. */
4488 {
4495 {
4505 {
4507 /* For better subsequent error-recovery, we indicate that
4508 there should have been a default argument. */
4511 }
4513 && !is_friend_decl
4514 /* Don't complain about an enclosing partial
4515 specialization. */
4520 /* A fixed parameter pack will be partially
4521 instantiated into a fixed length list. */
4523 {
4524 /* A primary class template can only have one
4525 parameter pack, at the end of the template
4526 parameter list. */
4531 else
4539 }
4540 }
4541 }
4542 }
4545 || is_partial
4546 || !is_primary
4548 /* For an ordinary class template, default template arguments are
4549 allowed at the innermost level, e.g.:
4550 template <class T = int>
4551 struct S {};
4552 but, in a partial specialization, they're not allowed even
4553 there, as we have in [temp.class.spec]:
4555 The template parameter list of a specialization shall not
4556 contain default template argument values.
4558 So, for a partial specialization, or for a function template
4559 (in C++98/C++03), we look at all of them. */
4560 ;
4561 else
4562 /* But, for a primary class template that is not a partial
4563 specialization we look at all template parameters except the
4564 innermost ones. */
4567 /* Figure out what error message to issue. */
4580 else
4584 /* If we're inside a class definition, there's no need to
4585 examine the parameters to the class itself. On the one
4586 hand, they will be checked when the class is defined, and,
4587 on the other, default arguments are valid in things like:
4588 template <class T = double>
4589 struct S { template <class U> void f(U); };
4590 Here the default argument for `S' has no bearing on the
4591 declaration of `f'. */
4593 else
4594 /* Check everything. */
4600 {
4607 {
4612 {
4614 {
4621 }
4623 /* Clear out the default argument so that we are not
4624 confused later. */
4626 }
4627 }
4629 /* At this point, if we're still interested in issuing messages,
4630 they must apply to classes surrounding the object declared. */
4634 }
4637 }
4639 /* Worker for push_template_decl_real, called via
4640 for_each_template_parm. DATA is really an int, indicating the
4641 level of the parameters we are interested in. If T is a template
4642 parameter of that level, return nonzero. */
4644 static int
4646 {
4652 else
4655 }
4657 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4658 parameters given by current_template_args, or reuses a
4659 previously existing one, if appropriate. Returns the DECL, or an
4660 equivalent one, if it is replaced via a call to duplicate_decls.
4662 If IS_FRIEND is true, DECL is a friend declaration. */
4664 tree
4666 {
4667 tree tmpl;
4668 tree args;
4669 tree info;
4670 tree ctx;
4674 /* True if the template is a member template, in the sense of
4675 [temp.mem]. */
4681 /* See if this is a partial specialization. */
4690 /* For a friend, we want the context of the friend function, not
4691 the type of which it is a friend. */
4695 /* In the case of a virtual function, we want the class in which
4696 it is defined. */
4698 else
4699 /* Otherwise, if we're currently defining some class, the DECL
4700 is assumed to be a member of the class. */
4709 /* See if this is a primary template. */
4712 /* A friend template that specifies a class context, i.e.
4713 template <typename T> friend void A<T>::f();
4714 is not primary. */
4716 else
4720 {
4725 {
4728 }
4730 {
4732 {
4733 /* [temp.mem]
4735 A destructor shall not be a member template. */
4738 }
4745 {
4746 /* [basic.stc.dynamic.allocation]
4748 An allocation function can be a function
4749 template. ... Template allocation functions shall
4750 have two or more parameters. */
4753 }
4754 }
4760 /* alias-declaration */
4762 else
4763 {
4766 }
4767 }
4769 /* Check to see that the rules regarding the use of default
4770 arguments are not being violated. */
4774 /* Ensure that there are no parameter packs in the type of this
4775 declaration that have not been expanded. */
4777 {
4778 /* Check each of the arguments individually to see if there are
4779 any bare parameter packs. */
4785 {
4788 {
4789 /* This is a PARM_DECL that contains unexpanded parameter
4790 packs. We have already complained about this in the
4791 check_for_bare_parameter_packs call, so just replace
4792 these types with ERROR_MARK_NODE. */
4795 }
4799 }
4801 /* Check for bare parameter packs in the return type and the
4802 exception specifiers. */
4804 /* Errors were already issued, set return type to int
4805 as the frontend doesn't expect error_mark_node as
4806 the return type. */
4810 }
4815 {
4818 }
4831 {
4836 /* If DECL is a TYPE_DECL for a class-template, then there won't
4837 be DECL_LANG_SPECIFIC. The information equivalent to
4838 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4842 {
4843 /* Since a template declaration already existed for this
4844 class-type, we must be redeclaring it here. Make sure
4845 that the redeclaration is valid. */
4847 current_template_parms);
4848 /* We don't need to create a new TEMPLATE_DECL; just use the
4849 one we already had. */
4851 }
4852 else
4853 {
4855 member_template_p);
4860 {
4861 /* A specialization of a member template of a template
4862 class. */
4866 }
4867 }
4868 }
4869 else
4870 {
4876 {
4879 }
4887 {
4888 tree new_tmpl;
4890 /* The declaration is a specialization of a member
4891 template, declared outside the class. Therefore, the
4892 innermost template arguments will be NULL, so we
4893 replace them with the arguments determined by the
4894 earlier call to check_explicit_specialization. */
4897 new_tmpl
4899 member_template_p);
4909 args,
4912 }
4914 /* Make sure the template headers we got make sense. */
4919 {
4924 }
4925 else
4927 {
4932 {
4936 else
4940 /* Avoid crash in import_export_decl. */
4943 }
4948 /* Can happen in erroneous input. */
4950 else
4952 }
4954 /* Check that the parms are used in the appropriate qualifying scopes
4955 in the declarator. */
4959 {
4965 /* Avoid crash in import_export_decl. */
4968 }
4969 }
4974 /* Push template declarations for global functions and types. Note
4975 that we do not try to push a global template friend declared in a
4976 template class; such a thing may well depend on the template
4977 parameters of the class. */
4980 {
4985 /* Hide template friend classes that haven't been declared yet. */
4987 {
4990 }
4991 }
4994 {
5000 {
5003 /* It is a conversion operator. See if the type converted to
5004 depends on innermost template operands. */
5007 depth))
5009 }
5011 /* Give template template parms a DECL_CONTEXT of the template
5012 for which they are a parameter. */
5015 {
5019 }
5020 }
5022 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5023 back to its most general template. If TMPL is a specialization,
5024 ARGS may only have the innermost set of arguments. Add the missing
5025 argument levels if necessary. */
5033 else
5034 {
5039 }
5042 }
5044 tree
5046 {
5048 }
5050 /* FN is an inheriting constructor that inherits from the constructor
5051 template INHERITED; turn FN into a constructor template with a matching
5052 template header. */
5054 tree
5056 {
5057 tree inner_parms
5060 tree parms
5071 }
5073 /* Called when a class template TYPE is redeclared with the indicated
5074 template PARMS, e.g.:
5076 template <class T> struct S;
5077 template <class T> struct S {}; */
5079 bool
5081 {
5082 tree tmpl;
5083 tree tmpl_parms;
5087 {
5090 }
5094 /* The type is nested in some template class. Nothing to worry
5095 about here; there are no new template parameters for the nested
5096 type. */
5100 {
5102 tmpl);
5104 }
5110 {
5120 }
5123 {
5124 tree tmpl_parm;
5125 tree parm;
5126 tree tmpl_default;
5127 tree parm_default;
5141 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5142 TEMPLATE_DECL. */
5152 {
5156 }
5159 {
5160 /* We have in [temp.param]:
5162 A template-parameter may not be given default arguments
5163 by two different declarations in the same scope. */
5168 }
5171 /* Update the previous template parameters (which are the ones
5172 that will really count) with the new default value. */
5175 /* Update the new parameters, too; they'll be used as the
5176 parameters for any members. */
5178 }
5181 }
5183 /* Simplify EXPR if it is a non-dependent expression. Returns the
5184 (possibly simplified) expression. */
5186 tree
5188 {
5192 /* If we're in a template, but EXPR isn't value dependent, simplify
5193 it. We're supposed to treat:
5195 template <typename T> void f(T[1 + 1]);
5196 template <typename T> void f(T[2]);
5198 as two declarations of the same function, for example. */
5202 {
5203 HOST_WIDE_INT saved_processing_template_decl;
5209 complain,
5214 }
5216 }
5218 tree
5220 {
5222 }
5224 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5225 template declaration, or a TYPE_DECL for an alias declaration. */
5227 bool
5229 {
5237 }
5239 /* Return TRUE iff is a specialization of an alias template. */
5241 bool
5243 {
5251 }
5253 /* Return the number of innermost template parameters in TMPL. */
5255 static int
5257 {
5260 }
5262 /* Return either TMPL or another template that it is equivalent to under DR
5263 1286: An alias that just changes the name of a template is equivalent to
5264 the other template. */
5266 static tree
5268 {
5271 {
5274 {
5279 {
5280 tree alias_args = INNERMOST_TEMPLATE_ARGS
5284 /* The alias type is equivalent to the pattern of the
5285 underlying template, so strip the alias. */
5288 }
5289 }
5291 }
5293 }
5295 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5296 must be a function or a pointer-to-function type, as specified
5297 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5298 and check that the resulting function has external linkage. */
5300 static tree
5302 {
5305 linkage_kind linkage;
5317 /* [temp.arg.nontype]/1
5319 A template-argument for a non-type, non-template template-parameter
5320 shall be one of:
5321 [...]
5322 -- the address of an object or function with external [C++11: or
5323 internal] linkage. */
5326 {
5330 else
5333 }
5337 {
5342 else
5347 }
5350 }
5352 /* Subroutine of convert_nontype_argument.
5353 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5354 Emit an error otherwise. */
5356 static bool
5358 tsubst_flags_t complain)
5359 {
5366 {
5370 }
5372 }
5374 /* Returns TRUE iff the address of OP is value-dependent.
5376 14.6.2.4 [temp.dep.temp]:
5377 A non-integral non-type template-argument is dependent if its type is
5378 dependent or it has either of the following forms
5379 qualified-id
5380 & qualified-id
5381 and contains a nested-name-specifier which specifies a class-name that
5382 names a dependent type.
5384 We generalize this to just say that the address of a member of a
5385 dependent class is value-dependent; the above doesn't cover the
5386 address of a static data member named with an unqualified-id. */
5388 static bool
5390 {
5391 /* We could use get_inner_reference here, but there's no need;
5392 this is only relevant for template non-type arguments, which
5393 can only be expressed as &id-expression. */
5395 {
5399 }
5402 }
5404 /* The next set of functions are used for providing helpful explanatory
5405 diagnostics for failed overload resolution. Their messages should be
5406 indented by two spaces for consistency with the messages in
5407 call.c */
5409 static int
5411 {
5413 }
5415 static int
5417 {
5422 }
5424 static int
5426 {
5428 }
5430 static int
5432 {
5438 }
5440 static int
5442 {
5446 }
5448 static int
5450 {
5453 " template parameter %qD is not a parameter pack, but "
5457 }
5459 static int
5461 {
5464 " template argument %qE does not match "
5468 }
5470 static int
5472 {
5476 }
5478 static int
5480 {
5486 }
5488 static int
5490 {
5492 {
5497 else
5499 " deduced conflicting values for non-type parameter "
5501 }
5503 }
5505 static int
5507 {
5510 " variable-sized array type %qT is not "
5512 arg);
5514 }
5516 static int
5518 {
5522 arg);
5524 }
5526 static int
5528 {
5535 }
5537 static int
5539 {
5541 }
5543 static int
5545 {
5547 }
5549 static int
5552 {
5558 }
5560 static int
5563 {
5566 {
5574 }
5576 }
5578 static int
5580 {
5583 " template parameters of a template template argument are "
5586 }
5588 static int
5590 {
5596 }
5598 static int
5600 {
5605 }
5607 static int
5609 {
5613 arg);
5615 }
5617 /* Attempt to convert the non-type template parameter EXPR to the
5618 indicated TYPE. If the conversion is successful, return the
5619 converted value. If the conversion is unsuccessful, return
5620 NULL_TREE if we issued an error message, or error_mark_node if we
5621 did not. We issue error messages for out-and-out bad template
5622 parameters, but not simply because the conversion failed, since we
5623 might be just trying to do argument deduction. Both TYPE and EXPR
5624 must be non-dependent.
5626 The conversion follows the special rules described in
5627 [temp.arg.nontype], and it is much more strict than an implicit
5628 conversion.
5630 This function is called twice for each template argument (see
5631 lookup_template_class for a more accurate description of this
5632 problem). This means that we need to handle expressions which
5633 are not valid in a C++ source, but can be created from the
5634 first call (for instance, casts to perform conversions). These
5635 hacks can go away after we fix the double coercion problem. */
5637 static tree
5639 {
5640 tree expr_type;
5642 /* Detect immediately string literals as invalid non-type argument.
5643 This special-case is not needed for correctness (we would easily
5644 catch this later), but only to provide better diagnostic for this
5645 common user mistake. As suggested by DR 100, we do not mention
5646 linkage issues in the diagnostic as this is not the point. */
5647 /* FIXME we're making this OK. */
5649 {
5655 }
5657 /* Add the ADDR_EXPR now for the benefit of
5658 value_dependent_expression_p. */
5661 {
5665 }
5667 /* If we are in a template, EXPR may be non-dependent, but still
5668 have a syntactic, rather than semantic, form. For example, EXPR
5669 might be a SCOPE_REF, rather than the VAR_DECL to which the
5670 SCOPE_REF refers. Preserving the qualifying scope is necessary
5671 so that access checking can be performed when the template is
5672 instantiated -- but here we need the resolved form so that we can
5673 convert the argument. */
5684 else
5687 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5688 to a non-type argument of "nullptr". */
5692 /* In C++11, integral or enumeration non-type template arguments can be
5693 arbitrary constant expressions. Pointer and pointer to
5694 member arguments can be general constant expressions that evaluate
5695 to a null value, but otherwise still need to be of a specific form. */
5697 {
5699 /* A PTRMEM_CST is already constant, and a valid template
5700 argument for a parameter of pointer to member type, we just want
5701 to leave it in that form rather than lower it to a
5706 {
5711 }
5712 }
5714 /* HACK: Due to double coercion, we can get a
5715 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5716 which is the tree that we built on the first call (see
5717 below when coercing to reference to object or to reference to
5718 function). We just strip everything and get to the arg.
5719 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5720 for examples. */
5722 {
5728 {
5729 /* ??? Maybe we could use convert_from_reference here, but we
5730 would need to relax its constraints because the NOP_EXPR
5731 could actually change the type to something more cv-qualified,
5732 and this is not folded by convert_from_reference. */
5737 && (same_type_ignoring_top_level_qualifiers_p
5740 {
5743 }
5744 }
5745 }
5747 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5748 parameter is a pointer to object, through decay and
5749 qualification conversion. Let's strip everything. */
5751 {
5756 {
5757 /* Skip the ADDR_EXPR only if it is part of the decay for
5758 an array. Otherwise, it is part of the original argument
5759 in the source code. */
5764 }
5765 }
5767 /* [temp.arg.nontype]/5, bullet 1
5769 For a non-type template-parameter of integral or enumeration type,
5770 integral promotions (_conv.prom_) and integral conversions
5771 (_conv.integral_) are applied. */
5773 {
5782 /* Notice that there are constant expressions like '4 % 0' which
5783 do not fold into integer constants. */
5785 {
5787 {
5798 /* else cxx_constant_value complained but gave us
5799 a real constant, so go ahead. */
5801 }
5802 else
5804 }
5806 /* Avoid typedef problems. */
5809 }
5810 /* [temp.arg.nontype]/5, bullet 2
5812 For a non-type template-parameter of type pointer to object,
5813 qualification conversions (_conv.qual_) and the array-to-pointer
5814 conversion (_conv.array_) are applied. */
5816 {
5817 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5819 A template-argument for a non-type, non-template template-parameter
5820 shall be one of: [...]
5822 -- the name of a non-type template-parameter;
5823 -- the address of an object or function with external linkage, [...]
5824 expressed as "& id-expression" where the & is optional if the name
5825 refers to a function or array, or if the corresponding
5826 template-parameter is a reference.
5828 Here, we do not care about functions, as they are invalid anyway
5829 for a parameter of type pointer-to-object. */
5832 /* Non-type template parameters are OK. */
5833 ;
5838 {
5840 {
5842 "because %qD is a variable, not the address of "
5846 }
5848 {
5853 }
5854 /* Other values, like integer constants, might be valid
5855 non-type arguments of some other type. */
5857 }
5858 else
5859 {
5860 tree decl;
5865 {
5870 }
5872 {
5877 }
5879 {
5884 }
5885 }
5894 }
5895 /* [temp.arg.nontype]/5, bullet 3
5897 For a non-type template-parameter of type reference to object, no
5898 conversions apply. The type referred to by the reference may be more
5899 cv-qualified than the (otherwise identical) type of the
5900 template-argument. The template-parameter is bound directly to the
5901 template-argument, which must be an lvalue. */
5903 {
5905 expr_type))
5909 {
5913 }
5916 {
5920 }
5922 /* [temp.arg.nontype]/1
5924 A template-argument for a non-type, non-template template-parameter
5925 shall be one of: [...]
5927 -- the address of an object or function with external linkage. */
5930 {
5933 {
5935 "because a reference variable does not have a constant "
5938 }
5939 }
5942 {
5947 }
5950 {
5955 }
5958 }
5959 /* [temp.arg.nontype]/5, bullet 4
5961 For a non-type template-parameter of type pointer to function, only
5962 the function-to-pointer conversion (_conv.func_) is applied. If the
5963 template-argument represents a set of overloaded functions (or a
5964 pointer to such), the matching function is selected from the set
5965 (_over.over_). */
5967 {
5968 /* If the argument is a template-id, we might not have enough
5969 context information to decay the pointer. */
5971 {
5975 }
5978 /* Null pointer values are OK in C++11. */
5984 }
5985 /* [temp.arg.nontype]/5, bullet 5
5987 For a non-type template-parameter of type reference to function, no
5988 conversions apply. If the template-argument represents a set of
5989 overloaded functions, the matching function is selected from the set
5990 (_over.over_). */
5992 {
5994 {
5999 }
6006 }
6007 /* [temp.arg.nontype]/5, bullet 6
6009 For a non-type template-parameter of type pointer to member function,
6010 no conversions apply. If the template-argument represents a set of
6011 overloaded member functions, the matching member function is selected
6012 from the set (_over.over_). */
6014 {
6019 /* [temp.arg.nontype] bullet 1 says the pointer to member
6020 expression must be a pointer-to-member constant. */
6024 /* There is no way to disable standard conversions in
6025 resolve_address_of_overloaded_function (called by
6026 instantiate_type). It is possible that the call succeeded by
6027 converting &B::I to &D::I (where B is a base of D), so we need
6028 to reject this conversion here.
6030 Actually, even if there was a way to disable standard conversions,
6031 it would still be better to reject them here so that we can
6032 provide a superior diagnostic. */
6034 {
6038 /* If we are just one standard conversion off, explain. */
6043 }
6044 }
6045 /* [temp.arg.nontype]/5, bullet 7
6047 For a non-type template-parameter of type pointer to data member,
6048 qualification conversions (_conv.qual_) are applied. */
6050 {
6051 /* [temp.arg.nontype] bullet 1 says the pointer to member
6052 expression must be a pointer-to-member constant. */
6059 }
6061 {
6063 {
6067 }
6069 }
6070 /* A template non-type parameter must be one of the above. */
6071 else
6074 /* Sanity check: did we actually convert the argument to the
6075 right type? */
6079 }
6081 /* Subroutine of coerce_template_template_parms, which returns 1 if
6082 PARM_PARM and ARG_PARM match using the rule for the template
6083 parameters of template template parameters. Both PARM and ARG are
6084 template parameters; the rest of the arguments are the same as for
6085 coerce_template_template_parms.
6086 */
6087 static int
6089 tree arg,
6090 tsubst_flags_t complain,
6091 tree in_decl,
6092 tree outer_args)
6093 {
6102 {
6104 /* We encounter instantiations of templates like
6105 template <template <template <class> class> class TT>
6106 class C; */
6107 {
6114 }
6115 /* Fall through. */
6120 /* Argument is a parameter pack but parameter is not. */
6125 /* The tsubst call is used to handle cases such as
6127 template <int> class C {};
6128 template <class T, template <T> class TT> class D {};
6129 D<int, C> d;
6131 i.e. the parameter list of TT depends on earlier parameters. */
6133 && !same_type_p
6140 /* Argument is a parameter pack but parameter is not. */
6147 }
6150 }
6153 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6154 template template parameters. Both PARM_PARMS and ARG_PARMS are
6155 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6156 or PARM_DECL.
6158 Consider the example:
6159 template <class T> class A;
6160 template<template <class U> class TT> class B;
6162 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6163 the parameters to A, and OUTER_ARGS contains A. */
6165 static int
6167 tree arg_parms,
6168 tsubst_flags_t complain,
6169 tree in_decl,
6170 tree outer_args)
6171 {
6182 /* Determine whether we have a parameter pack at the end of the
6183 template template parameter's template parameter list. */
6185 {
6192 {
6206 }
6207 }
6213 /* Check all of the template parameters except the parameter pack at
6214 the end (if any). */
6216 {
6225 outer_args))
6228 }
6231 {
6232 /* Check each of the template parameters in the template
6233 argument against the template parameter pack at the end of
6234 the template template parameter. */
6241 {
6248 outer_args))
6250 }
6251 }
6254 }
6256 /* Verifies that the deduced template arguments (in TARGS) for the
6257 template template parameters (in TPARMS) represent valid bindings,
6258 by comparing the template parameter list of each template argument
6259 to the template parameter list of its corresponding template
6260 template parameter, in accordance with DR150. This
6261 routine can only be called after all template arguments have been
6262 deduced. It will return TRUE if all of the template template
6263 parameter bindings are okay, FALSE otherwise. */
6264 bool
6266 {
6270 /* We're dealing with template parms in this process. */
6276 {
6281 {
6286 {
6287 /* Look inside the argument pack. */
6290 }
6293 {
6297 /* Extract the next argument from the argument
6298 pack. */
6302 /* Look at the pattern of the pack expansion. */
6305 /* Extract the template parameters from the template
6306 argument. */
6312 /* Verify that we can coerce the template template
6313 parameters from the template argument to the template
6314 parameter. This requires an exact match. */
6316 && !coerce_template_template_parms
6318 targ_parms,
6319 tf_none,
6320 tparm,
6321 targs))
6322 {
6325 }
6326 }
6327 }
6328 }
6330 out:
6334 }
6336 /* Since type attributes aren't mangled, we need to strip them from
6337 template type arguments. */
6339 static tree
6341 {
6342 tree mv;
6349 {
6354 }
6356 }
6358 /* Convert the indicated template ARG as necessary to match the
6359 indicated template PARM. Returns the converted ARG, or
6360 error_mark_node if the conversion was unsuccessful. Error and
6361 warning messages are issued under control of COMPLAIN. This
6362 conversion is for the Ith parameter in the parameter list. ARGS is
6363 the full set of template arguments deduced so far. */
6365 static tree
6367 tree arg,
6368 tree args,
6369 tsubst_flags_t complain,
6371 tree in_decl)
6372 {
6373 tree orig_arg;
6374 tree val;
6379 {
6380 /* The template argument was the name of some
6381 member function. That's usually
6382 invalid, but static members are OK. In any
6383 case, grab the underlying fields/functions
6384 and issue an error later if required. */
6387 }
6395 /* When determining whether an argument pack expansion is a template,
6396 look at the pattern. */
6400 /* Deal with an injected-class-name used as a template template arg. */
6402 {
6405 {
6415 }
6416 }
6418 is_tmpl_type =
6434 {
6436 {
6440 }
6443 "to refer to a type member of a template parameter, "
6448 typename_type,
6449 complain);
6452 }
6454 {
6456 {
6458 {
6468 else
6470 }
6471 }
6473 }
6475 {
6477 {
6483 else
6485 }
6487 }
6490 {
6492 {
6496 /* The number of argument required is not known yet.
6497 Just accept it for now. */
6499 else
6500 {
6502 tree argparm;
6504 /* Strip alias templates that are equivalent to another
6505 template. */
6511 args))
6512 {
6515 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6516 TEMPLATE_DECL. */
6518 {
6523 }
6524 }
6525 else
6526 {
6528 {
6534 }
6537 }
6538 }
6539 }
6540 else
6542 /* We only form one instance of each template specialization.
6543 Therefore, if we use a non-canonical variant (i.e., a
6544 typedef), any future messages referring to the type will use
6545 the typedef, which is confusing if those future uses do not
6546 themselves also use the typedef. */
6549 }
6550 else
6551 {
6558 {
6561 else
6562 {
6563 /* Not sure if this is reachable, but it doesn't hurt
6564 to be robust. */
6567 }
6568 }
6571 /* We used to call digest_init here. However, digest_init
6572 will report errors, which we don't want when complain
6573 is zero. More importantly, digest_init will try too
6574 hard to convert things: for example, `0' should not be
6575 converted to pointer type at this point according to
6576 the standard. Accepting this is not merely an
6577 extension, since deciding whether or not these
6578 conversions can occur is part of determining which
6579 function template to call, or whether a given explicit
6580 argument specification is valid. */
6582 else
6591 {
6592 /* Strip typedefs from the SCOPE_REF. */
6595 complain);
6598 }
6599 }
6602 }
6604 /* Coerces the remaining template arguments in INNER_ARGS (from
6605 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6606 Returns the coerced argument pack. PARM_IDX is the position of this
6607 parameter in the template parameter list. ARGS is the original
6608 template argument list. */
6609 static tree
6612 tree args,
6613 tree inner_args,
6615 tree new_args,
6617 tree in_decl,
6618 tsubst_flags_t complain)
6619 {
6622 tree packed_args;
6623 tree argument_pack;
6630 {
6631 /* When the template parameter is a non-type template parameter pack
6632 or template template parameter pack whose type or template
6633 parameters use parameter packs, we know exactly how many arguments
6634 we are looking for. Build a vector of the instantiated decls for
6635 these template parameters in PACKED_PARMS. */
6636 /* We can't use make_pack_expansion here because it would interpret a
6637 _DECL as a use rather than a declaration. */
6651 /* If we're doing a partial instantiation of a member template,
6652 verify that all of the types used for the non-type
6653 template parameter pack are, in fact, valid for non-type
6654 template parameters. */
6657 {
6660 {
6664 }
6665 }
6668 }
6669 else
6672 /* Convert the remaining arguments, which will be a part of the
6673 parameter pack "parm". */
6675 {
6681 {
6682 /* Once we've packed as many args as we have types, stop. */
6686 /* We don't know how many args we have yet, just
6687 use the unconverted ones for now. */
6689 else
6691 }
6694 {
6697 }
6698 else
6701 in_decl);
6705 }
6709 {
6713 }
6718 else
6719 {
6724 }
6727 #ifdef ENABLE_CHECKING
6730 #endif
6732 }
6734 /* Returns the number of pack expansions in the template argument vector
6735 ARGS. */
6737 static int
6739 {
6744 {
6748 }
6750 }
6752 /* Convert all template arguments to their appropriate types, and
6753 return a vector containing the innermost resulting template
6754 arguments. If any error occurs, return error_mark_node. Error and
6755 warning messages are issued under control of COMPLAIN.
6757 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6758 for arguments not specified in ARGS. Otherwise, if
6759 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6760 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6761 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6762 ARGS. */
6764 static tree
6766 tree args,
6767 tree in_decl,
6768 tsubst_flags_t complain,
6771 {
6773 tree orig_inner_args;
6774 tree inner_args;
6775 tree new_args;
6776 tree new_inner_args;
6780 /* When used as a boolean value, indicates whether this is a
6781 variadic template parameter list. Since it's an int, we can also
6782 subtract it from nparms to get the number of non-variadic
6783 parameters. */
6793 /* Determine if there are any parameter packs. */
6795 {
6801 }
6804 /* If there are no parameters that follow a parameter pack, we need to
6805 expand any argument packs so that we can deduce a parameter pack from
6806 some non-packed args followed by an argument pack, as in variadic85.C.
6807 If there are such parameters, we need to leave argument packs intact
6808 so the arguments are assigned properly. This can happen when dealing
6809 with a nested class inside a partial specialization of a class
6810 template, as in variadic92.C, or when deducing a template parameter pack
6811 from a sub-declarator, as in variadic114.C. */
6815 /* Count any pack expansion args. */
6821 && require_all_args
6822 && !variadic_args_p
6823 && (!use_default_args
6826 {
6828 {
6830 {
6834 }
6835 else
6841 }
6844 }
6845 /* We can't pass a pack expansion to a non-pack parameter of an alias
6846 template (DR 1430). */
6848 && variadic_args_p
6850 {
6852 {
6854 {
6860 {
6865 }
6866 }
6868 found:;
6869 }
6871 }
6873 /* We need to evaluate the template arguments, even though this
6874 template-id may be nested within a "sizeof". */
6883 {
6884 tree arg;
6885 tree parm;
6887 /* Get the Ith template parameter. */
6891 {
6894 }
6896 /* Calculate the next argument. */
6899 else
6904 {
6905 /* Some arguments will be placed in the
6906 template parameter pack PARM. */
6913 {
6914 /* We don't know how many args we have yet, just use the
6915 unconverted (and still packed) ones for now. */
6919 }
6923 /* Store this argument. */
6925 {
6926 lost++;
6927 /* We are done with all of the arguments. */
6929 }
6930 else
6931 {
6934 }
6937 }
6939 {
6941 {
6942 /* We don't know how many args we have yet, just
6943 use the unconverted ones for now. */
6947 }
6948 }
6950 {
6951 /* There must be a default arg in this case. */
6954 /* The position of the first default template argument,
6955 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6956 Record that. */
6960 }
6961 else
6965 {
6968 }
6970 /* This only occurs if there was an error in the template
6971 parameter list itself (which we would already have
6972 reported) that we are trying to recover from, e.g., a class
6973 template with a parameter list such as
6974 template<typename..., typename>. */
6976 else
6982 lost++;
6984 }
6989 {
6991 {
6996 }
6998 }
7003 #ifdef ENABLE_CHECKING
7007 #endif
7010 }
7012 /* Like coerce_template_parms. If PARMS represents all template
7013 parameters levels, this function returns a vector of vectors
7014 representing all the resulting argument levels. Note that in this
7015 case, only the innermost arguments are coerced because the
7016 outermost ones are supposed to have been coerced already.
7018 Otherwise, if PARMS represents only (the innermost) vector of
7019 parameters, this function returns a vector containing just the
7020 innermost resulting arguments. */
7022 static tree
7024 tree args,
7025 tree in_decl,
7026 tsubst_flags_t complain,
7029 {
7032 tree coerced_args;
7035 {
7037 tree level;
7043 {
7044 tree l;
7048 require_all_args,
7049 use_default_args);
7050 else
7057 }
7058 }
7059 else
7062 require_all_args,
7063 use_default_args);
7065 }
7067 /* Returns 1 if template args OT and NT are equivalent. */
7069 static int
7071 {
7078 /* For member templates */
7087 {
7104 }
7106 {
7107 /* We get here probably because we are in the middle of substituting
7108 into the pattern of a pack expansion. In that case the
7109 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
7110 interested in. So we want to use the initial pack argument for
7111 the comparison. */
7116 }
7121 else
7123 }
7125 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7126 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7127 NEWARG_PTR with the offending arguments if they are non-NULL. */
7129 static int
7132 {
7145 {
7150 {
7156 }
7157 }
7159 }
7161 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7162 of template arguments. Returns 0 otherwise. */
7164 int
7166 {
7168 }
7170 static void
7172 {
7182 /* We are called both from instantiate_decl, where we've already had a
7183 tinst_level pushed, and instantiate_template, where we haven't.
7184 Compensate. */
7195 else
7204 }
7207 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7208 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7209 documentation for TEMPLATE_ID_EXPR. */
7211 tree
7213 {
7214 tree type;
7222 {
7225 }
7228 {
7230 unknown_type_node,
7232 arglist);
7234 }
7241 }
7243 /* Within the scope of a template class S<T>, the name S gets bound
7244 (in build_self_reference) to a TYPE_DECL for the class, not a
7245 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7246 or one of its enclosing classes, and that type is a template,
7247 return the associated TEMPLATE_DECL. Otherwise, the original
7248 DECL is returned.
7250 Also handle the case when DECL is a TREE_LIST of ambiguous
7251 injected-class-names from different bases. */
7253 tree
7255 {
7259 /* DR 176: A lookup that finds an injected-class-name (10.2
7260 [class.member.lookup]) can result in an ambiguity in certain cases
7261 (for example, if it is found in more than one base class). If all of
7262 the injected-class-names that are found refer to specializations of
7263 the same class template, and if the name is followed by a
7264 template-argument-list, the reference refers to the class template
7265 itself and not a specialization thereof, and is not ambiguous. */
7267 {
7270 {
7276 }
7279 else
7281 }
7287 }
7289 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
7290 parameters, find the desired type.
7292 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7294 IN_DECL, if non-NULL, is the template declaration we are trying to
7295 instantiate.
7297 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7298 the class we are looking up.
7300 Issue error and warning messages under control of COMPLAIN.
7302 If the template class is really a local class in a template
7303 function, then the FUNCTION_CONTEXT is the function in which it is
7304 being instantiated.
7306 ??? Note that this function is currently called *twice* for each
7307 template-id: the first time from the parser, while creating the
7308 incomplete type (finish_template_type), and the second type during the
7309 real instantiation (instantiate_template_class). This is surely something
7310 that we want to avoid. It also causes some problems with argument
7311 coercion (see convert_nontype_argument for more information on this). */
7313 static tree
7316 {
7318 tree t;
7321 spec_entry elt;
7322 hashval_t hash;
7325 {
7329 else
7330 {
7337 }
7340 }
7342 {
7345 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7346 an implicit typename for the second A. Deal with it. */
7351 {
7354 }
7355 }
7358 {
7361 }
7365 {
7369 }
7371 {
7374 }
7376 /* Issue an error message if we didn't find a template. */
7378 {
7382 }
7385 /* Make sure it's a user visible template, if it was named by
7386 the user. */
7389 {
7391 {
7395 }
7397 }
7401 /* An alias that just changes the name of a template is equivalent to the
7402 other template, so if any of the arguments are pack expansions, strip
7403 the alias to avoid problems with a pack expansion passed to a non-pack
7404 alias template parameter (DR 1430). */
7409 {
7410 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7411 template arguments */
7413 tree parm;
7414 tree arglist2;
7415 tree outer;
7419 /* Consider an example where a template template parameter declared as
7421 template <class T, class U = std::allocator<T> > class TT
7423 The template parameter level of T and U are one level larger than
7424 of TT. To proper process the default argument of U, say when an
7425 instantiation `TT<int>' is seen, we need to build the full
7426 arguments containing {int} as the innermost level. Outer levels,
7427 available when not appearing as default template argument, can be
7428 obtained from the arguments of the enclosing template.
7430 Suppose that TT is later substituted with std::vector. The above
7431 instantiation is `TT<int, std::allocator<T> >' with TT at
7432 level 1, and T at level 2, while the template arguments at level 1
7433 becomes {std::vector} and the inner level 2 is {int}. */
7439 /* This is an argument of the current template, so we haven't set
7440 DECL_CONTEXT yet. */
7447 complain,
7457 }
7458 else
7459 {
7461 tree gen_tmpl;
7462 tree type_decl;
7470 /* An error occurred while building the template TEMPL, and a
7471 diagnostic has most certainly been emitted for that
7472 already. Let's propagate that error. */
7481 {
7482 /* We've been given an incomplete set of template arguments.
7483 For example, given:
7485 template <class T> struct S1 {
7486 template <class U> struct S2 {};
7487 template <class U> struct S2<U*> {};
7488 };
7490 we will be called with an ARGLIST of `U*', but the
7491 TEMPLATE will be `template <class T> template
7492 <class U> struct S1<T>::S2'. We must fill in the missing
7493 arguments. */
7494 arglist
7496 arglist);
7498 }
7500 /* Now we should have enough arguments. */
7503 /* From here on, we're only interested in the most general
7504 template. */
7506 /* Calculate the BOUND_ARGS. These will be the args that are
7507 actually tsubst'd into the definition to create the
7508 instantiation. */
7510 {
7511 /* We have multiple levels of arguments to coerce, at once. */
7521 {
7522 tree a;
7526 complain,
7529 else
7530 /* Outer levels should have already been coerced. */
7533 /* Don't process further if one of the levels fails. */
7535 {
7536 /* Restore the ARGLIST to its full size. */
7539 }
7543 /* We temporarily reduce the length of the ARGLIST so
7544 that coerce_template_parms will see only the arguments
7545 corresponding to the template parameters it is
7546 examining. */
7548 }
7550 /* Restore the ARGLIST to its full size. */
7554 }
7555 else
7556 arglist
7559 gen_tmpl,
7560 complain,
7565 /* We were unable to bind the arguments. */
7568 /* In the scope of a template class, explicit references to the
7569 template class refer to the type of the template, not any
7570 instantiation of it. For example, in:
7572 template <class T> class C { void f(C<T>); }
7574 the `C<T>' is just the same as `C'. Outside of the
7575 class, however, such a reference is an instantiation. */
7579 /* comp_template_args is expensive, check it last. */
7581 arglist))
7584 /* If we already have this specialization, return it. */
7596 /* If the deduced arguments are invalid, then the binding
7597 failed. */
7601 complain))
7608 {
7613 }
7623 /* Create the type. */
7625 {
7626 /* The user referred to a specialization of an alias
7627 template represented by GEN_TMPL.
7629 [temp.alias]/2 says:
7631 When a template-id refers to the specialization of an
7632 alias template, it is equivalent to the associated
7633 type obtained by substitution of its
7634 template-arguments for the template-parameters in the
7635 type-id of the alias template. */
7638 /* Note that the call above (by indirectly calling
7639 register_specialization in tsubst_decl) registers the
7640 TYPE_DECL representing the specialization of the alias
7641 template. So next time someone substitutes ARGLIST for
7642 the template parms into the alias template (GEN_TMPL),
7643 she'll get that TYPE_DECL back. */
7647 }
7649 {
7651 {
7660 }
7661 else
7662 {
7663 /* We don't want to call start_enum for this type, since
7664 the values for the enumeration constants may involve
7665 template parameters. And, no one should be interested
7666 in the enumeration constants for such a type. */
7669 }
7673 }
7675 {
7682 /* A local class. Make sure the decl gets registered properly. */
7687 /* This instantiation is another name for the primary
7688 template type. Set the TYPE_CANONICAL field
7689 appropriately. */
7692 /* Some of the template arguments require structural
7693 equality testing, so this template class requires
7694 structural equality testing. */
7696 }
7697 else
7700 /* If we called start_enum or pushtag above, this information
7701 will already be set up. */
7703 {
7710 }
7711 else
7715 {
7721 {
7724 }
7725 }
7727 /* Let's consider the explicit specialization of a member
7728 of a class template specialization that is implicitly instantiated,
7729 e.g.:
7730 template<class T>
7731 struct S
7732 {
7733 template<class U> struct M {}; //#0
7734 };
7736 template<>
7737 template<>
7738 struct S<int>::M<char> //#1
7739 {
7740 int i;
7741 };
7742 [temp.expl.spec]/4 says this is valid.
7744 In this case, when we write:
7745 S<int>::M<char> m;
7747 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7748 the one of #0.
7750 When we encounter #1, we want to store the partial instantiation
7751 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
7753 For all cases other than this "explicit specialization of member of a
7754 class template", we just want to store the most general template into
7755 the CLASSTYPE_TI_TEMPLATE of M.
7757 This case of "explicit specialization of member of a class template"
7758 only happens when:
7759 1/ the enclosing class is an instantiation of, and therefore not
7760 the same as, the context of the most general template, and
7761 2/ we aren't looking at the partial instantiation itself, i.e.
7762 the innermost arguments are not the same as the innermost parms of
7763 the most general template.
7765 So it's only when 1/ and 2/ happens that we want to use the partial
7766 instantiation of the member template in lieu of its most general
7767 template. */
7771 /* the enclosing class must be an instantiation... */
7774 {
7775 tree partial_inst_args;
7778 partial_inst_args =
7784 use_partial_inst_tmpl =
7785 /*...and we must not be looking at the partial instantiation
7786 itself. */
7788 partial_inst_args);
7789 }
7792 /* This case is easy; there are no member templates involved. */
7794 else
7795 {
7796 /* This is a full instantiation of a member template. Find
7797 the partial instantiation of which this is an instance. */
7799 /* Temporarily reduce by one the number of levels in the ARGLIST
7800 so as to avoid comparing the last set of arguments. */
7804 /* FOUND is either a proper class type, or an alias
7805 template specialization. In the later case, it's a
7806 TYPE_DECL, resulting from the substituting of arguments
7807 for parameters in the TYPE_DECL of the alias template
7808 done earlier. So be careful while getting the template
7809 of FOUND. */
7813 }
7824 /* Note this use of the partial instantiation so we can check it
7825 later in maybe_process_partial_specialization. */
7832 /* Now that the type has been registered on the instantiations
7833 list, we set up the enumerators. Because the enumeration
7834 constants may involve the enumeration type itself, we make
7835 sure to register the type first, and then create the
7836 constants. That way, doing tsubst_expr for the enumeration
7837 constants won't result in recursive calls here; we'll find
7838 the instantiation and exit above. */
7842 /* If the type makes use of template parameters, the
7843 code that generates debugging information will crash. */
7846 /* Possibly limit visibility based on template args. */
7851 }
7852 }
7854 /* Wrapper for lookup_template_class_1. */
7856 tree
7859 {
7860 tree ret;
7866 }
7867 \f
7868 struct pair_fn_data
7869 {
7870 tree_fn_t fn;
7872 /* True when we should also visit template parameters that occur in
7873 non-deduced contexts. */
7876 };
7878 /* Called from for_each_template_parm via walk_tree. */
7880 static tree
7882 {
7895 {
7899 /* Fall through. */
7922 /* Since we're not going to walk subtrees, we have to do this
7923 explicitly here. */
7927 /* Fall through. */
7930 /* Check the return type. */
7935 /* Check the parameter types. Since default arguments are not
7936 instantiated until they are needed, the TYPE_ARG_TYPES may
7937 contain expressions that involve template parameters. But,
7938 no-one should be looking at them yet. And, once they're
7939 instantiated, they don't contain template parameters, so
7940 there's no point in looking at them then, either. */
7941 {
7942 tree parm;
7949 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7950 want walk_tree walking into them itself. */
7952 }
7970 /* Fall through. */
7986 /* Record template parameters such as `T' inside `TT<T>'. */
7990 /* Fall through. */
8002 /* A template template parameter is encountered. */
8008 /* Already substituted template template parameter */
8031 /* If there's no type, then this thing must be some expression
8032 involving template parameters. */
8054 }
8056 /* We didn't find any template parameters we liked. */
8058 }
8060 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
8061 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
8062 call FN with the parameter and the DATA.
8063 If FN returns nonzero, the iteration is terminated, and
8064 for_each_template_parm returns 1. Otherwise, the iteration
8065 continues. If FN never returns a nonzero value, the value
8066 returned by for_each_template_parm is 0. If FN is NULL, it is
8067 considered to be the function which always returns 1.
8069 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
8070 parameters that occur in non-deduced contexts. When false, only
8071 visits those template parameters that can be deduced. */
8073 static int
8077 {
8081 /* Set up. */
8086 /* Walk the tree. (Conceptually, we would like to walk without
8087 duplicates, but for_each_template_parm_r recursively calls
8088 for_each_template_parm, so we would need to reorganize a fair
8089 bit to use walk_tree_without_duplicates, so we keep our own
8090 visited list.) */
8093 else
8096 for_each_template_parm_r,
8100 /* Clean up. */
8102 {
8105 }
8108 }
8110 /* Returns true if T depends on any template parameter. */
8112 int
8114 {
8141 else
8142 {
8145 }
8150 }
8152 /* Returns true iff current_function_decl is an incompletely instantiated
8153 template. Useful instead of processing_template_decl because the latter
8154 is set to 0 during fold_non_dependent_expr. */
8156 bool
8158 {
8167 }
8169 /* Returns true if T depends on any template parameter with level LEVEL. */
8171 int
8173 {
8176 }
8178 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8179 ill-formed translation unit, i.e. a variable or function that isn't
8180 usable in a constant expression. */
8184 {
8188 }
8190 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8191 neglectable and instantiated from within an erroneous instantiation. */
8193 static bool
8195 {
8206 }
8214 /* We're starting to instantiate D; record the template instantiation context
8215 for diagnostics and to restore it later. */
8217 int
8219 {
8223 {
8229 else
8237 }
8239 /* If the current instantiation caused problems, don't let it instantiate
8240 anything else. Do allow deduction substitution and decls usable in
8241 constant expressions. */
8258 }
8260 /* We're done instantiating this template; return to the instantiation
8261 context. */
8263 void
8265 {
8266 /* Restore the filename and line number stashed away when we started
8267 this instantiation. */
8271 }
8273 /* We're instantiating a deferred template; restore the template
8274 instantiation context in which the instantiation was requested, which
8275 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8277 static tree
8279 {
8291 }
8293 /* Returns the TINST_LEVEL which gives the original instantiation
8294 context. */
8298 {
8304 }
8306 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8307 vector of template arguments, as for tsubst.
8309 Returns an appropriate tsubst'd friend declaration. */
8311 static tree
8313 {
8314 tree new_friend;
8319 /* This was a friend declared with an explicit template
8320 argument list, e.g.:
8322 friend void f<>(T);
8324 to indicate that f was a template instantiation, not a new
8325 function declaration. Now, we have to figure out what
8326 instantiation of what template. */
8327 {
8329 tree new_args;
8330 tree tmpl;
8333 /* Friend functions are looked up in the containing namespace scope.
8334 We must enter that scope, to avoid finding member functions of the
8335 current class with same name. */
8350 tsk_none);
8352 }
8356 /* The NEW_FRIEND will look like an instantiation, to the
8357 compiler, but is not an instantiation from the point of view of
8358 the language. For example, we might have had:
8360 template <class T> struct S {
8361 template <class U> friend void f(T, U);
8362 };
8364 Then, in S<int>, template <class U> void f(int, U) is not an
8365 instantiation of anything. */
8371 {
8375 }
8377 /* The mangled name for the NEW_FRIEND is incorrect. The function
8378 is not a template instantiation and should not be mangled like
8379 one. Therefore, we forget the mangling here; we'll recompute it
8380 later if we need it. */
8382 {
8385 }
8388 {
8389 tree old_decl;
8390 tree new_friend_template_info;
8391 tree new_friend_result_template_info;
8392 tree ns;
8395 /* We must save some information from NEW_FRIEND before calling
8396 duplicate decls since that function will free NEW_FRIEND if
8397 possible. */
8399 new_friend_is_defn =
8404 {
8405 /* This declaration is a `primary' template. */
8408 new_friend_result_template_info
8410 }
8411 else
8414 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8418 /* Inside pushdecl_namespace_level, we will push into the
8419 current namespace. However, the friend function should go
8420 into the namespace of the template. */
8430 {
8431 /* This new friend declaration matched an existing
8432 declaration. For example, given:
8434 template <class T> void f(T);
8435 template <class U> class C {
8436 template <class T> friend void f(T) {}
8437 };
8439 the friend declaration actually provides the definition
8440 of `f', once C has been instantiated for some type. So,
8441 old_decl will be the out-of-class template declaration,
8442 while new_friend is the in-class definition.
8444 But, if `f' was called before this point, the
8445 instantiation of `f' will have DECL_TI_ARGS corresponding
8446 to `T' but not to `U', references to which might appear
8447 in the definition of `f'. Previously, the most general
8448 template for an instantiation of `f' was the out-of-class
8449 version; now it is the in-class version. Therefore, we
8450 run through all specialization of `f', adding to their
8451 DECL_TI_ARGS appropriately. In particular, they need a
8452 new set of outer arguments, corresponding to the
8453 arguments for this class instantiation.
8455 The same situation can arise with something like this:
8457 friend void f(int);
8458 template <class T> class C {
8459 friend void f(T) {}
8460 };
8462 when `C<int>' is instantiated. Now, `f(int)' is defined
8463 in the class. */
8466 /* On the other hand, if the in-class declaration does
8467 *not* provide a definition, then we don't want to alter
8468 existing definitions. We can just leave everything
8469 alone. */
8470 ;
8471 else
8472 {
8476 /* Overwrite whatever template info was there before, if
8477 any, with the new template information pertaining to
8478 the declaration. */
8482 {
8483 /* We should have called reregister_specialization in
8484 duplicate_decls. */
8489 /* Instantiate it if the global has already been used. */
8493 }
8494 else
8495 {
8496 tree t;
8498 /* Indicate that the old function template is a partial
8499 instantiation. */
8507 /* Reassign any specializations already in the hash table
8508 to the new more general template, and add the
8509 additional template args. */
8513 {
8515 spec_entry elt;
8527 register_specialization
8530 }
8532 }
8533 }
8535 /* The information from NEW_FRIEND has been merged into OLD_DECL
8536 by duplicate_decls. */
8538 }
8539 }
8540 else
8541 {
8545 /* In the code
8546 template <class T> class C {
8547 template <class U> friend void C1<U>::f (); // case 1
8548 friend void C2<T>::f (); // case 2
8549 };
8550 we only need to make sure CONTEXT is a complete type for
8551 case 2. To distinguish between the two cases, we note that
8552 CONTEXT of case 1 remains dependent type after tsubst while
8553 this isn't true for case 2. */
8563 {
8565 /* do_friend adds the TEMPLATE_DECL for any member friend
8566 template even if it isn't a member template, i.e.
8567 template <class T> friend A<T>::f();
8568 Look through it in that case. */
8572 /* Check to see that the declaration is really present, and,
8573 possibly obtain an improved declaration. */
8578 }
8579 }
8582 }
8584 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8585 template arguments, as for tsubst.
8587 Returns an appropriate tsubst'd friend type or error_mark_node on
8588 failure. */
8590 static tree
8592 {
8593 tree friend_type;
8594 tree tmpl;
8595 tree context;
8598 {
8601 }
8606 {
8609 else
8611 }
8613 /* Look for a class template declaration. We look for hidden names
8614 because two friend declarations of the same template are the
8615 same. For example, in:
8617 struct A {
8618 template <typename> friend class F;
8619 };
8620 template <typename> struct B {
8621 template <typename> friend class F;
8622 };
8624 both F templates are the same. */
8628 /* But, if we don't find one, it might be because we're in a
8629 situation like this:
8631 template <class T>
8632 struct S {
8633 template <class U>
8634 friend struct S;
8635 };
8637 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8638 for `S<int>', not the TEMPLATE_DECL. */
8640 {
8643 }
8646 {
8647 /* The friend template has already been declared. Just
8648 check to see that the declarations match, and install any new
8649 default parameters. We must tsubst the default parameters,
8650 of course. We only need the innermost template parameters
8651 because that is all that redeclare_class_template will look
8652 at. */
8655 {
8656 tree parms;
8657 location_t saved_input_location;
8666 }
8669 }
8670 else
8671 {
8672 /* The friend template has not already been declared. In this
8673 case, the instantiation of the template class will cause the
8674 injection of this template into the global scope. */
8679 /* The new TMPL is not an instantiation of anything, so we
8680 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8681 the new type because that is supposed to be the corresponding
8682 template decl, i.e., TMPL. */
8689 /* Inject this template into the global scope. */
8691 }
8694 {
8697 else
8699 }
8702 }
8704 /* Returns zero if TYPE cannot be completed later due to circularity.
8705 Otherwise returns one. */
8707 static int
8709 {
8719 else
8721 }
8725 /* Apply any attributes which had to be deferred until instantiation
8726 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8727 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8729 static void
8732 {
8734 tree t;
8739 {
8743 }
8746 {
8750 }
8751 else
8755 {
8760 {
8763 {
8770 {
8777 clauses
8781 else
8783 }
8784 /* If the first attribute argument is an identifier, don't
8785 pass it through tsubst. Attributes like mode, format,
8786 cleanup and several target specific attributes expect it
8787 unmodified. */
8790 {
8791 tree chain
8793 in_decl,
8798 chain);
8799 }
8800 else
8806 }
8807 else
8809 }
8812 }
8813 }
8815 /* Perform (or defer) access check for typedefs that were referenced
8816 from within the template TMPL code.
8817 This is a subroutine of instantiate_decl and instantiate_class_template.
8818 TMPL is the template to consider and TARGS is the list of arguments of
8819 that template. */
8821 static void
8823 {
8824 location_t saved_location;
8835 {
8847 /* Make access check error messages point to the location
8848 of the use of the typedef. */
8852 tf_warning_or_error);
8853 }
8855 }
8857 static tree
8859 {
8861 tree typedecl;
8862 tree pbinfo;
8863 tree base_list;
8865 tree fn_context;
8874 /* Figure out which template is being instantiated. */
8878 /* Determine what specialization of the original template to
8879 instantiate. */
8882 {
8885 }
8887 {
8888 /* This TYPE is actually an instantiation of a partial
8889 specialization. We replace the innermost set of ARGS with
8890 the arguments appropriate for substitution. For example,
8891 given:
8893 template <class T> struct S {};
8894 template <class T> struct S<T*> {};
8896 and supposing that we are instantiating S<int*>, ARGS will
8897 presently be {int*} -- but we need {int}. */
8900 }
8901 else
8902 {
8905 }
8907 /* If the template we're instantiating is incomplete, then clearly
8908 there's nothing we can do. */
8912 /* If we've recursively instantiated too many templates, stop. */
8916 /* Now we're really doing the instantiation. Mark the type as in
8917 the process of being defined. */
8920 /* We may be in the middle of deferred access check. Disable
8921 it now. */
8927 /* Use #pragma pack from the template context. */
8933 /* Set the input location to the most specialized template definition.
8934 This is needed if tsubsting causes an error. */
8946 {
8949 /* Adjust visibility for template arguments. */
8951 }
8957 /* We should never instantiate a nested class before its enclosing
8958 class; we need to look up the nested class by name before we can
8959 instantiate it, and that lookup should instantiate the enclosing
8960 class. */
8966 {
8967 tree pbase_binfo;
8968 tree pushed_scope;
8971 /* We must enter the scope containing the type, as that is where
8972 the accessibility of types named in dependent bases are
8973 looked up from. */
8976 /* Substitute into each of the bases to determine the actual
8977 basetypes. */
8979 {
8980 tree base;
8986 {
8987 expanded_bases =
8994 }
8997 {
8999 /* Extract the already-expanded base class. */
9001 else
9002 /* Substitute to figure out the base class. */
9004 NULL_TREE);
9012 }
9013 }
9015 /* The list is now in reverse order; correct that. */
9020 }
9021 /* Now call xref_basetypes to set up all the base-class
9022 information. */
9030 /* Now that our base classes are set up, enter the scope of the
9031 class, so that name lookups into base classes, etc. will work
9032 correctly. This is precisely analogous to what we do in
9033 begin_class_definition when defining an ordinary non-template
9034 class, except we also need to push the enclosing classes. */
9037 /* Now members are processed in the order of declaration. */
9040 {
9044 {
9046 {
9047 /* Build new CLASSTYPE_NESTED_UTDS. */
9049 tree newtag;
9055 /* If the member is a class template, then -- even after
9056 substitution -- there may be dependent types in the
9057 template argument list for the class. We increment
9058 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
9059 that function will assume that no types are dependent
9060 when outside of a template. */
9070 {
9074 /* Unfortunately, lookup_template_class sets
9075 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
9076 instantiation (i.e., for the type of a member
9077 template class nested within a template class.)
9078 This behavior is required for
9079 maybe_process_partial_specialization to work
9080 correctly, but is not accurate in this case;
9081 the TAG is not an instantiation of anything.
9082 (The corresponding TEMPLATE_DECL is an
9083 instantiation, but the TYPE is not.) */
9086 /* Now, we call pushtag to put this NEWTAG into the scope of
9087 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
9088 pushtag calling push_template_decl. We don't have to do
9089 this for enums because it will already have been done in
9090 tsubst_enum. */
9094 }
9095 }
9097 {
9098 /* Build new TYPE_METHODS. */
9099 tree r;
9108 /* Instantiate members marked with attribute used. */
9114 }
9115 else
9116 {
9117 /* Build new TYPE_FIELDS. */
9119 {
9120 tree condition;
9123 condition =
9133 }
9135 {
9136 tree r;
9140 /* The file and line for this declaration, to
9141 assist in error message reporting. Since we
9142 called push_tinst_level above, we don't need to
9143 restore these. */
9153 {
9154 /* A capture pack became multiple fields. */
9157 }
9160 {
9164 {
9165 /* In [temp.inst]:
9167 [t]he initialization (and any associated
9168 side-effects) of a static data member does
9169 not occur unless the static data member is
9170 itself used in a way that requires the
9171 definition of the static data member to
9172 exist.
9174 Therefore, we do not substitute into the
9175 initialized for the static data member here. */
9176 finish_static_data_member_decl
9182 /* Instantiate members marked with attribute used. */
9185 }
9187 {
9188 /* Determine whether R has a valid type and can be
9189 completed later. If R is invalid, then its type
9190 is replaced by error_mark_node. */
9196 {
9199 }
9200 }
9202 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9203 such a thing will already have been added to the field
9204 list by tsubst_enum in finish_member_declaration in the
9205 CLASSTYPE_NESTED_UTDS case above. */
9209 {
9212 }
9213 }
9214 }
9215 }
9216 }
9217 else
9218 {
9221 {
9222 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9228 {
9229 /* template <class T> friend class C; */
9232 }
9234 {
9235 /* template <class T> friend class C::D; */
9241 }
9244 {
9245 /* This could be either
9247 friend class T::C;
9249 when dependent_type_p is false or
9251 template <class U> friend class T::C;
9253 otherwise. */
9256 /* Bump processing_template_decl for correct
9257 dependent_type_p calculation. */
9262 }
9265 {
9266 /* friend class C;
9268 where C hasn't been declared yet. Let's lookup name
9269 from namespace scope directly, bypassing any name that
9270 come from dependent base class. */
9273 /* The call to xref_tag_from_type does injection for friend
9274 classes. */
9276 friend_type =
9280 }
9282 /* friend class C<T>; */
9285 /* Otherwise it's
9287 friend class C;
9289 where C is already declared or
9291 friend class C<int>;
9293 We don't have to do anything in these cases. */
9296 /* Trick make_friend_class into realizing that the friend
9297 we're adding is a template, not an ordinary class. It's
9298 important that we use make_friend_class since it will
9299 perform some error-checking and output cross-reference
9300 information. */
9308 }
9309 else
9310 {
9311 /* Build new DECL_FRIENDLIST. */
9312 tree r;
9314 /* The file and line for this declaration, to
9315 assist in error message reporting. Since we
9316 called push_tinst_level above, we don't need to
9317 restore these. */
9321 {
9324 }
9329 {
9332 }
9333 }
9334 }
9335 }
9338 {
9341 {
9346 /* We need to instantiate the capture list from the template
9347 after we've instantiated the closure members, but before we
9348 consider adding the conversion op. Also keep any captures
9349 that may have been added during instantiation of the op(). */
9351 tree tmpl_cap
9360 }
9361 else
9363 }
9365 /* Set the file and line number information to whatever is given for
9366 the class itself. This puts error messages involving generated
9367 implicit functions at a predictable point, and the same point
9368 that would be used for non-template classes. */
9375 /* We don't instantiate default arguments for member functions. 14.7.1:
9377 The implicit instantiation of a class template specialization causes
9378 the implicit instantiation of the declarations, but not of the
9379 definitions or default arguments, of the class member functions,
9380 member classes, static data members and member templates.... */
9382 /* Some typedefs referenced from within the template code need to be access
9383 checked at template instantiation time, i.e now. These types were
9384 added to the template at parsing time. Let's get those and perform
9385 the access checks then. */
9395 /* The vtable for a template class can be emitted in any translation
9396 unit in which the class is instantiated. When there is no key
9397 method, however, finish_struct_1 will already have added TYPE to
9398 the keyed_classes list. */
9403 }
9405 /* Wrapper for instantiate_class_template_1. */
9407 tree
9409 {
9410 tree ret;
9415 }
9417 static tree
9419 {
9420 tree r;
9426 else
9427 {
9434 }
9436 }
9438 /* Given a function parameter pack TMPL_PARM and some function parameters
9439 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9440 and set *SPEC_P to point at the next point in the list. */
9442 static tree
9444 {
9445 /* Collect all of the extra "packed" parameters into an
9446 argument pack. */
9447 tree parmvec;
9448 tree parmtypevec;
9459 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9464 {
9467 }
9469 /* Build the argument packs. */
9476 }
9478 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9479 NONTYPE_ARGUMENT_PACK. */
9481 static tree
9483 {
9485 }
9487 /* Return true iff the Ith element of the argument pack ARG_PACK is a
9488 pack expansion. */
9490 static bool
9492 {
9497 }
9500 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9502 static tree
9504 {
9511 }
9513 /* This is a subroutine of tsubst_pack_expansion.
9515 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9516 mechanism to store the (non complete list of) arguments of the
9517 substitution and return a non substituted pack expansion, in order
9518 to wait for when we have enough arguments to really perform the
9519 substitution. */
9521 static bool
9525 {
9526 /* If one pack has an expansion and another pack has a normal
9527 argument or if one pack has an empty argument and an another
9528 one hasn't then tsubst_pack_expansion cannot perform the
9529 substitution and need to fall back on the
9530 PACK_EXPANSION_EXTRA mechanism. */
9538 {
9541 parm_pack;
9543 {
9548 else
9550 }
9554 }
9556 }
9558 /* [temp.variadic]/6 says that:
9560 The instantiation of a pack expansion [...]
9561 produces a list E1,E2, ..., En, where N is the number of elements
9562 in the pack expansion parameters.
9564 This subroutine of tsubst_pack_expansion produces one of these Ei.
9566 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9567 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9568 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9569 INDEX is the index 'i' of the element Ei to produce. ARGS,
9570 COMPLAIN, and IN_DECL are the same parameters as for the
9571 tsubst_pack_expansion function.
9573 The function returns the resulting Ei upon successful completion,
9574 or error_mark_node.
9576 Note that this function possibly modifies the ARGS parameter, so
9577 it's the responsibility of the caller to restore it. */
9579 static tree
9581 tree parm_packs,
9583 tree args /* This parm gets
9585 tsubst_flags_t complain,
9586 tree in_decl)
9587 {
9588 tree t;
9591 /* For each parameter pack, change the substitution of the parameter
9592 pack to the ith argument in its argument pack, then expand the
9593 pattern. */
9595 {
9600 ith_elem_is_expansion |=
9603 /* Select the Ith argument from the pack. */
9606 {
9608 {
9612 }
9613 else
9615 }
9616 else
9617 {
9622 {
9624 /* Update the corresponding argument. */
9626 }
9627 else
9628 /* Re-use the ARGUMENT_PACK_SELECT. */
9630 }
9632 }
9634 /* Substitute into the PATTERN with the (possibly altered)
9635 arguments. */
9637 /* Expanding a fixed parameter pack from
9638 coerce_template_parameter_pack. */
9643 else
9646 /* If the Ith argument pack element is a pack expansion, then
9647 the Ith element resulting from the substituting is going to
9648 be a pack expansion as well. */
9653 }
9655 /* Substitute ARGS into T, which is an pack expansion
9656 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9657 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9658 (if only a partial substitution could be performed) or
9659 ERROR_MARK_NODE if there was an error. */
9660 tree
9662 tree in_decl)
9663 {
9664 tree pattern;
9668 tree result;
9676 /* Add in any args remembered from an earlier partial instantiation. */
9681 /* Determine the argument packs that will instantiate the parameter
9682 packs used in the expansion expression. While we're at it,
9683 compute the number of arguments to be expanded and make sure it
9684 is consistent. */
9687 {
9694 {
9698 else
9701 }
9703 {
9706 else
9707 {
9708 /* We can't rely on local_specializations for a parameter
9709 name used later in a function declaration (such as in a
9710 late-specified return type). Even if it exists, it might
9711 have the wrong value for a recursive call. Just make a
9712 dummy decl, since it's only used for its type. */
9715 /* Partial instantiation of the parm_pack, we can't build
9716 up an argument pack yet. */
9718 else
9721 }
9722 }
9725 else
9726 {
9732 }
9739 /* This can only happen if we forget to expand an argument
9740 pack somewhere else. Just return an error, silently. */
9741 {
9745 }
9748 {
9752 /* Don't bother trying to do a partial substitution with
9753 incomplete packs; we'll try again after deduction. */
9760 {
9766 pattern);
9767 else
9770 pattern);
9772 }
9774 /* Keep track of the parameter packs and their corresponding
9775 argument packs. */
9778 }
9779 else
9780 {
9781 /* We can't substitute for this parameter pack. We use a flag as
9782 well as the missing_level counter because function parameter
9783 packs don't have a level. */
9785 }
9786 }
9788 /* We cannot expand this expansion expression, because we don't have
9789 all of the argument packs we need. */
9791 {
9792 /* We got some full packs, but we can't substitute them in until we
9793 have values for all the packs. So remember these until then. */
9798 }
9800 {
9801 /* There were no real arguments, we're just replacing a parameter
9802 pack with another version of itself. Substitute into the
9803 pattern and return a PACK_EXPANSION_*. The caller will need to
9804 deal with that. */
9808 else
9812 }
9817 {
9818 /* We're in a late-specified return type, so create our own local
9819 specializations map; the current map is either NULL or (in the
9820 case of recursive unification) might have bindings that we don't
9821 want to use or alter. */
9824 }
9826 /* For each argument in each argument pack, substitute into the
9827 pattern. */
9830 {
9832 i,
9834 in_decl);
9837 {
9840 }
9841 }
9843 /* Update ARGS to restore the substitution from parameter packs to
9844 their argument packs. */
9846 {
9852 else
9853 {
9861 /* Update the corresponding argument. */
9865 else
9867 }
9868 }
9871 {
9874 }
9877 }
9879 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9880 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9881 parameter packs; all parms generated from a function parameter pack will
9882 have the same DECL_PARM_INDEX. */
9884 tree
9886 {
9888 tree patparm;
9891 {
9897 }
9898 else
9899 {
9904 }
9907 }
9909 /* Substitute ARGS into the vector or list of template arguments T. */
9911 static tree
9913 {
9925 {
9927 tree new_arg;
9932 {
9933 /* Substitute into an expansion expression. */
9937 /* Add to the expanded length adjustment the number of
9938 expanded arguments. We subtract one from this
9939 measurement, because the argument pack expression
9940 itself is already counted as 1 in
9941 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9942 the argument pack is empty. */
9944 }
9946 {
9947 /* Substitute into each of the arguments. */
9953 new_arg,
9967 }
9968 }
9969 else
9978 }
9983 /* Make space for the expanded arguments coming from template
9984 argument packs. */
9986 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9987 arguments for a member template.
9988 In that case each TREE_VEC in ORIG_T represents a level of template
9989 arguments, and ORIG_T won't carry any non defaulted argument count.
9990 It will rather be the nested TREE_VECs that will carry one.
9991 In other words, ORIG_T carries a non defaulted argument count only
9992 if it doesn't contain any nested TREE_VEC. */
9994 {
9998 }
10000 {
10004 {
10007 /* Now expand the template argument pack "in place". */
10010 }
10011 else
10012 {
10014 out++;
10015 }
10016 }
10019 }
10021 /* Return the result of substituting ARGS into the template parameters
10022 given by PARMS. If there are m levels of ARGS and m + n levels of
10023 PARMS, then the result will contain n levels of PARMS. For
10024 example, if PARMS is `template <class T> template <class U>
10025 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
10026 result will be `template <int*, double, class V>'. */
10028 static tree
10030 {
10034 /* When substituting into a template, we must set
10035 PROCESSING_TEMPLATE_DECL as the template parameters may be
10036 dependent if they are based on one-another, and the dependency
10037 predicates are short-circuit outside of templates. */
10044 {
10045 tree new_vec =
10050 {
10051 tree tuple;
10063 }
10069 }
10074 }
10076 /* Return the result of substituting ARGS into one template parameter
10077 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
10078 parameter and which TREE_PURPOSE is the default argument of the
10079 template parameter. */
10081 static tree
10083 {
10104 }
10106 /* Substitute the ARGS into the indicated aggregate (or enumeration)
10107 type T. If T is not an aggregate or enumeration type, it is
10108 handled as if by tsubst. IN_DECL is as for tsubst. If
10109 ENTERING_SCOPE is nonzero, T is the context for a template which
10110 we are presently tsubst'ing. Return the substituted value. */
10112 static tree
10114 tree args,
10115 tsubst_flags_t complain,
10116 tree in_decl,
10118 {
10123 {
10128 /* Else fall through. */
10132 {
10133 tree argvec;
10134 tree context;
10135 tree r;
10139 /* In "sizeof(X<I>)" we need to evaluate "I". */
10145 /* First, determine the context for the type we are looking
10146 up. */
10149 {
10152 /* If context is a nested class inside a class template,
10153 it may still need to be instantiated (c++/33959). */
10155 }
10157 /* Then, figure out what arguments are appropriate for the
10158 type we are trying to find. For example, given:
10160 template <class T> struct S;
10161 template <class T, class U> void f(T, U) { S<U> su; }
10163 and supposing that we are instantiating f<int, double>,
10164 then our ARGS will be {int, double}, but, when looking up
10165 S we only want {double}. */
10170 else
10171 {
10175 }
10181 }
10182 else
10183 /* This is not a template type, so there's nothing to do. */
10188 }
10189 }
10191 /* Substitute into the default argument ARG (a default argument for
10192 FN), which has the indicated TYPE. */
10194 tree
10196 {
10201 /* This can happen in invalid code. */
10205 /* This default argument came from a template. Instantiate the
10206 default argument here, not in tsubst. In the case of
10207 something like:
10209 template <class T>
10210 struct S {
10211 static T t();
10212 void f(T = t());
10213 };
10215 we must be careful to do name lookup in the scope of S<T>,
10216 rather than in the current class. */
10218 /* The "this" pointer is not valid in a default argument. */
10220 {
10225 }
10228 /* The default argument expression may cause implicitly defined
10229 member functions to be synthesized, which will result in garbage
10230 collection. We must treat this situation as if we were within
10231 the body of function so as to avoid collecting live data on the
10232 stack. */
10240 /* Restore the "this" pointer. */
10242 {
10245 }
10252 /* Make sure the default argument is reasonable. */
10258 }
10260 /* Substitute into all the default arguments for FN. */
10262 static void
10264 {
10265 tree arg;
10266 tree tmpl_args;
10270 /* If this function is not yet instantiated, we certainly don't need
10271 its default arguments. */
10274 /* Don't do this again for clones. */
10279 arg;
10285 complain);
10286 }
10288 /* Substitute the ARGS into the T, which is a _DECL. Return the
10289 result of the substitution. Issue error and warning messages under
10290 control of COMPLAIN. */
10292 static tree
10294 {
10295 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10296 location_t saved_loc;
10301 /* Set the filename and linenumber to improve error-reporting. */
10306 {
10308 {
10309 /* We can get here when processing a member function template,
10310 member class template, or template template parameter. */
10312 tree spec;
10313 tree tmpl_args;
10314 tree full_args;
10317 {
10318 /* Template template parameter is treated here. */
10322 /* If we get a real template back, return it. This can happen in
10323 the context of most_specialized_class. */
10335 complain);
10338 }
10340 /* We might already have an instance of this template.
10341 The ARGS are for the surrounding class type, so the
10342 full args contain the tsubst'd args for the context,
10343 plus the innermost args from the template decl. */
10347 /* Because this is a template, the arguments will still be
10348 dependent, even after substitution. If
10349 PROCESSING_TEMPLATE_DECL is not set, the dependency
10350 predicates will short-circuit. */
10358 /* If this is a default template template argument,
10359 tsubst might not have changed anything. */
10366 {
10369 }
10371 /* Make a new template decl. It will be similar to the
10372 original, but will record the current template arguments.
10373 We also create a new function declaration, which is just
10374 like the old one, but points to this new template, rather
10375 than the old one. */
10384 {
10385 tree new_type;
10393 /* For a partial specialization, we need to keep pointing to
10394 the primary template. */
10400 }
10401 else
10402 {
10403 tree new_decl;
10415 }
10421 /* The template parameters for this new template are all the
10422 template parameters for the old template, except the
10423 outermost level of parameters. */
10426 complain);
10432 /* Record this non-type partial instantiation. */
10436 }
10440 {
10441 tree ctx;
10444 tree gen_tmpl;
10445 tree type;
10450 /* Nobody should be tsubst'ing into non-template functions. */
10454 {
10455 tree spec;
10458 /* If T is not dependent, just return it. We have to
10459 increment PROCESSING_TEMPLATE_DECL because
10460 value_dependent_expression_p assumes that nothing is
10461 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10468 /* Calculate the most general template of which R is a
10469 specialization, and the complete set of arguments used to
10470 specialize R. */
10473 (DECL_TEMPLATE_RESULT
10479 /* Check to see if we already have this specialization. */
10484 {
10487 }
10489 /* We can see more levels of arguments than parameters if
10490 there was a specialization of a member template, like
10491 this:
10493 template <class T> struct S { template <class U> void f(); }
10494 template <> template <class U> void S<int>::f(U);
10496 Here, we'll be substituting into the specialization,
10497 because that's where we can find the code we actually
10498 want to generate, but we'll have enough arguments for
10499 the most general template.
10501 We also deal with the peculiar case:
10503 template <class T> struct S {
10504 template <class U> friend void f();
10505 };
10506 template <class U> void f() {}
10507 template S<int>;
10508 template void f<double>();
10510 Here, the ARGS for the instantiation of will be {int,
10511 double}. But, we only need as many ARGS as there are
10512 levels of template parameters in CODE_PATTERN. We are
10513 careful not to get fooled into reducing the ARGS in
10514 situations like:
10516 template <class T> struct S { template <class U> void f(U); }
10517 template <class T> template <> void S<T>::f(int) {}
10519 which we can spot because the pattern will be a
10520 specialization in this case. */
10522 parms_depth =
10527 }
10528 else
10529 {
10530 /* This special case arises when we have something like this:
10532 template <class T> struct S {
10533 friend void f<int>(int, double);
10534 };
10536 Here, the DECL_TI_TEMPLATE for the friend declaration
10537 will be an IDENTIFIER_NODE. We are being called from
10538 tsubst_friend_function, and we want only to create a
10539 new decl (R) with appropriate types so that we can call
10540 determine_specialization. */
10542 }
10545 {
10548 else
10552 }
10553 else
10554 {
10557 }
10562 /* If we hit excessive deduction depth, the type is bogus even if
10563 it isn't error_mark_node, so don't build a decl. */
10567 /* We do NOT check for matching decls pushed separately at this
10568 point, as they may not represent instantiations of this
10569 template, and in any case are considered separate under the
10570 discrete model. */
10574 /* Clear out the mangled name and RTL for the instantiation. */
10577 /* Leave DECL_INITIAL set on deleted instantiations. */
10582 /* OpenMP UDRs have the only argument a reference to the declared
10583 type. We want to diagnose if the declared type is a reference,
10584 which is invalid, but as references to references are usually
10585 quietly merged, diagnose it here. */
10587 {
10588 tree argtype
10593 "reference type %qT in "
10597 argtype);
10598 }
10601 /* Type-conversion operator. Reconstruct the name, in
10602 case it's the name of one of the template's parameters. */
10612 /* If this is an instantiation of a function with internal
10613 linkage, we already know what object file linkage will be
10614 assigned to the instantiation. */
10623 /* We'll re-clone as appropriate in instantiate_template. */
10626 /* If we aren't complaining now, return on error before we register
10627 the specialization so that we'll complain eventually. */
10633 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10634 this in the special friend case mentioned above where
10635 GEN_TMPL is NULL. */
10637 {
10642 tree new_r
10645 /* We instantiated this while substituting into
10646 the type earlier (template/friend54.C). */
10649 /* We're not supposed to instantiate default arguments
10650 until they are called, for a template. But, for a
10651 declaration like:
10653 template <class T> void f ()
10654 { extern void g(int i = T()); }
10656 we should do the substitution when the template is
10657 instantiated. We handle the member function case in
10658 instantiate_class_template since the default arguments
10659 might refer to other members of the class. */
10664 }
10665 else
10668 /* Copy the list of befriending classes. */
10672 {
10676 in_decl);
10677 }
10680 {
10686 /* If this is an instantiation of a member template, clone it.
10687 If it isn't, that'll be handled by
10688 clone_constructors_and_destructors. */
10691 }
10702 /* Possibly limit visibility based on template args. */
10705 {
10709 }
10717 }
10721 {
10729 {
10730 /* If there is a local specialization that isn't a
10731 parameter pack, it means that we're doing a "simple"
10732 substitution from inside tsubst_pack_expansion. Just
10733 return the local specialization (which will be a single
10734 parm). */
10741 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10742 the parameters in this function parameter pack. */
10746 {
10749 /* Zero-length parameter packs are boring. Just substitute
10750 into the chain. */
10754 }
10755 else
10756 {
10757 /* All we did was update the type. Make a note of that. */
10760 }
10761 }
10763 /* Loop through all of the parameters we'll build. When T is
10764 a function parameter pack, LEN is the number of expanded
10765 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10768 {
10775 /* We're on the Ith parameter of the function parameter
10776 pack. */
10777 {
10778 /* Get the Ith type. */
10781 /* Rename the parameter to include the index. */
10784 }
10786 /* We're dealing with a normal parameter. */
10794 {
10797 else
10800 }
10810 /* Keep track of the first new parameter we
10811 generate. That's what will be returned to the
10812 caller. */
10816 /* Build a proper chain of parameters when substituting
10817 into a function parameter pack. */
10820 }
10822 /* If cp_unevaluated_operand is set, we're just looking for a
10823 single dummy parameter, so don't keep going. */
10828 /* FIRST_R contains the start of the chain we've built. */
10830 }
10834 {
10841 {
10842 /* This field is a lambda capture pack. Return a TREE_VEC of
10843 the expanded fields to instantiate_class_template_1 and
10844 store them in the specializations hash table as a
10845 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
10849 {
10852 }
10853 else
10854 {
10855 /* All we did was update the type. Make a note of that. */
10858 }
10859 }
10862 {
10865 {
10869 }
10879 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10880 non-bit-fields DECL_INITIAL is a non-static data member
10881 initializer, which gets deferred instantiation. */
10887 {
10888 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10889 NSDMI in perform_member_init. Still set DECL_INITIAL
10890 so that we know there is one. */
10895 }
10896 /* We don't have to set DECL_CONTEXT here; it is set by
10897 finish_member_declaration. */
10905 }
10908 {
10916 }
10917 }
10921 /* We reach here only for member using decls. We also need to check
10922 uses_template_parms because DECL_DEPENDENT_P is not set for a
10923 using-declaration that designates a member of the current
10924 instantiation (c++/53549). */
10927 {
10934 else
10935 {
10938 }
10939 }
10940 else
10941 {
10944 }
10949 {
10952 tree spec;
10954 tree ctx;
10963 {
10964 /* If this is the canonical decl, we don't have to
10965 mess with instantiations, and often we can't (for
10966 typename, template type parms and such). Note that
10967 TYPE_NAME is not correct for the above test if
10968 we've copied the type for a typedef. */
10974 }
10976 /* Check to see if we already have the specialization we
10977 need. */
10980 {
10981 /* T is a static data member or namespace-scope entity.
10982 We have to substitute into namespace-scope variables
10983 (even though such entities are never templates) because
10984 of cases like:
10986 template <class T> void f() { extern T t; }
10988 where the entity referenced is not known until
10989 instantiation time. */
10993 {
10995 complain,
10997 /* If CTX is unchanged, then T is in fact the
10998 specialization we want. That situation occurs when
10999 referencing a static data member within in its own
11000 class. We can use pointer equality, rather than
11001 same_type_p, because DECL_CONTEXT is always
11002 canonical... */
11005 /* ... unless T is a member template; in which
11006 case our caller can be willing to create a
11007 specialization of that template represented
11008 by T. */
11012 }
11015 {
11023 }
11024 }
11025 else
11026 {
11027 /* A local variable. */
11029 /* Subsequent calls to pushdecl will fill this in. */
11032 }
11033 /* If we already have the specialization we need, there is
11034 nothing more to do. */
11036 {
11039 }
11041 /* Create a new node for the specialization we need. */
11044 {
11047 else
11054 }
11056 {
11057 /* Even if the original location is out of scope, the
11058 newly substituted one is not. */
11065 {
11066 /* It may seem that this case cannot occur, since:
11068 typedef void f();
11069 void g() { f x; }
11071 declares a function, not a variable. However:
11073 typedef void f();
11074 template <typename T> void g() { T t; }
11075 template void g<f>();
11077 is an attempt to declare a variable with function
11078 type. */
11080 /* R is not yet sufficiently initialized, so we
11081 just use its name. */
11084 }
11086 /* Wait until cp_finish_decl to set this again, to handle
11087 circular dependency (template/instantiate6.C). */
11092 {
11097 {
11100 }
11102 }
11103 }
11109 /* Clear out the mangled name and RTL for the instantiation. */
11113 /* The initializer must not be expanded until it is required;
11114 see [temp.inst]. */
11120 {
11121 /* Possibly limit visibility based on template args. */
11124 {
11128 }
11130 }
11133 {
11134 /* A static data member declaration is always marked
11135 external when it is declared in-class, even if an
11136 initializer is present. We mimic the non-template
11137 processing here. */
11143 }
11153 /* Preserve a typedef that names a type. */
11155 {
11158 }
11161 }
11166 }
11167 #undef RETURN
11169 out:
11170 /* Restore the file and line information. */
11174 }
11176 /* Substitute into the ARG_TYPES of a function type.
11177 If END is a TREE_CHAIN, leave it and any following types
11178 un-substituted. */
11180 static tree
11182 tree args,
11183 tree end,
11184 tsubst_flags_t complain,
11185 tree in_decl)
11186 {
11187 tree remaining_arg_types;
11191 tree default_arg;
11202 {
11203 /* For a pack expansion, perform substitution on the
11204 entire expression. Later on, we'll handle the arguments
11205 one-by-one. */
11210 /* So that we'll spin through the parameters, one by one. */
11212 else
11213 {
11214 /* We only partially substituted into the parameter
11215 pack. Our type is TYPE_PACK_EXPANSION. */
11218 }
11219 }
11232 {
11234 {
11238 }
11240 }
11241 /* DR 657. */
11245 /* Do array-to-pointer, function-to-pointer conversion, and ignore
11246 top-level qualifiers as required. */
11249 /* We do not substitute into default arguments here. The standard
11250 mandates that they be instantiated only when needed, which is
11251 done in build_over_call. */
11255 {
11256 /* We've instantiated a template before its default arguments
11257 have been parsed. This can happen for a nested template
11258 class, and is not an error unless we require the default
11259 argument in a call of this function. */
11260 remaining_arg_types =
11263 }
11264 else
11265 remaining_arg_types =
11267 }
11270 }
11272 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
11273 *not* handle the exception-specification for FNTYPE, because the
11274 initial substitution of explicitly provided template parameters
11275 during argument deduction forbids substitution into the
11276 exception-specification:
11278 [temp.deduct]
11280 All references in the function type of the function template to the
11281 corresponding template parameters are replaced by the specified tem-
11282 plate argument values. If a substitution in a template parameter or
11283 in the function type of the function template results in an invalid
11284 type, type deduction fails. [Note: The equivalent substitution in
11285 exception specifications is done only when the function is instanti-
11286 ated, at which point a program is ill-formed if the substitution
11287 results in an invalid type.] */
11289 static tree
11291 tree args,
11292 tsubst_flags_t complain,
11293 tree in_decl)
11294 {
11295 tree return_type;
11296 tree arg_types;
11297 tree fntype;
11299 /* The TYPE_CONTEXT is not used for function/method types. */
11302 /* Substitute the return type. */
11306 /* DR 486 clarifies that creation of a function type with an
11307 invalid return type is a deduction failure. */
11310 {
11312 {
11315 else
11317 }
11319 }
11320 /* And DR 657. */
11324 /* Substitute the argument types. */
11330 /* Construct a new type node and return it. */
11332 {
11337 }
11338 else
11339 {
11341 /* Don't pick up extra function qualifiers from the basetype. */
11344 {
11345 /* [temp.deduct]
11347 Type deduction may fail for any of the following
11348 reasons:
11350 -- Attempting to create "pointer to member of T" when T
11351 is not a class type. */
11354 r);
11356 }
11361 }
11365 }
11367 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11368 ARGS into that specification, and return the substituted
11369 specification. If there is no specification, return NULL_TREE. */
11371 static tree
11373 tree args,
11374 tsubst_flags_t complain,
11375 tree in_decl,
11377 {
11378 tree specs;
11379 tree new_specs;
11384 {
11385 /* A noexcept-specifier. */
11390 {
11391 /* Defer instantiation of noexcept-specifiers to avoid
11392 excessive instantiations (c++/49107). */
11395 {
11396 /* We already partially instantiated this member template,
11397 so combine the new args with the old. */
11402 }
11403 else
11404 {
11407 }
11408 }
11409 else
11410 new_specs = tsubst_copy_and_build
11414 }
11416 {
11419 else
11421 {
11422 tree spec;
11427 {
11428 /* Expand the pack expansion type. */
11431 in_decl);
11437 else
11438 {
11439 /* We're substituting into a member template, so
11440 we got a TYPE_PACK_EXPANSION back. Add that
11441 expansion and move on. */
11445 expanded_specs,
11446 complain);
11449 }
11450 }
11453 {
11456 else
11461 complain);
11462 }
11465 }
11466 }
11468 }
11470 /* Take the tree structure T and replace template parameters used
11471 therein with the argument vector ARGS. IN_DECL is an associated
11472 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11473 Issue error and warning messages under control of COMPLAIN. Note
11474 that we must be relatively non-tolerant of extensions here, in
11475 order to preserve conformance; if we allow substitutions that
11476 should not be allowed, we may allow argument deductions that should
11477 not succeed, and therefore report ambiguous overload situations
11478 where there are none. In theory, we could allow the substitution,
11479 but indicate that it should have failed, and allow our caller to
11480 make sure that the right thing happens, but we don't try to do this
11481 yet.
11483 This function is used for dealing with types, decls and the like;
11484 for expressions, use tsubst_expr or tsubst_copy. */
11486 tree
11488 {
11511 else
11516 /* Reuse typedefs. We need to do this to handle dependent attributes,
11517 such as attribute aligned. */
11520 {
11524 {
11525 /* DECL represents an alias template and we want to
11526 instantiate it. */
11530 }
11534 {
11538 }
11543 else
11544 /* The typedef is from a non-template context. */
11548 {
11550 r = cp_build_qualified_type_real
11554 }
11555 else
11556 {
11557 /* We don't have an instantiation yet, so drop the typedef. */
11562 }
11563 }
11576 {
11602 {
11608 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11609 needed. */
11615 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11616 with TREE_SIDE_EFFECTS that indicates this is not an integral
11617 constant expression. */
11620 {
11623 }
11626 }
11632 {
11645 {
11649 {
11650 /* See through ARGUMENT_PACK_SELECT arguments. */
11652 /* If the selected argument is an expansion E, that most
11653 likely means we were called from
11654 gen_elem_of_pack_expansion_instantiation during the
11655 substituting of pack an argument pack (which Ith
11656 element is a pack expansion, where I is
11657 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
11658 In this case, the Ith element resulting from this
11659 substituting is going to be a pack expansion, which
11660 pattern is the pattern of E. Let's return the
11661 pattern of E, and
11662 gen_elem_of_pack_expansion_instantiation will
11663 build the resulting pack expansion from it. */
11666 }
11667 }
11672 {
11674 /* If ARG is an argument pack, we don't actually want to
11675 perform a substitution here, because substitutions
11676 for argument packs are only done
11677 element-by-element. We can get to this point when
11678 substituting the type of a non-type template
11679 parameter pack, when that type actually contains
11680 template parameter packs from an outer template, e.g.,
11682 template<typename... Types> struct A {
11683 template<Types... Values> struct B { };
11684 }; */
11688 {
11694 return cp_build_qualified_type_real
11696 }
11698 {
11699 /* We are processing a type constructed from a
11700 template template parameter. */
11711 /* Consider this code:
11713 template <template <class> class Template>
11714 struct Internal {
11715 template <class Arg> using Bind = Template<Arg>;
11716 };
11718 template <template <class> class Template, class Arg>
11719 using Instantiate = Template<Arg>; //#0
11721 template <template <class> class Template,
11722 class Argument>
11723 using Bind =
11724 Instantiate<Internal<Template>::template Bind,
11725 Argument>; //#1
11727 When #1 is parsed, the
11728 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11729 parameter `Template' in #0 matches the
11730 UNBOUND_CLASS_TEMPLATE representing the argument
11731 `Internal<Template>::template Bind'; We then want
11732 to assemble the type `Bind<Argument>' that can't
11733 be fully created right now, because
11734 `Internal<Template>' not being complete, the Bind
11735 template cannot be looked up in that context. So
11736 we need to "store" `Bind<Argument>' for later
11737 when the context of Bind becomes complete. Let's
11738 store that in a TYPENAME_TYPE. */
11742 argvec),
11743 typename_type,
11744 complain);
11746 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11747 are resolving nested-types in the signature of a
11748 member function templates. Otherwise ARG is a
11749 TEMPLATE_DECL and is the real template to be
11750 instantiated. */
11758 complain);
11759 return cp_build_qualified_type_real
11761 }
11762 else
11763 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11765 }
11768 /* This can happen during the attempted tsubst'ing in
11769 unify. This means that we don't yet have any information
11770 about the template parameter in question. */
11773 /* Early in template argument deduction substitution, we don't
11774 want to reduce the level of 'auto', or it will be confused
11775 with a normal template parm in subsequent deduction. */
11779 /* If we get here, we must have been looking at a parm for a
11780 more deeply nested template. Make a new version of this
11781 template parameter, but with a lower level. */
11783 {
11788 {
11790 r = cp_build_qualified_type_real
11794 }
11795 else
11796 {
11807 /* We have reduced the level of the template
11808 template parameter, but not the levels of its
11809 template parameters, so canonical_type_parameter
11810 will not be able to find the canonical template
11811 template parameter for this level. Thus, we
11812 require structural equality checking to compare
11813 TEMPLATE_TEMPLATE_PARMs. */
11817 else
11821 {
11829 }
11830 }
11839 }
11842 }
11845 {
11853 {
11857 }
11860 {
11864 }
11867 {
11871 }
11877 }
11880 /* We should never be tsubsting a binfo. */
11884 /* A vector of template arguments. */
11890 {
11894 /* [temp.deduct]
11896 Type deduction may fail for any of the following
11897 reasons:
11899 -- Attempting to create a pointer to reference type.
11900 -- Attempting to create a reference to a reference type or
11901 a reference to void.
11903 Core issue 106 says that creating a reference to a reference
11904 during instantiation is no longer a cause for failure. We
11905 only enforce this check in strict C++98 mode. */
11909 {
11912 /* We keep track of the last time we issued this error
11913 message to avoid spewing a ton of messages during a
11914 single bad template instantiation. */
11917 {
11922 else
11925 }
11928 }
11932 {
11934 {
11937 type);
11938 else
11940 type);
11941 }
11943 }
11945 {
11949 }
11951 /* In C++0x, during template argument substitution, when there is an
11952 attempt to create a reference to a reference type, reference
11953 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11955 "If a template-argument for a template-parameter T names a type
11956 that is a reference to a type A, an attempt to create the type
11957 'lvalue reference to cv T' creates the type 'lvalue reference to
11958 A,' while an attempt to create the type type rvalue reference to
11959 cv T' creates the type T"
11960 */
11961 r = cp_build_reference_type
11964 else
11972 {
11974 pedwarn
11976 code == REFERENCE_TYPE
11979 else
11981 }
11984 /* Will this ever be needed for TYPE_..._TO values? */
11988 }
11990 {
11993 {
11994 /* [temp.deduct]
11996 Type deduction may fail for any of the following
11997 reasons:
11999 -- Attempting to create "pointer to member of T" when T
12000 is not a class type. */
12004 }
12006 {
12010 }
12012 {
12016 }
12019 {
12020 /* The type of the implicit object parameter gets its
12021 cv-qualifiers from the FUNCTION_TYPE. */
12022 tree memptr;
12023 tree method_type
12028 complain);
12029 }
12030 else
12033 complain);
12034 }
12037 {
12038 tree fntype;
12039 tree specs;
12044 /* Substitute the exception specification. */
12052 }
12054 {
12059 /* As an optimization, we avoid regenerating the array type if
12060 it will obviously be the same as T. */
12064 /* These checks should match the ones in grokdeclarator.
12066 [temp.deduct]
12068 The deduction may fail for any of the following reasons:
12070 -- Attempting to create an array with an element type that
12071 is void, a function type, or a reference type, or [DR337]
12072 an abstract class type. */
12076 {
12080 }
12088 {
12091 }
12094 }
12097 {
12107 {
12111 }
12113 {
12114 /* Normally, make_typename_type does not require that the CTX
12115 have complete type in order to allow things like:
12117 template <class T> struct S { typename S<T>::X Y; };
12119 But, such constructs have already been resolved by this
12120 point, so here CTX really should have complete type, unless
12121 it's a partial instantiation. */
12124 {
12128 }
12129 }
12136 {
12139 }
12142 {
12144 {
12148 else
12150 }
12152 {
12156 else
12158 }
12159 }
12161 return cp_build_qualified_type_real
12163 }
12166 {
12178 }
12181 {
12182 tree type;
12198 complain);
12199 }
12202 {
12203 tree type;
12221 else
12222 {
12226 /* In a template ~id could be either a complement expression
12227 or an unqualified-id naming a destructor; if instantiating
12228 it produces an expression, it's not an id-expression or
12229 member access. */
12232 }
12236 complain);
12237 }
12240 {
12244 }
12248 {
12250 tree packed_out =
12252 args,
12253 complain,
12254 in_decl);
12257 /* For template nontype argument packs, also substitute into
12258 the type. */
12263 }
12278 /* We should use one of the expression tsubsts for these codes. */
12284 }
12285 }
12287 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
12288 type of the expression on the left-hand side of the "." or "->"
12289 operator. */
12291 static tree
12294 {
12295 tree name;
12296 tree qualifying_scope;
12297 tree fns;
12298 tree optype;
12303 /* A baselink indicates a function from a base class. Both the
12304 BASELINK_ACCESS_BINFO and the base class referenced may
12305 indicate bases of the template class, rather than the
12306 instantiated class. In addition, lookups that were not
12307 ambiguous before may be ambiguous now. Therefore, we perform
12308 the lookup again. */
12315 {
12322 }
12330 /* If lookup found a single function, mark it as used at this
12331 point. (If it lookup found multiple functions the one selected
12332 later by overload resolution will be marked as used at that
12333 point.) */
12339 /* Add back the template arguments, if present. */
12344 template_args);
12345 /* Update the conversion operator type. */
12353 qualifying_scope,
12354 object_type);
12356 }
12358 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
12359 true if the qualified-id will be a postfix-expression in-and-of
12360 itself; false if more of the postfix-expression follows the
12361 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
12362 of "&". */
12364 static tree
12368 {
12369 tree expr;
12370 tree scope;
12371 tree name;
12373 tree template_args;
12378 /* Figure out what name to look up. */
12381 {
12389 }
12390 else
12391 {
12394 }
12396 /* Substitute into the qualifying scope. When there are no ARGS, we
12397 are just trying to simplify a non-dependent expression. In that
12398 case the qualifying scope may be dependent, and, in any case,
12399 substituting will not help. */
12402 {
12405 }
12406 else
12410 {
12415 }
12418 {
12420 {
12421 /* A BIT_NOT_EXPR is used to represent a destructor. */
12423 {
12427 }
12428 else
12431 }
12432 else
12436 {
12438 {
12442 }
12444 }
12445 }
12448 {
12450 scope);
12451 /* Remember that there was a reference to this entity. */
12453 }
12456 {
12462 }
12471 {
12472 expr = (adjust_result_of_qualified_name_lookup
12474 expr = (finish_qualified_id_expr
12478 }
12480 /* Expressions do not generally have reference type. */
12482 /* However, if we're about to form a pointer-to-member, we just
12483 want the referenced member referenced. */
12488 }
12490 /* Like tsubst, but deals with expressions. This function just replaces
12491 template parms; to finish processing the resultant expression, use
12492 tsubst_copy_and_build or tsubst_expr. */
12494 static tree
12496 {
12498 tree r;
12506 {
12511 {
12512 /* We get here for a use of 'this' in an NSDMI. */
12518 /* This can happen for a parameter name used later in a function
12519 declaration (such as in a late-specified return type). Just
12520 make a dummy decl, since it's only used for its type. */
12523 /* Give it the template pattern as its context; its true context
12524 hasn't been instantiated yet and this is good enough for
12525 mangling. */
12527 }
12535 {
12536 tree enum_type;
12537 tree v;
12541 /* There is no need to substitute into namespace-scope
12542 enumerators. */
12545 /* If ARGS is NULL, then T is known to be non-dependent. */
12549 /* Unfortunately, we cannot just call lookup_name here.
12550 Consider:
12552 template <int I> int f() {
12553 enum E { a = I };
12554 struct S { void g() { E e = a; } };
12555 };
12557 When we instantiate f<7>::S::g(), say, lookup_name is not
12558 clever enough to find f<7>::a. */
12559 enum_type
12569 /* We didn't find the name. That should never happen; if
12570 name-lookup found it during preliminary parsing, we
12571 should find it again here during instantiation. */
12573 }
12578 {
12579 /* Check for a local specialization set up by
12580 tsubst_pack_expansion. */
12582 {
12586 }
12588 /* When retrieving a capture pack from a generic lambda, remove the
12589 lambda call op's own template argument list from ARGS. Only the
12590 template arguments active for the closure type should be used to
12591 retrieve the pack specialization. */
12597 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
12598 tsubst_decl put in the hash table. */
12600 }
12603 {
12604 tree ctx;
12609 {
12612 {
12616 }
12618 }
12619 }
12628 {
12631 {
12633 {
12634 /* Just use name lookup to find a member alias for an
12635 anonymous union, but then add it to the hash table. */
12639 }
12640 else
12641 {
12642 /* This can happen for a variable used in a late-specified
12643 return type of a local lambda. Just make a dummy decl
12644 since it's only used for its type. */
12649 }
12650 }
12651 }
12652 else
12661 /* An OVERLOAD will always be a non-dependent overload set; an
12662 overload set from function scope will just be represented with an
12663 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12679 {
12680 /* Template template argument like the following example need
12681 special treatment:
12683 template <template <class> class TT> struct C {};
12684 template <class T> struct D {
12685 template <class U> struct E {};
12686 C<E> c; // #1
12687 };
12688 D<int> d; // #2
12690 We are processing the template argument `E' in #1 for
12691 the template instantiation #2. Originally, `E' is a
12692 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12693 have to substitute this with one having context `D<int>'. */
12697 }
12698 else
12699 /* Ordinary template template argument. */
12710 return build1
12716 {
12726 /* We only want to compute the number of arguments. */
12740 {
12747 else
12750 }
12751 else
12753 }
12755 {
12763 }
12764 /* Fall through */
12780 return build1
12785 {
12786 tree object;
12787 tree name;
12792 {
12796 }
12799 {
12809 }
12814 in_decl);
12815 else
12818 }
12856 return build_nt
12869 return build_nt
12876 {
12884 }
12890 {
12891 r = build_nt
12897 }
12900 {
12901 r = build_nt
12907 }
12910 {
12911 r = build_nt
12917 }
12920 {
12921 /* Substituted template arguments */
12930 }
12933 {
12953 }
12978 /* Fall through. */
12981 {
12984 }
12985 else
12989 /* This is handled by tsubst_copy_and_build. */
12995 in_decl),
12999 /* We shouldn't have built any of these during initial template
13000 generation. Instead, they should be built during instantiation
13001 in response to the saved STMT_IS_FULL_EXPR_P setting. */
13005 r = build2
13025 {
13026 /* Instantiate any typedefs in the type. */
13031 }
13034 /* These can sometimes show up in a partial instantiation, but never
13035 involve template parms. */
13040 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
13043 }
13044 }
13046 /* Like tsubst_copy, but specifically for OpenMP clauses. */
13048 static tree
13051 {
13055 {
13061 {
13064 {
13070 }
13071 /* FALLTHRU */
13099 {
13102 {
13109 }
13110 else
13112 }
13142 }
13143 }
13149 }
13151 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
13153 static tree
13155 tree in_decl)
13156 {
13157 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
13177 {
13180 else
13181 {
13185 }
13186 }
13191 #undef RECUR
13192 }
13194 /* Substitute one OMP_FOR iterator. */
13196 static void
13201 {
13202 #define RECUR(NODE) \
13203 tsubst_expr ((NODE), args, complain, in_decl, \
13204 integral_constant_expression_p)
13213 {
13214 /* We need to jump through some hoops to handle declarations in the
13215 for-init-statement, since we might need to handle auto deduction,
13216 but we need to keep control of initialization. */
13220 }
13221 else
13233 {
13235 {
13236 /* Declare the variable, but don't let that initialize it. */
13241 }
13249 complain);
13250 else
13257 }
13260 {
13261 /* Declare and initialize the variable. */
13264 }
13266 {
13267 tree c;
13269 {
13280 }
13282 {
13287 {
13290 }
13291 }
13292 }
13298 else
13302 {
13313 {
13320 }
13321 else
13327 {
13333 }
13337 {
13344 }
13345 else
13351 }
13357 #undef RECUR
13358 }
13360 /* Like tsubst_copy for expressions, etc. but also does semantic
13361 processing. */
13363 static tree
13366 {
13367 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13368 #define RECUR(NODE) \
13369 tsubst_expr ((NODE), args, complain, in_decl, \
13370 integral_constant_expression_p)
13373 tree r;
13374 location_t loc;
13386 {
13388 {
13389 tree_stmt_iterator i;
13393 }
13408 else
13417 {
13419 tree init;
13425 {
13428 tree decl;
13436 else
13438 }
13440 {
13441 /* Don't build up decls for a variadic capture proxy, we'll
13442 instantiate the elements directly as needed. */
13444 }
13445 else
13446 {
13450 {
13451 /* By marking the declaration as instantiated, we avoid
13452 trying to instantiate it. Since instantiate_decl can't
13453 handle local variables, and since we've already done
13454 all that needs to be done, that's the right thing to
13455 do. */
13460 /* Anonymous aggregates are a special case. */
13463 {
13466 {
13470 }
13472 }
13478 {
13483 }
13484 else
13485 {
13490 {
13491 /* For __PRETTY_FUNCTION__ we have to adjust the
13492 initializer. */
13496 }
13497 else
13498 {
13502 {
13503 /* If we had an initializer but it
13504 instantiated to nothing,
13505 value-initialize the object. This will
13506 only occur when the initializer was a
13507 pack expansion where the parameter packs
13508 used in that expansion were of length
13509 zero. */
13511 complain);
13514 }
13515 else
13517 }
13520 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
13523 }
13524 }
13525 }
13528 }
13543 {
13553 }
13580 {
13584 }
13592 else
13600 else
13627 {
13629 tree label;
13634 }
13640 /* Computed goto's must be tsubst'd into. On the other hand,
13641 non-computed gotos must not be; the identifier in question
13642 will have no binding. */
13644 else
13650 tmp = finish_asm_stmt
13657 {
13662 }
13667 {
13672 }
13673 else
13674 {
13679 else
13686 else
13692 else
13694 }
13698 {
13702 {
13704 /* Prevent instantiate_decl from trying to instantiate
13705 this variable. We've already done all that needs to be
13706 done. */
13709 }
13714 }
13720 {
13721 /* Local classes are not independent templates; they are
13722 instantiated along with their containing function. And this
13723 way we don't have to deal with pushing out of one local class
13724 to instantiate a member of another local class. */
13725 tree fn;
13726 /* Closures are handled by the LAMBDA_EXPR. */
13732 }
13736 {
13737 tree condition;
13740 condition =
13742 args,
13751 }
13775 {
13784 {
13789 }
13801 integral_constant_expression_p);
13810 else
13811 {
13819 }
13822 }
13867 {
13872 {
13875 }
13881 }
13882 else
13883 {
13890 {
13893 }
13896 {
13901 {
13904 }
13910 }
13911 else
13912 {
13916 }
13919 }
13923 {
13929 {
13933 {
13938 }
13942 }
13943 else
13944 {
13949 }
13950 }
13975 /* If the first operand was a statement, we're done with it. */
13979 complain));
13991 integral_constant_expression_p));
13992 }
13995 out:
13998 #undef RECUR
13999 #undef RETURN
14000 }
14002 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
14003 function. For description of the body see comment above
14004 cp_parser_omp_declare_reduction_exprs. */
14006 static void
14008 {
14014 tree_stmt_iterator tsi;
14025 {
14044 }
14046 {
14066 }
14067 }
14069 /* T is a postfix-expression that is not being used in a function
14070 call. Return the substituted version of T. */
14072 static tree
14074 tsubst_flags_t complain,
14075 tree in_decl)
14076 {
14080 else
14086 }
14088 /* Sentinel to disable certain warnings during template substitution. */
14096 };
14098 /* Like tsubst but deals with expressions and performs semantic
14099 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
14101 tree
14103 tree args,
14104 tsubst_flags_t complain,
14105 tree in_decl,
14108 {
14109 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
14110 #define RECUR(NODE) \
14111 tsubst_copy_and_build (NODE, args, complain, in_decl, \
14113 integral_constant_expression_p)
14116 location_t loc;
14125 /* N3276 decltype magic only applies to calls at the top level or on the
14126 right side of a comma. */
14131 {
14134 /* Fall through. */
14136 {
14137 tree decl;
14138 cp_id_kind idk;
14143 {
14146 }
14148 /* Look up the name. */
14151 /* By convention, expressions use ERROR_MARK_NODE to indicate
14152 failure, not NULL_TREE. */
14158 integral_constant_expression_p,
14166 input_location);
14172 }
14175 {
14176 tree object;
14184 {
14187 }
14188 else
14195 else
14197 }
14200 {
14204 {
14205 /* A type conversion to reference type will be enclosed in
14206 such an indirect ref, but the substitution of the cast
14207 will have also added such an indirect ref. */
14210 }
14211 else
14215 }
14223 {
14230 flags));
14231 }
14244 {
14245 tree type;
14251 {
14256 }
14262 {
14280 }
14283 }
14317 else
14319 in_decl);
14354 {
14357 tree r = build_x_binary_op
14361 ? ERROR_MARK
14365 ? ERROR_MARK
14373 }
14390 {
14399 }
14403 /* Fall through */
14406 {
14407 tree r;
14413 {
14414 /* When there are no ARGS, we are trying to evaluate a
14415 non-dependent expression from the parser. Trying to do
14416 the substitutions may not work. */
14419 }
14420 else
14421 {
14426 else
14429 /*integral_constant_expression_p=*/
14433 }
14437 else
14441 {
14443 {
14445 {
14449 }
14450 else
14454 }
14456 }
14458 }
14461 {
14471 }
14485 {
14487 tree r = build_x_modify_expr
14493 /* TREE_NO_WARNING must be set if either the expression was
14494 parenthesized or it uses an operator such as >>= rather
14495 than plain assignment. In the former case, it was already
14496 set and must be copied. In the latter case,
14497 build_x_modify_expr sets it and it must not be reset
14498 here. */
14503 }
14508 /* Remember that there was a reference to this entity. */
14514 {
14519 tree ret;
14523 else
14524 {
14528 }
14530 /* If there was an initializer in the original tree, but it
14531 instantiated to an empty list, then we should pass a
14532 non-NULL empty vector to tell build_new that it was an
14533 empty initializer() rather than no initializer. This can
14534 only happen when the initializer is a pack expansion whose
14535 parameter packs are of length zero. */
14538 else
14539 {
14543 else
14544 {
14547 }
14548 }
14555 complain);
14563 }
14571 complain));
14574 {
14578 integral_constant_expression_p);
14580 op0,
14583 }
14586 {
14587 tree function;
14592 tree ret;
14595 /* When we parsed the expression, we determined whether or
14596 not Koenig lookup should be performed. */
14599 {
14604 }
14606 {
14607 /* Do nothing; calling tsubst_copy_and_build on an identifier
14608 would incorrectly perform unqualified lookup again.
14610 Note that we can also have an IDENTIFIER_NODE if the earlier
14611 unqualified lookup found a member function; in that case
14612 koenig_p will be false and we do want to do the lookup
14613 again to find the instantiated member function.
14615 FIXME but doing that causes c++/15272, so we need to stop
14616 using IDENTIFIER_NODE in that situation. */
14618 }
14619 else
14620 {
14622 {
14628 }
14629 else
14634 /* Avoid error about taking the address of a constructor. */
14638 in_decl,
14640 integral_constant_expression_p);
14644 }
14649 {
14654 else
14655 {
14656 /* Expand the pack expansion and push each entry onto
14657 CALL_ARGS. */
14660 {
14665 {
14670 }
14671 }
14672 else
14673 {
14674 /* A partial substitution. Add one entry. */
14676 }
14677 }
14678 }
14680 /* We do not perform argument-dependent lookup if normal
14681 lookup finds a non-function, in accordance with the
14682 expected resolution of DR 218. */
14685 /* If lookup found a member function, the Koenig lookup is
14686 not appropriate, even if an unqualified-name was used
14687 to denote the function. */
14690 /* Only do this when substitution turns a dependent call
14691 into a non-dependent call. */
14698 {
14700 {
14701 /* For backwards compatibility and good diagnostics, try
14702 the unqualified lookup again if we aren't in SFINAE
14703 context. */
14704 tree unq = (tsubst_copy_and_build
14706 integral_constant_expression_p));
14711 {
14720 "%qD was not declared in this scope, "
14721 "and no declarations were found by "
14722 "argument-dependent lookup at the point "
14724 {
14728 {
14730 input_location);
14732 "declarations in dependent base %qT are "
14738 else
14742 }
14743 else
14746 }
14748 }
14749 }
14751 {
14756 }
14757 }
14759 /* Remember that there was a reference to this entity. */
14763 /* Put back tf_decltype for the actual call. */
14768 complain);
14770 {
14785 complain);
14786 else
14787 ret = (build_new_method_call
14792 complain));
14793 }
14794 else
14797 koenig_p,
14798 complain);
14803 }
14806 {
14811 {
14813 {
14818 }
14819 else
14820 {
14825 }
14826 }
14827 else
14828 {
14831 }
14835 }
14842 input_location));
14845 {
14853 {
14854 /* We have pack expansions, so expand those and
14855 create a new list out of it. */
14858 tree chain;
14861 /* Expand the argument expressions. */
14869 /* Build the rest of the list. */
14874 /* Determine the number of arguments. */
14876 {
14879 }
14882 else
14883 {
14884 /* Since we only performed a partial substitution into
14885 the argument pack, we only RETURN (a single list
14886 node. */
14893 }
14895 /* Convert the argument vectors into a TREE_LIST */
14898 {
14899 /* Grab the Ith values. */
14900 i--;
14903 value
14907 /* Build the list (backwards). */
14909 }
14912 }
14928 }
14931 {
14932 tree object;
14933 tree object_type;
14934 tree member;
14935 tree r;
14939 /* Remember that there was a reference to this entity. */
14949 else
14957 {
14959 {
14964 {
14967 }
14969 {
14974 }
14975 }
14976 }
14979 {
14980 /* Lookup the template functions now that we know what the
14981 scope is. */
14989 {
14992 args);
14993 member = (adjust_result_of_qualified_name_lookup
14995 object_type));
14996 }
14997 else
14998 {
15000 input_location);
15002 }
15003 }
15007 {
15009 {
15013 else
15016 }
15018 }
15020 {
15025 }
15029 complain);
15033 }
15040 {
15048 tree r;
15053 /* digest_init will do the wrong thing if we let it. */
15057 /* We do not want to process the index of aggregate
15058 initializers as they are identifier nodes which will be
15059 looked up by digest_init. */
15065 {
15067 /* An identifier index is looked up in the type
15068 being initialized, not the current scope. */
15073 {
15074 /* Substitute into the pack expansion. */
15076 in_decl);
15080 ;
15082 /* Just move the argument into place. */
15084 else
15085 {
15086 /* Update the length of the final CONSTRUCTOR
15087 arguments vector, and note that we will need to
15088 copy.*/
15091 }
15092 }
15093 else
15095 }
15098 {
15103 {
15105 {
15110 }
15111 else
15113 }
15114 }
15124 }
15127 {
15130 {
15133 }
15134 else
15135 {
15138 }
15139 }
15145 {
15146 /* We don't build decls for an instantiation of a
15147 variadic capture proxy, we instantiate the elements
15148 when needed. */
15151 }
15152 /* Fall through */
15155 {
15159 /* If the original type was a reference, we'll be wrapped in
15160 the appropriate INDIRECT_REF. */
15163 }
15174 {
15183 }
15186 {
15192 integral_constant_expression_p);
15196 /* If the resulting list of expression statement is empty,
15197 fold it further into void_zero_node. */
15202 }
15205 {
15219 /* For a function scope, we want to use tsubst so that we don't
15220 complain about referring to an auto function before its return
15221 type has been deduced. Otherwise, we want to use tsubst_copy so
15222 that we look up the existing field/parameter/variable rather
15223 than build a new one. */
15228 {
15229 /* Look up the parameter we want directly, as tsubst_copy
15230 doesn't do what we need. */
15236 /* FIXME Work around the parm not having DECL_CONTEXT set. */
15239 }
15240 else
15249 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
15251 /* Now that we know visibility, instantiate the type so we have a
15252 declaration of the op() for later calls to lambda_function. */
15258 }
15261 /* We can get here for a constant initializer of non-dependent type.
15262 FIXME stop folding in cp_parser_initializer_clause. */
15263 {
15265 complain);
15267 }
15271 integral_constant_expression_p));
15281 complain));
15284 /* Handle Objective-C++ constructs, if appropriate. */
15285 {
15286 tree subst
15291 }
15293 }
15295 #undef RECUR
15296 #undef RETURN
15297 out:
15300 }
15302 /* Verify that the instantiated ARGS are valid. For type arguments,
15303 make sure that the type's linkage is ok. For non-type arguments,
15304 make sure they are constants if they are integral or enumerations.
15305 Emit an error under control of COMPLAIN, and return TRUE on error. */
15307 static bool
15309 {
15313 {
15323 }
15325 {
15326 /* [basic.link]: A name with no linkage (notably, the name
15327 of a class or enumeration declared in a local scope)
15328 shall not be used to declare an entity with linkage.
15329 This implies that names with no linkage cannot be used as
15330 template arguments
15332 DR 757 relaxes this restriction for C++0x. */
15337 {
15338 /* DR 488 makes use of a type with no linkage cause
15339 type deduction to fail. */
15341 {
15344 else
15347 }
15349 }
15350 /* In order to avoid all sorts of complications, we do not
15351 allow variably-modified types as template arguments. */
15353 {
15357 }
15358 }
15359 /* Class template and alias template arguments should be OK. */
15361 ;
15362 /* A non-type argument of integral or enumerated type must be a
15363 constant. */
15367 {
15371 }
15373 }
15375 static bool
15377 {
15382 {
15385 }
15389 }
15391 /* We're out of SFINAE context now, so generate diagnostics for the access
15392 errors we saw earlier when instantiating D from TMPL and ARGS. */
15394 static void
15396 {
15408 }
15410 /* Instantiate the indicated variable, function, or alias template TMPL with
15411 the template arguments in TARG_PTR. */
15413 static tree
15415 {
15417 tree fndecl;
15418 tree gen_tmpl;
15419 tree spec;
15427 /* If this function is a clone, handle it specially. */
15429 {
15430 tree spec;
15431 tree clone;
15433 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
15434 DECL_CLONED_FUNCTION. */
15440 /* Look for the clone. */
15444 /* We should always have found the clone by now. */
15447 }
15452 /* Check to see if we already have this specialization. */
15455 /* The TMPL is a partial instantiation. To get a full set of
15456 arguments we must add the arguments used to perform the
15457 partial instantiation. */
15459 targ_ptr);
15461 /* It would be nice to avoid hashing here and then again in tsubst_decl,
15462 but it doesn't seem to be on the hot path. */
15471 {
15473 {
15477 }
15479 }
15482 complain))
15485 /* We are building a FUNCTION_DECL, during which the access of its
15486 parameters and return types have to be checked. However this
15487 FUNCTION_DECL which is the desired context for access checking
15488 is not built yet. We solve this chicken-and-egg problem by
15489 deferring all checks until we have the FUNCTION_DECL. */
15492 /* Instantiation of the function happens in the context of the function
15493 template, not the context of the overload resolution we're doing. */
15495 /* If there are dependent arguments, e.g. because we're doing partial
15496 ordering, make sure processing_template_decl stays set. */
15500 {
15504 }
15505 /* Substitute template parameters to obtain the specialization. */
15513 {
15516 }
15518 /* The DECL_TI_TEMPLATE should always be the immediate parent
15519 template, not the most general template. */
15522 /* Now we know the specialization, compute access previously
15523 deferred. */
15530 /* If we've just instantiated the main entry point for a function,
15531 instantiate all the alternate entry points as well. We do this
15532 by cloning the instantiation of the main entry point, not by
15533 instantiating the template clones. */
15538 {
15540 {
15541 /* Remember to reinstantiate when we're out of SFINAE so the user
15542 can see the errors. */
15544 }
15546 }
15548 }
15550 /* Wrapper for instantiate_template_1. */
15552 tree
15554 {
15555 tree ret;
15560 }
15562 /* Instantiate the alias template TMPL with ARGS. Also push a template
15563 instantiation level, which instantiate_template doesn't do because
15564 functions and variables have sufficient context established by the
15565 callers. */
15567 static tree
15569 {
15576 {
15579 }
15581 args =
15589 /* We can't free this if a pending_template entry or last_error_tinst_level
15590 is pointing at it. */
15596 }
15598 /* PARM is a template parameter pack for FN. Returns true iff
15599 PARM is used in a deducible way in the argument list of FN. */
15601 static bool
15603 {
15606 {
15608 tree packs;
15614 {
15615 /* The template parameter pack is used in a function parameter
15616 pack. If this is the end of the parameter list, the
15617 template parameter pack is deducible. */
15620 else
15621 /* Otherwise, not. Well, it could be deduced from
15622 a non-pack parameter, but doing so would end up with
15623 a deduction mismatch, so don't bother. */
15625 }
15626 }
15627 /* The template parameter pack isn't used in any function parameter
15628 packs, but it might be used deeper, e.g. tuple<Args...>. */
15630 }
15632 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
15633 NARGS elements of the arguments that are being used when calling
15634 it. TARGS is a vector into which the deduced template arguments
15635 are placed.
15637 Returns either a FUNCTION_DECL for the matching specialization of FN or
15638 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
15639 true, diagnostics will be printed to explain why it failed.
15641 If FN is a conversion operator, or we are trying to produce a specific
15642 specialization, RETURN_TYPE is the return type desired.
15644 The EXPLICIT_TARGS are explicit template arguments provided via a
15645 template-id.
15647 The parameter STRICT is one of:
15649 DEDUCE_CALL:
15650 We are deducing arguments for a function call, as in
15651 [temp.deduct.call].
15653 DEDUCE_CONV:
15654 We are deducing arguments for a conversion function, as in
15655 [temp.deduct.conv].
15657 DEDUCE_EXACT:
15658 We are deducing arguments when doing an explicit instantiation
15659 as in [temp.explicit], when determining an explicit specialization
15660 as in [temp.expl.spec], or when taking the address of a function
15661 template, as in [temp.deduct.funcaddr]. */
15663 tree
15665 tree explicit_targs,
15666 tree targs,
15669 tree return_type,
15670 unification_kind_t strict,
15674 {
15675 tree parms;
15676 tree fntype;
15684 tree tinst;
15690 /* In C++0x, it's possible to have a function template whose type depends
15691 on itself recursively. This is most obvious with decltype, but can also
15692 occur with enumeration scope (c++/48969). So we need to catch infinite
15693 recursion and reject the substitution at deduction time; this function
15694 will return error_mark_node for any repeated substitution.
15696 This also catches excessive recursion such as when f<N> depends on
15697 f<N-1> across all integers, and returns error_mark_node for all the
15698 substitutions back up to the initial one.
15700 This is, of course, not reentrant. */
15710 {
15711 /* [temp.deduct]
15713 The specified template arguments must match the template
15714 parameters in kind (i.e., type, nontype, template), and there
15715 must not be more arguments than there are parameters;
15716 otherwise type deduction fails.
15718 Nontype arguments must match the types of the corresponding
15719 nontype template parameters, or must be convertible to the
15720 types of the corresponding nontype parameters as specified in
15721 _temp.arg.nontype_, otherwise type deduction fails.
15723 All references in the function type of the function template
15724 to the corresponding template parameters are replaced by the
15725 specified template argument values. If a substitution in a
15726 template parameter or in the function type of the function
15727 template results in an invalid type, type deduction fails. */
15732 /* Adjust any explicit template arguments before entering the
15733 substitution context. */
15734 explicit_targs
15736 complain,
15742 /* Substitute the explicit args into the function type. This is
15743 necessary so that, for instance, explicitly declared function
15744 arguments can match null pointed constants. If we were given
15745 an incomplete set of explicit args, we must not do semantic
15746 processing during substitution as we could create partial
15747 instantiations. */
15749 {
15754 /* Dig out the actual parm. */
15757 {
15760 }
15762 {
15765 }
15768 /* No explicit argument for this template parameter. */
15772 {
15773 /* Mark the argument pack as "incomplete". We could
15774 still deduce more arguments during unification.
15775 We remove this mark in type_unification_real. */
15777 {
15781 }
15783 /* We have some incomplete argument packs. */
15785 }
15786 }
15790 {
15793 }
15796 /* Ignore any access checks; we'll see them again in
15797 instantiate_template and they might have the wrong
15798 access path at this point. */
15810 /* Place the explicitly specified arguments in TARGS. */
15813 }
15815 /* Never do unification on the 'this' parameter. */
15819 {
15828 }
15830 /* We allow incomplete unification without an error message here
15831 because the standard doesn't seem to explicitly prohibit it. Our
15832 callers must be ready to deal with unification failures in any
15833 event. */
15836 /* If we aren't explaining yet, push tinst context so we can see where
15837 any errors (e.g. from class instantiations triggered by instantiation
15838 of default template arguments) come from. If we are explaining, this
15839 context is redundant. */
15841 {
15844 }
15846 /* type_unification_real will pass back any access checks from default
15847 template argument substitution. */
15859 /* Now that we have bindings for all of the template arguments,
15860 ensure that the arguments deduced for the template template
15861 parameters have compatible template parameter lists. We cannot
15862 check this property before we have deduced all template
15863 arguments, because the template parameter types of a template
15864 template parameter might depend on prior template parameters
15865 deduced after the template template parameter. The following
15866 ill-formed example illustrates this issue:
15868 template<typename T, template<T> class C> void f(C<5>, T);
15870 template<int N> struct X {};
15872 void g() {
15873 f(X<5>(), 5l); // error: template argument deduction fails
15874 }
15876 The template parameter list of 'C' depends on the template type
15877 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
15878 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
15879 time that we deduce 'C'. */
15882 {
15885 }
15887 /* All is well so far. Now, check:
15889 [temp.deduct]
15891 When all template arguments have been deduced, all uses of
15892 template parameters in nondeduced contexts are replaced with
15893 the corresponding deduced argument values. If the
15894 substitution results in an invalid type, as described above,
15895 type deduction fails. */
15898 {
15901 }
15903 /* Also collect access checks from the instantiation. */
15916 /* Now perform any access checks encountered during substitution. */
15923 /* If we're looking for an exact match, check that what we got
15924 is indeed an exact match. It might not be if some template
15925 parameters are used in non-deduced contexts. But don't check
15926 for an exact match if we have dependent template arguments;
15927 in that case we're doing partial ordering, and we already know
15928 that we have two candidates that will provide the actual type. */
15930 {
15934 tree sarg
15940 {
15944 }
15945 }
15949 fail:
15952 {
15954 /* Reset once we're all the way out. */
15956 }
15958 /* We can't free this if a pending_template entry or last_error_tinst_level
15959 is pointing at it. */
15965 }
15967 /* Adjust types before performing type deduction, as described in
15968 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
15969 sections are symmetric. PARM is the type of a function parameter
15970 or the return type of the conversion function. ARG is the type of
15971 the argument passed to the call, or the type of the value
15972 initialized with the result of the conversion function.
15973 ARG_EXPR is the original argument expression, which may be null. */
15975 static int
15979 tree arg_expr)
15980 {
15984 {
15989 {
15990 /* Swap PARM and ARG throughout the remainder of this
15991 function; the handling is precisely symmetric since PARM
15992 will initialize ARG rather than vice versa. */
15997 }
16000 /* Core issue #873: Do the DR606 thing (see below) for these cases,
16001 too, but here handle it by stripping the reference from PARM
16002 rather than by adding it to ARG. */
16010 /* Nothing else to do in this case. */
16015 }
16018 {
16019 /* [temp.deduct.call]
16021 If P is not a reference type:
16023 --If A is an array type, the pointer type produced by the
16024 array-to-pointer standard conversion (_conv.array_) is
16025 used in place of A for type deduction; otherwise,
16027 --If A is a function type, the pointer type produced by
16028 the function-to-pointer standard conversion
16029 (_conv.func_) is used in place of A for type deduction;
16030 otherwise,
16032 --If A is a cv-qualified type, the top level
16033 cv-qualifiers of A's type are ignored for type
16034 deduction. */
16039 else
16041 }
16043 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
16044 of the form T&&, where T is a template parameter, and the argument
16045 is an lvalue, T is deduced as A& */
16051 /* try_one_overload doesn't provide an arg_expr, but
16052 functions are always lvalues. */
16056 /* [temp.deduct.call]
16058 If P is a cv-qualified type, the top level cv-qualifiers
16059 of P's type are ignored for type deduction. If P is a
16060 reference type, the type referred to by P is used for
16061 type deduction. */
16064 {
16067 }
16069 /* DR 322. For conversion deduction, remove a reference type on parm
16070 too (which has been swapped into ARG). */
16075 }
16077 /* Subroutine of unify_one_argument. PARM is a function parameter of a
16078 template which does contain any deducible template parameters; check if
16079 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
16080 unify_one_argument. */
16082 static int
16085 {
16086 tree type;
16090 else
16097 {
16101 }
16103 {
16108 }
16112 else
16114 }
16118 /* Returns true iff the expression EXPR is one from which a template
16119 argument can be deduced. In other words, if it's an undecorated
16120 use of a template non-type parameter. */
16122 static bool
16124 {
16126 }
16128 /* Returns true iff the array domain DOMAIN uses a template parameter in a
16129 deducible way; that is, if it has a max value of <PARM> - 1. */
16131 static bool
16133 {
16142 }
16144 /* Returns true iff the template arguments ARGS use a template parameter
16145 in a deducible way. */
16147 static bool
16149 {
16151 {
16156 else
16157 {
16164 else
16166 }
16169 }
16171 }
16173 /* Returns true iff TYPE contains any deducible references to template
16174 parameters, as per 14.8.2.5. */
16176 static bool
16178 {
16182 /* T
16183 cv-list T
16184 TT<T>
16185 TT<i>
16186 TT<> */
16191 /* T*
16192 T&
16193 T&& */
16197 /* T[integer-constant ]
16198 type [i] */
16203 /* T type ::*
16204 type T::*
16205 T T::*
16206 T (type ::*)()
16207 type (T::*)()
16208 type (type ::*)(T)
16209 type (T::*)(T)
16210 T (type ::*)(T)
16211 T (T::*)()
16212 T (T::*)(T) */
16215 || (uses_deducible_template_parms
16218 /* template-name <T> (where template-name refers to a class template)
16219 template-name <i> (where template-name refers to a class template) */
16226 /* type (T)
16227 T()
16228 T(T) */
16231 {
16240 }
16243 }
16245 /* Subroutine of type_unification_real and unify_pack_expansion to
16246 handle unification of a single P/A pair. Parameters are as
16247 for those functions. */
16249 static int
16253 {
16260 /* We can't deduce anything from this, but we might get all the
16261 template args from other function args. */
16264 /* Implicit conversions (Clause 4) will be performed on a function
16265 argument to convert it to the type of the corresponding function
16266 parameter if the parameter type contains no template-parameters that
16267 participate in template argument deduction. */
16269 /* For function parameters that contain no template-parameters at all,
16270 we have historically checked for convertibility in order to shortcut
16271 consideration of this candidate. */
16273 explain_p);
16276 /* For function parameters with only non-deducible template parameters,
16277 just return. */
16281 {
16283 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
16284 | UNIFY_ALLOW_MORE_CV_QUAL
16298 }
16300 /* We only do these transformations if this is the top-level
16301 parameter_type_list in a call or declaration matching; in other
16302 situations (nested function declarators, template argument lists) we
16303 won't be comparing a type to an expression, and we don't do any type
16304 adjustments. */
16306 {
16308 {
16311 {
16312 /* [temp.deduct.type] A template-argument can be
16313 deduced from a pointer to function or pointer
16314 to member function argument if the set of
16315 overloaded functions does not contain function
16316 templates and at most one of a set of
16317 overloaded functions provides a unique
16318 match. */
16325 }
16331 }
16333 arg_strict |=
16335 }
16336 else
16340 /* For deduction from an init-list we need the actual list. */
16344 }
16346 /* Most parms like fn_type_unification.
16348 If SUBR is 1, we're being called recursively (to unify the
16349 arguments of a function or method parameter of a function
16350 template).
16352 CHECKS is a pointer to a vector of access checks encountered while
16353 substituting default template arguments. */
16355 static int
16357 tree targs,
16358 tree xparms,
16362 unification_kind_t strict,
16366 {
16371 tree parms;
16380 /* Reset the number of non-defaulted template arguments contained
16381 in TARGS. */
16384 again:
16392 {
16397 /* For a function parameter pack that occurs at the end of the
16398 parameter-declaration-list, the type A of each remaining
16399 argument of the call is compared with the type P of the
16400 declarator-id of the function parameter pack. */
16406 /* For a function parameter pack that does not occur at the
16407 end of the parameter-declaration-list, the type of the
16408 parameter pack is a non-deduced context. */
16417 }
16422 {
16423 /* Unify the remaining arguments with the pack expansion type. */
16424 tree argvec;
16427 /* Allocate a TREE_VEC and copy in all of the arguments */
16432 /* Copy the parameter into parmvec. */
16438 /* Advance to the end of the list of parameters. */
16440 }
16442 /* Fail if we've reached the end of the parm list, and more args
16443 are present, and the parm list isn't variadic. */
16446 /* Fail if parms are left and they don't have default values. */
16449 {
16453 {
16454 count++;
16456 }
16458 }
16461 {
16462 tsubst_flags_t complain = (explain_p
16463 ? tf_warning_or_error
16467 {
16471 /* Clear the "incomplete" flags on all argument packs now so that
16472 substituting them into later default arguments works. */
16474 {
16477 }
16483 /* If this is an undeduced nontype parameter that depends on
16484 a type parameter, try another pass; its type may have been
16485 deduced from a later argument than the one from which
16486 this parameter can be deduced. */
16492 /* Core issue #226 (C++0x) [temp.deduct]:
16494 If a template argument has not been deduced, its
16495 default template argument, if any, is used.
16497 When we are in C++98 mode, TREE_PURPOSE will either
16498 be NULL_TREE or ERROR_MARK_NODE, so we do not need
16499 to explicitly check cxx_dialect here. */
16501 {
16516 else
16517 {
16519 /* The position of the first default template argument,
16520 is also the number of non-defaulted arguments in TARGS.
16521 Record that. */
16525 }
16526 }
16528 /* If the type parameter is a parameter pack, then it will
16529 be deduced to an empty parameter pack. */
16531 {
16532 tree arg;
16535 {
16539 }
16540 else
16547 }
16550 }
16551 }
16552 #ifdef ENABLE_CHECKING
16555 #endif
16558 }
16560 /* Subroutine of type_unification_real. Args are like the variables
16561 at the call site. ARG is an overloaded function (or template-id);
16562 we try deducing template args from each of the overloads, and if
16563 only one succeeds, we go with that. Modifies TARGS and returns
16564 true on success. */
16566 static bool
16568 tree targs,
16569 tree parm,
16570 tree arg,
16571 unification_kind_t strict,
16574 {
16581 {
16584 }
16585 else
16589 /* Handle `&x' where `x' is some static or non-static member
16590 function name. */
16596 /* Strip baselink information. */
16601 {
16602 /* If we got some explicit template args, we need to plug them into
16603 the affected templates before we try to unify, in case the
16604 explicit args will completely resolve the templates in question. */
16611 {
16624 {
16629 {
16632 }
16633 }
16636 }
16637 /* If no templates (or more than one) are fully resolved by the
16638 explicit arguments, this template-id is a non-deduced context; it
16639 could still be OK if we deduce all template arguments for the
16640 enclosing call through other arguments. */
16643 }
16646 /* If ARG is, for example, "(0, &f)" then its type will be unknown
16647 -- but the deduction does not succeed because the expression is
16648 not just the function on its own. */
16650 else
16656 {
16659 }
16661 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16662 to function or pointer to member function argument if the set of
16663 overloaded functions does not contain function templates and at most
16664 one of a set of overloaded functions provides a unique match.
16666 So if we found multiple possibilities, we return success but don't
16667 deduce anything. */
16670 {
16675 }
16680 }
16682 /* Core DR 115: In contexts where deduction is done and fails, or in
16683 contexts where deduction is not done, if a template argument list is
16684 specified and it, along with any default template arguments, identifies
16685 a single function template specialization, then the template-id is an
16686 lvalue for the function template specialization. */
16688 tree
16690 {
16703 {
16706 }
16708 {
16711 }
16713 {
16716 }
16719 {
16723 /* If we got some explicit template args, we need to plug them into
16724 the affected templates before we try to unify, in case the
16725 explicit args will completely resolve the templates in question. */
16733 {
16746 {
16749 {
16752 }
16754 {
16757 }
16758 }
16759 }
16761 {
16769 {
16770 tree base
16773 }
16777 }
16779 /* There were no good options and at least one bad one, so let the
16780 user know what the problem is. */
16782 }
16784 }
16786 /* Subroutine of resolve_overloaded_unification; does deduction for a single
16787 overload. Fills TARGS with any deduced arguments, or error_mark_node if
16788 different overloads deduce different arguments for a given parm.
16789 ADDR_P is true if the expression for which deduction is being
16790 performed was of the form "& fn" rather than simply "fn".
16792 Returns 1 on success. */
16794 static int
16796 tree orig_targs,
16797 tree targs,
16798 tree parm,
16799 tree arg,
16800 unification_kind_t strict,
16804 {
16806 tree tempargs;
16812 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16813 to function or pointer to member function argument if the set of
16814 overloaded functions does not contain function templates and at most
16815 one of a set of overloaded functions provides a unique match.
16817 So if this is a template, just return success. */
16829 /* We don't copy orig_targs for this because if we have already deduced
16830 some template args from previous args, unify would complain when we
16831 try to deduce a template parameter for the same argument, even though
16832 there isn't really a conflict. */
16839 /* First make sure we didn't deduce anything that conflicts with
16840 explicitly specified args. */
16842 {
16849 /* Since we're unifying against ourselves, we will fill in
16850 template args used in the function parm list with our own
16851 template parms. Discard them. */
16855 }
16858 {
16863 }
16866 }
16868 /* PARM is a template class (perhaps with unbound template
16869 parameters). ARG is a fully instantiated type. If ARG can be
16870 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
16871 TARGS are as for unify. */
16873 static tree
16876 {
16877 tree copy_of_targs;
16884 /* We need to make a new template argument vector for the call to
16885 unify. If we used TARGS, we'd clutter it up with the result of
16886 the attempted unification, even if this class didn't work out.
16887 We also don't want to commit ourselves to all the unifications
16888 we've already done, since unification is supposed to be done on
16889 an argument-by-argument basis. In other words, consider the
16890 following pathological case:
16892 template <int I, int J, int K>
16893 struct S {};
16895 template <int I, int J>
16896 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
16898 template <int I, int J, int K>
16899 void f(S<I, J, K>, S<I, I, I>);
16901 void g() {
16902 S<0, 0, 0> s0;
16903 S<0, 1, 2> s2;
16905 f(s0, s2);
16906 }
16908 Now, by the time we consider the unification involving `s2', we
16909 already know that we must have `f<0, 0, 0>'. But, even though
16910 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
16911 because there are two ways to unify base classes of S<0, 1, 2>
16912 with S<I, I, I>. If we kept the already deduced knowledge, we
16913 would reject the possibility I=1. */
16916 /* If unification failed, we're done. */
16922 }
16924 /* Given a template type PARM and a class type ARG, find the unique
16925 base type in ARG that is an instance of PARM. We do not examine
16926 ARG itself; only its base-classes. If there is not exactly one
16927 appropriate base class, return NULL_TREE. PARM may be the type of
16928 a partial specialization, as well as a plain template type. Used
16929 by unify. */
16931 static enum template_base_result
16934 {
16936 tree binfo;
16942 {
16943 /* The type could not be completed. */
16946 }
16948 /* Walk in inheritance graph order. The search order is not
16949 important, and this avoids multiple walks of virtual bases. */
16951 {
16956 {
16957 /* If there is more than one satisfactory baseclass, then:
16959 [temp.deduct.call]
16961 If they yield more than one possible deduced A, the type
16962 deduction fails.
16964 applies. */
16966 {
16969 }
16972 }
16973 }
16977 }
16979 /* Returns the level of DECL, which declares a template parameter. */
16981 static int
16983 {
16985 {
16995 }
16997 }
16999 /* Decide whether ARG can be unified with PARM, considering only the
17000 cv-qualifiers of each type, given STRICT as documented for unify.
17001 Returns nonzero iff the unification is OK on that basis. */
17003 static int
17005 {
17011 {
17012 /* Although a CVR qualifier is ignored when being applied to a
17013 substituted template parameter ([8.3.2]/1 for example), that
17014 does not allow us to unify "const T" with "int&" because both
17015 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
17016 It is ok when we're allowing additional CV qualifiers
17017 at the outer level [14.8.2.1]/3,1st bullet. */
17027 }
17038 }
17040 /* Determines the LEVEL and INDEX for the template parameter PARM. */
17041 void
17043 {
17047 {
17050 }
17051 else
17052 {
17055 }
17056 }
17058 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
17059 do { \
17060 if (unify (TP, TA, P, A, S, EP)) \
17061 return 1; \
17062 } while (0);
17064 /* Unifies the remaining arguments in PACKED_ARGS with the pack
17065 expansion at the end of PACKED_PARMS. Returns 0 if the type
17066 deduction succeeds, 1 otherwise. STRICT is the same as in
17067 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
17068 call argument list. We'll need to adjust the arguments to make them
17069 types. SUBR tells us if this is from a recursive call to
17070 type_unification_real, or for comparing two template argument
17071 lists. */
17073 static int
17077 {
17078 tree parm
17088 /* Determine the parameter packs we will be deducing from the
17089 pattern, and record their current deductions. */
17092 {
17096 /* Determine the index and level of this parameter pack. */
17099 /* Keep track of the parameter packs and their corresponding
17100 argument packs. */
17103 }
17105 /* Loop through all of the arguments that have not yet been
17106 unified and unify each with the pattern. */
17108 {
17109 tree parm;
17113 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
17114 or the element of its argument pack at the current index if
17115 this argument was explicitly specified. */
17117 {
17126 {
17129 }
17131 }
17133 /* If we had explicit template arguments, substitute them into the
17134 pattern before deduction. */
17136 {
17137 /* Some arguments might still be unspecified or dependent. */
17145 NULL_TREE);
17150 }
17151 else
17154 /* Unify the pattern with the current argument. */
17159 /* For each parameter pack, collect the deduced value. */
17161 {
17167 }
17168 }
17170 /* Verify that the results of unification with the parameter packs
17171 produce results consistent with what we've seen before, and make
17172 the deduced argument packs available. */
17174 {
17181 /* By default keep the original deduced argument pack.
17182 If necessary, more specific code is going to update the
17183 resulting deduced argument later down in this function. */
17187 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
17188 actually deduce anything. */
17196 {
17197 /* If we had fewer function args than explicit template args,
17198 just use the explicits. */
17203 }
17206 {
17207 tree result;
17208 /* Build the deduced *_ARGUMENT_PACK. */
17210 {
17215 }
17216 else
17221 /* Note the deduced argument packs for this parameter
17222 pack. */
17224 }
17228 {
17229 /* We only had the explicitly-provided arguments before, but
17230 now we have a complete set of arguments. */
17236 }
17237 else
17238 {
17244 /* Inconsistent unification of this parameter pack. */
17246 bad_old_arg,
17247 bad_new_arg);
17248 }
17249 }
17252 }
17254 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
17255 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
17256 parameters and return value are as for unify. */
17258 static int
17262 {
17263 tree parm_max;
17264 tree arg_max;
17268 /* Our representation of array types uses "N - 1" as the
17269 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
17270 not an integer constant. We cannot unify arbitrarily
17271 complex expressions, so we eliminate the MINUS_EXPRs
17272 here. */
17276 {
17279 }
17283 {
17284 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
17285 trying to unify the type of a variable with the type
17286 of a template parameter. For example:
17288 template <unsigned int N>
17289 void f (char (&) [N]);
17290 int g();
17291 void h(int i) {
17292 char a[g(i)];
17293 f(a);
17294 }
17296 Here, the type of the ARG will be "int [g(i)]", and
17297 may be a SAVE_EXPR, etc. */
17301 }
17303 /* If only one of the bounds used a MINUS_EXPR, compensate
17304 by adding one to the other bound. */
17307 integer_type_node,
17308 parm_max,
17309 integer_one_node);
17312 integer_type_node,
17313 arg_max,
17314 integer_one_node);
17318 }
17320 /* Deduce the value of template parameters. TPARMS is the (innermost)
17321 set of template parameters to a template. TARGS is the bindings
17322 for those template parameters, as determined thus far; TARGS may
17323 include template arguments for outer levels of template parameters
17324 as well. PARM is a parameter to a template function, or a
17325 subcomponent of that parameter; ARG is the corresponding argument.
17326 This function attempts to match PARM with ARG in a manner
17327 consistent with the existing assignments in TARGS. If more values
17328 are deduced, then TARGS is updated.
17330 Returns 0 if the type deduction succeeds, 1 otherwise. The
17331 parameter STRICT is a bitwise or of the following flags:
17333 UNIFY_ALLOW_NONE:
17334 Require an exact match between PARM and ARG.
17335 UNIFY_ALLOW_MORE_CV_QUAL:
17336 Allow the deduced ARG to be more cv-qualified (by qualification
17337 conversion) than ARG.
17338 UNIFY_ALLOW_LESS_CV_QUAL:
17339 Allow the deduced ARG to be less cv-qualified than ARG.
17340 UNIFY_ALLOW_DERIVED:
17341 Allow the deduced ARG to be a template base class of ARG,
17342 or a pointer to a template base class of the type pointed to by
17343 ARG.
17344 UNIFY_ALLOW_INTEGER:
17345 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
17346 case for more information.
17347 UNIFY_ALLOW_OUTER_LEVEL:
17348 This is the outermost level of a deduction. Used to determine validity
17349 of qualification conversions. A valid qualification conversion must
17350 have const qualified pointers leading up to the inner type which
17351 requires additional CV quals, except at the outer level, where const
17352 is not required [conv.qual]. It would be normal to set this flag in
17353 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
17354 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
17355 This is the outermost level of a deduction, and PARM can be more CV
17356 qualified at this point.
17357 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
17358 This is the outermost level of a deduction, and PARM can be less CV
17359 qualified at this point. */
17361 static int
17364 {
17366 tree targ;
17367 tree tparm;
17370 /* I don't think this will do the right thing with respect to types.
17371 But the only case I've seen it in so far has been array bounds, where
17372 signedness is the only information lost, and I think that will be
17373 okay. */
17381 /* We can't deduce anything from this, but we might get all the
17382 template args from other function args. */
17385 /* If PARM uses template parameters, then we can't bail out here,
17386 even if ARG == PARM, since we won't record unifications for the
17387 template parameters. We might need them if we're trying to
17388 figure out which of two things is more specialized. */
17392 /* Handle init lists early, so the rest of the function can assume
17393 we're dealing with a type. */
17395 {
17400 /* Replace T with std::initializer_list<T> for deduction. */
17407 /* We can only deduce from an initializer list argument if the
17408 parameter is std::initializer_list or an array; otherwise this
17409 is a non-deduced context. */
17414 else
17418 {
17425 {
17427 /* It should only be possible to get here for a call. */
17429 elt_strict |= maybe_adjust_types_for_deduction
17432 }
17435 explain_p);
17436 }
17440 {
17441 /* Also deduce from the length of the initializer list. */
17448 }
17450 /* If the std::initializer_list<T> deduction worked, replace the
17451 deduced A with std::initializer_list<A>. */
17453 {
17458 }
17460 }
17462 /* Immediately reject some pairs that won't unify because of
17463 cv-qualification mismatches. */
17466 /* It is the elements of the array which hold the cv quals of an array
17467 type, and the elements might be template type parms. We'll check
17468 when we recurse. */
17470 /* We check the cv-qualifiers when unifying with template type
17471 parameters below. We want to allow ARG `const T' to unify with
17472 PARM `T' for example, when computing which of two templates
17473 is more specialized, for example. */
17487 {
17491 /* In a type which contains a nested-name-specifier, template
17492 argument values cannot be deduced for template parameters used
17493 within the nested-name-specifier. */
17505 /* The PARM is not one we're trying to unify. Just check
17506 to see if it matches ARG. */
17507 {
17512 else
17514 }
17521 /* Check for mixed types and values. */
17529 {
17530 /* ARG must be constructed from a template class or a template
17531 template parameter. */
17535 {
17537 /* An alias template name is never deduced. */
17542 tree parm_parms
17543 = DECL_INNERMOST_TEMPLATE_PARMS
17548 /* The resolution to DR150 makes clear that default
17549 arguments for an N-argument may not be used to bind T
17550 to a template template parameter with fewer than N
17551 parameters. It is not safe to permit the binding of
17552 default arguments as an extension, as that may change
17553 the meaning of a conforming program. Consider:
17555 struct Dense { static const unsigned int dim = 1; };
17557 template <template <typename> class View,
17558 typename Block>
17559 void operator+(float, View<Block> const&);
17561 template <typename Block,
17562 unsigned int Dim = Block::dim>
17563 struct Lvalue_proxy { operator float() const; };
17565 void
17566 test_1d (void) {
17567 Lvalue_proxy<Dense> p;
17568 float b;
17569 b + p;
17570 }
17572 Here, if Lvalue_proxy is permitted to bind to View, then
17573 the global operator+ will be used; if they are not, the
17574 Lvalue_proxy will be converted to float. */
17576 full_argvec,
17578 (explain_p
17579 ? tf_warning_or_error
17586 /* Deduce arguments T, i from TT<T> or TT<i>.
17587 We check each element of PARMVEC and ARGVEC individually
17588 rather than the whole TREE_VEC since they can have
17589 different number of elements. */
17596 /* Check if the parameters end in a pack, making them
17597 variadic. */
17603 /* If the template argument list of P contains a pack
17604 expansion that is not the last template argument, the
17605 entire template argument list is a non-deduced
17606 context. */
17615 {
17620 }
17625 DEDUCE_EXACT,
17628 }
17631 /* Fall through to deduce template name. */
17632 }
17636 {
17637 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
17639 /* Simple cases: Value already set, does match or doesn't. */
17644 }
17645 else
17646 {
17647 /* If PARM is `const T' and ARG is only `int', we don't have
17648 a match unless we are allowing additional qualification.
17649 If ARG is `const int' and PARM is just `T' that's OK;
17650 that binds `const int' to `T'. */
17655 /* Consider the case where ARG is `const volatile int' and
17656 PARM is `const T'. Then, T should be `volatile int'. */
17657 arg = cp_build_qualified_type_real
17662 /* Simple cases: Value already set, does match or doesn't. */
17668 /* Make sure that ARG is not a variable-sized array. (Note
17669 that were talking about variable-sized arrays (like
17670 `int[n]'), rather than arrays of unknown size (like
17671 `int[]').) We'll get very confused by such a type since
17672 the bound of the array is not constant, and therefore
17673 not mangleable. Besides, such types are not allowed in
17674 ISO C++, so we can do as we please here. We do allow
17675 them for 'auto' deduction, since that isn't ABI-exposed. */
17679 /* Strip typedefs as in convert_template_argument. */
17681 }
17683 /* If ARG is a parameter pack or an expansion, we cannot unify
17684 against it unless PARM is also a parameter pack. */
17689 /* If the argument deduction results is a METHOD_TYPE,
17690 then there is a problem.
17691 METHOD_TYPE doesn't map to any real C++ type the result of
17692 the deduction can not be of that type. */
17706 {
17707 /* The PARM is not one we're trying to unify. Just check
17708 to see if it matches ARG. */
17714 }
17720 {
17725 }
17727 /* [temp.deduct.type] If, in the declaration of a function template
17728 with a non-type template-parameter, the non-type
17729 template-parameter is used in an expression in the function
17730 parameter-list and, if the corresponding template-argument is
17731 deduced, the template-argument type shall match the type of the
17732 template-parameter exactly, except that a template-argument
17733 deduced from an array bound may be of any integral type.
17734 The non-type parameter might use already deduced type parameters. */
17737 /* Template-parameter dependent expression. Just accept it for now.
17738 It will later be processed in convert_template_argument. */
17739 ;
17744 /* Convert the ARG to the type of PARM; the deduced non-type
17745 template argument must exactly match the types of the
17746 corresponding parameter. */
17749 /* We haven't deduced the type of this parameter yet. Try again
17750 later. */
17752 else
17755 /* If ARG is a parameter pack or an expansion, we cannot unify
17756 against it unless PARM is also a parameter pack. */
17766 {
17767 /* A pointer-to-member constant can be unified only with
17768 another constant. */
17772 /* Just unify the class member. It would be useless (and possibly
17773 wrong, depending on the strict flags) to unify also
17774 PTRMEM_CST_CLASS, because we want to be sure that both parm and
17775 arg refer to the same variable, even if through different
17776 classes. For instance:
17778 struct A { int x; };
17779 struct B : A { };
17781 Unification of &A::x and &B::x must succeed. */
17784 }
17787 {
17791 /* [temp.deduct.call]
17793 A can be another pointer or pointer to member type that can
17794 be converted to the deduced A via a qualification
17795 conversion (_conv.qual_).
17797 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
17798 This will allow for additional cv-qualification of the
17799 pointed-to types if appropriate. */
17802 /* The derived-to-base conversion only persists through one
17803 level of pointers. */
17808 }
17840 /* We have already checked cv-qualification at the top of the
17841 function. */
17845 /* As far as unification is concerned, this wins. Later checks
17846 will invalidate it if necessary. */
17849 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
17850 /* Type INTEGER_CST can come from ordinary constant template args. */
17862 {
17872 /* Check for pack expansions in the parameters. */
17874 {
17876 {
17878 /* We can unify against something with a trailing
17879 parameter pack. */
17881 else
17882 /* [temp.deduct.type]/9: If the template argument list of
17883 P contains a pack expansion that is not the last
17884 template argument, the entire template argument list
17885 is a non-deduced context. */
17887 }
17888 }
17890 /* If we don't have enough arguments to satisfy the parameters
17891 (not counting the pack expression at the end), or we have
17892 too many arguments for a parameter list that doesn't end in
17893 a pack expression, we can't unify. */
17899 /* Unify all of the parameters that precede the (optional)
17900 pack expression. */
17902 {
17907 }
17910 DEDUCE_EXACT,
17913 }
17921 {
17929 }
17932 {
17936 {
17937 /* First, we try to unify the PARM and ARG directly. */
17942 {
17943 /* Fallback to the special case allowed in
17944 [temp.deduct.call]:
17946 If P is a class, and P has the form
17947 template-id, then A can be a derived class of
17948 the deduced A. Likewise, if P is a pointer to
17949 a class of the form template-id, A can be a
17950 pointer to a derived class pointed to by the
17951 deduced A. */
17958 }
17959 }
17963 /* Perhaps PARM is something like S<U> and ARG is S<int>.
17964 Then, we should unify `int' and `U'. */
17966 else
17967 /* There's no chance of unification succeeding. */
17972 }
17979 {
17982 tree a;
17988 /* CV qualifications for methods can never be deduced, they must
17989 match exactly. We need to check them explicitly here,
17990 because type_unification_real treats them as any other
17991 cv-qualified parameter. */
17993 && (!check_cv_quals_for_unify
18013 }
18016 /* Unify a pointer to member with a pointer to member function, which
18017 deduces the type of the member as a function type. */
18019 {
18020 /* Check top-level cv qualifiers */
18028 /* Determine the type of the function we are unifying against. */
18032 }
18051 /* Matched cases are handled by the ARG == PARM test above. */
18055 /* A non-type template parameter that is a variable should be a
18056 an integral constant, in which case, it whould have been
18057 folded into its (constant) value. So we should not be getting
18058 a variable here. */
18069 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
18070 or UNDERLYING_TYPE nodes. */
18074 /* Unification fails if we hit an error node. */
18081 /* FALLTHRU */
18084 /* An unresolved overload is a nondeduced context. */
18089 /* We must be looking at an expression. This can happen with
18090 something like:
18092 template <int I>
18093 void foo(S<I>, S<I + 2>);
18095 This is a "nondeduced context":
18097 [deduct.type]
18099 The nondeduced contexts are:
18101 --A type that is a template-id in which one or more of
18102 the template-arguments is an expression that references
18103 a template-parameter.
18105 In these cases, we assume deduction succeeded, but don't
18106 actually infer any unifications. */
18111 else
18113 }
18114 }
18115 #undef RECUR_AND_CHECK_FAILURE
18116 \f
18117 /* Note that DECL can be defined in this translation unit, if
18118 required. */
18120 static void
18122 {
18123 tree clone;
18127 }
18129 /* Called if RESULT is explicitly instantiated, or is a member of an
18130 explicitly instantiated class. */
18132 void
18134 {
18137 /* If this entity has already been written out, it's too late to
18138 make any modifications. */
18142 /* For anonymous namespace we don't need to do anything. */
18144 {
18147 }
18150 /* The TREE_PUBLIC flag for function declarations will have been
18151 set correctly by tsubst. */
18154 /* This might have been set by an earlier implicit instantiation. */
18159 else
18160 {
18163 /* Always make artificials weak. */
18166 /* For WIN32 we also want to put explicit instantiations in
18167 linkonce sections. */
18170 }
18172 /* If EXTERN_P, then this function will not be emitted -- unless
18173 followed by an explicit instantiation, at which point its linkage
18174 will be adjusted. If !EXTERN_P, then this function will be
18175 emitted here. In neither circumstance do we want
18176 import_export_decl to adjust the linkage. */
18178 }
18180 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
18181 important template arguments. If any are missing, we check whether
18182 they're important by using error_mark_node for substituting into any
18183 args that were used for partial ordering (the ones between ARGS and END)
18184 and seeing if it bubbles up. */
18186 static bool
18188 {
18193 {
18196 }
18198 {
18202 }
18204 }
18206 /* Given two function templates PAT1 and PAT2, return:
18208 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
18209 -1 if PAT2 is more specialized than PAT1.
18210 0 if neither is more specialized.
18212 LEN indicates the number of parameters we should consider
18213 (defaulted parameters should not be considered).
18215 The 1998 std underspecified function template partial ordering, and
18216 DR214 addresses the issue. We take pairs of arguments, one from
18217 each of the templates, and deduce them against each other. One of
18218 the templates will be more specialized if all the *other*
18219 template's arguments deduce against its arguments and at least one
18220 of its arguments *does* *not* deduce against the other template's
18221 corresponding argument. Deduction is done as for class templates.
18222 The arguments used in deduction have reference and top level cv
18223 qualifiers removed. Iff both arguments were originally reference
18224 types *and* deduction succeeds in both directions, an lvalue reference
18225 wins against an rvalue reference and otherwise the template
18226 with the more cv-qualified argument wins for that pairing (if
18227 neither is more cv-qualified, they both are equal). Unlike regular
18228 deduction, after all the arguments have been deduced in this way,
18229 we do *not* verify the deduced template argument values can be
18230 substituted into non-deduced contexts.
18232 The logic can be a bit confusing here, because we look at deduce1 and
18233 targs1 to see if pat2 is at least as specialized, and vice versa; if we
18234 can find template arguments for pat1 to make arg1 look like arg2, that
18235 means that arg2 is at least as specialized as arg1. */
18237 int
18239 {
18252 /* Remove the this parameter from non-static member functions. If
18253 one is a non-static member function and the other is not a static
18254 member function, remove the first parameter from that function
18255 also. This situation occurs for operator functions where we
18256 locate both a member function (with this pointer) and non-member
18257 operator (with explicit first operand). */
18259 {
18264 }
18266 {
18269 {
18270 len--;
18272 }
18273 }
18275 /* If only one is a conversion operator, they are unordered. */
18279 /* Consider the return type for a conversion function */
18281 {
18284 len++;
18285 }
18287 processing_template_decl++;
18293 /* Stop when an ellipsis is seen. */
18295 {
18306 {
18307 /* When both arguments are pack expansions, we need only
18308 unify the patterns themselves. */
18312 /* This is the last comparison we need to do. */
18314 }
18317 {
18321 }
18324 {
18328 }
18334 {
18340 /* Setup the parameter vector, which contains only ARG1. */
18343 /* Setup the argument vector, which contains the remaining
18344 arguments. */
18353 /* We cannot deduce in the other direction, because ARG1 is
18354 a pack expansion but ARG2 is not. */
18356 }
18358 {
18364 /* Setup the parameter vector, which contains only ARG1. */
18367 /* Setup the argument vector, which contains the remaining
18368 arguments. */
18377 /* We cannot deduce in the other direction, because ARG2 is
18378 a pack expansion but ARG1 is not.*/
18380 }
18382 else
18383 {
18384 /* The normal case, where neither argument is a pack
18385 expansion. */
18392 }
18394 /* If we couldn't deduce arguments for tparms1 to make arg1 match
18395 arg2, then arg2 is not as specialized as arg1. */
18401 /* "If, for a given type, deduction succeeds in both directions
18402 (i.e., the types are identical after the transformations above)
18403 and both P and A were reference types (before being replaced with
18404 the type referred to above):
18405 - if the type from the argument template was an lvalue reference and
18406 the type from the parameter template was not, the argument type is
18407 considered to be more specialized than the other; otherwise,
18408 - if the type from the argument template is more cv-qualified
18409 than the type from the parameter template (as described above),
18410 the argument type is considered to be more specialized than the other;
18411 otherwise,
18412 - neither type is more specialized than the other." */
18415 {
18417 {
18420 else
18422 }
18424 {
18429 }
18430 }
18433 /* We've failed to deduce something in either direction.
18434 These must be unordered. */
18439 /* We have already processed all of the arguments in our
18440 handing of the pack expansion type. */
18445 }
18447 /* "In most cases, all template parameters must have values in order for
18448 deduction to succeed, but for partial ordering purposes a template
18449 parameter may remain without a value provided it is not used in the
18450 types being used for partial ordering."
18452 Thus, if we are missing any of the targs1 we need to substitute into
18453 origs1, then pat2 is not as specialized as pat1. This can happen when
18454 there is a nondeduced context. */
18460 processing_template_decl--;
18462 /* All things being equal, if the next argument is a pack expansion
18463 for one function but not for the other, prefer the
18464 non-variadic function. FIXME this is bogus; see c++/41958. */
18468 {
18471 }
18477 else
18479 }
18481 /* Determine which of two partial specializations of TMPL is more
18482 specialized.
18484 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
18485 to the first partial specialization. The TREE_VALUE is the
18486 innermost set of template parameters for the partial
18487 specialization. PAT2 is similar, but for the second template.
18489 Return 1 if the first partial specialization is more specialized;
18490 -1 if the second is more specialized; 0 if neither is more
18491 specialized.
18493 See [temp.class.order] for information about determining which of
18494 two templates is more specialized. */
18496 static int
18498 {
18499 tree targs;
18507 /* Just like what happens for functions, if we are ordering between
18508 different class template specializations, we may encounter dependent
18509 types in the arguments, and we need our dependency check functions
18510 to behave correctly. */
18516 {
18519 }
18525 {
18528 }
18531 /* In the case of a tie where at least one of the class templates
18532 has a parameter pack at the end, the template with the most
18533 non-packed parameters wins. */
18535 && any_deductions
18538 {
18544 /* We don't count the pack expansion at the end. */
18554 }
18557 }
18559 /* Return the template arguments that will produce the function signature
18560 DECL from the function template FN, with the explicit template
18561 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
18562 also match. Return NULL_TREE if no satisfactory arguments could be
18563 found. */
18565 static tree
18567 {
18571 tree decl_arg_types;
18574 tree arg;
18578 /* Never do unification on the 'this' parameter. */
18599 }
18601 /* Return the innermost template arguments that, when applied to a partial
18602 specialization of TMPL whose innermost template parameters are
18603 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
18604 ARGS.
18606 For example, suppose we have:
18608 template <class T, class U> struct S {};
18609 template <class T> struct S<T*, int> {};
18611 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
18612 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
18613 int}. The resulting vector will be {double}, indicating that `T'
18614 is bound to `double'. */
18616 static tree
18618 {
18620 tree deduced_args;
18621 tree innermost_deduced_args;
18625 {
18629 innermost_deduced_args);
18630 }
18631 else
18644 /* Verify that nondeduced template arguments agree with the type
18645 obtained from argument deduction.
18647 For example:
18649 struct A { typedef int X; };
18650 template <class T, class U> struct C {};
18651 template <class T> struct C<T, typename T::X> {};
18653 Then with the instantiation `C<A, int>', we can deduce that
18654 `T' is `A' but unify () does not check whether `typename T::X'
18655 is `int'. */
18661 /* We only need to check the innermost arguments; the other
18662 arguments will always agree. */
18667 /* Now that we have bindings for all of the template arguments,
18668 ensure that the arguments deduced for the template template
18669 parameters have compatible template parameter lists. See the use
18670 of template_template_parm_bindings_ok_p in fn_type_unification
18671 for more information. */
18676 }
18678 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
18679 Return the TREE_LIST node with the most specialized template, if
18680 any. If there is no most specialized template, the error_mark_node
18681 is returned.
18683 Note that this function does not look at, or modify, the
18684 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
18685 returned is one of the elements of INSTANTIATIONS, callers may
18686 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
18687 and retrieve it from the value returned. */
18689 tree
18691 {
18698 {
18704 fate--;
18709 fate++;
18714 {
18715 /* Equally specialized, move to next function. If there
18716 is no next function, nothing's most specialized. */
18721 }
18722 }
18725 /* Now verify that champ is better than everything earlier in the
18726 instantiation list. */
18734 {
18737 }
18739 processing_template_decl--;
18745 }
18747 /* If DECL is a specialization of some template, return the most
18748 general such template. Otherwise, returns NULL_TREE.
18750 For example, given:
18752 template <class T> struct S { template <class U> void f(U); };
18754 if TMPL is `template <class U> void S<int>::f(U)' this will return
18755 the full template. This function will not trace past partial
18756 specializations, however. For example, given in addition:
18758 template <class T> struct S<T*> { template <class U> void f(U); };
18760 if TMPL is `template <class U> void S<int*>::f(U)' this will return
18761 `template <class T> template <class U> S<T*>::f(U)'. */
18763 tree
18765 {
18766 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
18767 an immediate specialization. */
18769 {
18773 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
18774 template friend. */
18779 }
18781 /* Look for more and more general templates. */
18783 {
18784 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
18785 (See cp-tree.h for details.) */
18793 /* Stop if we run into an explicitly specialized class template. */
18800 }
18803 }
18805 /* Return the most specialized of the class template partial
18806 specializations which can produce TYPE, a specialization of some class
18807 template. The value returned is actually a TREE_LIST; the TREE_TYPE is
18808 a _TYPE node corresponding to the partial specialization, while the
18809 TREE_PURPOSE is the set of template arguments that must be
18810 substituted into the TREE_TYPE in order to generate TYPE.
18812 If the choice of partial specialization is ambiguous, a diagnostic
18813 is issued, and the error_mark_node is returned. If there are no
18814 partial specializations matching TYPE, then NULL_TREE is
18815 returned, indicating that the primary template should be used. */
18817 static tree
18819 {
18821 tree t;
18822 tree champ;
18831 /* For determining which partial specialization to use, only the
18832 innermost args are interesting. */
18834 {
18837 }
18840 {
18841 tree partial_spec_args;
18842 tree spec_args;
18851 {
18852 /* Discard the outer levels of args, and then substitute in the
18853 template args from the enclosing class. */
18855 partial_spec_args = tsubst_template_args
18858 /* And the same for the partial specialization TEMPLATE_DECL. */
18860 }
18862 partial_spec_args =
18864 partial_spec_args,
18878 partial_spec_args,
18879 args);
18881 {
18886 }
18887 }
18897 {
18900 ;
18901 else
18902 {
18904 {
18907 {
18910 }
18911 }
18913 }
18914 }
18918 {
18921 {
18924 }
18925 }
18928 {
18936 {
18939 }
18942 }
18945 }
18947 /* Explicitly instantiate DECL. */
18949 void
18951 {
18956 /* An error occurred, for which grokdeclarator has already issued
18957 an appropriate message. */
18960 {
18963 }
18965 {
18966 /* There is an asymmetry here in the way VAR_DECLs and
18967 FUNCTION_DECLs are handled by grokdeclarator. In the case of
18968 the latter, the DECL we get back will be marked as a
18969 template instantiation, and the appropriate
18970 DECL_TEMPLATE_INFO will be set up. This does not happen for
18971 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
18972 should handle VAR_DECLs as it currently handles
18973 FUNCTION_DECLs. */
18975 {
18978 }
18981 {
18984 }
18986 {
18991 }
18992 }
18994 {
18997 }
18998 else
19001 /* Check for various error cases. Note that if the explicit
19002 instantiation is valid the RESULT will currently be marked as an
19003 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
19004 until we get here. */
19007 {
19008 /* DR 259 [temp.spec].
19010 Both an explicit instantiation and a declaration of an explicit
19011 specialization shall not appear in a program unless the explicit
19012 instantiation follows a declaration of the explicit specialization.
19014 For a given set of template parameters, if an explicit
19015 instantiation of a template appears after a declaration of an
19016 explicit specialization for that template, the explicit
19017 instantiation has no effect. */
19019 }
19021 {
19022 /* [temp.spec]
19024 No program shall explicitly instantiate any template more
19025 than once.
19027 We check DECL_NOT_REALLY_EXTERN so as not to complain when
19028 the first instantiation was `extern' and the second is not,
19029 and EXTERN_P for the opposite case. */
19032 /* If an "extern" explicit instantiation follows an ordinary
19033 explicit instantiation, the template is instantiated. */
19036 }
19038 {
19041 }
19043 {
19046 }
19049 ;
19051 {
19054 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
19057 }
19058 else
19066 }
19068 static void
19070 {
19076 {
19079 }
19080 }
19082 /* Called from do_type_instantiation through binding_table_foreach to
19083 do recursive instantiation for the type bound in ENTRY. */
19084 static void
19086 {
19092 }
19094 /* Called from do_type_instantiation to instantiate a member
19095 (a member function or a static member variable) of an
19096 explicitly instantiated class template. */
19097 static void
19099 {
19104 }
19106 /* Perform an explicit instantiation of template class T. STORAGE, if
19107 non-null, is the RID for extern, inline or static. COMPLAIN is
19108 nonzero if this is called from the parser, zero if called recursively,
19109 since the standard is unclear (as detailed below). */
19111 void
19113 {
19123 {
19124 tree tmpl =
19128 else
19131 }
19136 {
19139 t);
19141 }
19144 {
19146 {
19148 {
19151 "ISO C++ 1998 forbids the use of %<extern%> on "
19153 }
19154 else
19156 "ISO C++ forbids the use of %qE"
19158 }
19166 else
19167 {
19169 storage);
19171 }
19172 }
19175 {
19176 /* DR 259 [temp.spec].
19178 Both an explicit instantiation and a declaration of an explicit
19179 specialization shall not appear in a program unless the explicit
19180 instantiation follows a declaration of the explicit specialization.
19182 For a given set of template parameters, if an explicit
19183 instantiation of a template appears after a declaration of an
19184 explicit specialization for that template, the explicit
19185 instantiation has no effect. */
19187 }
19189 {
19190 /* [temp.spec]
19192 No program shall explicitly instantiate any template more
19193 than once.
19195 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
19196 instantiation was `extern'. If EXTERN_P then the second is.
19197 These cases are OK. */
19204 /* If we've already instantiated the template, just return now. */
19207 }
19215 {
19216 tree tmp;
19218 /* In contrast to implicit instantiation, where only the
19219 declarations, and not the definitions, of members are
19220 instantiated, we have here:
19222 [temp.explicit]
19224 The explicit instantiation of a class template specialization
19225 implies the instantiation of all of its members not
19226 previously explicitly specialized in the translation unit
19227 containing the explicit instantiation.
19229 Of course, we can't instantiate member template classes, since
19230 we don't have any arguments for them. Note that the standard
19231 is unclear on whether the instantiation of the members are
19232 *explicit* instantiations or not. However, the most natural
19233 interpretation is that it should be an explicit instantiation. */
19248 }
19249 }
19251 /* Given a function DECL, which is a specialization of TMPL, modify
19252 DECL to be a re-instantiation of TMPL with the same template
19253 arguments. TMPL should be the template into which tsubst'ing
19254 should occur for DECL, not the most general template.
19256 One reason for doing this is a scenario like this:
19258 template <class T>
19259 void f(const T&, int i);
19261 void g() { f(3, 7); }
19263 template <class T>
19264 void f(const T& t, const int i) { }
19266 Note that when the template is first instantiated, with
19267 instantiate_template, the resulting DECL will have no name for the
19268 first parameter, and the wrong type for the second. So, when we go
19269 to instantiate the DECL, we regenerate it. */
19271 static void
19273 {
19274 /* The arguments used to instantiate DECL, from the most general
19275 template. */
19276 tree args;
19277 tree code_pattern;
19282 /* Make sure that we can see identifiers, and compute access
19283 correctly. */
19287 {
19288 tree decl_parm;
19289 tree pattern_parm;
19290 tree specs;
19304 specs);
19306 /* Merge parameter declarations. */
19309 pattern_parm
19313 {
19314 tree parm_type;
19315 tree attributes;
19320 NULL_TREE);
19326 {
19329 }
19332 }
19333 /* Merge any parameters that match with the function parameter
19334 pack. */
19336 {
19338 tree expanded_types;
19339 /* Expand the TYPE_PACK_EXPANSION that provides the types for
19340 the parameters in this function parameter pack. */
19345 {
19346 tree parm_type;
19347 tree attributes;
19350 /* Rename the parameter to include the index. */
19359 {
19362 }
19364 }
19365 }
19366 /* Merge additional specifiers from the CODE_PATTERN. */
19370 }
19372 {
19380 }
19381 else
19385 }
19387 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
19388 substituted to get DECL. */
19390 tree
19392 {
19395 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
19396 for the instantiation. This is not always the most general
19397 template. Consider, for example:
19399 template <class T>
19400 struct S { template <class U> void f();
19401 template <> void f<int>(); };
19403 and an instantiation of S<double>::f<int>. We want TD to be the
19404 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
19406 more general template. */
19408 /* We must also deal with friend templates. Given:
19410 template <class T> struct S {
19411 template <class U> friend void f() {};
19412 };
19414 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
19415 so far as the language is concerned, but that's still
19416 where we get the pattern for the instantiation from. On
19417 other hand, if the definition comes outside the class, say:
19419 template <class T> struct S {
19420 template <class U> friend void f();
19421 };
19422 template <class U> friend void f() {}
19424 we don't need to look any further. That's what the check for
19425 DECL_INITIAL is for. */
19429 {
19430 /* The present template, TD, should not be a definition. If it
19431 were a definition, we should be using it! Note that we
19432 cannot restructure the loop to just keep going until we find
19433 a template with a definition, since that might go too far if
19434 a specialization was declared, but not defined. */
19438 /* Fetch the more general template. */
19440 }
19443 }
19445 /* Returns true if we need to instantiate this template instance even if we
19446 know we aren't going to emit it.. */
19448 bool
19450 {
19451 /* We always instantiate inline functions so that we can inline them. An
19452 explicit instantiation declaration prohibits implicit instantiation of
19453 non-inline functions. With high levels of optimization, we would
19454 normally inline non-inline functions -- but we're not allowed to do
19455 that for "extern template" functions. Therefore, we check
19456 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
19460 /* And we need to instantiate static data members so that
19461 their initializers are available in integral constant
19462 expressions. */
19465 }
19467 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
19468 instantiate it now, modifying TREE_TYPE (fn). */
19470 void
19472 {
19475 /* Don't instantiate a noexcept-specification from template context. */
19490 {
19492 {
19507 }
19508 else
19510 }
19511 else
19512 {
19513 /* This is an implicitly declared function, so NOEX is a list of
19514 other functions to evaluate and merge. */
19515 tree elt;
19518 {
19520 tree subspec;
19524 }
19525 }
19530 {
19533 else
19535 }
19536 }
19538 /* Produce the definition of D, a _DECL generated from a template. If
19539 DEFER_OK is nonzero, then we don't have to actually do the
19540 instantiation now; we just have to do it sometime. Normally it is
19541 an error if this is an explicit instantiation but D is undefined.
19542 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
19543 explicitly instantiated class template. */
19545 tree
19548 {
19550 tree gen_args;
19551 tree args;
19552 tree td;
19553 tree code_pattern;
19554 tree spec;
19555 tree gen_tmpl;
19561 tree fn_context;
19564 /* This function should only be used to instantiate templates for
19565 functions and static member variables. */
19568 /* Variables are never deferred; if instantiation is required, they
19569 are instantiated right away. That allows for better code in the
19570 case that an expression refers to the value of the variable --
19571 if the variable has a constant value the referring expression can
19572 take advantage of that fact. */
19577 /* Don't instantiate cloned functions. Instead, instantiate the
19578 functions they cloned. */
19586 /* D has already been instantiated or explicitly specialized, so
19587 there's nothing for us to do here.
19589 It might seem reasonable to check whether or not D is an explicit
19590 instantiation, and, if so, stop here. But when an explicit
19591 instantiation is deferred until the end of the compilation,
19592 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
19593 the instantiation. */
19596 /* Check to see whether we know that this template will be
19597 instantiated in some other file, as with "extern template"
19598 extension. */
19601 /* In general, we do not instantiate such templates. */
19609 /* We should already have the extra args. */
19612 /* And what's in the hash table should match D. */
19616 /* This needs to happen before any tsubsting. */
19622 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
19623 for the instantiation. */
19627 /* We should never be trying to instantiate a member of a class
19628 template or partial specialization. */
19633 /* In the case of a friend template whose definition is provided
19634 outside the class, we may have too many arguments. Drop the
19635 ones we don't need. The same is true for specializations. */
19636 args = get_innermost_template_args
19638 else
19644 else
19647 /* We may be in the middle of deferred access check. Disable it now. */
19650 /* Unless an explicit instantiation directive has already determined
19651 the linkage of D, remember that a definition is available for
19652 this entity. */
19662 /* If D is a member of an explicitly instantiated class template,
19663 and no definition is available, treat it like an implicit
19664 instantiation. */
19667 {
19668 /* Leave linkage flags alone on instantiations with anonymous
19669 visibility. */
19671 {
19674 }
19676 }
19681 /* Defer all other templates, unless we have been explicitly
19682 forbidden from doing so. */
19684 template. */
19685 ! pattern_defined
19686 /* If it's OK to postpone instantiation, do so. */
19687 || defer_ok
19688 /* If this is a static data member that will be defined
19689 elsewhere, we don't want to instantiate the entire data
19690 member, but we do want to instantiate the initializer so that
19691 we can substitute that elsewhere. */
19693 {
19694 /* The definition of the static data member is now required so
19695 we must substitute the initializer. */
19699 {
19700 tree ns;
19701 tree init;
19708 args,
19711 /* Make sure the initializer is still constant, in case of
19712 circular dependency (template/instantiate6.C). */
19713 const_init
19717 LOOKUP_ONLYCONVERTING);
19720 }
19722 /* We restore the source position here because it's used by
19723 add_pending_template. */
19729 /* [temp.explicit]
19731 The definition of a non-exported function template, a
19732 non-exported member function template, or a non-exported
19733 member function or static data member of a class template
19734 shall be present in every translation unit in which it is
19735 explicitly instantiated. */
19739 /* If we're in unevaluated context, we just wanted to get the
19740 constant value; this isn't an odr use, so don't queue
19741 a full instantiation. */
19744 /* ??? Historically, we have instantiated inline functions, even
19745 when marked as "extern template". */
19748 {
19750 /* Capture module info. */
19754 }
19755 }
19756 /* Tell the repository that D is available in this translation unit
19757 -- and see if it is supposed to be instantiated here. */
19759 {
19760 /* In a PCH file, despite the fact that the repository hasn't
19761 requested instantiation in the PCH it is still possible that
19762 an instantiation will be required in a file that includes the
19763 PCH. */
19766 /* Instantiate inline functions so that the inliner can do its
19767 job, even though we'll not be emitting a copy of this
19768 function. */
19771 }
19777 else
19778 {
19783 }
19785 /* Mark D as instantiated so that recursive calls to
19786 instantiate_decl do not try to instantiate it again. */
19789 /* Regenerate the declaration in case the template has been modified
19790 by a subsequent redeclaration. */
19793 /* We already set the file and line above. Reset them now in case
19794 they changed as a result of calling regenerate_decl_from_template. */
19798 {
19799 tree init;
19802 /* Clear out DECL_RTL; whatever was there before may not be right
19803 since we've reset the type of the declaration. */
19807 /* The initializer is placed in DECL_INITIAL by
19808 regenerate_decl_from_template so we don't need to
19809 push/pop_access_scope again here. Pull it out so that
19810 cp_finish_decl can process it. */
19815 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
19816 initializer. That function will defer actual emission until
19817 we have a chance to determine linkage. */
19820 /* Enter the scope of D so that access-checking works correctly. */
19825 }
19829 {
19831 tree subst_decl;
19832 tree tmpl_parm;
19833 tree spec_parm;
19836 /* Save away the current list, in case we are instantiating one
19837 template from within the body of another. */
19840 /* Set up the list of local specializations. */
19843 /* Set up context. */
19847 else
19850 /* Some typedefs referenced from within the template code need to be
19851 access checked at template instantiation time, i.e now. These
19852 types were added to the template at parsing time. Let's get those
19853 and perform the access checks then. */
19855 gen_args);
19857 /* Create substitution entries for the parameters. */
19862 {
19866 }
19868 {
19870 {
19873 }
19874 else
19875 {
19876 /* Register the (value) argument pack as a specialization of
19877 TMPL_PARM, then move on. */
19880 }
19881 }
19884 /* Substitute into the body of the function. */
19888 else
19889 {
19894 /* Set the current input_location to the end of the function
19895 so that finish_function knows where we are. */
19896 input_location
19899 /* Remember if we saw an infinite loop in the template. */
19900 current_function_infinite_loop
19902 }
19904 /* We don't need the local specializations any more. */
19908 /* Finish the function. */
19912 else
19913 {
19916 }
19920 }
19922 /* We're not deferring instantiation any more. */
19930 out:
19940 }
19942 /* Run through the list of templates that we wish we could
19943 instantiate, and instantiate any we can. RETRIES is the
19944 number of times we retry pending template instantiation. */
19946 void
19948 {
19952 /* Instantiating templates may trigger vtable generation. This in turn
19953 may require further template instantiations. We place a limit here
19954 to avoid infinite loop. */
19956 {
19960 " instantiating %q+D, possibly from virtual table generation"
19964 /* Pretend that we defined it. */
19967 }
19969 do
19970 {
19975 {
19980 {
19981 tree fn;
19984 {
19988 fn;
19996 }
19999 }
20000 else
20001 {
20004 {
20005 instantiation
20011 }
20015 }
20018 /* If INSTANTIATION has been instantiated, then we don't
20019 need to consider it again in the future. */
20021 else
20022 {
20025 }
20028 }
20030 }
20034 }
20036 /* Substitute ARGVEC into T, which is a list of initializers for
20037 either base class or a non-static data member. The TREE_PURPOSEs
20038 are DECLs, and the TREE_VALUEs are the initializer values. Used by
20039 instantiate_decl. */
20041 static tree
20043 {
20047 {
20048 tree decl;
20049 tree init;
20055 {
20056 tree expr;
20057 tree arg;
20059 /* Expand the base class expansion type into separate base
20060 classes. */
20062 tf_warning_or_error,
20063 NULL_TREE);
20067 /* We'll be building separate TREE_LISTs of arguments for
20068 each base. */
20074 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
20075 expand each argument in the TREE_VALUE of t. */
20082 /* VOID_TYPE_NODE is used to indicate
20083 value-initialization. */
20084 {
20087 }
20088 else
20089 {
20090 /* Substitute parameter packs into each argument in the
20091 TREE_LIST. */
20094 {
20095 tree expanded_exprs;
20097 /* Expand the argument. */
20099 expanded_exprs
20101 tf_warning_or_error,
20102 NULL_TREE);
20106 /* Prepend each of the expanded expressions to the
20107 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
20109 {
20114 }
20115 }
20118 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
20119 since we built them backwards. */
20121 {
20124 }
20125 }
20126 }
20129 {
20131 {
20135 }
20136 else
20137 {
20138 tree tmp;
20153 /* If we had an initializer but it instantiated to nothing,
20154 value-initialize the object. This will only occur when
20155 the initializer was a pack expansion where the parameter
20156 packs used in that expansion were of length zero. */
20159 }
20162 {
20166 }
20167 }
20168 }
20170 }
20172 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
20174 static void
20176 {
20181 else
20183 }
20185 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
20186 is the instantiation (which should have been created with
20187 start_enum) and ARGS are the template arguments to use. */
20189 static void
20191 {
20192 tree e;
20198 {
20199 tree value;
20200 tree decl;
20203 /* Note that in a template enum, the TREE_VALUE is the
20204 CONST_DECL, not the corresponding INTEGER_CST. */
20209 /* Give this enumeration constant the correct access. */
20212 /* Actually build the enumerator itself. */
20213 build_enumerator
20215 }
20225 }
20227 /* DECL is a FUNCTION_DECL that is a template specialization. Return
20228 its type -- but without substituting the innermost set of template
20229 arguments. So, innermost set of template parameters will appear in
20230 the type. */
20232 tree
20234 {
20235 tree fn_type;
20236 tree tmpl;
20237 tree targs;
20238 tree tparms;
20246 /* There should be as many levels of arguments as there are levels
20247 of parameters. */
20253 /* No substitution is necessary. */
20254 ;
20255 else
20256 {
20258 tree partial_args;
20260 /* Replace the innermost level of the TARGS with NULL_TREEs to
20261 let tsubst know not to substitute for those parameters. */
20270 /* Make sure that we can see identifiers, and compute access
20271 correctly. */
20275 /* Now, do the (partial) substitution to figure out the
20276 appropriate function type. */
20280 /* Substitute into the template parameters to obtain the real
20281 innermost set of parameters. This step is important if the
20282 innermost set of template parameters contains value
20283 parameters whose types depend on outer template parameters. */
20288 }
20291 }
20293 /* Return truthvalue if we're processing a template different from
20294 the last one involved in diagnostics. */
20295 int
20297 {
20299 }
20301 /* Remember current template involved in diagnostics. */
20302 void
20304 {
20306 }
20310 {
20312 }
20314 /* [temp.param] Check that template non-type parm TYPE is of an allowable
20315 type. Return zero for ok, nonzero for disallowed. Issue error and
20316 warning messages under control of COMPLAIN. */
20318 static int
20320 {
20337 {
20340 else
20342 type);
20343 }
20345 }
20347 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
20348 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
20350 static bool
20352 {
20353 tree scope;
20355 /* [temp.dep.type]
20357 A type is dependent if it is:
20359 -- a template parameter. Template template parameters are types
20360 for us (since TYPE_P holds true for them) so we handle
20361 them here. */
20365 /* -- a qualified-id with a nested-name-specifier which contains a
20366 class-name that names a dependent type or whose unqualified-id
20367 names a dependent type. */
20370 /* -- a cv-qualified type where the cv-unqualified type is
20371 dependent. */
20373 /* -- a compound type constructed from any dependent type. */
20383 {
20384 tree arg_type;
20389 arg_type;
20394 }
20395 /* -- an array type constructed from any dependent type or whose
20396 size is specified by a constant expression that is
20397 value-dependent.
20399 We checked for type- and value-dependence of the bounds in
20400 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
20402 {
20407 }
20409 /* -- a template-id in which either the template name is a template
20410 parameter ... */
20413 /* ... or any of the template arguments is a dependent type or
20414 an expression that is type-dependent or value-dependent. */
20416 && (any_dependent_template_arguments_p
20420 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
20421 dependent; if the argument of the `typeof' expression is not
20422 type-dependent, then it should already been have resolved. */
20428 /* A template argument pack is dependent if any of its packed
20429 arguments are. */
20431 {
20437 }
20439 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
20440 be template parameters. */
20444 /* The standard does not specifically mention types that are local
20445 to template functions or local classes, but they should be
20446 considered dependent too. For example:
20448 template <int I> void f() {
20449 enum E { a = I };
20450 S<sizeof (E)> s;
20451 }
20453 The size of `E' cannot be known until the value of `I' has been
20454 determined. Therefore, `E' must be considered dependent. */
20458 /* Don't use type_dependent_expression_p here, as it can lead
20459 to infinite recursion trying to determine whether a lambda
20460 nested in a lambda is dependent (c++/47687). */
20464 && (any_dependent_template_arguments_p
20468 /* Other types are non-dependent. */
20470 }
20472 /* Returns TRUE if TYPE is dependent, in the sense of
20473 [temp.dep.type]. Note that a NULL type is considered dependent. */
20475 bool
20477 {
20478 /* If there are no template parameters in scope, then there can't be
20479 any dependent types. */
20481 {
20482 /* If we are not processing a template, then nobody should be
20483 providing us with a dependent type. */
20487 }
20489 /* If the type is NULL, we have not computed a type for the entity
20490 in question; in that case, the type is dependent. */
20494 /* Erroneous types can be considered non-dependent. */
20498 /* If we have not already computed the appropriate value for TYPE,
20499 do so now. */
20501 {
20504 }
20507 }
20509 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
20510 lookup. In other words, a dependent type that is not the current
20511 instantiation. */
20513 bool
20515 {
20518 }
20520 /* T is a SCOPE_REF; return whether we need to consider it
20521 instantiation-dependent so that we can check access at instantiation
20522 time even though we know which member it resolves to. */
20524 static bool
20526 {
20532 else
20534 }
20536 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
20537 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
20538 expression. */
20540 /* Note that this predicate is not appropriate for general expressions;
20541 only constant expressions (that satisfy potential_constant_expression)
20542 can be tested for value dependence. */
20544 bool
20546 {
20550 /* A name declared with a dependent type. */
20555 {
20557 /* A name that has not been looked up -- must be dependent. */
20561 /* A non-type template parm. */
20565 /* A non-type template parm. */
20571 /* A constant with literal type and is initialized
20572 with an expression that is value-dependent.
20574 Note that a non-dependent parenthesized initializer will have
20575 already been replaced with its constant value, so if we see
20576 a TREE_LIST it must be dependent. */
20589 /* These expressions are value-dependent if the type to which
20590 the cast occurs is dependent or the expression being casted
20591 is value-dependent. */
20592 {
20598 /* A functional cast has a list of operands. */
20601 {
20602 /* If there are no operands, it must be an expression such
20603 as "int()". This should not happen for aggregate types
20604 because it would form non-constant expressions. */
20609 }
20615 }
20620 /* FALLTHRU */
20623 /* A `sizeof' expression is value-dependent if the operand is
20624 type-dependent or is a pack expansion. */
20633 /* An 'encode' expression is value-dependent if the operand is
20634 type-dependent. */
20643 /* All instantiation-dependent expressions should also be considered
20644 value-dependent. */
20652 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
20653 is value-dependent. */
20654 {
20663 }
20666 {
20670 }
20681 {
20685 }
20688 {
20695 {
20697 /* In a call to a constexpr member function, look through the
20698 implicit ADDR_EXPR on the object argument so that it doesn't
20699 cause the call to be considered value-dependent. We also
20700 look through it in potential_constant_expression. */
20707 }
20709 }
20712 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
20713 type-dependent. */
20717 {
20719 tree val;
20724 }
20727 /* Treat a GNU statement expression as dependent to avoid crashing
20728 under fold_non_dependent_expr; it can't be constant. */
20732 /* A constant expression is value-dependent if any subexpression is
20733 value-dependent. */
20735 {
20742 {
20746 {
20749 /* In some cases, some of the operands may be missing.l
20750 (For example, in the case of PREDECREMENT_EXPR, the
20751 amount to increment by may be missing.) That doesn't
20752 make the expression dependent. */
20755 }
20756 }
20760 }
20762 }
20764 /* The expression is not value-dependent. */
20766 }
20768 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
20769 [temp.dep.expr]. Note that an expression with no type is
20770 considered dependent. Other parts of the compiler arrange for an
20771 expression with type-dependent subexpressions to have no type, so
20772 this function doesn't have to be fully recursive. */
20774 bool
20776 {
20783 /* An unresolved name is always dependent. */
20787 /* Some expression forms are never type-dependent. */
20800 /* The types of these expressions depends only on the type to which
20801 the cast occurs. */
20810 /* The types of these expressions depends only on the type created
20811 by the expression. */
20814 {
20815 /* For NEW_EXPR tree nodes created inside a template, either
20816 the object type itself or a TREE_LIST may appear as the
20817 operand 1. */
20820 /* This is an array type. We need to check array dimensions
20821 as well. */
20823 || value_dependent_expression_p
20825 else
20827 }
20830 {
20834 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
20835 contains an identifier associated by name lookup with one or more
20836 declarations declared with a dependent type, or...a
20837 nested-name-specifier or qualified-id that names a member of an
20838 unknown specialization. */
20841 }
20846 && (any_dependent_template_arguments_p
20858 {
20859 tree elt;
20863 {
20866 }
20868 }
20870 /* A static data member of the current instantiation with incomplete
20871 array type is type-dependent, as the definition and specializations
20872 can have different bounds. */
20879 /* An array of unknown bound depending on a variadic parameter, eg:
20881 template<typename... Args>
20882 void foo (Args... args)
20883 {
20884 int arr[] = { args... };
20885 }
20887 template<int... vals>
20888 void bar ()
20889 {
20890 int arr[] = { vals... };
20891 }
20893 If the array has no length and has an initializer, it must be that
20894 we couldn't determine its length in cp_complete_array_type because
20895 it is dependent. */
20903 {
20908 {
20914 }
20915 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
20919 /* Always dependent, on the number of arguments if nothing else. */
20927 {
20932 }
20937 {
20941 }
20943 }
20948 }
20950 /* walk_tree callback function for instantiation_dependent_expression_p,
20951 below. Returns non-zero if a dependent subexpression is found. */
20953 static tree
20956 {
20958 {
20959 /* We don't have to worry about decltype currently because decltype
20960 of an instantiation-dependent expr is a dependent type. This
20961 might change depending on the resolution of DR 1172. */
20964 }
20967 {
20968 /* Don't treat an argument list as dependent just because it has no
20969 TREE_TYPE. */
20976 /* A constant with a dependent initializer is dependent. */
20984 /* Handle expressions with type operands. */
20989 {
20994 {
20997 else
20998 {
21001 }
21002 }
21004 }
21016 /* In a template, finish_class_member_access_expr creates a
21017 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
21018 type-dependent, so that we can check access control at
21019 instantiation time (PR 42277). See also Core issue 1273. */
21026 else
21029 /* Treat statement-expressions as dependent. */
21035 }
21039 else
21041 }
21043 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
21044 sense defined by the ABI:
21046 "An expression is instantiation-dependent if it is type-dependent
21047 or value-dependent, or it has a subexpression that is type-dependent
21048 or value-dependent." */
21050 bool
21052 {
21053 tree result;
21064 }
21066 /* Like type_dependent_expression_p, but it also works while not processing
21067 a template definition, i.e. during substitution or mangling. */
21069 bool
21071 {
21077 }
21079 /* Returns TRUE if ARGS contains a type-dependent expression. */
21081 bool
21083 {
21085 tree arg;
21088 {
21091 }
21093 }
21095 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21096 expressions) contains any type-dependent expressions. */
21098 bool
21100 {
21106 }
21108 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21109 expressions) contains any value-dependent expressions. */
21111 bool
21113 {
21119 }
21121 /* Returns TRUE if the ARG (a template argument) is dependent. */
21123 bool
21125 {
21129 /* Assume a template argument that was wrongly written by the user
21130 is dependent. This is consistent with what
21131 any_dependent_template_arguments_p [that calls this function]
21132 does. */
21143 {
21147 {
21150 }
21153 }
21156 else
21159 }
21161 /* Returns true if ARGS (a collection of template arguments) contains
21162 any types that require structural equality testing. */
21164 bool
21166 {
21176 {
21179 {
21185 {
21186 /* Look inside the argument pack. */
21189 }
21192 {
21205 }
21206 }
21207 }
21210 }
21212 /* Returns true if ARGS (a collection of template arguments) contains
21213 any dependent arguments. */
21215 bool
21217 {
21227 {
21232 }
21235 }
21237 /* Returns TRUE if the template TMPL is dependent. */
21239 bool
21241 {
21243 {
21245 {
21249 }
21251 }
21253 /* Template template parameters are dependent. */
21257 /* So are names that have not been looked up. */
21260 /* So are member templates of dependent classes. */
21264 }
21266 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
21268 bool
21270 {
21273 }
21275 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
21276 is dependent. */
21278 bool
21280 {
21287 {
21308 {
21312 }
21316 {
21320 {
21325 }
21326 }
21327 }
21330 }
21332 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
21333 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
21334 no such TYPE can be found. Note that this function peers inside
21335 uninstantiated templates and therefore should be used only in
21336 extremely limited situations. ONLY_CURRENT_P restricts this
21337 peering to the currently open classes hierarchy (which is required
21338 when comparing types). */
21340 tree
21342 {
21343 tree scope;
21344 tree name;
21345 tree decl;
21347 tree pushed_scope;
21348 tree result;
21353 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
21354 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
21355 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
21356 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
21357 identifier of the TYPENAME_TYPE anymore.
21358 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
21359 TYPENAME_TYPE instead, we avoid messing up with a possible
21360 typedef variant case. */
21363 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
21364 it first before we can figure out what NAME refers to. */
21366 {
21368 /* Given a class template A with a dependent base with nested type C,
21369 typedef typename A::C::C C will land us here, as trying to resolve
21370 the initial A::C leads to the local C typedef, which leads back to
21371 A::C::C. So we break the recursion now. */
21373 else
21375 }
21376 /* If we don't know what SCOPE refers to, then we cannot resolve the
21377 TYPENAME_TYPE. */
21380 /* If the SCOPE is a template type parameter, we have no way of
21381 resolving the name. */
21384 /* If the SCOPE is not the current instantiation, there's no reason
21385 to look inside it. */
21388 /* If this is a typedef, we don't want to look inside (c++/11987). */
21391 /* If SCOPE isn't the template itself, it will not have a valid
21392 TYPE_FIELDS list. */
21394 /* scope is either the template itself or a compatible instantiation
21395 like X<T>, so look up the name in the original template. */
21397 else
21398 /* scope is a partial instantiation, so we can't do the lookup or we
21399 will lose the template arguments. */
21401 /* Enter the SCOPE so that name lookup will be resolved as if we
21402 were in the class definition. In particular, SCOPE will no
21403 longer be considered a dependent type. */
21405 /* Look up the declaration. */
21407 tf_warning_or_error);
21411 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
21412 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
21417 {
21421 }
21424 {
21425 tree tmpl;
21426 tree args;
21427 /* Obtain the template and the arguments. */
21430 /* Instantiate the template. */
21436 }
21438 /* Leave the SCOPE. */
21442 /* If we failed to resolve it, return the original typename. */
21446 /* If lookup found a typename type, resolve that too. */
21448 {
21449 /* Ill-formed programs can cause infinite recursion here, so we
21450 must catch that. */
21454 }
21456 /* Qualify the resulting type. */
21462 }
21464 /* EXPR is an expression which is not type-dependent. Return a proxy
21465 for EXPR that can be used to compute the types of larger
21466 expressions containing EXPR. */
21468 tree
21470 {
21471 tree inner_expr;
21473 #ifdef ENABLE_CHECKING
21474 /* Try to get a constant value for all non-dependent expressions in
21475 order to expose bugs in *_dependent_expression_p and constexpr. */
21478 #endif
21480 /* Preserve OVERLOADs; the functions must be available to resolve
21481 types. */
21492 /* There is no need to return a proxy for a variable. */
21495 /* Preserve string constants; conversions from string constants to
21496 "char *" are allowed, even though normally a "const char *"
21497 cannot be used to initialize a "char *". */
21500 /* Preserve arithmetic constants, as an optimization -- there is no
21501 reason to create a new node. */
21504 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
21505 There is at least one place where we want to know that a
21506 particular expression is a throw-expression: when checking a ?:
21507 expression, there are special rules if the second or third
21508 argument is a throw-expression. */
21512 /* Don't wrap an initializer list, we need to be able to look inside. */
21516 /* Don't wrap a dummy object, we need to be able to test for it. */
21535 /* If the type is unknown, it can't really be non-dependent */
21538 /* Otherwise, build a NON_DEPENDENT_EXPR. */
21540 }
21542 /* ARGS is a vector of expressions as arguments to a function call.
21543 Replace the arguments with equivalent non-dependent expressions.
21544 This modifies ARGS in place. */
21546 void
21548 {
21550 tree arg;
21553 {
21557 }
21558 }
21560 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
21561 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
21562 parms. */
21564 static tree
21566 {
21579 }
21581 tree
21583 {
21585 }
21587 tree
21589 {
21591 }
21593 /* Given type ARG, return std::initializer_list<ARG>. */
21595 static tree
21597 {
21598 tree std_init_list = namespace_binding
21600 tree argvec;
21602 {
21606 }
21611 }
21613 /* Replace auto in TYPE with std::initializer_list<auto>. */
21615 static tree
21617 {
21624 }
21626 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
21627 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
21629 tree
21631 {
21632 tree targs;
21638 /* Defining a subset of type-dependent expressions that we can deduce
21639 from ahead of time isn't worth the trouble. */
21642 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
21643 with either a new invented type template parameter U or, if the
21644 initializer is a braced-init-list (8.5.4), with
21645 std::initializer_list<U>. */
21653 {
21659 {
21662 }
21663 }
21664 else
21665 {
21676 {
21678 /* Try again at instantiation time. */
21681 /* If type is error_mark_node a diagnostic must have been
21682 emitted by now. Also, having a mention to '<type error>'
21683 in the diagnostic is not really useful to the user. */
21684 {
21688 else
21690 }
21692 }
21693 }
21695 /* If the list of declarators contains more than one declarator, the type
21696 of each declared variable is determined as described above. If the
21697 type deduced for the template parameter U is not the same in each
21698 deduction, the program is ill-formed. */
21701 {
21707 else
21711 }
21717 }
21719 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
21720 result. */
21722 tree
21724 {
21725 tree argvec;
21732 /* For a late-specified return type in a template type-parameter, we
21733 need to add a dummy argument level for its parmlist. */
21734 argvec = add_to_template_args
21739 }
21741 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
21742 'decltype(auto)'. */
21744 bool
21746 {
21751 else
21753 }
21755 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
21756 a use of `auto'. Returns NULL_TREE otherwise. */
21758 tree
21760 {
21762 }
21764 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
21765 'decltype(auto)' or a concept. */
21767 bool
21769 {
21771 }
21773 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
21774 a concept identifier) iff TYPE contains a use of a generic type. Returns
21775 NULL_TREE otherwise. */
21777 tree
21779 {
21781 }
21784 /* For a given template T, return the vector of typedefs referenced
21785 in T for which access check is needed at T instantiation time.
21786 T is either a FUNCTION_DECL or a RECORD_TYPE.
21787 Those typedefs were added to T by the function
21788 append_type_to_template_for_access_check. */
21792 {
21793 tree ti;
21804 {
21809 }
21812 }
21814 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
21815 tied to T. That list of typedefs will be access checked at
21816 T instantiation time.
21817 T is either a FUNCTION_DECL or a RECORD_TYPE.
21818 TYPE_DECL is a TYPE_DECL node representing a typedef.
21819 SCOPE is the scope through which TYPE_DECL is accessed.
21820 LOCATION is the location of the usage point of TYPE_DECL.
21822 This function is a subroutine of
21823 append_type_to_template_for_access_check. */
21825 static void
21827 tree type_decl,
21828 tree scope,
21829 location_t location)
21830 {
21831 qualified_typedef_usage_t typedef_usage;
21832 tree ti;
21839 && type_decl
21853 }
21855 /* Append TYPE_DECL to the template TEMPL.
21856 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
21857 At TEMPL instanciation time, TYPE_DECL will be checked to see
21858 if it can be accessed through SCOPE.
21859 LOCATION is the location of the usage point of TYPE_DECL.
21861 e.g. consider the following code snippet:
21863 class C
21864 {
21865 typedef int myint;
21866 };
21868 template<class U> struct S
21869 {
21870 C::myint mi; // <-- usage point of the typedef C::myint
21871 };
21873 S<char> s;
21875 At S<char> instantiation time, we need to check the access of C::myint
21876 In other words, we need to check the access of the myint typedef through
21877 the C scope. For that purpose, this function will add the myint typedef
21878 and the scope C through which its being accessed to a list of typedefs
21879 tied to the template S. That list will be walked at template instantiation
21880 time and access check performed on each typedefs it contains.
21881 Note that this particular code snippet should yield an error because
21882 myint is private to C. */
21884 void
21886 tree type_decl,
21887 tree scope,
21888 location_t location)
21889 {
21895 /* Make sure we don't append the type to the template twice. */
21902 }
21904 /* Convert the generic type parameters in PARM that match the types given in the
21905 range [START_IDX, END_IDX) from the current_template_parms into generic type
21906 packs. */
21908 tree
21910 {
21921 {
21922 /* Create a distinct parameter pack type from the current parm and add it
21923 to the replacement args to tsubst below into the generic function
21924 parameter. */
21939 }
21945 /* If there are more levels then build up the replacement with the outer
21946 template parms. */
21950 replacement);
21953 }
21956 /* Set up the hash tables for template instantiations. */
21958 void
21960 {
21962 hash_specialization,
21963 eq_specializations,
21964 ggc_free);
21966 hash_specialization,
21967 eq_specializations,
21968 ggc_free);
21969 }
21971 /* Print stats about the template hash tables for -fstats. */
21973 void
21975 {
21984 }