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1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992-2013 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". */
46 /* The type of functions taking a tree, and some additional data, and
47 returning an int. */
50 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
51 instantiations have been deferred, either because their definitions
52 were not yet available, or because we were putting off doing the work. */
56 };
71 /* Live only within one (recursive) call to tsubst_expr. We use
72 this to pass the statement expression node from the STMT_EXPR
73 to the EXPR_STMT that is its result. */
76 /* A map from local variable declarations in the body of the template
77 presently being instantiated to the corresponding instantiated
78 local variables. */
81 /* True if we've recursed into fn_type_unification too many times. */
85 {
86 tree tmpl;
87 tree args;
88 tree spec;
92 htab_t decl_specializations;
95 htab_t type_specializations;
97 /* Contains canonical template parameter types. The vector is indexed by
98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
99 TREE_LIST, whose TREE_VALUEs contain the canonical template
100 parameters of various types and levels. */
103 #define UNIFY_ALLOW_NONE 0
104 #define UNIFY_ALLOW_MORE_CV_QUAL 1
105 #define UNIFY_ALLOW_LESS_CV_QUAL 2
106 #define UNIFY_ALLOW_DERIVED 4
107 #define UNIFY_ALLOW_INTEGER 8
108 #define UNIFY_ALLOW_OUTER_LEVEL 16
109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
113 tbr_incomplete_type,
114 tbr_ambiguous_baseclass,
115 tbr_success
116 };
139 tree);
202 location_t);
210 /* Make the current scope suitable for access checking when we are
211 processing T. T can be FUNCTION_DECL for instantiated function
212 template, VAR_DECL for static member variable, or TYPE_DECL for
213 alias template (needed by instantiate_decl). */
215 static void
217 {
225 else
229 {
230 saved_access_scope = tree_cons
233 }
234 }
236 /* Restore the scope set up by push_access_scope. T is the node we
237 are processing. */
239 static void
241 {
243 {
246 }
250 else
252 }
254 /* Do any processing required when DECL (a member template
255 declaration) is finished. Returns the TEMPLATE_DECL corresponding
256 to DECL, unless it is a specialization, in which case the DECL
257 itself is returned. */
259 tree
261 {
268 {
269 tree type;
277 {
281 }
283 }
287 {
289 {
292 }
293 else
295 }
296 else
300 }
302 /* Create a template info node. */
304 tree
306 {
311 }
313 /* Return the template info node corresponding to T, whatever T is. */
315 tree
317 {
335 }
337 /* Returns the template nesting level of the indicated class TYPE.
339 For example, in:
340 template <class T>
341 struct A
342 {
343 template <class U>
344 struct B {};
345 };
347 A<T>::B<U> has depth two, while A<T> has depth one.
348 Both A<T>::B<int> and A<int>::B<U> have depth one, if
349 they are instantiations, not specializations.
351 This function is guaranteed to return 0 if passed NULL_TREE so
352 that, for example, `template_class_depth (current_class_type)' is
353 always safe. */
355 int
357 {
364 {
370 }
373 }
375 /* Subroutine of maybe_begin_member_template_processing.
376 Returns true if processing DECL needs us to push template parms. */
378 static bool
380 {
386 }
388 /* Subroutine of maybe_begin_member_template_processing.
389 Push the template parms in PARMS, starting from LEVELS steps into the
390 chain, and ending at the beginning, since template parms are listed
391 innermost first. */
393 static void
395 {
403 current_template_parms
409 NULL);
411 {
420 {
427 {
428 /* Make a CONST_DECL as is done in process_template_parm.
429 It is ugly that we recreate this here; the original
430 version built in process_template_parm is no longer
431 available. */
441 }
446 }
447 }
448 }
450 /* Restore the template parameter context for a member template or
451 a friend template defined in a class definition. */
453 void
455 {
456 tree parms;
460 {
465 {
468 }
471 }
473 /* Remember how many levels of template parameters we pushed so that
474 we can pop them later. */
476 }
478 /* Undo the effects of maybe_begin_member_template_processing. */
480 void
482 {
491 {
495 }
496 }
498 /* Return a new template argument vector which contains all of ARGS,
499 but has as its innermost set of arguments the EXTRA_ARGS. */
501 static tree
503 {
504 tree new_args;
522 }
524 /* Like add_to_template_args, but only the outermost ARGS are added to
525 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
526 (EXTRA_ARGS) levels are added. This function is used to combine
527 the template arguments from a partial instantiation with the
528 template arguments used to attain the full instantiation from the
529 partial instantiation. */
531 static tree
533 {
534 tree new_args;
536 /* If there are more levels of EXTRA_ARGS than there are ARGS,
537 something very fishy is going on. */
540 /* If *all* the new arguments will be the EXTRA_ARGS, just return
541 them. */
545 /* For the moment, we make ARGS look like it contains fewer levels. */
550 /* Now, we restore ARGS to its full dimensions. */
554 }
556 /* Return the N levels of innermost template arguments from the ARGS. */
558 tree
560 {
561 tree new_args;
567 /* If N is 1, just return the innermost set of template arguments. */
571 /* If we're not removing anything, just return the arguments we were
572 given. */
578 /* Make a new set of arguments, not containing the outer arguments. */
585 }
587 /* The inverse of get_innermost_template_args: Return all but the innermost
588 EXTRA_LEVELS levels of template arguments from the ARGS. */
590 static tree
592 {
593 tree new_args;
599 /* If N is 1, just return the outermost set of template arguments. */
603 /* If we're not removing anything, just return the arguments we were
604 given. */
609 /* Make a new set of arguments, not containing the inner arguments. */
616 }
618 /* We've got a template header coming up; push to a new level for storing
619 the parms. */
621 void
623 {
624 /* We use a non-tag-transparent scope here, which causes pushtag to
625 put tags in this scope, rather than in the enclosing class or
626 namespace scope. This is the right thing, since we want
627 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
628 global template class, push_template_decl handles putting the
629 TEMPLATE_DECL into top-level scope. For a nested template class,
630 e.g.:
632 template <class T> struct S1 {
633 template <class T> struct S2 {};
634 };
636 pushtag contains special code to call pushdecl_with_scope on the
637 TEMPLATE_DECL for S2. */
642 }
644 /* This routine is called when a specialization is declared. If it is
645 invalid to declare a specialization here, an error is reported and
646 false is returned, otherwise this routine will return true. */
648 static bool
650 {
653 /* [temp.expl.spec]
655 An explicit specialization shall be declared in the namespace of
656 which the template is a member, or, for member templates, in the
657 namespace of which the enclosing class or enclosing class
658 template is a member. An explicit specialization of a member
659 function, member class or static data member of a class template
660 shall be declared in the namespace of which the class template
661 is a member. */
663 {
666 }
668 /* [temp.expl.spec]
670 In an explicit specialization declaration for a member of a class
671 template or a member template that appears in namespace scope,
672 the member template and some of its enclosing class templates may
673 remain unspecialized, except that the declaration shall not
674 explicitly specialize a class member template if its enclosing
675 class templates are not explicitly specialized as well. */
677 {
680 }
683 }
685 /* We've just seen template <>. */
687 bool
689 {
693 }
695 /* Called at then end of processing a declaration preceded by
696 template<>. */
698 void
700 {
703 }
705 /* Any template <>'s that we have seen thus far are not referring to a
706 function specialization. */
708 void
710 {
713 }
715 /* We've just seen a template header. If SPECIALIZATION is nonzero,
716 it was of the form template <>. */
718 static void
720 {
722 template_header_count++;
723 }
725 /* We're beginning an explicit instantiation. */
727 void
729 {
732 }
735 void
737 {
740 }
742 /* An explicit specialization or partial specialization of TMPL is being
743 declared. Check that the namespace in which the specialization is
744 occurring is permissible. Returns false iff it is invalid to
745 specialize TMPL in the current namespace. */
747 static bool
749 {
752 /* [tmpl.expl.spec]
754 An explicit specialization shall be declared in the namespace of
755 which the template is a member, or, for member templates, in the
756 namespace of which the enclosing class or enclosing class
757 template is a member. An explicit specialization of a member
758 function, member class or static data member of a class template
759 shall be declared in the namespace of which the class template is
760 a member. */
763 {
766 }
768 /* Same or super-using namespace. */
770 else
771 {
775 }
776 }
778 /* SPEC is an explicit instantiation. Check that it is valid to
779 perform this explicit instantiation in the current namespace. */
781 static void
783 {
784 tree ns;
786 /* DR 275: An explicit instantiation shall appear in an enclosing
787 namespace of its template. */
793 }
795 /* The TYPE is being declared. If it is a template type, that means it
796 is a partial specialization. Do appropriate error-checking. */
798 tree
800 {
801 tree context;
806 /* A lambda that appears in specialization context is not itself a
807 specialization. */
812 {
816 }
821 {
826 else
829 }
831 {
832 /* This is for ordinary explicit specialization and partial
833 specialization of a template class such as:
835 template <> class C<int>;
837 or:
839 template <class T> class C<T*>;
841 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
845 {
850 {
854 }
855 }
861 /* Trying to define a specialization either without a template<> header
862 or in an inappropriate place. We've already given an error, so just
863 bail now so we don't actually define the specialization. */
865 }
871 {
872 /* This is for an explicit specialization of member class
873 template according to [temp.expl.spec/18]:
875 template <> template <class U> class C<int>::D;
877 The context `C<int>' must be an implicit instantiation.
878 Otherwise this is just a member class template declared
879 earlier like:
881 template <> class C<int> { template <class U> class D; };
882 template <> template <class U> class C<int>::D;
884 In the first case, `C<int>::D' is a specialization of `C<T>::D'
885 while in the second case, `C<int>::D' is a primary template
886 and `C<T>::D' may not exist. */
890 {
891 tree t;
896 {
899 }
901 /* Check for invalid specialization after instantiation:
903 template <> template <> class C<int>::D<int>;
904 template <> template <class U> class C<int>::D; */
908 {
911 {
912 /* We already have a full specialization of this partial
913 instantiation. Reassign it to the new member
914 specialization template. */
915 spec_entry elt;
932 }
934 /* But if we've had an implicit instantiation, that's a
935 problem ([temp.expl.spec]/6). */
938 }
940 /* Mark TYPE as a specialization. And as a result, we only
941 have one level of template argument for the innermost
942 class template. */
947 }
948 }
950 {
951 /* Someday C++0x may allow for enum template specialization. */
956 else
957 {
960 }
961 }
964 }
966 /* Returns nonzero if we can optimize the retrieval of specializations
967 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
968 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
972 {
975 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
976 parameter. */
978 /* The optimized lookup depends on the fact that the
979 template arguments for the member function template apply
980 purely to the containing class, which is not true if the
981 containing class is an explicit or partial
982 specialization. */
986 /* It is possible to have a template that is not a member
987 template and is not a member of a template class:
989 template <typename T>
990 struct S { friend A::f(); };
992 Here, the friend function is a template, but the context does
993 not have template information. The optimized lookup relies
994 on having ARGS be the template arguments for both the class
995 and the function template. */
997 }
999 /* Retrieve the specialization (in the sense of [temp.spec] - a
1000 specialization is either an instantiation or an explicit
1001 specialization) of TMPL for the given template ARGS. If there is
1002 no such specialization, return NULL_TREE. The ARGS are a vector of
1003 arguments, or a vector of vectors of arguments, in the case of
1004 templates with more than one level of parameters.
1006 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1007 then we search for a partial specialization matching ARGS. This
1008 parameter is ignored if TMPL is not a class template.
1010 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1011 result is a NONTYPE_ARGUMENT_PACK. */
1013 static tree
1015 {
1025 /* There should be as many levels of arguments as there are
1026 levels of parameters. */
1033 {
1034 tree class_template;
1035 tree class_specialization;
1037 tree fns;
1040 /* The template arguments actually apply to the containing
1041 class. Find the class specialization with those
1042 arguments. */
1044 class_specialization
1048 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1049 for the specialization. */
1053 /* Iterate through the methods with the indicated name, looking
1054 for the one that has an instance of TMPL. */
1057 {
1060 /* using-declarations can add base methods to the method vec,
1061 and we don't want those here. */
1064 }
1066 }
1067 else
1068 {
1070 spec_entry elt;
1071 htab_t specializations;
1079 else
1087 }
1090 }
1092 /* Like retrieve_specialization, but for local declarations. */
1094 static tree
1096 {
1104 }
1106 /* Returns nonzero iff DECL is a specialization of TMPL. */
1108 int
1110 {
1111 tree t;
1114 {
1120 }
1121 else
1122 {
1131 }
1134 }
1136 /* Returns nonzero iff DECL is a specialization of friend declaration
1137 FRIEND_DECL according to [temp.friend]. */
1139 bool
1141 {
1148 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1149 of a template class, we want to check if DECL is a specialization
1150 if this. */
1154 {
1155 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1158 }
1163 /* There is nothing to do if this is not a template friend. */
1170 /* [temp.friend/6]
1171 A member of a class template may be declared to be a friend of a
1172 non-template class. In this case, the corresponding member of
1173 every specialization of the class template is a friend of the
1174 class granting friendship.
1176 For example, given a template friend declaration
1178 template <class T> friend void A<T>::f();
1180 the member function below is considered a friend
1182 template <> struct A<int> {
1183 void f();
1184 };
1186 For this type of template friend, TEMPLATE_DEPTH below will be
1187 nonzero. To determine if DECL is a friend of FRIEND, we first
1188 check if the enclosing class is a specialization of another. */
1195 {
1196 /* Next, we check the members themselves. In order to handle
1197 a few tricky cases, such as when FRIEND_DECL's are
1199 template <class T> friend void A<T>::g(T t);
1200 template <class T> template <T t> friend void A<T>::h();
1202 and DECL's are
1204 void A<int>::g(int);
1205 template <int> void A<int>::h();
1207 we need to figure out ARGS, the template arguments from
1208 the context of DECL. This is required for template substitution
1209 of `T' in the function parameter of `g' and template parameter
1210 of `h' in the above examples. Here ARGS corresponds to `int'. */
1217 {
1219 {
1222 else
1224 current_depth++;
1225 }
1227 }
1230 {
1232 tree friend_type;
1233 tree decl_type;
1234 tree friend_args_type;
1235 tree decl_args_type;
1237 /* Make sure that both DECL and FRIEND_DECL are templates or
1238 non-templates. */
1244 {
1245 /* If both are templates, check template parameter list. */
1246 tree friend_parms
1251 friend_parms))
1255 }
1256 else
1264 /* Check if return types match. */
1268 /* Check if function parameter types match, ignoring the
1269 `this' parameter. */
1278 }
1279 else
1280 {
1281 /* DECL is a TYPE_DECL */
1285 /* Make sure that both DECL and FRIEND_DECL are templates or
1286 non-templates. */
1287 is_template
1294 {
1295 tree friend_parms;
1296 /* If both are templates, check the name of the two
1297 TEMPLATE_DECL's first because is_friend didn't. */
1302 /* Now check template parameter list. */
1303 friend_parms
1306 return comp_template_parms
1308 friend_parms);
1309 }
1310 else
1313 }
1314 }
1316 }
1318 /* Register the specialization SPEC as a specialization of TMPL with
1319 the indicated ARGS. IS_FRIEND indicates whether the specialization
1320 is actually just a friend declaration. Returns SPEC, or an
1321 equivalent prior declaration, if available.
1323 We also store instantiations of field packs in the hash table, even
1324 though they are not themselves templates, to make lookup easier. */
1326 static tree
1328 hashval_t hash)
1329 {
1330 tree fn;
1332 spec_entry elt;
1340 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1341 register it; we want the corresponding TEMPLATE_DECL instead.
1342 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1343 the more obvious `uses_template_parms (spec)' to avoid problems
1344 with default function arguments. In particular, given
1345 something like this:
1347 template <class T> void f(T t1, T t = T())
1349 the default argument expression is not substituted for in an
1350 instantiation unless and until it is actually needed. */
1354 /* We don't put these specializations in the hash table, but we might
1355 want to give an error about a mismatch. */
1357 else
1358 {
1366 slot =
1370 else
1372 }
1374 /* We can sometimes try to re-register a specialization that we've
1375 already got. In particular, regenerate_decl_from_template calls
1376 duplicate_decls which will update the specialization list. But,
1377 we'll still get called again here anyhow. It's more convenient
1378 to simply allow this than to try to prevent it. */
1382 {
1384 {
1387 {
1389 fn);
1391 }
1392 else
1393 {
1394 tree clone;
1395 /* This situation should occur only if the first
1396 specialization is an implicit instantiation, the
1397 second is an explicit specialization, and the
1398 implicit instantiation has not yet been used. That
1399 situation can occur if we have implicitly
1400 instantiated a member function and then specialized
1401 it later.
1403 We can also wind up here if a friend declaration that
1404 looked like an instantiation turns out to be a
1405 specialization:
1407 template <class T> void foo(T);
1408 class S { friend void foo<>(int) };
1409 template <> void foo(int);
1411 We transform the existing DECL in place so that any
1412 pointers to it become pointers to the updated
1413 declaration.
1415 If there was a definition for the template, but not
1416 for the specialization, we want this to look as if
1417 there were no definition, and vice versa. */
1420 /* The call to duplicate_decls will have applied
1421 [temp.expl.spec]:
1423 An explicit specialization of a function template
1424 is inline only if it is explicitly declared to be,
1425 and independently of whether its function template
1426 is.
1428 to the primary function; now copy the inline bits to
1429 the various clones. */
1431 {
1436 }
1440 }
1441 }
1443 {
1445 /* Dup decl failed, but this is a new definition. Set the
1446 line number so any errors match this new
1447 definition. */
1451 }
1452 }
1456 /* A specialization must be declared in the same namespace as the
1457 template it is specializing. */
1463 {
1471 /* TMPL is a forward declaration of a template function; keep a list
1472 of all specializations in case we need to reassign them to a friend
1473 template later in tsubst_friend_function. */
1476 }
1479 }
1481 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1482 TMPL and ARGS members, ignores SPEC. */
1486 static int
1488 {
1499 }
1501 /* Returns a hash for a template TMPL and template arguments ARGS. */
1503 static hashval_t
1505 {
1508 }
1510 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1511 ignoring SPEC. */
1513 static hashval_t
1515 {
1518 }
1520 /* Recursively calculate a hash value for a template argument ARG, for use
1521 in the hash tables of template specializations. */
1523 hashval_t
1525 {
1537 /* We can get one of these when re-hashing a previous entry in the middle
1538 of substituting into a pack expansion. Just look through it. */
1547 {
1555 {
1560 }
1582 {
1585 {
1588 }
1590 }
1594 {
1597 }
1608 val = iterative_hash_template_arg
1620 val);
1622 val);
1631 /* A lambda can't appear in a template arg, but don't crash on
1632 erroneous input. */
1644 /* Now hash operands as usual. */
1649 }
1652 {
1656 val);
1659 /* Otherwise just compare the types during lookup. */
1668 {
1673 }
1674 }
1677 }
1679 /* Unregister the specialization SPEC as a specialization of TMPL.
1680 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1681 if the SPEC was listed as a specialization of TMPL.
1683 Note that SPEC has been ggc_freed, so we can't look inside it. */
1685 bool
1687 {
1689 spec_entry elt;
1697 {
1702 }
1705 }
1707 /* Like register_specialization, but for local declarations. We are
1708 registering SPEC, an instantiation of TMPL. */
1710 static void
1712 {
1717 }
1719 /* TYPE is a class type. Returns true if TYPE is an explicitly
1720 specialized class. */
1722 bool
1724 {
1728 }
1730 /* Print the list of functions at FNS, going through all the overloads
1731 for each element of the list. Alternatively, FNS can not be a
1732 TREE_LIST, in which case it will be printed together with all the
1733 overloads.
1735 MORE and *STR should respectively be FALSE and NULL when the function
1736 is called from the outside. They are used internally on recursive
1737 calls. print_candidates manages the two parameters and leaves NULL
1738 in *STR when it ends. */
1740 static void
1742 {
1748 {
1752 }
1753 else
1754 {
1757 {
1758 /* Pick the prefix string. */
1760 {
1764 }
1768 }
1771 }
1774 {
1777 }
1778 }
1780 /* Print the list of candidate FNS in an error message. FNS can also
1781 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1783 void
1785 {
1789 }
1791 /* Returns the template (one of the functions given by TEMPLATE_ID)
1792 which can be specialized to match the indicated DECL with the
1793 explicit template args given in TEMPLATE_ID. The DECL may be
1794 NULL_TREE if none is available. In that case, the functions in
1795 TEMPLATE_ID are non-members.
1797 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1798 specialization of a member template.
1800 The TEMPLATE_COUNT is the number of references to qualifying
1801 template classes that appeared in the name of the function. See
1802 check_explicit_specialization for a more accurate description.
1804 TSK indicates what kind of template declaration (if any) is being
1805 declared. TSK_TEMPLATE indicates that the declaration given by
1806 DECL, though a FUNCTION_DECL, has template parameters, and is
1807 therefore a template function.
1809 The template args (those explicitly specified and those deduced)
1810 are output in a newly created vector *TARGS_OUT.
1812 If it is impossible to determine the result, an error message is
1813 issued. The error_mark_node is returned to indicate failure. */
1815 static tree
1817 tree decl,
1821 tmpl_spec_kind tsk)
1822 {
1823 tree fns;
1824 tree targs;
1825 tree explicit_targs;
1827 /* A TREE_LIST of templates of which DECL may be a specialization.
1828 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1829 corresponding TREE_PURPOSE is the set of template arguments that,
1830 when used to instantiate the template, would produce a function
1831 with the signature of DECL. */
1841 /* We shouldn't be specializing a member template of an
1842 unspecialized class template; we already gave an error in
1843 check_specialization_scope, now avoid crashing. */
1846 {
1849 }
1857 /* Check for baselinks. */
1862 {
1865 }
1867 /* Count the number of template headers specified for this
1868 specialization. */
1876 {
1880 {
1881 tree decl_arg_types;
1882 tree fn_arg_types;
1883 tree insttype;
1885 /* In case of explicit specialization, we need to check if
1886 the number of template headers appearing in the specialization
1887 is correct. This is usually done in check_explicit_specialization,
1888 but the check done there cannot be exhaustive when specializing
1889 member functions. Consider the following code:
1891 template <> void A<int>::f(int);
1892 template <> template <> void A<int>::f(int);
1894 Assuming that A<int> is not itself an explicit specialization
1895 already, the first line specializes "f" which is a non-template
1896 member function, whilst the second line specializes "f" which
1897 is a template member function. So both lines are syntactically
1898 correct, and check_explicit_specialization does not reject
1899 them.
1901 Here, we can do better, as we are matching the specialization
1902 against the declarations. We count the number of template
1903 headers, and we check if they match TEMPLATE_COUNT + 1
1904 (TEMPLATE_COUNT is the number of qualifying template classes,
1905 plus there must be another header for the member template
1906 itself).
1908 Notice that if header_count is zero, this is not a
1909 specialization but rather a template instantiation, so there
1910 is no check we can perform here. */
1914 /* Check that the number of template arguments at the
1915 innermost level for DECL is the same as for FN. */
1923 /* DECL might be a specialization of FN. */
1927 /* For a non-static member function, we need to make sure
1928 that the const qualification is the same. Since
1929 get_bindings does not try to merge the "this" parameter,
1930 we must do the comparison explicitly. */
1936 /* Skip the "this" parameter and, for constructors of
1937 classes with virtual bases, the VTT parameter. A
1938 full specialization of a constructor will have a VTT
1939 parameter, but a template never will. */
1940 decl_arg_types
1942 fn_arg_types
1945 /* Function templates cannot be specializations; there are
1946 no partial specializations of functions. Therefore, if
1947 the type of DECL does not match FN, there is no
1948 match. */
1950 {
1954 }
1956 /* See whether this function might be a specialization of this
1957 template. Suppress access control because we might be trying
1958 to make this specialization a friend, and we have already done
1959 access control for the declaration of the specialization. */
1965 /* We cannot deduce template arguments that when used to
1966 specialize TMPL will produce DECL. */
1969 /* Make sure that the deduced arguments actually work. */
1973 fn_arg_types
1978 /* Save this template, and the arguments deduced. */
1980 }
1982 /* FN is an ordinary member function, and we need a
1983 specialization of a member template. */
1984 ;
1986 /* We can get IDENTIFIER_NODEs here in certain erroneous
1987 cases. */
1988 ;
1990 /* This is just an ordinary non-member function. Nothing can
1991 be a specialization of that. */
1992 ;
1994 /* Cannot specialize functions that are created implicitly. */
1995 ;
1996 else
1997 {
1998 tree decl_arg_types;
2000 /* This is an ordinary member function. However, since
2001 we're here, we can assume its enclosing class is a
2002 template class. For example,
2004 template <typename T> struct S { void f(); };
2005 template <> void S<int>::f() {}
2007 Here, S<int>::f is a non-template, but S<int> is a
2008 template class. If FN has the same type as DECL, we
2009 might be in business. */
2012 /* Its enclosing class is an explicit specialization
2013 of a template class. This is not a candidate. */
2018 /* The return types differ. */
2021 /* Adjust the type of DECL in case FN is a static member. */
2028 decl_arg_types))
2029 /* They match! */
2031 }
2032 }
2035 {
2036 /* We have:
2038 [temp.expl.spec]
2040 It is possible for a specialization with a given function
2041 signature to be instantiated from more than one function
2042 template. In such cases, explicit specification of the
2043 template arguments must be used to uniquely identify the
2044 function template specialization being specialized.
2046 Note that here, there's no suggestion that we're supposed to
2047 determine which of the candidate templates is most
2048 specialized. However, we, also have:
2050 [temp.func.order]
2052 Partial ordering of overloaded function template
2053 declarations is used in the following contexts to select
2054 the function template to which a function template
2055 specialization refers:
2057 -- when an explicit specialization refers to a function
2058 template.
2060 So, we do use the partial ordering rules, at least for now.
2061 This extension can only serve to make invalid programs valid,
2062 so it's safe. And, there is strong anecdotal evidence that
2063 the committee intended the partial ordering rules to apply;
2064 the EDG front end has that behavior, and John Spicer claims
2065 that the committee simply forgot to delete the wording in
2066 [temp.expl.spec]. */
2069 {
2072 }
2073 }
2076 {
2084 }
2088 {
2094 }
2096 /* We have one, and exactly one, match. */
2098 {
2101 /* DECL is a re-declaration or partial instantiation of a template
2102 function. */
2105 /* It was a specialization of an ordinary member function in a
2106 template class. */
2108 }
2110 /* It was a specialization of a template. */
2113 {
2118 }
2119 else
2122 }
2124 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2125 but with the default argument values filled in from those in the
2126 TMPL_TYPES. */
2128 static tree
2130 tree tmpl_types)
2131 {
2132 tree new_spec_types;
2140 /* Substitute into the rest of the list. */
2141 new_spec_types =
2145 /* Add the default argument for this parameter. */
2148 new_spec_types);
2149 }
2151 /* DECL is an explicit specialization. Replicate default arguments
2152 from the template it specializes. (That way, code like:
2154 template <class T> void f(T = 3);
2155 template <> void f(double);
2156 void g () { f (); }
2158 works, as required.) An alternative approach would be to look up
2159 the correct default arguments at the call-site, but this approach
2160 is consistent with how implicit instantiations are handled. */
2162 static void
2164 {
2165 tree tmpl;
2166 tree spec_types;
2167 tree tmpl_types;
2168 tree new_spec_types;
2169 tree old_type;
2170 tree new_type;
2171 tree t;
2176 /* See if there's anything we need to do. */
2189 {
2190 /* Remove the this pointer, but remember the object's type for
2191 CV quals. */
2197 {
2198 /* DECL may contain more parameters than TMPL due to the extra
2199 in-charge parameter in constructors and destructors. */
2202 }
2204 {
2207 }
2208 }
2210 /* Compute the merged default arguments. */
2211 new_spec_types =
2214 /* Compute the new FUNCTION_TYPE. */
2216 {
2220 new_spec_types);
2223 /* Put the in-charge parameter back. */
2226 new_spec_types);
2230 new_spec_types);
2231 }
2232 else
2234 new_spec_types);
2240 }
2242 /* Return the number of template headers we expect to see for a definition
2243 or specialization of CTYPE or one of its non-template members. */
2245 int
2247 {
2251 {
2252 /* You're supposed to have one `template <...>' for every
2253 template class, but you don't need one for a full
2254 specialization. For example:
2256 template <class T> struct S{};
2257 template <> struct S<int> { void f(); };
2258 void S<int>::f () {}
2260 is correct; there shouldn't be a `template <>' for the
2261 definition of `S<int>::f'. */
2263 /* If CTYPE does not have template information of any
2264 kind, then it is not a template, nor is it nested
2265 within a template. */
2273 }
2276 }
2278 /* Do a simple sanity check on the template headers that precede the
2279 variable declaration DECL. */
2281 void
2283 {
2290 {
2296 "members of an explicitly specialized class are defined "
2298 }
2299 }
2301 /* Check to see if the function just declared, as indicated in
2302 DECLARATOR, and in DECL, is a specialization of a function
2303 template. We may also discover that the declaration is an explicit
2304 instantiation at this point.
2306 Returns DECL, or an equivalent declaration that should be used
2307 instead if all goes well. Issues an error message if something is
2308 amiss. Returns error_mark_node if the error is not easily
2309 recoverable.
2311 FLAGS is a bitmask consisting of the following flags:
2313 2: The function has a definition.
2314 4: The function is a friend.
2316 The TEMPLATE_COUNT is the number of references to qualifying
2317 template classes that appeared in the name of the function. For
2318 example, in
2320 template <class T> struct S { void f(); };
2321 void S<int>::f();
2323 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2324 classes are not counted in the TEMPLATE_COUNT, so that in
2326 template <class T> struct S {};
2327 template <> struct S<int> { void f(); }
2328 template <> void S<int>::f();
2330 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2331 invalid; there should be no template <>.)
2333 If the function is a specialization, it is marked as such via
2334 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2335 is set up correctly, and it is added to the list of specializations
2336 for that template. */
2338 tree
2340 tree decl,
2343 {
2351 tmpl_spec_kind tsk;
2354 {
2357 else
2359 }
2360 else
2364 {
2367 {
2370 }
2372 {
2374 /* This could be something like:
2376 template <class T> void f(T);
2377 class S { friend void f<>(int); } */
2379 else
2380 {
2381 /* This case handles bogus declarations like template <>
2382 template <class T> void f<int>(); */
2385 declarator);
2387 }
2388 }
2392 /* The error has already been reported in
2393 check_specialization_scope. */
2399 /* Fall through. */
2412 decl);
2415 else
2419 /* Fall through. */
2424 else
2430 {
2431 /* This case handles bogus declarations like template <>
2432 template <class T> void f<int>(); */
2437 else
2439 declarator);
2441 }
2444 /* This is a specialization of a member template, without
2445 specialization the containing class. Something like:
2447 template <class T> struct S {
2448 template <class U> void f (U);
2449 };
2450 template <> template <class U> void S<int>::f(U) {}
2452 That's a specialization -- but of the entire template. */
2458 }
2461 {
2465 {
2469 }
2470 }
2473 {
2477 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2479 {
2480 tree fns;
2485 else
2486 {
2487 /* If there is no class context, the explicit instantiation
2488 must be at namespace scope. */
2491 /* Find the namespace binding, using the declaration
2492 context. */
2496 {
2499 }
2500 else
2501 {
2507 }
2508 }
2511 }
2517 {
2519 /* A specialization in class scope. This is invalid,
2520 but the error will already have been flagged by
2521 check_specialization_scope. */
2523 else
2524 {
2525 /* It's not valid to write an explicit instantiation in
2526 class scope, e.g.:
2528 class C { template void f(); }
2530 This case is caught by the parser. However, on
2531 something like:
2533 template class C { void f(); };
2535 (which is invalid) we can get here. The error will be
2536 issued later. */
2537 ;
2538 }
2541 }
2544 {
2545 /* Find the list of functions in ctype that have the same
2546 name as the declared function. */
2552 {
2557 {
2558 /* From [temp.expl.spec]:
2560 If such an explicit specialization for the member
2561 of a class template names an implicitly-declared
2562 special member function (clause _special_), the
2563 program is ill-formed.
2565 Similar language is found in [temp.explicit]. */
2568 }
2571 }
2574 {
2578 }
2579 else
2580 {
2582 tree ovl;
2584 /* For a type-conversion operator, we cannot do a
2585 name-based lookup. We might be looking for `operator
2586 int' which will be a specialization of `operator T'.
2587 So, we find *all* the conversion operators, and then
2588 select from them. */
2596 {
2598 /* There are no more conversion functions. */
2601 /* Glue all these conversion functions together
2602 with those we already have. */
2605 }
2606 }
2609 {
2612 }
2613 else
2615 }
2617 /* Figure out what exactly is being specialized at this point.
2618 Note that for an explicit instantiation, even one for a
2619 member function, we cannot tell apriori whether the
2620 instantiation is for a member template, or just a member
2621 function of a template class. Even if a member template is
2622 being instantiated, the member template arguments may be
2623 elided if they can be deduced from the rest of the
2624 declaration. */
2627 member_specialization,
2628 template_count,
2629 tsk);
2632 /* We couldn't figure out what this declaration was
2633 specializing. */
2635 else
2636 {
2640 {
2641 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2642 is done by do_decl_instantiation later. */
2648 {
2649 /* If TMPL is not the most general template (for
2650 example, if TMPL is a friend template that is
2651 injected into namespace scope), then there will
2652 be too many levels of TARGS. Remove some of them
2653 here. */
2655 tree new_targs;
2662 }
2665 }
2667 /* If we thought that the DECL was a member function, but it
2668 turns out to be specializing a static member function,
2669 make DECL a static member function as well. */
2674 /* If this is a specialization of a member template of a
2675 template class, we want to return the TEMPLATE_DECL, not
2676 the specialization of it. */
2678 {
2683 {
2684 tree parm;
2688 /* We want to use the argument list specified in the
2689 definition, not in the original declaration. */
2694 }
2697 }
2699 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2702 /* Inherit default function arguments from the template
2703 DECL is specializing. */
2706 /* This specialization has the same protection as the
2707 template it specializes. */
2711 /* 7.1.1-1 [dcl.stc]
2713 A storage-class-specifier shall not be specified in an
2714 explicit specialization...
2716 The parser rejects these, so unless action is taken here,
2717 explicit function specializations will always appear with
2718 global linkage.
2720 The action recommended by the C++ CWG in response to C++
2721 defect report 605 is to make the storage class and linkage
2722 of the explicit specialization match the templated function:
2724 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2725 */
2727 {
2731 /* This specialization has the same linkage and visibility as
2732 the function template it specializes. */
2735 {
2738 }
2741 {
2744 }
2745 }
2747 /* If DECL is a friend declaration, declared using an
2748 unqualified name, the namespace associated with DECL may
2749 have been set incorrectly. For example, in:
2751 template <typename T> void f(T);
2752 namespace N {
2753 struct S { friend void f<int>(int); }
2754 }
2756 we will have set the DECL_CONTEXT for the friend
2757 declaration to N, rather than to the global namespace. */
2762 /* This is not really a declaration of a specialization.
2763 It's just the name of an instantiation. But, it's not
2764 a request for an instantiation, either. */
2767 /* This is indeed a specialization. In case of constructors
2768 and destructors, we need in-charge and not-in-charge
2769 versions in V3 ABI. */
2772 /* Register this specialization so that we can find it
2773 again. */
2775 }
2776 }
2779 }
2781 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2782 parameters. These are represented in the same format used for
2783 DECL_TEMPLATE_PARMS. */
2785 int
2787 {
2788 const_tree p1;
2789 const_tree p2;
2797 {
2809 {
2813 /* If either of the template parameters are invalid, assume
2814 they match for the sake of error recovery. */
2827 }
2828 }
2831 /* One set of parameters has more parameters lists than the
2832 other. */
2836 }
2838 /* Determine whether PARM is a parameter pack. */
2840 bool
2842 {
2843 /* Determine if we have a non-type template parameter pack. */
2850 /* If this is a list of template parameters, we could get a
2851 TYPE_DECL or a TEMPLATE_DECL. */
2855 /* Otherwise it must be a type template parameter. */
2859 }
2861 /* Determine if T is a function parameter pack. */
2863 bool
2865 {
2869 }
2871 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2872 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2874 tree
2876 {
2883 }
2885 /* Return true iff the function parameter PARAM_DECL was expanded
2886 from the function parameter pack PACK. */
2888 bool
2890 {
2895 /* The parameter pack and its pack arguments have the same
2896 DECL_PARM_INDEX. */
2898 }
2900 /* Determine whether ARGS describes a variadic template args list,
2901 i.e., one that is terminated by a template argument pack. */
2903 static bool
2905 {
2907 tree last_parm;
2921 }
2923 /* Generate a new name for the parameter pack name NAME (an
2924 IDENTIFIER_NODE) that incorporates its */
2926 static tree
2928 {
2929 /* Munge the name to include the parameter index. */
2930 #define NUMBUF_LEN 128
2944 }
2946 /* Return true if T is a primary function, class or alias template
2947 instantiation. */
2949 bool
2951 {
2965 }
2967 /* Return true if PARM is a template template parameter. */
2969 bool
2971 {
2973 }
2975 /* Return true iff PARM is a DECL representing a type template
2976 parameter. */
2978 bool
2980 {
2985 }
2987 /* Return the template parameters of T if T is a
2988 primary template instantiation, NULL otherwise. */
2990 tree
2992 {
2997 parms = INNERMOST_TEMPLATE_PARMS
3001 }
3003 /* Return the template parameters of the LEVELth level from the full list
3004 of template parameters PARMS. */
3006 tree
3008 {
3009 tree p;
3020 }
3022 /* Returns the template arguments of T if T is a template instantiation,
3023 NULL otherwise. */
3025 tree
3027 {
3035 }
3037 /* Return the argument pack elements of T if T is a template argument pack,
3038 NULL otherwise. */
3040 tree
3042 {
3048 }
3050 /* Structure used to track the progress of find_parameter_packs_r. */
3051 struct find_parameter_pack_data
3052 {
3053 /* TREE_LIST that will contain all of the parameter packs found by
3054 the traversal. */
3057 /* Set of AST nodes that have been visited by the traversal. */
3059 };
3061 /* Identifies all of the argument packs that occur in a template
3062 argument and appends them to the TREE_LIST inside DATA, which is a
3063 find_parameter_pack_data structure. This is a subroutine of
3064 make_pack_expansion and uses_parameter_packs. */
3065 static tree
3067 {
3073 /* Handle type aliases/typedefs. */
3075 {
3082 }
3084 /* Identify whether this is a parameter pack or not. */
3086 {
3102 {
3103 /* We don't want to walk into the type of a PARM_DECL,
3104 because we don't want to see the type parameter pack. */
3107 }
3110 /* Look through a lambda capture proxy to the field pack. */
3113 {
3119 }
3126 /* Not a parameter pack. */
3128 }
3131 {
3132 /* Add this parameter pack to the list. */
3134 }
3140 /* This switch statement will return immediately if we don't find a
3141 parameter pack. */
3143 {
3148 /* Check the template itself. */
3151 /* Check the template arguments. */
3167 /* Fall through. */
3209 }
3212 }
3214 /* Determines if the expression or type T uses any parameter packs. */
3215 bool
3217 {
3225 }
3227 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3228 representation a base-class initializer into a parameter pack
3229 expansion. If all goes well, the resulting node will be an
3230 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3231 respectively. */
3232 tree
3234 {
3235 tree result;
3244 {
3245 /* The only time we will see a TREE_LIST here is for a base
3246 class initializer. In this case, the TREE_PURPOSE will be a
3247 _TYPE node (representing the base class expansion we're
3248 initializing) and the TREE_VALUE will be a TREE_LIST
3249 containing the initialization arguments.
3251 The resulting expansion looks somewhat different from most
3252 expansions. Rather than returning just one _EXPANSION, we
3253 return a TREE_LIST whose TREE_PURPOSE is a
3254 TYPE_PACK_EXPANSION containing the bases that will be
3255 initialized. The TREE_VALUE will be identical to the
3256 original TREE_VALUE, which is a list of arguments that will
3257 be passed to each base. We do not introduce any new pack
3258 expansion nodes into the TREE_VALUE (although it is possible
3259 that some already exist), because the TREE_PURPOSE and
3260 TREE_VALUE all need to be expanded together with the same
3261 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3262 resulting TREE_PURPOSE will mention the parameter packs in
3263 both the bases and the arguments to the bases. */
3264 tree purpose;
3265 tree value;
3268 /* Determine which parameter packs will be used by the base
3269 class expansion. */
3276 {
3280 }
3283 {
3284 /* Collect the sets of parameter packs used in each of the
3285 initialization arguments. */
3287 {
3288 /* Determine which parameter packs will be expanded in this
3289 argument. */
3292 }
3293 }
3297 /* Create the pack expansion type for the base type. */
3302 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3303 they will rarely be compared to anything. */
3307 }
3312 /* Build the PACK_EXPANSION_* node. */
3313 result = for_types
3318 {
3319 /* Propagate type and const-expression information. */
3322 }
3323 else
3324 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3325 they will rarely be compared to anything. */
3328 /* Determine which parameter packs will be expanded. */
3334 /* Make sure we found some parameter packs. */
3336 {
3339 else
3342 }
3348 }
3350 /* Checks T for any "bare" parameter packs, which have not yet been
3351 expanded, and issues an error if any are found. This operation can
3352 only be done on full expressions or types (e.g., an expression
3353 statement, "if" condition, etc.), because we could have expressions like:
3355 foo(f(g(h(args)))...)
3357 where "args" is a parameter pack. check_for_bare_parameter_packs
3358 should not be called for the subexpressions args, h(args),
3359 g(h(args)), or f(g(h(args))), because we would produce erroneous
3360 error messages.
3362 Returns TRUE and emits an error if there were bare parameter packs,
3363 returns FALSE otherwise. */
3364 bool
3366 {
3382 {
3385 {
3394 else
3399 else
3403 }
3406 }
3409 }
3411 /* Expand any parameter packs that occur in the template arguments in
3412 ARGS. */
3413 tree
3415 {
3421 /* First, determine if we need to expand anything, and the number of
3422 slots we'll need. */
3424 {
3429 {
3433 else
3435 }
3436 else
3437 {
3439 num_result_args++;
3440 }
3441 }
3443 /* If no expansion is necessary, we're done. */
3447 /* Expand arguments. */
3450 non_default_args_count =
3453 {
3456 {
3463 }
3464 else
3465 {
3468 }
3469 }
3473 }
3475 /* Checks if DECL shadows a template parameter.
3477 [temp.local]: A template-parameter shall not be redeclared within its
3478 scope (including nested scopes).
3480 Emits an error and returns TRUE if the DECL shadows a parameter,
3481 returns FALSE otherwise. */
3483 bool
3485 {
3486 tree olddecl;
3488 /* If we're not in a template, we can't possibly shadow a template
3489 parameter. */
3493 /* Figure out what we're shadowing. */
3498 /* If there's no previous binding for this name, we're not shadowing
3499 anything, let alone a template parameter. */
3503 /* If we're not shadowing a template parameter, we're done. Note
3504 that OLDDECL might be an OVERLOAD (or perhaps even an
3505 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3506 node. */
3510 /* We check for decl != olddecl to avoid bogus errors for using a
3511 name inside a class. We check TPFI to avoid duplicate errors for
3512 inline member templates. */
3521 }
3523 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3524 ORIG_LEVEL, DECL, and TYPE. */
3526 static tree
3530 tree decl,
3531 tree type)
3532 {
3543 }
3545 /* Find the canonical type parameter for the given template type
3546 parameter. Returns the canonical type parameter, which may be TYPE
3547 if no such parameter existed. */
3549 static tree
3551 {
3552 tree list;
3566 else
3567 {
3572 }
3573 }
3575 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3576 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3577 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3578 new one is created. */
3580 static tree
3582 tsubst_flags_t complain)
3583 {
3588 {
3607 /* Template template parameters need this. */
3612 }
3615 }
3617 /* Process information from new template parameter PARM and append it
3618 to the LIST being built. This new parameter is a non-type
3619 parameter iff IS_NON_TYPE is true. This new parameter is a
3620 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3621 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3622 parameter list PARM belongs to. This is used used to create a
3623 proper canonical type for the type of PARM that is to be created,
3624 iff PARM is a type. If the size is not known, this parameter shall
3625 be set to 0. */
3627 tree
3630 {
3632 tree defval;
3633 tree err_parm_list;
3640 {
3644 {
3648 else
3650 }
3653 }
3654 else
3658 {
3664 {
3668 }
3669 else
3670 {
3671 /* [temp.param]
3673 The top-level cv-qualifiers on the template-parameter are
3674 ignored when determining its type. */
3677 {
3681 }
3684 {
3685 /* This template parameter is not a parameter pack, but it
3686 should be. Complain about "bare" parameter packs. */
3689 /* Recover by calling this a parameter pack. */
3691 }
3692 }
3694 /* A template parameter is not modifiable. */
3703 processing_template_decl,
3708 }
3709 else
3710 {
3711 tree t;
3715 {
3717 /* This is for distinguishing between real templates and template
3718 template parameters */
3722 }
3723 else
3724 {
3726 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3729 }
3736 processing_template_decl,
3740 }
3746 }
3748 /* The end of a template parameter list has been reached. Process the
3749 tree list into a parameter vector, converting each parameter into a more
3750 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3751 as PARM_DECLs. */
3753 tree
3755 {
3760 current_template_parms
3765 {
3769 }
3774 }
3776 /* end_template_decl is called after a template declaration is seen. */
3778 void
3780 {
3786 /* This matches the pushlevel in begin_template_parm_list. */
3791 }
3793 /* Takes a TREE_LIST representing a template parameter and convert it
3794 into an argument suitable to be passed to the type substitution
3795 functions. Note that If the TREE_LIST contains an error_mark
3796 node, the returned argument is error_mark_node. */
3798 static tree
3800 {
3813 {
3817 {
3818 /* Turn this argument into a TYPE_ARGUMENT_PACK
3819 with a single element, which expands T. */
3821 #ifdef ENABLE_CHECKING
3822 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3824 #endif
3829 }
3830 }
3831 else
3832 {
3836 {
3837 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3838 with a single element, which expands T. */
3841 #ifdef ENABLE_CHECKING
3842 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3844 #endif
3850 }
3851 }
3853 }
3855 /* Given a set of template parameters, return them as a set of template
3856 arguments. The template parameters are represented as a TREE_VEC, in
3857 the form documented in cp-tree.h for template arguments. */
3859 static tree
3861 {
3862 tree header;
3867 /* If there is only one level of template parameters, we do not
3868 create a TREE_VEC of TREE_VECs. Instead, we return a single
3869 TREE_VEC containing the arguments. */
3874 {
3882 #ifdef ENABLE_CHECKING
3884 #endif
3888 else
3890 }
3893 /* This can happen for template parms of a template template
3894 parameter, e.g:
3896 template<template<class T, class U> class TT> struct S;
3898 Consider the level of the parms of TT; T and U both have
3899 level 2; TT has no template parm of level 1. So in this case
3900 the first element of full_template_args is NULL_TREE. If we
3901 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
3902 of 2. This will make tsubst wrongly consider that T and U
3903 have level 1. Instead, let's create a dummy vector as the
3904 first element of full_template_args so that TMPL_ARGS_DEPTH
3905 returns the correct depth for args. */
3908 }
3910 /* Within the declaration of a template, return the currently active
3911 template parameters as an argument TREE_VEC. */
3913 static tree
3915 {
3917 }
3919 /* Update the declared TYPE by doing any lookups which were thought to be
3920 dependent, but are not now that we know the SCOPE of the declarator. */
3922 tree
3924 {
3935 /* Don't bother building up the args in this case. */
3937 {
3938 /* tsubst in the args corresponding to the template parameters,
3939 including auto if present. Most things will be unchanged, but
3940 make_typename_type and tsubst_qualified_id will resolve
3941 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3944 tree pushed;
3946 {
3950 }
3955 }
3961 {
3964 else
3966 }
3968 }
3970 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3971 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3972 a member template. Used by push_template_decl below. */
3974 static tree
3976 {
3984 }
3986 struct template_parm_data
3987 {
3988 /* The level of the template parameters we are currently
3989 processing. */
3992 /* The index of the specialization argument we are currently
3993 processing. */
3996 /* An array whose size is the number of template parameters. The
3997 elements are nonzero if the parameter has been used in any one
3998 of the arguments processed so far. */
4001 /* An array whose size is the number of template arguments. The
4002 elements are nonzero if the argument makes use of template
4003 parameters of this level. */
4005 };
4007 /* Subroutine of push_template_decl used to see if each template
4008 parameter in a partial specialization is used in the explicit
4009 argument list. If T is of the LEVEL given in DATA (which is
4010 treated as a template_parm_data*), then DATA->PARMS is marked
4011 appropriately. */
4013 static int
4015 {
4021 {
4024 }
4025 else
4026 {
4029 }
4032 {
4035 }
4037 /* Return zero so that for_each_template_parm will continue the
4038 traversal of the tree; we want to mark *every* template parm. */
4040 }
4042 /* Process the partial specialization DECL. */
4044 static tree
4046 {
4052 tree inner_parms;
4053 tree inst;
4066 /* We check that each of the template parameters given in the
4067 partial specialization is used in the argument list to the
4068 specialization. For example:
4070 template <class T> struct S;
4071 template <class T> struct S<T*>;
4073 The second declaration is OK because `T*' uses the template
4074 parameter T, whereas
4076 template <class T> struct S<int>;
4078 is no good. Even trickier is:
4080 template <class T>
4081 struct S1
4082 {
4083 template <class U>
4084 struct S2;
4085 template <class U>
4086 struct S2<T>;
4087 };
4089 The S2<T> declaration is actually invalid; it is a
4090 full-specialization. Of course,
4092 template <class U>
4093 struct S2<T (*)(U)>;
4095 or some such would have been OK. */
4103 {
4108 NULL,
4110 }
4113 {
4114 /* One of the template parms was not used in the
4115 specialization. */
4117 {
4120 }
4123 }
4128 /* [temp.class.spec]
4130 The argument list of the specialization shall not be identical to
4131 the implicit argument list of the primary template. */
4138 /* A partial specialization that replaces multiple parameters of the
4139 primary template with a pack expansion is less specialized for those
4140 parameters. */
4142 {
4144 "primary template because it replaces multiple parameters "
4148 }
4150 /* [temp.class.spec]
4152 A partially specialized non-type argument expression shall not
4153 involve template parameters of the partial specialization except
4154 when the argument expression is a simple identifier.
4156 The type of a template parameter corresponding to a specialized
4157 non-type argument shall not be dependent on a parameter of the
4158 specialization.
4160 Also, we verify that pack expansions only occur at the
4161 end of the argument list. */
4165 {
4172 {
4173 /* Extract the arguments from the argument pack. We'll be
4174 iterating over these in the following loop. */
4177 }
4180 {
4182 /* Get the Jth argument in the parameter pack. */
4186 {
4187 /* Pack expansions must come at the end of the
4188 argument list. */
4191 {
4195 else
4198 }
4199 }
4202 /* We only care about the pattern. */
4208 /* This next line is the `argument expression is not just a
4209 simple identifier' condition and also the `specialized
4210 non-type argument' bit. */
4212 {
4216 arg);
4217 else
4218 {
4219 /* Look at the corresponding template parameter,
4220 marking which template parameters its type depends
4221 upon. */
4225 {
4226 /* We haven't yet initialized TPD2. Do so now. */
4228 /* The number of parameters here is the number in the
4229 main template, which, as checked in the assertion
4230 above, is NARGS. */
4234 }
4236 /* Mark the template parameters. But this time, we're
4237 looking for the template parameters of the main
4238 template, not in the specialization. */
4245 NULL,
4249 {
4250 /* The type depended on some template parameters.
4251 If they are fully specialized in the
4252 specialization, that's OK. */
4261 "type %qT of template argument %qE depends "
4263 "type %qT of template argument %qE depends "
4265 type,
4266 arg);
4267 }
4268 }
4269 }
4270 }
4271 }
4273 /* We should only get here once. */
4291 {
4295 {
4299 "partial specialization of %qT after instantiation "
4301 }
4302 }
4305 }
4307 /* Check that a template declaration's use of default arguments and
4308 parameter packs is not invalid. Here, PARMS are the template
4309 parameters. IS_PRIMARY is true if DECL is the thing declared by
4310 a primary template. IS_PARTIAL is true if DECL is a partial
4311 specialization.
4313 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4314 declaration (but not a definition); 1 indicates a declaration, 2
4315 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4316 emitted for extraneous default arguments.
4318 Returns TRUE if there were no errors found, FALSE otherwise. */
4320 bool
4323 {
4326 tree parm_level;
4329 /* [temp.param]
4331 A default template-argument shall not be specified in a
4332 function template declaration or a function template definition, nor
4333 in the template-parameter-list of the definition of a member of a
4334 class template. */
4337 /* You can't have a function template declaration in a local
4338 scope, nor you can you define a member of a class template in a
4339 local scope. */
4345 /* A lambda doesn't have an explicit declaration; don't complain
4346 about the parms of the enclosing class. */
4353 /* If this is either a friend defined in the scope of the class
4354 or a member function. */
4360 /* And, if it was a member function, it really was defined in
4361 the scope of the class. */
4364 /* We already checked these parameters when the template was
4365 declared, so there's no need to do it again now. This function
4366 was defined in class scope, but we're processing its body now
4367 that the class is complete. */
4370 /* Core issue 226 (C++0x only): the following only applies to class
4371 templates. */
4374 {
4375 /* [temp.param]
4377 If a template-parameter has a default template-argument, all
4378 subsequent template-parameters shall have a default
4379 template-argument supplied. */
4381 {
4388 {
4398 {
4400 /* For better subsequent error-recovery, we indicate that
4401 there should have been a default argument. */
4404 }
4406 && !is_friend_decl
4407 /* Don't complain about an enclosing partial
4408 specialization. */
4413 {
4414 /* A primary class template can only have one
4415 parameter pack, at the end of the template
4416 parameter list. */
4421 else
4429 }
4430 }
4431 }
4432 }
4435 || is_partial
4436 || !is_primary
4438 /* For an ordinary class template, default template arguments are
4439 allowed at the innermost level, e.g.:
4440 template <class T = int>
4441 struct S {};
4442 but, in a partial specialization, they're not allowed even
4443 there, as we have in [temp.class.spec]:
4445 The template parameter list of a specialization shall not
4446 contain default template argument values.
4448 So, for a partial specialization, or for a function template
4449 (in C++98/C++03), we look at all of them. */
4450 ;
4451 else
4452 /* But, for a primary class template that is not a partial
4453 specialization we look at all template parameters except the
4454 innermost ones. */
4457 /* Figure out what error message to issue. */
4470 else
4474 /* If we're inside a class definition, there's no need to
4475 examine the parameters to the class itself. On the one
4476 hand, they will be checked when the class is defined, and,
4477 on the other, default arguments are valid in things like:
4478 template <class T = double>
4479 struct S { template <class U> void f(U); };
4480 Here the default argument for `S' has no bearing on the
4481 declaration of `f'. */
4483 else
4484 /* Check everything. */
4490 {
4497 {
4502 {
4504 {
4511 }
4513 /* Clear out the default argument so that we are not
4514 confused later. */
4516 }
4517 }
4519 /* At this point, if we're still interested in issuing messages,
4520 they must apply to classes surrounding the object declared. */
4524 }
4527 }
4529 /* Worker for push_template_decl_real, called via
4530 for_each_template_parm. DATA is really an int, indicating the
4531 level of the parameters we are interested in. If T is a template
4532 parameter of that level, return nonzero. */
4534 static int
4536 {
4542 else
4545 }
4547 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4548 parameters given by current_template_args, or reuses a
4549 previously existing one, if appropriate. Returns the DECL, or an
4550 equivalent one, if it is replaced via a call to duplicate_decls.
4552 If IS_FRIEND is true, DECL is a friend declaration. */
4554 tree
4556 {
4557 tree tmpl;
4558 tree args;
4559 tree info;
4560 tree ctx;
4564 /* True if the template is a member template, in the sense of
4565 [temp.mem]. */
4571 /* See if this is a partial specialization. */
4580 /* For a friend, we want the context of the friend function, not
4581 the type of which it is a friend. */
4585 /* In the case of a virtual function, we want the class in which
4586 it is defined. */
4588 else
4589 /* Otherwise, if we're currently defining some class, the DECL
4590 is assumed to be a member of the class. */
4599 /* See if this is a primary template. */
4601 /* A friend template that specifies a class context, i.e.
4602 template <typename T> friend void A<T>::f();
4603 is not primary. */
4605 else
4609 {
4614 {
4617 }
4619 {
4621 {
4622 /* [temp.mem]
4624 A destructor shall not be a member template. */
4627 }
4634 {
4635 /* [basic.stc.dynamic.allocation]
4637 An allocation function can be a function
4638 template. ... Template allocation functions shall
4639 have two or more parameters. */
4642 }
4643 }
4649 /* alias-declaration */
4651 else
4652 {
4655 }
4656 }
4658 /* Check to see that the rules regarding the use of default
4659 arguments are not being violated. */
4663 /* Ensure that there are no parameter packs in the type of this
4664 declaration that have not been expanded. */
4666 {
4667 /* Check each of the arguments individually to see if there are
4668 any bare parameter packs. */
4674 {
4677 {
4678 /* This is a PARM_DECL that contains unexpanded parameter
4679 packs. We have already complained about this in the
4680 check_for_bare_parameter_packs call, so just replace
4681 these types with ERROR_MARK_NODE. */
4684 }
4688 }
4690 /* Check for bare parameter packs in the return type and the
4691 exception specifiers. */
4693 /* Errors were already issued, set return type to int
4694 as the frontend doesn't expect error_mark_node as
4695 the return type. */
4699 }
4704 {
4707 }
4720 {
4725 /* If DECL is a TYPE_DECL for a class-template, then there won't
4726 be DECL_LANG_SPECIFIC. The information equivalent to
4727 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4731 {
4732 /* Since a template declaration already existed for this
4733 class-type, we must be redeclaring it here. Make sure
4734 that the redeclaration is valid. */
4736 current_template_parms);
4737 /* We don't need to create a new TEMPLATE_DECL; just use the
4738 one we already had. */
4740 }
4741 else
4742 {
4744 member_template_p);
4749 {
4750 /* A specialization of a member template of a template
4751 class. */
4755 }
4756 }
4757 }
4758 else
4759 {
4765 {
4768 }
4776 {
4777 tree new_tmpl;
4779 /* The declaration is a specialization of a member
4780 template, declared outside the class. Therefore, the
4781 innermost template arguments will be NULL, so we
4782 replace them with the arguments determined by the
4783 earlier call to check_explicit_specialization. */
4786 new_tmpl
4788 member_template_p);
4798 args,
4801 }
4803 /* Make sure the template headers we got make sense. */
4808 {
4811 }
4812 else
4814 {
4819 {
4823 else
4827 /* Avoid crash in import_export_decl. */
4830 }
4835 /* Can happen in erroneous input. */
4837 else
4839 }
4841 /* Check that the parms are used in the appropriate qualifying scopes
4842 in the declarator. */
4846 {
4852 /* Avoid crash in import_export_decl. */
4855 }
4856 }
4861 /* Push template declarations for global functions and types. Note
4862 that we do not try to push a global template friend declared in a
4863 template class; such a thing may well depend on the template
4864 parameters of the class. */
4867 {
4872 /* Hide template friend classes that haven't been declared yet. */
4874 {
4877 }
4878 }
4881 {
4887 {
4890 /* It is a conversion operator. See if the type converted to
4891 depends on innermost template operands. */
4894 depth))
4896 }
4898 /* Give template template parms a DECL_CONTEXT of the template
4899 for which they are a parameter. */
4902 {
4906 }
4907 }
4909 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4910 back to its most general template. If TMPL is a specialization,
4911 ARGS may only have the innermost set of arguments. Add the missing
4912 argument levels if necessary. */
4920 else
4921 {
4926 }
4929 }
4931 tree
4933 {
4935 }
4937 /* FN is an inheriting constructor that inherits from the constructor
4938 template INHERITED; turn FN into a constructor template with a matching
4939 template header. */
4941 tree
4943 {
4944 tree inner_parms
4947 tree parms
4958 }
4960 /* Called when a class template TYPE is redeclared with the indicated
4961 template PARMS, e.g.:
4963 template <class T> struct S;
4964 template <class T> struct S {}; */
4966 bool
4968 {
4969 tree tmpl;
4970 tree tmpl_parms;
4974 {
4977 }
4981 /* The type is nested in some template class. Nothing to worry
4982 about here; there are no new template parameters for the nested
4983 type. */
4987 {
4989 tmpl);
4991 }
4997 {
5007 }
5010 {
5011 tree tmpl_parm;
5012 tree parm;
5013 tree tmpl_default;
5014 tree parm_default;
5028 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5029 TEMPLATE_DECL. */
5039 {
5043 }
5046 {
5047 /* We have in [temp.param]:
5049 A template-parameter may not be given default arguments
5050 by two different declarations in the same scope. */
5055 }
5058 /* Update the previous template parameters (which are the ones
5059 that will really count) with the new default value. */
5062 /* Update the new parameters, too; they'll be used as the
5063 parameters for any members. */
5065 }
5068 }
5070 /* Simplify EXPR if it is a non-dependent expression. Returns the
5071 (possibly simplified) expression. */
5073 tree
5075 {
5079 /* If we're in a template, but EXPR isn't value dependent, simplify
5080 it. We're supposed to treat:
5082 template <typename T> void f(T[1 + 1]);
5083 template <typename T> void f(T[2]);
5085 as two declarations of the same function, for example. */
5089 {
5090 HOST_WIDE_INT saved_processing_template_decl;
5096 complain,
5101 }
5103 }
5105 tree
5107 {
5109 }
5111 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5112 template declaration, or a TYPE_DECL for an alias declaration. */
5114 bool
5116 {
5124 }
5126 /* Return TRUE iff is a specialization of an alias template. */
5128 bool
5130 {
5138 }
5140 /* Return either TMPL or another template that it is equivalent to under DR
5141 1286: An alias that just changes the name of a template is equivalent to
5142 the other template. */
5144 static tree
5146 {
5149 {
5152 {
5156 {
5157 /* The alias type is equivalent to the pattern of the
5158 underlying template, so strip the alias. */
5161 }
5162 }
5164 }
5166 }
5168 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5169 must be a function or a pointer-to-function type, as specified
5170 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5171 and check that the resulting function has external linkage. */
5173 static tree
5175 {
5178 linkage_kind linkage;
5190 /* [temp.arg.nontype]/1
5192 A template-argument for a non-type, non-template template-parameter
5193 shall be one of:
5194 [...]
5195 -- the address of an object or function with external [C++11: or
5196 internal] linkage. */
5199 {
5203 else
5206 }
5210 {
5215 else
5220 }
5223 }
5225 /* Subroutine of convert_nontype_argument.
5226 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5227 Emit an error otherwise. */
5229 static bool
5231 tsubst_flags_t complain)
5232 {
5239 {
5243 }
5245 }
5247 /* Returns TRUE iff the address of OP is value-dependent.
5249 14.6.2.4 [temp.dep.temp]:
5250 A non-integral non-type template-argument is dependent if its type is
5251 dependent or it has either of the following forms
5252 qualified-id
5253 & qualified-id
5254 and contains a nested-name-specifier which specifies a class-name that
5255 names a dependent type.
5257 We generalize this to just say that the address of a member of a
5258 dependent class is value-dependent; the above doesn't cover the
5259 address of a static data member named with an unqualified-id. */
5261 static bool
5263 {
5264 /* We could use get_inner_reference here, but there's no need;
5265 this is only relevant for template non-type arguments, which
5266 can only be expressed as &id-expression. */
5268 {
5272 }
5275 }
5277 /* The next set of functions are used for providing helpful explanatory
5278 diagnostics for failed overload resolution. Their messages should be
5279 indented by two spaces for consistency with the messages in
5280 call.c */
5282 static int
5284 {
5286 }
5288 static int
5290 {
5295 }
5297 static int
5299 {
5301 }
5303 static int
5305 {
5311 }
5313 static int
5315 {
5319 }
5321 static int
5323 {
5326 " template parameter %qD is not a parameter pack, but "
5330 }
5332 static int
5334 {
5337 " template argument %qE does not match "
5341 }
5343 static int
5345 {
5349 }
5351 static int
5353 {
5359 }
5361 static int
5363 {
5365 {
5370 else
5372 " deduced conflicting values for non-type parameter "
5374 }
5376 }
5378 static int
5380 {
5383 " variable-sized array type %qT is not "
5385 arg);
5387 }
5389 static int
5391 {
5395 arg);
5397 }
5399 static int
5401 {
5408 }
5410 static int
5412 {
5414 }
5416 static int
5418 {
5420 }
5422 static int
5425 {
5431 }
5433 static int
5436 {
5439 {
5447 }
5449 }
5451 static int
5453 {
5456 " template parameters of a template template argument are "
5459 }
5461 static int
5463 {
5469 }
5471 static int
5473 {
5478 }
5480 static int
5482 {
5486 arg);
5488 }
5490 /* Attempt to convert the non-type template parameter EXPR to the
5491 indicated TYPE. If the conversion is successful, return the
5492 converted value. If the conversion is unsuccessful, return
5493 NULL_TREE if we issued an error message, or error_mark_node if we
5494 did not. We issue error messages for out-and-out bad template
5495 parameters, but not simply because the conversion failed, since we
5496 might be just trying to do argument deduction. Both TYPE and EXPR
5497 must be non-dependent.
5499 The conversion follows the special rules described in
5500 [temp.arg.nontype], and it is much more strict than an implicit
5501 conversion.
5503 This function is called twice for each template argument (see
5504 lookup_template_class for a more accurate description of this
5505 problem). This means that we need to handle expressions which
5506 are not valid in a C++ source, but can be created from the
5507 first call (for instance, casts to perform conversions). These
5508 hacks can go away after we fix the double coercion problem. */
5510 static tree
5512 {
5513 tree expr_type;
5515 /* Detect immediately string literals as invalid non-type argument.
5516 This special-case is not needed for correctness (we would easily
5517 catch this later), but only to provide better diagnostic for this
5518 common user mistake. As suggested by DR 100, we do not mention
5519 linkage issues in the diagnostic as this is not the point. */
5520 /* FIXME we're making this OK. */
5522 {
5528 }
5530 /* Add the ADDR_EXPR now for the benefit of
5531 value_dependent_expression_p. */
5534 {
5538 }
5540 /* If we are in a template, EXPR may be non-dependent, but still
5541 have a syntactic, rather than semantic, form. For example, EXPR
5542 might be a SCOPE_REF, rather than the VAR_DECL to which the
5543 SCOPE_REF refers. Preserving the qualifying scope is necessary
5544 so that access checking can be performed when the template is
5545 instantiated -- but here we need the resolved form so that we can
5546 convert the argument. */
5557 else
5560 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5561 to a non-type argument of "nullptr". */
5565 /* In C++11, integral or enumeration non-type template arguments can be
5566 arbitrary constant expressions. Pointer and pointer to
5567 member arguments can be general constant expressions that evaluate
5568 to a null value, but otherwise still need to be of a specific form. */
5570 {
5572 /* A PTRMEM_CST is already constant, and a valid template
5573 argument for a parameter of pointer to member type, we just want
5574 to leave it in that form rather than lower it to a
5579 {
5584 }
5585 }
5587 /* HACK: Due to double coercion, we can get a
5588 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5589 which is the tree that we built on the first call (see
5590 below when coercing to reference to object or to reference to
5591 function). We just strip everything and get to the arg.
5592 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5593 for examples. */
5595 {
5601 {
5602 /* ??? Maybe we could use convert_from_reference here, but we
5603 would need to relax its constraints because the NOP_EXPR
5604 could actually change the type to something more cv-qualified,
5605 and this is not folded by convert_from_reference. */
5610 && (same_type_ignoring_top_level_qualifiers_p
5613 {
5616 }
5617 }
5618 }
5620 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5621 parameter is a pointer to object, through decay and
5622 qualification conversion. Let's strip everything. */
5624 {
5629 {
5630 /* Skip the ADDR_EXPR only if it is part of the decay for
5631 an array. Otherwise, it is part of the original argument
5632 in the source code. */
5637 }
5638 }
5640 /* [temp.arg.nontype]/5, bullet 1
5642 For a non-type template-parameter of integral or enumeration type,
5643 integral promotions (_conv.prom_) and integral conversions
5644 (_conv.integral_) are applied. */
5646 {
5655 /* Notice that there are constant expressions like '4 % 0' which
5656 do not fold into integer constants. */
5658 {
5660 {
5671 /* else cxx_constant_value complained but gave us
5672 a real constant, so go ahead. */
5674 }
5675 else
5677 }
5679 /* Avoid typedef problems. */
5682 }
5683 /* [temp.arg.nontype]/5, bullet 2
5685 For a non-type template-parameter of type pointer to object,
5686 qualification conversions (_conv.qual_) and the array-to-pointer
5687 conversion (_conv.array_) are applied. */
5689 {
5690 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5692 A template-argument for a non-type, non-template template-parameter
5693 shall be one of: [...]
5695 -- the name of a non-type template-parameter;
5696 -- the address of an object or function with external linkage, [...]
5697 expressed as "& id-expression" where the & is optional if the name
5698 refers to a function or array, or if the corresponding
5699 template-parameter is a reference.
5701 Here, we do not care about functions, as they are invalid anyway
5702 for a parameter of type pointer-to-object. */
5705 /* Non-type template parameters are OK. */
5706 ;
5711 {
5713 {
5715 "because %qD is a variable, not the address of "
5719 }
5721 {
5726 }
5727 /* Other values, like integer constants, might be valid
5728 non-type arguments of some other type. */
5730 }
5731 else
5732 {
5733 tree decl;
5738 {
5743 }
5745 {
5750 }
5752 {
5757 }
5758 }
5767 }
5768 /* [temp.arg.nontype]/5, bullet 3
5770 For a non-type template-parameter of type reference to object, no
5771 conversions apply. The type referred to by the reference may be more
5772 cv-qualified than the (otherwise identical) type of the
5773 template-argument. The template-parameter is bound directly to the
5774 template-argument, which must be an lvalue. */
5776 {
5778 expr_type))
5782 {
5786 }
5789 {
5793 }
5795 /* [temp.arg.nontype]/1
5797 A template-argument for a non-type, non-template template-parameter
5798 shall be one of: [...]
5800 -- the address of an object or function with external linkage. */
5803 {
5806 {
5808 "because a reference variable does not have a constant "
5811 }
5812 }
5815 {
5820 }
5823 {
5828 }
5831 }
5832 /* [temp.arg.nontype]/5, bullet 4
5834 For a non-type template-parameter of type pointer to function, only
5835 the function-to-pointer conversion (_conv.func_) is applied. If the
5836 template-argument represents a set of overloaded functions (or a
5837 pointer to such), the matching function is selected from the set
5838 (_over.over_). */
5840 {
5841 /* If the argument is a template-id, we might not have enough
5842 context information to decay the pointer. */
5844 {
5848 }
5851 /* Null pointer values are OK in C++11. */
5857 }
5858 /* [temp.arg.nontype]/5, bullet 5
5860 For a non-type template-parameter of type reference to function, no
5861 conversions apply. If the template-argument represents a set of
5862 overloaded functions, the matching function is selected from the set
5863 (_over.over_). */
5865 {
5867 {
5872 }
5879 }
5880 /* [temp.arg.nontype]/5, bullet 6
5882 For a non-type template-parameter of type pointer to member function,
5883 no conversions apply. If the template-argument represents a set of
5884 overloaded member functions, the matching member function is selected
5885 from the set (_over.over_). */
5887 {
5892 /* [temp.arg.nontype] bullet 1 says the pointer to member
5893 expression must be a pointer-to-member constant. */
5897 /* There is no way to disable standard conversions in
5898 resolve_address_of_overloaded_function (called by
5899 instantiate_type). It is possible that the call succeeded by
5900 converting &B::I to &D::I (where B is a base of D), so we need
5901 to reject this conversion here.
5903 Actually, even if there was a way to disable standard conversions,
5904 it would still be better to reject them here so that we can
5905 provide a superior diagnostic. */
5907 {
5911 /* If we are just one standard conversion off, explain. */
5916 }
5917 }
5918 /* [temp.arg.nontype]/5, bullet 7
5920 For a non-type template-parameter of type pointer to data member,
5921 qualification conversions (_conv.qual_) are applied. */
5923 {
5924 /* [temp.arg.nontype] bullet 1 says the pointer to member
5925 expression must be a pointer-to-member constant. */
5932 }
5934 {
5936 {
5940 }
5942 }
5943 /* A template non-type parameter must be one of the above. */
5944 else
5947 /* Sanity check: did we actually convert the argument to the
5948 right type? */
5952 }
5954 /* Subroutine of coerce_template_template_parms, which returns 1 if
5955 PARM_PARM and ARG_PARM match using the rule for the template
5956 parameters of template template parameters. Both PARM and ARG are
5957 template parameters; the rest of the arguments are the same as for
5958 coerce_template_template_parms.
5959 */
5960 static int
5962 tree arg,
5963 tsubst_flags_t complain,
5964 tree in_decl,
5965 tree outer_args)
5966 {
5975 {
5977 /* We encounter instantiations of templates like
5978 template <template <template <class> class> class TT>
5979 class C; */
5980 {
5987 }
5988 /* Fall through. */
5993 /* Argument is a parameter pack but parameter is not. */
5998 /* The tsubst call is used to handle cases such as
6000 template <int> class C {};
6001 template <class T, template <T> class TT> class D {};
6002 D<int, C> d;
6004 i.e. the parameter list of TT depends on earlier parameters. */
6006 && !same_type_p
6013 /* Argument is a parameter pack but parameter is not. */
6020 }
6023 }
6026 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6027 template template parameters. Both PARM_PARMS and ARG_PARMS are
6028 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6029 or PARM_DECL.
6031 Consider the example:
6032 template <class T> class A;
6033 template<template <class U> class TT> class B;
6035 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6036 the parameters to A, and OUTER_ARGS contains A. */
6038 static int
6040 tree arg_parms,
6041 tsubst_flags_t complain,
6042 tree in_decl,
6043 tree outer_args)
6044 {
6055 /* Determine whether we have a parameter pack at the end of the
6056 template template parameter's template parameter list. */
6058 {
6065 {
6079 }
6080 }
6086 /* Check all of the template parameters except the parameter pack at
6087 the end (if any). */
6089 {
6098 outer_args))
6101 }
6104 {
6105 /* Check each of the template parameters in the template
6106 argument against the template parameter pack at the end of
6107 the template template parameter. */
6114 {
6121 outer_args))
6123 }
6124 }
6127 }
6129 /* Verifies that the deduced template arguments (in TARGS) for the
6130 template template parameters (in TPARMS) represent valid bindings,
6131 by comparing the template parameter list of each template argument
6132 to the template parameter list of its corresponding template
6133 template parameter, in accordance with DR150. This
6134 routine can only be called after all template arguments have been
6135 deduced. It will return TRUE if all of the template template
6136 parameter bindings are okay, FALSE otherwise. */
6137 bool
6139 {
6143 /* We're dealing with template parms in this process. */
6149 {
6154 {
6159 {
6160 /* Look inside the argument pack. */
6163 }
6166 {
6170 /* Extract the next argument from the argument
6171 pack. */
6175 /* Look at the pattern of the pack expansion. */
6178 /* Extract the template parameters from the template
6179 argument. */
6185 /* Verify that we can coerce the template template
6186 parameters from the template argument to the template
6187 parameter. This requires an exact match. */
6189 && !coerce_template_template_parms
6191 targ_parms,
6192 tf_none,
6193 tparm,
6194 targs))
6195 {
6198 }
6199 }
6200 }
6201 }
6203 out:
6207 }
6209 /* Since type attributes aren't mangled, we need to strip them from
6210 template type arguments. */
6212 static tree
6214 {
6215 tree mv;
6222 {
6227 }
6229 }
6231 /* Convert the indicated template ARG as necessary to match the
6232 indicated template PARM. Returns the converted ARG, or
6233 error_mark_node if the conversion was unsuccessful. Error and
6234 warning messages are issued under control of COMPLAIN. This
6235 conversion is for the Ith parameter in the parameter list. ARGS is
6236 the full set of template arguments deduced so far. */
6238 static tree
6240 tree arg,
6241 tree args,
6242 tsubst_flags_t complain,
6244 tree in_decl)
6245 {
6246 tree orig_arg;
6247 tree val;
6252 {
6253 /* The template argument was the name of some
6254 member function. That's usually
6255 invalid, but static members are OK. In any
6256 case, grab the underlying fields/functions
6257 and issue an error later if required. */
6260 }
6268 /* When determining whether an argument pack expansion is a template,
6269 look at the pattern. */
6273 /* Deal with an injected-class-name used as a template template arg. */
6275 {
6278 {
6288 }
6289 }
6291 is_tmpl_type =
6307 {
6309 {
6313 }
6316 "to refer to a type member of a template parameter, "
6321 typename_type,
6322 complain);
6325 }
6327 {
6329 {
6331 {
6341 else
6343 }
6344 }
6346 }
6348 {
6350 {
6356 else
6358 }
6360 }
6363 {
6365 {
6369 /* The number of argument required is not known yet.
6370 Just accept it for now. */
6372 else
6373 {
6375 tree argparm;
6377 /* Strip alias templates that are equivalent to another
6378 template. */
6384 args))
6385 {
6388 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6389 TEMPLATE_DECL. */
6391 {
6396 }
6397 }
6398 else
6399 {
6401 {
6407 }
6410 }
6411 }
6412 }
6413 else
6415 /* We only form one instance of each template specialization.
6416 Therefore, if we use a non-canonical variant (i.e., a
6417 typedef), any future messages referring to the type will use
6418 the typedef, which is confusing if those future uses do not
6419 themselves also use the typedef. */
6422 }
6423 else
6424 {
6431 {
6434 else
6435 {
6436 /* Not sure if this is reachable, but it doesn't hurt
6437 to be robust. */
6440 }
6441 }
6444 /* We used to call digest_init here. However, digest_init
6445 will report errors, which we don't want when complain
6446 is zero. More importantly, digest_init will try too
6447 hard to convert things: for example, `0' should not be
6448 converted to pointer type at this point according to
6449 the standard. Accepting this is not merely an
6450 extension, since deciding whether or not these
6451 conversions can occur is part of determining which
6452 function template to call, or whether a given explicit
6453 argument specification is valid. */
6455 else
6464 {
6465 /* Strip typedefs from the SCOPE_REF. */
6468 complain);
6471 }
6472 }
6475 }
6477 /* Coerces the remaining template arguments in INNER_ARGS (from
6478 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6479 Returns the coerced argument pack. PARM_IDX is the position of this
6480 parameter in the template parameter list. ARGS is the original
6481 template argument list. */
6482 static tree
6485 tree args,
6486 tree inner_args,
6488 tree new_args,
6490 tree in_decl,
6491 tsubst_flags_t complain)
6492 {
6495 tree packed_args;
6496 tree argument_pack;
6506 {
6507 /* When the template parameter is a non-type template
6508 parameter pack whose type uses parameter packs, we need
6509 to look at each of the template arguments
6510 separately. Build a vector of the types for these
6511 non-type template parameters in PACKED_TYPES. */
6512 tree expansion
6520 /* Check that we have the right number of arguments. */
6524 {
6525 int needed_parms
6530 }
6532 /* If we aren't able to check the actual arguments now
6533 (because they haven't been expanded yet), we can at least
6534 verify that all of the types used for the non-type
6535 template parameter pack are, in fact, valid for non-type
6536 template parameters. */
6539 {
6542 {
6546 }
6547 }
6548 }
6550 /* Convert the remaining arguments, which will be a part of the
6551 parameter pack "parm". */
6553 {
6558 {
6559 /* When we have a vector of types (corresponding to the
6560 non-type template parameter pack that uses parameter
6561 packs in its type, as mention above), and the
6562 argument is not an expansion (which expands to a
6563 currently unknown number of arguments), clone the
6564 parm and give it the next type in PACKED_TYPES. */
6568 }
6571 {
6574 }
6575 else
6578 in_decl);
6582 }
6587 else
6588 {
6593 }
6596 #ifdef ENABLE_CHECKING
6599 #endif
6601 }
6603 /* Returns the number of pack expansions in the template argument vector
6604 ARGS. */
6606 static int
6608 {
6613 {
6617 }
6619 }
6621 /* Convert all template arguments to their appropriate types, and
6622 return a vector containing the innermost resulting template
6623 arguments. If any error occurs, return error_mark_node. Error and
6624 warning messages are issued under control of COMPLAIN.
6626 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6627 for arguments not specified in ARGS. Otherwise, if
6628 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6629 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6630 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6631 ARGS. */
6633 static tree
6635 tree args,
6636 tree in_decl,
6637 tsubst_flags_t complain,
6640 {
6642 tree inner_args;
6643 tree new_args;
6644 tree new_inner_args;
6648 /* When used as a boolean value, indicates whether this is a
6649 variadic template parameter list. Since it's an int, we can also
6650 subtract it from nparms to get the number of non-variadic
6651 parameters. */
6661 /* Determine if there are any parameter packs. */
6663 {
6669 }
6672 /* If there are no parameters that follow a parameter pack, we need to
6673 expand any argument packs so that we can deduce a parameter pack from
6674 some non-packed args followed by an argument pack, as in variadic85.C.
6675 If there are such parameters, we need to leave argument packs intact
6676 so the arguments are assigned properly. This can happen when dealing
6677 with a nested class inside a partial specialization of a class
6678 template, as in variadic92.C, or when deducing a template parameter pack
6679 from a sub-declarator, as in variadic114.C. */
6683 /* Count any pack expansion args. */
6689 && require_all_args
6690 && !variadic_args_p
6691 && (!use_default_args
6694 {
6696 {
6698 {
6702 }
6703 else
6709 }
6712 }
6713 /* We can't pass a pack expansion to a non-pack parameter of an alias
6714 template (DR 1430). */
6716 && variadic_args_p
6718 {
6720 {
6722 {
6728 {
6733 }
6734 }
6736 found:;
6737 }
6739 }
6741 /* We need to evaluate the template arguments, even though this
6742 template-id may be nested within a "sizeof". */
6750 {
6751 tree arg;
6752 tree parm;
6754 /* Get the Ith template parameter. */
6758 {
6761 }
6763 /* Calculate the next argument. */
6766 else
6771 {
6772 /* All remaining arguments will be placed in the
6773 template parameter pack PARM. */
6779 /* Store this argument. */
6781 lost++;
6784 /* We are done with all of the arguments. */
6788 }
6790 {
6792 {
6793 /* We don't know how many args we have yet, just
6794 use the unconverted ones for now. */
6797 }
6798 }
6800 {
6801 /* There must be a default arg in this case. */
6804 /* The position of the first default template argument,
6805 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6806 Record that. */
6809 }
6810 else
6814 {
6817 }
6819 /* This only occurs if there was an error in the template
6820 parameter list itself (which we would already have
6821 reported) that we are trying to recover from, e.g., a class
6822 template with a parameter list such as
6823 template<typename..., typename>. */
6825 else
6831 lost++;
6833 }
6840 #ifdef ENABLE_CHECKING
6844 #endif
6847 }
6849 /* Like coerce_template_parms. If PARMS represents all template
6850 parameters levels, this function returns a vector of vectors
6851 representing all the resulting argument levels. Note that in this
6852 case, only the innermost arguments are coerced because the
6853 outermost ones are supposed to have been coerced already.
6855 Otherwise, if PARMS represents only (the innermost) vector of
6856 parameters, this function returns a vector containing just the
6857 innermost resulting arguments. */
6859 static tree
6861 tree args,
6862 tree in_decl,
6863 tsubst_flags_t complain,
6866 {
6869 tree coerced_args;
6872 {
6874 tree level;
6880 {
6881 tree l;
6885 require_all_args,
6886 use_default_args);
6887 else
6894 }
6895 }
6896 else
6899 require_all_args,
6900 use_default_args);
6902 }
6904 /* Returns 1 if template args OT and NT are equivalent. */
6906 static int
6908 {
6915 /* For member templates */
6924 {
6941 }
6943 {
6944 /* We get here probably because we are in the middle of substituting
6945 into the pattern of a pack expansion. In that case the
6946 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6947 interested in. So we want to use the initial pack argument for
6948 the comparison. */
6953 }
6958 else
6960 }
6962 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
6963 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
6964 NEWARG_PTR with the offending arguments if they are non-NULL. */
6966 static int
6969 {
6982 {
6987 {
6993 }
6994 }
6996 }
6998 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6999 of template arguments. Returns 0 otherwise. */
7001 int
7003 {
7005 }
7007 static void
7009 {
7019 /* We are called both from instantiate_decl, where we've already had a
7020 tinst_level pushed, and instantiate_template, where we haven't.
7021 Compensate. */
7032 else
7041 }
7044 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7045 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7046 documentation for TEMPLATE_ID_EXPR. */
7048 tree
7050 {
7051 tree type;
7059 {
7062 }
7065 {
7067 unknown_type_node,
7069 arglist);
7071 }
7078 }
7080 /* Within the scope of a template class S<T>, the name S gets bound
7081 (in build_self_reference) to a TYPE_DECL for the class, not a
7082 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7083 or one of its enclosing classes, and that type is a template,
7084 return the associated TEMPLATE_DECL. Otherwise, the original
7085 DECL is returned.
7087 Also handle the case when DECL is a TREE_LIST of ambiguous
7088 injected-class-names from different bases. */
7090 tree
7092 {
7096 /* DR 176: A lookup that finds an injected-class-name (10.2
7097 [class.member.lookup]) can result in an ambiguity in certain cases
7098 (for example, if it is found in more than one base class). If all of
7099 the injected-class-names that are found refer to specializations of
7100 the same class template, and if the name is followed by a
7101 template-argument-list, the reference refers to the class template
7102 itself and not a specialization thereof, and is not ambiguous. */
7104 {
7107 {
7113 }
7116 else
7118 }
7124 }
7126 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
7127 parameters, find the desired type.
7129 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7131 IN_DECL, if non-NULL, is the template declaration we are trying to
7132 instantiate.
7134 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7135 the class we are looking up.
7137 Issue error and warning messages under control of COMPLAIN.
7139 If the template class is really a local class in a template
7140 function, then the FUNCTION_CONTEXT is the function in which it is
7141 being instantiated.
7143 ??? Note that this function is currently called *twice* for each
7144 template-id: the first time from the parser, while creating the
7145 incomplete type (finish_template_type), and the second type during the
7146 real instantiation (instantiate_template_class). This is surely something
7147 that we want to avoid. It also causes some problems with argument
7148 coercion (see convert_nontype_argument for more information on this). */
7150 static tree
7153 {
7155 tree t;
7158 spec_entry elt;
7159 hashval_t hash;
7162 {
7166 else
7167 {
7174 }
7177 }
7179 {
7182 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7183 an implicit typename for the second A. Deal with it. */
7188 {
7191 }
7192 }
7195 {
7198 }
7202 {
7206 }
7208 {
7211 }
7213 /* Issue an error message if we didn't find a template. */
7215 {
7219 }
7222 /* Make sure it's a user visible template, if it was named by
7223 the user. */
7226 {
7228 {
7232 }
7234 }
7238 /* An alias that just changes the name of a template is equivalent to the
7239 other template, so if any of the arguments are pack expansions, strip
7240 the alias to avoid problems with a pack expansion passed to a non-pack
7241 alias template parameter (DR 1430). */
7246 {
7247 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7248 template arguments */
7250 tree parm;
7251 tree arglist2;
7252 tree outer;
7256 /* Consider an example where a template template parameter declared as
7258 template <class T, class U = std::allocator<T> > class TT
7260 The template parameter level of T and U are one level larger than
7261 of TT. To proper process the default argument of U, say when an
7262 instantiation `TT<int>' is seen, we need to build the full
7263 arguments containing {int} as the innermost level. Outer levels,
7264 available when not appearing as default template argument, can be
7265 obtained from the arguments of the enclosing template.
7267 Suppose that TT is later substituted with std::vector. The above
7268 instantiation is `TT<int, std::allocator<T> >' with TT at
7269 level 1, and T at level 2, while the template arguments at level 1
7270 becomes {std::vector} and the inner level 2 is {int}. */
7276 /* This is an argument of the current template, so we haven't set
7277 DECL_CONTEXT yet. */
7284 complain,
7294 }
7295 else
7296 {
7298 tree gen_tmpl;
7299 tree type_decl;
7307 /* An error occurred while building the template TEMPL, and a
7308 diagnostic has most certainly been emitted for that
7309 already. Let's propagate that error. */
7318 {
7319 /* We've been given an incomplete set of template arguments.
7320 For example, given:
7322 template <class T> struct S1 {
7323 template <class U> struct S2 {};
7324 template <class U> struct S2<U*> {};
7325 };
7327 we will be called with an ARGLIST of `U*', but the
7328 TEMPLATE will be `template <class T> template
7329 <class U> struct S1<T>::S2'. We must fill in the missing
7330 arguments. */
7331 arglist
7333 arglist);
7335 }
7337 /* Now we should have enough arguments. */
7340 /* From here on, we're only interested in the most general
7341 template. */
7343 /* Calculate the BOUND_ARGS. These will be the args that are
7344 actually tsubst'd into the definition to create the
7345 instantiation. */
7347 {
7348 /* We have multiple levels of arguments to coerce, at once. */
7358 {
7359 tree a;
7363 complain,
7366 else
7367 /* Outer levels should have already been coerced. */
7370 /* Don't process further if one of the levels fails. */
7372 {
7373 /* Restore the ARGLIST to its full size. */
7376 }
7380 /* We temporarily reduce the length of the ARGLIST so
7381 that coerce_template_parms will see only the arguments
7382 corresponding to the template parameters it is
7383 examining. */
7385 }
7387 /* Restore the ARGLIST to its full size. */
7391 }
7392 else
7393 arglist
7396 gen_tmpl,
7397 complain,
7402 /* We were unable to bind the arguments. */
7405 /* In the scope of a template class, explicit references to the
7406 template class refer to the type of the template, not any
7407 instantiation of it. For example, in:
7409 template <class T> class C { void f(C<T>); }
7411 the `C<T>' is just the same as `C'. Outside of the
7412 class, however, such a reference is an instantiation. */
7416 /* comp_template_args is expensive, check it last. */
7418 arglist))
7421 /* If we already have this specialization, return it. */
7433 /* If the deduced arguments are invalid, then the binding
7434 failed. */
7438 complain))
7445 {
7450 }
7460 /* Create the type. */
7462 {
7464 {
7470 }
7471 else
7472 {
7473 /* We don't want to call start_enum for this type, since
7474 the values for the enumeration constants may involve
7475 template parameters. And, no one should be interested
7476 in the enumeration constants for such a type. */
7479 }
7483 }
7485 {
7486 /* The user referred to a specialization of an alias
7487 template represented by GEN_TMPL.
7489 [temp.alias]/2 says:
7491 When a template-id refers to the specialization of an
7492 alias template, it is equivalent to the associated
7493 type obtained by substitution of its
7494 template-arguments for the template-parameters in the
7495 type-id of the alias template. */
7498 /* Note that the call above (by indirectly calling
7499 register_specialization in tsubst_decl) registers the
7500 TYPE_DECL representing the specialization of the alias
7501 template. So next time someone substitutes ARGLIST for
7502 the template parms into the alias template (GEN_TMPL),
7503 she'll get that TYPE_DECL back. */
7507 }
7509 {
7516 /* A local class. Make sure the decl gets registered properly. */
7521 /* This instantiation is another name for the primary
7522 template type. Set the TYPE_CANONICAL field
7523 appropriately. */
7526 /* Some of the template arguments require structural
7527 equality testing, so this template class requires
7528 structural equality testing. */
7530 }
7531 else
7534 /* If we called start_enum or pushtag above, this information
7535 will already be set up. */
7537 {
7544 }
7545 else
7549 {
7555 {
7558 }
7559 }
7561 /* Let's consider the explicit specialization of a member
7562 of a class template specialization that is implicitely instantiated,
7563 e.g.:
7564 template<class T>
7565 struct S
7566 {
7567 template<class U> struct M {}; //#0
7568 };
7570 template<>
7571 template<>
7572 struct S<int>::M<char> //#1
7573 {
7574 int i;
7575 };
7576 [temp.expl.spec]/4 says this is valid.
7578 In this case, when we write:
7579 S<int>::M<char> m;
7581 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7582 the one of #0.
7584 When we encounter #1, we want to store the partial instantiation
7585 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
7587 For all cases other than this "explicit specialization of member of a
7588 class template", we just want to store the most general template into
7589 the CLASSTYPE_TI_TEMPLATE of M.
7591 This case of "explicit specialization of member of a class template"
7592 only happens when:
7593 1/ the enclosing class is an instantiation of, and therefore not
7594 the same as, the context of the most general template, and
7595 2/ we aren't looking at the partial instantiation itself, i.e.
7596 the innermost arguments are not the same as the innermost parms of
7597 the most general template.
7599 So it's only when 1/ and 2/ happens that we want to use the partial
7600 instantiation of the member template in lieu of its most general
7601 template. */
7605 /* the enclosing class must be an instantiation... */
7608 {
7609 tree partial_inst_args;
7612 partial_inst_args =
7618 use_partial_inst_tmpl =
7619 /*...and we must not be looking at the partial instantiation
7620 itself. */
7622 partial_inst_args);
7623 }
7626 /* This case is easy; there are no member templates involved. */
7628 else
7629 {
7630 /* This is a full instantiation of a member template. Find
7631 the partial instantiation of which this is an instance. */
7633 /* Temporarily reduce by one the number of levels in the ARGLIST
7634 so as to avoid comparing the last set of arguments. */
7638 /* FOUND is either a proper class type, or an alias
7639 template specialization. In the later case, it's a
7640 TYPE_DECL, resulting from the substituting of arguments
7641 for parameters in the TYPE_DECL of the alias template
7642 done earlier. So be careful while getting the template
7643 of FOUND. */
7647 }
7658 /* Note this use of the partial instantiation so we can check it
7659 later in maybe_process_partial_specialization. */
7665 /* Now that the type has been registered on the instantiations
7666 list, we set up the enumerators. Because the enumeration
7667 constants may involve the enumeration type itself, we make
7668 sure to register the type first, and then create the
7669 constants. That way, doing tsubst_expr for the enumeration
7670 constants won't result in recursive calls here; we'll find
7671 the instantiation and exit above. */
7675 /* If the type makes use of template parameters, the
7676 code that generates debugging information will crash. */
7679 /* Possibly limit visibility based on template args. */
7684 }
7685 }
7687 /* Wrapper for lookup_template_class_1. */
7689 tree
7692 {
7693 tree ret;
7699 }
7700 \f
7701 struct pair_fn_data
7702 {
7703 tree_fn_t fn;
7705 /* True when we should also visit template parameters that occur in
7706 non-deduced contexts. */
7709 };
7711 /* Called from for_each_template_parm via walk_tree. */
7713 static tree
7715 {
7728 {
7732 /* Fall through. */
7755 /* Since we're not going to walk subtrees, we have to do this
7756 explicitly here. */
7760 /* Fall through. */
7763 /* Check the return type. */
7768 /* Check the parameter types. Since default arguments are not
7769 instantiated until they are needed, the TYPE_ARG_TYPES may
7770 contain expressions that involve template parameters. But,
7771 no-one should be looking at them yet. And, once they're
7772 instantiated, they don't contain template parameters, so
7773 there's no point in looking at them then, either. */
7774 {
7775 tree parm;
7782 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7783 want walk_tree walking into them itself. */
7785 }
7803 /* Fall through. */
7819 /* Record template parameters such as `T' inside `TT<T>'. */
7823 /* Fall through. */
7835 /* A template template parameter is encountered. */
7841 /* Already substituted template template parameter */
7864 /* If there's no type, then this thing must be some expression
7865 involving template parameters. */
7887 }
7889 /* We didn't find any template parameters we liked. */
7891 }
7893 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7894 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7895 call FN with the parameter and the DATA.
7896 If FN returns nonzero, the iteration is terminated, and
7897 for_each_template_parm returns 1. Otherwise, the iteration
7898 continues. If FN never returns a nonzero value, the value
7899 returned by for_each_template_parm is 0. If FN is NULL, it is
7900 considered to be the function which always returns 1.
7902 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7903 parameters that occur in non-deduced contexts. When false, only
7904 visits those template parameters that can be deduced. */
7906 static int
7910 {
7914 /* Set up. */
7919 /* Walk the tree. (Conceptually, we would like to walk without
7920 duplicates, but for_each_template_parm_r recursively calls
7921 for_each_template_parm, so we would need to reorganize a fair
7922 bit to use walk_tree_without_duplicates, so we keep our own
7923 visited list.) */
7926 else
7929 for_each_template_parm_r,
7933 /* Clean up. */
7935 {
7938 }
7941 }
7943 /* Returns true if T depends on any template parameter. */
7945 int
7947 {
7974 else
7975 {
7978 }
7983 }
7985 /* Returns true iff current_function_decl is an incompletely instantiated
7986 template. Useful instead of processing_template_decl because the latter
7987 is set to 0 during fold_non_dependent_expr. */
7989 bool
7991 {
8000 }
8002 /* Returns true if T depends on any template parameter with level LEVEL. */
8004 int
8006 {
8009 }
8011 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8012 ill-formed translation unit, i.e. a variable or function that isn't
8013 usable in a constant expression. */
8017 {
8021 }
8023 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8024 neglectable and instantiated from within an erroneous instantiation. */
8026 static bool
8028 {
8039 }
8047 /* We're starting to instantiate D; record the template instantiation context
8048 for diagnostics and to restore it later. */
8050 int
8052 {
8056 {
8062 else
8070 }
8072 /* If the current instantiation caused problems, don't let it instantiate
8073 anything else. Do allow deduction substitution and decls usable in
8074 constant expressions. */
8091 }
8093 /* We're done instantiating this template; return to the instantiation
8094 context. */
8096 void
8098 {
8099 /* Restore the filename and line number stashed away when we started
8100 this instantiation. */
8104 }
8106 /* We're instantiating a deferred template; restore the template
8107 instantiation context in which the instantiation was requested, which
8108 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8110 static tree
8112 {
8124 }
8126 /* Returns the TINST_LEVEL which gives the original instantiation
8127 context. */
8131 {
8137 }
8139 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8140 vector of template arguments, as for tsubst.
8142 Returns an appropriate tsubst'd friend declaration. */
8144 static tree
8146 {
8147 tree new_friend;
8152 /* This was a friend declared with an explicit template
8153 argument list, e.g.:
8155 friend void f<>(T);
8157 to indicate that f was a template instantiation, not a new
8158 function declaration. Now, we have to figure out what
8159 instantiation of what template. */
8160 {
8162 tree new_args;
8163 tree tmpl;
8166 /* Friend functions are looked up in the containing namespace scope.
8167 We must enter that scope, to avoid finding member functions of the
8168 current class with same name. */
8183 tsk_none);
8185 }
8189 /* The NEW_FRIEND will look like an instantiation, to the
8190 compiler, but is not an instantiation from the point of view of
8191 the language. For example, we might have had:
8193 template <class T> struct S {
8194 template <class U> friend void f(T, U);
8195 };
8197 Then, in S<int>, template <class U> void f(int, U) is not an
8198 instantiation of anything. */
8204 {
8208 }
8210 /* The mangled name for the NEW_FRIEND is incorrect. The function
8211 is not a template instantiation and should not be mangled like
8212 one. Therefore, we forget the mangling here; we'll recompute it
8213 later if we need it. */
8215 {
8218 }
8221 {
8222 tree old_decl;
8223 tree new_friend_template_info;
8224 tree new_friend_result_template_info;
8225 tree ns;
8228 /* We must save some information from NEW_FRIEND before calling
8229 duplicate decls since that function will free NEW_FRIEND if
8230 possible. */
8232 new_friend_is_defn =
8237 {
8238 /* This declaration is a `primary' template. */
8241 new_friend_result_template_info
8243 }
8244 else
8247 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8251 /* Inside pushdecl_namespace_level, we will push into the
8252 current namespace. However, the friend function should go
8253 into the namespace of the template. */
8263 {
8264 /* This new friend declaration matched an existing
8265 declaration. For example, given:
8267 template <class T> void f(T);
8268 template <class U> class C {
8269 template <class T> friend void f(T) {}
8270 };
8272 the friend declaration actually provides the definition
8273 of `f', once C has been instantiated for some type. So,
8274 old_decl will be the out-of-class template declaration,
8275 while new_friend is the in-class definition.
8277 But, if `f' was called before this point, the
8278 instantiation of `f' will have DECL_TI_ARGS corresponding
8279 to `T' but not to `U', references to which might appear
8280 in the definition of `f'. Previously, the most general
8281 template for an instantiation of `f' was the out-of-class
8282 version; now it is the in-class version. Therefore, we
8283 run through all specialization of `f', adding to their
8284 DECL_TI_ARGS appropriately. In particular, they need a
8285 new set of outer arguments, corresponding to the
8286 arguments for this class instantiation.
8288 The same situation can arise with something like this:
8290 friend void f(int);
8291 template <class T> class C {
8292 friend void f(T) {}
8293 };
8295 when `C<int>' is instantiated. Now, `f(int)' is defined
8296 in the class. */
8299 /* On the other hand, if the in-class declaration does
8300 *not* provide a definition, then we don't want to alter
8301 existing definitions. We can just leave everything
8302 alone. */
8303 ;
8304 else
8305 {
8309 /* Overwrite whatever template info was there before, if
8310 any, with the new template information pertaining to
8311 the declaration. */
8315 {
8316 /* We should have called reregister_specialization in
8317 duplicate_decls. */
8322 /* Instantiate it if the global has already been used. */
8326 }
8327 else
8328 {
8329 tree t;
8331 /* Indicate that the old function template is a partial
8332 instantiation. */
8340 /* Reassign any specializations already in the hash table
8341 to the new more general template, and add the
8342 additional template args. */
8346 {
8348 spec_entry elt;
8360 register_specialization
8363 }
8365 }
8366 }
8368 /* The information from NEW_FRIEND has been merged into OLD_DECL
8369 by duplicate_decls. */
8371 }
8372 }
8373 else
8374 {
8378 /* In the code
8379 template <class T> class C {
8380 template <class U> friend void C1<U>::f (); // case 1
8381 friend void C2<T>::f (); // case 2
8382 };
8383 we only need to make sure CONTEXT is a complete type for
8384 case 2. To distinguish between the two cases, we note that
8385 CONTEXT of case 1 remains dependent type after tsubst while
8386 this isn't true for case 2. */
8396 {
8397 /* Check to see that the declaration is really present, and,
8398 possibly obtain an improved declaration. */
8404 }
8405 }
8408 }
8410 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8411 template arguments, as for tsubst.
8413 Returns an appropriate tsubst'd friend type or error_mark_node on
8414 failure. */
8416 static tree
8418 {
8419 tree friend_type;
8420 tree tmpl;
8421 tree context;
8424 {
8427 }
8432 {
8435 else
8437 }
8439 /* Look for a class template declaration. We look for hidden names
8440 because two friend declarations of the same template are the
8441 same. For example, in:
8443 struct A {
8444 template <typename> friend class F;
8445 };
8446 template <typename> struct B {
8447 template <typename> friend class F;
8448 };
8450 both F templates are the same. */
8454 /* But, if we don't find one, it might be because we're in a
8455 situation like this:
8457 template <class T>
8458 struct S {
8459 template <class U>
8460 friend struct S;
8461 };
8463 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8464 for `S<int>', not the TEMPLATE_DECL. */
8466 {
8469 }
8472 {
8473 /* The friend template has already been declared. Just
8474 check to see that the declarations match, and install any new
8475 default parameters. We must tsubst the default parameters,
8476 of course. We only need the innermost template parameters
8477 because that is all that redeclare_class_template will look
8478 at. */
8481 {
8482 tree parms;
8483 location_t saved_input_location;
8492 }
8495 }
8496 else
8497 {
8498 /* The friend template has not already been declared. In this
8499 case, the instantiation of the template class will cause the
8500 injection of this template into the global scope. */
8505 /* The new TMPL is not an instantiation of anything, so we
8506 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8507 the new type because that is supposed to be the corresponding
8508 template decl, i.e., TMPL. */
8515 /* Inject this template into the global scope. */
8517 }
8520 {
8523 else
8525 }
8528 }
8530 /* Returns zero if TYPE cannot be completed later due to circularity.
8531 Otherwise returns one. */
8533 static int
8535 {
8545 else
8547 }
8551 /* Apply any attributes which had to be deferred until instantiation
8552 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8553 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8555 static void
8558 {
8560 tree t;
8565 {
8569 }
8572 {
8576 }
8577 else
8581 {
8586 {
8589 {
8596 {
8603 clauses
8607 else
8609 }
8610 /* If the first attribute argument is an identifier, don't
8611 pass it through tsubst. Attributes like mode, format,
8612 cleanup and several target specific attributes expect it
8613 unmodified. */
8615 {
8616 tree chain
8618 in_decl,
8623 chain);
8624 }
8625 else
8631 }
8632 else
8634 }
8637 }
8638 }
8640 /* Perform (or defer) access check for typedefs that were referenced
8641 from within the template TMPL code.
8642 This is a subroutine of instantiate_decl and instantiate_class_template.
8643 TMPL is the template to consider and TARGS is the list of arguments of
8644 that template. */
8646 static void
8648 {
8649 location_t saved_location;
8660 {
8672 /* Make access check error messages point to the location
8673 of the use of the typedef. */
8677 tf_warning_or_error);
8678 }
8680 }
8682 static tree
8684 {
8686 tree typedecl;
8687 tree pbinfo;
8688 tree base_list;
8690 tree fn_context;
8699 /* Figure out which template is being instantiated. */
8703 /* Determine what specialization of the original template to
8704 instantiate. */
8707 {
8710 }
8712 {
8713 /* This TYPE is actually an instantiation of a partial
8714 specialization. We replace the innermost set of ARGS with
8715 the arguments appropriate for substitution. For example,
8716 given:
8718 template <class T> struct S {};
8719 template <class T> struct S<T*> {};
8721 and supposing that we are instantiating S<int*>, ARGS will
8722 presently be {int*} -- but we need {int}. */
8725 }
8726 else
8727 {
8730 }
8732 /* If the template we're instantiating is incomplete, then clearly
8733 there's nothing we can do. */
8737 /* If we've recursively instantiated too many templates, stop. */
8741 /* Now we're really doing the instantiation. Mark the type as in
8742 the process of being defined. */
8745 /* We may be in the middle of deferred access check. Disable
8746 it now. */
8752 /* Use #pragma pack from the template context. */
8758 /* Set the input location to the most specialized template definition.
8759 This is needed if tsubsting causes an error. */
8771 {
8774 /* Adjust visibility for template arguments. */
8776 }
8782 /* We should never instantiate a nested class before its enclosing
8783 class; we need to look up the nested class by name before we can
8784 instantiate it, and that lookup should instantiate the enclosing
8785 class. */
8791 {
8792 tree pbase_binfo;
8793 tree pushed_scope;
8796 /* We must enter the scope containing the type, as that is where
8797 the accessibility of types named in dependent bases are
8798 looked up from. */
8801 /* Substitute into each of the bases to determine the actual
8802 basetypes. */
8804 {
8805 tree base;
8811 {
8812 expanded_bases =
8819 }
8822 {
8824 /* Extract the already-expanded base class. */
8826 else
8827 /* Substitute to figure out the base class. */
8829 NULL_TREE);
8837 }
8838 }
8840 /* The list is now in reverse order; correct that. */
8845 }
8846 /* Now call xref_basetypes to set up all the base-class
8847 information. */
8855 /* Now that our base classes are set up, enter the scope of the
8856 class, so that name lookups into base classes, etc. will work
8857 correctly. This is precisely analogous to what we do in
8858 begin_class_definition when defining an ordinary non-template
8859 class, except we also need to push the enclosing classes. */
8862 /* Now members are processed in the order of declaration. */
8865 {
8869 {
8871 {
8872 /* Build new CLASSTYPE_NESTED_UTDS. */
8874 tree newtag;
8880 /* If the member is a class template, then -- even after
8881 substitution -- there may be dependent types in the
8882 template argument list for the class. We increment
8883 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8884 that function will assume that no types are dependent
8885 when outside of a template. */
8895 {
8899 /* Unfortunately, lookup_template_class sets
8900 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8901 instantiation (i.e., for the type of a member
8902 template class nested within a template class.)
8903 This behavior is required for
8904 maybe_process_partial_specialization to work
8905 correctly, but is not accurate in this case;
8906 the TAG is not an instantiation of anything.
8907 (The corresponding TEMPLATE_DECL is an
8908 instantiation, but the TYPE is not.) */
8911 /* Now, we call pushtag to put this NEWTAG into the scope of
8912 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8913 pushtag calling push_template_decl. We don't have to do
8914 this for enums because it will already have been done in
8915 tsubst_enum. */
8919 }
8920 }
8922 {
8923 /* Build new TYPE_METHODS. */
8924 tree r;
8933 /* Instantiate members marked with attribute used. */
8939 }
8940 else
8941 {
8942 /* Build new TYPE_FIELDS. */
8944 {
8945 tree condition;
8948 condition =
8958 }
8960 {
8961 tree r;
8965 /* The file and line for this declaration, to
8966 assist in error message reporting. Since we
8967 called push_tinst_level above, we don't need to
8968 restore these. */
8978 {
8979 /* A capture pack became multiple fields. */
8982 }
8985 {
8989 {
8990 /* In [temp.inst]:
8992 [t]he initialization (and any associated
8993 side-effects) of a static data member does
8994 not occur unless the static data member is
8995 itself used in a way that requires the
8996 definition of the static data member to
8997 exist.
8999 Therefore, we do not substitute into the
9000 initialized for the static data member here. */
9001 finish_static_data_member_decl
9007 /* Instantiate members marked with attribute used. */
9010 }
9012 {
9013 /* Determine whether R has a valid type and can be
9014 completed later. If R is invalid, then its type
9015 is replaced by error_mark_node. */
9021 {
9024 }
9025 }
9027 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9028 such a thing will already have been added to the field
9029 list by tsubst_enum in finish_member_declaration in the
9030 CLASSTYPE_NESTED_UTDS case above. */
9034 {
9037 }
9038 }
9039 }
9040 }
9041 }
9042 else
9043 {
9046 {
9047 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9053 {
9054 /* template <class T> friend class C; */
9057 }
9059 {
9060 /* template <class T> friend class C::D; */
9066 }
9069 {
9070 /* This could be either
9072 friend class T::C;
9074 when dependent_type_p is false or
9076 template <class U> friend class T::C;
9078 otherwise. */
9081 /* Bump processing_template_decl for correct
9082 dependent_type_p calculation. */
9087 }
9090 {
9091 /* friend class C;
9093 where C hasn't been declared yet. Let's lookup name
9094 from namespace scope directly, bypassing any name that
9095 come from dependent base class. */
9098 /* The call to xref_tag_from_type does injection for friend
9099 classes. */
9101 friend_type =
9105 }
9107 /* friend class C<T>; */
9110 /* Otherwise it's
9112 friend class C;
9114 where C is already declared or
9116 friend class C<int>;
9118 We don't have to do anything in these cases. */
9121 /* Trick make_friend_class into realizing that the friend
9122 we're adding is a template, not an ordinary class. It's
9123 important that we use make_friend_class since it will
9124 perform some error-checking and output cross-reference
9125 information. */
9133 }
9134 else
9135 {
9136 /* Build new DECL_FRIENDLIST. */
9137 tree r;
9139 /* The file and line for this declaration, to
9140 assist in error message reporting. Since we
9141 called push_tinst_level above, we don't need to
9142 restore these. */
9146 {
9149 }
9154 {
9157 }
9158 }
9159 }
9160 }
9163 {
9166 {
9171 /* We need to instantiate the capture list from the template
9172 after we've instantiated the closure members, but before we
9173 consider adding the conversion op. Also keep any captures
9174 that may have been added during instantiation of the op(). */
9176 tree tmpl_cap
9185 }
9186 else
9188 }
9190 /* Set the file and line number information to whatever is given for
9191 the class itself. This puts error messages involving generated
9192 implicit functions at a predictable point, and the same point
9193 that would be used for non-template classes. */
9200 /* We don't instantiate default arguments for member functions. 14.7.1:
9202 The implicit instantiation of a class template specialization causes
9203 the implicit instantiation of the declarations, but not of the
9204 definitions or default arguments, of the class member functions,
9205 member classes, static data members and member templates.... */
9207 /* Some typedefs referenced from within the template code need to be access
9208 checked at template instantiation time, i.e now. These types were
9209 added to the template at parsing time. Let's get those and perform
9210 the access checks then. */
9220 /* The vtable for a template class can be emitted in any translation
9221 unit in which the class is instantiated. When there is no key
9222 method, however, finish_struct_1 will already have added TYPE to
9223 the keyed_classes list. */
9228 }
9230 /* Wrapper for instantiate_class_template_1. */
9232 tree
9234 {
9235 tree ret;
9240 }
9242 static tree
9244 {
9245 tree r;
9251 else
9252 {
9259 /* Preserve the raw-reference nature of T. */
9263 }
9265 }
9267 /* Given a function parameter pack TMPL_PARM and some function parameters
9268 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9269 and set *SPEC_P to point at the next point in the list. */
9271 static tree
9273 {
9274 /* Collect all of the extra "packed" parameters into an
9275 argument pack. */
9276 tree parmvec;
9277 tree parmtypevec;
9288 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9293 {
9296 }
9298 /* Build the argument packs. */
9305 }
9307 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9308 NONTYPE_ARGUMENT_PACK. */
9310 static tree
9312 {
9314 }
9316 /* Return true iff the Ith element of the argument pack ARG_PACK is a
9317 pack expansion. */
9319 static bool
9321 {
9326 }
9329 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9331 static tree
9333 {
9340 }
9342 /* This is a subroutine of tsubst_pack_expansion.
9344 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9345 mechanism to store the (non complete list of) arguments of the
9346 substitution and return a non substituted pack expansion, in order
9347 to wait for when we have enough arguments to really perform the
9348 substitution. */
9350 static bool
9354 {
9355 /* If one pack has an expansion and another pack has a normal
9356 argument or if one pack has an empty argument and an another
9357 one hasn't then tsubst_pack_expansion cannot perform the
9358 substitution and need to fall back on the
9359 PACK_EXPANSION_EXTRA mechanism. */
9367 {
9370 parm_pack;
9372 {
9377 else
9379 }
9383 }
9385 }
9387 /* [temp.variadic]/6 says that:
9389 The instantiation of a pack expansion [...]
9390 produces a list E1,E2, ..., En, where N is the number of elements
9391 in the pack expansion parameters.
9393 This subroutine of tsubst_pack_expansion produces one of these Ei.
9395 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9396 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9397 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9398 INDEX is the index 'i' of the element Ei to produce. ARGS,
9399 COMPLAIN, and IN_DECL are the same parameters as for the
9400 tsubst_pack_expansion function.
9402 The function returns the resulting Ei upon successful completion,
9403 or error_mark_node.
9405 Note that this function possibly modifies the ARGS parameter, so
9406 it's the responsibility of the caller to restore it. */
9408 static tree
9410 tree parm_packs,
9412 tree args /* This parm gets
9414 tsubst_flags_t complain,
9415 tree in_decl)
9416 {
9417 tree t;
9420 /* For each parameter pack, change the substitution of the parameter
9421 pack to the ith argument in its argument pack, then expand the
9422 pattern. */
9424 {
9429 ith_elem_is_expansion |=
9432 /* Select the Ith argument from the pack. */
9435 {
9437 {
9441 }
9442 else
9444 }
9445 else
9446 {
9451 {
9453 /* Update the corresponding argument. */
9455 }
9456 else
9457 /* Re-use the ARGUMENT_PACK_SELECT. */
9459 }
9461 }
9463 /* Substitute into the PATTERN with the (possibly altered)
9464 arguments. */
9468 else
9471 /* If the Ith argument pack element is a pack expansion, then
9472 the Ith element resulting from the substituting is going to
9473 be a pack expansion as well. */
9478 }
9480 /* Substitute ARGS into T, which is an pack expansion
9481 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9482 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9483 (if only a partial substitution could be performed) or
9484 ERROR_MARK_NODE if there was an error. */
9485 tree
9487 tree in_decl)
9488 {
9489 tree pattern;
9493 tree result;
9501 /* Add in any args remembered from an earlier partial instantiation. */
9506 /* Determine the argument packs that will instantiate the parameter
9507 packs used in the expansion expression. While we're at it,
9508 compute the number of arguments to be expanded and make sure it
9509 is consistent. */
9512 {
9519 {
9523 else
9526 }
9528 {
9531 else
9532 {
9533 /* We can't rely on local_specializations for a parameter
9534 name used later in a function declaration (such as in a
9535 late-specified return type). Even if it exists, it might
9536 have the wrong value for a recursive call. Just make a
9537 dummy decl, since it's only used for its type. */
9540 /* Partial instantiation of the parm_pack, we can't build
9541 up an argument pack yet. */
9543 else
9546 }
9547 }
9550 else
9551 {
9557 }
9564 /* This can only happen if we forget to expand an argument
9565 pack somewhere else. Just return an error, silently. */
9566 {
9570 }
9573 {
9577 /* Don't bother trying to do a partial substitution with
9578 incomplete packs; we'll try again after deduction. */
9585 {
9591 pattern);
9592 else
9595 pattern);
9597 }
9599 /* Keep track of the parameter packs and their corresponding
9600 argument packs. */
9603 }
9604 else
9605 {
9606 /* We can't substitute for this parameter pack. We use a flag as
9607 well as the missing_level counter because function parameter
9608 packs don't have a level. */
9610 }
9611 }
9613 /* We cannot expand this expansion expression, because we don't have
9614 all of the argument packs we need. */
9616 {
9617 /* We got some full packs, but we can't substitute them in until we
9618 have values for all the packs. So remember these until then. */
9623 }
9625 {
9626 /* There were no real arguments, we're just replacing a parameter
9627 pack with another version of itself. Substitute into the
9628 pattern and return a PACK_EXPANSION_*. The caller will need to
9629 deal with that. */
9633 else
9637 }
9642 {
9643 /* We're in a late-specified return type, so create our own local
9644 specializations map; the current map is either NULL or (in the
9645 case of recursive unification) might have bindings that we don't
9646 want to use or alter. */
9649 }
9651 /* For each argument in each argument pack, substitute into the
9652 pattern. */
9655 {
9657 i,
9659 in_decl);
9662 {
9665 }
9666 }
9668 /* Update ARGS to restore the substitution from parameter packs to
9669 their argument packs. */
9671 {
9677 else
9678 {
9686 /* Update the corresponding argument. */
9690 else
9692 }
9693 }
9696 {
9699 }
9702 }
9704 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9705 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9706 parameter packs; all parms generated from a function parameter pack will
9707 have the same DECL_PARM_INDEX. */
9709 tree
9711 {
9713 tree patparm;
9716 {
9722 }
9723 else
9724 {
9729 }
9732 }
9734 /* Substitute ARGS into the vector or list of template arguments T. */
9736 static tree
9738 {
9750 {
9752 tree new_arg;
9757 {
9758 /* Substitute into an expansion expression. */
9762 /* Add to the expanded length adjustment the number of
9763 expanded arguments. We subtract one from this
9764 measurement, because the argument pack expression
9765 itself is already counted as 1 in
9766 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9767 the argument pack is empty. */
9769 }
9771 {
9772 /* Substitute into each of the arguments. */
9778 new_arg,
9792 }
9793 }
9794 else
9803 }
9808 /* Make space for the expanded arguments coming from template
9809 argument packs. */
9811 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9812 arguments for a member template.
9813 In that case each TREE_VEC in ORIG_T represents a level of template
9814 arguments, and ORIG_T won't carry any non defaulted argument count.
9815 It will rather be the nested TREE_VECs that will carry one.
9816 In other words, ORIG_T carries a non defaulted argument count only
9817 if it doesn't contain any nested TREE_VEC. */
9819 {
9823 }
9825 {
9829 {
9832 /* Now expand the template argument pack "in place". */
9835 }
9836 else
9837 {
9839 out++;
9840 }
9841 }
9844 }
9846 /* Return the result of substituting ARGS into the template parameters
9847 given by PARMS. If there are m levels of ARGS and m + n levels of
9848 PARMS, then the result will contain n levels of PARMS. For
9849 example, if PARMS is `template <class T> template <class U>
9850 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9851 result will be `template <int*, double, class V>'. */
9853 static tree
9855 {
9859 /* When substituting into a template, we must set
9860 PROCESSING_TEMPLATE_DECL as the template parameters may be
9861 dependent if they are based on one-another, and the dependency
9862 predicates are short-circuit outside of templates. */
9869 {
9870 tree new_vec =
9875 {
9876 tree tuple;
9888 }
9894 }
9899 }
9901 /* Return the result of substituting ARGS into one template parameter
9902 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9903 parameter and which TREE_PURPOSE is the default argument of the
9904 template parameter. */
9906 static tree
9908 {
9929 }
9931 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9932 type T. If T is not an aggregate or enumeration type, it is
9933 handled as if by tsubst. IN_DECL is as for tsubst. If
9934 ENTERING_SCOPE is nonzero, T is the context for a template which
9935 we are presently tsubst'ing. Return the substituted value. */
9937 static tree
9939 tree args,
9940 tsubst_flags_t complain,
9941 tree in_decl,
9943 {
9948 {
9953 /* Else fall through. */
9957 {
9958 tree argvec;
9959 tree context;
9960 tree r;
9964 /* In "sizeof(X<I>)" we need to evaluate "I". */
9970 /* First, determine the context for the type we are looking
9971 up. */
9974 {
9977 /* If context is a nested class inside a class template,
9978 it may still need to be instantiated (c++/33959). */
9980 }
9982 /* Then, figure out what arguments are appropriate for the
9983 type we are trying to find. For example, given:
9985 template <class T> struct S;
9986 template <class T, class U> void f(T, U) { S<U> su; }
9988 and supposing that we are instantiating f<int, double>,
9989 then our ARGS will be {int, double}, but, when looking up
9990 S we only want {double}. */
9995 else
9996 {
10000 }
10006 }
10007 else
10008 /* This is not a template type, so there's nothing to do. */
10013 }
10014 }
10016 /* Substitute into the default argument ARG (a default argument for
10017 FN), which has the indicated TYPE. */
10019 tree
10021 {
10026 /* This can happen in invalid code. */
10030 /* This default argument came from a template. Instantiate the
10031 default argument here, not in tsubst. In the case of
10032 something like:
10034 template <class T>
10035 struct S {
10036 static T t();
10037 void f(T = t());
10038 };
10040 we must be careful to do name lookup in the scope of S<T>,
10041 rather than in the current class. */
10043 /* The "this" pointer is not valid in a default argument. */
10045 {
10050 }
10053 /* The default argument expression may cause implicitly defined
10054 member functions to be synthesized, which will result in garbage
10055 collection. We must treat this situation as if we were within
10056 the body of function so as to avoid collecting live data on the
10057 stack. */
10065 /* Restore the "this" pointer. */
10067 {
10070 }
10077 /* Make sure the default argument is reasonable. */
10083 }
10085 /* Substitute into all the default arguments for FN. */
10087 static void
10089 {
10090 tree arg;
10091 tree tmpl_args;
10095 /* If this function is not yet instantiated, we certainly don't need
10096 its default arguments. */
10099 /* Don't do this again for clones. */
10104 arg;
10110 complain);
10111 }
10113 /* Substitute the ARGS into the T, which is a _DECL. Return the
10114 result of the substitution. Issue error and warning messages under
10115 control of COMPLAIN. */
10117 static tree
10119 {
10120 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10121 location_t saved_loc;
10126 /* Set the filename and linenumber to improve error-reporting. */
10131 {
10133 {
10134 /* We can get here when processing a member function template,
10135 member class template, or template template parameter. */
10137 tree spec;
10138 tree tmpl_args;
10139 tree full_args;
10142 {
10143 /* Template template parameter is treated here. */
10147 /* If we get a real template back, return it. This can happen in
10148 the context of most_specialized_class. */
10160 complain);
10163 }
10165 /* We might already have an instance of this template.
10166 The ARGS are for the surrounding class type, so the
10167 full args contain the tsubst'd args for the context,
10168 plus the innermost args from the template decl. */
10172 /* Because this is a template, the arguments will still be
10173 dependent, even after substitution. If
10174 PROCESSING_TEMPLATE_DECL is not set, the dependency
10175 predicates will short-circuit. */
10183 /* If this is a default template template argument,
10184 tsubst might not have changed anything. */
10191 {
10194 }
10196 /* Make a new template decl. It will be similar to the
10197 original, but will record the current template arguments.
10198 We also create a new function declaration, which is just
10199 like the old one, but points to this new template, rather
10200 than the old one. */
10209 {
10210 tree new_type;
10218 /* For a partial specialization, we need to keep pointing to
10219 the primary template. */
10225 }
10226 else
10227 {
10228 tree new_decl;
10240 }
10246 /* The template parameters for this new template are all the
10247 template parameters for the old template, except the
10248 outermost level of parameters. */
10251 complain);
10257 /* Record this non-type partial instantiation. */
10261 }
10265 {
10266 tree ctx;
10269 tree gen_tmpl;
10270 tree type;
10275 /* Nobody should be tsubst'ing into non-template functions. */
10279 {
10280 tree spec;
10283 /* If T is not dependent, just return it. We have to
10284 increment PROCESSING_TEMPLATE_DECL because
10285 value_dependent_expression_p assumes that nothing is
10286 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10293 /* Calculate the most general template of which R is a
10294 specialization, and the complete set of arguments used to
10295 specialize R. */
10298 (DECL_TEMPLATE_RESULT
10304 /* Check to see if we already have this specialization. */
10309 {
10312 }
10314 /* We can see more levels of arguments than parameters if
10315 there was a specialization of a member template, like
10316 this:
10318 template <class T> struct S { template <class U> void f(); }
10319 template <> template <class U> void S<int>::f(U);
10321 Here, we'll be substituting into the specialization,
10322 because that's where we can find the code we actually
10323 want to generate, but we'll have enough arguments for
10324 the most general template.
10326 We also deal with the peculiar case:
10328 template <class T> struct S {
10329 template <class U> friend void f();
10330 };
10331 template <class U> void f() {}
10332 template S<int>;
10333 template void f<double>();
10335 Here, the ARGS for the instantiation of will be {int,
10336 double}. But, we only need as many ARGS as there are
10337 levels of template parameters in CODE_PATTERN. We are
10338 careful not to get fooled into reducing the ARGS in
10339 situations like:
10341 template <class T> struct S { template <class U> void f(U); }
10342 template <class T> template <> void S<T>::f(int) {}
10344 which we can spot because the pattern will be a
10345 specialization in this case. */
10347 parms_depth =
10352 }
10353 else
10354 {
10355 /* This special case arises when we have something like this:
10357 template <class T> struct S {
10358 friend void f<int>(int, double);
10359 };
10361 Here, the DECL_TI_TEMPLATE for the friend declaration
10362 will be an IDENTIFIER_NODE. We are being called from
10363 tsubst_friend_function, and we want only to create a
10364 new decl (R) with appropriate types so that we can call
10365 determine_specialization. */
10367 }
10370 {
10373 else
10377 }
10378 else
10379 {
10382 }
10387 /* If we hit excessive deduction depth, the type is bogus even if
10388 it isn't error_mark_node, so don't build a decl. */
10392 /* We do NOT check for matching decls pushed separately at this
10393 point, as they may not represent instantiations of this
10394 template, and in any case are considered separate under the
10395 discrete model. */
10399 /* Clear out the mangled name and RTL for the instantiation. */
10402 /* Leave DECL_INITIAL set on deleted instantiations. */
10407 /* OpenMP UDRs have the only argument a reference to the declared
10408 type. We want to diagnose if the declared type is a reference,
10409 which is invalid, but as references to references are usually
10410 quietly merged, diagnose it here. */
10412 {
10413 tree argtype
10418 "reference type %qT in "
10422 argtype);
10423 }
10426 /* Type-conversion operator. Reconstruct the name, in
10427 case it's the name of one of the template's parameters. */
10437 /* If this is an instantiation of a function with internal
10438 linkage, we already know what object file linkage will be
10439 assigned to the instantiation. */
10448 /* We'll re-clone as appropriate in instantiate_template. */
10451 /* If we aren't complaining now, return on error before we register
10452 the specialization so that we'll complain eventually. */
10458 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10459 this in the special friend case mentioned above where
10460 GEN_TMPL is NULL. */
10462 {
10467 tree new_r
10470 /* We instantiated this while substituting into
10471 the type earlier (template/friend54.C). */
10474 /* We're not supposed to instantiate default arguments
10475 until they are called, for a template. But, for a
10476 declaration like:
10478 template <class T> void f ()
10479 { extern void g(int i = T()); }
10481 we should do the substitution when the template is
10482 instantiated. We handle the member function case in
10483 instantiate_class_template since the default arguments
10484 might refer to other members of the class. */
10489 }
10490 else
10493 /* Copy the list of befriending classes. */
10497 {
10501 in_decl);
10502 }
10505 {
10511 /* If this is an instantiation of a member template, clone it.
10512 If it isn't, that'll be handled by
10513 clone_constructors_and_destructors. */
10516 }
10527 /* Possibly limit visibility based on template args. */
10530 {
10534 }
10542 }
10546 {
10554 {
10555 /* If there is a local specialization that isn't a
10556 parameter pack, it means that we're doing a "simple"
10557 substitution from inside tsubst_pack_expansion. Just
10558 return the local specialization (which will be a single
10559 parm). */
10566 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10567 the parameters in this function parameter pack. */
10571 {
10574 /* Zero-length parameter packs are boring. Just substitute
10575 into the chain. */
10579 }
10580 else
10581 {
10582 /* All we did was update the type. Make a note of that. */
10585 }
10586 }
10588 /* Loop through all of the parameters we'll build. When T is
10589 a function parameter pack, LEN is the number of expanded
10590 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10593 {
10600 /* We're on the Ith parameter of the function parameter
10601 pack. */
10602 {
10603 /* Get the Ith type. */
10606 /* Rename the parameter to include the index. */
10609 }
10611 /* We're dealing with a normal parameter. */
10619 {
10622 else
10625 }
10635 /* Keep track of the first new parameter we
10636 generate. That's what will be returned to the
10637 caller. */
10641 /* Build a proper chain of parameters when substituting
10642 into a function parameter pack. */
10645 }
10647 /* If cp_unevaluated_operand is set, we're just looking for a
10648 single dummy parameter, so don't keep going. */
10653 /* FIRST_R contains the start of the chain we've built. */
10655 }
10659 {
10666 {
10667 /* This field is a lambda capture pack. Return a TREE_VEC of
10668 the expanded fields to instantiate_class_template_1 and
10669 store them in the specializations hash table as a
10670 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
10674 {
10677 }
10678 else
10679 {
10680 /* All we did was update the type. Make a note of that. */
10683 }
10684 }
10687 {
10690 {
10694 }
10704 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10705 non-bit-fields DECL_INITIAL is a non-static data member
10706 initializer, which gets deferred instantiation. */
10712 {
10713 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10714 NSDMI in perform_member_init. Still set DECL_INITIAL
10715 so that we know there is one. */
10720 }
10721 /* We don't have to set DECL_CONTEXT here; it is set by
10722 finish_member_declaration. */
10730 }
10733 {
10741 }
10742 }
10746 /* We reach here only for member using decls. We also need to check
10747 uses_template_parms because DECL_DEPENDENT_P is not set for a
10748 using-declaration that designates a member of the current
10749 instantiation (c++/53549). */
10752 {
10759 else
10760 {
10763 }
10764 }
10765 else
10766 {
10769 }
10774 {
10777 tree spec;
10779 tree ctx;
10785 {
10786 /* If this is the canonical decl, we don't have to
10787 mess with instantiations, and often we can't (for
10788 typename, template type parms and such). Note that
10789 TYPE_NAME is not correct for the above test if
10790 we've copied the type for a typedef. */
10796 }
10798 /* Check to see if we already have the specialization we
10799 need. */
10802 {
10803 /* T is a static data member or namespace-scope entity.
10804 We have to substitute into namespace-scope variables
10805 (even though such entities are never templates) because
10806 of cases like:
10808 template <class T> void f() { extern T t; }
10810 where the entity referenced is not known until
10811 instantiation time. */
10815 {
10817 complain,
10819 /* If CTX is unchanged, then T is in fact the
10820 specialization we want. That situation occurs when
10821 referencing a static data member within in its own
10822 class. We can use pointer equality, rather than
10823 same_type_p, because DECL_CONTEXT is always
10824 canonical... */
10827 /* ... unless T is a member template; in which
10828 case our caller can be willing to create a
10829 specialization of that template represented
10830 by T. */
10834 }
10837 {
10845 }
10846 }
10847 else
10848 {
10849 /* A local variable. */
10851 /* Subsequent calls to pushdecl will fill this in. */
10854 }
10855 /* If we already have the specialization we need, there is
10856 nothing more to do. */
10858 {
10861 }
10863 /* Create a new node for the specialization we need. */
10866 {
10869 else
10876 }
10878 {
10879 /* Even if the original location is out of scope, the
10880 newly substituted one is not. */
10887 {
10888 /* It may seem that this case cannot occur, since:
10890 typedef void f();
10891 void g() { f x; }
10893 declares a function, not a variable. However:
10895 typedef void f();
10896 template <typename T> void g() { T t; }
10897 template void g<f>();
10899 is an attempt to declare a variable with function
10900 type. */
10902 /* R is not yet sufficiently initialized, so we
10903 just use its name. */
10906 }
10908 /* Wait until cp_finish_decl to set this again, to handle
10909 circular dependency (template/instantiate6.C). */
10914 {
10919 {
10922 }
10924 }
10925 }
10931 /* Clear out the mangled name and RTL for the instantiation. */
10935 /* The initializer must not be expanded until it is required;
10936 see [temp.inst]. */
10942 {
10943 /* Possibly limit visibility based on template args. */
10946 {
10950 }
10952 }
10955 {
10956 /* A static data member declaration is always marked
10957 external when it is declared in-class, even if an
10958 initializer is present. We mimic the non-template
10959 processing here. */
10965 }
10968 else
10977 /* Preserve a typedef that names a type. */
10979 {
10982 }
10985 }
10990 }
10991 #undef RETURN
10993 out:
10994 /* Restore the file and line information. */
10998 }
11000 /* Substitute into the ARG_TYPES of a function type.
11001 If END is a TREE_CHAIN, leave it and any following types
11002 un-substituted. */
11004 static tree
11006 tree args,
11007 tree end,
11008 tsubst_flags_t complain,
11009 tree in_decl)
11010 {
11011 tree remaining_arg_types;
11015 tree default_arg;
11026 {
11027 /* For a pack expansion, perform substitution on the
11028 entire expression. Later on, we'll handle the arguments
11029 one-by-one. */
11034 /* So that we'll spin through the parameters, one by one. */
11036 else
11037 {
11038 /* We only partially substituted into the parameter
11039 pack. Our type is TYPE_PACK_EXPANSION. */
11042 }
11043 }
11056 {
11058 {
11062 }
11064 }
11065 /* DR 657. */
11069 /* Do array-to-pointer, function-to-pointer conversion, and ignore
11070 top-level qualifiers as required. */
11073 /* We do not substitute into default arguments here. The standard
11074 mandates that they be instantiated only when needed, which is
11075 done in build_over_call. */
11079 {
11080 /* We've instantiated a template before its default arguments
11081 have been parsed. This can happen for a nested template
11082 class, and is not an error unless we require the default
11083 argument in a call of this function. */
11084 remaining_arg_types =
11087 }
11088 else
11089 remaining_arg_types =
11091 }
11094 }
11096 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
11097 *not* handle the exception-specification for FNTYPE, because the
11098 initial substitution of explicitly provided template parameters
11099 during argument deduction forbids substitution into the
11100 exception-specification:
11102 [temp.deduct]
11104 All references in the function type of the function template to the
11105 corresponding template parameters are replaced by the specified tem-
11106 plate argument values. If a substitution in a template parameter or
11107 in the function type of the function template results in an invalid
11108 type, type deduction fails. [Note: The equivalent substitution in
11109 exception specifications is done only when the function is instanti-
11110 ated, at which point a program is ill-formed if the substitution
11111 results in an invalid type.] */
11113 static tree
11115 tree args,
11116 tsubst_flags_t complain,
11117 tree in_decl)
11118 {
11119 tree return_type;
11120 tree arg_types;
11121 tree fntype;
11123 /* The TYPE_CONTEXT is not used for function/method types. */
11126 /* Substitute the return type. */
11130 /* DR 486 clarifies that creation of a function type with an
11131 invalid return type is a deduction failure. */
11134 {
11136 {
11139 else
11141 }
11143 }
11144 /* And DR 657. */
11148 /* Substitute the argument types. */
11154 /* Construct a new type node and return it. */
11156 {
11161 }
11162 else
11163 {
11166 {
11167 /* [temp.deduct]
11169 Type deduction may fail for any of the following
11170 reasons:
11172 -- Attempting to create "pointer to member of T" when T
11173 is not a class type. */
11176 r);
11178 }
11183 }
11187 }
11189 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11190 ARGS into that specification, and return the substituted
11191 specification. If there is no specification, return NULL_TREE. */
11193 static tree
11195 tree args,
11196 tsubst_flags_t complain,
11197 tree in_decl,
11199 {
11200 tree specs;
11201 tree new_specs;
11206 {
11207 /* A noexcept-specifier. */
11212 {
11213 /* Defer instantiation of noexcept-specifiers to avoid
11214 excessive instantiations (c++/49107). */
11217 {
11218 /* We already partially instantiated this member template,
11219 so combine the new args with the old. */
11224 }
11225 else
11226 {
11229 }
11230 }
11231 else
11232 new_specs = tsubst_copy_and_build
11236 }
11238 {
11241 else
11243 {
11244 tree spec;
11249 {
11250 /* Expand the pack expansion type. */
11253 in_decl);
11259 else
11260 {
11261 /* We're substituting into a member template, so
11262 we got a TYPE_PACK_EXPANSION back. Add that
11263 expansion and move on. */
11267 expanded_specs,
11268 complain);
11271 }
11272 }
11275 {
11278 else
11283 complain);
11284 }
11287 }
11288 }
11290 }
11292 /* Take the tree structure T and replace template parameters used
11293 therein with the argument vector ARGS. IN_DECL is an associated
11294 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11295 Issue error and warning messages under control of COMPLAIN. Note
11296 that we must be relatively non-tolerant of extensions here, in
11297 order to preserve conformance; if we allow substitutions that
11298 should not be allowed, we may allow argument deductions that should
11299 not succeed, and therefore report ambiguous overload situations
11300 where there are none. In theory, we could allow the substitution,
11301 but indicate that it should have failed, and allow our caller to
11302 make sure that the right thing happens, but we don't try to do this
11303 yet.
11305 This function is used for dealing with types, decls and the like;
11306 for expressions, use tsubst_expr or tsubst_copy. */
11308 tree
11310 {
11333 else
11338 /* Reuse typedefs. We need to do this to handle dependent attributes,
11339 such as attribute aligned. */
11342 {
11346 {
11347 /* DECL represents an alias template and we want to
11348 instantiate it. */
11352 }
11356 {
11360 }
11365 else
11366 /* The typedef is from a non-template context. */
11370 {
11372 r = cp_build_qualified_type_real
11376 }
11377 else
11378 {
11379 /* We don't have an instantiation yet, so drop the typedef. */
11384 }
11385 }
11398 {
11424 {
11430 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11431 needed. */
11437 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11438 with TREE_SIDE_EFFECTS that indicates this is not an integral
11439 constant expression. */
11442 {
11445 }
11448 }
11454 {
11467 {
11471 {
11472 /* See through ARGUMENT_PACK_SELECT arguments. */
11474 /* If the selected argument is an expansion E, that most
11475 likely means we were called from
11476 gen_elem_of_pack_expansion_instantiation during the
11477 substituting of pack an argument pack (which Ith
11478 element is a pack expansion, where I is
11479 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
11480 In this case, the Ith element resulting from this
11481 substituting is going to be a pack expansion, which
11482 pattern is the pattern of E. Let's return the
11483 pattern of E, and
11484 gen_elem_of_pack_expansion_instantiation will
11485 build the resulting pack expansion from it. */
11488 }
11489 }
11494 {
11496 /* If ARG is an argument pack, we don't actually want to
11497 perform a substitution here, because substitutions
11498 for argument packs are only done
11499 element-by-element. We can get to this point when
11500 substituting the type of a non-type template
11501 parameter pack, when that type actually contains
11502 template parameter packs from an outer template, e.g.,
11504 template<typename... Types> struct A {
11505 template<Types... Values> struct B { };
11506 }; */
11510 {
11516 return cp_build_qualified_type_real
11518 }
11520 {
11521 /* We are processing a type constructed from a
11522 template template parameter. */
11533 /* Consider this code:
11535 template <template <class> class Template>
11536 struct Internal {
11537 template <class Arg> using Bind = Template<Arg>;
11538 };
11540 template <template <class> class Template, class Arg>
11541 using Instantiate = Template<Arg>; //#0
11543 template <template <class> class Template,
11544 class Argument>
11545 using Bind =
11546 Instantiate<Internal<Template>::template Bind,
11547 Argument>; //#1
11549 When #1 is parsed, the
11550 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11551 parameter `Template' in #0 matches the
11552 UNBOUND_CLASS_TEMPLATE representing the argument
11553 `Internal<Template>::template Bind'; We then want
11554 to assemble the type `Bind<Argument>' that can't
11555 be fully created right now, because
11556 `Internal<Template>' not being complete, the Bind
11557 template cannot be looked up in that context. So
11558 we need to "store" `Bind<Argument>' for later
11559 when the context of Bind becomes complete. Let's
11560 store that in a TYPENAME_TYPE. */
11564 argvec),
11565 typename_type,
11566 complain);
11568 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11569 are resolving nested-types in the signature of a
11570 member function templates. Otherwise ARG is a
11571 TEMPLATE_DECL and is the real template to be
11572 instantiated. */
11580 complain);
11581 return cp_build_qualified_type_real
11583 }
11584 else
11585 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11587 }
11590 /* This can happen during the attempted tsubst'ing in
11591 unify. This means that we don't yet have any information
11592 about the template parameter in question. */
11595 /* Early in template argument deduction substitution, we don't
11596 want to reduce the level of 'auto', or it will be confused
11597 with a normal template parm in subsequent deduction. */
11601 /* If we get here, we must have been looking at a parm for a
11602 more deeply nested template. Make a new version of this
11603 template parameter, but with a lower level. */
11605 {
11610 {
11612 r = cp_build_qualified_type_real
11616 }
11617 else
11618 {
11629 /* We have reduced the level of the template
11630 template parameter, but not the levels of its
11631 template parameters, so canonical_type_parameter
11632 will not be able to find the canonical template
11633 template parameter for this level. Thus, we
11634 require structural equality checking to compare
11635 TEMPLATE_TEMPLATE_PARMs. */
11639 else
11643 {
11651 }
11652 }
11661 }
11664 }
11667 {
11675 {
11679 }
11682 {
11686 }
11689 {
11693 }
11699 }
11702 /* We should never be tsubsting a binfo. */
11706 /* A vector of template arguments. */
11712 {
11716 /* [temp.deduct]
11718 Type deduction may fail for any of the following
11719 reasons:
11721 -- Attempting to create a pointer to reference type.
11722 -- Attempting to create a reference to a reference type or
11723 a reference to void.
11725 Core issue 106 says that creating a reference to a reference
11726 during instantiation is no longer a cause for failure. We
11727 only enforce this check in strict C++98 mode. */
11731 {
11734 /* We keep track of the last time we issued this error
11735 message to avoid spewing a ton of messages during a
11736 single bad template instantiation. */
11739 {
11744 else
11747 }
11750 }
11754 {
11756 {
11759 type);
11760 else
11762 type);
11763 }
11765 }
11767 {
11771 }
11773 /* In C++0x, during template argument substitution, when there is an
11774 attempt to create a reference to a reference type, reference
11775 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11777 "If a template-argument for a template-parameter T names a type
11778 that is a reference to a type A, an attempt to create the type
11779 'lvalue reference to cv T' creates the type 'lvalue reference to
11780 A,' while an attempt to create the type type rvalue reference to
11781 cv T' creates the type T"
11782 */
11783 r = cp_build_reference_type
11786 else
11793 {
11795 pedwarn
11797 code == REFERENCE_TYPE
11800 else
11802 }
11805 /* Will this ever be needed for TYPE_..._TO values? */
11809 }
11811 {
11814 {
11815 /* [temp.deduct]
11817 Type deduction may fail for any of the following
11818 reasons:
11820 -- Attempting to create "pointer to member of T" when T
11821 is not a class type. */
11825 }
11827 {
11831 }
11833 {
11837 }
11840 {
11841 /* The type of the implicit object parameter gets its
11842 cv-qualifiers from the FUNCTION_TYPE. */
11843 tree memptr;
11844 tree method_type
11849 complain);
11850 }
11851 else
11854 complain);
11855 }
11858 {
11859 tree fntype;
11860 tree specs;
11865 /* Substitute the exception specification. */
11873 }
11875 {
11880 /* As an optimization, we avoid regenerating the array type if
11881 it will obviously be the same as T. */
11885 /* These checks should match the ones in grokdeclarator.
11887 [temp.deduct]
11889 The deduction may fail for any of the following reasons:
11891 -- Attempting to create an array with an element type that
11892 is void, a function type, or a reference type, or [DR337]
11893 an abstract class type. */
11897 {
11901 }
11909 {
11912 }
11915 }
11918 {
11928 {
11932 }
11934 {
11935 /* Normally, make_typename_type does not require that the CTX
11936 have complete type in order to allow things like:
11938 template <class T> struct S { typename S<T>::X Y; };
11940 But, such constructs have already been resolved by this
11941 point, so here CTX really should have complete type, unless
11942 it's a partial instantiation. */
11945 {
11949 }
11950 }
11957 {
11960 }
11963 {
11965 {
11969 else
11971 }
11973 {
11977 else
11979 }
11980 }
11982 return cp_build_qualified_type_real
11984 }
11987 {
11999 }
12002 {
12003 tree type;
12019 complain);
12020 }
12023 {
12024 tree type;
12042 else
12043 {
12047 /* In a template ~id could be either a complement expression
12048 or an unqualified-id naming a destructor; if instantiating
12049 it produces an expression, it's not an id-expression or
12050 member access. */
12053 }
12057 complain);
12058 }
12061 {
12065 }
12069 {
12071 tree packed_out =
12073 args,
12074 complain,
12075 in_decl);
12078 /* For template nontype argument packs, also substitute into
12079 the type. */
12084 }
12099 /* We should use one of the expression tsubsts for these codes. */
12105 }
12106 }
12108 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
12109 type of the expression on the left-hand side of the "." or "->"
12110 operator. */
12112 static tree
12115 {
12116 tree name;
12117 tree qualifying_scope;
12118 tree fns;
12119 tree optype;
12124 /* A baselink indicates a function from a base class. Both the
12125 BASELINK_ACCESS_BINFO and the base class referenced may
12126 indicate bases of the template class, rather than the
12127 instantiated class. In addition, lookups that were not
12128 ambiguous before may be ambiguous now. Therefore, we perform
12129 the lookup again. */
12136 {
12143 }
12151 /* If lookup found a single function, mark it as used at this
12152 point. (If it lookup found multiple functions the one selected
12153 later by overload resolution will be marked as used at that
12154 point.) */
12160 /* Add back the template arguments, if present. */
12165 template_args);
12166 /* Update the conversion operator type. */
12174 qualifying_scope,
12175 object_type);
12177 }
12179 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
12180 true if the qualified-id will be a postfix-expression in-and-of
12181 itself; false if more of the postfix-expression follows the
12182 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
12183 of "&". */
12185 static tree
12189 {
12190 tree expr;
12191 tree scope;
12192 tree name;
12194 tree template_args;
12199 /* Figure out what name to look up. */
12202 {
12210 }
12211 else
12212 {
12215 }
12217 /* Substitute into the qualifying scope. When there are no ARGS, we
12218 are just trying to simplify a non-dependent expression. In that
12219 case the qualifying scope may be dependent, and, in any case,
12220 substituting will not help. */
12223 {
12226 }
12227 else
12231 {
12236 }
12239 {
12241 {
12242 /* A BIT_NOT_EXPR is used to represent a destructor. */
12244 {
12248 }
12249 else
12252 }
12253 else
12257 {
12259 {
12263 }
12265 }
12266 }
12269 {
12271 scope);
12272 /* Remember that there was a reference to this entity. */
12274 }
12277 {
12283 }
12292 {
12293 expr = (adjust_result_of_qualified_name_lookup
12295 expr = (finish_qualified_id_expr
12299 }
12301 /* Expressions do not generally have reference type. */
12303 /* However, if we're about to form a pointer-to-member, we just
12304 want the referenced member referenced. */
12309 }
12311 /* Like tsubst, but deals with expressions. This function just replaces
12312 template parms; to finish processing the resultant expression, use
12313 tsubst_copy_and_build or tsubst_expr. */
12315 static tree
12317 {
12319 tree r;
12327 {
12332 {
12333 /* We get here for a use of 'this' in an NSDMI. */
12339 /* This can happen for a parameter name used later in a function
12340 declaration (such as in a late-specified return type). Just
12341 make a dummy decl, since it's only used for its type. */
12344 /* Give it the template pattern as its context; its true context
12345 hasn't been instantiated yet and this is good enough for
12346 mangling. */
12348 }
12356 {
12357 tree enum_type;
12358 tree v;
12362 /* There is no need to substitute into namespace-scope
12363 enumerators. */
12366 /* If ARGS is NULL, then T is known to be non-dependent. */
12370 /* Unfortunately, we cannot just call lookup_name here.
12371 Consider:
12373 template <int I> int f() {
12374 enum E { a = I };
12375 struct S { void g() { E e = a; } };
12376 };
12378 When we instantiate f<7>::S::g(), say, lookup_name is not
12379 clever enough to find f<7>::a. */
12380 enum_type
12390 /* We didn't find the name. That should never happen; if
12391 name-lookup found it during preliminary parsing, we
12392 should find it again here during instantiation. */
12394 }
12399 {
12400 /* Check for a local specialization set up by
12401 tsubst_pack_expansion. */
12404 {
12408 }
12410 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
12411 tsubst_decl put in the hash table. */
12413 }
12416 {
12417 tree ctx;
12422 {
12425 {
12429 }
12431 }
12432 }
12441 {
12444 {
12446 {
12447 /* Just use name lookup to find a member alias for an
12448 anonymous union, but then add it to the hash table. */
12452 }
12453 else
12454 {
12457 }
12458 }
12459 }
12460 else
12469 /* An OVERLOAD will always be a non-dependent overload set; an
12470 overload set from function scope will just be represented with an
12471 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12487 {
12488 /* Template template argument like the following example need
12489 special treatment:
12491 template <template <class> class TT> struct C {};
12492 template <class T> struct D {
12493 template <class U> struct E {};
12494 C<E> c; // #1
12495 };
12496 D<int> d; // #2
12498 We are processing the template argument `E' in #1 for
12499 the template instantiation #2. Originally, `E' is a
12500 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12501 have to substitute this with one having context `D<int>'. */
12505 }
12506 else
12507 /* Ordinary template template argument. */
12518 return build1
12524 {
12534 /* We only want to compute the number of arguments. */
12548 {
12555 else
12558 }
12559 else
12561 }
12563 {
12571 }
12572 /* Fall through */
12588 return build1
12593 {
12594 tree object;
12595 tree name;
12600 {
12604 }
12607 {
12617 }
12622 in_decl);
12623 else
12626 }
12664 return build_nt
12677 return build_nt
12684 {
12692 }
12698 {
12699 r = build_nt
12705 }
12708 {
12709 r = build_nt
12715 }
12718 {
12719 r = build_nt
12725 }
12728 {
12729 /* Substituted template arguments */
12738 }
12741 {
12761 }
12786 /* Fall through. */
12789 {
12792 }
12793 else
12797 /* This is handled by tsubst_copy_and_build. */
12803 in_decl),
12807 /* We shouldn't have built any of these during initial template
12808 generation. Instead, they should be built during instantiation
12809 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12813 r = build2
12833 {
12834 /* Instantiate any typedefs in the type. */
12839 }
12842 /* These can sometimes show up in a partial instantiation, but never
12843 involve template parms. */
12848 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12851 }
12852 }
12854 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12856 static tree
12859 {
12863 {
12869 {
12872 {
12878 }
12879 /* FALLTHRU */
12907 {
12910 {
12917 }
12918 else
12920 }
12950 }
12951 }
12957 }
12959 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12961 static tree
12963 tree in_decl)
12964 {
12965 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
12985 {
12988 else
12989 {
12993 }
12994 }
12999 #undef RECUR
13000 }
13002 /* Substitute one OMP_FOR iterator. */
13004 static void
13009 {
13010 #define RECUR(NODE) \
13011 tsubst_expr ((NODE), args, complain, in_decl, \
13012 integral_constant_expression_p)
13020 /* Do this before substituting into decl to handle 'auto'. */
13025 {
13029 }
13034 {
13041 complain);
13042 else
13049 }
13052 {
13053 tree c;
13055 {
13066 }
13068 {
13073 {
13076 }
13077 }
13078 }
13084 else
13088 {
13099 {
13106 }
13107 else
13113 {
13119 }
13123 {
13130 }
13131 else
13137 }
13143 #undef RECUR
13144 }
13146 /* Like tsubst_copy for expressions, etc. but also does semantic
13147 processing. */
13149 static tree
13152 {
13153 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13154 #define RECUR(NODE) \
13155 tsubst_expr ((NODE), args, complain, in_decl, \
13156 integral_constant_expression_p)
13159 tree r;
13160 location_t loc;
13172 {
13174 {
13175 tree_stmt_iterator i;
13179 }
13194 else
13203 {
13205 tree init;
13211 {
13214 tree decl;
13222 else
13224 }
13226 {
13227 /* Don't build up decls for a variadic capture proxy, we'll
13228 instantiate the elements directly as needed. */
13230 }
13231 else
13232 {
13236 {
13237 /* By marking the declaration as instantiated, we avoid
13238 trying to instantiate it. Since instantiate_decl can't
13239 handle local variables, and since we've already done
13240 all that needs to be done, that's the right thing to
13241 do. */
13246 /* Anonymous aggregates are a special case. */
13249 {
13252 {
13256 }
13258 }
13264 {
13269 }
13270 else
13271 {
13276 {
13277 /* For __PRETTY_FUNCTION__ we have to adjust the
13278 initializer. */
13282 }
13283 else
13284 {
13288 {
13289 /* If we had an initializer but it
13290 instantiated to nothing,
13291 value-initialize the object. This will
13292 only occur when the initializer was a
13293 pack expansion where the parameter packs
13294 used in that expansion were of length
13295 zero. */
13297 complain);
13300 }
13301 else
13303 }
13306 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
13309 }
13310 }
13311 }
13314 }
13329 {
13339 }
13366 {
13370 }
13378 else
13386 else
13413 {
13415 tree label;
13420 }
13426 /* Computed goto's must be tsubst'd into. On the other hand,
13427 non-computed gotos must not be; the identifier in question
13428 will have no binding. */
13430 else
13436 tmp = finish_asm_stmt
13443 {
13448 }
13453 {
13458 }
13459 else
13460 {
13465 else
13472 else
13478 else
13480 }
13484 {
13488 {
13490 /* Prevent instantiate_decl from trying to instantiate
13491 this variable. We've already done all that needs to be
13492 done. */
13495 }
13500 }
13506 {
13507 /* Local classes are not independent templates; they are
13508 instantiated along with their containing function. And this
13509 way we don't have to deal with pushing out of one local class
13510 to instantiate a member of another local class. */
13511 tree fn;
13512 /* Closures are handled by the LAMBDA_EXPR. */
13518 }
13522 {
13523 tree condition;
13526 condition =
13528 args,
13537 }
13560 {
13569 {
13574 }
13586 integral_constant_expression_p);
13595 else
13596 {
13604 }
13607 }
13652 {
13657 {
13660 }
13666 }
13667 else
13668 {
13675 {
13678 }
13681 {
13686 {
13689 }
13695 }
13696 else
13697 {
13701 }
13704 }
13708 {
13714 {
13718 {
13723 }
13727 }
13728 else
13729 {
13734 }
13735 }
13753 /* If the first operand was a statement, we're done with it. */
13757 complain));
13764 integral_constant_expression_p));
13765 }
13768 out:
13771 #undef RECUR
13772 #undef RETURN
13773 }
13775 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
13776 function. For description of the body see comment above
13777 cp_parser_omp_declare_reduction_exprs. */
13779 static void
13781 {
13787 tree_stmt_iterator tsi;
13798 {
13817 }
13819 {
13839 }
13840 }
13842 /* T is a postfix-expression that is not being used in a function
13843 call. Return the substituted version of T. */
13845 static tree
13847 tsubst_flags_t complain,
13848 tree in_decl)
13849 {
13853 else
13859 }
13861 /* Like tsubst but deals with expressions and performs semantic
13862 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
13864 tree
13866 tree args,
13867 tsubst_flags_t complain,
13868 tree in_decl,
13871 {
13872 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
13873 #define RECUR(NODE) \
13874 tsubst_copy_and_build (NODE, args, complain, in_decl, \
13876 integral_constant_expression_p)
13879 location_t loc;
13888 /* N3276 decltype magic only applies to calls at the top level or on the
13889 right side of a comma. */
13894 {
13897 /* Fall through. */
13899 {
13900 tree decl;
13901 cp_id_kind idk;
13906 {
13909 }
13911 /* Look up the name. */
13914 /* By convention, expressions use ERROR_MARK_NODE to indicate
13915 failure, not NULL_TREE. */
13921 integral_constant_expression_p,
13929 input_location);
13933 {
13937 }
13939 }
13942 {
13943 tree object;
13951 {
13954 }
13955 else
13962 else
13964 }
13967 {
13971 {
13972 /* A type conversion to reference type will be enclosed in
13973 such an indirect ref, but the substitution of the cast
13974 will have also added such an indirect ref. */
13977 }
13978 else
13982 }
13990 {
13997 flags));
13998 }
14011 {
14012 tree type;
14018 {
14023 }
14029 {
14047 }
14051 }
14085 else
14087 in_decl);
14122 {
14123 tree r;
14127 r = build_x_binary_op
14131 ? ERROR_MARK
14135 ? ERROR_MARK
14145 }
14158 {
14167 }
14171 /* Fall through */
14174 {
14175 tree r;
14181 {
14182 /* When there are no ARGS, we are trying to evaluate a
14183 non-dependent expression from the parser. Trying to do
14184 the substitutions may not work. */
14187 }
14188 else
14189 {
14194 else
14197 /*integral_constant_expression_p=*/
14201 }
14205 else
14209 {
14211 {
14213 {
14217 }
14218 else
14222 }
14224 }
14226 }
14229 {
14239 }
14253 {
14254 tree r;
14258 r = build_x_modify_expr
14264 /* TREE_NO_WARNING must be set if either the expression was
14265 parenthesized or it uses an operator such as >>= rather
14266 than plain assignment. In the former case, it was already
14267 set and must be copied. In the latter case,
14268 build_x_modify_expr sets it and it must not be reset
14269 here. */
14276 }
14281 /* Remember that there was a reference to this entity. */
14287 {
14292 tree ret;
14296 else
14297 {
14301 }
14303 /* If there was an initializer in the original tree, but it
14304 instantiated to an empty list, then we should pass a
14305 non-NULL empty vector to tell build_new that it was an
14306 empty initializer() rather than no initializer. This can
14307 only happen when the initializer is a pack expansion whose
14308 parameter packs are of length zero. */
14311 else
14312 {
14316 else
14317 {
14320 }
14321 }
14328 complain);
14336 }
14344 complain));
14347 {
14351 integral_constant_expression_p);
14353 op0,
14356 }
14359 {
14360 tree function;
14365 tree ret;
14368 /* When we parsed the expression, we determined whether or
14369 not Koenig lookup should be performed. */
14372 {
14377 }
14379 {
14380 /* Do nothing; calling tsubst_copy_and_build on an identifier
14381 would incorrectly perform unqualified lookup again.
14383 Note that we can also have an IDENTIFIER_NODE if the earlier
14384 unqualified lookup found a member function; in that case
14385 koenig_p will be false and we do want to do the lookup
14386 again to find the instantiated member function.
14388 FIXME but doing that causes c++/15272, so we need to stop
14389 using IDENTIFIER_NODE in that situation. */
14391 }
14392 else
14393 {
14395 {
14401 }
14402 else
14407 /* Avoid error about taking the address of a constructor. */
14411 in_decl,
14413 integral_constant_expression_p);
14417 }
14422 {
14427 else
14428 {
14429 /* Expand the pack expansion and push each entry onto
14430 CALL_ARGS. */
14433 {
14438 {
14443 }
14444 }
14445 else
14446 {
14447 /* A partial substitution. Add one entry. */
14449 }
14450 }
14451 }
14453 /* We do not perform argument-dependent lookup if normal
14454 lookup finds a non-function, in accordance with the
14455 expected resolution of DR 218. */
14458 /* If lookup found a member function, the Koenig lookup is
14459 not appropriate, even if an unqualified-name was used
14460 to denote the function. */
14463 /* Only do this when substitution turns a dependent call
14464 into a non-dependent call. */
14468 tf_none);
14472 {
14474 {
14475 /* For backwards compatibility and good diagnostics, try
14476 the unqualified lookup again if we aren't in SFINAE
14477 context. */
14478 tree unq = (tsubst_copy_and_build
14480 integral_constant_expression_p));
14485 {
14494 "%qD was not declared in this scope, "
14495 "and no declarations were found by "
14496 "argument-dependent lookup at the point "
14498 {
14502 {
14504 "declarations in dependent base %qT are "
14510 else
14514 }
14515 else
14518 }
14520 }
14521 }
14523 {
14528 }
14529 }
14531 /* Remember that there was a reference to this entity. */
14535 /* Put back tf_decltype for the actual call. */
14540 complain);
14542 {
14557 complain);
14558 else
14559 ret = (build_new_method_call
14564 complain));
14565 }
14566 else
14569 koenig_p,
14570 complain);
14575 }
14578 {
14583 {
14585 {
14590 }
14591 else
14592 {
14597 }
14598 }
14599 else
14600 {
14603 }
14607 }
14614 input_location));
14617 {
14625 {
14626 /* We have pack expansions, so expand those and
14627 create a new list out of it. */
14630 tree chain;
14633 /* Expand the argument expressions. */
14641 /* Build the rest of the list. */
14646 /* Determine the number of arguments. */
14648 {
14651 }
14654 else
14655 {
14656 /* Since we only performed a partial substitution into
14657 the argument pack, we only RETURN (a single list
14658 node. */
14665 }
14667 /* Convert the argument vectors into a TREE_LIST */
14670 {
14671 /* Grab the Ith values. */
14672 i--;
14675 value
14679 /* Build the list (backwards). */
14681 }
14684 }
14700 }
14703 {
14704 tree object;
14705 tree object_type;
14706 tree member;
14710 /* Remember that there was a reference to this entity. */
14720 else
14728 {
14730 {
14735 {
14738 }
14740 {
14745 }
14746 }
14747 }
14750 {
14751 /* Lookup the template functions now that we know what the
14752 scope is. */
14760 {
14763 args);
14764 member = (adjust_result_of_qualified_name_lookup
14766 object_type));
14767 }
14768 else
14769 {
14771 input_location);
14773 }
14774 }
14778 {
14780 {
14784 else
14787 }
14789 }
14795 complain));
14796 }
14803 {
14811 tree r;
14816 /* digest_init will do the wrong thing if we let it. */
14820 /* We do not want to process the index of aggregate
14821 initializers as they are identifier nodes which will be
14822 looked up by digest_init. */
14828 {
14830 /* An identifier index is looked up in the type
14831 being initialized, not the current scope. */
14836 {
14837 /* Substitute into the pack expansion. */
14839 in_decl);
14843 ;
14845 /* Just move the argument into place. */
14847 else
14848 {
14849 /* Update the length of the final CONSTRUCTOR
14850 arguments vector, and note that we will need to
14851 copy.*/
14854 }
14855 }
14856 else
14858 }
14861 {
14866 {
14868 {
14873 }
14874 else
14876 }
14877 }
14887 }
14890 {
14893 {
14896 }
14897 else
14898 {
14901 }
14902 }
14908 {
14909 /* We don't build decls for an instantiation of a
14910 variadic capture proxy, we instantiate the elements
14911 when needed. */
14914 }
14915 /* Fall through */
14918 {
14922 /* If the original type was a reference, we'll be wrapped in
14923 the appropriate INDIRECT_REF. */
14926 }
14937 {
14946 }
14949 {
14955 integral_constant_expression_p);
14959 /* If the resulting list of expression statement is empty,
14960 fold it further into void_zero_node. */
14965 }
14968 {
14982 /* For a function scope, we want to use tsubst so that we don't
14983 complain about referring to an auto function before its return
14984 type has been deduced. Otherwise, we want to use tsubst_copy so
14985 that we look up the existing field/parameter/variable rather
14986 than build a new one. */
14991 {
14992 /* Look up the parameter we want directly, as tsubst_copy
14993 doesn't do what we need. */
14999 /* FIXME Work around the parm not having DECL_CONTEXT set. */
15002 }
15003 else
15012 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
15014 /* Now that we know visibility, instantiate the type so we have a
15015 declaration of the op() for later calls to lambda_function. */
15021 }
15024 /* We can get here for a constant initializer of non-dependent type.
15025 FIXME stop folding in cp_parser_initializer_clause. */
15026 {
15028 complain);
15030 }
15034 integral_constant_expression_p));
15044 complain));
15047 /* Handle Objective-C++ constructs, if appropriate. */
15048 {
15049 tree subst
15054 }
15056 }
15058 #undef RECUR
15059 #undef RETURN
15060 out:
15063 }
15065 /* Verify that the instantiated ARGS are valid. For type arguments,
15066 make sure that the type's linkage is ok. For non-type arguments,
15067 make sure they are constants if they are integral or enumerations.
15068 Emit an error under control of COMPLAIN, and return TRUE on error. */
15070 static bool
15072 {
15076 {
15086 }
15088 {
15089 /* [basic.link]: A name with no linkage (notably, the name
15090 of a class or enumeration declared in a local scope)
15091 shall not be used to declare an entity with linkage.
15092 This implies that names with no linkage cannot be used as
15093 template arguments
15095 DR 757 relaxes this restriction for C++0x. */
15100 {
15101 /* DR 488 makes use of a type with no linkage cause
15102 type deduction to fail. */
15104 {
15107 else
15110 }
15112 }
15113 /* In order to avoid all sorts of complications, we do not
15114 allow variably-modified types as template arguments. */
15116 {
15120 }
15121 }
15122 /* Class template and alias template arguments should be OK. */
15124 ;
15125 /* A non-type argument of integral or enumerated type must be a
15126 constant. */
15130 {
15134 }
15136 }
15138 static bool
15140 {
15145 {
15148 }
15152 }
15154 /* We're out of SFINAE context now, so generate diagnostics for the access
15155 errors we saw earlier when instantiating D from TMPL and ARGS. */
15157 static void
15159 {
15171 }
15173 /* Instantiate the indicated variable, function, or alias template TMPL with
15174 the template arguments in TARG_PTR. */
15176 static tree
15178 {
15180 tree fndecl;
15181 tree gen_tmpl;
15182 tree spec;
15190 /* If this function is a clone, handle it specially. */
15192 {
15193 tree spec;
15194 tree clone;
15196 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
15197 DECL_CLONED_FUNCTION. */
15203 /* Look for the clone. */
15207 /* We should always have found the clone by now. */
15210 }
15212 /* Check to see if we already have this specialization. */
15215 /* The TMPL is a partial instantiation. To get a full set of
15216 arguments we must add the arguments used to perform the
15217 partial instantiation. */
15219 targ_ptr);
15221 /* It would be nice to avoid hashing here and then again in tsubst_decl,
15222 but it doesn't seem to be on the hot path. */
15231 {
15233 {
15237 }
15239 }
15242 complain))
15245 /* We are building a FUNCTION_DECL, during which the access of its
15246 parameters and return types have to be checked. However this
15247 FUNCTION_DECL which is the desired context for access checking
15248 is not built yet. We solve this chicken-and-egg problem by
15249 deferring all checks until we have the FUNCTION_DECL. */
15252 /* Instantiation of the function happens in the context of the function
15253 template, not the context of the overload resolution we're doing. */
15255 /* If there are dependent arguments, e.g. because we're doing partial
15256 ordering, make sure processing_template_decl stays set. */
15260 {
15264 }
15265 /* Substitute template parameters to obtain the specialization. */
15273 {
15276 }
15278 /* The DECL_TI_TEMPLATE should always be the immediate parent
15279 template, not the most general template. */
15282 /* Now we know the specialization, compute access previously
15283 deferred. */
15290 /* If we've just instantiated the main entry point for a function,
15291 instantiate all the alternate entry points as well. We do this
15292 by cloning the instantiation of the main entry point, not by
15293 instantiating the template clones. */
15298 {
15300 {
15301 /* Remember to reinstantiate when we're out of SFINAE so the user
15302 can see the errors. */
15304 }
15306 }
15308 }
15310 /* Wrapper for instantiate_template_1. */
15312 tree
15314 {
15315 tree ret;
15320 }
15322 /* Instantiate the alias template TMPL with ARGS. Also push a template
15323 instantiation level, which instantiate_template doesn't do because
15324 functions and variables have sufficient context established by the
15325 callers. */
15327 static tree
15329 {
15336 {
15339 }
15341 args =
15349 /* We can't free this if a pending_template entry or last_error_tinst_level
15350 is pointing at it. */
15356 }
15358 /* PARM is a template parameter pack for FN. Returns true iff
15359 PARM is used in a deducible way in the argument list of FN. */
15361 static bool
15363 {
15366 {
15368 tree packs;
15374 {
15375 /* The template parameter pack is used in a function parameter
15376 pack. If this is the end of the parameter list, the
15377 template parameter pack is deducible. */
15380 else
15381 /* Otherwise, not. Well, it could be deduced from
15382 a non-pack parameter, but doing so would end up with
15383 a deduction mismatch, so don't bother. */
15385 }
15386 }
15387 /* The template parameter pack isn't used in any function parameter
15388 packs, but it might be used deeper, e.g. tuple<Args...>. */
15390 }
15392 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
15393 NARGS elements of the arguments that are being used when calling
15394 it. TARGS is a vector into which the deduced template arguments
15395 are placed.
15397 Return zero for success, 2 for an incomplete match that doesn't resolve
15398 all the types, and 1 for complete failure. An error message will be
15399 printed only for an incomplete match.
15401 If FN is a conversion operator, or we are trying to produce a specific
15402 specialization, RETURN_TYPE is the return type desired.
15404 The EXPLICIT_TARGS are explicit template arguments provided via a
15405 template-id.
15407 The parameter STRICT is one of:
15409 DEDUCE_CALL:
15410 We are deducing arguments for a function call, as in
15411 [temp.deduct.call].
15413 DEDUCE_CONV:
15414 We are deducing arguments for a conversion function, as in
15415 [temp.deduct.conv].
15417 DEDUCE_EXACT:
15418 We are deducing arguments when doing an explicit instantiation
15419 as in [temp.explicit], when determining an explicit specialization
15420 as in [temp.expl.spec], or when taking the address of a function
15421 template, as in [temp.deduct.funcaddr]. */
15423 tree
15425 tree explicit_targs,
15426 tree targs,
15429 tree return_type,
15430 unification_kind_t strict,
15434 {
15435 tree parms;
15436 tree fntype;
15444 tree tinst;
15450 /* In C++0x, it's possible to have a function template whose type depends
15451 on itself recursively. This is most obvious with decltype, but can also
15452 occur with enumeration scope (c++/48969). So we need to catch infinite
15453 recursion and reject the substitution at deduction time; this function
15454 will return error_mark_node for any repeated substitution.
15456 This also catches excessive recursion such as when f<N> depends on
15457 f<N-1> across all integers, and returns error_mark_node for all the
15458 substitutions back up to the initial one.
15460 This is, of course, not reentrant. */
15470 {
15471 /* [temp.deduct]
15473 The specified template arguments must match the template
15474 parameters in kind (i.e., type, nontype, template), and there
15475 must not be more arguments than there are parameters;
15476 otherwise type deduction fails.
15478 Nontype arguments must match the types of the corresponding
15479 nontype template parameters, or must be convertible to the
15480 types of the corresponding nontype parameters as specified in
15481 _temp.arg.nontype_, otherwise type deduction fails.
15483 All references in the function type of the function template
15484 to the corresponding template parameters are replaced by the
15485 specified template argument values. If a substitution in a
15486 template parameter or in the function type of the function
15487 template results in an invalid type, type deduction fails. */
15492 /* Adjust any explicit template arguments before entering the
15493 substitution context. */
15494 explicit_targs
15496 complain,
15502 /* Substitute the explicit args into the function type. This is
15503 necessary so that, for instance, explicitly declared function
15504 arguments can match null pointed constants. If we were given
15505 an incomplete set of explicit args, we must not do semantic
15506 processing during substitution as we could create partial
15507 instantiations. */
15509 {
15514 /* Dig out the actual parm. */
15517 {
15520 }
15522 {
15525 }
15528 /* No explicit argument for this template parameter. */
15532 {
15533 /* Mark the argument pack as "incomplete". We could
15534 still deduce more arguments during unification.
15535 We remove this mark in type_unification_real. */
15537 {
15541 }
15543 /* We have some incomplete argument packs. */
15545 }
15546 }
15550 {
15553 }
15556 /* Ignore any access checks; we'll see them again in
15557 instantiate_template and they might have the wrong
15558 access path at this point. */
15570 /* Place the explicitly specified arguments in TARGS. */
15573 }
15575 /* Never do unification on the 'this' parameter. */
15579 {
15588 }
15590 /* We allow incomplete unification without an error message here
15591 because the standard doesn't seem to explicitly prohibit it. Our
15592 callers must be ready to deal with unification failures in any
15593 event. */
15596 /* If we aren't explaining yet, push tinst context so we can see where
15597 any errors (e.g. from class instantiations triggered by instantiation
15598 of default template arguments) come from. If we are explaining, this
15599 context is redundant. */
15601 {
15604 }
15606 /* type_unification_real will pass back any access checks from default
15607 template argument substitution. */
15619 /* Now that we have bindings for all of the template arguments,
15620 ensure that the arguments deduced for the template template
15621 parameters have compatible template parameter lists. We cannot
15622 check this property before we have deduced all template
15623 arguments, because the template parameter types of a template
15624 template parameter might depend on prior template parameters
15625 deduced after the template template parameter. The following
15626 ill-formed example illustrates this issue:
15628 template<typename T, template<T> class C> void f(C<5>, T);
15630 template<int N> struct X {};
15632 void g() {
15633 f(X<5>(), 5l); // error: template argument deduction fails
15634 }
15636 The template parameter list of 'C' depends on the template type
15637 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
15638 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
15639 time that we deduce 'C'. */
15642 {
15645 }
15647 /* All is well so far. Now, check:
15649 [temp.deduct]
15651 When all template arguments have been deduced, all uses of
15652 template parameters in nondeduced contexts are replaced with
15653 the corresponding deduced argument values. If the
15654 substitution results in an invalid type, as described above,
15655 type deduction fails. */
15658 {
15661 }
15663 /* Also collect access checks from the instantiation. */
15676 /* Now perform any access checks encountered during substitution. */
15683 /* If we're looking for an exact match, check that what we got
15684 is indeed an exact match. It might not be if some template
15685 parameters are used in non-deduced contexts. */
15687 {
15691 tree sarg
15697 {
15701 }
15702 }
15706 fail:
15709 {
15711 /* Reset once we're all the way out. */
15713 }
15715 /* We can't free this if a pending_template entry or last_error_tinst_level
15716 is pointing at it. */
15722 }
15724 /* Adjust types before performing type deduction, as described in
15725 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
15726 sections are symmetric. PARM is the type of a function parameter
15727 or the return type of the conversion function. ARG is the type of
15728 the argument passed to the call, or the type of the value
15729 initialized with the result of the conversion function.
15730 ARG_EXPR is the original argument expression, which may be null. */
15732 static int
15736 tree arg_expr)
15737 {
15741 {
15746 {
15747 /* Swap PARM and ARG throughout the remainder of this
15748 function; the handling is precisely symmetric since PARM
15749 will initialize ARG rather than vice versa. */
15754 }
15757 /* Core issue #873: Do the DR606 thing (see below) for these cases,
15758 too, but here handle it by stripping the reference from PARM
15759 rather than by adding it to ARG. */
15767 /* Nothing else to do in this case. */
15772 }
15775 {
15776 /* [temp.deduct.call]
15778 If P is not a reference type:
15780 --If A is an array type, the pointer type produced by the
15781 array-to-pointer standard conversion (_conv.array_) is
15782 used in place of A for type deduction; otherwise,
15784 --If A is a function type, the pointer type produced by
15785 the function-to-pointer standard conversion
15786 (_conv.func_) is used in place of A for type deduction;
15787 otherwise,
15789 --If A is a cv-qualified type, the top level
15790 cv-qualifiers of A's type are ignored for type
15791 deduction. */
15796 else
15798 }
15800 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
15801 of the form T&&, where T is a template parameter, and the argument
15802 is an lvalue, T is deduced as A& */
15808 /* try_one_overload doesn't provide an arg_expr, but
15809 functions are always lvalues. */
15813 /* [temp.deduct.call]
15815 If P is a cv-qualified type, the top level cv-qualifiers
15816 of P's type are ignored for type deduction. If P is a
15817 reference type, the type referred to by P is used for
15818 type deduction. */
15821 {
15824 }
15826 /* DR 322. For conversion deduction, remove a reference type on parm
15827 too (which has been swapped into ARG). */
15832 }
15834 /* Subroutine of unify_one_argument. PARM is a function parameter of a
15835 template which does contain any deducible template parameters; check if
15836 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
15837 unify_one_argument. */
15839 static int
15842 {
15843 tree type;
15847 else
15854 {
15858 }
15860 {
15865 }
15869 else
15871 }
15875 /* Returns true iff the expression EXPR is one from which a template
15876 argument can be deduced. In other words, if it's an undecorated
15877 use of a template non-type parameter. */
15879 static bool
15881 {
15883 }
15885 /* Returns true iff the array domain DOMAIN uses a template parameter in a
15886 deducible way; that is, if it has a max value of <PARM> - 1. */
15888 static bool
15890 {
15899 }
15901 /* Returns true iff the template arguments ARGS use a template parameter
15902 in a deducible way. */
15904 static bool
15906 {
15908 {
15913 else
15914 {
15921 else
15923 }
15926 }
15928 }
15930 /* Returns true iff TYPE contains any deducible references to template
15931 parameters, as per 14.8.2.5. */
15933 static bool
15935 {
15939 /* T
15940 cv-list T
15941 TT<T>
15942 TT<i>
15943 TT<> */
15948 /* T*
15949 T&
15950 T&& */
15954 /* T[integer-constant ]
15955 type [i] */
15960 /* T type ::*
15961 type T::*
15962 T T::*
15963 T (type ::*)()
15964 type (T::*)()
15965 type (type ::*)(T)
15966 type (T::*)(T)
15967 T (type ::*)(T)
15968 T (T::*)()
15969 T (T::*)(T) */
15972 || (uses_deducible_template_parms
15975 /* template-name <T> (where template-name refers to a class template)
15976 template-name <i> (where template-name refers to a class template) */
15983 /* type (T)
15984 T()
15985 T(T) */
15988 {
15997 }
16000 }
16002 /* Subroutine of type_unification_real and unify_pack_expansion to
16003 handle unification of a single P/A pair. Parameters are as
16004 for those functions. */
16006 static int
16010 {
16017 /* We can't deduce anything from this, but we might get all the
16018 template args from other function args. */
16021 /* Implicit conversions (Clause 4) will be performed on a function
16022 argument to convert it to the type of the corresponding function
16023 parameter if the parameter type contains no template-parameters that
16024 participate in template argument deduction. */
16026 /* For function parameters that contain no template-parameters at all,
16027 we have historically checked for convertibility in order to shortcut
16028 consideration of this candidate. */
16030 explain_p);
16033 /* For function parameters with only non-deducible template parameters,
16034 just return. */
16038 {
16040 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
16041 | UNIFY_ALLOW_MORE_CV_QUAL
16055 }
16057 /* We only do these transformations if this is the top-level
16058 parameter_type_list in a call or declaration matching; in other
16059 situations (nested function declarators, template argument lists) we
16060 won't be comparing a type to an expression, and we don't do any type
16061 adjustments. */
16063 {
16065 {
16068 {
16069 /* [temp.deduct.type] A template-argument can be
16070 deduced from a pointer to function or pointer
16071 to member function argument if the set of
16072 overloaded functions does not contain function
16073 templates and at most one of a set of
16074 overloaded functions provides a unique
16075 match. */
16082 }
16088 }
16090 arg_strict |=
16092 }
16093 else
16097 /* For deduction from an init-list we need the actual list. */
16101 }
16103 /* Most parms like fn_type_unification.
16105 If SUBR is 1, we're being called recursively (to unify the
16106 arguments of a function or method parameter of a function
16107 template).
16109 CHECKS is a pointer to a vector of access checks encountered while
16110 substituting default template arguments. */
16112 static int
16114 tree targs,
16115 tree xparms,
16119 unification_kind_t strict,
16123 {
16128 tree parms;
16137 /* Reset the number of non-defaulted template arguments contained
16138 in TARGS. */
16141 again:
16149 {
16154 /* For a function parameter pack that occurs at the end of the
16155 parameter-declaration-list, the type A of each remaining
16156 argument of the call is compared with the type P of the
16157 declarator-id of the function parameter pack. */
16163 /* For a function parameter pack that does not occur at the
16164 end of the parameter-declaration-list, the type of the
16165 parameter pack is a non-deduced context. */
16174 }
16179 {
16180 /* Unify the remaining arguments with the pack expansion type. */
16181 tree argvec;
16184 /* Allocate a TREE_VEC and copy in all of the arguments */
16189 /* Copy the parameter into parmvec. */
16195 /* Advance to the end of the list of parameters. */
16197 }
16199 /* Fail if we've reached the end of the parm list, and more args
16200 are present, and the parm list isn't variadic. */
16203 /* Fail if parms are left and they don't have default values. */
16206 {
16210 {
16211 count++;
16213 }
16215 }
16218 {
16219 tsubst_flags_t complain = (explain_p
16220 ? tf_warning_or_error
16224 {
16228 /* Clear the "incomplete" flags on all argument packs now so that
16229 substituting them into later default arguments works. */
16231 {
16234 }
16240 /* If this is an undeduced nontype parameter that depends on
16241 a type parameter, try another pass; its type may have been
16242 deduced from a later argument than the one from which
16243 this parameter can be deduced. */
16249 /* Core issue #226 (C++0x) [temp.deduct]:
16251 If a template argument has not been deduced, its
16252 default template argument, if any, is used.
16254 When we are in C++98 mode, TREE_PURPOSE will either
16255 be NULL_TREE or ERROR_MARK_NODE, so we do not need
16256 to explicitly check cxx_dialect here. */
16258 {
16273 else
16274 {
16276 /* The position of the first default template argument,
16277 is also the number of non-defaulted arguments in TARGS.
16278 Record that. */
16282 }
16283 }
16285 /* If the type parameter is a parameter pack, then it will
16286 be deduced to an empty parameter pack. */
16288 {
16289 tree arg;
16292 {
16296 }
16297 else
16304 }
16307 }
16308 }
16309 #ifdef ENABLE_CHECKING
16312 #endif
16315 }
16317 /* Subroutine of type_unification_real. Args are like the variables
16318 at the call site. ARG is an overloaded function (or template-id);
16319 we try deducing template args from each of the overloads, and if
16320 only one succeeds, we go with that. Modifies TARGS and returns
16321 true on success. */
16323 static bool
16325 tree targs,
16326 tree parm,
16327 tree arg,
16328 unification_kind_t strict,
16331 {
16338 {
16341 }
16342 else
16346 /* Handle `&x' where `x' is some static or non-static member
16347 function name. */
16353 /* Strip baselink information. */
16358 {
16359 /* If we got some explicit template args, we need to plug them into
16360 the affected templates before we try to unify, in case the
16361 explicit args will completely resolve the templates in question. */
16368 {
16381 {
16386 {
16389 }
16390 }
16393 }
16394 /* If no templates (or more than one) are fully resolved by the
16395 explicit arguments, this template-id is a non-deduced context; it
16396 could still be OK if we deduce all template arguments for the
16397 enclosing call through other arguments. */
16400 }
16403 /* If ARG is, for example, "(0, &f)" then its type will be unknown
16404 -- but the deduction does not succeed because the expression is
16405 not just the function on its own. */
16407 else
16413 {
16416 }
16418 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16419 to function or pointer to member function argument if the set of
16420 overloaded functions does not contain function templates and at most
16421 one of a set of overloaded functions provides a unique match.
16423 So if we found multiple possibilities, we return success but don't
16424 deduce anything. */
16427 {
16432 }
16437 }
16439 /* Core DR 115: In contexts where deduction is done and fails, or in
16440 contexts where deduction is not done, if a template argument list is
16441 specified and it, along with any default template arguments, identifies
16442 a single function template specialization, then the template-id is an
16443 lvalue for the function template specialization. */
16445 tree
16447 {
16460 {
16463 }
16465 {
16468 }
16470 {
16473 }
16476 {
16480 /* If we got some explicit template args, we need to plug them into
16481 the affected templates before we try to unify, in case the
16482 explicit args will completely resolve the templates in question. */
16490 {
16503 {
16506 {
16509 }
16511 {
16514 }
16515 }
16516 }
16518 {
16526 {
16527 tree base
16530 }
16534 }
16536 /* There were no good options and at least one bad one, so let the
16537 user know what the problem is. */
16539 }
16541 }
16543 /* Subroutine of resolve_overloaded_unification; does deduction for a single
16544 overload. Fills TARGS with any deduced arguments, or error_mark_node if
16545 different overloads deduce different arguments for a given parm.
16546 ADDR_P is true if the expression for which deduction is being
16547 performed was of the form "& fn" rather than simply "fn".
16549 Returns 1 on success. */
16551 static int
16553 tree orig_targs,
16554 tree targs,
16555 tree parm,
16556 tree arg,
16557 unification_kind_t strict,
16561 {
16563 tree tempargs;
16569 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16570 to function or pointer to member function argument if the set of
16571 overloaded functions does not contain function templates and at most
16572 one of a set of overloaded functions provides a unique match.
16574 So if this is a template, just return success. */
16586 /* We don't copy orig_targs for this because if we have already deduced
16587 some template args from previous args, unify would complain when we
16588 try to deduce a template parameter for the same argument, even though
16589 there isn't really a conflict. */
16596 /* First make sure we didn't deduce anything that conflicts with
16597 explicitly specified args. */
16599 {
16606 /* Since we're unifying against ourselves, we will fill in
16607 template args used in the function parm list with our own
16608 template parms. Discard them. */
16612 }
16615 {
16620 }
16623 }
16625 /* PARM is a template class (perhaps with unbound template
16626 parameters). ARG is a fully instantiated type. If ARG can be
16627 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
16628 TARGS are as for unify. */
16630 static tree
16633 {
16634 tree copy_of_targs;
16641 /* We need to make a new template argument vector for the call to
16642 unify. If we used TARGS, we'd clutter it up with the result of
16643 the attempted unification, even if this class didn't work out.
16644 We also don't want to commit ourselves to all the unifications
16645 we've already done, since unification is supposed to be done on
16646 an argument-by-argument basis. In other words, consider the
16647 following pathological case:
16649 template <int I, int J, int K>
16650 struct S {};
16652 template <int I, int J>
16653 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
16655 template <int I, int J, int K>
16656 void f(S<I, J, K>, S<I, I, I>);
16658 void g() {
16659 S<0, 0, 0> s0;
16660 S<0, 1, 2> s2;
16662 f(s0, s2);
16663 }
16665 Now, by the time we consider the unification involving `s2', we
16666 already know that we must have `f<0, 0, 0>'. But, even though
16667 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
16668 because there are two ways to unify base classes of S<0, 1, 2>
16669 with S<I, I, I>. If we kept the already deduced knowledge, we
16670 would reject the possibility I=1. */
16673 /* If unification failed, we're done. */
16679 }
16681 /* Given a template type PARM and a class type ARG, find the unique
16682 base type in ARG that is an instance of PARM. We do not examine
16683 ARG itself; only its base-classes. If there is not exactly one
16684 appropriate base class, return NULL_TREE. PARM may be the type of
16685 a partial specialization, as well as a plain template type. Used
16686 by unify. */
16688 static enum template_base_result
16691 {
16693 tree binfo;
16699 {
16700 /* The type could not be completed. */
16703 }
16705 /* Walk in inheritance graph order. The search order is not
16706 important, and this avoids multiple walks of virtual bases. */
16708 {
16713 {
16714 /* If there is more than one satisfactory baseclass, then:
16716 [temp.deduct.call]
16718 If they yield more than one possible deduced A, the type
16719 deduction fails.
16721 applies. */
16723 {
16726 }
16729 }
16730 }
16734 }
16736 /* Returns the level of DECL, which declares a template parameter. */
16738 static int
16740 {
16742 {
16752 }
16754 }
16756 /* Decide whether ARG can be unified with PARM, considering only the
16757 cv-qualifiers of each type, given STRICT as documented for unify.
16758 Returns nonzero iff the unification is OK on that basis. */
16760 static int
16762 {
16768 {
16769 /* Although a CVR qualifier is ignored when being applied to a
16770 substituted template parameter ([8.3.2]/1 for example), that
16771 does not allow us to unify "const T" with "int&" because both
16772 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
16773 It is ok when we're allowing additional CV qualifiers
16774 at the outer level [14.8.2.1]/3,1st bullet. */
16784 }
16795 }
16797 /* Determines the LEVEL and INDEX for the template parameter PARM. */
16798 void
16800 {
16804 {
16807 }
16808 else
16809 {
16812 }
16813 }
16815 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
16816 do { \
16817 if (unify (TP, TA, P, A, S, EP)) \
16818 return 1; \
16819 } while (0);
16821 /* Unifies the remaining arguments in PACKED_ARGS with the pack
16822 expansion at the end of PACKED_PARMS. Returns 0 if the type
16823 deduction succeeds, 1 otherwise. STRICT is the same as in
16824 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
16825 call argument list. We'll need to adjust the arguments to make them
16826 types. SUBR tells us if this is from a recursive call to
16827 type_unification_real, or for comparing two template argument
16828 lists. */
16830 static int
16834 {
16835 tree parm
16842 /* Determine the parameter packs we will be deducing from the
16843 pattern, and record their current deductions. */
16846 {
16850 /* Determine the index and level of this parameter pack. */
16853 /* Keep track of the parameter packs and their corresponding
16854 argument packs. */
16857 }
16859 /* Loop through all of the arguments that have not yet been
16860 unified and unify each with the pattern. */
16862 {
16863 tree parm;
16867 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
16868 or the element of its argument pack at the current index if
16869 this argument was explicitly specified. */
16871 {
16880 {
16883 }
16885 }
16887 /* If we had explicit template arguments, substitute them into the
16888 pattern before deduction. */
16890 {
16891 /* Some arguments might still be unspecified or dependent. */
16899 NULL_TREE);
16904 }
16905 else
16908 /* Unify the pattern with the current argument. */
16913 /* For each parameter pack, collect the deduced value. */
16915 {
16921 }
16922 }
16924 /* Verify that the results of unification with the parameter packs
16925 produce results consistent with what we've seen before, and make
16926 the deduced argument packs available. */
16928 {
16935 /* By default keep the original deduced argument pack.
16936 If necessary, more specific code is going to update the
16937 resulting deduced argument later down in this function. */
16941 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
16942 actually deduce anything. */
16950 {
16951 /* If we had fewer function args than explicit template args,
16952 just use the explicits. */
16957 }
16960 {
16961 tree result;
16962 /* Build the deduced *_ARGUMENT_PACK. */
16964 {
16969 }
16970 else
16975 /* Note the deduced argument packs for this parameter
16976 pack. */
16978 }
16982 {
16983 /* We only had the explicitly-provided arguments before, but
16984 now we have a complete set of arguments. */
16990 }
16991 else
16992 {
16998 /* Inconsistent unification of this parameter pack. */
17000 bad_old_arg,
17001 bad_new_arg);
17002 }
17003 }
17006 }
17008 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
17009 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
17010 parameters and return value are as for unify. */
17012 static int
17016 {
17017 tree parm_max;
17018 tree arg_max;
17022 /* Our representation of array types uses "N - 1" as the
17023 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
17024 not an integer constant. We cannot unify arbitrarily
17025 complex expressions, so we eliminate the MINUS_EXPRs
17026 here. */
17030 {
17033 }
17037 {
17038 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
17039 trying to unify the type of a variable with the type
17040 of a template parameter. For example:
17042 template <unsigned int N>
17043 void f (char (&) [N]);
17044 int g();
17045 void h(int i) {
17046 char a[g(i)];
17047 f(a);
17048 }
17050 Here, the type of the ARG will be "int [g(i)]", and
17051 may be a SAVE_EXPR, etc. */
17055 }
17057 /* If only one of the bounds used a MINUS_EXPR, compensate
17058 by adding one to the other bound. */
17061 integer_type_node,
17062 parm_max,
17063 integer_one_node);
17066 integer_type_node,
17067 arg_max,
17068 integer_one_node);
17072 }
17074 /* Deduce the value of template parameters. TPARMS is the (innermost)
17075 set of template parameters to a template. TARGS is the bindings
17076 for those template parameters, as determined thus far; TARGS may
17077 include template arguments for outer levels of template parameters
17078 as well. PARM is a parameter to a template function, or a
17079 subcomponent of that parameter; ARG is the corresponding argument.
17080 This function attempts to match PARM with ARG in a manner
17081 consistent with the existing assignments in TARGS. If more values
17082 are deduced, then TARGS is updated.
17084 Returns 0 if the type deduction succeeds, 1 otherwise. The
17085 parameter STRICT is a bitwise or of the following flags:
17087 UNIFY_ALLOW_NONE:
17088 Require an exact match between PARM and ARG.
17089 UNIFY_ALLOW_MORE_CV_QUAL:
17090 Allow the deduced ARG to be more cv-qualified (by qualification
17091 conversion) than ARG.
17092 UNIFY_ALLOW_LESS_CV_QUAL:
17093 Allow the deduced ARG to be less cv-qualified than ARG.
17094 UNIFY_ALLOW_DERIVED:
17095 Allow the deduced ARG to be a template base class of ARG,
17096 or a pointer to a template base class of the type pointed to by
17097 ARG.
17098 UNIFY_ALLOW_INTEGER:
17099 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
17100 case for more information.
17101 UNIFY_ALLOW_OUTER_LEVEL:
17102 This is the outermost level of a deduction. Used to determine validity
17103 of qualification conversions. A valid qualification conversion must
17104 have const qualified pointers leading up to the inner type which
17105 requires additional CV quals, except at the outer level, where const
17106 is not required [conv.qual]. It would be normal to set this flag in
17107 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
17108 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
17109 This is the outermost level of a deduction, and PARM can be more CV
17110 qualified at this point.
17111 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
17112 This is the outermost level of a deduction, and PARM can be less CV
17113 qualified at this point. */
17115 static int
17118 {
17120 tree targ;
17121 tree tparm;
17124 /* I don't think this will do the right thing with respect to types.
17125 But the only case I've seen it in so far has been array bounds, where
17126 signedness is the only information lost, and I think that will be
17127 okay. */
17135 /* We can't deduce anything from this, but we might get all the
17136 template args from other function args. */
17139 /* If PARM uses template parameters, then we can't bail out here,
17140 even if ARG == PARM, since we won't record unifications for the
17141 template parameters. We might need them if we're trying to
17142 figure out which of two things is more specialized. */
17146 /* Handle init lists early, so the rest of the function can assume
17147 we're dealing with a type. */
17149 {
17154 /* Replace T with std::initializer_list<T> for deduction. */
17161 /* We can only deduce from an initializer list argument if the
17162 parameter is std::initializer_list or an array; otherwise this
17163 is a non-deduced context. */
17168 else
17172 {
17179 {
17181 /* It should only be possible to get here for a call. */
17183 elt_strict |= maybe_adjust_types_for_deduction
17186 }
17189 explain_p);
17190 }
17193 {
17194 /* Also deduce from the length of the initializer list. */
17199 }
17201 /* If the std::initializer_list<T> deduction worked, replace the
17202 deduced A with std::initializer_list<A>. */
17204 {
17209 }
17211 }
17213 /* Immediately reject some pairs that won't unify because of
17214 cv-qualification mismatches. */
17217 /* It is the elements of the array which hold the cv quals of an array
17218 type, and the elements might be template type parms. We'll check
17219 when we recurse. */
17221 /* We check the cv-qualifiers when unifying with template type
17222 parameters below. We want to allow ARG `const T' to unify with
17223 PARM `T' for example, when computing which of two templates
17224 is more specialized, for example. */
17238 {
17242 /* In a type which contains a nested-name-specifier, template
17243 argument values cannot be deduced for template parameters used
17244 within the nested-name-specifier. */
17256 /* The PARM is not one we're trying to unify. Just check
17257 to see if it matches ARG. */
17258 {
17263 else
17265 }
17272 /* Check for mixed types and values. */
17280 {
17281 /* ARG must be constructed from a template class or a template
17282 template parameter. */
17287 {
17291 tree parm_parms
17292 = DECL_INNERMOST_TEMPLATE_PARMS
17297 /* The resolution to DR150 makes clear that default
17298 arguments for an N-argument may not be used to bind T
17299 to a template template parameter with fewer than N
17300 parameters. It is not safe to permit the binding of
17301 default arguments as an extension, as that may change
17302 the meaning of a conforming program. Consider:
17304 struct Dense { static const unsigned int dim = 1; };
17306 template <template <typename> class View,
17307 typename Block>
17308 void operator+(float, View<Block> const&);
17310 template <typename Block,
17311 unsigned int Dim = Block::dim>
17312 struct Lvalue_proxy { operator float() const; };
17314 void
17315 test_1d (void) {
17316 Lvalue_proxy<Dense> p;
17317 float b;
17318 b + p;
17319 }
17321 Here, if Lvalue_proxy is permitted to bind to View, then
17322 the global operator+ will be used; if they are not, the
17323 Lvalue_proxy will be converted to float. */
17325 full_argvec,
17327 (explain_p
17328 ? tf_warning_or_error
17335 /* Deduce arguments T, i from TT<T> or TT<i>.
17336 We check each element of PARMVEC and ARGVEC individually
17337 rather than the whole TREE_VEC since they can have
17338 different number of elements. */
17345 /* Check if the parameters end in a pack, making them
17346 variadic. */
17352 /* If the template argument list of P contains a pack
17353 expansion that is not the last template argument, the
17354 entire template argument list is a non-deduced
17355 context. */
17364 {
17369 }
17374 DEDUCE_EXACT,
17377 }
17380 /* Fall through to deduce template name. */
17381 }
17385 {
17386 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
17388 /* Simple cases: Value already set, does match or doesn't. */
17393 }
17394 else
17395 {
17396 /* If PARM is `const T' and ARG is only `int', we don't have
17397 a match unless we are allowing additional qualification.
17398 If ARG is `const int' and PARM is just `T' that's OK;
17399 that binds `const int' to `T'. */
17404 /* Consider the case where ARG is `const volatile int' and
17405 PARM is `const T'. Then, T should be `volatile int'. */
17406 arg = cp_build_qualified_type_real
17411 /* Simple cases: Value already set, does match or doesn't. */
17417 /* Make sure that ARG is not a variable-sized array. (Note
17418 that were talking about variable-sized arrays (like
17419 `int[n]'), rather than arrays of unknown size (like
17420 `int[]').) We'll get very confused by such a type since
17421 the bound of the array is not constant, and therefore
17422 not mangleable. Besides, such types are not allowed in
17423 ISO C++, so we can do as we please here. We do allow
17424 them for 'auto' deduction, since that isn't ABI-exposed. */
17428 /* Strip typedefs as in convert_template_argument. */
17430 }
17432 /* If ARG is a parameter pack or an expansion, we cannot unify
17433 against it unless PARM is also a parameter pack. */
17438 /* If the argument deduction results is a METHOD_TYPE,
17439 then there is a problem.
17440 METHOD_TYPE doesn't map to any real C++ type the result of
17441 the deduction can not be of that type. */
17455 {
17456 /* The PARM is not one we're trying to unify. Just check
17457 to see if it matches ARG. */
17463 }
17469 {
17474 }
17476 /* [temp.deduct.type] If, in the declaration of a function template
17477 with a non-type template-parameter, the non-type
17478 template-parameter is used in an expression in the function
17479 parameter-list and, if the corresponding template-argument is
17480 deduced, the template-argument type shall match the type of the
17481 template-parameter exactly, except that a template-argument
17482 deduced from an array bound may be of any integral type.
17483 The non-type parameter might use already deduced type parameters. */
17486 /* Template-parameter dependent expression. Just accept it for now.
17487 It will later be processed in convert_template_argument. */
17488 ;
17493 /* Convert the ARG to the type of PARM; the deduced non-type
17494 template argument must exactly match the types of the
17495 corresponding parameter. */
17498 /* We haven't deduced the type of this parameter yet. Try again
17499 later. */
17501 else
17504 /* If ARG is a parameter pack or an expansion, we cannot unify
17505 against it unless PARM is also a parameter pack. */
17515 {
17516 /* A pointer-to-member constant can be unified only with
17517 another constant. */
17521 /* Just unify the class member. It would be useless (and possibly
17522 wrong, depending on the strict flags) to unify also
17523 PTRMEM_CST_CLASS, because we want to be sure that both parm and
17524 arg refer to the same variable, even if through different
17525 classes. For instance:
17527 struct A { int x; };
17528 struct B : A { };
17530 Unification of &A::x and &B::x must succeed. */
17533 }
17536 {
17540 /* [temp.deduct.call]
17542 A can be another pointer or pointer to member type that can
17543 be converted to the deduced A via a qualification
17544 conversion (_conv.qual_).
17546 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
17547 This will allow for additional cv-qualification of the
17548 pointed-to types if appropriate. */
17551 /* The derived-to-base conversion only persists through one
17552 level of pointers. */
17557 }
17589 /* We have already checked cv-qualification at the top of the
17590 function. */
17594 /* As far as unification is concerned, this wins. Later checks
17595 will invalidate it if necessary. */
17598 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
17599 /* Type INTEGER_CST can come from ordinary constant template args. */
17611 {
17621 /* Check for pack expansions in the parameters. */
17623 {
17625 {
17627 /* We can unify against something with a trailing
17628 parameter pack. */
17630 else
17631 /* [temp.deduct.type]/9: If the template argument list of
17632 P contains a pack expansion that is not the last
17633 template argument, the entire template argument list
17634 is a non-deduced context. */
17636 }
17637 }
17639 /* If we don't have enough arguments to satisfy the parameters
17640 (not counting the pack expression at the end), or we have
17641 too many arguments for a parameter list that doesn't end in
17642 a pack expression, we can't unify. */
17648 /* Unify all of the parameters that precede the (optional)
17649 pack expression. */
17651 {
17656 }
17659 DEDUCE_EXACT,
17662 }
17670 {
17678 }
17681 {
17685 {
17686 /* First, we try to unify the PARM and ARG directly. */
17691 {
17692 /* Fallback to the special case allowed in
17693 [temp.deduct.call]:
17695 If P is a class, and P has the form
17696 template-id, then A can be a derived class of
17697 the deduced A. Likewise, if P is a pointer to
17698 a class of the form template-id, A can be a
17699 pointer to a derived class pointed to by the
17700 deduced A. */
17707 }
17708 }
17712 /* Perhaps PARM is something like S<U> and ARG is S<int>.
17713 Then, we should unify `int' and `U'. */
17715 else
17716 /* There's no chance of unification succeeding. */
17721 }
17728 {
17731 tree a;
17737 /* CV qualifications for methods can never be deduced, they must
17738 match exactly. We need to check them explicitly here,
17739 because type_unification_real treats them as any other
17740 cv-qualified parameter. */
17742 && (!check_cv_quals_for_unify
17762 }
17765 /* Unify a pointer to member with a pointer to member function, which
17766 deduces the type of the member as a function type. */
17768 {
17769 /* Check top-level cv qualifiers */
17777 /* Determine the type of the function we are unifying against. */
17781 }
17800 /* Matched cases are handled by the ARG == PARM test above. */
17804 /* A non-type template parameter that is a variable should be a
17805 an integral constant, in which case, it whould have been
17806 folded into its (constant) value. So we should not be getting
17807 a variable here. */
17818 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
17819 or UNDERLYING_TYPE nodes. */
17823 /* Unification fails if we hit an error node. */
17827 /* An unresolved overload is a nondeduced context. */
17832 /* We must be looking at an expression. This can happen with
17833 something like:
17835 template <int I>
17836 void foo(S<I>, S<I + 2>);
17838 This is a "nondeduced context":
17840 [deduct.type]
17842 The nondeduced contexts are:
17844 --A type that is a template-id in which one or more of
17845 the template-arguments is an expression that references
17846 a template-parameter.
17848 In these cases, we assume deduction succeeded, but don't
17849 actually infer any unifications. */
17854 else
17856 }
17857 }
17858 #undef RECUR_AND_CHECK_FAILURE
17859 \f
17860 /* Note that DECL can be defined in this translation unit, if
17861 required. */
17863 static void
17865 {
17866 tree clone;
17870 }
17872 /* Called if RESULT is explicitly instantiated, or is a member of an
17873 explicitly instantiated class. */
17875 void
17877 {
17880 /* If this entity has already been written out, it's too late to
17881 make any modifications. */
17885 /* For anonymous namespace we don't need to do anything. */
17887 {
17890 }
17893 /* The TREE_PUBLIC flag for function declarations will have been
17894 set correctly by tsubst. */
17897 /* This might have been set by an earlier implicit instantiation. */
17902 else
17903 {
17905 /* Always make artificials weak. */
17908 /* For WIN32 we also want to put explicit instantiations in
17909 linkonce sections. */
17912 }
17914 /* If EXTERN_P, then this function will not be emitted -- unless
17915 followed by an explicit instantiation, at which point its linkage
17916 will be adjusted. If !EXTERN_P, then this function will be
17917 emitted here. In neither circumstance do we want
17918 import_export_decl to adjust the linkage. */
17920 }
17922 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
17923 important template arguments. If any are missing, we check whether
17924 they're important by using error_mark_node for substituting into any
17925 args that were used for partial ordering (the ones between ARGS and END)
17926 and seeing if it bubbles up. */
17928 static bool
17930 {
17935 {
17938 }
17940 {
17944 }
17946 }
17948 /* Given two function templates PAT1 and PAT2, return:
17950 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
17951 -1 if PAT2 is more specialized than PAT1.
17952 0 if neither is more specialized.
17954 LEN indicates the number of parameters we should consider
17955 (defaulted parameters should not be considered).
17957 The 1998 std underspecified function template partial ordering, and
17958 DR214 addresses the issue. We take pairs of arguments, one from
17959 each of the templates, and deduce them against each other. One of
17960 the templates will be more specialized if all the *other*
17961 template's arguments deduce against its arguments and at least one
17962 of its arguments *does* *not* deduce against the other template's
17963 corresponding argument. Deduction is done as for class templates.
17964 The arguments used in deduction have reference and top level cv
17965 qualifiers removed. Iff both arguments were originally reference
17966 types *and* deduction succeeds in both directions, an lvalue reference
17967 wins against an rvalue reference and otherwise the template
17968 with the more cv-qualified argument wins for that pairing (if
17969 neither is more cv-qualified, they both are equal). Unlike regular
17970 deduction, after all the arguments have been deduced in this way,
17971 we do *not* verify the deduced template argument values can be
17972 substituted into non-deduced contexts.
17974 The logic can be a bit confusing here, because we look at deduce1 and
17975 targs1 to see if pat2 is at least as specialized, and vice versa; if we
17976 can find template arguments for pat1 to make arg1 look like arg2, that
17977 means that arg2 is at least as specialized as arg1. */
17979 int
17981 {
17994 /* Remove the this parameter from non-static member functions. If
17995 one is a non-static member function and the other is not a static
17996 member function, remove the first parameter from that function
17997 also. This situation occurs for operator functions where we
17998 locate both a member function (with this pointer) and non-member
17999 operator (with explicit first operand). */
18001 {
18006 }
18008 {
18011 {
18012 len--;
18014 }
18015 }
18017 /* If only one is a conversion operator, they are unordered. */
18021 /* Consider the return type for a conversion function */
18023 {
18026 len++;
18027 }
18029 processing_template_decl++;
18035 /* Stop when an ellipsis is seen. */
18037 {
18048 {
18049 /* When both arguments are pack expansions, we need only
18050 unify the patterns themselves. */
18054 /* This is the last comparison we need to do. */
18056 }
18059 {
18063 }
18066 {
18070 }
18076 {
18082 /* Setup the parameter vector, which contains only ARG1. */
18085 /* Setup the argument vector, which contains the remaining
18086 arguments. */
18095 /* We cannot deduce in the other direction, because ARG1 is
18096 a pack expansion but ARG2 is not. */
18098 }
18100 {
18106 /* Setup the parameter vector, which contains only ARG1. */
18109 /* Setup the argument vector, which contains the remaining
18110 arguments. */
18119 /* We cannot deduce in the other direction, because ARG2 is
18120 a pack expansion but ARG1 is not.*/
18122 }
18124 else
18125 {
18126 /* The normal case, where neither argument is a pack
18127 expansion. */
18134 }
18136 /* If we couldn't deduce arguments for tparms1 to make arg1 match
18137 arg2, then arg2 is not as specialized as arg1. */
18143 /* "If, for a given type, deduction succeeds in both directions
18144 (i.e., the types are identical after the transformations above)
18145 and both P and A were reference types (before being replaced with
18146 the type referred to above):
18147 - if the type from the argument template was an lvalue reference and
18148 the type from the parameter template was not, the argument type is
18149 considered to be more specialized than the other; otherwise,
18150 - if the type from the argument template is more cv-qualified
18151 than the type from the parameter template (as described above),
18152 the argument type is considered to be more specialized than the other;
18153 otherwise,
18154 - neither type is more specialized than the other." */
18157 {
18159 {
18162 else
18164 }
18166 {
18171 }
18172 }
18175 /* We've failed to deduce something in either direction.
18176 These must be unordered. */
18181 /* We have already processed all of the arguments in our
18182 handing of the pack expansion type. */
18187 }
18189 /* "In most cases, all template parameters must have values in order for
18190 deduction to succeed, but for partial ordering purposes a template
18191 parameter may remain without a value provided it is not used in the
18192 types being used for partial ordering."
18194 Thus, if we are missing any of the targs1 we need to substitute into
18195 origs1, then pat2 is not as specialized as pat1. This can happen when
18196 there is a nondeduced context. */
18202 processing_template_decl--;
18204 /* All things being equal, if the next argument is a pack expansion
18205 for one function but not for the other, prefer the
18206 non-variadic function. FIXME this is bogus; see c++/41958. */
18210 {
18213 }
18219 else
18221 }
18223 /* Determine which of two partial specializations of MAIN_TMPL is more
18224 specialized.
18226 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
18227 to the first partial specialization. The TREE_VALUE is the
18228 innermost set of template parameters for the partial
18229 specialization. PAT2 is similar, but for the second template.
18231 Return 1 if the first partial specialization is more specialized;
18232 -1 if the second is more specialized; 0 if neither is more
18233 specialized.
18235 See [temp.class.order] for information about determining which of
18236 two templates is more specialized. */
18238 static int
18240 {
18241 tree targs;
18249 /* Just like what happens for functions, if we are ordering between
18250 different class template specializations, we may encounter dependent
18251 types in the arguments, and we need our dependency check functions
18252 to behave correctly. */
18258 {
18261 }
18267 {
18270 }
18273 /* In the case of a tie where at least one of the class templates
18274 has a parameter pack at the end, the template with the most
18275 non-packed parameters wins. */
18277 && any_deductions
18280 {
18286 /* We don't count the pack expansion at the end. */
18296 }
18299 }
18301 /* Return the template arguments that will produce the function signature
18302 DECL from the function template FN, with the explicit template
18303 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
18304 also match. Return NULL_TREE if no satisfactory arguments could be
18305 found. */
18307 static tree
18309 {
18313 tree decl_arg_types;
18316 tree arg;
18320 /* Never do unification on the 'this' parameter. */
18341 }
18343 /* Return the innermost template arguments that, when applied to a partial
18344 specialization of MAIN_TMPL whose innermost template parameters are
18345 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
18346 ARGS.
18348 For example, suppose we have:
18350 template <class T, class U> struct S {};
18351 template <class T> struct S<T*, int> {};
18353 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
18354 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
18355 int}. The resulting vector will be {double}, indicating that `T'
18356 is bound to `double'. */
18358 static tree
18360 {
18362 tree deduced_args;
18363 tree innermost_deduced_args;
18367 {
18371 innermost_deduced_args);
18372 }
18373 else
18386 /* Verify that nondeduced template arguments agree with the type
18387 obtained from argument deduction.
18389 For example:
18391 struct A { typedef int X; };
18392 template <class T, class U> struct C {};
18393 template <class T> struct C<T, typename T::X> {};
18395 Then with the instantiation `C<A, int>', we can deduce that
18396 `T' is `A' but unify () does not check whether `typename T::X'
18397 is `int'. */
18403 /* We only need to check the innermost arguments; the other
18404 arguments will always agree. */
18409 /* Now that we have bindings for all of the template arguments,
18410 ensure that the arguments deduced for the template template
18411 parameters have compatible template parameter lists. See the use
18412 of template_template_parm_bindings_ok_p in fn_type_unification
18413 for more information. */
18418 }
18420 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
18421 Return the TREE_LIST node with the most specialized template, if
18422 any. If there is no most specialized template, the error_mark_node
18423 is returned.
18425 Note that this function does not look at, or modify, the
18426 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
18427 returned is one of the elements of INSTANTIATIONS, callers may
18428 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
18429 and retrieve it from the value returned. */
18431 tree
18433 {
18440 {
18446 fate--;
18451 fate++;
18456 {
18457 /* Equally specialized, move to next function. If there
18458 is no next function, nothing's most specialized. */
18463 }
18464 }
18467 /* Now verify that champ is better than everything earlier in the
18468 instantiation list. */
18476 {
18479 }
18481 processing_template_decl--;
18487 }
18489 /* If DECL is a specialization of some template, return the most
18490 general such template. Otherwise, returns NULL_TREE.
18492 For example, given:
18494 template <class T> struct S { template <class U> void f(U); };
18496 if TMPL is `template <class U> void S<int>::f(U)' this will return
18497 the full template. This function will not trace past partial
18498 specializations, however. For example, given in addition:
18500 template <class T> struct S<T*> { template <class U> void f(U); };
18502 if TMPL is `template <class U> void S<int*>::f(U)' this will return
18503 `template <class T> template <class U> S<T*>::f(U)'. */
18505 tree
18507 {
18508 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
18509 an immediate specialization. */
18511 {
18515 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
18516 template friend. */
18521 }
18523 /* Look for more and more general templates. */
18525 {
18526 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
18527 (See cp-tree.h for details.) */
18535 /* Stop if we run into an explicitly specialized class template. */
18542 }
18545 }
18547 /* Return the most specialized of the class template partial
18548 specializations of TMPL which can produce TYPE, a specialization of
18549 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
18550 a _TYPE node corresponding to the partial specialization, while the
18551 TREE_PURPOSE is the set of template arguments that must be
18552 substituted into the TREE_TYPE in order to generate TYPE.
18554 If the choice of partial specialization is ambiguous, a diagnostic
18555 is issued, and the error_mark_node is returned. If there are no
18556 partial specializations of TMPL matching TYPE, then NULL_TREE is
18557 returned. */
18559 static tree
18561 {
18563 tree t;
18564 tree champ;
18567 tree args;
18573 /* For determining which partial specialization to use, only the
18574 innermost args are interesting. */
18576 {
18579 }
18582 {
18583 tree partial_spec_args;
18584 tree spec_args;
18593 {
18594 /* Discard the outer levels of args, and then substitute in the
18595 template args from the enclosing class. */
18597 partial_spec_args = tsubst_template_args
18600 /* And the same for the partial specialization TEMPLATE_DECL. */
18602 }
18604 partial_spec_args =
18607 partial_spec_args),
18621 partial_spec_args,
18622 args);
18624 {
18629 }
18630 }
18640 {
18643 ;
18644 else
18645 {
18647 {
18650 {
18653 }
18654 }
18656 }
18657 }
18661 {
18664 {
18667 }
18668 }
18671 {
18679 {
18682 }
18685 }
18688 }
18690 /* Explicitly instantiate DECL. */
18692 void
18694 {
18699 /* An error occurred, for which grokdeclarator has already issued
18700 an appropriate message. */
18703 {
18706 }
18708 {
18709 /* There is an asymmetry here in the way VAR_DECLs and
18710 FUNCTION_DECLs are handled by grokdeclarator. In the case of
18711 the latter, the DECL we get back will be marked as a
18712 template instantiation, and the appropriate
18713 DECL_TEMPLATE_INFO will be set up. This does not happen for
18714 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
18715 should handle VAR_DECLs as it currently handles
18716 FUNCTION_DECLs. */
18718 {
18721 }
18724 {
18727 }
18729 {
18734 }
18735 }
18737 {
18740 }
18741 else
18744 /* Check for various error cases. Note that if the explicit
18745 instantiation is valid the RESULT will currently be marked as an
18746 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
18747 until we get here. */
18750 {
18751 /* DR 259 [temp.spec].
18753 Both an explicit instantiation and a declaration of an explicit
18754 specialization shall not appear in a program unless the explicit
18755 instantiation follows a declaration of the explicit specialization.
18757 For a given set of template parameters, if an explicit
18758 instantiation of a template appears after a declaration of an
18759 explicit specialization for that template, the explicit
18760 instantiation has no effect. */
18762 }
18764 {
18765 /* [temp.spec]
18767 No program shall explicitly instantiate any template more
18768 than once.
18770 We check DECL_NOT_REALLY_EXTERN so as not to complain when
18771 the first instantiation was `extern' and the second is not,
18772 and EXTERN_P for the opposite case. */
18775 /* If an "extern" explicit instantiation follows an ordinary
18776 explicit instantiation, the template is instantiated. */
18779 }
18781 {
18784 }
18786 {
18789 }
18792 ;
18794 {
18797 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
18800 }
18801 else
18809 }
18811 static void
18813 {
18819 {
18822 }
18823 }
18825 /* Called from do_type_instantiation through binding_table_foreach to
18826 do recursive instantiation for the type bound in ENTRY. */
18827 static void
18829 {
18835 }
18837 /* Called from do_type_instantiation to instantiate a member
18838 (a member function or a static member variable) of an
18839 explicitly instantiated class template. */
18840 static void
18842 {
18847 }
18849 /* Perform an explicit instantiation of template class T. STORAGE, if
18850 non-null, is the RID for extern, inline or static. COMPLAIN is
18851 nonzero if this is called from the parser, zero if called recursively,
18852 since the standard is unclear (as detailed below). */
18854 void
18856 {
18866 {
18867 tree tmpl =
18871 else
18874 }
18879 {
18882 t);
18884 }
18887 {
18889 {
18891 {
18894 "ISO C++ 1998 forbids the use of %<extern%> on "
18896 }
18897 else
18899 "ISO C++ forbids the use of %qE"
18901 }
18909 else
18910 {
18912 storage);
18914 }
18915 }
18918 {
18919 /* DR 259 [temp.spec].
18921 Both an explicit instantiation and a declaration of an explicit
18922 specialization shall not appear in a program unless the explicit
18923 instantiation follows a declaration of the explicit specialization.
18925 For a given set of template parameters, if an explicit
18926 instantiation of a template appears after a declaration of an
18927 explicit specialization for that template, the explicit
18928 instantiation has no effect. */
18930 }
18932 {
18933 /* [temp.spec]
18935 No program shall explicitly instantiate any template more
18936 than once.
18938 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
18939 instantiation was `extern'. If EXTERN_P then the second is.
18940 These cases are OK. */
18947 /* If we've already instantiated the template, just return now. */
18950 }
18958 {
18959 tree tmp;
18961 /* In contrast to implicit instantiation, where only the
18962 declarations, and not the definitions, of members are
18963 instantiated, we have here:
18965 [temp.explicit]
18967 The explicit instantiation of a class template specialization
18968 implies the instantiation of all of its members not
18969 previously explicitly specialized in the translation unit
18970 containing the explicit instantiation.
18972 Of course, we can't instantiate member template classes, since
18973 we don't have any arguments for them. Note that the standard
18974 is unclear on whether the instantiation of the members are
18975 *explicit* instantiations or not. However, the most natural
18976 interpretation is that it should be an explicit instantiation. */
18991 }
18992 }
18994 /* Given a function DECL, which is a specialization of TMPL, modify
18995 DECL to be a re-instantiation of TMPL with the same template
18996 arguments. TMPL should be the template into which tsubst'ing
18997 should occur for DECL, not the most general template.
18999 One reason for doing this is a scenario like this:
19001 template <class T>
19002 void f(const T&, int i);
19004 void g() { f(3, 7); }
19006 template <class T>
19007 void f(const T& t, const int i) { }
19009 Note that when the template is first instantiated, with
19010 instantiate_template, the resulting DECL will have no name for the
19011 first parameter, and the wrong type for the second. So, when we go
19012 to instantiate the DECL, we regenerate it. */
19014 static void
19016 {
19017 /* The arguments used to instantiate DECL, from the most general
19018 template. */
19019 tree args;
19020 tree code_pattern;
19025 /* Make sure that we can see identifiers, and compute access
19026 correctly. */
19030 {
19031 tree decl_parm;
19032 tree pattern_parm;
19033 tree specs;
19047 specs);
19049 /* Merge parameter declarations. */
19052 pattern_parm
19056 {
19057 tree parm_type;
19058 tree attributes;
19063 NULL_TREE);
19069 {
19072 }
19075 }
19076 /* Merge any parameters that match with the function parameter
19077 pack. */
19079 {
19081 tree expanded_types;
19082 /* Expand the TYPE_PACK_EXPANSION that provides the types for
19083 the parameters in this function parameter pack. */
19088 {
19089 tree parm_type;
19090 tree attributes;
19093 /* Rename the parameter to include the index. */
19102 {
19105 }
19107 }
19108 }
19109 /* Merge additional specifiers from the CODE_PATTERN. */
19113 }
19115 {
19123 }
19124 else
19128 }
19130 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
19131 substituted to get DECL. */
19133 tree
19135 {
19138 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
19139 for the instantiation. This is not always the most general
19140 template. Consider, for example:
19142 template <class T>
19143 struct S { template <class U> void f();
19144 template <> void f<int>(); };
19146 and an instantiation of S<double>::f<int>. We want TD to be the
19147 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
19149 more general template. */
19151 /* We must also deal with friend templates. Given:
19153 template <class T> struct S {
19154 template <class U> friend void f() {};
19155 };
19157 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
19158 so far as the language is concerned, but that's still
19159 where we get the pattern for the instantiation from. On
19160 other hand, if the definition comes outside the class, say:
19162 template <class T> struct S {
19163 template <class U> friend void f();
19164 };
19165 template <class U> friend void f() {}
19167 we don't need to look any further. That's what the check for
19168 DECL_INITIAL is for. */
19172 {
19173 /* The present template, TD, should not be a definition. If it
19174 were a definition, we should be using it! Note that we
19175 cannot restructure the loop to just keep going until we find
19176 a template with a definition, since that might go too far if
19177 a specialization was declared, but not defined. */
19181 /* Fetch the more general template. */
19183 }
19186 }
19188 /* Returns true if we need to instantiate this template instance even if we
19189 know we aren't going to emit it.. */
19191 bool
19193 {
19194 /* We always instantiate inline functions so that we can inline them. An
19195 explicit instantiation declaration prohibits implicit instantiation of
19196 non-inline functions. With high levels of optimization, we would
19197 normally inline non-inline functions -- but we're not allowed to do
19198 that for "extern template" functions. Therefore, we check
19199 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
19203 /* And we need to instantiate static data members so that
19204 their initializers are available in integral constant
19205 expressions. */
19208 }
19210 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
19211 instantiate it now, modifying TREE_TYPE (fn). */
19213 void
19215 {
19229 {
19231 {
19246 }
19247 else
19249 }
19250 else
19251 {
19252 /* This is an implicitly declared function, so NOEX is a list of
19253 other functions to evaluate and merge. */
19254 tree elt;
19257 {
19259 tree subspec;
19263 }
19264 }
19269 {
19272 else
19274 }
19275 }
19277 /* Produce the definition of D, a _DECL generated from a template. If
19278 DEFER_OK is nonzero, then we don't have to actually do the
19279 instantiation now; we just have to do it sometime. Normally it is
19280 an error if this is an explicit instantiation but D is undefined.
19281 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
19282 explicitly instantiated class template. */
19284 tree
19287 {
19289 tree gen_args;
19290 tree args;
19291 tree td;
19292 tree code_pattern;
19293 tree spec;
19294 tree gen_tmpl;
19300 tree fn_context;
19303 /* This function should only be used to instantiate templates for
19304 functions and static member variables. */
19307 /* Variables are never deferred; if instantiation is required, they
19308 are instantiated right away. That allows for better code in the
19309 case that an expression refers to the value of the variable --
19310 if the variable has a constant value the referring expression can
19311 take advantage of that fact. */
19316 /* Don't instantiate cloned functions. Instead, instantiate the
19317 functions they cloned. */
19325 /* D has already been instantiated or explicitly specialized, so
19326 there's nothing for us to do here.
19328 It might seem reasonable to check whether or not D is an explicit
19329 instantiation, and, if so, stop here. But when an explicit
19330 instantiation is deferred until the end of the compilation,
19331 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
19332 the instantiation. */
19335 /* Check to see whether we know that this template will be
19336 instantiated in some other file, as with "extern template"
19337 extension. */
19340 /* In general, we do not instantiate such templates. */
19348 /* We should already have the extra args. */
19351 /* And what's in the hash table should match D. */
19355 /* This needs to happen before any tsubsting. */
19361 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
19362 for the instantiation. */
19366 /* We should never be trying to instantiate a member of a class
19367 template or partial specialization. */
19372 /* In the case of a friend template whose definition is provided
19373 outside the class, we may have too many arguments. Drop the
19374 ones we don't need. The same is true for specializations. */
19375 args = get_innermost_template_args
19377 else
19383 else
19386 /* We may be in the middle of deferred access check. Disable it now. */
19389 /* Unless an explicit instantiation directive has already determined
19390 the linkage of D, remember that a definition is available for
19391 this entity. */
19401 /* If D is a member of an explicitly instantiated class template,
19402 and no definition is available, treat it like an implicit
19403 instantiation. */
19406 {
19407 /* Leave linkage flags alone on instantiations with anonymous
19408 visibility. */
19410 {
19413 }
19415 }
19420 /* Defer all other templates, unless we have been explicitly
19421 forbidden from doing so. */
19423 template. */
19424 ! pattern_defined
19425 /* If it's OK to postpone instantiation, do so. */
19426 || defer_ok
19427 /* If this is a static data member that will be defined
19428 elsewhere, we don't want to instantiate the entire data
19429 member, but we do want to instantiate the initializer so that
19430 we can substitute that elsewhere. */
19432 {
19433 /* The definition of the static data member is now required so
19434 we must substitute the initializer. */
19438 {
19439 tree ns;
19440 tree init;
19447 args,
19450 /* Make sure the initializer is still constant, in case of
19451 circular dependency (template/instantiate6.C). */
19452 const_init
19456 LOOKUP_ONLYCONVERTING);
19459 }
19461 /* We restore the source position here because it's used by
19462 add_pending_template. */
19468 /* [temp.explicit]
19470 The definition of a non-exported function template, a
19471 non-exported member function template, or a non-exported
19472 member function or static data member of a class template
19473 shall be present in every translation unit in which it is
19474 explicitly instantiated. */
19478 /* If we're in unevaluated context, we just wanted to get the
19479 constant value; this isn't an odr use, so don't queue
19480 a full instantiation. */
19483 /* ??? Historically, we have instantiated inline functions, even
19484 when marked as "extern template". */
19488 }
19489 /* Tell the repository that D is available in this translation unit
19490 -- and see if it is supposed to be instantiated here. */
19492 {
19493 /* In a PCH file, despite the fact that the repository hasn't
19494 requested instantiation in the PCH it is still possible that
19495 an instantiation will be required in a file that includes the
19496 PCH. */
19499 /* Instantiate inline functions so that the inliner can do its
19500 job, even though we'll not be emitting a copy of this
19501 function. */
19504 }
19510 else
19511 {
19516 }
19518 /* Mark D as instantiated so that recursive calls to
19519 instantiate_decl do not try to instantiate it again. */
19522 /* Regenerate the declaration in case the template has been modified
19523 by a subsequent redeclaration. */
19526 /* We already set the file and line above. Reset them now in case
19527 they changed as a result of calling regenerate_decl_from_template. */
19531 {
19532 tree init;
19535 /* Clear out DECL_RTL; whatever was there before may not be right
19536 since we've reset the type of the declaration. */
19540 /* The initializer is placed in DECL_INITIAL by
19541 regenerate_decl_from_template so we don't need to
19542 push/pop_access_scope again here. Pull it out so that
19543 cp_finish_decl can process it. */
19548 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
19549 initializer. That function will defer actual emission until
19550 we have a chance to determine linkage. */
19553 /* Enter the scope of D so that access-checking works correctly. */
19558 }
19562 {
19564 tree subst_decl;
19565 tree tmpl_parm;
19566 tree spec_parm;
19569 /* Save away the current list, in case we are instantiating one
19570 template from within the body of another. */
19573 /* Set up the list of local specializations. */
19576 /* Set up context. */
19580 else
19583 /* Some typedefs referenced from within the template code need to be
19584 access checked at template instantiation time, i.e now. These
19585 types were added to the template at parsing time. Let's get those
19586 and perform the access checks then. */
19588 gen_args);
19590 /* Create substitution entries for the parameters. */
19595 {
19599 }
19601 {
19603 {
19606 }
19607 else
19608 {
19609 /* Register the (value) argument pack as a specialization of
19610 TMPL_PARM, then move on. */
19613 }
19614 }
19617 /* Substitute into the body of the function. */
19621 else
19622 {
19627 /* Set the current input_location to the end of the function
19628 so that finish_function knows where we are. */
19629 input_location
19631 }
19633 /* We don't need the local specializations any more. */
19637 /* Finish the function. */
19641 else
19642 {
19645 }
19649 }
19651 /* We're not deferring instantiation any more. */
19659 out:
19669 }
19671 /* Run through the list of templates that we wish we could
19672 instantiate, and instantiate any we can. RETRIES is the
19673 number of times we retry pending template instantiation. */
19675 void
19677 {
19681 /* Instantiating templates may trigger vtable generation. This in turn
19682 may require further template instantiations. We place a limit here
19683 to avoid infinite loop. */
19685 {
19689 " instantiating %q+D, possibly from virtual table generation"
19693 /* Pretend that we defined it. */
19696 }
19698 do
19699 {
19704 {
19709 {
19710 tree fn;
19713 {
19717 fn;
19725 }
19728 }
19729 else
19730 {
19733 {
19734 instantiation
19740 }
19744 }
19747 /* If INSTANTIATION has been instantiated, then we don't
19748 need to consider it again in the future. */
19750 else
19751 {
19754 }
19757 }
19759 }
19763 }
19765 /* Substitute ARGVEC into T, which is a list of initializers for
19766 either base class or a non-static data member. The TREE_PURPOSEs
19767 are DECLs, and the TREE_VALUEs are the initializer values. Used by
19768 instantiate_decl. */
19770 static tree
19772 {
19776 {
19777 tree decl;
19778 tree init;
19784 {
19785 tree expr;
19786 tree arg;
19788 /* Expand the base class expansion type into separate base
19789 classes. */
19791 tf_warning_or_error,
19792 NULL_TREE);
19796 /* We'll be building separate TREE_LISTs of arguments for
19797 each base. */
19803 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
19804 expand each argument in the TREE_VALUE of t. */
19811 /* VOID_TYPE_NODE is used to indicate
19812 value-initialization. */
19813 {
19816 }
19817 else
19818 {
19819 /* Substitute parameter packs into each argument in the
19820 TREE_LIST. */
19823 {
19824 tree expanded_exprs;
19826 /* Expand the argument. */
19828 expanded_exprs
19830 tf_warning_or_error,
19831 NULL_TREE);
19835 /* Prepend each of the expanded expressions to the
19836 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
19838 {
19843 }
19844 }
19847 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
19848 since we built them backwards. */
19850 {
19853 }
19854 }
19855 }
19858 {
19860 {
19864 }
19865 else
19866 {
19867 tree tmp;
19882 /* If we had an initializer but it instantiated to nothing,
19883 value-initialize the object. This will only occur when
19884 the initializer was a pack expansion where the parameter
19885 packs used in that expansion were of length zero. */
19888 }
19891 {
19895 }
19896 }
19897 }
19899 }
19901 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
19903 static void
19905 {
19910 else
19912 }
19914 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
19915 is the instantiation (which should have been created with
19916 start_enum) and ARGS are the template arguments to use. */
19918 static void
19920 {
19921 tree e;
19927 {
19928 tree value;
19929 tree decl;
19932 /* Note that in a template enum, the TREE_VALUE is the
19933 CONST_DECL, not the corresponding INTEGER_CST. */
19938 /* Give this enumeration constant the correct access. */
19941 /* Actually build the enumerator itself. */
19942 build_enumerator
19944 }
19954 }
19956 /* DECL is a FUNCTION_DECL that is a template specialization. Return
19957 its type -- but without substituting the innermost set of template
19958 arguments. So, innermost set of template parameters will appear in
19959 the type. */
19961 tree
19963 {
19964 tree fn_type;
19965 tree tmpl;
19966 tree targs;
19967 tree tparms;
19975 /* There should be as many levels of arguments as there are levels
19976 of parameters. */
19982 /* No substitution is necessary. */
19983 ;
19984 else
19985 {
19987 tree partial_args;
19989 /* Replace the innermost level of the TARGS with NULL_TREEs to
19990 let tsubst know not to substitute for those parameters. */
19999 /* Make sure that we can see identifiers, and compute access
20000 correctly. */
20004 /* Now, do the (partial) substitution to figure out the
20005 appropriate function type. */
20009 /* Substitute into the template parameters to obtain the real
20010 innermost set of parameters. This step is important if the
20011 innermost set of template parameters contains value
20012 parameters whose types depend on outer template parameters. */
20017 }
20020 }
20022 /* Return truthvalue if we're processing a template different from
20023 the last one involved in diagnostics. */
20024 int
20026 {
20028 }
20030 /* Remember current template involved in diagnostics. */
20031 void
20033 {
20035 }
20039 {
20041 }
20043 /* [temp.param] Check that template non-type parm TYPE is of an allowable
20044 type. Return zero for ok, nonzero for disallowed. Issue error and
20045 warning messages under control of COMPLAIN. */
20047 static int
20049 {
20066 {
20069 else
20071 type);
20072 }
20074 }
20076 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
20077 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
20079 static bool
20081 {
20082 tree scope;
20084 /* [temp.dep.type]
20086 A type is dependent if it is:
20088 -- a template parameter. Template template parameters are types
20089 for us (since TYPE_P holds true for them) so we handle
20090 them here. */
20094 /* -- a qualified-id with a nested-name-specifier which contains a
20095 class-name that names a dependent type or whose unqualified-id
20096 names a dependent type. */
20099 /* -- a cv-qualified type where the cv-unqualified type is
20100 dependent. */
20102 /* -- a compound type constructed from any dependent type. */
20112 {
20113 tree arg_type;
20118 arg_type;
20123 }
20124 /* -- an array type constructed from any dependent type or whose
20125 size is specified by a constant expression that is
20126 value-dependent.
20128 We checked for type- and value-dependence of the bounds in
20129 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
20131 {
20136 }
20138 /* -- a template-id in which either the template name is a template
20139 parameter ... */
20142 /* ... or any of the template arguments is a dependent type or
20143 an expression that is type-dependent or value-dependent. */
20145 && (any_dependent_template_arguments_p
20149 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
20150 dependent; if the argument of the `typeof' expression is not
20151 type-dependent, then it should already been have resolved. */
20157 /* A template argument pack is dependent if any of its packed
20158 arguments are. */
20160 {
20166 }
20168 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
20169 be template parameters. */
20173 /* The standard does not specifically mention types that are local
20174 to template functions or local classes, but they should be
20175 considered dependent too. For example:
20177 template <int I> void f() {
20178 enum E { a = I };
20179 S<sizeof (E)> s;
20180 }
20182 The size of `E' cannot be known until the value of `I' has been
20183 determined. Therefore, `E' must be considered dependent. */
20187 /* Don't use type_dependent_expression_p here, as it can lead
20188 to infinite recursion trying to determine whether a lambda
20189 nested in a lambda is dependent (c++/47687). */
20193 && (any_dependent_template_arguments_p
20197 /* Other types are non-dependent. */
20199 }
20201 /* Returns TRUE if TYPE is dependent, in the sense of
20202 [temp.dep.type]. Note that a NULL type is considered dependent. */
20204 bool
20206 {
20207 /* If there are no template parameters in scope, then there can't be
20208 any dependent types. */
20210 {
20211 /* If we are not processing a template, then nobody should be
20212 providing us with a dependent type. */
20216 }
20218 /* If the type is NULL, we have not computed a type for the entity
20219 in question; in that case, the type is dependent. */
20223 /* Erroneous types can be considered non-dependent. */
20227 /* If we have not already computed the appropriate value for TYPE,
20228 do so now. */
20230 {
20233 }
20236 }
20238 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
20239 lookup. In other words, a dependent type that is not the current
20240 instantiation. */
20242 bool
20244 {
20247 }
20249 /* T is a SCOPE_REF; return whether we need to consider it
20250 instantiation-dependent so that we can check access at instantiation
20251 time even though we know which member it resolves to. */
20253 static bool
20255 {
20261 else
20263 }
20265 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
20266 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
20267 expression. */
20269 /* Note that this predicate is not appropriate for general expressions;
20270 only constant expressions (that satisfy potential_constant_expression)
20271 can be tested for value dependence. */
20273 bool
20275 {
20279 /* A name declared with a dependent type. */
20284 {
20286 /* A name that has not been looked up -- must be dependent. */
20290 /* A non-type template parm. */
20294 /* A non-type template parm. */
20300 /* A constant with literal type and is initialized
20301 with an expression that is value-dependent.
20303 Note that a non-dependent parenthesized initializer will have
20304 already been replaced with its constant value, so if we see
20305 a TREE_LIST it must be dependent. */
20318 /* These expressions are value-dependent if the type to which
20319 the cast occurs is dependent or the expression being casted
20320 is value-dependent. */
20321 {
20327 /* A functional cast has a list of operands. */
20330 {
20331 /* If there are no operands, it must be an expression such
20332 as "int()". This should not happen for aggregate types
20333 because it would form non-constant expressions. */
20338 }
20344 }
20349 /* FALLTHRU */
20352 /* A `sizeof' expression is value-dependent if the operand is
20353 type-dependent or is a pack expansion. */
20362 /* An 'encode' expression is value-dependent if the operand is
20363 type-dependent. */
20372 /* All instantiation-dependent expressions should also be considered
20373 value-dependent. */
20381 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
20382 is value-dependent. */
20383 {
20392 }
20395 {
20399 }
20410 {
20414 }
20417 {
20424 {
20426 /* In a call to a constexpr member function, look through the
20427 implicit ADDR_EXPR on the object argument so that it doesn't
20428 cause the call to be considered value-dependent. We also
20429 look through it in potential_constant_expression. */
20436 }
20438 }
20441 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
20442 type-dependent. */
20446 {
20448 tree val;
20453 }
20456 /* Treat a GNU statement expression as dependent to avoid crashing
20457 under fold_non_dependent_expr; it can't be constant. */
20461 /* A constant expression is value-dependent if any subexpression is
20462 value-dependent. */
20464 {
20471 {
20475 {
20478 /* In some cases, some of the operands may be missing.l
20479 (For example, in the case of PREDECREMENT_EXPR, the
20480 amount to increment by may be missing.) That doesn't
20481 make the expression dependent. */
20484 }
20485 }
20489 }
20491 }
20493 /* The expression is not value-dependent. */
20495 }
20497 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
20498 [temp.dep.expr]. Note that an expression with no type is
20499 considered dependent. Other parts of the compiler arrange for an
20500 expression with type-dependent subexpressions to have no type, so
20501 this function doesn't have to be fully recursive. */
20503 bool
20505 {
20512 /* An unresolved name is always dependent. */
20516 /* Some expression forms are never type-dependent. */
20529 /* The types of these expressions depends only on the type to which
20530 the cast occurs. */
20539 /* The types of these expressions depends only on the type created
20540 by the expression. */
20543 {
20544 /* For NEW_EXPR tree nodes created inside a template, either
20545 the object type itself or a TREE_LIST may appear as the
20546 operand 1. */
20549 /* This is an array type. We need to check array dimensions
20550 as well. */
20552 || value_dependent_expression_p
20554 else
20556 }
20559 {
20563 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
20564 contains an identifier associated by name lookup with one or more
20565 declarations declared with a dependent type, or...a
20566 nested-name-specifier or qualified-id that names a member of an
20567 unknown specialization. */
20570 }
20575 && (any_dependent_template_arguments_p
20587 {
20588 tree elt;
20592 {
20595 }
20597 }
20599 /* A static data member of the current instantiation with incomplete
20600 array type is type-dependent, as the definition and specializations
20601 can have different bounds. */
20608 /* An array of unknown bound depending on a variadic parameter, eg:
20610 template<typename... Args>
20611 void foo (Args... args)
20612 {
20613 int arr[] = { args... };
20614 }
20616 template<int... vals>
20617 void bar ()
20618 {
20619 int arr[] = { vals... };
20620 }
20622 If the array has no length and has an initializer, it must be that
20623 we couldn't determine its length in cp_complete_array_type because
20624 it is dependent. */
20632 {
20637 {
20643 }
20644 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
20648 /* Always dependent, on the number of arguments if nothing else. */
20656 {
20661 }
20666 {
20670 }
20672 }
20677 }
20679 /* walk_tree callback function for instantiation_dependent_expression_p,
20680 below. Returns non-zero if a dependent subexpression is found. */
20682 static tree
20685 {
20687 {
20688 /* We don't have to worry about decltype currently because decltype
20689 of an instantiation-dependent expr is a dependent type. This
20690 might change depending on the resolution of DR 1172. */
20693 }
20696 {
20697 /* Don't treat an argument list as dependent just because it has no
20698 TREE_TYPE. */
20705 /* A constant with a dependent initializer is dependent. */
20713 /* Handle expressions with type operands. */
20718 {
20723 {
20726 else
20727 {
20730 }
20731 }
20733 }
20745 /* In a template, finish_class_member_access_expr creates a
20746 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
20747 type-dependent, so that we can check access control at
20748 instantiation time (PR 42277). See also Core issue 1273. */
20755 else
20758 /* Treat statement-expressions as dependent. */
20764 }
20768 else
20770 }
20772 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
20773 sense defined by the ABI:
20775 "An expression is instantiation-dependent if it is type-dependent
20776 or value-dependent, or it has a subexpression that is type-dependent
20777 or value-dependent." */
20779 bool
20781 {
20782 tree result;
20793 }
20795 /* Like type_dependent_expression_p, but it also works while not processing
20796 a template definition, i.e. during substitution or mangling. */
20798 bool
20800 {
20806 }
20808 /* Returns TRUE if ARGS contains a type-dependent expression. */
20810 bool
20812 {
20814 tree arg;
20817 {
20820 }
20822 }
20824 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
20825 expressions) contains any type-dependent expressions. */
20827 bool
20829 {
20835 }
20837 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
20838 expressions) contains any value-dependent expressions. */
20840 bool
20842 {
20848 }
20850 /* Returns TRUE if the ARG (a template argument) is dependent. */
20852 bool
20854 {
20858 /* Assume a template argument that was wrongly written by the user
20859 is dependent. This is consistent with what
20860 any_dependent_template_arguments_p [that calls this function]
20861 does. */
20872 {
20876 {
20879 }
20882 }
20885 else
20888 }
20890 /* Returns true if ARGS (a collection of template arguments) contains
20891 any types that require structural equality testing. */
20893 bool
20895 {
20905 {
20908 {
20914 {
20915 /* Look inside the argument pack. */
20918 }
20921 {
20934 }
20935 }
20936 }
20939 }
20941 /* Returns true if ARGS (a collection of template arguments) contains
20942 any dependent arguments. */
20944 bool
20946 {
20956 {
20961 }
20964 }
20966 /* Returns TRUE if the template TMPL is dependent. */
20968 bool
20970 {
20972 {
20974 {
20978 }
20980 }
20982 /* Template template parameters are dependent. */
20986 /* So are names that have not been looked up. */
20989 /* So are member templates of dependent classes. */
20993 }
20995 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
20997 bool
20999 {
21002 }
21004 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
21005 is dependent. */
21007 bool
21009 {
21016 {
21037 {
21041 }
21045 {
21049 {
21054 }
21055 }
21056 }
21059 }
21061 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
21062 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
21063 no such TYPE can be found. Note that this function peers inside
21064 uninstantiated templates and therefore should be used only in
21065 extremely limited situations. ONLY_CURRENT_P restricts this
21066 peering to the currently open classes hierarchy (which is required
21067 when comparing types). */
21069 tree
21071 {
21072 tree scope;
21073 tree name;
21074 tree decl;
21076 tree pushed_scope;
21077 tree result;
21082 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
21083 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
21084 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
21085 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
21086 identifier of the TYPENAME_TYPE anymore.
21087 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
21088 TYPENAME_TYPE instead, we avoid messing up with a possible
21089 typedef variant case. */
21092 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
21093 it first before we can figure out what NAME refers to. */
21095 {
21097 /* Given a class template A with a dependent base with nested type C,
21098 typedef typename A::C::C C will land us here, as trying to resolve
21099 the initial A::C leads to the local C typedef, which leads back to
21100 A::C::C. So we break the recursion now. */
21102 else
21104 }
21105 /* If we don't know what SCOPE refers to, then we cannot resolve the
21106 TYPENAME_TYPE. */
21109 /* If the SCOPE is a template type parameter, we have no way of
21110 resolving the name. */
21113 /* If the SCOPE is not the current instantiation, there's no reason
21114 to look inside it. */
21117 /* If this is a typedef, we don't want to look inside (c++/11987). */
21120 /* If SCOPE isn't the template itself, it will not have a valid
21121 TYPE_FIELDS list. */
21123 /* scope is either the template itself or a compatible instantiation
21124 like X<T>, so look up the name in the original template. */
21126 else
21127 /* scope is a partial instantiation, so we can't do the lookup or we
21128 will lose the template arguments. */
21130 /* Enter the SCOPE so that name lookup will be resolved as if we
21131 were in the class definition. In particular, SCOPE will no
21132 longer be considered a dependent type. */
21134 /* Look up the declaration. */
21136 tf_warning_or_error);
21140 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
21141 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
21146 {
21150 }
21153 {
21154 tree tmpl;
21155 tree args;
21156 /* Obtain the template and the arguments. */
21159 /* Instantiate the template. */
21165 }
21167 /* Leave the SCOPE. */
21171 /* If we failed to resolve it, return the original typename. */
21175 /* If lookup found a typename type, resolve that too. */
21177 {
21178 /* Ill-formed programs can cause infinite recursion here, so we
21179 must catch that. */
21183 }
21185 /* Qualify the resulting type. */
21191 }
21193 /* EXPR is an expression which is not type-dependent. Return a proxy
21194 for EXPR that can be used to compute the types of larger
21195 expressions containing EXPR. */
21197 tree
21199 {
21200 tree inner_expr;
21202 #ifdef ENABLE_CHECKING
21203 /* Try to get a constant value for all non-dependent expressions in
21204 order to expose bugs in *_dependent_expression_p and constexpr. */
21207 #endif
21209 /* Preserve OVERLOADs; the functions must be available to resolve
21210 types. */
21221 /* There is no need to return a proxy for a variable. */
21224 /* Preserve string constants; conversions from string constants to
21225 "char *" are allowed, even though normally a "const char *"
21226 cannot be used to initialize a "char *". */
21229 /* Preserve arithmetic constants, as an optimization -- there is no
21230 reason to create a new node. */
21233 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
21234 There is at least one place where we want to know that a
21235 particular expression is a throw-expression: when checking a ?:
21236 expression, there are special rules if the second or third
21237 argument is a throw-expression. */
21241 /* Don't wrap an initializer list, we need to be able to look inside. */
21245 /* Don't wrap a dummy object, we need to be able to test for it. */
21264 /* If the type is unknown, it can't really be non-dependent */
21267 /* Otherwise, build a NON_DEPENDENT_EXPR. */
21269 }
21271 /* ARGS is a vector of expressions as arguments to a function call.
21272 Replace the arguments with equivalent non-dependent expressions.
21273 This modifies ARGS in place. */
21275 void
21277 {
21279 tree arg;
21282 {
21286 }
21287 }
21289 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
21290 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
21291 parms. */
21293 static tree
21295 {
21308 }
21310 tree
21312 {
21314 }
21316 tree
21318 {
21320 }
21322 /* Given type ARG, return std::initializer_list<ARG>. */
21324 static tree
21326 {
21327 tree std_init_list = namespace_binding
21329 tree argvec;
21331 {
21335 }
21340 }
21342 /* Replace auto in TYPE with std::initializer_list<auto>. */
21344 static tree
21346 {
21353 }
21355 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
21356 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
21358 tree
21360 {
21361 tree targs;
21367 /* Defining a subset of type-dependent expressions that we can deduce
21368 from ahead of time isn't worth the trouble. */
21371 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
21372 with either a new invented type template parameter U or, if the
21373 initializer is a braced-init-list (8.5.4), with
21374 std::initializer_list<U>. */
21382 {
21387 {
21390 }
21391 }
21392 else
21393 {
21404 {
21406 /* Try again at instantiation time. */
21409 /* If type is error_mark_node a diagnostic must have been
21410 emitted by now. Also, having a mention to '<type error>'
21411 in the diagnostic is not really useful to the user. */
21412 {
21416 else
21418 }
21420 }
21421 }
21423 /* If the list of declarators contains more than one declarator, the type
21424 of each declared variable is determined as described above. If the
21425 type deduced for the template parameter U is not the same in each
21426 deduction, the program is ill-formed. */
21429 {
21435 else
21439 }
21445 }
21447 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
21448 result. */
21450 tree
21452 {
21453 tree argvec;
21460 /* For a late-specified return type in a template type-parameter, we
21461 need to add a dummy argument level for its parmlist. */
21462 argvec = add_to_template_args
21467 }
21469 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
21470 'decltype(auto)'. */
21472 bool
21474 {
21479 else
21481 }
21483 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
21484 a use of `auto'. Returns NULL_TREE otherwise. */
21486 tree
21488 {
21490 }
21492 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
21493 'decltype(auto)' or a concept. */
21495 bool
21497 {
21499 }
21501 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
21502 a concept identifier) iff TYPE contains a use of a generic type. Returns
21503 NULL_TREE otherwise. */
21505 tree
21507 {
21509 }
21512 /* For a given template T, return the vector of typedefs referenced
21513 in T for which access check is needed at T instantiation time.
21514 T is either a FUNCTION_DECL or a RECORD_TYPE.
21515 Those typedefs were added to T by the function
21516 append_type_to_template_for_access_check. */
21520 {
21521 tree ti;
21532 {
21537 }
21540 }
21542 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
21543 tied to T. That list of typedefs will be access checked at
21544 T instantiation time.
21545 T is either a FUNCTION_DECL or a RECORD_TYPE.
21546 TYPE_DECL is a TYPE_DECL node representing a typedef.
21547 SCOPE is the scope through which TYPE_DECL is accessed.
21548 LOCATION is the location of the usage point of TYPE_DECL.
21550 This function is a subroutine of
21551 append_type_to_template_for_access_check. */
21553 static void
21555 tree type_decl,
21556 tree scope,
21557 location_t location)
21558 {
21559 qualified_typedef_usage_t typedef_usage;
21560 tree ti;
21567 && type_decl
21581 }
21583 /* Append TYPE_DECL to the template TEMPL.
21584 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
21585 At TEMPL instanciation time, TYPE_DECL will be checked to see
21586 if it can be accessed through SCOPE.
21587 LOCATION is the location of the usage point of TYPE_DECL.
21589 e.g. consider the following code snippet:
21591 class C
21592 {
21593 typedef int myint;
21594 };
21596 template<class U> struct S
21597 {
21598 C::myint mi; // <-- usage point of the typedef C::myint
21599 };
21601 S<char> s;
21603 At S<char> instantiation time, we need to check the access of C::myint
21604 In other words, we need to check the access of the myint typedef through
21605 the C scope. For that purpose, this function will add the myint typedef
21606 and the scope C through which its being accessed to a list of typedefs
21607 tied to the template S. That list will be walked at template instantiation
21608 time and access check performed on each typedefs it contains.
21609 Note that this particular code snippet should yield an error because
21610 myint is private to C. */
21612 void
21614 tree type_decl,
21615 tree scope,
21616 location_t location)
21617 {
21623 /* Make sure we don't append the type to the template twice. */
21630 }
21632 /* Set up the hash tables for template instantiations. */
21634 void
21636 {
21638 hash_specialization,
21639 eq_specializations,
21640 ggc_free);
21642 hash_specialization,
21643 eq_specializations,
21644 ggc_free);
21645 }
21647 /* Print stats about the template hash tables for -fstats. */
21649 void
21651 {
21660 }