| blob | c2e251aaf859cb41476c41a3716fd4c7ee46b79c |
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. */
3520 }
3522 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3523 ORIG_LEVEL, DECL, and TYPE. */
3525 static tree
3529 tree decl,
3530 tree type)
3531 {
3542 }
3544 /* Find the canonical type parameter for the given template type
3545 parameter. Returns the canonical type parameter, which may be TYPE
3546 if no such parameter existed. */
3548 static tree
3550 {
3551 tree list;
3565 else
3566 {
3571 }
3572 }
3574 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3575 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3576 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3577 new one is created. */
3579 static tree
3581 tsubst_flags_t complain)
3582 {
3587 {
3606 /* Template template parameters need this. */
3611 }
3614 }
3616 /* Process information from new template parameter PARM and append it
3617 to the LIST being built. This new parameter is a non-type
3618 parameter iff IS_NON_TYPE is true. This new parameter is a
3619 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3620 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3621 parameter list PARM belongs to. This is used used to create a
3622 proper canonical type for the type of PARM that is to be created,
3623 iff PARM is a type. If the size is not known, this parameter shall
3624 be set to 0. */
3626 tree
3629 {
3631 tree defval;
3632 tree err_parm_list;
3639 {
3643 {
3647 else
3649 }
3652 }
3653 else
3657 {
3663 {
3667 }
3668 else
3669 {
3670 /* [temp.param]
3672 The top-level cv-qualifiers on the template-parameter are
3673 ignored when determining its type. */
3676 {
3680 }
3683 {
3684 /* This template parameter is not a parameter pack, but it
3685 should be. Complain about "bare" parameter packs. */
3688 /* Recover by calling this a parameter pack. */
3690 }
3691 }
3693 /* A template parameter is not modifiable. */
3702 processing_template_decl,
3707 }
3708 else
3709 {
3710 tree t;
3714 {
3716 /* This is for distinguishing between real templates and template
3717 template parameters */
3721 }
3722 else
3723 {
3725 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3728 }
3735 processing_template_decl,
3739 }
3745 }
3747 /* The end of a template parameter list has been reached. Process the
3748 tree list into a parameter vector, converting each parameter into a more
3749 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3750 as PARM_DECLs. */
3752 tree
3754 {
3759 current_template_parms
3764 {
3768 }
3773 }
3775 /* end_template_decl is called after a template declaration is seen. */
3777 void
3779 {
3785 /* This matches the pushlevel in begin_template_parm_list. */
3790 }
3792 /* Takes a TREE_LIST representing a template parameter and convert it
3793 into an argument suitable to be passed to the type substitution
3794 functions. Note that If the TREE_LIST contains an error_mark
3795 node, the returned argument is error_mark_node. */
3797 static tree
3799 {
3812 {
3816 {
3817 /* Turn this argument into a TYPE_ARGUMENT_PACK
3818 with a single element, which expands T. */
3820 #ifdef ENABLE_CHECKING
3821 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3823 #endif
3828 }
3829 }
3830 else
3831 {
3835 {
3836 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3837 with a single element, which expands T. */
3840 #ifdef ENABLE_CHECKING
3841 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3843 #endif
3849 }
3850 }
3852 }
3854 /* Given a set of template parameters, return them as a set of template
3855 arguments. The template parameters are represented as a TREE_VEC, in
3856 the form documented in cp-tree.h for template arguments. */
3858 static tree
3860 {
3861 tree header;
3866 /* If there is only one level of template parameters, we do not
3867 create a TREE_VEC of TREE_VECs. Instead, we return a single
3868 TREE_VEC containing the arguments. */
3873 {
3881 #ifdef ENABLE_CHECKING
3883 #endif
3887 else
3889 }
3892 /* This can happen for template parms of a template template
3893 parameter, e.g:
3895 template<template<class T, class U> class TT> struct S;
3897 Consider the level of the parms of TT; T and U both have
3898 level 2; TT has no template parm of level 1. So in this case
3899 the first element of full_template_args is NULL_TREE. If we
3900 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
3901 of 2. This will make tsubst wrongly consider that T and U
3902 have level 1. Instead, let's create a dummy vector as the
3903 first element of full_template_args so that TMPL_ARGS_DEPTH
3904 returns the correct depth for args. */
3907 }
3909 /* Within the declaration of a template, return the currently active
3910 template parameters as an argument TREE_VEC. */
3912 static tree
3914 {
3916 }
3918 /* Update the declared TYPE by doing any lookups which were thought to be
3919 dependent, but are not now that we know the SCOPE of the declarator. */
3921 tree
3923 {
3934 /* Don't bother building up the args in this case. */
3936 {
3937 /* tsubst in the args corresponding to the template parameters,
3938 including auto if present. Most things will be unchanged, but
3939 make_typename_type and tsubst_qualified_id will resolve
3940 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3943 tree pushed;
3945 {
3949 }
3954 }
3960 {
3963 else
3965 }
3967 }
3969 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3970 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3971 a member template. Used by push_template_decl below. */
3973 static tree
3975 {
3983 }
3985 struct template_parm_data
3986 {
3987 /* The level of the template parameters we are currently
3988 processing. */
3991 /* The index of the specialization argument we are currently
3992 processing. */
3995 /* An array whose size is the number of template parameters. The
3996 elements are nonzero if the parameter has been used in any one
3997 of the arguments processed so far. */
4000 /* An array whose size is the number of template arguments. The
4001 elements are nonzero if the argument makes use of template
4002 parameters of this level. */
4004 };
4006 /* Subroutine of push_template_decl used to see if each template
4007 parameter in a partial specialization is used in the explicit
4008 argument list. If T is of the LEVEL given in DATA (which is
4009 treated as a template_parm_data*), then DATA->PARMS is marked
4010 appropriately. */
4012 static int
4014 {
4020 {
4023 }
4024 else
4025 {
4028 }
4031 {
4034 }
4036 /* Return zero so that for_each_template_parm will continue the
4037 traversal of the tree; we want to mark *every* template parm. */
4039 }
4041 /* Process the partial specialization DECL. */
4043 static tree
4045 {
4051 tree inner_parms;
4052 tree inst;
4065 /* We check that each of the template parameters given in the
4066 partial specialization is used in the argument list to the
4067 specialization. For example:
4069 template <class T> struct S;
4070 template <class T> struct S<T*>;
4072 The second declaration is OK because `T*' uses the template
4073 parameter T, whereas
4075 template <class T> struct S<int>;
4077 is no good. Even trickier is:
4079 template <class T>
4080 struct S1
4081 {
4082 template <class U>
4083 struct S2;
4084 template <class U>
4085 struct S2<T>;
4086 };
4088 The S2<T> declaration is actually invalid; it is a
4089 full-specialization. Of course,
4091 template <class U>
4092 struct S2<T (*)(U)>;
4094 or some such would have been OK. */
4102 {
4107 NULL,
4109 }
4112 {
4113 /* One of the template parms was not used in the
4114 specialization. */
4116 {
4119 }
4122 }
4127 /* [temp.class.spec]
4129 The argument list of the specialization shall not be identical to
4130 the implicit argument list of the primary template. */
4137 /* A partial specialization that replaces multiple parameters of the
4138 primary template with a pack expansion is less specialized for those
4139 parameters. */
4141 {
4143 "primary template because it replaces multiple parameters "
4147 }
4149 /* [temp.class.spec]
4151 A partially specialized non-type argument expression shall not
4152 involve template parameters of the partial specialization except
4153 when the argument expression is a simple identifier.
4155 The type of a template parameter corresponding to a specialized
4156 non-type argument shall not be dependent on a parameter of the
4157 specialization.
4159 Also, we verify that pack expansions only occur at the
4160 end of the argument list. */
4164 {
4171 {
4172 /* Extract the arguments from the argument pack. We'll be
4173 iterating over these in the following loop. */
4176 }
4179 {
4181 /* Get the Jth argument in the parameter pack. */
4185 {
4186 /* Pack expansions must come at the end of the
4187 argument list. */
4190 {
4194 else
4197 }
4198 }
4201 /* We only care about the pattern. */
4207 /* This next line is the `argument expression is not just a
4208 simple identifier' condition and also the `specialized
4209 non-type argument' bit. */
4211 {
4215 arg);
4216 else
4217 {
4218 /* Look at the corresponding template parameter,
4219 marking which template parameters its type depends
4220 upon. */
4224 {
4225 /* We haven't yet initialized TPD2. Do so now. */
4227 /* The number of parameters here is the number in the
4228 main template, which, as checked in the assertion
4229 above, is NARGS. */
4233 }
4235 /* Mark the template parameters. But this time, we're
4236 looking for the template parameters of the main
4237 template, not in the specialization. */
4244 NULL,
4248 {
4249 /* The type depended on some template parameters.
4250 If they are fully specialized in the
4251 specialization, that's OK. */
4260 "type %qT of template argument %qE depends "
4262 "type %qT of template argument %qE depends "
4264 type,
4265 arg);
4266 }
4267 }
4268 }
4269 }
4270 }
4272 /* We should only get here once. */
4290 {
4294 {
4298 "partial specialization of %qT after instantiation "
4300 }
4301 }
4304 }
4306 /* Check that a template declaration's use of default arguments and
4307 parameter packs is not invalid. Here, PARMS are the template
4308 parameters. IS_PRIMARY is true if DECL is the thing declared by
4309 a primary template. IS_PARTIAL is true if DECL is a partial
4310 specialization.
4312 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4313 declaration (but not a definition); 1 indicates a declaration, 2
4314 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4315 emitted for extraneous default arguments.
4317 Returns TRUE if there were no errors found, FALSE otherwise. */
4319 bool
4322 {
4325 tree parm_level;
4328 /* [temp.param]
4330 A default template-argument shall not be specified in a
4331 function template declaration or a function template definition, nor
4332 in the template-parameter-list of the definition of a member of a
4333 class template. */
4336 /* You can't have a function template declaration in a local
4337 scope, nor you can you define a member of a class template in a
4338 local scope. */
4344 /* A lambda doesn't have an explicit declaration; don't complain
4345 about the parms of the enclosing class. */
4352 /* If this is either a friend defined in the scope of the class
4353 or a member function. */
4359 /* And, if it was a member function, it really was defined in
4360 the scope of the class. */
4363 /* We already checked these parameters when the template was
4364 declared, so there's no need to do it again now. This function
4365 was defined in class scope, but we're processing its body now
4366 that the class is complete. */
4369 /* Core issue 226 (C++0x only): the following only applies to class
4370 templates. */
4373 {
4374 /* [temp.param]
4376 If a template-parameter has a default template-argument, all
4377 subsequent template-parameters shall have a default
4378 template-argument supplied. */
4380 {
4387 {
4397 {
4399 /* For better subsequent error-recovery, we indicate that
4400 there should have been a default argument. */
4403 }
4405 && !is_friend_decl
4406 /* Don't complain about an enclosing partial
4407 specialization. */
4412 {
4413 /* A primary class template can only have one
4414 parameter pack, at the end of the template
4415 parameter list. */
4420 else
4428 }
4429 }
4430 }
4431 }
4434 || is_partial
4435 || !is_primary
4437 /* For an ordinary class template, default template arguments are
4438 allowed at the innermost level, e.g.:
4439 template <class T = int>
4440 struct S {};
4441 but, in a partial specialization, they're not allowed even
4442 there, as we have in [temp.class.spec]:
4444 The template parameter list of a specialization shall not
4445 contain default template argument values.
4447 So, for a partial specialization, or for a function template
4448 (in C++98/C++03), we look at all of them. */
4449 ;
4450 else
4451 /* But, for a primary class template that is not a partial
4452 specialization we look at all template parameters except the
4453 innermost ones. */
4456 /* Figure out what error message to issue. */
4469 else
4473 /* If we're inside a class definition, there's no need to
4474 examine the parameters to the class itself. On the one
4475 hand, they will be checked when the class is defined, and,
4476 on the other, default arguments are valid in things like:
4477 template <class T = double>
4478 struct S { template <class U> void f(U); };
4479 Here the default argument for `S' has no bearing on the
4480 declaration of `f'. */
4482 else
4483 /* Check everything. */
4489 {
4496 {
4501 {
4503 {
4510 }
4512 /* Clear out the default argument so that we are not
4513 confused later. */
4515 }
4516 }
4518 /* At this point, if we're still interested in issuing messages,
4519 they must apply to classes surrounding the object declared. */
4523 }
4526 }
4528 /* Worker for push_template_decl_real, called via
4529 for_each_template_parm. DATA is really an int, indicating the
4530 level of the parameters we are interested in. If T is a template
4531 parameter of that level, return nonzero. */
4533 static int
4535 {
4541 else
4544 }
4546 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4547 parameters given by current_template_args, or reuses a
4548 previously existing one, if appropriate. Returns the DECL, or an
4549 equivalent one, if it is replaced via a call to duplicate_decls.
4551 If IS_FRIEND is true, DECL is a friend declaration. */
4553 tree
4555 {
4556 tree tmpl;
4557 tree args;
4558 tree info;
4559 tree ctx;
4563 /* True if the template is a member template, in the sense of
4564 [temp.mem]. */
4570 /* See if this is a partial specialization. */
4579 /* For a friend, we want the context of the friend function, not
4580 the type of which it is a friend. */
4584 /* In the case of a virtual function, we want the class in which
4585 it is defined. */
4587 else
4588 /* Otherwise, if we're currently defining some class, the DECL
4589 is assumed to be a member of the class. */
4598 /* See if this is a primary template. */
4600 /* A friend template that specifies a class context, i.e.
4601 template <typename T> friend void A<T>::f();
4602 is not primary. */
4604 else
4608 {
4613 {
4616 }
4618 {
4620 {
4621 /* [temp.mem]
4623 A destructor shall not be a member template. */
4626 }
4633 {
4634 /* [basic.stc.dynamic.allocation]
4636 An allocation function can be a function
4637 template. ... Template allocation functions shall
4638 have two or more parameters. */
4641 }
4642 }
4648 /* alias-declaration */
4650 else
4651 {
4654 }
4655 }
4657 /* Check to see that the rules regarding the use of default
4658 arguments are not being violated. */
4662 /* Ensure that there are no parameter packs in the type of this
4663 declaration that have not been expanded. */
4665 {
4666 /* Check each of the arguments individually to see if there are
4667 any bare parameter packs. */
4673 {
4676 {
4677 /* This is a PARM_DECL that contains unexpanded parameter
4678 packs. We have already complained about this in the
4679 check_for_bare_parameter_packs call, so just replace
4680 these types with ERROR_MARK_NODE. */
4683 }
4687 }
4689 /* Check for bare parameter packs in the return type and the
4690 exception specifiers. */
4692 /* Errors were already issued, set return type to int
4693 as the frontend doesn't expect error_mark_node as
4694 the return type. */
4698 }
4703 {
4706 }
4719 {
4724 /* If DECL is a TYPE_DECL for a class-template, then there won't
4725 be DECL_LANG_SPECIFIC. The information equivalent to
4726 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4730 {
4731 /* Since a template declaration already existed for this
4732 class-type, we must be redeclaring it here. Make sure
4733 that the redeclaration is valid. */
4735 current_template_parms);
4736 /* We don't need to create a new TEMPLATE_DECL; just use the
4737 one we already had. */
4739 }
4740 else
4741 {
4743 member_template_p);
4748 {
4749 /* A specialization of a member template of a template
4750 class. */
4754 }
4755 }
4756 }
4757 else
4758 {
4764 {
4767 }
4775 {
4776 tree new_tmpl;
4778 /* The declaration is a specialization of a member
4779 template, declared outside the class. Therefore, the
4780 innermost template arguments will be NULL, so we
4781 replace them with the arguments determined by the
4782 earlier call to check_explicit_specialization. */
4785 new_tmpl
4787 member_template_p);
4797 args,
4800 }
4802 /* Make sure the template headers we got make sense. */
4807 {
4810 }
4811 else
4813 {
4818 {
4822 else
4826 /* Avoid crash in import_export_decl. */
4829 }
4834 /* Can happen in erroneous input. */
4836 else
4838 }
4840 /* Check that the parms are used in the appropriate qualifying scopes
4841 in the declarator. */
4845 {
4851 /* Avoid crash in import_export_decl. */
4854 }
4855 }
4860 /* Push template declarations for global functions and types. Note
4861 that we do not try to push a global template friend declared in a
4862 template class; such a thing may well depend on the template
4863 parameters of the class. */
4866 {
4871 /* Hide template friend classes that haven't been declared yet. */
4873 {
4876 }
4877 }
4880 {
4886 {
4889 /* It is a conversion operator. See if the type converted to
4890 depends on innermost template operands. */
4893 depth))
4895 }
4897 /* Give template template parms a DECL_CONTEXT of the template
4898 for which they are a parameter. */
4901 {
4905 }
4906 }
4908 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4909 back to its most general template. If TMPL is a specialization,
4910 ARGS may only have the innermost set of arguments. Add the missing
4911 argument levels if necessary. */
4919 else
4920 {
4925 }
4928 }
4930 tree
4932 {
4934 }
4936 /* FN is an inheriting constructor that inherits from the constructor
4937 template INHERITED; turn FN into a constructor template with a matching
4938 template header. */
4940 tree
4942 {
4943 tree inner_parms
4946 tree parms
4957 }
4959 /* Called when a class template TYPE is redeclared with the indicated
4960 template PARMS, e.g.:
4962 template <class T> struct S;
4963 template <class T> struct S {}; */
4965 bool
4967 {
4968 tree tmpl;
4969 tree tmpl_parms;
4973 {
4976 }
4980 /* The type is nested in some template class. Nothing to worry
4981 about here; there are no new template parameters for the nested
4982 type. */
4986 {
4988 tmpl);
4990 }
4996 {
5006 }
5009 {
5010 tree tmpl_parm;
5011 tree parm;
5012 tree tmpl_default;
5013 tree parm_default;
5027 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5028 TEMPLATE_DECL. */
5038 {
5042 }
5045 {
5046 /* We have in [temp.param]:
5048 A template-parameter may not be given default arguments
5049 by two different declarations in the same scope. */
5054 }
5057 /* Update the previous template parameters (which are the ones
5058 that will really count) with the new default value. */
5061 /* Update the new parameters, too; they'll be used as the
5062 parameters for any members. */
5064 }
5067 }
5069 /* Simplify EXPR if it is a non-dependent expression. Returns the
5070 (possibly simplified) expression. */
5072 tree
5074 {
5078 /* If we're in a template, but EXPR isn't value dependent, simplify
5079 it. We're supposed to treat:
5081 template <typename T> void f(T[1 + 1]);
5082 template <typename T> void f(T[2]);
5084 as two declarations of the same function, for example. */
5088 {
5089 HOST_WIDE_INT saved_processing_template_decl;
5095 complain,
5100 }
5102 }
5104 tree
5106 {
5108 }
5110 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5111 template declaration, or a TYPE_DECL for an alias declaration. */
5113 bool
5115 {
5123 }
5125 /* Return TRUE iff is a specialization of an alias template. */
5127 bool
5129 {
5137 }
5139 /* Return either TMPL or another template that it is equivalent to under DR
5140 1286: An alias that just changes the name of a template is equivalent to
5141 the other template. */
5143 static tree
5145 {
5148 {
5151 {
5155 {
5156 /* The alias type is equivalent to the pattern of the
5157 underlying template, so strip the alias. */
5160 }
5161 }
5163 }
5165 }
5167 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5168 must be a function or a pointer-to-function type, as specified
5169 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5170 and check that the resulting function has external linkage. */
5172 static tree
5174 {
5177 linkage_kind linkage;
5189 /* [temp.arg.nontype]/1
5191 A template-argument for a non-type, non-template template-parameter
5192 shall be one of:
5193 [...]
5194 -- the address of an object or function with external [C++11: or
5195 internal] linkage. */
5198 {
5202 else
5205 }
5209 {
5214 else
5219 }
5222 }
5224 /* Subroutine of convert_nontype_argument.
5225 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5226 Emit an error otherwise. */
5228 static bool
5230 tsubst_flags_t complain)
5231 {
5238 {
5242 }
5244 }
5246 /* Returns TRUE iff the address of OP is value-dependent.
5248 14.6.2.4 [temp.dep.temp]:
5249 A non-integral non-type template-argument is dependent if its type is
5250 dependent or it has either of the following forms
5251 qualified-id
5252 & qualified-id
5253 and contains a nested-name-specifier which specifies a class-name that
5254 names a dependent type.
5256 We generalize this to just say that the address of a member of a
5257 dependent class is value-dependent; the above doesn't cover the
5258 address of a static data member named with an unqualified-id. */
5260 static bool
5262 {
5263 /* We could use get_inner_reference here, but there's no need;
5264 this is only relevant for template non-type arguments, which
5265 can only be expressed as &id-expression. */
5267 {
5271 }
5274 }
5276 /* The next set of functions are used for providing helpful explanatory
5277 diagnostics for failed overload resolution. Their messages should be
5278 indented by two spaces for consistency with the messages in
5279 call.c */
5281 static int
5283 {
5285 }
5287 static int
5289 {
5294 }
5296 static int
5298 {
5300 }
5302 static int
5304 {
5310 }
5312 static int
5314 {
5318 }
5320 static int
5322 {
5325 " template parameter %qD is not a parameter pack, but "
5329 }
5331 static int
5333 {
5336 " template argument %qE does not match "
5340 }
5342 static int
5344 {
5348 }
5350 static int
5352 {
5358 }
5360 static int
5362 {
5364 {
5369 else
5371 " deduced conflicting values for non-type parameter "
5373 }
5375 }
5377 static int
5379 {
5382 " variable-sized array type %qT is not "
5384 arg);
5386 }
5388 static int
5390 {
5394 arg);
5396 }
5398 static int
5400 {
5407 }
5409 static int
5411 {
5413 }
5415 static int
5417 {
5419 }
5421 static int
5424 {
5430 }
5432 static int
5435 {
5438 {
5446 }
5448 }
5450 static int
5452 {
5455 " template parameters of a template template argument are "
5458 }
5460 static int
5462 {
5468 }
5470 static int
5472 {
5477 }
5479 static int
5481 {
5485 arg);
5487 }
5489 /* Attempt to convert the non-type template parameter EXPR to the
5490 indicated TYPE. If the conversion is successful, return the
5491 converted value. If the conversion is unsuccessful, return
5492 NULL_TREE if we issued an error message, or error_mark_node if we
5493 did not. We issue error messages for out-and-out bad template
5494 parameters, but not simply because the conversion failed, since we
5495 might be just trying to do argument deduction. Both TYPE and EXPR
5496 must be non-dependent.
5498 The conversion follows the special rules described in
5499 [temp.arg.nontype], and it is much more strict than an implicit
5500 conversion.
5502 This function is called twice for each template argument (see
5503 lookup_template_class for a more accurate description of this
5504 problem). This means that we need to handle expressions which
5505 are not valid in a C++ source, but can be created from the
5506 first call (for instance, casts to perform conversions). These
5507 hacks can go away after we fix the double coercion problem. */
5509 static tree
5511 {
5512 tree expr_type;
5514 /* Detect immediately string literals as invalid non-type argument.
5515 This special-case is not needed for correctness (we would easily
5516 catch this later), but only to provide better diagnostic for this
5517 common user mistake. As suggested by DR 100, we do not mention
5518 linkage issues in the diagnostic as this is not the point. */
5519 /* FIXME we're making this OK. */
5521 {
5527 }
5529 /* Add the ADDR_EXPR now for the benefit of
5530 value_dependent_expression_p. */
5533 {
5537 }
5539 /* If we are in a template, EXPR may be non-dependent, but still
5540 have a syntactic, rather than semantic, form. For example, EXPR
5541 might be a SCOPE_REF, rather than the VAR_DECL to which the
5542 SCOPE_REF refers. Preserving the qualifying scope is necessary
5543 so that access checking can be performed when the template is
5544 instantiated -- but here we need the resolved form so that we can
5545 convert the argument. */
5556 else
5559 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5560 to a non-type argument of "nullptr". */
5564 /* In C++11, integral or enumeration non-type template arguments can be
5565 arbitrary constant expressions. Pointer and pointer to
5566 member arguments can be general constant expressions that evaluate
5567 to a null value, but otherwise still need to be of a specific form. */
5569 {
5571 /* A PTRMEM_CST is already constant, and a valid template
5572 argument for a parameter of pointer to member type, we just want
5573 to leave it in that form rather than lower it to a
5578 {
5583 }
5584 }
5586 /* HACK: Due to double coercion, we can get a
5587 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5588 which is the tree that we built on the first call (see
5589 below when coercing to reference to object or to reference to
5590 function). We just strip everything and get to the arg.
5591 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5592 for examples. */
5594 {
5600 {
5601 /* ??? Maybe we could use convert_from_reference here, but we
5602 would need to relax its constraints because the NOP_EXPR
5603 could actually change the type to something more cv-qualified,
5604 and this is not folded by convert_from_reference. */
5609 && (same_type_ignoring_top_level_qualifiers_p
5612 {
5615 }
5616 }
5617 }
5619 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5620 parameter is a pointer to object, through decay and
5621 qualification conversion. Let's strip everything. */
5623 {
5628 {
5629 /* Skip the ADDR_EXPR only if it is part of the decay for
5630 an array. Otherwise, it is part of the original argument
5631 in the source code. */
5636 }
5637 }
5639 /* [temp.arg.nontype]/5, bullet 1
5641 For a non-type template-parameter of integral or enumeration type,
5642 integral promotions (_conv.prom_) and integral conversions
5643 (_conv.integral_) are applied. */
5645 {
5654 /* Notice that there are constant expressions like '4 % 0' which
5655 do not fold into integer constants. */
5657 {
5659 {
5670 /* else cxx_constant_value complained but gave us
5671 a real constant, so go ahead. */
5673 }
5674 else
5676 }
5678 /* Avoid typedef problems. */
5681 }
5682 /* [temp.arg.nontype]/5, bullet 2
5684 For a non-type template-parameter of type pointer to object,
5685 qualification conversions (_conv.qual_) and the array-to-pointer
5686 conversion (_conv.array_) are applied. */
5688 {
5689 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5691 A template-argument for a non-type, non-template template-parameter
5692 shall be one of: [...]
5694 -- the name of a non-type template-parameter;
5695 -- the address of an object or function with external linkage, [...]
5696 expressed as "& id-expression" where the & is optional if the name
5697 refers to a function or array, or if the corresponding
5698 template-parameter is a reference.
5700 Here, we do not care about functions, as they are invalid anyway
5701 for a parameter of type pointer-to-object. */
5704 /* Non-type template parameters are OK. */
5705 ;
5710 {
5712 {
5714 "because %qD is a variable, not the address of "
5718 }
5720 {
5725 }
5726 /* Other values, like integer constants, might be valid
5727 non-type arguments of some other type. */
5729 }
5730 else
5731 {
5732 tree decl;
5737 {
5742 }
5744 {
5749 }
5751 {
5756 }
5757 }
5766 }
5767 /* [temp.arg.nontype]/5, bullet 3
5769 For a non-type template-parameter of type reference to object, no
5770 conversions apply. The type referred to by the reference may be more
5771 cv-qualified than the (otherwise identical) type of the
5772 template-argument. The template-parameter is bound directly to the
5773 template-argument, which must be an lvalue. */
5775 {
5777 expr_type))
5781 {
5785 }
5788 {
5792 }
5794 /* [temp.arg.nontype]/1
5796 A template-argument for a non-type, non-template template-parameter
5797 shall be one of: [...]
5799 -- the address of an object or function with external linkage. */
5802 {
5805 {
5807 "because a reference variable does not have a constant "
5810 }
5811 }
5814 {
5819 }
5822 {
5827 }
5830 }
5831 /* [temp.arg.nontype]/5, bullet 4
5833 For a non-type template-parameter of type pointer to function, only
5834 the function-to-pointer conversion (_conv.func_) is applied. If the
5835 template-argument represents a set of overloaded functions (or a
5836 pointer to such), the matching function is selected from the set
5837 (_over.over_). */
5839 {
5840 /* If the argument is a template-id, we might not have enough
5841 context information to decay the pointer. */
5843 {
5847 }
5850 /* Null pointer values are OK in C++11. */
5856 }
5857 /* [temp.arg.nontype]/5, bullet 5
5859 For a non-type template-parameter of type reference to function, no
5860 conversions apply. If the template-argument represents a set of
5861 overloaded functions, the matching function is selected from the set
5862 (_over.over_). */
5864 {
5866 {
5871 }
5878 }
5879 /* [temp.arg.nontype]/5, bullet 6
5881 For a non-type template-parameter of type pointer to member function,
5882 no conversions apply. If the template-argument represents a set of
5883 overloaded member functions, the matching member function is selected
5884 from the set (_over.over_). */
5886 {
5891 /* [temp.arg.nontype] bullet 1 says the pointer to member
5892 expression must be a pointer-to-member constant. */
5896 /* There is no way to disable standard conversions in
5897 resolve_address_of_overloaded_function (called by
5898 instantiate_type). It is possible that the call succeeded by
5899 converting &B::I to &D::I (where B is a base of D), so we need
5900 to reject this conversion here.
5902 Actually, even if there was a way to disable standard conversions,
5903 it would still be better to reject them here so that we can
5904 provide a superior diagnostic. */
5906 {
5910 /* If we are just one standard conversion off, explain. */
5915 }
5916 }
5917 /* [temp.arg.nontype]/5, bullet 7
5919 For a non-type template-parameter of type pointer to data member,
5920 qualification conversions (_conv.qual_) are applied. */
5922 {
5923 /* [temp.arg.nontype] bullet 1 says the pointer to member
5924 expression must be a pointer-to-member constant. */
5931 }
5933 {
5935 {
5939 }
5941 }
5942 /* A template non-type parameter must be one of the above. */
5943 else
5946 /* Sanity check: did we actually convert the argument to the
5947 right type? */
5951 }
5953 /* Subroutine of coerce_template_template_parms, which returns 1 if
5954 PARM_PARM and ARG_PARM match using the rule for the template
5955 parameters of template template parameters. Both PARM and ARG are
5956 template parameters; the rest of the arguments are the same as for
5957 coerce_template_template_parms.
5958 */
5959 static int
5961 tree arg,
5962 tsubst_flags_t complain,
5963 tree in_decl,
5964 tree outer_args)
5965 {
5974 {
5976 /* We encounter instantiations of templates like
5977 template <template <template <class> class> class TT>
5978 class C; */
5979 {
5986 }
5987 /* Fall through. */
5992 /* Argument is a parameter pack but parameter is not. */
5997 /* The tsubst call is used to handle cases such as
5999 template <int> class C {};
6000 template <class T, template <T> class TT> class D {};
6001 D<int, C> d;
6003 i.e. the parameter list of TT depends on earlier parameters. */
6005 && !same_type_p
6012 /* Argument is a parameter pack but parameter is not. */
6019 }
6022 }
6025 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6026 template template parameters. Both PARM_PARMS and ARG_PARMS are
6027 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6028 or PARM_DECL.
6030 Consider the example:
6031 template <class T> class A;
6032 template<template <class U> class TT> class B;
6034 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6035 the parameters to A, and OUTER_ARGS contains A. */
6037 static int
6039 tree arg_parms,
6040 tsubst_flags_t complain,
6041 tree in_decl,
6042 tree outer_args)
6043 {
6054 /* Determine whether we have a parameter pack at the end of the
6055 template template parameter's template parameter list. */
6057 {
6064 {
6078 }
6079 }
6085 /* Check all of the template parameters except the parameter pack at
6086 the end (if any). */
6088 {
6097 outer_args))
6100 }
6103 {
6104 /* Check each of the template parameters in the template
6105 argument against the template parameter pack at the end of
6106 the template template parameter. */
6113 {
6120 outer_args))
6122 }
6123 }
6126 }
6128 /* Verifies that the deduced template arguments (in TARGS) for the
6129 template template parameters (in TPARMS) represent valid bindings,
6130 by comparing the template parameter list of each template argument
6131 to the template parameter list of its corresponding template
6132 template parameter, in accordance with DR150. This
6133 routine can only be called after all template arguments have been
6134 deduced. It will return TRUE if all of the template template
6135 parameter bindings are okay, FALSE otherwise. */
6136 bool
6138 {
6142 /* We're dealing with template parms in this process. */
6148 {
6153 {
6158 {
6159 /* Look inside the argument pack. */
6162 }
6165 {
6169 /* Extract the next argument from the argument
6170 pack. */
6174 /* Look at the pattern of the pack expansion. */
6177 /* Extract the template parameters from the template
6178 argument. */
6184 /* Verify that we can coerce the template template
6185 parameters from the template argument to the template
6186 parameter. This requires an exact match. */
6188 && !coerce_template_template_parms
6190 targ_parms,
6191 tf_none,
6192 tparm,
6193 targs))
6194 {
6197 }
6198 }
6199 }
6200 }
6202 out:
6206 }
6208 /* Since type attributes aren't mangled, we need to strip them from
6209 template type arguments. */
6211 static tree
6213 {
6214 tree mv;
6221 {
6226 }
6228 }
6230 /* Convert the indicated template ARG as necessary to match the
6231 indicated template PARM. Returns the converted ARG, or
6232 error_mark_node if the conversion was unsuccessful. Error and
6233 warning messages are issued under control of COMPLAIN. This
6234 conversion is for the Ith parameter in the parameter list. ARGS is
6235 the full set of template arguments deduced so far. */
6237 static tree
6239 tree arg,
6240 tree args,
6241 tsubst_flags_t complain,
6243 tree in_decl)
6244 {
6245 tree orig_arg;
6246 tree val;
6251 {
6252 /* The template argument was the name of some
6253 member function. That's usually
6254 invalid, but static members are OK. In any
6255 case, grab the underlying fields/functions
6256 and issue an error later if required. */
6259 }
6267 /* When determining whether an argument pack expansion is a template,
6268 look at the pattern. */
6272 /* Deal with an injected-class-name used as a template template arg. */
6274 {
6277 {
6287 }
6288 }
6290 is_tmpl_type =
6306 {
6308 {
6312 }
6315 "to refer to a type member of a template parameter, "
6320 typename_type,
6321 complain);
6324 }
6326 {
6328 {
6330 {
6340 else
6342 }
6343 }
6345 }
6347 {
6349 {
6355 else
6357 }
6359 }
6362 {
6364 {
6368 /* The number of argument required is not known yet.
6369 Just accept it for now. */
6371 else
6372 {
6374 tree argparm;
6376 /* Strip alias templates that are equivalent to another
6377 template. */
6383 args))
6384 {
6387 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6388 TEMPLATE_DECL. */
6390 {
6395 }
6396 }
6397 else
6398 {
6400 {
6406 }
6409 }
6410 }
6411 }
6412 else
6414 /* We only form one instance of each template specialization.
6415 Therefore, if we use a non-canonical variant (i.e., a
6416 typedef), any future messages referring to the type will use
6417 the typedef, which is confusing if those future uses do not
6418 themselves also use the typedef. */
6421 }
6422 else
6423 {
6430 {
6433 else
6434 {
6435 /* Not sure if this is reachable, but it doesn't hurt
6436 to be robust. */
6439 }
6440 }
6443 /* We used to call digest_init here. However, digest_init
6444 will report errors, which we don't want when complain
6445 is zero. More importantly, digest_init will try too
6446 hard to convert things: for example, `0' should not be
6447 converted to pointer type at this point according to
6448 the standard. Accepting this is not merely an
6449 extension, since deciding whether or not these
6450 conversions can occur is part of determining which
6451 function template to call, or whether a given explicit
6452 argument specification is valid. */
6454 else
6463 {
6464 /* Strip typedefs from the SCOPE_REF. */
6467 complain);
6470 }
6471 }
6474 }
6476 /* Coerces the remaining template arguments in INNER_ARGS (from
6477 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6478 Returns the coerced argument pack. PARM_IDX is the position of this
6479 parameter in the template parameter list. ARGS is the original
6480 template argument list. */
6481 static tree
6484 tree args,
6485 tree inner_args,
6487 tree new_args,
6489 tree in_decl,
6490 tsubst_flags_t complain)
6491 {
6494 tree packed_args;
6495 tree argument_pack;
6505 {
6506 /* When the template parameter is a non-type template
6507 parameter pack whose type uses parameter packs, we need
6508 to look at each of the template arguments
6509 separately. Build a vector of the types for these
6510 non-type template parameters in PACKED_TYPES. */
6511 tree expansion
6519 /* Check that we have the right number of arguments. */
6523 {
6524 int needed_parms
6529 }
6531 /* If we aren't able to check the actual arguments now
6532 (because they haven't been expanded yet), we can at least
6533 verify that all of the types used for the non-type
6534 template parameter pack are, in fact, valid for non-type
6535 template parameters. */
6538 {
6541 {
6545 }
6546 }
6547 }
6549 /* Convert the remaining arguments, which will be a part of the
6550 parameter pack "parm". */
6552 {
6557 {
6558 /* When we have a vector of types (corresponding to the
6559 non-type template parameter pack that uses parameter
6560 packs in its type, as mention above), and the
6561 argument is not an expansion (which expands to a
6562 currently unknown number of arguments), clone the
6563 parm and give it the next type in PACKED_TYPES. */
6567 }
6570 {
6573 }
6574 else
6577 in_decl);
6581 }
6586 else
6587 {
6592 }
6595 #ifdef ENABLE_CHECKING
6598 #endif
6600 }
6602 /* Returns the number of pack expansions in the template argument vector
6603 ARGS. */
6605 static int
6607 {
6612 {
6616 }
6618 }
6620 /* Convert all template arguments to their appropriate types, and
6621 return a vector containing the innermost resulting template
6622 arguments. If any error occurs, return error_mark_node. Error and
6623 warning messages are issued under control of COMPLAIN.
6625 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6626 for arguments not specified in ARGS. Otherwise, if
6627 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6628 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6629 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6630 ARGS. */
6632 static tree
6634 tree args,
6635 tree in_decl,
6636 tsubst_flags_t complain,
6639 {
6641 tree inner_args;
6642 tree new_args;
6643 tree new_inner_args;
6647 /* When used as a boolean value, indicates whether this is a
6648 variadic template parameter list. Since it's an int, we can also
6649 subtract it from nparms to get the number of non-variadic
6650 parameters. */
6660 /* Determine if there are any parameter packs. */
6662 {
6668 }
6671 /* If there are no parameters that follow a parameter pack, we need to
6672 expand any argument packs so that we can deduce a parameter pack from
6673 some non-packed args followed by an argument pack, as in variadic85.C.
6674 If there are such parameters, we need to leave argument packs intact
6675 so the arguments are assigned properly. This can happen when dealing
6676 with a nested class inside a partial specialization of a class
6677 template, as in variadic92.C, or when deducing a template parameter pack
6678 from a sub-declarator, as in variadic114.C. */
6682 /* Count any pack expansion args. */
6688 && require_all_args
6689 && !variadic_args_p
6690 && (!use_default_args
6693 {
6695 {
6697 {
6701 }
6702 else
6708 }
6711 }
6712 /* We can't pass a pack expansion to a non-pack parameter of an alias
6713 template (DR 1430). */
6715 && variadic_args_p
6717 {
6719 {
6721 {
6727 {
6732 }
6733 }
6735 found:;
6736 }
6738 }
6740 /* We need to evaluate the template arguments, even though this
6741 template-id may be nested within a "sizeof". */
6749 {
6750 tree arg;
6751 tree parm;
6753 /* Get the Ith template parameter. */
6757 {
6760 }
6762 /* Calculate the next argument. */
6765 else
6770 {
6771 /* All remaining arguments will be placed in the
6772 template parameter pack PARM. */
6778 /* Store this argument. */
6780 lost++;
6783 /* We are done with all of the arguments. */
6787 }
6789 {
6791 {
6792 /* We don't know how many args we have yet, just
6793 use the unconverted ones for now. */
6796 }
6797 }
6799 {
6800 /* There must be a default arg in this case. */
6803 /* The position of the first default template argument,
6804 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6805 Record that. */
6808 }
6809 else
6813 {
6816 }
6818 /* This only occurs if there was an error in the template
6819 parameter list itself (which we would already have
6820 reported) that we are trying to recover from, e.g., a class
6821 template with a parameter list such as
6822 template<typename..., typename>. */
6824 else
6830 lost++;
6832 }
6839 #ifdef ENABLE_CHECKING
6843 #endif
6846 }
6848 /* Like coerce_template_parms. If PARMS represents all template
6849 parameters levels, this function returns a vector of vectors
6850 representing all the resulting argument levels. Note that in this
6851 case, only the innermost arguments are coerced because the
6852 outermost ones are supposed to have been coerced already.
6854 Otherwise, if PARMS represents only (the innermost) vector of
6855 parameters, this function returns a vector containing just the
6856 innermost resulting arguments. */
6858 static tree
6860 tree args,
6861 tree in_decl,
6862 tsubst_flags_t complain,
6865 {
6868 tree coerced_args;
6871 {
6873 tree level;
6879 {
6880 tree l;
6884 require_all_args,
6885 use_default_args);
6886 else
6893 }
6894 }
6895 else
6898 require_all_args,
6899 use_default_args);
6901 }
6903 /* Returns 1 if template args OT and NT are equivalent. */
6905 static int
6907 {
6914 /* For member templates */
6923 {
6940 }
6942 {
6943 /* We get here probably because we are in the middle of substituting
6944 into the pattern of a pack expansion. In that case the
6945 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6946 interested in. So we want to use the initial pack argument for
6947 the comparison. */
6952 }
6957 else
6959 }
6961 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
6962 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
6963 NEWARG_PTR with the offending arguments if they are non-NULL. */
6965 static int
6968 {
6981 {
6986 {
6992 }
6993 }
6995 }
6997 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6998 of template arguments. Returns 0 otherwise. */
7000 int
7002 {
7004 }
7006 static void
7008 {
7018 /* We are called both from instantiate_decl, where we've already had a
7019 tinst_level pushed, and instantiate_template, where we haven't.
7020 Compensate. */
7031 else
7040 }
7043 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7044 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7045 documentation for TEMPLATE_ID_EXPR. */
7047 tree
7049 {
7050 tree type;
7058 {
7061 }
7064 {
7066 unknown_type_node,
7068 arglist);
7070 }
7077 }
7079 /* Within the scope of a template class S<T>, the name S gets bound
7080 (in build_self_reference) to a TYPE_DECL for the class, not a
7081 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7082 or one of its enclosing classes, and that type is a template,
7083 return the associated TEMPLATE_DECL. Otherwise, the original
7084 DECL is returned.
7086 Also handle the case when DECL is a TREE_LIST of ambiguous
7087 injected-class-names from different bases. */
7089 tree
7091 {
7095 /* DR 176: A lookup that finds an injected-class-name (10.2
7096 [class.member.lookup]) can result in an ambiguity in certain cases
7097 (for example, if it is found in more than one base class). If all of
7098 the injected-class-names that are found refer to specializations of
7099 the same class template, and if the name is followed by a
7100 template-argument-list, the reference refers to the class template
7101 itself and not a specialization thereof, and is not ambiguous. */
7103 {
7106 {
7112 }
7115 else
7117 }
7123 }
7125 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
7126 parameters, find the desired type.
7128 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7130 IN_DECL, if non-NULL, is the template declaration we are trying to
7131 instantiate.
7133 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7134 the class we are looking up.
7136 Issue error and warning messages under control of COMPLAIN.
7138 If the template class is really a local class in a template
7139 function, then the FUNCTION_CONTEXT is the function in which it is
7140 being instantiated.
7142 ??? Note that this function is currently called *twice* for each
7143 template-id: the first time from the parser, while creating the
7144 incomplete type (finish_template_type), and the second type during the
7145 real instantiation (instantiate_template_class). This is surely something
7146 that we want to avoid. It also causes some problems with argument
7147 coercion (see convert_nontype_argument for more information on this). */
7149 static tree
7152 {
7154 tree t;
7157 spec_entry elt;
7158 hashval_t hash;
7161 {
7165 else
7166 {
7173 }
7176 }
7178 {
7181 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7182 an implicit typename for the second A. Deal with it. */
7187 {
7190 }
7191 }
7194 {
7197 }
7201 {
7205 }
7207 {
7210 }
7212 /* Issue an error message if we didn't find a template. */
7214 {
7218 }
7221 /* Make sure it's a user visible template, if it was named by
7222 the user. */
7225 {
7227 {
7231 }
7233 }
7237 /* An alias that just changes the name of a template is equivalent to the
7238 other template, so if any of the arguments are pack expansions, strip
7239 the alias to avoid problems with a pack expansion passed to a non-pack
7240 alias template parameter (DR 1430). */
7245 {
7246 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7247 template arguments */
7249 tree parm;
7250 tree arglist2;
7251 tree outer;
7255 /* Consider an example where a template template parameter declared as
7257 template <class T, class U = std::allocator<T> > class TT
7259 The template parameter level of T and U are one level larger than
7260 of TT. To proper process the default argument of U, say when an
7261 instantiation `TT<int>' is seen, we need to build the full
7262 arguments containing {int} as the innermost level. Outer levels,
7263 available when not appearing as default template argument, can be
7264 obtained from the arguments of the enclosing template.
7266 Suppose that TT is later substituted with std::vector. The above
7267 instantiation is `TT<int, std::allocator<T> >' with TT at
7268 level 1, and T at level 2, while the template arguments at level 1
7269 becomes {std::vector} and the inner level 2 is {int}. */
7275 /* This is an argument of the current template, so we haven't set
7276 DECL_CONTEXT yet. */
7283 complain,
7293 }
7294 else
7295 {
7297 tree gen_tmpl;
7298 tree type_decl;
7306 /* An error occurred while building the template TEMPL, and a
7307 diagnostic has most certainly been emitted for that
7308 already. Let's propagate that error. */
7317 {
7318 /* We've been given an incomplete set of template arguments.
7319 For example, given:
7321 template <class T> struct S1 {
7322 template <class U> struct S2 {};
7323 template <class U> struct S2<U*> {};
7324 };
7326 we will be called with an ARGLIST of `U*', but the
7327 TEMPLATE will be `template <class T> template
7328 <class U> struct S1<T>::S2'. We must fill in the missing
7329 arguments. */
7330 arglist
7332 arglist);
7334 }
7336 /* Now we should have enough arguments. */
7339 /* From here on, we're only interested in the most general
7340 template. */
7342 /* Calculate the BOUND_ARGS. These will be the args that are
7343 actually tsubst'd into the definition to create the
7344 instantiation. */
7346 {
7347 /* We have multiple levels of arguments to coerce, at once. */
7357 {
7358 tree a;
7362 complain,
7365 else
7366 /* Outer levels should have already been coerced. */
7369 /* Don't process further if one of the levels fails. */
7371 {
7372 /* Restore the ARGLIST to its full size. */
7375 }
7379 /* We temporarily reduce the length of the ARGLIST so
7380 that coerce_template_parms will see only the arguments
7381 corresponding to the template parameters it is
7382 examining. */
7384 }
7386 /* Restore the ARGLIST to its full size. */
7390 }
7391 else
7392 arglist
7395 gen_tmpl,
7396 complain,
7401 /* We were unable to bind the arguments. */
7404 /* In the scope of a template class, explicit references to the
7405 template class refer to the type of the template, not any
7406 instantiation of it. For example, in:
7408 template <class T> class C { void f(C<T>); }
7410 the `C<T>' is just the same as `C'. Outside of the
7411 class, however, such a reference is an instantiation. */
7415 /* comp_template_args is expensive, check it last. */
7417 arglist))
7420 /* If we already have this specialization, return it. */
7432 /* If the deduced arguments are invalid, then the binding
7433 failed. */
7437 complain))
7444 {
7449 }
7459 /* Create the type. */
7461 {
7463 {
7469 }
7470 else
7471 {
7472 /* We don't want to call start_enum for this type, since
7473 the values for the enumeration constants may involve
7474 template parameters. And, no one should be interested
7475 in the enumeration constants for such a type. */
7478 }
7482 }
7484 {
7485 /* The user referred to a specialization of an alias
7486 template represented by GEN_TMPL.
7488 [temp.alias]/2 says:
7490 When a template-id refers to the specialization of an
7491 alias template, it is equivalent to the associated
7492 type obtained by substitution of its
7493 template-arguments for the template-parameters in the
7494 type-id of the alias template. */
7497 /* Note that the call above (by indirectly calling
7498 register_specialization in tsubst_decl) registers the
7499 TYPE_DECL representing the specialization of the alias
7500 template. So next time someone substitutes ARGLIST for
7501 the template parms into the alias template (GEN_TMPL),
7502 she'll get that TYPE_DECL back. */
7506 }
7508 {
7515 /* A local class. Make sure the decl gets registered properly. */
7520 /* This instantiation is another name for the primary
7521 template type. Set the TYPE_CANONICAL field
7522 appropriately. */
7525 /* Some of the template arguments require structural
7526 equality testing, so this template class requires
7527 structural equality testing. */
7529 }
7530 else
7533 /* If we called start_enum or pushtag above, this information
7534 will already be set up. */
7536 {
7543 }
7544 else
7548 {
7554 {
7557 }
7558 }
7560 /* Let's consider the explicit specialization of a member
7561 of a class template specialization that is implicitely instantiated,
7562 e.g.:
7563 template<class T>
7564 struct S
7565 {
7566 template<class U> struct M {}; //#0
7567 };
7569 template<>
7570 template<>
7571 struct S<int>::M<char> //#1
7572 {
7573 int i;
7574 };
7575 [temp.expl.spec]/4 says this is valid.
7577 In this case, when we write:
7578 S<int>::M<char> m;
7580 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7581 the one of #0.
7583 When we encounter #1, we want to store the partial instantiation
7584 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
7586 For all cases other than this "explicit specialization of member of a
7587 class template", we just want to store the most general template into
7588 the CLASSTYPE_TI_TEMPLATE of M.
7590 This case of "explicit specialization of member of a class template"
7591 only happens when:
7592 1/ the enclosing class is an instantiation of, and therefore not
7593 the same as, the context of the most general template, and
7594 2/ we aren't looking at the partial instantiation itself, i.e.
7595 the innermost arguments are not the same as the innermost parms of
7596 the most general template.
7598 So it's only when 1/ and 2/ happens that we want to use the partial
7599 instantiation of the member template in lieu of its most general
7600 template. */
7604 /* the enclosing class must be an instantiation... */
7607 {
7608 tree partial_inst_args;
7611 partial_inst_args =
7617 use_partial_inst_tmpl =
7618 /*...and we must not be looking at the partial instantiation
7619 itself. */
7621 partial_inst_args);
7622 }
7625 /* This case is easy; there are no member templates involved. */
7627 else
7628 {
7629 /* This is a full instantiation of a member template. Find
7630 the partial instantiation of which this is an instance. */
7632 /* Temporarily reduce by one the number of levels in the ARGLIST
7633 so as to avoid comparing the last set of arguments. */
7637 /* FOUND is either a proper class type, or an alias
7638 template specialization. In the later case, it's a
7639 TYPE_DECL, resulting from the substituting of arguments
7640 for parameters in the TYPE_DECL of the alias template
7641 done earlier. So be careful while getting the template
7642 of FOUND. */
7646 }
7657 /* Note this use of the partial instantiation so we can check it
7658 later in maybe_process_partial_specialization. */
7664 /* Now that the type has been registered on the instantiations
7665 list, we set up the enumerators. Because the enumeration
7666 constants may involve the enumeration type itself, we make
7667 sure to register the type first, and then create the
7668 constants. That way, doing tsubst_expr for the enumeration
7669 constants won't result in recursive calls here; we'll find
7670 the instantiation and exit above. */
7674 /* If the type makes use of template parameters, the
7675 code that generates debugging information will crash. */
7678 /* Possibly limit visibility based on template args. */
7683 }
7684 }
7686 /* Wrapper for lookup_template_class_1. */
7688 tree
7691 {
7692 tree ret;
7698 }
7699 \f
7700 struct pair_fn_data
7701 {
7702 tree_fn_t fn;
7704 /* True when we should also visit template parameters that occur in
7705 non-deduced contexts. */
7708 };
7710 /* Called from for_each_template_parm via walk_tree. */
7712 static tree
7714 {
7727 {
7731 /* Fall through. */
7754 /* Since we're not going to walk subtrees, we have to do this
7755 explicitly here. */
7759 /* Fall through. */
7762 /* Check the return type. */
7767 /* Check the parameter types. Since default arguments are not
7768 instantiated until they are needed, the TYPE_ARG_TYPES may
7769 contain expressions that involve template parameters. But,
7770 no-one should be looking at them yet. And, once they're
7771 instantiated, they don't contain template parameters, so
7772 there's no point in looking at them then, either. */
7773 {
7774 tree parm;
7781 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7782 want walk_tree walking into them itself. */
7784 }
7802 /* Fall through. */
7818 /* Record template parameters such as `T' inside `TT<T>'. */
7822 /* Fall through. */
7834 /* A template template parameter is encountered. */
7840 /* Already substituted template template parameter */
7863 /* If there's no type, then this thing must be some expression
7864 involving template parameters. */
7886 }
7888 /* We didn't find any template parameters we liked. */
7890 }
7892 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7893 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7894 call FN with the parameter and the DATA.
7895 If FN returns nonzero, the iteration is terminated, and
7896 for_each_template_parm returns 1. Otherwise, the iteration
7897 continues. If FN never returns a nonzero value, the value
7898 returned by for_each_template_parm is 0. If FN is NULL, it is
7899 considered to be the function which always returns 1.
7901 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7902 parameters that occur in non-deduced contexts. When false, only
7903 visits those template parameters that can be deduced. */
7905 static int
7909 {
7913 /* Set up. */
7918 /* Walk the tree. (Conceptually, we would like to walk without
7919 duplicates, but for_each_template_parm_r recursively calls
7920 for_each_template_parm, so we would need to reorganize a fair
7921 bit to use walk_tree_without_duplicates, so we keep our own
7922 visited list.) */
7925 else
7928 for_each_template_parm_r,
7932 /* Clean up. */
7934 {
7937 }
7940 }
7942 /* Returns true if T depends on any template parameter. */
7944 int
7946 {
7973 else
7974 {
7977 }
7982 }
7984 /* Returns true iff current_function_decl is an incompletely instantiated
7985 template. Useful instead of processing_template_decl because the latter
7986 is set to 0 during fold_non_dependent_expr. */
7988 bool
7990 {
7999 }
8001 /* Returns true if T depends on any template parameter with level LEVEL. */
8003 int
8005 {
8008 }
8010 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8011 ill-formed translation unit, i.e. a variable or function that isn't
8012 usable in a constant expression. */
8016 {
8020 }
8022 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8023 neglectable and instantiated from within an erroneous instantiation. */
8025 static bool
8027 {
8038 }
8046 /* We're starting to instantiate D; record the template instantiation context
8047 for diagnostics and to restore it later. */
8049 int
8051 {
8055 {
8061 else
8069 }
8071 /* If the current instantiation caused problems, don't let it instantiate
8072 anything else. Do allow deduction substitution and decls usable in
8073 constant expressions. */
8090 }
8092 /* We're done instantiating this template; return to the instantiation
8093 context. */
8095 void
8097 {
8098 /* Restore the filename and line number stashed away when we started
8099 this instantiation. */
8103 }
8105 /* We're instantiating a deferred template; restore the template
8106 instantiation context in which the instantiation was requested, which
8107 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8109 static tree
8111 {
8123 }
8125 /* Returns the TINST_LEVEL which gives the original instantiation
8126 context. */
8130 {
8136 }
8138 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8139 vector of template arguments, as for tsubst.
8141 Returns an appropriate tsubst'd friend declaration. */
8143 static tree
8145 {
8146 tree new_friend;
8151 /* This was a friend declared with an explicit template
8152 argument list, e.g.:
8154 friend void f<>(T);
8156 to indicate that f was a template instantiation, not a new
8157 function declaration. Now, we have to figure out what
8158 instantiation of what template. */
8159 {
8161 tree new_args;
8162 tree tmpl;
8165 /* Friend functions are looked up in the containing namespace scope.
8166 We must enter that scope, to avoid finding member functions of the
8167 current class with same name. */
8182 tsk_none);
8184 }
8188 /* The NEW_FRIEND will look like an instantiation, to the
8189 compiler, but is not an instantiation from the point of view of
8190 the language. For example, we might have had:
8192 template <class T> struct S {
8193 template <class U> friend void f(T, U);
8194 };
8196 Then, in S<int>, template <class U> void f(int, U) is not an
8197 instantiation of anything. */
8203 {
8207 }
8209 /* The mangled name for the NEW_FRIEND is incorrect. The function
8210 is not a template instantiation and should not be mangled like
8211 one. Therefore, we forget the mangling here; we'll recompute it
8212 later if we need it. */
8214 {
8217 }
8220 {
8221 tree old_decl;
8222 tree new_friend_template_info;
8223 tree new_friend_result_template_info;
8224 tree ns;
8227 /* We must save some information from NEW_FRIEND before calling
8228 duplicate decls since that function will free NEW_FRIEND if
8229 possible. */
8231 new_friend_is_defn =
8236 {
8237 /* This declaration is a `primary' template. */
8240 new_friend_result_template_info
8242 }
8243 else
8246 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8250 /* Inside pushdecl_namespace_level, we will push into the
8251 current namespace. However, the friend function should go
8252 into the namespace of the template. */
8262 {
8263 /* This new friend declaration matched an existing
8264 declaration. For example, given:
8266 template <class T> void f(T);
8267 template <class U> class C {
8268 template <class T> friend void f(T) {}
8269 };
8271 the friend declaration actually provides the definition
8272 of `f', once C has been instantiated for some type. So,
8273 old_decl will be the out-of-class template declaration,
8274 while new_friend is the in-class definition.
8276 But, if `f' was called before this point, the
8277 instantiation of `f' will have DECL_TI_ARGS corresponding
8278 to `T' but not to `U', references to which might appear
8279 in the definition of `f'. Previously, the most general
8280 template for an instantiation of `f' was the out-of-class
8281 version; now it is the in-class version. Therefore, we
8282 run through all specialization of `f', adding to their
8283 DECL_TI_ARGS appropriately. In particular, they need a
8284 new set of outer arguments, corresponding to the
8285 arguments for this class instantiation.
8287 The same situation can arise with something like this:
8289 friend void f(int);
8290 template <class T> class C {
8291 friend void f(T) {}
8292 };
8294 when `C<int>' is instantiated. Now, `f(int)' is defined
8295 in the class. */
8298 /* On the other hand, if the in-class declaration does
8299 *not* provide a definition, then we don't want to alter
8300 existing definitions. We can just leave everything
8301 alone. */
8302 ;
8303 else
8304 {
8308 /* Overwrite whatever template info was there before, if
8309 any, with the new template information pertaining to
8310 the declaration. */
8314 {
8315 /* We should have called reregister_specialization in
8316 duplicate_decls. */
8321 /* Instantiate it if the global has already been used. */
8325 }
8326 else
8327 {
8328 tree t;
8330 /* Indicate that the old function template is a partial
8331 instantiation. */
8339 /* Reassign any specializations already in the hash table
8340 to the new more general template, and add the
8341 additional template args. */
8345 {
8347 spec_entry elt;
8359 register_specialization
8362 }
8364 }
8365 }
8367 /* The information from NEW_FRIEND has been merged into OLD_DECL
8368 by duplicate_decls. */
8370 }
8371 }
8372 else
8373 {
8377 /* In the code
8378 template <class T> class C {
8379 template <class U> friend void C1<U>::f (); // case 1
8380 friend void C2<T>::f (); // case 2
8381 };
8382 we only need to make sure CONTEXT is a complete type for
8383 case 2. To distinguish between the two cases, we note that
8384 CONTEXT of case 1 remains dependent type after tsubst while
8385 this isn't true for case 2. */
8395 {
8396 /* Check to see that the declaration is really present, and,
8397 possibly obtain an improved declaration. */
8403 }
8404 }
8407 }
8409 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8410 template arguments, as for tsubst.
8412 Returns an appropriate tsubst'd friend type or error_mark_node on
8413 failure. */
8415 static tree
8417 {
8418 tree friend_type;
8419 tree tmpl;
8420 tree context;
8423 {
8426 }
8431 {
8434 else
8436 }
8438 /* Look for a class template declaration. We look for hidden names
8439 because two friend declarations of the same template are the
8440 same. For example, in:
8442 struct A {
8443 template <typename> friend class F;
8444 };
8445 template <typename> struct B {
8446 template <typename> friend class F;
8447 };
8449 both F templates are the same. */
8453 /* But, if we don't find one, it might be because we're in a
8454 situation like this:
8456 template <class T>
8457 struct S {
8458 template <class U>
8459 friend struct S;
8460 };
8462 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8463 for `S<int>', not the TEMPLATE_DECL. */
8465 {
8468 }
8471 {
8472 /* The friend template has already been declared. Just
8473 check to see that the declarations match, and install any new
8474 default parameters. We must tsubst the default parameters,
8475 of course. We only need the innermost template parameters
8476 because that is all that redeclare_class_template will look
8477 at. */
8480 {
8481 tree parms;
8482 location_t saved_input_location;
8491 }
8494 }
8495 else
8496 {
8497 /* The friend template has not already been declared. In this
8498 case, the instantiation of the template class will cause the
8499 injection of this template into the global scope. */
8504 /* The new TMPL is not an instantiation of anything, so we
8505 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8506 the new type because that is supposed to be the corresponding
8507 template decl, i.e., TMPL. */
8514 /* Inject this template into the global scope. */
8516 }
8519 {
8522 else
8524 }
8527 }
8529 /* Returns zero if TYPE cannot be completed later due to circularity.
8530 Otherwise returns one. */
8532 static int
8534 {
8544 else
8546 }
8548 /* Apply any attributes which had to be deferred until instantiation
8549 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8550 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8552 static void
8555 {
8557 tree t;
8562 {
8566 }
8569 {
8573 }
8574 else
8578 {
8583 {
8586 {
8589 /* If the first attribute argument is an identifier, don't
8590 pass it through tsubst. Attributes like mode, format,
8591 cleanup and several target specific attributes expect it
8592 unmodified. */
8597 {
8598 tree chain
8600 in_decl,
8605 chain);
8606 }
8607 else
8613 }
8614 else
8616 }
8619 }
8620 }
8622 /* Perform (or defer) access check for typedefs that were referenced
8623 from within the template TMPL code.
8624 This is a subroutine of instantiate_decl and instantiate_class_template.
8625 TMPL is the template to consider and TARGS is the list of arguments of
8626 that template. */
8628 static void
8630 {
8631 location_t saved_location;
8642 {
8654 /* Make access check error messages point to the location
8655 of the use of the typedef. */
8659 tf_warning_or_error);
8660 }
8662 }
8664 static tree
8666 {
8668 tree typedecl;
8669 tree pbinfo;
8670 tree base_list;
8672 tree fn_context;
8681 /* Figure out which template is being instantiated. */
8685 /* Determine what specialization of the original template to
8686 instantiate. */
8689 {
8692 }
8694 {
8695 /* This TYPE is actually an instantiation of a partial
8696 specialization. We replace the innermost set of ARGS with
8697 the arguments appropriate for substitution. For example,
8698 given:
8700 template <class T> struct S {};
8701 template <class T> struct S<T*> {};
8703 and supposing that we are instantiating S<int*>, ARGS will
8704 presently be {int*} -- but we need {int}. */
8707 }
8708 else
8709 {
8712 }
8714 /* If the template we're instantiating is incomplete, then clearly
8715 there's nothing we can do. */
8719 /* If we've recursively instantiated too many templates, stop. */
8723 /* Now we're really doing the instantiation. Mark the type as in
8724 the process of being defined. */
8727 /* We may be in the middle of deferred access check. Disable
8728 it now. */
8734 /* Use #pragma pack from the template context. */
8740 /* Set the input location to the most specialized template definition.
8741 This is needed if tsubsting causes an error. */
8753 {
8756 /* Adjust visibility for template arguments. */
8758 }
8764 /* We should never instantiate a nested class before its enclosing
8765 class; we need to look up the nested class by name before we can
8766 instantiate it, and that lookup should instantiate the enclosing
8767 class. */
8773 {
8774 tree pbase_binfo;
8775 tree pushed_scope;
8778 /* We must enter the scope containing the type, as that is where
8779 the accessibility of types named in dependent bases are
8780 looked up from. */
8783 /* Substitute into each of the bases to determine the actual
8784 basetypes. */
8786 {
8787 tree base;
8793 {
8794 expanded_bases =
8801 }
8804 {
8806 /* Extract the already-expanded base class. */
8808 else
8809 /* Substitute to figure out the base class. */
8811 NULL_TREE);
8819 }
8820 }
8822 /* The list is now in reverse order; correct that. */
8827 }
8828 /* Now call xref_basetypes to set up all the base-class
8829 information. */
8837 /* Now that our base classes are set up, enter the scope of the
8838 class, so that name lookups into base classes, etc. will work
8839 correctly. This is precisely analogous to what we do in
8840 begin_class_definition when defining an ordinary non-template
8841 class, except we also need to push the enclosing classes. */
8844 /* Now members are processed in the order of declaration. */
8847 {
8851 {
8853 {
8854 /* Build new CLASSTYPE_NESTED_UTDS. */
8856 tree newtag;
8862 /* If the member is a class template, then -- even after
8863 substitution -- there may be dependent types in the
8864 template argument list for the class. We increment
8865 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8866 that function will assume that no types are dependent
8867 when outside of a template. */
8877 {
8881 /* Unfortunately, lookup_template_class sets
8882 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8883 instantiation (i.e., for the type of a member
8884 template class nested within a template class.)
8885 This behavior is required for
8886 maybe_process_partial_specialization to work
8887 correctly, but is not accurate in this case;
8888 the TAG is not an instantiation of anything.
8889 (The corresponding TEMPLATE_DECL is an
8890 instantiation, but the TYPE is not.) */
8893 /* Now, we call pushtag to put this NEWTAG into the scope of
8894 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8895 pushtag calling push_template_decl. We don't have to do
8896 this for enums because it will already have been done in
8897 tsubst_enum. */
8901 }
8902 }
8904 {
8905 /* Build new TYPE_METHODS. */
8906 tree r;
8915 /* Instantiate members marked with attribute used. */
8918 }
8919 else
8920 {
8921 /* Build new TYPE_FIELDS. */
8923 {
8924 tree condition;
8927 condition =
8937 }
8939 {
8940 tree r;
8944 /* The file and line for this declaration, to
8945 assist in error message reporting. Since we
8946 called push_tinst_level above, we don't need to
8947 restore these. */
8957 {
8958 /* A capture pack became multiple fields. */
8961 }
8964 {
8968 {
8969 /* In [temp.inst]:
8971 [t]he initialization (and any associated
8972 side-effects) of a static data member does
8973 not occur unless the static data member is
8974 itself used in a way that requires the
8975 definition of the static data member to
8976 exist.
8978 Therefore, we do not substitute into the
8979 initialized for the static data member here. */
8980 finish_static_data_member_decl
8986 /* Instantiate members marked with attribute used. */
8989 }
8991 {
8992 /* Determine whether R has a valid type and can be
8993 completed later. If R is invalid, then its type
8994 is replaced by error_mark_node. */
9000 {
9003 }
9004 }
9006 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9007 such a thing will already have been added to the field
9008 list by tsubst_enum in finish_member_declaration in the
9009 CLASSTYPE_NESTED_UTDS case above. */
9013 {
9016 }
9017 }
9018 }
9019 }
9020 }
9021 else
9022 {
9025 {
9026 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9032 {
9033 /* template <class T> friend class C; */
9036 }
9038 {
9039 /* template <class T> friend class C::D; */
9045 }
9048 {
9049 /* This could be either
9051 friend class T::C;
9053 when dependent_type_p is false or
9055 template <class U> friend class T::C;
9057 otherwise. */
9060 /* Bump processing_template_decl for correct
9061 dependent_type_p calculation. */
9066 }
9069 {
9070 /* friend class C;
9072 where C hasn't been declared yet. Let's lookup name
9073 from namespace scope directly, bypassing any name that
9074 come from dependent base class. */
9077 /* The call to xref_tag_from_type does injection for friend
9078 classes. */
9080 friend_type =
9084 }
9086 /* friend class C<T>; */
9089 /* Otherwise it's
9091 friend class C;
9093 where C is already declared or
9095 friend class C<int>;
9097 We don't have to do anything in these cases. */
9100 /* Trick make_friend_class into realizing that the friend
9101 we're adding is a template, not an ordinary class. It's
9102 important that we use make_friend_class since it will
9103 perform some error-checking and output cross-reference
9104 information. */
9112 }
9113 else
9114 {
9115 /* Build new DECL_FRIENDLIST. */
9116 tree r;
9118 /* The file and line for this declaration, to
9119 assist in error message reporting. Since we
9120 called push_tinst_level above, we don't need to
9121 restore these. */
9125 {
9128 }
9133 {
9136 }
9137 }
9138 }
9139 }
9142 {
9145 {
9150 /* We need to instantiate the capture list from the template
9151 after we've instantiated the closure members, but before we
9152 consider adding the conversion op. Also keep any captures
9153 that may have been added during instantiation of the op(). */
9155 tree tmpl_cap
9164 }
9165 else
9167 }
9169 /* Set the file and line number information to whatever is given for
9170 the class itself. This puts error messages involving generated
9171 implicit functions at a predictable point, and the same point
9172 that would be used for non-template classes. */
9179 /* We don't instantiate default arguments for member functions. 14.7.1:
9181 The implicit instantiation of a class template specialization causes
9182 the implicit instantiation of the declarations, but not of the
9183 definitions or default arguments, of the class member functions,
9184 member classes, static data members and member templates.... */
9186 /* Some typedefs referenced from within the template code need to be access
9187 checked at template instantiation time, i.e now. These types were
9188 added to the template at parsing time. Let's get those and perform
9189 the access checks then. */
9199 /* The vtable for a template class can be emitted in any translation
9200 unit in which the class is instantiated. When there is no key
9201 method, however, finish_struct_1 will already have added TYPE to
9202 the keyed_classes list. */
9207 }
9209 /* Wrapper for instantiate_class_template_1. */
9211 tree
9213 {
9214 tree ret;
9219 }
9221 static tree
9223 {
9224 tree r;
9230 else
9231 {
9238 /* Preserve the raw-reference nature of T. */
9242 }
9244 }
9246 /* Given a function parameter pack TMPL_PARM and some function parameters
9247 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9248 and set *SPEC_P to point at the next point in the list. */
9250 static tree
9252 {
9253 /* Collect all of the extra "packed" parameters into an
9254 argument pack. */
9255 tree parmvec;
9256 tree parmtypevec;
9267 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9272 {
9275 }
9277 /* Build the argument packs. */
9284 }
9286 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9287 NONTYPE_ARGUMENT_PACK. */
9289 static tree
9291 {
9293 }
9295 /* Return true iff the Ith element of the argument pack ARG_PACK is a
9296 pack expansion. */
9298 static bool
9300 {
9305 }
9308 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9310 static tree
9312 {
9319 }
9321 /* This is a subroutine of tsubst_pack_expansion.
9323 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9324 mechanism to store the (non complete list of) arguments of the
9325 substitution and return a non substituted pack expansion, in order
9326 to wait for when we have enough arguments to really perform the
9327 substitution. */
9329 static bool
9333 {
9334 /* If one pack has an expansion and another pack has a normal
9335 argument or if one pack has an empty argument and an another
9336 one hasn't then tsubst_pack_expansion cannot perform the
9337 substitution and need to fall back on the
9338 PACK_EXPANSION_EXTRA mechanism. */
9346 {
9349 parm_pack;
9351 {
9356 else
9358 }
9362 }
9364 }
9366 /* [temp.variadic]/6 says that:
9368 The instantiation of a pack expansion [...]
9369 produces a list E1,E2, ..., En, where N is the number of elements
9370 in the pack expansion parameters.
9372 This subroutine of tsubst_pack_expansion produces one of these Ei.
9374 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9375 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9376 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9377 INDEX is the index 'i' of the element Ei to produce. ARGS,
9378 COMPLAIN, and IN_DECL are the same parameters as for the
9379 tsubst_pack_expansion function.
9381 The function returns the resulting Ei upon successful completion,
9382 or error_mark_node.
9384 Note that this function possibly modifies the ARGS parameter, so
9385 it's the responsibility of the caller to restore it. */
9387 static tree
9389 tree parm_packs,
9391 tree args /* This parm gets
9393 tsubst_flags_t complain,
9394 tree in_decl)
9395 {
9396 tree t;
9399 /* For each parameter pack, change the substitution of the parameter
9400 pack to the ith argument in its argument pack, then expand the
9401 pattern. */
9403 {
9408 ith_elem_is_expansion |=
9411 /* Select the Ith argument from the pack. */
9414 {
9416 {
9420 }
9421 else
9423 }
9424 else
9425 {
9430 {
9432 /* Update the corresponding argument. */
9434 }
9435 else
9436 /* Re-use the ARGUMENT_PACK_SELECT. */
9438 }
9440 }
9442 /* Substitute into the PATTERN with the (possibly altered)
9443 arguments. */
9447 else
9450 /* If the Ith argument pack element is a pack expansion, then
9451 the Ith element resulting from the substituting is going to
9452 be a pack expansion as well. */
9457 }
9459 /* Substitute ARGS into T, which is an pack expansion
9460 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9461 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9462 (if only a partial substitution could be performed) or
9463 ERROR_MARK_NODE if there was an error. */
9464 tree
9466 tree in_decl)
9467 {
9468 tree pattern;
9472 tree result;
9480 /* Add in any args remembered from an earlier partial instantiation. */
9485 /* Determine the argument packs that will instantiate the parameter
9486 packs used in the expansion expression. While we're at it,
9487 compute the number of arguments to be expanded and make sure it
9488 is consistent. */
9491 {
9498 {
9502 else
9505 }
9507 {
9510 else
9511 {
9512 /* We can't rely on local_specializations for a parameter
9513 name used later in a function declaration (such as in a
9514 late-specified return type). Even if it exists, it might
9515 have the wrong value for a recursive call. Just make a
9516 dummy decl, since it's only used for its type. */
9519 /* Partial instantiation of the parm_pack, we can't build
9520 up an argument pack yet. */
9522 else
9525 }
9526 }
9529 else
9530 {
9536 }
9543 /* This can only happen if we forget to expand an argument
9544 pack somewhere else. Just return an error, silently. */
9545 {
9549 }
9552 {
9556 /* Don't bother trying to do a partial substitution with
9557 incomplete packs; we'll try again after deduction. */
9564 {
9570 pattern);
9571 else
9574 pattern);
9576 }
9578 /* Keep track of the parameter packs and their corresponding
9579 argument packs. */
9582 }
9583 else
9584 {
9585 /* We can't substitute for this parameter pack. We use a flag as
9586 well as the missing_level counter because function parameter
9587 packs don't have a level. */
9589 }
9590 }
9592 /* We cannot expand this expansion expression, because we don't have
9593 all of the argument packs we need. */
9595 {
9596 /* We got some full packs, but we can't substitute them in until we
9597 have values for all the packs. So remember these until then. */
9602 }
9604 {
9605 /* There were no real arguments, we're just replacing a parameter
9606 pack with another version of itself. Substitute into the
9607 pattern and return a PACK_EXPANSION_*. The caller will need to
9608 deal with that. */
9612 else
9616 }
9621 {
9622 /* We're in a late-specified return type, so create our own local
9623 specializations map; the current map is either NULL or (in the
9624 case of recursive unification) might have bindings that we don't
9625 want to use or alter. */
9628 }
9630 /* For each argument in each argument pack, substitute into the
9631 pattern. */
9634 {
9636 i,
9638 in_decl);
9641 {
9644 }
9645 }
9647 /* Update ARGS to restore the substitution from parameter packs to
9648 their argument packs. */
9650 {
9656 else
9657 {
9665 /* Update the corresponding argument. */
9669 else
9671 }
9672 }
9675 {
9678 }
9681 }
9683 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9684 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9685 parameter packs; all parms generated from a function parameter pack will
9686 have the same DECL_PARM_INDEX. */
9688 tree
9690 {
9692 tree patparm;
9695 {
9701 }
9702 else
9703 {
9708 }
9711 }
9713 /* Substitute ARGS into the vector or list of template arguments T. */
9715 static tree
9717 {
9729 {
9731 tree new_arg;
9736 {
9737 /* Substitute into an expansion expression. */
9741 /* Add to the expanded length adjustment the number of
9742 expanded arguments. We subtract one from this
9743 measurement, because the argument pack expression
9744 itself is already counted as 1 in
9745 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9746 the argument pack is empty. */
9748 }
9750 {
9751 /* Substitute into each of the arguments. */
9757 new_arg,
9771 }
9772 }
9773 else
9782 }
9787 /* Make space for the expanded arguments coming from template
9788 argument packs. */
9790 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9791 arguments for a member template.
9792 In that case each TREE_VEC in ORIG_T represents a level of template
9793 arguments, and ORIG_T won't carry any non defaulted argument count.
9794 It will rather be the nested TREE_VECs that will carry one.
9795 In other words, ORIG_T carries a non defaulted argument count only
9796 if it doesn't contain any nested TREE_VEC. */
9798 {
9802 }
9804 {
9808 {
9811 /* Now expand the template argument pack "in place". */
9814 }
9815 else
9816 {
9818 out++;
9819 }
9820 }
9823 }
9825 /* Return the result of substituting ARGS into the template parameters
9826 given by PARMS. If there are m levels of ARGS and m + n levels of
9827 PARMS, then the result will contain n levels of PARMS. For
9828 example, if PARMS is `template <class T> template <class U>
9829 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9830 result will be `template <int*, double, class V>'. */
9832 static tree
9834 {
9838 /* When substituting into a template, we must set
9839 PROCESSING_TEMPLATE_DECL as the template parameters may be
9840 dependent if they are based on one-another, and the dependency
9841 predicates are short-circuit outside of templates. */
9848 {
9849 tree new_vec =
9854 {
9855 tree tuple;
9867 }
9873 }
9878 }
9880 /* Return the result of substituting ARGS into one template parameter
9881 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9882 parameter and which TREE_PURPOSE is the default argument of the
9883 template parameter. */
9885 static tree
9887 {
9908 }
9910 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9911 type T. If T is not an aggregate or enumeration type, it is
9912 handled as if by tsubst. IN_DECL is as for tsubst. If
9913 ENTERING_SCOPE is nonzero, T is the context for a template which
9914 we are presently tsubst'ing. Return the substituted value. */
9916 static tree
9918 tree args,
9919 tsubst_flags_t complain,
9920 tree in_decl,
9922 {
9927 {
9932 /* Else fall through. */
9936 {
9937 tree argvec;
9938 tree context;
9939 tree r;
9943 /* In "sizeof(X<I>)" we need to evaluate "I". */
9949 /* First, determine the context for the type we are looking
9950 up. */
9953 {
9956 /* If context is a nested class inside a class template,
9957 it may still need to be instantiated (c++/33959). */
9959 }
9961 /* Then, figure out what arguments are appropriate for the
9962 type we are trying to find. For example, given:
9964 template <class T> struct S;
9965 template <class T, class U> void f(T, U) { S<U> su; }
9967 and supposing that we are instantiating f<int, double>,
9968 then our ARGS will be {int, double}, but, when looking up
9969 S we only want {double}. */
9974 else
9975 {
9979 }
9985 }
9986 else
9987 /* This is not a template type, so there's nothing to do. */
9992 }
9993 }
9995 /* Substitute into the default argument ARG (a default argument for
9996 FN), which has the indicated TYPE. */
9998 tree
10000 {
10005 /* This can happen in invalid code. */
10009 /* This default argument came from a template. Instantiate the
10010 default argument here, not in tsubst. In the case of
10011 something like:
10013 template <class T>
10014 struct S {
10015 static T t();
10016 void f(T = t());
10017 };
10019 we must be careful to do name lookup in the scope of S<T>,
10020 rather than in the current class. */
10022 /* The "this" pointer is not valid in a default argument. */
10024 {
10029 }
10032 /* The default argument expression may cause implicitly defined
10033 member functions to be synthesized, which will result in garbage
10034 collection. We must treat this situation as if we were within
10035 the body of function so as to avoid collecting live data on the
10036 stack. */
10044 /* Restore the "this" pointer. */
10046 {
10049 }
10056 /* Make sure the default argument is reasonable. */
10062 }
10064 /* Substitute into all the default arguments for FN. */
10066 static void
10068 {
10069 tree arg;
10070 tree tmpl_args;
10074 /* If this function is not yet instantiated, we certainly don't need
10075 its default arguments. */
10078 /* Don't do this again for clones. */
10083 arg;
10089 complain);
10090 }
10092 /* Substitute the ARGS into the T, which is a _DECL. Return the
10093 result of the substitution. Issue error and warning messages under
10094 control of COMPLAIN. */
10096 static tree
10098 {
10099 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10100 location_t saved_loc;
10105 /* Set the filename and linenumber to improve error-reporting. */
10110 {
10112 {
10113 /* We can get here when processing a member function template,
10114 member class template, or template template parameter. */
10116 tree spec;
10117 tree tmpl_args;
10118 tree full_args;
10121 {
10122 /* Template template parameter is treated here. */
10126 /* If we get a real template back, return it. This can happen in
10127 the context of most_specialized_class. */
10139 complain);
10142 }
10144 /* We might already have an instance of this template.
10145 The ARGS are for the surrounding class type, so the
10146 full args contain the tsubst'd args for the context,
10147 plus the innermost args from the template decl. */
10151 /* Because this is a template, the arguments will still be
10152 dependent, even after substitution. If
10153 PROCESSING_TEMPLATE_DECL is not set, the dependency
10154 predicates will short-circuit. */
10162 /* If this is a default template template argument,
10163 tsubst might not have changed anything. */
10170 {
10173 }
10175 /* Make a new template decl. It will be similar to the
10176 original, but will record the current template arguments.
10177 We also create a new function declaration, which is just
10178 like the old one, but points to this new template, rather
10179 than the old one. */
10188 {
10189 tree new_type;
10197 /* For a partial specialization, we need to keep pointing to
10198 the primary template. */
10204 }
10205 else
10206 {
10207 tree new_decl;
10219 }
10225 /* The template parameters for this new template are all the
10226 template parameters for the old template, except the
10227 outermost level of parameters. */
10230 complain);
10236 /* Record this non-type partial instantiation. */
10240 }
10244 {
10245 tree ctx;
10248 tree gen_tmpl;
10249 tree type;
10254 /* Nobody should be tsubst'ing into non-template functions. */
10258 {
10259 tree spec;
10262 /* If T is not dependent, just return it. We have to
10263 increment PROCESSING_TEMPLATE_DECL because
10264 value_dependent_expression_p assumes that nothing is
10265 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10272 /* Calculate the most general template of which R is a
10273 specialization, and the complete set of arguments used to
10274 specialize R. */
10277 (DECL_TEMPLATE_RESULT
10283 /* Check to see if we already have this specialization. */
10288 {
10291 }
10293 /* We can see more levels of arguments than parameters if
10294 there was a specialization of a member template, like
10295 this:
10297 template <class T> struct S { template <class U> void f(); }
10298 template <> template <class U> void S<int>::f(U);
10300 Here, we'll be substituting into the specialization,
10301 because that's where we can find the code we actually
10302 want to generate, but we'll have enough arguments for
10303 the most general template.
10305 We also deal with the peculiar case:
10307 template <class T> struct S {
10308 template <class U> friend void f();
10309 };
10310 template <class U> void f() {}
10311 template S<int>;
10312 template void f<double>();
10314 Here, the ARGS for the instantiation of will be {int,
10315 double}. But, we only need as many ARGS as there are
10316 levels of template parameters in CODE_PATTERN. We are
10317 careful not to get fooled into reducing the ARGS in
10318 situations like:
10320 template <class T> struct S { template <class U> void f(U); }
10321 template <class T> template <> void S<T>::f(int) {}
10323 which we can spot because the pattern will be a
10324 specialization in this case. */
10326 parms_depth =
10331 }
10332 else
10333 {
10334 /* This special case arises when we have something like this:
10336 template <class T> struct S {
10337 friend void f<int>(int, double);
10338 };
10340 Here, the DECL_TI_TEMPLATE for the friend declaration
10341 will be an IDENTIFIER_NODE. We are being called from
10342 tsubst_friend_function, and we want only to create a
10343 new decl (R) with appropriate types so that we can call
10344 determine_specialization. */
10346 }
10349 {
10352 else
10356 }
10357 else
10358 {
10361 }
10366 /* If we hit excessive deduction depth, the type is bogus even if
10367 it isn't error_mark_node, so don't build a decl. */
10371 /* We do NOT check for matching decls pushed separately at this
10372 point, as they may not represent instantiations of this
10373 template, and in any case are considered separate under the
10374 discrete model. */
10378 /* Clear out the mangled name and RTL for the instantiation. */
10381 /* Leave DECL_INITIAL set on deleted instantiations. */
10387 /* Type-conversion operator. Reconstruct the name, in
10388 case it's the name of one of the template's parameters. */
10398 /* If this is an instantiation of a function with internal
10399 linkage, we already know what object file linkage will be
10400 assigned to the instantiation. */
10409 /* We'll re-clone as appropriate in instantiate_template. */
10412 /* If we aren't complaining now, return on error before we register
10413 the specialization so that we'll complain eventually. */
10419 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10420 this in the special friend case mentioned above where
10421 GEN_TMPL is NULL. */
10423 {
10428 tree new_r
10431 /* We instantiated this while substituting into
10432 the type earlier (template/friend54.C). */
10435 /* We're not supposed to instantiate default arguments
10436 until they are called, for a template. But, for a
10437 declaration like:
10439 template <class T> void f ()
10440 { extern void g(int i = T()); }
10442 we should do the substitution when the template is
10443 instantiated. We handle the member function case in
10444 instantiate_class_template since the default arguments
10445 might refer to other members of the class. */
10450 }
10451 else
10454 /* Copy the list of befriending classes. */
10458 {
10462 in_decl);
10463 }
10466 {
10472 /* If this is an instantiation of a member template, clone it.
10473 If it isn't, that'll be handled by
10474 clone_constructors_and_destructors. */
10477 }
10488 /* Possibly limit visibility based on template args. */
10491 {
10495 }
10503 }
10507 {
10515 {
10516 /* If there is a local specialization that isn't a
10517 parameter pack, it means that we're doing a "simple"
10518 substitution from inside tsubst_pack_expansion. Just
10519 return the local specialization (which will be a single
10520 parm). */
10527 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10528 the parameters in this function parameter pack. */
10532 {
10535 /* Zero-length parameter packs are boring. Just substitute
10536 into the chain. */
10540 }
10541 else
10542 {
10543 /* All we did was update the type. Make a note of that. */
10546 }
10547 }
10549 /* Loop through all of the parameters we'll build. When T is
10550 a function parameter pack, LEN is the number of expanded
10551 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10554 {
10561 /* We're on the Ith parameter of the function parameter
10562 pack. */
10563 {
10564 /* Get the Ith type. */
10567 /* Rename the parameter to include the index. */
10570 }
10572 /* We're dealing with a normal parameter. */
10580 {
10583 else
10586 }
10596 /* Keep track of the first new parameter we
10597 generate. That's what will be returned to the
10598 caller. */
10602 /* Build a proper chain of parameters when substituting
10603 into a function parameter pack. */
10606 }
10608 /* If cp_unevaluated_operand is set, we're just looking for a
10609 single dummy parameter, so don't keep going. */
10614 /* FIRST_R contains the start of the chain we've built. */
10616 }
10620 {
10627 {
10628 /* This field is a lambda capture pack. Return a TREE_VEC of
10629 the expanded fields to instantiate_class_template_1 and
10630 store them in the specializations hash table as a
10631 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
10635 {
10638 }
10639 else
10640 {
10641 /* All we did was update the type. Make a note of that. */
10644 }
10645 }
10648 {
10651 {
10655 }
10665 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10666 non-bit-fields DECL_INITIAL is a non-static data member
10667 initializer, which gets deferred instantiation. */
10673 {
10674 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10675 NSDMI in perform_member_init. Still set DECL_INITIAL
10676 so that we know there is one. */
10681 }
10682 /* We don't have to set DECL_CONTEXT here; it is set by
10683 finish_member_declaration. */
10691 }
10694 {
10702 }
10703 }
10707 /* We reach here only for member using decls. We also need to check
10708 uses_template_parms because DECL_DEPENDENT_P is not set for a
10709 using-declaration that designates a member of the current
10710 instantiation (c++/53549). */
10713 {
10720 else
10721 {
10724 }
10725 }
10726 else
10727 {
10730 }
10735 {
10738 tree spec;
10740 tree ctx;
10746 {
10747 /* If this is the canonical decl, we don't have to
10748 mess with instantiations, and often we can't (for
10749 typename, template type parms and such). Note that
10750 TYPE_NAME is not correct for the above test if
10751 we've copied the type for a typedef. */
10757 }
10759 /* Check to see if we already have the specialization we
10760 need. */
10763 {
10764 /* T is a static data member or namespace-scope entity.
10765 We have to substitute into namespace-scope variables
10766 (even though such entities are never templates) because
10767 of cases like:
10769 template <class T> void f() { extern T t; }
10771 where the entity referenced is not known until
10772 instantiation time. */
10776 {
10778 complain,
10780 /* If CTX is unchanged, then T is in fact the
10781 specialization we want. That situation occurs when
10782 referencing a static data member within in its own
10783 class. We can use pointer equality, rather than
10784 same_type_p, because DECL_CONTEXT is always
10785 canonical... */
10788 /* ... unless T is a member template; in which
10789 case our caller can be willing to create a
10790 specialization of that template represented
10791 by T. */
10795 }
10798 {
10806 }
10807 }
10808 else
10809 {
10810 /* A local variable. */
10812 /* Subsequent calls to pushdecl will fill this in. */
10815 }
10816 /* If we already have the specialization we need, there is
10817 nothing more to do. */
10819 {
10822 }
10824 /* Create a new node for the specialization we need. */
10827 {
10830 else
10837 }
10839 {
10840 /* Even if the original location is out of scope, the
10841 newly substituted one is not. */
10848 {
10849 /* It may seem that this case cannot occur, since:
10851 typedef void f();
10852 void g() { f x; }
10854 declares a function, not a variable. However:
10856 typedef void f();
10857 template <typename T> void g() { T t; }
10858 template void g<f>();
10860 is an attempt to declare a variable with function
10861 type. */
10863 /* R is not yet sufficiently initialized, so we
10864 just use its name. */
10867 }
10869 /* Wait until cp_finish_decl to set this again, to handle
10870 circular dependency (template/instantiate6.C). */
10875 {
10880 {
10883 }
10885 }
10886 }
10892 /* Clear out the mangled name and RTL for the instantiation. */
10896 /* The initializer must not be expanded until it is required;
10897 see [temp.inst]. */
10903 {
10904 /* Possibly limit visibility based on template args. */
10907 {
10911 }
10913 }
10916 {
10917 /* A static data member declaration is always marked
10918 external when it is declared in-class, even if an
10919 initializer is present. We mimic the non-template
10920 processing here. */
10926 }
10929 else
10938 /* Preserve a typedef that names a type. */
10940 {
10943 }
10946 }
10951 }
10952 #undef RETURN
10954 out:
10955 /* Restore the file and line information. */
10959 }
10961 /* Substitute into the ARG_TYPES of a function type.
10962 If END is a TREE_CHAIN, leave it and any following types
10963 un-substituted. */
10965 static tree
10967 tree args,
10968 tree end,
10969 tsubst_flags_t complain,
10970 tree in_decl)
10971 {
10972 tree remaining_arg_types;
10976 tree default_arg;
10987 {
10988 /* For a pack expansion, perform substitution on the
10989 entire expression. Later on, we'll handle the arguments
10990 one-by-one. */
10995 /* So that we'll spin through the parameters, one by one. */
10997 else
10998 {
10999 /* We only partially substituted into the parameter
11000 pack. Our type is TYPE_PACK_EXPANSION. */
11003 }
11004 }
11017 {
11019 {
11023 }
11025 }
11026 /* DR 657. */
11030 /* Do array-to-pointer, function-to-pointer conversion, and ignore
11031 top-level qualifiers as required. */
11034 /* We do not substitute into default arguments here. The standard
11035 mandates that they be instantiated only when needed, which is
11036 done in build_over_call. */
11040 {
11041 /* We've instantiated a template before its default arguments
11042 have been parsed. This can happen for a nested template
11043 class, and is not an error unless we require the default
11044 argument in a call of this function. */
11045 remaining_arg_types =
11048 }
11049 else
11050 remaining_arg_types =
11052 }
11055 }
11057 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
11058 *not* handle the exception-specification for FNTYPE, because the
11059 initial substitution of explicitly provided template parameters
11060 during argument deduction forbids substitution into the
11061 exception-specification:
11063 [temp.deduct]
11065 All references in the function type of the function template to the
11066 corresponding template parameters are replaced by the specified tem-
11067 plate argument values. If a substitution in a template parameter or
11068 in the function type of the function template results in an invalid
11069 type, type deduction fails. [Note: The equivalent substitution in
11070 exception specifications is done only when the function is instanti-
11071 ated, at which point a program is ill-formed if the substitution
11072 results in an invalid type.] */
11074 static tree
11076 tree args,
11077 tsubst_flags_t complain,
11078 tree in_decl)
11079 {
11080 tree return_type;
11081 tree arg_types;
11082 tree fntype;
11084 /* The TYPE_CONTEXT is not used for function/method types. */
11087 /* Substitute the return type. */
11091 /* DR 486 clarifies that creation of a function type with an
11092 invalid return type is a deduction failure. */
11095 {
11097 {
11100 else
11102 }
11104 }
11105 /* And DR 657. */
11109 /* Substitute the argument types. */
11115 /* Construct a new type node and return it. */
11117 {
11122 }
11123 else
11124 {
11127 {
11128 /* [temp.deduct]
11130 Type deduction may fail for any of the following
11131 reasons:
11133 -- Attempting to create "pointer to member of T" when T
11134 is not a class type. */
11137 r);
11139 }
11144 }
11148 }
11150 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11151 ARGS into that specification, and return the substituted
11152 specification. If there is no specification, return NULL_TREE. */
11154 static tree
11156 tree args,
11157 tsubst_flags_t complain,
11158 tree in_decl,
11160 {
11161 tree specs;
11162 tree new_specs;
11167 {
11168 /* A noexcept-specifier. */
11173 {
11174 /* Defer instantiation of noexcept-specifiers to avoid
11175 excessive instantiations (c++/49107). */
11178 {
11179 /* We already partially instantiated this member template,
11180 so combine the new args with the old. */
11185 }
11186 else
11187 {
11190 }
11191 }
11192 else
11193 new_specs = tsubst_copy_and_build
11197 }
11199 {
11202 else
11204 {
11205 tree spec;
11210 {
11211 /* Expand the pack expansion type. */
11214 in_decl);
11220 else
11221 {
11222 /* We're substituting into a member template, so
11223 we got a TYPE_PACK_EXPANSION back. Add that
11224 expansion and move on. */
11228 expanded_specs,
11229 complain);
11232 }
11233 }
11236 {
11239 else
11244 complain);
11245 }
11248 }
11249 }
11251 }
11253 /* Take the tree structure T and replace template parameters used
11254 therein with the argument vector ARGS. IN_DECL is an associated
11255 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11256 Issue error and warning messages under control of COMPLAIN. Note
11257 that we must be relatively non-tolerant of extensions here, in
11258 order to preserve conformance; if we allow substitutions that
11259 should not be allowed, we may allow argument deductions that should
11260 not succeed, and therefore report ambiguous overload situations
11261 where there are none. In theory, we could allow the substitution,
11262 but indicate that it should have failed, and allow our caller to
11263 make sure that the right thing happens, but we don't try to do this
11264 yet.
11266 This function is used for dealing with types, decls and the like;
11267 for expressions, use tsubst_expr or tsubst_copy. */
11269 tree
11271 {
11294 else
11299 /* Reuse typedefs. We need to do this to handle dependent attributes,
11300 such as attribute aligned. */
11303 {
11307 {
11308 /* DECL represents an alias template and we want to
11309 instantiate it. */
11313 }
11317 {
11321 }
11326 else
11327 /* The typedef is from a non-template context. */
11331 {
11333 r = cp_build_qualified_type_real
11337 }
11338 else
11339 {
11340 /* We don't have an instantiation yet, so drop the typedef. */
11345 }
11346 }
11359 {
11385 {
11391 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11392 needed. */
11398 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11399 with TREE_SIDE_EFFECTS that indicates this is not an integral
11400 constant expression. */
11403 {
11406 }
11409 }
11415 {
11428 {
11432 {
11433 /* See through ARGUMENT_PACK_SELECT arguments. */
11435 /* If the selected argument is an expansion E, that most
11436 likely means we were called from
11437 gen_elem_of_pack_expansion_instantiation during the
11438 substituting of pack an argument pack (which Ith
11439 element is a pack expansion, where I is
11440 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
11441 In this case, the Ith element resulting from this
11442 substituting is going to be a pack expansion, which
11443 pattern is the pattern of E. Let's return the
11444 pattern of E, and
11445 gen_elem_of_pack_expansion_instantiation will
11446 build the resulting pack expansion from it. */
11449 }
11450 }
11455 {
11457 /* If ARG is an argument pack, we don't actually want to
11458 perform a substitution here, because substitutions
11459 for argument packs are only done
11460 element-by-element. We can get to this point when
11461 substituting the type of a non-type template
11462 parameter pack, when that type actually contains
11463 template parameter packs from an outer template, e.g.,
11465 template<typename... Types> struct A {
11466 template<Types... Values> struct B { };
11467 }; */
11471 {
11477 return cp_build_qualified_type_real
11479 }
11481 {
11482 /* We are processing a type constructed from a
11483 template template parameter. */
11494 /* Consider this code:
11496 template <template <class> class Template>
11497 struct Internal {
11498 template <class Arg> using Bind = Template<Arg>;
11499 };
11501 template <template <class> class Template, class Arg>
11502 using Instantiate = Template<Arg>; //#0
11504 template <template <class> class Template,
11505 class Argument>
11506 using Bind =
11507 Instantiate<Internal<Template>::template Bind,
11508 Argument>; //#1
11510 When #1 is parsed, the
11511 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11512 parameter `Template' in #0 matches the
11513 UNBOUND_CLASS_TEMPLATE representing the argument
11514 `Internal<Template>::template Bind'; We then want
11515 to assemble the type `Bind<Argument>' that can't
11516 be fully created right now, because
11517 `Internal<Template>' not being complete, the Bind
11518 template cannot be looked up in that context. So
11519 we need to "store" `Bind<Argument>' for later
11520 when the context of Bind becomes complete. Let's
11521 store that in a TYPENAME_TYPE. */
11525 argvec),
11526 typename_type,
11527 complain);
11529 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11530 are resolving nested-types in the signature of a
11531 member function templates. Otherwise ARG is a
11532 TEMPLATE_DECL and is the real template to be
11533 instantiated. */
11541 complain);
11542 return cp_build_qualified_type_real
11544 }
11545 else
11546 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11548 }
11551 /* This can happen during the attempted tsubst'ing in
11552 unify. This means that we don't yet have any information
11553 about the template parameter in question. */
11556 /* Early in template argument deduction substitution, we don't
11557 want to reduce the level of 'auto', or it will be confused
11558 with a normal template parm in subsequent deduction. */
11562 /* If we get here, we must have been looking at a parm for a
11563 more deeply nested template. Make a new version of this
11564 template parameter, but with a lower level. */
11566 {
11571 {
11573 r = cp_build_qualified_type_real
11577 }
11578 else
11579 {
11590 /* We have reduced the level of the template
11591 template parameter, but not the levels of its
11592 template parameters, so canonical_type_parameter
11593 will not be able to find the canonical template
11594 template parameter for this level. Thus, we
11595 require structural equality checking to compare
11596 TEMPLATE_TEMPLATE_PARMs. */
11600 else
11604 {
11612 }
11613 }
11622 }
11625 }
11628 {
11636 {
11640 }
11643 {
11647 }
11650 {
11654 }
11660 }
11663 /* We should never be tsubsting a binfo. */
11667 /* A vector of template arguments. */
11673 {
11677 /* [temp.deduct]
11679 Type deduction may fail for any of the following
11680 reasons:
11682 -- Attempting to create a pointer to reference type.
11683 -- Attempting to create a reference to a reference type or
11684 a reference to void.
11686 Core issue 106 says that creating a reference to a reference
11687 during instantiation is no longer a cause for failure. We
11688 only enforce this check in strict C++98 mode. */
11692 {
11695 /* We keep track of the last time we issued this error
11696 message to avoid spewing a ton of messages during a
11697 single bad template instantiation. */
11700 {
11705 else
11708 }
11711 }
11715 {
11717 {
11720 type);
11721 else
11723 type);
11724 }
11726 }
11728 {
11732 }
11734 /* In C++0x, during template argument substitution, when there is an
11735 attempt to create a reference to a reference type, reference
11736 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11738 "If a template-argument for a template-parameter T names a type
11739 that is a reference to a type A, an attempt to create the type
11740 'lvalue reference to cv T' creates the type 'lvalue reference to
11741 A,' while an attempt to create the type type rvalue reference to
11742 cv T' creates the type T"
11743 */
11744 r = cp_build_reference_type
11747 else
11754 {
11756 pedwarn
11758 code == REFERENCE_TYPE
11761 else
11763 }
11766 /* Will this ever be needed for TYPE_..._TO values? */
11770 }
11772 {
11775 {
11776 /* [temp.deduct]
11778 Type deduction may fail for any of the following
11779 reasons:
11781 -- Attempting to create "pointer to member of T" when T
11782 is not a class type. */
11786 }
11788 {
11792 }
11794 {
11798 }
11801 {
11802 /* The type of the implicit object parameter gets its
11803 cv-qualifiers from the FUNCTION_TYPE. */
11804 tree memptr;
11805 tree method_type
11810 complain);
11811 }
11812 else
11815 complain);
11816 }
11819 {
11820 tree fntype;
11821 tree specs;
11826 /* Substitute the exception specification. */
11834 }
11836 {
11841 /* As an optimization, we avoid regenerating the array type if
11842 it will obviously be the same as T. */
11846 /* These checks should match the ones in grokdeclarator.
11848 [temp.deduct]
11850 The deduction may fail for any of the following reasons:
11852 -- Attempting to create an array with an element type that
11853 is void, a function type, or a reference type, or [DR337]
11854 an abstract class type. */
11858 {
11862 }
11870 {
11873 }
11876 }
11879 {
11889 {
11893 }
11895 {
11896 /* Normally, make_typename_type does not require that the CTX
11897 have complete type in order to allow things like:
11899 template <class T> struct S { typename S<T>::X Y; };
11901 But, such constructs have already been resolved by this
11902 point, so here CTX really should have complete type, unless
11903 it's a partial instantiation. */
11906 {
11910 }
11911 }
11918 {
11921 }
11924 {
11926 {
11930 else
11932 }
11934 {
11938 else
11940 }
11941 }
11943 return cp_build_qualified_type_real
11945 }
11948 {
11960 }
11963 {
11964 tree type;
11980 complain);
11981 }
11984 {
11985 tree type;
12003 else
12004 {
12008 /* In a template ~id could be either a complement expression
12009 or an unqualified-id naming a destructor; if instantiating
12010 it produces an expression, it's not an id-expression or
12011 member access. */
12014 }
12018 complain);
12019 }
12022 {
12026 }
12030 {
12032 tree packed_out =
12034 args,
12035 complain,
12036 in_decl);
12039 /* For template nontype argument packs, also substitute into
12040 the type. */
12045 }
12060 /* We should use one of the expression tsubsts for these codes. */
12066 }
12067 }
12069 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
12070 type of the expression on the left-hand side of the "." or "->"
12071 operator. */
12073 static tree
12076 {
12077 tree name;
12078 tree qualifying_scope;
12079 tree fns;
12080 tree optype;
12085 /* A baselink indicates a function from a base class. Both the
12086 BASELINK_ACCESS_BINFO and the base class referenced may
12087 indicate bases of the template class, rather than the
12088 instantiated class. In addition, lookups that were not
12089 ambiguous before may be ambiguous now. Therefore, we perform
12090 the lookup again. */
12097 {
12104 }
12112 /* If lookup found a single function, mark it as used at this
12113 point. (If it lookup found multiple functions the one selected
12114 later by overload resolution will be marked as used at that
12115 point.) */
12121 /* Add back the template arguments, if present. */
12126 template_args);
12127 /* Update the conversion operator type. */
12135 qualifying_scope,
12136 object_type);
12138 }
12140 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
12141 true if the qualified-id will be a postfix-expression in-and-of
12142 itself; false if more of the postfix-expression follows the
12143 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
12144 of "&". */
12146 static tree
12150 {
12151 tree expr;
12152 tree scope;
12153 tree name;
12155 tree template_args;
12160 /* Figure out what name to look up. */
12163 {
12171 }
12172 else
12173 {
12176 }
12178 /* Substitute into the qualifying scope. When there are no ARGS, we
12179 are just trying to simplify a non-dependent expression. In that
12180 case the qualifying scope may be dependent, and, in any case,
12181 substituting will not help. */
12184 {
12187 }
12188 else
12192 {
12197 }
12200 {
12202 {
12203 /* A BIT_NOT_EXPR is used to represent a destructor. */
12205 {
12209 }
12210 else
12213 }
12214 else
12218 {
12220 {
12224 }
12226 }
12227 }
12230 {
12232 scope);
12233 /* Remember that there was a reference to this entity. */
12235 }
12238 {
12244 }
12253 {
12254 expr = (adjust_result_of_qualified_name_lookup
12256 expr = (finish_qualified_id_expr
12260 }
12262 /* Expressions do not generally have reference type. */
12264 /* However, if we're about to form a pointer-to-member, we just
12265 want the referenced member referenced. */
12270 }
12272 /* Like tsubst, but deals with expressions. This function just replaces
12273 template parms; to finish processing the resultant expression, use
12274 tsubst_copy_and_build or tsubst_expr. */
12276 static tree
12278 {
12280 tree r;
12288 {
12293 {
12294 /* We get here for a use of 'this' in an NSDMI. */
12300 /* This can happen for a parameter name used later in a function
12301 declaration (such as in a late-specified return type). Just
12302 make a dummy decl, since it's only used for its type. */
12305 /* Give it the template pattern as its context; its true context
12306 hasn't been instantiated yet and this is good enough for
12307 mangling. */
12309 }
12317 {
12318 tree enum_type;
12319 tree v;
12323 /* There is no need to substitute into namespace-scope
12324 enumerators. */
12327 /* If ARGS is NULL, then T is known to be non-dependent. */
12331 /* Unfortunately, we cannot just call lookup_name here.
12332 Consider:
12334 template <int I> int f() {
12335 enum E { a = I };
12336 struct S { void g() { E e = a; } };
12337 };
12339 When we instantiate f<7>::S::g(), say, lookup_name is not
12340 clever enough to find f<7>::a. */
12341 enum_type
12351 /* We didn't find the name. That should never happen; if
12352 name-lookup found it during preliminary parsing, we
12353 should find it again here during instantiation. */
12355 }
12360 {
12361 /* Check for a local specialization set up by
12362 tsubst_pack_expansion. */
12365 {
12369 }
12371 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
12372 tsubst_decl put in the hash table. */
12374 }
12377 {
12378 tree ctx;
12383 {
12386 {
12390 }
12392 }
12393 }
12402 {
12405 {
12407 {
12408 /* Just use name lookup to find a member alias for an
12409 anonymous union, but then add it to the hash table. */
12413 }
12414 else
12415 {
12418 }
12419 }
12420 }
12421 else
12430 /* An OVERLOAD will always be a non-dependent overload set; an
12431 overload set from function scope will just be represented with an
12432 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12447 {
12448 /* Template template argument like the following example need
12449 special treatment:
12451 template <template <class> class TT> struct C {};
12452 template <class T> struct D {
12453 template <class U> struct E {};
12454 C<E> c; // #1
12455 };
12456 D<int> d; // #2
12458 We are processing the template argument `E' in #1 for
12459 the template instantiation #2. Originally, `E' is a
12460 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12461 have to substitute this with one having context `D<int>'. */
12465 }
12466 else
12467 /* Ordinary template template argument. */
12478 return build1
12484 {
12494 /* We only want to compute the number of arguments. */
12508 {
12515 else
12518 }
12519 else
12521 }
12523 {
12531 }
12532 /* Fall through */
12548 return build1
12553 {
12554 tree object;
12555 tree name;
12560 {
12564 }
12567 {
12577 }
12582 in_decl);
12583 else
12586 }
12624 return build_nt
12637 return build_nt
12644 {
12652 }
12658 {
12659 r = build_nt
12665 }
12668 {
12669 r = build_nt
12675 }
12678 {
12679 r = build_nt
12685 }
12688 {
12689 /* Substituted template arguments */
12698 }
12701 {
12721 }
12746 /* Fall through. */
12749 {
12752 }
12753 else
12757 /* This is handled by tsubst_copy_and_build. */
12763 in_decl),
12767 /* We shouldn't have built any of these during initial template
12768 generation. Instead, they should be built during instantiation
12769 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12773 r = build2
12793 {
12794 /* Instantiate any typedefs in the type. */
12799 }
12802 /* These can sometimes show up in a partial instantiation, but never
12803 involve template parms. */
12808 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12811 }
12812 }
12814 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12816 static tree
12818 tree in_decl)
12819 {
12823 {
12829 {
12832 {
12838 }
12839 /* FALLTHRU */
12863 }
12864 }
12867 }
12869 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12871 static tree
12873 tree in_decl)
12874 {
12875 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
12895 {
12898 else
12899 {
12903 }
12904 }
12909 #undef RECUR
12910 }
12912 /* Substitute one OMP_FOR iterator. */
12914 static void
12919 {
12920 #define RECUR(NODE) \
12921 tsubst_expr ((NODE), args, complain, in_decl, \
12922 integral_constant_expression_p)
12930 /* Do this before substituting into decl to handle 'auto'. */
12935 {
12939 }
12944 {
12951 complain);
12952 else
12959 }
12962 {
12963 tree c;
12965 {
12976 }
12978 {
12983 {
12986 }
12987 }
12988 }
12994 else
12998 {
13009 {
13016 }
13017 else
13023 {
13029 }
13033 {
13040 }
13041 else
13047 }
13053 #undef RECUR
13054 }
13056 /* Like tsubst_copy for expressions, etc. but also does semantic
13057 processing. */
13059 static tree
13062 {
13063 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13064 #define RECUR(NODE) \
13065 tsubst_expr ((NODE), args, complain, in_decl, \
13066 integral_constant_expression_p)
13069 tree r;
13070 location_t loc;
13082 {
13084 {
13085 tree_stmt_iterator i;
13089 }
13104 else
13113 {
13115 tree init;
13121 {
13124 tree decl;
13132 else
13134 }
13136 {
13137 /* Don't build up decls for a variadic capture proxy, we'll
13138 instantiate the elements directly as needed. */
13140 }
13141 else
13142 {
13146 {
13147 /* By marking the declaration as instantiated, we avoid
13148 trying to instantiate it. Since instantiate_decl can't
13149 handle local variables, and since we've already done
13150 all that needs to be done, that's the right thing to
13151 do. */
13156 /* Anonymous aggregates are a special case. */
13159 {
13162 {
13166 }
13168 }
13171 else
13172 {
13177 {
13178 /* For __PRETTY_FUNCTION__ we have to adjust the
13179 initializer. */
13183 }
13184 else
13185 {
13189 {
13190 /* If we had an initializer but it
13191 instantiated to nothing,
13192 value-initialize the object. This will
13193 only occur when the initializer was a
13194 pack expansion where the parameter packs
13195 used in that expansion were of length
13196 zero. */
13198 complain);
13201 }
13202 else
13204 }
13207 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
13210 }
13211 }
13212 }
13215 }
13230 {
13240 }
13267 {
13271 }
13279 else
13287 else
13314 {
13316 tree label;
13321 }
13327 /* Computed goto's must be tsubst'd into. On the other hand,
13328 non-computed gotos must not be; the identifier in question
13329 will have no binding. */
13331 else
13337 tmp = finish_asm_stmt
13344 {
13349 }
13354 {
13359 }
13360 else
13361 {
13366 else
13373 else
13379 else
13381 }
13385 {
13389 {
13391 /* Prevent instantiate_decl from trying to instantiate
13392 this variable. We've already done all that needs to be
13393 done. */
13396 }
13401 }
13407 {
13408 /* Local classes are not independent templates; they are
13409 instantiated along with their containing function. And this
13410 way we don't have to deal with pushing out of one local class
13411 to instantiate a member of another local class. */
13412 tree fn;
13413 /* Closures are handled by the LAMBDA_EXPR. */
13419 }
13423 {
13424 tree condition;
13427 condition =
13429 args,
13438 }
13459 {
13480 integral_constant_expression_p);
13490 }
13522 {
13527 {
13530 }
13535 }
13536 else
13537 {
13544 {
13547 }
13550 {
13555 {
13558 }
13562 }
13563 else
13564 {
13568 }
13570 }
13574 {
13580 {
13584 {
13589 }
13593 }
13594 else
13595 {
13600 }
13601 }
13619 /* If the first operand was a statement, we're done with it. */
13623 complain));
13630 integral_constant_expression_p));
13631 }
13634 out:
13637 #undef RECUR
13638 #undef RETURN
13639 }
13641 /* T is a postfix-expression that is not being used in a function
13642 call. Return the substituted version of T. */
13644 static tree
13646 tsubst_flags_t complain,
13647 tree in_decl)
13648 {
13652 else
13658 }
13660 /* Like tsubst but deals with expressions and performs semantic
13661 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
13663 tree
13665 tree args,
13666 tsubst_flags_t complain,
13667 tree in_decl,
13670 {
13671 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
13672 #define RECUR(NODE) \
13673 tsubst_copy_and_build (NODE, args, complain, in_decl, \
13675 integral_constant_expression_p)
13678 location_t loc;
13687 /* N3276 decltype magic only applies to calls at the top level or on the
13688 right side of a comma. */
13693 {
13696 /* Fall through. */
13698 {
13699 tree decl;
13700 cp_id_kind idk;
13705 {
13708 }
13710 /* Look up the name. */
13713 /* By convention, expressions use ERROR_MARK_NODE to indicate
13714 failure, not NULL_TREE. */
13720 integral_constant_expression_p,
13728 input_location);
13732 {
13736 }
13738 }
13741 {
13742 tree object;
13750 {
13753 }
13754 else
13761 else
13763 }
13766 {
13770 {
13771 /* A type conversion to reference type will be enclosed in
13772 such an indirect ref, but the substitution of the cast
13773 will have also added such an indirect ref. */
13776 }
13777 else
13781 }
13789 {
13796 flags));
13797 }
13810 {
13811 tree type;
13817 {
13822 }
13828 {
13846 }
13850 }
13884 else
13886 in_decl);
13921 {
13922 tree r;
13926 r = build_x_binary_op
13930 ? ERROR_MARK
13934 ? ERROR_MARK
13944 }
13957 {
13966 }
13970 /* Fall through */
13973 {
13974 tree r;
13980 {
13981 /* When there are no ARGS, we are trying to evaluate a
13982 non-dependent expression from the parser. Trying to do
13983 the substitutions may not work. */
13986 }
13987 else
13988 {
13993 else
13996 /*integral_constant_expression_p=*/
14000 }
14004 else
14008 {
14010 {
14012 {
14016 }
14017 else
14021 }
14023 }
14025 }
14028 {
14038 }
14052 {
14053 tree r;
14057 r = build_x_modify_expr
14063 /* TREE_NO_WARNING must be set if either the expression was
14064 parenthesized or it uses an operator such as >>= rather
14065 than plain assignment. In the former case, it was already
14066 set and must be copied. In the latter case,
14067 build_x_modify_expr sets it and it must not be reset
14068 here. */
14075 }
14080 /* Remember that there was a reference to this entity. */
14086 {
14091 tree ret;
14095 else
14096 {
14100 }
14102 /* If there was an initializer in the original tree, but it
14103 instantiated to an empty list, then we should pass a
14104 non-NULL empty vector to tell build_new that it was an
14105 empty initializer() rather than no initializer. This can
14106 only happen when the initializer is a pack expansion whose
14107 parameter packs are of length zero. */
14110 else
14111 {
14115 else
14116 {
14119 }
14120 }
14127 complain);
14135 }
14143 complain));
14146 {
14150 integral_constant_expression_p);
14152 op0,
14155 }
14158 {
14159 tree function;
14164 tree ret;
14167 /* When we parsed the expression, we determined whether or
14168 not Koenig lookup should be performed. */
14171 {
14176 }
14178 {
14179 /* Do nothing; calling tsubst_copy_and_build on an identifier
14180 would incorrectly perform unqualified lookup again.
14182 Note that we can also have an IDENTIFIER_NODE if the earlier
14183 unqualified lookup found a member function; in that case
14184 koenig_p will be false and we do want to do the lookup
14185 again to find the instantiated member function.
14187 FIXME but doing that causes c++/15272, so we need to stop
14188 using IDENTIFIER_NODE in that situation. */
14190 }
14191 else
14192 {
14194 {
14200 }
14201 else
14206 /* Avoid error about taking the address of a constructor. */
14210 in_decl,
14212 integral_constant_expression_p);
14216 }
14221 {
14226 else
14227 {
14228 /* Expand the pack expansion and push each entry onto
14229 CALL_ARGS. */
14232 {
14237 {
14242 }
14243 }
14244 else
14245 {
14246 /* A partial substitution. Add one entry. */
14248 }
14249 }
14250 }
14252 /* We do not perform argument-dependent lookup if normal
14253 lookup finds a non-function, in accordance with the
14254 expected resolution of DR 218. */
14257 /* If lookup found a member function, the Koenig lookup is
14258 not appropriate, even if an unqualified-name was used
14259 to denote the function. */
14262 /* Only do this when substitution turns a dependent call
14263 into a non-dependent call. */
14267 tf_none);
14271 {
14273 {
14274 /* For backwards compatibility and good diagnostics, try
14275 the unqualified lookup again if we aren't in SFINAE
14276 context. */
14277 tree unq = (tsubst_copy_and_build
14279 integral_constant_expression_p));
14284 {
14293 "%qD was not declared in this scope, "
14294 "and no declarations were found by "
14295 "argument-dependent lookup at the point "
14297 {
14301 {
14303 "declarations in dependent base %qT are "
14309 else
14313 }
14314 else
14317 }
14319 }
14320 }
14322 {
14327 }
14328 }
14330 /* Remember that there was a reference to this entity. */
14334 /* Put back tf_decltype for the actual call. */
14339 complain);
14341 {
14356 complain);
14357 else
14358 ret = (build_new_method_call
14363 complain));
14364 }
14365 else
14368 koenig_p,
14369 complain);
14374 }
14377 {
14382 {
14384 {
14389 }
14390 else
14391 {
14396 }
14397 }
14398 else
14399 {
14402 }
14406 }
14413 input_location));
14416 {
14424 {
14425 /* We have pack expansions, so expand those and
14426 create a new list out of it. */
14429 tree chain;
14432 /* Expand the argument expressions. */
14440 /* Build the rest of the list. */
14445 /* Determine the number of arguments. */
14447 {
14450 }
14453 else
14454 {
14455 /* Since we only performed a partial substitution into
14456 the argument pack, we only RETURN (a single list
14457 node. */
14464 }
14466 /* Convert the argument vectors into a TREE_LIST */
14469 {
14470 /* Grab the Ith values. */
14471 i--;
14474 value
14478 /* Build the list (backwards). */
14480 }
14483 }
14499 }
14502 {
14503 tree object;
14504 tree object_type;
14505 tree member;
14509 /* Remember that there was a reference to this entity. */
14519 else
14527 {
14529 {
14534 {
14537 }
14539 {
14544 }
14545 }
14546 }
14549 {
14550 /* Lookup the template functions now that we know what the
14551 scope is. */
14559 {
14562 args);
14563 member = (adjust_result_of_qualified_name_lookup
14565 object_type));
14566 }
14567 else
14568 {
14570 input_location);
14572 }
14573 }
14577 {
14579 {
14583 else
14586 }
14588 }
14594 complain));
14595 }
14602 {
14610 tree r;
14615 /* digest_init will do the wrong thing if we let it. */
14619 /* We do not want to process the index of aggregate
14620 initializers as they are identifier nodes which will be
14621 looked up by digest_init. */
14627 {
14629 /* An identifier index is looked up in the type
14630 being initialized, not the current scope. */
14635 {
14636 /* Substitute into the pack expansion. */
14638 in_decl);
14642 ;
14644 /* Just move the argument into place. */
14646 else
14647 {
14648 /* Update the length of the final CONSTRUCTOR
14649 arguments vector, and note that we will need to
14650 copy.*/
14653 }
14654 }
14655 else
14657 }
14660 {
14665 {
14667 {
14672 }
14673 else
14675 }
14676 }
14686 }
14689 {
14692 {
14695 }
14696 else
14697 {
14700 }
14701 }
14707 {
14708 /* We don't build decls for an instantiation of a
14709 variadic capture proxy, we instantiate the elements
14710 when needed. */
14713 }
14714 /* Fall through */
14717 {
14721 /* If the original type was a reference, we'll be wrapped in
14722 the appropriate INDIRECT_REF. */
14725 }
14736 {
14745 }
14748 {
14754 integral_constant_expression_p);
14758 /* If the resulting list of expression statement is empty,
14759 fold it further into void_zero_node. */
14764 }
14767 {
14781 /* For a function scope, we want to use tsubst so that we don't
14782 complain about referring to an auto function before its return
14783 type has been deduced. Otherwise, we want to use tsubst_copy so
14784 that we look up the existing field/parameter/variable rather
14785 than build a new one. */
14790 {
14791 /* Look up the parameter we want directly, as tsubst_copy
14792 doesn't do what we need. */
14798 /* FIXME Work around the parm not having DECL_CONTEXT set. */
14801 }
14802 else
14811 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
14813 /* Now that we know visibility, instantiate the type so we have a
14814 declaration of the op() for later calls to lambda_function. */
14820 }
14823 /* We can get here for a constant initializer of non-dependent type.
14824 FIXME stop folding in cp_parser_initializer_clause. */
14825 {
14827 complain);
14829 }
14833 integral_constant_expression_p));
14843 complain));
14846 /* Handle Objective-C++ constructs, if appropriate. */
14847 {
14848 tree subst
14853 }
14855 }
14857 #undef RECUR
14858 #undef RETURN
14859 out:
14862 }
14864 /* Verify that the instantiated ARGS are valid. For type arguments,
14865 make sure that the type's linkage is ok. For non-type arguments,
14866 make sure they are constants if they are integral or enumerations.
14867 Emit an error under control of COMPLAIN, and return TRUE on error. */
14869 static bool
14871 {
14875 {
14885 }
14887 {
14888 /* [basic.link]: A name with no linkage (notably, the name
14889 of a class or enumeration declared in a local scope)
14890 shall not be used to declare an entity with linkage.
14891 This implies that names with no linkage cannot be used as
14892 template arguments
14894 DR 757 relaxes this restriction for C++0x. */
14899 {
14900 /* DR 488 makes use of a type with no linkage cause
14901 type deduction to fail. */
14903 {
14906 else
14909 }
14911 }
14912 /* In order to avoid all sorts of complications, we do not
14913 allow variably-modified types as template arguments. */
14915 {
14919 }
14920 }
14921 /* Class template and alias template arguments should be OK. */
14923 ;
14924 /* A non-type argument of integral or enumerated type must be a
14925 constant. */
14929 {
14933 }
14935 }
14937 static bool
14939 {
14944 {
14947 }
14951 }
14953 /* We're out of SFINAE context now, so generate diagnostics for the access
14954 errors we saw earlier when instantiating D from TMPL and ARGS. */
14956 static void
14958 {
14970 }
14972 /* Instantiate the indicated variable, function, or alias template TMPL with
14973 the template arguments in TARG_PTR. */
14975 static tree
14977 {
14979 tree fndecl;
14980 tree gen_tmpl;
14981 tree spec;
14989 /* If this function is a clone, handle it specially. */
14991 {
14992 tree spec;
14993 tree clone;
14995 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
14996 DECL_CLONED_FUNCTION. */
15002 /* Look for the clone. */
15006 /* We should always have found the clone by now. */
15009 }
15011 /* Check to see if we already have this specialization. */
15014 /* The TMPL is a partial instantiation. To get a full set of
15015 arguments we must add the arguments used to perform the
15016 partial instantiation. */
15018 targ_ptr);
15020 /* It would be nice to avoid hashing here and then again in tsubst_decl,
15021 but it doesn't seem to be on the hot path. */
15030 {
15032 {
15036 }
15038 }
15041 complain))
15044 /* We are building a FUNCTION_DECL, during which the access of its
15045 parameters and return types have to be checked. However this
15046 FUNCTION_DECL which is the desired context for access checking
15047 is not built yet. We solve this chicken-and-egg problem by
15048 deferring all checks until we have the FUNCTION_DECL. */
15051 /* Instantiation of the function happens in the context of the function
15052 template, not the context of the overload resolution we're doing. */
15054 /* If there are dependent arguments, e.g. because we're doing partial
15055 ordering, make sure processing_template_decl stays set. */
15059 {
15063 }
15064 /* Substitute template parameters to obtain the specialization. */
15072 {
15075 }
15077 /* The DECL_TI_TEMPLATE should always be the immediate parent
15078 template, not the most general template. */
15081 /* Now we know the specialization, compute access previously
15082 deferred. */
15089 /* If we've just instantiated the main entry point for a function,
15090 instantiate all the alternate entry points as well. We do this
15091 by cloning the instantiation of the main entry point, not by
15092 instantiating the template clones. */
15097 {
15099 {
15100 /* Remember to reinstantiate when we're out of SFINAE so the user
15101 can see the errors. */
15103 }
15105 }
15107 }
15109 /* Wrapper for instantiate_template_1. */
15111 tree
15113 {
15114 tree ret;
15119 }
15121 /* Instantiate the alias template TMPL with ARGS. Also push a template
15122 instantiation level, which instantiate_template doesn't do because
15123 functions and variables have sufficient context established by the
15124 callers. */
15126 static tree
15128 {
15135 {
15138 }
15140 args =
15148 /* We can't free this if a pending_template entry or last_error_tinst_level
15149 is pointing at it. */
15155 }
15157 /* PARM is a template parameter pack for FN. Returns true iff
15158 PARM is used in a deducible way in the argument list of FN. */
15160 static bool
15162 {
15165 {
15167 tree packs;
15173 {
15174 /* The template parameter pack is used in a function parameter
15175 pack. If this is the end of the parameter list, the
15176 template parameter pack is deducible. */
15179 else
15180 /* Otherwise, not. Well, it could be deduced from
15181 a non-pack parameter, but doing so would end up with
15182 a deduction mismatch, so don't bother. */
15184 }
15185 }
15186 /* The template parameter pack isn't used in any function parameter
15187 packs, but it might be used deeper, e.g. tuple<Args...>. */
15189 }
15191 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
15192 NARGS elements of the arguments that are being used when calling
15193 it. TARGS is a vector into which the deduced template arguments
15194 are placed.
15196 Return zero for success, 2 for an incomplete match that doesn't resolve
15197 all the types, and 1 for complete failure. An error message will be
15198 printed only for an incomplete match.
15200 If FN is a conversion operator, or we are trying to produce a specific
15201 specialization, RETURN_TYPE is the return type desired.
15203 The EXPLICIT_TARGS are explicit template arguments provided via a
15204 template-id.
15206 The parameter STRICT is one of:
15208 DEDUCE_CALL:
15209 We are deducing arguments for a function call, as in
15210 [temp.deduct.call].
15212 DEDUCE_CONV:
15213 We are deducing arguments for a conversion function, as in
15214 [temp.deduct.conv].
15216 DEDUCE_EXACT:
15217 We are deducing arguments when doing an explicit instantiation
15218 as in [temp.explicit], when determining an explicit specialization
15219 as in [temp.expl.spec], or when taking the address of a function
15220 template, as in [temp.deduct.funcaddr]. */
15222 tree
15224 tree explicit_targs,
15225 tree targs,
15228 tree return_type,
15229 unification_kind_t strict,
15233 {
15234 tree parms;
15235 tree fntype;
15243 tree tinst;
15249 /* In C++0x, it's possible to have a function template whose type depends
15250 on itself recursively. This is most obvious with decltype, but can also
15251 occur with enumeration scope (c++/48969). So we need to catch infinite
15252 recursion and reject the substitution at deduction time; this function
15253 will return error_mark_node for any repeated substitution.
15255 This also catches excessive recursion such as when f<N> depends on
15256 f<N-1> across all integers, and returns error_mark_node for all the
15257 substitutions back up to the initial one.
15259 This is, of course, not reentrant. */
15269 {
15270 /* [temp.deduct]
15272 The specified template arguments must match the template
15273 parameters in kind (i.e., type, nontype, template), and there
15274 must not be more arguments than there are parameters;
15275 otherwise type deduction fails.
15277 Nontype arguments must match the types of the corresponding
15278 nontype template parameters, or must be convertible to the
15279 types of the corresponding nontype parameters as specified in
15280 _temp.arg.nontype_, otherwise type deduction fails.
15282 All references in the function type of the function template
15283 to the corresponding template parameters are replaced by the
15284 specified template argument values. If a substitution in a
15285 template parameter or in the function type of the function
15286 template results in an invalid type, type deduction fails. */
15291 /* Adjust any explicit template arguments before entering the
15292 substitution context. */
15293 explicit_targs
15295 complain,
15301 /* Substitute the explicit args into the function type. This is
15302 necessary so that, for instance, explicitly declared function
15303 arguments can match null pointed constants. If we were given
15304 an incomplete set of explicit args, we must not do semantic
15305 processing during substitution as we could create partial
15306 instantiations. */
15308 {
15313 /* Dig out the actual parm. */
15316 {
15319 }
15321 {
15324 }
15327 /* No explicit argument for this template parameter. */
15331 {
15332 /* Mark the argument pack as "incomplete". We could
15333 still deduce more arguments during unification.
15334 We remove this mark in type_unification_real. */
15336 {
15340 }
15342 /* We have some incomplete argument packs. */
15344 }
15345 }
15349 {
15352 }
15355 /* Ignore any access checks; we'll see them again in
15356 instantiate_template and they might have the wrong
15357 access path at this point. */
15369 /* Place the explicitly specified arguments in TARGS. */
15372 }
15374 /* Never do unification on the 'this' parameter. */
15378 {
15387 }
15389 /* We allow incomplete unification without an error message here
15390 because the standard doesn't seem to explicitly prohibit it. Our
15391 callers must be ready to deal with unification failures in any
15392 event. */
15395 /* If we aren't explaining yet, push tinst context so we can see where
15396 any errors (e.g. from class instantiations triggered by instantiation
15397 of default template arguments) come from. If we are explaining, this
15398 context is redundant. */
15400 {
15403 }
15405 /* type_unification_real will pass back any access checks from default
15406 template argument substitution. */
15418 /* Now that we have bindings for all of the template arguments,
15419 ensure that the arguments deduced for the template template
15420 parameters have compatible template parameter lists. We cannot
15421 check this property before we have deduced all template
15422 arguments, because the template parameter types of a template
15423 template parameter might depend on prior template parameters
15424 deduced after the template template parameter. The following
15425 ill-formed example illustrates this issue:
15427 template<typename T, template<T> class C> void f(C<5>, T);
15429 template<int N> struct X {};
15431 void g() {
15432 f(X<5>(), 5l); // error: template argument deduction fails
15433 }
15435 The template parameter list of 'C' depends on the template type
15436 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
15437 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
15438 time that we deduce 'C'. */
15441 {
15444 }
15446 /* All is well so far. Now, check:
15448 [temp.deduct]
15450 When all template arguments have been deduced, all uses of
15451 template parameters in nondeduced contexts are replaced with
15452 the corresponding deduced argument values. If the
15453 substitution results in an invalid type, as described above,
15454 type deduction fails. */
15457 {
15460 }
15462 /* Also collect access checks from the instantiation. */
15475 /* Now perform any access checks encountered during substitution. */
15482 /* If we're looking for an exact match, check that what we got
15483 is indeed an exact match. It might not be if some template
15484 parameters are used in non-deduced contexts. */
15486 {
15490 tree sarg
15496 {
15500 }
15501 }
15505 fail:
15508 {
15510 /* Reset once we're all the way out. */
15512 }
15514 /* We can't free this if a pending_template entry or last_error_tinst_level
15515 is pointing at it. */
15521 }
15523 /* Adjust types before performing type deduction, as described in
15524 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
15525 sections are symmetric. PARM is the type of a function parameter
15526 or the return type of the conversion function. ARG is the type of
15527 the argument passed to the call, or the type of the value
15528 initialized with the result of the conversion function.
15529 ARG_EXPR is the original argument expression, which may be null. */
15531 static int
15535 tree arg_expr)
15536 {
15540 {
15545 {
15546 /* Swap PARM and ARG throughout the remainder of this
15547 function; the handling is precisely symmetric since PARM
15548 will initialize ARG rather than vice versa. */
15553 }
15556 /* Core issue #873: Do the DR606 thing (see below) for these cases,
15557 too, but here handle it by stripping the reference from PARM
15558 rather than by adding it to ARG. */
15566 /* Nothing else to do in this case. */
15571 }
15574 {
15575 /* [temp.deduct.call]
15577 If P is not a reference type:
15579 --If A is an array type, the pointer type produced by the
15580 array-to-pointer standard conversion (_conv.array_) is
15581 used in place of A for type deduction; otherwise,
15583 --If A is a function type, the pointer type produced by
15584 the function-to-pointer standard conversion
15585 (_conv.func_) is used in place of A for type deduction;
15586 otherwise,
15588 --If A is a cv-qualified type, the top level
15589 cv-qualifiers of A's type are ignored for type
15590 deduction. */
15595 else
15597 }
15599 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
15600 of the form T&&, where T is a template parameter, and the argument
15601 is an lvalue, T is deduced as A& */
15607 /* try_one_overload doesn't provide an arg_expr, but
15608 functions are always lvalues. */
15612 /* [temp.deduct.call]
15614 If P is a cv-qualified type, the top level cv-qualifiers
15615 of P's type are ignored for type deduction. If P is a
15616 reference type, the type referred to by P is used for
15617 type deduction. */
15620 {
15623 }
15625 /* DR 322. For conversion deduction, remove a reference type on parm
15626 too (which has been swapped into ARG). */
15631 }
15633 /* Subroutine of unify_one_argument. PARM is a function parameter of a
15634 template which does contain any deducible template parameters; check if
15635 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
15636 unify_one_argument. */
15638 static int
15641 {
15642 tree type;
15646 else
15653 {
15657 }
15659 {
15664 }
15668 else
15670 }
15674 /* Returns true iff the expression EXPR is one from which a template
15675 argument can be deduced. In other words, if it's an undecorated
15676 use of a template non-type parameter. */
15678 static bool
15680 {
15682 }
15684 /* Returns true iff the array domain DOMAIN uses a template parameter in a
15685 deducible way; that is, if it has a max value of <PARM> - 1. */
15687 static bool
15689 {
15698 }
15700 /* Returns true iff the template arguments ARGS use a template parameter
15701 in a deducible way. */
15703 static bool
15705 {
15707 {
15712 else
15713 {
15720 else
15722 }
15725 }
15727 }
15729 /* Returns true iff TYPE contains any deducible references to template
15730 parameters, as per 14.8.2.5. */
15732 static bool
15734 {
15738 /* T
15739 cv-list T
15740 TT<T>
15741 TT<i>
15742 TT<> */
15747 /* T*
15748 T&
15749 T&& */
15753 /* T[integer-constant ]
15754 type [i] */
15759 /* T type ::*
15760 type T::*
15761 T T::*
15762 T (type ::*)()
15763 type (T::*)()
15764 type (type ::*)(T)
15765 type (T::*)(T)
15766 T (type ::*)(T)
15767 T (T::*)()
15768 T (T::*)(T) */
15771 || (uses_deducible_template_parms
15774 /* template-name <T> (where template-name refers to a class template)
15775 template-name <i> (where template-name refers to a class template) */
15782 /* type (T)
15783 T()
15784 T(T) */
15787 {
15796 }
15799 }
15801 /* Subroutine of type_unification_real and unify_pack_expansion to
15802 handle unification of a single P/A pair. Parameters are as
15803 for those functions. */
15805 static int
15809 {
15816 /* We can't deduce anything from this, but we might get all the
15817 template args from other function args. */
15820 /* Implicit conversions (Clause 4) will be performed on a function
15821 argument to convert it to the type of the corresponding function
15822 parameter if the parameter type contains no template-parameters that
15823 participate in template argument deduction. */
15825 /* For function parameters that contain no template-parameters at all,
15826 we have historically checked for convertibility in order to shortcut
15827 consideration of this candidate. */
15829 explain_p);
15832 /* For function parameters with only non-deducible template parameters,
15833 just return. */
15837 {
15839 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
15840 | UNIFY_ALLOW_MORE_CV_QUAL
15854 }
15856 /* We only do these transformations if this is the top-level
15857 parameter_type_list in a call or declaration matching; in other
15858 situations (nested function declarators, template argument lists) we
15859 won't be comparing a type to an expression, and we don't do any type
15860 adjustments. */
15862 {
15864 {
15867 {
15868 /* [temp.deduct.type] A template-argument can be
15869 deduced from a pointer to function or pointer
15870 to member function argument if the set of
15871 overloaded functions does not contain function
15872 templates and at most one of a set of
15873 overloaded functions provides a unique
15874 match. */
15881 }
15887 }
15889 arg_strict |=
15891 }
15892 else
15896 /* For deduction from an init-list we need the actual list. */
15900 }
15902 /* Most parms like fn_type_unification.
15904 If SUBR is 1, we're being called recursively (to unify the
15905 arguments of a function or method parameter of a function
15906 template).
15908 CHECKS is a pointer to a vector of access checks encountered while
15909 substituting default template arguments. */
15911 static int
15913 tree targs,
15914 tree xparms,
15918 unification_kind_t strict,
15922 {
15927 tree parms;
15936 /* Reset the number of non-defaulted template arguments contained
15937 in TARGS. */
15940 again:
15948 {
15953 /* For a function parameter pack that occurs at the end of the
15954 parameter-declaration-list, the type A of each remaining
15955 argument of the call is compared with the type P of the
15956 declarator-id of the function parameter pack. */
15962 /* For a function parameter pack that does not occur at the
15963 end of the parameter-declaration-list, the type of the
15964 parameter pack is a non-deduced context. */
15973 }
15978 {
15979 /* Unify the remaining arguments with the pack expansion type. */
15980 tree argvec;
15983 /* Allocate a TREE_VEC and copy in all of the arguments */
15988 /* Copy the parameter into parmvec. */
15994 /* Advance to the end of the list of parameters. */
15996 }
15998 /* Fail if we've reached the end of the parm list, and more args
15999 are present, and the parm list isn't variadic. */
16002 /* Fail if parms are left and they don't have default values. */
16005 {
16009 {
16010 count++;
16012 }
16014 }
16017 {
16018 tsubst_flags_t complain = (explain_p
16019 ? tf_warning_or_error
16023 {
16027 /* Clear the "incomplete" flags on all argument packs now so that
16028 substituting them into later default arguments works. */
16030 {
16033 }
16039 /* If this is an undeduced nontype parameter that depends on
16040 a type parameter, try another pass; its type may have been
16041 deduced from a later argument than the one from which
16042 this parameter can be deduced. */
16048 /* Core issue #226 (C++0x) [temp.deduct]:
16050 If a template argument has not been deduced, its
16051 default template argument, if any, is used.
16053 When we are in C++98 mode, TREE_PURPOSE will either
16054 be NULL_TREE or ERROR_MARK_NODE, so we do not need
16055 to explicitly check cxx_dialect here. */
16057 {
16072 else
16073 {
16075 /* The position of the first default template argument,
16076 is also the number of non-defaulted arguments in TARGS.
16077 Record that. */
16081 }
16082 }
16084 /* If the type parameter is a parameter pack, then it will
16085 be deduced to an empty parameter pack. */
16087 {
16088 tree arg;
16091 {
16095 }
16096 else
16103 }
16106 }
16107 }
16108 #ifdef ENABLE_CHECKING
16111 #endif
16114 }
16116 /* Subroutine of type_unification_real. Args are like the variables
16117 at the call site. ARG is an overloaded function (or template-id);
16118 we try deducing template args from each of the overloads, and if
16119 only one succeeds, we go with that. Modifies TARGS and returns
16120 true on success. */
16122 static bool
16124 tree targs,
16125 tree parm,
16126 tree arg,
16127 unification_kind_t strict,
16130 {
16137 {
16140 }
16141 else
16145 /* Handle `&x' where `x' is some static or non-static member
16146 function name. */
16152 /* Strip baselink information. */
16157 {
16158 /* If we got some explicit template args, we need to plug them into
16159 the affected templates before we try to unify, in case the
16160 explicit args will completely resolve the templates in question. */
16167 {
16180 {
16185 {
16188 }
16189 }
16192 }
16193 /* If no templates (or more than one) are fully resolved by the
16194 explicit arguments, this template-id is a non-deduced context; it
16195 could still be OK if we deduce all template arguments for the
16196 enclosing call through other arguments. */
16199 }
16202 /* If ARG is, for example, "(0, &f)" then its type will be unknown
16203 -- but the deduction does not succeed because the expression is
16204 not just the function on its own. */
16206 else
16212 {
16215 }
16217 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16218 to function or pointer to member function argument if the set of
16219 overloaded functions does not contain function templates and at most
16220 one of a set of overloaded functions provides a unique match.
16222 So if we found multiple possibilities, we return success but don't
16223 deduce anything. */
16226 {
16231 }
16236 }
16238 /* Core DR 115: In contexts where deduction is done and fails, or in
16239 contexts where deduction is not done, if a template argument list is
16240 specified and it, along with any default template arguments, identifies
16241 a single function template specialization, then the template-id is an
16242 lvalue for the function template specialization. */
16244 tree
16246 {
16259 {
16262 }
16264 {
16267 }
16269 {
16272 }
16275 {
16279 /* If we got some explicit template args, we need to plug them into
16280 the affected templates before we try to unify, in case the
16281 explicit args will completely resolve the templates in question. */
16289 {
16302 {
16305 {
16308 }
16310 {
16313 }
16314 }
16315 }
16317 {
16325 {
16326 tree base
16329 }
16333 }
16335 /* There were no good options and at least one bad one, so let the
16336 user know what the problem is. */
16338 }
16340 }
16342 /* Subroutine of resolve_overloaded_unification; does deduction for a single
16343 overload. Fills TARGS with any deduced arguments, or error_mark_node if
16344 different overloads deduce different arguments for a given parm.
16345 ADDR_P is true if the expression for which deduction is being
16346 performed was of the form "& fn" rather than simply "fn".
16348 Returns 1 on success. */
16350 static int
16352 tree orig_targs,
16353 tree targs,
16354 tree parm,
16355 tree arg,
16356 unification_kind_t strict,
16360 {
16362 tree tempargs;
16368 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16369 to function or pointer to member function argument if the set of
16370 overloaded functions does not contain function templates and at most
16371 one of a set of overloaded functions provides a unique match.
16373 So if this is a template, just return success. */
16385 /* We don't copy orig_targs for this because if we have already deduced
16386 some template args from previous args, unify would complain when we
16387 try to deduce a template parameter for the same argument, even though
16388 there isn't really a conflict. */
16395 /* First make sure we didn't deduce anything that conflicts with
16396 explicitly specified args. */
16398 {
16405 /* Since we're unifying against ourselves, we will fill in
16406 template args used in the function parm list with our own
16407 template parms. Discard them. */
16411 }
16414 {
16419 }
16422 }
16424 /* PARM is a template class (perhaps with unbound template
16425 parameters). ARG is a fully instantiated type. If ARG can be
16426 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
16427 TARGS are as for unify. */
16429 static tree
16432 {
16433 tree copy_of_targs;
16440 /* We need to make a new template argument vector for the call to
16441 unify. If we used TARGS, we'd clutter it up with the result of
16442 the attempted unification, even if this class didn't work out.
16443 We also don't want to commit ourselves to all the unifications
16444 we've already done, since unification is supposed to be done on
16445 an argument-by-argument basis. In other words, consider the
16446 following pathological case:
16448 template <int I, int J, int K>
16449 struct S {};
16451 template <int I, int J>
16452 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
16454 template <int I, int J, int K>
16455 void f(S<I, J, K>, S<I, I, I>);
16457 void g() {
16458 S<0, 0, 0> s0;
16459 S<0, 1, 2> s2;
16461 f(s0, s2);
16462 }
16464 Now, by the time we consider the unification involving `s2', we
16465 already know that we must have `f<0, 0, 0>'. But, even though
16466 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
16467 because there are two ways to unify base classes of S<0, 1, 2>
16468 with S<I, I, I>. If we kept the already deduced knowledge, we
16469 would reject the possibility I=1. */
16472 /* If unification failed, we're done. */
16478 }
16480 /* Given a template type PARM and a class type ARG, find the unique
16481 base type in ARG that is an instance of PARM. We do not examine
16482 ARG itself; only its base-classes. If there is not exactly one
16483 appropriate base class, return NULL_TREE. PARM may be the type of
16484 a partial specialization, as well as a plain template type. Used
16485 by unify. */
16487 static enum template_base_result
16490 {
16492 tree binfo;
16498 {
16499 /* The type could not be completed. */
16502 }
16504 /* Walk in inheritance graph order. The search order is not
16505 important, and this avoids multiple walks of virtual bases. */
16507 {
16512 {
16513 /* If there is more than one satisfactory baseclass, then:
16515 [temp.deduct.call]
16517 If they yield more than one possible deduced A, the type
16518 deduction fails.
16520 applies. */
16522 {
16525 }
16528 }
16529 }
16533 }
16535 /* Returns the level of DECL, which declares a template parameter. */
16537 static int
16539 {
16541 {
16551 }
16553 }
16555 /* Decide whether ARG can be unified with PARM, considering only the
16556 cv-qualifiers of each type, given STRICT as documented for unify.
16557 Returns nonzero iff the unification is OK on that basis. */
16559 static int
16561 {
16567 {
16568 /* Although a CVR qualifier is ignored when being applied to a
16569 substituted template parameter ([8.3.2]/1 for example), that
16570 does not allow us to unify "const T" with "int&" because both
16571 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
16572 It is ok when we're allowing additional CV qualifiers
16573 at the outer level [14.8.2.1]/3,1st bullet. */
16583 }
16594 }
16596 /* Determines the LEVEL and INDEX for the template parameter PARM. */
16597 void
16599 {
16603 {
16606 }
16607 else
16608 {
16611 }
16612 }
16614 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
16615 do { \
16616 if (unify (TP, TA, P, A, S, EP)) \
16617 return 1; \
16618 } while (0);
16620 /* Unifies the remaining arguments in PACKED_ARGS with the pack
16621 expansion at the end of PACKED_PARMS. Returns 0 if the type
16622 deduction succeeds, 1 otherwise. STRICT is the same as in
16623 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
16624 call argument list. We'll need to adjust the arguments to make them
16625 types. SUBR tells us if this is from a recursive call to
16626 type_unification_real, or for comparing two template argument
16627 lists. */
16629 static int
16633 {
16634 tree parm
16641 /* Determine the parameter packs we will be deducing from the
16642 pattern, and record their current deductions. */
16645 {
16649 /* Determine the index and level of this parameter pack. */
16652 /* Keep track of the parameter packs and their corresponding
16653 argument packs. */
16656 }
16658 /* Loop through all of the arguments that have not yet been
16659 unified and unify each with the pattern. */
16661 {
16662 tree parm;
16666 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
16667 or the element of its argument pack at the current index if
16668 this argument was explicitly specified. */
16670 {
16679 {
16682 }
16684 }
16686 /* If we had explicit template arguments, substitute them into the
16687 pattern before deduction. */
16689 {
16690 /* Some arguments might still be unspecified or dependent. */
16698 NULL_TREE);
16703 }
16704 else
16707 /* Unify the pattern with the current argument. */
16712 /* For each parameter pack, collect the deduced value. */
16714 {
16720 }
16721 }
16723 /* Verify that the results of unification with the parameter packs
16724 produce results consistent with what we've seen before, and make
16725 the deduced argument packs available. */
16727 {
16734 /* By default keep the original deduced argument pack.
16735 If necessary, more specific code is going to update the
16736 resulting deduced argument later down in this function. */
16740 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
16741 actually deduce anything. */
16749 {
16750 /* If we had fewer function args than explicit template args,
16751 just use the explicits. */
16756 }
16759 {
16760 tree result;
16761 /* Build the deduced *_ARGUMENT_PACK. */
16763 {
16768 }
16769 else
16774 /* Note the deduced argument packs for this parameter
16775 pack. */
16777 }
16781 {
16782 /* We only had the explicitly-provided arguments before, but
16783 now we have a complete set of arguments. */
16789 }
16790 else
16791 {
16797 /* Inconsistent unification of this parameter pack. */
16799 bad_old_arg,
16800 bad_new_arg);
16801 }
16802 }
16805 }
16807 /* Deduce the value of template parameters. TPARMS is the (innermost)
16808 set of template parameters to a template. TARGS is the bindings
16809 for those template parameters, as determined thus far; TARGS may
16810 include template arguments for outer levels of template parameters
16811 as well. PARM is a parameter to a template function, or a
16812 subcomponent of that parameter; ARG is the corresponding argument.
16813 This function attempts to match PARM with ARG in a manner
16814 consistent with the existing assignments in TARGS. If more values
16815 are deduced, then TARGS is updated.
16817 Returns 0 if the type deduction succeeds, 1 otherwise. The
16818 parameter STRICT is a bitwise or of the following flags:
16820 UNIFY_ALLOW_NONE:
16821 Require an exact match between PARM and ARG.
16822 UNIFY_ALLOW_MORE_CV_QUAL:
16823 Allow the deduced ARG to be more cv-qualified (by qualification
16824 conversion) than ARG.
16825 UNIFY_ALLOW_LESS_CV_QUAL:
16826 Allow the deduced ARG to be less cv-qualified than ARG.
16827 UNIFY_ALLOW_DERIVED:
16828 Allow the deduced ARG to be a template base class of ARG,
16829 or a pointer to a template base class of the type pointed to by
16830 ARG.
16831 UNIFY_ALLOW_INTEGER:
16832 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
16833 case for more information.
16834 UNIFY_ALLOW_OUTER_LEVEL:
16835 This is the outermost level of a deduction. Used to determine validity
16836 of qualification conversions. A valid qualification conversion must
16837 have const qualified pointers leading up to the inner type which
16838 requires additional CV quals, except at the outer level, where const
16839 is not required [conv.qual]. It would be normal to set this flag in
16840 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
16841 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
16842 This is the outermost level of a deduction, and PARM can be more CV
16843 qualified at this point.
16844 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
16845 This is the outermost level of a deduction, and PARM can be less CV
16846 qualified at this point. */
16848 static int
16851 {
16853 tree targ;
16854 tree tparm;
16857 /* I don't think this will do the right thing with respect to types.
16858 But the only case I've seen it in so far has been array bounds, where
16859 signedness is the only information lost, and I think that will be
16860 okay. */
16868 /* We can't deduce anything from this, but we might get all the
16869 template args from other function args. */
16872 /* If PARM uses template parameters, then we can't bail out here,
16873 even if ARG == PARM, since we won't record unifications for the
16874 template parameters. We might need them if we're trying to
16875 figure out which of two things is more specialized. */
16879 /* Handle init lists early, so the rest of the function can assume
16880 we're dealing with a type. */
16882 {
16887 /* Replace T with std::initializer_list<T> for deduction. */
16893 /* We can only deduce from an initializer list argument if the
16894 parameter is std::initializer_list; otherwise this is a
16895 non-deduced context. */
16901 {
16908 {
16910 /* It should only be possible to get here for a call. */
16912 elt_strict |= maybe_adjust_types_for_deduction
16915 }
16918 explain_p);
16919 }
16921 /* If the std::initializer_list<T> deduction worked, replace the
16922 deduced A with std::initializer_list<A>. */
16924 {
16929 }
16931 }
16933 /* Immediately reject some pairs that won't unify because of
16934 cv-qualification mismatches. */
16937 /* It is the elements of the array which hold the cv quals of an array
16938 type, and the elements might be template type parms. We'll check
16939 when we recurse. */
16941 /* We check the cv-qualifiers when unifying with template type
16942 parameters below. We want to allow ARG `const T' to unify with
16943 PARM `T' for example, when computing which of two templates
16944 is more specialized, for example. */
16958 {
16962 /* In a type which contains a nested-name-specifier, template
16963 argument values cannot be deduced for template parameters used
16964 within the nested-name-specifier. */
16976 /* The PARM is not one we're trying to unify. Just check
16977 to see if it matches ARG. */
16978 {
16983 else
16985 }
16992 /* Check for mixed types and values. */
17000 {
17001 /* ARG must be constructed from a template class or a template
17002 template parameter. */
17007 {
17011 tree parm_parms
17012 = DECL_INNERMOST_TEMPLATE_PARMS
17017 /* The resolution to DR150 makes clear that default
17018 arguments for an N-argument may not be used to bind T
17019 to a template template parameter with fewer than N
17020 parameters. It is not safe to permit the binding of
17021 default arguments as an extension, as that may change
17022 the meaning of a conforming program. Consider:
17024 struct Dense { static const unsigned int dim = 1; };
17026 template <template <typename> class View,
17027 typename Block>
17028 void operator+(float, View<Block> const&);
17030 template <typename Block,
17031 unsigned int Dim = Block::dim>
17032 struct Lvalue_proxy { operator float() const; };
17034 void
17035 test_1d (void) {
17036 Lvalue_proxy<Dense> p;
17037 float b;
17038 b + p;
17039 }
17041 Here, if Lvalue_proxy is permitted to bind to View, then
17042 the global operator+ will be used; if they are not, the
17043 Lvalue_proxy will be converted to float. */
17045 full_argvec,
17047 (explain_p
17048 ? tf_warning_or_error
17055 /* Deduce arguments T, i from TT<T> or TT<i>.
17056 We check each element of PARMVEC and ARGVEC individually
17057 rather than the whole TREE_VEC since they can have
17058 different number of elements. */
17065 /* Check if the parameters end in a pack, making them
17066 variadic. */
17072 /* If the template argument list of P contains a pack
17073 expansion that is not the last template argument, the
17074 entire template argument list is a non-deduced
17075 context. */
17084 {
17089 }
17094 DEDUCE_EXACT,
17097 }
17100 /* Fall through to deduce template name. */
17101 }
17105 {
17106 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
17108 /* Simple cases: Value already set, does match or doesn't. */
17113 }
17114 else
17115 {
17116 /* If PARM is `const T' and ARG is only `int', we don't have
17117 a match unless we are allowing additional qualification.
17118 If ARG is `const int' and PARM is just `T' that's OK;
17119 that binds `const int' to `T'. */
17124 /* Consider the case where ARG is `const volatile int' and
17125 PARM is `const T'. Then, T should be `volatile int'. */
17126 arg = cp_build_qualified_type_real
17131 /* Simple cases: Value already set, does match or doesn't. */
17137 /* Make sure that ARG is not a variable-sized array. (Note
17138 that were talking about variable-sized arrays (like
17139 `int[n]'), rather than arrays of unknown size (like
17140 `int[]').) We'll get very confused by such a type since
17141 the bound of the array is not constant, and therefore
17142 not mangleable. Besides, such types are not allowed in
17143 ISO C++, so we can do as we please here. We do allow
17144 them for 'auto' deduction, since that isn't ABI-exposed. */
17148 /* Strip typedefs as in convert_template_argument. */
17150 }
17152 /* If ARG is a parameter pack or an expansion, we cannot unify
17153 against it unless PARM is also a parameter pack. */
17158 /* If the argument deduction results is a METHOD_TYPE,
17159 then there is a problem.
17160 METHOD_TYPE doesn't map to any real C++ type the result of
17161 the deduction can not be of that type. */
17175 {
17176 /* The PARM is not one we're trying to unify. Just check
17177 to see if it matches ARG. */
17183 }
17189 {
17194 }
17196 /* [temp.deduct.type] If, in the declaration of a function template
17197 with a non-type template-parameter, the non-type
17198 template-parameter is used in an expression in the function
17199 parameter-list and, if the corresponding template-argument is
17200 deduced, the template-argument type shall match the type of the
17201 template-parameter exactly, except that a template-argument
17202 deduced from an array bound may be of any integral type.
17203 The non-type parameter might use already deduced type parameters. */
17206 /* Template-parameter dependent expression. Just accept it for now.
17207 It will later be processed in convert_template_argument. */
17208 ;
17213 /* Convert the ARG to the type of PARM; the deduced non-type
17214 template argument must exactly match the types of the
17215 corresponding parameter. */
17218 /* We haven't deduced the type of this parameter yet. Try again
17219 later. */
17221 else
17224 /* If ARG is a parameter pack or an expansion, we cannot unify
17225 against it unless PARM is also a parameter pack. */
17235 {
17236 /* A pointer-to-member constant can be unified only with
17237 another constant. */
17241 /* Just unify the class member. It would be useless (and possibly
17242 wrong, depending on the strict flags) to unify also
17243 PTRMEM_CST_CLASS, because we want to be sure that both parm and
17244 arg refer to the same variable, even if through different
17245 classes. For instance:
17247 struct A { int x; };
17248 struct B : A { };
17250 Unification of &A::x and &B::x must succeed. */
17253 }
17256 {
17260 /* [temp.deduct.call]
17262 A can be another pointer or pointer to member type that can
17263 be converted to the deduced A via a qualification
17264 conversion (_conv.qual_).
17266 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
17267 This will allow for additional cv-qualification of the
17268 pointed-to types if appropriate. */
17271 /* The derived-to-base conversion only persists through one
17272 level of pointers. */
17277 }
17294 {
17295 tree parm_max;
17296 tree arg_max;
17300 /* Our representation of array types uses "N - 1" as the
17301 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
17302 not an integer constant. We cannot unify arbitrarily
17303 complex expressions, so we eliminate the MINUS_EXPRs
17304 here. */
17308 {
17311 }
17315 {
17316 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
17317 trying to unify the type of a variable with the type
17318 of a template parameter. For example:
17320 template <unsigned int N>
17321 void f (char (&) [N]);
17322 int g();
17323 void h(int i) {
17324 char a[g(i)];
17325 f(a);
17326 }
17328 Here, the type of the ARG will be "int [g(i)]", and
17329 may be a SAVE_EXPR, etc. */
17333 }
17335 /* If only one of the bounds used a MINUS_EXPR, compensate
17336 by adding one to the other bound. */
17339 integer_type_node,
17340 parm_max,
17341 integer_one_node);
17344 integer_type_node,
17345 arg_max,
17346 integer_one_node);
17350 }
17364 /* We have already checked cv-qualification at the top of the
17365 function. */
17369 /* As far as unification is concerned, this wins. Later checks
17370 will invalidate it if necessary. */
17373 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
17374 /* Type INTEGER_CST can come from ordinary constant template args. */
17386 {
17396 /* Check for pack expansions in the parameters. */
17398 {
17400 {
17402 /* We can unify against something with a trailing
17403 parameter pack. */
17405 else
17406 /* [temp.deduct.type]/9: If the template argument list of
17407 P contains a pack expansion that is not the last
17408 template argument, the entire template argument list
17409 is a non-deduced context. */
17411 }
17412 }
17414 /* If we don't have enough arguments to satisfy the parameters
17415 (not counting the pack expression at the end), or we have
17416 too many arguments for a parameter list that doesn't end in
17417 a pack expression, we can't unify. */
17423 /* Unify all of the parameters that precede the (optional)
17424 pack expression. */
17426 {
17431 }
17434 DEDUCE_EXACT,
17437 }
17445 {
17453 }
17456 {
17460 {
17461 /* First, we try to unify the PARM and ARG directly. */
17466 {
17467 /* Fallback to the special case allowed in
17468 [temp.deduct.call]:
17470 If P is a class, and P has the form
17471 template-id, then A can be a derived class of
17472 the deduced A. Likewise, if P is a pointer to
17473 a class of the form template-id, A can be a
17474 pointer to a derived class pointed to by the
17475 deduced A. */
17482 }
17483 }
17487 /* Perhaps PARM is something like S<U> and ARG is S<int>.
17488 Then, we should unify `int' and `U'. */
17490 else
17491 /* There's no chance of unification succeeding. */
17496 }
17503 {
17506 tree a;
17512 /* CV qualifications for methods can never be deduced, they must
17513 match exactly. We need to check them explicitly here,
17514 because type_unification_real treats them as any other
17515 cv-qualified parameter. */
17517 && (!check_cv_quals_for_unify
17537 }
17540 /* Unify a pointer to member with a pointer to member function, which
17541 deduces the type of the member as a function type. */
17543 {
17544 /* Check top-level cv qualifiers */
17552 /* Determine the type of the function we are unifying against. */
17556 }
17575 /* Matched cases are handled by the ARG == PARM test above. */
17579 /* A non-type template parameter that is a variable should be a
17580 an integral constant, in which case, it whould have been
17581 folded into its (constant) value. So we should not be getting
17582 a variable here. */
17593 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
17594 or UNDERLYING_TYPE nodes. */
17598 /* Unification fails if we hit an error node. */
17602 /* An unresolved overload is a nondeduced context. */
17607 /* We must be looking at an expression. This can happen with
17608 something like:
17610 template <int I>
17611 void foo(S<I>, S<I + 2>);
17613 This is a "nondeduced context":
17615 [deduct.type]
17617 The nondeduced contexts are:
17619 --A type that is a template-id in which one or more of
17620 the template-arguments is an expression that references
17621 a template-parameter.
17623 In these cases, we assume deduction succeeded, but don't
17624 actually infer any unifications. */
17629 else
17631 }
17632 }
17633 #undef RECUR_AND_CHECK_FAILURE
17634 \f
17635 /* Note that DECL can be defined in this translation unit, if
17636 required. */
17638 static void
17640 {
17641 tree clone;
17645 }
17647 /* Called if RESULT is explicitly instantiated, or is a member of an
17648 explicitly instantiated class. */
17650 void
17652 {
17655 /* If this entity has already been written out, it's too late to
17656 make any modifications. */
17660 /* For anonymous namespace we don't need to do anything. */
17662 {
17665 }
17668 /* The TREE_PUBLIC flag for function declarations will have been
17669 set correctly by tsubst. */
17672 /* This might have been set by an earlier implicit instantiation. */
17677 else
17678 {
17680 /* Always make artificials weak. */
17683 /* For WIN32 we also want to put explicit instantiations in
17684 linkonce sections. */
17687 }
17689 /* If EXTERN_P, then this function will not be emitted -- unless
17690 followed by an explicit instantiation, at which point its linkage
17691 will be adjusted. If !EXTERN_P, then this function will be
17692 emitted here. In neither circumstance do we want
17693 import_export_decl to adjust the linkage. */
17695 }
17697 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
17698 important template arguments. If any are missing, we check whether
17699 they're important by using error_mark_node for substituting into any
17700 args that were used for partial ordering (the ones between ARGS and END)
17701 and seeing if it bubbles up. */
17703 static bool
17705 {
17710 {
17713 }
17715 {
17719 }
17721 }
17723 /* Given two function templates PAT1 and PAT2, return:
17725 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
17726 -1 if PAT2 is more specialized than PAT1.
17727 0 if neither is more specialized.
17729 LEN indicates the number of parameters we should consider
17730 (defaulted parameters should not be considered).
17732 The 1998 std underspecified function template partial ordering, and
17733 DR214 addresses the issue. We take pairs of arguments, one from
17734 each of the templates, and deduce them against each other. One of
17735 the templates will be more specialized if all the *other*
17736 template's arguments deduce against its arguments and at least one
17737 of its arguments *does* *not* deduce against the other template's
17738 corresponding argument. Deduction is done as for class templates.
17739 The arguments used in deduction have reference and top level cv
17740 qualifiers removed. Iff both arguments were originally reference
17741 types *and* deduction succeeds in both directions, an lvalue reference
17742 wins against an rvalue reference and otherwise the template
17743 with the more cv-qualified argument wins for that pairing (if
17744 neither is more cv-qualified, they both are equal). Unlike regular
17745 deduction, after all the arguments have been deduced in this way,
17746 we do *not* verify the deduced template argument values can be
17747 substituted into non-deduced contexts.
17749 The logic can be a bit confusing here, because we look at deduce1 and
17750 targs1 to see if pat2 is at least as specialized, and vice versa; if we
17751 can find template arguments for pat1 to make arg1 look like arg2, that
17752 means that arg2 is at least as specialized as arg1. */
17754 int
17756 {
17769 /* Remove the this parameter from non-static member functions. If
17770 one is a non-static member function and the other is not a static
17771 member function, remove the first parameter from that function
17772 also. This situation occurs for operator functions where we
17773 locate both a member function (with this pointer) and non-member
17774 operator (with explicit first operand). */
17776 {
17781 }
17783 {
17786 {
17787 len--;
17789 }
17790 }
17792 /* If only one is a conversion operator, they are unordered. */
17796 /* Consider the return type for a conversion function */
17798 {
17801 len++;
17802 }
17804 processing_template_decl++;
17810 /* Stop when an ellipsis is seen. */
17812 {
17823 {
17824 /* When both arguments are pack expansions, we need only
17825 unify the patterns themselves. */
17829 /* This is the last comparison we need to do. */
17831 }
17834 {
17838 }
17841 {
17845 }
17851 {
17857 /* Setup the parameter vector, which contains only ARG1. */
17860 /* Setup the argument vector, which contains the remaining
17861 arguments. */
17870 /* We cannot deduce in the other direction, because ARG1 is
17871 a pack expansion but ARG2 is not. */
17873 }
17875 {
17881 /* Setup the parameter vector, which contains only ARG1. */
17884 /* Setup the argument vector, which contains the remaining
17885 arguments. */
17894 /* We cannot deduce in the other direction, because ARG2 is
17895 a pack expansion but ARG1 is not.*/
17897 }
17899 else
17900 {
17901 /* The normal case, where neither argument is a pack
17902 expansion. */
17909 }
17911 /* If we couldn't deduce arguments for tparms1 to make arg1 match
17912 arg2, then arg2 is not as specialized as arg1. */
17918 /* "If, for a given type, deduction succeeds in both directions
17919 (i.e., the types are identical after the transformations above)
17920 and both P and A were reference types (before being replaced with
17921 the type referred to above):
17922 - if the type from the argument template was an lvalue reference and
17923 the type from the parameter template was not, the argument type is
17924 considered to be more specialized than the other; otherwise,
17925 - if the type from the argument template is more cv-qualified
17926 than the type from the parameter template (as described above),
17927 the argument type is considered to be more specialized than the other;
17928 otherwise,
17929 - neither type is more specialized than the other." */
17932 {
17934 {
17937 else
17939 }
17941 {
17946 }
17947 }
17950 /* We've failed to deduce something in either direction.
17951 These must be unordered. */
17956 /* We have already processed all of the arguments in our
17957 handing of the pack expansion type. */
17962 }
17964 /* "In most cases, all template parameters must have values in order for
17965 deduction to succeed, but for partial ordering purposes a template
17966 parameter may remain without a value provided it is not used in the
17967 types being used for partial ordering."
17969 Thus, if we are missing any of the targs1 we need to substitute into
17970 origs1, then pat2 is not as specialized as pat1. This can happen when
17971 there is a nondeduced context. */
17977 processing_template_decl--;
17979 /* All things being equal, if the next argument is a pack expansion
17980 for one function but not for the other, prefer the
17981 non-variadic function. FIXME this is bogus; see c++/41958. */
17985 {
17988 }
17994 else
17996 }
17998 /* Determine which of two partial specializations of MAIN_TMPL is more
17999 specialized.
18001 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
18002 to the first partial specialization. The TREE_VALUE is the
18003 innermost set of template parameters for the partial
18004 specialization. PAT2 is similar, but for the second template.
18006 Return 1 if the first partial specialization is more specialized;
18007 -1 if the second is more specialized; 0 if neither is more
18008 specialized.
18010 See [temp.class.order] for information about determining which of
18011 two templates is more specialized. */
18013 static int
18015 {
18016 tree targs;
18024 /* Just like what happens for functions, if we are ordering between
18025 different class template specializations, we may encounter dependent
18026 types in the arguments, and we need our dependency check functions
18027 to behave correctly. */
18033 {
18036 }
18042 {
18045 }
18048 /* In the case of a tie where at least one of the class templates
18049 has a parameter pack at the end, the template with the most
18050 non-packed parameters wins. */
18052 && any_deductions
18055 {
18061 /* We don't count the pack expansion at the end. */
18071 }
18074 }
18076 /* Return the template arguments that will produce the function signature
18077 DECL from the function template FN, with the explicit template
18078 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
18079 also match. Return NULL_TREE if no satisfactory arguments could be
18080 found. */
18082 static tree
18084 {
18088 tree decl_arg_types;
18091 tree arg;
18095 /* Never do unification on the 'this' parameter. */
18116 }
18118 /* Return the innermost template arguments that, when applied to a partial
18119 specialization of MAIN_TMPL whose innermost template parameters are
18120 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
18121 ARGS.
18123 For example, suppose we have:
18125 template <class T, class U> struct S {};
18126 template <class T> struct S<T*, int> {};
18128 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
18129 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
18130 int}. The resulting vector will be {double}, indicating that `T'
18131 is bound to `double'. */
18133 static tree
18135 {
18137 tree deduced_args;
18138 tree innermost_deduced_args;
18142 {
18146 innermost_deduced_args);
18147 }
18148 else
18161 /* Verify that nondeduced template arguments agree with the type
18162 obtained from argument deduction.
18164 For example:
18166 struct A { typedef int X; };
18167 template <class T, class U> struct C {};
18168 template <class T> struct C<T, typename T::X> {};
18170 Then with the instantiation `C<A, int>', we can deduce that
18171 `T' is `A' but unify () does not check whether `typename T::X'
18172 is `int'. */
18178 /* We only need to check the innermost arguments; the other
18179 arguments will always agree. */
18184 /* Now that we have bindings for all of the template arguments,
18185 ensure that the arguments deduced for the template template
18186 parameters have compatible template parameter lists. See the use
18187 of template_template_parm_bindings_ok_p in fn_type_unification
18188 for more information. */
18193 }
18195 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
18196 Return the TREE_LIST node with the most specialized template, if
18197 any. If there is no most specialized template, the error_mark_node
18198 is returned.
18200 Note that this function does not look at, or modify, the
18201 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
18202 returned is one of the elements of INSTANTIATIONS, callers may
18203 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
18204 and retrieve it from the value returned. */
18206 tree
18208 {
18215 {
18221 fate--;
18226 fate++;
18231 {
18232 /* Equally specialized, move to next function. If there
18233 is no next function, nothing's most specialized. */
18238 }
18239 }
18242 /* Now verify that champ is better than everything earlier in the
18243 instantiation list. */
18251 {
18254 }
18256 processing_template_decl--;
18262 }
18264 /* If DECL is a specialization of some template, return the most
18265 general such template. Otherwise, returns NULL_TREE.
18267 For example, given:
18269 template <class T> struct S { template <class U> void f(U); };
18271 if TMPL is `template <class U> void S<int>::f(U)' this will return
18272 the full template. This function will not trace past partial
18273 specializations, however. For example, given in addition:
18275 template <class T> struct S<T*> { template <class U> void f(U); };
18277 if TMPL is `template <class U> void S<int*>::f(U)' this will return
18278 `template <class T> template <class U> S<T*>::f(U)'. */
18280 tree
18282 {
18283 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
18284 an immediate specialization. */
18286 {
18290 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
18291 template friend. */
18296 }
18298 /* Look for more and more general templates. */
18300 {
18301 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
18302 (See cp-tree.h for details.) */
18310 /* Stop if we run into an explicitly specialized class template. */
18317 }
18320 }
18322 /* Return the most specialized of the class template partial
18323 specializations of TMPL which can produce TYPE, a specialization of
18324 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
18325 a _TYPE node corresponding to the partial specialization, while the
18326 TREE_PURPOSE is the set of template arguments that must be
18327 substituted into the TREE_TYPE in order to generate TYPE.
18329 If the choice of partial specialization is ambiguous, a diagnostic
18330 is issued, and the error_mark_node is returned. If there are no
18331 partial specializations of TMPL matching TYPE, then NULL_TREE is
18332 returned. */
18334 static tree
18336 {
18338 tree t;
18339 tree champ;
18342 tree args;
18348 /* For determining which partial specialization to use, only the
18349 innermost args are interesting. */
18351 {
18354 }
18357 {
18358 tree partial_spec_args;
18359 tree spec_args;
18368 {
18369 /* Discard the outer levels of args, and then substitute in the
18370 template args from the enclosing class. */
18372 partial_spec_args = tsubst_template_args
18375 /* And the same for the partial specialization TEMPLATE_DECL. */
18377 }
18379 partial_spec_args =
18382 partial_spec_args),
18396 partial_spec_args,
18397 args);
18399 {
18404 }
18405 }
18415 {
18418 ;
18419 else
18420 {
18422 {
18425 {
18428 }
18429 }
18431 }
18432 }
18436 {
18439 {
18442 }
18443 }
18446 {
18454 {
18457 }
18460 }
18463 }
18465 /* Explicitly instantiate DECL. */
18467 void
18469 {
18474 /* An error occurred, for which grokdeclarator has already issued
18475 an appropriate message. */
18478 {
18481 }
18483 {
18484 /* There is an asymmetry here in the way VAR_DECLs and
18485 FUNCTION_DECLs are handled by grokdeclarator. In the case of
18486 the latter, the DECL we get back will be marked as a
18487 template instantiation, and the appropriate
18488 DECL_TEMPLATE_INFO will be set up. This does not happen for
18489 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
18490 should handle VAR_DECLs as it currently handles
18491 FUNCTION_DECLs. */
18493 {
18496 }
18499 {
18502 }
18504 {
18509 }
18510 }
18512 {
18515 }
18516 else
18519 /* Check for various error cases. Note that if the explicit
18520 instantiation is valid the RESULT will currently be marked as an
18521 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
18522 until we get here. */
18525 {
18526 /* DR 259 [temp.spec].
18528 Both an explicit instantiation and a declaration of an explicit
18529 specialization shall not appear in a program unless the explicit
18530 instantiation follows a declaration of the explicit specialization.
18532 For a given set of template parameters, if an explicit
18533 instantiation of a template appears after a declaration of an
18534 explicit specialization for that template, the explicit
18535 instantiation has no effect. */
18537 }
18539 {
18540 /* [temp.spec]
18542 No program shall explicitly instantiate any template more
18543 than once.
18545 We check DECL_NOT_REALLY_EXTERN so as not to complain when
18546 the first instantiation was `extern' and the second is not,
18547 and EXTERN_P for the opposite case. */
18550 /* If an "extern" explicit instantiation follows an ordinary
18551 explicit instantiation, the template is instantiated. */
18554 }
18556 {
18559 }
18561 {
18564 }
18567 ;
18569 {
18572 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
18575 }
18576 else
18584 }
18586 static void
18588 {
18594 {
18597 }
18598 }
18600 /* Called from do_type_instantiation through binding_table_foreach to
18601 do recursive instantiation for the type bound in ENTRY. */
18602 static void
18604 {
18610 }
18612 /* Called from do_type_instantiation to instantiate a member
18613 (a member function or a static member variable) of an
18614 explicitly instantiated class template. */
18615 static void
18617 {
18622 }
18624 /* Perform an explicit instantiation of template class T. STORAGE, if
18625 non-null, is the RID for extern, inline or static. COMPLAIN is
18626 nonzero if this is called from the parser, zero if called recursively,
18627 since the standard is unclear (as detailed below). */
18629 void
18631 {
18641 {
18642 tree tmpl =
18646 else
18649 }
18654 {
18657 t);
18659 }
18662 {
18664 {
18666 {
18669 "ISO C++ 1998 forbids the use of %<extern%> on "
18671 }
18672 else
18674 "ISO C++ forbids the use of %qE"
18676 }
18684 else
18685 {
18687 storage);
18689 }
18690 }
18693 {
18694 /* DR 259 [temp.spec].
18696 Both an explicit instantiation and a declaration of an explicit
18697 specialization shall not appear in a program unless the explicit
18698 instantiation follows a declaration of the explicit specialization.
18700 For a given set of template parameters, if an explicit
18701 instantiation of a template appears after a declaration of an
18702 explicit specialization for that template, the explicit
18703 instantiation has no effect. */
18705 }
18707 {
18708 /* [temp.spec]
18710 No program shall explicitly instantiate any template more
18711 than once.
18713 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
18714 instantiation was `extern'. If EXTERN_P then the second is.
18715 These cases are OK. */
18722 /* If we've already instantiated the template, just return now. */
18725 }
18733 {
18734 tree tmp;
18736 /* In contrast to implicit instantiation, where only the
18737 declarations, and not the definitions, of members are
18738 instantiated, we have here:
18740 [temp.explicit]
18742 The explicit instantiation of a class template specialization
18743 implies the instantiation of all of its members not
18744 previously explicitly specialized in the translation unit
18745 containing the explicit instantiation.
18747 Of course, we can't instantiate member template classes, since
18748 we don't have any arguments for them. Note that the standard
18749 is unclear on whether the instantiation of the members are
18750 *explicit* instantiations or not. However, the most natural
18751 interpretation is that it should be an explicit instantiation. */
18766 }
18767 }
18769 /* Given a function DECL, which is a specialization of TMPL, modify
18770 DECL to be a re-instantiation of TMPL with the same template
18771 arguments. TMPL should be the template into which tsubst'ing
18772 should occur for DECL, not the most general template.
18774 One reason for doing this is a scenario like this:
18776 template <class T>
18777 void f(const T&, int i);
18779 void g() { f(3, 7); }
18781 template <class T>
18782 void f(const T& t, const int i) { }
18784 Note that when the template is first instantiated, with
18785 instantiate_template, the resulting DECL will have no name for the
18786 first parameter, and the wrong type for the second. So, when we go
18787 to instantiate the DECL, we regenerate it. */
18789 static void
18791 {
18792 /* The arguments used to instantiate DECL, from the most general
18793 template. */
18794 tree args;
18795 tree code_pattern;
18800 /* Make sure that we can see identifiers, and compute access
18801 correctly. */
18805 {
18806 tree decl_parm;
18807 tree pattern_parm;
18808 tree specs;
18822 specs);
18824 /* Merge parameter declarations. */
18827 pattern_parm
18831 {
18832 tree parm_type;
18833 tree attributes;
18838 NULL_TREE);
18844 {
18847 }
18850 }
18851 /* Merge any parameters that match with the function parameter
18852 pack. */
18854 {
18856 tree expanded_types;
18857 /* Expand the TYPE_PACK_EXPANSION that provides the types for
18858 the parameters in this function parameter pack. */
18863 {
18864 tree parm_type;
18865 tree attributes;
18868 /* Rename the parameter to include the index. */
18877 {
18880 }
18882 }
18883 }
18884 /* Merge additional specifiers from the CODE_PATTERN. */
18888 }
18890 {
18898 }
18899 else
18903 }
18905 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
18906 substituted to get DECL. */
18908 tree
18910 {
18913 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
18914 for the instantiation. This is not always the most general
18915 template. Consider, for example:
18917 template <class T>
18918 struct S { template <class U> void f();
18919 template <> void f<int>(); };
18921 and an instantiation of S<double>::f<int>. We want TD to be the
18922 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
18924 more general template. */
18926 /* We must also deal with friend templates. Given:
18928 template <class T> struct S {
18929 template <class U> friend void f() {};
18930 };
18932 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
18933 so far as the language is concerned, but that's still
18934 where we get the pattern for the instantiation from. On
18935 other hand, if the definition comes outside the class, say:
18937 template <class T> struct S {
18938 template <class U> friend void f();
18939 };
18940 template <class U> friend void f() {}
18942 we don't need to look any further. That's what the check for
18943 DECL_INITIAL is for. */
18947 {
18948 /* The present template, TD, should not be a definition. If it
18949 were a definition, we should be using it! Note that we
18950 cannot restructure the loop to just keep going until we find
18951 a template with a definition, since that might go too far if
18952 a specialization was declared, but not defined. */
18956 /* Fetch the more general template. */
18958 }
18961 }
18963 /* Returns true if we need to instantiate this template instance even if we
18964 know we aren't going to emit it.. */
18966 bool
18968 {
18969 /* We always instantiate inline functions so that we can inline them. An
18970 explicit instantiation declaration prohibits implicit instantiation of
18971 non-inline functions. With high levels of optimization, we would
18972 normally inline non-inline functions -- but we're not allowed to do
18973 that for "extern template" functions. Therefore, we check
18974 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
18978 /* And we need to instantiate static data members so that
18979 their initializers are available in integral constant
18980 expressions. */
18983 }
18985 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
18986 instantiate it now, modifying TREE_TYPE (fn). */
18988 void
18990 {
19004 {
19006 {
19021 }
19022 else
19024 }
19025 else
19026 {
19027 /* This is an implicitly declared function, so NOEX is a list of
19028 other functions to evaluate and merge. */
19029 tree elt;
19032 {
19034 tree subspec;
19038 }
19039 }
19044 {
19047 else
19049 }
19050 }
19052 /* Produce the definition of D, a _DECL generated from a template. If
19053 DEFER_OK is nonzero, then we don't have to actually do the
19054 instantiation now; we just have to do it sometime. Normally it is
19055 an error if this is an explicit instantiation but D is undefined.
19056 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
19057 explicitly instantiated class template. */
19059 tree
19062 {
19064 tree gen_args;
19065 tree args;
19066 tree td;
19067 tree code_pattern;
19068 tree spec;
19069 tree gen_tmpl;
19075 tree fn_context;
19078 /* This function should only be used to instantiate templates for
19079 functions and static member variables. */
19082 /* Variables are never deferred; if instantiation is required, they
19083 are instantiated right away. That allows for better code in the
19084 case that an expression refers to the value of the variable --
19085 if the variable has a constant value the referring expression can
19086 take advantage of that fact. */
19091 /* Don't instantiate cloned functions. Instead, instantiate the
19092 functions they cloned. */
19100 /* D has already been instantiated or explicitly specialized, so
19101 there's nothing for us to do here.
19103 It might seem reasonable to check whether or not D is an explicit
19104 instantiation, and, if so, stop here. But when an explicit
19105 instantiation is deferred until the end of the compilation,
19106 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
19107 the instantiation. */
19110 /* Check to see whether we know that this template will be
19111 instantiated in some other file, as with "extern template"
19112 extension. */
19115 /* In general, we do not instantiate such templates. */
19123 /* We should already have the extra args. */
19126 /* And what's in the hash table should match D. */
19130 /* This needs to happen before any tsubsting. */
19136 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
19137 for the instantiation. */
19141 /* We should never be trying to instantiate a member of a class
19142 template or partial specialization. */
19147 /* In the case of a friend template whose definition is provided
19148 outside the class, we may have too many arguments. Drop the
19149 ones we don't need. The same is true for specializations. */
19150 args = get_innermost_template_args
19152 else
19158 else
19161 /* We may be in the middle of deferred access check. Disable it now. */
19164 /* Unless an explicit instantiation directive has already determined
19165 the linkage of D, remember that a definition is available for
19166 this entity. */
19176 /* If D is a member of an explicitly instantiated class template,
19177 and no definition is available, treat it like an implicit
19178 instantiation. */
19181 {
19182 /* Leave linkage flags alone on instantiations with anonymous
19183 visibility. */
19185 {
19188 }
19190 }
19195 /* Defer all other templates, unless we have been explicitly
19196 forbidden from doing so. */
19198 template. */
19199 ! pattern_defined
19200 /* If it's OK to postpone instantiation, do so. */
19201 || defer_ok
19202 /* If this is a static data member that will be defined
19203 elsewhere, we don't want to instantiate the entire data
19204 member, but we do want to instantiate the initializer so that
19205 we can substitute that elsewhere. */
19207 {
19208 /* The definition of the static data member is now required so
19209 we must substitute the initializer. */
19213 {
19214 tree ns;
19215 tree init;
19222 args,
19225 /* Make sure the initializer is still constant, in case of
19226 circular dependency (template/instantiate6.C). */
19227 const_init
19231 LOOKUP_ONLYCONVERTING);
19234 }
19236 /* We restore the source position here because it's used by
19237 add_pending_template. */
19243 /* [temp.explicit]
19245 The definition of a non-exported function template, a
19246 non-exported member function template, or a non-exported
19247 member function or static data member of a class template
19248 shall be present in every translation unit in which it is
19249 explicitly instantiated. */
19253 /* If we're in unevaluated context, we just wanted to get the
19254 constant value; this isn't an odr use, so don't queue
19255 a full instantiation. */
19258 /* ??? Historically, we have instantiated inline functions, even
19259 when marked as "extern template". */
19263 }
19264 /* Tell the repository that D is available in this translation unit
19265 -- and see if it is supposed to be instantiated here. */
19267 {
19268 /* In a PCH file, despite the fact that the repository hasn't
19269 requested instantiation in the PCH it is still possible that
19270 an instantiation will be required in a file that includes the
19271 PCH. */
19274 /* Instantiate inline functions so that the inliner can do its
19275 job, even though we'll not be emitting a copy of this
19276 function. */
19279 }
19285 else
19286 {
19291 }
19293 /* Mark D as instantiated so that recursive calls to
19294 instantiate_decl do not try to instantiate it again. */
19297 /* Regenerate the declaration in case the template has been modified
19298 by a subsequent redeclaration. */
19301 /* We already set the file and line above. Reset them now in case
19302 they changed as a result of calling regenerate_decl_from_template. */
19306 {
19307 tree init;
19310 /* Clear out DECL_RTL; whatever was there before may not be right
19311 since we've reset the type of the declaration. */
19315 /* The initializer is placed in DECL_INITIAL by
19316 regenerate_decl_from_template so we don't need to
19317 push/pop_access_scope again here. Pull it out so that
19318 cp_finish_decl can process it. */
19323 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
19324 initializer. That function will defer actual emission until
19325 we have a chance to determine linkage. */
19328 /* Enter the scope of D so that access-checking works correctly. */
19333 }
19337 {
19339 tree subst_decl;
19340 tree tmpl_parm;
19341 tree spec_parm;
19343 /* Save away the current list, in case we are instantiating one
19344 template from within the body of another. */
19347 /* Set up the list of local specializations. */
19350 /* Set up context. */
19353 /* Some typedefs referenced from within the template code need to be
19354 access checked at template instantiation time, i.e now. These
19355 types were added to the template at parsing time. Let's get those
19356 and perform the access checks then. */
19358 gen_args);
19360 /* Create substitution entries for the parameters. */
19365 {
19369 }
19371 {
19373 {
19376 }
19377 else
19378 {
19379 /* Register the (value) argument pack as a specialization of
19380 TMPL_PARM, then move on. */
19383 }
19384 }
19387 /* Substitute into the body of the function. */
19392 /* Set the current input_location to the end of the function
19393 so that finish_function knows where we are. */
19396 /* We don't need the local specializations any more. */
19400 /* Finish the function. */
19403 }
19405 /* We're not deferring instantiation any more. */
19413 out:
19423 }
19425 /* Run through the list of templates that we wish we could
19426 instantiate, and instantiate any we can. RETRIES is the
19427 number of times we retry pending template instantiation. */
19429 void
19431 {
19435 /* Instantiating templates may trigger vtable generation. This in turn
19436 may require further template instantiations. We place a limit here
19437 to avoid infinite loop. */
19439 {
19443 " instantiating %q+D, possibly from virtual table generation"
19447 /* Pretend that we defined it. */
19450 }
19452 do
19453 {
19458 {
19463 {
19464 tree fn;
19467 {
19471 fn;
19479 }
19482 }
19483 else
19484 {
19487 {
19488 instantiation
19494 }
19498 }
19501 /* If INSTANTIATION has been instantiated, then we don't
19502 need to consider it again in the future. */
19504 else
19505 {
19508 }
19511 }
19513 }
19517 }
19519 /* Substitute ARGVEC into T, which is a list of initializers for
19520 either base class or a non-static data member. The TREE_PURPOSEs
19521 are DECLs, and the TREE_VALUEs are the initializer values. Used by
19522 instantiate_decl. */
19524 static tree
19526 {
19530 {
19531 tree decl;
19532 tree init;
19538 {
19539 tree expr;
19540 tree arg;
19542 /* Expand the base class expansion type into separate base
19543 classes. */
19545 tf_warning_or_error,
19546 NULL_TREE);
19550 /* We'll be building separate TREE_LISTs of arguments for
19551 each base. */
19557 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
19558 expand each argument in the TREE_VALUE of t. */
19565 /* VOID_TYPE_NODE is used to indicate
19566 value-initialization. */
19567 {
19570 }
19571 else
19572 {
19573 /* Substitute parameter packs into each argument in the
19574 TREE_LIST. */
19577 {
19578 tree expanded_exprs;
19580 /* Expand the argument. */
19582 expanded_exprs
19584 tf_warning_or_error,
19585 NULL_TREE);
19589 /* Prepend each of the expanded expressions to the
19590 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
19592 {
19597 }
19598 }
19601 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
19602 since we built them backwards. */
19604 {
19607 }
19608 }
19609 }
19612 {
19614 {
19618 }
19619 else
19620 {
19621 tree tmp;
19636 /* If we had an initializer but it instantiated to nothing,
19637 value-initialize the object. This will only occur when
19638 the initializer was a pack expansion where the parameter
19639 packs used in that expansion were of length zero. */
19642 }
19645 {
19649 }
19650 }
19651 }
19653 }
19655 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
19657 static void
19659 {
19664 else
19666 }
19668 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
19669 is the instantiation (which should have been created with
19670 start_enum) and ARGS are the template arguments to use. */
19672 static void
19674 {
19675 tree e;
19681 {
19682 tree value;
19683 tree decl;
19686 /* Note that in a template enum, the TREE_VALUE is the
19687 CONST_DECL, not the corresponding INTEGER_CST. */
19692 /* Give this enumeration constant the correct access. */
19695 /* Actually build the enumerator itself. */
19696 build_enumerator
19698 }
19708 }
19710 /* DECL is a FUNCTION_DECL that is a template specialization. Return
19711 its type -- but without substituting the innermost set of template
19712 arguments. So, innermost set of template parameters will appear in
19713 the type. */
19715 tree
19717 {
19718 tree fn_type;
19719 tree tmpl;
19720 tree targs;
19721 tree tparms;
19729 /* There should be as many levels of arguments as there are levels
19730 of parameters. */
19736 /* No substitution is necessary. */
19737 ;
19738 else
19739 {
19741 tree partial_args;
19743 /* Replace the innermost level of the TARGS with NULL_TREEs to
19744 let tsubst know not to substitute for those parameters. */
19753 /* Make sure that we can see identifiers, and compute access
19754 correctly. */
19758 /* Now, do the (partial) substitution to figure out the
19759 appropriate function type. */
19763 /* Substitute into the template parameters to obtain the real
19764 innermost set of parameters. This step is important if the
19765 innermost set of template parameters contains value
19766 parameters whose types depend on outer template parameters. */
19771 }
19774 }
19776 /* Return truthvalue if we're processing a template different from
19777 the last one involved in diagnostics. */
19778 int
19780 {
19782 }
19784 /* Remember current template involved in diagnostics. */
19785 void
19787 {
19789 }
19793 {
19795 }
19797 /* [temp.param] Check that template non-type parm TYPE is of an allowable
19798 type. Return zero for ok, nonzero for disallowed. Issue error and
19799 warning messages under control of COMPLAIN. */
19801 static int
19803 {
19820 {
19823 else
19825 type);
19826 }
19828 }
19830 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
19831 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
19833 static bool
19835 {
19836 tree scope;
19838 /* [temp.dep.type]
19840 A type is dependent if it is:
19842 -- a template parameter. Template template parameters are types
19843 for us (since TYPE_P holds true for them) so we handle
19844 them here. */
19848 /* -- a qualified-id with a nested-name-specifier which contains a
19849 class-name that names a dependent type or whose unqualified-id
19850 names a dependent type. */
19853 /* -- a cv-qualified type where the cv-unqualified type is
19854 dependent. */
19856 /* -- a compound type constructed from any dependent type. */
19866 {
19867 tree arg_type;
19872 arg_type;
19877 }
19878 /* -- an array type constructed from any dependent type or whose
19879 size is specified by a constant expression that is
19880 value-dependent.
19882 We checked for type- and value-dependence of the bounds in
19883 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
19885 {
19890 }
19892 /* -- a template-id in which either the template name is a template
19893 parameter ... */
19896 /* ... or any of the template arguments is a dependent type or
19897 an expression that is type-dependent or value-dependent. */
19899 && (any_dependent_template_arguments_p
19903 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
19904 dependent; if the argument of the `typeof' expression is not
19905 type-dependent, then it should already been have resolved. */
19911 /* A template argument pack is dependent if any of its packed
19912 arguments are. */
19914 {
19920 }
19922 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
19923 be template parameters. */
19927 /* The standard does not specifically mention types that are local
19928 to template functions or local classes, but they should be
19929 considered dependent too. For example:
19931 template <int I> void f() {
19932 enum E { a = I };
19933 S<sizeof (E)> s;
19934 }
19936 The size of `E' cannot be known until the value of `I' has been
19937 determined. Therefore, `E' must be considered dependent. */
19941 /* Don't use type_dependent_expression_p here, as it can lead
19942 to infinite recursion trying to determine whether a lambda
19943 nested in a lambda is dependent (c++/47687). */
19947 && (any_dependent_template_arguments_p
19951 /* Other types are non-dependent. */
19953 }
19955 /* Returns TRUE if TYPE is dependent, in the sense of
19956 [temp.dep.type]. Note that a NULL type is considered dependent. */
19958 bool
19960 {
19961 /* If there are no template parameters in scope, then there can't be
19962 any dependent types. */
19964 {
19965 /* If we are not processing a template, then nobody should be
19966 providing us with a dependent type. */
19970 }
19972 /* If the type is NULL, we have not computed a type for the entity
19973 in question; in that case, the type is dependent. */
19977 /* Erroneous types can be considered non-dependent. */
19981 /* If we have not already computed the appropriate value for TYPE,
19982 do so now. */
19984 {
19987 }
19990 }
19992 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
19993 lookup. In other words, a dependent type that is not the current
19994 instantiation. */
19996 bool
19998 {
20001 }
20003 /* T is a SCOPE_REF; return whether we need to consider it
20004 instantiation-dependent so that we can check access at instantiation
20005 time even though we know which member it resolves to. */
20007 static bool
20009 {
20015 else
20017 }
20019 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
20020 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
20021 expression. */
20023 /* Note that this predicate is not appropriate for general expressions;
20024 only constant expressions (that satisfy potential_constant_expression)
20025 can be tested for value dependence. */
20027 bool
20029 {
20033 /* A name declared with a dependent type. */
20038 {
20040 /* A name that has not been looked up -- must be dependent. */
20044 /* A non-type template parm. */
20048 /* A non-type template parm. */
20054 /* A constant with literal type and is initialized
20055 with an expression that is value-dependent.
20057 Note that a non-dependent parenthesized initializer will have
20058 already been replaced with its constant value, so if we see
20059 a TREE_LIST it must be dependent. */
20072 /* These expressions are value-dependent if the type to which
20073 the cast occurs is dependent or the expression being casted
20074 is value-dependent. */
20075 {
20081 /* A functional cast has a list of operands. */
20084 {
20085 /* If there are no operands, it must be an expression such
20086 as "int()". This should not happen for aggregate types
20087 because it would form non-constant expressions. */
20092 }
20098 }
20103 /* FALLTHRU */
20106 /* A `sizeof' expression is value-dependent if the operand is
20107 type-dependent or is a pack expansion. */
20116 /* An 'encode' expression is value-dependent if the operand is
20117 type-dependent. */
20126 /* All instantiation-dependent expressions should also be considered
20127 value-dependent. */
20135 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
20136 is value-dependent. */
20137 {
20146 }
20149 {
20153 }
20164 {
20168 }
20171 {
20178 {
20180 /* In a call to a constexpr member function, look through the
20181 implicit ADDR_EXPR on the object argument so that it doesn't
20182 cause the call to be considered value-dependent. We also
20183 look through it in potential_constant_expression. */
20190 }
20192 }
20195 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
20196 type-dependent. */
20200 {
20202 tree val;
20207 }
20210 /* Treat a GNU statement expression as dependent to avoid crashing
20211 under fold_non_dependent_expr; it can't be constant. */
20215 /* A constant expression is value-dependent if any subexpression is
20216 value-dependent. */
20218 {
20225 {
20229 {
20232 /* In some cases, some of the operands may be missing.l
20233 (For example, in the case of PREDECREMENT_EXPR, the
20234 amount to increment by may be missing.) That doesn't
20235 make the expression dependent. */
20238 }
20239 }
20243 }
20245 }
20247 /* The expression is not value-dependent. */
20249 }
20251 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
20252 [temp.dep.expr]. Note that an expression with no type is
20253 considered dependent. Other parts of the compiler arrange for an
20254 expression with type-dependent subexpressions to have no type, so
20255 this function doesn't have to be fully recursive. */
20257 bool
20259 {
20266 /* An unresolved name is always dependent. */
20270 /* Some expression forms are never type-dependent. */
20283 /* The types of these expressions depends only on the type to which
20284 the cast occurs. */
20293 /* The types of these expressions depends only on the type created
20294 by the expression. */
20297 {
20298 /* For NEW_EXPR tree nodes created inside a template, either
20299 the object type itself or a TREE_LIST may appear as the
20300 operand 1. */
20303 /* This is an array type. We need to check array dimensions
20304 as well. */
20306 || value_dependent_expression_p
20308 else
20310 }
20313 {
20317 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
20318 contains an identifier associated by name lookup with one or more
20319 declarations declared with a dependent type, or...a
20320 nested-name-specifier or qualified-id that names a member of an
20321 unknown specialization. */
20324 }
20329 && (any_dependent_template_arguments_p
20341 {
20342 tree elt;
20346 {
20349 }
20351 }
20353 /* A static data member of the current instantiation with incomplete
20354 array type is type-dependent, as the definition and specializations
20355 can have different bounds. */
20362 /* An array of unknown bound depending on a variadic parameter, eg:
20364 template<typename... Args>
20365 void foo (Args... args)
20366 {
20367 int arr[] = { args... };
20368 }
20370 template<int... vals>
20371 void bar ()
20372 {
20373 int arr[] = { vals... };
20374 }
20376 If the array has no length and has an initializer, it must be that
20377 we couldn't determine its length in cp_complete_array_type because
20378 it is dependent. */
20386 {
20391 {
20397 }
20398 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
20406 {
20411 }
20416 {
20420 }
20422 }
20427 }
20429 /* walk_tree callback function for instantiation_dependent_expression_p,
20430 below. Returns non-zero if a dependent subexpression is found. */
20432 static tree
20435 {
20437 {
20438 /* We don't have to worry about decltype currently because decltype
20439 of an instantiation-dependent expr is a dependent type. This
20440 might change depending on the resolution of DR 1172. */
20443 }
20446 {
20447 /* Don't treat an argument list as dependent just because it has no
20448 TREE_TYPE. */
20455 /* A constant with a dependent initializer is dependent. */
20463 /* Handle expressions with type operands. */
20468 {
20473 {
20476 else
20477 {
20480 }
20481 }
20483 }
20495 /* In a template, finish_class_member_access_expr creates a
20496 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
20497 type-dependent, so that we can check access control at
20498 instantiation time (PR 42277). See also Core issue 1273. */
20505 else
20508 /* Treat statement-expressions as dependent. */
20514 }
20518 else
20520 }
20522 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
20523 sense defined by the ABI:
20525 "An expression is instantiation-dependent if it is type-dependent
20526 or value-dependent, or it has a subexpression that is type-dependent
20527 or value-dependent." */
20529 bool
20531 {
20532 tree result;
20543 }
20545 /* Like type_dependent_expression_p, but it also works while not processing
20546 a template definition, i.e. during substitution or mangling. */
20548 bool
20550 {
20556 }
20558 /* Returns TRUE if ARGS contains a type-dependent expression. */
20560 bool
20562 {
20564 tree arg;
20567 {
20570 }
20572 }
20574 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
20575 expressions) contains any type-dependent expressions. */
20577 bool
20579 {
20585 }
20587 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
20588 expressions) contains any value-dependent expressions. */
20590 bool
20592 {
20598 }
20600 /* Returns TRUE if the ARG (a template argument) is dependent. */
20602 bool
20604 {
20608 /* Assume a template argument that was wrongly written by the user
20609 is dependent. This is consistent with what
20610 any_dependent_template_arguments_p [that calls this function]
20611 does. */
20622 {
20626 {
20629 }
20632 }
20635 else
20638 }
20640 /* Returns true if ARGS (a collection of template arguments) contains
20641 any types that require structural equality testing. */
20643 bool
20645 {
20655 {
20658 {
20664 {
20665 /* Look inside the argument pack. */
20668 }
20671 {
20684 }
20685 }
20686 }
20689 }
20691 /* Returns true if ARGS (a collection of template arguments) contains
20692 any dependent arguments. */
20694 bool
20696 {
20706 {
20711 }
20714 }
20716 /* Returns TRUE if the template TMPL is dependent. */
20718 bool
20720 {
20722 {
20724 {
20728 }
20730 }
20732 /* Template template parameters are dependent. */
20736 /* So are names that have not been looked up. */
20739 /* So are member templates of dependent classes. */
20743 }
20745 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
20747 bool
20749 {
20752 }
20754 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
20755 is dependent. */
20757 bool
20759 {
20766 {
20787 {
20791 }
20795 {
20799 {
20804 }
20805 }
20806 }
20809 }
20811 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
20812 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
20813 no such TYPE can be found. Note that this function peers inside
20814 uninstantiated templates and therefore should be used only in
20815 extremely limited situations. ONLY_CURRENT_P restricts this
20816 peering to the currently open classes hierarchy (which is required
20817 when comparing types). */
20819 tree
20821 {
20822 tree scope;
20823 tree name;
20824 tree decl;
20826 tree pushed_scope;
20827 tree result;
20832 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
20833 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
20834 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
20835 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
20836 identifier of the TYPENAME_TYPE anymore.
20837 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
20838 TYPENAME_TYPE instead, we avoid messing up with a possible
20839 typedef variant case. */
20842 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
20843 it first before we can figure out what NAME refers to. */
20845 {
20847 /* Given a class template A with a dependent base with nested type C,
20848 typedef typename A::C::C C will land us here, as trying to resolve
20849 the initial A::C leads to the local C typedef, which leads back to
20850 A::C::C. So we break the recursion now. */
20852 else
20854 }
20855 /* If we don't know what SCOPE refers to, then we cannot resolve the
20856 TYPENAME_TYPE. */
20859 /* If the SCOPE is a template type parameter, we have no way of
20860 resolving the name. */
20863 /* If the SCOPE is not the current instantiation, there's no reason
20864 to look inside it. */
20867 /* If this is a typedef, we don't want to look inside (c++/11987). */
20870 /* If SCOPE isn't the template itself, it will not have a valid
20871 TYPE_FIELDS list. */
20873 /* scope is either the template itself or a compatible instantiation
20874 like X<T>, so look up the name in the original template. */
20876 else
20877 /* scope is a partial instantiation, so we can't do the lookup or we
20878 will lose the template arguments. */
20880 /* Enter the SCOPE so that name lookup will be resolved as if we
20881 were in the class definition. In particular, SCOPE will no
20882 longer be considered a dependent type. */
20884 /* Look up the declaration. */
20886 tf_warning_or_error);
20890 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
20891 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
20896 {
20900 }
20903 {
20904 tree tmpl;
20905 tree args;
20906 /* Obtain the template and the arguments. */
20909 /* Instantiate the template. */
20915 }
20917 /* Leave the SCOPE. */
20921 /* If we failed to resolve it, return the original typename. */
20925 /* If lookup found a typename type, resolve that too. */
20927 {
20928 /* Ill-formed programs can cause infinite recursion here, so we
20929 must catch that. */
20933 }
20935 /* Qualify the resulting type. */
20941 }
20943 /* EXPR is an expression which is not type-dependent. Return a proxy
20944 for EXPR that can be used to compute the types of larger
20945 expressions containing EXPR. */
20947 tree
20949 {
20950 tree inner_expr;
20952 #ifdef ENABLE_CHECKING
20953 /* Try to get a constant value for all non-dependent expressions in
20954 order to expose bugs in *_dependent_expression_p and constexpr. */
20957 #endif
20959 /* Preserve OVERLOADs; the functions must be available to resolve
20960 types. */
20971 /* There is no need to return a proxy for a variable. */
20974 /* Preserve string constants; conversions from string constants to
20975 "char *" are allowed, even though normally a "const char *"
20976 cannot be used to initialize a "char *". */
20979 /* Preserve arithmetic constants, as an optimization -- there is no
20980 reason to create a new node. */
20983 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
20984 There is at least one place where we want to know that a
20985 particular expression is a throw-expression: when checking a ?:
20986 expression, there are special rules if the second or third
20987 argument is a throw-expression. */
20991 /* Don't wrap an initializer list, we need to be able to look inside. */
20995 /* Don't wrap a dummy object, we need to be able to test for it. */
21014 /* If the type is unknown, it can't really be non-dependent */
21017 /* Otherwise, build a NON_DEPENDENT_EXPR. */
21019 }
21021 /* ARGS is a vector of expressions as arguments to a function call.
21022 Replace the arguments with equivalent non-dependent expressions.
21023 This modifies ARGS in place. */
21025 void
21027 {
21029 tree arg;
21032 {
21036 }
21037 }
21039 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
21040 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
21041 parms. */
21043 static tree
21045 {
21058 }
21060 tree
21062 {
21064 }
21066 tree
21068 {
21070 }
21072 /* Given type ARG, return std::initializer_list<ARG>. */
21074 static tree
21076 {
21077 tree std_init_list = namespace_binding
21079 tree argvec;
21081 {
21085 }
21090 }
21092 /* Replace auto in TYPE with std::initializer_list<auto>. */
21094 static tree
21096 {
21103 }
21105 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
21106 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
21108 tree
21110 {
21111 tree targs;
21117 /* Defining a subset of type-dependent expressions that we can deduce
21118 from ahead of time isn't worth the trouble. */
21121 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
21122 with either a new invented type template parameter U or, if the
21123 initializer is a braced-init-list (8.5.4), with
21124 std::initializer_list<U>. */
21132 {
21137 {
21140 }
21141 }
21142 else
21143 {
21154 {
21156 /* Try again at instantiation time. */
21159 /* If type is error_mark_node a diagnostic must have been
21160 emitted by now. Also, having a mention to '<type error>'
21161 in the diagnostic is not really useful to the user. */
21162 {
21166 else
21168 }
21170 }
21171 }
21173 /* If the list of declarators contains more than one declarator, the type
21174 of each declared variable is determined as described above. If the
21175 type deduced for the template parameter U is not the same in each
21176 deduction, the program is ill-formed. */
21179 {
21185 else
21189 }
21195 }
21197 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
21198 result. */
21200 tree
21202 {
21203 tree argvec;
21210 /* For a late-specified return type in a template type-parameter, we
21211 need to add a dummy argument level for its parmlist. */
21212 argvec = add_to_template_args
21217 }
21219 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
21220 'decltype(auto)'. */
21222 bool
21224 {
21229 else
21231 }
21233 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
21234 a use of `auto'. Returns NULL_TREE otherwise. */
21236 tree
21238 {
21240 }
21242 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
21243 'decltype(auto)' or a concept. */
21245 bool
21247 {
21249 }
21251 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
21252 a concept identifier) iff TYPE contains a use of a generic type. Returns
21253 NULL_TREE otherwise. */
21255 tree
21257 {
21259 }
21262 /* For a given template T, return the vector of typedefs referenced
21263 in T for which access check is needed at T instantiation time.
21264 T is either a FUNCTION_DECL or a RECORD_TYPE.
21265 Those typedefs were added to T by the function
21266 append_type_to_template_for_access_check. */
21270 {
21271 tree ti;
21282 {
21287 }
21290 }
21292 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
21293 tied to T. That list of typedefs will be access checked at
21294 T instantiation time.
21295 T is either a FUNCTION_DECL or a RECORD_TYPE.
21296 TYPE_DECL is a TYPE_DECL node representing a typedef.
21297 SCOPE is the scope through which TYPE_DECL is accessed.
21298 LOCATION is the location of the usage point of TYPE_DECL.
21300 This function is a subroutine of
21301 append_type_to_template_for_access_check. */
21303 static void
21305 tree type_decl,
21306 tree scope,
21307 location_t location)
21308 {
21309 qualified_typedef_usage_t typedef_usage;
21310 tree ti;
21317 && type_decl
21331 }
21333 /* Append TYPE_DECL to the template TEMPL.
21334 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
21335 At TEMPL instanciation time, TYPE_DECL will be checked to see
21336 if it can be accessed through SCOPE.
21337 LOCATION is the location of the usage point of TYPE_DECL.
21339 e.g. consider the following code snippet:
21341 class C
21342 {
21343 typedef int myint;
21344 };
21346 template<class U> struct S
21347 {
21348 C::myint mi; // <-- usage point of the typedef C::myint
21349 };
21351 S<char> s;
21353 At S<char> instantiation time, we need to check the access of C::myint
21354 In other words, we need to check the access of the myint typedef through
21355 the C scope. For that purpose, this function will add the myint typedef
21356 and the scope C through which its being accessed to a list of typedefs
21357 tied to the template S. That list will be walked at template instantiation
21358 time and access check performed on each typedefs it contains.
21359 Note that this particular code snippet should yield an error because
21360 myint is private to C. */
21362 void
21364 tree type_decl,
21365 tree scope,
21366 location_t location)
21367 {
21373 /* Make sure we don't append the type to the template twice. */
21380 }
21382 /* Set up the hash tables for template instantiations. */
21384 void
21386 {
21388 hash_specialization,
21389 eq_specializations,
21390 ggc_free);
21392 hash_specialization,
21393 eq_specializations,
21394 ggc_free);
21395 }
21397 /* Print stats about the template hash tables for -fstats. */
21399 void
21401 {
21410 }