| blob | 95c6464e61b43cbdb3e034f7f3ce440b2014898e |
1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011, 2012
4 Free Software Foundation, Inc.
5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
6 Rewritten by Jason Merrill (jason@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
13 any later version.
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
48 /* The type of functions taking a tree, and some additional data, and
49 returning an int. */
52 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
53 instantiations have been deferred, either because their definitions
54 were not yet available, or because we were putting off doing the work. */
58 };
73 /* Live only within one (recursive) call to tsubst_expr. We use
74 this to pass the statement expression node from the STMT_EXPR
75 to the EXPR_STMT that is its result. */
78 /* A map from local variable declarations in the body of the template
79 presently being instantiated to the corresponding instantiated
80 local variables. */
84 {
85 tree tmpl;
86 tree args;
87 tree spec;
91 htab_t decl_specializations;
94 htab_t type_specializations;
96 /* Contains canonical template parameter types. The vector is indexed by
97 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
98 TREE_LIST, whose TREE_VALUEs contain the canonical template
99 parameters of various types and levels. */
102 #define UNIFY_ALLOW_NONE 0
103 #define UNIFY_ALLOW_MORE_CV_QUAL 1
104 #define UNIFY_ALLOW_LESS_CV_QUAL 2
105 #define UNIFY_ALLOW_DERIVED 4
106 #define UNIFY_ALLOW_INTEGER 8
107 #define UNIFY_ALLOW_OUTER_LEVEL 16
108 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
109 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
112 tbr_incomplete_type,
113 tbr_ambiguous_baseclass,
114 tbr_success
115 };
136 tree);
198 location_t);
206 /* Make the current scope suitable for access checking when we are
207 processing T. T can be FUNCTION_DECL for instantiated function
208 template, or VAR_DECL for static member variable (need by
209 instantiate_decl). */
211 static void
213 {
221 else
225 {
226 saved_access_scope = tree_cons
229 }
230 }
232 /* Restore the scope set up by push_access_scope. T is the node we
233 are processing. */
235 static void
237 {
239 {
242 }
246 else
248 }
250 /* Do any processing required when DECL (a member template
251 declaration) is finished. Returns the TEMPLATE_DECL corresponding
252 to DECL, unless it is a specialization, in which case the DECL
253 itself is returned. */
255 tree
257 {
264 {
265 tree type;
273 {
277 }
279 }
283 {
285 {
288 }
289 else
291 }
292 else
296 }
298 /* Create a template info node. */
300 tree
302 {
307 }
309 /* Return the template info node corresponding to T, whatever T is. */
311 tree
313 {
331 }
333 /* Returns the template nesting level of the indicated class TYPE.
335 For example, in:
336 template <class T>
337 struct A
338 {
339 template <class U>
340 struct B {};
341 };
343 A<T>::B<U> has depth two, while A<T> has depth one.
344 Both A<T>::B<int> and A<int>::B<U> have depth one, if
345 they are instantiations, not specializations.
347 This function is guaranteed to return 0 if passed NULL_TREE so
348 that, for example, `template_class_depth (current_class_type)' is
349 always safe. */
351 int
353 {
360 {
366 }
369 }
371 /* Subroutine of maybe_begin_member_template_processing.
372 Returns true if processing DECL needs us to push template parms. */
374 static bool
376 {
382 }
384 /* Subroutine of maybe_begin_member_template_processing.
385 Push the template parms in PARMS, starting from LEVELS steps into the
386 chain, and ending at the beginning, since template parms are listed
387 innermost first. */
389 static void
391 {
399 current_template_parms
405 NULL);
407 {
416 {
423 {
424 /* Make a CONST_DECL as is done in process_template_parm.
425 It is ugly that we recreate this here; the original
426 version built in process_template_parm is no longer
427 available. */
437 }
442 }
443 }
444 }
446 /* Restore the template parameter context for a member template or
447 a friend template defined in a class definition. */
449 void
451 {
452 tree parms;
456 {
461 {
464 }
467 }
469 /* Remember how many levels of template parameters we pushed so that
470 we can pop them later. */
472 }
474 /* Undo the effects of maybe_begin_member_template_processing. */
476 void
478 {
487 {
491 }
492 }
494 /* Return a new template argument vector which contains all of ARGS,
495 but has as its innermost set of arguments the EXTRA_ARGS. */
497 static tree
499 {
500 tree new_args;
518 }
520 /* Like add_to_template_args, but only the outermost ARGS are added to
521 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
522 (EXTRA_ARGS) levels are added. This function is used to combine
523 the template arguments from a partial instantiation with the
524 template arguments used to attain the full instantiation from the
525 partial instantiation. */
527 static tree
529 {
530 tree new_args;
532 /* If there are more levels of EXTRA_ARGS than there are ARGS,
533 something very fishy is going on. */
536 /* If *all* the new arguments will be the EXTRA_ARGS, just return
537 them. */
541 /* For the moment, we make ARGS look like it contains fewer levels. */
546 /* Now, we restore ARGS to its full dimensions. */
550 }
552 /* Return the N levels of innermost template arguments from the ARGS. */
554 tree
556 {
557 tree new_args;
563 /* If N is 1, just return the innermost set of template arguments. */
567 /* If we're not removing anything, just return the arguments we were
568 given. */
574 /* Make a new set of arguments, not containing the outer arguments. */
581 }
583 /* The inverse of get_innermost_template_args: Return all but the innermost
584 EXTRA_LEVELS levels of template arguments from the ARGS. */
586 static tree
588 {
589 tree new_args;
595 /* If N is 1, just return the outermost set of template arguments. */
599 /* If we're not removing anything, just return the arguments we were
600 given. */
605 /* Make a new set of arguments, not containing the inner arguments. */
612 }
614 /* We've got a template header coming up; push to a new level for storing
615 the parms. */
617 void
619 {
620 /* We use a non-tag-transparent scope here, which causes pushtag to
621 put tags in this scope, rather than in the enclosing class or
622 namespace scope. This is the right thing, since we want
623 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
624 global template class, push_template_decl handles putting the
625 TEMPLATE_DECL into top-level scope. For a nested template class,
626 e.g.:
628 template <class T> struct S1 {
629 template <class T> struct S2 {};
630 };
632 pushtag contains special code to call pushdecl_with_scope on the
633 TEMPLATE_DECL for S2. */
638 }
640 /* This routine is called when a specialization is declared. If it is
641 invalid to declare a specialization here, an error is reported and
642 false is returned, otherwise this routine will return true. */
644 static bool
646 {
649 /* [temp.expl.spec]
651 An explicit specialization shall be declared in the namespace of
652 which the template is a member, or, for member templates, in the
653 namespace of which the enclosing class or enclosing class
654 template is a member. An explicit specialization of a member
655 function, member class or static data member of a class template
656 shall be declared in the namespace of which the class template
657 is a member. */
659 {
662 }
664 /* [temp.expl.spec]
666 In an explicit specialization declaration for a member of a class
667 template or a member template that appears in namespace scope,
668 the member template and some of its enclosing class templates may
669 remain unspecialized, except that the declaration shall not
670 explicitly specialize a class member template if its enclosing
671 class templates are not explicitly specialized as well. */
673 {
676 }
679 }
681 /* We've just seen template <>. */
683 bool
685 {
689 }
691 /* Called at then end of processing a declaration preceded by
692 template<>. */
694 void
696 {
699 }
701 /* Any template <>'s that we have seen thus far are not referring to a
702 function specialization. */
704 void
706 {
709 }
711 /* We've just seen a template header. If SPECIALIZATION is nonzero,
712 it was of the form template <>. */
714 static void
716 {
718 template_header_count++;
719 }
721 /* We're beginning an explicit instantiation. */
723 void
725 {
728 }
731 void
733 {
736 }
738 /* An explicit specialization or partial specialization TMPL is being
739 declared. Check that the namespace in which the specialization is
740 occurring is permissible. Returns false iff it is invalid to
741 specialize TMPL in the current namespace. */
743 static bool
745 {
748 /* [tmpl.expl.spec]
750 An explicit specialization shall be declared in the namespace of
751 which the template is a member, or, for member templates, in the
752 namespace of which the enclosing class or enclosing class
753 template is a member. An explicit specialization of a member
754 function, member class or static data member of a class template
755 shall be declared in the namespace of which the class template is
756 a member. */
759 {
762 }
764 /* Same or super-using namespace. */
766 else
767 {
771 }
772 }
774 /* SPEC is an explicit instantiation. Check that it is valid to
775 perform this explicit instantiation in the current namespace. */
777 static void
779 {
780 tree ns;
782 /* DR 275: An explicit instantiation shall appear in an enclosing
783 namespace of its template. */
789 }
791 /* The TYPE is being declared. If it is a template type, that means it
792 is a partial specialization. Do appropriate error-checking. */
794 tree
796 {
797 tree context;
803 {
807 }
812 /* Consider non-class instantiations of alias templates as
813 well. */
818 {
819 /* This is for ordinary explicit specialization and partial
820 specialization of a template class such as:
822 template <> class C<int>;
824 or:
826 template <class T> class C<T*>;
828 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
833 {
837 {
841 }
842 }
848 {
852 }
853 }
859 {
860 /* This is for an explicit specialization of member class
861 template according to [temp.expl.spec/18]:
863 template <> template <class U> class C<int>::D;
865 The context `C<int>' must be an implicit instantiation.
866 Otherwise this is just a member class template declared
867 earlier like:
869 template <> class C<int> { template <class U> class D; };
870 template <> template <class U> class C<int>::D;
872 In the first case, `C<int>::D' is a specialization of `C<T>::D'
873 while in the second case, `C<int>::D' is a primary template
874 and `C<T>::D' may not exist. */
878 {
879 tree t;
884 {
887 }
889 /* Check for invalid specialization after instantiation:
891 template <> template <> class C<int>::D<int>;
892 template <> template <class U> class C<int>::D; */
896 {
899 {
900 /* We already have a full specialization of this partial
901 instantiation. Reassign it to the new member
902 specialization template. */
903 spec_entry elt;
920 }
922 /* But if we've had an implicit instantiation, that's a
923 problem ([temp.expl.spec]/6). */
926 }
928 /* Mark TYPE as a specialization. And as a result, we only
929 have one level of template argument for the innermost
930 class template. */
934 }
935 }
937 {
938 /* Someday C++0x may allow for enum template specialization. */
943 else
944 {
947 }
948 }
951 }
953 /* Returns nonzero if we can optimize the retrieval of specializations
954 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
955 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
959 {
962 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
963 parameter. */
965 /* The optimized lookup depends on the fact that the
966 template arguments for the member function template apply
967 purely to the containing class, which is not true if the
968 containing class is an explicit or partial
969 specialization. */
973 /* It is possible to have a template that is not a member
974 template and is not a member of a template class:
976 template <typename T>
977 struct S { friend A::f(); };
979 Here, the friend function is a template, but the context does
980 not have template information. The optimized lookup relies
981 on having ARGS be the template arguments for both the class
982 and the function template. */
984 }
986 /* Retrieve the specialization (in the sense of [temp.spec] - a
987 specialization is either an instantiation or an explicit
988 specialization) of TMPL for the given template ARGS. If there is
989 no such specialization, return NULL_TREE. The ARGS are a vector of
990 arguments, or a vector of vectors of arguments, in the case of
991 templates with more than one level of parameters.
993 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
994 then we search for a partial specialization matching ARGS. This
995 parameter is ignored if TMPL is not a class template. */
997 static tree
999 {
1005 /* There should be as many levels of arguments as there are
1006 levels of parameters. */
1011 {
1012 tree class_template;
1013 tree class_specialization;
1015 tree fns;
1018 /* The template arguments actually apply to the containing
1019 class. Find the class specialization with those
1020 arguments. */
1022 class_specialization
1026 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1027 for the specialization. */
1031 /* Iterate through the methods with the indicated name, looking
1032 for the one that has an instance of TMPL. */
1035 {
1038 /* using-declarations can add base methods to the method vec,
1039 and we don't want those here. */
1042 }
1044 }
1045 else
1046 {
1048 spec_entry elt;
1049 htab_t specializations;
1057 else
1065 }
1068 }
1070 /* Like retrieve_specialization, but for local declarations. */
1072 static tree
1074 {
1082 }
1084 /* Returns nonzero iff DECL is a specialization of TMPL. */
1086 int
1088 {
1089 tree t;
1092 {
1098 }
1099 else
1100 {
1109 }
1112 }
1114 /* Returns nonzero iff DECL is a specialization of friend declaration
1115 FRIEND_DECL according to [temp.friend]. */
1117 bool
1119 {
1126 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1127 of a template class, we want to check if DECL is a specialization
1128 if this. */
1132 {
1133 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1136 }
1141 /* There is nothing to do if this is not a template friend. */
1148 /* [temp.friend/6]
1149 A member of a class template may be declared to be a friend of a
1150 non-template class. In this case, the corresponding member of
1151 every specialization of the class template is a friend of the
1152 class granting friendship.
1154 For example, given a template friend declaration
1156 template <class T> friend void A<T>::f();
1158 the member function below is considered a friend
1160 template <> struct A<int> {
1161 void f();
1162 };
1164 For this type of template friend, TEMPLATE_DEPTH below will be
1165 nonzero. To determine if DECL is a friend of FRIEND, we first
1166 check if the enclosing class is a specialization of another. */
1173 {
1174 /* Next, we check the members themselves. In order to handle
1175 a few tricky cases, such as when FRIEND_DECL's are
1177 template <class T> friend void A<T>::g(T t);
1178 template <class T> template <T t> friend void A<T>::h();
1180 and DECL's are
1182 void A<int>::g(int);
1183 template <int> void A<int>::h();
1185 we need to figure out ARGS, the template arguments from
1186 the context of DECL. This is required for template substitution
1187 of `T' in the function parameter of `g' and template parameter
1188 of `h' in the above examples. Here ARGS corresponds to `int'. */
1195 {
1197 {
1200 else
1202 current_depth++;
1203 }
1205 }
1208 {
1210 tree friend_type;
1211 tree decl_type;
1212 tree friend_args_type;
1213 tree decl_args_type;
1215 /* Make sure that both DECL and FRIEND_DECL are templates or
1216 non-templates. */
1222 {
1223 /* If both are templates, check template parameter list. */
1224 tree friend_parms
1229 friend_parms))
1233 }
1234 else
1242 /* Check if return types match. */
1246 /* Check if function parameter types match, ignoring the
1247 `this' parameter. */
1256 }
1257 else
1258 {
1259 /* DECL is a TYPE_DECL */
1263 /* Make sure that both DECL and FRIEND_DECL are templates or
1264 non-templates. */
1265 is_template
1272 {
1273 tree friend_parms;
1274 /* If both are templates, check the name of the two
1275 TEMPLATE_DECL's first because is_friend didn't. */
1280 /* Now check template parameter list. */
1281 friend_parms
1284 return comp_template_parms
1286 friend_parms);
1287 }
1288 else
1291 }
1292 }
1294 }
1296 /* Register the specialization SPEC as a specialization of TMPL with
1297 the indicated ARGS. IS_FRIEND indicates whether the specialization
1298 is actually just a friend declaration. Returns SPEC, or an
1299 equivalent prior declaration, if available. */
1301 static tree
1303 hashval_t hash)
1304 {
1305 tree fn;
1307 spec_entry elt;
1313 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1314 register it; we want the corresponding TEMPLATE_DECL instead.
1315 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1316 the more obvious `uses_template_parms (spec)' to avoid problems
1317 with default function arguments. In particular, given
1318 something like this:
1320 template <class T> void f(T t1, T t = T())
1322 the default argument expression is not substituted for in an
1323 instantiation unless and until it is actually needed. */
1327 /* We don't put these specializations in the hash table, but we might
1328 want to give an error about a mismatch. */
1330 else
1331 {
1339 slot =
1343 else
1345 }
1347 /* We can sometimes try to re-register a specialization that we've
1348 already got. In particular, regenerate_decl_from_template calls
1349 duplicate_decls which will update the specialization list. But,
1350 we'll still get called again here anyhow. It's more convenient
1351 to simply allow this than to try to prevent it. */
1355 {
1357 {
1360 {
1362 fn);
1364 }
1365 else
1366 {
1367 tree clone;
1368 /* This situation should occur only if the first
1369 specialization is an implicit instantiation, the
1370 second is an explicit specialization, and the
1371 implicit instantiation has not yet been used. That
1372 situation can occur if we have implicitly
1373 instantiated a member function and then specialized
1374 it later.
1376 We can also wind up here if a friend declaration that
1377 looked like an instantiation turns out to be a
1378 specialization:
1380 template <class T> void foo(T);
1381 class S { friend void foo<>(int) };
1382 template <> void foo(int);
1384 We transform the existing DECL in place so that any
1385 pointers to it become pointers to the updated
1386 declaration.
1388 If there was a definition for the template, but not
1389 for the specialization, we want this to look as if
1390 there were no definition, and vice versa. */
1393 /* The call to duplicate_decls will have applied
1394 [temp.expl.spec]:
1396 An explicit specialization of a function template
1397 is inline only if it is explicitly declared to be,
1398 and independently of whether its function template
1399 is.
1401 to the primary function; now copy the inline bits to
1402 the various clones. */
1404 {
1409 }
1413 }
1414 }
1416 {
1418 /* Dup decl failed, but this is a new definition. Set the
1419 line number so any errors match this new
1420 definition. */
1424 }
1425 }
1429 /* A specialization must be declared in the same namespace as the
1430 template it is specializing. */
1436 {
1444 /* TMPL is a forward declaration of a template function; keep a list
1445 of all specializations in case we need to reassign them to a friend
1446 template later in tsubst_friend_function. */
1449 }
1452 }
1454 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1455 TMPL and ARGS members, ignores SPEC. */
1457 static int
1459 {
1465 }
1467 /* Returns a hash for a template TMPL and template arguments ARGS. */
1469 static hashval_t
1471 {
1474 }
1476 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1477 ignoring SPEC. */
1479 static hashval_t
1481 {
1484 }
1486 /* Recursively calculate a hash value for a template argument ARG, for use
1487 in the hash tables of template specializations. */
1489 hashval_t
1491 {
1503 /* We can get one of these when re-hashing a previous entry in the middle
1504 of substituting into a pack expansion. Just look through it. */
1513 {
1521 {
1526 }
1548 {
1551 {
1554 }
1556 }
1560 {
1563 }
1574 val = iterative_hash_template_arg
1586 val);
1588 val);
1597 /* A lambda can't appear in a template arg, but don't crash on
1598 erroneous input. */
1610 /* Now hash operands as usual. */
1615 }
1618 {
1622 val);
1625 /* Otherwise just compare the types during lookup. */
1634 {
1639 }
1640 }
1643 }
1645 /* Unregister the specialization SPEC as a specialization of TMPL.
1646 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1647 if the SPEC was listed as a specialization of TMPL.
1649 Note that SPEC has been ggc_freed, so we can't look inside it. */
1651 bool
1653 {
1655 spec_entry elt;
1663 {
1668 }
1671 }
1673 /* Like register_specialization, but for local declarations. We are
1674 registering SPEC, an instantiation of TMPL. */
1676 static void
1678 {
1683 }
1685 /* TYPE is a class type. Returns true if TYPE is an explicitly
1686 specialized class. */
1688 bool
1690 {
1694 }
1696 /* Print the list of functions at FNS, going through all the overloads
1697 for each element of the list. Alternatively, FNS can not be a
1698 TREE_LIST, in which case it will be printed together with all the
1699 overloads.
1701 MORE and *STR should respectively be FALSE and NULL when the function
1702 is called from the outside. They are used internally on recursive
1703 calls. print_candidates manages the two parameters and leaves NULL
1704 in *STR when it ends. */
1706 static void
1708 {
1714 {
1718 }
1719 else
1720 {
1722 {
1723 /* Pick the prefix string. */
1725 {
1728 }
1732 }
1735 }
1738 {
1741 }
1742 }
1744 /* Print the list of candidate FNS in an error message. FNS can also
1745 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1747 void
1749 {
1753 }
1755 /* Returns the template (one of the functions given by TEMPLATE_ID)
1756 which can be specialized to match the indicated DECL with the
1757 explicit template args given in TEMPLATE_ID. The DECL may be
1758 NULL_TREE if none is available. In that case, the functions in
1759 TEMPLATE_ID are non-members.
1761 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1762 specialization of a member template.
1764 The TEMPLATE_COUNT is the number of references to qualifying
1765 template classes that appeared in the name of the function. See
1766 check_explicit_specialization for a more accurate description.
1768 TSK indicates what kind of template declaration (if any) is being
1769 declared. TSK_TEMPLATE indicates that the declaration given by
1770 DECL, though a FUNCTION_DECL, has template parameters, and is
1771 therefore a template function.
1773 The template args (those explicitly specified and those deduced)
1774 are output in a newly created vector *TARGS_OUT.
1776 If it is impossible to determine the result, an error message is
1777 issued. The error_mark_node is returned to indicate failure. */
1779 static tree
1781 tree decl,
1785 tmpl_spec_kind tsk)
1786 {
1787 tree fns;
1788 tree targs;
1789 tree explicit_targs;
1791 /* A TREE_LIST of templates of which DECL may be a specialization.
1792 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1793 corresponding TREE_PURPOSE is the set of template arguments that,
1794 when used to instantiate the template, would produce a function
1795 with the signature of DECL. */
1811 /* Check for baselinks. */
1816 {
1819 }
1821 /* Count the number of template headers specified for this
1822 specialization. */
1830 {
1834 {
1835 tree decl_arg_types;
1836 tree fn_arg_types;
1837 tree insttype;
1839 /* In case of explicit specialization, we need to check if
1840 the number of template headers appearing in the specialization
1841 is correct. This is usually done in check_explicit_specialization,
1842 but the check done there cannot be exhaustive when specializing
1843 member functions. Consider the following code:
1845 template <> void A<int>::f(int);
1846 template <> template <> void A<int>::f(int);
1848 Assuming that A<int> is not itself an explicit specialization
1849 already, the first line specializes "f" which is a non-template
1850 member function, whilst the second line specializes "f" which
1851 is a template member function. So both lines are syntactically
1852 correct, and check_explicit_specialization does not reject
1853 them.
1855 Here, we can do better, as we are matching the specialization
1856 against the declarations. We count the number of template
1857 headers, and we check if they match TEMPLATE_COUNT + 1
1858 (TEMPLATE_COUNT is the number of qualifying template classes,
1859 plus there must be another header for the member template
1860 itself).
1862 Notice that if header_count is zero, this is not a
1863 specialization but rather a template instantiation, so there
1864 is no check we can perform here. */
1868 /* Check that the number of template arguments at the
1869 innermost level for DECL is the same as for FN. */
1877 /* DECL might be a specialization of FN. */
1881 /* For a non-static member function, we need to make sure
1882 that the const qualification is the same. Since
1883 get_bindings does not try to merge the "this" parameter,
1884 we must do the comparison explicitly. */
1890 /* Skip the "this" parameter and, for constructors of
1891 classes with virtual bases, the VTT parameter. A
1892 full specialization of a constructor will have a VTT
1893 parameter, but a template never will. */
1894 decl_arg_types
1896 fn_arg_types
1899 /* Function templates cannot be specializations; there are
1900 no partial specializations of functions. Therefore, if
1901 the type of DECL does not match FN, there is no
1902 match. */
1904 {
1908 }
1910 /* See whether this function might be a specialization of this
1911 template. */
1915 /* We cannot deduce template arguments that when used to
1916 specialize TMPL will produce DECL. */
1919 /* Make sure that the deduced arguments actually work. */
1923 fn_arg_types
1928 /* Save this template, and the arguments deduced. */
1930 }
1932 /* FN is an ordinary member function, and we need a
1933 specialization of a member template. */
1934 ;
1936 /* We can get IDENTIFIER_NODEs here in certain erroneous
1937 cases. */
1938 ;
1940 /* This is just an ordinary non-member function. Nothing can
1941 be a specialization of that. */
1942 ;
1944 /* Cannot specialize functions that are created implicitly. */
1945 ;
1946 else
1947 {
1948 tree decl_arg_types;
1950 /* This is an ordinary member function. However, since
1951 we're here, we can assume it's enclosing class is a
1952 template class. For example,
1954 template <typename T> struct S { void f(); };
1955 template <> void S<int>::f() {}
1957 Here, S<int>::f is a non-template, but S<int> is a
1958 template class. If FN has the same type as DECL, we
1959 might be in business. */
1962 /* Its enclosing class is an explicit specialization
1963 of a template class. This is not a candidate. */
1968 /* The return types differ. */
1971 /* Adjust the type of DECL in case FN is a static member. */
1978 decl_arg_types))
1979 /* They match! */
1981 }
1982 }
1985 {
1986 /* We have:
1988 [temp.expl.spec]
1990 It is possible for a specialization with a given function
1991 signature to be instantiated from more than one function
1992 template. In such cases, explicit specification of the
1993 template arguments must be used to uniquely identify the
1994 function template specialization being specialized.
1996 Note that here, there's no suggestion that we're supposed to
1997 determine which of the candidate templates is most
1998 specialized. However, we, also have:
2000 [temp.func.order]
2002 Partial ordering of overloaded function template
2003 declarations is used in the following contexts to select
2004 the function template to which a function template
2005 specialization refers:
2007 -- when an explicit specialization refers to a function
2008 template.
2010 So, we do use the partial ordering rules, at least for now.
2011 This extension can only serve to make invalid programs valid,
2012 so it's safe. And, there is strong anecdotal evidence that
2013 the committee intended the partial ordering rules to apply;
2014 the EDG front end has that behavior, and John Spicer claims
2015 that the committee simply forgot to delete the wording in
2016 [temp.expl.spec]. */
2019 {
2022 }
2023 }
2026 {
2034 }
2038 {
2044 }
2046 /* We have one, and exactly one, match. */
2048 {
2051 /* DECL is a re-declaration or partial instantiation of a template
2052 function. */
2055 /* It was a specialization of an ordinary member function in a
2056 template class. */
2058 }
2060 /* It was a specialization of a template. */
2063 {
2068 }
2069 else
2072 }
2074 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2075 but with the default argument values filled in from those in the
2076 TMPL_TYPES. */
2078 static tree
2080 tree tmpl_types)
2081 {
2082 tree new_spec_types;
2090 /* Substitute into the rest of the list. */
2091 new_spec_types =
2095 /* Add the default argument for this parameter. */
2098 new_spec_types);
2099 }
2101 /* DECL is an explicit specialization. Replicate default arguments
2102 from the template it specializes. (That way, code like:
2104 template <class T> void f(T = 3);
2105 template <> void f(double);
2106 void g () { f (); }
2108 works, as required.) An alternative approach would be to look up
2109 the correct default arguments at the call-site, but this approach
2110 is consistent with how implicit instantiations are handled. */
2112 static void
2114 {
2115 tree tmpl;
2116 tree spec_types;
2117 tree tmpl_types;
2118 tree new_spec_types;
2119 tree old_type;
2120 tree new_type;
2121 tree t;
2126 /* See if there's anything we need to do. */
2139 {
2140 /* Remove the this pointer, but remember the object's type for
2141 CV quals. */
2147 {
2148 /* DECL may contain more parameters than TMPL due to the extra
2149 in-charge parameter in constructors and destructors. */
2152 }
2154 {
2157 }
2158 }
2160 /* Compute the merged default arguments. */
2161 new_spec_types =
2164 /* Compute the new FUNCTION_TYPE. */
2166 {
2170 new_spec_types);
2173 /* Put the in-charge parameter back. */
2176 new_spec_types);
2180 new_spec_types);
2181 }
2182 else
2184 new_spec_types);
2190 }
2192 /* Check to see if the function just declared, as indicated in
2193 DECLARATOR, and in DECL, is a specialization of a function
2194 template. We may also discover that the declaration is an explicit
2195 instantiation at this point.
2197 Returns DECL, or an equivalent declaration that should be used
2198 instead if all goes well. Issues an error message if something is
2199 amiss. Returns error_mark_node if the error is not easily
2200 recoverable.
2202 FLAGS is a bitmask consisting of the following flags:
2204 2: The function has a definition.
2205 4: The function is a friend.
2207 The TEMPLATE_COUNT is the number of references to qualifying
2208 template classes that appeared in the name of the function. For
2209 example, in
2211 template <class T> struct S { void f(); };
2212 void S<int>::f();
2214 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2215 classes are not counted in the TEMPLATE_COUNT, so that in
2217 template <class T> struct S {};
2218 template <> struct S<int> { void f(); }
2219 template <> void S<int>::f();
2221 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2222 invalid; there should be no template <>.)
2224 If the function is a specialization, it is marked as such via
2225 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2226 is set up correctly, and it is added to the list of specializations
2227 for that template. */
2229 tree
2231 tree decl,
2234 {
2242 tmpl_spec_kind tsk;
2245 {
2248 else
2250 }
2251 else
2255 {
2258 {
2261 }
2263 {
2265 /* This could be something like:
2267 template <class T> void f(T);
2268 class S { friend void f<>(int); } */
2270 else
2271 {
2272 /* This case handles bogus declarations like template <>
2273 template <class T> void f<int>(); */
2276 declarator);
2278 }
2279 }
2283 /* The error has already been reported in
2284 check_specialization_scope. */
2290 /* Fall through. */
2303 decl);
2306 else
2310 /* Fall through. */
2315 else
2321 {
2322 /* This case handles bogus declarations like template <>
2323 template <class T> void f<int>(); */
2328 else
2330 declarator);
2332 }
2335 /* This is a specialization of a member template, without
2336 specialization the containing class. Something like:
2338 template <class T> struct S {
2339 template <class U> void f (U);
2340 };
2341 template <> template <class U> void S<int>::f(U) {}
2343 That's a specialization -- but of the entire template. */
2349 }
2352 {
2356 {
2360 }
2361 }
2364 {
2368 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2370 {
2371 tree fns;
2376 else
2377 {
2378 /* If there is no class context, the explicit instantiation
2379 must be at namespace scope. */
2382 /* Find the namespace binding, using the declaration
2383 context. */
2387 {
2390 }
2391 else
2392 {
2398 }
2399 }
2402 }
2408 {
2410 /* A specialization in class scope. This is invalid,
2411 but the error will already have been flagged by
2412 check_specialization_scope. */
2414 else
2415 {
2416 /* It's not valid to write an explicit instantiation in
2417 class scope, e.g.:
2419 class C { template void f(); }
2421 This case is caught by the parser. However, on
2422 something like:
2424 template class C { void f(); };
2426 (which is invalid) we can get here. The error will be
2427 issued later. */
2428 ;
2429 }
2432 }
2435 IDENTIFIER_NODE))
2436 {
2437 /* Find the list of functions in ctype that have the same
2438 name as the declared function. */
2444 {
2449 {
2450 /* From [temp.expl.spec]:
2452 If such an explicit specialization for the member
2453 of a class template names an implicitly-declared
2454 special member function (clause _special_), the
2455 program is ill-formed.
2457 Similar language is found in [temp.explicit]. */
2460 }
2463 }
2466 {
2470 }
2471 else
2472 {
2474 tree ovl;
2476 /* For a type-conversion operator, we cannot do a
2477 name-based lookup. We might be looking for `operator
2478 int' which will be a specialization of `operator T'.
2479 So, we find *all* the conversion operators, and then
2480 select from them. */
2488 {
2490 /* There are no more conversion functions. */
2493 /* Glue all these conversion functions together
2494 with those we already have. */
2497 }
2498 }
2501 {
2504 }
2505 else
2507 }
2509 /* Figure out what exactly is being specialized at this point.
2510 Note that for an explicit instantiation, even one for a
2511 member function, we cannot tell apriori whether the
2512 instantiation is for a member template, or just a member
2513 function of a template class. Even if a member template is
2514 being instantiated, the member template arguments may be
2515 elided if they can be deduced from the rest of the
2516 declaration. */
2519 member_specialization,
2520 template_count,
2521 tsk);
2524 /* We couldn't figure out what this declaration was
2525 specializing. */
2527 else
2528 {
2532 {
2533 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2534 is done by do_decl_instantiation later. */
2540 {
2541 /* If TMPL is not the most general template (for
2542 example, if TMPL is a friend template that is
2543 injected into namespace scope), then there will
2544 be too many levels of TARGS. Remove some of them
2545 here. */
2547 tree new_targs;
2554 }
2557 }
2559 /* If we thought that the DECL was a member function, but it
2560 turns out to be specializing a static member function,
2561 make DECL a static member function as well. */
2566 /* If this is a specialization of a member template of a
2567 template class, we want to return the TEMPLATE_DECL, not
2568 the specialization of it. */
2570 {
2575 {
2576 tree parm;
2580 /* We want to use the argument list specified in the
2581 definition, not in the original declaration. */
2586 }
2589 }
2591 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2594 /* Inherit default function arguments from the template
2595 DECL is specializing. */
2598 /* This specialization has the same protection as the
2599 template it specializes. */
2603 /* 7.1.1-1 [dcl.stc]
2605 A storage-class-specifier shall not be specified in an
2606 explicit specialization...
2608 The parser rejects these, so unless action is taken here,
2609 explicit function specializations will always appear with
2610 global linkage.
2612 The action recommended by the C++ CWG in response to C++
2613 defect report 605 is to make the storage class and linkage
2614 of the explicit specialization match the templated function:
2616 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2617 */
2619 {
2623 /* This specialization has the same linkage and visibility as
2624 the function template it specializes. */
2627 {
2630 }
2633 {
2636 }
2637 }
2639 /* If DECL is a friend declaration, declared using an
2640 unqualified name, the namespace associated with DECL may
2641 have been set incorrectly. For example, in:
2643 template <typename T> void f(T);
2644 namespace N {
2645 struct S { friend void f<int>(int); }
2646 }
2648 we will have set the DECL_CONTEXT for the friend
2649 declaration to N, rather than to the global namespace. */
2654 /* This is not really a declaration of a specialization.
2655 It's just the name of an instantiation. But, it's not
2656 a request for an instantiation, either. */
2659 /* This is indeed a specialization. In case of constructors
2660 and destructors, we need in-charge and not-in-charge
2661 versions in V3 ABI. */
2664 /* Register this specialization so that we can find it
2665 again. */
2667 }
2668 }
2671 }
2673 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2674 parameters. These are represented in the same format used for
2675 DECL_TEMPLATE_PARMS. */
2677 int
2679 {
2680 const_tree p1;
2681 const_tree p2;
2689 {
2701 {
2705 /* If either of the template parameters are invalid, assume
2706 they match for the sake of error recovery. */
2719 }
2720 }
2723 /* One set of parameters has more parameters lists than the
2724 other. */
2728 }
2730 /* Determine whether PARM is a parameter pack. */
2732 bool
2734 {
2735 /* Determine if we have a non-type template parameter pack. */
2742 /* If this is a list of template parameters, we could get a
2743 TYPE_DECL or a TEMPLATE_DECL. */
2747 /* Otherwise it must be a type template parameter. */
2751 }
2753 /* Determine if T is a function parameter pack. */
2755 bool
2757 {
2761 }
2763 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2764 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2766 tree
2768 {
2775 }
2777 /* Return true iff the function parameter PARAM_DECL was expanded
2778 from the function parameter pack PACK. */
2780 bool
2782 {
2787 /* The parameter pack and its pack arguments have the same
2788 DECL_PARM_INDEX. */
2790 }
2792 /* Determine whether ARGS describes a variadic template args list,
2793 i.e., one that is terminated by a template argument pack. */
2795 static bool
2797 {
2799 tree last_parm;
2813 }
2815 /* Generate a new name for the parameter pack name NAME (an
2816 IDENTIFIER_NODE) that incorporates its */
2818 static tree
2820 {
2821 /* Munge the name to include the parameter index. */
2822 #define NUMBUF_LEN 128
2834 }
2836 /* Return true if T is a primary function, class or alias template
2837 instantiation. */
2839 bool
2841 {
2858 }
2860 /* Return true if PARM is a template template parameter. */
2862 bool
2864 {
2866 }
2868 /* Return true iff PARM is a DECL representing a type template
2869 parameter. */
2871 bool
2873 {
2878 }
2880 /* Return the template parameters of T if T is a
2881 primary template instantiation, NULL otherwise. */
2883 tree
2885 {
2890 parms = INNERMOST_TEMPLATE_PARMS
2894 }
2896 /* Return the template parameters of the LEVELth level from the full list
2897 of template parameters PARMS. */
2899 tree
2901 {
2902 tree p;
2913 }
2915 /* Returns the template arguments of T if T is a template instantiation,
2916 NULL otherwise. */
2918 tree
2920 {
2928 }
2930 /* Return the argument pack elements of T if T is a template argument pack,
2931 NULL otherwise. */
2933 tree
2935 {
2941 }
2943 /* Structure used to track the progress of find_parameter_packs_r. */
2944 struct find_parameter_pack_data
2945 {
2946 /* TREE_LIST that will contain all of the parameter packs found by
2947 the traversal. */
2950 /* Set of AST nodes that have been visited by the traversal. */
2952 };
2954 /* Identifies all of the argument packs that occur in a template
2955 argument and appends them to the TREE_LIST inside DATA, which is a
2956 find_parameter_pack_data structure. This is a subroutine of
2957 make_pack_expansion and uses_parameter_packs. */
2958 static tree
2960 {
2966 /* Handle type aliases/typedefs. */
2971 {
2978 }
2980 /* Identify whether this is a parameter pack or not. */
2982 {
2997 {
2998 /* We don't want to walk into the type of a PARM_DECL,
2999 because we don't want to see the type parameter pack. */
3002 }
3009 /* Not a parameter pack. */
3011 }
3014 {
3015 /* Add this parameter pack to the list. */
3017 }
3023 /* This switch statement will return immediately if we don't find a
3024 parameter pack. */
3026 {
3031 /* Check the template itself. */
3034 /* Check the template arguments. */
3050 /* Fall through. */
3092 }
3095 }
3097 /* Determines if the expression or type T uses any parameter packs. */
3098 bool
3100 {
3108 }
3110 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3111 representation a base-class initializer into a parameter pack
3112 expansion. If all goes well, the resulting node will be an
3113 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3114 respectively. */
3115 tree
3117 {
3118 tree result;
3127 {
3128 /* The only time we will see a TREE_LIST here is for a base
3129 class initializer. In this case, the TREE_PURPOSE will be a
3130 _TYPE node (representing the base class expansion we're
3131 initializing) and the TREE_VALUE will be a TREE_LIST
3132 containing the initialization arguments.
3134 The resulting expansion looks somewhat different from most
3135 expansions. Rather than returning just one _EXPANSION, we
3136 return a TREE_LIST whose TREE_PURPOSE is a
3137 TYPE_PACK_EXPANSION containing the bases that will be
3138 initialized. The TREE_VALUE will be identical to the
3139 original TREE_VALUE, which is a list of arguments that will
3140 be passed to each base. We do not introduce any new pack
3141 expansion nodes into the TREE_VALUE (although it is possible
3142 that some already exist), because the TREE_PURPOSE and
3143 TREE_VALUE all need to be expanded together with the same
3144 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3145 resulting TREE_PURPOSE will mention the parameter packs in
3146 both the bases and the arguments to the bases. */
3147 tree purpose;
3148 tree value;
3151 /* Determine which parameter packs will be used by the base
3152 class expansion. */
3159 {
3163 }
3166 {
3167 /* Collect the sets of parameter packs used in each of the
3168 initialization arguments. */
3170 {
3171 /* Determine which parameter packs will be expanded in this
3172 argument. */
3175 }
3176 }
3180 /* Create the pack expansion type for the base type. */
3185 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3186 they will rarely be compared to anything. */
3190 }
3195 /* Build the PACK_EXPANSION_* node. */
3196 result = for_types
3201 {
3202 /* Propagate type and const-expression information. */
3205 }
3206 else
3207 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3208 they will rarely be compared to anything. */
3211 /* Determine which parameter packs will be expanded. */
3217 /* Make sure we found some parameter packs. */
3219 {
3222 else
3225 }
3231 }
3233 /* Checks T for any "bare" parameter packs, which have not yet been
3234 expanded, and issues an error if any are found. This operation can
3235 only be done on full expressions or types (e.g., an expression
3236 statement, "if" condition, etc.), because we could have expressions like:
3238 foo(f(g(h(args)))...)
3240 where "args" is a parameter pack. check_for_bare_parameter_packs
3241 should not be called for the subexpressions args, h(args),
3242 g(h(args)), or f(g(h(args))), because we would produce erroneous
3243 error messages.
3245 Returns TRUE and emits an error if there were bare parameter packs,
3246 returns FALSE otherwise. */
3247 bool
3249 {
3265 {
3268 {
3277 else
3282 else
3286 }
3289 }
3292 }
3294 /* Expand any parameter packs that occur in the template arguments in
3295 ARGS. */
3296 tree
3298 {
3304 /* First, determine if we need to expand anything, and the number of
3305 slots we'll need. */
3307 {
3312 {
3316 else
3318 }
3319 else
3320 {
3322 num_result_args++;
3323 }
3324 }
3326 /* If no expansion is necessary, we're done. */
3330 /* Expand arguments. */
3333 non_default_args_count =
3336 {
3339 {
3346 }
3347 else
3348 {
3351 }
3352 }
3356 }
3358 /* Checks if DECL shadows a template parameter.
3360 [temp.local]: A template-parameter shall not be redeclared within its
3361 scope (including nested scopes).
3363 Emits an error and returns TRUE if the DECL shadows a parameter,
3364 returns FALSE otherwise. */
3366 bool
3368 {
3369 tree olddecl;
3371 /* If we're not in a template, we can't possibly shadow a template
3372 parameter. */
3376 /* Figure out what we're shadowing. */
3381 /* If there's no previous binding for this name, we're not shadowing
3382 anything, let alone a template parameter. */
3386 /* If we're not shadowing a template parameter, we're done. Note
3387 that OLDDECL might be an OVERLOAD (or perhaps even an
3388 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3389 node. */
3393 /* We check for decl != olddecl to avoid bogus errors for using a
3394 name inside a class. We check TPFI to avoid duplicate errors for
3395 inline member templates. */
3403 }
3405 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3406 ORIG_LEVEL, DECL, and TYPE. */
3408 static tree
3412 tree decl,
3413 tree type)
3414 {
3425 }
3427 /* Find the canonical type parameter for the given template type
3428 parameter. Returns the canonical type parameter, which may be TYPE
3429 if no such parameter existed. */
3431 static tree
3433 {
3434 tree list;
3448 else
3449 {
3454 }
3455 }
3457 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3458 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3459 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3460 new one is created. */
3462 static tree
3464 tsubst_flags_t complain)
3465 {
3470 {
3489 /* Template template parameters need this. */
3494 }
3497 }
3499 /* Process information from new template parameter PARM and append it
3500 to the LIST being built. This new parameter is a non-type
3501 parameter iff IS_NON_TYPE is true. This new parameter is a
3502 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3503 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3504 parameter list PARM belongs to. This is used used to create a
3505 proper canonical type for the type of PARM that is to be created,
3506 iff PARM is a type. If the size is not known, this parameter shall
3507 be set to 0. */
3509 tree
3512 {
3514 tree defval;
3515 tree err_parm_list;
3522 {
3526 {
3530 else
3532 }
3535 }
3536 else
3540 {
3546 {
3550 }
3551 else
3552 {
3553 /* [temp.param]
3555 The top-level cv-qualifiers on the template-parameter are
3556 ignored when determining its type. */
3559 {
3563 }
3566 {
3567 /* This template parameter is not a parameter pack, but it
3568 should be. Complain about "bare" parameter packs. */
3571 /* Recover by calling this a parameter pack. */
3573 }
3574 }
3576 /* A template parameter is not modifiable. */
3585 processing_template_decl,
3590 }
3591 else
3592 {
3593 tree t;
3597 {
3599 /* This is for distinguishing between real templates and template
3600 template parameters */
3604 }
3605 else
3606 {
3608 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3611 }
3618 processing_template_decl,
3622 }
3628 }
3630 /* The end of a template parameter list has been reached. Process the
3631 tree list into a parameter vector, converting each parameter into a more
3632 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3633 as PARM_DECLs. */
3635 tree
3637 {
3642 current_template_parms
3647 {
3651 }
3656 }
3658 /* end_template_decl is called after a template declaration is seen. */
3660 void
3662 {
3668 /* This matches the pushlevel in begin_template_parm_list. */
3673 }
3675 /* Takes a TREE_LIST representing a template parameter and convert it
3676 into an argument suitable to be passed to the type substitution
3677 functions. Note that If the TREE_LIST contains an error_mark
3678 node, the returned argument is error_mark_node. */
3680 static tree
3682 {
3695 {
3699 {
3700 /* Turn this argument into a TYPE_ARGUMENT_PACK
3701 with a single element, which expands T. */
3703 #ifdef ENABLE_CHECKING
3704 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3706 #endif
3711 }
3712 }
3713 else
3714 {
3718 {
3719 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3720 with a single element, which expands T. */
3723 #ifdef ENABLE_CHECKING
3724 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3726 #endif
3732 }
3733 }
3735 }
3737 /* This function returns TRUE if PARM_PACK is a template parameter
3738 pack and if ARG_PACK is what template_parm_to_arg returned when
3739 passed PARM_PACK. */
3741 static bool
3743 {
3744 /* For clarity in the comments below let's use the representation
3745 argument_pack<elements>' to denote an argument pack and its
3746 elements.
3748 In the 'if' block below, we want to detect cases where
3749 ARG_PACK is argument_pack<PARM_PACK...>. I.e, we want to
3750 check if ARG_PACK is an argument pack which sole element is
3751 the expansion of PARM_PACK. That argument pack is typically
3752 created by template_parm_to_arg when passed a parameter
3753 pack. */
3758 {
3763 /* The argument pack that the parameter maps to is just an
3764 expansion of the parameter itself, such as one would
3765 find in the implicit typedef of a class inside the
3766 class itself. Consider this parameter "unsubstituted",
3767 so that we will maintain the outer pack expansion. */
3769 }
3771 }
3773 /* Within the declaration of a template, return all levels of template
3774 parameters that apply. The template parameters are represented as
3775 a TREE_VEC, in the form documented in cp-tree.h for template
3776 arguments. */
3778 static tree
3780 {
3781 tree header;
3786 /* If there is only one level of template parameters, we do not
3787 create a TREE_VEC of TREE_VECs. Instead, we return a single
3788 TREE_VEC containing the arguments. */
3793 {
3801 #ifdef ENABLE_CHECKING
3803 #endif
3807 else
3809 }
3812 /* This can happen for template parms of a template template
3813 parameter, e.g:
3815 template<template<class T, class U> class TT> struct S;
3817 Consider the level of the parms of TT; T and U both have
3818 level 2; TT has no template parm of level 1. So in this case
3819 the first element of full_template_args is NULL_TREE. If we
3820 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
3821 of 2. This will make tsubst wrongly consider that T and U
3822 have level 1. Instead, let's create a dummy vector as the
3823 first element of full_template_args so that TMPL_ARG_DEPTH
3824 returns the correct depth for args. */
3827 }
3829 /* Update the declared TYPE by doing any lookups which were thought to be
3830 dependent, but are not now that we know the SCOPE of the declarator. */
3832 tree
3834 {
3845 /* Don't bother building up the args in this case. */
3847 {
3848 /* tsubst in the args corresponding to the template parameters,
3849 including auto if present. Most things will be unchanged, but
3850 make_typename_type and tsubst_qualified_id will resolve
3851 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3854 tree pushed;
3856 {
3860 }
3865 }
3871 {
3874 else
3876 }
3878 }
3880 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3881 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3882 a member template. Used by push_template_decl below. */
3884 static tree
3886 {
3894 }
3896 struct template_parm_data
3897 {
3898 /* The level of the template parameters we are currently
3899 processing. */
3902 /* The index of the specialization argument we are currently
3903 processing. */
3906 /* An array whose size is the number of template parameters. The
3907 elements are nonzero if the parameter has been used in any one
3908 of the arguments processed so far. */
3911 /* An array whose size is the number of template arguments. The
3912 elements are nonzero if the argument makes use of template
3913 parameters of this level. */
3915 };
3917 /* Subroutine of push_template_decl used to see if each template
3918 parameter in a partial specialization is used in the explicit
3919 argument list. If T is of the LEVEL given in DATA (which is
3920 treated as a template_parm_data*), then DATA->PARMS is marked
3921 appropriately. */
3923 static int
3925 {
3931 {
3934 }
3935 else
3936 {
3939 }
3942 {
3945 }
3947 /* Return zero so that for_each_template_parm will continue the
3948 traversal of the tree; we want to mark *every* template parm. */
3950 }
3952 /* Process the partial specialization DECL. */
3954 static tree
3956 {
3962 tree inner_parms;
3963 tree inst;
3976 /* We check that each of the template parameters given in the
3977 partial specialization is used in the argument list to the
3978 specialization. For example:
3980 template <class T> struct S;
3981 template <class T> struct S<T*>;
3983 The second declaration is OK because `T*' uses the template
3984 parameter T, whereas
3986 template <class T> struct S<int>;
3988 is no good. Even trickier is:
3990 template <class T>
3991 struct S1
3992 {
3993 template <class U>
3994 struct S2;
3995 template <class U>
3996 struct S2<T>;
3997 };
3999 The S2<T> declaration is actually invalid; it is a
4000 full-specialization. Of course,
4002 template <class U>
4003 struct S2<T (*)(U)>;
4005 or some such would have been OK. */
4013 {
4018 NULL,
4020 }
4023 {
4024 /* One of the template parms was not used in the
4025 specialization. */
4027 {
4030 }
4033 }
4038 /* [temp.class.spec]
4040 The argument list of the specialization shall not be identical to
4041 the implicit argument list of the primary template. */
4048 /* A partial specialization that replaces multiple parameters of the
4049 primary template with a pack expansion is less specialized for those
4050 parameters. */
4052 {
4054 "primary template because it replaces multiple parameters "
4058 }
4060 /* [temp.class.spec]
4062 A partially specialized non-type argument expression shall not
4063 involve template parameters of the partial specialization except
4064 when the argument expression is a simple identifier.
4066 The type of a template parameter corresponding to a specialized
4067 non-type argument shall not be dependent on a parameter of the
4068 specialization.
4070 Also, we verify that pack expansions only occur at the
4071 end of the argument list. */
4075 {
4082 {
4083 /* Extract the arguments from the argument pack. We'll be
4084 iterating over these in the following loop. */
4087 }
4090 {
4092 /* Get the Jth argument in the parameter pack. */
4096 {
4097 /* Pack expansions must come at the end of the
4098 argument list. */
4101 {
4105 else
4108 }
4109 }
4112 /* We only care about the pattern. */
4118 /* This next line is the `argument expression is not just a
4119 simple identifier' condition and also the `specialized
4120 non-type argument' bit. */
4122 {
4126 arg);
4127 else
4128 {
4129 /* Look at the corresponding template parameter,
4130 marking which template parameters its type depends
4131 upon. */
4135 {
4136 /* We haven't yet initialized TPD2. Do so now. */
4138 /* The number of parameters here is the number in the
4139 main template, which, as checked in the assertion
4140 above, is NARGS. */
4144 }
4146 /* Mark the template parameters. But this time, we're
4147 looking for the template parameters of the main
4148 template, not in the specialization. */
4155 NULL,
4159 {
4160 /* The type depended on some template parameters.
4161 If they are fully specialized in the
4162 specialization, that's OK. */
4171 "type %qT of template argument %qE depends "
4173 "type %qT of template argument %qE depends "
4175 type,
4176 arg);
4177 }
4178 }
4179 }
4180 }
4181 }
4183 /* We should only get here once. */
4193 {
4197 {
4201 "partial specialization of %qT after instantiation "
4203 }
4204 }
4207 }
4209 /* Check that a template declaration's use of default arguments and
4210 parameter packs is not invalid. Here, PARMS are the template
4211 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4212 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4213 specialization.
4216 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4217 declaration (but not a definition); 1 indicates a declaration, 2
4218 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4219 emitted for extraneous default arguments.
4221 Returns TRUE if there were no errors found, FALSE otherwise. */
4223 bool
4226 {
4229 tree parm_level;
4232 /* [temp.param]
4234 A default template-argument shall not be specified in a
4235 function template declaration or a function template definition, nor
4236 in the template-parameter-list of the definition of a member of a
4237 class template. */
4240 /* You can't have a function template declaration in a local
4241 scope, nor you can you define a member of a class template in a
4242 local scope. */
4249 /* If this is either a friend defined in the scope of the class
4250 or a member function. */
4256 /* And, if it was a member function, it really was defined in
4257 the scope of the class. */
4260 /* We already checked these parameters when the template was
4261 declared, so there's no need to do it again now. This function
4262 was defined in class scope, but we're processing it's body now
4263 that the class is complete. */
4266 /* Core issue 226 (C++0x only): the following only applies to class
4267 templates. */
4269 {
4270 /* [temp.param]
4272 If a template-parameter has a default template-argument, all
4273 subsequent template-parameters shall have a default
4274 template-argument supplied. */
4276 {
4283 {
4293 {
4295 /* For better subsequent error-recovery, we indicate that
4296 there should have been a default argument. */
4299 }
4301 && !is_partial
4302 && !is_friend_decl
4303 /* Don't complain about an enclosing partial
4304 specialization. */
4309 {
4310 /* A primary class template can only have one
4311 parameter pack, at the end of the template
4312 parameter list. */
4317 else
4325 }
4326 }
4327 }
4328 }
4331 || is_partial
4332 || !is_primary
4334 /* For an ordinary class template, default template arguments are
4335 allowed at the innermost level, e.g.:
4336 template <class T = int>
4337 struct S {};
4338 but, in a partial specialization, they're not allowed even
4339 there, as we have in [temp.class.spec]:
4341 The template parameter list of a specialization shall not
4342 contain default template argument values.
4344 So, for a partial specialization, or for a function template
4345 (in C++98/C++03), we look at all of them. */
4346 ;
4347 else
4348 /* But, for a primary class template that is not a partial
4349 specialization we look at all template parameters except the
4350 innermost ones. */
4353 /* Figure out what error message to issue. */
4366 else
4370 /* If we're inside a class definition, there's no need to
4371 examine the parameters to the class itself. On the one
4372 hand, they will be checked when the class is defined, and,
4373 on the other, default arguments are valid in things like:
4374 template <class T = double>
4375 struct S { template <class U> void f(U); };
4376 Here the default argument for `S' has no bearing on the
4377 declaration of `f'. */
4379 else
4380 /* Check everything. */
4386 {
4393 {
4398 {
4400 {
4407 }
4409 /* Clear out the default argument so that we are not
4410 confused later. */
4412 }
4413 }
4415 /* At this point, if we're still interested in issuing messages,
4416 they must apply to classes surrounding the object declared. */
4420 }
4423 }
4425 /* Worker for push_template_decl_real, called via
4426 for_each_template_parm. DATA is really an int, indicating the
4427 level of the parameters we are interested in. If T is a template
4428 parameter of that level, return nonzero. */
4430 static int
4432 {
4438 else
4441 }
4443 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4444 parameters given by current_template_args, or reuses a
4445 previously existing one, if appropriate. Returns the DECL, or an
4446 equivalent one, if it is replaced via a call to duplicate_decls.
4448 If IS_FRIEND is true, DECL is a friend declaration. */
4450 tree
4452 {
4453 tree tmpl;
4454 tree args;
4455 tree info;
4456 tree ctx;
4460 /* True if the template is a member template, in the sense of
4461 [temp.mem]. */
4467 /* See if this is a partial specialization. */
4476 /* For a friend, we want the context of the friend function, not
4477 the type of which it is a friend. */
4481 /* In the case of a virtual function, we want the class in which
4482 it is defined. */
4484 else
4485 /* Otherwise, if we're currently defining some class, the DECL
4486 is assumed to be a member of the class. */
4495 /* See if this is a primary template. */
4497 /* A friend template that specifies a class context, i.e.
4498 template <typename T> friend void A<T>::f();
4499 is not primary. */
4501 else
4505 {
4510 {
4513 }
4515 {
4517 {
4518 /* [temp.mem]
4520 A destructor shall not be a member template. */
4523 }
4530 {
4531 /* [basic.stc.dynamic.allocation]
4533 An allocation function can be a function
4534 template. ... Template allocation functions shall
4535 have two or more parameters. */
4538 }
4539 }
4545 /* alias-declaration */
4547 else
4548 {
4551 }
4552 }
4554 /* Check to see that the rules regarding the use of default
4555 arguments are not being violated. */
4559 /* Ensure that there are no parameter packs in the type of this
4560 declaration that have not been expanded. */
4562 {
4563 /* Check each of the arguments individually to see if there are
4564 any bare parameter packs. */
4570 {
4573 {
4574 /* This is a PARM_DECL that contains unexpanded parameter
4575 packs. We have already complained about this in the
4576 check_for_bare_parameter_packs call, so just replace
4577 these types with ERROR_MARK_NODE. */
4580 }
4584 }
4586 /* Check for bare parameter packs in the return type and the
4587 exception specifiers. */
4589 /* Errors were already issued, set return type to int
4590 as the frontend doesn't expect error_mark_node as
4591 the return type. */
4595 }
4600 {
4603 }
4614 {
4619 /* If DECL is a TYPE_DECL for a class-template, then there won't
4620 be DECL_LANG_SPECIFIC. The information equivalent to
4621 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4625 {
4626 /* Since a template declaration already existed for this
4627 class-type, we must be redeclaring it here. Make sure
4628 that the redeclaration is valid. */
4630 current_template_parms);
4631 /* We don't need to create a new TEMPLATE_DECL; just use the
4632 one we already had. */
4634 }
4635 else
4636 {
4638 member_template_p);
4643 {
4644 /* A specialization of a member template of a template
4645 class. */
4649 }
4650 }
4651 }
4652 else
4653 {
4659 {
4662 }
4670 {
4671 tree new_tmpl;
4673 /* The declaration is a specialization of a member
4674 template, declared outside the class. Therefore, the
4675 innermost template arguments will be NULL, so we
4676 replace them with the arguments determined by the
4677 earlier call to check_explicit_specialization. */
4680 new_tmpl
4682 member_template_p);
4692 args,
4695 }
4697 /* Make sure the template headers we got make sense. */
4702 {
4705 }
4706 else
4708 {
4713 {
4717 else
4722 }
4727 /* Can happen in erroneous input. */
4729 else
4733 }
4735 /* Check that the parms are used in the appropriate qualifying scopes
4736 in the declarator. */
4740 {
4746 /* Avoid crash in import_export_decl. */
4749 }
4750 }
4755 /* Push template declarations for global functions and types. Note
4756 that we do not try to push a global template friend declared in a
4757 template class; such a thing may well depend on the template
4758 parameters of the class. */
4761 {
4766 /* Hide template friend classes that haven't been declared yet. */
4768 {
4771 }
4772 }
4775 {
4781 {
4784 /* It is a conversion operator. See if the type converted to
4785 depends on innermost template operands. */
4788 depth))
4790 }
4792 /* Give template template parms a DECL_CONTEXT of the template
4793 for which they are a parameter. */
4796 {
4800 }
4801 }
4803 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4804 back to its most general template. If TMPL is a specialization,
4805 ARGS may only have the innermost set of arguments. Add the missing
4806 argument levels if necessary. */
4814 else
4815 {
4820 }
4823 }
4825 tree
4827 {
4829 }
4831 /* Called when a class template TYPE is redeclared with the indicated
4832 template PARMS, e.g.:
4834 template <class T> struct S;
4835 template <class T> struct S {}; */
4837 bool
4839 {
4840 tree tmpl;
4841 tree tmpl_parms;
4845 {
4848 }
4852 /* The type is nested in some template class. Nothing to worry
4853 about here; there are no new template parameters for the nested
4854 type. */
4858 {
4860 tmpl);
4862 }
4868 {
4878 }
4881 {
4882 tree tmpl_parm;
4883 tree parm;
4884 tree tmpl_default;
4885 tree parm_default;
4899 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4900 TEMPLATE_DECL. */
4910 {
4914 }
4917 {
4918 /* We have in [temp.param]:
4920 A template-parameter may not be given default arguments
4921 by two different declarations in the same scope. */
4926 }
4929 /* Update the previous template parameters (which are the ones
4930 that will really count) with the new default value. */
4933 /* Update the new parameters, too; they'll be used as the
4934 parameters for any members. */
4936 }
4939 }
4941 /* Simplify EXPR if it is a non-dependent expression. Returns the
4942 (possibly simplified) expression. */
4944 static tree
4946 {
4950 /* If we're in a template, but EXPR isn't value dependent, simplify
4951 it. We're supposed to treat:
4953 template <typename T> void f(T[1 + 1]);
4954 template <typename T> void f(T[2]);
4956 as two declarations of the same function, for example. */
4961 {
4962 HOST_WIDE_INT saved_processing_template_decl;
4968 complain,
4973 }
4975 }
4977 tree
4979 {
4981 }
4983 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
4984 template declaration, or a TYPE_DECL for an alias declaration. */
4986 bool
4988 {
4996 }
4998 /* Return TRUE iff is a specialization of an alias template. */
5000 bool
5002 {
5007 }
5009 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5010 must be a function or a pointer-to-function type, as specified
5011 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5012 and check that the resulting function has external linkage. */
5014 static tree
5016 {
5019 linkage_kind linkage;
5031 /* [temp.arg.nontype]/1
5033 A template-argument for a non-type, non-template template-parameter
5034 shall be one of:
5035 [...]
5036 -- the address of an object or function with external [C++11: or
5037 internal] linkage. */
5040 {
5045 else
5050 }
5053 }
5055 /* Subroutine of convert_nontype_argument.
5056 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5057 Emit an error otherwise. */
5059 static bool
5061 tsubst_flags_t complain)
5062 {
5069 {
5073 }
5075 }
5077 /* Returns TRUE iff the address of OP is value-dependent.
5079 14.6.2.4 [temp.dep.temp]:
5080 A non-integral non-type template-argument is dependent if its type is
5081 dependent or it has either of the following forms
5082 qualified-id
5083 & qualified-id
5084 and contains a nested-name-specifier which specifies a class-name that
5085 names a dependent type.
5087 We generalize this to just say that the address of a member of a
5088 dependent class is value-dependent; the above doesn't cover the
5089 address of a static data member named with an unqualified-id. */
5091 static bool
5093 {
5094 /* We could use get_inner_reference here, but there's no need;
5095 this is only relevant for template non-type arguments, which
5096 can only be expressed as &id-expression. */
5098 {
5102 }
5105 }
5107 /* The next set of functions are used for providing helpful explanatory
5108 diagnostics for failed overload resolution. Their messages should be
5109 indented by two spaces for consistency with the messages in
5110 call.c */
5112 static int
5114 {
5116 }
5118 static int
5120 {
5125 }
5127 static int
5129 {
5131 }
5133 static int
5135 {
5141 }
5143 static int
5145 {
5149 }
5151 static int
5153 {
5156 " template parameter %qD is not a parameter pack, but "
5160 }
5162 static int
5164 {
5167 " template argument %qE does not match "
5171 }
5173 static int
5175 {
5179 }
5181 static int
5183 {
5189 }
5191 static int
5193 {
5195 {
5200 else
5202 " deduced conflicting values for non-type parameter "
5204 }
5206 }
5208 static int
5210 {
5213 " variable-sized array type %qT is not "
5215 arg);
5217 }
5219 static int
5221 {
5225 arg);
5227 }
5229 static int
5231 {
5238 }
5240 static int
5242 {
5244 }
5246 static int
5248 {
5250 }
5252 static int
5255 {
5260 }
5262 static int
5265 {
5268 {
5276 }
5278 }
5280 static int
5282 {
5285 " template parameters of a template template argument are "
5288 }
5290 static int
5292 {
5298 }
5300 static int
5302 {
5307 }
5309 static int
5311 {
5315 arg);
5317 }
5319 /* Attempt to convert the non-type template parameter EXPR to the
5320 indicated TYPE. If the conversion is successful, return the
5321 converted value. If the conversion is unsuccessful, return
5322 NULL_TREE if we issued an error message, or error_mark_node if we
5323 did not. We issue error messages for out-and-out bad template
5324 parameters, but not simply because the conversion failed, since we
5325 might be just trying to do argument deduction. Both TYPE and EXPR
5326 must be non-dependent.
5328 The conversion follows the special rules described in
5329 [temp.arg.nontype], and it is much more strict than an implicit
5330 conversion.
5332 This function is called twice for each template argument (see
5333 lookup_template_class for a more accurate description of this
5334 problem). This means that we need to handle expressions which
5335 are not valid in a C++ source, but can be created from the
5336 first call (for instance, casts to perform conversions). These
5337 hacks can go away after we fix the double coercion problem. */
5339 static tree
5341 {
5342 tree expr_type;
5344 /* Detect immediately string literals as invalid non-type argument.
5345 This special-case is not needed for correctness (we would easily
5346 catch this later), but only to provide better diagnostic for this
5347 common user mistake. As suggested by DR 100, we do not mention
5348 linkage issues in the diagnostic as this is not the point. */
5349 /* FIXME we're making this OK. */
5351 {
5357 }
5359 /* Add the ADDR_EXPR now for the benefit of
5360 value_dependent_expression_p. */
5363 {
5367 }
5369 /* If we are in a template, EXPR may be non-dependent, but still
5370 have a syntactic, rather than semantic, form. For example, EXPR
5371 might be a SCOPE_REF, rather than the VAR_DECL to which the
5372 SCOPE_REF refers. Preserving the qualifying scope is necessary
5373 so that access checking can be performed when the template is
5374 instantiated -- but here we need the resolved form so that we can
5375 convert the argument. */
5386 else
5389 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5390 to a non-type argument of "nullptr". */
5394 /* In C++11, integral or enumeration non-type template arguments can be
5395 arbitrary constant expressions. Pointer and pointer to
5396 member arguments can be general constant expressions that evaluate
5397 to a null value, but otherwise still need to be of a specific form. */
5399 {
5401 /* A PTRMEM_CST is already constant, and a valid template
5402 argument for a parameter of pointer to member type, we just want
5403 to leave it in that form rather than lower it to a
5408 {
5413 }
5414 }
5416 /* HACK: Due to double coercion, we can get a
5417 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5418 which is the tree that we built on the first call (see
5419 below when coercing to reference to object or to reference to
5420 function). We just strip everything and get to the arg.
5421 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5422 for examples. */
5424 {
5430 {
5431 /* ??? Maybe we could use convert_from_reference here, but we
5432 would need to relax its constraints because the NOP_EXPR
5433 could actually change the type to something more cv-qualified,
5434 and this is not folded by convert_from_reference. */
5445 }
5446 }
5448 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5449 parameter is a pointer to object, through decay and
5450 qualification conversion. Let's strip everything. */
5452 {
5456 /* Skip the ADDR_EXPR only if it is part of the decay for
5457 an array. Otherwise, it is part of the original argument
5458 in the source code. */
5462 }
5464 /* [temp.arg.nontype]/5, bullet 1
5466 For a non-type template-parameter of integral or enumeration type,
5467 integral promotions (_conv.prom_) and integral conversions
5468 (_conv.integral_) are applied. */
5470 {
5479 /* Notice that there are constant expressions like '4 % 0' which
5480 do not fold into integer constants. */
5482 {
5484 {
5495 /* else cxx_constant_value complained but gave us
5496 a real constant, so go ahead. */
5498 }
5499 else
5501 }
5502 }
5503 /* [temp.arg.nontype]/5, bullet 2
5505 For a non-type template-parameter of type pointer to object,
5506 qualification conversions (_conv.qual_) and the array-to-pointer
5507 conversion (_conv.array_) are applied. */
5509 {
5510 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5512 A template-argument for a non-type, non-template template-parameter
5513 shall be one of: [...]
5515 -- the name of a non-type template-parameter;
5516 -- the address of an object or function with external linkage, [...]
5517 expressed as "& id-expression" where the & is optional if the name
5518 refers to a function or array, or if the corresponding
5519 template-parameter is a reference.
5521 Here, we do not care about functions, as they are invalid anyway
5522 for a parameter of type pointer-to-object. */
5525 /* Non-type template parameters are OK. */
5526 ;
5531 {
5533 {
5535 "because %qD is a variable, not the address of "
5539 }
5540 /* Other values, like integer constants, might be valid
5541 non-type arguments of some other type. */
5543 }
5544 else
5545 {
5546 tree decl;
5551 {
5556 }
5558 {
5563 }
5565 {
5570 }
5571 }
5580 }
5581 /* [temp.arg.nontype]/5, bullet 3
5583 For a non-type template-parameter of type reference to object, no
5584 conversions apply. The type referred to by the reference may be more
5585 cv-qualified than the (otherwise identical) type of the
5586 template-argument. The template-parameter is bound directly to the
5587 template-argument, which must be an lvalue. */
5589 {
5591 expr_type))
5595 {
5599 }
5602 {
5606 }
5608 /* [temp.arg.nontype]/1
5610 A template-argument for a non-type, non-template template-parameter
5611 shall be one of: [...]
5613 -- the address of an object or function with external linkage. */
5616 {
5619 {
5621 "because a reference variable does not have a constant "
5624 }
5625 }
5628 {
5633 }
5636 {
5641 }
5644 }
5645 /* [temp.arg.nontype]/5, bullet 4
5647 For a non-type template-parameter of type pointer to function, only
5648 the function-to-pointer conversion (_conv.func_) is applied. If the
5649 template-argument represents a set of overloaded functions (or a
5650 pointer to such), the matching function is selected from the set
5651 (_over.over_). */
5653 {
5654 /* If the argument is a template-id, we might not have enough
5655 context information to decay the pointer. */
5657 {
5661 }
5664 /* Null pointer values are OK in C++11. */
5672 {
5676 }
5677 }
5678 /* [temp.arg.nontype]/5, bullet 5
5680 For a non-type template-parameter of type reference to function, no
5681 conversions apply. If the template-argument represents a set of
5682 overloaded functions, the matching function is selected from the set
5683 (_over.over_). */
5685 {
5687 {
5692 }
5699 }
5700 /* [temp.arg.nontype]/5, bullet 6
5702 For a non-type template-parameter of type pointer to member function,
5703 no conversions apply. If the template-argument represents a set of
5704 overloaded member functions, the matching member function is selected
5705 from the set (_over.over_). */
5707 {
5712 /* [temp.arg.nontype] bullet 1 says the pointer to member
5713 expression must be a pointer-to-member constant. */
5717 /* There is no way to disable standard conversions in
5718 resolve_address_of_overloaded_function (called by
5719 instantiate_type). It is possible that the call succeeded by
5720 converting &B::I to &D::I (where B is a base of D), so we need
5721 to reject this conversion here.
5723 Actually, even if there was a way to disable standard conversions,
5724 it would still be better to reject them here so that we can
5725 provide a superior diagnostic. */
5727 {
5731 /* If we are just one standard conversion off, explain. */
5736 }
5737 }
5738 /* [temp.arg.nontype]/5, bullet 7
5740 For a non-type template-parameter of type pointer to data member,
5741 qualification conversions (_conv.qual_) are applied. */
5743 {
5744 /* [temp.arg.nontype] bullet 1 says the pointer to member
5745 expression must be a pointer-to-member constant. */
5752 }
5754 {
5756 {
5760 }
5762 }
5763 /* A template non-type parameter must be one of the above. */
5764 else
5767 /* Sanity check: did we actually convert the argument to the
5768 right type? */
5772 }
5774 /* Subroutine of coerce_template_template_parms, which returns 1 if
5775 PARM_PARM and ARG_PARM match using the rule for the template
5776 parameters of template template parameters. Both PARM and ARG are
5777 template parameters; the rest of the arguments are the same as for
5778 coerce_template_template_parms.
5779 */
5780 static int
5782 tree arg,
5783 tsubst_flags_t complain,
5784 tree in_decl,
5785 tree outer_args)
5786 {
5795 {
5797 /* We encounter instantiations of templates like
5798 template <template <template <class> class> class TT>
5799 class C; */
5800 {
5807 }
5808 /* Fall through. */
5813 /* Argument is a parameter pack but parameter is not. */
5818 /* The tsubst call is used to handle cases such as
5820 template <int> class C {};
5821 template <class T, template <T> class TT> class D {};
5822 D<int, C> d;
5824 i.e. the parameter list of TT depends on earlier parameters. */
5826 && !same_type_p
5833 /* Argument is a parameter pack but parameter is not. */
5840 }
5843 }
5846 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5847 template template parameters. Both PARM_PARMS and ARG_PARMS are
5848 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5849 or PARM_DECL.
5851 Consider the example:
5852 template <class T> class A;
5853 template<template <class U> class TT> class B;
5855 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5856 the parameters to A, and OUTER_ARGS contains A. */
5858 static int
5860 tree arg_parms,
5861 tsubst_flags_t complain,
5862 tree in_decl,
5863 tree outer_args)
5864 {
5875 /* Determine whether we have a parameter pack at the end of the
5876 template template parameter's template parameter list. */
5878 {
5885 {
5899 }
5900 }
5906 /* Check all of the template parameters except the parameter pack at
5907 the end (if any). */
5909 {
5918 outer_args))
5921 }
5924 {
5925 /* Check each of the template parameters in the template
5926 argument against the template parameter pack at the end of
5927 the template template parameter. */
5934 {
5941 outer_args))
5943 }
5944 }
5947 }
5949 /* Verifies that the deduced template arguments (in TARGS) for the
5950 template template parameters (in TPARMS) represent valid bindings,
5951 by comparing the template parameter list of each template argument
5952 to the template parameter list of its corresponding template
5953 template parameter, in accordance with DR150. This
5954 routine can only be called after all template arguments have been
5955 deduced. It will return TRUE if all of the template template
5956 parameter bindings are okay, FALSE otherwise. */
5957 bool
5959 {
5963 /* We're dealing with template parms in this process. */
5969 {
5974 {
5979 {
5980 /* Look inside the argument pack. */
5983 }
5986 {
5990 /* Extract the next argument from the argument
5991 pack. */
5995 /* Look at the pattern of the pack expansion. */
5998 /* Extract the template parameters from the template
5999 argument. */
6005 /* Verify that we can coerce the template template
6006 parameters from the template argument to the template
6007 parameter. This requires an exact match. */
6009 && !coerce_template_template_parms
6011 targ_parms,
6012 tf_none,
6013 tparm,
6014 targs))
6015 {
6018 }
6019 }
6020 }
6021 }
6023 out:
6027 }
6029 /* Since type attributes aren't mangled, we need to strip them from
6030 template type arguments. */
6032 static tree
6034 {
6035 tree mv;
6042 {
6047 }
6049 }
6051 /* Convert the indicated template ARG as necessary to match the
6052 indicated template PARM. Returns the converted ARG, or
6053 error_mark_node if the conversion was unsuccessful. Error and
6054 warning messages are issued under control of COMPLAIN. This
6055 conversion is for the Ith parameter in the parameter list. ARGS is
6056 the full set of template arguments deduced so far. */
6058 static tree
6060 tree arg,
6061 tree args,
6062 tsubst_flags_t complain,
6064 tree in_decl)
6065 {
6066 tree orig_arg;
6067 tree val;
6072 {
6073 /* The template argument was the name of some
6074 member function. That's usually
6075 invalid, but static members are OK. In any
6076 case, grab the underlying fields/functions
6077 and issue an error later if required. */
6080 }
6088 /* When determining whether an argument pack expansion is a template,
6089 look at the pattern. */
6093 /* Deal with an injected-class-name used as a template template arg. */
6095 {
6098 {
6108 }
6109 }
6111 is_tmpl_type =
6127 {
6129 {
6133 }
6136 "to refer to a type member of a template parameter, "
6141 typename_type,
6145 }
6147 {
6149 {
6151 {
6161 else
6163 }
6164 }
6166 }
6168 {
6170 {
6176 else
6178 }
6180 }
6183 {
6185 {
6189 /* The number of argument required is not known yet.
6190 Just accept it for now. */
6192 else
6193 {
6195 tree argparm;
6201 args))
6202 {
6205 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6206 TEMPLATE_DECL. */
6208 {
6213 }
6214 }
6215 else
6216 {
6218 {
6224 }
6227 }
6228 }
6229 }
6230 else
6232 /* We only form one instance of each template specialization.
6233 Therefore, if we use a non-canonical variant (i.e., a
6234 typedef), any future messages referring to the type will use
6235 the typedef, which is confusing if those future uses do not
6236 themselves also use the typedef. */
6239 }
6240 else
6241 {
6248 {
6251 else
6252 {
6253 /* Not sure if this is reachable, but it doesn't hurt
6254 to be robust. */
6257 }
6258 }
6260 /* We used to call digest_init here. However, digest_init
6261 will report errors, which we don't want when complain
6262 is zero. More importantly, digest_init will try too
6263 hard to convert things: for example, `0' should not be
6264 converted to pointer type at this point according to
6265 the standard. Accepting this is not merely an
6266 extension, since deciding whether or not these
6267 conversions can occur is part of determining which
6268 function template to call, or whether a given explicit
6269 argument specification is valid. */
6271 else
6280 {
6281 /* Strip typedefs from the SCOPE_REF. */
6284 complain);
6287 }
6288 }
6291 }
6293 /* Coerces the remaining template arguments in INNER_ARGS (from
6294 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6295 Returns the coerced argument pack. PARM_IDX is the position of this
6296 parameter in the template parameter list. ARGS is the original
6297 template argument list. */
6298 static tree
6301 tree args,
6302 tree inner_args,
6304 tree new_args,
6306 tree in_decl,
6307 tsubst_flags_t complain)
6308 {
6311 tree packed_args;
6312 tree argument_pack;
6322 {
6323 /* When the template parameter is a non-type template
6324 parameter pack whose type uses parameter packs, we need
6325 to look at each of the template arguments
6326 separately. Build a vector of the types for these
6327 non-type template parameters in PACKED_TYPES. */
6328 tree expansion
6336 /* Check that we have the right number of arguments. */
6340 {
6341 int needed_parms
6346 }
6348 /* If we aren't able to check the actual arguments now
6349 (because they haven't been expanded yet), we can at least
6350 verify that all of the types used for the non-type
6351 template parameter pack are, in fact, valid for non-type
6352 template parameters. */
6355 {
6358 {
6362 }
6363 }
6364 }
6366 /* Convert the remaining arguments, which will be a part of the
6367 parameter pack "parm". */
6369 {
6374 {
6375 /* When we have a vector of types (corresponding to the
6376 non-type template parameter pack that uses parameter
6377 packs in its type, as mention above), and the
6378 argument is not an expansion (which expands to a
6379 currently unknown number of arguments), clone the
6380 parm and give it the next type in PACKED_TYPES. */
6384 }
6387 {
6390 }
6391 else
6394 in_decl);
6398 }
6403 else
6404 {
6409 }
6412 #ifdef ENABLE_CHECKING
6415 #endif
6417 }
6419 /* Returns true if the template argument vector ARGS contains
6420 any pack expansions, false otherwise. */
6422 static bool
6424 {
6431 }
6433 /* Convert all template arguments to their appropriate types, and
6434 return a vector containing the innermost resulting template
6435 arguments. If any error occurs, return error_mark_node. Error and
6436 warning messages are issued under control of COMPLAIN.
6438 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6439 for arguments not specified in ARGS. Otherwise, if
6440 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6441 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6442 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6443 ARGS. */
6445 static tree
6447 tree args,
6448 tree in_decl,
6449 tsubst_flags_t complain,
6452 {
6454 tree inner_args;
6455 tree new_args;
6456 tree new_inner_args;
6460 /* When used as a boolean value, indicates whether this is a
6461 variadic template parameter list. Since it's an int, we can also
6462 subtract it from nparms to get the number of non-variadic
6463 parameters. */
6472 /* Determine if there are any parameter packs. */
6474 {
6480 }
6483 /* If there are no parameters that follow a parameter pack, we need to
6484 expand any argument packs so that we can deduce a parameter pack from
6485 some non-packed args followed by an argument pack, as in variadic85.C.
6486 If there are such parameters, we need to leave argument packs intact
6487 so the arguments are assigned properly. This can happen when dealing
6488 with a nested class inside a partial specialization of a class
6489 template, as in variadic92.C, or when deducing a template parameter pack
6490 from a sub-declarator, as in variadic114.C. */
6497 && require_all_args
6499 && (!use_default_args
6502 {
6504 {
6506 {
6510 }
6511 else
6517 }
6520 }
6522 /* We need to evaluate the template arguments, even though this
6523 template-id may be nested within a "sizeof". */
6531 {
6532 tree arg;
6533 tree parm;
6535 /* Get the Ith template parameter. */
6539 {
6542 }
6544 /* Calculate the next argument. */
6547 else
6552 {
6553 /* All remaining arguments will be placed in the
6554 template parameter pack PARM. */
6560 /* Store this argument. */
6562 lost++;
6565 /* We are done with all of the arguments. */
6569 }
6571 {
6573 {
6574 /* We don't know how many args we have yet, just
6575 use the unconverted ones for now. */
6578 }
6579 }
6581 {
6582 /* There must be a default arg in this case. */
6585 /* The position of the first default template argument,
6586 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6587 Record that. */
6590 }
6591 else
6595 {
6598 }
6600 /* This only occurs if there was an error in the template
6601 parameter list itself (which we would already have
6602 reported) that we are trying to recover from, e.g., a class
6603 template with a parameter list such as
6604 template<typename..., typename>. */
6606 else
6612 lost++;
6614 }
6621 #ifdef ENABLE_CHECKING
6625 #endif
6628 }
6630 /* Returns 1 if template args OT and NT are equivalent. */
6632 static int
6634 {
6641 /* For member templates */
6650 {
6667 }
6669 {
6670 /* We get here probably because we are in the middle of substituting
6671 into the pattern of a pack expansion. In that case the
6672 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6673 interested in. So we want to use the initial pack argument for
6674 the comparison. */
6679 }
6684 else
6686 }
6688 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
6689 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
6690 NEWARG_PTR with the offending arguments if they are non-NULL. */
6692 static int
6695 {
6708 {
6713 {
6719 }
6720 }
6722 }
6724 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6725 of template arguments. Returns 0 otherwise. */
6727 int
6729 {
6731 }
6733 static void
6735 {
6745 /* We are called both from instantiate_decl, where we've already had a
6746 tinst_level pushed, and instantiate_template, where we haven't.
6747 Compensate. */
6758 else
6767 }
6770 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6771 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6772 documentation for TEMPLATE_ID_EXPR. */
6774 tree
6776 {
6777 tree type;
6785 {
6788 }
6791 {
6793 unknown_type_node,
6795 arglist);
6797 }
6804 }
6806 /* Within the scope of a template class S<T>, the name S gets bound
6807 (in build_self_reference) to a TYPE_DECL for the class, not a
6808 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6809 or one of its enclosing classes, and that type is a template,
6810 return the associated TEMPLATE_DECL. Otherwise, the original
6811 DECL is returned.
6813 Also handle the case when DECL is a TREE_LIST of ambiguous
6814 injected-class-names from different bases. */
6816 tree
6818 {
6822 /* DR 176: A lookup that finds an injected-class-name (10.2
6823 [class.member.lookup]) can result in an ambiguity in certain cases
6824 (for example, if it is found in more than one base class). If all of
6825 the injected-class-names that are found refer to specializations of
6826 the same class template, and if the name is followed by a
6827 template-argument-list, the reference refers to the class template
6828 itself and not a specialization thereof, and is not ambiguous. */
6830 {
6833 {
6839 }
6842 else
6844 }
6850 }
6852 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6853 parameters, find the desired type.
6855 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6857 IN_DECL, if non-NULL, is the template declaration we are trying to
6858 instantiate.
6860 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6861 the class we are looking up.
6863 Issue error and warning messages under control of COMPLAIN.
6865 If the template class is really a local class in a template
6866 function, then the FUNCTION_CONTEXT is the function in which it is
6867 being instantiated.
6869 ??? Note that this function is currently called *twice* for each
6870 template-id: the first time from the parser, while creating the
6871 incomplete type (finish_template_type), and the second type during the
6872 real instantiation (instantiate_template_class). This is surely something
6873 that we want to avoid. It also causes some problems with argument
6874 coercion (see convert_nontype_argument for more information on this). */
6876 static tree
6879 {
6881 tree t;
6884 spec_entry elt;
6885 hashval_t hash;
6888 {
6892 else
6893 {
6900 }
6903 }
6905 {
6908 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6909 an implicit typename for the second A. Deal with it. */
6914 {
6917 }
6918 }
6921 {
6924 }
6928 {
6932 }
6934 /* Issue an error message if we didn't find a template. */
6936 {
6940 }
6943 /* Make sure it's a user visible template, if it was named by
6944 the user. */
6947 {
6949 {
6953 }
6955 }
6960 {
6961 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6962 template arguments */
6964 tree parm;
6965 tree arglist2;
6966 tree outer;
6970 /* Consider an example where a template template parameter declared as
6972 template <class T, class U = std::allocator<T> > class TT
6974 The template parameter level of T and U are one level larger than
6975 of TT. To proper process the default argument of U, say when an
6976 instantiation `TT<int>' is seen, we need to build the full
6977 arguments containing {int} as the innermost level. Outer levels,
6978 available when not appearing as default template argument, can be
6979 obtained from the arguments of the enclosing template.
6981 Suppose that TT is later substituted with std::vector. The above
6982 instantiation is `TT<int, std::allocator<T> >' with TT at
6983 level 1, and T at level 2, while the template arguments at level 1
6984 becomes {std::vector} and the inner level 2 is {int}. */
6990 /* This is an argument of the current template, so we haven't set
6991 DECL_CONTEXT yet. */
6998 complain,
7008 }
7009 else
7010 {
7012 tree gen_tmpl;
7013 tree type_decl;
7021 /* An error occured while building the template TEMPL, and a
7022 diagnostic has most certainly been emitted for that
7023 already. Let's propagate that error. */
7032 {
7033 /* We've been given an incomplete set of template arguments.
7034 For example, given:
7036 template <class T> struct S1 {
7037 template <class U> struct S2 {};
7038 template <class U> struct S2<U*> {};
7039 };
7041 we will be called with an ARGLIST of `U*', but the
7042 TEMPLATE will be `template <class T> template
7043 <class U> struct S1<T>::S2'. We must fill in the missing
7044 arguments. */
7045 arglist
7047 arglist);
7049 }
7051 /* Now we should have enough arguments. */
7054 /* From here on, we're only interested in the most general
7055 template. */
7057 /* Calculate the BOUND_ARGS. These will be the args that are
7058 actually tsubst'd into the definition to create the
7059 instantiation. */
7061 {
7062 /* We have multiple levels of arguments to coerce, at once. */
7072 {
7073 tree a;
7077 complain,
7080 else
7081 /* Outer levels should have already been coerced. */
7084 /* Don't process further if one of the levels fails. */
7086 {
7087 /* Restore the ARGLIST to its full size. */
7090 }
7094 /* We temporarily reduce the length of the ARGLIST so
7095 that coerce_template_parms will see only the arguments
7096 corresponding to the template parameters it is
7097 examining. */
7099 }
7101 /* Restore the ARGLIST to its full size. */
7105 }
7106 else
7107 arglist
7110 gen_tmpl,
7111 complain,
7116 /* We were unable to bind the arguments. */
7119 /* In the scope of a template class, explicit references to the
7120 template class refer to the type of the template, not any
7121 instantiation of it. For example, in:
7123 template <class T> class C { void f(C<T>); }
7125 the `C<T>' is just the same as `C'. Outside of the
7126 class, however, such a reference is an instantiation. */
7130 /* comp_template_args is expensive, check it last. */
7132 arglist))
7135 /* If we already have this specialization, return it. */
7147 /* If the deduced arguments are invalid, then the binding
7148 failed. */
7152 complain))
7159 {
7164 }
7174 /* Create the type. */
7176 {
7178 {
7184 }
7185 else
7186 {
7187 /* We don't want to call start_enum for this type, since
7188 the values for the enumeration constants may involve
7189 template parameters. And, no one should be interested
7190 in the enumeration constants for such a type. */
7193 }
7197 }
7199 {
7200 /* The user referred to a specialization of an alias
7201 template represented by GEN_TMPL.
7203 [temp.alias]/2 says:
7205 When a template-id refers to the specialization of an
7206 alias template, it is equivalent to the associated
7207 type obtained by substitution of its
7208 template-arguments for the template-parameters in the
7209 type-id of the alias template. */
7212 /* Note that the call above (by indirectly calling
7213 register_specialization in tsubst_decl) registers the
7214 TYPE_DECL representing the specialization of the alias
7215 template. So next time someone substitutes ARGLIST for
7216 the template parms into the alias template (GEN_TMPL),
7217 she'll get that TYPE_DECL back. */
7221 }
7223 {
7230 /* A local class. Make sure the decl gets registered properly. */
7235 /* This instantiation is another name for the primary
7236 template type. Set the TYPE_CANONICAL field
7237 appropriately. */
7240 /* Some of the template arguments require structural
7241 equality testing, so this template class requires
7242 structural equality testing. */
7244 }
7245 else
7248 /* If we called start_enum or pushtag above, this information
7249 will already be set up. */
7251 {
7258 }
7259 else
7263 {
7269 {
7272 }
7273 }
7275 /* Let's consider the explicit specialization of a member
7276 of a class template specialization that is implicitely instantiated,
7277 e.g.:
7278 template<class T>
7279 struct S
7280 {
7281 template<class U> struct M {}; //#0
7282 };
7284 template<>
7285 template<>
7286 struct S<int>::M<char> //#1
7287 {
7288 int i;
7289 };
7290 [temp.expl.spec]/4 says this is valid.
7292 In this case, when we write:
7293 S<int>::M<char> m;
7295 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7296 the one of #0.
7298 When we encounter #1, we want to store the partial instantiation
7299 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7301 For all cases other than this "explicit specialization of member of a
7302 class template", we just want to store the most general template into
7303 the CLASSTYPE_TI_TEMPLATE of M.
7305 This case of "explicit specialization of member of a class template"
7306 only happens when:
7307 1/ the enclosing class is an instantiation of, and therefore not
7308 the same as, the context of the most general template, and
7309 2/ we aren't looking at the partial instantiation itself, i.e.
7310 the innermost arguments are not the same as the innermost parms of
7311 the most general template.
7313 So it's only when 1/ and 2/ happens that we want to use the partial
7314 instantiation of the member template in lieu of its most general
7315 template. */
7319 /* the enclosing class must be an instantiation... */
7322 {
7323 tree partial_inst_args;
7326 partial_inst_args =
7332 use_partial_inst_tmpl =
7333 /*...and we must not be looking at the partial instantiation
7334 itself. */
7336 partial_inst_args);
7337 }
7340 /* This case is easy; there are no member templates involved. */
7342 else
7343 {
7344 /* This is a full instantiation of a member template. Find
7345 the partial instantiation of which this is an instance. */
7347 /* Temporarily reduce by one the number of levels in the ARGLIST
7348 so as to avoid comparing the last set of arguments. */
7352 /* FOUND is either a proper class type, or an alias
7353 template specialization. In the later case, it's a
7354 TYPE_DECL, resulting from the substituting of arguments
7355 for parameters in the TYPE_DECL of the alias template
7356 done earlier. So be careful while getting the template
7357 of FOUND. */
7361 }
7372 /* Note this use of the partial instantiation so we can check it
7373 later in maybe_process_partial_specialization. */
7379 /* Now that the type has been registered on the instantiations
7380 list, we set up the enumerators. Because the enumeration
7381 constants may involve the enumeration type itself, we make
7382 sure to register the type first, and then create the
7383 constants. That way, doing tsubst_expr for the enumeration
7384 constants won't result in recursive calls here; we'll find
7385 the instantiation and exit above. */
7389 /* If the type makes use of template parameters, the
7390 code that generates debugging information will crash. */
7393 /* Possibly limit visibility based on template args. */
7398 }
7399 }
7401 /* Wrapper for lookup_template_class_1. */
7403 tree
7406 {
7407 tree ret;
7413 }
7414 \f
7415 struct pair_fn_data
7416 {
7417 tree_fn_t fn;
7419 /* True when we should also visit template parameters that occur in
7420 non-deduced contexts. */
7423 };
7425 /* Called from for_each_template_parm via walk_tree. */
7427 static tree
7429 {
7442 {
7446 /* Fall through. */
7469 /* Since we're not going to walk subtrees, we have to do this
7470 explicitly here. */
7474 /* Fall through. */
7477 /* Check the return type. */
7482 /* Check the parameter types. Since default arguments are not
7483 instantiated until they are needed, the TYPE_ARG_TYPES may
7484 contain expressions that involve template parameters. But,
7485 no-one should be looking at them yet. And, once they're
7486 instantiated, they don't contain template parameters, so
7487 there's no point in looking at them then, either. */
7488 {
7489 tree parm;
7496 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7497 want walk_tree walking into them itself. */
7499 }
7517 /* Fall through. */
7533 /* Record template parameters such as `T' inside `TT<T>'. */
7537 /* Fall through. */
7549 /* A template template parameter is encountered. */
7555 /* Already substituted template template parameter */
7578 /* If there's no type, then this thing must be some expression
7579 involving template parameters. */
7601 }
7603 /* We didn't find any template parameters we liked. */
7605 }
7607 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7608 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7609 call FN with the parameter and the DATA.
7610 If FN returns nonzero, the iteration is terminated, and
7611 for_each_template_parm returns 1. Otherwise, the iteration
7612 continues. If FN never returns a nonzero value, the value
7613 returned by for_each_template_parm is 0. If FN is NULL, it is
7614 considered to be the function which always returns 1.
7616 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7617 parameters that occur in non-deduced contexts. When false, only
7618 visits those template parameters that can be deduced. */
7620 static int
7624 {
7628 /* Set up. */
7633 /* Walk the tree. (Conceptually, we would like to walk without
7634 duplicates, but for_each_template_parm_r recursively calls
7635 for_each_template_parm, so we would need to reorganize a fair
7636 bit to use walk_tree_without_duplicates, so we keep our own
7637 visited list.) */
7640 else
7643 for_each_template_parm_r,
7647 /* Clean up. */
7649 {
7652 }
7655 }
7657 /* Returns true if T depends on any template parameter. */
7659 int
7661 {
7688 else
7689 {
7692 }
7697 }
7699 /* Returns true iff current_function_decl is an incompletely instantiated
7700 template. Useful instead of processing_template_decl because the latter
7701 is set to 0 during fold_non_dependent_expr. */
7703 bool
7705 {
7714 }
7716 /* Returns true if T depends on any template parameter with level LEVEL. */
7718 int
7720 {
7723 }
7725 /* Returns TRUE iff INST is an instantiation we don't need to do in an
7726 ill-formed translation unit, i.e. a variable or function that isn't
7727 usable in a constant expression. */
7731 {
7735 }
7737 /* Returns TRUE iff we should refuse to instantiate DECL because it's
7738 neglectable and instantiated from within an erroneous instantiation. */
7740 static bool
7742 {
7753 }
7757 #ifdef GATHER_STATISTICS
7759 #endif
7762 /* We're starting to instantiate D; record the template instantiation context
7763 for diagnostics and to restore it later. */
7765 int
7767 {
7771 {
7777 else
7785 }
7787 /* If the current instantiation caused problems, don't let it instantiate
7788 anything else. Do allow deduction substitution and decls usable in
7789 constant expressions. */
7802 #ifdef GATHER_STATISTICS
7805 #endif
7808 }
7810 /* We're done instantiating this template; return to the instantiation
7811 context. */
7813 void
7815 {
7816 /* Restore the filename and line number stashed away when we started
7817 this instantiation. */
7821 }
7823 /* We're instantiating a deferred template; restore the template
7824 instantiation context in which the instantiation was requested, which
7825 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7827 static tree
7829 {
7841 }
7843 /* Returns the TINST_LEVEL which gives the original instantiation
7844 context. */
7848 {
7854 }
7856 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7857 vector of template arguments, as for tsubst.
7859 Returns an appropriate tsubst'd friend declaration. */
7861 static tree
7863 {
7864 tree new_friend;
7869 /* This was a friend declared with an explicit template
7870 argument list, e.g.:
7872 friend void f<>(T);
7874 to indicate that f was a template instantiation, not a new
7875 function declaration. Now, we have to figure out what
7876 instantiation of what template. */
7877 {
7879 tree new_args;
7880 tree tmpl;
7883 /* Friend functions are looked up in the containing namespace scope.
7884 We must enter that scope, to avoid finding member functions of the
7885 current class with same name. */
7900 tsk_none);
7902 }
7906 /* The NEW_FRIEND will look like an instantiation, to the
7907 compiler, but is not an instantiation from the point of view of
7908 the language. For example, we might have had:
7910 template <class T> struct S {
7911 template <class U> friend void f(T, U);
7912 };
7914 Then, in S<int>, template <class U> void f(int, U) is not an
7915 instantiation of anything. */
7921 {
7925 }
7927 /* The mangled name for the NEW_FRIEND is incorrect. The function
7928 is not a template instantiation and should not be mangled like
7929 one. Therefore, we forget the mangling here; we'll recompute it
7930 later if we need it. */
7932 {
7935 }
7938 {
7939 tree old_decl;
7940 tree new_friend_template_info;
7941 tree new_friend_result_template_info;
7942 tree ns;
7945 /* We must save some information from NEW_FRIEND before calling
7946 duplicate decls since that function will free NEW_FRIEND if
7947 possible. */
7949 new_friend_is_defn =
7954 {
7955 /* This declaration is a `primary' template. */
7958 new_friend_result_template_info
7960 }
7961 else
7964 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7968 /* Inside pushdecl_namespace_level, we will push into the
7969 current namespace. However, the friend function should go
7970 into the namespace of the template. */
7980 {
7981 /* This new friend declaration matched an existing
7982 declaration. For example, given:
7984 template <class T> void f(T);
7985 template <class U> class C {
7986 template <class T> friend void f(T) {}
7987 };
7989 the friend declaration actually provides the definition
7990 of `f', once C has been instantiated for some type. So,
7991 old_decl will be the out-of-class template declaration,
7992 while new_friend is the in-class definition.
7994 But, if `f' was called before this point, the
7995 instantiation of `f' will have DECL_TI_ARGS corresponding
7996 to `T' but not to `U', references to which might appear
7997 in the definition of `f'. Previously, the most general
7998 template for an instantiation of `f' was the out-of-class
7999 version; now it is the in-class version. Therefore, we
8000 run through all specialization of `f', adding to their
8001 DECL_TI_ARGS appropriately. In particular, they need a
8002 new set of outer arguments, corresponding to the
8003 arguments for this class instantiation.
8005 The same situation can arise with something like this:
8007 friend void f(int);
8008 template <class T> class C {
8009 friend void f(T) {}
8010 };
8012 when `C<int>' is instantiated. Now, `f(int)' is defined
8013 in the class. */
8016 /* On the other hand, if the in-class declaration does
8017 *not* provide a definition, then we don't want to alter
8018 existing definitions. We can just leave everything
8019 alone. */
8020 ;
8021 else
8022 {
8026 /* Overwrite whatever template info was there before, if
8027 any, with the new template information pertaining to
8028 the declaration. */
8032 {
8033 /* We should have called reregister_specialization in
8034 duplicate_decls. */
8039 /* Instantiate it if the global has already been used. */
8043 }
8044 else
8045 {
8046 tree t;
8048 /* Indicate that the old function template is a partial
8049 instantiation. */
8057 /* Reassign any specializations already in the hash table
8058 to the new more general template, and add the
8059 additional template args. */
8063 {
8065 spec_entry elt;
8077 register_specialization
8080 }
8082 }
8083 }
8085 /* The information from NEW_FRIEND has been merged into OLD_DECL
8086 by duplicate_decls. */
8088 }
8089 }
8090 else
8091 {
8095 /* In the code
8096 template <class T> class C {
8097 template <class U> friend void C1<U>::f (); // case 1
8098 friend void C2<T>::f (); // case 2
8099 };
8100 we only need to make sure CONTEXT is a complete type for
8101 case 2. To distinguish between the two cases, we note that
8102 CONTEXT of case 1 remains dependent type after tsubst while
8103 this isn't true for case 2. */
8113 {
8114 /* Check to see that the declaration is really present, and,
8115 possibly obtain an improved declaration. */
8121 }
8122 }
8125 }
8127 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8128 template arguments, as for tsubst.
8130 Returns an appropriate tsubst'd friend type or error_mark_node on
8131 failure. */
8133 static tree
8135 {
8136 tree friend_type;
8137 tree tmpl;
8138 tree context;
8143 {
8146 else
8148 }
8150 /* Look for a class template declaration. We look for hidden names
8151 because two friend declarations of the same template are the
8152 same. For example, in:
8154 struct A {
8155 template <typename> friend class F;
8156 };
8157 template <typename> struct B {
8158 template <typename> friend class F;
8159 };
8161 both F templates are the same. */
8165 /* But, if we don't find one, it might be because we're in a
8166 situation like this:
8168 template <class T>
8169 struct S {
8170 template <class U>
8171 friend struct S;
8172 };
8174 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8175 for `S<int>', not the TEMPLATE_DECL. */
8177 {
8180 }
8183 {
8184 /* The friend template has already been declared. Just
8185 check to see that the declarations match, and install any new
8186 default parameters. We must tsubst the default parameters,
8187 of course. We only need the innermost template parameters
8188 because that is all that redeclare_class_template will look
8189 at. */
8192 {
8193 tree parms;
8194 location_t saved_input_location;
8203 }
8206 }
8207 else
8208 {
8209 /* The friend template has not already been declared. In this
8210 case, the instantiation of the template class will cause the
8211 injection of this template into the global scope. */
8216 /* The new TMPL is not an instantiation of anything, so we
8217 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8218 the new type because that is supposed to be the corresponding
8219 template decl, i.e., TMPL. */
8226 /* Inject this template into the global scope. */
8228 }
8231 {
8234 else
8236 }
8239 }
8241 /* Returns zero if TYPE cannot be completed later due to circularity.
8242 Otherwise returns one. */
8244 static int
8246 {
8256 else
8258 }
8260 /* Apply any attributes which had to be deferred until instantiation
8261 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8262 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8264 static void
8267 {
8269 tree t;
8274 {
8278 }
8281 {
8285 }
8286 else
8290 {
8295 {
8298 {
8301 /* If the first attribute argument is an identifier, don't
8302 pass it through tsubst. Attributes like mode, format,
8303 cleanup and several target specific attributes expect it
8304 unmodified. */
8310 {
8311 tree chain
8313 in_decl,
8318 chain);
8319 }
8320 else
8326 }
8327 else
8329 }
8332 }
8333 }
8335 /* Perform (or defer) access check for typedefs that were referenced
8336 from within the template TMPL code.
8337 This is a subroutine of instantiate_decl and instantiate_class_template.
8338 TMPL is the template to consider and TARGS is the list of arguments of
8339 that template. */
8341 static void
8343 {
8344 location_t saved_location;
8357 {
8369 /* Make access check error messages point to the location
8370 of the use of the typedef. */
8374 }
8376 }
8378 static tree
8380 {
8382 tree typedecl;
8383 tree pbinfo;
8384 tree base_list;
8386 tree fn_context;
8395 /* Figure out which template is being instantiated. */
8399 /* Determine what specialization of the original template to
8400 instantiate. */
8403 {
8406 }
8408 {
8409 /* This TYPE is actually an instantiation of a partial
8410 specialization. We replace the innermost set of ARGS with
8411 the arguments appropriate for substitution. For example,
8412 given:
8414 template <class T> struct S {};
8415 template <class T> struct S<T*> {};
8417 and supposing that we are instantiating S<int*>, ARGS will
8418 presently be {int*} -- but we need {int}. */
8421 }
8422 else
8423 {
8426 }
8428 /* If the template we're instantiating is incomplete, then clearly
8429 there's nothing we can do. */
8433 /* If we've recursively instantiated too many templates, stop. */
8437 /* Now we're really doing the instantiation. Mark the type as in
8438 the process of being defined. */
8441 /* We may be in the middle of deferred access check. Disable
8442 it now. */
8448 /* Use #pragma pack from the template context. */
8454 /* Set the input location to the most specialized template definition.
8455 This is needed if tsubsting causes an error. */
8467 {
8470 /* Adjust visibility for template arguments. */
8472 }
8477 /* We should never instantiate a nested class before its enclosing
8478 class; we need to look up the nested class by name before we can
8479 instantiate it, and that lookup should instantiate the enclosing
8480 class. */
8486 {
8487 tree pbase_binfo;
8488 tree pushed_scope;
8491 /* We must enter the scope containing the type, as that is where
8492 the accessibility of types named in dependent bases are
8493 looked up from. */
8496 /* Substitute into each of the bases to determine the actual
8497 basetypes. */
8499 {
8500 tree base;
8506 {
8507 expanded_bases =
8514 }
8517 {
8519 /* Extract the already-expanded base class. */
8521 else
8522 /* Substitute to figure out the base class. */
8524 NULL_TREE);
8532 }
8533 }
8535 /* The list is now in reverse order; correct that. */
8540 }
8541 /* Now call xref_basetypes to set up all the base-class
8542 information. */
8550 /* Now that our base classes are set up, enter the scope of the
8551 class, so that name lookups into base classes, etc. will work
8552 correctly. This is precisely analogous to what we do in
8553 begin_class_definition when defining an ordinary non-template
8554 class, except we also need to push the enclosing classes. */
8557 /* Now members are processed in the order of declaration. */
8560 {
8564 {
8566 {
8567 /* Build new CLASSTYPE_NESTED_UTDS. */
8569 tree newtag;
8575 /* If the member is a class template, then -- even after
8576 substitution -- there may be dependent types in the
8577 template argument list for the class. We increment
8578 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8579 that function will assume that no types are dependent
8580 when outside of a template. */
8590 {
8594 /* Unfortunately, lookup_template_class sets
8595 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8596 instantiation (i.e., for the type of a member
8597 template class nested within a template class.)
8598 This behavior is required for
8599 maybe_process_partial_specialization to work
8600 correctly, but is not accurate in this case;
8601 the TAG is not an instantiation of anything.
8602 (The corresponding TEMPLATE_DECL is an
8603 instantiation, but the TYPE is not.) */
8606 /* Now, we call pushtag to put this NEWTAG into the scope of
8607 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8608 pushtag calling push_template_decl. We don't have to do
8609 this for enums because it will already have been done in
8610 tsubst_enum. */
8614 }
8615 }
8618 {
8619 /* Build new TYPE_METHODS. */
8620 tree r;
8629 /* Instantiate members marked with attribute used. */
8632 }
8633 else
8634 {
8635 /* Build new TYPE_FIELDS. */
8637 {
8638 tree condition;
8641 condition =
8651 }
8653 {
8654 tree r;
8656 /* The file and line for this declaration, to
8657 assist in error message reporting. Since we
8658 called push_tinst_level above, we don't need to
8659 restore these. */
8668 {
8669 /* In [temp.inst]:
8671 [t]he initialization (and any associated
8672 side-effects) of a static data member does
8673 not occur unless the static data member is
8674 itself used in a way that requires the
8675 definition of the static data member to
8676 exist.
8678 Therefore, we do not substitute into the
8679 initialized for the static data member here. */
8680 finish_static_data_member_decl
8686 /* Instantiate members marked with attribute used. */
8689 }
8691 {
8692 /* Determine whether R has a valid type and can be
8693 completed later. If R is invalid, then it is
8694 replaced by error_mark_node so that it will not be
8695 added to TYPE_FIELDS. */
8701 {
8704 }
8705 }
8707 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8708 such a thing will already have been added to the field
8709 list by tsubst_enum in finish_member_declaration in the
8710 CLASSTYPE_NESTED_UTDS case above. */
8714 {
8717 }
8718 }
8719 }
8720 }
8721 else
8722 {
8724 {
8725 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8731 {
8732 /* template <class T> friend class C; */
8735 }
8737 {
8738 /* template <class T> friend class C::D; */
8744 }
8747 {
8748 /* This could be either
8750 friend class T::C;
8752 when dependent_type_p is false or
8754 template <class U> friend class T::C;
8756 otherwise. */
8759 /* Bump processing_template_decl for correct
8760 dependent_type_p calculation. */
8765 }
8768 {
8769 /* friend class C;
8771 where C hasn't been declared yet. Let's lookup name
8772 from namespace scope directly, bypassing any name that
8773 come from dependent base class. */
8776 /* The call to xref_tag_from_type does injection for friend
8777 classes. */
8779 friend_type =
8783 }
8785 /* friend class C<T>; */
8788 /* Otherwise it's
8790 friend class C;
8792 where C is already declared or
8794 friend class C<int>;
8796 We don't have to do anything in these cases. */
8799 /* Trick make_friend_class into realizing that the friend
8800 we're adding is a template, not an ordinary class. It's
8801 important that we use make_friend_class since it will
8802 perform some error-checking and output cross-reference
8803 information. */
8811 }
8812 else
8813 {
8814 /* Build new DECL_FRIENDLIST. */
8815 tree r;
8817 /* The file and line for this declaration, to
8818 assist in error message reporting. Since we
8819 called push_tinst_level above, we don't need to
8820 restore these. */
8824 {
8827 }
8832 {
8835 }
8836 }
8837 }
8838 }
8841 {
8844 {
8853 }
8854 else
8856 }
8858 /* Set the file and line number information to whatever is given for
8859 the class itself. This puts error messages involving generated
8860 implicit functions at a predictable point, and the same point
8861 that would be used for non-template classes. */
8868 /* We don't instantiate default arguments for member functions. 14.7.1:
8870 The implicit instantiation of a class template specialization causes
8871 the implicit instantiation of the declarations, but not of the
8872 definitions or default arguments, of the class member functions,
8873 member classes, static data members and member templates.... */
8875 /* Some typedefs referenced from within the template code need to be access
8876 checked at template instantiation time, i.e now. These types were
8877 added to the template at parsing time. Let's get those and perform
8878 the access checks then. */
8888 /* The vtable for a template class can be emitted in any translation
8889 unit in which the class is instantiated. When there is no key
8890 method, however, finish_struct_1 will already have added TYPE to
8891 the keyed_classes list. */
8896 }
8898 /* Wrapper for instantiate_class_template_1. */
8900 tree
8902 {
8903 tree ret;
8908 }
8910 static tree
8912 {
8913 tree r;
8919 else
8920 {
8927 /* Preserve the raw-reference nature of T. */
8931 }
8933 }
8935 /* Given a function parameter pack TMPL_PARM and some function parameters
8936 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
8937 and set *SPEC_P to point at the next point in the list. */
8939 static tree
8941 {
8942 /* Collect all of the extra "packed" parameters into an
8943 argument pack. */
8944 tree parmvec;
8945 tree parmtypevec;
8956 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
8961 {
8964 }
8966 /* Build the argument packs. */
8973 }
8975 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
8976 NONTYPE_ARGUMENT_PACK. */
8978 static tree
8980 {
8982 }
8984 /* Substitute ARGS into T, which is an pack expansion
8985 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
8986 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
8987 (if only a partial substitution could be performed) or
8988 ERROR_MARK_NODE if there was an error. */
8989 tree
8991 tree in_decl)
8992 {
8993 tree pattern;
8999 tree result;
9007 /* Add in any args remembered from an earlier partial instantiation. */
9012 /* Determine the argument packs that will instantiate the parameter
9013 packs used in the expansion expression. While we're at it,
9014 compute the number of arguments to be expanded and make sure it
9015 is consistent. */
9018 {
9025 {
9029 else
9032 }
9034 {
9037 else
9038 {
9039 /* We can't rely on local_specializations for a parameter
9040 name used later in a function declaration (such as in a
9041 late-specified return type). Even if it exists, it might
9042 have the wrong value for a recursive call. Just make a
9043 dummy decl, since it's only used for its type. */
9046 /* Partial instantiation of the parm_pack, we can't build
9047 up an argument pack yet. */
9049 else
9052 }
9053 }
9054 else
9055 {
9061 }
9068 /* This can only happen if we forget to expand an argument
9069 pack somewhere else. Just return an error, silently. */
9070 {
9074 }
9077 /* The argument pack that the parameter maps to is just an
9078 expansion of the parameter itself, such as one would find
9079 in the implicit typedef of a class inside the class itself.
9080 Consider this parameter "unsubstituted", so that we will
9081 maintain the outer pack expansion. */
9085 {
9089 /* Don't bother trying to do a partial substitution with
9090 incomplete packs; we'll try again after deduction. */
9097 {
9103 pattern);
9104 else
9107 pattern);
9109 }
9115 else
9118 /* Keep track of the parameter packs and their corresponding
9119 argument packs. */
9122 }
9123 else
9124 {
9125 /* We can't substitute for this parameter pack. We use a flag as
9126 well as the missing_level counter because function parameter
9127 packs don't have a level. */
9131 }
9132 }
9134 /* We cannot expand this expansion expression, because we don't have
9135 all of the argument packs we need. */
9137 {
9139 {
9140 /* We got some full packs, but we can't substitute them in until we
9141 have values for all the packs. So remember these until then. */
9142 tree save_args;
9146 /* The call to add_to_template_args above assumes no overlap
9147 between saved args and new args, so prune away any fake
9148 args, i.e. those that satisfied arg_from_parm_pack_p above. */
9150 {
9156 }
9157 else
9161 }
9162 else
9163 {
9164 /* There were no real arguments, we're just replacing a parameter
9165 pack with another version of itself. Substitute into the
9166 pattern and return a PACK_EXPANSION_*. The caller will need to
9167 deal with that. */
9171 else
9174 }
9176 }
9178 /* We could not find any argument packs that work. */
9183 {
9184 /* We're in a late-specified return type, so create our own local
9185 specializations map; the current map is either NULL or (in the
9186 case of recursive unification) might have bindings that we don't
9187 want to use or alter. */
9190 }
9192 /* For each argument in each argument pack, substitute into the
9193 pattern. */
9196 {
9197 /* For parameter pack, change the substitution of the parameter
9198 pack to the ith argument in its argument pack, then expand
9199 the pattern. */
9201 {
9203 tree arg;
9205 /* Select the Ith argument from the pack. */
9207 {
9209 {
9214 }
9215 else
9217 }
9218 else
9219 {
9224 {
9227 /* Update the corresponding argument. */
9229 }
9230 else
9231 /* Re-use the ARGUMENT_PACK_SELECT. */
9233 }
9235 }
9237 /* Substitute into the PATTERN with the altered arguments. */
9242 else
9246 {
9249 }
9250 }
9252 /* Update ARGS to restore the substitution from parameter packs to
9253 their argument packs. */
9255 {
9260 else
9261 {
9265 /* Update the corresponding argument. */
9269 else
9271 }
9272 }
9275 {
9278 }
9281 }
9283 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9284 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9285 parameter packs; all parms generated from a function parameter pack will
9286 have the same DECL_PARM_INDEX. */
9288 tree
9290 {
9292 tree patparm;
9295 {
9301 }
9302 else
9303 {
9308 }
9311 }
9313 /* Substitute ARGS into the vector or list of template arguments T. */
9315 static tree
9317 {
9329 {
9331 tree new_arg;
9336 {
9337 /* Substitute into an expansion expression. */
9341 /* Add to the expanded length adjustment the number of
9342 expanded arguments. We subtract one from this
9343 measurement, because the argument pack expression
9344 itself is already counted as 1 in
9345 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9346 the argument pack is empty. */
9348 }
9350 {
9351 /* Substitute into each of the arguments. */
9357 new_arg,
9371 }
9372 }
9373 else
9382 }
9387 /* Make space for the expanded arguments coming from template
9388 argument packs. */
9390 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9391 arguments for a member template.
9392 In that case each TREE_VEC in ORIG_T represents a level of template
9393 arguments, and ORIG_T won't carry any non defaulted argument count.
9394 It will rather be the nested TREE_VECs that will carry one.
9395 In other words, ORIG_T carries a non defaulted argument count only
9396 if it doesn't contain any nested TREE_VEC. */
9398 {
9402 }
9404 {
9408 {
9411 /* Now expand the template argument pack "in place". */
9414 }
9415 else
9416 {
9418 out++;
9419 }
9420 }
9423 }
9425 /* Return the result of substituting ARGS into the template parameters
9426 given by PARMS. If there are m levels of ARGS and m + n levels of
9427 PARMS, then the result will contain n levels of PARMS. For
9428 example, if PARMS is `template <class T> template <class U>
9429 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9430 result will be `template <int*, double, class V>'. */
9432 static tree
9434 {
9438 /* When substituting into a template, we must set
9439 PROCESSING_TEMPLATE_DECL as the template parameters may be
9440 dependent if they are based on one-another, and the dependency
9441 predicates are short-circuit outside of templates. */
9448 {
9449 tree new_vec =
9454 {
9455 tree tuple;
9467 }
9473 }
9478 }
9480 /* Return the result of substituting ARGS into one template parameter
9481 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9482 parameter and which TREE_PURPOSE is the default argument of the
9483 template parameter. */
9485 static tree
9487 {
9508 }
9510 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9511 type T. If T is not an aggregate or enumeration type, it is
9512 handled as if by tsubst. IN_DECL is as for tsubst. If
9513 ENTERING_SCOPE is nonzero, T is the context for a template which
9514 we are presently tsubst'ing. Return the substituted value. */
9516 static tree
9518 tree args,
9519 tsubst_flags_t complain,
9520 tree in_decl,
9522 {
9527 {
9532 /* Else fall through. */
9536 {
9537 tree argvec;
9538 tree context;
9539 tree r;
9543 /* In "sizeof(X<I>)" we need to evaluate "I". */
9549 /* First, determine the context for the type we are looking
9550 up. */
9553 {
9556 /* If context is a nested class inside a class template,
9557 it may still need to be instantiated (c++/33959). */
9559 }
9561 /* Then, figure out what arguments are appropriate for the
9562 type we are trying to find. For example, given:
9564 template <class T> struct S;
9565 template <class T, class U> void f(T, U) { S<U> su; }
9567 and supposing that we are instantiating f<int, double>,
9568 then our ARGS will be {int, double}, but, when looking up
9569 S we only want {double}. */
9574 else
9575 {
9579 }
9585 }
9586 else
9587 /* This is not a template type, so there's nothing to do. */
9592 }
9593 }
9595 /* Substitute into the default argument ARG (a default argument for
9596 FN), which has the indicated TYPE. */
9598 tree
9600 {
9604 /* This can happen in invalid code. */
9608 /* This default argument came from a template. Instantiate the
9609 default argument here, not in tsubst. In the case of
9610 something like:
9612 template <class T>
9613 struct S {
9614 static T t();
9615 void f(T = t());
9616 };
9618 we must be careful to do name lookup in the scope of S<T>,
9619 rather than in the current class. */
9621 /* The "this" pointer is not valid in a default argument. */
9623 {
9628 }
9631 /* The default argument expression may cause implicitly defined
9632 member functions to be synthesized, which will result in garbage
9633 collection. We must treat this situation as if we were within
9634 the body of function so as to avoid collecting live data on the
9635 stack. */
9643 /* Restore the "this" pointer. */
9645 {
9648 }
9650 /* Make sure the default argument is reasonable. */
9656 }
9658 /* Substitute into all the default arguments for FN. */
9660 static void
9662 {
9663 tree arg;
9664 tree tmpl_args;
9668 /* If this function is not yet instantiated, we certainly don't need
9669 its default arguments. */
9672 /* Don't do this again for clones. */
9677 arg;
9683 }
9685 /* Substitute the ARGS into the T, which is a _DECL. Return the
9686 result of the substitution. Issue error and warning messages under
9687 control of COMPLAIN. */
9689 static tree
9691 {
9692 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
9693 location_t saved_loc;
9698 /* Set the filename and linenumber to improve error-reporting. */
9703 {
9705 {
9706 /* We can get here when processing a member function template,
9707 member class template, or template template parameter. */
9709 tree spec;
9710 tree tmpl_args;
9711 tree full_args;
9714 {
9715 /* Template template parameter is treated here. */
9728 complain);
9731 }
9733 /* We might already have an instance of this template.
9734 The ARGS are for the surrounding class type, so the
9735 full args contain the tsubst'd args for the context,
9736 plus the innermost args from the template decl. */
9740 /* Because this is a template, the arguments will still be
9741 dependent, even after substitution. If
9742 PROCESSING_TEMPLATE_DECL is not set, the dependency
9743 predicates will short-circuit. */
9751 /* If this is a default template template argument,
9752 tsubst might not have changed anything. */
9759 {
9762 }
9764 /* Make a new template decl. It will be similar to the
9765 original, but will record the current template arguments.
9766 We also create a new function declaration, which is just
9767 like the old one, but points to this new template, rather
9768 than the old one. */
9777 {
9778 tree new_type;
9790 }
9791 else
9792 {
9793 tree new_decl;
9805 }
9811 /* The template parameters for this new template are all the
9812 template parameters for the old template, except the
9813 outermost level of parameters. */
9816 complain);
9822 /* Record this non-type partial instantiation. */
9826 }
9830 {
9831 tree ctx;
9834 tree gen_tmpl;
9835 tree type;
9840 /* Nobody should be tsubst'ing into non-template functions. */
9844 {
9845 tree spec;
9848 /* If T is not dependent, just return it. We have to
9849 increment PROCESSING_TEMPLATE_DECL because
9850 value_dependent_expression_p assumes that nothing is
9851 dependent when PROCESSING_TEMPLATE_DECL is zero. */
9858 /* Calculate the most general template of which R is a
9859 specialization, and the complete set of arguments used to
9860 specialize R. */
9863 (DECL_TEMPLATE_RESULT
9869 /* Check to see if we already have this specialization. */
9874 {
9877 }
9879 /* We can see more levels of arguments than parameters if
9880 there was a specialization of a member template, like
9881 this:
9883 template <class T> struct S { template <class U> void f(); }
9884 template <> template <class U> void S<int>::f(U);
9886 Here, we'll be substituting into the specialization,
9887 because that's where we can find the code we actually
9888 want to generate, but we'll have enough arguments for
9889 the most general template.
9891 We also deal with the peculiar case:
9893 template <class T> struct S {
9894 template <class U> friend void f();
9895 };
9896 template <class U> void f() {}
9897 template S<int>;
9898 template void f<double>();
9900 Here, the ARGS for the instantiation of will be {int,
9901 double}. But, we only need as many ARGS as there are
9902 levels of template parameters in CODE_PATTERN. We are
9903 careful not to get fooled into reducing the ARGS in
9904 situations like:
9906 template <class T> struct S { template <class U> void f(U); }
9907 template <class T> template <> void S<T>::f(int) {}
9909 which we can spot because the pattern will be a
9910 specialization in this case. */
9912 parms_depth =
9917 }
9918 else
9919 {
9920 /* This special case arises when we have something like this:
9922 template <class T> struct S {
9923 friend void f<int>(int, double);
9924 };
9926 Here, the DECL_TI_TEMPLATE for the friend declaration
9927 will be an IDENTIFIER_NODE. We are being called from
9928 tsubst_friend_function, and we want only to create a
9929 new decl (R) with appropriate types so that we can call
9930 determine_specialization. */
9932 }
9935 {
9938 else
9942 }
9943 else
9944 {
9947 }
9952 /* We do NOT check for matching decls pushed separately at this
9953 point, as they may not represent instantiations of this
9954 template, and in any case are considered separate under the
9955 discrete model. */
9959 /* Clear out the mangled name and RTL for the instantiation. */
9962 /* Leave DECL_INITIAL set on deleted instantiations. */
9968 /* Type-conversion operator. Reconstruct the name, in
9969 case it's the name of one of the template's parameters. */
9979 /* If this is an instantiation of a function with internal
9980 linkage, we already know what object file linkage will be
9981 assigned to the instantiation. */
9990 /* We'll re-clone as appropriate in instantiate_template. */
9993 /* If we aren't complaining now, return on error before we register
9994 the specialization so that we'll complain eventually. */
10000 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10001 this in the special friend case mentioned above where
10002 GEN_TMPL is NULL. */
10004 {
10010 /* We're not supposed to instantiate default arguments
10011 until they are called, for a template. But, for a
10012 declaration like:
10014 template <class T> void f ()
10015 { extern void g(int i = T()); }
10017 we should do the substitution when the template is
10018 instantiated. We handle the member function case in
10019 instantiate_class_template since the default arguments
10020 might refer to other members of the class. */
10025 }
10026 else
10029 /* Copy the list of befriending classes. */
10033 {
10037 in_decl);
10038 }
10041 {
10045 /* If this is an instantiation of a member template, clone it.
10046 If it isn't, that'll be handled by
10047 clone_constructors_and_destructors. */
10050 }
10061 /* Possibly limit visibility based on template args. */
10064 {
10068 }
10076 }
10080 {
10088 {
10089 /* If there is a local specialization that isn't a
10090 parameter pack, it means that we're doing a "simple"
10091 substitution from inside tsubst_pack_expansion. Just
10092 return the local specialization (which will be a single
10093 parm). */
10100 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10101 the parameters in this function parameter pack. */
10105 {
10108 /* Zero-length parameter packs are boring. Just substitute
10109 into the chain. */
10113 }
10114 else
10115 {
10116 /* All we did was update the type. Make a note of that. */
10119 }
10120 }
10122 /* Loop through all of the parameter's we'll build. When T is
10123 a function parameter pack, LEN is the number of expanded
10124 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10127 {
10134 /* We're on the Ith parameter of the function parameter
10135 pack. */
10136 {
10137 /* An argument of a function parameter pack is not a parameter
10138 pack. */
10141 /* Get the Ith type. */
10145 /* Rename the parameter to include the index. */
10148 }
10150 /* We're dealing with a normal parameter. */
10158 {
10161 else
10164 }
10174 /* Keep track of the first new parameter we
10175 generate. That's what will be returned to the
10176 caller. */
10180 /* Build a proper chain of parameters when substituting
10181 into a function parameter pack. */
10184 }
10186 /* If cp_unevaluated_operand is set, we're just looking for a
10187 single dummy parameter, so don't keep going. */
10192 /* FIRST_R contains the start of the chain we've built. */
10194 }
10198 {
10199 tree type;
10209 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10210 non-bit-fields DECL_INITIAL is a non-static data member
10211 initializer, which gets deferred instantiation. */
10217 {
10218 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10219 NSDMI in perform_member_init. Still set DECL_INITIAL
10220 so that we know there is one. */
10225 }
10226 /* We don't have to set DECL_CONTEXT here; it is set by
10227 finish_member_declaration. */
10234 }
10238 /* We reach here only for member using decls. */
10240 {
10241 r = do_class_using_decl
10246 else
10247 {
10250 }
10251 }
10252 else
10253 {
10256 }
10261 {
10264 tree spec;
10266 tree ctx;
10272 {
10273 /* If this is the canonical decl, we don't have to
10274 mess with instantiations, and often we can't (for
10275 typename, template type parms and such). Note that
10276 TYPE_NAME is not correct for the above test if
10277 we've copied the type for a typedef. */
10283 }
10285 /* Check to see if we already have the specialization we
10286 need. */
10289 {
10290 /* T is a static data member or namespace-scope entity.
10291 We have to substitute into namespace-scope variables
10292 (even though such entities are never templates) because
10293 of cases like:
10295 template <class T> void f() { extern T t; }
10297 where the entity referenced is not known until
10298 instantiation time. */
10302 {
10304 complain,
10306 /* If CTX is unchanged, then T is in fact the
10307 specialization we want. That situation occurs when
10308 referencing a static data member within in its own
10309 class. We can use pointer equality, rather than
10310 same_type_p, because DECL_CONTEXT is always
10311 canonical... */
10314 /* ... unless T is a member template; in which
10315 case our caller can be willing to create a
10316 specialization of that template represented
10317 by T. */
10321 }
10324 {
10332 }
10333 }
10334 else
10335 {
10336 /* A local variable. */
10338 /* Subsequent calls to pushdecl will fill this in. */
10341 }
10342 /* If we already have the specialization we need, there is
10343 nothing more to do. */
10345 {
10348 }
10350 /* Create a new node for the specialization we need. */
10353 {
10356 else
10363 }
10365 {
10366 /* Even if the original location is out of scope, the
10367 newly substituted one is not. */
10374 {
10375 /* It may seem that this case cannot occur, since:
10377 typedef void f();
10378 void g() { f x; }
10380 declares a function, not a variable. However:
10382 typedef void f();
10383 template <typename T> void g() { T t; }
10384 template void g<f>();
10386 is an attempt to declare a variable with function
10387 type. */
10389 /* R is not yet sufficiently initialized, so we
10390 just use its name. */
10393 }
10395 /* Wait until cp_finish_decl to set this again, to handle
10396 circular dependency (template/instantiate6.C). */
10401 {
10406 {
10409 }
10411 }
10412 }
10418 /* Clear out the mangled name and RTL for the instantiation. */
10422 /* The initializer must not be expanded until it is required;
10423 see [temp.inst]. */
10429 {
10430 /* Possibly limit visibility based on template args. */
10433 {
10437 }
10439 }
10442 {
10443 /* A static data member declaration is always marked
10444 external when it is declared in-class, even if an
10445 initializer is present. We mimic the non-template
10446 processing here. */
10452 }
10454 {
10455 /* We're substituting this var in a decltype outside of its
10456 scope, such as for a lambda return type. Don't add it to
10457 local_specializations, do perform auto deduction. */
10460 {
10461 tree init
10467 }
10468 }
10469 else
10478 /* Preserve a typedef that names a type. */
10480 {
10483 }
10486 }
10491 }
10492 #undef RETURN
10494 out:
10495 /* Restore the file and line information. */
10499 }
10501 /* Substitute into the ARG_TYPES of a function type.
10502 If END is a TREE_CHAIN, leave it and any following types
10503 un-substituted. */
10505 static tree
10507 tree args,
10508 tree end,
10509 tsubst_flags_t complain,
10510 tree in_decl)
10511 {
10512 tree remaining_arg_types;
10516 tree default_arg;
10527 {
10528 /* For a pack expansion, perform substitution on the
10529 entire expression. Later on, we'll handle the arguments
10530 one-by-one. */
10535 /* So that we'll spin through the parameters, one by one. */
10537 else
10538 {
10539 /* We only partially substituted into the parameter
10540 pack. Our type is TYPE_PACK_EXPANSION. */
10543 }
10544 }
10557 {
10559 {
10563 }
10565 }
10567 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10568 top-level qualifiers as required. */
10571 /* We do not substitute into default arguments here. The standard
10572 mandates that they be instantiated only when needed, which is
10573 done in build_over_call. */
10577 {
10578 /* We've instantiated a template before its default arguments
10579 have been parsed. This can happen for a nested template
10580 class, and is not an error unless we require the default
10581 argument in a call of this function. */
10582 remaining_arg_types =
10585 remaining_arg_types);
10586 }
10587 else
10588 remaining_arg_types =
10590 }
10593 }
10595 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10596 *not* handle the exception-specification for FNTYPE, because the
10597 initial substitution of explicitly provided template parameters
10598 during argument deduction forbids substitution into the
10599 exception-specification:
10601 [temp.deduct]
10603 All references in the function type of the function template to the
10604 corresponding template parameters are replaced by the specified tem-
10605 plate argument values. If a substitution in a template parameter or
10606 in the function type of the function template results in an invalid
10607 type, type deduction fails. [Note: The equivalent substitution in
10608 exception specifications is done only when the function is instanti-
10609 ated, at which point a program is ill-formed if the substitution
10610 results in an invalid type.] */
10612 static tree
10614 tree args,
10615 tsubst_flags_t complain,
10616 tree in_decl)
10617 {
10618 tree return_type;
10619 tree arg_types;
10620 tree fntype;
10622 /* The TYPE_CONTEXT is not used for function/method types. */
10625 /* Substitute the return type. */
10629 /* The standard does not presently indicate that creation of a
10630 function type with an invalid return type is a deduction failure.
10631 However, that is clearly analogous to creating an array of "void"
10632 or a reference to a reference. This is core issue #486. */
10635 {
10637 {
10640 else
10642 }
10644 }
10646 /* Substitute the argument types. */
10652 /* Construct a new type node and return it. */
10654 {
10657 }
10658 else
10659 {
10662 {
10663 /* [temp.deduct]
10665 Type deduction may fail for any of the following
10666 reasons:
10668 -- Attempting to create "pointer to member of T" when T
10669 is not a class type. */
10672 r);
10674 }
10678 }
10682 }
10684 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
10685 ARGS into that specification, and return the substituted
10686 specification. If there is no specification, return NULL_TREE. */
10688 static tree
10690 tree args,
10691 tsubst_flags_t complain,
10692 tree in_decl,
10694 {
10695 tree specs;
10696 tree new_specs;
10701 {
10702 /* A noexcept-specifier. */
10707 {
10708 /* Defer instantiation of noexcept-specifiers to avoid
10709 excessive instantiations (c++/49107). */
10712 {
10713 /* We already partially instantiated this member template,
10714 so combine the new args with the old. */
10719 }
10720 else
10721 {
10724 }
10725 }
10726 else
10727 new_specs = tsubst_copy_and_build
10731 }
10733 {
10736 else
10738 {
10739 tree spec;
10744 {
10745 /* Expand the pack expansion type. */
10748 in_decl);
10754 else
10755 {
10756 /* We're substituting into a member template, so
10757 we got a TYPE_PACK_EXPANSION back. Add that
10758 expansion and move on. */
10762 expanded_specs,
10763 complain);
10766 }
10767 }
10770 {
10773 else
10778 complain);
10779 }
10782 }
10783 }
10785 }
10787 /* Take the tree structure T and replace template parameters used
10788 therein with the argument vector ARGS. IN_DECL is an associated
10789 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
10790 Issue error and warning messages under control of COMPLAIN. Note
10791 that we must be relatively non-tolerant of extensions here, in
10792 order to preserve conformance; if we allow substitutions that
10793 should not be allowed, we may allow argument deductions that should
10794 not succeed, and therefore report ambiguous overload situations
10795 where there are none. In theory, we could allow the substitution,
10796 but indicate that it should have failed, and allow our caller to
10797 make sure that the right thing happens, but we don't try to do this
10798 yet.
10800 This function is used for dealing with types, decls and the like;
10801 for expressions, use tsubst_expr or tsubst_copy. */
10803 tree
10805 {
10828 else
10833 /* Reuse typedefs. We need to do this to handle dependent attributes,
10834 such as attribute aligned. */
10837 {
10844 {
10845 /* DECL represents an alias template and we want to
10846 instantiate it. Let's substitute our arguments for the
10847 template parameters into the declaration and get the
10848 resulting type. */
10850 }
10854 {
10858 }
10863 else
10864 /* The typedef is from a non-template context. */
10868 {
10870 r = cp_build_qualified_type_real
10874 }
10875 else
10876 /* We don't have an instantiation yet, so drop the typedef. */
10878 }
10891 {
10917 {
10923 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
10924 needed. */
10930 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
10931 with TREE_SIDE_EFFECTS that indicates this is not an integral
10932 constant expression. */
10935 {
10938 }
10941 }
10947 {
10960 {
10964 /* See through ARGUMENT_PACK_SELECT arguments. */
10966 }
10971 {
10973 /* If ARG is an argument pack, we don't actually want to
10974 perform a substitution here, because substitutions
10975 for argument packs are only done
10976 element-by-element. We can get to this point when
10977 substituting the type of a non-type template
10978 parameter pack, when that type actually contains
10979 template parameter packs from an outer template, e.g.,
10981 template<typename... Types> struct A {
10982 template<Types... Values> struct B { };
10983 }; */
10987 {
10993 return cp_build_qualified_type_real
10995 }
10997 {
10998 /* We are processing a type constructed from a
10999 template template parameter. */
11010 /* Consider this code:
11012 template <template <class> class Template>
11013 struct Internal {
11014 template <class Arg> using Bind = Template<Arg>;
11015 };
11017 template <template <class> class Template, class Arg>
11018 using Instantiate = Template<Arg>; //#0
11020 template <template <class> class Template,
11021 class Argument>
11022 using Bind =
11023 Instantiate<Internal<Template>::template Bind,
11024 Argument>; //#1
11026 When #1 is parsed, the
11027 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11028 parameter `Template' in #0 matches the
11029 UNBOUND_CLASS_TEMPLATE representing the argument
11030 `Internal<Template>::template Bind'; We then want
11031 to assemble the type `Bind<Argument>' that can't
11032 be fully created right now, because
11033 `Internal<Template>' not being complete, the Bind
11034 template cannot be looked up in that context. So
11035 we need to "store" `Bind<Argument>' for later
11036 when the context of Bind becomes complete. Let's
11037 store that in a TYPENAME_TYPE. */
11041 argvec),
11042 typename_type,
11043 complain);
11045 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11046 are resolving nested-types in the signature of a
11047 member function templates. Otherwise ARG is a
11048 TEMPLATE_DECL and is the real template to be
11049 instantiated. */
11057 complain);
11058 return cp_build_qualified_type_real
11060 }
11061 else
11062 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11064 }
11067 /* This can happen during the attempted tsubst'ing in
11068 unify. This means that we don't yet have any information
11069 about the template parameter in question. */
11072 /* Early in template argument deduction substitution, we don't
11073 want to reduce the level of 'auto', or it will be confused
11074 with a normal template parm in subsequent deduction. */
11078 /* If we get here, we must have been looking at a parm for a
11079 more deeply nested template. Make a new version of this
11080 template parameter, but with a lower level. */
11082 {
11087 {
11089 r = cp_build_qualified_type_real
11093 }
11094 else
11095 {
11106 /* We have reduced the level of the template
11107 template parameter, but not the levels of its
11108 template parameters, so canonical_type_parameter
11109 will not be able to find the canonical template
11110 template parameter for this level. Thus, we
11111 require structural equality checking to compare
11112 TEMPLATE_TEMPLATE_PARMs. */
11116 else
11120 {
11128 }
11129 }
11138 }
11141 }
11144 {
11152 {
11156 }
11159 {
11163 }
11166 {
11170 }
11176 }
11179 /* We should never be tsubsting a binfo. */
11183 /* A vector of template arguments. */
11189 {
11193 /* [temp.deduct]
11195 Type deduction may fail for any of the following
11196 reasons:
11198 -- Attempting to create a pointer to reference type.
11199 -- Attempting to create a reference to a reference type or
11200 a reference to void.
11202 Core issue 106 says that creating a reference to a reference
11203 during instantiation is no longer a cause for failure. We
11204 only enforce this check in strict C++98 mode. */
11208 {
11211 /* We keep track of the last time we issued this error
11212 message to avoid spewing a ton of messages during a
11213 single bad template instantiation. */
11216 {
11221 else
11224 }
11227 }
11229 {
11233 }
11235 /* In C++0x, during template argument substitution, when there is an
11236 attempt to create a reference to a reference type, reference
11237 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11239 "If a template-argument for a template-parameter T names a type
11240 that is a reference to a type A, an attempt to create the type
11241 'lvalue reference to cv T' creates the type 'lvalue reference to
11242 A,' while an attempt to create the type type rvalue reference to
11243 cv T' creates the type T"
11244 */
11245 r = cp_build_reference_type
11248 else
11253 /* Will this ever be needed for TYPE_..._TO values? */
11257 }
11259 {
11262 {
11263 /* [temp.deduct]
11265 Type deduction may fail for any of the following
11266 reasons:
11268 -- Attempting to create "pointer to member of T" when T
11269 is not a class type. */
11273 }
11275 {
11279 }
11281 {
11285 }
11288 {
11289 /* The type of the implicit object parameter gets its
11290 cv-qualifiers from the FUNCTION_TYPE. */
11291 tree memptr;
11295 complain);
11296 }
11297 else
11300 complain);
11301 }
11304 {
11305 tree fntype;
11306 tree specs;
11311 /* Substitute the exception specification. */
11319 }
11321 {
11326 /* As an optimization, we avoid regenerating the array type if
11327 it will obviously be the same as T. */
11331 /* These checks should match the ones in grokdeclarator.
11333 [temp.deduct]
11335 The deduction may fail for any of the following reasons:
11337 -- Attempting to create an array with an element type that
11338 is void, a function type, or a reference type, or [DR337]
11339 an abstract class type. */
11343 {
11347 }
11349 {
11352 type);
11354 }
11359 {
11362 }
11365 }
11368 {
11378 {
11382 }
11384 {
11385 /* Normally, make_typename_type does not require that the CTX
11386 have complete type in order to allow things like:
11388 template <class T> struct S { typename S<T>::X Y; };
11390 But, such constructs have already been resolved by this
11391 point, so here CTX really should have complete type, unless
11392 it's a partial instantiation. */
11395 {
11399 }
11400 }
11407 {
11410 }
11413 {
11415 {
11419 else
11421 }
11423 {
11427 else
11429 }
11430 }
11432 return cp_build_qualified_type_real
11434 }
11437 {
11449 }
11452 {
11453 tree type;
11469 complain);
11470 }
11473 {
11474 tree type;
11490 else
11491 type = finish_decltype_type
11496 complain);
11497 }
11500 {
11504 }
11508 {
11510 tree packed_out =
11512 args,
11513 complain,
11514 in_decl);
11517 /* For template nontype argument packs, also substitute into
11518 the type. */
11523 }
11538 /* We should use one of the expression tsubsts for these codes. */
11544 }
11545 }
11547 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11548 type of the expression on the left-hand side of the "." or "->"
11549 operator. */
11551 static tree
11554 {
11555 tree name;
11556 tree qualifying_scope;
11557 tree fns;
11558 tree optype;
11563 /* A baselink indicates a function from a base class. Both the
11564 BASELINK_ACCESS_BINFO and the base class referenced may
11565 indicate bases of the template class, rather than the
11566 instantiated class. In addition, lookups that were not
11567 ambiguous before may be ambiguous now. Therefore, we perform
11568 the lookup again. */
11575 {
11582 }
11590 /* If lookup found a single function, mark it as used at this
11591 point. (If it lookup found multiple functions the one selected
11592 later by overload resolution will be marked as used at that
11593 point.) */
11599 /* Add back the template arguments, if present. */
11604 template_args);
11605 /* Update the conversion operator type. */
11613 qualifying_scope,
11614 object_type);
11616 }
11618 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11619 true if the qualified-id will be a postfix-expression in-and-of
11620 itself; false if more of the postfix-expression follows the
11621 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11622 of "&". */
11624 static tree
11628 {
11629 tree expr;
11630 tree scope;
11631 tree name;
11633 tree template_args;
11638 /* Figure out what name to look up. */
11641 {
11649 }
11650 else
11651 {
11654 }
11656 /* Substitute into the qualifying scope. When there are no ARGS, we
11657 are just trying to simplify a non-dependent expression. In that
11658 case the qualifying scope may be dependent, and, in any case,
11659 substituting will not help. */
11662 {
11665 }
11666 else
11670 {
11675 }
11678 {
11680 {
11681 /* A BIT_NOT_EXPR is used to represent a destructor. */
11683 {
11687 }
11688 else
11691 }
11692 else
11696 {
11698 {
11702 }
11704 }
11705 }
11708 {
11710 scope);
11711 /* Remember that there was a reference to this entity. */
11713 }
11716 {
11722 }
11731 {
11732 expr = (adjust_result_of_qualified_name_lookup
11734 expr = (finish_qualified_id_expr
11738 }
11740 /* Expressions do not generally have reference type. */
11742 /* However, if we're about to form a pointer-to-member, we just
11743 want the referenced member referenced. */
11748 }
11750 /* Like tsubst, but deals with expressions. This function just replaces
11751 template parms; to finish processing the resultant expression, use
11752 tsubst_copy_and_build or tsubst_expr. */
11754 static tree
11756 {
11758 tree r;
11766 {
11771 {
11772 /* We get here for a use of 'this' in an NSDMI. */
11778 /* This can happen for a parameter name used later in a function
11779 declaration (such as in a late-specified return type). Just
11780 make a dummy decl, since it's only used for its type. */
11783 /* Give it the template pattern as its context; its true context
11784 hasn't been instantiated yet and this is good enough for
11785 mangling. */
11787 }
11795 {
11796 tree enum_type;
11797 tree v;
11801 /* There is no need to substitute into namespace-scope
11802 enumerators. */
11805 /* If ARGS is NULL, then T is known to be non-dependent. */
11809 /* Unfortunately, we cannot just call lookup_name here.
11810 Consider:
11812 template <int I> int f() {
11813 enum E { a = I };
11814 struct S { void g() { E e = a; } };
11815 };
11817 When we instantiate f<7>::S::g(), say, lookup_name is not
11818 clever enough to find f<7>::a. */
11819 enum_type
11829 /* We didn't find the name. That should never happen; if
11830 name-lookup found it during preliminary parsing, we
11831 should find it again here during instantiation. */
11833 }
11838 {
11839 tree ctx;
11844 {
11847 {
11851 }
11853 }
11854 }
11870 /* An OVERLOAD will always be a non-dependent overload set; an
11871 overload set from function scope will just be represented with an
11872 IDENTIFIER_NODE, and from class scope with a BASELINK. */
11887 {
11888 /* Template template argument like the following example need
11889 special treatment:
11891 template <template <class> class TT> struct C {};
11892 template <class T> struct D {
11893 template <class U> struct E {};
11894 C<E> c; // #1
11895 };
11896 D<int> d; // #2
11898 We are processing the template argument `E' in #1 for
11899 the template instantiation #2. Originally, `E' is a
11900 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
11901 have to substitute this with one having context `D<int>'. */
11905 }
11906 else
11907 /* Ordinary template template argument. */
11918 return build1
11924 {
11926 tree expanded;
11931 /* We only want to compute the number of arguments. */
11946 {
11953 else
11956 }
11957 else
11959 }
11960 /* Fall through */
11975 return build1
11980 {
11981 tree object;
11982 tree name;
11987 {
11991 }
11994 {
12004 }
12009 in_decl);
12010 else
12013 }
12051 return build_nt
12064 return build_nt
12071 {
12079 }
12084 {
12085 r = build_nt
12091 }
12094 {
12095 r = build_nt
12101 }
12104 {
12105 r = build_nt
12111 }
12114 {
12115 /* Substituted template arguments */
12124 }
12127 {
12147 }
12172 {
12175 }
12176 else
12180 /* This is handled by tsubst_copy_and_build. */
12186 in_decl),
12190 /* We shouldn't have built any of these during initial template
12191 generation. Instead, they should be built during instantiation
12192 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12196 r = build2
12216 {
12217 /* Instantiate any typedefs in the type. */
12222 }
12225 /* These can sometimes show up in a partial instantiation, but never
12226 involve template parms. */
12231 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12234 }
12235 }
12237 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12239 static tree
12241 tree in_decl)
12242 {
12246 {
12252 {
12255 {
12261 }
12262 /* FALLTHRU */
12286 }
12287 }
12290 }
12292 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12294 static tree
12296 tree in_decl)
12297 {
12298 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
12318 {
12321 else
12322 {
12326 }
12327 }
12332 #undef RECUR
12333 }
12335 /* Substitute one OMP_FOR iterator. */
12337 static void
12342 {
12343 #define RECUR(NODE) \
12344 tsubst_expr ((NODE), args, complain, in_decl, \
12345 integral_constant_expression_p)
12353 /* Do this before substituting into decl to handle 'auto'. */
12358 {
12362 }
12367 {
12374 complain);
12375 else
12382 }
12385 {
12386 tree c;
12388 {
12399 }
12401 {
12406 {
12409 }
12410 }
12411 }
12417 else
12421 {
12432 {
12439 }
12440 else
12446 {
12452 }
12456 {
12463 }
12464 else
12470 }
12476 #undef RECUR
12477 }
12479 /* Like tsubst_copy for expressions, etc. but also does semantic
12480 processing. */
12482 static tree
12485 {
12486 #define RECUR(NODE) \
12487 tsubst_expr ((NODE), args, complain, in_decl, \
12488 integral_constant_expression_p)
12501 {
12503 {
12504 tree_stmt_iterator i;
12508 }
12523 else
12532 {
12534 tree init;
12540 {
12543 tree decl;
12551 else
12553 }
12554 else
12555 {
12559 {
12560 /* By marking the declaration as instantiated, we avoid
12561 trying to instantiate it. Since instantiate_decl can't
12562 handle local variables, and since we've already done
12563 all that needs to be done, that's the right thing to
12564 do. */
12569 /* Anonymous aggregates are a special case. */
12572 {
12575 }
12578 else
12579 {
12584 {
12585 /* For __PRETTY_FUNCTION__ we have to adjust the
12586 initializer. */
12590 }
12591 else
12592 {
12596 {
12597 /* If we had an initializer but it
12598 instantiated to nothing,
12599 value-initialize the object. This will
12600 only occur when the initializer was a
12601 pack expansion where the parameter packs
12602 used in that expansion were of length
12603 zero. */
12605 complain);
12608 }
12609 else
12611 }
12614 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12617 }
12618 }
12619 }
12622 }
12637 {
12647 }
12674 {
12678 }
12686 else
12694 else
12721 {
12723 tree label;
12728 }
12734 /* Computed goto's must be tsubst'd into. On the other hand,
12735 non-computed gotos must not be; the identifier in question
12736 will have no binding. */
12738 else
12744 tmp = finish_asm_stmt
12751 {
12756 }
12761 {
12766 }
12767 else
12768 {
12773 else
12780 else
12786 else
12788 }
12792 {
12796 {
12798 /* Prevent instantiate_decl from trying to instantiate
12799 this variable. We've already done all that needs to be
12800 done. */
12803 }
12808 }
12814 {
12815 /* Local classes are not independent templates; they are
12816 instantiated along with their containing function. And this
12817 way we don't have to deal with pushing out of one local class
12818 to instantiate a member of another local class. */
12819 tree fn;
12820 /* Closures are handled by the LAMBDA_EXPR. */
12826 }
12830 {
12831 tree condition;
12834 condition =
12836 args,
12845 }
12866 {
12883 integral_constant_expression_p);
12897 }
12929 {
12934 {
12937 }
12942 }
12943 else
12944 {
12951 {
12954 }
12957 {
12962 {
12965 }
12969 }
12970 else
12971 {
12975 }
12977 }
12981 {
12987 {
12991 {
12996 }
13000 }
13001 else
13002 {
13007 }
13008 }
13026 /* If the first operand was a statement, we're done with it. */
13030 complain);
13037 integral_constant_expression_p);
13038 }
13041 #undef RECUR
13042 }
13044 /* T is a postfix-expression that is not being used in a function
13045 call. Return the substituted version of T. */
13047 static tree
13049 tsubst_flags_t complain,
13050 tree in_decl)
13051 {
13055 else
13061 }
13063 /* Like tsubst but deals with expressions and performs semantic
13064 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
13066 tree
13068 tree args,
13069 tsubst_flags_t complain,
13070 tree in_decl,
13073 {
13074 #define RECUR(NODE) \
13075 tsubst_copy_and_build (NODE, args, complain, in_decl, \
13077 integral_constant_expression_p)
13079 tree op1;
13085 {
13088 /* Fall through. */
13090 {
13091 tree decl;
13092 cp_id_kind idk;
13097 {
13100 }
13102 /* Look up the name. */
13105 /* By convention, expressions use ERROR_MARK_NODE to indicate
13106 failure, not NULL_TREE. */
13112 integral_constant_expression_p,
13120 input_location);
13124 {
13128 }
13130 }
13133 {
13134 tree object;
13142 {
13145 }
13146 else
13153 else
13155 }
13158 {
13162 {
13163 /* A type conversion to reference type will be enclosed in
13164 such an indirect ref, but the substitution of the cast
13165 will have also added such an indirect ref. */
13168 }
13169 else
13172 }
13175 return build_nop
13180 {
13187 flags);
13188 }
13191 return build1
13201 {
13202 tree type;
13208 {
13213 }
13219 {
13237 }
13241 }
13273 else
13275 in_decl);
13309 {
13310 tree r;
13314 r = build_x_binary_op
13318 ? ERROR_MARK
13322 ? ERROR_MARK
13325 complain);
13332 }
13346 /* Fall through */
13351 {
13352 /* When there are no ARGS, we are trying to evaluate a
13353 non-dependent expression from the parser. Trying to do
13354 the substitutions may not work. */
13357 }
13358 else
13359 {
13367 }
13371 else
13376 {
13386 }
13400 {
13401 tree r = build_x_modify_expr
13406 complain);
13407 /* TREE_NO_WARNING must be set if either the expression was
13408 parenthesized or it uses an operator such as >>= rather
13409 than plain assignment. In the former case, it was already
13410 set and must be copied. In the latter case,
13411 build_x_modify_expr sets it and it must not be reset
13412 here. */
13416 }
13421 /* Remember that there was a reference to this entity. */
13427 {
13432 tree ret;
13436 else
13437 {
13441 }
13443 /* If there was an initializer in the original tree, but it
13444 instantiated to an empty list, then we should pass a
13445 non-NULL empty vector to tell build_new that it was an
13446 empty initializer() rather than no initializer. This can
13447 only happen when the initializer is a pack expansion whose
13448 parameter packs are of length zero. */
13451 else
13452 {
13456 else
13457 {
13460 }
13461 }
13468 complain);
13476 }
13479 return delete_sanity
13484 complain);
13490 complain);
13493 {
13494 tree function;
13499 tree ret;
13502 /* When we parsed the expression, we determined whether or
13503 not Koenig lookup should be performed. */
13506 {
13511 }
13513 {
13514 /* Do nothing; calling tsubst_copy_and_build on an identifier
13515 would incorrectly perform unqualified lookup again.
13517 Note that we can also have an IDENTIFIER_NODE if the earlier
13518 unqualified lookup found a member function; in that case
13519 koenig_p will be false and we do want to do the lookup
13520 again to find the instantiated member function.
13522 FIXME but doing that causes c++/15272, so we need to stop
13523 using IDENTIFIER_NODE in that situation. */
13525 }
13526 else
13527 {
13529 {
13535 }
13536 else
13540 in_decl,
13542 integral_constant_expression_p);
13546 }
13551 {
13557 else
13558 {
13559 /* Expand the pack expansion and push each entry onto
13560 CALL_ARGS. */
13563 {
13568 {
13573 }
13574 }
13575 else
13576 {
13577 /* A partial substitution. Add one entry. */
13579 }
13580 }
13581 }
13583 /* We do not perform argument-dependent lookup if normal
13584 lookup finds a non-function, in accordance with the
13585 expected resolution of DR 218. */
13588 /* If lookup found a member function, the Koenig lookup is
13589 not appropriate, even if an unqualified-name was used
13590 to denote the function. */
13593 /* Only do this when substitution turns a dependent call
13594 into a non-dependent call. */
13598 tf_none);
13602 {
13604 {
13605 /* For backwards compatibility and good diagnostics, try
13606 the unqualified lookup again if we aren't in SFINAE
13607 context. */
13608 tree unq = (tsubst_copy_and_build
13610 integral_constant_expression_p));
13615 {
13624 "%qD was not declared in this scope, "
13625 "and no declarations were found by "
13626 "argument-dependent lookup at the point "
13631 {
13633 "declarations in dependent base %qT are "
13639 else
13643 }
13644 else
13648 }
13649 }
13651 {
13655 }
13656 }
13658 /* Remember that there was a reference to this entity. */
13665 {
13680 complain);
13681 else
13682 ret = (build_new_method_call
13687 complain));
13688 }
13689 else
13692 koenig_p,
13693 complain);
13698 }
13701 {
13706 {
13708 {
13713 }
13714 else
13715 {
13720 }
13721 }
13722 else
13723 {
13726 }
13730 }
13733 return finish_pseudo_destructor_expr
13739 {
13747 {
13748 /* We have pack expansions, so expand those and
13749 create a new list out of it. */
13752 tree chain;
13755 /* Expand the argument expressions. */
13763 /* Build the rest of the list. */
13768 /* Determine the number of arguments. */
13770 {
13773 }
13776 else
13777 {
13778 /* Since we only performed a partial substitution into
13779 the argument pack, we only return a single list
13780 node. */
13787 }
13789 /* Convert the argument vectors into a TREE_LIST */
13792 {
13793 /* Grab the Ith values. */
13794 i--;
13797 value
13801 /* Build the list (backwards). */
13803 }
13806 }
13822 }
13825 {
13826 tree object;
13827 tree object_type;
13828 tree member;
13832 /* Remember that there was a reference to this entity. */
13842 else
13850 {
13852 {
13857 {
13860 }
13862 {
13866 }
13867 }
13868 }
13871 {
13872 /* Lookup the template functions now that we know what the
13873 scope is. */
13881 {
13884 args);
13885 member = (adjust_result_of_qualified_name_lookup
13887 object_type));
13888 }
13889 else
13890 {
13892 input_location);
13894 }
13895 }
13899 {
13901 {
13905 else
13908 }
13910 }
13916 complain);
13917 }
13920 return build_throw
13924 {
13932 tree r;
13937 /* digest_init will do the wrong thing if we let it. */
13941 /* We do not want to process the index of aggregate
13942 initializers as they are identifier nodes which will be
13943 looked up by digest_init. */
13949 {
13954 {
13955 /* Substitute into the pack expansion. */
13957 in_decl);
13961 ;
13963 /* Just move the argument into place. */
13965 else
13966 {
13967 /* Update the length of the final CONSTRUCTOR
13968 arguments vector, and note that we will need to
13969 copy.*/
13972 }
13973 }
13974 else
13976 }
13979 {
13984 {
13986 {
13991 }
13992 else
13994 }
13995 }
14005 }
14008 {
14011 {
14014 }
14015 else
14016 {
14019 }
14020 }
14025 /* Fall through */
14028 {
14032 /* If the original type was a reference, we'll be wrapped in
14033 the appropriate INDIRECT_REF. */
14036 }
14047 {
14056 }
14059 {
14065 integral_constant_expression_p);
14069 /* If the resulting list of expression statement is empty,
14070 fold it further into void_zero_node. */
14075 }
14078 {
14100 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
14102 /* Now that we know visibility, instantiate the type so we have a
14103 declaration of the op() for later calls to lambda_function. */
14106 /* The capture list refers to closure members, so this needs to
14107 wait until after we finish instantiating the type. */
14112 }
14115 /* We can get here for a constant initializer of non-dependent type.
14116 FIXME stop folding in cp_parser_initializer_clause. */
14118 {
14122 }
14126 integral_constant_expression_p);
14129 /* Handle Objective-C++ constructs, if appropriate. */
14130 {
14131 tree subst
14136 }
14138 }
14140 #undef RECUR
14141 }
14143 /* Verify that the instantiated ARGS are valid. For type arguments,
14144 make sure that the type's linkage is ok. For non-type arguments,
14145 make sure they are constants if they are integral or enumerations.
14146 Emit an error under control of COMPLAIN, and return TRUE on error. */
14148 static bool
14150 {
14152 {
14162 }
14164 {
14165 /* [basic.link]: A name with no linkage (notably, the name
14166 of a class or enumeration declared in a local scope)
14167 shall not be used to declare an entity with linkage.
14168 This implies that names with no linkage cannot be used as
14169 template arguments
14171 DR 757 relaxes this restriction for C++0x. */
14176 {
14177 /* DR 488 makes use of a type with no linkage cause
14178 type deduction to fail. */
14180 {
14183 else
14186 }
14188 }
14189 /* In order to avoid all sorts of complications, we do not
14190 allow variably-modified types as template arguments. */
14192 {
14196 }
14197 }
14198 /* A non-type argument of integral or enumerated type must be a
14199 constant. */
14203 {
14207 }
14209 }
14211 static bool
14213 {
14218 {
14221 }
14225 }
14227 /* In C++0x, it's possible to have a function template whose type depends
14228 on itself recursively. This is most obvious with decltype, but can also
14229 occur with enumeration scope (c++/48969). So we need to catch infinite
14230 recursion and reject the substitution at deduction time; this function
14231 will return error_mark_node for any repeated substitution.
14233 This also catches excessive recursion such as when f<N> depends on
14234 f<N-1> across all integers, and returns error_mark_node for all the
14235 substitutions back up to the initial one.
14237 This is, of course, not reentrant. */
14239 static tree
14241 {
14248 tree tinst;
14249 tree r;
14256 {
14260 }
14264 /* We will do access checks in instantiate_template. */
14271 {
14274 /* Reset once we're all the way out. */
14276 }
14279 /* We can't free this if a pending_template entry or last_error_tinst_level
14280 is pointing at it. */
14285 }
14287 /* Instantiate the indicated variable or function template TMPL with
14288 the template arguments in TARG_PTR. */
14290 static tree
14292 {
14294 tree fndecl;
14295 tree gen_tmpl;
14296 tree spec;
14303 /* If this function is a clone, handle it specially. */
14305 {
14306 tree spec;
14307 tree clone;
14309 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
14310 DECL_CLONED_FUNCTION. */
14316 /* Look for the clone. */
14320 /* We should always have found the clone by now. */
14323 }
14325 /* Check to see if we already have this specialization. */
14328 /* The TMPL is a partial instantiation. To get a full set of
14329 arguments we must add the arguments used to perform the
14330 partial instantiation. */
14332 targ_ptr);
14334 /* It would be nice to avoid hashing here and then again in tsubst_decl,
14335 but it doesn't seem to be on the hot path. */
14347 complain))
14350 /* We are building a FUNCTION_DECL, during which the access of its
14351 parameters and return types have to be checked. However this
14352 FUNCTION_DECL which is the desired context for access checking
14353 is not built yet. We solve this chicken-and-egg problem by
14354 deferring all checks until we have the FUNCTION_DECL. */
14357 /* Instantiation of the function happens in the context of the function
14358 template, not the context of the overload resolution we're doing. */
14361 {
14365 }
14366 /* Substitute template parameters to obtain the specialization. */
14376 /* The DECL_TI_TEMPLATE should always be the immediate parent
14377 template, not the most general template. */
14380 /* Now we know the specialization, compute access previously
14381 deferred. */
14387 /* If we've just instantiated the main entry point for a function,
14388 instantiate all the alternate entry points as well. We do this
14389 by cloning the instantiation of the main entry point, not by
14390 instantiating the template clones. */
14395 }
14397 /* Wrapper for instantiate_template_1. */
14399 tree
14401 {
14402 tree ret;
14407 }
14409 /* PARM is a template parameter pack for FN. Returns true iff
14410 PARM is used in a deducible way in the argument list of FN. */
14412 static bool
14414 {
14417 {
14419 tree packs;
14425 {
14426 /* The template parameter pack is used in a function parameter
14427 pack. If this is the end of the parameter list, the
14428 template parameter pack is deducible. */
14431 else
14432 /* Otherwise, not. Well, it could be deduced from
14433 a non-pack parameter, but doing so would end up with
14434 a deduction mismatch, so don't bother. */
14436 }
14437 }
14438 /* The template parameter pack isn't used in any function parameter
14439 packs, but it might be used deeper, e.g. tuple<Args...>. */
14441 }
14443 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
14444 NARGS elements of the arguments that are being used when calling
14445 it. TARGS is a vector into which the deduced template arguments
14446 are placed.
14448 Return zero for success, 2 for an incomplete match that doesn't resolve
14449 all the types, and 1 for complete failure. An error message will be
14450 printed only for an incomplete match.
14452 If FN is a conversion operator, or we are trying to produce a specific
14453 specialization, RETURN_TYPE is the return type desired.
14455 The EXPLICIT_TARGS are explicit template arguments provided via a
14456 template-id.
14458 The parameter STRICT is one of:
14460 DEDUCE_CALL:
14461 We are deducing arguments for a function call, as in
14462 [temp.deduct.call].
14464 DEDUCE_CONV:
14465 We are deducing arguments for a conversion function, as in
14466 [temp.deduct.conv].
14468 DEDUCE_EXACT:
14469 We are deducing arguments when doing an explicit instantiation
14470 as in [temp.explicit], when determining an explicit specialization
14471 as in [temp.expl.spec], or when taking the address of a function
14472 template, as in [temp.deduct.funcaddr]. */
14474 int
14476 tree explicit_targs,
14477 tree targs,
14480 tree return_type,
14481 unification_kind_t strict,
14484 {
14485 tree parms;
14486 tree fntype;
14493 {
14494 /* [temp.deduct]
14496 The specified template arguments must match the template
14497 parameters in kind (i.e., type, nontype, template), and there
14498 must not be more arguments than there are parameters;
14499 otherwise type deduction fails.
14501 Nontype arguments must match the types of the corresponding
14502 nontype template parameters, or must be convertible to the
14503 types of the corresponding nontype parameters as specified in
14504 _temp.arg.nontype_, otherwise type deduction fails.
14506 All references in the function type of the function template
14507 to the corresponding template parameters are replaced by the
14508 specified template argument values. If a substitution in a
14509 template parameter or in the function type of the function
14510 template results in an invalid type, type deduction fails. */
14513 tree converted_args;
14519 converted_args
14521 (explain_p
14522 ? tf_warning_or_error
14529 /* Substitute the explicit args into the function type. This is
14530 necessary so that, for instance, explicitly declared function
14531 arguments can match null pointed constants. If we were given
14532 an incomplete set of explicit args, we must not do semantic
14533 processing during substitution as we could create partial
14534 instantiations. */
14536 {
14541 /* Dig out the actual parm. */
14544 {
14547 }
14549 {
14552 }
14555 /* No explicit argument for this template parameter. */
14559 {
14560 /* Mark the argument pack as "incomplete". We could
14561 still deduce more arguments during unification.
14562 We remove this mark in type_unification_real. */
14564 {
14568 }
14570 /* We have some incomplete argument packs. */
14572 }
14573 }
14577 (explain_p
14578 ? tf_warning_or_error
14585 /* Place the explicitly specified arguments in TARGS. */
14588 }
14590 /* Never do unification on the 'this' parameter. */
14594 {
14603 }
14605 /* We allow incomplete unification without an error message here
14606 because the standard doesn't seem to explicitly prohibit it. Our
14607 callers must be ready to deal with unification failures in any
14608 event. */
14613 /* Now that we have bindings for all of the template arguments,
14614 ensure that the arguments deduced for the template template
14615 parameters have compatible template parameter lists. We cannot
14616 check this property before we have deduced all template
14617 arguments, because the template parameter types of a template
14618 template parameter might depend on prior template parameters
14619 deduced after the template template parameter. The following
14620 ill-formed example illustrates this issue:
14622 template<typename T, template<T> class C> void f(C<5>, T);
14624 template<int N> struct X {};
14626 void g() {
14627 f(X<5>(), 5l); // error: template argument deduction fails
14628 }
14630 The template parameter list of 'C' depends on the template type
14631 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
14632 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
14633 time that we deduce 'C'. */
14635 && !template_template_parm_bindings_ok_p
14640 /* All is well so far. Now, check:
14642 [temp.deduct]
14644 When all template arguments have been deduced, all uses of
14645 template parameters in nondeduced contexts are replaced with
14646 the corresponding deduced argument values. If the
14647 substitution results in an invalid type, as described above,
14648 type deduction fails. */
14649 {
14651 (explain_p
14652 ? tf_warning_or_error
14657 /* If we're looking for an exact match, check that what we got
14658 is indeed an exact match. It might not be if some template
14659 parameters are used in non-deduced contexts. */
14661 {
14664 tree sarg
14672 }
14673 }
14676 }
14678 /* Adjust types before performing type deduction, as described in
14679 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
14680 sections are symmetric. PARM is the type of a function parameter
14681 or the return type of the conversion function. ARG is the type of
14682 the argument passed to the call, or the type of the value
14683 initialized with the result of the conversion function.
14684 ARG_EXPR is the original argument expression, which may be null. */
14686 static int
14690 tree arg_expr)
14691 {
14695 {
14700 {
14701 /* Swap PARM and ARG throughout the remainder of this
14702 function; the handling is precisely symmetric since PARM
14703 will initialize ARG rather than vice versa. */
14708 }
14711 /* Core issue #873: Do the DR606 thing (see below) for these cases,
14712 too, but here handle it by stripping the reference from PARM
14713 rather than by adding it to ARG. */
14721 /* Nothing else to do in this case. */
14726 }
14729 {
14730 /* [temp.deduct.call]
14732 If P is not a reference type:
14734 --If A is an array type, the pointer type produced by the
14735 array-to-pointer standard conversion (_conv.array_) is
14736 used in place of A for type deduction; otherwise,
14738 --If A is a function type, the pointer type produced by
14739 the function-to-pointer standard conversion
14740 (_conv.func_) is used in place of A for type deduction;
14741 otherwise,
14743 --If A is a cv-qualified type, the top level
14744 cv-qualifiers of A's type are ignored for type
14745 deduction. */
14750 else
14752 }
14754 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
14755 of the form T&&, where T is a template parameter, and the argument
14756 is an lvalue, T is deduced as A& */
14762 /* try_one_overload doesn't provide an arg_expr, but
14763 functions are always lvalues. */
14767 /* [temp.deduct.call]
14769 If P is a cv-qualified type, the top level cv-qualifiers
14770 of P's type are ignored for type deduction. If P is a
14771 reference type, the type referred to by P is used for
14772 type deduction. */
14775 {
14778 }
14780 /* DR 322. For conversion deduction, remove a reference type on parm
14781 too (which has been swapped into ARG). */
14786 }
14788 /* Subroutine of unify_one_argument. PARM is a function parameter of a
14789 template which does contain any deducible template parameters; check if
14790 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
14791 unify_one_argument. */
14793 static int
14796 {
14797 tree type;
14801 else
14808 {
14812 }
14814 {
14819 }
14823 else
14825 }
14827 /* Subroutine of type_unification_real and unify_pack_expansion to
14828 handle unification of a single P/A pair. Parameters are as
14829 for those functions. */
14831 static int
14835 {
14842 /* We can't deduce anything from this, but we might get all the
14843 template args from other function args. */
14846 /* FIXME uses_deducible_template_parms */
14849 explain_p);
14852 {
14854 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
14855 | UNIFY_ALLOW_MORE_CV_QUAL
14869 }
14871 /* We only do these transformations if this is the top-level
14872 parameter_type_list in a call or declaration matching; in other
14873 situations (nested function declarators, template argument lists) we
14874 won't be comparing a type to an expression, and we don't do any type
14875 adjustments. */
14877 {
14879 {
14882 {
14883 /* [temp.deduct.type] A template-argument can be
14884 deduced from a pointer to function or pointer
14885 to member function argument if the set of
14886 overloaded functions does not contain function
14887 templates and at most one of a set of
14888 overloaded functions provides a unique
14889 match. */
14896 }
14902 }
14904 arg_strict |=
14906 }
14907 else
14911 /* For deduction from an init-list we need the actual list. */
14915 }
14917 /* Most parms like fn_type_unification.
14919 If SUBR is 1, we're being called recursively (to unify the
14920 arguments of a function or method parameter of a function
14921 template). */
14923 static int
14925 tree targs,
14926 tree xparms,
14930 unification_kind_t strict,
14933 {
14938 tree parms;
14947 /* Reset the number of non-defaulted template arguments contained
14948 in TARGS. */
14951 again:
14959 {
14964 /* For a function parameter pack that occurs at the end of the
14965 parameter-declaration-list, the type A of each remaining
14966 argument of the call is compared with the type P of the
14967 declarator-id of the function parameter pack. */
14973 /* For a function parameter pack that does not occur at the
14974 end of the parameter-declaration-list, the type of the
14975 parameter pack is a non-deduced context. */
14984 }
14989 {
14990 /* Unify the remaining arguments with the pack expansion type. */
14991 tree argvec;
14994 /* Allocate a TREE_VEC and copy in all of the arguments */
14999 /* Copy the parameter into parmvec. */
15005 /* Advance to the end of the list of parameters. */
15007 }
15009 /* Fail if we've reached the end of the parm list, and more args
15010 are present, and the parm list isn't variadic. */
15013 /* Fail if parms are left and they don't have default values. */
15016 {
15020 {
15021 count++;
15023 }
15025 }
15028 {
15029 tsubst_flags_t complain = (explain_p
15030 ? tf_warning_or_error
15033 /* Check to see if we need another pass before we start clearing
15034 ARGUMENT_PACK_INCOMPLETE_P. */
15036 {
15044 /* If this is an undeduced nontype parameter that depends on
15045 a type parameter, try another pass; its type may have been
15046 deduced from a later argument than the one from which
15047 this parameter can be deduced. */
15052 }
15055 {
15059 /* Clear the "incomplete" flags on all argument packs now so that
15060 substituting them into later default arguments works. */
15062 {
15065 }
15071 /* Core issue #226 (C++0x) [temp.deduct]:
15073 If a template argument has not been deduced, its
15074 default template argument, if any, is used.
15076 When we are in C++98 mode, TREE_PURPOSE will either
15077 be NULL_TREE or ERROR_MARK_NODE, so we do not need
15078 to explicitly check cxx_dialect here. */
15080 {
15092 else
15093 {
15095 /* The position of the first default template argument,
15096 is also the number of non-defaulted arguments in TARGS.
15097 Record that. */
15101 }
15102 }
15104 /* If the type parameter is a parameter pack, then it will
15105 be deduced to an empty parameter pack. */
15107 {
15108 tree arg;
15111 {
15115 }
15116 else
15123 }
15126 }
15127 }
15128 #ifdef ENABLE_CHECKING
15131 #endif
15134 }
15136 /* Subroutine of type_unification_real. Args are like the variables
15137 at the call site. ARG is an overloaded function (or template-id);
15138 we try deducing template args from each of the overloads, and if
15139 only one succeeds, we go with that. Modifies TARGS and returns
15140 true on success. */
15142 static bool
15144 tree targs,
15145 tree parm,
15146 tree arg,
15147 unification_kind_t strict,
15150 {
15157 {
15160 }
15161 else
15165 /* Handle `&x' where `x' is some static or non-static member
15166 function name. */
15172 /* Strip baselink information. */
15177 {
15178 /* If we got some explicit template args, we need to plug them into
15179 the affected templates before we try to unify, in case the
15180 explicit args will completely resolve the templates in question. */
15187 {
15198 {
15203 {
15206 }
15207 }
15211 }
15212 /* If no templates (or more than one) are fully resolved by the
15213 explicit arguments, this template-id is a non-deduced context; it
15214 could still be OK if we deduce all template arguments for the
15215 enclosing call through other arguments. */
15218 }
15221 /* If ARG is, for example, "(0, &f)" then its type will be unknown
15222 -- but the deduction does not succeed because the expression is
15223 not just the function on its own. */
15225 else
15231 {
15234 }
15236 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15237 to function or pointer to member function argument if the set of
15238 overloaded functions does not contain function templates and at most
15239 one of a set of overloaded functions provides a unique match.
15241 So if we found multiple possibilities, we return success but don't
15242 deduce anything. */
15245 {
15250 }
15255 }
15257 /* Core DR 115: In contexts where deduction is done and fails, or in
15258 contexts where deduction is not done, if a template argument list is
15259 specified and it, along with any default template arguments, identifies
15260 a single function template specialization, then the template-id is an
15261 lvalue for the function template specialization. */
15263 tree
15265 {
15278 {
15281 }
15283 {
15286 }
15288 {
15291 }
15294 {
15298 /* If we got some explicit template args, we need to plug them into
15299 the affected templates before we try to unify, in case the
15300 explicit args will completely resolve the templates in question. */
15308 {
15319 {
15322 {
15325 }
15327 {
15330 }
15331 }
15333 }
15335 {
15343 {
15344 tree base
15347 }
15351 }
15353 /* There were no good options and at least one bad one, so let the
15354 user know what the problem is. */
15356 }
15358 }
15360 /* Subroutine of resolve_overloaded_unification; does deduction for a single
15361 overload. Fills TARGS with any deduced arguments, or error_mark_node if
15362 different overloads deduce different arguments for a given parm.
15363 ADDR_P is true if the expression for which deduction is being
15364 performed was of the form "& fn" rather than simply "fn".
15366 Returns 1 on success. */
15368 static int
15370 tree orig_targs,
15371 tree targs,
15372 tree parm,
15373 tree arg,
15374 unification_kind_t strict,
15378 {
15380 tree tempargs;
15383 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15384 to function or pointer to member function argument if the set of
15385 overloaded functions does not contain function templates and at most
15386 one of a set of overloaded functions provides a unique match.
15388 So if this is a template, just return success. */
15400 /* We don't copy orig_targs for this because if we have already deduced
15401 some template args from previous args, unify would complain when we
15402 try to deduce a template parameter for the same argument, even though
15403 there isn't really a conflict. */
15410 /* First make sure we didn't deduce anything that conflicts with
15411 explicitly specified args. */
15413 {
15420 /* Since we're unifying against ourselves, we will fill in
15421 template args used in the function parm list with our own
15422 template parms. Discard them. */
15426 }
15429 {
15434 }
15437 }
15439 /* PARM is a template class (perhaps with unbound template
15440 parameters). ARG is a fully instantiated type. If ARG can be
15441 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
15442 TARGS are as for unify. */
15444 static tree
15447 {
15448 tree copy_of_targs;
15455 /* We need to make a new template argument vector for the call to
15456 unify. If we used TARGS, we'd clutter it up with the result of
15457 the attempted unification, even if this class didn't work out.
15458 We also don't want to commit ourselves to all the unifications
15459 we've already done, since unification is supposed to be done on
15460 an argument-by-argument basis. In other words, consider the
15461 following pathological case:
15463 template <int I, int J, int K>
15464 struct S {};
15466 template <int I, int J>
15467 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
15469 template <int I, int J, int K>
15470 void f(S<I, J, K>, S<I, I, I>);
15472 void g() {
15473 S<0, 0, 0> s0;
15474 S<0, 1, 2> s2;
15476 f(s0, s2);
15477 }
15479 Now, by the time we consider the unification involving `s2', we
15480 already know that we must have `f<0, 0, 0>'. But, even though
15481 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
15482 because there are two ways to unify base classes of S<0, 1, 2>
15483 with S<I, I, I>. If we kept the already deduced knowledge, we
15484 would reject the possibility I=1. */
15487 /* If unification failed, we're done. */
15493 }
15495 /* Given a template type PARM and a class type ARG, find the unique
15496 base type in ARG that is an instance of PARM. We do not examine
15497 ARG itself; only its base-classes. If there is not exactly one
15498 appropriate base class, return NULL_TREE. PARM may be the type of
15499 a partial specialization, as well as a plain template type. Used
15500 by unify. */
15502 static enum template_base_result
15505 {
15507 tree binfo;
15513 {
15514 /* The type could not be completed. */
15517 }
15519 /* Walk in inheritance graph order. The search order is not
15520 important, and this avoids multiple walks of virtual bases. */
15522 {
15527 {
15528 /* If there is more than one satisfactory baseclass, then:
15530 [temp.deduct.call]
15532 If they yield more than one possible deduced A, the type
15533 deduction fails.
15535 applies. */
15537 {
15540 }
15543 }
15544 }
15548 }
15550 /* Returns the level of DECL, which declares a template parameter. */
15552 static int
15554 {
15556 {
15566 }
15568 }
15570 /* Decide whether ARG can be unified with PARM, considering only the
15571 cv-qualifiers of each type, given STRICT as documented for unify.
15572 Returns nonzero iff the unification is OK on that basis. */
15574 static int
15576 {
15582 {
15583 /* Although a CVR qualifier is ignored when being applied to a
15584 substituted template parameter ([8.3.2]/1 for example), that
15585 does not allow us to unify "const T" with "int&" because both
15586 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
15587 It is ok when we're allowing additional CV qualifiers
15588 at the outer level [14.8.2.1]/3,1st bullet. */
15598 }
15609 }
15611 /* Determines the LEVEL and INDEX for the template parameter PARM. */
15612 void
15614 {
15618 {
15621 }
15622 else
15623 {
15626 }
15627 }
15629 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
15630 do { \
15631 if (unify (TP, TA, P, A, S, EP)) \
15632 return 1; \
15633 } while (0);
15635 /* Unifies the remaining arguments in PACKED_ARGS with the pack
15636 expansion at the end of PACKED_PARMS. Returns 0 if the type
15637 deduction succeeds, 1 otherwise. STRICT is the same as in
15638 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
15639 call argument list. We'll need to adjust the arguments to make them
15640 types. SUBR tells us if this is from a recursive call to
15641 type_unification_real, or for comparing two template argument
15642 lists. */
15644 static int
15648 {
15649 tree parm
15656 /* Determine the parameter packs we will be deducing from the
15657 pattern, and record their current deductions. */
15660 {
15664 /* Determine the index and level of this parameter pack. */
15667 /* Keep track of the parameter packs and their corresponding
15668 argument packs. */
15671 }
15673 /* Loop through all of the arguments that have not yet been
15674 unified and unify each with the pattern. */
15676 {
15677 tree parm;
15681 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
15682 or the element of its argument pack at the current index if
15683 this argument was explicitly specified. */
15685 {
15694 {
15697 }
15699 }
15701 /* If we had explicit template arguments, substitute them into the
15702 pattern before deduction. */
15704 {
15705 /* Some arguments might still be unspecified or dependent. */
15713 NULL_TREE);
15718 }
15719 else
15722 /* Unify the pattern with the current argument. */
15727 /* For each parameter pack, collect the deduced value. */
15729 {
15735 }
15736 }
15738 /* Verify that the results of unification with the parameter packs
15739 produce results consistent with what we've seen before, and make
15740 the deduced argument packs available. */
15742 {
15749 /* By default keep the original deduced argument pack.
15750 If necessary, more specific code is going to update the
15751 resulting deduced argument later down in this function. */
15755 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
15756 actually deduce anything. */
15764 {
15765 /* If we had fewer function args than explicit template args,
15766 just use the explicits. */
15771 }
15774 {
15775 tree result;
15776 /* Build the deduced *_ARGUMENT_PACK. */
15778 {
15783 }
15784 else
15789 /* Note the deduced argument packs for this parameter
15790 pack. */
15792 }
15796 {
15797 /* We only had the explicitly-provided arguments before, but
15798 now we have a complete set of arguments. */
15804 }
15805 else
15806 {
15812 /* Inconsistent unification of this parameter pack. */
15814 bad_old_arg,
15815 bad_new_arg);
15816 }
15817 }
15820 }
15822 /* Deduce the value of template parameters. TPARMS is the (innermost)
15823 set of template parameters to a template. TARGS is the bindings
15824 for those template parameters, as determined thus far; TARGS may
15825 include template arguments for outer levels of template parameters
15826 as well. PARM is a parameter to a template function, or a
15827 subcomponent of that parameter; ARG is the corresponding argument.
15828 This function attempts to match PARM with ARG in a manner
15829 consistent with the existing assignments in TARGS. If more values
15830 are deduced, then TARGS is updated.
15832 Returns 0 if the type deduction succeeds, 1 otherwise. The
15833 parameter STRICT is a bitwise or of the following flags:
15835 UNIFY_ALLOW_NONE:
15836 Require an exact match between PARM and ARG.
15837 UNIFY_ALLOW_MORE_CV_QUAL:
15838 Allow the deduced ARG to be more cv-qualified (by qualification
15839 conversion) than ARG.
15840 UNIFY_ALLOW_LESS_CV_QUAL:
15841 Allow the deduced ARG to be less cv-qualified than ARG.
15842 UNIFY_ALLOW_DERIVED:
15843 Allow the deduced ARG to be a template base class of ARG,
15844 or a pointer to a template base class of the type pointed to by
15845 ARG.
15846 UNIFY_ALLOW_INTEGER:
15847 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
15848 case for more information.
15849 UNIFY_ALLOW_OUTER_LEVEL:
15850 This is the outermost level of a deduction. Used to determine validity
15851 of qualification conversions. A valid qualification conversion must
15852 have const qualified pointers leading up to the inner type which
15853 requires additional CV quals, except at the outer level, where const
15854 is not required [conv.qual]. It would be normal to set this flag in
15855 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
15856 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
15857 This is the outermost level of a deduction, and PARM can be more CV
15858 qualified at this point.
15859 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
15860 This is the outermost level of a deduction, and PARM can be less CV
15861 qualified at this point. */
15863 static int
15866 {
15868 tree targ;
15869 tree tparm;
15872 /* I don't think this will do the right thing with respect to types.
15873 But the only case I've seen it in so far has been array bounds, where
15874 signedness is the only information lost, and I think that will be
15875 okay. */
15883 /* We can't deduce anything from this, but we might get all the
15884 template args from other function args. */
15887 /* If PARM uses template parameters, then we can't bail out here,
15888 even if ARG == PARM, since we won't record unifications for the
15889 template parameters. We might need them if we're trying to
15890 figure out which of two things is more specialized. */
15894 /* Handle init lists early, so the rest of the function can assume
15895 we're dealing with a type. */
15897 {
15902 /* Replace T with std::initializer_list<T> for deduction. */
15908 /* We can only deduce from an initializer list argument if the
15909 parameter is std::initializer_list; otherwise this is a
15910 non-deduced context. */
15916 {
15923 {
15925 /* It should only be possible to get here for a call. */
15927 elt_strict |= maybe_adjust_types_for_deduction
15930 }
15933 explain_p);
15934 }
15936 /* If the std::initializer_list<T> deduction worked, replace the
15937 deduced A with std::initializer_list<A>. */
15939 {
15944 }
15946 }
15948 /* Immediately reject some pairs that won't unify because of
15949 cv-qualification mismatches. */
15952 /* It is the elements of the array which hold the cv quals of an array
15953 type, and the elements might be template type parms. We'll check
15954 when we recurse. */
15956 /* We check the cv-qualifiers when unifying with template type
15957 parameters below. We want to allow ARG `const T' to unify with
15958 PARM `T' for example, when computing which of two templates
15959 is more specialized, for example. */
15973 {
15977 /* In a type which contains a nested-name-specifier, template
15978 argument values cannot be deduced for template parameters used
15979 within the nested-name-specifier. */
15991 /* The PARM is not one we're trying to unify. Just check
15992 to see if it matches ARG. */
15993 {
15998 else
16000 }
16007 /* Check for mixed types and values. */
16015 {
16016 /* ARG must be constructed from a template class or a template
16017 template parameter. */
16022 {
16026 tree parm_parms
16027 = DECL_INNERMOST_TEMPLATE_PARMS
16032 /* The resolution to DR150 makes clear that default
16033 arguments for an N-argument may not be used to bind T
16034 to a template template parameter with fewer than N
16035 parameters. It is not safe to permit the binding of
16036 default arguments as an extension, as that may change
16037 the meaning of a conforming program. Consider:
16039 struct Dense { static const unsigned int dim = 1; };
16041 template <template <typename> class View,
16042 typename Block>
16043 void operator+(float, View<Block> const&);
16045 template <typename Block,
16046 unsigned int Dim = Block::dim>
16047 struct Lvalue_proxy { operator float() const; };
16049 void
16050 test_1d (void) {
16051 Lvalue_proxy<Dense> p;
16052 float b;
16053 b + p;
16054 }
16056 Here, if Lvalue_proxy is permitted to bind to View, then
16057 the global operator+ will be used; if they are not, the
16058 Lvalue_proxy will be converted to float. */
16060 full_argvec,
16062 (explain_p
16063 ? tf_warning_or_error
16070 /* Deduce arguments T, i from TT<T> or TT<i>.
16071 We check each element of PARMVEC and ARGVEC individually
16072 rather than the whole TREE_VEC since they can have
16073 different number of elements. */
16080 /* Check if the parameters end in a pack, making them
16081 variadic. */
16091 {
16096 }
16101 DEDUCE_EXACT,
16104 }
16107 /* Fall through to deduce template name. */
16108 }
16112 {
16113 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
16115 /* Simple cases: Value already set, does match or doesn't. */
16120 }
16121 else
16122 {
16123 /* If PARM is `const T' and ARG is only `int', we don't have
16124 a match unless we are allowing additional qualification.
16125 If ARG is `const int' and PARM is just `T' that's OK;
16126 that binds `const int' to `T'. */
16131 /* Consider the case where ARG is `const volatile int' and
16132 PARM is `const T'. Then, T should be `volatile int'. */
16133 arg = cp_build_qualified_type_real
16138 /* Simple cases: Value already set, does match or doesn't. */
16144 /* Make sure that ARG is not a variable-sized array. (Note
16145 that were talking about variable-sized arrays (like
16146 `int[n]'), rather than arrays of unknown size (like
16147 `int[]').) We'll get very confused by such a type since
16148 the bound of the array is not constant, and therefore
16149 not mangleable. Besides, such types are not allowed in
16150 ISO C++, so we can do as we please here. We do allow
16151 them for 'auto' deduction, since that isn't ABI-exposed. */
16155 /* Strip typedefs as in convert_template_argument. */
16157 }
16159 /* If ARG is a parameter pack or an expansion, we cannot unify
16160 against it unless PARM is also a parameter pack. */
16165 /* If the argument deduction results is a METHOD_TYPE,
16166 then there is a problem.
16167 METHOD_TYPE doesn't map to any real C++ type the result of
16168 the deduction can not be of that type. */
16182 {
16183 /* The PARM is not one we're trying to unify. Just check
16184 to see if it matches ARG. */
16190 }
16196 {
16201 }
16203 /* [temp.deduct.type] If, in the declaration of a function template
16204 with a non-type template-parameter, the non-type
16205 template-parameter is used in an expression in the function
16206 parameter-list and, if the corresponding template-argument is
16207 deduced, the template-argument type shall match the type of the
16208 template-parameter exactly, except that a template-argument
16209 deduced from an array bound may be of any integral type.
16210 The non-type parameter might use already deduced type parameters. */
16213 /* Template-parameter dependent expression. Just accept it for now.
16214 It will later be processed in convert_template_argument. */
16215 ;
16221 /* Convert the ARG to the type of PARM; the deduced non-type
16222 template argument must exactly match the types of the
16223 corresponding parameter. */
16226 /* We haven't deduced the type of this parameter yet. Try again
16227 later. */
16229 else
16232 /* If ARG is a parameter pack or an expansion, we cannot unify
16233 against it unless PARM is also a parameter pack. */
16243 {
16244 /* A pointer-to-member constant can be unified only with
16245 another constant. */
16249 /* Just unify the class member. It would be useless (and possibly
16250 wrong, depending on the strict flags) to unify also
16251 PTRMEM_CST_CLASS, because we want to be sure that both parm and
16252 arg refer to the same variable, even if through different
16253 classes. For instance:
16255 struct A { int x; };
16256 struct B : A { };
16258 Unification of &A::x and &B::x must succeed. */
16261 }
16264 {
16268 /* [temp.deduct.call]
16270 A can be another pointer or pointer to member type that can
16271 be converted to the deduced A via a qualification
16272 conversion (_conv.qual_).
16274 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
16275 This will allow for additional cv-qualification of the
16276 pointed-to types if appropriate. */
16279 /* The derived-to-base conversion only persists through one
16280 level of pointers. */
16285 }
16300 {
16301 tree parm_max;
16302 tree arg_max;
16306 /* Our representation of array types uses "N - 1" as the
16307 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
16308 not an integer constant. We cannot unify arbitrarily
16309 complex expressions, so we eliminate the MINUS_EXPRs
16310 here. */
16314 {
16317 }
16321 {
16322 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
16323 trying to unify the type of a variable with the type
16324 of a template parameter. For example:
16326 template <unsigned int N>
16327 void f (char (&) [N]);
16328 int g();
16329 void h(int i) {
16330 char a[g(i)];
16331 f(a);
16332 }
16334 Here, the type of the ARG will be "int [g(i)]", and
16335 may be a SAVE_EXPR, etc. */
16339 }
16341 /* If only one of the bounds used a MINUS_EXPR, compensate
16342 by adding one to the other bound. */
16345 integer_type_node,
16346 parm_max,
16347 integer_one_node);
16350 integer_type_node,
16351 arg_max,
16352 integer_one_node);
16356 }
16371 /* We have already checked cv-qualification at the top of the
16372 function. */
16376 /* As far as unification is concerned, this wins. Later checks
16377 will invalidate it if necessary. */
16380 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
16381 /* Type INTEGER_CST can come from ordinary constant template args. */
16393 {
16403 /* Check for pack expansions in the parameters. */
16405 {
16407 {
16409 /* We can unify against something with a trailing
16410 parameter pack. */
16412 else
16413 /* [temp.deduct.type]/9: If the template argument list of
16414 P contains a pack expansion that is not the last
16415 template argument, the entire template argument list
16416 is a non-deduced context. */
16418 }
16419 }
16421 /* If we don't have enough arguments to satisfy the parameters
16422 (not counting the pack expression at the end), or we have
16423 too many arguments for a parameter list that doesn't end in
16424 a pack expression, we can't unify. */
16430 /* Unify all of the parameters that precede the (optional)
16431 pack expression. */
16433 {
16438 }
16441 DEDUCE_EXACT,
16444 }
16452 {
16460 }
16463 {
16467 {
16468 /* First, we try to unify the PARM and ARG directly. */
16473 {
16474 /* Fallback to the special case allowed in
16475 [temp.deduct.call]:
16477 If P is a class, and P has the form
16478 template-id, then A can be a derived class of
16479 the deduced A. Likewise, if P is a pointer to
16480 a class of the form template-id, A can be a
16481 pointer to a derived class pointed to by the
16482 deduced A. */
16489 }
16490 }
16494 /* Perhaps PARM is something like S<U> and ARG is S<int>.
16495 Then, we should unify `int' and `U'. */
16497 else
16498 /* There's no chance of unification succeeding. */
16503 }
16510 {
16513 tree a;
16519 /* CV qualifications for methods can never be deduced, they must
16520 match exactly. We need to check them explicitly here,
16521 because type_unification_real treats them as any other
16522 cv-qualified parameter. */
16524 && (!check_cv_quals_for_unify
16544 }
16547 /* Unify a pointer to member with a pointer to member function, which
16548 deduces the type of the member as a function type. */
16550 {
16551 tree method_type;
16552 tree fntype;
16554 /* Check top-level cv qualifiers */
16562 /* Determine the type of the function we are unifying against. */
16564 fntype =
16568 /* Extract the cv-qualifiers of the member function from the
16569 implicit object parameter and place them on the function
16570 type to be restored later. */
16573 }
16592 /* Matched cases are handled by the ARG == PARM test above. */
16596 /* A non-type template parameter that is a variable should be a
16597 an integral constant, in which case, it whould have been
16598 folded into its (constant) value. So we should not be getting
16599 a variable here. */
16610 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
16611 or UNDERLYING_TYPE nodes. */
16615 /* Unification fails if we hit an error node. */
16619 /* An unresolved overload is a nondeduced context. */
16624 /* We must be looking at an expression. This can happen with
16625 something like:
16627 template <int I>
16628 void foo(S<I>, S<I + 2>);
16630 This is a "nondeduced context":
16632 [deduct.type]
16634 The nondeduced contexts are:
16636 --A type that is a template-id in which one or more of
16637 the template-arguments is an expression that references
16638 a template-parameter.
16640 In these cases, we assume deduction succeeded, but don't
16641 actually infer any unifications. */
16646 else
16648 }
16649 }
16650 #undef RECUR_AND_CHECK_FAILURE
16651 \f
16652 /* Note that DECL can be defined in this translation unit, if
16653 required. */
16655 static void
16657 {
16658 tree clone;
16662 }
16664 /* Called if RESULT is explicitly instantiated, or is a member of an
16665 explicitly instantiated class. */
16667 void
16669 {
16672 /* If this entity has already been written out, it's too late to
16673 make any modifications. */
16678 /* The TREE_PUBLIC flag for function declarations will have been
16679 set correctly by tsubst. */
16682 /* This might have been set by an earlier implicit instantiation. */
16687 else
16688 {
16690 /* Always make artificials weak. */
16693 /* For WIN32 we also want to put explicit instantiations in
16694 linkonce sections. */
16697 }
16699 /* If EXTERN_P, then this function will not be emitted -- unless
16700 followed by an explicit instantiation, at which point its linkage
16701 will be adjusted. If !EXTERN_P, then this function will be
16702 emitted here. In neither circumstance do we want
16703 import_export_decl to adjust the linkage. */
16705 }
16707 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
16708 important template arguments. If any are missing, we check whether
16709 they're important by using error_mark_node for substituting into any
16710 args that were used for partial ordering (the ones between ARGS and END)
16711 and seeing if it bubbles up. */
16713 static bool
16715 {
16720 {
16723 }
16725 {
16729 }
16731 }
16733 /* Given two function templates PAT1 and PAT2, return:
16735 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
16736 -1 if PAT2 is more specialized than PAT1.
16737 0 if neither is more specialized.
16739 LEN indicates the number of parameters we should consider
16740 (defaulted parameters should not be considered).
16742 The 1998 std underspecified function template partial ordering, and
16743 DR214 addresses the issue. We take pairs of arguments, one from
16744 each of the templates, and deduce them against each other. One of
16745 the templates will be more specialized if all the *other*
16746 template's arguments deduce against its arguments and at least one
16747 of its arguments *does* *not* deduce against the other template's
16748 corresponding argument. Deduction is done as for class templates.
16749 The arguments used in deduction have reference and top level cv
16750 qualifiers removed. Iff both arguments were originally reference
16751 types *and* deduction succeeds in both directions, the template
16752 with the more cv-qualified argument wins for that pairing (if
16753 neither is more cv-qualified, they both are equal). Unlike regular
16754 deduction, after all the arguments have been deduced in this way,
16755 we do *not* verify the deduced template argument values can be
16756 substituted into non-deduced contexts.
16758 The logic can be a bit confusing here, because we look at deduce1 and
16759 targs1 to see if pat2 is at least as specialized, and vice versa; if we
16760 can find template arguments for pat1 to make arg1 look like arg2, that
16761 means that arg2 is at least as specialized as arg1. */
16763 int
16765 {
16778 /* Remove the this parameter from non-static member functions. If
16779 one is a non-static member function and the other is not a static
16780 member function, remove the first parameter from that function
16781 also. This situation occurs for operator functions where we
16782 locate both a member function (with this pointer) and non-member
16783 operator (with explicit first operand). */
16785 {
16790 }
16792 {
16795 {
16796 len--;
16798 }
16799 }
16801 /* If only one is a conversion operator, they are unordered. */
16805 /* Consider the return type for a conversion function */
16807 {
16810 len++;
16811 }
16813 processing_template_decl++;
16819 /* Stop when an ellipsis is seen. */
16821 {
16830 {
16831 /* When both arguments are pack expansions, we need only
16832 unify the patterns themselves. */
16836 /* This is the last comparison we need to do. */
16838 }
16841 {
16844 }
16847 {
16850 }
16856 {
16862 /* Setup the parameter vector, which contains only ARG1. */
16865 /* Setup the argument vector, which contains the remaining
16866 arguments. */
16875 /* We cannot deduce in the other direction, because ARG1 is
16876 a pack expansion but ARG2 is not. */
16878 }
16880 {
16886 /* Setup the parameter vector, which contains only ARG1. */
16889 /* Setup the argument vector, which contains the remaining
16890 arguments. */
16899 /* We cannot deduce in the other direction, because ARG2 is
16900 a pack expansion but ARG1 is not.*/
16902 }
16904 else
16905 {
16906 /* The normal case, where neither argument is a pack
16907 expansion. */
16914 }
16916 /* If we couldn't deduce arguments for tparms1 to make arg1 match
16917 arg2, then arg2 is not as specialized as arg1. */
16923 /* "If, for a given type, deduction succeeds in both directions
16924 (i.e., the types are identical after the transformations above)
16925 and if the type from the argument template is more cv-qualified
16926 than the type from the parameter template (as described above)
16927 that type is considered to be more specialized than the other. If
16928 neither type is more cv-qualified than the other then neither type
16929 is more specialized than the other." */
16933 {
16938 }
16941 /* We've failed to deduce something in either direction.
16942 These must be unordered. */
16947 /* We have already processed all of the arguments in our
16948 handing of the pack expansion type. */
16953 }
16955 /* "In most cases, all template parameters must have values in order for
16956 deduction to succeed, but for partial ordering purposes a template
16957 parameter may remain without a value provided it is not used in the
16958 types being used for partial ordering."
16960 Thus, if we are missing any of the targs1 we need to substitute into
16961 origs1, then pat2 is not as specialized as pat1. This can happen when
16962 there is a nondeduced context. */
16968 processing_template_decl--;
16970 /* All things being equal, if the next argument is a pack expansion
16971 for one function but not for the other, prefer the
16972 non-variadic function. FIXME this is bogus; see c++/41958. */
16976 {
16979 }
16985 else
16987 }
16989 /* Determine which of two partial specializations is more specialized.
16991 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
16992 to the first partial specialization. The TREE_VALUE is the
16993 innermost set of template parameters for the partial
16994 specialization. PAT2 is similar, but for the second template.
16996 Return 1 if the first partial specialization is more specialized;
16997 -1 if the second is more specialized; 0 if neither is more
16998 specialized.
17000 See [temp.class.order] for information about determining which of
17001 two templates is more specialized. */
17003 static int
17005 {
17006 tree targs;
17014 /* Just like what happens for functions, if we are ordering between
17015 different class template specializations, we may encounter dependent
17016 types in the arguments, and we need our dependency check functions
17017 to behave correctly. */
17023 {
17026 }
17032 {
17035 }
17038 /* In the case of a tie where at least one of the class templates
17039 has a parameter pack at the end, the template with the most
17040 non-packed parameters wins. */
17042 && any_deductions
17045 {
17051 /* We don't count the pack expansion at the end. */
17061 }
17064 }
17066 /* Return the template arguments that will produce the function signature
17067 DECL from the function template FN, with the explicit template
17068 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
17069 also match. Return NULL_TREE if no satisfactory arguments could be
17070 found. */
17072 static tree
17074 {
17077 tree decl_type;
17078 tree decl_arg_types;
17081 tree arg;
17083 /* Substitute the explicit template arguments into the type of DECL.
17084 The call to fn_type_unification will handle substitution into the
17085 FN. */
17088 {
17089 tree tmpl;
17090 tree converted_args;
17094 else
17095 /* We can get here for some invalid specializations. */
17098 converted_args
17101 tf_none,
17110 }
17112 /* Never do unification on the 'this' parameter. */
17131 }
17133 /* Return the innermost template arguments that, when applied to a
17134 template specialization whose innermost template parameters are
17135 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
17136 ARGS.
17138 For example, suppose we have:
17140 template <class T, class U> struct S {};
17141 template <class T> struct S<T*, int> {};
17143 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
17144 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
17145 int}. The resulting vector will be {double}, indicating that `T'
17146 is bound to `double'. */
17148 static tree
17150 {
17152 tree deduced_args;
17153 tree innermost_deduced_args;
17157 {
17161 innermost_deduced_args);
17162 }
17163 else
17176 /* Verify that nondeduced template arguments agree with the type
17177 obtained from argument deduction.
17179 For example:
17181 struct A { typedef int X; };
17182 template <class T, class U> struct C {};
17183 template <class T> struct C<T, typename T::X> {};
17185 Then with the instantiation `C<A, int>', we can deduce that
17186 `T' is `A' but unify () does not check whether `typename T::X'
17187 is `int'. */
17190 /* We only need to check the innermost arguments; the other
17191 arguments will always agree. */
17196 /* Now that we have bindings for all of the template arguments,
17197 ensure that the arguments deduced for the template template
17198 parameters have compatible template parameter lists. See the use
17199 of template_template_parm_bindings_ok_p in fn_type_unification
17200 for more information. */
17205 }
17207 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
17208 Return the TREE_LIST node with the most specialized template, if
17209 any. If there is no most specialized template, the error_mark_node
17210 is returned.
17212 Note that this function does not look at, or modify, the
17213 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
17214 returned is one of the elements of INSTANTIATIONS, callers may
17215 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
17216 and retrieve it from the value returned. */
17218 tree
17220 {
17227 {
17233 fate--;
17238 fate++;
17243 {
17244 /* Equally specialized, move to next function. If there
17245 is no next function, nothing's most specialized. */
17250 }
17251 }
17254 /* Now verify that champ is better than everything earlier in the
17255 instantiation list. */
17263 {
17266 }
17268 processing_template_decl--;
17274 }
17276 /* If DECL is a specialization of some template, return the most
17277 general such template. Otherwise, returns NULL_TREE.
17279 For example, given:
17281 template <class T> struct S { template <class U> void f(U); };
17283 if TMPL is `template <class U> void S<int>::f(U)' this will return
17284 the full template. This function will not trace past partial
17285 specializations, however. For example, given in addition:
17287 template <class T> struct S<T*> { template <class U> void f(U); };
17289 if TMPL is `template <class U> void S<int*>::f(U)' this will return
17290 `template <class T> template <class U> S<T*>::f(U)'. */
17292 tree
17294 {
17295 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
17296 an immediate specialization. */
17298 {
17302 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
17303 template friend. */
17308 }
17310 /* Look for more and more general templates. */
17312 {
17313 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
17314 (See cp-tree.h for details.) */
17322 /* Stop if we run into an explicitly specialized class template. */
17329 }
17332 }
17334 /* Return the most specialized of the class template partial
17335 specializations of TMPL which can produce TYPE, a specialization of
17336 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
17337 a _TYPE node corresponding to the partial specialization, while the
17338 TREE_PURPOSE is the set of template arguments that must be
17339 substituted into the TREE_TYPE in order to generate TYPE.
17341 If the choice of partial specialization is ambiguous, a diagnostic
17342 is issued, and the error_mark_node is returned. If there are no
17343 partial specializations of TMPL matching TYPE, then NULL_TREE is
17344 returned. */
17346 static tree
17348 {
17350 tree t;
17351 tree champ;
17354 tree args;
17360 /* For determining which partial specialization to use, only the
17361 innermost args are interesting. */
17363 {
17366 }
17369 {
17370 tree partial_spec_args;
17371 tree spec_args;
17379 {
17382 /* Discard the outer levels of args, and then substitute in the
17383 template args from the enclosing class. */
17385 partial_spec_args = tsubst_template_args
17388 /* PARMS already refers to just the innermost parms, but the
17389 template parms in partial_spec_args had their levels lowered
17390 by tsubst, so we need to do the same for the parm list. We
17391 can't just tsubst the TREE_VEC itself, as tsubst wants to
17392 treat a TREE_VEC as an argument vector. */
17398 }
17400 partial_spec_args =
17403 partial_spec_args),
17414 partial_spec_args,
17415 args);
17417 {
17422 }
17423 }
17433 {
17436 ;
17437 else
17438 {
17440 {
17443 {
17446 }
17447 }
17449 }
17450 }
17454 {
17457 {
17460 }
17461 }
17464 {
17472 {
17475 }
17478 }
17481 }
17483 /* Explicitly instantiate DECL. */
17485 void
17487 {
17492 /* An error occurred, for which grokdeclarator has already issued
17493 an appropriate message. */
17496 {
17499 }
17501 {
17502 /* There is an asymmetry here in the way VAR_DECLs and
17503 FUNCTION_DECLs are handled by grokdeclarator. In the case of
17504 the latter, the DECL we get back will be marked as a
17505 template instantiation, and the appropriate
17506 DECL_TEMPLATE_INFO will be set up. This does not happen for
17507 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
17508 should handle VAR_DECLs as it currently handles
17509 FUNCTION_DECLs. */
17511 {
17514 }
17517 {
17520 }
17522 {
17527 }
17528 }
17530 {
17533 }
17534 else
17537 /* Check for various error cases. Note that if the explicit
17538 instantiation is valid the RESULT will currently be marked as an
17539 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
17540 until we get here. */
17543 {
17544 /* DR 259 [temp.spec].
17546 Both an explicit instantiation and a declaration of an explicit
17547 specialization shall not appear in a program unless the explicit
17548 instantiation follows a declaration of the explicit specialization.
17550 For a given set of template parameters, if an explicit
17551 instantiation of a template appears after a declaration of an
17552 explicit specialization for that template, the explicit
17553 instantiation has no effect. */
17555 }
17557 {
17558 /* [temp.spec]
17560 No program shall explicitly instantiate any template more
17561 than once.
17563 We check DECL_NOT_REALLY_EXTERN so as not to complain when
17564 the first instantiation was `extern' and the second is not,
17565 and EXTERN_P for the opposite case. */
17568 /* If an "extern" explicit instantiation follows an ordinary
17569 explicit instantiation, the template is instantiated. */
17572 }
17574 {
17577 }
17579 {
17582 }
17585 ;
17587 {
17590 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
17593 }
17594 else
17602 }
17604 static void
17606 {
17612 {
17615 }
17616 }
17618 /* Called from do_type_instantiation through binding_table_foreach to
17619 do recursive instantiation for the type bound in ENTRY. */
17620 static void
17622 {
17628 }
17630 /* Called from do_type_instantiation to instantiate a member
17631 (a member function or a static member variable) of an
17632 explicitly instantiated class template. */
17633 static void
17635 {
17640 }
17642 /* Perform an explicit instantiation of template class T. STORAGE, if
17643 non-null, is the RID for extern, inline or static. COMPLAIN is
17644 nonzero if this is called from the parser, zero if called recursively,
17645 since the standard is unclear (as detailed below). */
17647 void
17649 {
17659 {
17660 tree tmpl =
17664 else
17667 }
17672 {
17675 t);
17677 }
17680 {
17682 {
17684 {
17687 "ISO C++ 1998 forbids the use of %<extern%> on "
17689 }
17690 else
17692 "ISO C++ forbids the use of %qE"
17694 }
17702 else
17703 {
17705 storage);
17707 }
17708 }
17711 {
17712 /* DR 259 [temp.spec].
17714 Both an explicit instantiation and a declaration of an explicit
17715 specialization shall not appear in a program unless the explicit
17716 instantiation follows a declaration of the explicit specialization.
17718 For a given set of template parameters, if an explicit
17719 instantiation of a template appears after a declaration of an
17720 explicit specialization for that template, the explicit
17721 instantiation has no effect. */
17723 }
17725 {
17726 /* [temp.spec]
17728 No program shall explicitly instantiate any template more
17729 than once.
17731 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
17732 instantiation was `extern'. If EXTERN_P then the second is.
17733 These cases are OK. */
17740 /* If we've already instantiated the template, just return now. */
17743 }
17751 {
17752 tree tmp;
17754 /* In contrast to implicit instantiation, where only the
17755 declarations, and not the definitions, of members are
17756 instantiated, we have here:
17758 [temp.explicit]
17760 The explicit instantiation of a class template specialization
17761 implies the instantiation of all of its members not
17762 previously explicitly specialized in the translation unit
17763 containing the explicit instantiation.
17765 Of course, we can't instantiate member template classes, since
17766 we don't have any arguments for them. Note that the standard
17767 is unclear on whether the instantiation of the members are
17768 *explicit* instantiations or not. However, the most natural
17769 interpretation is that it should be an explicit instantiation. */
17784 }
17785 }
17787 /* Given a function DECL, which is a specialization of TMPL, modify
17788 DECL to be a re-instantiation of TMPL with the same template
17789 arguments. TMPL should be the template into which tsubst'ing
17790 should occur for DECL, not the most general template.
17792 One reason for doing this is a scenario like this:
17794 template <class T>
17795 void f(const T&, int i);
17797 void g() { f(3, 7); }
17799 template <class T>
17800 void f(const T& t, const int i) { }
17802 Note that when the template is first instantiated, with
17803 instantiate_template, the resulting DECL will have no name for the
17804 first parameter, and the wrong type for the second. So, when we go
17805 to instantiate the DECL, we regenerate it. */
17807 static void
17809 {
17810 /* The arguments used to instantiate DECL, from the most general
17811 template. */
17812 tree args;
17813 tree code_pattern;
17818 /* Make sure that we can see identifiers, and compute access
17819 correctly. */
17823 {
17824 tree decl_parm;
17825 tree pattern_parm;
17826 tree specs;
17840 specs);
17842 /* Merge parameter declarations. */
17845 pattern_parm
17849 {
17850 tree parm_type;
17851 tree attributes;
17856 NULL_TREE);
17862 {
17865 }
17868 }
17869 /* Merge any parameters that match with the function parameter
17870 pack. */
17872 {
17874 tree expanded_types;
17875 /* Expand the TYPE_PACK_EXPANSION that provides the types for
17876 the parameters in this function parameter pack. */
17881 {
17882 tree parm_type;
17883 tree attributes;
17886 /* Rename the parameter to include the index. */
17895 {
17898 }
17900 }
17901 }
17902 /* Merge additional specifiers from the CODE_PATTERN. */
17906 }
17908 {
17916 }
17917 else
17921 }
17923 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
17924 substituted to get DECL. */
17926 tree
17928 {
17931 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
17932 for the instantiation. This is not always the most general
17933 template. Consider, for example:
17935 template <class T>
17936 struct S { template <class U> void f();
17937 template <> void f<int>(); };
17939 and an instantiation of S<double>::f<int>. We want TD to be the
17940 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
17942 more general template. */
17944 /* We must also deal with friend templates. Given:
17946 template <class T> struct S {
17947 template <class U> friend void f() {};
17948 };
17950 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
17951 so far as the language is concerned, but that's still
17952 where we get the pattern for the instantiation from. On
17953 other hand, if the definition comes outside the class, say:
17955 template <class T> struct S {
17956 template <class U> friend void f();
17957 };
17958 template <class U> friend void f() {}
17960 we don't need to look any further. That's what the check for
17961 DECL_INITIAL is for. */
17965 {
17966 /* The present template, TD, should not be a definition. If it
17967 were a definition, we should be using it! Note that we
17968 cannot restructure the loop to just keep going until we find
17969 a template with a definition, since that might go too far if
17970 a specialization was declared, but not defined. */
17974 /* Fetch the more general template. */
17976 }
17979 }
17981 /* Returns true if we need to instantiate this template instance even if we
17982 know we aren't going to emit it.. */
17984 bool
17986 {
17987 /* We always instantiate inline functions so that we can inline them. An
17988 explicit instantiation declaration prohibits implicit instantiation of
17989 non-inline functions. With high levels of optimization, we would
17990 normally inline non-inline functions -- but we're not allowed to do
17991 that for "extern template" functions. Therefore, we check
17992 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
17996 /* And we need to instantiate static data members so that
17997 their initializers are available in integral constant
17998 expressions. */
18001 }
18003 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
18004 instantiate it now, modifying TREE_TYPE (fn). */
18006 void
18008 {
18022 {
18024 {
18037 }
18038 else
18040 }
18041 else
18042 {
18043 /* This is an implicitly declared function, so NOEX is a list of
18044 other functions to evaluate and merge. */
18045 tree elt;
18048 {
18050 tree subspec;
18054 }
18055 }
18060 {
18063 else
18065 }
18066 }
18068 /* Produce the definition of D, a _DECL generated from a template. If
18069 DEFER_OK is nonzero, then we don't have to actually do the
18070 instantiation now; we just have to do it sometime. Normally it is
18071 an error if this is an explicit instantiation but D is undefined.
18072 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
18073 explicitly instantiated class template. */
18075 tree
18078 {
18080 tree gen_args;
18081 tree args;
18082 tree td;
18083 tree code_pattern;
18084 tree spec;
18085 tree gen_tmpl;
18089 tree fn_context;
18092 /* This function should only be used to instantiate templates for
18093 functions and static member variables. */
18097 /* Variables are never deferred; if instantiation is required, they
18098 are instantiated right away. That allows for better code in the
18099 case that an expression refers to the value of the variable --
18100 if the variable has a constant value the referring expression can
18101 take advantage of that fact. */
18106 /* Don't instantiate cloned functions. Instead, instantiate the
18107 functions they cloned. */
18115 /* D has already been instantiated or explicitly specialized, so
18116 there's nothing for us to do here.
18118 It might seem reasonable to check whether or not D is an explicit
18119 instantiation, and, if so, stop here. But when an explicit
18120 instantiation is deferred until the end of the compilation,
18121 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
18122 the instantiation. */
18125 /* Check to see whether we know that this template will be
18126 instantiated in some other file, as with "extern template"
18127 extension. */
18130 /* In general, we do not instantiate such templates. */
18138 /* We should already have the extra args. */
18141 /* And what's in the hash table should match D. */
18145 /* This needs to happen before any tsubsting. */
18151 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
18152 for the instantiation. */
18156 /* We should never be trying to instantiate a member of a class
18157 template or partial specialization. */
18162 /* In the case of a friend template whose definition is provided
18163 outside the class, we may have too many arguments. Drop the
18164 ones we don't need. The same is true for specializations. */
18165 args = get_innermost_template_args
18167 else
18173 else
18176 /* We may be in the middle of deferred access check. Disable it now. */
18179 /* Unless an explicit instantiation directive has already determined
18180 the linkage of D, remember that a definition is available for
18181 this entity. */
18191 /* If D is a member of an explicitly instantiated class template,
18192 and no definition is available, treat it like an implicit
18193 instantiation. */
18196 {
18197 /* Leave linkage flags alone on instantiations with anonymous
18198 visibility. */
18200 {
18203 }
18205 }
18210 /* Recheck the substitutions to obtain any warning messages
18211 about ignoring cv qualifiers. Don't do this for artificial decls,
18212 as it breaks the context-sensitive substitution for lambda op(). */
18214 {
18218 /* Make sure that we can see identifiers, and compute access
18219 correctly. D is already the target FUNCTION_DECL with the
18220 right context. */
18224 {
18228 /* Don't simply tsubst the function type, as that will give
18229 duplicate warnings about poor parameter qualifications.
18230 The function arguments are the same as the decl_arguments
18231 without the top level cv qualifiers. */
18233 }
18237 }
18239 /* Defer all other templates, unless we have been explicitly
18240 forbidden from doing so. */
18242 template. */
18243 ! pattern_defined
18244 /* If it's OK to postpone instantiation, do so. */
18245 || defer_ok
18246 /* If this is a static data member that will be defined
18247 elsewhere, we don't want to instantiate the entire data
18248 member, but we do want to instantiate the initializer so that
18249 we can substitute that elsewhere. */
18251 {
18252 /* The definition of the static data member is now required so
18253 we must substitute the initializer. */
18257 {
18258 tree ns;
18259 tree init;
18266 args,
18269 /* Make sure the initializer is still constant, in case of
18270 circular dependency (template/instantiate6.C). */
18271 const_init
18275 LOOKUP_ONLYCONVERTING);
18278 }
18280 /* We restore the source position here because it's used by
18281 add_pending_template. */
18287 /* [temp.explicit]
18289 The definition of a non-exported function template, a
18290 non-exported member function template, or a non-exported
18291 member function or static data member of a class template
18292 shall be present in every translation unit in which it is
18293 explicitly instantiated. */
18297 /* If we're in unevaluated context, we just wanted to get the
18298 constant value; this isn't an odr use, so don't queue
18299 a full instantiation. */
18302 /* ??? Historically, we have instantiated inline functions, even
18303 when marked as "extern template". */
18307 }
18308 /* Tell the repository that D is available in this translation unit
18309 -- and see if it is supposed to be instantiated here. */
18311 {
18312 /* In a PCH file, despite the fact that the repository hasn't
18313 requested instantiation in the PCH it is still possible that
18314 an instantiation will be required in a file that includes the
18315 PCH. */
18318 /* Instantiate inline functions so that the inliner can do its
18319 job, even though we'll not be emitting a copy of this
18320 function. */
18323 }
18332 /* Mark D as instantiated so that recursive calls to
18333 instantiate_decl do not try to instantiate it again. */
18336 /* Regenerate the declaration in case the template has been modified
18337 by a subsequent redeclaration. */
18340 /* We already set the file and line above. Reset them now in case
18341 they changed as a result of calling regenerate_decl_from_template. */
18345 {
18346 tree init;
18349 /* Clear out DECL_RTL; whatever was there before may not be right
18350 since we've reset the type of the declaration. */
18354 /* The initializer is placed in DECL_INITIAL by
18355 regenerate_decl_from_template so we don't need to
18356 push/pop_access_scope again here. Pull it out so that
18357 cp_finish_decl can process it. */
18362 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
18363 initializer. That function will defer actual emission until
18364 we have a chance to determine linkage. */
18367 /* Enter the scope of D so that access-checking works correctly. */
18372 }
18376 {
18378 tree subst_decl;
18379 tree tmpl_parm;
18380 tree spec_parm;
18382 /* Save away the current list, in case we are instantiating one
18383 template from within the body of another. */
18386 /* Set up the list of local specializations. */
18389 /* Set up context. */
18392 /* Some typedefs referenced from within the template code need to be
18393 access checked at template instantiation time, i.e now. These
18394 types were added to the template at parsing time. Let's get those
18395 and perform the access checks then. */
18397 gen_args);
18399 /* Create substitution entries for the parameters. */
18404 {
18408 }
18410 {
18412 {
18415 }
18416 else
18417 {
18418 /* Register the (value) argument pack as a specialization of
18419 TMPL_PARM, then move on. */
18422 }
18423 }
18426 /* Substitute into the body of the function. */
18431 /* Set the current input_location to the end of the function
18432 so that finish_function knows where we are. */
18435 /* We don't need the local specializations any more. */
18439 /* Finish the function. */
18442 }
18444 /* We're not deferring instantiation any more. */
18452 out:
18460 }
18462 /* Run through the list of templates that we wish we could
18463 instantiate, and instantiate any we can. RETRIES is the
18464 number of times we retry pending template instantiation. */
18466 void
18468 {
18472 /* Instantiating templates may trigger vtable generation. This in turn
18473 may require further template instantiations. We place a limit here
18474 to avoid infinite loop. */
18476 {
18480 " instantiating %q+D, possibly from virtual table generation"
18484 /* Pretend that we defined it. */
18487 }
18489 do
18490 {
18495 {
18500 {
18501 tree fn;
18504 {
18508 fn;
18516 }
18519 }
18520 else
18521 {
18524 {
18525 instantiation
18531 }
18535 }
18538 /* If INSTANTIATION has been instantiated, then we don't
18539 need to consider it again in the future. */
18541 else
18542 {
18545 }
18548 }
18550 }
18554 }
18556 /* Substitute ARGVEC into T, which is a list of initializers for
18557 either base class or a non-static data member. The TREE_PURPOSEs
18558 are DECLs, and the TREE_VALUEs are the initializer values. Used by
18559 instantiate_decl. */
18561 static tree
18563 {
18567 {
18568 tree decl;
18569 tree init;
18575 {
18576 tree expr;
18577 tree arg;
18579 /* Expand the base class expansion type into separate base
18580 classes. */
18582 tf_warning_or_error,
18583 NULL_TREE);
18587 /* We'll be building separate TREE_LISTs of arguments for
18588 each base. */
18594 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
18595 expand each argument in the TREE_VALUE of t. */
18602 /* VOID_TYPE_NODE is used to indicate
18603 value-initialization. */
18604 {
18607 }
18608 else
18609 {
18610 /* Substitute parameter packs into each argument in the
18611 TREE_LIST. */
18614 {
18615 tree expanded_exprs;
18617 /* Expand the argument. */
18619 expanded_exprs
18621 tf_warning_or_error,
18622 NULL_TREE);
18626 /* Prepend each of the expanded expressions to the
18627 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
18629 {
18634 }
18635 }
18638 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
18639 since we built them backwards. */
18641 {
18644 }
18645 }
18646 }
18649 {
18651 {
18655 }
18656 else
18657 {
18658 tree tmp;
18673 /* If we had an initializer but it instantiated to nothing,
18674 value-initialize the object. This will only occur when
18675 the initializer was a pack expansion where the parameter
18676 packs used in that expansion were of length zero. */
18679 }
18682 {
18686 }
18687 }
18688 }
18690 }
18692 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
18694 static void
18696 {
18701 else
18703 }
18705 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
18706 is the instantiation (which should have been created with
18707 start_enum) and ARGS are the template arguments to use. */
18709 static void
18711 {
18712 tree e;
18718 {
18719 tree value;
18720 tree decl;
18723 /* Note that in a template enum, the TREE_VALUE is the
18724 CONST_DECL, not the corresponding INTEGER_CST. */
18729 /* Give this enumeration constant the correct access. */
18732 /* Actually build the enumerator itself. */
18733 build_enumerator
18735 }
18745 }
18747 /* DECL is a FUNCTION_DECL that is a template specialization. Return
18748 its type -- but without substituting the innermost set of template
18749 arguments. So, innermost set of template parameters will appear in
18750 the type. */
18752 tree
18754 {
18755 tree fn_type;
18756 tree tmpl;
18757 tree targs;
18758 tree tparms;
18766 /* There should be as many levels of arguments as there are levels
18767 of parameters. */
18773 /* No substitution is necessary. */
18774 ;
18775 else
18776 {
18778 tree partial_args;
18780 /* Replace the innermost level of the TARGS with NULL_TREEs to
18781 let tsubst know not to substitute for those parameters. */
18790 /* Make sure that we can see identifiers, and compute access
18791 correctly. */
18795 /* Now, do the (partial) substitution to figure out the
18796 appropriate function type. */
18800 /* Substitute into the template parameters to obtain the real
18801 innermost set of parameters. This step is important if the
18802 innermost set of template parameters contains value
18803 parameters whose types depend on outer template parameters. */
18808 }
18811 }
18813 /* Return truthvalue if we're processing a template different from
18814 the last one involved in diagnostics. */
18815 int
18817 {
18819 }
18821 /* Remember current template involved in diagnostics. */
18822 void
18824 {
18826 }
18830 {
18832 }
18834 /* [temp.param] Check that template non-type parm TYPE is of an allowable
18835 type. Return zero for ok, nonzero for disallowed. Issue error and
18836 warning messages under control of COMPLAIN. */
18838 static int
18840 {
18857 {
18860 else
18862 type);
18863 }
18865 }
18867 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
18868 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
18870 static bool
18872 {
18873 tree scope;
18875 /* [temp.dep.type]
18877 A type is dependent if it is:
18879 -- a template parameter. Template template parameters are types
18880 for us (since TYPE_P holds true for them) so we handle
18881 them here. */
18885 /* -- a qualified-id with a nested-name-specifier which contains a
18886 class-name that names a dependent type or whose unqualified-id
18887 names a dependent type. */
18890 /* -- a cv-qualified type where the cv-unqualified type is
18891 dependent. */
18893 /* -- a compound type constructed from any dependent type. */
18903 {
18904 tree arg_type;
18909 arg_type;
18914 }
18915 /* -- an array type constructed from any dependent type or whose
18916 size is specified by a constant expression that is
18917 value-dependent.
18919 We checked for type- and value-dependence of the bounds in
18920 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
18922 {
18927 }
18929 /* -- a template-id in which either the template name is a template
18930 parameter ... */
18933 /* ... or any of the template arguments is a dependent type or
18934 an expression that is type-dependent or value-dependent. */
18936 && (any_dependent_template_arguments_p
18940 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
18941 dependent; if the argument of the `typeof' expression is not
18942 type-dependent, then it should already been have resolved. */
18948 /* A template argument pack is dependent if any of its packed
18949 arguments are. */
18951 {
18957 }
18959 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
18960 be template parameters. */
18964 /* The standard does not specifically mention types that are local
18965 to template functions or local classes, but they should be
18966 considered dependent too. For example:
18968 template <int I> void f() {
18969 enum E { a = I };
18970 S<sizeof (E)> s;
18971 }
18973 The size of `E' cannot be known until the value of `I' has been
18974 determined. Therefore, `E' must be considered dependent. */
18978 /* Don't use type_dependent_expression_p here, as it can lead
18979 to infinite recursion trying to determine whether a lambda
18980 nested in a lambda is dependent (c++/47687). */
18984 && (any_dependent_template_arguments_p
18988 /* Other types are non-dependent. */
18990 }
18992 /* Returns TRUE if TYPE is dependent, in the sense of
18993 [temp.dep.type]. Note that a NULL type is considered dependent. */
18995 bool
18997 {
18998 /* If there are no template parameters in scope, then there can't be
18999 any dependent types. */
19001 {
19002 /* If we are not processing a template, then nobody should be
19003 providing us with a dependent type. */
19007 }
19009 /* If the type is NULL, we have not computed a type for the entity
19010 in question; in that case, the type is dependent. */
19014 /* Erroneous types can be considered non-dependent. */
19018 /* If we have not already computed the appropriate value for TYPE,
19019 do so now. */
19021 {
19024 }
19027 }
19029 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
19030 lookup. In other words, a dependent type that is not the current
19031 instantiation. */
19033 bool
19035 {
19038 }
19040 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
19041 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
19042 expression. */
19044 /* Note that this predicate is not appropriate for general expressions;
19045 only constant expressions (that satisfy potential_constant_expression)
19046 can be tested for value dependence.
19048 We should really also have a predicate for "instantiation-dependent".
19050 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent.
19051 (what about instantiation-dependent constant-expressions?)
19052 is_late_template_attribute: defer if instantiation-dependent.
19053 compute_array_index_type: proceed if constant and not t- or v-dependent
19054 if instantiation-dependent, need to remember full expression
19055 uses_template_parms: FIXME - need to audit callers
19056 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p?
19057 dependent_type_p [array_type]: dependent if index type is dependent
19058 (or non-constant?)
19059 static_assert - instantiation-dependent */
19061 bool
19063 {
19067 /* A name declared with a dependent type. */
19072 {
19074 /* A name that has not been looked up -- must be dependent. */
19078 /* A non-type template parm. */
19082 /* A non-type template parm. */
19088 /* A constant with literal type and is initialized
19089 with an expression that is value-dependent. */
19101 /* These expressions are value-dependent if the type to which
19102 the cast occurs is dependent or the expression being casted
19103 is value-dependent. */
19104 {
19110 /* A functional cast has a list of operands. */
19113 {
19114 /* If there are no operands, it must be an expression such
19115 as "int()". This should not happen for aggregate types
19116 because it would form non-constant expressions. */
19121 }
19127 }
19132 /* A `sizeof' expression is value-dependent if the operand is
19133 type-dependent or is a pack expansion. */
19142 /* An 'encode' expression is value-dependent if the operand is
19143 type-dependent. */
19152 {
19155 }
19162 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
19163 is value-dependent. */
19164 {
19173 }
19176 {
19180 }
19191 {
19195 }
19198 {
19205 {
19207 /* In a call to a constexpr member function, look through the
19208 implicit ADDR_EXPR on the object argument so that it doesn't
19209 cause the call to be considered value-dependent. We also
19210 look through it in potential_constant_expression. */
19217 }
19219 }
19222 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
19223 type-dependent. */
19227 {
19229 tree val;
19234 }
19237 /* Treat a GNU statement expression as dependent to avoid crashing
19238 under fold_non_dependent_expr; it can't be constant. */
19242 /* A constant expression is value-dependent if any subexpression is
19243 value-dependent. */
19245 {
19252 {
19256 {
19259 /* In some cases, some of the operands may be missing.l
19260 (For example, in the case of PREDECREMENT_EXPR, the
19261 amount to increment by may be missing.) That doesn't
19262 make the expression dependent. */
19265 }
19266 }
19270 }
19272 }
19274 /* The expression is not value-dependent. */
19276 }
19278 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
19279 [temp.dep.expr]. Note that an expression with no type is
19280 considered dependent. Other parts of the compiler arrange for an
19281 expression with type-dependent subexpressions to have no type, so
19282 this function doesn't have to be fully recursive. */
19284 bool
19286 {
19293 /* An unresolved name is always dependent. */
19298 /* Some expression forms are never type-dependent. */
19311 /* The types of these expressions depends only on the type to which
19312 the cast occurs. */
19321 /* The types of these expressions depends only on the type created
19322 by the expression. */
19325 {
19326 /* For NEW_EXPR tree nodes created inside a template, either
19327 the object type itself or a TREE_LIST may appear as the
19328 operand 1. */
19331 /* This is an array type. We need to check array dimensions
19332 as well. */
19334 || value_dependent_expression_p
19336 else
19338 }
19341 {
19345 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
19346 contains an identifier associated by name lookup with one or more
19347 declarations declared with a dependent type, or...a
19348 nested-name-specifier or qualified-id that names a member of an
19349 unknown specialization. */
19352 }
19357 && (any_dependent_template_arguments_p
19369 {
19370 tree elt;
19374 {
19377 }
19379 }
19381 /* A static data member of the current instantiation with incomplete
19382 array type is type-dependent, as the definition and specializations
19383 can have different bounds. */
19391 {
19396 {
19402 }
19403 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
19411 {
19416 }
19421 {
19425 }
19427 }
19432 }
19434 /* Like type_dependent_expression_p, but it also works while not processing
19435 a template definition, i.e. during substitution or mangling. */
19437 bool
19439 {
19445 }
19447 /* Returns TRUE if ARGS contains a type-dependent expression. */
19449 bool
19451 {
19453 tree arg;
19456 {
19459 }
19461 }
19463 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19464 expressions) contains any type-dependent expressions. */
19466 bool
19468 {
19474 }
19476 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19477 expressions) contains any value-dependent expressions. */
19479 bool
19481 {
19487 }
19489 /* Returns TRUE if the ARG (a template argument) is dependent. */
19491 bool
19493 {
19497 /* Assume a template argument that was wrongly written by the user
19498 is dependent. This is consistent with what
19499 any_dependent_template_arguments_p [that calls this function]
19500 does. */
19511 {
19515 {
19518 }
19521 }
19524 else
19527 }
19529 /* Returns true if ARGS (a collection of template arguments) contains
19530 any types that require structural equality testing. */
19532 bool
19534 {
19544 {
19547 {
19553 {
19554 /* Look inside the argument pack. */
19557 }
19560 {
19574 }
19575 }
19576 }
19579 }
19581 /* Returns true if ARGS (a collection of template arguments) contains
19582 any dependent arguments. */
19584 bool
19586 {
19596 {
19601 }
19604 }
19606 /* Returns TRUE if the template TMPL is dependent. */
19608 bool
19610 {
19612 {
19614 {
19618 }
19620 }
19622 /* Template template parameters are dependent. */
19626 /* So are names that have not been looked up. */
19630 /* So are member templates of dependent classes. */
19634 }
19636 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
19638 bool
19640 {
19643 }
19645 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
19646 is dependent. */
19648 bool
19650 {
19657 {
19678 {
19682 }
19686 {
19690 {
19695 }
19696 }
19697 }
19700 }
19702 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
19703 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
19704 no such TYPE can be found. Note that this function peers inside
19705 uninstantiated templates and therefore should be used only in
19706 extremely limited situations. ONLY_CURRENT_P restricts this
19707 peering to the currently open classes hierarchy (which is required
19708 when comparing types). */
19710 tree
19712 {
19713 tree scope;
19714 tree name;
19715 tree decl;
19717 tree pushed_scope;
19718 tree result;
19723 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
19724 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
19725 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
19726 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
19727 identifier of the TYPENAME_TYPE anymore.
19728 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
19729 TYPENAME_TYPE instead, we avoid messing up with a possible
19730 typedef variant case. */
19733 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
19734 it first before we can figure out what NAME refers to. */
19737 /* If we don't know what SCOPE refers to, then we cannot resolve the
19738 TYPENAME_TYPE. */
19741 /* If the SCOPE is a template type parameter, we have no way of
19742 resolving the name. */
19745 /* If the SCOPE is not the current instantiation, there's no reason
19746 to look inside it. */
19749 /* If this is a typedef, we don't want to look inside (c++/11987). */
19752 /* If SCOPE isn't the template itself, it will not have a valid
19753 TYPE_FIELDS list. */
19755 /* scope is either the template itself or a compatible instantiation
19756 like X<T>, so look up the name in the original template. */
19758 else
19759 /* scope is a partial instantiation, so we can't do the lookup or we
19760 will lose the template arguments. */
19762 /* Enter the SCOPE so that name lookup will be resolved as if we
19763 were in the class definition. In particular, SCOPE will no
19764 longer be considered a dependent type. */
19766 /* Look up the declaration. */
19768 tf_warning_or_error);
19772 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
19773 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
19778 {
19782 }
19785 {
19786 tree tmpl;
19787 tree args;
19788 /* Obtain the template and the arguments. */
19791 /* Instantiate the template. */
19797 }
19799 /* Leave the SCOPE. */
19803 /* If we failed to resolve it, return the original typename. */
19807 /* If lookup found a typename type, resolve that too. */
19809 {
19810 /* Ill-formed programs can cause infinite recursion here, so we
19811 must catch that. */
19815 }
19817 /* Qualify the resulting type. */
19823 }
19825 /* EXPR is an expression which is not type-dependent. Return a proxy
19826 for EXPR that can be used to compute the types of larger
19827 expressions containing EXPR. */
19829 tree
19831 {
19832 tree inner_expr;
19834 #ifdef ENABLE_CHECKING
19835 /* Try to get a constant value for all non-type-dependent expressions in
19836 order to expose bugs in *_dependent_expression_p and constexpr. */
19839 #endif
19841 /* Preserve OVERLOADs; the functions must be available to resolve
19842 types. */
19853 /* There is no need to return a proxy for a variable. */
19856 /* Preserve string constants; conversions from string constants to
19857 "char *" are allowed, even though normally a "const char *"
19858 cannot be used to initialize a "char *". */
19861 /* Preserve arithmetic constants, as an optimization -- there is no
19862 reason to create a new node. */
19865 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
19866 There is at least one place where we want to know that a
19867 particular expression is a throw-expression: when checking a ?:
19868 expression, there are special rules if the second or third
19869 argument is a throw-expression. */
19873 /* Don't wrap an initializer list, we need to be able to look inside. */
19877 /* Don't wrap a dummy object, we need to be able to test for it. */
19896 /* If the type is unknown, it can't really be non-dependent */
19899 /* Otherwise, build a NON_DEPENDENT_EXPR. */
19901 }
19903 /* ARGS is a vector of expressions as arguments to a function call.
19904 Replace the arguments with equivalent non-dependent expressions.
19905 This modifies ARGS in place. */
19907 void
19909 {
19911 tree arg;
19914 {
19918 }
19919 }
19921 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
19922 with a level one deeper than the actual template parms. */
19924 tree
19926 {
19939 }
19941 /* Given type ARG, return std::initializer_list<ARG>. */
19943 static tree
19945 {
19946 tree std_init_list = namespace_binding
19948 tree argvec;
19950 {
19954 }
19959 }
19961 /* Replace auto in TYPE with std::initializer_list<auto>. */
19963 static tree
19965 {
19972 }
19974 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
19975 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
19977 tree
19979 {
19988 /* Defining a subset of type-dependent expressions that we can deduce
19989 from ahead of time isn't worth the trouble. */
19992 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
19993 with either a new invented type template parameter U or, if the
19994 initializer is a braced-init-list (8.5.4), with
19995 std::initializer_list<U>. */
20011 {
20013 /* Try again at instantiation time. */
20016 /* If type is error_mark_node a diagnostic must have been
20017 emitted by now. Also, having a mention to '<type error>'
20018 in the diagnostic is not really useful to the user. */
20019 {
20023 else
20025 }
20027 }
20029 /* If the list of declarators contains more than one declarator, the type
20030 of each declared variable is determined as described above. If the
20031 type deduced for the template parameter U is not the same in each
20032 deduction, the program is ill-formed. */
20035 {
20041 else
20045 }
20051 }
20053 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
20054 result. */
20056 tree
20058 {
20059 tree argvec;
20066 /* For a late-specified return type in a template type-parameter, we
20067 need to add a dummy argument level for its parmlist. */
20068 argvec = add_to_template_args
20073 }
20075 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
20077 bool
20079 {
20083 else
20085 }
20087 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
20088 appear as a type-specifier for the declaration in question, we don't
20089 have to look through the whole type. */
20091 tree
20093 {
20110 }
20112 /* For a given template T, return the vector of typedefs referenced
20113 in T for which access check is needed at T instantiation time.
20114 T is either a FUNCTION_DECL or a RECORD_TYPE.
20115 Those typedefs were added to T by the function
20116 append_type_to_template_for_access_check. */
20120 {
20121 tree ti;
20132 {
20137 }
20140 }
20142 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
20143 tied to T. That list of typedefs will be access checked at
20144 T instantiation time.
20145 T is either a FUNCTION_DECL or a RECORD_TYPE.
20146 TYPE_DECL is a TYPE_DECL node representing a typedef.
20147 SCOPE is the scope through which TYPE_DECL is accessed.
20148 LOCATION is the location of the usage point of TYPE_DECL.
20150 This function is a subroutine of
20151 append_type_to_template_for_access_check. */
20153 static void
20155 tree type_decl,
20156 tree scope,
20157 location_t location)
20158 {
20159 qualified_typedef_usage_t typedef_usage;
20160 tree ti;
20167 && type_decl
20183 }
20185 /* Append TYPE_DECL to the template TEMPL.
20186 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
20187 At TEMPL instanciation time, TYPE_DECL will be checked to see
20188 if it can be accessed through SCOPE.
20189 LOCATION is the location of the usage point of TYPE_DECL.
20191 e.g. consider the following code snippet:
20193 class C
20194 {
20195 typedef int myint;
20196 };
20198 template<class U> struct S
20199 {
20200 C::myint mi; // <-- usage point of the typedef C::myint
20201 };
20203 S<char> s;
20205 At S<char> instantiation time, we need to check the access of C::myint
20206 In other words, we need to check the access of the myint typedef through
20207 the C scope. For that purpose, this function will add the myint typedef
20208 and the scope C through which its being accessed to a list of typedefs
20209 tied to the template S. That list will be walked at template instantiation
20210 time and access check performed on each typedefs it contains.
20211 Note that this particular code snippet should yield an error because
20212 myint is private to C. */
20214 void
20216 tree type_decl,
20217 tree scope,
20218 location_t location)
20219 {
20225 /* Make sure we don't append the type to the template twice. */
20234 }
20236 /* Set up the hash tables for template instantiations. */
20238 void
20240 {
20242 hash_specialization,
20243 eq_specializations,
20244 ggc_free);
20246 hash_specialization,
20247 eq_specializations,
20248 ggc_free);
20249 }
20251 /* Print stats about the template hash tables for -fstats. */
20253 void
20255 {
20264 }