| blob | 78714745452c079f46db03e11e6dbad382aabd60 |
1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2015 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
4 Rewritten by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Known bugs or deficiencies include:
24 all methods must be provided in header files; can't use a source
25 file that contains only the method templates and "just win". */
59 /* The type of functions taking a tree, and some additional data, and
60 returning an int. */
63 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
64 instantiations have been deferred, either because their definitions
65 were not yet available, or because we were putting off doing the work. */
69 };
84 /* Live only within one (recursive) call to tsubst_expr. We use
85 this to pass the statement expression node from the STMT_EXPR
86 to the EXPR_STMT that is its result. */
89 /* True if we've recursed into fn_type_unification too many times. */
93 {
94 tree tmpl;
95 tree args;
96 tree spec;
97 };
100 {
103 };
109 /* Contains canonical template parameter types. The vector is indexed by
110 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
111 TREE_LIST, whose TREE_VALUEs contain the canonical template
112 parameters of various types and levels. */
115 #define UNIFY_ALLOW_NONE 0
116 #define UNIFY_ALLOW_MORE_CV_QUAL 1
117 #define UNIFY_ALLOW_LESS_CV_QUAL 2
118 #define UNIFY_ALLOW_DERIVED 4
119 #define UNIFY_ALLOW_INTEGER 8
120 #define UNIFY_ALLOW_OUTER_LEVEL 16
121 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
122 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
125 tbr_incomplete_type,
126 tbr_ambiguous_baseclass,
127 tbr_success
128 };
151 tree);
213 location_t);
221 /* Make the current scope suitable for access checking when we are
222 processing T. T can be FUNCTION_DECL for instantiated function
223 template, VAR_DECL for static member variable, or TYPE_DECL for
224 alias template (needed by instantiate_decl). */
226 static void
228 {
236 else
240 {
241 saved_access_scope = tree_cons
244 }
245 }
247 /* Restore the scope set up by push_access_scope. T is the node we
248 are processing. */
250 static void
252 {
254 {
257 }
261 else
263 }
265 /* Do any processing required when DECL (a member template
266 declaration) is finished. Returns the TEMPLATE_DECL corresponding
267 to DECL, unless it is a specialization, in which case the DECL
268 itself is returned. */
270 tree
272 {
279 {
280 tree type;
288 {
292 }
294 }
298 {
300 {
303 }
304 else
306 }
307 else
311 }
313 /* Create a template info node. */
315 tree
317 {
322 }
324 /* Return the template info node corresponding to T, whatever T is. */
326 tree
328 {
349 }
351 /* Returns the template nesting level of the indicated class TYPE.
353 For example, in:
354 template <class T>
355 struct A
356 {
357 template <class U>
358 struct B {};
359 };
361 A<T>::B<U> has depth two, while A<T> has depth one.
362 Both A<T>::B<int> and A<int>::B<U> have depth one, if
363 they are instantiations, not specializations.
365 This function is guaranteed to return 0 if passed NULL_TREE so
366 that, for example, `template_class_depth (current_class_type)' is
367 always safe. */
369 int
371 {
378 {
384 }
387 }
389 /* Subroutine of maybe_begin_member_template_processing.
390 Returns true if processing DECL needs us to push template parms. */
392 static bool
394 {
400 }
402 /* Subroutine of maybe_begin_member_template_processing.
403 Push the template parms in PARMS, starting from LEVELS steps into the
404 chain, and ending at the beginning, since template parms are listed
405 innermost first. */
407 static void
409 {
417 current_template_parms
423 NULL);
425 {
434 {
441 {
442 /* Make a CONST_DECL as is done in process_template_parm.
443 It is ugly that we recreate this here; the original
444 version built in process_template_parm is no longer
445 available. */
455 }
460 }
461 }
462 }
464 /* Restore the template parameter context for a member template, a
465 friend template defined in a class definition, or a non-template
466 member of template class. */
468 void
470 {
471 tree parms;
476 {
479 /* Disregard full specializations (c++/60999). */
482 }
485 {
490 {
493 }
496 }
498 /* Remember how many levels of template parameters we pushed so that
499 we can pop them later. */
501 }
503 /* Undo the effects of maybe_begin_member_template_processing. */
505 void
507 {
516 {
520 }
521 }
523 /* Return a new template argument vector which contains all of ARGS,
524 but has as its innermost set of arguments the EXTRA_ARGS. */
526 static tree
528 {
529 tree new_args;
547 }
549 /* Like add_to_template_args, but only the outermost ARGS are added to
550 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
551 (EXTRA_ARGS) levels are added. This function is used to combine
552 the template arguments from a partial instantiation with the
553 template arguments used to attain the full instantiation from the
554 partial instantiation. */
556 static tree
558 {
559 tree new_args;
561 /* If there are more levels of EXTRA_ARGS than there are ARGS,
562 something very fishy is going on. */
565 /* If *all* the new arguments will be the EXTRA_ARGS, just return
566 them. */
570 /* For the moment, we make ARGS look like it contains fewer levels. */
575 /* Now, we restore ARGS to its full dimensions. */
579 }
581 /* Return the N levels of innermost template arguments from the ARGS. */
583 tree
585 {
586 tree new_args;
592 /* If N is 1, just return the innermost set of template arguments. */
596 /* If we're not removing anything, just return the arguments we were
597 given. */
603 /* Make a new set of arguments, not containing the outer arguments. */
610 }
612 /* The inverse of get_innermost_template_args: Return all but the innermost
613 EXTRA_LEVELS levels of template arguments from the ARGS. */
615 static tree
617 {
618 tree new_args;
624 /* If N is 1, just return the outermost set of template arguments. */
628 /* If we're not removing anything, just return the arguments we were
629 given. */
634 /* Make a new set of arguments, not containing the inner arguments. */
641 }
643 /* We've got a template header coming up; push to a new level for storing
644 the parms. */
646 void
648 {
649 /* We use a non-tag-transparent scope here, which causes pushtag to
650 put tags in this scope, rather than in the enclosing class or
651 namespace scope. This is the right thing, since we want
652 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
653 global template class, push_template_decl handles putting the
654 TEMPLATE_DECL into top-level scope. For a nested template class,
655 e.g.:
657 template <class T> struct S1 {
658 template <class T> struct S2 {};
659 };
661 pushtag contains special code to call pushdecl_with_scope on the
662 TEMPLATE_DECL for S2. */
667 }
669 /* This routine is called when a specialization is declared. If it is
670 invalid to declare a specialization here, an error is reported and
671 false is returned, otherwise this routine will return true. */
673 static bool
675 {
678 /* [temp.expl.spec]
680 An explicit specialization shall be declared in the namespace of
681 which the template is a member, or, for member templates, in the
682 namespace of which the enclosing class or enclosing class
683 template is a member. An explicit specialization of a member
684 function, member class or static data member of a class template
685 shall be declared in the namespace of which the class template
686 is a member. */
688 {
691 }
693 /* [temp.expl.spec]
695 In an explicit specialization declaration for a member of a class
696 template or a member template that appears in namespace scope,
697 the member template and some of its enclosing class templates may
698 remain unspecialized, except that the declaration shall not
699 explicitly specialize a class member template if its enclosing
700 class templates are not explicitly specialized as well. */
702 {
705 }
708 }
710 /* We've just seen template <>. */
712 bool
714 {
718 }
720 /* Called at then end of processing a declaration preceded by
721 template<>. */
723 void
725 {
728 }
730 /* Any template <>'s that we have seen thus far are not referring to a
731 function specialization. */
733 void
735 {
738 }
740 /* We've just seen a template header. If SPECIALIZATION is nonzero,
741 it was of the form template <>. */
743 static void
745 {
747 template_header_count++;
748 }
750 /* We're beginning an explicit instantiation. */
752 void
754 {
757 }
760 void
762 {
765 }
767 /* An explicit specialization or partial specialization of TMPL is being
768 declared. Check that the namespace in which the specialization is
769 occurring is permissible. Returns false iff it is invalid to
770 specialize TMPL in the current namespace. */
772 static bool
774 {
777 /* [tmpl.expl.spec]
779 An explicit specialization shall be declared in the namespace of
780 which the template is a member, or, for member templates, in the
781 namespace of which the enclosing class or enclosing class
782 template is a member. An explicit specialization of a member
783 function, member class or static data member of a class template
784 shall be declared in the namespace of which the class template is
785 a member. */
788 {
791 }
793 /* Same or super-using namespace. */
795 else
796 {
800 }
801 }
803 /* SPEC is an explicit instantiation. Check that it is valid to
804 perform this explicit instantiation in the current namespace. */
806 static void
808 {
809 tree ns;
811 /* DR 275: An explicit instantiation shall appear in an enclosing
812 namespace of its template. */
818 }
820 /* The TYPE is being declared. If it is a template type, that means it
821 is a partial specialization. Do appropriate error-checking. */
823 tree
825 {
826 tree context;
831 /* A lambda that appears in specialization context is not itself a
832 specialization. */
837 {
841 }
846 {
851 else
854 }
856 {
857 /* This is for ordinary explicit specialization and partial
858 specialization of a template class such as:
860 template <> class C<int>;
862 or:
864 template <class T> class C<T*>;
866 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
870 {
877 {
881 }
882 }
888 /* Trying to define a specialization either without a template<> header
889 or in an inappropriate place. We've already given an error, so just
890 bail now so we don't actually define the specialization. */
892 }
898 {
899 /* This is for an explicit specialization of member class
900 template according to [temp.expl.spec/18]:
902 template <> template <class U> class C<int>::D;
904 The context `C<int>' must be an implicit instantiation.
905 Otherwise this is just a member class template declared
906 earlier like:
908 template <> class C<int> { template <class U> class D; };
909 template <> template <class U> class C<int>::D;
911 In the first case, `C<int>::D' is a specialization of `C<T>::D'
912 while in the second case, `C<int>::D' is a primary template
913 and `C<T>::D' may not exist. */
917 {
918 tree t;
923 {
926 }
928 /* Check for invalid specialization after instantiation:
930 template <> template <> class C<int>::D<int>;
931 template <> template <class U> class C<int>::D; */
935 {
939 {
940 /* We already have a full specialization of this partial
941 instantiation, or a full specialization has been
942 looked up but not instantiated. Reassign it to the
943 new member specialization template. */
944 spec_entry elt;
956 spec_entry **slot
961 }
962 else
963 /* But if we've had an implicit instantiation, that's a
964 problem ([temp.expl.spec]/6). */
967 }
969 /* Mark TYPE as a specialization. And as a result, we only
970 have one level of template argument for the innermost
971 class template. */
976 }
977 }
979 {
980 /* Someday C++0x may allow for enum template specialization. */
985 else
986 {
989 }
990 }
993 }
995 /* Returns nonzero if we can optimize the retrieval of specializations
996 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
997 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
1001 {
1004 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
1005 parameter. */
1007 /* The optimized lookup depends on the fact that the
1008 template arguments for the member function template apply
1009 purely to the containing class, which is not true if the
1010 containing class is an explicit or partial
1011 specialization. */
1015 /* It is possible to have a template that is not a member
1016 template and is not a member of a template class:
1018 template <typename T>
1019 struct S { friend A::f(); };
1021 Here, the friend function is a template, but the context does
1022 not have template information. The optimized lookup relies
1023 on having ARGS be the template arguments for both the class
1024 and the function template. */
1026 }
1028 /* Retrieve the specialization (in the sense of [temp.spec] - a
1029 specialization is either an instantiation or an explicit
1030 specialization) of TMPL for the given template ARGS. If there is
1031 no such specialization, return NULL_TREE. The ARGS are a vector of
1032 arguments, or a vector of vectors of arguments, in the case of
1033 templates with more than one level of parameters.
1035 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1036 then we search for a partial specialization matching ARGS. This
1037 parameter is ignored if TMPL is not a class template.
1039 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1040 result is a NONTYPE_ARGUMENT_PACK. */
1042 static tree
1044 {
1054 /* There should be as many levels of arguments as there are
1055 levels of parameters. */
1062 {
1063 tree class_template;
1064 tree class_specialization;
1066 tree fns;
1069 /* The template arguments actually apply to the containing
1070 class. Find the class specialization with those
1071 arguments. */
1073 class_specialization
1077 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1078 for the specialization. */
1082 /* Iterate through the methods with the indicated name, looking
1083 for the one that has an instance of TMPL. */
1086 {
1089 /* using-declarations can add base methods to the method vec,
1090 and we don't want those here. */
1093 }
1095 }
1096 else
1097 {
1099 spec_entry elt;
1108 else
1116 }
1119 }
1121 /* Like retrieve_specialization, but for local declarations. */
1123 static tree
1125 {
1131 }
1133 /* Returns nonzero iff DECL is a specialization of TMPL. */
1135 int
1137 {
1138 tree t;
1141 {
1147 }
1148 else
1149 {
1158 }
1161 }
1163 /* Returns nonzero iff DECL is a specialization of friend declaration
1164 FRIEND_DECL according to [temp.friend]. */
1166 bool
1168 {
1175 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1176 of a template class, we want to check if DECL is a specialization
1177 if this. */
1181 {
1182 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1185 }
1190 /* There is nothing to do if this is not a template friend. */
1197 /* [temp.friend/6]
1198 A member of a class template may be declared to be a friend of a
1199 non-template class. In this case, the corresponding member of
1200 every specialization of the class template is a friend of the
1201 class granting friendship.
1203 For example, given a template friend declaration
1205 template <class T> friend void A<T>::f();
1207 the member function below is considered a friend
1209 template <> struct A<int> {
1210 void f();
1211 };
1213 For this type of template friend, TEMPLATE_DEPTH below will be
1214 nonzero. To determine if DECL is a friend of FRIEND, we first
1215 check if the enclosing class is a specialization of another. */
1222 {
1223 /* Next, we check the members themselves. In order to handle
1224 a few tricky cases, such as when FRIEND_DECL's are
1226 template <class T> friend void A<T>::g(T t);
1227 template <class T> template <T t> friend void A<T>::h();
1229 and DECL's are
1231 void A<int>::g(int);
1232 template <int> void A<int>::h();
1234 we need to figure out ARGS, the template arguments from
1235 the context of DECL. This is required for template substitution
1236 of `T' in the function parameter of `g' and template parameter
1237 of `h' in the above examples. Here ARGS corresponds to `int'. */
1244 {
1246 {
1249 else
1251 current_depth++;
1252 }
1254 }
1257 {
1259 tree friend_type;
1260 tree decl_type;
1261 tree friend_args_type;
1262 tree decl_args_type;
1264 /* Make sure that both DECL and FRIEND_DECL are templates or
1265 non-templates. */
1271 {
1272 /* If both are templates, check template parameter list. */
1273 tree friend_parms
1278 friend_parms))
1282 }
1283 else
1291 /* Check if return types match. */
1295 /* Check if function parameter types match, ignoring the
1296 `this' parameter. */
1305 }
1306 else
1307 {
1308 /* DECL is a TYPE_DECL */
1312 /* Make sure that both DECL and FRIEND_DECL are templates or
1313 non-templates. */
1314 is_template
1321 {
1322 tree friend_parms;
1323 /* If both are templates, check the name of the two
1324 TEMPLATE_DECL's first because is_friend didn't. */
1329 /* Now check template parameter list. */
1330 friend_parms
1333 return comp_template_parms
1335 friend_parms);
1336 }
1337 else
1340 }
1341 }
1343 }
1345 /* Register the specialization SPEC as a specialization of TMPL with
1346 the indicated ARGS. IS_FRIEND indicates whether the specialization
1347 is actually just a friend declaration. Returns SPEC, or an
1348 equivalent prior declaration, if available.
1350 We also store instantiations of field packs in the hash table, even
1351 though they are not themselves templates, to make lookup easier. */
1353 static tree
1355 hashval_t hash)
1356 {
1357 tree fn;
1359 spec_entry elt;
1367 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1368 register it; we want the corresponding TEMPLATE_DECL instead.
1369 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1370 the more obvious `uses_template_parms (spec)' to avoid problems
1371 with default function arguments. In particular, given
1372 something like this:
1374 template <class T> void f(T t1, T t = T())
1376 the default argument expression is not substituted for in an
1377 instantiation unless and until it is actually needed. */
1381 /* We don't put these specializations in the hash table, but we might
1382 want to give an error about a mismatch. */
1384 else
1385 {
1393 slot =
1397 else
1399 }
1401 /* We can sometimes try to re-register a specialization that we've
1402 already got. In particular, regenerate_decl_from_template calls
1403 duplicate_decls which will update the specialization list. But,
1404 we'll still get called again here anyhow. It's more convenient
1405 to simply allow this than to try to prevent it. */
1409 {
1411 {
1414 {
1416 fn);
1418 }
1419 else
1420 {
1421 tree clone;
1422 /* This situation should occur only if the first
1423 specialization is an implicit instantiation, the
1424 second is an explicit specialization, and the
1425 implicit instantiation has not yet been used. That
1426 situation can occur if we have implicitly
1427 instantiated a member function and then specialized
1428 it later.
1430 We can also wind up here if a friend declaration that
1431 looked like an instantiation turns out to be a
1432 specialization:
1434 template <class T> void foo(T);
1435 class S { friend void foo<>(int) };
1436 template <> void foo(int);
1438 We transform the existing DECL in place so that any
1439 pointers to it become pointers to the updated
1440 declaration.
1442 If there was a definition for the template, but not
1443 for the specialization, we want this to look as if
1444 there were no definition, and vice versa. */
1447 /* The call to duplicate_decls will have applied
1448 [temp.expl.spec]:
1450 An explicit specialization of a function template
1451 is inline only if it is explicitly declared to be,
1452 and independently of whether its function template
1453 is.
1455 to the primary function; now copy the inline bits to
1456 the various clones. */
1458 {
1465 }
1469 }
1470 }
1472 {
1474 /* Dup decl failed, but this is a new definition. Set the
1475 line number so any errors match this new
1476 definition. */
1480 }
1481 }
1485 /* A specialization must be declared in the same namespace as the
1486 template it is specializing. */
1492 {
1501 /* If TMPL is a forward declaration of a template function, keep a list
1502 of all specializations in case we need to reassign them to a friend
1503 template later in tsubst_friend_function.
1505 Also keep a list of all variable template instantiations so that
1506 process_partial_specialization can check whether a later partial
1507 specialization would have used it. */
1510 }
1513 }
1515 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1516 TMPL and ARGS members, ignores SPEC. */
1520 bool
1522 {
1531 }
1533 /* Returns a hash for a template TMPL and template arguments ARGS. */
1535 static hashval_t
1537 {
1540 }
1542 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1543 ignoring SPEC. */
1545 hashval_t
1547 {
1549 }
1551 /* Recursively calculate a hash value for a template argument ARG, for use
1552 in the hash tables of template specializations. */
1554 hashval_t
1556 {
1568 /* We can get one of these when re-hashing a previous entry in the middle
1569 of substituting into a pack expansion. Just look through it. */
1578 {
1586 {
1591 }
1613 {
1617 {
1620 }
1622 }
1626 {
1629 }
1640 val = iterative_hash_template_arg
1652 val);
1654 val);
1663 /* A lambda can't appear in a template arg, but don't crash on
1664 erroneous input. */
1676 /* Now hash operands as usual. */
1681 }
1684 {
1687 {
1688 // We want an alias specialization that survived strip_typedefs
1689 // to hash differently from its TYPE_CANONICAL, to avoid hash
1690 // collisions that compare as different in template_args_equal.
1691 // These could be dependent specializations that strip_typedefs
1692 // left alone, or untouched specializations because
1693 // coerce_template_parms returns the unconverted template
1694 // arguments if it sees incomplete argument packs.
1697 }
1700 val);
1703 /* Otherwise just compare the types during lookup. */
1712 {
1717 }
1718 }
1721 }
1723 /* Unregister the specialization SPEC as a specialization of TMPL.
1724 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1725 if the SPEC was listed as a specialization of TMPL.
1727 Note that SPEC has been ggc_freed, so we can't look inside it. */
1729 bool
1731 {
1733 spec_entry elt;
1741 {
1746 }
1749 }
1751 /* Like register_specialization, but for local declarations. We are
1752 registering SPEC, an instantiation of TMPL. */
1754 static void
1756 {
1758 }
1760 /* TYPE is a class type. Returns true if TYPE is an explicitly
1761 specialized class. */
1763 bool
1765 {
1769 }
1771 /* Print the list of functions at FNS, going through all the overloads
1772 for each element of the list. Alternatively, FNS can not be a
1773 TREE_LIST, in which case it will be printed together with all the
1774 overloads.
1776 MORE and *STR should respectively be FALSE and NULL when the function
1777 is called from the outside. They are used internally on recursive
1778 calls. print_candidates manages the two parameters and leaves NULL
1779 in *STR when it ends. */
1781 static void
1783 {
1789 {
1793 }
1794 else
1795 {
1798 {
1799 /* Pick the prefix string. */
1801 {
1805 }
1809 }
1812 }
1815 {
1818 }
1819 }
1821 /* Print the list of candidate FNS in an error message. FNS can also
1822 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1824 void
1826 {
1830 }
1832 /* Returns the template (one of the functions given by TEMPLATE_ID)
1833 which can be specialized to match the indicated DECL with the
1834 explicit template args given in TEMPLATE_ID. The DECL may be
1835 NULL_TREE if none is available. In that case, the functions in
1836 TEMPLATE_ID are non-members.
1838 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1839 specialization of a member template.
1841 The TEMPLATE_COUNT is the number of references to qualifying
1842 template classes that appeared in the name of the function. See
1843 check_explicit_specialization for a more accurate description.
1845 TSK indicates what kind of template declaration (if any) is being
1846 declared. TSK_TEMPLATE indicates that the declaration given by
1847 DECL, though a FUNCTION_DECL, has template parameters, and is
1848 therefore a template function.
1850 The template args (those explicitly specified and those deduced)
1851 are output in a newly created vector *TARGS_OUT.
1853 If it is impossible to determine the result, an error message is
1854 issued. The error_mark_node is returned to indicate failure. */
1856 static tree
1858 tree decl,
1862 tmpl_spec_kind tsk)
1863 {
1864 tree fns;
1865 tree targs;
1866 tree explicit_targs;
1868 /* A TREE_LIST of templates of which DECL may be a specialization.
1869 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1870 corresponding TREE_PURPOSE is the set of template arguments that,
1871 when used to instantiate the template, would produce a function
1872 with the signature of DECL. */
1882 /* We shouldn't be specializing a member template of an
1883 unspecialized class template; we already gave an error in
1884 check_specialization_scope, now avoid crashing. */
1887 {
1890 }
1898 /* Check for baselinks. */
1903 {
1906 }
1908 {
1911 }
1913 /* Count the number of template headers specified for this
1914 specialization. */
1924 {
1928 {
1929 tree decl_arg_types;
1930 tree fn_arg_types;
1931 tree insttype;
1933 /* In case of explicit specialization, we need to check if
1934 the number of template headers appearing in the specialization
1935 is correct. This is usually done in check_explicit_specialization,
1936 but the check done there cannot be exhaustive when specializing
1937 member functions. Consider the following code:
1939 template <> void A<int>::f(int);
1940 template <> template <> void A<int>::f(int);
1942 Assuming that A<int> is not itself an explicit specialization
1943 already, the first line specializes "f" which is a non-template
1944 member function, whilst the second line specializes "f" which
1945 is a template member function. So both lines are syntactically
1946 correct, and check_explicit_specialization does not reject
1947 them.
1949 Here, we can do better, as we are matching the specialization
1950 against the declarations. We count the number of template
1951 headers, and we check if they match TEMPLATE_COUNT + 1
1952 (TEMPLATE_COUNT is the number of qualifying template classes,
1953 plus there must be another header for the member template
1954 itself).
1956 Notice that if header_count is zero, this is not a
1957 specialization but rather a template instantiation, so there
1958 is no check we can perform here. */
1962 /* Check that the number of template arguments at the
1963 innermost level for DECL is the same as for FN. */
1971 /* DECL might be a specialization of FN. */
1975 /* For a non-static member function, we need to make sure
1976 that the const qualification is the same. Since
1977 get_bindings does not try to merge the "this" parameter,
1978 we must do the comparison explicitly. */
1984 /* Skip the "this" parameter and, for constructors of
1985 classes with virtual bases, the VTT parameter. A
1986 full specialization of a constructor will have a VTT
1987 parameter, but a template never will. */
1988 decl_arg_types
1990 fn_arg_types
1993 /* Function templates cannot be specializations; there are
1994 no partial specializations of functions. Therefore, if
1995 the type of DECL does not match FN, there is no
1996 match. */
1998 {
2002 }
2004 /* See whether this function might be a specialization of this
2005 template. Suppress access control because we might be trying
2006 to make this specialization a friend, and we have already done
2007 access control for the declaration of the specialization. */
2013 /* We cannot deduce template arguments that when used to
2014 specialize TMPL will produce DECL. */
2017 /* Make sure that the deduced arguments actually work. */
2021 fn_arg_types
2026 /* Save this template, and the arguments deduced. */
2028 }
2030 /* FN is an ordinary member function, and we need a
2031 specialization of a member template. */
2032 ;
2034 /* We can get IDENTIFIER_NODEs here in certain erroneous
2035 cases. */
2036 ;
2038 /* This is just an ordinary non-member function. Nothing can
2039 be a specialization of that. */
2040 ;
2042 /* Cannot specialize functions that are created implicitly. */
2043 ;
2044 else
2045 {
2046 tree decl_arg_types;
2048 /* This is an ordinary member function. However, since
2049 we're here, we can assume its enclosing class is a
2050 template class. For example,
2052 template <typename T> struct S { void f(); };
2053 template <> void S<int>::f() {}
2055 Here, S<int>::f is a non-template, but S<int> is a
2056 template class. If FN has the same type as DECL, we
2057 might be in business. */
2060 /* Its enclosing class is an explicit specialization
2061 of a template class. This is not a candidate. */
2066 /* The return types differ. */
2069 /* Adjust the type of DECL in case FN is a static member. */
2076 decl_arg_types))
2077 /* They match! */
2079 }
2080 }
2083 {
2084 /* We have:
2086 [temp.expl.spec]
2088 It is possible for a specialization with a given function
2089 signature to be instantiated from more than one function
2090 template. In such cases, explicit specification of the
2091 template arguments must be used to uniquely identify the
2092 function template specialization being specialized.
2094 Note that here, there's no suggestion that we're supposed to
2095 determine which of the candidate templates is most
2096 specialized. However, we, also have:
2098 [temp.func.order]
2100 Partial ordering of overloaded function template
2101 declarations is used in the following contexts to select
2102 the function template to which a function template
2103 specialization refers:
2105 -- when an explicit specialization refers to a function
2106 template.
2108 So, we do use the partial ordering rules, at least for now.
2109 This extension can only serve to make invalid programs valid,
2110 so it's safe. And, there is strong anecdotal evidence that
2111 the committee intended the partial ordering rules to apply;
2112 the EDG front end has that behavior, and John Spicer claims
2113 that the committee simply forgot to delete the wording in
2114 [temp.expl.spec]. */
2117 {
2120 }
2121 }
2124 {
2132 }
2136 {
2142 }
2144 /* We have one, and exactly one, match. */
2146 {
2149 /* DECL is a re-declaration or partial instantiation of a template
2150 function. */
2153 /* It was a specialization of an ordinary member function in a
2154 template class. */
2156 }
2158 /* It was a specialization of a template. */
2161 {
2166 }
2167 else
2170 }
2172 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2173 but with the default argument values filled in from those in the
2174 TMPL_TYPES. */
2176 static tree
2178 tree tmpl_types)
2179 {
2180 tree new_spec_types;
2188 /* Substitute into the rest of the list. */
2189 new_spec_types =
2193 /* Add the default argument for this parameter. */
2196 new_spec_types);
2197 }
2199 /* DECL is an explicit specialization. Replicate default arguments
2200 from the template it specializes. (That way, code like:
2202 template <class T> void f(T = 3);
2203 template <> void f(double);
2204 void g () { f (); }
2206 works, as required.) An alternative approach would be to look up
2207 the correct default arguments at the call-site, but this approach
2208 is consistent with how implicit instantiations are handled. */
2210 static void
2212 {
2213 tree tmpl;
2214 tree spec_types;
2215 tree tmpl_types;
2216 tree new_spec_types;
2217 tree old_type;
2218 tree new_type;
2219 tree t;
2224 /* See if there's anything we need to do. */
2237 {
2238 /* Remove the this pointer, but remember the object's type for
2239 CV quals. */
2245 {
2246 /* DECL may contain more parameters than TMPL due to the extra
2247 in-charge parameter in constructors and destructors. */
2250 }
2252 {
2255 }
2256 }
2258 /* Compute the merged default arguments. */
2259 new_spec_types =
2262 /* Compute the new FUNCTION_TYPE. */
2264 {
2268 new_spec_types);
2271 /* Put the in-charge parameter back. */
2274 new_spec_types);
2278 new_spec_types);
2279 }
2280 else
2282 new_spec_types);
2292 }
2294 /* Return the number of template headers we expect to see for a definition
2295 or specialization of CTYPE or one of its non-template members. */
2297 int
2299 {
2303 {
2304 /* You're supposed to have one `template <...>' for every
2305 template class, but you don't need one for a full
2306 specialization. For example:
2308 template <class T> struct S{};
2309 template <> struct S<int> { void f(); };
2310 void S<int>::f () {}
2312 is correct; there shouldn't be a `template <>' for the
2313 definition of `S<int>::f'. */
2315 /* If CTYPE does not have template information of any
2316 kind, then it is not a template, nor is it nested
2317 within a template. */
2325 }
2328 }
2330 /* Do a simple sanity check on the template headers that precede the
2331 variable declaration DECL. */
2333 void
2335 {
2340 {
2343 "variable templates only available with "
2346 // Namespace-scope variable templates should have a template header.
2348 }
2350 {
2357 "members of an explicitly specialized class are defined "
2359 }
2360 }
2362 /* Check to see if the function just declared, as indicated in
2363 DECLARATOR, and in DECL, is a specialization of a function
2364 template. We may also discover that the declaration is an explicit
2365 instantiation at this point.
2367 Returns DECL, or an equivalent declaration that should be used
2368 instead if all goes well. Issues an error message if something is
2369 amiss. Returns error_mark_node if the error is not easily
2370 recoverable.
2372 FLAGS is a bitmask consisting of the following flags:
2374 2: The function has a definition.
2375 4: The function is a friend.
2377 The TEMPLATE_COUNT is the number of references to qualifying
2378 template classes that appeared in the name of the function. For
2379 example, in
2381 template <class T> struct S { void f(); };
2382 void S<int>::f();
2384 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2385 classes are not counted in the TEMPLATE_COUNT, so that in
2387 template <class T> struct S {};
2388 template <> struct S<int> { void f(); }
2389 template <> void S<int>::f();
2391 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2392 invalid; there should be no template <>.)
2394 If the function is a specialization, it is marked as such via
2395 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2396 is set up correctly, and it is added to the list of specializations
2397 for that template. */
2399 tree
2401 tree decl,
2404 {
2412 tmpl_spec_kind tsk;
2415 {
2418 else
2420 }
2421 else
2425 {
2428 {
2431 }
2433 {
2435 /* This could be something like:
2437 template <class T> void f(T);
2438 class S { friend void f<>(int); } */
2440 else
2441 {
2442 /* This case handles bogus declarations like template <>
2443 template <class T> void f<int>(); */
2446 declarator);
2448 }
2449 }
2453 /* The error has already been reported in
2454 check_specialization_scope. */
2460 /* Fall through. */
2473 decl);
2476 else
2480 /* Fall through. */
2483 /* In cases like template<> constexpr bool v = true;
2484 We'll give an error in check_template_variable. */
2490 else
2496 {
2497 /* This case handles bogus declarations like template <>
2498 template <class T> void f<int>(); */
2502 declarator);
2504 {
2505 /* Partial specialization of variable template. */
2509 }
2513 else
2517 ok:;
2518 }
2521 /* This is a specialization of a member template, without
2522 specialization the containing class. Something like:
2524 template <class T> struct S {
2525 template <class U> void f (U);
2526 };
2527 template <> template <class U> void S<int>::f(U) {}
2529 That's a specialization -- but of the entire template. */
2535 }
2538 /* This doesn't apply to variable templates. */
2541 {
2545 {
2549 }
2550 }
2553 {
2558 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2560 {
2561 tree fns;
2566 else
2567 {
2568 /* If there is no class context, the explicit instantiation
2569 must be at namespace scope. */
2572 /* Find the namespace binding, using the declaration
2573 context. */
2577 {
2580 }
2581 else
2582 {
2588 }
2589 }
2592 }
2598 {
2600 /* A specialization in class scope. This is invalid,
2601 but the error will already have been flagged by
2602 check_specialization_scope. */
2604 else
2605 {
2606 /* It's not valid to write an explicit instantiation in
2607 class scope, e.g.:
2609 class C { template void f(); }
2611 This case is caught by the parser. However, on
2612 something like:
2614 template class C { void f(); };
2616 (which is invalid) we can get here. The error will be
2617 issued later. */
2618 ;
2619 }
2622 }
2625 {
2626 // We'll match variable templates in start_decl.
2630 /* Find the list of functions in ctype that have the same
2631 name as the declared function. */
2637 {
2642 {
2643 /* From [temp.expl.spec]:
2645 If such an explicit specialization for the member
2646 of a class template names an implicitly-declared
2647 special member function (clause _special_), the
2648 program is ill-formed.
2650 Similar language is found in [temp.explicit]. */
2653 }
2656 }
2659 {
2663 }
2664 else
2665 {
2667 tree ovl;
2669 /* For a type-conversion operator, we cannot do a
2670 name-based lookup. We might be looking for `operator
2671 int' which will be a specialization of `operator T'.
2672 So, we find *all* the conversion operators, and then
2673 select from them. */
2681 {
2683 /* There are no more conversion functions. */
2686 /* Glue all these conversion functions together
2687 with those we already have. */
2690 }
2691 }
2694 {
2697 }
2698 else
2700 }
2702 /* Figure out what exactly is being specialized at this point.
2703 Note that for an explicit instantiation, even one for a
2704 member function, we cannot tell apriori whether the
2705 instantiation is for a member template, or just a member
2706 function of a template class. Even if a member template is
2707 being instantiated, the member template arguments may be
2708 elided if they can be deduced from the rest of the
2709 declaration. */
2712 member_specialization,
2713 template_count,
2714 tsk);
2717 /* We couldn't figure out what this declaration was
2718 specializing. */
2720 else
2721 {
2725 {
2726 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2727 is done by do_decl_instantiation later. */
2733 {
2734 /* If TMPL is not the most general template (for
2735 example, if TMPL is a friend template that is
2736 injected into namespace scope), then there will
2737 be too many levels of TARGS. Remove some of them
2738 here. */
2740 tree new_targs;
2747 }
2750 }
2752 /* If we thought that the DECL was a member function, but it
2753 turns out to be specializing a static member function,
2754 make DECL a static member function as well. */
2760 /* If this is a specialization of a member template of a
2761 template class, we want to return the TEMPLATE_DECL, not
2762 the specialization of it. */
2764 {
2769 {
2770 tree parm;
2774 /* We want to use the argument list specified in the
2775 definition, not in the original declaration. */
2780 }
2783 }
2785 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2791 /* Inherit default function arguments from the template
2792 DECL is specializing. */
2796 /* This specialization has the same protection as the
2797 template it specializes. */
2801 /* 7.1.1-1 [dcl.stc]
2803 A storage-class-specifier shall not be specified in an
2804 explicit specialization...
2806 The parser rejects these, so unless action is taken here,
2807 explicit function specializations will always appear with
2808 global linkage.
2810 The action recommended by the C++ CWG in response to C++
2811 defect report 605 is to make the storage class and linkage
2812 of the explicit specialization match the templated function:
2814 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2815 */
2817 {
2821 /* This specialization has the same linkage and visibility as
2822 the function template it specializes. */
2825 {
2828 }
2831 {
2834 }
2835 }
2837 /* If DECL is a friend declaration, declared using an
2838 unqualified name, the namespace associated with DECL may
2839 have been set incorrectly. For example, in:
2841 template <typename T> void f(T);
2842 namespace N {
2843 struct S { friend void f<int>(int); }
2844 }
2846 we will have set the DECL_CONTEXT for the friend
2847 declaration to N, rather than to the global namespace. */
2852 /* This is not really a declaration of a specialization.
2853 It's just the name of an instantiation. But, it's not
2854 a request for an instantiation, either. */
2857 /* A specialization is not necessarily COMDAT. */
2863 /* Register this specialization so that we can find it
2864 again. */
2867 /* A 'structor should already have clones. */
2873 }
2874 }
2877 }
2879 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2880 parameters. These are represented in the same format used for
2881 DECL_TEMPLATE_PARMS. */
2883 int
2885 {
2886 const_tree p1;
2887 const_tree p2;
2895 {
2907 {
2911 /* If either of the template parameters are invalid, assume
2912 they match for the sake of error recovery. */
2925 }
2926 }
2929 /* One set of parameters has more parameters lists than the
2930 other. */
2934 }
2936 /* Determine whether PARM is a parameter pack. */
2938 bool
2940 {
2941 /* Determine if we have a non-type template parameter pack. */
2948 /* If this is a list of template parameters, we could get a
2949 TYPE_DECL or a TEMPLATE_DECL. */
2953 /* Otherwise it must be a type template parameter. */
2957 }
2959 /* Determine if T is a function parameter pack. */
2961 bool
2963 {
2967 }
2969 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2970 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2972 tree
2974 {
2981 }
2983 /* Return true iff the function parameter PARAM_DECL was expanded
2984 from the function parameter pack PACK. */
2986 bool
2988 {
2993 /* The parameter pack and its pack arguments have the same
2994 DECL_PARM_INDEX. */
2996 }
2998 /* Determine whether ARGS describes a variadic template args list,
2999 i.e., one that is terminated by a template argument pack. */
3001 static bool
3003 {
3005 tree last_parm;
3019 }
3021 /* Generate a new name for the parameter pack name NAME (an
3022 IDENTIFIER_NODE) that incorporates its */
3024 static tree
3026 {
3027 /* Munge the name to include the parameter index. */
3028 #define NUMBUF_LEN 128
3042 }
3044 /* Return true if T is a primary function, class or alias template
3045 instantiation. */
3047 bool
3049 {
3063 }
3065 /* Return true if PARM is a template template parameter. */
3067 bool
3069 {
3071 }
3073 /* Return true iff PARM is a DECL representing a type template
3074 parameter. */
3076 bool
3078 {
3083 }
3085 /* Return the template parameters of T if T is a
3086 primary template instantiation, NULL otherwise. */
3088 tree
3090 {
3095 parms = INNERMOST_TEMPLATE_PARMS
3099 }
3101 /* Return the template parameters of the LEVELth level from the full list
3102 of template parameters PARMS. */
3104 tree
3106 {
3107 tree p;
3118 }
3120 /* Returns the template arguments of T if T is a template instantiation,
3121 NULL otherwise. */
3123 tree
3125 {
3133 }
3135 /* Return the argument pack elements of T if T is a template argument pack,
3136 NULL otherwise. */
3138 tree
3140 {
3146 }
3148 /* Structure used to track the progress of find_parameter_packs_r. */
3149 struct find_parameter_pack_data
3150 {
3151 /* TREE_LIST that will contain all of the parameter packs found by
3152 the traversal. */
3155 /* Set of AST nodes that have been visited by the traversal. */
3157 };
3159 /* Identifies all of the argument packs that occur in a template
3160 argument and appends them to the TREE_LIST inside DATA, which is a
3161 find_parameter_pack_data structure. This is a subroutine of
3162 make_pack_expansion and uses_parameter_packs. */
3163 static tree
3165 {
3171 /* Handle type aliases/typedefs. */
3173 {
3180 }
3182 /* Identify whether this is a parameter pack or not. */
3184 {
3200 {
3201 /* We don't want to walk into the type of a PARM_DECL,
3202 because we don't want to see the type parameter pack. */
3205 }
3208 /* Look through a lambda capture proxy to the field pack. */
3211 {
3217 }
3224 /* Not a parameter pack. */
3226 }
3229 {
3230 /* Add this parameter pack to the list. */
3232 }
3238 /* This switch statement will return immediately if we don't find a
3239 parameter pack. */
3241 {
3246 /* Check the template itself. */
3249 /* Check the template arguments. */
3265 /* Fall through. */
3307 }
3310 }
3312 /* Determines if the expression or type T uses any parameter packs. */
3313 bool
3315 {
3323 }
3325 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3326 representation a base-class initializer into a parameter pack
3327 expansion. If all goes well, the resulting node will be an
3328 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3329 respectively. */
3330 tree
3332 {
3333 tree result;
3342 {
3343 /* A TREE_LIST with a non-null TREE_PURPOSE is for a base
3344 class initializer. In this case, the TREE_PURPOSE will be a
3345 _TYPE node (representing the base class expansion we're
3346 initializing) and the TREE_VALUE will be a TREE_LIST
3347 containing the initialization arguments.
3349 The resulting expansion looks somewhat different from most
3350 expansions. Rather than returning just one _EXPANSION, we
3351 return a TREE_LIST whose TREE_PURPOSE is a
3352 TYPE_PACK_EXPANSION containing the bases that will be
3353 initialized. The TREE_VALUE will be identical to the
3354 original TREE_VALUE, which is a list of arguments that will
3355 be passed to each base. We do not introduce any new pack
3356 expansion nodes into the TREE_VALUE (although it is possible
3357 that some already exist), because the TREE_PURPOSE and
3358 TREE_VALUE all need to be expanded together with the same
3359 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3360 resulting TREE_PURPOSE will mention the parameter packs in
3361 both the bases and the arguments to the bases. */
3362 tree purpose;
3363 tree value;
3366 /* Determine which parameter packs will be used by the base
3367 class expansion. */
3374 {
3378 }
3381 {
3382 /* Collect the sets of parameter packs used in each of the
3383 initialization arguments. */
3385 {
3386 /* Determine which parameter packs will be expanded in this
3387 argument. */
3390 }
3391 }
3395 /* Create the pack expansion type for the base type. */
3400 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3401 they will rarely be compared to anything. */
3405 }
3410 /* Build the PACK_EXPANSION_* node. */
3411 result = for_types
3416 {
3417 /* Propagate type and const-expression information. */
3420 }
3421 else
3422 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3423 they will rarely be compared to anything. */
3426 /* Determine which parameter packs will be expanded. */
3432 /* Make sure we found some parameter packs. */
3434 {
3437 else
3440 }
3446 }
3448 /* Checks T for any "bare" parameter packs, which have not yet been
3449 expanded, and issues an error if any are found. This operation can
3450 only be done on full expressions or types (e.g., an expression
3451 statement, "if" condition, etc.), because we could have expressions like:
3453 foo(f(g(h(args)))...)
3455 where "args" is a parameter pack. check_for_bare_parameter_packs
3456 should not be called for the subexpressions args, h(args),
3457 g(h(args)), or f(g(h(args))), because we would produce erroneous
3458 error messages.
3460 Returns TRUE and emits an error if there were bare parameter packs,
3461 returns FALSE otherwise. */
3462 bool
3464 {
3480 {
3483 {
3492 else
3497 else
3501 }
3504 }
3507 }
3509 /* Expand any parameter packs that occur in the template arguments in
3510 ARGS. */
3511 tree
3513 {
3519 /* First, determine if we need to expand anything, and the number of
3520 slots we'll need. */
3522 {
3527 {
3531 else
3533 }
3534 else
3535 {
3537 num_result_args++;
3538 }
3539 }
3541 /* If no expansion is necessary, we're done. */
3545 /* Expand arguments. */
3548 non_default_args_count =
3551 {
3554 {
3561 }
3562 else
3563 {
3566 }
3567 }
3571 }
3573 /* Checks if DECL shadows a template parameter.
3575 [temp.local]: A template-parameter shall not be redeclared within its
3576 scope (including nested scopes).
3578 Emits an error and returns TRUE if the DECL shadows a parameter,
3579 returns FALSE otherwise. */
3581 bool
3583 {
3584 tree olddecl;
3586 /* If we're not in a template, we can't possibly shadow a template
3587 parameter. */
3591 /* Figure out what we're shadowing. */
3596 /* If there's no previous binding for this name, we're not shadowing
3597 anything, let alone a template parameter. */
3601 /* If we're not shadowing a template parameter, we're done. Note
3602 that OLDDECL might be an OVERLOAD (or perhaps even an
3603 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3604 node. */
3608 /* We check for decl != olddecl to avoid bogus errors for using a
3609 name inside a class. We check TPFI to avoid duplicate errors for
3610 inline member templates. */
3616 /* Don't complain about the injected class name, as we've already
3617 complained about the class itself. */
3624 }
3626 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3627 ORIG_LEVEL, DECL, and TYPE. */
3629 static tree
3633 tree decl,
3634 tree type)
3635 {
3646 }
3648 /* Find the canonical type parameter for the given template type
3649 parameter. Returns the canonical type parameter, which may be TYPE
3650 if no such parameter existed. */
3652 static tree
3654 {
3655 tree list;
3669 else
3670 {
3675 }
3676 }
3678 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3679 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3680 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3681 new one is created. */
3683 static tree
3685 tsubst_flags_t complain)
3686 {
3691 {
3710 /* Template template parameters need this. */
3715 }
3718 }
3720 /* Process information from new template parameter PARM and append it
3721 to the LIST being built. This new parameter is a non-type
3722 parameter iff IS_NON_TYPE is true. This new parameter is a
3723 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3724 is in PARM_LOC. */
3726 tree
3729 {
3731 tree defval;
3738 {
3742 {
3746 else
3748 }
3751 }
3754 {
3760 {
3761 /* [temp.param]
3763 The top-level cv-qualifiers on the template-parameter are
3764 ignored when determining its type. */
3769 && !is_parameter_pack
3770 /* If we're in a nested template parameter list, the template
3771 template parameter could be a parameter pack. */
3773 {
3774 /* This template parameter is not a parameter pack, but it
3775 should be. Complain about "bare" parameter packs. */
3778 /* Recover by calling this a parameter pack. */
3780 }
3781 }
3783 /* A template parameter is not modifiable. */
3792 processing_template_decl,
3797 }
3798 else
3799 {
3800 tree t;
3804 {
3806 /* This is for distinguishing between real templates and template
3807 template parameters */
3811 }
3812 else
3813 {
3815 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3818 }
3825 processing_template_decl,
3829 }
3835 }
3837 /* The end of a template parameter list has been reached. Process the
3838 tree list into a parameter vector, converting each parameter into a more
3839 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3840 as PARM_DECLs. */
3842 tree
3844 {
3849 current_template_parms
3854 {
3858 }
3863 }
3865 /* end_template_decl is called after a template declaration is seen. */
3867 void
3869 {
3875 /* This matches the pushlevel in begin_template_parm_list. */
3880 }
3882 /* Takes a TREE_LIST representing a template parameter and convert it
3883 into an argument suitable to be passed to the type substitution
3884 functions. Note that If the TREE_LIST contains an error_mark
3885 node, the returned argument is error_mark_node. */
3887 static tree
3889 {
3902 {
3906 {
3907 /* Turn this argument into a TYPE_ARGUMENT_PACK
3908 with a single element, which expands T. */
3910 #ifdef ENABLE_CHECKING
3911 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3913 #endif
3918 }
3919 }
3920 else
3921 {
3925 {
3926 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3927 with a single element, which expands T. */
3930 #ifdef ENABLE_CHECKING
3931 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3933 #endif
3940 }
3941 else
3943 }
3945 }
3947 /* Given a set of template parameters, return them as a set of template
3948 arguments. The template parameters are represented as a TREE_VEC, in
3949 the form documented in cp-tree.h for template arguments. */
3951 static tree
3953 {
3954 tree header;
3959 /* If there is only one level of template parameters, we do not
3960 create a TREE_VEC of TREE_VECs. Instead, we return a single
3961 TREE_VEC containing the arguments. */
3966 {
3974 #ifdef ENABLE_CHECKING
3976 #endif
3980 else
3982 }
3985 /* This can happen for template parms of a template template
3986 parameter, e.g:
3988 template<template<class T, class U> class TT> struct S;
3990 Consider the level of the parms of TT; T and U both have
3991 level 2; TT has no template parm of level 1. So in this case
3992 the first element of full_template_args is NULL_TREE. If we
3993 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
3994 of 2. This will make tsubst wrongly consider that T and U
3995 have level 1. Instead, let's create a dummy vector as the
3996 first element of full_template_args so that TMPL_ARGS_DEPTH
3997 returns the correct depth for args. */
4000 }
4002 /* Within the declaration of a template, return the currently active
4003 template parameters as an argument TREE_VEC. */
4005 static tree
4007 {
4009 }
4011 /* Update the declared TYPE by doing any lookups which were thought to be
4012 dependent, but are not now that we know the SCOPE of the declarator. */
4014 tree
4016 {
4027 /* Don't bother building up the args in this case. */
4029 {
4030 /* tsubst in the args corresponding to the template parameters,
4031 including auto if present. Most things will be unchanged, but
4032 make_typename_type and tsubst_qualified_id will resolve
4033 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4036 tree pushed;
4038 {
4042 }
4047 }
4053 {
4056 else
4058 }
4060 }
4062 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4063 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4064 a member template. Used by push_template_decl below. */
4066 static tree
4068 {
4076 }
4078 struct template_parm_data
4079 {
4080 /* The level of the template parameters we are currently
4081 processing. */
4084 /* The index of the specialization argument we are currently
4085 processing. */
4088 /* An array whose size is the number of template parameters. The
4089 elements are nonzero if the parameter has been used in any one
4090 of the arguments processed so far. */
4093 /* An array whose size is the number of template arguments. The
4094 elements are nonzero if the argument makes use of template
4095 parameters of this level. */
4097 };
4099 /* Subroutine of push_template_decl used to see if each template
4100 parameter in a partial specialization is used in the explicit
4101 argument list. If T is of the LEVEL given in DATA (which is
4102 treated as a template_parm_data*), then DATA->PARMS is marked
4103 appropriately. */
4105 static int
4107 {
4115 {
4118 }
4120 /* Return zero so that for_each_template_parm will continue the
4121 traversal of the tree; we want to mark *every* template parm. */
4123 }
4125 /* Process the partial specialization DECL. */
4127 static tree
4129 {
4136 tree inner_parms;
4137 tree inst;
4150 /* We check that each of the template parameters given in the
4151 partial specialization is used in the argument list to the
4152 specialization. For example:
4154 template <class T> struct S;
4155 template <class T> struct S<T*>;
4157 The second declaration is OK because `T*' uses the template
4158 parameter T, whereas
4160 template <class T> struct S<int>;
4162 is no good. Even trickier is:
4164 template <class T>
4165 struct S1
4166 {
4167 template <class U>
4168 struct S2;
4169 template <class U>
4170 struct S2<T>;
4171 };
4173 The S2<T> declaration is actually invalid; it is a
4174 full-specialization. Of course,
4176 template <class U>
4177 struct S2<T (*)(U)>;
4179 or some such would have been OK. */
4187 {
4192 NULL,
4194 }
4197 {
4198 /* One of the template parms was not used in a deduced context in the
4199 specialization. */
4201 {
4205 }
4209 }
4214 /* [temp.class.spec]
4216 The argument list of the specialization shall not be identical to
4217 the implicit argument list of the primary template. */
4218 tree main_args
4224 /* A partial specialization that replaces multiple parameters of the
4225 primary template with a pack expansion is less specialized for those
4226 parameters. */
4228 {
4230 "primary template because it replaces multiple parameters "
4234 }
4236 /* [temp.class.spec]
4238 A partially specialized non-type argument expression shall not
4239 involve template parameters of the partial specialization except
4240 when the argument expression is a simple identifier.
4242 The type of a template parameter corresponding to a specialized
4243 non-type argument shall not be dependent on a parameter of the
4244 specialization.
4246 Also, we verify that pack expansions only occur at the
4247 end of the argument list. */
4251 {
4258 {
4259 /* Extract the arguments from the argument pack. We'll be
4260 iterating over these in the following loop. */
4263 }
4266 {
4268 /* Get the Jth argument in the parameter pack. */
4272 {
4273 /* Pack expansions must come at the end of the
4274 argument list. */
4277 {
4281 else
4284 }
4285 }
4288 /* We only care about the pattern. */
4294 /* This next two lines are the `argument expression is not just a
4295 simple identifier' condition and also the `specialized
4296 non-type argument' bit. */
4300 {
4304 arg);
4305 else
4306 {
4307 /* Look at the corresponding template parameter,
4308 marking which template parameters its type depends
4309 upon. */
4313 {
4314 /* We haven't yet initialized TPD2. Do so now. */
4316 /* The number of parameters here is the number in the
4317 main template, which, as checked in the assertion
4318 above, is NARGS. */
4322 }
4324 /* Mark the template parameters. But this time, we're
4325 looking for the template parameters of the main
4326 template, not in the specialization. */
4333 NULL,
4337 {
4338 /* The type depended on some template parameters.
4339 If they are fully specialized in the
4340 specialization, that's OK. */
4349 "type %qT of template argument %qE depends "
4351 "type %qT of template argument %qE depends "
4353 type,
4354 arg);
4355 }
4356 }
4357 }
4358 }
4359 }
4361 /* We should only get here once. */
4380 {
4386 {
4389 {
4393 "partial specialization of %qD after instantiation "
4395 }
4396 }
4397 }
4400 }
4402 /* PARM is a template parameter of some form; return the corresponding
4403 TEMPLATE_PARM_INDEX. */
4405 static tree
4407 {
4419 }
4421 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4422 parameter packs used by the template parameter PARM. */
4424 static void
4426 {
4427 /* A type parm can't refer to another parm. */
4431 {
4435 }
4442 }
4444 /* PARM is a template parameter pack. Return any parameter packs used in
4445 its type or the type of any of its template parameters. If there are
4446 any such packs, it will be instantiated into a fixed template parameter
4447 list by partial instantiation rather than be fully deduced. */
4449 tree
4451 {
4452 /* This can only be true in a member template. */
4455 /* This can only be true for a parameter pack. */
4458 /* A type parm can't refer to another parm. */
4471 }
4473 /* Check that a template declaration's use of default arguments and
4474 parameter packs is not invalid. Here, PARMS are the template
4475 parameters. IS_PRIMARY is true if DECL is the thing declared by
4476 a primary template. IS_PARTIAL is true if DECL is a partial
4477 specialization.
4479 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4480 declaration (but not a definition); 1 indicates a declaration, 2
4481 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4482 emitted for extraneous default arguments.
4484 Returns TRUE if there were no errors found, FALSE otherwise. */
4486 bool
4489 {
4492 tree parm_level;
4495 /* [temp.param]
4497 A default template-argument shall not be specified in a
4498 function template declaration or a function template definition, nor
4499 in the template-parameter-list of the definition of a member of a
4500 class template. */
4504 /* You can't have a function template declaration in a local
4505 scope, nor you can you define a member of a class template in a
4506 local scope. */
4514 /* A lambda doesn't have an explicit declaration; don't complain
4515 about the parms of the enclosing class. */
4522 /* If this is either a friend defined in the scope of the class
4523 or a member function. */
4529 /* And, if it was a member function, it really was defined in
4530 the scope of the class. */
4533 /* We already checked these parameters when the template was
4534 declared, so there's no need to do it again now. This function
4535 was defined in class scope, but we're processing its body now
4536 that the class is complete. */
4539 /* Core issue 226 (C++0x only): the following only applies to class
4540 templates. */
4543 {
4544 /* [temp.param]
4546 If a template-parameter has a default template-argument, all
4547 subsequent template-parameters shall have a default
4548 template-argument supplied. */
4550 {
4557 {
4567 {
4569 /* For better subsequent error-recovery, we indicate that
4570 there should have been a default argument. */
4573 }
4575 && !is_friend_decl
4576 /* Don't complain about an enclosing partial
4577 specialization. */
4582 /* A fixed parameter pack will be partially
4583 instantiated into a fixed length list. */
4585 {
4586 /* A primary class template can only have one
4587 parameter pack, at the end of the template
4588 parameter list. */
4596 }
4597 }
4598 }
4599 }
4602 || is_partial
4603 || !is_primary
4605 /* For an ordinary class template, default template arguments are
4606 allowed at the innermost level, e.g.:
4607 template <class T = int>
4608 struct S {};
4609 but, in a partial specialization, they're not allowed even
4610 there, as we have in [temp.class.spec]:
4612 The template parameter list of a specialization shall not
4613 contain default template argument values.
4615 So, for a partial specialization, or for a function template
4616 (in C++98/C++03), we look at all of them. */
4617 ;
4618 else
4619 /* But, for a primary class template that is not a partial
4620 specialization we look at all template parameters except the
4621 innermost ones. */
4624 /* Figure out what error message to issue. */
4637 else
4641 /* If we're inside a class definition, there's no need to
4642 examine the parameters to the class itself. On the one
4643 hand, they will be checked when the class is defined, and,
4644 on the other, default arguments are valid in things like:
4645 template <class T = double>
4646 struct S { template <class U> void f(U); };
4647 Here the default argument for `S' has no bearing on the
4648 declaration of `f'. */
4650 else
4651 /* Check everything. */
4657 {
4664 {
4669 {
4671 {
4678 }
4680 /* Clear out the default argument so that we are not
4681 confused later. */
4683 }
4684 }
4686 /* At this point, if we're still interested in issuing messages,
4687 they must apply to classes surrounding the object declared. */
4691 }
4694 }
4696 /* Worker for push_template_decl_real, called via
4697 for_each_template_parm. DATA is really an int, indicating the
4698 level of the parameters we are interested in. If T is a template
4699 parameter of that level, return nonzero. */
4701 static int
4703 {
4709 else
4712 }
4714 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4715 parameters given by current_template_args, or reuses a
4716 previously existing one, if appropriate. Returns the DECL, or an
4717 equivalent one, if it is replaced via a call to duplicate_decls.
4719 If IS_FRIEND is true, DECL is a friend declaration. */
4721 tree
4723 {
4724 tree tmpl;
4725 tree args;
4726 tree info;
4727 tree ctx;
4731 /* True if the template is a member template, in the sense of
4732 [temp.mem]. */
4738 /* See if this is a partial specialization. */
4751 /* For a friend, we want the context of the friend function, not
4752 the type of which it is a friend. */
4756 /* In the case of a virtual function, we want the class in which
4757 it is defined. */
4759 else
4760 /* Otherwise, if we're currently defining some class, the DECL
4761 is assumed to be a member of the class. */
4770 /* See if this is a primary template. */
4773 /* A friend template that specifies a class context, i.e.
4774 template <typename T> friend void A<T>::f();
4775 is not primary. */
4780 else
4784 {
4789 {
4792 }
4794 {
4796 {
4799 }
4801 {
4802 /* [temp.mem]
4804 A destructor shall not be a member template. */
4807 }
4814 {
4815 /* [basic.stc.dynamic.allocation]
4817 An allocation function can be a function
4818 template. ... Template allocation functions shall
4819 have two or more parameters. */
4822 }
4823 }
4829 /* alias-declaration */
4833 else
4834 {
4837 }
4838 }
4840 /* Check to see that the rules regarding the use of default
4841 arguments are not being violated. */
4845 /* Ensure that there are no parameter packs in the type of this
4846 declaration that have not been expanded. */
4848 {
4849 /* Check each of the arguments individually to see if there are
4850 any bare parameter packs. */
4856 {
4859 {
4860 /* This is a PARM_DECL that contains unexpanded parameter
4861 packs. We have already complained about this in the
4862 check_for_bare_parameter_packs call, so just replace
4863 these types with ERROR_MARK_NODE. */
4866 }
4870 }
4872 /* Check for bare parameter packs in the return type and the
4873 exception specifiers. */
4875 /* Errors were already issued, set return type to int
4876 as the frontend doesn't expect error_mark_node as
4877 the return type. */
4881 }
4886 {
4889 }
4902 {
4907 /* If DECL is a TYPE_DECL for a class-template, then there won't
4908 be DECL_LANG_SPECIFIC. The information equivalent to
4909 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4913 {
4914 /* Since a template declaration already existed for this
4915 class-type, we must be redeclaring it here. Make sure
4916 that the redeclaration is valid. */
4918 current_template_parms);
4919 /* We don't need to create a new TEMPLATE_DECL; just use the
4920 one we already had. */
4922 }
4923 else
4924 {
4926 member_template_p);
4931 {
4932 /* A specialization of a member template of a template
4933 class. */
4937 }
4938 }
4939 }
4940 else
4941 {
4947 {
4950 }
4958 {
4959 tree new_tmpl;
4961 /* The declaration is a specialization of a member
4962 template, declared outside the class. Therefore, the
4963 innermost template arguments will be NULL, so we
4964 replace them with the arguments determined by the
4965 earlier call to check_explicit_specialization. */
4968 new_tmpl
4970 member_template_p);
4980 args,
4983 }
4985 /* Make sure the template headers we got make sense. */
4990 {
4995 }
4996 else
4998 {
5003 {
5007 else
5011 /* Avoid crash in import_export_decl. */
5014 }
5019 /* Can happen in erroneous input. */
5021 else
5023 }
5025 /* Check that the parms are used in the appropriate qualifying scopes
5026 in the declarator. */
5030 {
5036 /* Avoid crash in import_export_decl. */
5039 }
5040 }
5045 /* Push template declarations for global functions and types. Note
5046 that we do not try to push a global template friend declared in a
5047 template class; such a thing may well depend on the template
5048 parameters of the class. */
5051 {
5056 /* Hide template friend classes that haven't been declared yet. */
5058 {
5061 }
5062 }
5065 {
5071 {
5074 /* It is a conversion operator. See if the type converted to
5075 depends on innermost template operands. */
5078 depth))
5080 }
5082 /* Give template template parms a DECL_CONTEXT of the template
5083 for which they are a parameter. */
5086 {
5090 }
5091 }
5093 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5094 back to its most general template. If TMPL is a specialization,
5095 ARGS may only have the innermost set of arguments. Add the missing
5096 argument levels if necessary. */
5104 else
5105 {
5110 }
5113 && !is_friend
5116 /* Set DECL_COMDAT on template instantiations; if we force
5117 them to be emitted by explicit instantiation or -frepo,
5118 mark_needed will tell cgraph to do the right thing. */
5122 }
5124 tree
5126 {
5128 }
5130 /* FN is an inheriting constructor that inherits from the constructor
5131 template INHERITED; turn FN into a constructor template with a matching
5132 template header. */
5134 tree
5136 {
5137 tree inner_parms
5140 tree parms
5151 }
5153 /* Called when a class template TYPE is redeclared with the indicated
5154 template PARMS, e.g.:
5156 template <class T> struct S;
5157 template <class T> struct S {}; */
5159 bool
5161 {
5162 tree tmpl;
5163 tree tmpl_parms;
5167 {
5170 }
5174 /* The type is nested in some template class. Nothing to worry
5175 about here; there are no new template parameters for the nested
5176 type. */
5180 {
5182 tmpl);
5184 }
5190 {
5200 }
5203 {
5204 tree tmpl_parm;
5205 tree parm;
5206 tree tmpl_default;
5207 tree parm_default;
5221 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5222 TEMPLATE_DECL. */
5232 {
5236 }
5239 {
5240 /* We have in [temp.param]:
5242 A template-parameter may not be given default arguments
5243 by two different declarations in the same scope. */
5248 }
5251 /* Update the previous template parameters (which are the ones
5252 that will really count) with the new default value. */
5255 /* Update the new parameters, too; they'll be used as the
5256 parameters for any members. */
5258 }
5261 }
5263 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5264 to be used when the caller has already checked
5265 (processing_template_decl
5266 && !instantiation_dependent_expression_p (expr)
5267 && potential_constant_expression (expr))
5268 and cleared processing_template_decl. */
5270 tree
5272 {
5275 complain,
5279 }
5281 /* Simplify EXPR if it is a non-dependent expression. Returns the
5282 (possibly simplified) expression. */
5284 tree
5286 {
5290 /* If we're in a template, but EXPR isn't value dependent, simplify
5291 it. We're supposed to treat:
5293 template <typename T> void f(T[1 + 1]);
5294 template <typename T> void f(T[2]);
5296 as two declarations of the same function, for example. */
5300 {
5301 processing_template_decl_sentinel s;
5303 }
5305 }
5307 tree
5309 {
5311 }
5313 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5314 template declaration, or a TYPE_DECL for an alias declaration. */
5316 bool
5318 {
5326 }
5328 /* Return TRUE iff T is a specialization of an alias template. */
5330 bool
5332 {
5333 /* It's an alias template specialization if it's an alias and its
5334 TYPE_NAME is a specialization of a primary template. */
5336 {
5340 {
5343 }
5344 }
5346 }
5348 /* Return TRUE iff T is a specialization of an alias template with
5349 dependent template-arguments. */
5351 bool
5353 {
5355 && (any_dependent_template_arguments_p
5357 }
5359 /* Return the number of innermost template parameters in TMPL. */
5361 static int
5363 {
5366 }
5368 /* Return either TMPL or another template that it is equivalent to under DR
5369 1286: An alias that just changes the name of a template is equivalent to
5370 the other template. */
5372 static tree
5374 {
5377 {
5380 {
5385 {
5386 tree alias_args = INNERMOST_TEMPLATE_ARGS
5390 /* The alias type is equivalent to the pattern of the
5391 underlying template, so strip the alias. */
5394 }
5395 }
5397 }
5399 }
5401 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5402 must be a function or a pointer-to-function type, as specified
5403 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5404 and check that the resulting function has external linkage. */
5406 static tree
5408 tsubst_flags_t complain)
5409 {
5412 linkage_kind linkage;
5424 /* [temp.arg.nontype]/1
5426 A template-argument for a non-type, non-template template-parameter
5427 shall be one of:
5428 [...]
5429 -- the address of an object or function with external [C++11: or
5430 internal] linkage. */
5433 {
5435 {
5441 else
5444 }
5446 }
5450 {
5452 {
5457 else
5461 }
5463 }
5466 }
5468 /* Subroutine of convert_nontype_argument.
5469 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5470 Emit an error otherwise. */
5472 static bool
5474 tsubst_flags_t complain)
5475 {
5486 {
5490 }
5492 }
5494 /* Returns TRUE iff the address of OP is value-dependent.
5496 14.6.2.4 [temp.dep.temp]:
5497 A non-integral non-type template-argument is dependent if its type is
5498 dependent or it has either of the following forms
5499 qualified-id
5500 & qualified-id
5501 and contains a nested-name-specifier which specifies a class-name that
5502 names a dependent type.
5504 We generalize this to just say that the address of a member of a
5505 dependent class is value-dependent; the above doesn't cover the
5506 address of a static data member named with an unqualified-id. */
5508 static bool
5510 {
5511 /* We could use get_inner_reference here, but there's no need;
5512 this is only relevant for template non-type arguments, which
5513 can only be expressed as &id-expression. */
5515 {
5519 }
5522 }
5524 /* The next set of functions are used for providing helpful explanatory
5525 diagnostics for failed overload resolution. Their messages should be
5526 indented by two spaces for consistency with the messages in
5527 call.c */
5529 static int
5531 {
5533 }
5535 static int
5537 {
5542 }
5544 static int
5546 {
5548 }
5550 static int
5552 {
5558 }
5560 static int
5562 {
5566 }
5568 static int
5570 {
5573 " template parameter %qD is not a parameter pack, but "
5577 }
5579 static int
5581 {
5584 " template argument %qE does not match "
5588 }
5590 static int
5592 {
5596 }
5598 static int
5600 {
5606 }
5608 static int
5610 {
5612 {
5617 else
5619 " deduced conflicting values for non-type parameter "
5621 }
5623 }
5625 static int
5627 {
5630 " variable-sized array type %qT is not "
5632 arg);
5634 }
5636 static int
5638 {
5642 arg);
5644 }
5646 static int
5648 {
5650 {
5656 else
5661 }
5663 }
5665 static int
5667 {
5669 }
5671 static int
5674 {
5676 }
5678 static int
5681 {
5687 }
5689 static int
5692 {
5695 {
5703 }
5705 }
5707 static int
5709 {
5712 " template parameters of a template template argument are "
5715 }
5717 static int
5719 {
5725 }
5727 static int
5729 {
5734 }
5736 static int
5738 {
5742 arg);
5744 }
5746 /* Attempt to convert the non-type template parameter EXPR to the
5747 indicated TYPE. If the conversion is successful, return the
5748 converted value. If the conversion is unsuccessful, return
5749 NULL_TREE if we issued an error message, or error_mark_node if we
5750 did not. We issue error messages for out-and-out bad template
5751 parameters, but not simply because the conversion failed, since we
5752 might be just trying to do argument deduction. Both TYPE and EXPR
5753 must be non-dependent.
5755 The conversion follows the special rules described in
5756 [temp.arg.nontype], and it is much more strict than an implicit
5757 conversion.
5759 This function is called twice for each template argument (see
5760 lookup_template_class for a more accurate description of this
5761 problem). This means that we need to handle expressions which
5762 are not valid in a C++ source, but can be created from the
5763 first call (for instance, casts to perform conversions). These
5764 hacks can go away after we fix the double coercion problem. */
5766 static tree
5768 {
5769 tree expr_type;
5771 /* Detect immediately string literals as invalid non-type argument.
5772 This special-case is not needed for correctness (we would easily
5773 catch this later), but only to provide better diagnostic for this
5774 common user mistake. As suggested by DR 100, we do not mention
5775 linkage issues in the diagnostic as this is not the point. */
5776 /* FIXME we're making this OK. */
5778 {
5784 }
5786 /* Add the ADDR_EXPR now for the benefit of
5787 value_dependent_expression_p. */
5790 {
5794 }
5796 /* If we are in a template, EXPR may be non-dependent, but still
5797 have a syntactic, rather than semantic, form. For example, EXPR
5798 might be a SCOPE_REF, rather than the VAR_DECL to which the
5799 SCOPE_REF refers. Preserving the qualifying scope is necessary
5800 so that access checking can be performed when the template is
5801 instantiated -- but here we need the resolved form so that we can
5802 convert the argument. */
5808 && processing_template_decl
5817 else
5820 /* If the argument is non-dependent, perform any conversions in
5821 non-dependent context as well. */
5826 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5827 to a non-type argument of "nullptr". */
5831 /* In C++11, integral or enumeration non-type template arguments can be
5832 arbitrary constant expressions. Pointer and pointer to
5833 member arguments can be general constant expressions that evaluate
5834 to a null value, but otherwise still need to be of a specific form. */
5836 {
5838 /* A PTRMEM_CST is already constant, and a valid template
5839 argument for a parameter of pointer to member type, we just want
5840 to leave it in that form rather than lower it to a
5845 {
5850 }
5851 }
5853 /* HACK: Due to double coercion, we can get a
5854 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5855 which is the tree that we built on the first call (see
5856 below when coercing to reference to object or to reference to
5857 function). We just strip everything and get to the arg.
5858 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5859 for examples. */
5861 {
5867 {
5868 /* ??? Maybe we could use convert_from_reference here, but we
5869 would need to relax its constraints because the NOP_EXPR
5870 could actually change the type to something more cv-qualified,
5871 and this is not folded by convert_from_reference. */
5876 && (same_type_ignoring_top_level_qualifiers_p
5879 {
5882 }
5883 }
5884 }
5886 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5887 parameter is a pointer to object, through decay and
5888 qualification conversion. Let's strip everything. */
5890 {
5895 {
5896 /* Skip the ADDR_EXPR only if it is part of the decay for
5897 an array. Otherwise, it is part of the original argument
5898 in the source code. */
5903 }
5904 }
5906 /* [temp.arg.nontype]/5, bullet 1
5908 For a non-type template-parameter of integral or enumeration type,
5909 integral promotions (_conv.prom_) and integral conversions
5910 (_conv.integral_) are applied. */
5912 {
5921 /* Notice that there are constant expressions like '4 % 0' which
5922 do not fold into integer constants. */
5924 {
5926 {
5937 /* else cxx_constant_value complained but gave us
5938 a real constant, so go ahead. */
5940 }
5941 else
5943 }
5945 /* Avoid typedef problems. */
5948 }
5949 /* [temp.arg.nontype]/5, bullet 2
5951 For a non-type template-parameter of type pointer to object,
5952 qualification conversions (_conv.qual_) and the array-to-pointer
5953 conversion (_conv.array_) are applied. */
5955 {
5956 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5958 A template-argument for a non-type, non-template template-parameter
5959 shall be one of: [...]
5961 -- the name of a non-type template-parameter;
5962 -- the address of an object or function with external linkage, [...]
5963 expressed as "& id-expression" where the & is optional if the name
5964 refers to a function or array, or if the corresponding
5965 template-parameter is a reference.
5967 Here, we do not care about functions, as they are invalid anyway
5968 for a parameter of type pointer-to-object. */
5971 /* Non-type template parameters are OK. */
5972 ;
5977 {
5979 {
5982 "because %qD is a variable, not the address of "
5985 }
5987 {
5993 }
5994 /* Other values, like integer constants, might be valid
5995 non-type arguments of some other type. */
5997 }
5998 else
5999 {
6000 tree decl;
6005 {
6010 }
6012 {
6018 }
6020 {
6025 }
6026 }
6035 }
6036 /* [temp.arg.nontype]/5, bullet 3
6038 For a non-type template-parameter of type reference to object, no
6039 conversions apply. The type referred to by the reference may be more
6040 cv-qualified than the (otherwise identical) type of the
6041 template-argument. The template-parameter is bound directly to the
6042 template-argument, which must be an lvalue. */
6044 {
6046 expr_type))
6050 {
6055 }
6058 {
6063 }
6065 /* [temp.arg.nontype]/1
6067 A template-argument for a non-type, non-template template-parameter
6068 shall be one of: [...]
6070 -- the address of an object or function with external linkage. */
6073 {
6076 {
6079 "because a reference variable does not have a constant "
6082 }
6083 }
6086 {
6092 }
6095 {
6101 }
6104 }
6105 /* [temp.arg.nontype]/5, bullet 4
6107 For a non-type template-parameter of type pointer to function, only
6108 the function-to-pointer conversion (_conv.func_) is applied. If the
6109 template-argument represents a set of overloaded functions (or a
6110 pointer to such), the matching function is selected from the set
6111 (_over.over_). */
6113 {
6114 /* If the argument is a template-id, we might not have enough
6115 context information to decay the pointer. */
6117 {
6121 }
6124 /* Null pointer values are OK in C++11. */
6130 }
6131 /* [temp.arg.nontype]/5, bullet 5
6133 For a non-type template-parameter of type reference to function, no
6134 conversions apply. If the template-argument represents a set of
6135 overloaded functions, the matching function is selected from the set
6136 (_over.over_). */
6138 {
6140 {
6142 {
6147 }
6149 }
6156 }
6157 /* [temp.arg.nontype]/5, bullet 6
6159 For a non-type template-parameter of type pointer to member function,
6160 no conversions apply. If the template-argument represents a set of
6161 overloaded member functions, the matching member function is selected
6162 from the set (_over.over_). */
6164 {
6169 /* [temp.arg.nontype] bullet 1 says the pointer to member
6170 expression must be a pointer-to-member constant. */
6174 /* There is no way to disable standard conversions in
6175 resolve_address_of_overloaded_function (called by
6176 instantiate_type). It is possible that the call succeeded by
6177 converting &B::I to &D::I (where B is a base of D), so we need
6178 to reject this conversion here.
6180 Actually, even if there was a way to disable standard conversions,
6181 it would still be better to reject them here so that we can
6182 provide a superior diagnostic. */
6184 {
6186 {
6190 /* If we are just one standard conversion off, explain. */
6194 }
6196 }
6197 }
6198 /* [temp.arg.nontype]/5, bullet 7
6200 For a non-type template-parameter of type pointer to data member,
6201 qualification conversions (_conv.qual_) are applied. */
6203 {
6204 /* [temp.arg.nontype] bullet 1 says the pointer to member
6205 expression must be a pointer-to-member constant. */
6212 }
6214 {
6216 {
6221 }
6223 }
6224 /* A template non-type parameter must be one of the above. */
6225 else
6228 /* Sanity check: did we actually convert the argument to the
6229 right type? */
6233 }
6235 /* Subroutine of coerce_template_template_parms, which returns 1 if
6236 PARM_PARM and ARG_PARM match using the rule for the template
6237 parameters of template template parameters. Both PARM and ARG are
6238 template parameters; the rest of the arguments are the same as for
6239 coerce_template_template_parms.
6240 */
6241 static int
6243 tree arg,
6244 tsubst_flags_t complain,
6245 tree in_decl,
6246 tree outer_args)
6247 {
6256 {
6258 /* We encounter instantiations of templates like
6259 template <template <template <class> class> class TT>
6260 class C; */
6261 {
6268 }
6269 /* Fall through. */
6274 /* Argument is a parameter pack but parameter is not. */
6279 /* The tsubst call is used to handle cases such as
6281 template <int> class C {};
6282 template <class T, template <T> class TT> class D {};
6283 D<int, C> d;
6285 i.e. the parameter list of TT depends on earlier parameters. */
6287 && !same_type_p
6294 /* Argument is a parameter pack but parameter is not. */
6301 }
6304 }
6307 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6308 template template parameters. Both PARM_PARMS and ARG_PARMS are
6309 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6310 or PARM_DECL.
6312 Consider the example:
6313 template <class T> class A;
6314 template<template <class U> class TT> class B;
6316 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6317 the parameters to A, and OUTER_ARGS contains A. */
6319 static int
6321 tree arg_parms,
6322 tsubst_flags_t complain,
6323 tree in_decl,
6324 tree outer_args)
6325 {
6336 /* Determine whether we have a parameter pack at the end of the
6337 template template parameter's template parameter list. */
6339 {
6346 {
6360 }
6361 }
6367 /* Check all of the template parameters except the parameter pack at
6368 the end (if any). */
6370 {
6379 outer_args))
6382 }
6385 {
6386 /* Check each of the template parameters in the template
6387 argument against the template parameter pack at the end of
6388 the template template parameter. */
6395 {
6402 outer_args))
6404 }
6405 }
6408 }
6410 /* Verifies that the deduced template arguments (in TARGS) for the
6411 template template parameters (in TPARMS) represent valid bindings,
6412 by comparing the template parameter list of each template argument
6413 to the template parameter list of its corresponding template
6414 template parameter, in accordance with DR150. This
6415 routine can only be called after all template arguments have been
6416 deduced. It will return TRUE if all of the template template
6417 parameter bindings are okay, FALSE otherwise. */
6418 bool
6420 {
6424 /* We're dealing with template parms in this process. */
6430 {
6435 {
6440 {
6441 /* Look inside the argument pack. */
6444 }
6447 {
6451 /* Extract the next argument from the argument
6452 pack. */
6456 /* Look at the pattern of the pack expansion. */
6459 /* Extract the template parameters from the template
6460 argument. */
6466 /* Verify that we can coerce the template template
6467 parameters from the template argument to the template
6468 parameter. This requires an exact match. */
6470 && !coerce_template_template_parms
6472 targ_parms,
6473 tf_none,
6474 tparm,
6475 targs))
6476 {
6479 }
6480 }
6481 }
6482 }
6484 out:
6488 }
6490 /* Since type attributes aren't mangled, we need to strip them from
6491 template type arguments. */
6493 static tree
6495 {
6504 }
6506 /* Convert the indicated template ARG as necessary to match the
6507 indicated template PARM. Returns the converted ARG, or
6508 error_mark_node if the conversion was unsuccessful. Error and
6509 warning messages are issued under control of COMPLAIN. This
6510 conversion is for the Ith parameter in the parameter list. ARGS is
6511 the full set of template arguments deduced so far. */
6513 static tree
6515 tree arg,
6516 tree args,
6517 tsubst_flags_t complain,
6519 tree in_decl)
6520 {
6521 tree orig_arg;
6522 tree val;
6530 {
6531 /* The template argument was the name of some
6532 member function. That's usually
6533 invalid, but static members are OK. In any
6534 case, grab the underlying fields/functions
6535 and issue an error later if required. */
6538 }
6546 /* When determining whether an argument pack expansion is a template,
6547 look at the pattern. */
6551 /* Deal with an injected-class-name used as a template template arg. */
6553 {
6556 {
6566 }
6567 }
6569 is_tmpl_type =
6585 {
6587 {
6591 }
6594 "to refer to a type member of a template parameter, "
6599 typename_type,
6600 complain);
6603 }
6605 {
6607 {
6609 {
6621 else
6624 }
6625 }
6627 }
6629 {
6631 {
6638 else
6641 }
6643 }
6646 {
6648 {
6652 /* The number of argument required is not known yet.
6653 Just accept it for now. */
6655 else
6656 {
6658 tree argparm;
6660 /* Strip alias templates that are equivalent to another
6661 template. */
6667 args))
6668 {
6671 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6672 TEMPLATE_DECL. */
6674 {
6679 }
6680 }
6681 else
6682 {
6684 {
6691 }
6694 }
6695 }
6696 }
6697 else
6699 /* We only form one instance of each template specialization.
6700 Therefore, if we use a non-canonical variant (i.e., a
6701 typedef), any future messages referring to the type will use
6702 the typedef, which is confusing if those future uses do not
6703 themselves also use the typedef. */
6706 }
6707 else
6708 {
6715 {
6718 else
6719 {
6720 /* Not sure if this is reachable, but it doesn't hurt
6721 to be robust. */
6724 }
6725 }
6728 /* We used to call digest_init here. However, digest_init
6729 will report errors, which we don't want when complain
6730 is zero. More importantly, digest_init will try too
6731 hard to convert things: for example, `0' should not be
6732 converted to pointer type at this point according to
6733 the standard. Accepting this is not merely an
6734 extension, since deciding whether or not these
6735 conversions can occur is part of determining which
6736 function template to call, or whether a given explicit
6737 argument specification is valid. */
6739 else
6740 {
6743 }
6751 {
6752 /* Strip typedefs from the SCOPE_REF. */
6755 complain);
6758 }
6759 }
6762 }
6764 /* Coerces the remaining template arguments in INNER_ARGS (from
6765 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6766 Returns the coerced argument pack. PARM_IDX is the position of this
6767 parameter in the template parameter list. ARGS is the original
6768 template argument list. */
6769 static tree
6772 tree args,
6773 tree inner_args,
6775 tree new_args,
6777 tree in_decl,
6778 tsubst_flags_t complain)
6779 {
6782 tree packed_args;
6783 tree argument_pack;
6790 {
6791 /* When the template parameter is a non-type template parameter pack
6792 or template template parameter pack whose type or template
6793 parameters use parameter packs, we know exactly how many arguments
6794 we are looking for. Build a vector of the instantiated decls for
6795 these template parameters in PACKED_PARMS. */
6796 /* We can't use make_pack_expansion here because it would interpret a
6797 _DECL as a use rather than a declaration. */
6811 /* If we're doing a partial instantiation of a member template,
6812 verify that all of the types used for the non-type
6813 template parameter pack are, in fact, valid for non-type
6814 template parameters. */
6817 {
6820 {
6824 }
6825 /* We don't know how many args we have yet, just
6826 use the unconverted ones for now. */
6828 }
6831 }
6832 else
6835 /* Convert the remaining arguments, which will be a part of the
6836 parameter pack "parm". */
6838 {
6844 {
6845 /* Once we've packed as many args as we have types, stop. */
6849 /* We don't know how many args we have yet, just
6850 use the unconverted ones for now. */
6852 else
6854 }
6857 {
6860 }
6861 else
6864 in_decl);
6868 }
6872 {
6877 }
6882 else
6883 {
6888 }
6891 #ifdef ENABLE_CHECKING
6894 #endif
6896 }
6898 /* Returns the number of pack expansions in the template argument vector
6899 ARGS. */
6901 static int
6903 {
6908 {
6912 }
6914 }
6916 /* Convert all template arguments to their appropriate types, and
6917 return a vector containing the innermost resulting template
6918 arguments. If any error occurs, return error_mark_node. Error and
6919 warning messages are issued under control of COMPLAIN.
6921 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6922 for arguments not specified in ARGS. Otherwise, if
6923 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6924 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6925 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6926 ARGS. */
6928 static tree
6930 tree args,
6931 tree in_decl,
6932 tsubst_flags_t complain,
6935 {
6937 tree orig_inner_args;
6938 tree inner_args;
6939 tree new_args;
6940 tree new_inner_args;
6944 /* When used as a boolean value, indicates whether this is a
6945 variadic template parameter list. Since it's an int, we can also
6946 subtract it from nparms to get the number of non-variadic
6947 parameters. */
6952 /* Likewise for parameters with default arguments. */
6960 /* Determine if there are any parameter packs or default arguments. */
6962 {
6970 }
6973 /* If there are no parameters that follow a parameter pack, we need to
6974 expand any argument packs so that we can deduce a parameter pack from
6975 some non-packed args followed by an argument pack, as in variadic85.C.
6976 If there are such parameters, we need to leave argument packs intact
6977 so the arguments are assigned properly. This can happen when dealing
6978 with a nested class inside a partial specialization of a class
6979 template, as in variadic92.C, or when deducing a template parameter pack
6980 from a sub-declarator, as in variadic114.C. */
6984 /* Count any pack expansion args. */
6990 && require_all_args
6991 && !variadic_args_p
6992 && (!use_default_args
6995 {
6997 {
6999 {
7003 }
7004 else
7010 }
7013 }
7014 /* We can't pass a pack expansion to a non-pack parameter of an alias
7015 template (DR 1430). */
7017 && variadic_args_p
7019 {
7021 {
7023 {
7029 {
7034 }
7035 }
7037 found:;
7038 }
7040 }
7042 /* We need to evaluate the template arguments, even though this
7043 template-id may be nested within a "sizeof". */
7052 {
7053 tree arg;
7054 tree parm;
7056 /* Get the Ith template parameter. */
7060 {
7063 }
7065 /* Calculate the next argument. */
7068 else
7073 {
7074 /* Some arguments will be placed in the
7075 template parameter pack PARM. */
7082 {
7083 /* We don't know how many args we have yet, just use the
7084 unconverted (and still packed) ones for now. */
7088 }
7092 /* Store this argument. */
7094 {
7095 lost++;
7096 /* We are done with all of the arguments. */
7098 }
7099 else
7100 {
7103 }
7106 }
7108 {
7110 {
7111 /* "If every valid specialization of a variadic template
7112 requires an empty template parameter pack, the template is
7113 ill-formed, no diagnostic required." So check that the
7114 pattern works with this parameter. */
7119 in_decl);
7121 {
7125 }
7127 /* Recover from missing typename. */
7131 /* We don't know how many args we have yet, just
7132 use the unconverted ones for now. */
7136 }
7137 }
7139 {
7140 /* There must be a default arg in this case. */
7143 /* The position of the first default template argument,
7144 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
7145 Record that. */
7149 }
7150 else
7154 {
7157 }
7159 /* This only occurs if there was an error in the template
7160 parameter list itself (which we would already have
7161 reported) that we are trying to recover from, e.g., a class
7162 template with a parameter list such as
7163 template<typename..., typename>. */
7165 else
7171 lost++;
7173 }
7178 {
7180 {
7185 }
7187 }
7192 #ifdef ENABLE_CHECKING
7196 #endif
7199 }
7201 /* Like coerce_template_parms. If PARMS represents all template
7202 parameters levels, this function returns a vector of vectors
7203 representing all the resulting argument levels. Note that in this
7204 case, only the innermost arguments are coerced because the
7205 outermost ones are supposed to have been coerced already.
7207 Otherwise, if PARMS represents only (the innermost) vector of
7208 parameters, this function returns a vector containing just the
7209 innermost resulting arguments. */
7211 static tree
7213 tree args,
7214 tree in_decl,
7215 tsubst_flags_t complain,
7218 {
7221 tree coerced_args;
7224 {
7226 tree level;
7232 {
7233 tree l;
7237 require_all_args,
7238 use_default_args);
7239 else
7246 }
7247 }
7248 else
7251 require_all_args,
7252 use_default_args);
7254 }
7256 /* Returns 1 if template args OT and NT are equivalent. */
7258 static int
7260 {
7267 /* For member templates */
7276 {
7293 }
7295 {
7296 /* We get here probably because we are in the middle of substituting
7297 into the pattern of a pack expansion. In that case the
7298 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
7299 interested in. So we want to use the initial pack argument for
7300 the comparison. */
7305 }
7307 {
7310 /* Don't treat an alias template specialization with dependent
7311 arguments as equivalent to its underlying type when used as a
7312 template argument; we need them to be distinct so that we
7313 substitute into the specialization arguments at instantiation
7314 time. And aliases can't be equivalent without being ==, so
7315 we don't need to look any deeper. */
7318 else
7320 }
7323 else
7324 {
7325 /* Try to treat a template non-type argument that has been converted
7326 to the parameter type as equivalent to one that hasn't yet. */
7339 }
7340 }
7342 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7343 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7344 NEWARG_PTR with the offending arguments if they are non-NULL. */
7346 static int
7349 {
7362 {
7367 {
7373 }
7374 }
7376 }
7378 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7379 of template arguments. Returns 0 otherwise. */
7381 int
7383 {
7385 }
7387 static void
7389 {
7399 /* We are called both from instantiate_decl, where we've already had a
7400 tinst_level pushed, and instantiate_template, where we haven't.
7401 Compensate. */
7412 else
7421 }
7424 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7425 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7426 documentation for TEMPLATE_ID_EXPR. */
7428 tree
7430 {
7431 tree type;
7439 {
7442 }
7445 {
7447 unknown_type_node,
7449 arglist);
7451 }
7458 }
7460 /* Within the scope of a template class S<T>, the name S gets bound
7461 (in build_self_reference) to a TYPE_DECL for the class, not a
7462 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7463 or one of its enclosing classes, and that type is a template,
7464 return the associated TEMPLATE_DECL. Otherwise, the original
7465 DECL is returned.
7467 Also handle the case when DECL is a TREE_LIST of ambiguous
7468 injected-class-names from different bases. */
7470 tree
7472 {
7476 /* DR 176: A lookup that finds an injected-class-name (10.2
7477 [class.member.lookup]) can result in an ambiguity in certain cases
7478 (for example, if it is found in more than one base class). If all of
7479 the injected-class-names that are found refer to specializations of
7480 the same class template, and if the name is followed by a
7481 template-argument-list, the reference refers to the class template
7482 itself and not a specialization thereof, and is not ambiguous. */
7484 {
7487 {
7493 }
7496 else
7498 }
7504 }
7506 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
7507 parameters, find the desired type.
7509 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7511 IN_DECL, if non-NULL, is the template declaration we are trying to
7512 instantiate.
7514 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7515 the class we are looking up.
7517 Issue error and warning messages under control of COMPLAIN.
7519 If the template class is really a local class in a template
7520 function, then the FUNCTION_CONTEXT is the function in which it is
7521 being instantiated.
7523 ??? Note that this function is currently called *twice* for each
7524 template-id: the first time from the parser, while creating the
7525 incomplete type (finish_template_type), and the second type during the
7526 real instantiation (instantiate_template_class). This is surely something
7527 that we want to avoid. It also causes some problems with argument
7528 coercion (see convert_nontype_argument for more information on this). */
7530 static tree
7533 {
7535 tree t;
7538 spec_entry elt;
7539 hashval_t hash;
7542 {
7546 else
7547 {
7554 }
7557 }
7559 {
7562 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7563 an implicit typename for the second A. Deal with it. */
7568 {
7571 }
7572 }
7575 {
7578 }
7580 {
7584 }
7586 {
7589 }
7591 /* Issue an error message if we didn't find a template. */
7593 {
7597 }
7600 /* Make sure it's a user visible template, if it was named by
7601 the user. */
7604 {
7606 {
7610 }
7612 }
7616 /* An alias that just changes the name of a template is equivalent to the
7617 other template, so if any of the arguments are pack expansions, strip
7618 the alias to avoid problems with a pack expansion passed to a non-pack
7619 alias template parameter (DR 1430). */
7624 {
7625 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7626 template arguments */
7628 tree parm;
7629 tree arglist2;
7630 tree outer;
7634 /* Consider an example where a template template parameter declared as
7636 template <class T, class U = std::allocator<T> > class TT
7638 The template parameter level of T and U are one level larger than
7639 of TT. To proper process the default argument of U, say when an
7640 instantiation `TT<int>' is seen, we need to build the full
7641 arguments containing {int} as the innermost level. Outer levels,
7642 available when not appearing as default template argument, can be
7643 obtained from the arguments of the enclosing template.
7645 Suppose that TT is later substituted with std::vector. The above
7646 instantiation is `TT<int, std::allocator<T> >' with TT at
7647 level 1, and T at level 2, while the template arguments at level 1
7648 becomes {std::vector} and the inner level 2 is {int}. */
7654 /* This is an argument of the current template, so we haven't set
7655 DECL_CONTEXT yet. */
7662 complain,
7672 }
7673 else
7674 {
7676 tree gen_tmpl;
7677 tree type_decl;
7685 /* An error occurred while building the template TEMPL, and a
7686 diagnostic has most certainly been emitted for that
7687 already. Let's propagate that error. */
7696 {
7697 /* We've been given an incomplete set of template arguments.
7698 For example, given:
7700 template <class T> struct S1 {
7701 template <class U> struct S2 {};
7702 template <class U> struct S2<U*> {};
7703 };
7705 we will be called with an ARGLIST of `U*', but the
7706 TEMPLATE will be `template <class T> template
7707 <class U> struct S1<T>::S2'. We must fill in the missing
7708 arguments. */
7709 arglist
7711 arglist);
7713 }
7715 /* Now we should have enough arguments. */
7718 /* From here on, we're only interested in the most general
7719 template. */
7721 /* Calculate the BOUND_ARGS. These will be the args that are
7722 actually tsubst'd into the definition to create the
7723 instantiation. */
7725 complain,
7730 /* We were unable to bind the arguments. */
7733 /* In the scope of a template class, explicit references to the
7734 template class refer to the type of the template, not any
7735 instantiation of it. For example, in:
7737 template <class T> class C { void f(C<T>); }
7739 the `C<T>' is just the same as `C'. Outside of the
7740 class, however, such a reference is an instantiation. */
7744 /* comp_template_args is expensive, check it last. */
7746 arglist))
7749 /* If we already have this specialization, return it. */
7760 /* If the deduced arguments are invalid, then the binding
7761 failed. */
7765 complain))
7772 {
7777 }
7787 /* Create the type. */
7789 {
7790 /* The user referred to a specialization of an alias
7791 template represented by GEN_TMPL.
7793 [temp.alias]/2 says:
7795 When a template-id refers to the specialization of an
7796 alias template, it is equivalent to the associated
7797 type obtained by substitution of its
7798 template-arguments for the template-parameters in the
7799 type-id of the alias template. */
7802 /* Note that the call above (by indirectly calling
7803 register_specialization in tsubst_decl) registers the
7804 TYPE_DECL representing the specialization of the alias
7805 template. So next time someone substitutes ARGLIST for
7806 the template parms into the alias template (GEN_TMPL),
7807 she'll get that TYPE_DECL back. */
7811 }
7813 {
7815 {
7824 }
7825 else
7826 {
7827 /* We don't want to call start_enum for this type, since
7828 the values for the enumeration constants may involve
7829 template parameters. And, no one should be interested
7830 in the enumeration constants for such a type. */
7833 }
7837 }
7839 {
7846 /* A local class. Make sure the decl gets registered properly. */
7851 /* This instantiation is another name for the primary
7852 template type. Set the TYPE_CANONICAL field
7853 appropriately. */
7856 /* Some of the template arguments require structural
7857 equality testing, so this template class requires
7858 structural equality testing. */
7860 }
7861 else
7864 /* If we called start_enum or pushtag above, this information
7865 will already be set up. */
7867 {
7874 }
7875 else
7879 {
7885 {
7888 }
7889 }
7893 {
7896 {
7899 else
7903 }
7904 }
7906 /* Let's consider the explicit specialization of a member
7907 of a class template specialization that is implicitly instantiated,
7908 e.g.:
7909 template<class T>
7910 struct S
7911 {
7912 template<class U> struct M {}; //#0
7913 };
7915 template<>
7916 template<>
7917 struct S<int>::M<char> //#1
7918 {
7919 int i;
7920 };
7921 [temp.expl.spec]/4 says this is valid.
7923 In this case, when we write:
7924 S<int>::M<char> m;
7926 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7927 the one of #0.
7929 When we encounter #1, we want to store the partial instantiation
7930 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
7932 For all cases other than this "explicit specialization of member of a
7933 class template", we just want to store the most general template into
7934 the CLASSTYPE_TI_TEMPLATE of M.
7936 This case of "explicit specialization of member of a class template"
7937 only happens when:
7938 1/ the enclosing class is an instantiation of, and therefore not
7939 the same as, the context of the most general template, and
7940 2/ we aren't looking at the partial instantiation itself, i.e.
7941 the innermost arguments are not the same as the innermost parms of
7942 the most general template.
7944 So it's only when 1/ and 2/ happens that we want to use the partial
7945 instantiation of the member template in lieu of its most general
7946 template. */
7950 /* the enclosing class must be an instantiation... */
7953 {
7954 tree partial_inst_args;
7957 partial_inst_args =
7963 use_partial_inst_tmpl =
7964 /*...and we must not be looking at the partial instantiation
7965 itself. */
7967 partial_inst_args);
7968 }
7971 /* This case is easy; there are no member templates involved. */
7973 else
7974 {
7975 /* This is a full instantiation of a member template. Find
7976 the partial instantiation of which this is an instance. */
7978 /* Temporarily reduce by one the number of levels in the ARGLIST
7979 so as to avoid comparing the last set of arguments. */
7983 /* FOUND is either a proper class type, or an alias
7984 template specialization. In the later case, it's a
7985 TYPE_DECL, resulting from the substituting of arguments
7986 for parameters in the TYPE_DECL of the alias template
7987 done earlier. So be careful while getting the template
7988 of FOUND. */
7992 }
8002 /* Note this use of the partial instantiation so we can check it
8003 later in maybe_process_partial_specialization. */
8010 /* Now that the type has been registered on the instantiations
8011 list, we set up the enumerators. Because the enumeration
8012 constants may involve the enumeration type itself, we make
8013 sure to register the type first, and then create the
8014 constants. That way, doing tsubst_expr for the enumeration
8015 constants won't result in recursive calls here; we'll find
8016 the instantiation and exit above. */
8020 /* If the type makes use of template parameters, the
8021 code that generates debugging information will crash. */
8024 /* Possibly limit visibility based on template args. */
8031 }
8032 }
8034 /* Wrapper for lookup_template_class_1. */
8036 tree
8039 {
8040 tree ret;
8046 }
8048 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST.
8049 The type of the expression is the unknown_type_node since the
8050 template-id could refer to an explicit or partial specialization. */
8052 tree
8054 {
8057 }
8059 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
8061 tree
8063 {
8077 }
8078 \f
8079 struct pair_fn_data
8080 {
8081 tree_fn_t fn;
8083 /* True when we should also visit template parameters that occur in
8084 non-deduced contexts. */
8087 };
8089 /* Called from for_each_template_parm via walk_tree. */
8091 static tree
8093 {
8106 {
8110 /* Fall through. */
8133 /* Since we're not going to walk subtrees, we have to do this
8134 explicitly here. */
8138 /* Fall through. */
8141 /* Check the return type. */
8146 /* Check the parameter types. Since default arguments are not
8147 instantiated until they are needed, the TYPE_ARG_TYPES may
8148 contain expressions that involve template parameters. But,
8149 no-one should be looking at them yet. And, once they're
8150 instantiated, they don't contain template parameters, so
8151 there's no point in looking at them then, either. */
8152 {
8153 tree parm;
8160 /* Since we've already handled the TYPE_ARG_TYPES, we don't
8161 want walk_tree walking into them itself. */
8163 }
8181 /* Fall through. */
8197 /* Record template parameters such as `T' inside `TT<T>'. */
8201 /* Fall through. */
8213 /* A template template parameter is encountered. */
8219 /* Already substituted template template parameter */
8242 /* If there's no type, then this thing must be some expression
8243 involving template parameters. */
8265 }
8267 /* We didn't find any template parameters we liked. */
8269 }
8271 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
8272 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
8273 call FN with the parameter and the DATA.
8274 If FN returns nonzero, the iteration is terminated, and
8275 for_each_template_parm returns 1. Otherwise, the iteration
8276 continues. If FN never returns a nonzero value, the value
8277 returned by for_each_template_parm is 0. If FN is NULL, it is
8278 considered to be the function which always returns 1.
8280 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
8281 parameters that occur in non-deduced contexts. When false, only
8282 visits those template parameters that can be deduced. */
8284 static int
8288 {
8292 /* Set up. */
8297 /* Walk the tree. (Conceptually, we would like to walk without
8298 duplicates, but for_each_template_parm_r recursively calls
8299 for_each_template_parm, so we would need to reorganize a fair
8300 bit to use walk_tree_without_duplicates, so we keep our own
8301 visited list.) */
8304 else
8307 for_each_template_parm_r,
8311 /* Clean up. */
8313 {
8316 }
8319 }
8321 /* Returns true if T depends on any template parameter. */
8323 int
8325 {
8355 else
8356 {
8359 }
8364 }
8366 /* Returns true iff current_function_decl is an incompletely instantiated
8367 template. Useful instead of processing_template_decl because the latter
8368 is set to 0 during instantiate_non_dependent_expr. */
8370 bool
8372 {
8381 }
8383 /* Returns true if T depends on any template parameter with level LEVEL. */
8385 int
8387 {
8390 }
8392 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8393 ill-formed translation unit, i.e. a variable or function that isn't
8394 usable in a constant expression. */
8398 {
8402 }
8404 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8405 neglectable and instantiated from within an erroneous instantiation. */
8407 static bool
8409 {
8420 }
8428 /* We're starting to instantiate D; record the template instantiation context
8429 for diagnostics and to restore it later. */
8431 bool
8433 {
8435 }
8437 /* We're starting to instantiate D; record the template instantiation context
8438 at LOC for diagnostics and to restore it later. */
8440 bool
8442 {
8446 {
8448 "template instantiation depth exceeds maximum of %d"
8450 max_tinst_depth);
8452 }
8454 /* If the current instantiation caused problems, don't let it instantiate
8455 anything else. Do allow deduction substitution and decls usable in
8456 constant expressions. */
8473 }
8475 /* We're done instantiating this template; return to the instantiation
8476 context. */
8478 void
8480 {
8481 /* Restore the filename and line number stashed away when we started
8482 this instantiation. */
8486 }
8488 /* We're instantiating a deferred template; restore the template
8489 instantiation context in which the instantiation was requested, which
8490 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8492 static tree
8494 {
8506 }
8508 /* Returns the TINST_LEVEL which gives the original instantiation
8509 context. */
8513 {
8519 }
8521 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8522 vector of template arguments, as for tsubst.
8524 Returns an appropriate tsubst'd friend declaration. */
8526 static tree
8528 {
8529 tree new_friend;
8534 /* This was a friend declared with an explicit template
8535 argument list, e.g.:
8537 friend void f<>(T);
8539 to indicate that f was a template instantiation, not a new
8540 function declaration. Now, we have to figure out what
8541 instantiation of what template. */
8542 {
8544 tree new_args;
8545 tree tmpl;
8548 /* Friend functions are looked up in the containing namespace scope.
8549 We must enter that scope, to avoid finding member functions of the
8550 current class with same name. */
8565 tsk_none);
8567 }
8571 /* The NEW_FRIEND will look like an instantiation, to the
8572 compiler, but is not an instantiation from the point of view of
8573 the language. For example, we might have had:
8575 template <class T> struct S {
8576 template <class U> friend void f(T, U);
8577 };
8579 Then, in S<int>, template <class U> void f(int, U) is not an
8580 instantiation of anything. */
8586 {
8590 }
8592 /* The mangled name for the NEW_FRIEND is incorrect. The function
8593 is not a template instantiation and should not be mangled like
8594 one. Therefore, we forget the mangling here; we'll recompute it
8595 later if we need it. */
8597 {
8600 }
8603 {
8604 tree old_decl;
8605 tree new_friend_template_info;
8606 tree new_friend_result_template_info;
8607 tree ns;
8610 /* We must save some information from NEW_FRIEND before calling
8611 duplicate decls since that function will free NEW_FRIEND if
8612 possible. */
8614 new_friend_is_defn =
8619 {
8620 /* This declaration is a `primary' template. */
8623 new_friend_result_template_info
8625 }
8626 else
8629 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8633 /* Inside pushdecl_namespace_level, we will push into the
8634 current namespace. However, the friend function should go
8635 into the namespace of the template. */
8645 {
8646 /* This new friend declaration matched an existing
8647 declaration. For example, given:
8649 template <class T> void f(T);
8650 template <class U> class C {
8651 template <class T> friend void f(T) {}
8652 };
8654 the friend declaration actually provides the definition
8655 of `f', once C has been instantiated for some type. So,
8656 old_decl will be the out-of-class template declaration,
8657 while new_friend is the in-class definition.
8659 But, if `f' was called before this point, the
8660 instantiation of `f' will have DECL_TI_ARGS corresponding
8661 to `T' but not to `U', references to which might appear
8662 in the definition of `f'. Previously, the most general
8663 template for an instantiation of `f' was the out-of-class
8664 version; now it is the in-class version. Therefore, we
8665 run through all specialization of `f', adding to their
8666 DECL_TI_ARGS appropriately. In particular, they need a
8667 new set of outer arguments, corresponding to the
8668 arguments for this class instantiation.
8670 The same situation can arise with something like this:
8672 friend void f(int);
8673 template <class T> class C {
8674 friend void f(T) {}
8675 };
8677 when `C<int>' is instantiated. Now, `f(int)' is defined
8678 in the class. */
8681 /* On the other hand, if the in-class declaration does
8682 *not* provide a definition, then we don't want to alter
8683 existing definitions. We can just leave everything
8684 alone. */
8685 ;
8686 else
8687 {
8691 /* Overwrite whatever template info was there before, if
8692 any, with the new template information pertaining to
8693 the declaration. */
8697 {
8698 /* We should have called reregister_specialization in
8699 duplicate_decls. */
8704 /* Instantiate it if the global has already been used. */
8708 }
8709 else
8710 {
8711 tree t;
8713 /* Indicate that the old function template is a partial
8714 instantiation. */
8722 /* Reassign any specializations already in the hash table
8723 to the new more general template, and add the
8724 additional template args. */
8728 {
8730 spec_entry elt;
8742 register_specialization
8745 }
8747 }
8748 }
8750 /* The information from NEW_FRIEND has been merged into OLD_DECL
8751 by duplicate_decls. */
8753 }
8754 }
8755 else
8756 {
8760 /* In the code
8761 template <class T> class C {
8762 template <class U> friend void C1<U>::f (); // case 1
8763 friend void C2<T>::f (); // case 2
8764 };
8765 we only need to make sure CONTEXT is a complete type for
8766 case 2. To distinguish between the two cases, we note that
8767 CONTEXT of case 1 remains dependent type after tsubst while
8768 this isn't true for case 2. */
8778 {
8780 /* do_friend adds the TEMPLATE_DECL for any member friend
8781 template even if it isn't a member template, i.e.
8782 template <class T> friend A<T>::f();
8783 Look through it in that case. */
8787 /* Check to see that the declaration is really present, and,
8788 possibly obtain an improved declaration. */
8793 }
8794 }
8797 }
8799 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8800 template arguments, as for tsubst.
8802 Returns an appropriate tsubst'd friend type or error_mark_node on
8803 failure. */
8805 static tree
8807 {
8808 tree friend_type;
8809 tree tmpl;
8810 tree context;
8813 {
8816 }
8821 {
8824 else
8826 }
8828 /* Look for a class template declaration. We look for hidden names
8829 because two friend declarations of the same template are the
8830 same. For example, in:
8832 struct A {
8833 template <typename> friend class F;
8834 };
8835 template <typename> struct B {
8836 template <typename> friend class F;
8837 };
8839 both F templates are the same. */
8843 /* But, if we don't find one, it might be because we're in a
8844 situation like this:
8846 template <class T>
8847 struct S {
8848 template <class U>
8849 friend struct S;
8850 };
8852 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8853 for `S<int>', not the TEMPLATE_DECL. */
8855 {
8858 }
8861 {
8862 /* The friend template has already been declared. Just
8863 check to see that the declarations match, and install any new
8864 default parameters. We must tsubst the default parameters,
8865 of course. We only need the innermost template parameters
8866 because that is all that redeclare_class_template will look
8867 at. */
8870 {
8871 tree parms;
8872 location_t saved_input_location;
8881 }
8884 }
8885 else
8886 {
8887 /* The friend template has not already been declared. In this
8888 case, the instantiation of the template class will cause the
8889 injection of this template into the global scope. */
8894 /* The new TMPL is not an instantiation of anything, so we
8895 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8896 the new type because that is supposed to be the corresponding
8897 template decl, i.e., TMPL. */
8904 /* Inject this template into the global scope. */
8906 }
8909 {
8912 else
8914 }
8917 }
8919 /* Returns zero if TYPE cannot be completed later due to circularity.
8920 Otherwise returns one. */
8922 static int
8924 {
8934 else
8936 }
8940 /* Apply any attributes which had to be deferred until instantiation
8941 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8942 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8944 static void
8947 {
8949 tree t;
8954 {
8958 }
8961 {
8965 }
8966 else
8970 {
8975 {
8978 {
8985 {
8992 clauses
8996 else
8998 }
8999 /* If the first attribute argument is an identifier, don't
9000 pass it through tsubst. Attributes like mode, format,
9001 cleanup and several target specific attributes expect it
9002 unmodified. */
9005 {
9006 tree chain
9008 in_decl,
9013 chain);
9014 }
9016 {
9017 /* An attribute pack expansion. */
9019 tree pack = (tsubst_pack_expansion
9023 {
9027 }
9029 }
9030 else
9036 }
9037 else
9039 }
9042 }
9043 }
9045 /* Perform (or defer) access check for typedefs that were referenced
9046 from within the template TMPL code.
9047 This is a subroutine of instantiate_decl and instantiate_class_template.
9048 TMPL is the template to consider and TARGS is the list of arguments of
9049 that template. */
9051 static void
9053 {
9054 location_t saved_location;
9065 {
9077 /* Make access check error messages point to the location
9078 of the use of the typedef. */
9082 tf_warning_or_error);
9083 }
9085 }
9087 static tree
9089 {
9091 tree typedecl;
9092 tree pbinfo;
9093 tree base_list;
9095 tree fn_context;
9104 /* Figure out which template is being instantiated. */
9108 /* Determine what specialization of the original template to
9109 instantiate. */
9112 {
9115 }
9117 {
9118 /* This TYPE is actually an instantiation of a partial
9119 specialization. We replace the innermost set of ARGS with
9120 the arguments appropriate for substitution. For example,
9121 given:
9123 template <class T> struct S {};
9124 template <class T> struct S<T*> {};
9126 and supposing that we are instantiating S<int*>, ARGS will
9127 presently be {int*} -- but we need {int}. */
9130 }
9131 else
9132 {
9135 }
9137 /* If the template we're instantiating is incomplete, then clearly
9138 there's nothing we can do. */
9142 /* If we've recursively instantiated too many templates, stop. */
9146 /* Now we're really doing the instantiation. Mark the type as in
9147 the process of being defined. */
9150 /* We may be in the middle of deferred access check. Disable
9151 it now. */
9155 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
9160 /* Use #pragma pack from the template context. */
9166 /* Set the input location to the most specialized template definition.
9167 This is needed if tsubsting causes an error. */
9179 {
9182 /* Adjust visibility for template arguments. */
9184 }
9190 /* We should never instantiate a nested class before its enclosing
9191 class; we need to look up the nested class by name before we can
9192 instantiate it, and that lookup should instantiate the enclosing
9193 class. */
9199 {
9200 tree pbase_binfo;
9201 tree pushed_scope;
9204 /* We must enter the scope containing the type, as that is where
9205 the accessibility of types named in dependent bases are
9206 looked up from. */
9209 /* Substitute into each of the bases to determine the actual
9210 basetypes. */
9212 {
9213 tree base;
9219 {
9220 expanded_bases =
9227 }
9230 {
9232 /* Extract the already-expanded base class. */
9234 else
9235 /* Substitute to figure out the base class. */
9237 NULL_TREE);
9245 }
9246 }
9248 /* The list is now in reverse order; correct that. */
9253 }
9254 /* Now call xref_basetypes to set up all the base-class
9255 information. */
9263 /* Now that our base classes are set up, enter the scope of the
9264 class, so that name lookups into base classes, etc. will work
9265 correctly. This is precisely analogous to what we do in
9266 begin_class_definition when defining an ordinary non-template
9267 class, except we also need to push the enclosing classes. */
9270 /* Now members are processed in the order of declaration. */
9273 {
9277 {
9279 {
9280 /* Build new CLASSTYPE_NESTED_UTDS. */
9282 tree newtag;
9288 /* If the member is a class template, then -- even after
9289 substitution -- there may be dependent types in the
9290 template argument list for the class. We increment
9291 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
9292 that function will assume that no types are dependent
9293 when outside of a template. */
9303 {
9307 /* Unfortunately, lookup_template_class sets
9308 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
9309 instantiation (i.e., for the type of a member
9310 template class nested within a template class.)
9311 This behavior is required for
9312 maybe_process_partial_specialization to work
9313 correctly, but is not accurate in this case;
9314 the TAG is not an instantiation of anything.
9315 (The corresponding TEMPLATE_DECL is an
9316 instantiation, but the TYPE is not.) */
9319 /* Now, we call pushtag to put this NEWTAG into the scope of
9320 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
9321 pushtag calling push_template_decl. We don't have to do
9322 this for enums because it will already have been done in
9323 tsubst_enum. */
9327 }
9328 }
9330 {
9331 /* Build new TYPE_METHODS. */
9332 tree r;
9341 /* Instantiate members marked with attribute used. */
9347 }
9350 /* A closure type for a lambda in a default argument for a
9351 member template. Ignore it; it will be instantiated with
9353 else
9354 {
9355 /* Build new TYPE_FIELDS. */
9357 {
9358 tree condition;
9361 condition =
9371 }
9373 {
9374 tree r;
9378 /* The file and line for this declaration, to
9379 assist in error message reporting. Since we
9380 called push_tinst_level above, we don't need to
9381 restore these. */
9391 {
9392 /* A capture pack became multiple fields. */
9395 }
9398 {
9402 {
9403 /* In [temp.inst]:
9405 [t]he initialization (and any associated
9406 side-effects) of a static data member does
9407 not occur unless the static data member is
9408 itself used in a way that requires the
9409 definition of the static data member to
9410 exist.
9412 Therefore, we do not substitute into the
9413 initialized for the static data member here. */
9414 finish_static_data_member_decl
9420 /* Instantiate members marked with attribute used. */
9423 }
9425 {
9426 /* Determine whether R has a valid type and can be
9427 completed later. If R is invalid, then its type
9428 is replaced by error_mark_node. */
9434 {
9437 }
9438 }
9440 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9441 such a thing will already have been added to the field
9442 list by tsubst_enum in finish_member_declaration in the
9443 CLASSTYPE_NESTED_UTDS case above. */
9447 {
9450 }
9451 }
9452 }
9453 }
9454 }
9455 else
9456 {
9459 {
9460 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9466 {
9467 /* template <class T> friend class C; */
9470 }
9472 {
9473 /* template <class T> friend class C::D; */
9479 }
9482 {
9483 /* This could be either
9485 friend class T::C;
9487 when dependent_type_p is false or
9489 template <class U> friend class T::C;
9491 otherwise. */
9494 /* Bump processing_template_decl for correct
9495 dependent_type_p calculation. */
9500 }
9503 {
9504 /* friend class C;
9506 where C hasn't been declared yet. Let's lookup name
9507 from namespace scope directly, bypassing any name that
9508 come from dependent base class. */
9511 /* The call to xref_tag_from_type does injection for friend
9512 classes. */
9514 friend_type =
9518 }
9520 /* friend class C<T>; */
9523 /* Otherwise it's
9525 friend class C;
9527 where C is already declared or
9529 friend class C<int>;
9531 We don't have to do anything in these cases. */
9534 /* Trick make_friend_class into realizing that the friend
9535 we're adding is a template, not an ordinary class. It's
9536 important that we use make_friend_class since it will
9537 perform some error-checking and output cross-reference
9538 information. */
9546 }
9547 else
9548 {
9549 /* Build new DECL_FRIENDLIST. */
9550 tree r;
9552 /* The file and line for this declaration, to
9553 assist in error message reporting. Since we
9554 called push_tinst_level above, we don't need to
9555 restore these. */
9559 {
9562 }
9567 {
9570 }
9571 }
9572 }
9573 }
9576 {
9579 {
9584 /* We need to instantiate the capture list from the template
9585 after we've instantiated the closure members, but before we
9586 consider adding the conversion op. Also keep any captures
9587 that may have been added during instantiation of the op(). */
9589 tree tmpl_cap
9598 }
9599 else
9601 }
9603 /* Set the file and line number information to whatever is given for
9604 the class itself. This puts error messages involving generated
9605 implicit functions at a predictable point, and the same point
9606 that would be used for non-template classes. */
9613 /* We don't instantiate default arguments for member functions. 14.7.1:
9615 The implicit instantiation of a class template specialization causes
9616 the implicit instantiation of the declarations, but not of the
9617 definitions or default arguments, of the class member functions,
9618 member classes, static data members and member templates.... */
9620 /* Some typedefs referenced from within the template code need to be access
9621 checked at template instantiation time, i.e now. These types were
9622 added to the template at parsing time. Let's get those and perform
9623 the access checks then. */
9633 /* The vtable for a template class can be emitted in any translation
9634 unit in which the class is instantiated. When there is no key
9635 method, however, finish_struct_1 will already have added TYPE to
9636 the keyed_classes list. */
9641 }
9643 /* Wrapper for instantiate_class_template_1. */
9645 tree
9647 {
9648 tree ret;
9653 }
9655 static tree
9657 {
9658 tree r;
9664 else
9665 {
9672 }
9674 }
9676 /* Given a function parameter pack TMPL_PARM and some function parameters
9677 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9678 and set *SPEC_P to point at the next point in the list. */
9680 static tree
9682 {
9683 /* Collect all of the extra "packed" parameters into an
9684 argument pack. */
9685 tree parmvec;
9686 tree parmtypevec;
9697 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9702 {
9705 }
9707 /* Build the argument packs. */
9714 }
9716 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9717 NONTYPE_ARGUMENT_PACK. */
9719 static tree
9721 {
9723 }
9725 /* Return true iff the Ith element of the argument pack ARG_PACK is a
9726 pack expansion. */
9728 static bool
9730 {
9735 }
9738 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9740 static tree
9742 {
9749 }
9751 /* This is a subroutine of tsubst_pack_expansion.
9753 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9754 mechanism to store the (non complete list of) arguments of the
9755 substitution and return a non substituted pack expansion, in order
9756 to wait for when we have enough arguments to really perform the
9757 substitution. */
9759 static bool
9763 {
9764 /* If one pack has an expansion and another pack has a normal
9765 argument or if one pack has an empty argument and an another
9766 one hasn't then tsubst_pack_expansion cannot perform the
9767 substitution and need to fall back on the
9768 PACK_EXPANSION_EXTRA mechanism. */
9776 {
9779 parm_pack;
9781 {
9786 else
9788 }
9792 }
9794 }
9796 /* [temp.variadic]/6 says that:
9798 The instantiation of a pack expansion [...]
9799 produces a list E1,E2, ..., En, where N is the number of elements
9800 in the pack expansion parameters.
9802 This subroutine of tsubst_pack_expansion produces one of these Ei.
9804 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9805 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9806 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9807 INDEX is the index 'i' of the element Ei to produce. ARGS,
9808 COMPLAIN, and IN_DECL are the same parameters as for the
9809 tsubst_pack_expansion function.
9811 The function returns the resulting Ei upon successful completion,
9812 or error_mark_node.
9814 Note that this function possibly modifies the ARGS parameter, so
9815 it's the responsibility of the caller to restore it. */
9817 static tree
9819 tree parm_packs,
9821 tree args /* This parm gets
9823 tsubst_flags_t complain,
9824 tree in_decl)
9825 {
9826 tree t;
9829 /* For each parameter pack, change the substitution of the parameter
9830 pack to the ith argument in its argument pack, then expand the
9831 pattern. */
9833 {
9838 ith_elem_is_expansion |=
9841 /* Select the Ith argument from the pack. */
9844 {
9846 {
9851 }
9852 else
9854 }
9855 else
9856 {
9861 {
9863 /* Update the corresponding argument. */
9865 }
9866 else
9867 /* Re-use the ARGUMENT_PACK_SELECT. */
9869 }
9871 }
9873 /* Substitute into the PATTERN with the (possibly altered)
9874 arguments. */
9876 /* Expanding a fixed parameter pack from
9877 coerce_template_parameter_pack. */
9882 else
9885 /* If the Ith argument pack element is a pack expansion, then
9886 the Ith element resulting from the substituting is going to
9887 be a pack expansion as well. */
9892 }
9894 /* Substitute ARGS into T, which is an pack expansion
9895 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9896 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9897 (if only a partial substitution could be performed) or
9898 ERROR_MARK_NODE if there was an error. */
9899 tree
9901 tree in_decl)
9902 {
9903 tree pattern;
9907 tree result;
9915 /* Add in any args remembered from an earlier partial instantiation. */
9920 /* Determine the argument packs that will instantiate the parameter
9921 packs used in the expansion expression. While we're at it,
9922 compute the number of arguments to be expanded and make sure it
9923 is consistent. */
9926 {
9933 {
9937 else
9940 }
9942 {
9945 else
9946 {
9947 /* We can't rely on local_specializations for a parameter
9948 name used later in a function declaration (such as in a
9949 late-specified return type). Even if it exists, it might
9950 have the wrong value for a recursive call. Just make a
9951 dummy decl, since it's only used for its type. */
9954 /* Partial instantiation of the parm_pack, we can't build
9955 up an argument pack yet. */
9957 else
9960 }
9961 }
9964 else
9965 {
9971 }
9978 /* This can only happen if we forget to expand an argument
9979 pack somewhere else. Just return an error, silently. */
9980 {
9984 }
9987 {
9991 /* Don't bother trying to do a partial substitution with
9992 incomplete packs; we'll try again after deduction. */
9999 {
10005 pattern);
10006 else
10009 pattern);
10011 }
10013 /* Keep track of the parameter packs and their corresponding
10014 argument packs. */
10017 }
10018 else
10019 {
10020 /* We can't substitute for this parameter pack. We use a flag as
10021 well as the missing_level counter because function parameter
10022 packs don't have a level. */
10024 }
10025 }
10027 /* If the expansion is just T..., return the matching argument pack. */
10030 {
10035 /* Otherwise use the normal path so we get convert_from_reference. */
10036 }
10038 /* We cannot expand this expansion expression, because we don't have
10039 all of the argument packs we need. */
10041 {
10042 /* We got some full packs, but we can't substitute them in until we
10043 have values for all the packs. So remember these until then. */
10048 }
10050 {
10051 /* There were no real arguments, we're just replacing a parameter
10052 pack with another version of itself. Substitute into the
10053 pattern and return a PACK_EXPANSION_*. The caller will need to
10054 deal with that. */
10058 else
10062 }
10067 {
10068 /* We're in a late-specified return type, so create our own local
10069 specializations map; the current map is either NULL or (in the
10070 case of recursive unification) might have bindings that we don't
10071 want to use or alter. */
10074 }
10076 /* For each argument in each argument pack, substitute into the
10077 pattern. */
10080 {
10082 i,
10084 in_decl);
10087 {
10090 }
10091 }
10093 /* Update ARGS to restore the substitution from parameter packs to
10094 their argument packs. */
10096 {
10102 else
10103 {
10111 /* Update the corresponding argument. */
10115 else
10117 }
10118 }
10121 {
10124 }
10127 }
10129 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
10130 TMPL. We do this using DECL_PARM_INDEX, which should work even with
10131 parameter packs; all parms generated from a function parameter pack will
10132 have the same DECL_PARM_INDEX. */
10134 tree
10136 {
10138 tree patparm;
10141 {
10147 }
10148 else
10149 {
10154 }
10157 }
10159 /* Substitute ARGS into the vector or list of template arguments T. */
10161 static tree
10163 {
10175 {
10177 tree new_arg;
10182 {
10183 /* Substitute into an expansion expression. */
10187 /* Add to the expanded length adjustment the number of
10188 expanded arguments. We subtract one from this
10189 measurement, because the argument pack expression
10190 itself is already counted as 1 in
10191 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
10192 the argument pack is empty. */
10194 }
10196 {
10197 /* Substitute into each of the arguments. */
10203 new_arg,
10217 }
10218 }
10219 else
10228 }
10233 /* Make space for the expanded arguments coming from template
10234 argument packs. */
10236 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
10237 arguments for a member template.
10238 In that case each TREE_VEC in ORIG_T represents a level of template
10239 arguments, and ORIG_T won't carry any non defaulted argument count.
10240 It will rather be the nested TREE_VECs that will carry one.
10241 In other words, ORIG_T carries a non defaulted argument count only
10242 if it doesn't contain any nested TREE_VEC. */
10244 {
10248 }
10250 {
10254 {
10257 /* Now expand the template argument pack "in place". */
10260 }
10261 else
10262 {
10264 out++;
10265 }
10266 }
10269 }
10271 /* Return the result of substituting ARGS into the template parameters
10272 given by PARMS. If there are m levels of ARGS and m + n levels of
10273 PARMS, then the result will contain n levels of PARMS. For
10274 example, if PARMS is `template <class T> template <class U>
10275 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
10276 result will be `template <int*, double, class V>'. */
10278 static tree
10280 {
10284 /* When substituting into a template, we must set
10285 PROCESSING_TEMPLATE_DECL as the template parameters may be
10286 dependent if they are based on one-another, and the dependency
10287 predicates are short-circuit outside of templates. */
10294 {
10295 tree new_vec =
10300 {
10301 tree tuple;
10313 }
10319 }
10324 }
10326 /* Return the result of substituting ARGS into one template parameter
10327 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
10328 parameter and which TREE_PURPOSE is the default argument of the
10329 template parameter. */
10331 static tree
10333 {
10354 }
10356 /* Substitute the ARGS into the indicated aggregate (or enumeration)
10357 type T. If T is not an aggregate or enumeration type, it is
10358 handled as if by tsubst. IN_DECL is as for tsubst. If
10359 ENTERING_SCOPE is nonzero, T is the context for a template which
10360 we are presently tsubst'ing. Return the substituted value. */
10362 static tree
10364 tree args,
10365 tsubst_flags_t complain,
10366 tree in_decl,
10368 {
10373 {
10378 /* Else fall through. */
10382 {
10383 tree argvec;
10384 tree context;
10385 tree r;
10389 /* In "sizeof(X<I>)" we need to evaluate "I". */
10395 /* First, determine the context for the type we are looking
10396 up. */
10399 {
10402 /* If context is a nested class inside a class template,
10403 it may still need to be instantiated (c++/33959). */
10405 }
10407 /* Then, figure out what arguments are appropriate for the
10408 type we are trying to find. For example, given:
10410 template <class T> struct S;
10411 template <class T, class U> void f(T, U) { S<U> su; }
10413 and supposing that we are instantiating f<int, double>,
10414 then our ARGS will be {int, double}, but, when looking up
10415 S we only want {double}. */
10420 else
10421 {
10425 }
10431 }
10432 else
10433 /* This is not a template type, so there's nothing to do. */
10438 }
10439 }
10441 /* Substitute into the default argument ARG (a default argument for
10442 FN), which has the indicated TYPE. */
10444 tree
10446 {
10451 /* This can happen in invalid code. */
10455 /* This default argument came from a template. Instantiate the
10456 default argument here, not in tsubst. In the case of
10457 something like:
10459 template <class T>
10460 struct S {
10461 static T t();
10462 void f(T = t());
10463 };
10465 we must be careful to do name lookup in the scope of S<T>,
10466 rather than in the current class. */
10468 /* The "this" pointer is not valid in a default argument. */
10470 {
10475 }
10478 /* The default argument expression may cause implicitly defined
10479 member functions to be synthesized, which will result in garbage
10480 collection. We must treat this situation as if we were within
10481 the body of function so as to avoid collecting live data on the
10482 stack. */
10490 /* Restore the "this" pointer. */
10492 {
10495 }
10502 /* Make sure the default argument is reasonable. */
10508 }
10510 /* Substitute into all the default arguments for FN. */
10512 static void
10514 {
10515 tree arg;
10516 tree tmpl_args;
10520 /* If this function is not yet instantiated, we certainly don't need
10521 its default arguments. */
10524 /* Don't do this again for clones. */
10529 arg;
10535 complain);
10536 }
10538 /* Substitute the ARGS into the T, which is a _DECL. Return the
10539 result of the substitution. Issue error and warning messages under
10540 control of COMPLAIN. */
10542 static tree
10544 {
10545 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10546 location_t saved_loc;
10551 /* Set the filename and linenumber to improve error-reporting. */
10556 {
10558 {
10559 /* We can get here when processing a member function template,
10560 member class template, or template template parameter. */
10562 tree spec;
10563 tree tmpl_args;
10564 tree full_args;
10567 {
10568 /* Template template parameter is treated here. */
10572 /* If we get a real template back, return it. This can happen in
10573 the context of most_specialized_partial_spec. */
10585 complain);
10588 }
10590 /* We might already have an instance of this template.
10591 The ARGS are for the surrounding class type, so the
10592 full args contain the tsubst'd args for the context,
10593 plus the innermost args from the template decl. */
10597 /* Because this is a template, the arguments will still be
10598 dependent, even after substitution. If
10599 PROCESSING_TEMPLATE_DECL is not set, the dependency
10600 predicates will short-circuit. */
10608 /* If this is a default template template argument,
10609 tsubst might not have changed anything. */
10616 {
10619 }
10621 /* Make a new template decl. It will be similar to the
10622 original, but will record the current template arguments.
10623 We also create a new function declaration, which is just
10624 like the old one, but points to this new template, rather
10625 than the old one. */
10634 {
10635 tree new_type;
10643 /* For a partial specialization, we need to keep pointing to
10644 the primary template. */
10650 }
10651 else
10652 {
10653 tree new_decl;
10665 }
10671 /* The template parameters for this new template are all the
10672 template parameters for the old template, except the
10673 outermost level of parameters. */
10676 complain);
10682 /* Record this non-type partial instantiation. */
10686 }
10690 {
10691 tree ctx;
10694 tree gen_tmpl;
10695 tree type;
10700 /* Nobody should be tsubst'ing into non-template functions. */
10704 {
10705 tree spec;
10708 /* If T is not dependent, just return it. We have to
10709 increment PROCESSING_TEMPLATE_DECL because
10710 value_dependent_expression_p assumes that nothing is
10711 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10718 /* Calculate the most general template of which R is a
10719 specialization, and the complete set of arguments used to
10720 specialize R. */
10723 (DECL_TEMPLATE_RESULT
10729 /* Check to see if we already have this specialization. */
10734 {
10737 }
10739 /* We can see more levels of arguments than parameters if
10740 there was a specialization of a member template, like
10741 this:
10743 template <class T> struct S { template <class U> void f(); }
10744 template <> template <class U> void S<int>::f(U);
10746 Here, we'll be substituting into the specialization,
10747 because that's where we can find the code we actually
10748 want to generate, but we'll have enough arguments for
10749 the most general template.
10751 We also deal with the peculiar case:
10753 template <class T> struct S {
10754 template <class U> friend void f();
10755 };
10756 template <class U> void f() {}
10757 template S<int>;
10758 template void f<double>();
10760 Here, the ARGS for the instantiation of will be {int,
10761 double}. But, we only need as many ARGS as there are
10762 levels of template parameters in CODE_PATTERN. We are
10763 careful not to get fooled into reducing the ARGS in
10764 situations like:
10766 template <class T> struct S { template <class U> void f(U); }
10767 template <class T> template <> void S<T>::f(int) {}
10769 which we can spot because the pattern will be a
10770 specialization in this case. */
10772 parms_depth =
10777 }
10778 else
10779 {
10780 /* This special case arises when we have something like this:
10782 template <class T> struct S {
10783 friend void f<int>(int, double);
10784 };
10786 Here, the DECL_TI_TEMPLATE for the friend declaration
10787 will be an IDENTIFIER_NODE. We are being called from
10788 tsubst_friend_function, and we want only to create a
10789 new decl (R) with appropriate types so that we can call
10790 determine_specialization. */
10792 }
10795 {
10798 else
10802 }
10803 else
10804 {
10807 }
10812 /* If we hit excessive deduction depth, the type is bogus even if
10813 it isn't error_mark_node, so don't build a decl. */
10817 /* We do NOT check for matching decls pushed separately at this
10818 point, as they may not represent instantiations of this
10819 template, and in any case are considered separate under the
10820 discrete model. */
10824 /* Clear out the mangled name and RTL for the instantiation. */
10827 /* Leave DECL_INITIAL set on deleted instantiations. */
10832 /* OpenMP UDRs have the only argument a reference to the declared
10833 type. We want to diagnose if the declared type is a reference,
10834 which is invalid, but as references to references are usually
10835 quietly merged, diagnose it here. */
10837 {
10838 tree argtype
10843 "reference type %qT in "
10847 argtype);
10848 }
10851 /* Type-conversion operator. Reconstruct the name, in
10852 case it's the name of one of the template's parameters. */
10862 /* If this is an instantiation of a function with internal
10863 linkage, we already know what object file linkage will be
10864 assigned to the instantiation. */
10873 /* We'll re-clone as appropriate in instantiate_template. */
10876 /* If we aren't complaining now, return on error before we register
10877 the specialization so that we'll complain eventually. */
10883 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10884 this in the special friend case mentioned above where
10885 GEN_TMPL is NULL. */
10887 {
10892 tree new_r
10895 /* We instantiated this while substituting into
10896 the type earlier (template/friend54.C). */
10899 /* We're not supposed to instantiate default arguments
10900 until they are called, for a template. But, for a
10901 declaration like:
10903 template <class T> void f ()
10904 { extern void g(int i = T()); }
10906 we should do the substitution when the template is
10907 instantiated. We handle the member function case in
10908 instantiate_class_template since the default arguments
10909 might refer to other members of the class. */
10914 }
10915 else
10918 /* Copy the list of befriending classes. */
10922 {
10926 in_decl);
10927 }
10930 {
10936 /* If this is an instantiation of a member template, clone it.
10937 If it isn't, that'll be handled by
10938 clone_constructors_and_destructors. */
10941 }
10952 /* Possibly limit visibility based on template args. */
10955 {
10959 }
10967 }
10971 {
10979 {
10980 /* If there is a local specialization that isn't a
10981 parameter pack, it means that we're doing a "simple"
10982 substitution from inside tsubst_pack_expansion. Just
10983 return the local specialization (which will be a single
10984 parm). */
10991 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10992 the parameters in this function parameter pack. */
10996 {
10999 /* Zero-length parameter packs are boring. Just substitute
11000 into the chain. */
11004 }
11005 else
11006 {
11007 /* All we did was update the type. Make a note of that. */
11010 }
11011 }
11013 /* Loop through all of the parameters we'll build. When T is
11014 a function parameter pack, LEN is the number of expanded
11015 types in EXPANDED_TYPES; otherwise, LEN is 1. */
11018 {
11025 /* We're on the Ith parameter of the function parameter
11026 pack. */
11027 {
11028 /* Get the Ith type. */
11031 /* Rename the parameter to include the index. */
11034 }
11036 /* We're dealing with a normal parameter. */
11044 {
11047 else
11050 }
11060 /* Keep track of the first new parameter we
11061 generate. That's what will be returned to the
11062 caller. */
11066 /* Build a proper chain of parameters when substituting
11067 into a function parameter pack. */
11070 }
11072 /* If cp_unevaluated_operand is set, we're just looking for a
11073 single dummy parameter, so don't keep going. */
11078 /* FIRST_R contains the start of the chain we've built. */
11080 }
11084 {
11091 {
11092 /* This field is a lambda capture pack. Return a TREE_VEC of
11093 the expanded fields to instantiate_class_template_1 and
11094 store them in the specializations hash table as a
11095 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
11099 {
11102 }
11103 else
11104 {
11105 /* All we did was update the type. Make a note of that. */
11108 }
11109 }
11112 {
11115 {
11119 }
11129 /* For bit-fields, DECL_INITIAL gives the number of bits. For
11130 non-bit-fields DECL_INITIAL is a non-static data member
11131 initializer, which gets deferred instantiation. */
11137 {
11138 /* Set up DECL_TEMPLATE_INFO so that we can get at the
11139 NSDMI in perform_member_init. Still set DECL_INITIAL
11140 so that we know there is one. */
11145 }
11146 /* We don't have to set DECL_CONTEXT here; it is set by
11147 finish_member_declaration. */
11155 }
11158 {
11166 }
11167 }
11171 /* We reach here only for member using decls. We also need to check
11172 uses_template_parms because DECL_DEPENDENT_P is not set for a
11173 using-declaration that designates a member of the current
11174 instantiation (c++/53549). */
11177 {
11184 else
11185 {
11188 }
11189 }
11190 else
11191 {
11194 }
11199 {
11202 tree spec;
11204 tree ctx;
11213 {
11214 /* If this is the canonical decl, we don't have to
11215 mess with instantiations, and often we can't (for
11216 typename, template type parms and such). Note that
11217 TYPE_NAME is not correct for the above test if
11218 we've copied the type for a typedef. */
11224 }
11226 /* Check to see if we already have the specialization we
11227 need. */
11230 {
11231 /* T is a static data member or namespace-scope entity.
11232 We have to substitute into namespace-scope variables
11233 (even though such entities are never templates) because
11234 of cases like:
11236 template <class T> void f() { extern T t; }
11238 where the entity referenced is not known until
11239 instantiation time. */
11243 {
11245 complain,
11247 /* If CTX is unchanged, then T is in fact the
11248 specialization we want. That situation occurs when
11249 referencing a static data member within in its own
11250 class. We can use pointer equality, rather than
11251 same_type_p, because DECL_CONTEXT is always
11252 canonical... */
11254 /* ... unless T is a member template; in which
11255 case our caller can be willing to create a
11256 specialization of that template represented
11257 by T. */
11261 }
11264 {
11272 }
11273 }
11274 else
11275 {
11276 /* A local variable. */
11278 /* Subsequent calls to pushdecl will fill this in. */
11281 }
11282 /* If we already have the specialization we need, there is
11283 nothing more to do. */
11285 {
11288 }
11290 /* Create a new node for the specialization we need. */
11293 {
11296 else
11303 }
11305 {
11306 /* Even if the original location is out of scope, the
11307 newly substituted one is not. */
11314 {
11315 /* It may seem that this case cannot occur, since:
11317 typedef void f();
11318 void g() { f x; }
11320 declares a function, not a variable. However:
11322 typedef void f();
11323 template <typename T> void g() { T t; }
11324 template void g<f>();
11326 is an attempt to declare a variable with function
11327 type. */
11329 /* R is not yet sufficiently initialized, so we
11330 just use its name. */
11333 }
11335 /* Wait until cp_finish_decl to set this again, to handle
11336 circular dependency (template/instantiate6.C). */
11341 {
11346 {
11349 }
11351 }
11354 }
11360 /* Clear out the mangled name and RTL for the instantiation. */
11364 /* The initializer must not be expanded until it is required;
11365 see [temp.inst]. */
11371 {
11372 /* Possibly limit visibility based on template args. */
11375 {
11379 }
11381 }
11384 {
11385 /* A static data member declaration is always marked
11386 external when it is declared in-class, even if an
11387 initializer is present. We mimic the non-template
11388 processing here. */
11394 }
11404 /* Preserve a typedef that names a type. */
11406 {
11409 }
11412 }
11417 }
11418 #undef RETURN
11420 out:
11421 /* Restore the file and line information. */
11425 }
11427 /* Substitute into the ARG_TYPES of a function type.
11428 If END is a TREE_CHAIN, leave it and any following types
11429 un-substituted. */
11431 static tree
11433 tree args,
11434 tree end,
11435 tsubst_flags_t complain,
11436 tree in_decl)
11437 {
11438 tree remaining_arg_types;
11442 tree default_arg;
11453 {
11454 /* For a pack expansion, perform substitution on the
11455 entire expression. Later on, we'll handle the arguments
11456 one-by-one. */
11461 /* So that we'll spin through the parameters, one by one. */
11463 else
11464 {
11465 /* We only partially substituted into the parameter
11466 pack. Our type is TYPE_PACK_EXPANSION. */
11469 }
11470 }
11483 {
11485 {
11489 }
11491 }
11492 /* DR 657. */
11496 /* Do array-to-pointer, function-to-pointer conversion, and ignore
11497 top-level qualifiers as required. */
11500 /* We do not substitute into default arguments here. The standard
11501 mandates that they be instantiated only when needed, which is
11502 done in build_over_call. */
11506 {
11507 /* We've instantiated a template before its default arguments
11508 have been parsed. This can happen for a nested template
11509 class, and is not an error unless we require the default
11510 argument in a call of this function. */
11511 remaining_arg_types =
11514 }
11515 else
11516 remaining_arg_types =
11518 }
11521 }
11523 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
11524 *not* handle the exception-specification for FNTYPE, because the
11525 initial substitution of explicitly provided template parameters
11526 during argument deduction forbids substitution into the
11527 exception-specification:
11529 [temp.deduct]
11531 All references in the function type of the function template to the
11532 corresponding template parameters are replaced by the specified tem-
11533 plate argument values. If a substitution in a template parameter or
11534 in the function type of the function template results in an invalid
11535 type, type deduction fails. [Note: The equivalent substitution in
11536 exception specifications is done only when the function is instanti-
11537 ated, at which point a program is ill-formed if the substitution
11538 results in an invalid type.] */
11540 static tree
11542 tree args,
11543 tsubst_flags_t complain,
11544 tree in_decl)
11545 {
11546 tree return_type;
11548 tree fntype;
11550 /* The TYPE_CONTEXT is not used for function/method types. */
11553 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
11554 failure. */
11558 {
11559 /* Substitute the argument types. */
11571 {
11572 /* DR 1207: 'this' is in scope in the trailing return type. */
11574 }
11576 /* Substitute the return type. */
11580 {
11583 }
11584 }
11585 else
11586 /* Substitute the return type. */
11591 /* DR 486 clarifies that creation of a function type with an
11592 invalid return type is a deduction failure. */
11595 {
11597 {
11600 else
11602 }
11604 }
11605 /* And DR 657. */
11610 {
11611 /* Substitute the argument types. */
11616 }
11618 /* Construct a new type node and return it. */
11620 {
11625 }
11626 else
11627 {
11629 /* Don't pick up extra function qualifiers from the basetype. */
11632 {
11633 /* [temp.deduct]
11635 Type deduction may fail for any of the following
11636 reasons:
11638 -- Attempting to create "pointer to member of T" when T
11639 is not a class type. */
11642 r);
11644 }
11649 }
11656 }
11658 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11659 ARGS into that specification, and return the substituted
11660 specification. If there is no specification, return NULL_TREE. */
11662 static tree
11664 tree args,
11665 tsubst_flags_t complain,
11666 tree in_decl,
11668 {
11669 tree specs;
11670 tree new_specs;
11675 {
11676 /* A noexcept-specifier. */
11681 {
11682 /* Defer instantiation of noexcept-specifiers to avoid
11683 excessive instantiations (c++/49107). */
11686 {
11687 /* We already partially instantiated this member template,
11688 so combine the new args with the old. */
11693 }
11694 else
11695 {
11698 }
11699 }
11700 else
11701 new_specs = tsubst_copy_and_build
11705 }
11707 {
11710 else
11712 {
11713 tree spec;
11718 {
11719 /* Expand the pack expansion type. */
11722 in_decl);
11728 else
11729 {
11730 /* We're substituting into a member template, so
11731 we got a TYPE_PACK_EXPANSION back. Add that
11732 expansion and move on. */
11736 expanded_specs,
11737 complain);
11740 }
11741 }
11744 {
11747 else
11752 complain);
11753 }
11756 }
11757 }
11759 }
11761 /* Take the tree structure T and replace template parameters used
11762 therein with the argument vector ARGS. IN_DECL is an associated
11763 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11764 Issue error and warning messages under control of COMPLAIN. Note
11765 that we must be relatively non-tolerant of extensions here, in
11766 order to preserve conformance; if we allow substitutions that
11767 should not be allowed, we may allow argument deductions that should
11768 not succeed, and therefore report ambiguous overload situations
11769 where there are none. In theory, we could allow the substitution,
11770 but indicate that it should have failed, and allow our caller to
11771 make sure that the right thing happens, but we don't try to do this
11772 yet.
11774 This function is used for dealing with types, decls and the like;
11775 for expressions, use tsubst_expr or tsubst_copy. */
11777 tree
11779 {
11802 else
11807 /* Reuse typedefs. We need to do this to handle dependent attributes,
11808 such as attribute aligned. */
11811 {
11815 {
11816 /* DECL represents an alias template and we want to
11817 instantiate it. */
11821 }
11825 {
11829 }
11834 else
11835 /* The typedef is from a non-template context. */
11839 {
11841 r = cp_build_qualified_type_real
11845 }
11846 else
11847 {
11848 /* We don't have an instantiation yet, so drop the typedef. */
11853 }
11854 }
11867 {
11893 {
11899 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11900 needed. */
11906 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11907 with TREE_SIDE_EFFECTS that indicates this is not an integral
11908 constant expression. */
11911 {
11914 }
11917 }
11923 {
11936 {
11940 {
11941 /* See through ARGUMENT_PACK_SELECT arguments. */
11943 /* If the selected argument is an expansion E, that most
11944 likely means we were called from
11945 gen_elem_of_pack_expansion_instantiation during the
11946 substituting of pack an argument pack (which Ith
11947 element is a pack expansion, where I is
11948 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
11949 In this case, the Ith element resulting from this
11950 substituting is going to be a pack expansion, which
11951 pattern is the pattern of E. Let's return the
11952 pattern of E, and
11953 gen_elem_of_pack_expansion_instantiation will
11954 build the resulting pack expansion from it. */
11956 {
11957 /* Make sure we aren't throwing away arg info. */
11960 }
11961 }
11962 }
11967 {
11969 /* If ARG is an argument pack, we don't actually want to
11970 perform a substitution here, because substitutions
11971 for argument packs are only done
11972 element-by-element. We can get to this point when
11973 substituting the type of a non-type template
11974 parameter pack, when that type actually contains
11975 template parameter packs from an outer template, e.g.,
11977 template<typename... Types> struct A {
11978 template<Types... Values> struct B { };
11979 }; */
11983 {
11989 return cp_build_qualified_type_real
11991 }
11993 {
11994 /* We are processing a type constructed from a
11995 template template parameter. */
12006 /* Consider this code:
12008 template <template <class> class Template>
12009 struct Internal {
12010 template <class Arg> using Bind = Template<Arg>;
12011 };
12013 template <template <class> class Template, class Arg>
12014 using Instantiate = Template<Arg>; //#0
12016 template <template <class> class Template,
12017 class Argument>
12018 using Bind =
12019 Instantiate<Internal<Template>::template Bind,
12020 Argument>; //#1
12022 When #1 is parsed, the
12023 BOUND_TEMPLATE_TEMPLATE_PARM representing the
12024 parameter `Template' in #0 matches the
12025 UNBOUND_CLASS_TEMPLATE representing the argument
12026 `Internal<Template>::template Bind'; We then want
12027 to assemble the type `Bind<Argument>' that can't
12028 be fully created right now, because
12029 `Internal<Template>' not being complete, the Bind
12030 template cannot be looked up in that context. So
12031 we need to "store" `Bind<Argument>' for later
12032 when the context of Bind becomes complete. Let's
12033 store that in a TYPENAME_TYPE. */
12037 argvec),
12038 typename_type,
12039 complain);
12041 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
12042 are resolving nested-types in the signature of a
12043 member function templates. Otherwise ARG is a
12044 TEMPLATE_DECL and is the real template to be
12045 instantiated. */
12053 complain);
12054 return cp_build_qualified_type_real
12056 }
12057 else
12058 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
12060 }
12063 /* This can happen during the attempted tsubst'ing in
12064 unify. This means that we don't yet have any information
12065 about the template parameter in question. */
12068 /* Early in template argument deduction substitution, we don't
12069 want to reduce the level of 'auto', or it will be confused
12070 with a normal template parm in subsequent deduction. */
12074 /* If we get here, we must have been looking at a parm for a
12075 more deeply nested template. Make a new version of this
12076 template parameter, but with a lower level. */
12078 {
12083 {
12085 r = cp_build_qualified_type_real
12089 }
12090 else
12091 {
12102 /* We have reduced the level of the template
12103 template parameter, but not the levels of its
12104 template parameters, so canonical_type_parameter
12105 will not be able to find the canonical template
12106 template parameter for this level. Thus, we
12107 require structural equality checking to compare
12108 TEMPLATE_TEMPLATE_PARMs. */
12112 else
12116 {
12124 }
12125 }
12134 }
12137 }
12140 {
12148 {
12152 }
12155 {
12159 }
12162 {
12166 }
12172 }
12175 /* We should never be tsubsting a binfo. */
12179 /* A vector of template arguments. */
12185 {
12189 /* [temp.deduct]
12191 Type deduction may fail for any of the following
12192 reasons:
12194 -- Attempting to create a pointer to reference type.
12195 -- Attempting to create a reference to a reference type or
12196 a reference to void.
12198 Core issue 106 says that creating a reference to a reference
12199 during instantiation is no longer a cause for failure. We
12200 only enforce this check in strict C++98 mode. */
12204 {
12207 /* We keep track of the last time we issued this error
12208 message to avoid spewing a ton of messages during a
12209 single bad template instantiation. */
12212 {
12217 else
12220 }
12223 }
12227 {
12229 {
12232 type);
12233 else
12235 type);
12236 }
12238 }
12240 {
12244 }
12246 /* In C++0x, during template argument substitution, when there is an
12247 attempt to create a reference to a reference type, reference
12248 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
12250 "If a template-argument for a template-parameter T names a type
12251 that is a reference to a type A, an attempt to create the type
12252 'lvalue reference to cv T' creates the type 'lvalue reference to
12253 A,' while an attempt to create the type type rvalue reference to
12254 cv T' creates the type T"
12255 */
12256 r = cp_build_reference_type
12259 else
12264 /* Will this ever be needed for TYPE_..._TO values? */
12268 }
12270 {
12273 {
12274 /* [temp.deduct]
12276 Type deduction may fail for any of the following
12277 reasons:
12279 -- Attempting to create "pointer to member of T" when T
12280 is not a class type. */
12284 }
12286 {
12290 }
12292 {
12296 }
12299 {
12300 /* The type of the implicit object parameter gets its
12301 cv-qualifiers from the FUNCTION_TYPE. */
12302 tree memptr;
12303 tree method_type
12308 complain);
12309 }
12310 else
12313 complain);
12314 }
12317 {
12318 tree fntype;
12319 tree specs;
12324 /* Substitute the exception specification. */
12332 }
12334 {
12339 /* As an optimization, we avoid regenerating the array type if
12340 it will obviously be the same as T. */
12344 /* These checks should match the ones in create_array_type_for_decl.
12346 [temp.deduct]
12348 The deduction may fail for any of the following reasons:
12350 -- Attempting to create an array with an element type that
12351 is void, a function type, or a reference type, or [DR337]
12352 an abstract class type. */
12358 {
12362 }
12370 {
12373 }
12376 }
12379 {
12389 {
12393 }
12395 {
12396 /* Normally, make_typename_type does not require that the CTX
12397 have complete type in order to allow things like:
12399 template <class T> struct S { typename S<T>::X Y; };
12401 But, such constructs have already been resolved by this
12402 point, so here CTX really should have complete type, unless
12403 it's a partial instantiation. */
12406 {
12410 }
12411 }
12418 {
12421 }
12424 {
12426 {
12430 else
12432 }
12434 {
12438 else
12440 }
12441 }
12443 return cp_build_qualified_type_real
12445 }
12448 {
12460 }
12463 {
12464 tree type;
12480 complain);
12481 }
12484 {
12485 tree type;
12503 else
12504 {
12508 /* In a template ~id could be either a complement expression
12509 or an unqualified-id naming a destructor; if instantiating
12510 it produces an expression, it's not an id-expression or
12511 member access. */
12514 }
12519 }
12522 {
12526 }
12530 {
12532 tree packed_out =
12534 args,
12535 complain,
12536 in_decl);
12539 /* For template nontype argument packs, also substitute into
12540 the type. */
12545 }
12561 /* We should use one of the expression tsubsts for these codes. */
12567 }
12568 }
12570 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
12571 type of the expression on the left-hand side of the "." or "->"
12572 operator. */
12574 static tree
12577 {
12578 tree name;
12579 tree qualifying_scope;
12580 tree fns;
12581 tree optype;
12586 /* A baselink indicates a function from a base class. Both the
12587 BASELINK_ACCESS_BINFO and the base class referenced may
12588 indicate bases of the template class, rather than the
12589 instantiated class. In addition, lookups that were not
12590 ambiguous before may be ambiguous now. Therefore, we perform
12591 the lookup again. */
12598 {
12605 }
12613 /* If lookup found a single function, mark it as used at this
12614 point. (If it lookup found multiple functions the one selected
12615 later by overload resolution will be marked as used at that
12616 point.) */
12623 /* Add back the template arguments, if present. */
12628 template_args);
12629 /* Update the conversion operator type. */
12637 qualifying_scope,
12638 object_type);
12640 }
12642 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
12643 true if the qualified-id will be a postfix-expression in-and-of
12644 itself; false if more of the postfix-expression follows the
12645 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
12646 of "&". */
12648 static tree
12652 {
12653 tree expr;
12654 tree scope;
12655 tree name;
12657 tree template_args;
12662 /* Figure out what name to look up. */
12665 {
12673 }
12674 else
12675 {
12678 }
12680 /* Substitute into the qualifying scope. When there are no ARGS, we
12681 are just trying to simplify a non-dependent expression. In that
12682 case the qualifying scope may be dependent, and, in any case,
12683 substituting will not help. */
12686 {
12689 }
12690 else
12694 {
12699 }
12702 {
12704 {
12705 /* A BIT_NOT_EXPR is used to represent a destructor. */
12707 {
12711 }
12712 else
12715 }
12716 else
12720 {
12722 {
12726 }
12728 }
12729 }
12732 {
12734 scope);
12735 /* Remember that there was a reference to this entity. */
12738 }
12741 {
12747 }
12756 {
12757 expr = (adjust_result_of_qualified_name_lookup
12759 expr = (finish_qualified_id_expr
12763 }
12765 /* Expressions do not generally have reference type. */
12767 /* However, if we're about to form a pointer-to-member, we just
12768 want the referenced member referenced. */
12773 }
12775 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
12776 initializer, DECL is the substituted VAR_DECL. Other arguments are as
12777 for tsubst. */
12779 static tree
12782 {
12789 {
12790 /* If we had an initializer but it
12791 instantiated to nothing,
12792 value-initialize the object. This will
12793 only occur when the initializer was a
12794 pack expansion where the parameter packs
12795 used in that expansion were of length
12796 zero. */
12798 complain);
12801 }
12804 }
12806 /* Like tsubst, but deals with expressions. This function just replaces
12807 template parms; to finish processing the resultant expression, use
12808 tsubst_copy_and_build or tsubst_expr. */
12810 static tree
12812 {
12814 tree r;
12822 {
12827 {
12828 /* We get here for a use of 'this' in an NSDMI. */
12830 && current_function_decl
12834 /* This can happen for a parameter name used later in a function
12835 declaration (such as in a late-specified return type). Just
12836 make a dummy decl, since it's only used for its type. */
12839 /* Give it the template pattern as its context; its true context
12840 hasn't been instantiated yet and this is good enough for
12841 mangling. */
12843 }
12852 {
12853 tree enum_type;
12854 tree v;
12858 /* There is no need to substitute into namespace-scope
12859 enumerators. */
12862 /* If ARGS is NULL, then T is known to be non-dependent. */
12866 /* Unfortunately, we cannot just call lookup_name here.
12867 Consider:
12869 template <int I> int f() {
12870 enum E { a = I };
12871 struct S { void g() { E e = a; } };
12872 };
12874 When we instantiate f<7>::S::g(), say, lookup_name is not
12875 clever enough to find f<7>::a. */
12876 enum_type
12886 /* We didn't find the name. That should never happen; if
12887 name-lookup found it during preliminary parsing, we
12888 should find it again here during instantiation. */
12890 }
12895 {
12896 /* Check for a local specialization set up by
12897 tsubst_pack_expansion. */
12899 {
12903 }
12905 /* When retrieving a capture pack from a generic lambda, remove the
12906 lambda call op's own template argument list from ARGS. Only the
12907 template arguments active for the closure type should be used to
12908 retrieve the pack specialization. */
12914 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
12915 tsubst_decl put in the hash table. */
12917 }
12920 {
12921 tree ctx;
12926 {
12929 {
12933 }
12935 }
12936 }
12945 {
12948 {
12949 /* First try name lookup to find the instantiation. */
12952 {
12953 /* Make sure that the one we found is the one we want. */
12958 }
12962 else
12963 {
12964 /* This can happen for a variable used in a
12965 late-specified return type of a local lambda, or for a
12966 local static or constant. Building a new VAR_DECL
12967 should be OK in all those cases. */
12970 {
12971 /* We can't call cp_finish_decl, so handle the
12972 initializer by hand. */
12983 }
12988 {
12991 at_eof);
12993 /* A use of a local constant decays to its value.
12994 FIXME update for core DR 696. */
12996 }
12997 }
12998 /* Remember this for subsequent uses. */
13001 }
13002 }
13003 else
13013 /* An OVERLOAD will always be a non-dependent overload set; an
13014 overload set from function scope will just be represented with an
13015 IDENTIFIER_NODE, and from class scope with a BASELINK. */
13031 {
13032 /* Template template argument like the following example need
13033 special treatment:
13035 template <template <class> class TT> struct C {};
13036 template <class T> struct D {
13037 template <class U> struct E {};
13038 C<E> c; // #1
13039 };
13040 D<int> d; // #2
13042 We are processing the template argument `E' in #1 for
13043 the template instantiation #2. Originally, `E' is a
13044 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
13045 have to substitute this with one having context `D<int>'. */
13049 }
13050 else
13051 /* Ordinary template template argument. */
13062 {
13066 }
13070 {
13080 /* We only want to compute the number of arguments. */
13094 {
13101 else
13104 }
13105 else
13107 }
13109 {
13117 }
13118 /* Fall through */
13134 {
13138 }
13141 {
13142 tree object;
13143 tree name;
13148 {
13152 }
13155 {
13165 }
13170 in_decl);
13171 else
13174 }
13212 {
13216 }
13219 {
13224 }
13227 {
13231 }
13234 {
13242 }
13248 {
13255 }
13258 {
13265 }
13268 {
13275 }
13278 {
13279 /* Substituted template arguments */
13288 }
13291 {
13311 }
13336 /* Fall through. */
13339 {
13342 }
13343 else
13347 /* This is handled by tsubst_copy_and_build. */
13351 {
13355 }
13358 /* We shouldn't have built any of these during initial template
13359 generation. Instead, they should be built during instantiation
13360 in response to the saved STMT_IS_FULL_EXPR_P setting. */
13364 {
13374 }
13392 {
13393 /* Instantiate any typedefs in the type. */
13398 }
13401 /* These can sometimes show up in a partial instantiation, but never
13402 involve template parms. */
13407 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
13410 }
13411 }
13413 /* Like tsubst_copy, but specifically for OpenMP clauses. */
13415 static tree
13418 {
13422 {
13428 {
13431 {
13437 }
13438 /* FALLTHRU */
13466 {
13469 {
13476 }
13477 else
13479 }
13509 }
13510 }
13516 }
13518 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
13520 static tree
13522 tree in_decl)
13523 {
13524 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
13544 {
13547 else
13548 {
13552 }
13553 }
13558 #undef RECUR
13559 }
13561 /* Substitute one OMP_FOR iterator. */
13563 static void
13568 {
13569 #define RECUR(NODE) \
13570 tsubst_expr ((NODE), args, complain, in_decl, \
13571 integral_constant_expression_p)
13580 {
13581 /* We need to jump through some hoops to handle declarations in the
13582 for-init-statement, since we might need to handle auto deduction,
13583 but we need to keep control of initialization. */
13587 }
13588 else
13600 {
13602 {
13603 /* Declare the variable, but don't let that initialize it. */
13608 }
13613 {
13618 }
13619 else
13626 }
13629 {
13630 /* Declare and initialize the variable. */
13633 }
13635 {
13636 tree c;
13638 {
13649 }
13651 {
13656 {
13659 }
13660 }
13661 }
13664 {
13668 }
13669 else
13673 {
13684 {
13692 }
13693 else
13699 {
13705 }
13709 {
13717 }
13718 else
13724 }
13730 #undef RECUR
13731 }
13733 /* Like tsubst_copy for expressions, etc. but also does semantic
13734 processing. */
13736 static tree
13739 {
13740 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13741 #define RECUR(NODE) \
13742 tsubst_expr ((NODE), args, complain, in_decl, \
13743 integral_constant_expression_p)
13746 tree r;
13747 location_t loc;
13759 {
13761 {
13762 tree_stmt_iterator i;
13766 }
13781 else
13790 {
13792 tree init;
13798 {
13801 tree decl;
13809 else
13811 }
13813 {
13814 /* Don't build up decls for a variadic capture proxy, we'll
13815 instantiate the elements directly as needed. */
13817 }
13818 else
13819 {
13823 {
13824 /* By marking the declaration as instantiated, we avoid
13825 trying to instantiate it. Since instantiate_decl can't
13826 handle local variables, and since we've already done
13827 all that needs to be done, that's the right thing to
13828 do. */
13833 /* Anonymous aggregates are a special case. */
13836 {
13839 {
13843 }
13845 }
13851 {
13856 }
13857 else
13858 {
13863 {
13864 /* For __PRETTY_FUNCTION__ we have to adjust the
13865 initializer. */
13869 }
13870 else
13874 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
13877 }
13878 }
13879 }
13882 }
13897 {
13907 }
13934 {
13938 }
13946 else
13954 else
13975 {
13979 }
13983 {
13985 tree label;
13990 }
13996 /* Computed goto's must be tsubst'd into. On the other hand,
13997 non-computed gotos must not be; the identifier in question
13998 will have no binding. */
14000 else
14006 {
14022 }
14027 {
14032 }
14033 else
14034 {
14039 else
14046 else
14052 else
14054 }
14058 {
14062 {
14064 /* Prevent instantiate_decl from trying to instantiate
14065 this variable. We've already done all that needs to be
14066 done. */
14069 }
14074 }
14080 {
14081 /* Local classes are not independent templates; they are
14082 instantiated along with their containing function. And this
14083 way we don't have to deal with pushing out of one local class
14084 to instantiate a member of another local class. */
14085 tree fn;
14086 /* Closures are handled by the LAMBDA_EXPR. */
14092 }
14096 {
14097 tree condition;
14100 condition =
14102 args,
14111 }
14136 {
14145 {
14150 }
14162 integral_constant_expression_p);
14171 else
14172 {
14180 }
14183 }
14242 {
14247 {
14250 }
14256 }
14257 else
14258 {
14265 {
14268 }
14271 {
14276 {
14279 }
14285 }
14286 else
14287 {
14291 }
14294 }
14298 {
14304 {
14308 {
14313 }
14317 }
14318 else
14319 {
14324 }
14325 }
14329 {
14333 }
14353 /* If the first operand was a statement, we're done with it. */
14357 complain));
14369 integral_constant_expression_p));
14370 }
14373 out:
14376 #undef RECUR
14377 #undef RETURN
14378 }
14380 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
14381 function. For description of the body see comment above
14382 cp_parser_omp_declare_reduction_exprs. */
14384 static void
14386 {
14392 tree_stmt_iterator tsi;
14403 {
14422 }
14424 {
14444 }
14445 }
14447 /* T is a postfix-expression that is not being used in a function
14448 call. Return the substituted version of T. */
14450 static tree
14452 tsubst_flags_t complain,
14453 tree in_decl)
14454 {
14458 else
14464 }
14466 /* Like tsubst but deals with expressions and performs semantic
14467 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
14469 tree
14471 tree args,
14472 tsubst_flags_t complain,
14473 tree in_decl,
14476 {
14477 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
14478 #define RECUR(NODE) \
14479 tsubst_copy_and_build (NODE, args, complain, in_decl, \
14481 integral_constant_expression_p)
14484 location_t loc;
14493 /* N3276 decltype magic only applies to calls at the top level or on the
14494 right side of a comma. */
14499 {
14502 /* Fall through. */
14504 {
14505 tree decl;
14506 cp_id_kind idk;
14511 {
14514 }
14516 /* Look up the name. */
14519 /* By convention, expressions use ERROR_MARK_NODE to indicate
14520 failure, not NULL_TREE. */
14526 integral_constant_expression_p,
14534 input_location);
14538 {
14542 }
14544 }
14547 {
14548 tree object;
14556 {
14559 }
14560 else
14567 else
14569 }
14572 {
14576 {
14577 /* A type conversion to reference type will be enclosed in
14578 such an indirect ref, but the substitution of the cast
14579 will have also added such an indirect ref. */
14582 }
14583 else
14587 }
14590 {
14594 }
14597 {
14604 flags));
14605 }
14608 {
14612 }
14619 {
14620 tree type;
14626 {
14631 }
14637 {
14655 }
14658 }
14692 else
14694 in_decl);
14729 {
14734 tree r = build_x_binary_op
14736 op0,
14738 ? ERROR_MARK
14740 op1,
14742 ? ERROR_MARK
14750 }
14753 {
14757 }
14770 {
14779 }
14783 /* Fall through */
14786 {
14787 tree r;
14793 {
14794 /* When there are no ARGS, we are trying to evaluate a
14795 non-dependent expression from the parser. Trying to do
14796 the substitutions may not work. */
14799 }
14800 else
14801 {
14806 else
14809 /*integral_constant_expression_p=*/
14813 }
14817 else
14821 {
14823 {
14825 {
14829 }
14830 else
14834 }
14836 }
14838 }
14841 {
14851 }
14867 {
14871 tree r = build_x_modify_expr
14874 /* TREE_NO_WARNING must be set if either the expression was
14875 parenthesized or it uses an operator such as >>= rather
14876 than plain assignment. In the former case, it was already
14877 set and must be copied. In the latter case,
14878 build_x_modify_expr sets it and it must not be reset
14879 here. */
14884 }
14889 /* Remember that there was a reference to this entity. */
14896 {
14901 tree ret;
14905 else
14906 {
14910 }
14912 /* If there was an initializer in the original tree, but it
14913 instantiated to an empty list, then we should pass a
14914 non-NULL empty vector to tell build_new that it was an
14915 empty initializer() rather than no initializer. This can
14916 only happen when the initializer is a pack expansion whose
14917 parameter packs are of length zero. */
14920 else
14921 {
14925 else
14926 {
14929 }
14930 }
14936 complain);
14944 }
14947 {
14953 complain));
14954 }
14957 {
14961 integral_constant_expression_p);
14963 op0,
14966 }
14969 {
14970 tree function;
14975 tree ret;
14978 /* When we parsed the expression, we determined whether or
14979 not Koenig lookup should be performed. */
14982 {
14987 }
14989 {
14990 /* Do nothing; calling tsubst_copy_and_build on an identifier
14991 would incorrectly perform unqualified lookup again.
14993 Note that we can also have an IDENTIFIER_NODE if the earlier
14994 unqualified lookup found a member function; in that case
14995 koenig_p will be false and we do want to do the lookup
14996 again to find the instantiated member function.
14998 FIXME but doing that causes c++/15272, so we need to stop
14999 using IDENTIFIER_NODE in that situation. */
15001 }
15002 else
15003 {
15005 {
15011 }
15012 else
15017 /* Avoid error about taking the address of a constructor. */
15021 in_decl,
15023 integral_constant_expression_p);
15027 }
15032 {
15037 else
15038 {
15039 /* Expand the pack expansion and push each entry onto
15040 CALL_ARGS. */
15043 {
15048 {
15053 }
15054 }
15055 else
15056 {
15057 /* A partial substitution. Add one entry. */
15059 }
15060 }
15061 }
15063 /* We do not perform argument-dependent lookup if normal
15064 lookup finds a non-function, in accordance with the
15065 expected resolution of DR 218. */
15068 /* If lookup found a member function, the Koenig lookup is
15069 not appropriate, even if an unqualified-name was used
15070 to denote the function. */
15073 /* Only do this when substitution turns a dependent call
15074 into a non-dependent call. */
15081 {
15083 {
15084 /* For backwards compatibility and good diagnostics, try
15085 the unqualified lookup again if we aren't in SFINAE
15086 context. */
15087 tree unq = (tsubst_copy_and_build
15089 integral_constant_expression_p));
15094 {
15103 "%qD was not declared in this scope, "
15104 "and no declarations were found by "
15105 "argument-dependent lookup at the point "
15107 {
15111 {
15113 input_location);
15115 "declarations in dependent base %qT are "
15121 else
15125 }
15126 else
15129 }
15131 }
15132 }
15134 {
15139 }
15140 }
15142 /* Remember that there was a reference to this entity. */
15147 /* Put back tf_decltype for the actual call. */
15152 complain);
15154 {
15169 complain);
15170 else
15171 ret = (build_new_method_call
15176 complain));
15177 }
15178 else
15181 koenig_p,
15182 complain);
15187 }
15190 {
15196 {
15198 {
15203 }
15204 else
15205 {
15210 }
15212 }
15213 else
15214 {
15217 }
15221 }
15224 {
15229 input_location));
15230 }
15233 {
15241 {
15242 /* We have pack expansions, so expand those and
15243 create a new list out of it. */
15246 tree chain;
15249 /* Expand the argument expressions. */
15257 /* Build the rest of the list. */
15262 /* Determine the number of arguments. */
15264 {
15267 }
15270 else
15271 {
15272 /* Since we only performed a partial substitution into
15273 the argument pack, we only RETURN (a single list
15274 node. */
15281 }
15283 /* Convert the argument vectors into a TREE_LIST */
15286 {
15287 /* Grab the Ith values. */
15288 i--;
15291 value
15295 /* Build the list (backwards). */
15297 }
15300 }
15316 }
15319 {
15320 tree object;
15321 tree object_type;
15322 tree member;
15323 tree r;
15327 /* Remember that there was a reference to this entity. */
15338 else
15346 {
15348 {
15353 {
15356 }
15358 {
15363 }
15364 }
15365 }
15368 {
15369 /* Lookup the template functions now that we know what the
15370 scope is. */
15378 {
15381 args);
15382 member = (adjust_result_of_qualified_name_lookup
15384 object_type));
15385 }
15386 else
15387 {
15389 input_location);
15391 }
15392 }
15396 {
15398 {
15402 else
15405 }
15407 }
15409 {
15414 }
15418 complain);
15422 }
15429 {
15437 tree r;
15442 /* digest_init will do the wrong thing if we let it. */
15446 /* We do not want to process the index of aggregate
15447 initializers as they are identifier nodes which will be
15448 looked up by digest_init. */
15454 {
15456 /* An identifier index is looked up in the type
15457 being initialized, not the current scope. */
15462 {
15463 /* Substitute into the pack expansion. */
15465 in_decl);
15469 ;
15471 /* Just move the argument into place. */
15473 else
15474 {
15475 /* Update the length of the final CONSTRUCTOR
15476 arguments vector, and note that we will need to
15477 copy.*/
15480 }
15481 }
15482 else
15484 }
15487 {
15492 {
15494 {
15499 }
15500 else
15502 }
15503 }
15513 }
15516 {
15519 {
15522 }
15523 else
15524 {
15527 }
15528 }
15534 {
15535 /* We don't build decls for an instantiation of a
15536 variadic capture proxy, we instantiate the elements
15537 when needed. */
15540 }
15541 /* Fall through */
15544 {
15546 /* ??? We're doing a subset of finish_id_expression here. */
15548 && !processing_template_decl
15549 && !cp_unevaluated_operand
15552 {
15554 /* Replace an evaluated use of the thread_local variable with
15555 a call to its wrapper. */
15557 }
15562 /* If the original type was a reference, we'll be wrapped in
15563 the appropriate INDIRECT_REF. */
15566 }
15569 {
15573 }
15580 {
15591 }
15594 {
15600 integral_constant_expression_p);
15604 /* If the resulting list of expression statement is empty,
15605 fold it further into void_node. */
15610 }
15613 {
15627 /* For a function scope, we want to use tsubst so that we don't
15628 complain about referring to an auto function before its return
15629 type has been deduced. Otherwise, we want to use tsubst_copy so
15630 that we look up the existing field/parameter/variable rather
15631 than build a new one. */
15636 {
15637 /* Look up the parameter we want directly, as tsubst_copy
15638 doesn't do what we need. */
15644 /* FIXME Work around the parm not having DECL_CONTEXT set. */
15647 }
15648 else
15657 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
15659 /* Now that we know visibility, instantiate the type so we have a
15660 declaration of the op() for later calls to lambda_function. */
15666 }
15669 /* We can get here for a constant initializer of non-dependent type.
15670 FIXME stop folding in cp_parser_initializer_clause. */
15671 {
15673 complain);
15675 }
15679 integral_constant_expression_p));
15685 {
15690 complain));
15691 }
15694 /* Handle Objective-C++ constructs, if appropriate. */
15695 {
15696 tree subst
15701 }
15703 }
15705 #undef RECUR
15706 #undef RETURN
15707 out:
15710 }
15712 /* Verify that the instantiated ARGS are valid. For type arguments,
15713 make sure that the type's linkage is ok. For non-type arguments,
15714 make sure they are constants if they are integral or enumerations.
15715 Emit an error under control of COMPLAIN, and return TRUE on error. */
15717 static bool
15719 {
15723 {
15733 }
15735 {
15736 /* [basic.link]: A name with no linkage (notably, the name
15737 of a class or enumeration declared in a local scope)
15738 shall not be used to declare an entity with linkage.
15739 This implies that names with no linkage cannot be used as
15740 template arguments
15742 DR 757 relaxes this restriction for C++0x. */
15747 {
15748 /* DR 488 makes use of a type with no linkage cause
15749 type deduction to fail. */
15751 {
15754 else
15757 }
15759 }
15760 /* In order to avoid all sorts of complications, we do not
15761 allow variably-modified types as template arguments. */
15763 {
15767 }
15768 }
15769 /* Class template and alias template arguments should be OK. */
15771 ;
15772 /* A non-type argument of integral or enumerated type must be a
15773 constant. */
15778 {
15782 }
15784 }
15786 static bool
15788 {
15793 {
15796 }
15800 }
15802 /* We're out of SFINAE context now, so generate diagnostics for the access
15803 errors we saw earlier when instantiating D from TMPL and ARGS. */
15805 static void
15807 {
15819 }
15821 /* Instantiate the indicated variable, function, or alias template TMPL with
15822 the template arguments in TARG_PTR. */
15824 static tree
15826 {
15828 tree fndecl;
15829 tree gen_tmpl;
15830 tree spec;
15838 /* If this function is a clone, handle it specially. */
15840 {
15841 tree spec;
15842 tree clone;
15844 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
15845 DECL_CLONED_FUNCTION. */
15851 /* Look for the clone. */
15855 /* We should always have found the clone by now. */
15858 }
15863 /* Check to see if we already have this specialization. */
15866 /* The TMPL is a partial instantiation. To get a full set of
15867 arguments we must add the arguments used to perform the
15868 partial instantiation. */
15870 targ_ptr);
15872 /* It would be nice to avoid hashing here and then again in tsubst_decl,
15873 but it doesn't seem to be on the hot path. */
15882 {
15884 {
15888 }
15890 }
15893 complain))
15896 /* We are building a FUNCTION_DECL, during which the access of its
15897 parameters and return types have to be checked. However this
15898 FUNCTION_DECL which is the desired context for access checking
15899 is not built yet. We solve this chicken-and-egg problem by
15900 deferring all checks until we have the FUNCTION_DECL. */
15903 /* Instantiation of the function happens in the context of the function
15904 template, not the context of the overload resolution we're doing. */
15906 /* If there are dependent arguments, e.g. because we're doing partial
15907 ordering, make sure processing_template_decl stays set. */
15911 {
15915 }
15920 {
15921 /* We need to determine if we're using a partial or explicit
15922 specialization now, because the type of the variable could be
15923 different. */
15929 {
15933 }
15934 }
15936 /* Substitute template parameters to obtain the specialization. */
15943 {
15946 }
15948 /* The DECL_TI_TEMPLATE should always be the immediate parent
15949 template, not the most general template. */
15952 /* Now we know the specialization, compute access previously
15953 deferred. */
15960 /* If we've just instantiated the main entry point for a function,
15961 instantiate all the alternate entry points as well. We do this
15962 by cloning the instantiation of the main entry point, not by
15963 instantiating the template clones. */
15968 {
15970 {
15971 /* Remember to reinstantiate when we're out of SFINAE so the user
15972 can see the errors. */
15974 }
15976 }
15978 }
15980 /* Wrapper for instantiate_template_1. */
15982 tree
15984 {
15985 tree ret;
15990 }
15992 /* Instantiate the alias template TMPL with ARGS. Also push a template
15993 instantiation level, which instantiate_template doesn't do because
15994 functions and variables have sufficient context established by the
15995 callers. */
15997 static tree
15999 {
16006 {
16009 }
16011 args =
16019 /* We can't free this if a pending_template entry or last_error_tinst_level
16020 is pointing at it. */
16026 }
16028 /* PARM is a template parameter pack for FN. Returns true iff
16029 PARM is used in a deducible way in the argument list of FN. */
16031 static bool
16033 {
16036 {
16038 tree packs;
16044 {
16045 /* The template parameter pack is used in a function parameter
16046 pack. If this is the end of the parameter list, the
16047 template parameter pack is deducible. */
16050 else
16051 /* Otherwise, not. Well, it could be deduced from
16052 a non-pack parameter, but doing so would end up with
16053 a deduction mismatch, so don't bother. */
16055 }
16056 }
16057 /* The template parameter pack isn't used in any function parameter
16058 packs, but it might be used deeper, e.g. tuple<Args...>. */
16060 }
16062 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
16063 NARGS elements of the arguments that are being used when calling
16064 it. TARGS is a vector into which the deduced template arguments
16065 are placed.
16067 Returns either a FUNCTION_DECL for the matching specialization of FN or
16068 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
16069 true, diagnostics will be printed to explain why it failed.
16071 If FN is a conversion operator, or we are trying to produce a specific
16072 specialization, RETURN_TYPE is the return type desired.
16074 The EXPLICIT_TARGS are explicit template arguments provided via a
16075 template-id.
16077 The parameter STRICT is one of:
16079 DEDUCE_CALL:
16080 We are deducing arguments for a function call, as in
16081 [temp.deduct.call].
16083 DEDUCE_CONV:
16084 We are deducing arguments for a conversion function, as in
16085 [temp.deduct.conv].
16087 DEDUCE_EXACT:
16088 We are deducing arguments when doing an explicit instantiation
16089 as in [temp.explicit], when determining an explicit specialization
16090 as in [temp.expl.spec], or when taking the address of a function
16091 template, as in [temp.deduct.funcaddr]. */
16093 tree
16095 tree explicit_targs,
16096 tree targs,
16099 tree return_type,
16100 unification_kind_t strict,
16104 {
16105 tree parms;
16106 tree fntype;
16114 tree tinst;
16120 /* In C++0x, it's possible to have a function template whose type depends
16121 on itself recursively. This is most obvious with decltype, but can also
16122 occur with enumeration scope (c++/48969). So we need to catch infinite
16123 recursion and reject the substitution at deduction time; this function
16124 will return error_mark_node for any repeated substitution.
16126 This also catches excessive recursion such as when f<N> depends on
16127 f<N-1> across all integers, and returns error_mark_node for all the
16128 substitutions back up to the initial one.
16130 This is, of course, not reentrant. */
16140 {
16141 /* [temp.deduct]
16143 The specified template arguments must match the template
16144 parameters in kind (i.e., type, nontype, template), and there
16145 must not be more arguments than there are parameters;
16146 otherwise type deduction fails.
16148 Nontype arguments must match the types of the corresponding
16149 nontype template parameters, or must be convertible to the
16150 types of the corresponding nontype parameters as specified in
16151 _temp.arg.nontype_, otherwise type deduction fails.
16153 All references in the function type of the function template
16154 to the corresponding template parameters are replaced by the
16155 specified template argument values. If a substitution in a
16156 template parameter or in the function type of the function
16157 template results in an invalid type, type deduction fails. */
16162 /* Adjust any explicit template arguments before entering the
16163 substitution context. */
16164 explicit_targs
16166 complain,
16172 /* Substitute the explicit args into the function type. This is
16173 necessary so that, for instance, explicitly declared function
16174 arguments can match null pointed constants. If we were given
16175 an incomplete set of explicit args, we must not do semantic
16176 processing during substitution as we could create partial
16177 instantiations. */
16179 {
16184 /* Dig out the actual parm. */
16187 {
16190 }
16192 {
16195 }
16198 /* No explicit argument for this template parameter. */
16202 {
16203 /* Mark the argument pack as "incomplete". We could
16204 still deduce more arguments during unification.
16205 We remove this mark in type_unification_real. */
16207 {
16211 }
16213 /* We have some incomplete argument packs. */
16215 }
16216 }
16220 {
16223 }
16226 /* Ignore any access checks; we'll see them again in
16227 instantiate_template and they might have the wrong
16228 access path at this point. */
16240 /* Place the explicitly specified arguments in TARGS. */
16243 }
16245 /* Never do unification on the 'this' parameter. */
16249 {
16258 }
16260 /* We allow incomplete unification without an error message here
16261 because the standard doesn't seem to explicitly prohibit it. Our
16262 callers must be ready to deal with unification failures in any
16263 event. */
16266 /* If we aren't explaining yet, push tinst context so we can see where
16267 any errors (e.g. from class instantiations triggered by instantiation
16268 of default template arguments) come from. If we are explaining, this
16269 context is redundant. */
16271 {
16274 }
16276 /* type_unification_real will pass back any access checks from default
16277 template argument substitution. */
16289 /* Now that we have bindings for all of the template arguments,
16290 ensure that the arguments deduced for the template template
16291 parameters have compatible template parameter lists. We cannot
16292 check this property before we have deduced all template
16293 arguments, because the template parameter types of a template
16294 template parameter might depend on prior template parameters
16295 deduced after the template template parameter. The following
16296 ill-formed example illustrates this issue:
16298 template<typename T, template<T> class C> void f(C<5>, T);
16300 template<int N> struct X {};
16302 void g() {
16303 f(X<5>(), 5l); // error: template argument deduction fails
16304 }
16306 The template parameter list of 'C' depends on the template type
16307 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
16308 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
16309 time that we deduce 'C'. */
16312 {
16315 }
16317 /* All is well so far. Now, check:
16319 [temp.deduct]
16321 When all template arguments have been deduced, all uses of
16322 template parameters in nondeduced contexts are replaced with
16323 the corresponding deduced argument values. If the
16324 substitution results in an invalid type, as described above,
16325 type deduction fails. */
16328 {
16331 }
16333 /* Also collect access checks from the instantiation. */
16346 /* Now perform any access checks encountered during substitution. */
16353 /* If we're looking for an exact match, check that what we got
16354 is indeed an exact match. It might not be if some template
16355 parameters are used in non-deduced contexts. But don't check
16356 for an exact match if we have dependent template arguments;
16357 in that case we're doing partial ordering, and we already know
16358 that we have two candidates that will provide the actual type. */
16360 {
16364 tree sarg
16370 {
16374 }
16375 }
16379 fail:
16382 {
16384 /* Reset once we're all the way out. */
16386 }
16388 /* We can't free this if a pending_template entry or last_error_tinst_level
16389 is pointing at it. */
16395 }
16397 /* Adjust types before performing type deduction, as described in
16398 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
16399 sections are symmetric. PARM is the type of a function parameter
16400 or the return type of the conversion function. ARG is the type of
16401 the argument passed to the call, or the type of the value
16402 initialized with the result of the conversion function.
16403 ARG_EXPR is the original argument expression, which may be null. */
16405 static int
16409 tree arg_expr)
16410 {
16414 {
16419 {
16420 /* Swap PARM and ARG throughout the remainder of this
16421 function; the handling is precisely symmetric since PARM
16422 will initialize ARG rather than vice versa. */
16427 }
16430 /* Core issue #873: Do the DR606 thing (see below) for these cases,
16431 too, but here handle it by stripping the reference from PARM
16432 rather than by adding it to ARG. */
16440 /* Nothing else to do in this case. */
16445 }
16448 {
16449 /* [temp.deduct.call]
16451 If P is not a reference type:
16453 --If A is an array type, the pointer type produced by the
16454 array-to-pointer standard conversion (_conv.array_) is
16455 used in place of A for type deduction; otherwise,
16457 --If A is a function type, the pointer type produced by
16458 the function-to-pointer standard conversion
16459 (_conv.func_) is used in place of A for type deduction;
16460 otherwise,
16462 --If A is a cv-qualified type, the top level
16463 cv-qualifiers of A's type are ignored for type
16464 deduction. */
16469 else
16471 }
16473 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
16474 of the form T&&, where T is a template parameter, and the argument
16475 is an lvalue, T is deduced as A& */
16481 /* try_one_overload doesn't provide an arg_expr, but
16482 functions are always lvalues. */
16486 /* [temp.deduct.call]
16488 If P is a cv-qualified type, the top level cv-qualifiers
16489 of P's type are ignored for type deduction. If P is a
16490 reference type, the type referred to by P is used for
16491 type deduction. */
16494 {
16497 }
16499 /* DR 322. For conversion deduction, remove a reference type on parm
16500 too (which has been swapped into ARG). */
16505 }
16507 /* Subroutine of unify_one_argument. PARM is a function parameter of a
16508 template which does contain any deducible template parameters; check if
16509 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
16510 unify_one_argument. */
16512 static int
16515 {
16516 tree type;
16520 else
16527 {
16531 }
16533 {
16538 }
16542 else
16544 }
16548 /* Returns true iff the expression EXPR is one from which a template
16549 argument can be deduced. In other words, if it's an undecorated
16550 use of a template non-type parameter. */
16552 static bool
16554 {
16556 }
16558 /* Returns true iff the array domain DOMAIN uses a template parameter in a
16559 deducible way; that is, if it has a max value of <PARM> - 1. */
16561 static bool
16563 {
16572 }
16574 /* Returns true iff the template arguments ARGS use a template parameter
16575 in a deducible way. */
16577 static bool
16579 {
16581 {
16586 else
16587 {
16594 else
16596 }
16599 }
16601 }
16603 /* Returns true iff TYPE contains any deducible references to template
16604 parameters, as per 14.8.2.5. */
16606 static bool
16608 {
16612 /* T
16613 cv-list T
16614 TT<T>
16615 TT<i>
16616 TT<> */
16621 /* T*
16622 T&
16623 T&& */
16627 /* T[integer-constant ]
16628 type [i] */
16633 /* T type ::*
16634 type T::*
16635 T T::*
16636 T (type ::*)()
16637 type (T::*)()
16638 type (type ::*)(T)
16639 type (T::*)(T)
16640 T (type ::*)(T)
16641 T (T::*)()
16642 T (T::*)(T) */
16645 || (uses_deducible_template_parms
16648 /* template-name <T> (where template-name refers to a class template)
16649 template-name <i> (where template-name refers to a class template) */
16656 /* type (T)
16657 T()
16658 T(T) */
16661 {
16670 }
16673 }
16675 /* Subroutine of type_unification_real and unify_pack_expansion to
16676 handle unification of a single P/A pair. Parameters are as
16677 for those functions. */
16679 static int
16683 {
16690 /* We can't deduce anything from this, but we might get all the
16691 template args from other function args. */
16694 /* Implicit conversions (Clause 4) will be performed on a function
16695 argument to convert it to the type of the corresponding function
16696 parameter if the parameter type contains no template-parameters that
16697 participate in template argument deduction. */
16699 /* For function parameters that contain no template-parameters at all,
16700 we have historically checked for convertibility in order to shortcut
16701 consideration of this candidate. */
16703 explain_p);
16706 /* For function parameters with only non-deducible template parameters,
16707 just return. */
16711 {
16713 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
16714 | UNIFY_ALLOW_MORE_CV_QUAL
16728 }
16730 /* We only do these transformations if this is the top-level
16731 parameter_type_list in a call or declaration matching; in other
16732 situations (nested function declarators, template argument lists) we
16733 won't be comparing a type to an expression, and we don't do any type
16734 adjustments. */
16736 {
16738 {
16741 {
16742 /* [temp.deduct.type] A template-argument can be
16743 deduced from a pointer to function or pointer
16744 to member function argument if the set of
16745 overloaded functions does not contain function
16746 templates and at most one of a set of
16747 overloaded functions provides a unique
16748 match. */
16755 }
16761 }
16763 arg_strict |=
16765 }
16766 else
16771 /* For deduction from an init-list we need the actual list. */
16775 }
16777 /* Most parms like fn_type_unification.
16779 If SUBR is 1, we're being called recursively (to unify the
16780 arguments of a function or method parameter of a function
16781 template).
16783 CHECKS is a pointer to a vector of access checks encountered while
16784 substituting default template arguments. */
16786 static int
16788 tree targs,
16789 tree xparms,
16793 unification_kind_t strict,
16797 {
16802 tree parms;
16811 /* Reset the number of non-defaulted template arguments contained
16812 in TARGS. */
16815 again:
16823 {
16828 /* For a function parameter pack that occurs at the end of the
16829 parameter-declaration-list, the type A of each remaining
16830 argument of the call is compared with the type P of the
16831 declarator-id of the function parameter pack. */
16837 /* For a function parameter pack that does not occur at the
16838 end of the parameter-declaration-list, the type of the
16839 parameter pack is a non-deduced context. */
16848 }
16853 {
16854 /* Unify the remaining arguments with the pack expansion type. */
16855 tree argvec;
16858 /* Allocate a TREE_VEC and copy in all of the arguments */
16863 /* Copy the parameter into parmvec. */
16869 /* Advance to the end of the list of parameters. */
16871 }
16873 /* Fail if we've reached the end of the parm list, and more args
16874 are present, and the parm list isn't variadic. */
16877 /* Fail if parms are left and they don't have default values and
16878 they aren't all deduced as empty packs (c++/57397). This is
16879 consistent with sufficient_parms_p. */
16882 {
16886 do
16887 {
16890 count++;
16892 }
16896 type_pack_p);
16897 }
16900 {
16901 tsubst_flags_t complain = (explain_p
16902 ? tf_warning_or_error
16906 {
16910 /* Clear the "incomplete" flags on all argument packs now so that
16911 substituting them into later default arguments works. */
16913 {
16916 }
16922 /* If this is an undeduced nontype parameter that depends on
16923 a type parameter, try another pass; its type may have been
16924 deduced from a later argument than the one from which
16925 this parameter can be deduced. */
16931 /* Core issue #226 (C++0x) [temp.deduct]:
16933 If a template argument has not been deduced, its
16934 default template argument, if any, is used.
16936 When we are in C++98 mode, TREE_PURPOSE will either
16937 be NULL_TREE or ERROR_MARK_NODE, so we do not need
16938 to explicitly check cxx_dialect here. */
16940 {
16955 else
16956 {
16958 /* The position of the first default template argument,
16959 is also the number of non-defaulted arguments in TARGS.
16960 Record that. */
16964 }
16965 }
16967 /* If the type parameter is a parameter pack, then it will
16968 be deduced to an empty parameter pack. */
16970 {
16971 tree arg;
16974 {
16978 }
16979 else
16986 }
16989 }
16990 }
16991 #ifdef ENABLE_CHECKING
16994 #endif
16997 }
16999 /* Subroutine of type_unification_real. Args are like the variables
17000 at the call site. ARG is an overloaded function (or template-id);
17001 we try deducing template args from each of the overloads, and if
17002 only one succeeds, we go with that. Modifies TARGS and returns
17003 true on success. */
17005 static bool
17007 tree targs,
17008 tree parm,
17009 tree arg,
17010 unification_kind_t strict,
17013 {
17020 {
17023 }
17024 else
17028 /* Handle `&x' where `x' is some static or non-static member
17029 function name. */
17035 /* Strip baselink information. */
17040 {
17041 /* If we got some explicit template args, we need to plug them into
17042 the affected templates before we try to unify, in case the
17043 explicit args will completely resolve the templates in question. */
17050 {
17063 {
17068 {
17071 }
17072 }
17075 }
17076 /* If no templates (or more than one) are fully resolved by the
17077 explicit arguments, this template-id is a non-deduced context; it
17078 could still be OK if we deduce all template arguments for the
17079 enclosing call through other arguments. */
17082 }
17085 /* If ARG is, for example, "(0, &f)" then its type will be unknown
17086 -- but the deduction does not succeed because the expression is
17087 not just the function on its own. */
17089 else
17095 {
17098 }
17100 /* [temp.deduct.type] A template-argument can be deduced from a pointer
17101 to function or pointer to member function argument if the set of
17102 overloaded functions does not contain function templates and at most
17103 one of a set of overloaded functions provides a unique match.
17105 So if we found multiple possibilities, we return success but don't
17106 deduce anything. */
17109 {
17113 {
17118 /* Don't forget explicit template arguments in a pack. */
17122 }
17123 }
17128 }
17130 /* Core DR 115: In contexts where deduction is done and fails, or in
17131 contexts where deduction is not done, if a template argument list is
17132 specified and it, along with any default template arguments, identifies
17133 a single function template specialization, then the template-id is an
17134 lvalue for the function template specialization. */
17136 tree
17138 {
17151 {
17154 }
17156 {
17159 }
17161 {
17164 }
17167 {
17171 /* If we got some explicit template args, we need to plug them into
17172 the affected templates before we try to unify, in case the
17173 explicit args will completely resolve the templates in question. */
17181 {
17194 {
17197 {
17200 }
17202 {
17205 }
17206 }
17207 }
17209 {
17217 {
17218 tree base
17221 }
17225 }
17227 /* There were no good options and at least one bad one, so let the
17228 user know what the problem is. */
17230 }
17232 }
17234 /* Subroutine of resolve_overloaded_unification; does deduction for a single
17235 overload. Fills TARGS with any deduced arguments, or error_mark_node if
17236 different overloads deduce different arguments for a given parm.
17237 ADDR_P is true if the expression for which deduction is being
17238 performed was of the form "& fn" rather than simply "fn".
17240 Returns 1 on success. */
17242 static int
17244 tree orig_targs,
17245 tree targs,
17246 tree parm,
17247 tree arg,
17248 unification_kind_t strict,
17252 {
17254 tree tempargs;
17260 /* [temp.deduct.type] A template-argument can be deduced from a pointer
17261 to function or pointer to member function argument if the set of
17262 overloaded functions does not contain function templates and at most
17263 one of a set of overloaded functions provides a unique match.
17265 So if this is a template, just return success. */
17277 /* We don't copy orig_targs for this because if we have already deduced
17278 some template args from previous args, unify would complain when we
17279 try to deduce a template parameter for the same argument, even though
17280 there isn't really a conflict. */
17287 /* First make sure we didn't deduce anything that conflicts with
17288 explicitly specified args. */
17290 {
17297 /* Since we're unifying against ourselves, we will fill in
17298 template args used in the function parm list with our own
17299 template parms. Discard them. */
17303 }
17306 {
17311 }
17314 }
17316 /* PARM is a template class (perhaps with unbound template
17317 parameters). ARG is a fully instantiated type. If ARG can be
17318 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
17319 TARGS are as for unify. */
17321 static tree
17324 {
17325 tree copy_of_targs;
17332 /* We need to make a new template argument vector for the call to
17333 unify. If we used TARGS, we'd clutter it up with the result of
17334 the attempted unification, even if this class didn't work out.
17335 We also don't want to commit ourselves to all the unifications
17336 we've already done, since unification is supposed to be done on
17337 an argument-by-argument basis. In other words, consider the
17338 following pathological case:
17340 template <int I, int J, int K>
17341 struct S {};
17343 template <int I, int J>
17344 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
17346 template <int I, int J, int K>
17347 void f(S<I, J, K>, S<I, I, I>);
17349 void g() {
17350 S<0, 0, 0> s0;
17351 S<0, 1, 2> s2;
17353 f(s0, s2);
17354 }
17356 Now, by the time we consider the unification involving `s2', we
17357 already know that we must have `f<0, 0, 0>'. But, even though
17358 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
17359 because there are two ways to unify base classes of S<0, 1, 2>
17360 with S<I, I, I>. If we kept the already deduced knowledge, we
17361 would reject the possibility I=1. */
17364 /* If unification failed, we're done. */
17370 }
17372 /* Given a template type PARM and a class type ARG, find the unique
17373 base type in ARG that is an instance of PARM. We do not examine
17374 ARG itself; only its base-classes. If there is not exactly one
17375 appropriate base class, return NULL_TREE. PARM may be the type of
17376 a partial specialization, as well as a plain template type. Used
17377 by unify. */
17379 static enum template_base_result
17382 {
17384 tree binfo;
17390 {
17391 /* The type could not be completed. */
17394 }
17396 /* Walk in inheritance graph order. The search order is not
17397 important, and this avoids multiple walks of virtual bases. */
17399 {
17404 {
17405 /* If there is more than one satisfactory baseclass, then:
17407 [temp.deduct.call]
17409 If they yield more than one possible deduced A, the type
17410 deduction fails.
17412 applies. */
17414 {
17417 }
17420 }
17421 }
17425 }
17427 /* Returns the level of DECL, which declares a template parameter. */
17429 static int
17431 {
17433 {
17443 }
17445 }
17447 /* Decide whether ARG can be unified with PARM, considering only the
17448 cv-qualifiers of each type, given STRICT as documented for unify.
17449 Returns nonzero iff the unification is OK on that basis. */
17451 static int
17453 {
17459 {
17460 /* Although a CVR qualifier is ignored when being applied to a
17461 substituted template parameter ([8.3.2]/1 for example), that
17462 does not allow us to unify "const T" with "int&" because both
17463 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
17464 It is ok when we're allowing additional CV qualifiers
17465 at the outer level [14.8.2.1]/3,1st bullet. */
17475 }
17486 }
17488 /* Determines the LEVEL and INDEX for the template parameter PARM. */
17489 void
17491 {
17495 {
17498 }
17499 else
17500 {
17503 }
17504 }
17506 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
17507 do { \
17508 if (unify (TP, TA, P, A, S, EP)) \
17509 return 1; \
17510 } while (0);
17512 /* Unifies the remaining arguments in PACKED_ARGS with the pack
17513 expansion at the end of PACKED_PARMS. Returns 0 if the type
17514 deduction succeeds, 1 otherwise. STRICT is the same as in
17515 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
17516 call argument list. We'll need to adjust the arguments to make them
17517 types. SUBR tells us if this is from a recursive call to
17518 type_unification_real, or for comparing two template argument
17519 lists. */
17521 static int
17525 {
17526 tree parm
17536 /* Determine the parameter packs we will be deducing from the
17537 pattern, and record their current deductions. */
17540 {
17544 /* Determine the index and level of this parameter pack. */
17547 /* Keep track of the parameter packs and their corresponding
17548 argument packs. */
17551 }
17553 /* Loop through all of the arguments that have not yet been
17554 unified and unify each with the pattern. */
17556 {
17557 tree parm;
17561 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
17562 or the element of its argument pack at the current index if
17563 this argument was explicitly specified. */
17565 {
17574 {
17577 }
17579 }
17581 /* If we had explicit template arguments, substitute them into the
17582 pattern before deduction. */
17584 {
17585 /* Some arguments might still be unspecified or dependent. */
17593 NULL_TREE);
17598 }
17599 else
17602 /* Unify the pattern with the current argument. */
17607 /* For each parameter pack, collect the deduced value. */
17609 {
17615 }
17616 }
17618 /* Verify that the results of unification with the parameter packs
17619 produce results consistent with what we've seen before, and make
17620 the deduced argument packs available. */
17622 {
17629 /* By default keep the original deduced argument pack.
17630 If necessary, more specific code is going to update the
17631 resulting deduced argument later down in this function. */
17635 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
17636 actually deduce anything. */
17644 {
17645 /* If we had fewer function args than explicit template args,
17646 just use the explicits. */
17651 }
17654 {
17655 tree result;
17656 /* Build the deduced *_ARGUMENT_PACK. */
17658 {
17663 }
17664 else
17669 /* Note the deduced argument packs for this parameter
17670 pack. */
17672 }
17676 {
17677 /* We only had the explicitly-provided arguments before, but
17678 now we have a complete set of arguments. */
17684 }
17685 else
17686 {
17692 /* Inconsistent unification of this parameter pack. */
17694 bad_old_arg,
17695 bad_new_arg);
17696 }
17697 }
17700 }
17702 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
17703 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
17704 parameters and return value are as for unify. */
17706 static int
17710 {
17711 tree parm_max;
17712 tree arg_max;
17716 /* Our representation of array types uses "N - 1" as the
17717 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
17718 not an integer constant. We cannot unify arbitrarily
17719 complex expressions, so we eliminate the MINUS_EXPRs
17720 here. */
17724 {
17727 }
17731 {
17732 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
17733 trying to unify the type of a variable with the type
17734 of a template parameter. For example:
17736 template <unsigned int N>
17737 void f (char (&) [N]);
17738 int g();
17739 void h(int i) {
17740 char a[g(i)];
17741 f(a);
17742 }
17744 Here, the type of the ARG will be "int [g(i)]", and
17745 may be a SAVE_EXPR, etc. */
17749 }
17751 /* If only one of the bounds used a MINUS_EXPR, compensate
17752 by adding one to the other bound. */
17755 integer_type_node,
17756 parm_max,
17757 integer_one_node);
17760 integer_type_node,
17761 arg_max,
17762 integer_one_node);
17766 }
17768 /* Deduce the value of template parameters. TPARMS is the (innermost)
17769 set of template parameters to a template. TARGS is the bindings
17770 for those template parameters, as determined thus far; TARGS may
17771 include template arguments for outer levels of template parameters
17772 as well. PARM is a parameter to a template function, or a
17773 subcomponent of that parameter; ARG is the corresponding argument.
17774 This function attempts to match PARM with ARG in a manner
17775 consistent with the existing assignments in TARGS. If more values
17776 are deduced, then TARGS is updated.
17778 Returns 0 if the type deduction succeeds, 1 otherwise. The
17779 parameter STRICT is a bitwise or of the following flags:
17781 UNIFY_ALLOW_NONE:
17782 Require an exact match between PARM and ARG.
17783 UNIFY_ALLOW_MORE_CV_QUAL:
17784 Allow the deduced ARG to be more cv-qualified (by qualification
17785 conversion) than ARG.
17786 UNIFY_ALLOW_LESS_CV_QUAL:
17787 Allow the deduced ARG to be less cv-qualified than ARG.
17788 UNIFY_ALLOW_DERIVED:
17789 Allow the deduced ARG to be a template base class of ARG,
17790 or a pointer to a template base class of the type pointed to by
17791 ARG.
17792 UNIFY_ALLOW_INTEGER:
17793 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
17794 case for more information.
17795 UNIFY_ALLOW_OUTER_LEVEL:
17796 This is the outermost level of a deduction. Used to determine validity
17797 of qualification conversions. A valid qualification conversion must
17798 have const qualified pointers leading up to the inner type which
17799 requires additional CV quals, except at the outer level, where const
17800 is not required [conv.qual]. It would be normal to set this flag in
17801 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
17802 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
17803 This is the outermost level of a deduction, and PARM can be more CV
17804 qualified at this point.
17805 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
17806 This is the outermost level of a deduction, and PARM can be less CV
17807 qualified at this point. */
17809 static int
17812 {
17814 tree targ;
17815 tree tparm;
17818 /* I don't think this will do the right thing with respect to types.
17819 But the only case I've seen it in so far has been array bounds, where
17820 signedness is the only information lost, and I think that will be
17821 okay. */
17829 /* We can't deduce anything from this, but we might get all the
17830 template args from other function args. */
17833 /* If PARM uses template parameters, then we can't bail out here,
17834 even if ARG == PARM, since we won't record unifications for the
17835 template parameters. We might need them if we're trying to
17836 figure out which of two things is more specialized. */
17840 /* Handle init lists early, so the rest of the function can assume
17841 we're dealing with a type. */
17843 {
17848 /* Replace T with std::initializer_list<T> for deduction. */
17855 /* We can only deduce from an initializer list argument if the
17856 parameter is std::initializer_list or an array; otherwise this
17857 is a non-deduced context. */
17862 else
17863 {
17865 /* Deduction is defined in terms of a single type, so just punt
17866 on the (bizarre) std::initializer_list<T...>. */
17869 }
17872 {
17879 {
17883 /* It should only be possible to get here for a call. */
17885 elt_strict |= maybe_adjust_types_for_deduction
17888 }
17891 explain_p);
17892 }
17896 {
17897 /* Also deduce from the length of the initializer list. */
17904 }
17906 /* If the std::initializer_list<T> deduction worked, replace the
17907 deduced A with std::initializer_list<A>. */
17909 {
17914 }
17916 }
17918 /* Immediately reject some pairs that won't unify because of
17919 cv-qualification mismatches. */
17922 /* It is the elements of the array which hold the cv quals of an array
17923 type, and the elements might be template type parms. We'll check
17924 when we recurse. */
17926 /* We check the cv-qualifiers when unifying with template type
17927 parameters below. We want to allow ARG `const T' to unify with
17928 PARM `T' for example, when computing which of two templates
17929 is more specialized, for example. */
17943 {
17947 /* In a type which contains a nested-name-specifier, template
17948 argument values cannot be deduced for template parameters used
17949 within the nested-name-specifier. */
17961 /* The PARM is not one we're trying to unify. Just check
17962 to see if it matches ARG. */
17963 {
17968 else
17970 }
17977 /* Check for mixed types and values. */
17985 {
17986 /* ARG must be constructed from a template class or a template
17987 template parameter. */
17991 {
17993 /* An alias template name is never deduced. */
17998 tree parm_parms
17999 = DECL_INNERMOST_TEMPLATE_PARMS
18004 /* The resolution to DR150 makes clear that default
18005 arguments for an N-argument may not be used to bind T
18006 to a template template parameter with fewer than N
18007 parameters. It is not safe to permit the binding of
18008 default arguments as an extension, as that may change
18009 the meaning of a conforming program. Consider:
18011 struct Dense { static const unsigned int dim = 1; };
18013 template <template <typename> class View,
18014 typename Block>
18015 void operator+(float, View<Block> const&);
18017 template <typename Block,
18018 unsigned int Dim = Block::dim>
18019 struct Lvalue_proxy { operator float() const; };
18021 void
18022 test_1d (void) {
18023 Lvalue_proxy<Dense> p;
18024 float b;
18025 b + p;
18026 }
18028 Here, if Lvalue_proxy is permitted to bind to View, then
18029 the global operator+ will be used; if they are not, the
18030 Lvalue_proxy will be converted to float. */
18032 full_argvec,
18034 (explain_p
18035 ? tf_warning_or_error
18042 /* Deduce arguments T, i from TT<T> or TT<i>.
18043 We check each element of PARMVEC and ARGVEC individually
18044 rather than the whole TREE_VEC since they can have
18045 different number of elements. */
18052 /* Check if the parameters end in a pack, making them
18053 variadic. */
18059 /* If the template argument list of P contains a pack
18060 expansion that is not the last template argument, the
18061 entire template argument list is a non-deduced
18062 context. */
18071 {
18076 }
18081 DEDUCE_EXACT,
18084 }
18087 /* Fall through to deduce template name. */
18088 }
18092 {
18093 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
18095 /* Simple cases: Value already set, does match or doesn't. */
18100 }
18101 else
18102 {
18103 /* If PARM is `const T' and ARG is only `int', we don't have
18104 a match unless we are allowing additional qualification.
18105 If ARG is `const int' and PARM is just `T' that's OK;
18106 that binds `const int' to `T'. */
18111 /* Consider the case where ARG is `const volatile int' and
18112 PARM is `const T'. Then, T should be `volatile int'. */
18113 arg = cp_build_qualified_type_real
18118 /* Simple cases: Value already set, does match or doesn't. */
18124 /* Make sure that ARG is not a variable-sized array. (Note
18125 that were talking about variable-sized arrays (like
18126 `int[n]'), rather than arrays of unknown size (like
18127 `int[]').) We'll get very confused by such a type since
18128 the bound of the array is not constant, and therefore
18129 not mangleable. Besides, such types are not allowed in
18130 ISO C++, so we can do as we please here. We do allow
18131 them for 'auto' deduction, since that isn't ABI-exposed. */
18135 /* Strip typedefs as in convert_template_argument. */
18137 }
18139 /* If ARG is a parameter pack or an expansion, we cannot unify
18140 against it unless PARM is also a parameter pack. */
18145 /* If the argument deduction results is a METHOD_TYPE,
18146 then there is a problem.
18147 METHOD_TYPE doesn't map to any real C++ type the result of
18148 the deduction can not be of that type. */
18162 {
18163 /* The PARM is not one we're trying to unify. Just check
18164 to see if it matches ARG. */
18170 }
18176 {
18181 }
18183 /* [temp.deduct.type] If, in the declaration of a function template
18184 with a non-type template-parameter, the non-type
18185 template-parameter is used in an expression in the function
18186 parameter-list and, if the corresponding template-argument is
18187 deduced, the template-argument type shall match the type of the
18188 template-parameter exactly, except that a template-argument
18189 deduced from an array bound may be of any integral type.
18190 The non-type parameter might use already deduced type parameters. */
18193 /* Template-parameter dependent expression. Just accept it for now.
18194 It will later be processed in convert_template_argument. */
18195 ;
18200 /* Convert the ARG to the type of PARM; the deduced non-type
18201 template argument must exactly match the types of the
18202 corresponding parameter. */
18205 /* We haven't deduced the type of this parameter yet. Try again
18206 later. */
18208 else
18211 /* If ARG is a parameter pack or an expansion, we cannot unify
18212 against it unless PARM is also a parameter pack. */
18217 {
18220 }
18225 {
18226 /* A pointer-to-member constant can be unified only with
18227 another constant. */
18231 /* Just unify the class member. It would be useless (and possibly
18232 wrong, depending on the strict flags) to unify also
18233 PTRMEM_CST_CLASS, because we want to be sure that both parm and
18234 arg refer to the same variable, even if through different
18235 classes. For instance:
18237 struct A { int x; };
18238 struct B : A { };
18240 Unification of &A::x and &B::x must succeed. */
18243 }
18246 {
18250 /* [temp.deduct.call]
18252 A can be another pointer or pointer to member type that can
18253 be converted to the deduced A via a qualification
18254 conversion (_conv.qual_).
18256 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
18257 This will allow for additional cv-qualification of the
18258 pointed-to types if appropriate. */
18261 /* The derived-to-base conversion only persists through one
18262 level of pointers. */
18267 }
18299 /* We have already checked cv-qualification at the top of the
18300 function. */
18304 /* As far as unification is concerned, this wins. Later checks
18305 will invalidate it if necessary. */
18308 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
18309 /* Type INTEGER_CST can come from ordinary constant template args. */
18321 {
18331 /* Check for pack expansions in the parameters. */
18333 {
18335 {
18337 /* We can unify against something with a trailing
18338 parameter pack. */
18340 else
18341 /* [temp.deduct.type]/9: If the template argument list of
18342 P contains a pack expansion that is not the last
18343 template argument, the entire template argument list
18344 is a non-deduced context. */
18346 }
18347 }
18349 /* If we don't have enough arguments to satisfy the parameters
18350 (not counting the pack expression at the end), or we have
18351 too many arguments for a parameter list that doesn't end in
18352 a pack expression, we can't unify. */
18358 /* Unify all of the parameters that precede the (optional)
18359 pack expression. */
18361 {
18366 }
18369 DEDUCE_EXACT,
18372 }
18380 {
18388 }
18393 {
18397 {
18398 /* First, we try to unify the PARM and ARG directly. */
18403 {
18404 /* Fallback to the special case allowed in
18405 [temp.deduct.call]:
18407 If P is a class, and P has the form
18408 template-id, then A can be a derived class of
18409 the deduced A. Likewise, if P is a pointer to
18410 a class of the form template-id, A can be a
18411 pointer to a derived class pointed to by the
18412 deduced A. */
18419 }
18420 }
18424 /* Perhaps PARM is something like S<U> and ARG is S<int>.
18425 Then, we should unify `int' and `U'. */
18427 else
18428 /* There's no chance of unification succeeding. */
18433 }
18440 {
18443 tree a;
18449 /* CV qualifications for methods can never be deduced, they must
18450 match exactly. We need to check them explicitly here,
18451 because type_unification_real treats them as any other
18452 cv-qualified parameter. */
18454 && (!check_cv_quals_for_unify
18474 }
18477 /* Unify a pointer to member with a pointer to member function, which
18478 deduces the type of the member as a function type. */
18480 {
18481 /* Check top-level cv qualifiers */
18489 /* Determine the type of the function we are unifying against. */
18493 }
18512 /* Matched cases are handled by the ARG == PARM test above. */
18516 /* A non-type template parameter that is a variable should be a
18517 an integral constant, in which case, it whould have been
18518 folded into its (constant) value. So we should not be getting
18519 a variable here. */
18530 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
18531 or UNDERLYING_TYPE nodes. */
18535 /* Unification fails if we hit an error node. */
18540 {
18545 }
18546 /* FALLTHRU */
18549 /* An unresolved overload is a nondeduced context. */
18554 /* We must be looking at an expression. This can happen with
18555 something like:
18557 template <int I>
18558 void foo(S<I>, S<I + 2>);
18560 This is a "nondeduced context":
18562 [deduct.type]
18564 The nondeduced contexts are:
18566 --A type that is a template-id in which one or more of
18567 the template-arguments is an expression that references
18568 a template-parameter.
18570 In these cases, we assume deduction succeeded, but don't
18571 actually infer any unifications. */
18576 else
18578 }
18579 }
18580 #undef RECUR_AND_CHECK_FAILURE
18581 \f
18582 /* Note that DECL can be defined in this translation unit, if
18583 required. */
18585 static void
18587 {
18588 tree clone;
18592 }
18594 /* Called if RESULT is explicitly instantiated, or is a member of an
18595 explicitly instantiated class. */
18597 void
18599 {
18602 /* If this entity has already been written out, it's too late to
18603 make any modifications. */
18607 /* For anonymous namespace we don't need to do anything. */
18609 {
18612 }
18615 /* The TREE_PUBLIC flag for function declarations will have been
18616 set correctly by tsubst. */
18619 /* This might have been set by an earlier implicit instantiation. */
18624 else
18625 {
18628 /* Always make artificials weak. */
18631 /* For WIN32 we also want to put explicit instantiations in
18632 linkonce sections. */
18635 }
18637 /* If EXTERN_P, then this function will not be emitted -- unless
18638 followed by an explicit instantiation, at which point its linkage
18639 will be adjusted. If !EXTERN_P, then this function will be
18640 emitted here. In neither circumstance do we want
18641 import_export_decl to adjust the linkage. */
18643 }
18645 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
18646 important template arguments. If any are missing, we check whether
18647 they're important by using error_mark_node for substituting into any
18648 args that were used for partial ordering (the ones between ARGS and END)
18649 and seeing if it bubbles up. */
18651 static bool
18653 {
18658 {
18661 }
18663 {
18667 }
18669 }
18671 /* Given two function templates PAT1 and PAT2, return:
18673 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
18674 -1 if PAT2 is more specialized than PAT1.
18675 0 if neither is more specialized.
18677 LEN indicates the number of parameters we should consider
18678 (defaulted parameters should not be considered).
18680 The 1998 std underspecified function template partial ordering, and
18681 DR214 addresses the issue. We take pairs of arguments, one from
18682 each of the templates, and deduce them against each other. One of
18683 the templates will be more specialized if all the *other*
18684 template's arguments deduce against its arguments and at least one
18685 of its arguments *does* *not* deduce against the other template's
18686 corresponding argument. Deduction is done as for class templates.
18687 The arguments used in deduction have reference and top level cv
18688 qualifiers removed. Iff both arguments were originally reference
18689 types *and* deduction succeeds in both directions, an lvalue reference
18690 wins against an rvalue reference and otherwise the template
18691 with the more cv-qualified argument wins for that pairing (if
18692 neither is more cv-qualified, they both are equal). Unlike regular
18693 deduction, after all the arguments have been deduced in this way,
18694 we do *not* verify the deduced template argument values can be
18695 substituted into non-deduced contexts.
18697 The logic can be a bit confusing here, because we look at deduce1 and
18698 targs1 to see if pat2 is at least as specialized, and vice versa; if we
18699 can find template arguments for pat1 to make arg1 look like arg2, that
18700 means that arg2 is at least as specialized as arg1. */
18702 int
18704 {
18717 /* Remove the this parameter from non-static member functions. If
18718 one is a non-static member function and the other is not a static
18719 member function, remove the first parameter from that function
18720 also. This situation occurs for operator functions where we
18721 locate both a member function (with this pointer) and non-member
18722 operator (with explicit first operand). */
18724 {
18729 }
18731 {
18734 {
18735 len--;
18737 }
18738 }
18740 /* If only one is a conversion operator, they are unordered. */
18744 /* Consider the return type for a conversion function */
18746 {
18749 len++;
18750 }
18752 processing_template_decl++;
18758 /* Stop when an ellipsis is seen. */
18760 {
18771 {
18772 /* When both arguments are pack expansions, we need only
18773 unify the patterns themselves. */
18777 /* This is the last comparison we need to do. */
18779 }
18782 {
18786 }
18789 {
18793 }
18799 {
18805 /* Setup the parameter vector, which contains only ARG1. */
18808 /* Setup the argument vector, which contains the remaining
18809 arguments. */
18818 /* We cannot deduce in the other direction, because ARG1 is
18819 a pack expansion but ARG2 is not. */
18821 }
18823 {
18829 /* Setup the parameter vector, which contains only ARG1. */
18832 /* Setup the argument vector, which contains the remaining
18833 arguments. */
18842 /* We cannot deduce in the other direction, because ARG2 is
18843 a pack expansion but ARG1 is not.*/
18845 }
18847 else
18848 {
18849 /* The normal case, where neither argument is a pack
18850 expansion. */
18857 }
18859 /* If we couldn't deduce arguments for tparms1 to make arg1 match
18860 arg2, then arg2 is not as specialized as arg1. */
18866 /* "If, for a given type, deduction succeeds in both directions
18867 (i.e., the types are identical after the transformations above)
18868 and both P and A were reference types (before being replaced with
18869 the type referred to above):
18870 - if the type from the argument template was an lvalue reference and
18871 the type from the parameter template was not, the argument type is
18872 considered to be more specialized than the other; otherwise,
18873 - if the type from the argument template is more cv-qualified
18874 than the type from the parameter template (as described above),
18875 the argument type is considered to be more specialized than the other;
18876 otherwise,
18877 - neither type is more specialized than the other." */
18880 {
18882 {
18885 else
18887 }
18889 {
18894 }
18895 }
18898 /* We've failed to deduce something in either direction.
18899 These must be unordered. */
18904 /* We have already processed all of the arguments in our
18905 handing of the pack expansion type. */
18910 }
18912 /* "In most cases, all template parameters must have values in order for
18913 deduction to succeed, but for partial ordering purposes a template
18914 parameter may remain without a value provided it is not used in the
18915 types being used for partial ordering."
18917 Thus, if we are missing any of the targs1 we need to substitute into
18918 origs1, then pat2 is not as specialized as pat1. This can happen when
18919 there is a nondeduced context. */
18925 processing_template_decl--;
18927 /* All things being equal, if the next argument is a pack expansion
18928 for one function but not for the other, prefer the
18929 non-variadic function. FIXME this is bogus; see c++/41958. */
18933 {
18936 }
18942 else
18944 }
18946 /* Determine which of two partial specializations of TMPL is more
18947 specialized.
18949 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
18950 to the first partial specialization. The TREE_PURPOSE is the
18951 innermost set of template parameters for the partial
18952 specialization. PAT2 is similar, but for the second template.
18954 Return 1 if the first partial specialization is more specialized;
18955 -1 if the second is more specialized; 0 if neither is more
18956 specialized.
18958 See [temp.class.order] for information about determining which of
18959 two templates is more specialized. */
18961 static int
18963 {
18964 tree targs;
18975 /* Just like what happens for functions, if we are ordering between
18976 different template specializations, we may encounter dependent
18977 types in the arguments, and we need our dependency check functions
18978 to behave correctly. */
18982 {
18985 }
18989 {
18992 }
18995 /* In the case of a tie where at least one of the templates
18996 has a parameter pack at the end, the template with the most
18997 non-packed parameters wins. */
18999 && any_deductions
19002 {
19008 /* We don't count the pack expansion at the end. */
19018 }
19021 }
19023 /* Return the template arguments that will produce the function signature
19024 DECL from the function template FN, with the explicit template
19025 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
19026 also match. Return NULL_TREE if no satisfactory arguments could be
19027 found. */
19029 static tree
19031 {
19035 tree decl_arg_types;
19038 tree arg;
19042 /* Never do unification on the 'this' parameter. */
19063 }
19065 /* Return the innermost template arguments that, when applied to a partial
19066 specialization of TMPL whose innermost template parameters are
19067 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
19068 ARGS.
19070 For example, suppose we have:
19072 template <class T, class U> struct S {};
19073 template <class T> struct S<T*, int> {};
19075 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
19076 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
19077 int}. The resulting vector will be {double}, indicating that `T'
19078 is bound to `double'. */
19080 static tree
19082 {
19084 tree deduced_args;
19085 tree innermost_deduced_args;
19089 {
19093 innermost_deduced_args);
19094 }
19095 else
19108 /* Verify that nondeduced template arguments agree with the type
19109 obtained from argument deduction.
19111 For example:
19113 struct A { typedef int X; };
19114 template <class T, class U> struct C {};
19115 template <class T> struct C<T, typename T::X> {};
19117 Then with the instantiation `C<A, int>', we can deduce that
19118 `T' is `A' but unify () does not check whether `typename T::X'
19119 is `int'. */
19125 /* We only need to check the innermost arguments; the other
19126 arguments will always agree. */
19131 /* Now that we have bindings for all of the template arguments,
19132 ensure that the arguments deduced for the template template
19133 parameters have compatible template parameter lists. See the use
19134 of template_template_parm_bindings_ok_p in fn_type_unification
19135 for more information. */
19140 }
19142 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
19143 Return the TREE_LIST node with the most specialized template, if
19144 any. If there is no most specialized template, the error_mark_node
19145 is returned.
19147 Note that this function does not look at, or modify, the
19148 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
19149 returned is one of the elements of INSTANTIATIONS, callers may
19150 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
19151 and retrieve it from the value returned. */
19153 tree
19155 {
19162 {
19168 fate--;
19173 fate++;
19178 {
19179 /* Equally specialized, move to next function. If there
19180 is no next function, nothing's most specialized. */
19185 }
19186 }
19189 /* Now verify that champ is better than everything earlier in the
19190 instantiation list. */
19198 {
19201 }
19203 processing_template_decl--;
19209 }
19211 /* If DECL is a specialization of some template, return the most
19212 general such template. Otherwise, returns NULL_TREE.
19214 For example, given:
19216 template <class T> struct S { template <class U> void f(U); };
19218 if TMPL is `template <class U> void S<int>::f(U)' this will return
19219 the full template. This function will not trace past partial
19220 specializations, however. For example, given in addition:
19222 template <class T> struct S<T*> { template <class U> void f(U); };
19224 if TMPL is `template <class U> void S<int*>::f(U)' this will return
19225 `template <class T> template <class U> S<T*>::f(U)'. */
19227 tree
19229 {
19231 {
19234 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
19235 template friend, or a FIELD_DECL for a capture pack. */
19238 }
19240 /* Look for more and more general templates. */
19242 {
19243 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
19244 (See cp-tree.h for details.) */
19253 /* Stop if we run into an explicitly specialized class template. */
19260 }
19263 }
19265 /* Return the most specialized of the template partial specializations
19266 which can produce TARGET, a specialization of some class or variable
19267 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
19268 a TEMPLATE_DECL node corresponding to the partial specialization, while
19269 the TREE_PURPOSE is the set of template arguments that must be
19270 substituted into the template pattern in order to generate TARGET.
19272 If the choice of partial specialization is ambiguous, a diagnostic
19273 is issued, and the error_mark_node is returned. If there are no
19274 partial specializations matching TARGET, then NULL_TREE is
19275 returned, indicating that the primary template should be used. */
19277 static tree
19279 {
19281 tree t;
19282 tree champ;
19289 {
19293 }
19295 {
19298 }
19300 {
19304 }
19305 else
19310 /* For determining which partial specialization to use, only the
19311 innermost args are interesting. */
19313 {
19316 }
19319 {
19320 tree partial_spec_args;
19321 tree spec_args;
19329 {
19330 /* Discard the outer levels of args, and then substitute in the
19331 template args from the enclosing class. */
19333 partial_spec_args = tsubst_template_args
19336 /* And the same for the partial specialization TEMPLATE_DECL. */
19338 }
19340 partial_spec_args =
19342 partial_spec_args,
19356 partial_spec_args,
19357 args);
19359 {
19364 }
19365 }
19375 {
19378 ;
19379 else
19380 {
19382 {
19385 {
19388 }
19389 }
19391 }
19392 }
19396 {
19399 {
19402 }
19403 }
19406 {
19413 else
19417 {
19422 }
19425 }
19428 }
19430 /* Explicitly instantiate DECL. */
19432 void
19434 {
19439 /* An error occurred, for which grokdeclarator has already issued
19440 an appropriate message. */
19443 {
19446 }
19452 {
19453 /* There is an asymmetry here in the way VAR_DECLs and
19454 FUNCTION_DECLs are handled by grokdeclarator. In the case of
19455 the latter, the DECL we get back will be marked as a
19456 template instantiation, and the appropriate
19457 DECL_TEMPLATE_INFO will be set up. This does not happen for
19458 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
19459 should handle VAR_DECLs as it currently handles
19460 FUNCTION_DECLs. */
19462 {
19465 }
19468 {
19471 }
19473 {
19478 }
19479 }
19481 {
19484 }
19485 else
19488 /* Check for various error cases. Note that if the explicit
19489 instantiation is valid the RESULT will currently be marked as an
19490 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
19491 until we get here. */
19494 {
19495 /* DR 259 [temp.spec].
19497 Both an explicit instantiation and a declaration of an explicit
19498 specialization shall not appear in a program unless the explicit
19499 instantiation follows a declaration of the explicit specialization.
19501 For a given set of template parameters, if an explicit
19502 instantiation of a template appears after a declaration of an
19503 explicit specialization for that template, the explicit
19504 instantiation has no effect. */
19506 }
19508 {
19509 /* [temp.spec]
19511 No program shall explicitly instantiate any template more
19512 than once.
19514 We check DECL_NOT_REALLY_EXTERN so as not to complain when
19515 the first instantiation was `extern' and the second is not,
19516 and EXTERN_P for the opposite case. */
19519 /* If an "extern" explicit instantiation follows an ordinary
19520 explicit instantiation, the template is instantiated. */
19523 }
19525 {
19528 }
19530 {
19533 }
19536 ;
19538 {
19541 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
19544 }
19545 else
19553 }
19555 static void
19557 {
19563 {
19566 }
19567 }
19569 /* Called from do_type_instantiation through binding_table_foreach to
19570 do recursive instantiation for the type bound in ENTRY. */
19571 static void
19573 {
19579 }
19581 /* Called from do_type_instantiation to instantiate a member
19582 (a member function or a static member variable) of an
19583 explicitly instantiated class template. */
19584 static void
19586 {
19591 }
19593 /* Perform an explicit instantiation of template class T. STORAGE, if
19594 non-null, is the RID for extern, inline or static. COMPLAIN is
19595 nonzero if this is called from the parser, zero if called recursively,
19596 since the standard is unclear (as detailed below). */
19598 void
19600 {
19610 {
19611 tree tmpl =
19615 else
19618 }
19623 {
19626 t);
19628 }
19631 {
19633 {
19635 {
19638 "ISO C++ 1998 forbids the use of %<extern%> on "
19640 }
19641 else
19643 "ISO C++ forbids the use of %qE"
19645 }
19653 else
19654 {
19656 storage);
19658 }
19659 }
19662 {
19663 /* DR 259 [temp.spec].
19665 Both an explicit instantiation and a declaration of an explicit
19666 specialization shall not appear in a program unless the explicit
19667 instantiation follows a declaration of the explicit specialization.
19669 For a given set of template parameters, if an explicit
19670 instantiation of a template appears after a declaration of an
19671 explicit specialization for that template, the explicit
19672 instantiation has no effect. */
19674 }
19676 {
19677 /* [temp.spec]
19679 No program shall explicitly instantiate any template more
19680 than once.
19682 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
19683 instantiation was `extern'. If EXTERN_P then the second is.
19684 These cases are OK. */
19691 /* If we've already instantiated the template, just return now. */
19694 }
19702 {
19703 tree tmp;
19705 /* In contrast to implicit instantiation, where only the
19706 declarations, and not the definitions, of members are
19707 instantiated, we have here:
19709 [temp.explicit]
19711 The explicit instantiation of a class template specialization
19712 implies the instantiation of all of its members not
19713 previously explicitly specialized in the translation unit
19714 containing the explicit instantiation.
19716 Of course, we can't instantiate member template classes, since
19717 we don't have any arguments for them. Note that the standard
19718 is unclear on whether the instantiation of the members are
19719 *explicit* instantiations or not. However, the most natural
19720 interpretation is that it should be an explicit instantiation. */
19735 }
19736 }
19738 /* Given a function DECL, which is a specialization of TMPL, modify
19739 DECL to be a re-instantiation of TMPL with the same template
19740 arguments. TMPL should be the template into which tsubst'ing
19741 should occur for DECL, not the most general template.
19743 One reason for doing this is a scenario like this:
19745 template <class T>
19746 void f(const T&, int i);
19748 void g() { f(3, 7); }
19750 template <class T>
19751 void f(const T& t, const int i) { }
19753 Note that when the template is first instantiated, with
19754 instantiate_template, the resulting DECL will have no name for the
19755 first parameter, and the wrong type for the second. So, when we go
19756 to instantiate the DECL, we regenerate it. */
19758 static void
19760 {
19761 /* The arguments used to instantiate DECL, from the most general
19762 template. */
19763 tree args;
19764 tree code_pattern;
19769 /* Make sure that we can see identifiers, and compute access
19770 correctly. */
19774 {
19775 tree decl_parm;
19776 tree pattern_parm;
19777 tree specs;
19791 specs);
19793 /* Merge parameter declarations. */
19796 pattern_parm
19800 {
19801 tree parm_type;
19802 tree attributes;
19807 NULL_TREE);
19813 {
19816 }
19819 }
19820 /* Merge any parameters that match with the function parameter
19821 pack. */
19823 {
19825 tree expanded_types;
19826 /* Expand the TYPE_PACK_EXPANSION that provides the types for
19827 the parameters in this function parameter pack. */
19832 {
19833 tree parm_type;
19834 tree attributes;
19837 /* Rename the parameter to include the index. */
19846 {
19849 }
19851 }
19852 }
19853 /* Merge additional specifiers from the CODE_PATTERN. */
19857 }
19859 {
19867 }
19868 else
19872 }
19874 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
19875 substituted to get DECL. */
19877 tree
19879 {
19882 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
19883 for the instantiation. This is not always the most general
19884 template. Consider, for example:
19886 template <class T>
19887 struct S { template <class U> void f();
19888 template <> void f<int>(); };
19890 and an instantiation of S<double>::f<int>. We want TD to be the
19891 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
19893 more general template. */
19895 /* We must also deal with friend templates. Given:
19897 template <class T> struct S {
19898 template <class U> friend void f() {};
19899 };
19901 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
19902 so far as the language is concerned, but that's still
19903 where we get the pattern for the instantiation from. On
19904 other hand, if the definition comes outside the class, say:
19906 template <class T> struct S {
19907 template <class U> friend void f();
19908 };
19909 template <class U> friend void f() {}
19911 we don't need to look any further. That's what the check for
19912 DECL_INITIAL is for. */
19916 {
19917 /* The present template, TD, should not be a definition. If it
19918 were a definition, we should be using it! Note that we
19919 cannot restructure the loop to just keep going until we find
19920 a template with a definition, since that might go too far if
19921 a specialization was declared, but not defined. */
19923 /* Fetch the more general template. */
19925 }
19928 }
19930 /* Returns true if we need to instantiate this template instance even if we
19931 know we aren't going to emit it.. */
19933 bool
19935 {
19936 /* We always instantiate inline functions so that we can inline them. An
19937 explicit instantiation declaration prohibits implicit instantiation of
19938 non-inline functions. With high levels of optimization, we would
19939 normally inline non-inline functions -- but we're not allowed to do
19940 that for "extern template" functions. Therefore, we check
19941 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
19945 /* And we need to instantiate static data members so that
19946 their initializers are available in integral constant
19947 expressions. */
19950 }
19952 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
19953 instantiate it now, modifying TREE_TYPE (fn). */
19955 void
19957 {
19960 /* Don't instantiate a noexcept-specification from template context. */
19975 {
19979 {
19994 }
19995 else
19999 }
20002 {
20005 else
20007 }
20008 }
20010 /* Produce the definition of D, a _DECL generated from a template. If
20011 DEFER_OK is nonzero, then we don't have to actually do the
20012 instantiation now; we just have to do it sometime. Normally it is
20013 an error if this is an explicit instantiation but D is undefined.
20014 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
20015 explicitly instantiated class template. */
20017 tree
20020 {
20022 tree gen_args;
20023 tree args;
20024 tree td;
20025 tree code_pattern;
20026 tree spec;
20027 tree gen_tmpl;
20034 tree fn_context;
20037 /* This function should only be used to instantiate templates for
20038 functions and static member variables. */
20041 /* Variables are never deferred; if instantiation is required, they
20042 are instantiated right away. That allows for better code in the
20043 case that an expression refers to the value of the variable --
20044 if the variable has a constant value the referring expression can
20045 take advantage of that fact. */
20050 /* Don't instantiate cloned functions. Instead, instantiate the
20051 functions they cloned. */
20059 /* D has already been instantiated or explicitly specialized, so
20060 there's nothing for us to do here.
20062 It might seem reasonable to check whether or not D is an explicit
20063 instantiation, and, if so, stop here. But when an explicit
20064 instantiation is deferred until the end of the compilation,
20065 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
20066 the instantiation. */
20069 /* Check to see whether we know that this template will be
20070 instantiated in some other file, as with "extern template"
20071 extension. */
20074 /* In general, we do not instantiate such templates. */
20082 /* We should already have the extra args. */
20085 /* And what's in the hash table should match D. */
20089 /* This needs to happen before any tsubsting. */
20095 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
20096 for the instantiation. */
20100 /* We should never be trying to instantiate a member of a class
20101 template or partial specialization. */
20106 /* In the case of a friend template whose definition is provided
20107 outside the class, we may have too many arguments. Drop the
20108 ones we don't need. The same is true for specializations. */
20109 args = get_innermost_template_args
20111 else
20115 {
20120 }
20121 else
20122 {
20125 }
20127 /* We may be in the middle of deferred access check. Disable it now. */
20130 /* Unless an explicit instantiation directive has already determined
20131 the linkage of D, remember that a definition is available for
20132 this entity. */
20142 /* If D is a member of an explicitly instantiated class template,
20143 and no definition is available, treat it like an implicit
20144 instantiation. */
20147 {
20148 /* Leave linkage flags alone on instantiations with anonymous
20149 visibility. */
20151 {
20154 }
20156 }
20158 /* Defer all other templates, unless we have been explicitly
20159 forbidden from doing so. */
20161 template. */
20162 ! pattern_defined
20163 /* If it's OK to postpone instantiation, do so. */
20164 || defer_ok
20165 /* If this is a static data member that will be defined
20166 elsewhere, we don't want to instantiate the entire data
20167 member, but we do want to instantiate the initializer so that
20168 we can substitute that elsewhere. */
20170 /* Handle here a deleted function too, avoid generating
20171 its body (c++/61080). */
20173 {
20174 /* The definition of the static data member is now required so
20175 we must substitute the initializer. */
20179 {
20180 tree ns;
20181 tree init;
20190 args,
20193 /* If instantiating the initializer involved instantiating this
20194 again, don't call cp_finish_decl twice. */
20196 {
20197 /* Make sure the initializer is still constant, in case of
20198 circular dependency (template/instantiate6.C). */
20199 const_init
20203 LOOKUP_ONLYCONVERTING);
20204 }
20208 }
20210 /* We restore the source position here because it's used by
20211 add_pending_template. */
20217 /* [temp.explicit]
20219 The definition of a non-exported function template, a
20220 non-exported member function template, or a non-exported
20221 member function or static data member of a class template
20222 shall be present in every translation unit in which it is
20223 explicitly instantiated. */
20227 /* If we're in unevaluated context, we just wanted to get the
20228 constant value; this isn't an odr use, so don't queue
20229 a full instantiation. */
20232 /* ??? Historically, we have instantiated inline functions, even
20233 when marked as "extern template". */
20237 }
20238 /* Tell the repository that D is available in this translation unit
20239 -- and see if it is supposed to be instantiated here. */
20241 {
20242 /* In a PCH file, despite the fact that the repository hasn't
20243 requested instantiation in the PCH it is still possible that
20244 an instantiation will be required in a file that includes the
20245 PCH. */
20248 /* Instantiate inline functions so that the inliner can do its
20249 job, even though we'll not be emitting a copy of this
20250 function. */
20253 }
20259 else
20260 {
20265 }
20267 /* Mark D as instantiated so that recursive calls to
20268 instantiate_decl do not try to instantiate it again. */
20271 /* Regenerate the declaration in case the template has been modified
20272 by a subsequent redeclaration. */
20275 /* We already set the file and line above. Reset them now in case
20276 they changed as a result of calling regenerate_decl_from_template. */
20280 {
20281 tree init;
20284 /* Clear out DECL_RTL; whatever was there before may not be right
20285 since we've reset the type of the declaration. */
20289 /* The initializer is placed in DECL_INITIAL by
20290 regenerate_decl_from_template so we don't need to
20291 push/pop_access_scope again here. Pull it out so that
20292 cp_finish_decl can process it. */
20297 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
20298 initializer. That function will defer actual emission until
20299 we have a chance to determine linkage. */
20302 /* Enter the scope of D so that access-checking works correctly. */
20315 }
20319 {
20321 tree subst_decl;
20322 tree tmpl_parm;
20323 tree spec_parm;
20326 /* Save away the current list, in case we are instantiating one
20327 template from within the body of another. */
20330 /* Set up the list of local specializations. */
20333 /* Set up context. */
20337 else
20340 /* Some typedefs referenced from within the template code need to be
20341 access checked at template instantiation time, i.e now. These
20342 types were added to the template at parsing time. Let's get those
20343 and perform the access checks then. */
20345 gen_args);
20347 /* Create substitution entries for the parameters. */
20352 {
20356 }
20358 {
20360 {
20363 }
20364 else
20365 {
20366 /* Register the (value) argument pack as a specialization of
20367 TMPL_PARM, then move on. */
20370 }
20371 }
20374 /* Substitute into the body of the function. */
20378 else
20379 {
20384 /* Set the current input_location to the end of the function
20385 so that finish_function knows where we are. */
20386 input_location
20389 /* Remember if we saw an infinite loop in the template. */
20390 current_function_infinite_loop
20392 }
20394 /* We don't need the local specializations any more. */
20398 /* Finish the function. */
20402 else
20403 {
20406 }
20410 }
20412 /* We're not deferring instantiation any more. */
20420 out:
20430 }
20432 /* Run through the list of templates that we wish we could
20433 instantiate, and instantiate any we can. RETRIES is the
20434 number of times we retry pending template instantiation. */
20436 void
20438 {
20442 /* Instantiating templates may trigger vtable generation. This in turn
20443 may require further template instantiations. We place a limit here
20444 to avoid infinite loop. */
20446 {
20450 "template instantiation depth exceeds maximum of %d"
20451 " instantiating %q+D, possibly from virtual table generation"
20455 /* Pretend that we defined it. */
20458 }
20460 do
20461 {
20466 {
20471 {
20472 tree fn;
20475 {
20479 fn;
20487 }
20490 }
20491 else
20492 {
20495 {
20496 instantiation
20502 }
20506 }
20509 /* If INSTANTIATION has been instantiated, then we don't
20510 need to consider it again in the future. */
20512 else
20513 {
20516 }
20519 }
20521 }
20525 }
20527 /* Substitute ARGVEC into T, which is a list of initializers for
20528 either base class or a non-static data member. The TREE_PURPOSEs
20529 are DECLs, and the TREE_VALUEs are the initializer values. Used by
20530 instantiate_decl. */
20532 static tree
20534 {
20538 {
20539 tree decl;
20540 tree init;
20546 {
20547 tree expr;
20548 tree arg;
20550 /* Expand the base class expansion type into separate base
20551 classes. */
20553 tf_warning_or_error,
20554 NULL_TREE);
20558 /* We'll be building separate TREE_LISTs of arguments for
20559 each base. */
20565 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
20566 expand each argument in the TREE_VALUE of t. */
20573 /* VOID_TYPE_NODE is used to indicate
20574 value-initialization. */
20575 {
20578 }
20579 else
20580 {
20581 /* Substitute parameter packs into each argument in the
20582 TREE_LIST. */
20585 {
20586 tree expanded_exprs;
20588 /* Expand the argument. */
20590 expanded_exprs
20592 tf_warning_or_error,
20593 NULL_TREE);
20597 /* Prepend each of the expanded expressions to the
20598 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
20600 {
20605 }
20606 }
20609 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
20610 since we built them backwards. */
20612 {
20615 }
20616 }
20617 }
20620 {
20622 {
20626 }
20627 else
20628 {
20629 tree tmp;
20644 /* If we had an initializer but it instantiated to nothing,
20645 value-initialize the object. This will only occur when
20646 the initializer was a pack expansion where the parameter
20647 packs used in that expansion were of length zero. */
20650 }
20653 {
20657 }
20658 }
20659 }
20661 }
20663 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
20665 static void
20667 {
20672 else
20674 }
20676 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
20677 is the instantiation (which should have been created with
20678 start_enum) and ARGS are the template arguments to use. */
20680 static void
20682 {
20683 tree e;
20689 {
20690 tree value;
20691 tree decl;
20694 /* Note that in a template enum, the TREE_VALUE is the
20695 CONST_DECL, not the corresponding INTEGER_CST. */
20700 /* Give this enumeration constant the correct access. */
20703 /* Actually build the enumerator itself. */
20704 build_enumerator
20706 }
20716 }
20718 /* DECL is a FUNCTION_DECL that is a template specialization. Return
20719 its type -- but without substituting the innermost set of template
20720 arguments. So, innermost set of template parameters will appear in
20721 the type. */
20723 tree
20725 {
20726 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
20728 }
20730 /* Return truthvalue if we're processing a template different from
20731 the last one involved in diagnostics. */
20732 bool
20734 {
20736 }
20738 /* Remember current template involved in diagnostics. */
20739 void
20741 {
20743 }
20747 {
20749 }
20751 /* Return TRUE if current_function_decl is being instantiated, false
20752 otherwise. */
20754 bool
20756 {
20759 }
20761 /* [temp.param] Check that template non-type parm TYPE is of an allowable
20762 type. Return zero for ok, nonzero for disallowed. Issue error and
20763 warning messages under control of COMPLAIN. */
20765 static int
20767 {
20784 {
20787 else
20789 type);
20790 }
20792 }
20794 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
20795 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
20797 static bool
20799 {
20800 tree scope;
20802 /* [temp.dep.type]
20804 A type is dependent if it is:
20806 -- a template parameter. Template template parameters are types
20807 for us (since TYPE_P holds true for them) so we handle
20808 them here. */
20812 /* -- a qualified-id with a nested-name-specifier which contains a
20813 class-name that names a dependent type or whose unqualified-id
20814 names a dependent type. */
20817 /* -- a cv-qualified type where the cv-unqualified type is
20818 dependent.
20819 No code is necessary for this bullet; the code below handles
20820 cv-qualified types, and we don't want to strip aliases with
20821 TYPE_MAIN_VARIANT because of DR 1558. */
20822 /* -- a compound type constructed from any dependent type. */
20832 {
20833 tree arg_type;
20838 arg_type;
20843 }
20844 /* -- an array type constructed from any dependent type or whose
20845 size is specified by a constant expression that is
20846 value-dependent.
20848 We checked for type- and value-dependence of the bounds in
20849 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
20851 {
20856 }
20858 /* -- a template-id in which either the template name is a template
20859 parameter ... */
20862 /* ... or any of the template arguments is a dependent type or
20863 an expression that is type-dependent or value-dependent. */
20865 && (any_dependent_template_arguments_p
20868 /* For an alias template specialization, check the arguments both to the
20869 class template and the alias template. */
20871 && (any_dependent_template_arguments_p
20875 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
20876 dependent; if the argument of the `typeof' expression is not
20877 type-dependent, then it should already been have resolved. */
20883 /* A template argument pack is dependent if any of its packed
20884 arguments are. */
20886 {
20892 }
20894 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
20895 be template parameters. */
20899 /* The standard does not specifically mention types that are local
20900 to template functions or local classes, but they should be
20901 considered dependent too. For example:
20903 template <int I> void f() {
20904 enum E { a = I };
20905 S<sizeof (E)> s;
20906 }
20908 The size of `E' cannot be known until the value of `I' has been
20909 determined. Therefore, `E' must be considered dependent. */
20913 /* Don't use type_dependent_expression_p here, as it can lead
20914 to infinite recursion trying to determine whether a lambda
20915 nested in a lambda is dependent (c++/47687). */
20919 && (any_dependent_template_arguments_p
20923 /* Other types are non-dependent. */
20925 }
20927 /* Returns TRUE if TYPE is dependent, in the sense of
20928 [temp.dep.type]. Note that a NULL type is considered dependent. */
20930 bool
20932 {
20933 /* If there are no template parameters in scope, then there can't be
20934 any dependent types. */
20936 {
20937 /* If we are not processing a template, then nobody should be
20938 providing us with a dependent type. */
20942 }
20944 /* If the type is NULL, we have not computed a type for the entity
20945 in question; in that case, the type is dependent. */
20949 /* Erroneous types can be considered non-dependent. */
20953 /* If we have not already computed the appropriate value for TYPE,
20954 do so now. */
20956 {
20959 }
20962 }
20964 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
20965 lookup. In other words, a dependent type that is not the current
20966 instantiation. */
20968 bool
20970 {
20973 }
20975 /* T is a SCOPE_REF; return whether we need to consider it
20976 instantiation-dependent so that we can check access at instantiation
20977 time even though we know which member it resolves to. */
20979 static bool
20981 {
20987 else
20989 }
20991 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
20992 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
20993 expression. */
20995 /* Note that this predicate is not appropriate for general expressions;
20996 only constant expressions (that satisfy potential_constant_expression)
20997 can be tested for value dependence. */
20999 bool
21001 {
21005 /* A name declared with a dependent type. */
21010 {
21012 /* A name that has not been looked up -- must be dependent. */
21016 /* A non-type template parm. */
21020 /* A non-type template parm. */
21026 /* A constant with literal type and is initialized
21027 with an expression that is value-dependent.
21029 Note that a non-dependent parenthesized initializer will have
21030 already been replaced with its constant value, so if we see
21031 a TREE_LIST it must be dependent. */
21035 /* cp_finish_decl doesn't fold reference initializers. */
21046 /* These expressions are value-dependent if the type to which
21047 the cast occurs is dependent or the expression being casted
21048 is value-dependent. */
21049 {
21055 /* A functional cast has a list of operands. */
21058 {
21059 /* If there are no operands, it must be an expression such
21060 as "int()". This should not happen for aggregate types
21061 because it would form non-constant expressions. */
21066 }
21072 }
21077 /* FALLTHRU */
21080 /* A `sizeof' expression is value-dependent if the operand is
21081 type-dependent or is a pack expansion. */
21090 /* An 'encode' expression is value-dependent if the operand is
21091 type-dependent. */
21100 /* All instantiation-dependent expressions should also be considered
21101 value-dependent. */
21109 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
21110 is value-dependent. */
21111 {
21120 }
21123 {
21127 }
21138 {
21142 }
21145 {
21152 {
21154 /* In a call to a constexpr member function, look through the
21155 implicit ADDR_EXPR on the object argument so that it doesn't
21156 cause the call to be considered value-dependent. We also
21157 look through it in potential_constant_expression. */
21164 }
21166 }
21169 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
21170 type-dependent. */
21174 {
21176 tree val;
21183 }
21186 /* Treat a GNU statement expression as dependent to avoid crashing
21187 under instantiate_non_dependent_expr; it can't be constant. */
21191 /* A constant expression is value-dependent if any subexpression is
21192 value-dependent. */
21194 {
21201 {
21205 {
21208 /* In some cases, some of the operands may be missing.l
21209 (For example, in the case of PREDECREMENT_EXPR, the
21210 amount to increment by may be missing.) That doesn't
21211 make the expression dependent. */
21214 }
21215 }
21219 }
21221 }
21223 /* The expression is not value-dependent. */
21225 }
21227 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
21228 [temp.dep.expr]. Note that an expression with no type is
21229 considered dependent. Other parts of the compiler arrange for an
21230 expression with type-dependent subexpressions to have no type, so
21231 this function doesn't have to be fully recursive. */
21233 bool
21235 {
21242 /* An unresolved name is always dependent. */
21246 /* Some expression forms are never type-dependent. */
21259 /* The types of these expressions depends only on the type to which
21260 the cast occurs. */
21269 /* The types of these expressions depends only on the type created
21270 by the expression. */
21273 {
21274 /* For NEW_EXPR tree nodes created inside a template, either
21275 the object type itself or a TREE_LIST may appear as the
21276 operand 1. */
21279 /* This is an array type. We need to check array dimensions
21280 as well. */
21282 || value_dependent_expression_p
21284 else
21286 }
21289 {
21293 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
21294 contains an identifier associated by name lookup with one or more
21295 declarations declared with a dependent type, or...a
21296 nested-name-specifier or qualified-id that names a member of an
21297 unknown specialization. */
21300 }
21305 && (any_dependent_template_arguments_p
21317 {
21318 tree elt;
21322 {
21325 }
21327 }
21329 /* A static data member of the current instantiation with incomplete
21330 array type is type-dependent, as the definition and specializations
21331 can have different bounds. */
21338 /* An array of unknown bound depending on a variadic parameter, eg:
21340 template<typename... Args>
21341 void foo (Args... args)
21342 {
21343 int arr[] = { args... };
21344 }
21346 template<int... vals>
21347 void bar ()
21348 {
21349 int arr[] = { vals... };
21350 }
21352 If the array has no length and has an initializer, it must be that
21353 we couldn't determine its length in cp_complete_array_type because
21354 it is dependent. */
21361 /* A variable template specialization is type-dependent if it has any
21362 dependent template arguments. */
21370 {
21375 {
21381 }
21382 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
21386 /* Always dependent, on the number of arguments if nothing else. */
21391 {
21396 }
21399 {
21404 }
21409 {
21413 }
21415 }
21420 }
21422 /* walk_tree callback function for instantiation_dependent_expression_p,
21423 below. Returns non-zero if a dependent subexpression is found. */
21425 static tree
21428 {
21430 {
21431 /* We don't have to worry about decltype currently because decltype
21432 of an instantiation-dependent expr is a dependent type. This
21433 might change depending on the resolution of DR 1172. */
21436 }
21439 {
21440 /* Don't treat an argument list as dependent just because it has no
21441 TREE_TYPE. */
21448 /* A constant with a dependent initializer is dependent. */
21456 /* Handle expressions with type operands. */
21461 {
21466 {
21469 else
21470 {
21473 }
21474 }
21476 }
21488 /* In a template, finish_class_member_access_expr creates a
21489 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
21490 type-dependent, so that we can check access control at
21491 instantiation time (PR 42277). See also Core issue 1273. */
21498 else
21501 /* Treat statement-expressions as dependent. */
21507 }
21511 else
21513 }
21515 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
21516 sense defined by the ABI:
21518 "An expression is instantiation-dependent if it is type-dependent
21519 or value-dependent, or it has a subexpression that is type-dependent
21520 or value-dependent." */
21522 bool
21524 {
21525 tree result;
21536 }
21538 /* Like type_dependent_expression_p, but it also works while not processing
21539 a template definition, i.e. during substitution or mangling. */
21541 bool
21543 {
21549 }
21551 /* Returns TRUE if ARGS contains a type-dependent expression. */
21553 bool
21555 {
21557 tree arg;
21560 {
21563 }
21565 }
21567 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21568 expressions) contains any type-dependent expressions. */
21570 bool
21572 {
21578 }
21580 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21581 expressions) contains any value-dependent expressions. */
21583 bool
21585 {
21591 }
21593 /* Returns TRUE if the ARG (a template argument) is dependent. */
21595 bool
21597 {
21601 /* Assume a template argument that was wrongly written by the user
21602 is dependent. This is consistent with what
21603 any_dependent_template_arguments_p [that calls this function]
21604 does. */
21615 {
21619 {
21622 }
21625 }
21628 else
21631 }
21633 /* Returns true if ARGS (a collection of template arguments) contains
21634 any types that require structural equality testing. */
21636 bool
21638 {
21648 {
21651 {
21657 {
21658 /* Look inside the argument pack. */
21661 }
21664 {
21677 }
21678 }
21679 }
21682 }
21684 /* Returns true if ARGS (a collection of template arguments) contains
21685 any dependent arguments. */
21687 bool
21689 {
21699 {
21704 }
21707 }
21709 /* Returns TRUE if the template TMPL is dependent. */
21711 bool
21713 {
21715 {
21717 {
21721 }
21723 }
21725 /* Template template parameters are dependent. */
21729 /* So are names that have not been looked up. */
21732 /* So are member templates of dependent classes. */
21736 }
21738 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
21740 bool
21742 {
21745 }
21747 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
21748 is dependent. */
21750 bool
21752 {
21759 {
21780 {
21784 }
21788 {
21792 {
21797 }
21798 }
21799 }
21802 }
21804 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
21805 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
21806 no such TYPE can be found. Note that this function peers inside
21807 uninstantiated templates and therefore should be used only in
21808 extremely limited situations. ONLY_CURRENT_P restricts this
21809 peering to the currently open classes hierarchy (which is required
21810 when comparing types). */
21812 tree
21814 {
21815 tree scope;
21816 tree name;
21817 tree decl;
21819 tree pushed_scope;
21820 tree result;
21825 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
21826 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
21827 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
21828 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
21829 identifier of the TYPENAME_TYPE anymore.
21830 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
21831 TYPENAME_TYPE instead, we avoid messing up with a possible
21832 typedef variant case. */
21835 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
21836 it first before we can figure out what NAME refers to. */
21838 {
21840 /* Given a class template A with a dependent base with nested type C,
21841 typedef typename A::C::C C will land us here, as trying to resolve
21842 the initial A::C leads to the local C typedef, which leads back to
21843 A::C::C. So we break the recursion now. */
21845 else
21847 }
21848 /* If we don't know what SCOPE refers to, then we cannot resolve the
21849 TYPENAME_TYPE. */
21852 /* If the SCOPE is a template type parameter, we have no way of
21853 resolving the name. */
21856 /* If the SCOPE is not the current instantiation, there's no reason
21857 to look inside it. */
21860 /* If this is a typedef, we don't want to look inside (c++/11987). */
21863 /* If SCOPE isn't the template itself, it will not have a valid
21864 TYPE_FIELDS list. */
21866 /* scope is either the template itself or a compatible instantiation
21867 like X<T>, so look up the name in the original template. */
21869 else
21870 /* scope is a partial instantiation, so we can't do the lookup or we
21871 will lose the template arguments. */
21873 /* Enter the SCOPE so that name lookup will be resolved as if we
21874 were in the class definition. In particular, SCOPE will no
21875 longer be considered a dependent type. */
21877 /* Look up the declaration. */
21879 tf_warning_or_error);
21883 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
21884 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
21889 {
21893 }
21896 {
21897 tree tmpl;
21898 tree args;
21899 /* Obtain the template and the arguments. */
21902 /* Instantiate the template. */
21908 }
21910 /* Leave the SCOPE. */
21914 /* If we failed to resolve it, return the original typename. */
21918 /* If lookup found a typename type, resolve that too. */
21920 {
21921 /* Ill-formed programs can cause infinite recursion here, so we
21922 must catch that. */
21926 }
21928 /* Qualify the resulting type. */
21934 }
21936 /* EXPR is an expression which is not type-dependent. Return a proxy
21937 for EXPR that can be used to compute the types of larger
21938 expressions containing EXPR. */
21940 tree
21942 {
21943 tree inner_expr;
21945 #ifdef ENABLE_CHECKING
21946 /* Try to get a constant value for all non-dependent expressions in
21947 order to expose bugs in *_dependent_expression_p and constexpr. */
21950 #endif
21952 /* Preserve OVERLOADs; the functions must be available to resolve
21953 types. */
21964 /* There is no need to return a proxy for a variable. */
21967 /* Preserve string constants; conversions from string constants to
21968 "char *" are allowed, even though normally a "const char *"
21969 cannot be used to initialize a "char *". */
21972 /* Preserve void and arithmetic constants, as an optimization -- there is no
21973 reason to create a new node. */
21978 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
21979 There is at least one place where we want to know that a
21980 particular expression is a throw-expression: when checking a ?:
21981 expression, there are special rules if the second or third
21982 argument is a throw-expression. */
21986 /* Don't wrap an initializer list, we need to be able to look inside. */
21990 /* Don't wrap a dummy object, we need to be able to test for it. */
22009 /* If the type is unknown, it can't really be non-dependent */
22012 /* Otherwise, build a NON_DEPENDENT_EXPR. */
22014 }
22016 /* ARGS is a vector of expressions as arguments to a function call.
22017 Replace the arguments with equivalent non-dependent expressions.
22018 This modifies ARGS in place. */
22020 void
22022 {
22024 tree arg;
22027 {
22031 }
22032 }
22034 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
22035 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
22036 parms. */
22038 static tree
22040 {
22053 }
22055 tree
22057 {
22059 }
22061 tree
22063 {
22065 }
22067 /* Given type ARG, return std::initializer_list<ARG>. */
22069 static tree
22071 {
22072 tree std_init_list = namespace_binding
22074 tree argvec;
22076 {
22080 }
22085 }
22087 /* Replace auto in TYPE with std::initializer_list<auto>. */
22089 static tree
22091 {
22098 }
22100 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
22101 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
22103 tree
22105 {
22106 tree targs;
22112 /* Defining a subset of type-dependent expressions that we can deduce
22113 from ahead of time isn't worth the trouble. */
22116 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
22117 with either a new invented type template parameter U or, if the
22118 initializer is a braced-init-list (8.5.4), with
22119 std::initializer_list<U>. */
22121 {
22126 else
22127 {
22131 "for deduction to %<std::initializer_list%>, use copy-"
22134 }
22135 }
22141 {
22147 {
22150 }
22151 }
22152 else
22153 {
22164 {
22166 /* Try again at instantiation time. */
22169 /* If type is error_mark_node a diagnostic must have been
22170 emitted by now. Also, having a mention to '<type error>'
22171 in the diagnostic is not really useful to the user. */
22172 {
22176 else
22178 }
22180 }
22181 }
22183 /* If the list of declarators contains more than one declarator, the type
22184 of each declared variable is determined as described above. If the
22185 type deduced for the template parameter U is not the same in each
22186 deduction, the program is ill-formed. */
22189 {
22195 else
22199 }
22205 }
22207 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
22208 result. */
22210 tree
22212 {
22213 tree argvec;
22220 /* For a late-specified return type in a template type-parameter, we
22221 need to add a dummy argument level for its parmlist. */
22222 argvec = add_to_template_args
22227 }
22229 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
22230 'decltype(auto)'. */
22232 bool
22234 {
22239 else
22241 }
22243 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
22244 a use of `auto'. Returns NULL_TREE otherwise. */
22246 tree
22248 {
22250 }
22252 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
22253 'decltype(auto)' or a concept. */
22255 bool
22257 {
22259 }
22261 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
22262 a concept identifier) iff TYPE contains a use of a generic type. Returns
22263 NULL_TREE otherwise. */
22265 tree
22267 {
22269 }
22272 /* For a given template T, return the vector of typedefs referenced
22273 in T for which access check is needed at T instantiation time.
22274 T is either a FUNCTION_DECL or a RECORD_TYPE.
22275 Those typedefs were added to T by the function
22276 append_type_to_template_for_access_check. */
22280 {
22281 tree ti;
22292 {
22297 }
22300 }
22302 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
22303 tied to T. That list of typedefs will be access checked at
22304 T instantiation time.
22305 T is either a FUNCTION_DECL or a RECORD_TYPE.
22306 TYPE_DECL is a TYPE_DECL node representing a typedef.
22307 SCOPE is the scope through which TYPE_DECL is accessed.
22308 LOCATION is the location of the usage point of TYPE_DECL.
22310 This function is a subroutine of
22311 append_type_to_template_for_access_check. */
22313 static void
22315 tree type_decl,
22316 tree scope,
22317 location_t location)
22318 {
22319 qualified_typedef_usage_t typedef_usage;
22320 tree ti;
22327 && type_decl
22341 }
22343 /* Append TYPE_DECL to the template TEMPL.
22344 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
22345 At TEMPL instanciation time, TYPE_DECL will be checked to see
22346 if it can be accessed through SCOPE.
22347 LOCATION is the location of the usage point of TYPE_DECL.
22349 e.g. consider the following code snippet:
22351 class C
22352 {
22353 typedef int myint;
22354 };
22356 template<class U> struct S
22357 {
22358 C::myint mi; // <-- usage point of the typedef C::myint
22359 };
22361 S<char> s;
22363 At S<char> instantiation time, we need to check the access of C::myint
22364 In other words, we need to check the access of the myint typedef through
22365 the C scope. For that purpose, this function will add the myint typedef
22366 and the scope C through which its being accessed to a list of typedefs
22367 tied to the template S. That list will be walked at template instantiation
22368 time and access check performed on each typedefs it contains.
22369 Note that this particular code snippet should yield an error because
22370 myint is private to C. */
22372 void
22374 tree type_decl,
22375 tree scope,
22376 location_t location)
22377 {
22383 /* Make sure we don't append the type to the template twice. */
22390 }
22392 /* Convert the generic type parameters in PARM that match the types given in the
22393 range [START_IDX, END_IDX) from the current_template_parms into generic type
22394 packs. */
22396 tree
22398 {
22409 {
22410 /* Create a distinct parameter pack type from the current parm and add it
22411 to the replacement args to tsubst below into the generic function
22412 parameter. */
22427 }
22433 /* If there are more levels then build up the replacement with the outer
22434 template parms. */
22438 replacement);
22441 }
22444 /* Set up the hash tables for template instantiations. */
22446 void
22448 {
22451 }
22453 /* Print stats about the template hash tables for -fstats. */
22455 void
22457 {
22466 }