| blob | c66eaccc6be28fa671232c93994ef660178ce3d7 |
1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001 Free Software Foundation, Inc.
4 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
5 Rewritten by Jason Merrill (jason@cygnus.com).
7 This file is part of GNU CC.
9 GNU CC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2, or (at your option)
12 any later version.
14 GNU CC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GNU CC; see the file COPYING. If not, write to
21 the Free Software Foundation, 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
46 /* The type of functions taking a tree, and some additional data, and
47 returning an int. */
52 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
53 instantiations have been deferred, either because their definitions
54 were not yet available, or because we were putting off doing the
55 work. The TREE_PURPOSE of each entry is a SRCLOC indicating where
56 the instantiate request occurred; the TREE_VALUE is a either a DECL
57 (for a function or static data member), or a TYPE (for a class)
58 indicating what we are hoping to instantiate. */
74 /* A map from local variable declarations in the body of the template
75 presently being instantiated to the corresponding instantiated
76 local variables. */
79 #define obstack_chunk_alloc xmalloc
80 #define obstack_chunk_free free
82 #define UNIFY_ALLOW_NONE 0
83 #define UNIFY_ALLOW_MORE_CV_QUAL 1
84 #define UNIFY_ALLOW_LESS_CV_QUAL 2
85 #define UNIFY_ALLOW_DERIVED 4
86 #define UNIFY_ALLOW_INTEGER 8
87 #define UNIFY_ALLOW_OUTER_LEVEL 16
88 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
89 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
92 virtual, or a base class of a virtual
93 base. */
95 type with the desired type. */
115 tree*));
174 /* Called once to initialize pt.c. */
176 void
178 {
183 }
185 /* Do any processing required when DECL (a member template declaration
186 using TEMPLATE_PARAMETERS as its innermost parameter list) is
187 finished. Returns the TEMPLATE_DECL corresponding to DECL, unless
188 it is a specialization, in which case the DECL itself is returned. */
190 tree
192 tree decl;
193 {
197 /* By returning NULL_TREE, the parser will just ignore this
198 declaration. We have already issued the error. */
201 {
202 /* Assume that the class is the only declspec. */
206 {
210 }
212 }
216 {
218 {
221 }
222 else
224 }
225 else
229 }
231 /* Returns the template nesting level of the indicated class TYPE.
233 For example, in:
234 template <class T>
235 struct A
236 {
237 template <class U>
238 struct B {};
239 };
241 A<T>::B<U> has depth two, while A<T> has depth one.
242 Both A<T>::B<int> and A<int>::B<U> have depth one, if
243 COUNT_SPECIALIZATIONS is 0 or if they are instantiations, not
244 specializations.
246 This function is guaranteed to return 0 if passed NULL_TREE so
247 that, for example, `template_class_depth (current_class_type)' is
248 always safe. */
250 static int
252 tree type;
254 {
261 {
263 {
266 && ((count_specializations
270 }
271 else
272 {
275 && ((count_specializations
279 }
280 }
283 }
285 /* Returns the template nesting level of the indicated class TYPE.
286 Like template_class_depth_real, but instantiations do not count in
287 the depth. */
289 int
291 tree type;
292 {
294 }
296 /* Returns 1 if processing DECL as part of do_pending_inlines
297 needs us to push template parms. */
299 static int
301 tree decl;
302 {
308 }
310 /* Subroutine of maybe_begin_member_template_processing.
311 Push the template parms in PARMS, starting from LEVELS steps into the
312 chain, and ending at the beginning, since template parms are listed
313 innermost first. */
315 static void
317 tree parmlist;
319 {
327 current_template_parms
334 {
339 {
346 {
347 /* Make a CONST_DECL as is done in process_template_parm.
348 It is ugly that we recreate this here; the original
349 version built in process_template_parm is no longer
350 available. */
357 }
362 }
363 }
364 }
366 /* Restore the template parameter context for a member template or
367 a friend template defined in a class definition. */
369 void
371 tree decl;
372 {
373 tree parms;
377 {
382 {
385 }
388 }
390 /* Remember how many levels of template parameters we pushed so that
391 we can pop them later. */
398 }
400 /* Undo the effects of begin_member_template_processing. */
402 void
404 {
414 {
418 }
419 }
421 /* Returns non-zero iff T is a member template function. We must be
422 careful as in
424 template <class T> class C { void f(); }
426 Here, f is a template function, and a member, but not a member
427 template. This function does not concern itself with the origin of
428 T, only its present state. So if we have
430 template <class T> class C { template <class U> void f(U); }
432 then neither C<int>::f<char> nor C<T>::f<double> is considered
433 to be a member template. But, `template <class U> void
434 C<int>::f(U)' is considered a member template. */
436 int
438 tree t;
439 {
441 /* Anything that isn't a function or a template function is
442 certainly not a member template. */
445 /* A local class can't have member templates. */
450 /* If there are more levels of template parameters than
451 there are template classes surrounding the declaration,
452 then we have a member template. */
455 }
458 /* Returns non-zero iff T is a member template class. See
459 is_member_template for a description of what precisely constitutes
460 a member template. */
462 int
464 tree t;
465 {
467 /* Anything that isn't a class template, is certainly not a member
468 template. */
472 /* Anything whose context isn't a class type is surely not a
473 member template. */
476 /* If there are more levels of template parameters than there are
477 template classes surrounding the declaration, then we have a
478 member template. */
481 }
482 #endif
484 /* Return a new template argument vector which contains all of ARGS,
485 but has as its innermost set of arguments the EXTRA_ARGS. */
487 static tree
489 tree args;
490 tree extra_args;
491 {
492 tree new_args;
507 }
509 /* Like add_to_template_args, but only the outermost ARGS are added to
510 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
511 (EXTRA_ARGS) levels are added. This function is used to combine
512 the template arguments from a partial instantiation with the
513 template arguments used to attain the full instantiation from the
514 partial instantiation. */
516 static tree
518 tree args;
519 tree extra_args;
520 {
521 tree new_args;
523 /* If there are more levels of EXTRA_ARGS than there are ARGS,
524 something very fishy is going on. */
528 /* If *all* the new arguments will be the EXTRA_ARGS, just return
529 them. */
533 /* For the moment, we make ARGS look like it contains fewer levels. */
538 /* Now, we restore ARGS to its full dimensions. */
542 }
544 /* Return the N levels of innermost template arguments from the ARGS. */
546 tree
548 tree args;
550 {
551 tree new_args;
557 /* If N is 1, just return the innermost set of template arguments. */
561 /* If we're not removing anything, just return the arguments we were
562 given. */
568 /* Make a new set of arguments, not containing the outer arguments. */
575 }
577 /* We've got a template header coming up; push to a new level for storing
578 the parms. */
580 void
582 {
583 /* We use a non-tag-transparent scope here, which causes pushtag to
584 put tags in this scope, rather than in the enclosing class or
585 namespace scope. This is the right thing, since we want
586 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
587 global template class, push_template_decl handles putting the
588 TEMPLATE_DECL into top-level scope. For a nested template class,
589 e.g.:
591 template <class T> struct S1 {
592 template <class T> struct S2 {};
593 };
595 pushtag contains special code to call pushdecl_with_scope on the
596 TEMPLATE_DECL for S2. */
601 }
603 /* This routine is called when a specialization is declared. If it is
604 illegal to declare a specialization here, an error is reported. */
606 static void
608 {
611 /* [temp.expl.spec]
613 An explicit specialization shall be declared in the namespace of
614 which the template is a member, or, for member templates, in the
615 namespace of which the enclosing class or enclosing class
616 template is a member. An explicit specialization of a member
617 function, member class or static data member of a class template
618 shall be declared in the namespace of which the class template
619 is a member. */
622 scope);
624 /* [temp.expl.spec]
626 In an explicit specialization declaration for a member of a class
627 template or a member template that appears in namespace scope,
628 the member template and some of its enclosing class templates may
629 remain unspecialized, except that the declaration shall not
630 explicitly specialize a class member template if its enclosing
631 class templates are not explicitly specialized as well. */
634 }
636 /* We've just seen template <>. */
638 void
640 {
644 }
646 /* Called at then end of processing a declaration preceded by
647 template<>. */
649 void
651 {
654 }
656 /* Any template <>'s that we have seen thus far are not referring to a
657 function specialization. */
659 void
661 {
664 }
666 /* We've just seen a template header. If SPECIALIZATION is non-zero,
667 it was of the form template <>. */
669 static void
672 {
674 template_header_count++;
675 }
677 /* We're beginning an explicit instantiation. */
679 void
681 {
683 }
686 void
688 {
691 }
693 /* The TYPE is being declared. If it is a template type, that means it
694 is a partial specialization. Do appropriate error-checking. */
696 void
698 tree type;
699 {
701 {
704 {
707 {
711 }
715 }
718 }
721 }
723 /* Retrieve the specialization (in the sense of [temp.spec] - a
724 specialization is either an instantiation or an explicit
725 specialization) of TMPL for the given template ARGS. If there is
726 no such specialization, return NULL_TREE. The ARGS are a vector of
727 arguments, or a vector of vectors of arguments, in the case of
728 templates with more than one level of parameters. */
730 static tree
732 tree tmpl;
733 tree args;
734 {
735 tree s;
739 /* There should be as many levels of arguments as there are
740 levels of parameters. */
752 }
754 /* Like retrieve_specialization, but for local declarations. */
756 static tree
758 tree tmpl;
759 {
761 }
763 /* Returns non-zero iff DECL is a specialization of TMPL. */
765 int
767 tree decl;
768 tree tmpl;
769 {
770 tree t;
773 {
779 }
780 else
781 {
790 }
793 }
795 /* Register the specialization SPEC as a specialization of TMPL with
796 the indicated ARGS. Returns SPEC, or an equivalent prior
797 declaration, if available. */
799 static tree
801 tree spec;
802 tree tmpl;
803 tree args;
804 {
805 tree s;
811 /* This is the FUNCTION_DECL for a partial instantiation. Don't
812 register it; we want the corresponding TEMPLATE_DECL instead.
813 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
814 the more obvious `uses_template_parms (spec)' to avoid problems
815 with default function arguments. In particular, given
816 something like this:
818 template <class T> void f(T t1, T t = T())
820 the default argument expression is not substituted for in an
821 instantiation unless and until it is actually needed. */
824 /* There should be as many levels of arguments as there are
825 levels of parameters. */
833 {
836 /* We can sometimes try to re-register a specialization that we've
837 already got. In particular, regenerate_decl_from_template
838 calls duplicate_decls which will update the specialization
839 list. But, we'll still get called again here anyhow. It's
840 more convenient to simply allow this than to try to prevent it. */
844 {
846 {
848 {
851 {
853 fn);
855 }
856 else
857 {
858 /* This situation should occur only if the first
859 specialization is an implicit instantiation,
860 the second is an explicit specialization, and
861 the implicit instantiation has not yet been
862 used. That situation can occur if we have
863 implicitly instantiated a member function and
864 then specialized it later.
866 We can also wind up here if a friend
867 declaration that looked like an instantiation
868 turns out to be a specialization:
870 template <class T> void foo(T);
871 class S { friend void foo<>(int) };
872 template <> void foo(int);
874 We transform the existing DECL in place so that
875 any pointers to it become pointers to the
876 updated declaration.
878 If there was a definition for the template, but
879 not for the specialization, we want this to
880 look as if there is no definition, and vice
881 versa. */
886 }
887 }
889 {
892 }
893 }
894 }
895 }
901 }
903 /* Unregister the specialization SPEC as a specialization of TMPL.
904 Returns nonzero if the SPEC was listed as a specialization of
905 TMPL. */
907 static int
909 tree spec;
910 tree tmpl;
911 {
918 {
921 }
924 }
926 /* Like register_specialization, but for local declarations. We are
927 registering SPEC, an instantiation of TMPL. */
929 static void
931 tree spec;
932 tree tmpl;
933 {
938 }
940 /* Print the list of candidate FNS in an error message. */
942 void
944 tree fns;
945 {
946 tree fn;
951 {
952 tree f;
957 }
958 }
960 /* Returns the template (one of the functions given by TEMPLATE_ID)
961 which can be specialized to match the indicated DECL with the
962 explicit template args given in TEMPLATE_ID. The DECL may be
963 NULL_TREE if none is available. In that case, the functions in
964 TEMPLATE_ID are non-members.
966 If NEED_MEMBER_TEMPLATE is non-zero the function is known to be a
967 specialization of a member template.
969 The template args (those explicitly specified and those deduced)
970 are output in a newly created vector *TARGS_OUT.
972 If it is impossible to determine the result, an error message is
973 issued. The error_mark_node is returned to indicate failure. */
975 static tree
977 need_member_template)
978 tree template_id;
979 tree decl;
982 {
983 tree fns;
984 tree targs;
985 tree explicit_targs;
1000 /* Check for baselinks. */
1005 {
1008 }
1011 {
1012 tree tmpl;
1017 /* DECL might be a specialization of FN. */
1020 /* FN is an ordinary member function, and we need a
1021 specialization of a member template. */
1024 /* We can get IDENTIFIER_NODEs here in certain erroneous
1025 cases. */
1028 /* This is just an ordinary non-member function. Nothing can
1029 be a specialization of that. */
1031 else
1032 {
1033 tree decl_arg_types;
1035 /* This is an ordinary member function. However, since
1036 we're here, we can assume it's enclosing class is a
1037 template class. For example,
1039 template <typename T> struct S { void f(); };
1040 template <> void S<int>::f() {}
1042 Here, S<int>::f is a non-template, but S<int> is a
1043 template class. If FN has the same type as DECL, we
1044 might be in business. */
1047 /* The return types differ. */
1050 /* Adjust the type of DECL in case FN is a static member. */
1057 decl_arg_types))
1058 /* They match! */
1062 }
1064 /* See whether this function might be a specialization of this
1065 template. */
1069 /* We cannot deduce template arguments that when used to
1070 specialize TMPL will produce DECL. */
1073 /* Save this template, and the arguments deduced. */
1075 }
1078 {
1079 /* We have:
1081 [temp.expl.spec]
1083 It is possible for a specialization with a given function
1084 signature to be instantiated from more than one function
1085 template. In such cases, explicit specification of the
1086 template arguments must be used to uniquely identify the
1087 function template specialization being specialized.
1089 Note that here, there's no suggestion that we're supposed to
1090 determine which of the candidate templates is most
1091 specialized. However, we, also have:
1093 [temp.func.order]
1095 Partial ordering of overloaded function template
1096 declarations is used in the following contexts to select
1097 the function template to which a function template
1098 specialization refers:
1100 -- when an explicit specialization refers to a function
1101 template.
1103 So, we do use the partial ordering rules, at least for now.
1104 This extension can only serve to make illegal programs legal,
1105 so it's safe. And, there is strong anecdotal evidence that
1106 the committee intended the partial ordering rules to apply;
1107 the EDG front-end has that behavior, and John Spicer claims
1108 that the committee simply forgot to delete the wording in
1109 [temp.expl.spec]. */
1112 {
1115 }
1116 }
1119 {
1123 }
1127 {
1133 }
1135 /* We have one, and exactly one, match. */
1137 {
1138 /* It was a specialization of an ordinary member function in a
1139 template class. */
1142 }
1144 /* It was a specialization of a template. */
1147 {
1152 }
1153 else
1156 }
1158 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
1159 but with the default argument values filled in from those in the
1160 TMPL_TYPES. */
1162 static tree
1164 tmpl_types)
1165 tree spec_types;
1166 tree tmpl_types;
1167 {
1168 tree new_spec_types;
1176 /* Substitute into the rest of the list. */
1177 new_spec_types =
1181 /* Add the default argument for this parameter. */
1184 new_spec_types);
1185 }
1187 /* DECL is an explicit specialization. Replicate default arguments
1188 from the template it specializes. (That way, code like:
1190 template <class T> void f(T = 3);
1191 template <> void f(double);
1192 void g () { f (); }
1194 works, as required.) An alternative approach would be to look up
1195 the correct default arguments at the call-site, but this approach
1196 is consistent with how implicit instantiations are handled. */
1198 static void
1200 tree decl;
1201 {
1202 tree tmpl;
1203 tree spec_types;
1204 tree tmpl_types;
1205 tree new_spec_types;
1206 tree old_type;
1207 tree new_type;
1208 tree t;
1212 /* See if there's anything we need to do. */
1225 {
1226 /* Remove the this pointer, but remember the object's type for
1227 CV quals. */
1233 {
1234 /* DECL may contain more parameters than TMPL due to the extra
1235 in-charge parameter in constructors and destructors. */
1238 }
1239 }
1241 /* Compute the merged default arguments. */
1242 new_spec_types =
1245 /* Compute the new FUNCTION_TYPE. */
1247 {
1249 /* Put the in-charge parameter back. */
1252 new_spec_types);
1256 new_spec_types);
1257 }
1258 else
1260 new_spec_types);
1266 }
1268 /* Check to see if the function just declared, as indicated in
1269 DECLARATOR, and in DECL, is a specialization of a function
1270 template. We may also discover that the declaration is an explicit
1271 instantiation at this point.
1273 Returns DECL, or an equivalent declaration that should be used
1274 instead if all goes well. Issues an error message if something is
1275 amiss. Returns error_mark_node if the error is not easily
1276 recoverable.
1278 FLAGS is a bitmask consisting of the following flags:
1280 2: The function has a definition.
1281 4: The function is a friend.
1283 The TEMPLATE_COUNT is the number of references to qualifying
1284 template classes that appeared in the name of the function. For
1285 example, in
1287 template <class T> struct S { void f(); };
1288 void S<int>::f();
1290 the TEMPLATE_COUNT would be 1. However, explicitly specialized
1291 classes are not counted in the TEMPLATE_COUNT, so that in
1293 template <class T> struct S {};
1294 template <> struct S<int> { void f(); }
1295 template <> void S<int>::f();
1297 the TEMPLATE_COUNT would be 0. (Note that this declaration is
1298 illegal; there should be no template <>.)
1300 If the function is a specialization, it is marked as such via
1301 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
1302 is set up correctly, and it is added to the list of specializations
1303 for that template. */
1305 tree
1307 tree declarator;
1308 tree decl;
1311 {
1319 tmpl_spec_kind tsk;
1324 {
1327 {
1330 }
1332 {
1334 /* This could be something like:
1336 template <class T> void f(T);
1337 class S { friend void f<>(int); } */
1339 else
1340 {
1341 /* This case handles bogus declarations like template <>
1342 template <class T> void f<int>(); */
1345 declarator);
1347 }
1348 }
1352 /* The error has already been reported in
1353 check_specialization_scope. */
1359 /* Fall through. */
1370 decl);
1373 /* Fall through. */
1378 else
1384 {
1386 decl);
1388 }
1393 {
1394 /* For backwards compatibility, we accept:
1396 template <class T> struct S { void f(); };
1397 void S<int>::f() {} // Missing template <>
1399 That used to be legal C++. */
1401 cp_pedwarn
1405 }
1410 {
1411 /* This case handles bogus declarations like template <>
1412 template <class T> void f<int>(); */
1416 declarator);
1417 else
1419 declarator);
1421 }
1424 /* This is a specialization of a member template, without
1425 specialization the containing class. Something like:
1427 template <class T> struct S {
1428 template <class U> void f (U);
1429 };
1430 template <> template <class U> void S<int>::f(U) {}
1432 That's a specialization -- but of the entire template. */
1438 }
1441 {
1445 {
1446 cp_pedwarn
1449 }
1452 }
1455 {
1459 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
1461 {
1462 tree fns;
1468 else
1471 declarator =
1473 }
1479 {
1481 /* A specialization in class scope. This is illegal,
1482 but the error will already have been flagged by
1483 check_specialization_scope. */
1485 else
1486 {
1487 /* It's not legal to write an explicit instantiation in
1488 class scope, e.g.:
1490 class C { template void f(); }
1492 This case is caught by the parser. However, on
1493 something like:
1495 template class C { void f(); };
1497 (which is illegal) we can get here. The error will be
1498 issued later. */
1499 ;
1500 }
1503 }
1505 {
1506 /* A friend declaration. We can't do much, because we don't
1507 know what this resolves to, yet. */
1512 }
1515 IDENTIFIER_NODE))
1516 {
1517 /* Find the list of functions in ctype that have the same
1518 name as the declared function. */
1525 {
1530 {
1531 /* From [temp.expl.spec]:
1533 If such an explicit specialization for the member
1534 of a class template names an implicitly-declared
1535 special member function (clause _special_), the
1536 program is ill-formed.
1538 Similar language is found in [temp.explicit]. */
1541 }
1544 }
1547 {
1551 }
1552 else
1553 {
1554 tree methods;
1556 /* For a type-conversion operator, we cannot do a
1557 name-based lookup. We might be looking for `operator
1558 int' which will be a specialization of `operator T'.
1559 So, we find *all* the conversion operators, and then
1560 select from them. */
1566 {
1570 /* There are no more conversion functions. */
1573 /* Glue all these conversion functions together
1574 with those we already have. */
1577 }
1578 }
1581 {
1585 }
1586 else
1588 }
1590 /* Figure out what exactly is being specialized at this point.
1591 Note that for an explicit instantiation, even one for a
1592 member function, we cannot tell apriori whether the
1593 instantiation is for a member template, or just a member
1594 function of a template class. Even if a member template is
1595 being instantiated, the member template arguments may be
1596 elided if they can be deduced from the rest of the
1597 declaration. */
1600 member_specialization);
1603 /* We couldn't figure out what this declaration was
1604 specializing. */
1606 else
1607 {
1611 {
1612 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
1613 is done by do_decl_instantiation later. */
1619 {
1620 /* If TMPL is not the most general template (for
1621 example, if TMPL is a friend template that is
1622 injected into namespace scope), then there will
1623 be too many levels of TARGS. Remove some of them
1624 here. */
1626 tree new_targs;
1633 }
1636 }
1638 /* If this is a specialization of a member template of a
1639 template class. In we want to return the TEMPLATE_DECL,
1640 not the specialization of it. */
1642 {
1646 }
1648 /* If we thought that the DECL was a member function, but it
1649 turns out to be specializing a static member function,
1650 make DECL a static member function as well. */
1653 {
1656 }
1658 /* Set up the DECL_TEMPLATE_INFO for DECL. */
1661 /* Inherit default function arguments from the template
1662 DECL is specializing. */
1665 /* Mangle the function name appropriately. Note that we do
1666 not mangle specializations of non-template member
1667 functions of template classes, e.g. with
1669 template <class T> struct S { void f(); }
1671 and given the specialization
1673 template <> void S<int>::f() {}
1675 we do not mangle S<int>::f() here. That's because it's
1676 just an ordinary member function and doesn't need special
1677 treatment. We do this here so that the ordinary,
1678 non-template, name-mangling algorithm will not be used
1679 later. */
1685 /* This is not really a declaration of a specialization.
1686 It's just the name of an instantiation. But, it's not
1687 a request for an instantiation, either. */
1690 /* This is indeed a specialization. In case of constructors
1691 and destructors, we need in-charge and not-in-charge
1692 versions in V3 ABI. */
1695 /* Register this specialization so that we can find it
1696 again. */
1698 }
1699 }
1702 }
1704 /* TYPE is being declared. Verify that the use of template headers
1705 and such is reasonable. Issue error messages if not. */
1707 void
1709 tree type;
1710 {
1712 {
1713 /* We are in the scope of some `template <...>' header. */
1715 int context_depth
1720 /* This is OK; the template headers are for the context. We
1721 are actually too lenient here; like
1722 check_explicit_specialization we should consider the number
1723 of template types included in the actual declaration. For
1724 example,
1726 template <class T> struct S {
1727 template <class U> template <class V>
1728 struct I {};
1729 };
1731 is illegal, but:
1733 template <class T> struct S {
1734 template <class U> struct I;
1735 };
1737 template <class T> template <class U.
1738 struct S<T>::I {};
1740 is not. */
1741 ;
1743 /* There are two many template parameter lists. */
1745 }
1746 }
1748 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
1749 parameters. These are represented in the same format used for
1750 DECL_TEMPLATE_PARMS. */
1753 tree parms1;
1754 tree parms2;
1755 {
1756 tree p1;
1757 tree p2;
1765 {
1777 {
1788 }
1789 }
1792 /* One set of parameters has more parameters lists than the
1793 other. */
1797 }
1799 /* Complain if DECL shadows a template parameter.
1801 [temp.local]: A template-parameter shall not be redeclared within its
1802 scope (including nested scopes). */
1804 void
1806 tree decl;
1807 {
1808 tree olddecl;
1810 /* If we're not in a template, we can't possibly shadow a template
1811 parameter. */
1815 /* Figure out what we're shadowing. */
1820 /* If there's no previous binding for this name, we're not shadowing
1821 anything, let alone a template parameter. */
1825 /* If we're not shadowing a template parameter, we're done. Note
1826 that OLDDECL might be an OVERLOAD (or perhaps even an
1827 ERROR_MARK), so we can't just blithely assume it to be a _DECL
1828 node. */
1832 /* We check for decl != olddecl to avoid bogus errors for using a
1833 name inside a class. We check TPFI to avoid duplicate errors for
1834 inline member templates. */
1841 }
1843 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
1844 ORIG_LEVEL, DECL, and TYPE. */
1846 static tree
1851 tree decl;
1852 tree type;
1853 {
1862 }
1864 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
1865 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
1866 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
1867 new one is created. */
1869 static tree
1871 tree index;
1872 tree type;
1874 {
1878 {
1879 tree decl
1882 type);
1883 tree t
1893 /* Template template parameters need this. */
1896 }
1899 }
1901 /* Process information from new template parameter NEXT and append it to the
1902 LIST being built. */
1904 tree
1907 {
1908 tree parm;
1910 tree defval;
1920 {
1925 else
1928 }
1929 else
1933 {
1935 /* is a const-param */
1939 /* [temp.param]
1941 The top-level cv-qualifiers on the template-parameter are
1942 ignored when determining its type. */
1945 /* A template parameter is not modifiable. */
1952 processing_template_decl,
1954 }
1955 else
1956 {
1957 tree t;
1961 {
1963 /* This is for distinguishing between real templates and template
1964 template parameters */
1968 }
1969 else
1970 {
1972 /* parm is either IDENTIFIER_NODE or NULL_TREE */
1974 }
1981 processing_template_decl,
1983 }
1989 }
1991 /* The end of a template parameter list has been reached. Process the
1992 tree list into a parameter vector, converting each parameter into a more
1993 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
1994 as PARM_DECLs. */
1996 tree
1998 tree parms;
1999 {
2001 tree parm;
2004 current_template_parms
2009 parm;
2016 }
2018 /* end_template_decl is called after a template declaration is seen. */
2020 void
2022 {
2028 /* This matches the pushlevel in begin_template_parm_list. */
2033 }
2035 /* Given a template argument vector containing the template PARMS.
2036 The innermost PARMS are given first. */
2038 tree
2040 {
2041 tree header;
2046 /* If there is only one level of template parameters, we do not
2047 create a TREE_VEC of TREE_VECs. Instead, we return a single
2048 TREE_VEC containing the arguments. */
2053 {
2059 {
2062 /* T will be a list if we are called from within a
2063 begin/end_template_parm_list pair, but a vector directly
2064 if within a begin/end_member_template_processing pair. */
2066 {
2072 else
2075 }
2076 }
2080 else
2082 }
2085 }
2087 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
2088 template PARMS. Used by push_template_decl below. */
2090 static tree
2092 tree decl;
2093 tree parms;
2094 {
2099 {
2109 }
2112 }
2114 struct template_parm_data
2115 {
2116 /* The level of the template parameters we are currently
2117 processing. */
2120 /* The index of the specialization argument we are currently
2121 processing. */
2124 /* An array whose size is the number of template parameters. The
2125 elements are non-zero if the parameter has been used in any one
2126 of the arguments processed so far. */
2129 /* An array whose size is the number of template arguments. The
2130 elements are non-zero if the argument makes use of template
2131 parameters of this level. */
2133 };
2135 /* Subroutine of push_template_decl used to see if each template
2136 parameter in a partial specialization is used in the explicit
2137 argument list. If T is of the LEVEL given in DATA (which is
2138 treated as a template_parm_data*), then DATA->PARMS is marked
2139 appropriately. */
2141 static int
2143 tree t;
2145 {
2151 {
2154 }
2155 else
2156 {
2159 }
2162 {
2165 }
2167 /* Return zero so that for_each_template_parm will continue the
2168 traversal of the tree; we want to mark *every* template parm. */
2170 }
2172 /* Process the partial specialization DECL. */
2174 static tree
2176 tree decl;
2177 {
2191 /* We check that each of the template parameters given in the
2192 partial specialization is used in the argument list to the
2193 specialization. For example:
2195 template <class T> struct S;
2196 template <class T> struct S<T*>;
2198 The second declaration is OK because `T*' uses the template
2199 parameter T, whereas
2201 template <class T> struct S<int>;
2203 is no good. Even trickier is:
2205 template <class T>
2206 struct S1
2207 {
2208 template <class U>
2209 struct S2;
2210 template <class U>
2211 struct S2<T>;
2212 };
2214 The S2<T> declaration is actually illegal; it is a
2215 full-specialization. Of course,
2217 template <class U>
2218 struct S2<T (*)(U)>;
2220 or some such would have been OK. */
2228 {
2233 }
2236 {
2237 /* One of the template parms was not used in the
2238 specialization. */
2240 {
2243 }
2247 }
2249 /* [temp.class.spec]
2251 The argument list of the specialization shall not be identical to
2252 the implicit argument list of the primary template. */
2259 /* [temp.class.spec]
2261 A partially specialized non-type argument expression shall not
2262 involve template parameters of the partial specialization except
2263 when the argument expression is a simple identifier.
2265 The type of a template parameter corresponding to a specialized
2266 non-type argument shall not be dependent on a parameter of the
2267 specialization. */
2271 {
2276 /* This next line is the `argument expression is not just a
2277 simple identifier' condition and also the `specialized
2278 non-type argument' bit. */
2280 {
2283 else
2284 {
2285 /* Look at the corresponding template parameter,
2286 marking which template parameters its type depends
2287 upon. */
2288 tree type =
2290 i)));
2293 {
2294 /* We haven't yet initialized TPD2. Do so now. */
2295 tpd2.arg_uses_template_parms
2297 /* The number of parameters here is the number in the
2298 main template, which, as checked in the assertion
2299 above, is NARGS. */
2303 }
2305 /* Mark the template parameters. But this time, we're
2306 looking for the template parameters of the main
2307 template, not in the specialization. */
2316 {
2317 /* The type depended on some template parameters.
2318 If they are fully specialized in the
2319 specialization, that's OK. */
2324 {
2326 type,
2327 arg);
2329 }
2330 }
2331 }
2332 }
2333 }
2336 /* We've already got this specialization. */
2344 }
2346 /* Check that a template declaration's use of default arguments is not
2347 invalid. Here, PARMS are the template parameters. IS_PRIMARY is
2348 non-zero if DECL is the thing declared by a primary template.
2349 IS_PARTIAL is non-zero if DECL is a partial specialization. */
2351 static void
2353 tree decl;
2354 tree parms;
2357 {
2360 tree parm_level;
2362 /* [temp.param]
2364 A default template-argument shall not be specified in a
2365 function template declaration or a function template definition, nor
2366 in the template-parameter-list of the definition of a member of a
2367 class template. */
2370 /* You can't have a function template declaration in a local
2371 scope, nor you can you define a member of a class template in a
2372 local scope. */
2378 /* If this is either a friend defined in the scope of the class
2379 or a member function. */
2384 current_class_type)))
2385 /* And, if it was a member function, it really was defined in
2386 the scope of the class. */
2388 /* We already checked these parameters when the template was
2389 declared, so there's no need to do it again now. This function
2390 was defined in class scope, but we're processing it's body now
2391 that the class is complete. */
2394 /* [temp.param]
2396 If a template-parameter has a default template-argument, all
2397 subsequent template-parameters shall have a default
2398 template-argument supplied. */
2400 {
2407 {
2412 {
2414 /* For better subsequent error-recovery, we indicate that
2415 there should have been a default argument. */
2417 }
2418 }
2419 }
2422 /* For an ordinary class template, default template arguments are
2423 allowed at the innermost level, e.g.:
2424 template <class T = int>
2425 struct S {};
2426 but, in a partial specialization, they're not allowed even
2427 there, as we have in [temp.class.spec]:
2429 The template parameter list of a specialization shall not
2430 contain default template argument values.
2432 So, for a partial specialization, or for a function template,
2433 we look at all of them. */
2434 ;
2435 else
2436 /* But, for a primary class template that is not a partial
2437 specialization we look at all template parameters except the
2438 innermost ones. */
2441 /* Figure out what error message to issue. */
2446 else
2450 /* If we're inside a class definition, there's no need to
2451 examine the parameters to the class itself. On the one
2452 hand, they will be checked when the class is defined, and,
2453 on the other, default arguments are legal in things like:
2454 template <class T = double>
2455 struct S { template <class U> void f(U); };
2456 Here the default argument for `S' has no bearing on the
2457 declaration of `f'. */
2459 else
2460 /* Check everything. */
2466 {
2474 {
2476 {
2479 }
2481 /* Clear out the default argument so that we are not
2482 confused later. */
2484 }
2486 /* At this point, if we're still interested in issuing messages,
2487 they must apply to classes surrounding the object declared. */
2490 }
2491 }
2493 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
2494 parameters given by current_template_args, or reuses a
2495 previously existing one, if appropriate. Returns the DECL, or an
2496 equivalent one, if it is replaced via a call to duplicate_decls.
2498 If IS_FRIEND is non-zero, DECL is a friend declaration. */
2500 tree
2502 tree decl;
2504 {
2505 tree tmpl;
2506 tree args;
2507 tree info;
2508 tree ctx;
2513 /* See if this is a partial specialization. */
2521 /* For a friend, we want the context of the friend function, not
2522 the type of which it is a friend. */
2526 /* In the case of a virtual function, we want the class in which
2527 it is defined. */
2529 else
2530 /* Otherwise, if we're currently defining some class, the DECL
2531 is assumed to be a member of the class. */
2540 /* See if this is a primary template. */
2544 {
2555 else
2557 }
2559 /* Check to see that the rules regarding the use of default
2560 arguments are not being violated. */
2573 {
2578 /* If DECL is a TYPE_DECL for a class-template, then there won't
2579 be DECL_LANG_SPECIFIC. The information equivalent to
2580 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
2584 {
2585 /* Since a template declaration already existed for this
2586 class-type, we must be redeclaring it here. Make sure
2587 that the redeclaration is legal. */
2589 current_template_parms);
2590 /* We don't need to create a new TEMPLATE_DECL; just use the
2591 one we already had. */
2593 }
2594 else
2595 {
2601 {
2602 /* A specialization of a member template of a template
2603 class. */
2607 }
2608 }
2609 }
2610 else
2611 {
2616 {
2622 else
2623 {
2626 }
2627 }
2629 {
2632 }
2633 else
2640 {
2641 tree new_tmpl;
2643 /* The declaration is a specialization of a member
2644 template, declared outside the class. Therefore, the
2645 innermost template arguments will be NULL, so we
2646 replace them with the arguments determined by the
2647 earlier call to check_explicit_specialization. */
2650 new_tmpl
2661 args);
2663 }
2665 /* Make sure the template headers we got make sense. */
2670 {
2673 }
2674 else
2676 {
2681 {
2685 else
2689 }
2691 /* Perhaps we should also check that the parms are used in the
2692 appropriate qualifying scopes in the declarator? */
2696 else
2698 }
2699 }
2704 /* Push template declarations for global functions and types. Note
2705 that we do not try to push a global template friend declared in a
2706 template class; such a thing may well depend on the template
2707 parameters of the class. */
2718 {
2723 }
2728 }
2730 tree
2732 tree decl;
2733 {
2735 }
2737 /* Called when a class template TYPE is redeclared with the indicated
2738 template PARMS, e.g.:
2740 template <class T> struct S;
2741 template <class T> struct S {}; */
2743 void
2745 tree type;
2746 tree parms;
2747 {
2748 tree tmpl;
2749 tree tmpl_parms;
2753 {
2756 }
2760 /* The type is nested in some template class. Nothing to worry
2761 about here; there are no new template parameters for the nested
2762 type. */
2769 {
2776 }
2779 {
2786 {
2790 }
2793 {
2794 /* We have in [temp.param]:
2796 A template-parameter may not be given default arguments
2797 by two different declarations in the same scope. */
2801 }
2804 /* Update the previous template parameters (which are the ones
2805 that will really count) with the new default value. */
2808 /* Update the new parameters, too; they'll be used as the
2809 parameters for any members. */
2811 }
2812 }
2814 /* Attempt to convert the non-type template parameter EXPR to the
2815 indicated TYPE. If the conversion is successful, return the
2816 converted value. If the conversion is unsuccessful, return
2817 NULL_TREE if we issued an error message, or error_mark_node if we
2818 did not. We issue error messages for out-and-out bad template
2819 parameters, but not simply because the conversion failed, since we
2820 might be just trying to do argument deduction. By the time this
2821 function is called, neither TYPE nor EXPR may make use of template
2822 parameters. */
2824 static tree
2826 tree type;
2827 tree expr;
2828 {
2831 /* A template-argument for a non-type, non-template
2832 template-parameter shall be one of:
2834 --an integral constant-expression of integral or enumeration
2835 type; or
2837 --the name of a non-type template-parameter; or
2839 --the name of an object or function with external linkage,
2840 including function templates and function template-ids but
2841 excluding non-static class members, expressed as id-expression;
2842 or
2844 --the address of an object or function with external linkage,
2845 including function templates and function template-ids but
2846 excluding non-static class members, expressed as & id-expression
2847 where the & is optional if the name refers to a function or
2848 array; or
2850 --a pointer to member expressed as described in _expr.unary.op_. */
2852 /* An integral constant-expression can include const variables or
2853 enumerators. Simplify things by folding them to their values,
2854 unless we're about to bind the declaration to a reference
2855 parameter. */
2861 /* OK for now. We'll check that it has external linkage later.
2862 Check this first since if expr_type is the unknown_type_node
2863 we would otherwise complain below. */
2864 ;
2867 {
2870 }
2875 /* If expr is the address of an overloaded function, we
2876 will get the unknown_type_node at this point. */
2878 {
2879 tree referent;
2887 else
2888 {
2890 {
2891 bad_argument:
2894 {
2897 else
2899 }
2905 }
2909 }
2912 {
2913 cp_error ("string literal %E is not a valid template argument because it is the address of an object with static linkage",
2914 referent);
2916 }
2919 /* We'll check that it has external linkage later. */
2920 ;
2924 {
2927 }
2928 }
2932 /* The next two are g++ extensions. */
2935 {
2937 {
2938 non_constant:
2940 expr);
2942 }
2943 }
2944 else
2945 {
2948 }
2951 {
2955 /* For a non-type template-parameter of integral or enumeration
2956 type, integral promotions (_conv.prom_) and integral
2957 conversions (_conv.integral_) are applied. */
2961 /* It's safe to call digest_init in this case; we know we're
2962 just converting one integral constant expression to another. */
2966 /* Curiously, some TREE_CONSTANT integral expressions do not
2967 simplify to integer constants. For example, `3 % 0',
2968 remains a TRUNC_MOD_EXPR. */
2975 /* These are g++ extensions. */
2987 {
2991 {
2992 tree e;
2994 /* For a non-type template-parameter of type pointer to data
2995 member, qualification conversions (_conv.qual_) are
2996 applied. */
2999 /* The call to perform_qualification_conversions will
3000 insert a NOP_EXPR over EXPR to do express conversion,
3001 if necessary. But, that will confuse us if we use
3002 this (converted) template parameter to instantiate
3003 another template; then the thing will not look like a
3004 valid template argument. So, just make a new
3005 constant, of the appropriate type. */
3008 }
3010 {
3011 /* For a non-type template-parameter of type pointer to
3012 function, only the function-to-pointer conversion
3013 (_conv.func_) is applied. If the template-argument
3014 represents a set of overloaded functions (or a pointer to
3015 such), the matching function is selected from the set
3016 (_over.over_). */
3017 tree fns;
3018 tree fn;
3022 else
3031 {
3034 else
3036 }
3043 }
3044 else
3045 {
3046 /* For a non-type template-parameter of type pointer to
3047 object, qualification conversions (_conv.qual_) and the
3048 array-to-pointer conversion (_conv.array_) are applied.
3049 [Note: In particular, neither the null pointer conversion
3050 (_conv.ptr_) nor the derived-to-base conversion
3051 (_conv.ptr_) are applied. Although 0 is a valid
3052 template-argument for a non-type template-parameter of
3053 integral type, it is not a valid template-argument for a
3054 non-type template-parameter of pointer type.]
3056 The call to decay_conversion performs the
3057 array-to-pointer conversion, if appropriate. */
3062 else
3064 }
3065 }
3069 {
3072 /* If this expression already has reference type, get the
3073 underling object. */
3075 {
3079 }
3082 {
3083 /* For a non-type template-parameter of type reference to
3084 function, no conversions apply. If the
3085 template-argument represents a set of overloaded
3086 functions, the matching function is selected from the
3087 set (_over.over_). */
3088 tree fn;
3096 {
3098 /* Don't issue an error here; we might get a different
3099 function if the overloading had worked out
3100 differently. */
3102 else
3104 }
3111 }
3112 else
3113 {
3114 /* For a non-type template-parameter of type reference to
3115 object, no conversions apply. The type referred to by the
3116 reference may be more cv-qualified than the (otherwise
3117 identical) type of the template-argument. The
3118 template-parameter is bound directly to the
3119 template-argument, which must be an lvalue. */
3123 expr_type)
3126 }
3130 }
3134 {
3137 /* For a non-type template-parameter of type pointer to member
3138 function, no conversions apply. If the template-argument
3139 represents a set of overloaded member functions, the
3140 matching member function is selected from the set
3141 (_over.over_). */
3148 {
3149 /* A ptr-to-member constant. */
3152 else
3154 }
3167 }
3171 /* All non-type parameters must have one of these types. */
3174 }
3177 }
3179 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
3180 template template parameters. Both PARM_PARMS and ARG_PARMS are
3181 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
3182 or PARM_DECL.
3184 ARG_PARMS may contain more parameters than PARM_PARMS. If this is
3185 the case, then extra parameters must have default arguments.
3187 Consider the example:
3188 template <class T, class Allocator = allocator> class vector;
3189 template<template <class U> class TT> class C;
3191 C<vector> is a valid instantiation. PARM_PARMS for the above code
3192 contains a TYPE_DECL (for U), ARG_PARMS contains two TYPE_DECLs (for
3193 T and Allocator) and OUTER_ARGS contains the argument that is used to
3194 substitute the TT parameter. */
3196 static int
3202 {
3212 /* The rule here is opposite of coerce_template_parms. */
3219 {
3231 {
3236 /* We encounter instantiations of templates like
3237 template <template <template <class> class> class TT>
3238 class C; */
3239 {
3245 outer_args))
3247 }
3251 /* The tsubst call is used to handle cases such as
3252 template <class T, template <T> class TT> class D;
3253 i.e. the parameter list of TT depends on earlier parameters. */
3262 }
3263 }
3265 }
3267 /* Convert the indicated template ARG as necessary to match the
3268 indicated template PARM. Returns the converted ARG, or
3269 error_mark_node if the conversion was unsuccessful. Error messages
3270 are issued if COMPLAIN is non-zero. This conversion is for the Ith
3271 parameter in the parameter list. ARGS is the full set of template
3272 arguments deduced so far. */
3274 static tree
3276 tree parm;
3277 tree arg;
3278 tree args;
3281 tree in_decl;
3282 {
3283 tree val;
3284 tree inner_args;
3292 {
3293 /* The template argument was the name of some
3294 member function. That's usually
3295 illegal, but static members are OK. In any
3296 case, grab the underlying fields/functions
3297 and issue an error later if required. */
3300 }
3306 /* Check if it is a class template. If REQUIRES_TMPL_TYPE is true,
3307 we also accept implicitly created TYPE_DECL as a valid argument.
3308 This is necessary to handle the case where we pass a template name
3309 to a template template parameter in a scope where we've derived from
3310 in instantiation of that template, so the template name refers to that
3311 instantiation. We really ought to handle this better. */
3312 is_tmpl_type
3320 && requires_tmpl_type
3331 {
3336 complain);
3338 }
3340 {
3342 {
3344 {
3351 else
3353 }
3354 }
3356 }
3358 {
3360 {
3365 else
3367 }
3369 }
3372 {
3374 {
3380 {
3383 /* TEMPLATE_TEMPLATE_PARM node is preferred over
3384 TEMPLATE_DECL. */
3388 }
3389 else
3390 {
3392 {
3396 }
3399 }
3400 }
3401 else
3402 {
3405 {
3406 /* [basic.link]: A name with no linkage (notably, the
3407 name of a class or enumeration declared in a local
3408 scope) shall not be used to declare an entity with
3409 linkage. This implies that names with no linkage
3410 cannot be used as template arguments. */
3413 {
3415 cp_pedwarn
3417 else
3418 cp_error
3422 }
3423 }
3424 }
3425 }
3426 else
3427 {
3437 /* We used to call digest_init here. However, digest_init
3438 will report errors, which we don't want when complain
3439 is zero. More importantly, digest_init will try too
3440 hard to convert things: for example, `0' should not be
3441 converted to pointer type at this point according to
3442 the standard. Accepting this is not merely an
3443 extension, since deciding whether or not these
3444 conversions can occur is part of determining which
3445 function template to call, or whether a given explicit
3446 argument specification is legal. */
3448 else
3456 }
3459 }
3461 /* Convert all template arguments to their appropriate types, and
3462 return a vector containing the innermost resulting template
3463 arguments. If any error occurs, return error_mark_node, and, if
3464 COMPLAIN is non-zero, issue an error message. Some error messages
3465 are issued even if COMPLAIN is zero; for instance, if a template
3466 argument is composed from a local class.
3468 If REQUIRE_ALL_ARGUMENTS is non-zero, all arguments must be
3469 provided in ARGLIST, or else trailing parameters must have default
3470 values. If REQUIRE_ALL_ARGUMENTS is zero, we will attempt argument
3471 deduction for any unspecified trailing arguments. */
3473 static tree
3475 complain,
3476 require_all_arguments)
3478 tree in_decl;
3481 {
3483 tree inner_args;
3484 tree new_args;
3485 tree new_inner_args;
3493 && require_all_arguments
3495 {
3497 {
3503 }
3506 }
3511 {
3512 tree arg;
3513 tree parm;
3515 /* Get the Ith template parameter. */
3518 /* Calculate the Ith argument. */
3520 {
3523 }
3526 /* If no template argument was supplied, look for a default
3527 value. */
3529 {
3530 /* There was no default value. */
3533 }
3536 else
3538 in_decl);
3540 /* Now, convert the Ith argument, as necessary. */
3542 /* We're out of arguments. */
3543 {
3546 }
3548 {
3551 }
3552 else
3555 in_decl);
3558 lost++;
3560 }
3566 }
3568 /* Returns 1 if template args OT and NT are equivalent. */
3570 static int
3573 {
3578 /* For member templates */
3584 else
3586 }
3588 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
3589 of template arguments. Returns 0 otherwise. */
3591 int
3594 {
3601 {
3607 }
3609 }
3611 /* Given class template name and parameter list, produce a user-friendly name
3612 for the instantiation. */
3618 {
3625 else
3629 #define ccat(c) obstack_1grow (&scratch_obstack, (c));
3630 #define cat(s) obstack_grow (&scratch_obstack, (s), strlen (s))
3638 {
3646 {
3649 }
3651 {
3653 {
3654 /* Already substituted with real template. Just output
3655 the template name here */
3658 {
3659 /* The template may be defined in a namespace, or
3660 may be a member template. */
3666 }
3668 }
3669 else
3670 /* Output the parameter declaration */
3673 }
3674 else
3678 {
3679 /* New list cell was built because old chain link was in
3680 use. */
3683 }
3684 /* No need to check arglist against parmlist here; we did that
3685 in coerce_template_parms, called from lookup_template_class. */
3687 }
3688 {
3692 offset--;
3695 /* B<C<char> >, not B<C<char>> */
3698 }
3702 }
3704 static tree
3706 tree t;
3707 {
3709 /* Specializations have already had their names set up in
3710 lookup_template_class. */
3712 {
3715 /* For non-primary templates, the template parameters are
3716 implicit from their surrounding context. */
3718 {
3727 }
3728 }
3731 }
3733 static void
3735 tree d;
3736 {
3745 /* We are called both from instantiate_decl, where we've already had a
3746 tinst_level pushed, and instantiate_template, where we haven't.
3747 Compensate. */
3759 }
3762 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS (which
3763 may be either a _DECL or an overloaded function or an
3764 IDENTIFIER_NODE), and ARGLIST. */
3766 tree
3769 {
3770 tree type;
3773 {
3776 }
3784 else
3786 }
3788 /* Within the scope of a template class S<T>, the name S gets bound
3789 (in build_self_reference) to a TYPE_DECL for the class, not a
3790 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
3791 or one of its enclosing classes, and that type is a template,
3792 return the associated TEMPLATE_DECL. Otherwise, the original
3793 DECL is returned. */
3795 static tree
3797 tree decl;
3798 {
3805 }
3807 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
3808 parameters, find the desired type.
3810 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
3811 (Actually ARGLIST may be either a TREE_LIST or a TREE_VEC. It will
3812 be a TREE_LIST if called directly from the parser, and a TREE_VEC
3813 otherwise.)
3815 IN_DECL, if non-NULL, is the template declaration we are trying to
3816 instantiate.
3818 If ENTERING_SCOPE is non-zero, we are about to enter the scope of
3819 the class we are looking up.
3821 If COMPLAIN is non-zero, issue error messages.
3823 If the template class is really a local class in a template
3824 function, then the FUNCTION_CONTEXT is the function in which it is
3825 being instantiated. */
3827 tree
3830 tree in_decl;
3831 tree context;
3834 {
3836 tree t;
3839 {
3843 else
3844 {
3851 }
3854 }
3856 {
3859 /* If we are declaring a constructor, say A<T>::A<T>, we will get
3860 an implicit typename for the second A. Deal with it. */
3865 {
3868 }
3869 }
3872 {
3875 }
3878 {
3882 }
3884 /* With something like `template <class T> class X class X { ... };'
3885 we could end up with D1 having nothing but an IDENTIFIER_VALUE.
3886 We don't want to do that, but we have to deal with the situation,
3887 so let's give them some syntax errors to chew on instead of a
3888 crash. Alternatively D1 might not be a template type at all. */
3890 {
3894 }
3897 {
3899 {
3903 }
3905 }
3908 {
3909 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
3910 template arguments */
3912 tree parm;
3913 tree arglist2;
3925 }
3926 else
3927 {
3929 tree gen_tmpl;
3930 tree type_decl;
3943 {
3944 /* We've been given an incomplete set of template arguments.
3945 For example, given:
3947 template <class T> struct S1 {
3948 template <class U> struct S2 {};
3949 template <class U> struct S2<U*> {};
3950 };
3952 we will be called with an ARGLIST of `U*', but the
3953 TEMPLATE will be `template <class T> template
3954 <class U> struct S1<T>::S2'. We must fill in the missing
3955 arguments. */
3956 arglist
3958 arglist);
3960 }
3962 /* Now we should enough arguments. */
3965 /* From here on, we're only interested in the most general
3966 template. */
3969 /* Calculate the BOUND_ARGS. These will be the args that are
3970 actually tsubst'd into the definition to create the
3971 instantiation. */
3973 {
3974 /* We have multiple levels of arguments to coerce, at once. */
3984 {
3990 /* We temporarily reduce the length of the ARGLIST so
3991 that coerce_template_parms will see only the arguments
3992 corresponding to the template parameters it is
3993 examining. */
3995 }
3997 /* Restore the ARGLIST to its full size. */
4001 }
4002 else
4003 arglist
4010 /* We were unable to bind the arguments. */
4013 /* In the scope of a template class, explicit references to the
4014 template class refer to the type of the template, not any
4015 instantiation of it. For example, in:
4017 template <class T> class C { void f(C<T>); }
4019 the `C<T>' is just the same as `C'. Outside of the
4020 class, however, such a reference is an instantiation. */
4022 arglist))
4023 {
4027 {
4028 tree ctx;
4030 /* Note that we use DECL_CONTEXT, rather than
4031 CP_DECL_CONTEXT, so that the termination test is
4032 always just `ctx'. We're not interested in namespace
4033 scopes. */
4035 ctx;
4041 /* We're not in the scope of the class, so the
4042 TEMPLATE_TYPE is not the type we want after
4043 all. */
4045 }
4046 }
4054 {
4057 /* Use the move-to-front heuristic to speed up future
4058 searches. */
4065 }
4067 /* This type is a "partial instantiation" if any of the template
4068 arguments still involve template parameters. Note that we set
4069 IS_PARTIAL_INSTANTIATION for partial specializations as
4070 well. */
4076 {
4081 }
4088 /* Create the type. */
4090 {
4092 {
4095 }
4096 else
4097 /* We don't want to call start_enum for this type, since
4098 the values for the enumeration constants may involve
4099 template parameters. And, no one should be interested
4100 in the enumeration constants for such a type. */
4102 }
4103 else
4104 {
4112 /* A local class. Make sure the decl gets registered properly. */
4115 }
4117 /* If we called start_enum or pushtag above, this information
4118 will already be set up. */
4120 {
4130 }
4131 else
4134 /* Set up the template information. We have to figure out which
4135 template is the immediate parent if this is a full
4136 instantiation. */
4139 /* This case is easy; there are no member templates involved. */
4141 else
4142 {
4143 /* This is a full instantiation of a member template. Look
4144 for a partial instantiation of which this is an instance. */
4148 {
4152 /* We only want partial instantiations, here, not
4153 specializations or full instantiations. */
4158 /* Temporarily reduce by one the number of levels in the
4159 ARGLIST and in FOUND so as to avoid comparing the
4160 last set of arguments. */
4164 /* See if the arguments match. If they do, then TMPL is
4165 the partial instantiation we want. */
4168 /* Restore the argument vectors to their full size. */
4173 {
4176 }
4177 }
4180 {
4181 /* There was no partial instantiation. This happens
4182 where C<T> is a member template of A<T> and it's used
4183 in something like
4185 template <typename T> struct B { A<T>::C<int> m; };
4186 B<float>;
4188 Create the partial instantiation.
4189 */
4194 }
4195 }
4204 /* Now that the type has been registered on the instantiations
4205 list, we set up the enumerators. Because the enumeration
4206 constants may involve the enumeration type itself, we make
4207 sure to register the type first, and then create the
4208 constants. That way, doing tsubst_expr for the enumeration
4209 constants won't result in recursive calls here; we'll find
4210 the instantiation and exit above. */
4213 /* Reset the name of the type, now that CLASSTYPE_TEMPLATE_INFO
4214 is set up. */
4219 {
4222 else
4226 /* For backwards compatibility; code that uses
4227 -fexternal-templates expects looking up a template to
4228 instantiate it. I think DDD still relies on this.
4229 (jason 8/20/1998) */
4231 && flag_external_templates
4235 }
4236 else
4237 /* If the type makes use of template parameters, the
4238 code that generates debugging information will crash. */
4242 }
4243 }
4244 \f
4245 struct pair_fn_data
4246 {
4247 tree_fn_t fn;
4249 };
4251 /* Called from for_each_template_parm via walk_tree. */
4253 static tree
4258 {
4269 {
4273 /* Fall through. */
4285 /* Since we're not going to walk subtrees, we have to do this
4286 explicitly here. */
4289 /* Fall through. */
4292 /* Check the return type. */
4296 /* Check the parameter types. Since default arguments are not
4297 instantiated until they are needed, the TYPE_ARG_TYPES may
4298 contain expressions that involve template parameters. But,
4299 no-one should be looking at them yet. And, once they're
4300 instantiated, they don't contain template parameters, so
4301 there's no point in looking at them then, either. */
4302 {
4303 tree parm;
4309 /* Since we've already handled the TYPE_ARG_TYPES, we don't
4310 want walk_tree walking into them itself. */
4312 }
4320 /* Fall through. */
4330 /* Record template parameters such as `T' inside `TT<T>'. */
4333 /* Fall through. */
4345 /* A template template parameter is encountered */
4350 /* Already substituted template template parameter */
4368 /* If there's no type, then this thing must be some expression
4369 involving template parameters. */
4391 }
4393 /* We didn't find any template parameters we liked. */
4395 }
4397 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
4398 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
4399 call FN with the parameter and the DATA.
4400 If FN returns non-zero, the iteration is terminated, and
4401 for_each_template_parm returns 1. Otherwise, the iteration
4402 continues. If FN never returns a non-zero value, the value
4403 returned by for_each_template_parm is 0. If FN is NULL, it is
4404 considered to be the function which always returns 1. */
4406 static int
4408 tree t;
4409 tree_fn_t fn;
4411 {
4414 /* Set up. */
4418 /* Walk the tree. (Conceptually, we would like to walk without
4419 duplicates, but for_each_template_parm_r recursively calls
4420 for_each_template_parm, so we would need to reorganize a fair
4421 bit to use walk_tree_without_duplicates.) */
4423 for_each_template_parm_r,
4426 }
4428 int
4430 tree t;
4431 {
4433 }
4437 #ifdef GATHER_STATISTICS
4439 #endif
4443 /* We're starting to instantiate D; record the template instantiation context
4444 for diagnostics and to restore it later. */
4446 static int
4448 tree d;
4449 {
4453 {
4454 /* If the instantiation in question still has unbound template parms,
4455 we don't really care if we can't instantiate it, so just return.
4456 This happens with base instantiation for implicit `typename'. */
4461 cp_error ("template instantiation depth exceeds maximum of %d (use -ftemplate-depth-NN to increase the maximum) instantiating `%D'",
4467 }
4474 #ifdef GATHER_STATISTICS
4477 #endif
4481 }
4483 /* We're done instantiating this template; return to the instantiation
4484 context. */
4486 void
4488 {
4491 /* Restore the filename and line number stashed away when we started
4492 this instantiation. */
4500 }
4502 /* We're instantiating a deferred template; restore the template
4503 instantiation context in which the instantiation was requested, which
4504 is one step out from LEVEL. */
4506 static void
4508 tree level;
4509 {
4510 tree t;
4518 }
4520 /* Return the outermost template instantiation context, for use with
4521 -falt-external-templates. */
4523 tree
4525 {
4530 ;
4532 }
4534 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
4535 vector of template arguments, as for tsubst.
4537 Returns an appropriate tsubst'd friend declaration. */
4539 static tree
4541 tree decl;
4542 tree args;
4543 {
4544 tree new_friend;
4554 /* This was a friend declared with an explicit template
4555 argument list, e.g.:
4557 friend void f<>(T);
4559 to indicate that f was a template instantiation, not a new
4560 function declaration. Now, we have to figure out what
4561 instantiation of what template. */
4562 {
4564 tree new_args;
4565 tree tmpl;
4568 /* Friend functions are looked up in the containing namespace scope.
4569 We must enter that scope, to avoid finding member functions of the
4570 current cless with same name. */
4585 }
4589 /* The NEW_FRIEND will look like an instantiation, to the
4590 compiler, but is not an instantiation from the point of view of
4591 the language. For example, we might have had:
4593 template <class T> struct S {
4594 template <class U> friend void f(T, U);
4595 };
4597 Then, in S<int>, template <class U> void f(int, U) is not an
4598 instantiation of anything. */
4601 {
4605 }
4607 /* The mangled name for the NEW_FRIEND is incorrect. The call to
4608 tsubst will have resulted in a call to
4609 set_mangled_name_for_template_decl. But, the function is not a
4610 template instantiation and should not be mangled like one.
4611 Therefore, we remangle the function name. We don't have to do
4612 this if the NEW_FRIEND is a template since
4613 set_mangled_name_for_template_decl doesn't do anything if the
4614 function declaration still uses template arguments. */
4616 {
4620 }
4623 {
4624 tree old_decl;
4625 tree new_friend_template_info;
4626 tree new_friend_result_template_info;
4627 tree ns;
4630 /* We must save some information from NEW_FRIEND before calling
4631 duplicate decls since that function will free NEW_FRIEND if
4632 possible. */
4635 {
4636 /* This declaration is a `primary' template. */
4639 new_friend_is_defn
4641 new_friend_result_template_info
4643 }
4644 else
4645 {
4648 }
4650 /* Inside pushdecl_namespace_level, we will push into the
4651 current namespace. However, the friend function should go
4652 into the namespace of the template. */
4659 {
4660 /* This new friend declaration matched an existing
4661 declaration. For example, given:
4663 template <class T> void f(T);
4664 template <class U> class C {
4665 template <class T> friend void f(T) {}
4666 };
4668 the friend declaration actually provides the definition
4669 of `f', once C has been instantiated for some type. So,
4670 old_decl will be the out-of-class template declaration,
4671 while new_friend is the in-class definition.
4673 But, if `f' was called before this point, the
4674 instantiation of `f' will have DECL_TI_ARGS corresponding
4675 to `T' but not to `U', references to which might appear
4676 in the definition of `f'. Previously, the most general
4677 template for an instantiation of `f' was the out-of-class
4678 version; now it is the in-class version. Therefore, we
4679 run through all specialization of `f', adding to their
4680 DECL_TI_ARGS appropriately. In particular, they need a
4681 new set of outer arguments, corresponding to the
4682 arguments for this class instantiation.
4684 The same situation can arise with something like this:
4686 friend void f(int);
4687 template <class T> class C {
4688 friend void f(T) {}
4689 };
4691 when `C<int>' is instantiated. Now, `f(int)' is defined
4692 in the class. */
4695 /* On the other hand, if the in-class declaration does
4696 *not* provide a definition, then we don't want to alter
4697 existing definitions. We can just leave everything
4698 alone. */
4699 ;
4700 else
4701 {
4702 /* Overwrite whatever template info was there before, if
4703 any, with the new template information pertaining to
4704 the declaration. */
4708 /* duplicate_decls will take care of this case. */
4709 ;
4710 else
4711 {
4712 tree t;
4713 tree new_friend_args;
4722 {
4728 }
4730 /* Now, since specializations are always supposed to
4731 hang off of the most general template, we must move
4732 them. */
4735 {
4740 }
4741 }
4742 }
4744 /* The information from NEW_FRIEND has been merged into OLD_DECL
4745 by duplicate_decls. */
4747 }
4748 }
4750 {
4751 /* Check to see that the declaration is really present, and,
4752 possibly obtain an improved declaration. */
4754 new_friend);
4758 }
4760 done:
4764 }
4766 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
4767 template arguments, as for tsubst.
4769 Returns an appropriate tsubst'd friend type or error_mark_node on
4770 failure. */
4772 static tree
4774 tree friend_tmpl;
4775 tree args;
4776 {
4777 tree friend_type;
4778 tree tmpl;
4780 /* First, we look for a class template. */
4783 /* But, if we don't find one, it might be because we're in a
4784 situation like this:
4786 template <class T>
4787 struct S {
4788 template <class U>
4789 friend struct S;
4790 };
4792 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
4793 for `S<int>', not the TEMPLATE_DECL. */
4795 {
4798 }
4801 {
4802 /* The friend template has already been declared. Just
4803 check to see that the declarations match, and install any new
4804 default parameters. We must tsubst the default parameters,
4805 of course. We only need the innermost template parameters
4806 because that is all that redeclare_class_template will look
4807 at. */
4808 tree parms
4815 }
4816 else
4817 {
4818 /* The friend template has not already been declared. In this
4819 case, the instantiation of the template class will cause the
4820 injection of this template into the global scope. */
4823 /* The new TMPL is not an instantiation of anything, so we
4824 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
4825 the new type because that is supposed to be the corresponding
4826 template decl, i.e., TMPL. */
4831 /* Inject this template into the global scope. */
4833 }
4836 }
4838 tree
4840 tree type;
4841 {
4843 tree typedecl;
4851 /* Figure out which template is being instantiated. */
4855 /* Figure out which arguments are being used to do the
4856 instantiation. */
4861 /* If this is a partial instantiation, then we can't instantiate
4862 the type; there's no telling whether or not one of the
4863 template parameters might eventually be instantiated to some
4864 value that results in a specialization being used. For
4865 example, consider:
4867 template <class T>
4868 struct S {};
4870 template <class U>
4871 void f(S<U>);
4873 template <>
4874 struct S<int> {};
4876 Now, the `S<U>' in `f<int>' is the specialization, not an
4877 instantiation of the original template. */
4880 /* Determine what specialization of the original template to
4881 instantiate. */
4883 /* There's no telling which specialization is appropriate at this
4884 point. Since all peeking at the innards of this partial
4885 instantiation are extensions (like the "implicit typename"
4886 extension, which allows users to omit the keyword `typename' on
4887 names that are declared as types in template base classes), we
4888 are free to do what we please.
4890 Trying to figure out which partial instantiation to use can
4891 cause a crash. (Some of the template arguments don't even have
4892 types.) So, we just use the most general version. */
4894 else
4895 {
4899 {
4904 {
4906 args))
4907 {
4910 }
4911 }
4914 }
4915 }
4919 else
4922 /* If the template we're instantiating is incomplete, then clearly
4923 there's nothing we can do. */
4927 /* If this is a partial instantiation, don't tsubst anything. We will
4928 only use this type for implicit typename, so the actual contents don't
4929 matter. All that matters is whether a particular name is a type. */
4931 {
4932 /* The fields set here must be kept in sync with those cleared
4933 in begin_class_definition. */
4940 /* Pretend that the type is complete, so that we will look
4941 inside it during name lookup and such. */
4944 }
4946 /* If we've recursively instantiated too many templates, stop. */
4950 /* Now we're really doing the instantiation. Mark the type as in
4951 the process of being defined. */
4957 {
4958 /* This TYPE is actually a instantiation of of a partial
4959 specialization. We replace the innermost set of ARGS with
4960 the arguments appropriate for substitution. For example,
4961 given:
4963 template <class T> struct S {};
4964 template <class T> struct S<T*> {};
4966 and supposing that we are instantiating S<int*>, ARGS will
4967 present be {int*} but we need {int}. */
4968 tree inner_args
4970 args);
4972 /* If there were multiple levels in ARGS, replacing the
4973 innermost level would alter CLASSTYPE_TI_ARGS, which we don't
4974 want, so we make a copy first. */
4976 {
4979 }
4980 else
4982 }
4985 {
4987 {
4993 }
4994 else
4995 {
4997 SET_CLASSTYPE_INTERFACE_UNKNOWN_X
5002 }
5003 }
5004 else
5005 {
5008 }
5040 {
5045 /* Substitute into each of the bases to determine the actual
5046 basetypes. */
5048 {
5049 tree base;
5050 tree access;
5051 tree pbase;
5055 /* Substitute to figure out the base class. */
5061 /* Calculate the correct access node. */
5063 {
5068 else
5070 }
5071 else
5072 {
5077 else
5079 }
5082 }
5084 /* The list is now in reverse order; correct that. */
5087 /* Now call xref_basetypes to set up all the base-class
5088 information. */
5094 type,
5095 base_list);
5096 }
5098 /* Now that our base classes are set up, enter the scope of the
5099 class, so that name lookups into base classes, etc. will work
5100 correctly. This is precisely analogous to what we do in
5101 begin_class_definition when defining an ordinary non-template
5102 class. */
5106 {
5109 tree newtag;
5113 {
5115 /* Unfortunately, lookup_template_class sets
5116 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
5117 instantiation (i.e., for the type of a member template
5118 class nested within a template class.) This behavior is
5119 required for maybe_process_partial_specialization to work
5120 correctly, but is not accurate in this case; the TAG is not
5121 an instantiation of anything. (The corresponding
5122 TEMPLATE_DECL is an instantiation, but the TYPE is not.) */
5125 /* Now, we call pushtag to put this NEWTAG into the scope of
5126 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
5127 pushtag calling push_template_decl. We don't have to do
5128 this for enums because it will already have been done in
5129 tsubst_enum. */
5133 }
5134 }
5136 /* Don't replace enum constants here. */
5139 {
5140 tree r;
5142 /* The the file and line for this declaration, to assist in
5143 error message reporting. Since we called push_tinst_level
5144 above, we don't need to restore these. */
5150 {
5151 tree init;
5156 else
5165 }
5167 /* R will have a TREE_CHAIN if and only if it has already been
5168 processed by finish_member_declaration. This can happen
5169 if, for example, it is a TYPE_DECL for a class-scoped
5170 ENUMERAL_TYPE; such a thing will already have been added to
5171 the field list by tsubst_enum above. */
5173 {
5176 }
5177 }
5179 /* Set up the list (TYPE_METHODS) and vector (CLASSTYPE_METHOD_VEC)
5180 for this instantiation. */
5182 {
5186 }
5188 /* Construct the DECL_FRIENDLIST for the new class type. */
5193 {
5194 tree friends;
5202 args));
5203 else
5205 }
5210 {
5212 tree new_friend_type;
5218 NULL_TREE);
5219 else
5220 {
5223 /* The call to xref_tag_from_type does injection for friend
5224 classes. */
5226 new_friend_type =
5229 }
5232 /* Trick make_friend_class into realizing that the friend
5233 we're adding is a template, not an ordinary class. It's
5234 important that we use make_friend_class since it will
5235 perform some error-checking and output cross-reference
5236 information. */
5244 }
5248 {
5251 }
5253 /* Set the file and line number information to whatever is given for
5254 the class itself. This puts error messages involving generated
5255 implicit functions at a predictable point, and the same point
5256 that would be used for non-template classes. */
5264 /* Clear this now so repo_template_used is happy. */
5268 /* Now that the class is complete, instantiate default arguments for
5269 any member functions. We don't do this earlier because the
5270 default arguments may reference members of the class. */
5274 /* Implicitly generated member functions will not have template
5275 information; they are not instantiations, but instead are
5276 created "fresh" for each instantiation. */
5285 }
5287 static int
5290 {
5295 /* Don't care if one declares its arg const and the other doesn't -- the
5296 main variant of the arg type is all that matters. */
5301 }
5303 /* If arg is a non-type template parameter that does not depend on template
5304 arguments, fold it like we weren't in the body of a template. */
5306 static tree
5308 tree arg;
5309 {
5310 /* If we're not in a template, ARG is already as simple as it's going to
5311 get, and trying to reprocess the trees will break. */
5316 {
5317 /* Sometimes, one of the args was an expression involving a
5318 template constant parameter, like N - 1. Now that we've
5319 tsubst'd, we might have something like 2 - 1. This will
5320 confuse lookup_template_class, so we do constant folding
5321 here. We have to unset processing_template_decl, to
5322 fool build_expr_from_tree() into building an actual
5323 tree. */
5329 }
5331 }
5333 /* Substitute ARGS into the vector of template arguments T. */
5335 static tree
5337 tree t;
5338 tree args;
5340 {
5347 {
5352 else
5355 NULL_TREE));
5362 }
5372 }
5374 /* Return the result of substituting ARGS into the template parameters
5375 given by PARMS. If there are m levels of ARGS and m + n levels of
5376 PARMS, then the result will contain n levels of PARMS. For
5377 example, if PARMS is `template <class T> template <class U>
5378 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
5379 result will be `template <int*, double, class V>'. */
5381 static tree
5383 tree parms;
5384 tree args;
5386 {
5394 {
5395 tree new_vec =
5400 {
5401 tree default_value =
5403 tree parm_decl =
5408 NULL_TREE),
5410 NULL_TREE));
5411 }
5417 }
5420 }
5422 /* Substitute the ARGS into the indicated aggregate (or enumeration)
5423 type T. If T is not an aggregate or enumeration type, it is
5424 handled as if by tsubst. IN_DECL is as for tsubst. If
5425 ENTERING_SCOPE is non-zero, T is the context for a template which
5426 we are presently tsubst'ing. Return the substituted value. */
5428 static tree
5430 tree t;
5431 tree args;
5433 tree in_decl;
5435 {
5440 {
5443 {
5444 tree r = build_ptrmemfunc_type
5447 complain);
5448 }
5450 /* else fall through */
5454 {
5455 tree argvec;
5456 tree context;
5457 tree r;
5459 /* First, determine the context for the type we are looking
5460 up. */
5463 complain,
5465 else
5468 /* Then, figure out what arguments are appropriate for the
5469 type we are trying to find. For example, given:
5471 template <class T> struct S;
5472 template <class T, class U> void f(T, U) { S<U> su; }
5474 and supposing that we are instantiating f<int, double>,
5475 then our ARGS will be {int, double}, but, when looking up
5476 S we only want {double}. */
5478 complain);
5486 complain);
5487 }
5488 else
5489 /* This is not a template type, so there's nothing to do. */
5494 }
5495 }
5497 /* Substitute into the default argument ARG (a default argument for
5498 FN), which has the indicated TYPE. */
5500 tree
5502 tree fn;
5503 tree type;
5504 tree arg;
5505 {
5506 /* This default argument came from a template. Instantiate the
5507 default argument here, not in tsubst. In the case of
5508 something like:
5510 template <class T>
5511 struct S {
5512 static T t();
5513 void f(T = t());
5514 };
5516 we must be careful to do name lookup in the scope of S<T>,
5517 rather than in the current class. */
5526 /* Make sure the default argument is reasonable. */
5530 }
5532 /* Substitute into all the default arguments for FN. */
5534 static void
5536 tree fn;
5537 {
5538 tree arg;
5539 tree tmpl_args;
5543 /* If this function is not yet instantiated, we certainly don't need
5544 its default arguments. */
5549 arg;
5555 }
5557 /* Substitute the ARGS into the T, which is a _DECL. TYPE is the
5558 (already computed) substitution of ARGS into TREE_TYPE (T), if
5559 appropriate. Return the result of the substitution. */
5561 static tree
5563 tree t;
5564 tree args;
5565 tree type;
5566 {
5572 /* Set the filename and linenumber to improve error-reporting. */
5579 {
5581 {
5582 /* We can get here when processing a member template function
5583 of a template class. */
5585 tree spec;
5589 {
5590 /* We might already have an instance of this template.
5591 The ARGS are for the surrounding class type, so the
5592 full args contain the tsubst'd args for the context,
5593 plus the innermost args from the template decl. */
5597 tree full_args;
5602 /* tsubst_template_arg_vector doesn't copy the vector if
5603 nothing changed. But, *something* should have
5604 changed. */
5609 {
5612 }
5613 }
5615 /* Make a new template decl. It will be similar to the
5616 original, but will record the current template arguments.
5617 We also create a new function declaration, which is just
5618 like the old one, but points to this new template, rather
5619 than the old one. */
5625 {
5630 }
5643 {
5650 }
5651 else
5652 {
5659 }
5665 /* The template parameters for this new template are all the
5666 template parameters for the old template, except the
5667 outermost level of parameters. */
5675 /* We don't partially instantiate partial specializations. */
5679 /* Record this partial instantiation. */
5683 }
5687 {
5688 tree ctx;
5691 tree gen_tmpl;
5696 /* Nobody should be tsubst'ing into non-template functions. */
5700 {
5701 tree spec;
5703 /* Calculate the most general template of which R is a
5704 specialization, and the complete set of arguments used to
5705 specialize R. */
5707 argvec
5712 /* Check to see if we already have this specialization. */
5716 {
5719 }
5721 /* We can see more levels of arguments than parameters if
5722 there was a specialization of a member template, like
5723 this:
5725 template <class T> struct S { template <class U> void f(); }
5726 template <> template <class U> void S<int>::f(U);
5728 Here, we'll be substituting into the specialization,
5729 because that's where we can find the code we actually
5730 want to generate, but we'll have enough arguments for
5731 the most general template.
5733 We also deal with the peculiar case:
5735 template <class T> struct S {
5736 template <class U> friend void f();
5737 };
5738 template <class U> void f() {}
5739 template S<int>;
5740 template void f<double>();
5742 Here, the ARGS for the instantiation of will be {int,
5743 double}. But, we only need as many ARGS as there are
5744 levels of template parameters in CODE_PATTERN. We are
5745 careful not to get fooled into reducing the ARGS in
5746 situations like:
5748 template <class T> struct S { template <class U> void f(U); }
5749 template <class T> template <> void S<T>::f(int) {}
5751 which we can spot because the pattern will be a
5752 specialization in this case. */
5754 parms_depth =
5759 }
5760 else
5761 {
5762 /* This special case arises when we have something like this:
5764 template <class T> struct S {
5765 friend void f<int>(int, double);
5766 };
5768 Here, the DECL_TI_TEMPLATE for the friend declaration
5769 will be a LOOKUP_EXPR or an IDENTIFIER_NODE. We are
5770 being called from tsubst_friend_function, and we want
5771 only to create a new decl (R) with appropriate types so
5772 that we can call determine_specialization. */
5778 }
5781 {
5784 else
5789 }
5790 else
5791 {
5794 }
5799 /* We do NOT check for matching decls pushed separately at this
5800 point, as they may not represent instantiations of this
5801 template, and in any case are considered separate under the
5802 discrete model. */
5814 {
5815 /* Type-conversion operator. Reconstruct the name, in
5816 case it's the name of one of the template's parameters. */
5819 else
5821 }
5838 {
5843 }
5845 /* Set up the DECL_TEMPLATE_INFO for R and compute its mangled
5846 name. There's no need to do this in the special friend
5847 case mentioned above where GEN_TMPL is NULL. */
5849 {
5855 /* Set the mangled name for R. */
5857 {
5860 else
5862 }
5863 else
5864 {
5865 /* Instantiations of template functions must be mangled
5866 specially, in order to conform to 14.5.5.1
5867 [temp.over.link]. */
5870 /* TMPL will be NULL if this is a specialization of a
5871 member function of a template class. */
5877 else
5879 }
5884 /* Like grokfndecl. If we don't do this, pushdecl will
5885 mess up our TREE_CHAIN because it doesn't find a
5886 previous decl. Sigh. */
5893 /* We're not supposed to instantiate default arguments
5894 until they are called, for a template. But, for a
5895 declaration like:
5897 template <class T> void f ()
5898 { extern void g(int i = T()); }
5900 we should do the substitution when the template is
5901 instantiated. We handle the member function case in
5902 instantiate_class_template since the default arguments
5903 might refer to other members of the class. */
5908 }
5910 /* Copy the list of befriending classes. */
5914 {
5918 in_decl);
5919 }
5922 {
5926 /* If this is an instantiation of a member template, clone it.
5927 If it isn't, that'll be handled by
5928 clone_constructors_and_destructors. */
5931 }
5934 }
5938 {
5945 else
5958 }
5962 {
5967 /* We don't have to set DECL_CONTEXT here; it is set by
5968 finish_member_declaration. */
5974 }
5978 {
5983 }
5989 {
5990 /* If this is the canonical decl, we don't have to mess with
5991 instantiations, and often we can't (for typename, template
5992 type parms and such). Note that TYPE_NAME is not correct for
5993 the above test if we've copied the type for a typedef. */
5996 }
5998 /* Fall through. */
6001 {
6004 tree spec;
6006 tree ctx;
6009 /* Assume this is a non-local variable. */
6016 else
6017 {
6018 /* Subsequent calls to pushdecl will fill this in. */
6022 }
6024 /* Check to see if we already have this specialization. */
6026 {
6031 }
6032 else
6036 {
6039 }
6046 /* Don't try to expand the initializer until someone tries to use
6047 this variable; otherwise we run into circular dependencies. */
6052 /* For __PRETTY_FUNCTION__ we have to adjust the initializer. */
6054 {
6056 args,
6058 NULL_TREE);
6060 }
6062 /* Even if the original location is out of scope, the newly
6063 substituted one is not. */
6068 {
6069 /* A static data member declaration is always marked
6070 external when it is declared in-class, even if an
6071 initializer is present. We mimic the non-template
6072 processing here. */
6078 }
6079 else
6085 }
6090 }
6092 /* Restore the file and line information. */
6097 }
6099 /* Substitue into the ARG_TYPES of a function type. */
6101 static tree
6103 tree arg_types;
6104 tree args;
6106 tree in_decl;
6107 {
6108 tree remaining_arg_types;
6109 tree type;
6123 {
6125 {
6129 }
6131 }
6133 /* Do array-to-pointer, function-to-pointer conversion, and ignore
6134 top-level qualifiers as required. */
6137 /* Note that we do not substitute into default arguments here. The
6138 standard mandates that they be instantiated only when needed,
6139 which is done in build_over_call. */
6141 remaining_arg_types);
6143 }
6145 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
6146 *not* handle the exception-specification for FNTYPE, because the
6147 initial substitution of explicitly provided template parameters
6148 during argument deduction forbids substitution into the
6149 exception-specification:
6151 [temp.deduct]
6153 All references in the function type of the function template to the
6154 corresponding template parameters are replaced by the specified tem-
6155 plate argument values. If a substitution in a template parameter or
6156 in the function type of the function template results in an invalid
6157 type, type deduction fails. [Note: The equivalent substitution in
6158 exception specifications is done only when the function is instanti-
6159 ated, at which point a program is ill-formed if the substitution
6160 results in an invalid type.] */
6162 static tree
6164 tree t;
6165 tree args;
6167 tree in_decl;
6168 {
6169 tree return_type;
6170 tree arg_types;
6171 tree fntype;
6173 /* The TYPE_CONTEXT is not used for function/method types. */
6176 /* Substitue the return type. */
6181 /* Substitue the argument types. */
6187 /* Construct a new type node and return it. */
6190 else
6191 {
6194 {
6195 /* [temp.deduct]
6197 Type deduction may fail for any of the following
6198 reasons:
6200 -- Attempting to create "pointer to member of T" when T
6201 is not a class type. */
6204 r);
6206 }
6210 }
6215 }
6217 /* Substitute into the PARMS of a call-declarator. */
6219 static tree
6221 tree parms;
6222 tree args;
6224 tree in_decl;
6225 {
6226 tree new_parms;
6227 tree type;
6228 tree defarg;
6236 /* Figure out the type of this parameter. */
6239 /* Figure out the default argument as well. Note that we use
6240 tsubst_expr since the default argument is really an expression. */
6243 /* Chain this parameter on to the front of those we have already
6244 processed. We don't use hash_tree_cons because that function
6245 doesn't check TREE_PARMLIST. */
6248 /* And note that these are parameters. */
6252 }
6254 /* Take the tree structure T and replace template parameters used
6255 therein with the argument vector ARGS. IN_DECL is an associated
6256 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
6257 An appropriate error message is issued only if COMPLAIN is
6258 non-zero. Note that we must be relatively non-tolerant of
6259 extensions here, in order to preserve conformance; if we allow
6260 substitutions that should not be allowed, we may allow argument
6261 deductions that should not succeed, and therefore report ambiguous
6262 overload situations where there are none. In theory, we could
6263 allow the substitution, but indicate that it should have failed,
6264 and allow our caller to make sure that the right thing happens, but
6265 we don't try to do this yet.
6267 This function is used for dealing with types, decls and the like;
6268 for expressions, use tsubst_expr or tsubst_copy. */
6270 tree
6274 tree in_decl;
6275 {
6287 else
6306 {
6334 {
6341 /* See if we can reduce this expression to something simpler. */
6347 /* When providing explicit arguments to a template
6348 function, but leaving some arguments for subsequent
6349 deduction, MAX may be template-dependent even if we're
6350 not PROCESSING_TEMPLATE_DECL. We still need to check for
6351 template parms, though; MAX won't be an INTEGER_CST for
6352 dynamic arrays, either. */
6355 {
6359 integer_one_node);
6361 }
6364 {
6365 /* Still allow an explicit array of size zero. */
6368 }
6372 {
6373 /* [temp.deduct]
6375 Type deduction may fail for any of the following
6376 reasons:
6378 Attempting to create an array with a size that is
6379 zero or negative. */
6384 }
6387 }
6393 {
6403 {
6406 }
6407 else
6408 {
6411 }
6414 {
6424 {
6426 {
6428 return cp_build_qualified_type_real
6430 complain);
6431 }
6433 {
6434 /* We are processing a type constructed from
6435 a template template parameter */
6441 /* We can get a TEMPLATE_TEMPLATE_PARM here when
6442 we are resolving nested-types in the signature of
6443 a member function templates.
6444 Otherwise ARG is a TEMPLATE_DECL and is the real
6445 template to be instantiated. */
6453 complain);
6456 complain);
6457 }
6458 else
6459 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
6461 }
6462 }
6463 else
6467 /* This can happen during the attempted tsubst'ing in
6468 unify. This means that we don't yet have any information
6469 about the template parameter in question. */
6472 /* If we get here, we must have been looking at a parm for a
6473 more deeply nested template. Make a new version of this
6474 template parameter, but with a lower level. */
6476 {
6481 {
6484 complain);
6485 }
6486 else
6487 {
6498 {
6506 }
6507 }
6516 }
6519 }
6522 {
6530 {
6534 }
6537 {
6541 }
6544 {
6548 }
6554 {
6557 }
6558 else
6561 }
6564 {
6565 /* A binfo node. We always need to make a copy, of the node
6566 itself and of its BINFO_BASETYPES. */
6570 /* Make sure type isn't a typedef copy. */
6575 {
6580 }
6582 }
6584 /* Otherwise, a vector of template arguments. */
6589 {
6598 /* [temp.deduct]
6600 Type deduction may fail for any of the following
6601 reasons:
6603 -- Attempting to create a pointer to reference type.
6604 -- Attempting to create a reference to a reference type or
6605 a reference to void. */
6608 {
6612 /* We keep track of the last time we issued this error
6613 message to avoid spewing a ton of messages during a
6614 single bad template instantiation. */
6617 {
6620 else
6623 type);
6626 }
6629 }
6632 else
6637 /* Will this ever be needed for TYPE_..._TO values? */
6641 }
6643 {
6646 {
6647 /* [temp.deduct]
6649 Type deduction may fail for any of the following
6650 reasons:
6652 -- Attempting to create "pointer to member of T" when T
6653 is not a class type. */
6656 r);
6658 }
6660 }
6663 {
6664 tree fntype;
6665 tree raises;
6671 /* Substitue the exception specification. */
6674 {
6679 else
6681 {
6688 }
6690 }
6692 }
6694 {
6699 /* As an optimization, we avoid regenerating the array type if
6700 it will obviously be the same as T. */
6704 /* These checks should match the ones in grokdeclarator.
6706 [temp.deduct]
6708 The deduction may fail for any of the following reasons:
6710 -- Attempting to create an array with an element type that
6711 is void, a function type, or a reference type. */
6715 {
6719 }
6723 }
6727 {
6729 in_decl);
6731 in_decl);
6737 }
6741 {
6743 in_decl);
6748 }
6751 {
6761 {
6764 ctx);
6766 }
6768 {
6769 /* Normally, make_typename_type does not require that the CTX
6770 have complete type in order to allow things like:
6772 template <class T> struct S { typename S<T>::X Y; };
6774 But, such constructs have already been resolved by this
6775 point, so here CTX really should have complete type, unless
6776 it's a partial instantiation. */
6779 {
6783 }
6784 }
6792 complain);
6793 }
6796 {
6798 in_decl);
6802 }
6805 {
6807 in_decl);
6811 }
6814 {
6816 in_decl);
6818 in_decl);
6823 }
6826 {
6828 in_decl);
6829 tree e2 = (tsubst_call_declarator_parms
6839 }
6842 {
6844 in_decl);
6850 }
6853 {
6855 in_decl);
6860 }
6863 {
6866 tree type;
6867 tree str;
6869 /* This code should match declare_hidden_char_array in
6870 c-common.c. */
6878 }
6884 }
6885 }
6887 /* Like tsubst, but deals with expressions. This function just replaces
6888 template parms; to finish processing the resultant expression, use
6889 tsubst_expr. */
6891 tree
6895 tree in_decl;
6896 {
6898 tree r;
6906 {
6911 {
6912 tree enum_type;
6913 tree v;
6916 /* This is a global enumeration constant. */
6919 /* Unfortunately, we cannot just call lookup_name here.
6920 Consider:
6922 template <int I> int f() {
6923 enum E { a = I };
6924 struct S { void g() { E e = a; } };
6925 };
6927 When we instantiate f<7>::S::g(), say, lookup_name is not
6928 clever enough to find f<7>::a. */
6929 enum_type
6939 /* We didn't find the name. That should never happen; if
6940 name-lookup found it during preliminary parsing, we
6941 should find it again here during instantiation. */
6943 }
6948 {
6949 tree ctx;
6955 }
6968 else
6972 {
6973 /* We must tsbust into a LOOKUP_EXPR in case the names to
6974 which it refers is a conversion operator; in that case the
6975 name will change. We avoid making unnecessary copies,
6976 however. */
6981 {
6985 }
6988 }
6996 return build1
7013 return build1
7057 return build_nt
7062 {
7066 else
7067 /* Sometimes FN is a LOOKUP_EXPR. */
7069 return build_nt
7071 in_decl),
7072 NULL_TREE);
7073 }
7076 {
7079 {
7083 }
7086 {
7094 }
7095 else
7097 return build_nt
7101 NULL_TREE);
7102 }
7105 /* This processing should really occur in tsubst_expr, However,
7106 tsubst_expr does not recurse into expressions, since it
7107 assumes that there aren't any statements inside them.
7108 Instead, it simply calls build_expr_from_tree. So, we need
7109 to expand the STMT_EXPR here. */
7111 {
7116 }
7123 {
7124 r = build_nt
7129 }
7132 {
7133 r = build_nt
7139 }
7142 {
7143 r = build_nt
7149 }
7152 {
7153 /* Substituted template arguments */
7155 in_decl);
7158 {
7159 tree chain;
7162 }
7164 {
7169 }
7171 return lookup_template_function
7173 }
7176 {
7196 }
7218 {
7222 else
7224 }
7225 else
7229 {
7230 r = build
7236 }
7240 in_decl),
7248 }
7249 }
7251 /* Like tsubst_copy, but also does semantic processing. */
7253 tree
7257 tree in_decl;
7258 {
7259 tree stmt;
7268 {
7271 finish_named_return_value
7278 {
7279 tree member_init_list;
7280 tree base_init_list;
7283 member_init_list
7285 base_init_list
7290 }
7305 {
7306 tree decl;
7307 tree init;
7313 else
7314 {
7319 {
7321 /* Make sure the type is instantiated now. */
7325 /* By marking the declaration as instantiated, we avoid
7326 trying to instantiate it. Since instantiate_decl can't
7327 handle local variables, and since we've already done
7328 all that needs to be done, that's the right thing to
7329 do. */
7334 }
7335 }
7337 }
7340 {
7341 tree tmp;
7350 stmt);
7355 }
7359 {
7364 stmt);
7367 }
7371 {
7378 stmt);
7379 }
7383 {
7384 tree tmp;
7390 stmt);
7393 {
7396 }
7399 {
7403 }
7406 }
7410 {
7411 tree substmt;
7420 }
7434 {
7435 tree val;
7443 }
7450 in_decl));
7462 /* Computed goto's must be tsubst'd into. On the other hand,
7463 non-computed gotos must not be; the identifier in question
7464 will have no binding. */
7466 else
7478 in_decl));
7484 {
7490 stmt);
7491 }
7492 else
7493 {
7494 tree handler;
7498 else
7505 else
7513 else
7515 }
7519 {
7520 tree decl;
7521 tree blocks;
7526 {
7529 /* Prevent instantiate_decl from trying to instantiate
7530 this variable. We've already done all that needs to be
7531 done. */
7533 }
7534 else
7539 }
7550 }
7552 }
7554 /* TMPL is a TEMPLATE_DECL for a cloned constructor or destructor.
7555 Instantiate it with the ARGS. */
7557 static tree
7559 tree tmpl;
7560 tree args;
7561 {
7562 tree spec;
7563 tree clone;
7565 /* Instantiated the cloned function, rather than the clone. */
7568 /* Then, see if we've already cloned the instantiation. */
7575 /* If we haven't, do so know. */
7579 /* Look again. */
7586 /* We should always have found the clone by now. */
7589 }
7591 /* Instantiate the indicated variable or function template TMPL with
7592 the template arguments in TARG_PTR. */
7594 tree
7597 {
7598 tree clone;
7599 tree fndecl;
7600 tree gen_tmpl;
7601 tree spec;
7603 tree inner_args;
7610 /* If this function is a clone, handle it specially. */
7614 /* Check to see if we already have this specialization. */
7621 {
7622 /* The TMPL is a partial instantiation. To get a full set of
7623 arguments we must add the arguments used to perform the
7624 partial instantiation. */
7626 targ_ptr);
7628 /* Check to see if we already have this specialization. */
7632 }
7638 {
7641 {
7644 {
7648 }
7649 }
7650 }
7652 /* substitute template parameters */
7655 /* The DECL_TI_TEMPLATE should always be the immediate parent
7656 template, not the most general template. */
7662 /* If we've just instantiated the main entry point for a function,
7663 instantiate all the alternate entry points as well. */
7670 }
7672 /* The FN is a TEMPLATE_DECL for a function. The ARGS are the
7673 arguments that are being used when calling it. TARGS is a vector
7674 into which the deduced template arguments are placed.
7676 Return zero for success, 2 for an incomplete match that doesn't resolve
7677 all the types, and 1 for complete failure. An error message will be
7678 printed only for an incomplete match.
7680 If FN is a conversion operator, or we are trying to produce a specific
7681 specialization, RETURN_TYPE is the return type desired.
7683 The EXPLICIT_TARGS are explicit template arguments provided via a
7684 template-id.
7686 The parameter STRICT is one of:
7688 DEDUCE_CALL:
7689 We are deducing arguments for a function call, as in
7690 [temp.deduct.call].
7692 DEDUCE_CONV:
7693 We are deducing arguments for a conversion function, as in
7694 [temp.deduct.conv].
7696 DEDUCE_EXACT:
7697 We are deducing arguments when doing an explicit instantiation
7698 as in [temp.explicit], when determining an explicit specialization
7699 as in [temp.expl.spec], or when taking the address of a function
7700 template, as in [temp.deduct.funcaddr].
7702 DEDUCE_ORDER:
7703 We are deducing arguments when calculating the partial
7704 ordering between specializations of function or class
7705 templates, as in [temp.func.order] and [temp.class.order].
7707 LEN is the number of parms to consider before returning success, or -1
7708 for all. This is used in partial ordering to avoid comparing parms for
7709 which no actual argument was passed, since they are not considered in
7710 overload resolution (and are explicitly excluded from consideration in
7711 partial ordering in [temp.func.order]/6). */
7713 int
7717 unification_kind_t strict;
7719 {
7720 tree parms;
7721 tree fntype;
7728 {
7729 /* [temp.deduct]
7731 The specified template arguments must match the template
7732 parameters in kind (i.e., type, nontype, template), and there
7733 must not be more arguments than there are parameters;
7734 otherwise type deduction fails.
7736 Nontype arguments must match the types of the corresponding
7737 nontype template parameters, or must be convertible to the
7738 types of the corresponding nontype parameters as specified in
7739 _temp.arg.nontype_, otherwise type deduction fails.
7741 All references in the function type of the function template
7742 to the corresponding template parameters are replaced by the
7743 specified template argument values. If a substitution in a
7744 template parameter or in the function type of the function
7745 template results in an invalid type, type deduction fails. */
7747 tree converted_args;
7749 converted_args
7760 /* Place the explicitly specified arguments in TARGS. */
7763 }
7766 /* Never do unification on the 'this' parameter. */
7771 {
7772 /* We've been given a return type to match, prepend it. */
7777 }
7779 /* We allow incomplete unification without an error message here
7780 because the standard doesn't seem to explicitly prohibit it. Our
7781 callers must be ready to deal with unification failures in any
7782 event. */
7788 /* All is well so far. Now, check:
7790 [temp.deduct]
7792 When all template arguments have been deduced, all uses of
7793 template parameters in nondeduced contexts are replaced with
7794 the corresponding deduced argument values. If the
7795 substitution results in an invalid type, as described above,
7796 type deduction fails. */
7802 }
7804 /* Adjust types before performing type deduction, as described in
7805 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
7806 sections are symmetric. PARM is the type of a function parameter
7807 or the return type of the conversion function. ARG is the type of
7808 the argument passed to the call, or the type of the value
7809 initialized with the result of the conversion function. */
7811 static int
7813 unification_kind_t strict;
7816 {
7820 {
7825 {
7826 /* Swap PARM and ARG throughout the remainder of this
7827 function; the handling is precisely symmetric since PARM
7828 will initialize ARG rather than vice versa. */
7833 }
7836 /* There is nothing to do in this case. */
7840 /* DR 214. [temp.func.order] is underspecified, and leads to no
7841 ordering between things like `T *' and `T const &' for `U *'.
7842 The former has T=U and the latter T=U*. The former looks more
7843 specialized and John Spicer considers it well-formed (the EDG
7844 compiler accepts it).
7846 John also confirms that deduction should proceed as in a function
7847 call. Which implies the usual ARG and PARM bashing as DEDUCE_CALL.
7848 However, in ordering, ARG can have REFERENCE_TYPE, but no argument
7849 to an actual call can have such a type.
7851 When deducing against a REFERENCE_TYPE, we can either not change
7852 PARM's type, or we can change ARG's type too. The latter, though
7853 seemingly more safe, turns out to give the following quirk. Consider
7854 deducing a call to a `const int *' with the following template
7855 function parameters
7856 #1; T const *const & ; T = int
7857 #2; T *const & ; T = const int
7858 #3; T * ; T = const int
7859 It looks like #1 is the more specialized. Taken pairwise, #1 is
7860 more specialized than #2 and #2 is more specialized than #3, yet
7861 there is no ordering between #1 and #3.
7863 So, if ARG is a reference, we look though it when PARM is
7864 not a refence. When both are references we don't change either. */
7866 {
7872 }
7876 }
7879 {
7880 /* [temp.deduct.call]
7882 If P is not a reference type:
7884 --If A is an array type, the pointer type produced by the
7885 array-to-pointer standard conversion (_conv.array_) is
7886 used in place of A for type deduction; otherwise,
7888 --If A is a function type, the pointer type produced by
7889 the function-to-pointer standard conversion
7890 (_conv.func_) is used in place of A for type deduction;
7891 otherwise,
7893 --If A is a cv-qualified type, the top level
7894 cv-qualifiers of A's type are ignored for type
7895 deduction. */
7900 else
7902 }
7904 skip_arg:;
7905 /* [temp.deduct.call]
7907 If P is a cv-qualified type, the top level cv-qualifiers
7908 of P's type are ignored for type deduction. If P is a
7909 reference type, the type referred to by P is used for
7910 type deduction. */
7913 {
7916 }
7918 }
7920 /* Most parms like fn_type_unification.
7922 If SUBR is 1, we're being called recursively (to unify the
7923 arguments of a function or method parameter of a function
7924 template). */
7926 static int
7931 unification_kind_t strict;
7933 {
7942 /* ARGS could be NULL (via a call from parse.y to
7943 build_x_function_call). */
7949 {
7969 }
7976 && args
7978 {
7987 /* We can't deduce anything from this, but we might get all the
7988 template args from other function args. */
7991 /* Conversions will be performed on a function argument that
7992 corresponds with a function parameter that contains only
7993 non-deducible template parameters and explicitly specified
7994 template parameters. */
7996 {
7997 tree type;
8001 else
8002 {
8005 }
8008 {
8011 }
8012 else
8013 /* It might work; we shouldn't check now, because we might
8014 get into infinite recursion. Overload resolution will
8015 handle it. */
8019 }
8022 {
8025 {
8026 /* [temp.deduct.type] A template-argument can be deduced from
8027 a pointer to function or pointer to member function
8028 argument if the set of overloaded functions does not
8029 contain function templates and at most one of a set of
8030 overloaded functions provides a unique match. */
8037 }
8039 }
8041 {
8049 }
8051 /* Are we done with the interesting parms? */
8054 }
8055 /* Fail if we've reached the end of the parm list, and more args
8056 are present, and the parm list isn't variadic. */
8059 /* Fail if parms are left and they don't have default values. */
8067 {
8071 }
8073 }
8075 /* Subroutine of type_unification_real. Args are like the variables at the
8076 call site. ARG is an overloaded function (or template-id); we try
8077 deducing template args from each of the overloads, and if only one
8078 succeeds, we go with that. Modifies TARGS and returns 0 on success. */
8080 static int
8082 sub_strict)
8084 unification_kind_t strict;
8086 {
8094 /* Handle `&x' where `x' is some static or non-static member
8095 function name. */
8101 /* Strip baselink information. */
8106 {
8107 /* If we got some explicit template args, we need to plug them into
8108 the affected templates before we try to unify, in case the
8109 explicit args will completely resolve the templates in question. */
8115 {
8123 expl_subargs);
8125 {
8127 NULL_TREE);
8132 }
8133 }
8134 }
8136 {
8138 {
8143 type,
8145 }
8146 }
8147 else
8150 /* [temp.deduct.type] A template-argument can be deduced from a pointer
8151 to function or pointer to member function argument if the set of
8152 overloaded functions does not contain function templates and at most
8153 one of a set of overloaded functions provides a unique match.
8155 So if we found multiple possibilities, we return success but don't
8156 deduce anything. */
8159 {
8164 }
8169 }
8171 /* Subroutine of resolve_overloaded_unification; does deduction for a single
8172 overload. Fills TARGS with any deduced arguments, or error_mark_node if
8173 different overloads deduce different arguments for a given parm.
8174 Returns 1 on success. */
8176 static int
8178 sub_strict)
8180 unification_kind_t strict;
8182 {
8184 tree tempargs;
8187 /* [temp.deduct.type] A template-argument can be deduced from a pointer
8188 to function or pointer to member function argument if the set of
8189 overloaded functions does not contain function templates and at most
8190 one of a set of overloaded functions provides a unique match.
8192 So if this is a template, just return success. */
8199 /* We don't copy orig_targs for this because if we have already deduced
8200 some template args from previous args, unify would complain when we
8201 try to deduce a template parameter for the same argument, even though
8202 there isn't really a conflict. */
8209 /* First make sure we didn't deduce anything that conflicts with
8210 explicitly specified args. */
8212 {
8219 {
8220 /* Since we're unifying against ourselves, we will fill in template
8221 args used in the function parm list with our own template parms.
8222 Discard them. */
8225 }
8228 }
8231 {
8236 }
8239 }
8241 /* Verify that nondeduce template argument agrees with the type
8242 obtained from argument deduction. Return nonzero if the
8243 verification fails.
8245 For example:
8247 struct A { typedef int X; };
8248 template <class T, class U> struct C {};
8249 template <class T> struct C<T, typename T::X> {};
8251 Then with the instantiation `C<A, int>', we can deduce that
8252 `T' is `A' but unify () does not check whether `typename T::X'
8253 is `int'. This function ensure that they agree.
8255 TARGS, PARMS are the same as the arguments of unify.
8256 ARGS contains template arguments from all levels. */
8258 static int
8261 {
8272 {
8276 /* In case we are deducing from a function argument of a function
8277 templates, some parameters may not be deduced yet. So we
8278 make sure that only fully substituted elements of PARM are
8279 compared below. */
8283 }
8285 }
8287 /* PARM is a template class (perhaps with unbound template
8288 parameters). ARG is a fully instantiated type. If ARG can be
8289 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
8290 TARGS are as for unify. */
8292 static tree
8294 tree tparms;
8295 tree targs;
8296 tree parm;
8297 tree arg;
8298 {
8299 tree copy_of_targs;
8305 /* We need to make a new template argument vector for the call to
8306 unify. If we used TARGS, we'd clutter it up with the result of
8307 the attempted unification, even if this class didn't work out.
8308 We also don't want to commit ourselves to all the unifications
8309 we've already done, since unification is supposed to be done on
8310 an argument-by-argument basis. In other words, consider the
8311 following pathological case:
8313 template <int I, int J, int K>
8314 struct S {};
8316 template <int I, int J>
8317 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
8319 template <int I, int J, int K>
8320 void f(S<I, J, K>, S<I, I, I>);
8322 void g() {
8323 S<0, 0, 0> s0;
8324 S<0, 1, 2> s2;
8326 f(s0, s2);
8327 }
8329 Now, by the time we consider the unification involving `s2', we
8330 already know that we must have `f<0, 0, 0>'. But, even though
8331 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is not legal
8332 because there are two ways to unify base classes of S<0, 1, 2>
8333 with S<I, I, I>. If we kept the already deduced knowledge, we
8334 would reject the possibility I=1. */
8337 /* If unification failed, we're done. */
8343 }
8345 /* Subroutine of get_template_base. RVAL, if non-NULL, is a base we
8346 have already discovered to be satisfactory. ARG_BINFO is the binfo
8347 for the base class of ARG that we are currently examining. */
8349 static tree
8352 tree tparms;
8353 tree targs;
8354 tree arg_binfo;
8355 tree rval;
8356 tree parm;
8358 {
8359 tree binfos;
8364 {
8368 /* If there is more than one satisfactory baseclass, then:
8370 [temp.deduct.call]
8372 If they yield more than one possible deduced A, the type
8373 deduction fails.
8375 applies. */
8380 }
8385 /* Process base types. */
8387 {
8391 /* Skip this base, if we've already seen it. */
8395 this_virtual =
8398 /* When searching for a non-virtual, we cannot mark virtually
8399 found binfos. */
8404 parm,
8405 base_binfo,
8406 rval,
8409 /* If we discovered more than one matching base class, we can
8410 stop now. */
8413 }
8416 }
8418 /* Given a template type PARM and a class type ARG, find the unique
8419 base type in ARG that is an instance of PARM. We do not examine
8420 ARG itself; only its base-classes. If there is no appropriate base
8421 class, return NULL_TREE. If there is more than one, return
8422 error_mark_node. PARM may be the type of a partial specialization,
8423 as well as a plain template type. Used by unify. */
8425 static tree
8427 tree tparms;
8428 tree targs;
8429 tree parm;
8430 tree arg;
8431 {
8432 tree rval;
8433 tree arg_binfo;
8440 NULL_TREE,
8441 GTB_IGNORE_TYPE);
8443 /* Since get_template_base_recursive marks the bases classes, we
8444 must unmark them here. */
8448 }
8450 /* Returns the level of DECL, which declares a template parameter. */
8452 static int
8454 tree decl;
8455 {
8457 {
8468 }
8469 }
8471 /* Decide whether ARG can be unified with PARM, considering only the
8472 cv-qualifiers of each type, given STRICT as documented for unify.
8473 Returns non-zero iff the unification is OK on that basis.*/
8475 static int
8478 tree arg;
8479 tree parm;
8480 {
8490 }
8492 /* Takes parameters as for type_unification. Returns 0 if the
8493 type deduction succeeds, 1 otherwise. The parameter STRICT is a
8494 bitwise or of the following flags:
8496 UNIFY_ALLOW_NONE:
8497 Require an exact match between PARM and ARG.
8498 UNIFY_ALLOW_MORE_CV_QUAL:
8499 Allow the deduced ARG to be more cv-qualified (by qualification
8500 conversion) than ARG.
8501 UNIFY_ALLOW_LESS_CV_QUAL:
8502 Allow the deduced ARG to be less cv-qualified than ARG.
8503 UNIFY_ALLOW_DERIVED:
8504 Allow the deduced ARG to be a template base class of ARG,
8505 or a pointer to a template base class of the type pointed to by
8506 ARG.
8507 UNIFY_ALLOW_INTEGER:
8508 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
8509 case for more information.
8510 UNIFY_ALLOW_OUTER_LEVEL:
8511 This is the outermost level of a deduction. Used to determine validity
8512 of qualification conversions. A valid qualification conversion must
8513 have const qualified pointers leading up to the inner type which
8514 requires additional CV quals, except at the outer level, where const
8515 is not required [conv.qual]. It would be normal to set this flag in
8516 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
8517 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
8518 This is the outermost level of a deduction, and PARM can be more CV
8519 qualified at this point.
8520 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
8521 This is the outermost level of a deduction, and PARM can be less CV
8522 qualified at this point. */
8524 static int
8528 {
8530 tree targ;
8531 tree tparm;
8534 /* I don't think this will do the right thing with respect to types.
8535 But the only case I've seen it in so far has been array bounds, where
8536 signedness is the only information lost, and I think that will be
8537 okay. */
8544 /* We can't deduce anything from this, but we might get all the
8545 template args from other function args. */
8548 /* If PARM uses template parameters, then we can't bail out here,
8549 even if ARG == PARM, since we won't record unifications for the
8550 template parameters. We might need them if we're trying to
8551 figure out which of two things is more specialized. */
8555 /* Immediately reject some pairs that won't unify because of
8556 cv-qualification mismatches. */
8559 /* We check the cv-qualifiers when unifying with template type
8560 parameters below. We want to allow ARG `const T' to unify with
8561 PARM `T' for example, when computing which of two templates
8562 is more specialized, for example. */
8576 {
8578 /* In a type which contains a nested-name-specifier, template
8579 argument values cannot be deduced for template parameters used
8580 within the nested-name-specifier. */
8590 /* The PARM is not one we're trying to unify. Just check
8591 to see if it matches ARG. */
8598 /* Check for mixed types and values. */
8606 {
8607 /* ARG must be constructed from a template class or a template
8608 template parameter. */
8613 {
8617 tree argtmplvec
8621 /* The parameter and argument roles have to be switched here
8622 in order to handle default arguments properly. For example,
8623 template<template <class> class TT> void f(TT<int>)
8624 should be able to accept vector<int> which comes from
8625 template <class T, class Allocator = allocator>
8626 class vector. */
8632 /* Deduce arguments T, i from TT<T> or TT<i>.
8633 We check each element of PARMVEC and ARGVEC individually
8634 rather than the whole TREE_VEC since they can have
8635 different number of elements. */
8638 {
8643 UNIFY_ALLOW_NONE))
8645 }
8646 }
8649 /* Fall through to deduce template name. */
8650 }
8654 {
8655 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
8657 /* Simple cases: Value already set, does match or doesn't. */
8662 }
8663 else
8664 {
8665 /* If PARM is `const T' and ARG is only `int', we don't have
8666 a match unless we are allowing additional qualification.
8667 If ARG is `const int' and PARM is just `T' that's OK;
8668 that binds `const int' to `T'. */
8673 /* Consider the case where ARG is `const volatile int' and
8674 PARM is `const T'. Then, T should be `volatile int'. */
8675 arg =
8683 /* Simple cases: Value already set, does match or doesn't. */
8688 }
8690 /* Make sure that ARG is not a variable-sized array. (Note that
8691 were talking about variable-sized arrays (like `int[n]'),
8692 rather than arrays of unknown size (like `int[]').) We'll
8693 get very confused by such a type since the bound of the array
8694 will not be computable in an instantiation. Besides, such
8695 types are not allowed in ISO C++, so we can do as we please
8696 here. */
8712 /* The PARM is not one we're trying to unify. Just check
8713 to see if it matches ARG. */
8721 {
8727 else
8729 }
8731 /* [temp.deduct.type] If, in the declaration of a function template
8732 with a non-type template-parameter, the non-type
8733 template-parameter is used in an expression in the function
8734 parameter-list and, if the corresponding template-argument is
8735 deduced, the template-argument type shall match the type of the
8736 template-parameter exactly, except that a template-argument
8737 deduced from an array bound may be of any integral type.
8738 The non-type parameter might use already deduced type parameters. */
8746 else
8753 {
8757 /* [temp.deduct.call]
8759 A can be another pointer or pointer to member type that can
8760 be converted to the deduced A via a qualification
8761 conversion (_conv.qual_).
8763 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
8764 This will allow for additional cv-qualification of the
8765 pointed-to types if appropriate. */
8768 /* The derived-to-base conversion only persists through one
8769 level of pointers. */
8774 }
8793 UNIFY_ALLOW_NONE);
8806 {
8815 }
8816 /* We have already checked cv-qualification at the top of the
8817 function. */
8821 /* As far as unification is concerned, this wins. Later checks
8822 will invalidate it if necessary. */
8825 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
8826 /* Type INTEGER_CST can come from ordinary constant template args. */
8836 {
8845 UNIFY_ALLOW_NONE))
8848 }
8856 {
8863 strict);
8864 }
8867 {
8871 {
8872 /* First, we try to unify the PARM and ARG directly. */
8877 {
8878 /* Fallback to the special case allowed in
8879 [temp.deduct.call]:
8881 If P is a class, and P has the form
8882 template-id, then A can be a derived class of
8883 the deduced A. Likewise, if P is a pointer to
8884 a class of the form template-id, A can be a
8885 pointer to a derived class pointed to by the
8886 deduced A. */
8892 }
8893 }
8897 /* Perhaps PARM is something like S<U> and ARG is S<int>.
8898 Then, we should unify `int' and `U'. */
8900 else
8901 /* There's no chance of unification succeeding. */
8906 }
8930 strict);
8938 /* Matched cases are handled by the ARG == PARM test above. */
8943 {
8944 /* We handle this case specially, since it comes up with
8945 arrays. In particular, something like:
8947 template <int N> void f(int (&x)[N]);
8949 Here, we are trying to unify the range type, which
8950 looks like [0 ... (N - 1)]. */
8958 }
8959 /* else fall through */
8963 {
8965 /* We're looking at an expression. This can happen with
8966 something like:
8968 template <int I>
8969 void foo(S<I>, S<I + 2>);
8971 This is a "nondeduced context":
8973 [deduct.type]
8975 The nondeduced contexts are:
8977 --A type that is a template-id in which one or more of
8978 the template-arguments is an expression that references
8979 a template-parameter.
8981 In these cases, we assume deduction succeeded, but don't
8982 actually infer any unifications. */
8987 else
8989 }
8990 else
8995 }
8996 }
8997 \f
8998 /* Called if RESULT is explicitly instantiated, or is a member of an
8999 explicitly instantiated class, or if using -frepo and the
9000 instantiation of RESULT has been assigned to this file. */
9002 void
9004 tree result;
9006 {
9008 /* The TREE_PUBLIC flag for function declarations will have been
9009 set correctly by tsubst. */
9012 /* We used to set this unconditionally; we moved that to
9013 do_decl_instantiation so it wouldn't get set on members of
9014 explicit class template instantiations. But we still need to set
9015 it here for the 'extern template' case in order to suppress
9016 implicit instantiations. */
9021 {
9025 /* Always make artificials weak. */
9028 /* For WIN32 we also want to put explicit instantiations in
9029 linkonce sections. */
9032 }
9035 }
9037 /* Given two function templates PAT1 and PAT2, return:
9039 DEDUCE should be DEDUCE_EXACT or DEDUCE_ORDER.
9041 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
9042 -1 if PAT2 is more specialized than PAT1.
9043 0 if neither is more specialized.
9045 LEN is passed through to fn_type_unification. */
9047 int
9052 {
9053 tree targs;
9067 }
9069 /* Given two class template specialization list nodes PAT1 and PAT2, return:
9071 1 if PAT1 is more specialized than PAT2 as described in [temp.class.order].
9072 -1 if PAT2 is more specialized than PAT1.
9073 0 if neither is more specialized. */
9075 int
9078 {
9079 tree targs;
9093 }
9095 /* Return the template arguments that will produce the function signature
9096 DECL from the function template FN, with the explicit template
9097 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is 1, the return type must
9098 also match. Return NULL_TREE if no satisfactory arguments could be
9099 found. DEDUCE and LEN are passed through to fn_type_unification. */
9101 static tree
9105 {
9108 tree decl_type;
9109 tree decl_arg_types;
9112 /* Substitute the explicit template arguments into the type of DECL.
9113 The call to fn_type_unification will handle substitution into the
9114 FN. */
9117 {
9118 tree tmpl;
9119 tree converted_args;
9123 else
9124 /* We can get here for some illegal specializations. */
9127 converted_args
9136 NULL_TREE);
9139 }
9142 /* Never do unification on the 'this' parameter. */
9147 decl_arg_types,
9156 }
9158 /* For most uses, we want to check the return type. */
9160 tree
9163 {
9165 }
9167 /* But for resolve_overloaded_unification, we only care about the parameter
9168 types. */
9170 static tree
9173 {
9175 }
9177 /* Return the innermost template arguments that, when applied to a
9178 template specialization whose innermost template parameters are
9179 TPARMS, and whose specialization arguments are ARGS, yield the
9180 ARGS.
9182 For example, suppose we have:
9184 template <class T, class U> struct S {};
9185 template <class T> struct S<T*, int> {};
9187 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
9188 {T}, the PARMS will be {T*, int} and the ARGS will be {double*,
9189 int}. The resulting vector will be {double}, indicating that `T'
9190 is bound to `double'. */
9192 static tree
9195 {
9200 UNIFY_ALLOW_NONE))
9211 }
9213 /* In INSTANTIATIONS is a list of <INSTANTIATION, TEMPLATE> pairs.
9214 Pick the most specialized template, and return the corresponding
9215 instantiation, or if there is no corresponding instantiation, the
9216 template itself. If there is no most specialized template,
9217 error_mark_node is returned. If there are no templates at all,
9218 NULL_TREE is returned. */
9220 tree
9222 tree instantiations;
9223 {
9232 {
9236 ;
9237 else
9238 {
9240 {
9244 }
9246 }
9247 }
9250 {
9255 }
9258 }
9260 /* Return the most specialized of the list of templates in FNS that can
9261 produce an instantiation matching DECL, given the explicit template
9262 arguments EXPLICIT_ARGS. */
9264 static tree
9267 {
9272 {
9278 }
9281 }
9283 /* If DECL is a specialization of some template, return the most
9284 general such template. Otherwise, returns NULL_TREE.
9286 For example, given:
9288 template <class T> struct S { template <class U> void f(U); };
9290 if TMPL is `template <class U> void S<int>::f(U)' this will return
9291 the full template. This function will not trace past partial
9292 specializations, however. For example, given in addition:
9294 template <class T> struct S<T*> { template <class U> void f(U); };
9296 if TMPL is `template <class U> void S<int*>::f(U)' this will return
9297 `template <class T> template <class U> S<T*>::f(U)'. */
9299 tree
9301 tree decl;
9302 {
9303 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
9304 an immediate specialization. */
9306 {
9310 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
9311 template friend. */
9316 }
9318 /* Look for more and more general templates. */
9320 {
9321 /* The DECL_TI_TEMPLATE can be a LOOKUP_EXPR or IDENTIFIER_NODE
9322 in some cases. (See cp-tree.h for details.) */
9326 /* Stop if we run into an explicitly specialized class template. */
9333 }
9336 }
9338 /* Return the most specialized of the class template specializations
9339 of TMPL which can produce an instantiation matching ARGS, or
9340 error_mark_node if the choice is ambiguous. */
9342 static tree
9344 tree tmpl;
9345 tree args;
9346 {
9348 tree t;
9349 tree champ;
9354 {
9355 tree spec_args
9358 {
9361 }
9362 }
9371 {
9374 ;
9375 else
9376 {
9378 {
9382 }
9384 }
9385 }
9388 {
9392 }
9395 }
9397 /* called from the parser. */
9399 void
9402 {
9408 /* An error occurred, for which grokdeclarator has already issued
9409 an appropriate message. */
9412 {
9415 }
9417 {
9418 /* There is an asymmetry here in the way VAR_DECLs and
9419 FUNCTION_DECLs are handled by grokdeclarator. In the case of
9420 the latter, the DECL we get back will be marked as a
9421 template instantiation, and the appropriate
9422 DECL_TEMPLATE_INFO will be set up. This does not happen for
9423 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
9424 should handle VAR_DECLs as it currently handles
9425 FUNCTION_DECLs. */
9428 {
9431 }
9432 }
9434 {
9437 }
9438 else
9441 /* Check for various error cases. Note that if the explicit
9442 instantiation is legal the RESULT will currently be marked as an
9443 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
9444 until we get here. */
9447 {
9448 /* [temp.spec]
9450 No program shall both explicitly instantiate and explicitly
9451 specialize a template. */
9455 }
9457 {
9458 /* [temp.spec]
9460 No program shall explicitly instantiate any template more
9461 than once.
9463 We check DECL_INTERFACE_KNOWN so as not to complain when the first
9464 instantiation was `extern' and the second is not, and EXTERN_P for
9465 the opposite case. If -frepo, chances are we already got marked
9466 as an explicit instantiation because of the repo file. */
9470 /* If we've already instantiated the template, just return now. */
9473 }
9475 {
9478 }
9480 {
9483 }
9489 ;
9491 {
9495 }
9496 else
9498 storage);
9505 }
9507 void
9509 tree t;
9511 {
9518 {
9521 }
9522 }
9524 /* Perform an explicit instantiation of template class T. STORAGE, if
9525 non-null, is the RID for extern, inline or static. COMPLAIN is
9526 non-zero if this is called from the parser, zero if called recursively,
9527 since the standard is unclear (as detailed below). */
9529 void
9533 {
9542 {
9545 }
9549 /* With -fexternal-templates, explicit instantiations are treated the same
9550 as implicit ones. */
9555 {
9558 t);
9560 }
9563 {
9574 else
9575 {
9577 storage);
9579 }
9580 }
9583 {
9584 /* [temp.spec]
9586 No program shall both explicitly instantiate and explicitly
9587 specialize a template. */
9589 {
9592 }
9594 }
9596 {
9597 /* [temp.spec]
9599 No program shall explicitly instantiate any template more
9600 than once.
9602 If CLASSTYPE_INTERFACE_ONLY, then the first explicit instantiation
9603 was `extern'. If EXTERN_P then the second is. If -frepo, chances
9604 are we already got marked as an explicit instantion because of the
9605 repo file. All these cases are OK. */
9610 /* If we've already instantiated the template, just return now. */
9613 }
9621 {
9622 tree tmp;
9624 /* In contrast to implicit instantiation, where only the
9625 declarations, and not the definitions, of members are
9626 instantiated, we have here:
9628 [temp.explicit]
9630 The explicit instantiation of a class template specialization
9631 implies the instantiation of all of its members not
9632 previously explicitly specialized in the translation unit
9633 containing the explicit instantiation.
9635 Of course, we can't instantiate member template classes, since
9636 we don't have any arguments for them. Note that the standard
9637 is unclear on whether the instantiation of the members are
9638 *explicit* instantiations or not. We choose to be generous,
9639 and not set DECL_EXPLICIT_INSTANTIATION. Therefore, we allow
9640 the explicit instantiation of a class where some of the members
9641 have no definition in the current translation unit. */
9647 {
9652 }
9656 {
9661 }
9667 }
9668 }
9670 /* Given a function DECL, which is a specialization of TMPL, modify
9671 DECL to be a re-instantiation of TMPL with the same template
9672 arguments. TMPL should be the template into which tsubst'ing
9673 should occur for DECL, not the most general template.
9675 One reason for doing this is a scenario like this:
9677 template <class T>
9678 void f(const T&, int i);
9680 void g() { f(3, 7); }
9682 template <class T>
9683 void f(const T& t, const int i) { }
9685 Note that when the template is first instantiated, with
9686 instantiate_template, the resulting DECL will have no name for the
9687 first parameter, and the wrong type for the second. So, when we go
9688 to instantiate the DECL, we regenerate it. */
9690 static void
9692 tree decl;
9693 tree tmpl;
9694 {
9695 /* The most general version of TMPL. */
9696 tree gen_tmpl;
9697 /* The arguments used to instantiate DECL, from the most general
9698 template. */
9699 tree args;
9700 tree code_pattern;
9701 tree new_decl;
9707 /* Unregister the specialization so that when we tsubst we will not
9708 just return DECL. We don't have to unregister DECL from TMPL
9709 because if would only be registered there if it were a partial
9710 instantiation of a specialization, which it isn't: it's a full
9711 instantiation. */
9715 /* If the DECL was not unregistered then something peculiar is
9716 happening: we created a specialization but did not call
9717 register_specialization for it. */
9721 /* Make sure that we can see identifiers, and compute access
9722 correctly, for the class members used in the declaration of
9723 this static variable. */
9726 /* Do the substitution to get the new declaration. */
9730 {
9731 /* Set up DECL_INITIAL, since tsubst doesn't. */
9735 /* Pop the class context we pushed above. */
9737 }
9739 {
9740 /* Convince duplicate_decls to use the DECL_ARGUMENTS from the
9741 new decl. */
9743 /* And don't complain about a duplicate definition. */
9745 }
9747 /* The immediate parent of the new template is still whatever it was
9748 before, even though tsubst sets DECL_TI_TEMPLATE up as the most
9749 general template. We also reset the DECL_ASSEMBLER_NAME since
9750 tsubst always calculates the name as if the function in question
9751 were really a template instance, and sometimes, with friend
9752 functions, this is not so. See tsubst_friend_function for
9753 details. */
9759 /* Call duplicate decls to merge the old and new declarations. */
9762 /* Now, re-register the specialization. */
9764 }
9766 /* Produce the definition of D, a _DECL generated from a template. If
9767 DEFER_OK is non-zero, then we don't have to actually do the
9768 instantiation now; we just have to do it sometime. */
9770 tree
9772 tree d;
9774 {
9777 tree td;
9778 tree code_pattern;
9779 tree spec;
9780 tree gen_tmpl;
9786 /* This function should only be used to instantiate templates for
9787 functions and static member variables. */
9791 /* Don't instantiate cloned functions. Instead, instantiate the
9792 functions they cloned. */
9797 /* D has already been instantiated. It might seem reasonable to
9798 check whether or not D is an explicit instantiation, and, if so,
9799 stop here. But when an explicit instantiation is deferred
9800 until the end of the compilation, DECL_EXPLICIT_INSTANTIATION
9801 is set, even though we still need to do the instantiation. */
9804 /* If we already have a specialization of this declaration, then
9805 there's no reason to instantiate it. Note that
9806 retrieve_specialization gives us both instantiations and
9807 specializations, so we must explicitly check
9808 DECL_TEMPLATE_SPECIALIZATION. */
9814 /* This needs to happen before any tsubsting. */
9820 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
9821 for the instantiation. This is not always the most general
9822 template. Consider, for example:
9824 template <class T>
9825 struct S { template <class U> void f();
9826 template <> void f<int>(); };
9828 and an instantiation of S<double>::f<int>. We want TD to be the
9829 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
9832 more general template. */
9834 /* We must also deal with friend templates. Given:
9836 template <class T> struct S {
9837 template <class U> friend void f() {};
9838 };
9840 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
9841 so far as the language is concerned, but that's still
9842 where we get the pattern for the instantiation from. On
9843 other hand, if the definition comes outside the class, say:
9845 template <class T> struct S {
9846 template <class U> friend void f();
9847 };
9848 template <class U> friend void f() {}
9850 we don't need to look any further. That's what the check for
9851 DECL_INITIAL is for. */
9855 {
9856 /* The present template, TD, should not be a definition. If it
9857 were a definition, we should be using it! Note that we
9858 cannot restructure the loop to just keep going until we find
9859 a template with a definition, since that might go too far if
9860 a specialization was declared, but not defined. */
9865 /* Fetch the more general template. */
9867 }
9873 else
9880 {
9884 {
9886 {
9889 }
9891 {
9894 }
9895 else
9897 }
9901 }
9903 /* We need to set up DECL_INITIAL regardless, if
9904 the variable is initialized in the class body. */
9906 ;
9907 /* Reject all external templates except inline functions. */
9912 /* Defer all other templates, unless we have been explicitly
9913 forbidden from doing so. We restore the source position here
9914 because it's used by add_pending_template. */
9916 {
9922 /* [temp.explicit]
9924 The definition of a non-exported function template, a
9925 non-exported member function template, or a non-exported
9926 member function or static data member of a class template
9927 shall be present in every translation unit in which it is
9928 explicitly instantiated. */
9930 d);
9934 }
9940 /* We're now committed to instantiating this template. Mark it as
9941 instantiated so that recursive calls to instantiate_decl do not
9942 try to instantiate it again. */
9945 /* Regenerate the declaration in case the template has been modified
9946 by a subsequent redeclaration. */
9949 /* We already set the file and line above. Reset them now in case
9950 they changed as a result of calling regenerate_decl_from_template. */
9955 {
9959 else
9960 {
9963 }
9965 }
9967 {
9968 htab_t saved_local_specializations;
9970 /* Save away the current list, in case we are instantiating one
9971 template from within the body of another. */
9974 /* Set up the list of local specializations. */
9976 htab_hash_pointer,
9977 htab_eq_pointer,
9978 NULL);
9980 /* Set up context. */
9983 /* We already set up __FUNCTION__, etc., so we don't want to do
9984 it again now. */
9987 /* Substitute into the body of the function. */
9991 /* We don't need the local specializations any more. */
9995 /* Finish the function. */
9997 }
9999 /* We're not deferring instantiation any more. */
10005 out:
10014 }
10016 /* Run through the list of templates that we wish we could
10017 instantiate, and instantiate any we can. */
10019 int
10021 {
10026 do
10027 {
10032 {
10038 {
10039 tree fn;
10042 {
10046 fn;
10051 {
10054 }
10055 }
10058 /* If INSTANTIATION has been instantiated, then we don't
10059 need to consider it again in the future. */
10061 else
10063 }
10064 else
10065 {
10068 {
10072 {
10075 }
10076 }
10080 /* If INSTANTIATION has been instantiated, then we don't
10081 need to consider it again in the future. */
10083 else
10085 }
10088 }
10091 /* Go through the things that are template instantiations if we are
10092 using guiding declarations. */
10095 {
10097 tree fn;
10098 tree args;
10103 /* If the FN is already defined, then it was either already
10104 instantiated or, even though guiding declarations were
10105 allowed, a non-template definition was provided. */
10106 ;
10107 else
10108 {
10114 }
10116 /* Remove this entry from the chain. */
10118 }
10120 }
10124 }
10126 /* Substitute ARGVEC into T, which is a list of initializers for
10127 either base class or a non-static data member. The TREE_PURPOSEs
10128 are DECLs, and the TREE_VALUEs are the initializer values. Used by
10129 instantiate_decl. */
10131 static tree
10134 {
10139 {
10140 tree decl;
10141 tree init;
10142 tree val;
10145 NULL_TREE);
10147 NULL_TREE);
10150 ;
10154 else
10159 }
10161 }
10163 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
10165 static void
10167 tree decl;
10168 {
10173 else
10175 }
10177 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
10178 is the instantiation (which should have been created with
10179 start_enum) and ARGS are the template arguments to use. */
10181 static void
10183 tree tag;
10184 tree newtag;
10185 tree args;
10186 {
10187 tree e;
10190 {
10191 tree value;
10193 /* Note that in a template enum, the TREE_VALUE is the
10194 CONST_DECL, not the corresponding INTEGER_CST. */
10197 NULL_TREE);
10199 /* Give this enumeration constant the correct access. */
10202 /* Actually build the enumerator itself. */
10204 }
10209 }
10211 /* DECL is a FUNCTION_DECL that is a template specialization. Return
10212 its type -- but without substituting the innermost set of template
10213 arguments. So, innermost set of template parameters will appear in
10214 the type. If CONTEXTP is non-NULL, then the partially substituted
10215 DECL_CONTEXT (if any) will also be filled in. Similarly, TPARMSP
10216 will be filled in with the substituted template parameters, if it
10217 is non-NULL. */
10219 tree
10221 tree decl;
10224 {
10226 tree fn_type;
10227 tree tmpl;
10228 tree targs;
10229 tree tparms;
10237 /* There should be as many levels of arguments as there are levels
10238 of parameters. */
10246 /* No substitution is necessary. */
10247 ;
10248 else
10249 {
10251 tree partial_args;
10253 /* Replace the innermost level of the TARGS with NULL_TREEs to
10254 let tsubst know not to substitute for those parameters. */
10263 /* Now, do the (partial) substitution to figure out the
10264 appropriate function type. */
10269 /* Substitute into the template parameters to obtain the real
10270 innermost set of parameters. This step is important if the
10271 innermost set of template parameters contains value
10272 parameters whose types depend on outer template parameters. */
10275 }
10283 }
10285 /* Set the DECL_ASSEMBLER_NAME for DECL, which is a FUNCTION_DECL that
10286 is either an instantiation or specialization of a template
10287 function. */
10289 static void
10291 tree decl;
10292 {
10294 tree fn_type;
10295 tree ret_type;
10296 tree parm_types;
10297 tree tparms;
10298 tree targs;
10303 /* Under the new ABI, we don't need special machinery. */
10305 {
10308 }
10310 /* The names of template functions must be mangled so as to indicate
10311 what template is being specialized with what template arguments.
10312 For example, each of the following three functions must get
10313 different mangled names:
10315 void f(int);
10316 template <> void f<7>(int);
10317 template <> void f<8>(int); */
10321 /* This DECL is for a partial instantiation. There's no need to
10322 mangle the name of such an entity. */
10325 /* We now compute the PARMS and RET_TYPE to give to
10326 build_decl_overload_real. The PARMS and RET_TYPE are the
10327 parameter and return types of the template, after all but the
10328 innermost template arguments have been substituted, not the
10329 parameter and return types of the function DECL. For example,
10330 given:
10332 template <class T> T f(T);
10334 both PARMS and RET_TYPE should be `T' even if DECL is `int f(int)'.
10335 A more subtle example is:
10337 template <class T> struct S { template <class U> void f(T, U); }
10339 Here, if DECL is `void S<int>::f(int, double)', PARMS should be
10340 {int, U}. Thus, the args that we want to subsitute into the
10341 return and parameter type for the function are those in TARGS,
10342 with the innermost level omitted. */
10345 /* Now, get the innermost parameters and arguments, and figure out
10346 the parameter and return types. */
10352 /* For a static member function, we generate a fake `this' pointer,
10353 for the purposes of mangling. This indicates of which class the
10354 function is a member. Because of:
10356 [class.static]
10358 There shall not be a static and a nonstatic member function
10359 with the same name and the same parameter types
10361 we don't have to worry that this will result in a clash with a
10362 non-static member function. */
10366 /* There should be the same number of template parameters as
10367 template arguments. */
10371 /* Actually set the DECL_ASSEMBLER_NAME. */
10377 }
10379 /* Return truthvalue if we're processing a template different from
10380 the last one involved in diagnostics. */
10381 int
10383 {
10385 }
10387 /* Remember current template involved in diagnostics. */
10388 void
10390 {
10392 }
10394 tree
10396 {
10398 }
10400 /* [temp.param] Check that template non-type parm TYPE is of an allowable
10401 type. Return zero for ok, non-zero for disallowed. If COMPLAIN is
10402 non-zero, then complain. */
10404 static int
10406 tree type;
10408 {
10428 type);
10430 }