1 /* Handle parameterized types (templates) for GNU C++. 2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011, 2012 4 Free Software Foundation, Inc. 5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing. 6 Rewritten by Jason Merrill (jason@cygnus.com). 7 8 This file is part of GCC. 9 10 GCC is free software; you can redistribute it and/or modify 11 it under the terms of the GNU General Public License as published by 12 the Free Software Foundation; either version 3, or (at your option) 13 any later version. 14 15 GCC is distributed in the hope that it will be useful, 16 but WITHOUT ANY WARRANTY; without even the implied warranty of 17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 GNU General Public License for more details. 19 20 You should have received a copy of the GNU General Public License 21 along with GCC; see the file COPYING3. If not see 22 <http://www.gnu.org/licenses/>. */ 23 24 /* Known bugs or deficiencies include: 25 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". */ 28 29 #include "config.h" 30 #include "system.h" 31 #include "coretypes.h" 32 #include "tm.h" 33 #include "tree.h" 34 #include "intl.h" 35 #include "pointer-set.h" 36 #include "flags.h" 37 #include "cp-tree.h" 38 #include "c-family/c-common.h" 39 #include "c-family/c-objc.h" 40 #include "cp-objcp-common.h" 41 #include "tree-inline.h" 42 #include "decl.h" 43 #include "output.h" 44 #include "toplev.h" 45 #include "timevar.h" 46 #include "tree-iterator.h" 47 #include "vecprim.h" 48 49 /* The type of functions taking a tree, and some additional data, and 50 returning an int. */ 51 typedef int (*tree_fn_t) (tree, void*); 52 53 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose 54 instantiations have been deferred, either because their definitions 55 were not yet available, or because we were putting off doing the work. */ 56 struct GTY ((chain_next ("%h.next"))) pending_template { 57 struct pending_template *next; 58 struct tinst_level *tinst; 59 }; 60 61 static GTY(()) struct pending_template *pending_templates; 62 static GTY(()) struct pending_template *last_pending_template; 63 64 int processing_template_parmlist; 65 static int template_header_count; 66 67 static GTY(()) tree saved_trees; 68 static VEC(int,heap) *inline_parm_levels; 69 70 static GTY(()) struct tinst_level *current_tinst_level; 71 72 static GTY(()) tree saved_access_scope; 73 74 /* Live only within one (recursive) call to tsubst_expr. We use 75 this to pass the statement expression node from the STMT_EXPR 76 to the EXPR_STMT that is its result. */ 77 static tree cur_stmt_expr; 78 79 /* A map from local variable declarations in the body of the template 80 presently being instantiated to the corresponding instantiated 81 local variables. */ 82 static htab_t local_specializations; 83 84 typedef struct GTY(()) spec_entry 85 { 86 tree tmpl; 87 tree args; 88 tree spec; 89 } spec_entry; 90 91 static GTY ((param_is (spec_entry))) 92 htab_t decl_specializations; 93 94 static GTY ((param_is (spec_entry))) 95 htab_t type_specializations; 96 97 /* Contains canonical template parameter types. The vector is indexed by 98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a 99 TREE_LIST, whose TREE_VALUEs contain the canonical template 100 parameters of various types and levels. */ 101 static GTY(()) VEC(tree,gc) *canonical_template_parms; 102 103 #define UNIFY_ALLOW_NONE 0 104 #define UNIFY_ALLOW_MORE_CV_QUAL 1 105 #define UNIFY_ALLOW_LESS_CV_QUAL 2 106 #define UNIFY_ALLOW_DERIVED 4 107 #define UNIFY_ALLOW_INTEGER 8 108 #define UNIFY_ALLOW_OUTER_LEVEL 16 109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32 110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64 111 112 enum template_base_result { 113 tbr_incomplete_type, 114 tbr_ambiguous_baseclass, 115 tbr_success 116 }; 117 118 static void push_access_scope (tree); 119 static void pop_access_scope (tree); 120 static void push_deduction_access_scope (tree); 121 static void pop_deduction_access_scope (tree); 122 static bool resolve_overloaded_unification (tree, tree, tree, tree, 123 unification_kind_t, int, 124 bool); 125 static int try_one_overload (tree, tree, tree, tree, tree, 126 unification_kind_t, int, bool, bool); 127 static int unify (tree, tree, tree, tree, int, bool); 128 static void add_pending_template (tree); 129 static tree reopen_tinst_level (struct tinst_level *); 130 static tree tsubst_initializer_list (tree, tree); 131 static tree get_class_bindings (tree, tree, tree); 132 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t, 133 bool, bool); 134 static void tsubst_enum (tree, tree, tree); 135 static tree add_to_template_args (tree, tree); 136 static tree add_outermost_template_args (tree, tree); 137 static bool check_instantiated_args (tree, tree, tsubst_flags_t); 138 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*, 139 tree); 140 static int type_unification_real (tree, tree, tree, const tree *, 141 unsigned int, int, unification_kind_t, int, 142 bool); 143 static void note_template_header (int); 144 static tree convert_nontype_argument_function (tree, tree); 145 static tree convert_nontype_argument (tree, tree, tsubst_flags_t); 146 static tree convert_template_argument (tree, tree, tree, 147 tsubst_flags_t, int, tree); 148 static int for_each_template_parm (tree, tree_fn_t, void*, 149 struct pointer_set_t*, bool); 150 static tree expand_template_argument_pack (tree); 151 static tree build_template_parm_index (int, int, int, int, tree, tree); 152 static bool inline_needs_template_parms (tree); 153 static void push_inline_template_parms_recursive (tree, int); 154 static tree retrieve_local_specialization (tree); 155 static void register_local_specialization (tree, tree); 156 static hashval_t hash_specialization (const void *p); 157 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t); 158 static int mark_template_parm (tree, void *); 159 static int template_parm_this_level_p (tree, void *); 160 static tree tsubst_friend_function (tree, tree); 161 static tree tsubst_friend_class (tree, tree); 162 static int can_complete_type_without_circularity (tree); 163 static tree get_bindings (tree, tree, tree, bool); 164 static int template_decl_level (tree); 165 static int check_cv_quals_for_unify (int, tree, tree); 166 static void template_parm_level_and_index (tree, int*, int*); 167 static int unify_pack_expansion (tree, tree, tree, 168 tree, unification_kind_t, bool, bool); 169 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree); 170 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree); 171 static tree tsubst_template_parms (tree, tree, tsubst_flags_t); 172 static void regenerate_decl_from_template (tree, tree); 173 static tree most_specialized_class (tree, tree, tsubst_flags_t); 174 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int); 175 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree); 176 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree); 177 static bool check_specialization_scope (void); 178 static tree process_partial_specialization (tree); 179 static void set_current_access_from_decl (tree); 180 static enum template_base_result get_template_base (tree, tree, tree, tree, 181 bool , tree *); 182 static tree try_class_unification (tree, tree, tree, tree, bool); 183 static int coerce_template_template_parms (tree, tree, tsubst_flags_t, 184 tree, tree); 185 static bool template_template_parm_bindings_ok_p (tree, tree); 186 static int template_args_equal (tree, tree); 187 static void tsubst_default_arguments (tree); 188 static tree for_each_template_parm_r (tree *, int *, void *); 189 static tree copy_default_args_to_explicit_spec_1 (tree, tree); 190 static void copy_default_args_to_explicit_spec (tree); 191 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t); 192 static int eq_local_specializations (const void *, const void *); 193 static bool dependent_template_arg_p (tree); 194 static bool any_template_arguments_need_structural_equality_p (tree); 195 static bool dependent_type_p_r (tree); 196 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool); 197 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree); 198 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree); 199 static tree tsubst_decl (tree, tree, tsubst_flags_t); 200 static void perform_typedefs_access_check (tree tmpl, tree targs); 201 static void append_type_to_template_for_access_check_1 (tree, tree, tree, 202 location_t); 203 static tree listify (tree); 204 static tree listify_autos (tree, tree); 205 static tree template_parm_to_arg (tree t); 206 static bool arg_from_parm_pack_p (tree, tree); 207 static tree current_template_args (void); 208 static tree fixup_template_type_parm_type (tree, int); 209 static tree fixup_template_parm_index (tree, tree, int); 210 static tree tsubst_template_parm (tree, tree, tsubst_flags_t); 211 212 /* Make the current scope suitable for access checking when we are 213 processing T. T can be FUNCTION_DECL for instantiated function 214 template, or VAR_DECL for static member variable (need by 215 instantiate_decl). */ 216 217 static void 218 push_access_scope (tree t) 219 { 220 gcc_assert (TREE_CODE (t) == FUNCTION_DECL 221 || TREE_CODE (t) == VAR_DECL); 222 223 if (DECL_FRIEND_CONTEXT (t)) 224 push_nested_class (DECL_FRIEND_CONTEXT (t)); 225 else if (DECL_CLASS_SCOPE_P (t)) 226 push_nested_class (DECL_CONTEXT (t)); 227 else 228 push_to_top_level (); 229 230 if (TREE_CODE (t) == FUNCTION_DECL) 231 { 232 saved_access_scope = tree_cons 233 (NULL_TREE, current_function_decl, saved_access_scope); 234 current_function_decl = t; 235 } 236 } 237 238 /* Restore the scope set up by push_access_scope. T is the node we 239 are processing. */ 240 241 static void 242 pop_access_scope (tree t) 243 { 244 if (TREE_CODE (t) == FUNCTION_DECL) 245 { 246 current_function_decl = TREE_VALUE (saved_access_scope); 247 saved_access_scope = TREE_CHAIN (saved_access_scope); 248 } 249 250 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t)) 251 pop_nested_class (); 252 else 253 pop_from_top_level (); 254 } 255 256 /* Do any processing required when DECL (a member template 257 declaration) is finished. Returns the TEMPLATE_DECL corresponding 258 to DECL, unless it is a specialization, in which case the DECL 259 itself is returned. */ 260 261 tree 262 finish_member_template_decl (tree decl) 263 { 264 if (decl == error_mark_node) 265 return error_mark_node; 266 267 gcc_assert (DECL_P (decl)); 268 269 if (TREE_CODE (decl) == TYPE_DECL) 270 { 271 tree type; 272 273 type = TREE_TYPE (decl); 274 if (type == error_mark_node) 275 return error_mark_node; 276 if (MAYBE_CLASS_TYPE_P (type) 277 && CLASSTYPE_TEMPLATE_INFO (type) 278 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type)) 279 { 280 tree tmpl = CLASSTYPE_TI_TEMPLATE (type); 281 check_member_template (tmpl); 282 return tmpl; 283 } 284 return NULL_TREE; 285 } 286 else if (TREE_CODE (decl) == FIELD_DECL) 287 error ("data member %qD cannot be a member template", decl); 288 else if (DECL_TEMPLATE_INFO (decl)) 289 { 290 if (!DECL_TEMPLATE_SPECIALIZATION (decl)) 291 { 292 check_member_template (DECL_TI_TEMPLATE (decl)); 293 return DECL_TI_TEMPLATE (decl); 294 } 295 else 296 return decl; 297 } 298 else 299 error ("invalid member template declaration %qD", decl); 300 301 return error_mark_node; 302 } 303 304 /* Create a template info node. */ 305 306 tree 307 build_template_info (tree template_decl, tree template_args) 308 { 309 tree result = make_node (TEMPLATE_INFO); 310 TI_TEMPLATE (result) = template_decl; 311 TI_ARGS (result) = template_args; 312 return result; 313 } 314 315 /* Return the template info node corresponding to T, whatever T is. */ 316 317 tree 318 get_template_info (const_tree t) 319 { 320 tree tinfo = NULL_TREE; 321 322 if (!t || t == error_mark_node) 323 return NULL; 324 325 if (DECL_P (t) && DECL_LANG_SPECIFIC (t)) 326 tinfo = DECL_TEMPLATE_INFO (t); 327 328 if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t)) 329 t = TREE_TYPE (t); 330 331 if (TAGGED_TYPE_P (t)) 332 tinfo = TYPE_TEMPLATE_INFO (t); 333 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM) 334 tinfo = TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t); 335 336 return tinfo; 337 } 338 339 /* Returns the template nesting level of the indicated class TYPE. 340 341 For example, in: 342 template <class T> 343 struct A 344 { 345 template <class U> 346 struct B {}; 347 }; 348 349 A<T>::B<U> has depth two, while A<T> has depth one. 350 Both A<T>::B<int> and A<int>::B<U> have depth one, if 351 they are instantiations, not specializations. 352 353 This function is guaranteed to return 0 if passed NULL_TREE so 354 that, for example, `template_class_depth (current_class_type)' is 355 always safe. */ 356 357 int 358 template_class_depth (tree type) 359 { 360 int depth; 361 362 for (depth = 0; 363 type && TREE_CODE (type) != NAMESPACE_DECL; 364 type = (TREE_CODE (type) == FUNCTION_DECL) 365 ? CP_DECL_CONTEXT (type) : CP_TYPE_CONTEXT (type)) 366 { 367 tree tinfo = get_template_info (type); 368 369 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo)) 370 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo)))) 371 ++depth; 372 } 373 374 return depth; 375 } 376 377 /* Subroutine of maybe_begin_member_template_processing. 378 Returns true if processing DECL needs us to push template parms. */ 379 380 static bool 381 inline_needs_template_parms (tree decl) 382 { 383 if (! DECL_TEMPLATE_INFO (decl)) 384 return false; 385 386 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl))) 387 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl))); 388 } 389 390 /* Subroutine of maybe_begin_member_template_processing. 391 Push the template parms in PARMS, starting from LEVELS steps into the 392 chain, and ending at the beginning, since template parms are listed 393 innermost first. */ 394 395 static void 396 push_inline_template_parms_recursive (tree parmlist, int levels) 397 { 398 tree parms = TREE_VALUE (parmlist); 399 int i; 400 401 if (levels > 1) 402 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1); 403 404 ++processing_template_decl; 405 current_template_parms 406 = tree_cons (size_int (processing_template_decl), 407 parms, current_template_parms); 408 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1; 409 410 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec, 411 NULL); 412 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i) 413 { 414 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i)); 415 416 if (parm == error_mark_node) 417 continue; 418 419 gcc_assert (DECL_P (parm)); 420 421 switch (TREE_CODE (parm)) 422 { 423 case TYPE_DECL: 424 case TEMPLATE_DECL: 425 pushdecl (parm); 426 break; 427 428 case PARM_DECL: 429 { 430 /* Make a CONST_DECL as is done in process_template_parm. 431 It is ugly that we recreate this here; the original 432 version built in process_template_parm is no longer 433 available. */ 434 tree decl = build_decl (DECL_SOURCE_LOCATION (parm), 435 CONST_DECL, DECL_NAME (parm), 436 TREE_TYPE (parm)); 437 DECL_ARTIFICIAL (decl) = 1; 438 TREE_CONSTANT (decl) = 1; 439 TREE_READONLY (decl) = 1; 440 DECL_INITIAL (decl) = DECL_INITIAL (parm); 441 SET_DECL_TEMPLATE_PARM_P (decl); 442 pushdecl (decl); 443 } 444 break; 445 446 default: 447 gcc_unreachable (); 448 } 449 } 450 } 451 452 /* Restore the template parameter context for a member template or 453 a friend template defined in a class definition. */ 454 455 void 456 maybe_begin_member_template_processing (tree decl) 457 { 458 tree parms; 459 int levels = 0; 460 461 if (inline_needs_template_parms (decl)) 462 { 463 parms = DECL_TEMPLATE_PARMS (most_general_template (decl)); 464 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl; 465 466 if (DECL_TEMPLATE_SPECIALIZATION (decl)) 467 { 468 --levels; 469 parms = TREE_CHAIN (parms); 470 } 471 472 push_inline_template_parms_recursive (parms, levels); 473 } 474 475 /* Remember how many levels of template parameters we pushed so that 476 we can pop them later. */ 477 VEC_safe_push (int, heap, inline_parm_levels, levels); 478 } 479 480 /* Undo the effects of maybe_begin_member_template_processing. */ 481 482 void 483 maybe_end_member_template_processing (void) 484 { 485 int i; 486 int last; 487 488 if (VEC_length (int, inline_parm_levels) == 0) 489 return; 490 491 last = VEC_pop (int, inline_parm_levels); 492 for (i = 0; i < last; ++i) 493 { 494 --processing_template_decl; 495 current_template_parms = TREE_CHAIN (current_template_parms); 496 poplevel (0, 0, 0); 497 } 498 } 499 500 /* Return a new template argument vector which contains all of ARGS, 501 but has as its innermost set of arguments the EXTRA_ARGS. */ 502 503 static tree 504 add_to_template_args (tree args, tree extra_args) 505 { 506 tree new_args; 507 int extra_depth; 508 int i; 509 int j; 510 511 if (args == NULL_TREE || extra_args == error_mark_node) 512 return extra_args; 513 514 extra_depth = TMPL_ARGS_DEPTH (extra_args); 515 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth); 516 517 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i) 518 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i)); 519 520 for (j = 1; j <= extra_depth; ++j, ++i) 521 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j)); 522 523 return new_args; 524 } 525 526 /* Like add_to_template_args, but only the outermost ARGS are added to 527 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH 528 (EXTRA_ARGS) levels are added. This function is used to combine 529 the template arguments from a partial instantiation with the 530 template arguments used to attain the full instantiation from the 531 partial instantiation. */ 532 533 static tree 534 add_outermost_template_args (tree args, tree extra_args) 535 { 536 tree new_args; 537 538 /* If there are more levels of EXTRA_ARGS than there are ARGS, 539 something very fishy is going on. */ 540 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args)); 541 542 /* If *all* the new arguments will be the EXTRA_ARGS, just return 543 them. */ 544 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args)) 545 return extra_args; 546 547 /* For the moment, we make ARGS look like it contains fewer levels. */ 548 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args); 549 550 new_args = add_to_template_args (args, extra_args); 551 552 /* Now, we restore ARGS to its full dimensions. */ 553 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args); 554 555 return new_args; 556 } 557 558 /* Return the N levels of innermost template arguments from the ARGS. */ 559 560 tree 561 get_innermost_template_args (tree args, int n) 562 { 563 tree new_args; 564 int extra_levels; 565 int i; 566 567 gcc_assert (n >= 0); 568 569 /* If N is 1, just return the innermost set of template arguments. */ 570 if (n == 1) 571 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args)); 572 573 /* If we're not removing anything, just return the arguments we were 574 given. */ 575 extra_levels = TMPL_ARGS_DEPTH (args) - n; 576 gcc_assert (extra_levels >= 0); 577 if (extra_levels == 0) 578 return args; 579 580 /* Make a new set of arguments, not containing the outer arguments. */ 581 new_args = make_tree_vec (n); 582 for (i = 1; i <= n; ++i) 583 SET_TMPL_ARGS_LEVEL (new_args, i, 584 TMPL_ARGS_LEVEL (args, i + extra_levels)); 585 586 return new_args; 587 } 588 589 /* The inverse of get_innermost_template_args: Return all but the innermost 590 EXTRA_LEVELS levels of template arguments from the ARGS. */ 591 592 static tree 593 strip_innermost_template_args (tree args, int extra_levels) 594 { 595 tree new_args; 596 int n = TMPL_ARGS_DEPTH (args) - extra_levels; 597 int i; 598 599 gcc_assert (n >= 0); 600 601 /* If N is 1, just return the outermost set of template arguments. */ 602 if (n == 1) 603 return TMPL_ARGS_LEVEL (args, 1); 604 605 /* If we're not removing anything, just return the arguments we were 606 given. */ 607 gcc_assert (extra_levels >= 0); 608 if (extra_levels == 0) 609 return args; 610 611 /* Make a new set of arguments, not containing the inner arguments. */ 612 new_args = make_tree_vec (n); 613 for (i = 1; i <= n; ++i) 614 SET_TMPL_ARGS_LEVEL (new_args, i, 615 TMPL_ARGS_LEVEL (args, i)); 616 617 return new_args; 618 } 619 620 /* We've got a template header coming up; push to a new level for storing 621 the parms. */ 622 623 void 624 begin_template_parm_list (void) 625 { 626 /* We use a non-tag-transparent scope here, which causes pushtag to 627 put tags in this scope, rather than in the enclosing class or 628 namespace scope. This is the right thing, since we want 629 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a 630 global template class, push_template_decl handles putting the 631 TEMPLATE_DECL into top-level scope. For a nested template class, 632 e.g.: 633 634 template <class T> struct S1 { 635 template <class T> struct S2 {}; 636 }; 637 638 pushtag contains special code to call pushdecl_with_scope on the 639 TEMPLATE_DECL for S2. */ 640 begin_scope (sk_template_parms, NULL); 641 ++processing_template_decl; 642 ++processing_template_parmlist; 643 note_template_header (0); 644 } 645 646 /* This routine is called when a specialization is declared. If it is 647 invalid to declare a specialization here, an error is reported and 648 false is returned, otherwise this routine will return true. */ 649 650 static bool 651 check_specialization_scope (void) 652 { 653 tree scope = current_scope (); 654 655 /* [temp.expl.spec] 656 657 An explicit specialization shall be declared in the namespace of 658 which the template is a member, or, for member templates, in the 659 namespace of which the enclosing class or enclosing class 660 template is a member. An explicit specialization of a member 661 function, member class or static data member of a class template 662 shall be declared in the namespace of which the class template 663 is a member. */ 664 if (scope && TREE_CODE (scope) != NAMESPACE_DECL) 665 { 666 error ("explicit specialization in non-namespace scope %qD", scope); 667 return false; 668 } 669 670 /* [temp.expl.spec] 671 672 In an explicit specialization declaration for a member of a class 673 template or a member template that appears in namespace scope, 674 the member template and some of its enclosing class templates may 675 remain unspecialized, except that the declaration shall not 676 explicitly specialize a class member template if its enclosing 677 class templates are not explicitly specialized as well. */ 678 if (current_template_parms) 679 { 680 error ("enclosing class templates are not explicitly specialized"); 681 return false; 682 } 683 684 return true; 685 } 686 687 /* We've just seen template <>. */ 688 689 bool 690 begin_specialization (void) 691 { 692 begin_scope (sk_template_spec, NULL); 693 note_template_header (1); 694 return check_specialization_scope (); 695 } 696 697 /* Called at then end of processing a declaration preceded by 698 template<>. */ 699 700 void 701 end_specialization (void) 702 { 703 finish_scope (); 704 reset_specialization (); 705 } 706 707 /* Any template <>'s that we have seen thus far are not referring to a 708 function specialization. */ 709 710 void 711 reset_specialization (void) 712 { 713 processing_specialization = 0; 714 template_header_count = 0; 715 } 716 717 /* We've just seen a template header. If SPECIALIZATION is nonzero, 718 it was of the form template <>. */ 719 720 static void 721 note_template_header (int specialization) 722 { 723 processing_specialization = specialization; 724 template_header_count++; 725 } 726 727 /* We're beginning an explicit instantiation. */ 728 729 void 730 begin_explicit_instantiation (void) 731 { 732 gcc_assert (!processing_explicit_instantiation); 733 processing_explicit_instantiation = true; 734 } 735 736 737 void 738 end_explicit_instantiation (void) 739 { 740 gcc_assert (processing_explicit_instantiation); 741 processing_explicit_instantiation = false; 742 } 743 744 /* An explicit specialization or partial specialization TMPL is being 745 declared. Check that the namespace in which the specialization is 746 occurring is permissible. Returns false iff it is invalid to 747 specialize TMPL in the current namespace. */ 748 749 static bool 750 check_specialization_namespace (tree tmpl) 751 { 752 tree tpl_ns = decl_namespace_context (tmpl); 753 754 /* [tmpl.expl.spec] 755 756 An explicit specialization shall be declared in the namespace of 757 which the template is a member, or, for member templates, in the 758 namespace of which the enclosing class or enclosing class 759 template is a member. An explicit specialization of a member 760 function, member class or static data member of a class template 761 shall be declared in the namespace of which the class template is 762 a member. */ 763 if (current_scope() != DECL_CONTEXT (tmpl) 764 && !at_namespace_scope_p ()) 765 { 766 error ("specialization of %qD must appear at namespace scope", tmpl); 767 return false; 768 } 769 if (is_associated_namespace (current_namespace, tpl_ns)) 770 /* Same or super-using namespace. */ 771 return true; 772 else 773 { 774 permerror (input_location, "specialization of %qD in different namespace", tmpl); 775 permerror (input_location, " from definition of %q+#D", tmpl); 776 return false; 777 } 778 } 779 780 /* SPEC is an explicit instantiation. Check that it is valid to 781 perform this explicit instantiation in the current namespace. */ 782 783 static void 784 check_explicit_instantiation_namespace (tree spec) 785 { 786 tree ns; 787 788 /* DR 275: An explicit instantiation shall appear in an enclosing 789 namespace of its template. */ 790 ns = decl_namespace_context (spec); 791 if (!is_ancestor (current_namespace, ns)) 792 permerror (input_location, "explicit instantiation of %qD in namespace %qD " 793 "(which does not enclose namespace %qD)", 794 spec, current_namespace, ns); 795 } 796 797 /* The TYPE is being declared. If it is a template type, that means it 798 is a partial specialization. Do appropriate error-checking. */ 799 800 tree 801 maybe_process_partial_specialization (tree type) 802 { 803 tree context; 804 805 if (type == error_mark_node) 806 return error_mark_node; 807 808 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM) 809 { 810 error ("name of class shadows template template parameter %qD", 811 TYPE_NAME (type)); 812 return error_mark_node; 813 } 814 815 context = TYPE_CONTEXT (type); 816 817 if ((CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type)) 818 /* Consider non-class instantiations of alias templates as 819 well. */ 820 || (TYPE_P (type) 821 && TYPE_TEMPLATE_INFO (type) 822 && DECL_LANG_SPECIFIC (TYPE_NAME (type)) 823 && DECL_USE_TEMPLATE (TYPE_NAME (type)))) 824 { 825 /* This is for ordinary explicit specialization and partial 826 specialization of a template class such as: 827 828 template <> class C<int>; 829 830 or: 831 832 template <class T> class C<T*>; 833 834 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */ 835 836 if (CLASS_TYPE_P (type) 837 && CLASSTYPE_IMPLICIT_INSTANTIATION (type) 838 && !COMPLETE_TYPE_P (type)) 839 { 840 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type)); 841 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type); 842 if (processing_template_decl) 843 { 844 if (push_template_decl (TYPE_MAIN_DECL (type)) 845 == error_mark_node) 846 return error_mark_node; 847 } 848 } 849 else if (CLASS_TYPE_P (type) 850 && CLASSTYPE_TEMPLATE_INSTANTIATION (type)) 851 error ("specialization of %qT after instantiation", type); 852 853 if (DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (type))) 854 { 855 error ("partial specialization of alias template %qD", 856 TYPE_TI_TEMPLATE (type)); 857 return error_mark_node; 858 } 859 } 860 else if (CLASS_TYPE_P (type) 861 && !CLASSTYPE_USE_TEMPLATE (type) 862 && CLASSTYPE_TEMPLATE_INFO (type) 863 && context && CLASS_TYPE_P (context) 864 && CLASSTYPE_TEMPLATE_INFO (context)) 865 { 866 /* This is for an explicit specialization of member class 867 template according to [temp.expl.spec/18]: 868 869 template <> template <class U> class C<int>::D; 870 871 The context `C<int>' must be an implicit instantiation. 872 Otherwise this is just a member class template declared 873 earlier like: 874 875 template <> class C<int> { template <class U> class D; }; 876 template <> template <class U> class C<int>::D; 877 878 In the first case, `C<int>::D' is a specialization of `C<T>::D' 879 while in the second case, `C<int>::D' is a primary template 880 and `C<T>::D' may not exist. */ 881 882 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context) 883 && !COMPLETE_TYPE_P (type)) 884 { 885 tree t; 886 tree tmpl = CLASSTYPE_TI_TEMPLATE (type); 887 888 if (current_namespace 889 != decl_namespace_context (tmpl)) 890 { 891 permerror (input_location, "specializing %q#T in different namespace", type); 892 permerror (input_location, " from definition of %q+#D", tmpl); 893 } 894 895 /* Check for invalid specialization after instantiation: 896 897 template <> template <> class C<int>::D<int>; 898 template <> template <class U> class C<int>::D; */ 899 900 for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl); 901 t; t = TREE_CHAIN (t)) 902 { 903 tree inst = TREE_VALUE (t); 904 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst)) 905 { 906 /* We already have a full specialization of this partial 907 instantiation. Reassign it to the new member 908 specialization template. */ 909 spec_entry elt; 910 spec_entry *entry; 911 void **slot; 912 913 elt.tmpl = most_general_template (tmpl); 914 elt.args = CLASSTYPE_TI_ARGS (inst); 915 elt.spec = inst; 916 917 htab_remove_elt (type_specializations, &elt); 918 919 elt.tmpl = tmpl; 920 elt.args = INNERMOST_TEMPLATE_ARGS (elt.args); 921 922 slot = htab_find_slot (type_specializations, &elt, INSERT); 923 entry = ggc_alloc_spec_entry (); 924 *entry = elt; 925 *slot = entry; 926 } 927 else if (COMPLETE_OR_OPEN_TYPE_P (inst)) 928 /* But if we've had an implicit instantiation, that's a 929 problem ([temp.expl.spec]/6). */ 930 error ("specialization %qT after instantiation %qT", 931 type, inst); 932 } 933 934 /* Mark TYPE as a specialization. And as a result, we only 935 have one level of template argument for the innermost 936 class template. */ 937 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type); 938 CLASSTYPE_TI_ARGS (type) 939 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)); 940 } 941 } 942 else if (processing_specialization) 943 { 944 /* Someday C++0x may allow for enum template specialization. */ 945 if (cxx_dialect > cxx98 && TREE_CODE (type) == ENUMERAL_TYPE 946 && CLASS_TYPE_P (context) && CLASSTYPE_USE_TEMPLATE (context)) 947 pedwarn (input_location, OPT_pedantic, "template specialization " 948 "of %qD not allowed by ISO C++", type); 949 else 950 { 951 error ("explicit specialization of non-template %qT", type); 952 return error_mark_node; 953 } 954 } 955 956 return type; 957 } 958 959 /* Returns nonzero if we can optimize the retrieval of specializations 960 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we 961 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */ 962 963 static inline bool 964 optimize_specialization_lookup_p (tree tmpl) 965 { 966 return (DECL_FUNCTION_TEMPLATE_P (tmpl) 967 && DECL_CLASS_SCOPE_P (tmpl) 968 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template 969 parameter. */ 970 && CLASS_TYPE_P (DECL_CONTEXT (tmpl)) 971 /* The optimized lookup depends on the fact that the 972 template arguments for the member function template apply 973 purely to the containing class, which is not true if the 974 containing class is an explicit or partial 975 specialization. */ 976 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl)) 977 && !DECL_MEMBER_TEMPLATE_P (tmpl) 978 && !DECL_CONV_FN_P (tmpl) 979 /* It is possible to have a template that is not a member 980 template and is not a member of a template class: 981 982 template <typename T> 983 struct S { friend A::f(); }; 984 985 Here, the friend function is a template, but the context does 986 not have template information. The optimized lookup relies 987 on having ARGS be the template arguments for both the class 988 and the function template. */ 989 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl))); 990 } 991 992 /* Retrieve the specialization (in the sense of [temp.spec] - a 993 specialization is either an instantiation or an explicit 994 specialization) of TMPL for the given template ARGS. If there is 995 no such specialization, return NULL_TREE. The ARGS are a vector of 996 arguments, or a vector of vectors of arguments, in the case of 997 templates with more than one level of parameters. 998 999 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true, 1000 then we search for a partial specialization matching ARGS. This 1001 parameter is ignored if TMPL is not a class template. */ 1002 1003 static tree 1004 retrieve_specialization (tree tmpl, tree args, hashval_t hash) 1005 { 1006 if (args == error_mark_node) 1007 return NULL_TREE; 1008 1009 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL); 1010 1011 /* There should be as many levels of arguments as there are 1012 levels of parameters. */ 1013 gcc_assert (TMPL_ARGS_DEPTH (args) 1014 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl))); 1015 1016 if (optimize_specialization_lookup_p (tmpl)) 1017 { 1018 tree class_template; 1019 tree class_specialization; 1020 VEC(tree,gc) *methods; 1021 tree fns; 1022 int idx; 1023 1024 /* The template arguments actually apply to the containing 1025 class. Find the class specialization with those 1026 arguments. */ 1027 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl)); 1028 class_specialization 1029 = retrieve_specialization (class_template, args, 0); 1030 if (!class_specialization) 1031 return NULL_TREE; 1032 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC 1033 for the specialization. */ 1034 idx = class_method_index_for_fn (class_specialization, tmpl); 1035 if (idx == -1) 1036 return NULL_TREE; 1037 /* Iterate through the methods with the indicated name, looking 1038 for the one that has an instance of TMPL. */ 1039 methods = CLASSTYPE_METHOD_VEC (class_specialization); 1040 for (fns = VEC_index (tree, methods, idx); fns; fns = OVL_NEXT (fns)) 1041 { 1042 tree fn = OVL_CURRENT (fns); 1043 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl 1044 /* using-declarations can add base methods to the method vec, 1045 and we don't want those here. */ 1046 && DECL_CONTEXT (fn) == class_specialization) 1047 return fn; 1048 } 1049 return NULL_TREE; 1050 } 1051 else 1052 { 1053 spec_entry *found; 1054 spec_entry elt; 1055 htab_t specializations; 1056 1057 elt.tmpl = tmpl; 1058 elt.args = args; 1059 elt.spec = NULL_TREE; 1060 1061 if (DECL_CLASS_TEMPLATE_P (tmpl)) 1062 specializations = type_specializations; 1063 else 1064 specializations = decl_specializations; 1065 1066 if (hash == 0) 1067 hash = hash_specialization (&elt); 1068 found = (spec_entry *) htab_find_with_hash (specializations, &elt, hash); 1069 if (found) 1070 return found->spec; 1071 } 1072 1073 return NULL_TREE; 1074 } 1075 1076 /* Like retrieve_specialization, but for local declarations. */ 1077 1078 static tree 1079 retrieve_local_specialization (tree tmpl) 1080 { 1081 tree spec; 1082 1083 if (local_specializations == NULL) 1084 return NULL_TREE; 1085 1086 spec = (tree) htab_find_with_hash (local_specializations, tmpl, 1087 htab_hash_pointer (tmpl)); 1088 return spec ? TREE_PURPOSE (spec) : NULL_TREE; 1089 } 1090 1091 /* Returns nonzero iff DECL is a specialization of TMPL. */ 1092 1093 int 1094 is_specialization_of (tree decl, tree tmpl) 1095 { 1096 tree t; 1097 1098 if (TREE_CODE (decl) == FUNCTION_DECL) 1099 { 1100 for (t = decl; 1101 t != NULL_TREE; 1102 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE) 1103 if (t == tmpl) 1104 return 1; 1105 } 1106 else 1107 { 1108 gcc_assert (TREE_CODE (decl) == TYPE_DECL); 1109 1110 for (t = TREE_TYPE (decl); 1111 t != NULL_TREE; 1112 t = CLASSTYPE_USE_TEMPLATE (t) 1113 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE) 1114 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl))) 1115 return 1; 1116 } 1117 1118 return 0; 1119 } 1120 1121 /* Returns nonzero iff DECL is a specialization of friend declaration 1122 FRIEND_DECL according to [temp.friend]. */ 1123 1124 bool 1125 is_specialization_of_friend (tree decl, tree friend_decl) 1126 { 1127 bool need_template = true; 1128 int template_depth; 1129 1130 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL 1131 || TREE_CODE (decl) == TYPE_DECL); 1132 1133 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function 1134 of a template class, we want to check if DECL is a specialization 1135 if this. */ 1136 if (TREE_CODE (friend_decl) == FUNCTION_DECL 1137 && DECL_TEMPLATE_INFO (friend_decl) 1138 && !DECL_USE_TEMPLATE (friend_decl)) 1139 { 1140 /* We want a TEMPLATE_DECL for `is_specialization_of'. */ 1141 friend_decl = DECL_TI_TEMPLATE (friend_decl); 1142 need_template = false; 1143 } 1144 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL 1145 && !PRIMARY_TEMPLATE_P (friend_decl)) 1146 need_template = false; 1147 1148 /* There is nothing to do if this is not a template friend. */ 1149 if (TREE_CODE (friend_decl) != TEMPLATE_DECL) 1150 return false; 1151 1152 if (is_specialization_of (decl, friend_decl)) 1153 return true; 1154 1155 /* [temp.friend/6] 1156 A member of a class template may be declared to be a friend of a 1157 non-template class. In this case, the corresponding member of 1158 every specialization of the class template is a friend of the 1159 class granting friendship. 1160 1161 For example, given a template friend declaration 1162 1163 template <class T> friend void A<T>::f(); 1164 1165 the member function below is considered a friend 1166 1167 template <> struct A<int> { 1168 void f(); 1169 }; 1170 1171 For this type of template friend, TEMPLATE_DEPTH below will be 1172 nonzero. To determine if DECL is a friend of FRIEND, we first 1173 check if the enclosing class is a specialization of another. */ 1174 1175 template_depth = template_class_depth (CP_DECL_CONTEXT (friend_decl)); 1176 if (template_depth 1177 && DECL_CLASS_SCOPE_P (decl) 1178 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)), 1179 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl)))) 1180 { 1181 /* Next, we check the members themselves. In order to handle 1182 a few tricky cases, such as when FRIEND_DECL's are 1183 1184 template <class T> friend void A<T>::g(T t); 1185 template <class T> template <T t> friend void A<T>::h(); 1186 1187 and DECL's are 1188 1189 void A<int>::g(int); 1190 template <int> void A<int>::h(); 1191 1192 we need to figure out ARGS, the template arguments from 1193 the context of DECL. This is required for template substitution 1194 of `T' in the function parameter of `g' and template parameter 1195 of `h' in the above examples. Here ARGS corresponds to `int'. */ 1196 1197 tree context = DECL_CONTEXT (decl); 1198 tree args = NULL_TREE; 1199 int current_depth = 0; 1200 1201 while (current_depth < template_depth) 1202 { 1203 if (CLASSTYPE_TEMPLATE_INFO (context)) 1204 { 1205 if (current_depth == 0) 1206 args = TYPE_TI_ARGS (context); 1207 else 1208 args = add_to_template_args (TYPE_TI_ARGS (context), args); 1209 current_depth++; 1210 } 1211 context = TYPE_CONTEXT (context); 1212 } 1213 1214 if (TREE_CODE (decl) == FUNCTION_DECL) 1215 { 1216 bool is_template; 1217 tree friend_type; 1218 tree decl_type; 1219 tree friend_args_type; 1220 tree decl_args_type; 1221 1222 /* Make sure that both DECL and FRIEND_DECL are templates or 1223 non-templates. */ 1224 is_template = DECL_TEMPLATE_INFO (decl) 1225 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl)); 1226 if (need_template ^ is_template) 1227 return false; 1228 else if (is_template) 1229 { 1230 /* If both are templates, check template parameter list. */ 1231 tree friend_parms 1232 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl), 1233 args, tf_none); 1234 if (!comp_template_parms 1235 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)), 1236 friend_parms)) 1237 return false; 1238 1239 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl)); 1240 } 1241 else 1242 decl_type = TREE_TYPE (decl); 1243 1244 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args, 1245 tf_none, NULL_TREE); 1246 if (friend_type == error_mark_node) 1247 return false; 1248 1249 /* Check if return types match. */ 1250 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type))) 1251 return false; 1252 1253 /* Check if function parameter types match, ignoring the 1254 `this' parameter. */ 1255 friend_args_type = TYPE_ARG_TYPES (friend_type); 1256 decl_args_type = TYPE_ARG_TYPES (decl_type); 1257 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl)) 1258 friend_args_type = TREE_CHAIN (friend_args_type); 1259 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl)) 1260 decl_args_type = TREE_CHAIN (decl_args_type); 1261 1262 return compparms (decl_args_type, friend_args_type); 1263 } 1264 else 1265 { 1266 /* DECL is a TYPE_DECL */ 1267 bool is_template; 1268 tree decl_type = TREE_TYPE (decl); 1269 1270 /* Make sure that both DECL and FRIEND_DECL are templates or 1271 non-templates. */ 1272 is_template 1273 = CLASSTYPE_TEMPLATE_INFO (decl_type) 1274 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type)); 1275 1276 if (need_template ^ is_template) 1277 return false; 1278 else if (is_template) 1279 { 1280 tree friend_parms; 1281 /* If both are templates, check the name of the two 1282 TEMPLATE_DECL's first because is_friend didn't. */ 1283 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type)) 1284 != DECL_NAME (friend_decl)) 1285 return false; 1286 1287 /* Now check template parameter list. */ 1288 friend_parms 1289 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl), 1290 args, tf_none); 1291 return comp_template_parms 1292 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)), 1293 friend_parms); 1294 } 1295 else 1296 return (DECL_NAME (decl) 1297 == DECL_NAME (friend_decl)); 1298 } 1299 } 1300 return false; 1301 } 1302 1303 /* Register the specialization SPEC as a specialization of TMPL with 1304 the indicated ARGS. IS_FRIEND indicates whether the specialization 1305 is actually just a friend declaration. Returns SPEC, or an 1306 equivalent prior declaration, if available. */ 1307 1308 static tree 1309 register_specialization (tree spec, tree tmpl, tree args, bool is_friend, 1310 hashval_t hash) 1311 { 1312 tree fn; 1313 void **slot = NULL; 1314 spec_entry elt; 1315 1316 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec)); 1317 1318 if (TREE_CODE (spec) == FUNCTION_DECL 1319 && uses_template_parms (DECL_TI_ARGS (spec))) 1320 /* This is the FUNCTION_DECL for a partial instantiation. Don't 1321 register it; we want the corresponding TEMPLATE_DECL instead. 1322 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than 1323 the more obvious `uses_template_parms (spec)' to avoid problems 1324 with default function arguments. In particular, given 1325 something like this: 1326 1327 template <class T> void f(T t1, T t = T()) 1328 1329 the default argument expression is not substituted for in an 1330 instantiation unless and until it is actually needed. */ 1331 return spec; 1332 1333 if (optimize_specialization_lookup_p (tmpl)) 1334 /* We don't put these specializations in the hash table, but we might 1335 want to give an error about a mismatch. */ 1336 fn = retrieve_specialization (tmpl, args, 0); 1337 else 1338 { 1339 elt.tmpl = tmpl; 1340 elt.args = args; 1341 elt.spec = spec; 1342 1343 if (hash == 0) 1344 hash = hash_specialization (&elt); 1345 1346 slot = 1347 htab_find_slot_with_hash (decl_specializations, &elt, hash, INSERT); 1348 if (*slot) 1349 fn = ((spec_entry *) *slot)->spec; 1350 else 1351 fn = NULL_TREE; 1352 } 1353 1354 /* We can sometimes try to re-register a specialization that we've 1355 already got. In particular, regenerate_decl_from_template calls 1356 duplicate_decls which will update the specialization list. But, 1357 we'll still get called again here anyhow. It's more convenient 1358 to simply allow this than to try to prevent it. */ 1359 if (fn == spec) 1360 return spec; 1361 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec)) 1362 { 1363 if (DECL_TEMPLATE_INSTANTIATION (fn)) 1364 { 1365 if (DECL_ODR_USED (fn) 1366 || DECL_EXPLICIT_INSTANTIATION (fn)) 1367 { 1368 error ("specialization of %qD after instantiation", 1369 fn); 1370 return error_mark_node; 1371 } 1372 else 1373 { 1374 tree clone; 1375 /* This situation should occur only if the first 1376 specialization is an implicit instantiation, the 1377 second is an explicit specialization, and the 1378 implicit instantiation has not yet been used. That 1379 situation can occur if we have implicitly 1380 instantiated a member function and then specialized 1381 it later. 1382 1383 We can also wind up here if a friend declaration that 1384 looked like an instantiation turns out to be a 1385 specialization: 1386 1387 template <class T> void foo(T); 1388 class S { friend void foo<>(int) }; 1389 template <> void foo(int); 1390 1391 We transform the existing DECL in place so that any 1392 pointers to it become pointers to the updated 1393 declaration. 1394 1395 If there was a definition for the template, but not 1396 for the specialization, we want this to look as if 1397 there were no definition, and vice versa. */ 1398 DECL_INITIAL (fn) = NULL_TREE; 1399 duplicate_decls (spec, fn, is_friend); 1400 /* The call to duplicate_decls will have applied 1401 [temp.expl.spec]: 1402 1403 An explicit specialization of a function template 1404 is inline only if it is explicitly declared to be, 1405 and independently of whether its function template 1406 is. 1407 1408 to the primary function; now copy the inline bits to 1409 the various clones. */ 1410 FOR_EACH_CLONE (clone, fn) 1411 { 1412 DECL_DECLARED_INLINE_P (clone) 1413 = DECL_DECLARED_INLINE_P (fn); 1414 DECL_SOURCE_LOCATION (clone) 1415 = DECL_SOURCE_LOCATION (fn); 1416 } 1417 check_specialization_namespace (fn); 1418 1419 return fn; 1420 } 1421 } 1422 else if (DECL_TEMPLATE_SPECIALIZATION (fn)) 1423 { 1424 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec)) 1425 /* Dup decl failed, but this is a new definition. Set the 1426 line number so any errors match this new 1427 definition. */ 1428 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec); 1429 1430 return fn; 1431 } 1432 } 1433 else if (fn) 1434 return duplicate_decls (spec, fn, is_friend); 1435 1436 /* A specialization must be declared in the same namespace as the 1437 template it is specializing. */ 1438 if (DECL_TEMPLATE_SPECIALIZATION (spec) 1439 && !check_specialization_namespace (tmpl)) 1440 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl); 1441 1442 if (slot != NULL /* !optimize_specialization_lookup_p (tmpl) */) 1443 { 1444 spec_entry *entry = ggc_alloc_spec_entry (); 1445 gcc_assert (tmpl && args && spec); 1446 *entry = elt; 1447 *slot = entry; 1448 if (TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec) 1449 && PRIMARY_TEMPLATE_P (tmpl) 1450 && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE) 1451 /* TMPL is a forward declaration of a template function; keep a list 1452 of all specializations in case we need to reassign them to a friend 1453 template later in tsubst_friend_function. */ 1454 DECL_TEMPLATE_INSTANTIATIONS (tmpl) 1455 = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl)); 1456 } 1457 1458 return spec; 1459 } 1460 1461 /* Returns true iff two spec_entry nodes are equivalent. Only compares the 1462 TMPL and ARGS members, ignores SPEC. */ 1463 1464 static int 1465 eq_specializations (const void *p1, const void *p2) 1466 { 1467 const spec_entry *e1 = (const spec_entry *)p1; 1468 const spec_entry *e2 = (const spec_entry *)p2; 1469 1470 return (e1->tmpl == e2->tmpl 1471 && comp_template_args (e1->args, e2->args)); 1472 } 1473 1474 /* Returns a hash for a template TMPL and template arguments ARGS. */ 1475 1476 static hashval_t 1477 hash_tmpl_and_args (tree tmpl, tree args) 1478 { 1479 hashval_t val = DECL_UID (tmpl); 1480 return iterative_hash_template_arg (args, val); 1481 } 1482 1483 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members, 1484 ignoring SPEC. */ 1485 1486 static hashval_t 1487 hash_specialization (const void *p) 1488 { 1489 const spec_entry *e = (const spec_entry *)p; 1490 return hash_tmpl_and_args (e->tmpl, e->args); 1491 } 1492 1493 /* Recursively calculate a hash value for a template argument ARG, for use 1494 in the hash tables of template specializations. */ 1495 1496 hashval_t 1497 iterative_hash_template_arg (tree arg, hashval_t val) 1498 { 1499 unsigned HOST_WIDE_INT i; 1500 enum tree_code code; 1501 char tclass; 1502 1503 if (arg == NULL_TREE) 1504 return iterative_hash_object (arg, val); 1505 1506 if (!TYPE_P (arg)) 1507 STRIP_NOPS (arg); 1508 1509 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT) 1510 /* We can get one of these when re-hashing a previous entry in the middle 1511 of substituting into a pack expansion. Just look through it. */ 1512 arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg); 1513 1514 code = TREE_CODE (arg); 1515 tclass = TREE_CODE_CLASS (code); 1516 1517 val = iterative_hash_object (code, val); 1518 1519 switch (code) 1520 { 1521 case ERROR_MARK: 1522 return val; 1523 1524 case IDENTIFIER_NODE: 1525 return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val); 1526 1527 case TREE_VEC: 1528 { 1529 int i, len = TREE_VEC_LENGTH (arg); 1530 for (i = 0; i < len; ++i) 1531 val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val); 1532 return val; 1533 } 1534 1535 case TYPE_PACK_EXPANSION: 1536 case EXPR_PACK_EXPANSION: 1537 val = iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val); 1538 return iterative_hash_template_arg (PACK_EXPANSION_EXTRA_ARGS (arg), val); 1539 1540 case TYPE_ARGUMENT_PACK: 1541 case NONTYPE_ARGUMENT_PACK: 1542 return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val); 1543 1544 case TREE_LIST: 1545 for (; arg; arg = TREE_CHAIN (arg)) 1546 val = iterative_hash_template_arg (TREE_VALUE (arg), val); 1547 return val; 1548 1549 case OVERLOAD: 1550 for (; arg; arg = OVL_NEXT (arg)) 1551 val = iterative_hash_template_arg (OVL_CURRENT (arg), val); 1552 return val; 1553 1554 case CONSTRUCTOR: 1555 { 1556 tree field, value; 1557 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value) 1558 { 1559 val = iterative_hash_template_arg (field, val); 1560 val = iterative_hash_template_arg (value, val); 1561 } 1562 return val; 1563 } 1564 1565 case PARM_DECL: 1566 if (!DECL_ARTIFICIAL (arg)) 1567 { 1568 val = iterative_hash_object (DECL_PARM_INDEX (arg), val); 1569 val = iterative_hash_object (DECL_PARM_LEVEL (arg), val); 1570 } 1571 return iterative_hash_template_arg (TREE_TYPE (arg), val); 1572 1573 case TARGET_EXPR: 1574 return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val); 1575 1576 case PTRMEM_CST: 1577 val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val); 1578 return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val); 1579 1580 case TEMPLATE_PARM_INDEX: 1581 val = iterative_hash_template_arg 1582 (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val); 1583 val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val); 1584 return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val); 1585 1586 case TRAIT_EXPR: 1587 val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val); 1588 val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val); 1589 return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val); 1590 1591 case BASELINK: 1592 val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)), 1593 val); 1594 return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)), 1595 val); 1596 1597 case MODOP_EXPR: 1598 val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val); 1599 code = TREE_CODE (TREE_OPERAND (arg, 1)); 1600 val = iterative_hash_object (code, val); 1601 return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val); 1602 1603 case LAMBDA_EXPR: 1604 /* A lambda can't appear in a template arg, but don't crash on 1605 erroneous input. */ 1606 gcc_assert (seen_error ()); 1607 return val; 1608 1609 case CAST_EXPR: 1610 case IMPLICIT_CONV_EXPR: 1611 case STATIC_CAST_EXPR: 1612 case REINTERPRET_CAST_EXPR: 1613 case CONST_CAST_EXPR: 1614 case DYNAMIC_CAST_EXPR: 1615 case NEW_EXPR: 1616 val = iterative_hash_template_arg (TREE_TYPE (arg), val); 1617 /* Now hash operands as usual. */ 1618 break; 1619 1620 default: 1621 break; 1622 } 1623 1624 switch (tclass) 1625 { 1626 case tcc_type: 1627 if (TYPE_CANONICAL (arg)) 1628 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)), 1629 val); 1630 else if (TREE_CODE (arg) == DECLTYPE_TYPE) 1631 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val); 1632 /* Otherwise just compare the types during lookup. */ 1633 return val; 1634 1635 case tcc_declaration: 1636 case tcc_constant: 1637 return iterative_hash_expr (arg, val); 1638 1639 default: 1640 gcc_assert (IS_EXPR_CODE_CLASS (tclass)); 1641 { 1642 unsigned n = cp_tree_operand_length (arg); 1643 for (i = 0; i < n; ++i) 1644 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val); 1645 return val; 1646 } 1647 } 1648 gcc_unreachable (); 1649 return 0; 1650 } 1651 1652 /* Unregister the specialization SPEC as a specialization of TMPL. 1653 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true 1654 if the SPEC was listed as a specialization of TMPL. 1655 1656 Note that SPEC has been ggc_freed, so we can't look inside it. */ 1657 1658 bool 1659 reregister_specialization (tree spec, tree tinfo, tree new_spec) 1660 { 1661 spec_entry *entry; 1662 spec_entry elt; 1663 1664 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo)); 1665 elt.args = TI_ARGS (tinfo); 1666 elt.spec = NULL_TREE; 1667 1668 entry = (spec_entry *) htab_find (decl_specializations, &elt); 1669 if (entry != NULL) 1670 { 1671 gcc_assert (entry->spec == spec || entry->spec == new_spec); 1672 gcc_assert (new_spec != NULL_TREE); 1673 entry->spec = new_spec; 1674 return 1; 1675 } 1676 1677 return 0; 1678 } 1679 1680 /* Compare an entry in the local specializations hash table P1 (which 1681 is really a pointer to a TREE_LIST) with P2 (which is really a 1682 DECL). */ 1683 1684 static int 1685 eq_local_specializations (const void *p1, const void *p2) 1686 { 1687 return TREE_VALUE ((const_tree) p1) == (const_tree) p2; 1688 } 1689 1690 /* Hash P1, an entry in the local specializations table. */ 1691 1692 static hashval_t 1693 hash_local_specialization (const void* p1) 1694 { 1695 return htab_hash_pointer (TREE_VALUE ((const_tree) p1)); 1696 } 1697 1698 /* Like register_specialization, but for local declarations. We are 1699 registering SPEC, an instantiation of TMPL. */ 1700 1701 static void 1702 register_local_specialization (tree spec, tree tmpl) 1703 { 1704 void **slot; 1705 1706 slot = htab_find_slot_with_hash (local_specializations, tmpl, 1707 htab_hash_pointer (tmpl), INSERT); 1708 *slot = build_tree_list (spec, tmpl); 1709 } 1710 1711 /* TYPE is a class type. Returns true if TYPE is an explicitly 1712 specialized class. */ 1713 1714 bool 1715 explicit_class_specialization_p (tree type) 1716 { 1717 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type)) 1718 return false; 1719 return !uses_template_parms (CLASSTYPE_TI_ARGS (type)); 1720 } 1721 1722 /* Print the list of functions at FNS, going through all the overloads 1723 for each element of the list. Alternatively, FNS can not be a 1724 TREE_LIST, in which case it will be printed together with all the 1725 overloads. 1726 1727 MORE and *STR should respectively be FALSE and NULL when the function 1728 is called from the outside. They are used internally on recursive 1729 calls. print_candidates manages the two parameters and leaves NULL 1730 in *STR when it ends. */ 1731 1732 static void 1733 print_candidates_1 (tree fns, bool more, const char **str) 1734 { 1735 tree fn, fn2; 1736 char *spaces = NULL; 1737 1738 for (fn = fns; fn; fn = OVL_NEXT (fn)) 1739 if (TREE_CODE (fn) == TREE_LIST) 1740 { 1741 for (fn2 = fn; fn2 != NULL_TREE; fn2 = TREE_CHAIN (fn2)) 1742 print_candidates_1 (TREE_VALUE (fn2), 1743 TREE_CHAIN (fn2) || more, str); 1744 } 1745 else 1746 { 1747 if (!*str) 1748 { 1749 /* Pick the prefix string. */ 1750 if (!more && !OVL_NEXT (fns)) 1751 { 1752 error ("candidate is: %+#D", OVL_CURRENT (fn)); 1753 continue; 1754 } 1755 1756 *str = _("candidates are:"); 1757 spaces = get_spaces (*str); 1758 } 1759 error ("%s %+#D", *str, OVL_CURRENT (fn)); 1760 *str = spaces ? spaces : *str; 1761 } 1762 1763 if (!more) 1764 { 1765 free (spaces); 1766 *str = NULL; 1767 } 1768 } 1769 1770 /* Print the list of candidate FNS in an error message. FNS can also 1771 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */ 1772 1773 void 1774 print_candidates (tree fns) 1775 { 1776 const char *str = NULL; 1777 print_candidates_1 (fns, false, &str); 1778 gcc_assert (str == NULL); 1779 } 1780 1781 /* Returns the template (one of the functions given by TEMPLATE_ID) 1782 which can be specialized to match the indicated DECL with the 1783 explicit template args given in TEMPLATE_ID. The DECL may be 1784 NULL_TREE if none is available. In that case, the functions in 1785 TEMPLATE_ID are non-members. 1786 1787 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a 1788 specialization of a member template. 1789 1790 The TEMPLATE_COUNT is the number of references to qualifying 1791 template classes that appeared in the name of the function. See 1792 check_explicit_specialization for a more accurate description. 1793 1794 TSK indicates what kind of template declaration (if any) is being 1795 declared. TSK_TEMPLATE indicates that the declaration given by 1796 DECL, though a FUNCTION_DECL, has template parameters, and is 1797 therefore a template function. 1798 1799 The template args (those explicitly specified and those deduced) 1800 are output in a newly created vector *TARGS_OUT. 1801 1802 If it is impossible to determine the result, an error message is 1803 issued. The error_mark_node is returned to indicate failure. */ 1804 1805 static tree 1806 determine_specialization (tree template_id, 1807 tree decl, 1808 tree* targs_out, 1809 int need_member_template, 1810 int template_count, 1811 tmpl_spec_kind tsk) 1812 { 1813 tree fns; 1814 tree targs; 1815 tree explicit_targs; 1816 tree candidates = NULL_TREE; 1817 /* A TREE_LIST of templates of which DECL may be a specialization. 1818 The TREE_VALUE of each node is a TEMPLATE_DECL. The 1819 corresponding TREE_PURPOSE is the set of template arguments that, 1820 when used to instantiate the template, would produce a function 1821 with the signature of DECL. */ 1822 tree templates = NULL_TREE; 1823 int header_count; 1824 cp_binding_level *b; 1825 1826 *targs_out = NULL_TREE; 1827 1828 if (template_id == error_mark_node || decl == error_mark_node) 1829 return error_mark_node; 1830 1831 fns = TREE_OPERAND (template_id, 0); 1832 explicit_targs = TREE_OPERAND (template_id, 1); 1833 1834 if (fns == error_mark_node) 1835 return error_mark_node; 1836 1837 /* Check for baselinks. */ 1838 if (BASELINK_P (fns)) 1839 fns = BASELINK_FUNCTIONS (fns); 1840 1841 if (!is_overloaded_fn (fns)) 1842 { 1843 error ("%qD is not a function template", fns); 1844 return error_mark_node; 1845 } 1846 1847 /* Count the number of template headers specified for this 1848 specialization. */ 1849 header_count = 0; 1850 for (b = current_binding_level; 1851 b->kind == sk_template_parms; 1852 b = b->level_chain) 1853 ++header_count; 1854 1855 for (; fns; fns = OVL_NEXT (fns)) 1856 { 1857 tree fn = OVL_CURRENT (fns); 1858 1859 if (TREE_CODE (fn) == TEMPLATE_DECL) 1860 { 1861 tree decl_arg_types; 1862 tree fn_arg_types; 1863 tree insttype; 1864 1865 /* In case of explicit specialization, we need to check if 1866 the number of template headers appearing in the specialization 1867 is correct. This is usually done in check_explicit_specialization, 1868 but the check done there cannot be exhaustive when specializing 1869 member functions. Consider the following code: 1870 1871 template <> void A<int>::f(int); 1872 template <> template <> void A<int>::f(int); 1873 1874 Assuming that A<int> is not itself an explicit specialization 1875 already, the first line specializes "f" which is a non-template 1876 member function, whilst the second line specializes "f" which 1877 is a template member function. So both lines are syntactically 1878 correct, and check_explicit_specialization does not reject 1879 them. 1880 1881 Here, we can do better, as we are matching the specialization 1882 against the declarations. We count the number of template 1883 headers, and we check if they match TEMPLATE_COUNT + 1 1884 (TEMPLATE_COUNT is the number of qualifying template classes, 1885 plus there must be another header for the member template 1886 itself). 1887 1888 Notice that if header_count is zero, this is not a 1889 specialization but rather a template instantiation, so there 1890 is no check we can perform here. */ 1891 if (header_count && header_count != template_count + 1) 1892 continue; 1893 1894 /* Check that the number of template arguments at the 1895 innermost level for DECL is the same as for FN. */ 1896 if (current_binding_level->kind == sk_template_parms 1897 && !current_binding_level->explicit_spec_p 1898 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn)) 1899 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS 1900 (current_template_parms)))) 1901 continue; 1902 1903 /* DECL might be a specialization of FN. */ 1904 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl)); 1905 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn)); 1906 1907 /* For a non-static member function, we need to make sure 1908 that the const qualification is the same. Since 1909 get_bindings does not try to merge the "this" parameter, 1910 we must do the comparison explicitly. */ 1911 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) 1912 && !same_type_p (TREE_VALUE (fn_arg_types), 1913 TREE_VALUE (decl_arg_types))) 1914 continue; 1915 1916 /* Skip the "this" parameter and, for constructors of 1917 classes with virtual bases, the VTT parameter. A 1918 full specialization of a constructor will have a VTT 1919 parameter, but a template never will. */ 1920 decl_arg_types 1921 = skip_artificial_parms_for (decl, decl_arg_types); 1922 fn_arg_types 1923 = skip_artificial_parms_for (fn, fn_arg_types); 1924 1925 /* Check that the number of function parameters matches. 1926 For example, 1927 template <class T> void f(int i = 0); 1928 template <> void f<int>(); 1929 The specialization f<int> is invalid but is not caught 1930 by get_bindings below. */ 1931 if (cxx_dialect < cxx11 1932 && list_length (fn_arg_types) != list_length (decl_arg_types)) 1933 continue; 1934 1935 /* Function templates cannot be specializations; there are 1936 no partial specializations of functions. Therefore, if 1937 the type of DECL does not match FN, there is no 1938 match. */ 1939 if (tsk == tsk_template) 1940 { 1941 if (compparms (fn_arg_types, decl_arg_types)) 1942 candidates = tree_cons (NULL_TREE, fn, candidates); 1943 continue; 1944 } 1945 1946 /* See whether this function might be a specialization of this 1947 template. */ 1948 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true); 1949 1950 if (!targs) 1951 /* We cannot deduce template arguments that when used to 1952 specialize TMPL will produce DECL. */ 1953 continue; 1954 1955 if (cxx_dialect >= cxx11) 1956 { 1957 /* Make sure that the deduced arguments actually work. */ 1958 insttype = tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE); 1959 if (insttype == error_mark_node) 1960 continue; 1961 fn_arg_types 1962 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (insttype)); 1963 if (!compparms (fn_arg_types, decl_arg_types)) 1964 continue; 1965 } 1966 1967 /* Save this template, and the arguments deduced. */ 1968 templates = tree_cons (targs, fn, templates); 1969 } 1970 else if (need_member_template) 1971 /* FN is an ordinary member function, and we need a 1972 specialization of a member template. */ 1973 ; 1974 else if (TREE_CODE (fn) != FUNCTION_DECL) 1975 /* We can get IDENTIFIER_NODEs here in certain erroneous 1976 cases. */ 1977 ; 1978 else if (!DECL_FUNCTION_MEMBER_P (fn)) 1979 /* This is just an ordinary non-member function. Nothing can 1980 be a specialization of that. */ 1981 ; 1982 else if (DECL_ARTIFICIAL (fn)) 1983 /* Cannot specialize functions that are created implicitly. */ 1984 ; 1985 else 1986 { 1987 tree decl_arg_types; 1988 1989 /* This is an ordinary member function. However, since 1990 we're here, we can assume it's enclosing class is a 1991 template class. For example, 1992 1993 template <typename T> struct S { void f(); }; 1994 template <> void S<int>::f() {} 1995 1996 Here, S<int>::f is a non-template, but S<int> is a 1997 template class. If FN has the same type as DECL, we 1998 might be in business. */ 1999 2000 if (!DECL_TEMPLATE_INFO (fn)) 2001 /* Its enclosing class is an explicit specialization 2002 of a template class. This is not a candidate. */ 2003 continue; 2004 2005 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)), 2006 TREE_TYPE (TREE_TYPE (fn)))) 2007 /* The return types differ. */ 2008 continue; 2009 2010 /* Adjust the type of DECL in case FN is a static member. */ 2011 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl)); 2012 if (DECL_STATIC_FUNCTION_P (fn) 2013 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl)) 2014 decl_arg_types = TREE_CHAIN (decl_arg_types); 2015 2016 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)), 2017 decl_arg_types)) 2018 /* They match! */ 2019 candidates = tree_cons (NULL_TREE, fn, candidates); 2020 } 2021 } 2022 2023 if (templates && TREE_CHAIN (templates)) 2024 { 2025 /* We have: 2026 2027 [temp.expl.spec] 2028 2029 It is possible for a specialization with a given function 2030 signature to be instantiated from more than one function 2031 template. In such cases, explicit specification of the 2032 template arguments must be used to uniquely identify the 2033 function template specialization being specialized. 2034 2035 Note that here, there's no suggestion that we're supposed to 2036 determine which of the candidate templates is most 2037 specialized. However, we, also have: 2038 2039 [temp.func.order] 2040 2041 Partial ordering of overloaded function template 2042 declarations is used in the following contexts to select 2043 the function template to which a function template 2044 specialization refers: 2045 2046 -- when an explicit specialization refers to a function 2047 template. 2048 2049 So, we do use the partial ordering rules, at least for now. 2050 This extension can only serve to make invalid programs valid, 2051 so it's safe. And, there is strong anecdotal evidence that 2052 the committee intended the partial ordering rules to apply; 2053 the EDG front end has that behavior, and John Spicer claims 2054 that the committee simply forgot to delete the wording in 2055 [temp.expl.spec]. */ 2056 tree tmpl = most_specialized_instantiation (templates); 2057 if (tmpl != error_mark_node) 2058 { 2059 templates = tmpl; 2060 TREE_CHAIN (templates) = NULL_TREE; 2061 } 2062 } 2063 2064 if (templates == NULL_TREE && candidates == NULL_TREE) 2065 { 2066 error ("template-id %qD for %q+D does not match any template " 2067 "declaration", template_id, decl); 2068 if (header_count && header_count != template_count + 1) 2069 inform (input_location, "saw %d %<template<>%>, need %d for " 2070 "specializing a member function template", 2071 header_count, template_count + 1); 2072 return error_mark_node; 2073 } 2074 else if ((templates && TREE_CHAIN (templates)) 2075 || (candidates && TREE_CHAIN (candidates)) 2076 || (templates && candidates)) 2077 { 2078 error ("ambiguous template specialization %qD for %q+D", 2079 template_id, decl); 2080 candidates = chainon (candidates, templates); 2081 print_candidates (candidates); 2082 return error_mark_node; 2083 } 2084 2085 /* We have one, and exactly one, match. */ 2086 if (candidates) 2087 { 2088 tree fn = TREE_VALUE (candidates); 2089 *targs_out = copy_node (DECL_TI_ARGS (fn)); 2090 /* DECL is a re-declaration or partial instantiation of a template 2091 function. */ 2092 if (TREE_CODE (fn) == TEMPLATE_DECL) 2093 return fn; 2094 /* It was a specialization of an ordinary member function in a 2095 template class. */ 2096 return DECL_TI_TEMPLATE (fn); 2097 } 2098 2099 /* It was a specialization of a template. */ 2100 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates))); 2101 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs)) 2102 { 2103 *targs_out = copy_node (targs); 2104 SET_TMPL_ARGS_LEVEL (*targs_out, 2105 TMPL_ARGS_DEPTH (*targs_out), 2106 TREE_PURPOSE (templates)); 2107 } 2108 else 2109 *targs_out = TREE_PURPOSE (templates); 2110 return TREE_VALUE (templates); 2111 } 2112 2113 /* Returns a chain of parameter types, exactly like the SPEC_TYPES, 2114 but with the default argument values filled in from those in the 2115 TMPL_TYPES. */ 2116 2117 static tree 2118 copy_default_args_to_explicit_spec_1 (tree spec_types, 2119 tree tmpl_types) 2120 { 2121 tree new_spec_types; 2122 2123 if (!spec_types) 2124 return NULL_TREE; 2125 2126 if (spec_types == void_list_node) 2127 return void_list_node; 2128 2129 /* Substitute into the rest of the list. */ 2130 new_spec_types = 2131 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types), 2132 TREE_CHAIN (tmpl_types)); 2133 2134 /* Add the default argument for this parameter. */ 2135 return hash_tree_cons (TREE_PURPOSE (tmpl_types), 2136 TREE_VALUE (spec_types), 2137 new_spec_types); 2138 } 2139 2140 /* DECL is an explicit specialization. Replicate default arguments 2141 from the template it specializes. (That way, code like: 2142 2143 template <class T> void f(T = 3); 2144 template <> void f(double); 2145 void g () { f (); } 2146 2147 works, as required.) An alternative approach would be to look up 2148 the correct default arguments at the call-site, but this approach 2149 is consistent with how implicit instantiations are handled. */ 2150 2151 static void 2152 copy_default_args_to_explicit_spec (tree decl) 2153 { 2154 tree tmpl; 2155 tree spec_types; 2156 tree tmpl_types; 2157 tree new_spec_types; 2158 tree old_type; 2159 tree new_type; 2160 tree t; 2161 tree object_type = NULL_TREE; 2162 tree in_charge = NULL_TREE; 2163 tree vtt = NULL_TREE; 2164 2165 /* See if there's anything we need to do. */ 2166 tmpl = DECL_TI_TEMPLATE (decl); 2167 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl))); 2168 for (t = tmpl_types; t; t = TREE_CHAIN (t)) 2169 if (TREE_PURPOSE (t)) 2170 break; 2171 if (!t) 2172 return; 2173 2174 old_type = TREE_TYPE (decl); 2175 spec_types = TYPE_ARG_TYPES (old_type); 2176 2177 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl)) 2178 { 2179 /* Remove the this pointer, but remember the object's type for 2180 CV quals. */ 2181 object_type = TREE_TYPE (TREE_VALUE (spec_types)); 2182 spec_types = TREE_CHAIN (spec_types); 2183 tmpl_types = TREE_CHAIN (tmpl_types); 2184 2185 if (DECL_HAS_IN_CHARGE_PARM_P (decl)) 2186 { 2187 /* DECL may contain more parameters than TMPL due to the extra 2188 in-charge parameter in constructors and destructors. */ 2189 in_charge = spec_types; 2190 spec_types = TREE_CHAIN (spec_types); 2191 } 2192 if (DECL_HAS_VTT_PARM_P (decl)) 2193 { 2194 vtt = spec_types; 2195 spec_types = TREE_CHAIN (spec_types); 2196 } 2197 } 2198 2199 /* Compute the merged default arguments. */ 2200 new_spec_types = 2201 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types); 2202 2203 /* Compute the new FUNCTION_TYPE. */ 2204 if (object_type) 2205 { 2206 if (vtt) 2207 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt), 2208 TREE_VALUE (vtt), 2209 new_spec_types); 2210 2211 if (in_charge) 2212 /* Put the in-charge parameter back. */ 2213 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge), 2214 TREE_VALUE (in_charge), 2215 new_spec_types); 2216 2217 new_type = build_method_type_directly (object_type, 2218 TREE_TYPE (old_type), 2219 new_spec_types); 2220 } 2221 else 2222 new_type = build_function_type (TREE_TYPE (old_type), 2223 new_spec_types); 2224 new_type = cp_build_type_attribute_variant (new_type, 2225 TYPE_ATTRIBUTES (old_type)); 2226 new_type = build_exception_variant (new_type, 2227 TYPE_RAISES_EXCEPTIONS (old_type)); 2228 TREE_TYPE (decl) = new_type; 2229 } 2230 2231 /* Check to see if the function just declared, as indicated in 2232 DECLARATOR, and in DECL, is a specialization of a function 2233 template. We may also discover that the declaration is an explicit 2234 instantiation at this point. 2235 2236 Returns DECL, or an equivalent declaration that should be used 2237 instead if all goes well. Issues an error message if something is 2238 amiss. Returns error_mark_node if the error is not easily 2239 recoverable. 2240 2241 FLAGS is a bitmask consisting of the following flags: 2242 2243 2: The function has a definition. 2244 4: The function is a friend. 2245 2246 The TEMPLATE_COUNT is the number of references to qualifying 2247 template classes that appeared in the name of the function. For 2248 example, in 2249 2250 template <class T> struct S { void f(); }; 2251 void S<int>::f(); 2252 2253 the TEMPLATE_COUNT would be 1. However, explicitly specialized 2254 classes are not counted in the TEMPLATE_COUNT, so that in 2255 2256 template <class T> struct S {}; 2257 template <> struct S<int> { void f(); } 2258 template <> void S<int>::f(); 2259 2260 the TEMPLATE_COUNT would be 0. (Note that this declaration is 2261 invalid; there should be no template <>.) 2262 2263 If the function is a specialization, it is marked as such via 2264 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO 2265 is set up correctly, and it is added to the list of specializations 2266 for that template. */ 2267 2268 tree 2269 check_explicit_specialization (tree declarator, 2270 tree decl, 2271 int template_count, 2272 int flags) 2273 { 2274 int have_def = flags & 2; 2275 int is_friend = flags & 4; 2276 int specialization = 0; 2277 int explicit_instantiation = 0; 2278 int member_specialization = 0; 2279 tree ctype = DECL_CLASS_CONTEXT (decl); 2280 tree dname = DECL_NAME (decl); 2281 tmpl_spec_kind tsk; 2282 2283 if (is_friend) 2284 { 2285 if (!processing_specialization) 2286 tsk = tsk_none; 2287 else 2288 tsk = tsk_excessive_parms; 2289 } 2290 else 2291 tsk = current_tmpl_spec_kind (template_count); 2292 2293 switch (tsk) 2294 { 2295 case tsk_none: 2296 if (processing_specialization) 2297 { 2298 specialization = 1; 2299 SET_DECL_TEMPLATE_SPECIALIZATION (decl); 2300 } 2301 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR) 2302 { 2303 if (is_friend) 2304 /* This could be something like: 2305 2306 template <class T> void f(T); 2307 class S { friend void f<>(int); } */ 2308 specialization = 1; 2309 else 2310 { 2311 /* This case handles bogus declarations like template <> 2312 template <class T> void f<int>(); */ 2313 2314 error ("template-id %qD in declaration of primary template", 2315 declarator); 2316 return decl; 2317 } 2318 } 2319 break; 2320 2321 case tsk_invalid_member_spec: 2322 /* The error has already been reported in 2323 check_specialization_scope. */ 2324 return error_mark_node; 2325 2326 case tsk_invalid_expl_inst: 2327 error ("template parameter list used in explicit instantiation"); 2328 2329 /* Fall through. */ 2330 2331 case tsk_expl_inst: 2332 if (have_def) 2333 error ("definition provided for explicit instantiation"); 2334 2335 explicit_instantiation = 1; 2336 break; 2337 2338 case tsk_excessive_parms: 2339 case tsk_insufficient_parms: 2340 if (tsk == tsk_excessive_parms) 2341 error ("too many template parameter lists in declaration of %qD", 2342 decl); 2343 else if (template_header_count) 2344 error("too few template parameter lists in declaration of %qD", decl); 2345 else 2346 error("explicit specialization of %qD must be introduced by " 2347 "%<template <>%>", decl); 2348 2349 /* Fall through. */ 2350 case tsk_expl_spec: 2351 SET_DECL_TEMPLATE_SPECIALIZATION (decl); 2352 if (ctype) 2353 member_specialization = 1; 2354 else 2355 specialization = 1; 2356 break; 2357 2358 case tsk_template: 2359 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR) 2360 { 2361 /* This case handles bogus declarations like template <> 2362 template <class T> void f<int>(); */ 2363 2364 if (uses_template_parms (declarator)) 2365 error ("function template partial specialization %qD " 2366 "is not allowed", declarator); 2367 else 2368 error ("template-id %qD in declaration of primary template", 2369 declarator); 2370 return decl; 2371 } 2372 2373 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype)) 2374 /* This is a specialization of a member template, without 2375 specialization the containing class. Something like: 2376 2377 template <class T> struct S { 2378 template <class U> void f (U); 2379 }; 2380 template <> template <class U> void S<int>::f(U) {} 2381 2382 That's a specialization -- but of the entire template. */ 2383 specialization = 1; 2384 break; 2385 2386 default: 2387 gcc_unreachable (); 2388 } 2389 2390 if (specialization || member_specialization) 2391 { 2392 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl)); 2393 for (; t; t = TREE_CHAIN (t)) 2394 if (TREE_PURPOSE (t)) 2395 { 2396 permerror (input_location, 2397 "default argument specified in explicit specialization"); 2398 break; 2399 } 2400 } 2401 2402 if (specialization || member_specialization || explicit_instantiation) 2403 { 2404 tree tmpl = NULL_TREE; 2405 tree targs = NULL_TREE; 2406 2407 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */ 2408 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR) 2409 { 2410 tree fns; 2411 2412 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE); 2413 if (ctype) 2414 fns = dname; 2415 else 2416 { 2417 /* If there is no class context, the explicit instantiation 2418 must be at namespace scope. */ 2419 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl)); 2420 2421 /* Find the namespace binding, using the declaration 2422 context. */ 2423 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname, 2424 false, true); 2425 if (fns == error_mark_node || !is_overloaded_fn (fns)) 2426 { 2427 error ("%qD is not a template function", dname); 2428 fns = error_mark_node; 2429 } 2430 else 2431 { 2432 tree fn = OVL_CURRENT (fns); 2433 if (!is_associated_namespace (CP_DECL_CONTEXT (decl), 2434 CP_DECL_CONTEXT (fn))) 2435 error ("%qD is not declared in %qD", 2436 decl, current_namespace); 2437 } 2438 } 2439 2440 declarator = lookup_template_function (fns, NULL_TREE); 2441 } 2442 2443 if (declarator == error_mark_node) 2444 return error_mark_node; 2445 2446 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype)) 2447 { 2448 if (!explicit_instantiation) 2449 /* A specialization in class scope. This is invalid, 2450 but the error will already have been flagged by 2451 check_specialization_scope. */ 2452 return error_mark_node; 2453 else 2454 { 2455 /* It's not valid to write an explicit instantiation in 2456 class scope, e.g.: 2457 2458 class C { template void f(); } 2459 2460 This case is caught by the parser. However, on 2461 something like: 2462 2463 template class C { void f(); }; 2464 2465 (which is invalid) we can get here. The error will be 2466 issued later. */ 2467 ; 2468 } 2469 2470 return decl; 2471 } 2472 else if (ctype != NULL_TREE 2473 && (TREE_CODE (TREE_OPERAND (declarator, 0)) == 2474 IDENTIFIER_NODE)) 2475 { 2476 /* Find the list of functions in ctype that have the same 2477 name as the declared function. */ 2478 tree name = TREE_OPERAND (declarator, 0); 2479 tree fns = NULL_TREE; 2480 int idx; 2481 2482 if (constructor_name_p (name, ctype)) 2483 { 2484 int is_constructor = DECL_CONSTRUCTOR_P (decl); 2485 2486 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype) 2487 : !CLASSTYPE_DESTRUCTORS (ctype)) 2488 { 2489 /* From [temp.expl.spec]: 2490 2491 If such an explicit specialization for the member 2492 of a class template names an implicitly-declared 2493 special member function (clause _special_), the 2494 program is ill-formed. 2495 2496 Similar language is found in [temp.explicit]. */ 2497 error ("specialization of implicitly-declared special member function"); 2498 return error_mark_node; 2499 } 2500 2501 name = is_constructor ? ctor_identifier : dtor_identifier; 2502 } 2503 2504 if (!DECL_CONV_FN_P (decl)) 2505 { 2506 idx = lookup_fnfields_1 (ctype, name); 2507 if (idx >= 0) 2508 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx); 2509 } 2510 else 2511 { 2512 VEC(tree,gc) *methods; 2513 tree ovl; 2514 2515 /* For a type-conversion operator, we cannot do a 2516 name-based lookup. We might be looking for `operator 2517 int' which will be a specialization of `operator T'. 2518 So, we find *all* the conversion operators, and then 2519 select from them. */ 2520 fns = NULL_TREE; 2521 2522 methods = CLASSTYPE_METHOD_VEC (ctype); 2523 if (methods) 2524 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT; 2525 VEC_iterate (tree, methods, idx, ovl); 2526 ++idx) 2527 { 2528 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl))) 2529 /* There are no more conversion functions. */ 2530 break; 2531 2532 /* Glue all these conversion functions together 2533 with those we already have. */ 2534 for (; ovl; ovl = OVL_NEXT (ovl)) 2535 fns = ovl_cons (OVL_CURRENT (ovl), fns); 2536 } 2537 } 2538 2539 if (fns == NULL_TREE) 2540 { 2541 error ("no member function %qD declared in %qT", name, ctype); 2542 return error_mark_node; 2543 } 2544 else 2545 TREE_OPERAND (declarator, 0) = fns; 2546 } 2547 2548 /* Figure out what exactly is being specialized at this point. 2549 Note that for an explicit instantiation, even one for a 2550 member function, we cannot tell apriori whether the 2551 instantiation is for a member template, or just a member 2552 function of a template class. Even if a member template is 2553 being instantiated, the member template arguments may be 2554 elided if they can be deduced from the rest of the 2555 declaration. */ 2556 tmpl = determine_specialization (declarator, decl, 2557 &targs, 2558 member_specialization, 2559 template_count, 2560 tsk); 2561 2562 if (!tmpl || tmpl == error_mark_node) 2563 /* We couldn't figure out what this declaration was 2564 specializing. */ 2565 return error_mark_node; 2566 else 2567 { 2568 tree gen_tmpl = most_general_template (tmpl); 2569 2570 if (explicit_instantiation) 2571 { 2572 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that 2573 is done by do_decl_instantiation later. */ 2574 2575 int arg_depth = TMPL_ARGS_DEPTH (targs); 2576 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)); 2577 2578 if (arg_depth > parm_depth) 2579 { 2580 /* If TMPL is not the most general template (for 2581 example, if TMPL is a friend template that is 2582 injected into namespace scope), then there will 2583 be too many levels of TARGS. Remove some of them 2584 here. */ 2585 int i; 2586 tree new_targs; 2587 2588 new_targs = make_tree_vec (parm_depth); 2589 for (i = arg_depth - parm_depth; i < arg_depth; ++i) 2590 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth)) 2591 = TREE_VEC_ELT (targs, i); 2592 targs = new_targs; 2593 } 2594 2595 return instantiate_template (tmpl, targs, tf_error); 2596 } 2597 2598 /* If we thought that the DECL was a member function, but it 2599 turns out to be specializing a static member function, 2600 make DECL a static member function as well. */ 2601 if (DECL_STATIC_FUNCTION_P (tmpl) 2602 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl)) 2603 revert_static_member_fn (decl); 2604 2605 /* If this is a specialization of a member template of a 2606 template class, we want to return the TEMPLATE_DECL, not 2607 the specialization of it. */ 2608 if (tsk == tsk_template) 2609 { 2610 tree result = DECL_TEMPLATE_RESULT (tmpl); 2611 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl); 2612 DECL_INITIAL (result) = NULL_TREE; 2613 if (have_def) 2614 { 2615 tree parm; 2616 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl); 2617 DECL_SOURCE_LOCATION (result) 2618 = DECL_SOURCE_LOCATION (decl); 2619 /* We want to use the argument list specified in the 2620 definition, not in the original declaration. */ 2621 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl); 2622 for (parm = DECL_ARGUMENTS (result); parm; 2623 parm = DECL_CHAIN (parm)) 2624 DECL_CONTEXT (parm) = result; 2625 } 2626 return register_specialization (tmpl, gen_tmpl, targs, 2627 is_friend, 0); 2628 } 2629 2630 /* Set up the DECL_TEMPLATE_INFO for DECL. */ 2631 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs); 2632 2633 /* Inherit default function arguments from the template 2634 DECL is specializing. */ 2635 copy_default_args_to_explicit_spec (decl); 2636 2637 /* This specialization has the same protection as the 2638 template it specializes. */ 2639 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl); 2640 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl); 2641 2642 /* 7.1.1-1 [dcl.stc] 2643 2644 A storage-class-specifier shall not be specified in an 2645 explicit specialization... 2646 2647 The parser rejects these, so unless action is taken here, 2648 explicit function specializations will always appear with 2649 global linkage. 2650 2651 The action recommended by the C++ CWG in response to C++ 2652 defect report 605 is to make the storage class and linkage 2653 of the explicit specialization match the templated function: 2654 2655 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605 2656 */ 2657 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl)) 2658 { 2659 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl); 2660 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL); 2661 2662 /* This specialization has the same linkage and visibility as 2663 the function template it specializes. */ 2664 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func); 2665 if (! TREE_PUBLIC (decl)) 2666 { 2667 DECL_INTERFACE_KNOWN (decl) = 1; 2668 DECL_NOT_REALLY_EXTERN (decl) = 1; 2669 } 2670 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func); 2671 if (DECL_VISIBILITY_SPECIFIED (tmpl_func)) 2672 { 2673 DECL_VISIBILITY_SPECIFIED (decl) = 1; 2674 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func); 2675 } 2676 } 2677 2678 /* If DECL is a friend declaration, declared using an 2679 unqualified name, the namespace associated with DECL may 2680 have been set incorrectly. For example, in: 2681 2682 template <typename T> void f(T); 2683 namespace N { 2684 struct S { friend void f<int>(int); } 2685 } 2686 2687 we will have set the DECL_CONTEXT for the friend 2688 declaration to N, rather than to the global namespace. */ 2689 if (DECL_NAMESPACE_SCOPE_P (decl)) 2690 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl); 2691 2692 if (is_friend && !have_def) 2693 /* This is not really a declaration of a specialization. 2694 It's just the name of an instantiation. But, it's not 2695 a request for an instantiation, either. */ 2696 SET_DECL_IMPLICIT_INSTANTIATION (decl); 2697 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl)) 2698 /* This is indeed a specialization. In case of constructors 2699 and destructors, we need in-charge and not-in-charge 2700 versions in V3 ABI. */ 2701 clone_function_decl (decl, /*update_method_vec_p=*/0); 2702 2703 /* Register this specialization so that we can find it 2704 again. */ 2705 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0); 2706 } 2707 } 2708 2709 return decl; 2710 } 2711 2712 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template 2713 parameters. These are represented in the same format used for 2714 DECL_TEMPLATE_PARMS. */ 2715 2716 int 2717 comp_template_parms (const_tree parms1, const_tree parms2) 2718 { 2719 const_tree p1; 2720 const_tree p2; 2721 2722 if (parms1 == parms2) 2723 return 1; 2724 2725 for (p1 = parms1, p2 = parms2; 2726 p1 != NULL_TREE && p2 != NULL_TREE; 2727 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2)) 2728 { 2729 tree t1 = TREE_VALUE (p1); 2730 tree t2 = TREE_VALUE (p2); 2731 int i; 2732 2733 gcc_assert (TREE_CODE (t1) == TREE_VEC); 2734 gcc_assert (TREE_CODE (t2) == TREE_VEC); 2735 2736 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2)) 2737 return 0; 2738 2739 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i) 2740 { 2741 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i)); 2742 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i)); 2743 2744 /* If either of the template parameters are invalid, assume 2745 they match for the sake of error recovery. */ 2746 if (parm1 == error_mark_node || parm2 == error_mark_node) 2747 return 1; 2748 2749 if (TREE_CODE (parm1) != TREE_CODE (parm2)) 2750 return 0; 2751 2752 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM 2753 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1) 2754 == TEMPLATE_TYPE_PARAMETER_PACK (parm2))) 2755 continue; 2756 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2))) 2757 return 0; 2758 } 2759 } 2760 2761 if ((p1 != NULL_TREE) != (p2 != NULL_TREE)) 2762 /* One set of parameters has more parameters lists than the 2763 other. */ 2764 return 0; 2765 2766 return 1; 2767 } 2768 2769 /* Determine whether PARM is a parameter pack. */ 2770 2771 bool 2772 template_parameter_pack_p (const_tree parm) 2773 { 2774 /* Determine if we have a non-type template parameter pack. */ 2775 if (TREE_CODE (parm) == PARM_DECL) 2776 return (DECL_TEMPLATE_PARM_P (parm) 2777 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))); 2778 if (TREE_CODE (parm) == TEMPLATE_PARM_INDEX) 2779 return TEMPLATE_PARM_PARAMETER_PACK (parm); 2780 2781 /* If this is a list of template parameters, we could get a 2782 TYPE_DECL or a TEMPLATE_DECL. */ 2783 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL) 2784 parm = TREE_TYPE (parm); 2785 2786 /* Otherwise it must be a type template parameter. */ 2787 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM 2788 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM) 2789 && TEMPLATE_TYPE_PARAMETER_PACK (parm)); 2790 } 2791 2792 /* Determine if T is a function parameter pack. */ 2793 2794 bool 2795 function_parameter_pack_p (const_tree t) 2796 { 2797 if (t && TREE_CODE (t) == PARM_DECL) 2798 return FUNCTION_PARAMETER_PACK_P (t); 2799 return false; 2800 } 2801 2802 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST. 2803 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */ 2804 2805 tree 2806 get_function_template_decl (const_tree primary_func_tmpl_inst) 2807 { 2808 if (! primary_func_tmpl_inst 2809 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL 2810 || ! primary_template_instantiation_p (primary_func_tmpl_inst)) 2811 return NULL; 2812 2813 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst)); 2814 } 2815 2816 /* Return true iff the function parameter PARAM_DECL was expanded 2817 from the function parameter pack PACK. */ 2818 2819 bool 2820 function_parameter_expanded_from_pack_p (tree param_decl, tree pack) 2821 { 2822 if (DECL_ARTIFICIAL (param_decl) 2823 || !function_parameter_pack_p (pack)) 2824 return false; 2825 2826 /* The parameter pack and its pack arguments have the same 2827 DECL_PARM_INDEX. */ 2828 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl); 2829 } 2830 2831 /* Determine whether ARGS describes a variadic template args list, 2832 i.e., one that is terminated by a template argument pack. */ 2833 2834 static bool 2835 template_args_variadic_p (tree args) 2836 { 2837 int nargs; 2838 tree last_parm; 2839 2840 if (args == NULL_TREE) 2841 return false; 2842 2843 args = INNERMOST_TEMPLATE_ARGS (args); 2844 nargs = TREE_VEC_LENGTH (args); 2845 2846 if (nargs == 0) 2847 return false; 2848 2849 last_parm = TREE_VEC_ELT (args, nargs - 1); 2850 2851 return ARGUMENT_PACK_P (last_parm); 2852 } 2853 2854 /* Generate a new name for the parameter pack name NAME (an 2855 IDENTIFIER_NODE) that incorporates its */ 2856 2857 static tree 2858 make_ith_pack_parameter_name (tree name, int i) 2859 { 2860 /* Munge the name to include the parameter index. */ 2861 #define NUMBUF_LEN 128 2862 char numbuf[NUMBUF_LEN]; 2863 char* newname; 2864 int newname_len; 2865 2866 snprintf (numbuf, NUMBUF_LEN, "%i", i); 2867 newname_len = IDENTIFIER_LENGTH (name) 2868 + strlen (numbuf) + 2; 2869 newname = (char*)alloca (newname_len); 2870 snprintf (newname, newname_len, 2871 "%s#%i", IDENTIFIER_POINTER (name), i); 2872 return get_identifier (newname); 2873 } 2874 2875 /* Return true if T is a primary function, class or alias template 2876 instantiation. */ 2877 2878 bool 2879 primary_template_instantiation_p (const_tree t) 2880 { 2881 if (!t) 2882 return false; 2883 2884 if (TREE_CODE (t) == FUNCTION_DECL) 2885 return DECL_LANG_SPECIFIC (t) 2886 && DECL_TEMPLATE_INSTANTIATION (t) 2887 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t)); 2888 else if (CLASS_TYPE_P (t) && !TYPE_DECL_ALIAS_P (TYPE_NAME (t))) 2889 return CLASSTYPE_TEMPLATE_INSTANTIATION (t) 2890 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t)); 2891 else if (TYPE_P (t) 2892 && TYPE_TEMPLATE_INFO (t) 2893 && PRIMARY_TEMPLATE_P (TYPE_TI_TEMPLATE (t)) 2894 && DECL_TEMPLATE_INSTANTIATION (TYPE_NAME (t))) 2895 return true; 2896 return false; 2897 } 2898 2899 /* Return true if PARM is a template template parameter. */ 2900 2901 bool 2902 template_template_parameter_p (const_tree parm) 2903 { 2904 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm); 2905 } 2906 2907 /* Return the template parameters of T if T is a 2908 primary template instantiation, NULL otherwise. */ 2909 2910 tree 2911 get_primary_template_innermost_parameters (const_tree t) 2912 { 2913 tree parms = NULL, template_info = NULL; 2914 2915 if ((template_info = get_template_info (t)) 2916 && primary_template_instantiation_p (t)) 2917 parms = INNERMOST_TEMPLATE_PARMS 2918 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info))); 2919 2920 return parms; 2921 } 2922 2923 /* Return the template parameters of the LEVELth level from the full list 2924 of template parameters PARMS. */ 2925 2926 tree 2927 get_template_parms_at_level (tree parms, int level) 2928 { 2929 tree p; 2930 if (!parms 2931 || TREE_CODE (parms) != TREE_LIST 2932 || level > TMPL_PARMS_DEPTH (parms)) 2933 return NULL_TREE; 2934 2935 for (p = parms; p; p = TREE_CHAIN (p)) 2936 if (TMPL_PARMS_DEPTH (p) == level) 2937 return p; 2938 2939 return NULL_TREE; 2940 } 2941 2942 /* Returns the template arguments of T if T is a template instantiation, 2943 NULL otherwise. */ 2944 2945 tree 2946 get_template_innermost_arguments (const_tree t) 2947 { 2948 tree args = NULL, template_info = NULL; 2949 2950 if ((template_info = get_template_info (t)) 2951 && TI_ARGS (template_info)) 2952 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info)); 2953 2954 return args; 2955 } 2956 2957 /* Return the argument pack elements of T if T is a template argument pack, 2958 NULL otherwise. */ 2959 2960 tree 2961 get_template_argument_pack_elems (const_tree t) 2962 { 2963 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK 2964 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK) 2965 return NULL; 2966 2967 return ARGUMENT_PACK_ARGS (t); 2968 } 2969 2970 /* Structure used to track the progress of find_parameter_packs_r. */ 2971 struct find_parameter_pack_data 2972 { 2973 /* TREE_LIST that will contain all of the parameter packs found by 2974 the traversal. */ 2975 tree* parameter_packs; 2976 2977 /* Set of AST nodes that have been visited by the traversal. */ 2978 struct pointer_set_t *visited; 2979 }; 2980 2981 /* Identifies all of the argument packs that occur in a template 2982 argument and appends them to the TREE_LIST inside DATA, which is a 2983 find_parameter_pack_data structure. This is a subroutine of 2984 make_pack_expansion and uses_parameter_packs. */ 2985 static tree 2986 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data) 2987 { 2988 tree t = *tp; 2989 struct find_parameter_pack_data* ppd = 2990 (struct find_parameter_pack_data*)data; 2991 bool parameter_pack_p = false; 2992 2993 /* Handle type aliases/typedefs. */ 2994 if (TYPE_P (t) 2995 && TYPE_NAME (t) 2996 && TREE_CODE (TYPE_NAME (t)) == TYPE_DECL 2997 && TYPE_DECL_ALIAS_P (TYPE_NAME (t))) 2998 { 2999 if (TYPE_TEMPLATE_INFO (t)) 3000 cp_walk_tree (&TYPE_TI_ARGS (t), 3001 &find_parameter_packs_r, 3002 ppd, ppd->visited); 3003 *walk_subtrees = 0; 3004 return NULL_TREE; 3005 } 3006 3007 /* Identify whether this is a parameter pack or not. */ 3008 switch (TREE_CODE (t)) 3009 { 3010 case TEMPLATE_PARM_INDEX: 3011 if (TEMPLATE_PARM_PARAMETER_PACK (t)) 3012 parameter_pack_p = true; 3013 break; 3014 3015 case TEMPLATE_TYPE_PARM: 3016 t = TYPE_MAIN_VARIANT (t); 3017 case TEMPLATE_TEMPLATE_PARM: 3018 if (TEMPLATE_TYPE_PARAMETER_PACK (t)) 3019 parameter_pack_p = true; 3020 break; 3021 3022 case PARM_DECL: 3023 if (FUNCTION_PARAMETER_PACK_P (t)) 3024 { 3025 /* We don't want to walk into the type of a PARM_DECL, 3026 because we don't want to see the type parameter pack. */ 3027 *walk_subtrees = 0; 3028 parameter_pack_p = true; 3029 } 3030 break; 3031 3032 case BASES: 3033 parameter_pack_p = true; 3034 break; 3035 default: 3036 /* Not a parameter pack. */ 3037 break; 3038 } 3039 3040 if (parameter_pack_p) 3041 { 3042 /* Add this parameter pack to the list. */ 3043 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs); 3044 } 3045 3046 if (TYPE_P (t)) 3047 cp_walk_tree (&TYPE_CONTEXT (t), 3048 &find_parameter_packs_r, ppd, ppd->visited); 3049 3050 /* This switch statement will return immediately if we don't find a 3051 parameter pack. */ 3052 switch (TREE_CODE (t)) 3053 { 3054 case TEMPLATE_PARM_INDEX: 3055 return NULL_TREE; 3056 3057 case BOUND_TEMPLATE_TEMPLATE_PARM: 3058 /* Check the template itself. */ 3059 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)), 3060 &find_parameter_packs_r, ppd, ppd->visited); 3061 /* Check the template arguments. */ 3062 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd, 3063 ppd->visited); 3064 *walk_subtrees = 0; 3065 return NULL_TREE; 3066 3067 case TEMPLATE_TYPE_PARM: 3068 case TEMPLATE_TEMPLATE_PARM: 3069 return NULL_TREE; 3070 3071 case PARM_DECL: 3072 return NULL_TREE; 3073 3074 case RECORD_TYPE: 3075 if (TYPE_PTRMEMFUNC_P (t)) 3076 return NULL_TREE; 3077 /* Fall through. */ 3078 3079 case UNION_TYPE: 3080 case ENUMERAL_TYPE: 3081 if (TYPE_TEMPLATE_INFO (t)) 3082 cp_walk_tree (&TI_ARGS (TYPE_TEMPLATE_INFO (t)), 3083 &find_parameter_packs_r, ppd, ppd->visited); 3084 3085 *walk_subtrees = 0; 3086 return NULL_TREE; 3087 3088 case CONSTRUCTOR: 3089 case TEMPLATE_DECL: 3090 cp_walk_tree (&TREE_TYPE (t), 3091 &find_parameter_packs_r, ppd, ppd->visited); 3092 return NULL_TREE; 3093 3094 case TYPENAME_TYPE: 3095 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r, 3096 ppd, ppd->visited); 3097 *walk_subtrees = 0; 3098 return NULL_TREE; 3099 3100 case TYPE_PACK_EXPANSION: 3101 case EXPR_PACK_EXPANSION: 3102 *walk_subtrees = 0; 3103 return NULL_TREE; 3104 3105 case INTEGER_TYPE: 3106 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r, 3107 ppd, ppd->visited); 3108 *walk_subtrees = 0; 3109 return NULL_TREE; 3110 3111 case IDENTIFIER_NODE: 3112 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd, 3113 ppd->visited); 3114 *walk_subtrees = 0; 3115 return NULL_TREE; 3116 3117 default: 3118 return NULL_TREE; 3119 } 3120 3121 return NULL_TREE; 3122 } 3123 3124 /* Determines if the expression or type T uses any parameter packs. */ 3125 bool 3126 uses_parameter_packs (tree t) 3127 { 3128 tree parameter_packs = NULL_TREE; 3129 struct find_parameter_pack_data ppd; 3130 ppd.parameter_packs = ¶meter_packs; 3131 ppd.visited = pointer_set_create (); 3132 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited); 3133 pointer_set_destroy (ppd.visited); 3134 return parameter_packs != NULL_TREE; 3135 } 3136 3137 /* Turn ARG, which may be an expression, type, or a TREE_LIST 3138 representation a base-class initializer into a parameter pack 3139 expansion. If all goes well, the resulting node will be an 3140 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST, 3141 respectively. */ 3142 tree 3143 make_pack_expansion (tree arg) 3144 { 3145 tree result; 3146 tree parameter_packs = NULL_TREE; 3147 bool for_types = false; 3148 struct find_parameter_pack_data ppd; 3149 3150 if (!arg || arg == error_mark_node) 3151 return arg; 3152 3153 if (TREE_CODE (arg) == TREE_LIST) 3154 { 3155 /* The only time we will see a TREE_LIST here is for a base 3156 class initializer. In this case, the TREE_PURPOSE will be a 3157 _TYPE node (representing the base class expansion we're 3158 initializing) and the TREE_VALUE will be a TREE_LIST 3159 containing the initialization arguments. 3160 3161 The resulting expansion looks somewhat different from most 3162 expansions. Rather than returning just one _EXPANSION, we 3163 return a TREE_LIST whose TREE_PURPOSE is a 3164 TYPE_PACK_EXPANSION containing the bases that will be 3165 initialized. The TREE_VALUE will be identical to the 3166 original TREE_VALUE, which is a list of arguments that will 3167 be passed to each base. We do not introduce any new pack 3168 expansion nodes into the TREE_VALUE (although it is possible 3169 that some already exist), because the TREE_PURPOSE and 3170 TREE_VALUE all need to be expanded together with the same 3171 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the 3172 resulting TREE_PURPOSE will mention the parameter packs in 3173 both the bases and the arguments to the bases. */ 3174 tree purpose; 3175 tree value; 3176 tree parameter_packs = NULL_TREE; 3177 3178 /* Determine which parameter packs will be used by the base 3179 class expansion. */ 3180 ppd.visited = pointer_set_create (); 3181 ppd.parameter_packs = ¶meter_packs; 3182 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r, 3183 &ppd, ppd.visited); 3184 3185 if (parameter_packs == NULL_TREE) 3186 { 3187 error ("base initializer expansion %<%T%> contains no parameter packs", arg); 3188 pointer_set_destroy (ppd.visited); 3189 return error_mark_node; 3190 } 3191 3192 if (TREE_VALUE (arg) != void_type_node) 3193 { 3194 /* Collect the sets of parameter packs used in each of the 3195 initialization arguments. */ 3196 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value)) 3197 { 3198 /* Determine which parameter packs will be expanded in this 3199 argument. */ 3200 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r, 3201 &ppd, ppd.visited); 3202 } 3203 } 3204 3205 pointer_set_destroy (ppd.visited); 3206 3207 /* Create the pack expansion type for the base type. */ 3208 purpose = cxx_make_type (TYPE_PACK_EXPANSION); 3209 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg)); 3210 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs; 3211 3212 /* Just use structural equality for these TYPE_PACK_EXPANSIONS; 3213 they will rarely be compared to anything. */ 3214 SET_TYPE_STRUCTURAL_EQUALITY (purpose); 3215 3216 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE); 3217 } 3218 3219 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL) 3220 for_types = true; 3221 3222 /* Build the PACK_EXPANSION_* node. */ 3223 result = for_types 3224 ? cxx_make_type (TYPE_PACK_EXPANSION) 3225 : make_node (EXPR_PACK_EXPANSION); 3226 SET_PACK_EXPANSION_PATTERN (result, arg); 3227 if (TREE_CODE (result) == EXPR_PACK_EXPANSION) 3228 { 3229 /* Propagate type and const-expression information. */ 3230 TREE_TYPE (result) = TREE_TYPE (arg); 3231 TREE_CONSTANT (result) = TREE_CONSTANT (arg); 3232 } 3233 else 3234 /* Just use structural equality for these TYPE_PACK_EXPANSIONS; 3235 they will rarely be compared to anything. */ 3236 SET_TYPE_STRUCTURAL_EQUALITY (result); 3237 3238 /* Determine which parameter packs will be expanded. */ 3239 ppd.parameter_packs = ¶meter_packs; 3240 ppd.visited = pointer_set_create (); 3241 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited); 3242 pointer_set_destroy (ppd.visited); 3243 3244 /* Make sure we found some parameter packs. */ 3245 if (parameter_packs == NULL_TREE) 3246 { 3247 if (TYPE_P (arg)) 3248 error ("expansion pattern %<%T%> contains no argument packs", arg); 3249 else 3250 error ("expansion pattern %<%E%> contains no argument packs", arg); 3251 return error_mark_node; 3252 } 3253 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs; 3254 3255 PACK_EXPANSION_LOCAL_P (result) = at_function_scope_p (); 3256 3257 return result; 3258 } 3259 3260 /* Checks T for any "bare" parameter packs, which have not yet been 3261 expanded, and issues an error if any are found. This operation can 3262 only be done on full expressions or types (e.g., an expression 3263 statement, "if" condition, etc.), because we could have expressions like: 3264 3265 foo(f(g(h(args)))...) 3266 3267 where "args" is a parameter pack. check_for_bare_parameter_packs 3268 should not be called for the subexpressions args, h(args), 3269 g(h(args)), or f(g(h(args))), because we would produce erroneous 3270 error messages. 3271 3272 Returns TRUE and emits an error if there were bare parameter packs, 3273 returns FALSE otherwise. */ 3274 bool 3275 check_for_bare_parameter_packs (tree t) 3276 { 3277 tree parameter_packs = NULL_TREE; 3278 struct find_parameter_pack_data ppd; 3279 3280 if (!processing_template_decl || !t || t == error_mark_node) 3281 return false; 3282 3283 if (TREE_CODE (t) == TYPE_DECL) 3284 t = TREE_TYPE (t); 3285 3286 ppd.parameter_packs = ¶meter_packs; 3287 ppd.visited = pointer_set_create (); 3288 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited); 3289 pointer_set_destroy (ppd.visited); 3290 3291 if (parameter_packs) 3292 { 3293 error ("parameter packs not expanded with %<...%>:"); 3294 while (parameter_packs) 3295 { 3296 tree pack = TREE_VALUE (parameter_packs); 3297 tree name = NULL_TREE; 3298 3299 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM 3300 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM) 3301 name = TYPE_NAME (pack); 3302 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX) 3303 name = DECL_NAME (TEMPLATE_PARM_DECL (pack)); 3304 else 3305 name = DECL_NAME (pack); 3306 3307 if (name) 3308 inform (input_location, " %qD", name); 3309 else 3310 inform (input_location, " <anonymous>"); 3311 3312 parameter_packs = TREE_CHAIN (parameter_packs); 3313 } 3314 3315 return true; 3316 } 3317 3318 return false; 3319 } 3320 3321 /* Expand any parameter packs that occur in the template arguments in 3322 ARGS. */ 3323 tree 3324 expand_template_argument_pack (tree args) 3325 { 3326 tree result_args = NULL_TREE; 3327 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0; 3328 int num_result_args = -1; 3329 int non_default_args_count = -1; 3330 3331 /* First, determine if we need to expand anything, and the number of 3332 slots we'll need. */ 3333 for (in_arg = 0; in_arg < nargs; ++in_arg) 3334 { 3335 tree arg = TREE_VEC_ELT (args, in_arg); 3336 if (arg == NULL_TREE) 3337 return args; 3338 if (ARGUMENT_PACK_P (arg)) 3339 { 3340 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg)); 3341 if (num_result_args < 0) 3342 num_result_args = in_arg + num_packed; 3343 else 3344 num_result_args += num_packed; 3345 } 3346 else 3347 { 3348 if (num_result_args >= 0) 3349 num_result_args++; 3350 } 3351 } 3352 3353 /* If no expansion is necessary, we're done. */ 3354 if (num_result_args < 0) 3355 return args; 3356 3357 /* Expand arguments. */ 3358 result_args = make_tree_vec (num_result_args); 3359 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args)) 3360 non_default_args_count = 3361 GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args); 3362 for (in_arg = 0; in_arg < nargs; ++in_arg) 3363 { 3364 tree arg = TREE_VEC_ELT (args, in_arg); 3365 if (ARGUMENT_PACK_P (arg)) 3366 { 3367 tree packed = ARGUMENT_PACK_ARGS (arg); 3368 int i, num_packed = TREE_VEC_LENGTH (packed); 3369 for (i = 0; i < num_packed; ++i, ++out_arg) 3370 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i); 3371 if (non_default_args_count > 0) 3372 non_default_args_count += num_packed; 3373 } 3374 else 3375 { 3376 TREE_VEC_ELT (result_args, out_arg) = arg; 3377 ++out_arg; 3378 } 3379 } 3380 if (non_default_args_count >= 0) 3381 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count); 3382 return result_args; 3383 } 3384 3385 /* Checks if DECL shadows a template parameter. 3386 3387 [temp.local]: A template-parameter shall not be redeclared within its 3388 scope (including nested scopes). 3389 3390 Emits an error and returns TRUE if the DECL shadows a parameter, 3391 returns FALSE otherwise. */ 3392 3393 bool 3394 check_template_shadow (tree decl) 3395 { 3396 tree olddecl; 3397 3398 /* If we're not in a template, we can't possibly shadow a template 3399 parameter. */ 3400 if (!current_template_parms) 3401 return true; 3402 3403 /* Figure out what we're shadowing. */ 3404 if (TREE_CODE (decl) == OVERLOAD) 3405 decl = OVL_CURRENT (decl); 3406 olddecl = innermost_non_namespace_value (DECL_NAME (decl)); 3407 3408 /* If there's no previous binding for this name, we're not shadowing 3409 anything, let alone a template parameter. */ 3410 if (!olddecl) 3411 return true; 3412 3413 /* If we're not shadowing a template parameter, we're done. Note 3414 that OLDDECL might be an OVERLOAD (or perhaps even an 3415 ERROR_MARK), so we can't just blithely assume it to be a _DECL 3416 node. */ 3417 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl)) 3418 return true; 3419 3420 /* We check for decl != olddecl to avoid bogus errors for using a 3421 name inside a class. We check TPFI to avoid duplicate errors for 3422 inline member templates. */ 3423 if (decl == olddecl 3424 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms)) 3425 return true; 3426 3427 error ("declaration of %q+#D", decl); 3428 error (" shadows template parm %q+#D", olddecl); 3429 return false; 3430 } 3431 3432 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL, 3433 ORIG_LEVEL, DECL, and TYPE. NUM_SIBLINGS is the total number of 3434 template parameters. */ 3435 3436 static tree 3437 build_template_parm_index (int index, 3438 int level, 3439 int orig_level, 3440 int num_siblings, 3441 tree decl, 3442 tree type) 3443 { 3444 tree t = make_node (TEMPLATE_PARM_INDEX); 3445 TEMPLATE_PARM_IDX (t) = index; 3446 TEMPLATE_PARM_LEVEL (t) = level; 3447 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level; 3448 TEMPLATE_PARM_NUM_SIBLINGS (t) = num_siblings; 3449 TEMPLATE_PARM_DECL (t) = decl; 3450 TREE_TYPE (t) = type; 3451 TREE_CONSTANT (t) = TREE_CONSTANT (decl); 3452 TREE_READONLY (t) = TREE_READONLY (decl); 3453 3454 return t; 3455 } 3456 3457 /* Find the canonical type parameter for the given template type 3458 parameter. Returns the canonical type parameter, which may be TYPE 3459 if no such parameter existed. */ 3460 3461 static tree 3462 canonical_type_parameter (tree type) 3463 { 3464 tree list; 3465 int idx = TEMPLATE_TYPE_IDX (type); 3466 if (!canonical_template_parms) 3467 canonical_template_parms = VEC_alloc (tree, gc, idx+1); 3468 3469 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx) 3470 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE); 3471 3472 list = VEC_index (tree, canonical_template_parms, idx); 3473 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL)) 3474 list = TREE_CHAIN (list); 3475 3476 if (list) 3477 return TREE_VALUE (list); 3478 else 3479 { 3480 VEC_replace(tree, canonical_template_parms, idx, 3481 tree_cons (NULL_TREE, type, 3482 VEC_index (tree, canonical_template_parms, idx))); 3483 return type; 3484 } 3485 } 3486 3487 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose 3488 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a 3489 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a 3490 new one is created. */ 3491 3492 static tree 3493 reduce_template_parm_level (tree index, tree type, int levels, tree args, 3494 tsubst_flags_t complain) 3495 { 3496 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE 3497 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index)) 3498 != TEMPLATE_PARM_LEVEL (index) - levels) 3499 || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index)))) 3500 { 3501 tree orig_decl = TEMPLATE_PARM_DECL (index); 3502 tree decl, t; 3503 3504 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl), 3505 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type); 3506 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl); 3507 TREE_READONLY (decl) = TREE_READONLY (orig_decl); 3508 DECL_ARTIFICIAL (decl) = 1; 3509 SET_DECL_TEMPLATE_PARM_P (decl); 3510 3511 t = build_template_parm_index (TEMPLATE_PARM_IDX (index), 3512 TEMPLATE_PARM_LEVEL (index) - levels, 3513 TEMPLATE_PARM_ORIG_LEVEL (index), 3514 TEMPLATE_PARM_NUM_SIBLINGS (index), 3515 decl, type); 3516 TEMPLATE_PARM_DESCENDANTS (index) = t; 3517 TEMPLATE_PARM_PARAMETER_PACK (t) 3518 = TEMPLATE_PARM_PARAMETER_PACK (index); 3519 3520 /* Template template parameters need this. */ 3521 if (TREE_CODE (decl) == TEMPLATE_DECL) 3522 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms 3523 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)), 3524 args, complain); 3525 } 3526 3527 return TEMPLATE_PARM_DESCENDANTS (index); 3528 } 3529 3530 /* Process information from new template parameter PARM and append it 3531 to the LIST being built. This new parameter is a non-type 3532 parameter iff IS_NON_TYPE is true. This new parameter is a 3533 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM 3534 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template 3535 parameter list PARM belongs to. This is used used to create a 3536 proper canonical type for the type of PARM that is to be created, 3537 iff PARM is a type. If the size is not known, this parameter shall 3538 be set to 0. */ 3539 3540 tree 3541 process_template_parm (tree list, location_t parm_loc, tree parm, 3542 bool is_non_type, bool is_parameter_pack, 3543 unsigned num_template_parms) 3544 { 3545 tree decl = 0; 3546 tree defval; 3547 tree err_parm_list; 3548 int idx = 0; 3549 3550 gcc_assert (TREE_CODE (parm) == TREE_LIST); 3551 defval = TREE_PURPOSE (parm); 3552 3553 if (list) 3554 { 3555 tree p = tree_last (list); 3556 3557 if (p && TREE_VALUE (p) != error_mark_node) 3558 { 3559 p = TREE_VALUE (p); 3560 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL) 3561 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p)); 3562 else 3563 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p)); 3564 } 3565 3566 ++idx; 3567 } 3568 else 3569 idx = 0; 3570 3571 if (is_non_type) 3572 { 3573 parm = TREE_VALUE (parm); 3574 3575 SET_DECL_TEMPLATE_PARM_P (parm); 3576 3577 if (TREE_TYPE (parm) == error_mark_node) 3578 { 3579 err_parm_list = build_tree_list (defval, parm); 3580 TREE_VALUE (err_parm_list) = error_mark_node; 3581 return chainon (list, err_parm_list); 3582 } 3583 else 3584 { 3585 /* [temp.param] 3586 3587 The top-level cv-qualifiers on the template-parameter are 3588 ignored when determining its type. */ 3589 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm)); 3590 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1)) 3591 { 3592 err_parm_list = build_tree_list (defval, parm); 3593 TREE_VALUE (err_parm_list) = error_mark_node; 3594 return chainon (list, err_parm_list); 3595 } 3596 3597 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack) 3598 { 3599 /* This template parameter is not a parameter pack, but it 3600 should be. Complain about "bare" parameter packs. */ 3601 check_for_bare_parameter_packs (TREE_TYPE (parm)); 3602 3603 /* Recover by calling this a parameter pack. */ 3604 is_parameter_pack = true; 3605 } 3606 } 3607 3608 /* A template parameter is not modifiable. */ 3609 TREE_CONSTANT (parm) = 1; 3610 TREE_READONLY (parm) = 1; 3611 decl = build_decl (parm_loc, 3612 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm)); 3613 TREE_CONSTANT (decl) = 1; 3614 TREE_READONLY (decl) = 1; 3615 DECL_INITIAL (parm) = DECL_INITIAL (decl) 3616 = build_template_parm_index (idx, processing_template_decl, 3617 processing_template_decl, 3618 num_template_parms, 3619 decl, TREE_TYPE (parm)); 3620 3621 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)) 3622 = is_parameter_pack; 3623 } 3624 else 3625 { 3626 tree t; 3627 parm = TREE_VALUE (TREE_VALUE (parm)); 3628 3629 if (parm && TREE_CODE (parm) == TEMPLATE_DECL) 3630 { 3631 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM); 3632 /* This is for distinguishing between real templates and template 3633 template parameters */ 3634 TREE_TYPE (parm) = t; 3635 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t; 3636 decl = parm; 3637 } 3638 else 3639 { 3640 t = cxx_make_type (TEMPLATE_TYPE_PARM); 3641 /* parm is either IDENTIFIER_NODE or NULL_TREE. */ 3642 decl = build_decl (parm_loc, 3643 TYPE_DECL, parm, t); 3644 } 3645 3646 TYPE_NAME (t) = decl; 3647 TYPE_STUB_DECL (t) = decl; 3648 parm = decl; 3649 TEMPLATE_TYPE_PARM_INDEX (t) 3650 = build_template_parm_index (idx, processing_template_decl, 3651 processing_template_decl, 3652 num_template_parms, 3653 decl, TREE_TYPE (parm)); 3654 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack; 3655 TYPE_CANONICAL (t) = canonical_type_parameter (t); 3656 } 3657 DECL_ARTIFICIAL (decl) = 1; 3658 SET_DECL_TEMPLATE_PARM_P (decl); 3659 pushdecl (decl); 3660 parm = build_tree_list (defval, parm); 3661 return chainon (list, parm); 3662 } 3663 3664 /* The end of a template parameter list has been reached. Process the 3665 tree list into a parameter vector, converting each parameter into a more 3666 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others 3667 as PARM_DECLs. */ 3668 3669 tree 3670 end_template_parm_list (tree parms) 3671 { 3672 int nparms; 3673 tree parm, next; 3674 tree saved_parmlist = make_tree_vec (list_length (parms)); 3675 3676 current_template_parms 3677 = tree_cons (size_int (processing_template_decl), 3678 saved_parmlist, current_template_parms); 3679 3680 for (parm = parms, nparms = 0; parm; parm = next, nparms++) 3681 { 3682 next = TREE_CHAIN (parm); 3683 TREE_VEC_ELT (saved_parmlist, nparms) = parm; 3684 TREE_CHAIN (parm) = NULL_TREE; 3685 } 3686 3687 --processing_template_parmlist; 3688 3689 return saved_parmlist; 3690 } 3691 3692 /* Create a new type almost identical to TYPE but which has the 3693 following differences: 3694 3695 1/ T has a new TEMPLATE_PARM_INDEX that carries the new number of 3696 template sibling parameters of T. 3697 3698 2/ T has a new canonical type that matches the new number 3699 of sibling parms. 3700 3701 3/ From now on, T is going to be what lookups referring to the 3702 name of TYPE will return. No lookup should return TYPE anymore. 3703 3704 NUM_PARMS is the new number of sibling parms TYPE belongs to. 3705 3706 This is a subroutine of fixup_template_parms. */ 3707 3708 static tree 3709 fixup_template_type_parm_type (tree type, int num_parms) 3710 { 3711 tree orig_idx = TEMPLATE_TYPE_PARM_INDEX (type), idx; 3712 tree t; 3713 /* This is the decl which name is inserted into the symbol table for 3714 the template parm type. So whenever we lookup the type name, this 3715 is the DECL we get. */ 3716 tree decl; 3717 3718 /* Do not fix up the type twice. */ 3719 if (orig_idx && TEMPLATE_PARM_NUM_SIBLINGS (orig_idx) != 0) 3720 return type; 3721 3722 t = copy_type (type); 3723 decl = TYPE_NAME (t); 3724 3725 TYPE_MAIN_VARIANT (t) = t; 3726 TYPE_NEXT_VARIANT (t)= NULL_TREE; 3727 TYPE_POINTER_TO (t) = 0; 3728 TYPE_REFERENCE_TO (t) = 0; 3729 3730 idx = build_template_parm_index (TEMPLATE_PARM_IDX (orig_idx), 3731 TEMPLATE_PARM_LEVEL (orig_idx), 3732 TEMPLATE_PARM_ORIG_LEVEL (orig_idx), 3733 num_parms, 3734 decl, t); 3735 TEMPLATE_PARM_DESCENDANTS (idx) = TEMPLATE_PARM_DESCENDANTS (orig_idx); 3736 TEMPLATE_PARM_PARAMETER_PACK (idx) = TEMPLATE_PARM_PARAMETER_PACK (orig_idx); 3737 TEMPLATE_TYPE_PARM_INDEX (t) = idx; 3738 3739 TYPE_STUB_DECL (t) = decl; 3740 TEMPLATE_TYPE_DECL (t) = decl; 3741 if (TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM) 3742 TREE_TYPE (DECL_TEMPLATE_RESULT (decl)) = t; 3743 3744 /* Update the type associated to the type name stored in the symbol 3745 table. Now, whenever the type name is looked up, the resulting 3746 type is properly fixed up. */ 3747 TREE_TYPE (decl) = t; 3748 3749 TYPE_CANONICAL (t) = canonical_type_parameter (t); 3750 3751 return t; 3752 } 3753 3754 /* Create and return a new TEMPLATE_PARM_INDEX that is almost 3755 identical to I, but that is fixed up as to: 3756 3757 1/ carry the number of sibling parms (NUM_PARMS) of the template 3758 parm represented by I. 3759 3760 2/ replace all references to template parm types declared before I 3761 (in the same template parm list as I) by references to template 3762 parm types contained in ARGS. ARGS should contain the list of 3763 template parms that have been fixed up so far, in a form suitable 3764 to be passed to tsubst. 3765 3766 This is a subroutine of fixup_template_parms. */ 3767 3768 static tree 3769 fixup_template_parm_index (tree i, tree args, int num_parms) 3770 { 3771 tree index, decl, type; 3772 3773 if (i == NULL_TREE 3774 || TREE_CODE (i) != TEMPLATE_PARM_INDEX 3775 /* Do not fix up the index twice. */ 3776 || (TEMPLATE_PARM_NUM_SIBLINGS (i) != 0)) 3777 return i; 3778 3779 decl = TEMPLATE_PARM_DECL (i); 3780 type = TREE_TYPE (decl); 3781 3782 index = build_template_parm_index (TEMPLATE_PARM_IDX (i), 3783 TEMPLATE_PARM_LEVEL (i), 3784 TEMPLATE_PARM_ORIG_LEVEL (i), 3785 num_parms, 3786 decl, type); 3787 3788 TEMPLATE_PARM_DESCENDANTS (index) = TEMPLATE_PARM_DESCENDANTS (i); 3789 TEMPLATE_PARM_PARAMETER_PACK (index) = TEMPLATE_PARM_PARAMETER_PACK (i); 3790 3791 type = tsubst (type, args, tf_none, NULL_TREE); 3792 3793 TREE_TYPE (decl) = type; 3794 TREE_TYPE (index) = type; 3795 3796 return index; 3797 } 3798 3799 /* 3800 This is a subroutine of fixup_template_parms. 3801 3802 It computes the canonical type of the type of the template 3803 parameter PARM_DESC and update all references to that type so that 3804 they use the newly computed canonical type. No access check is 3805 performed during the fixup. PARM_DESC is a TREE_LIST which 3806 TREE_VALUE is the template parameter and its TREE_PURPOSE is the 3807 default argument of the template parm if any. IDX is the index of 3808 the template parameter, starting at 0. NUM_PARMS is the number of 3809 template parameters in the set PARM_DESC belongs to. ARGLIST is a 3810 TREE_VEC containing the full set of template parameters in a form 3811 suitable to be passed to substs functions as their ARGS 3812 argument. This is what current_template_args returns for a given 3813 template. The innermost vector of args in ARGLIST is the set of 3814 template parms that have been fixed up so far. This function adds 3815 the fixed up parameter into that vector. */ 3816 3817 static void 3818 fixup_template_parm (tree parm_desc, 3819 int idx, 3820 int num_parms, 3821 tree arglist) 3822 { 3823 tree parm = TREE_VALUE (parm_desc); 3824 tree fixedup_args = INNERMOST_TEMPLATE_ARGS (arglist); 3825 3826 push_deferring_access_checks (dk_no_check); 3827 3828 if (TREE_CODE (parm) == TYPE_DECL) 3829 { 3830 /* PARM is a template type parameter. Fix up its type, add 3831 the fixed-up template parm to the vector of fixed-up 3832 template parms so far, and substitute the fixed-up 3833 template parms into the default argument of this 3834 parameter. */ 3835 tree t = 3836 fixup_template_type_parm_type (TREE_TYPE (parm), num_parms); 3837 TREE_TYPE (parm) = t; 3838 3839 TREE_VEC_ELT (fixedup_args, idx) = template_parm_to_arg (parm_desc); 3840 } 3841 else if (TREE_CODE (parm) == TEMPLATE_DECL) 3842 { 3843 /* PARM is a template template parameter. This is going to 3844 be interesting. */ 3845 tree tparms, targs, innermost_args, t; 3846 int j; 3847 3848 /* First, fix up the parms of the template template parm 3849 because the parms are involved in defining the new canonical 3850 type of the template template parm. */ 3851 3852 /* So we need to substitute the template parm types that have 3853 been fixed up so far into the template parms of this template 3854 template parm. E.g, consider this: 3855 3856 template<class T, template<T u> class TT> class S; 3857 3858 In this case we want to substitute T into the 3859 template parameters of TT. 3860 3861 So let's walk the template parms of PARM here, and 3862 tsubst ARGLIST into into each of the template 3863 parms. */ 3864 3865 /* For this substitution we need to build the full set of 3866 template parameters and use that as arguments for the 3867 tsubsting function. */ 3868 tparms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (parm)); 3869 3870 /* This will contain the innermost parms of PARM into which 3871 we have substituted so far. */ 3872 innermost_args = make_tree_vec (TREE_VEC_LENGTH (tparms)); 3873 targs = add_to_template_args (arglist, innermost_args); 3874 for (j = 0; j < TREE_VEC_LENGTH (tparms); ++j) 3875 { 3876 tree parameter; 3877 3878 parameter = TREE_VEC_ELT (tparms, j); 3879 3880 /* INNERMOST_ARGS needs to have at least the same number 3881 of elements as the index PARAMETER, ortherwise 3882 tsubsting into PARAMETER will result in partially 3883 instantiating it, reducing its tempate parm 3884 level. Let's tactically fill INNERMOST_ARGS for that 3885 purpose. */ 3886 TREE_VEC_ELT (innermost_args, j) = 3887 template_parm_to_arg (parameter); 3888 3889 fixup_template_parm (parameter, j, 3890 TREE_VEC_LENGTH (tparms), 3891 targs); 3892 } 3893 3894 /* Now fix up the type of the template template parm. */ 3895 3896 t = fixup_template_type_parm_type (TREE_TYPE (parm), num_parms); 3897 TREE_TYPE (parm) = t; 3898 3899 TREE_VEC_ELT (fixedup_args, idx) = 3900 template_parm_to_arg (parm_desc); 3901 } 3902 else if (TREE_CODE (parm) == PARM_DECL) 3903 { 3904 /* PARM is a non-type template parameter. We need to: 3905 3906 * Fix up its TEMPLATE_PARM_INDEX to make it carry the 3907 proper number of sibling parameters. 3908 3909 * Make lookups of the template parameter return a reference 3910 to the fixed-up index. No lookup should return references 3911 to the former index anymore. 3912 3913 * Substitute the template parms that got fixed up so far 3914 3915 * into the type of PARM. */ 3916 3917 tree index = DECL_INITIAL (parm); 3918 3919 /* PUSHED_DECL is the decl added to the symbol table with 3920 the name of the parameter. E,g: 3921 3922 template<class T, T u> //#0 3923 auto my_function(T t) -> decltype(u); //#1 3924 3925 Here, when looking up u at //#1, we get the decl of u 3926 resulting from the declaration in #0. This is what 3927 PUSHED_DECL is. We need to replace the reference to the 3928 old TEMPLATE_PARM_INDEX carried by PUSHED_DECL by the 3929 fixed-up TEMPLATE_PARM_INDEX. */ 3930 tree pushed_decl = TEMPLATE_PARM_DECL (index); 3931 3932 /* Let's fix up the TEMPLATE_PARM_INDEX then. Note that we must 3933 fixup the type of PUSHED_DECL as well and luckily 3934 fixup_template_parm_index does it for us too. */ 3935 tree fixed_up_index = 3936 fixup_template_parm_index (index, arglist, num_parms); 3937 3938 DECL_INITIAL (pushed_decl) = DECL_INITIAL (parm) = fixed_up_index; 3939 3940 /* Add this fixed up PARM to the template parms we've fixed 3941 up so far and use that to substitute the fixed-up 3942 template parms into the type of PARM. */ 3943 TREE_VEC_ELT (fixedup_args, idx) = 3944 template_parm_to_arg (parm_desc); 3945 TREE_TYPE (parm) = tsubst (TREE_TYPE (parm), arglist, 3946 tf_none, NULL_TREE); 3947 } 3948 3949 TREE_PURPOSE (parm_desc) = 3950 tsubst_template_arg (TREE_PURPOSE (parm_desc), 3951 arglist, tf_none, parm); 3952 3953 pop_deferring_access_checks (); 3954 } 3955 3956 /* Walk the current template parms and properly compute the canonical 3957 types of the dependent types created during 3958 cp_parser_template_parameter_list. */ 3959 3960 void 3961 fixup_template_parms (void) 3962 { 3963 tree arglist; 3964 tree parameter_vec; 3965 tree fixedup_args; 3966 int i, num_parms; 3967 3968 parameter_vec = INNERMOST_TEMPLATE_PARMS (current_template_parms); 3969 if (parameter_vec == NULL_TREE) 3970 return; 3971 3972 num_parms = TREE_VEC_LENGTH (parameter_vec); 3973 3974 /* This vector contains the current innermost template parms that 3975 have been fixed up so far. The form of FIXEDUP_ARGS is suitable 3976 to be passed to tsubst* functions as their ARGS argument. */ 3977 fixedup_args = make_tree_vec (num_parms); 3978 3979 /* This vector contains the full set of template parms in a form 3980 suitable to be passed to substs functions as their ARGS 3981 argument. */ 3982 arglist = current_template_args (); 3983 arglist = add_outermost_template_args (arglist, fixedup_args); 3984 3985 /* Let's do the proper fixup now. */ 3986 for (i = 0; i < num_parms; ++i) 3987 fixup_template_parm (TREE_VEC_ELT (parameter_vec, i), 3988 i, num_parms, arglist); 3989 } 3990 3991 /* end_template_decl is called after a template declaration is seen. */ 3992 3993 void 3994 end_template_decl (void) 3995 { 3996 reset_specialization (); 3997 3998 if (! processing_template_decl) 3999 return; 4000 4001 /* This matches the pushlevel in begin_template_parm_list. */ 4002 finish_scope (); 4003 4004 --processing_template_decl; 4005 current_template_parms = TREE_CHAIN (current_template_parms); 4006 } 4007 4008 /* Takes a TREE_LIST representing a template parameter and convert it 4009 into an argument suitable to be passed to the type substitution 4010 functions. Note that If the TREE_LIST contains an error_mark 4011 node, the returned argument is error_mark_node. */ 4012 4013 static tree 4014 template_parm_to_arg (tree t) 4015 { 4016 4017 if (t == NULL_TREE 4018 || TREE_CODE (t) != TREE_LIST) 4019 return t; 4020 4021 if (error_operand_p (TREE_VALUE (t))) 4022 return error_mark_node; 4023 4024 t = TREE_VALUE (t); 4025 4026 if (TREE_CODE (t) == TYPE_DECL 4027 || TREE_CODE (t) == TEMPLATE_DECL) 4028 { 4029 t = TREE_TYPE (t); 4030 4031 if (TEMPLATE_TYPE_PARAMETER_PACK (t)) 4032 { 4033 /* Turn this argument into a TYPE_ARGUMENT_PACK 4034 with a single element, which expands T. */ 4035 tree vec = make_tree_vec (1); 4036 #ifdef ENABLE_CHECKING 4037 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT 4038 (vec, TREE_VEC_LENGTH (vec)); 4039 #endif 4040 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t); 4041 4042 t = cxx_make_type (TYPE_ARGUMENT_PACK); 4043 SET_ARGUMENT_PACK_ARGS (t, vec); 4044 } 4045 } 4046 else 4047 { 4048 t = DECL_INITIAL (t); 4049 4050 if (TEMPLATE_PARM_PARAMETER_PACK (t)) 4051 { 4052 /* Turn this argument into a NONTYPE_ARGUMENT_PACK 4053 with a single element, which expands T. */ 4054 tree vec = make_tree_vec (1); 4055 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t)); 4056 #ifdef ENABLE_CHECKING 4057 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT 4058 (vec, TREE_VEC_LENGTH (vec)); 4059 #endif 4060 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t); 4061 4062 t = make_node (NONTYPE_ARGUMENT_PACK); 4063 SET_ARGUMENT_PACK_ARGS (t, vec); 4064 TREE_TYPE (t) = type; 4065 } 4066 } 4067 return t; 4068 } 4069 4070 /* This function returns TRUE if PARM_PACK is a template parameter 4071 pack and if ARG_PACK is what template_parm_to_arg returned when 4072 passed PARM_PACK. */ 4073 4074 static bool 4075 arg_from_parm_pack_p (tree arg_pack, tree parm_pack) 4076 { 4077 /* For clarity in the comments below let's use the representation 4078 argument_pack<elements>' to denote an argument pack and its 4079 elements. 4080 4081 In the 'if' block below, we want to detect cases where 4082 ARG_PACK is argument_pack<PARM_PACK...>. I.e, we want to 4083 check if ARG_PACK is an argument pack which sole element is 4084 the expansion of PARM_PACK. That argument pack is typically 4085 created by template_parm_to_arg when passed a parameter 4086 pack. */ 4087 4088 if (arg_pack 4089 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1 4090 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0))) 4091 { 4092 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0); 4093 tree pattern = PACK_EXPANSION_PATTERN (expansion); 4094 /* So we have an argument_pack<P...>. We want to test if P 4095 is actually PARM_PACK. We will not use cp_tree_equal to 4096 test P and PARM_PACK because during type fixup (by 4097 fixup_template_parm) P can be a pre-fixup version of a 4098 type and PARM_PACK be its post-fixup version. 4099 cp_tree_equal would consider them as different even 4100 though we would want to consider them compatible for our 4101 precise purpose here. 4102 4103 Thus we are going to consider that P and PARM_PACK are 4104 compatible if they have the same DECL. */ 4105 if ((/* If ARG_PACK is a type parameter pack named by the 4106 same DECL as parm_pack ... */ 4107 (TYPE_P (pattern) 4108 && TYPE_P (parm_pack) 4109 && TYPE_NAME (pattern) == TYPE_NAME (parm_pack)) 4110 /* ... or if PARM_PACK is a non-type parameter named by the 4111 same DECL as ARG_PACK. Note that PARM_PACK being a 4112 non-type parameter means it's either a PARM_DECL or a 4113 TEMPLATE_PARM_INDEX. */ 4114 || (TREE_CODE (pattern) == TEMPLATE_PARM_INDEX 4115 && ((TREE_CODE (parm_pack) == PARM_DECL 4116 && (TEMPLATE_PARM_DECL (pattern) 4117 == TEMPLATE_PARM_DECL (DECL_INITIAL (parm_pack)))) 4118 || (TREE_CODE (parm_pack) == TEMPLATE_PARM_INDEX 4119 && (TEMPLATE_PARM_DECL (pattern) 4120 == TEMPLATE_PARM_DECL (parm_pack)))))) 4121 && template_parameter_pack_p (pattern)) 4122 return true; 4123 } 4124 return false; 4125 } 4126 4127 /* Within the declaration of a template, return all levels of template 4128 parameters that apply. The template parameters are represented as 4129 a TREE_VEC, in the form documented in cp-tree.h for template 4130 arguments. */ 4131 4132 static tree 4133 current_template_args (void) 4134 { 4135 tree header; 4136 tree args = NULL_TREE; 4137 int length = TMPL_PARMS_DEPTH (current_template_parms); 4138 int l = length; 4139 4140 /* If there is only one level of template parameters, we do not 4141 create a TREE_VEC of TREE_VECs. Instead, we return a single 4142 TREE_VEC containing the arguments. */ 4143 if (length > 1) 4144 args = make_tree_vec (length); 4145 4146 for (header = current_template_parms; header; header = TREE_CHAIN (header)) 4147 { 4148 tree a = copy_node (TREE_VALUE (header)); 4149 int i; 4150 4151 TREE_TYPE (a) = NULL_TREE; 4152 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i) 4153 TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i)); 4154 4155 #ifdef ENABLE_CHECKING 4156 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a)); 4157 #endif 4158 4159 if (length > 1) 4160 TREE_VEC_ELT (args, --l) = a; 4161 else 4162 args = a; 4163 } 4164 4165 if (length > 1 && TREE_VEC_ELT (args, 0) == NULL_TREE) 4166 /* This can happen for template parms of a template template 4167 parameter, e.g: 4168 4169 template<template<class T, class U> class TT> struct S; 4170 4171 Consider the level of the parms of TT; T and U both have 4172 level 2; TT has no template parm of level 1. So in this case 4173 the first element of full_template_args is NULL_TREE. If we 4174 leave it like this TMPL_ARG_DEPTH on args returns 1 instead 4175 of 2. This will make tsubst wrongly consider that T and U 4176 have level 1. Instead, let's create a dummy vector as the 4177 first element of full_template_args so that TMPL_ARG_DEPTH 4178 returns the correct depth for args. */ 4179 TREE_VEC_ELT (args, 0) = make_tree_vec (1); 4180 return args; 4181 } 4182 4183 /* Update the declared TYPE by doing any lookups which were thought to be 4184 dependent, but are not now that we know the SCOPE of the declarator. */ 4185 4186 tree 4187 maybe_update_decl_type (tree orig_type, tree scope) 4188 { 4189 tree type = orig_type; 4190 4191 if (type == NULL_TREE) 4192 return type; 4193 4194 if (TREE_CODE (orig_type) == TYPE_DECL) 4195 type = TREE_TYPE (type); 4196 4197 if (scope && TYPE_P (scope) && dependent_type_p (scope) 4198 && dependent_type_p (type) 4199 /* Don't bother building up the args in this case. */ 4200 && TREE_CODE (type) != TEMPLATE_TYPE_PARM) 4201 { 4202 /* tsubst in the args corresponding to the template parameters, 4203 including auto if present. Most things will be unchanged, but 4204 make_typename_type and tsubst_qualified_id will resolve 4205 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */ 4206 tree args = current_template_args (); 4207 tree auto_node = type_uses_auto (type); 4208 tree pushed; 4209 if (auto_node) 4210 { 4211 tree auto_vec = make_tree_vec (1); 4212 TREE_VEC_ELT (auto_vec, 0) = auto_node; 4213 args = add_to_template_args (args, auto_vec); 4214 } 4215 pushed = push_scope (scope); 4216 type = tsubst (type, args, tf_warning_or_error, NULL_TREE); 4217 if (pushed) 4218 pop_scope (scope); 4219 } 4220 4221 if (type == error_mark_node) 4222 return orig_type; 4223 4224 if (TREE_CODE (orig_type) == TYPE_DECL) 4225 { 4226 if (same_type_p (type, TREE_TYPE (orig_type))) 4227 type = orig_type; 4228 else 4229 type = TYPE_NAME (type); 4230 } 4231 return type; 4232 } 4233 4234 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated 4235 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is 4236 a member template. Used by push_template_decl below. */ 4237 4238 static tree 4239 build_template_decl (tree decl, tree parms, bool member_template_p) 4240 { 4241 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE); 4242 DECL_TEMPLATE_PARMS (tmpl) = parms; 4243 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl); 4244 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl); 4245 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p; 4246 4247 return tmpl; 4248 } 4249 4250 struct template_parm_data 4251 { 4252 /* The level of the template parameters we are currently 4253 processing. */ 4254 int level; 4255 4256 /* The index of the specialization argument we are currently 4257 processing. */ 4258 int current_arg; 4259 4260 /* An array whose size is the number of template parameters. The 4261 elements are nonzero if the parameter has been used in any one 4262 of the arguments processed so far. */ 4263 int* parms; 4264 4265 /* An array whose size is the number of template arguments. The 4266 elements are nonzero if the argument makes use of template 4267 parameters of this level. */ 4268 int* arg_uses_template_parms; 4269 }; 4270 4271 /* Subroutine of push_template_decl used to see if each template 4272 parameter in a partial specialization is used in the explicit 4273 argument list. If T is of the LEVEL given in DATA (which is 4274 treated as a template_parm_data*), then DATA->PARMS is marked 4275 appropriately. */ 4276 4277 static int 4278 mark_template_parm (tree t, void* data) 4279 { 4280 int level; 4281 int idx; 4282 struct template_parm_data* tpd = (struct template_parm_data*) data; 4283 4284 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX) 4285 { 4286 level = TEMPLATE_PARM_LEVEL (t); 4287 idx = TEMPLATE_PARM_IDX (t); 4288 } 4289 else 4290 { 4291 level = TEMPLATE_TYPE_LEVEL (t); 4292 idx = TEMPLATE_TYPE_IDX (t); 4293 } 4294 4295 if (level == tpd->level) 4296 { 4297 tpd->parms[idx] = 1; 4298 tpd->arg_uses_template_parms[tpd->current_arg] = 1; 4299 } 4300 4301 /* Return zero so that for_each_template_parm will continue the 4302 traversal of the tree; we want to mark *every* template parm. */ 4303 return 0; 4304 } 4305 4306 /* Process the partial specialization DECL. */ 4307 4308 static tree 4309 process_partial_specialization (tree decl) 4310 { 4311 tree type = TREE_TYPE (decl); 4312 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type); 4313 tree specargs = CLASSTYPE_TI_ARGS (type); 4314 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs); 4315 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl); 4316 tree inner_parms; 4317 tree inst; 4318 int nargs = TREE_VEC_LENGTH (inner_args); 4319 int ntparms; 4320 int i; 4321 bool did_error_intro = false; 4322 struct template_parm_data tpd; 4323 struct template_parm_data tpd2; 4324 4325 gcc_assert (current_template_parms); 4326 4327 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms); 4328 ntparms = TREE_VEC_LENGTH (inner_parms); 4329 4330 /* We check that each of the template parameters given in the 4331 partial specialization is used in the argument list to the 4332 specialization. For example: 4333 4334 template <class T> struct S; 4335 template <class T> struct S<T*>; 4336 4337 The second declaration is OK because `T*' uses the template 4338 parameter T, whereas 4339 4340 template <class T> struct S<int>; 4341 4342 is no good. Even trickier is: 4343 4344 template <class T> 4345 struct S1 4346 { 4347 template <class U> 4348 struct S2; 4349 template <class U> 4350 struct S2<T>; 4351 }; 4352 4353 The S2<T> declaration is actually invalid; it is a 4354 full-specialization. Of course, 4355 4356 template <class U> 4357 struct S2<T (*)(U)>; 4358 4359 or some such would have been OK. */ 4360 tpd.level = TMPL_PARMS_DEPTH (current_template_parms); 4361 tpd.parms = XALLOCAVEC (int, ntparms); 4362 memset (tpd.parms, 0, sizeof (int) * ntparms); 4363 4364 tpd.arg_uses_template_parms = XALLOCAVEC (int, nargs); 4365 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs); 4366 for (i = 0; i < nargs; ++i) 4367 { 4368 tpd.current_arg = i; 4369 for_each_template_parm (TREE_VEC_ELT (inner_args, i), 4370 &mark_template_parm, 4371 &tpd, 4372 NULL, 4373 /*include_nondeduced_p=*/false); 4374 } 4375 for (i = 0; i < ntparms; ++i) 4376 if (tpd.parms[i] == 0) 4377 { 4378 /* One of the template parms was not used in the 4379 specialization. */ 4380 if (!did_error_intro) 4381 { 4382 error ("template parameters not used in partial specialization:"); 4383 did_error_intro = true; 4384 } 4385 4386 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i))); 4387 } 4388 4389 if (did_error_intro) 4390 return error_mark_node; 4391 4392 /* [temp.class.spec] 4393 4394 The argument list of the specialization shall not be identical to 4395 the implicit argument list of the primary template. */ 4396 if (comp_template_args 4397 (inner_args, 4398 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE 4399 (maintmpl))))) 4400 error ("partial specialization %qT does not specialize any template arguments", type); 4401 4402 /* [temp.class.spec] 4403 4404 A partially specialized non-type argument expression shall not 4405 involve template parameters of the partial specialization except 4406 when the argument expression is a simple identifier. 4407 4408 The type of a template parameter corresponding to a specialized 4409 non-type argument shall not be dependent on a parameter of the 4410 specialization. 4411 4412 Also, we verify that pack expansions only occur at the 4413 end of the argument list. */ 4414 gcc_assert (nargs == DECL_NTPARMS (maintmpl)); 4415 tpd2.parms = 0; 4416 for (i = 0; i < nargs; ++i) 4417 { 4418 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i)); 4419 tree arg = TREE_VEC_ELT (inner_args, i); 4420 tree packed_args = NULL_TREE; 4421 int j, len = 1; 4422 4423 if (ARGUMENT_PACK_P (arg)) 4424 { 4425 /* Extract the arguments from the argument pack. We'll be 4426 iterating over these in the following loop. */ 4427 packed_args = ARGUMENT_PACK_ARGS (arg); 4428 len = TREE_VEC_LENGTH (packed_args); 4429 } 4430 4431 for (j = 0; j < len; j++) 4432 { 4433 if (packed_args) 4434 /* Get the Jth argument in the parameter pack. */ 4435 arg = TREE_VEC_ELT (packed_args, j); 4436 4437 if (PACK_EXPANSION_P (arg)) 4438 { 4439 /* Pack expansions must come at the end of the 4440 argument list. */ 4441 if ((packed_args && j < len - 1) 4442 || (!packed_args && i < nargs - 1)) 4443 { 4444 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION) 4445 error ("parameter pack argument %qE must be at the " 4446 "end of the template argument list", arg); 4447 else 4448 error ("parameter pack argument %qT must be at the " 4449 "end of the template argument list", arg); 4450 } 4451 } 4452 4453 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION) 4454 /* We only care about the pattern. */ 4455 arg = PACK_EXPANSION_PATTERN (arg); 4456 4457 if (/* These first two lines are the `non-type' bit. */ 4458 !TYPE_P (arg) 4459 && TREE_CODE (arg) != TEMPLATE_DECL 4460 /* This next line is the `argument expression is not just a 4461 simple identifier' condition and also the `specialized 4462 non-type argument' bit. */ 4463 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX) 4464 { 4465 if ((!packed_args && tpd.arg_uses_template_parms[i]) 4466 || (packed_args && uses_template_parms (arg))) 4467 error ("template argument %qE involves template parameter(s)", 4468 arg); 4469 else 4470 { 4471 /* Look at the corresponding template parameter, 4472 marking which template parameters its type depends 4473 upon. */ 4474 tree type = TREE_TYPE (parm); 4475 4476 if (!tpd2.parms) 4477 { 4478 /* We haven't yet initialized TPD2. Do so now. */ 4479 tpd2.arg_uses_template_parms = XALLOCAVEC (int, nargs); 4480 /* The number of parameters here is the number in the 4481 main template, which, as checked in the assertion 4482 above, is NARGS. */ 4483 tpd2.parms = XALLOCAVEC (int, nargs); 4484 tpd2.level = 4485 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl)); 4486 } 4487 4488 /* Mark the template parameters. But this time, we're 4489 looking for the template parameters of the main 4490 template, not in the specialization. */ 4491 tpd2.current_arg = i; 4492 tpd2.arg_uses_template_parms[i] = 0; 4493 memset (tpd2.parms, 0, sizeof (int) * nargs); 4494 for_each_template_parm (type, 4495 &mark_template_parm, 4496 &tpd2, 4497 NULL, 4498 /*include_nondeduced_p=*/false); 4499 4500 if (tpd2.arg_uses_template_parms [i]) 4501 { 4502 /* The type depended on some template parameters. 4503 If they are fully specialized in the 4504 specialization, that's OK. */ 4505 int j; 4506 int count = 0; 4507 for (j = 0; j < nargs; ++j) 4508 if (tpd2.parms[j] != 0 4509 && tpd.arg_uses_template_parms [j]) 4510 ++count; 4511 if (count != 0) 4512 error_n (input_location, count, 4513 "type %qT of template argument %qE depends " 4514 "on a template parameter", 4515 "type %qT of template argument %qE depends " 4516 "on template parameters", 4517 type, 4518 arg); 4519 } 4520 } 4521 } 4522 } 4523 } 4524 4525 /* We should only get here once. */ 4526 gcc_assert (!COMPLETE_TYPE_P (type)); 4527 4528 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl) 4529 = tree_cons (specargs, inner_parms, 4530 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)); 4531 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type; 4532 4533 for (inst = DECL_TEMPLATE_INSTANTIATIONS (maintmpl); inst; 4534 inst = TREE_CHAIN (inst)) 4535 { 4536 tree inst_type = TREE_VALUE (inst); 4537 if (COMPLETE_TYPE_P (inst_type) 4538 && CLASSTYPE_IMPLICIT_INSTANTIATION (inst_type)) 4539 { 4540 tree spec = most_specialized_class (inst_type, maintmpl, tf_none); 4541 if (spec && TREE_TYPE (spec) == type) 4542 permerror (input_location, 4543 "partial specialization of %qT after instantiation " 4544 "of %qT", type, inst_type); 4545 } 4546 } 4547 4548 return decl; 4549 } 4550 4551 /* Check that a template declaration's use of default arguments and 4552 parameter packs is not invalid. Here, PARMS are the template 4553 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by 4554 a primary template. IS_PARTIAL is nonzero if DECL is a partial 4555 specialization. 4556 4557 4558 IS_FRIEND_DECL is nonzero if DECL is a friend function template 4559 declaration (but not a definition); 1 indicates a declaration, 2 4560 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are 4561 emitted for extraneous default arguments. 4562 4563 Returns TRUE if there were no errors found, FALSE otherwise. */ 4564 4565 bool 4566 check_default_tmpl_args (tree decl, tree parms, int is_primary, 4567 int is_partial, int is_friend_decl) 4568 { 4569 const char *msg; 4570 int last_level_to_check; 4571 tree parm_level; 4572 bool no_errors = true; 4573 4574 /* [temp.param] 4575 4576 A default template-argument shall not be specified in a 4577 function template declaration or a function template definition, nor 4578 in the template-parameter-list of the definition of a member of a 4579 class template. */ 4580 4581 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL) 4582 /* You can't have a function template declaration in a local 4583 scope, nor you can you define a member of a class template in a 4584 local scope. */ 4585 return true; 4586 4587 if (current_class_type 4588 && !TYPE_BEING_DEFINED (current_class_type) 4589 && DECL_LANG_SPECIFIC (decl) 4590 && DECL_DECLARES_FUNCTION_P (decl) 4591 /* If this is either a friend defined in the scope of the class 4592 or a member function. */ 4593 && (DECL_FUNCTION_MEMBER_P (decl) 4594 ? same_type_p (DECL_CONTEXT (decl), current_class_type) 4595 : DECL_FRIEND_CONTEXT (decl) 4596 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type) 4597 : false) 4598 /* And, if it was a member function, it really was defined in 4599 the scope of the class. */ 4600 && (!DECL_FUNCTION_MEMBER_P (decl) 4601 || DECL_INITIALIZED_IN_CLASS_P (decl))) 4602 /* We already checked these parameters when the template was 4603 declared, so there's no need to do it again now. This function 4604 was defined in class scope, but we're processing it's body now 4605 that the class is complete. */ 4606 return true; 4607 4608 /* Core issue 226 (C++0x only): the following only applies to class 4609 templates. */ 4610 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL) 4611 { 4612 /* [temp.param] 4613 4614 If a template-parameter has a default template-argument, all 4615 subsequent template-parameters shall have a default 4616 template-argument supplied. */ 4617 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level)) 4618 { 4619 tree inner_parms = TREE_VALUE (parm_level); 4620 int ntparms = TREE_VEC_LENGTH (inner_parms); 4621 int seen_def_arg_p = 0; 4622 int i; 4623 4624 for (i = 0; i < ntparms; ++i) 4625 { 4626 tree parm = TREE_VEC_ELT (inner_parms, i); 4627 4628 if (parm == error_mark_node) 4629 continue; 4630 4631 if (TREE_PURPOSE (parm)) 4632 seen_def_arg_p = 1; 4633 else if (seen_def_arg_p 4634 && !template_parameter_pack_p (TREE_VALUE (parm))) 4635 { 4636 error ("no default argument for %qD", TREE_VALUE (parm)); 4637 /* For better subsequent error-recovery, we indicate that 4638 there should have been a default argument. */ 4639 TREE_PURPOSE (parm) = error_mark_node; 4640 no_errors = false; 4641 } 4642 else if (is_primary 4643 && !is_partial 4644 && !is_friend_decl 4645 /* Don't complain about an enclosing partial 4646 specialization. */ 4647 && parm_level == parms 4648 && TREE_CODE (decl) == TYPE_DECL 4649 && i < ntparms - 1 4650 && template_parameter_pack_p (TREE_VALUE (parm))) 4651 { 4652 /* A primary class template can only have one 4653 parameter pack, at the end of the template 4654 parameter list. */ 4655 4656 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL) 4657 error ("parameter pack %qE must be at the end of the" 4658 " template parameter list", TREE_VALUE (parm)); 4659 else 4660 error ("parameter pack %qT must be at the end of the" 4661 " template parameter list", 4662 TREE_TYPE (TREE_VALUE (parm))); 4663 4664 TREE_VALUE (TREE_VEC_ELT (inner_parms, i)) 4665 = error_mark_node; 4666 no_errors = false; 4667 } 4668 } 4669 } 4670 } 4671 4672 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL) 4673 || is_partial 4674 || !is_primary 4675 || is_friend_decl) 4676 /* For an ordinary class template, default template arguments are 4677 allowed at the innermost level, e.g.: 4678 template <class T = int> 4679 struct S {}; 4680 but, in a partial specialization, they're not allowed even 4681 there, as we have in [temp.class.spec]: 4682 4683 The template parameter list of a specialization shall not 4684 contain default template argument values. 4685 4686 So, for a partial specialization, or for a function template 4687 (in C++98/C++03), we look at all of them. */ 4688 ; 4689 else 4690 /* But, for a primary class template that is not a partial 4691 specialization we look at all template parameters except the 4692 innermost ones. */ 4693 parms = TREE_CHAIN (parms); 4694 4695 /* Figure out what error message to issue. */ 4696 if (is_friend_decl == 2) 4697 msg = G_("default template arguments may not be used in function template " 4698 "friend re-declaration"); 4699 else if (is_friend_decl) 4700 msg = G_("default template arguments may not be used in function template " 4701 "friend declarations"); 4702 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98)) 4703 msg = G_("default template arguments may not be used in function templates " 4704 "without -std=c++11 or -std=gnu++11"); 4705 else if (is_partial) 4706 msg = G_("default template arguments may not be used in " 4707 "partial specializations"); 4708 else 4709 msg = G_("default argument for template parameter for class enclosing %qD"); 4710 4711 if (current_class_type && TYPE_BEING_DEFINED (current_class_type)) 4712 /* If we're inside a class definition, there's no need to 4713 examine the parameters to the class itself. On the one 4714 hand, they will be checked when the class is defined, and, 4715 on the other, default arguments are valid in things like: 4716 template <class T = double> 4717 struct S { template <class U> void f(U); }; 4718 Here the default argument for `S' has no bearing on the 4719 declaration of `f'. */ 4720 last_level_to_check = template_class_depth (current_class_type) + 1; 4721 else 4722 /* Check everything. */ 4723 last_level_to_check = 0; 4724 4725 for (parm_level = parms; 4726 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check; 4727 parm_level = TREE_CHAIN (parm_level)) 4728 { 4729 tree inner_parms = TREE_VALUE (parm_level); 4730 int i; 4731 int ntparms; 4732 4733 ntparms = TREE_VEC_LENGTH (inner_parms); 4734 for (i = 0; i < ntparms; ++i) 4735 { 4736 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node) 4737 continue; 4738 4739 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i))) 4740 { 4741 if (msg) 4742 { 4743 no_errors = false; 4744 if (is_friend_decl == 2) 4745 return no_errors; 4746 4747 error (msg, decl); 4748 msg = 0; 4749 } 4750 4751 /* Clear out the default argument so that we are not 4752 confused later. */ 4753 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE; 4754 } 4755 } 4756 4757 /* At this point, if we're still interested in issuing messages, 4758 they must apply to classes surrounding the object declared. */ 4759 if (msg) 4760 msg = G_("default argument for template parameter for class " 4761 "enclosing %qD"); 4762 } 4763 4764 return no_errors; 4765 } 4766 4767 /* Worker for push_template_decl_real, called via 4768 for_each_template_parm. DATA is really an int, indicating the 4769 level of the parameters we are interested in. If T is a template 4770 parameter of that level, return nonzero. */ 4771 4772 static int 4773 template_parm_this_level_p (tree t, void* data) 4774 { 4775 int this_level = *(int *)data; 4776 int level; 4777 4778 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX) 4779 level = TEMPLATE_PARM_LEVEL (t); 4780 else 4781 level = TEMPLATE_TYPE_LEVEL (t); 4782 return level == this_level; 4783 } 4784 4785 /* Creates a TEMPLATE_DECL for the indicated DECL using the template 4786 parameters given by current_template_args, or reuses a 4787 previously existing one, if appropriate. Returns the DECL, or an 4788 equivalent one, if it is replaced via a call to duplicate_decls. 4789 4790 If IS_FRIEND is true, DECL is a friend declaration. */ 4791 4792 tree 4793 push_template_decl_real (tree decl, bool is_friend) 4794 { 4795 tree tmpl; 4796 tree args; 4797 tree info; 4798 tree ctx; 4799 int primary; 4800 int is_partial; 4801 int new_template_p = 0; 4802 /* True if the template is a member template, in the sense of 4803 [temp.mem]. */ 4804 bool member_template_p = false; 4805 4806 if (decl == error_mark_node || !current_template_parms) 4807 return error_mark_node; 4808 4809 /* See if this is a partial specialization. */ 4810 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl) 4811 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE 4812 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl))); 4813 4814 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl)) 4815 is_friend = true; 4816 4817 if (is_friend) 4818 /* For a friend, we want the context of the friend function, not 4819 the type of which it is a friend. */ 4820 ctx = CP_DECL_CONTEXT (decl); 4821 else if (CP_DECL_CONTEXT (decl) 4822 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL) 4823 /* In the case of a virtual function, we want the class in which 4824 it is defined. */ 4825 ctx = CP_DECL_CONTEXT (decl); 4826 else 4827 /* Otherwise, if we're currently defining some class, the DECL 4828 is assumed to be a member of the class. */ 4829 ctx = current_scope (); 4830 4831 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL) 4832 ctx = NULL_TREE; 4833 4834 if (!DECL_CONTEXT (decl)) 4835 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace); 4836 4837 /* See if this is a primary template. */ 4838 if (is_friend && ctx) 4839 /* A friend template that specifies a class context, i.e. 4840 template <typename T> friend void A<T>::f(); 4841 is not primary. */ 4842 primary = 0; 4843 else 4844 primary = template_parm_scope_p (); 4845 4846 if (primary) 4847 { 4848 if (DECL_CLASS_SCOPE_P (decl)) 4849 member_template_p = true; 4850 if (TREE_CODE (decl) == TYPE_DECL 4851 && ANON_AGGRNAME_P (DECL_NAME (decl))) 4852 { 4853 error ("template class without a name"); 4854 return error_mark_node; 4855 } 4856 else if (TREE_CODE (decl) == FUNCTION_DECL) 4857 { 4858 if (DECL_DESTRUCTOR_P (decl)) 4859 { 4860 /* [temp.mem] 4861 4862 A destructor shall not be a member template. */ 4863 error ("destructor %qD declared as member template", decl); 4864 return error_mark_node; 4865 } 4866 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl)) 4867 && (!prototype_p (TREE_TYPE (decl)) 4868 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node 4869 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl))) 4870 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl)))) 4871 == void_list_node))) 4872 { 4873 /* [basic.stc.dynamic.allocation] 4874 4875 An allocation function can be a function 4876 template. ... Template allocation functions shall 4877 have two or more parameters. */ 4878 error ("invalid template declaration of %qD", decl); 4879 return error_mark_node; 4880 } 4881 } 4882 else if (DECL_IMPLICIT_TYPEDEF_P (decl) 4883 && CLASS_TYPE_P (TREE_TYPE (decl))) 4884 /* OK */; 4885 else if (TREE_CODE (decl) == TYPE_DECL 4886 && TYPE_DECL_ALIAS_P (decl)) 4887 /* alias-declaration */ 4888 gcc_assert (!DECL_ARTIFICIAL (decl)); 4889 else 4890 { 4891 error ("template declaration of %q#D", decl); 4892 return error_mark_node; 4893 } 4894 } 4895 4896 /* Check to see that the rules regarding the use of default 4897 arguments are not being violated. */ 4898 check_default_tmpl_args (decl, current_template_parms, 4899 primary, is_partial, /*is_friend_decl=*/0); 4900 4901 /* Ensure that there are no parameter packs in the type of this 4902 declaration that have not been expanded. */ 4903 if (TREE_CODE (decl) == FUNCTION_DECL) 4904 { 4905 /* Check each of the arguments individually to see if there are 4906 any bare parameter packs. */ 4907 tree type = TREE_TYPE (decl); 4908 tree arg = DECL_ARGUMENTS (decl); 4909 tree argtype = TYPE_ARG_TYPES (type); 4910 4911 while (arg && argtype) 4912 { 4913 if (!FUNCTION_PARAMETER_PACK_P (arg) 4914 && check_for_bare_parameter_packs (TREE_TYPE (arg))) 4915 { 4916 /* This is a PARM_DECL that contains unexpanded parameter 4917 packs. We have already complained about this in the 4918 check_for_bare_parameter_packs call, so just replace 4919 these types with ERROR_MARK_NODE. */ 4920 TREE_TYPE (arg) = error_mark_node; 4921 TREE_VALUE (argtype) = error_mark_node; 4922 } 4923 4924 arg = DECL_CHAIN (arg); 4925 argtype = TREE_CHAIN (argtype); 4926 } 4927 4928 /* Check for bare parameter packs in the return type and the 4929 exception specifiers. */ 4930 if (check_for_bare_parameter_packs (TREE_TYPE (type))) 4931 /* Errors were already issued, set return type to int 4932 as the frontend doesn't expect error_mark_node as 4933 the return type. */ 4934 TREE_TYPE (type) = integer_type_node; 4935 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type))) 4936 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE; 4937 } 4938 else if (check_for_bare_parameter_packs ((TREE_CODE (decl) == TYPE_DECL 4939 && TYPE_DECL_ALIAS_P (decl)) 4940 ? DECL_ORIGINAL_TYPE (decl) 4941 : TREE_TYPE (decl))) 4942 { 4943 TREE_TYPE (decl) = error_mark_node; 4944 return error_mark_node; 4945 } 4946 4947 if (is_partial) 4948 return process_partial_specialization (decl); 4949 4950 args = current_template_args (); 4951 4952 if (!ctx 4953 || TREE_CODE (ctx) == FUNCTION_DECL 4954 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx)) 4955 || (is_friend && !DECL_TEMPLATE_INFO (decl))) 4956 { 4957 if (DECL_LANG_SPECIFIC (decl) 4958 && DECL_TEMPLATE_INFO (decl) 4959 && DECL_TI_TEMPLATE (decl)) 4960 tmpl = DECL_TI_TEMPLATE (decl); 4961 /* If DECL is a TYPE_DECL for a class-template, then there won't 4962 be DECL_LANG_SPECIFIC. The information equivalent to 4963 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */ 4964 else if (DECL_IMPLICIT_TYPEDEF_P (decl) 4965 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl)) 4966 && TYPE_TI_TEMPLATE (TREE_TYPE (decl))) 4967 { 4968 /* Since a template declaration already existed for this 4969 class-type, we must be redeclaring it here. Make sure 4970 that the redeclaration is valid. */ 4971 redeclare_class_template (TREE_TYPE (decl), 4972 current_template_parms); 4973 /* We don't need to create a new TEMPLATE_DECL; just use the 4974 one we already had. */ 4975 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl)); 4976 } 4977 else 4978 { 4979 tmpl = build_template_decl (decl, current_template_parms, 4980 member_template_p); 4981 new_template_p = 1; 4982 4983 if (DECL_LANG_SPECIFIC (decl) 4984 && DECL_TEMPLATE_SPECIALIZATION (decl)) 4985 { 4986 /* A specialization of a member template of a template 4987 class. */ 4988 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl); 4989 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl); 4990 DECL_TEMPLATE_INFO (decl) = NULL_TREE; 4991 } 4992 } 4993 } 4994 else 4995 { 4996 tree a, t, current, parms; 4997 int i; 4998 tree tinfo = get_template_info (decl); 4999 5000 if (!tinfo) 5001 { 5002 error ("template definition of non-template %q#D", decl); 5003 return error_mark_node; 5004 } 5005 5006 tmpl = TI_TEMPLATE (tinfo); 5007 5008 if (DECL_FUNCTION_TEMPLATE_P (tmpl) 5009 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl) 5010 && DECL_TEMPLATE_SPECIALIZATION (decl) 5011 && DECL_MEMBER_TEMPLATE_P (tmpl)) 5012 { 5013 tree new_tmpl; 5014 5015 /* The declaration is a specialization of a member 5016 template, declared outside the class. Therefore, the 5017 innermost template arguments will be NULL, so we 5018 replace them with the arguments determined by the 5019 earlier call to check_explicit_specialization. */ 5020 args = DECL_TI_ARGS (decl); 5021 5022 new_tmpl 5023 = build_template_decl (decl, current_template_parms, 5024 member_template_p); 5025 DECL_TEMPLATE_RESULT (new_tmpl) = decl; 5026 TREE_TYPE (new_tmpl) = TREE_TYPE (decl); 5027 DECL_TI_TEMPLATE (decl) = new_tmpl; 5028 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl); 5029 DECL_TEMPLATE_INFO (new_tmpl) 5030 = build_template_info (tmpl, args); 5031 5032 register_specialization (new_tmpl, 5033 most_general_template (tmpl), 5034 args, 5035 is_friend, 0); 5036 return decl; 5037 } 5038 5039 /* Make sure the template headers we got make sense. */ 5040 5041 parms = DECL_TEMPLATE_PARMS (tmpl); 5042 i = TMPL_PARMS_DEPTH (parms); 5043 if (TMPL_ARGS_DEPTH (args) != i) 5044 { 5045 error ("expected %d levels of template parms for %q#D, got %d", 5046 i, decl, TMPL_ARGS_DEPTH (args)); 5047 } 5048 else 5049 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms)) 5050 { 5051 a = TMPL_ARGS_LEVEL (args, i); 5052 t = INNERMOST_TEMPLATE_PARMS (parms); 5053 5054 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a)) 5055 { 5056 if (current == decl) 5057 error ("got %d template parameters for %q#D", 5058 TREE_VEC_LENGTH (a), decl); 5059 else 5060 error ("got %d template parameters for %q#T", 5061 TREE_VEC_LENGTH (a), current); 5062 error (" but %d required", TREE_VEC_LENGTH (t)); 5063 return error_mark_node; 5064 } 5065 5066 if (current == decl) 5067 current = ctx; 5068 else if (current == NULL_TREE) 5069 /* Can happen in erroneous input. */ 5070 break; 5071 else 5072 current = (TYPE_P (current) 5073 ? TYPE_CONTEXT (current) 5074 : DECL_CONTEXT (current)); 5075 } 5076 5077 /* Check that the parms are used in the appropriate qualifying scopes 5078 in the declarator. */ 5079 if (!comp_template_args 5080 (TI_ARGS (tinfo), 5081 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl))))) 5082 { 5083 error ("\ 5084 template arguments to %qD do not match original template %qD", 5085 decl, DECL_TEMPLATE_RESULT (tmpl)); 5086 if (!uses_template_parms (TI_ARGS (tinfo))) 5087 inform (input_location, "use template<> for an explicit specialization"); 5088 /* Avoid crash in import_export_decl. */ 5089 DECL_INTERFACE_KNOWN (decl) = 1; 5090 return error_mark_node; 5091 } 5092 } 5093 5094 DECL_TEMPLATE_RESULT (tmpl) = decl; 5095 TREE_TYPE (tmpl) = TREE_TYPE (decl); 5096 5097 /* Push template declarations for global functions and types. Note 5098 that we do not try to push a global template friend declared in a 5099 template class; such a thing may well depend on the template 5100 parameters of the class. */ 5101 if (new_template_p && !ctx 5102 && !(is_friend && template_class_depth (current_class_type) > 0)) 5103 { 5104 tmpl = pushdecl_namespace_level (tmpl, is_friend); 5105 if (tmpl == error_mark_node) 5106 return error_mark_node; 5107 5108 /* Hide template friend classes that haven't been declared yet. */ 5109 if (is_friend && TREE_CODE (decl) == TYPE_DECL) 5110 { 5111 DECL_ANTICIPATED (tmpl) = 1; 5112 DECL_FRIEND_P (tmpl) = 1; 5113 } 5114 } 5115 5116 if (primary) 5117 { 5118 tree parms = DECL_TEMPLATE_PARMS (tmpl); 5119 int i; 5120 5121 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl; 5122 if (DECL_CONV_FN_P (tmpl)) 5123 { 5124 int depth = TMPL_PARMS_DEPTH (parms); 5125 5126 /* It is a conversion operator. See if the type converted to 5127 depends on innermost template operands. */ 5128 5129 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)), 5130 depth)) 5131 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1; 5132 } 5133 5134 /* Give template template parms a DECL_CONTEXT of the template 5135 for which they are a parameter. */ 5136 parms = INNERMOST_TEMPLATE_PARMS (parms); 5137 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i) 5138 { 5139 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i)); 5140 if (TREE_CODE (parm) == TEMPLATE_DECL) 5141 DECL_CONTEXT (parm) = tmpl; 5142 } 5143 } 5144 5145 /* The DECL_TI_ARGS of DECL contains full set of arguments referring 5146 back to its most general template. If TMPL is a specialization, 5147 ARGS may only have the innermost set of arguments. Add the missing 5148 argument levels if necessary. */ 5149 if (DECL_TEMPLATE_INFO (tmpl)) 5150 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args); 5151 5152 info = build_template_info (tmpl, args); 5153 5154 if (DECL_IMPLICIT_TYPEDEF_P (decl)) 5155 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info); 5156 else 5157 { 5158 if (primary && !DECL_LANG_SPECIFIC (decl)) 5159 retrofit_lang_decl (decl); 5160 if (DECL_LANG_SPECIFIC (decl)) 5161 DECL_TEMPLATE_INFO (decl) = info; 5162 } 5163 5164 return DECL_TEMPLATE_RESULT (tmpl); 5165 } 5166 5167 tree 5168 push_template_decl (tree decl) 5169 { 5170 return push_template_decl_real (decl, false); 5171 } 5172 5173 /* Called when a class template TYPE is redeclared with the indicated 5174 template PARMS, e.g.: 5175 5176 template <class T> struct S; 5177 template <class T> struct S {}; */ 5178 5179 bool 5180 redeclare_class_template (tree type, tree parms) 5181 { 5182 tree tmpl; 5183 tree tmpl_parms; 5184 int i; 5185 5186 if (!TYPE_TEMPLATE_INFO (type)) 5187 { 5188 error ("%qT is not a template type", type); 5189 return false; 5190 } 5191 5192 tmpl = TYPE_TI_TEMPLATE (type); 5193 if (!PRIMARY_TEMPLATE_P (tmpl)) 5194 /* The type is nested in some template class. Nothing to worry 5195 about here; there are no new template parameters for the nested 5196 type. */ 5197 return true; 5198 5199 if (!parms) 5200 { 5201 error ("template specifiers not specified in declaration of %qD", 5202 tmpl); 5203 return false; 5204 } 5205 5206 parms = INNERMOST_TEMPLATE_PARMS (parms); 5207 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl); 5208 5209 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms)) 5210 { 5211 error_n (input_location, TREE_VEC_LENGTH (parms), 5212 "redeclared with %d template parameter", 5213 "redeclared with %d template parameters", 5214 TREE_VEC_LENGTH (parms)); 5215 inform_n (input_location, TREE_VEC_LENGTH (tmpl_parms), 5216 "previous declaration %q+D used %d template parameter", 5217 "previous declaration %q+D used %d template parameters", 5218 tmpl, TREE_VEC_LENGTH (tmpl_parms)); 5219 return false; 5220 } 5221 5222 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i) 5223 { 5224 tree tmpl_parm; 5225 tree parm; 5226 tree tmpl_default; 5227 tree parm_default; 5228 5229 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node 5230 || TREE_VEC_ELT (parms, i) == error_mark_node) 5231 continue; 5232 5233 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i)); 5234 if (tmpl_parm == error_mark_node) 5235 return false; 5236 5237 parm = TREE_VALUE (TREE_VEC_ELT (parms, i)); 5238 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)); 5239 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i)); 5240 5241 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or 5242 TEMPLATE_DECL. */ 5243 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm) 5244 || (TREE_CODE (tmpl_parm) != TYPE_DECL 5245 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm))) 5246 || (TREE_CODE (tmpl_parm) != PARM_DECL 5247 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm)) 5248 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))) 5249 || (TREE_CODE (tmpl_parm) == PARM_DECL 5250 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm)) 5251 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))))) 5252 { 5253 error ("template parameter %q+#D", tmpl_parm); 5254 error ("redeclared here as %q#D", parm); 5255 return false; 5256 } 5257 5258 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE) 5259 { 5260 /* We have in [temp.param]: 5261 5262 A template-parameter may not be given default arguments 5263 by two different declarations in the same scope. */ 5264 error_at (input_location, "redefinition of default argument for %q#D", parm); 5265 inform (DECL_SOURCE_LOCATION (tmpl_parm), 5266 "original definition appeared here"); 5267 return false; 5268 } 5269 5270 if (parm_default != NULL_TREE) 5271 /* Update the previous template parameters (which are the ones 5272 that will really count) with the new default value. */ 5273 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default; 5274 else if (tmpl_default != NULL_TREE) 5275 /* Update the new parameters, too; they'll be used as the 5276 parameters for any members. */ 5277 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default; 5278 } 5279 5280 return true; 5281 } 5282 5283 /* Simplify EXPR if it is a non-dependent expression. Returns the 5284 (possibly simplified) expression. */ 5285 5286 static tree 5287 fold_non_dependent_expr_sfinae (tree expr, tsubst_flags_t complain) 5288 { 5289 if (expr == NULL_TREE) 5290 return NULL_TREE; 5291 5292 /* If we're in a template, but EXPR isn't value dependent, simplify 5293 it. We're supposed to treat: 5294 5295 template <typename T> void f(T[1 + 1]); 5296 template <typename T> void f(T[2]); 5297 5298 as two declarations of the same function, for example. */ 5299 if (processing_template_decl 5300 && !type_dependent_expression_p (expr) 5301 && potential_constant_expression (expr) 5302 && !value_dependent_expression_p (expr)) 5303 { 5304 HOST_WIDE_INT saved_processing_template_decl; 5305 5306 saved_processing_template_decl = processing_template_decl; 5307 processing_template_decl = 0; 5308 expr = tsubst_copy_and_build (expr, 5309 /*args=*/NULL_TREE, 5310 complain, 5311 /*in_decl=*/NULL_TREE, 5312 /*function_p=*/false, 5313 /*integral_constant_expression_p=*/true); 5314 processing_template_decl = saved_processing_template_decl; 5315 } 5316 return expr; 5317 } 5318 5319 tree 5320 fold_non_dependent_expr (tree expr) 5321 { 5322 return fold_non_dependent_expr_sfinae (expr, tf_error); 5323 } 5324 5325 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias 5326 template declaration, or a TYPE_DECL for an alias declaration. */ 5327 5328 bool 5329 alias_type_or_template_p (tree t) 5330 { 5331 if (t == NULL_TREE) 5332 return false; 5333 return ((TREE_CODE (t) == TYPE_DECL && TYPE_DECL_ALIAS_P (t)) 5334 || (TYPE_P (t) 5335 && TYPE_NAME (t) 5336 && TYPE_DECL_ALIAS_P (TYPE_NAME (t))) 5337 || DECL_ALIAS_TEMPLATE_P (t)); 5338 } 5339 5340 /* Return TRUE iff is a specialization of an alias template. */ 5341 5342 bool 5343 alias_template_specialization_p (tree t) 5344 { 5345 if (t == NULL_TREE) 5346 return false; 5347 return (primary_template_instantiation_p (t) 5348 && DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (t))); 5349 } 5350 5351 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which 5352 must be a function or a pointer-to-function type, as specified 5353 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set, 5354 and check that the resulting function has external linkage. */ 5355 5356 static tree 5357 convert_nontype_argument_function (tree type, tree expr) 5358 { 5359 tree fns = expr; 5360 tree fn, fn_no_ptr; 5361 linkage_kind linkage; 5362 5363 fn = instantiate_type (type, fns, tf_none); 5364 if (fn == error_mark_node) 5365 return error_mark_node; 5366 5367 fn_no_ptr = fn; 5368 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR) 5369 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0); 5370 if (BASELINK_P (fn_no_ptr)) 5371 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr); 5372 5373 /* [temp.arg.nontype]/1 5374 5375 A template-argument for a non-type, non-template template-parameter 5376 shall be one of: 5377 [...] 5378 -- the address of an object or function with external [C++11: or 5379 internal] linkage. */ 5380 linkage = decl_linkage (fn_no_ptr); 5381 if (cxx_dialect >= cxx0x ? linkage == lk_none : linkage != lk_external) 5382 { 5383 if (cxx_dialect >= cxx0x) 5384 error ("%qE is not a valid template argument for type %qT " 5385 "because %qD has no linkage", 5386 expr, type, fn_no_ptr); 5387 else 5388 error ("%qE is not a valid template argument for type %qT " 5389 "because %qD does not have external linkage", 5390 expr, type, fn_no_ptr); 5391 return NULL_TREE; 5392 } 5393 5394 return fn; 5395 } 5396 5397 /* Subroutine of convert_nontype_argument. 5398 Check if EXPR of type TYPE is a valid pointer-to-member constant. 5399 Emit an error otherwise. */ 5400 5401 static bool 5402 check_valid_ptrmem_cst_expr (tree type, tree expr, 5403 tsubst_flags_t complain) 5404 { 5405 STRIP_NOPS (expr); 5406 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST)) 5407 return true; 5408 if (cxx_dialect >= cxx0x && null_member_pointer_value_p (expr)) 5409 return true; 5410 if (complain & tf_error) 5411 { 5412 error ("%qE is not a valid template argument for type %qT", 5413 expr, type); 5414 error ("it must be a pointer-to-member of the form %<&X::Y%>"); 5415 } 5416 return false; 5417 } 5418 5419 /* Returns TRUE iff the address of OP is value-dependent. 5420 5421 14.6.2.4 [temp.dep.temp]: 5422 A non-integral non-type template-argument is dependent if its type is 5423 dependent or it has either of the following forms 5424 qualified-id 5425 & qualified-id 5426 and contains a nested-name-specifier which specifies a class-name that 5427 names a dependent type. 5428 5429 We generalize this to just say that the address of a member of a 5430 dependent class is value-dependent; the above doesn't cover the 5431 address of a static data member named with an unqualified-id. */ 5432 5433 static bool 5434 has_value_dependent_address (tree op) 5435 { 5436 /* We could use get_inner_reference here, but there's no need; 5437 this is only relevant for template non-type arguments, which 5438 can only be expressed as &id-expression. */ 5439 if (DECL_P (op)) 5440 { 5441 tree ctx = CP_DECL_CONTEXT (op); 5442 if (TYPE_P (ctx) && dependent_type_p (ctx)) 5443 return true; 5444 } 5445 5446 return false; 5447 } 5448 5449 /* The next set of functions are used for providing helpful explanatory 5450 diagnostics for failed overload resolution. Their messages should be 5451 indented by two spaces for consistency with the messages in 5452 call.c */ 5453 5454 static int 5455 unify_success (bool explain_p ATTRIBUTE_UNUSED) 5456 { 5457 return 0; 5458 } 5459 5460 static int 5461 unify_parameter_deduction_failure (bool explain_p, tree parm) 5462 { 5463 if (explain_p) 5464 inform (input_location, 5465 " couldn't deduce template parameter %qD", parm); 5466 return 1; 5467 } 5468 5469 static int 5470 unify_invalid (bool explain_p ATTRIBUTE_UNUSED) 5471 { 5472 return 1; 5473 } 5474 5475 static int 5476 unify_cv_qual_mismatch (bool explain_p, tree parm, tree arg) 5477 { 5478 if (explain_p) 5479 inform (input_location, 5480 " types %qT and %qT have incompatible cv-qualifiers", 5481 parm, arg); 5482 return 1; 5483 } 5484 5485 static int 5486 unify_type_mismatch (bool explain_p, tree parm, tree arg) 5487 { 5488 if (explain_p) 5489 inform (input_location, " mismatched types %qT and %qT", parm, arg); 5490 return 1; 5491 } 5492 5493 static int 5494 unify_parameter_pack_mismatch (bool explain_p, tree parm, tree arg) 5495 { 5496 if (explain_p) 5497 inform (input_location, 5498 " template parameter %qD is not a parameter pack, but " 5499 "argument %qD is", 5500 parm, arg); 5501 return 1; 5502 } 5503 5504 static int 5505 unify_ptrmem_cst_mismatch (bool explain_p, tree parm, tree arg) 5506 { 5507 if (explain_p) 5508 inform (input_location, 5509 " template argument %qE does not match " 5510 "pointer-to-member constant %qE", 5511 arg, parm); 5512 return 1; 5513 } 5514 5515 static int 5516 unify_expression_unequal (bool explain_p, tree parm, tree arg) 5517 { 5518 if (explain_p) 5519 inform (input_location, " %qE is not equivalent to %qE", parm, arg); 5520 return 1; 5521 } 5522 5523 static int 5524 unify_parameter_pack_inconsistent (bool explain_p, tree old_arg, tree new_arg) 5525 { 5526 if (explain_p) 5527 inform (input_location, 5528 " inconsistent parameter pack deduction with %qT and %qT", 5529 old_arg, new_arg); 5530 return 1; 5531 } 5532 5533 static int 5534 unify_inconsistency (bool explain_p, tree parm, tree first, tree second) 5535 { 5536 if (explain_p) 5537 { 5538 if (TYPE_P (parm)) 5539 inform (input_location, 5540 " deduced conflicting types for parameter %qT (%qT and %qT)", 5541 parm, first, second); 5542 else 5543 inform (input_location, 5544 " deduced conflicting values for non-type parameter " 5545 "%qE (%qE and %qE)", parm, first, second); 5546 } 5547 return 1; 5548 } 5549 5550 static int 5551 unify_vla_arg (bool explain_p, tree arg) 5552 { 5553 if (explain_p) 5554 inform (input_location, 5555 " variable-sized array type %qT is not " 5556 "a valid template argument", 5557 arg); 5558 return 1; 5559 } 5560 5561 static int 5562 unify_method_type_error (bool explain_p, tree arg) 5563 { 5564 if (explain_p) 5565 inform (input_location, 5566 " member function type %qT is not a valid template argument", 5567 arg); 5568 return 1; 5569 } 5570 5571 static int 5572 unify_arity (bool explain_p, int have, int wanted) 5573 { 5574 if (explain_p) 5575 inform_n (input_location, wanted, 5576 " candidate expects %d argument, %d provided", 5577 " candidate expects %d arguments, %d provided", 5578 wanted, have); 5579 return 1; 5580 } 5581 5582 static int 5583 unify_too_many_arguments (bool explain_p, int have, int wanted) 5584 { 5585 return unify_arity (explain_p, have, wanted); 5586 } 5587 5588 static int 5589 unify_too_few_arguments (bool explain_p, int have, int wanted) 5590 { 5591 return unify_arity (explain_p, have, wanted); 5592 } 5593 5594 static int 5595 unify_arg_conversion (bool explain_p, tree to_type, 5596 tree from_type, tree arg) 5597 { 5598 if (explain_p) 5599 inform (input_location, " cannot convert %qE (type %qT) to type %qT", 5600 arg, from_type, to_type); 5601 return 1; 5602 } 5603 5604 static int 5605 unify_no_common_base (bool explain_p, enum template_base_result r, 5606 tree parm, tree arg) 5607 { 5608 if (explain_p) 5609 switch (r) 5610 { 5611 case tbr_ambiguous_baseclass: 5612 inform (input_location, " %qT is an ambiguous base class of %qT", 5613 arg, parm); 5614 break; 5615 default: 5616 inform (input_location, " %qT is not derived from %qT", arg, parm); 5617 break; 5618 } 5619 return 1; 5620 } 5621 5622 static int 5623 unify_inconsistent_template_template_parameters (bool explain_p) 5624 { 5625 if (explain_p) 5626 inform (input_location, 5627 " template parameters of a template template argument are " 5628 "inconsistent with other deduced template arguments"); 5629 return 1; 5630 } 5631 5632 static int 5633 unify_template_deduction_failure (bool explain_p, tree parm, tree arg) 5634 { 5635 if (explain_p) 5636 inform (input_location, 5637 " can't deduce a template for %qT from non-template type %qT", 5638 parm, arg); 5639 return 1; 5640 } 5641 5642 static int 5643 unify_template_argument_mismatch (bool explain_p, tree parm, tree arg) 5644 { 5645 if (explain_p) 5646 inform (input_location, 5647 " template argument %qE does not match %qD", arg, parm); 5648 return 1; 5649 } 5650 5651 static int 5652 unify_overload_resolution_failure (bool explain_p, tree arg) 5653 { 5654 if (explain_p) 5655 inform (input_location, 5656 " could not resolve address from overloaded function %qE", 5657 arg); 5658 return 1; 5659 } 5660 5661 /* Attempt to convert the non-type template parameter EXPR to the 5662 indicated TYPE. If the conversion is successful, return the 5663 converted value. If the conversion is unsuccessful, return 5664 NULL_TREE if we issued an error message, or error_mark_node if we 5665 did not. We issue error messages for out-and-out bad template 5666 parameters, but not simply because the conversion failed, since we 5667 might be just trying to do argument deduction. Both TYPE and EXPR 5668 must be non-dependent. 5669 5670 The conversion follows the special rules described in 5671 [temp.arg.nontype], and it is much more strict than an implicit 5672 conversion. 5673 5674 This function is called twice for each template argument (see 5675 lookup_template_class for a more accurate description of this 5676 problem). This means that we need to handle expressions which 5677 are not valid in a C++ source, but can be created from the 5678 first call (for instance, casts to perform conversions). These 5679 hacks can go away after we fix the double coercion problem. */ 5680 5681 static tree 5682 convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain) 5683 { 5684 tree expr_type; 5685 5686 /* Detect immediately string literals as invalid non-type argument. 5687 This special-case is not needed for correctness (we would easily 5688 catch this later), but only to provide better diagnostic for this 5689 common user mistake. As suggested by DR 100, we do not mention 5690 linkage issues in the diagnostic as this is not the point. */ 5691 /* FIXME we're making this OK. */ 5692 if (TREE_CODE (expr) == STRING_CST) 5693 { 5694 if (complain & tf_error) 5695 error ("%qE is not a valid template argument for type %qT " 5696 "because string literals can never be used in this context", 5697 expr, type); 5698 return NULL_TREE; 5699 } 5700 5701 /* Add the ADDR_EXPR now for the benefit of 5702 value_dependent_expression_p. */ 5703 if (TYPE_PTROBV_P (type) 5704 && TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE) 5705 expr = decay_conversion (expr); 5706 5707 /* If we are in a template, EXPR may be non-dependent, but still 5708 have a syntactic, rather than semantic, form. For example, EXPR 5709 might be a SCOPE_REF, rather than the VAR_DECL to which the 5710 SCOPE_REF refers. Preserving the qualifying scope is necessary 5711 so that access checking can be performed when the template is 5712 instantiated -- but here we need the resolved form so that we can 5713 convert the argument. */ 5714 if (TYPE_REF_OBJ_P (type) 5715 && has_value_dependent_address (expr)) 5716 /* If we want the address and it's value-dependent, don't fold. */; 5717 else if (!type_unknown_p (expr)) 5718 expr = fold_non_dependent_expr_sfinae (expr, complain); 5719 if (error_operand_p (expr)) 5720 return error_mark_node; 5721 expr_type = TREE_TYPE (expr); 5722 if (TREE_CODE (type) == REFERENCE_TYPE) 5723 expr = mark_lvalue_use (expr); 5724 else 5725 expr = mark_rvalue_use (expr); 5726 5727 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied 5728 to a non-type argument of "nullptr". */ 5729 if (expr == nullptr_node 5730 && (TYPE_PTR_P (type) || TYPE_PTR_TO_MEMBER_P (type))) 5731 expr = convert (type, expr); 5732 5733 /* In C++11, integral or enumeration non-type template arguments can be 5734 arbitrary constant expressions. Pointer and pointer to 5735 member arguments can be general constant expressions that evaluate 5736 to a null value, but otherwise still need to be of a specific form. */ 5737 if (cxx_dialect >= cxx0x) 5738 { 5739 if (TREE_CODE (expr) == PTRMEM_CST) 5740 /* A PTRMEM_CST is already constant, and a valid template 5741 argument for a parameter of pointer to member type, we just want 5742 to leave it in that form rather than lower it to a 5743 CONSTRUCTOR. */; 5744 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type)) 5745 expr = maybe_constant_value (expr); 5746 else if (TYPE_PTR_P (type) 5747 || TYPE_PTR_TO_MEMBER_P (type)) 5748 { 5749 tree folded = maybe_constant_value (expr); 5750 if (TYPE_PTR_P (type) ? integer_zerop (folded) 5751 : null_member_pointer_value_p (folded)) 5752 expr = folded; 5753 } 5754 } 5755 5756 /* HACK: Due to double coercion, we can get a 5757 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here, 5758 which is the tree that we built on the first call (see 5759 below when coercing to reference to object or to reference to 5760 function). We just strip everything and get to the arg. 5761 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C 5762 for examples. */ 5763 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type)) 5764 { 5765 tree probe_type, probe = expr; 5766 if (REFERENCE_REF_P (probe)) 5767 probe = TREE_OPERAND (probe, 0); 5768 probe_type = TREE_TYPE (probe); 5769 if (TREE_CODE (probe) == NOP_EXPR) 5770 { 5771 /* ??? Maybe we could use convert_from_reference here, but we 5772 would need to relax its constraints because the NOP_EXPR 5773 could actually change the type to something more cv-qualified, 5774 and this is not folded by convert_from_reference. */ 5775 tree addr = TREE_OPERAND (probe, 0); 5776 gcc_assert (TREE_CODE (probe_type) == REFERENCE_TYPE); 5777 gcc_assert (TREE_CODE (addr) == ADDR_EXPR); 5778 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE); 5779 gcc_assert (same_type_ignoring_top_level_qualifiers_p 5780 (TREE_TYPE (probe_type), 5781 TREE_TYPE (TREE_TYPE (addr)))); 5782 5783 expr = TREE_OPERAND (addr, 0); 5784 expr_type = TREE_TYPE (expr); 5785 } 5786 } 5787 5788 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the 5789 parameter is a pointer to object, through decay and 5790 qualification conversion. Let's strip everything. */ 5791 else if (TREE_CODE (expr) == NOP_EXPR && TYPE_PTROBV_P (type)) 5792 { 5793 STRIP_NOPS (expr); 5794 gcc_assert (TREE_CODE (expr) == ADDR_EXPR); 5795 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE); 5796 /* Skip the ADDR_EXPR only if it is part of the decay for 5797 an array. Otherwise, it is part of the original argument 5798 in the source code. */ 5799 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE) 5800 expr = TREE_OPERAND (expr, 0); 5801 expr_type = TREE_TYPE (expr); 5802 } 5803 5804 /* [temp.arg.nontype]/5, bullet 1 5805 5806 For a non-type template-parameter of integral or enumeration type, 5807 integral promotions (_conv.prom_) and integral conversions 5808 (_conv.integral_) are applied. */ 5809 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type)) 5810 { 5811 tree t = build_integral_nontype_arg_conv (type, expr, complain); 5812 t = maybe_constant_value (t); 5813 if (t != error_mark_node) 5814 expr = t; 5815 5816 if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr))) 5817 return error_mark_node; 5818 5819 /* Notice that there are constant expressions like '4 % 0' which 5820 do not fold into integer constants. */ 5821 if (TREE_CODE (expr) != INTEGER_CST) 5822 { 5823 if (complain & tf_error) 5824 { 5825 int errs = errorcount, warns = warningcount; 5826 if (processing_template_decl 5827 && !require_potential_constant_expression (expr)) 5828 return NULL_TREE; 5829 expr = cxx_constant_value (expr); 5830 if (errorcount > errs || warningcount > warns) 5831 inform (EXPR_LOC_OR_HERE (expr), 5832 "in template argument for type %qT ", type); 5833 if (expr == error_mark_node) 5834 return NULL_TREE; 5835 /* else cxx_constant_value complained but gave us 5836 a real constant, so go ahead. */ 5837 gcc_assert (TREE_CODE (expr) == INTEGER_CST); 5838 } 5839 else 5840 return NULL_TREE; 5841 } 5842 } 5843 /* [temp.arg.nontype]/5, bullet 2 5844 5845 For a non-type template-parameter of type pointer to object, 5846 qualification conversions (_conv.qual_) and the array-to-pointer 5847 conversion (_conv.array_) are applied. */ 5848 else if (TYPE_PTROBV_P (type)) 5849 { 5850 /* [temp.arg.nontype]/1 (TC1 version, DR 49): 5851 5852 A template-argument for a non-type, non-template template-parameter 5853 shall be one of: [...] 5854 5855 -- the name of a non-type template-parameter; 5856 -- the address of an object or function with external linkage, [...] 5857 expressed as "& id-expression" where the & is optional if the name 5858 refers to a function or array, or if the corresponding 5859 template-parameter is a reference. 5860 5861 Here, we do not care about functions, as they are invalid anyway 5862 for a parameter of type pointer-to-object. */ 5863 5864 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr)) 5865 /* Non-type template parameters are OK. */ 5866 ; 5867 else if (cxx_dialect >= cxx0x && integer_zerop (expr)) 5868 /* Null pointer values are OK in C++11. */; 5869 else if (TREE_CODE (expr) != ADDR_EXPR 5870 && TREE_CODE (expr_type) != ARRAY_TYPE) 5871 { 5872 if (TREE_CODE (expr) == VAR_DECL) 5873 { 5874 error ("%qD is not a valid template argument " 5875 "because %qD is a variable, not the address of " 5876 "a variable", 5877 expr, expr); 5878 return NULL_TREE; 5879 } 5880 /* Other values, like integer constants, might be valid 5881 non-type arguments of some other type. */ 5882 return error_mark_node; 5883 } 5884 else 5885 { 5886 tree decl; 5887 5888 decl = ((TREE_CODE (expr) == ADDR_EXPR) 5889 ? TREE_OPERAND (expr, 0) : expr); 5890 if (TREE_CODE (decl) != VAR_DECL) 5891 { 5892 error ("%qE is not a valid template argument of type %qT " 5893 "because %qE is not a variable", 5894 expr, type, decl); 5895 return NULL_TREE; 5896 } 5897 else if (cxx_dialect < cxx0x && !DECL_EXTERNAL_LINKAGE_P (decl)) 5898 { 5899 error ("%qE is not a valid template argument of type %qT " 5900 "because %qD does not have external linkage", 5901 expr, type, decl); 5902 return NULL_TREE; 5903 } 5904 else if (cxx_dialect >= cxx0x && decl_linkage (decl) == lk_none) 5905 { 5906 error ("%qE is not a valid template argument of type %qT " 5907 "because %qD has no linkage", 5908 expr, type, decl); 5909 return NULL_TREE; 5910 } 5911 } 5912 5913 expr = decay_conversion (expr); 5914 if (expr == error_mark_node) 5915 return error_mark_node; 5916 5917 expr = perform_qualification_conversions (type, expr); 5918 if (expr == error_mark_node) 5919 return error_mark_node; 5920 } 5921 /* [temp.arg.nontype]/5, bullet 3 5922 5923 For a non-type template-parameter of type reference to object, no 5924 conversions apply. The type referred to by the reference may be more 5925 cv-qualified than the (otherwise identical) type of the 5926 template-argument. The template-parameter is bound directly to the 5927 template-argument, which must be an lvalue. */ 5928 else if (TYPE_REF_OBJ_P (type)) 5929 { 5930 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type), 5931 expr_type)) 5932 return error_mark_node; 5933 5934 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type)) 5935 { 5936 error ("%qE is not a valid template argument for type %qT " 5937 "because of conflicts in cv-qualification", expr, type); 5938 return NULL_TREE; 5939 } 5940 5941 if (!real_lvalue_p (expr)) 5942 { 5943 error ("%qE is not a valid template argument for type %qT " 5944 "because it is not an lvalue", expr, type); 5945 return NULL_TREE; 5946 } 5947 5948 /* [temp.arg.nontype]/1 5949 5950 A template-argument for a non-type, non-template template-parameter 5951 shall be one of: [...] 5952 5953 -- the address of an object or function with external linkage. */ 5954 if (TREE_CODE (expr) == INDIRECT_REF 5955 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0)))) 5956 { 5957 expr = TREE_OPERAND (expr, 0); 5958 if (DECL_P (expr)) 5959 { 5960 error ("%q#D is not a valid template argument for type %qT " 5961 "because a reference variable does not have a constant " 5962 "address", expr, type); 5963 return NULL_TREE; 5964 } 5965 } 5966 5967 if (!DECL_P (expr)) 5968 { 5969 error ("%qE is not a valid template argument for type %qT " 5970 "because it is not an object with external linkage", 5971 expr, type); 5972 return NULL_TREE; 5973 } 5974 5975 if (!DECL_EXTERNAL_LINKAGE_P (expr)) 5976 { 5977 error ("%qE is not a valid template argument for type %qT " 5978 "because object %qD has not external linkage", 5979 expr, type, expr); 5980 return NULL_TREE; 5981 } 5982 5983 expr = build_nop (type, build_address (expr)); 5984 } 5985 /* [temp.arg.nontype]/5, bullet 4 5986 5987 For a non-type template-parameter of type pointer to function, only 5988 the function-to-pointer conversion (_conv.func_) is applied. If the 5989 template-argument represents a set of overloaded functions (or a 5990 pointer to such), the matching function is selected from the set 5991 (_over.over_). */ 5992 else if (TYPE_PTRFN_P (type)) 5993 { 5994 /* If the argument is a template-id, we might not have enough 5995 context information to decay the pointer. */ 5996 if (!type_unknown_p (expr_type)) 5997 { 5998 expr = decay_conversion (expr); 5999 if (expr == error_mark_node) 6000 return error_mark_node; 6001 } 6002 6003 if (cxx_dialect >= cxx0x && integer_zerop (expr)) 6004 /* Null pointer values are OK in C++11. */ 6005 return perform_qualification_conversions (type, expr); 6006 6007 expr = convert_nontype_argument_function (type, expr); 6008 if (!expr || expr == error_mark_node) 6009 return expr; 6010 6011 if (TREE_CODE (expr) != ADDR_EXPR) 6012 { 6013 error ("%qE is not a valid template argument for type %qT", expr, type); 6014 error ("it must be the address of a function with external linkage"); 6015 return NULL_TREE; 6016 } 6017 } 6018 /* [temp.arg.nontype]/5, bullet 5 6019 6020 For a non-type template-parameter of type reference to function, no 6021 conversions apply. If the template-argument represents a set of 6022 overloaded functions, the matching function is selected from the set 6023 (_over.over_). */ 6024 else if (TYPE_REFFN_P (type)) 6025 { 6026 if (TREE_CODE (expr) == ADDR_EXPR) 6027 { 6028 error ("%qE is not a valid template argument for type %qT " 6029 "because it is a pointer", expr, type); 6030 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0)); 6031 return NULL_TREE; 6032 } 6033 6034 expr = convert_nontype_argument_function (TREE_TYPE (type), expr); 6035 if (!expr || expr == error_mark_node) 6036 return expr; 6037 6038 expr = build_nop (type, build_address (expr)); 6039 } 6040 /* [temp.arg.nontype]/5, bullet 6 6041 6042 For a non-type template-parameter of type pointer to member function, 6043 no conversions apply. If the template-argument represents a set of 6044 overloaded member functions, the matching member function is selected 6045 from the set (_over.over_). */ 6046 else if (TYPE_PTRMEMFUNC_P (type)) 6047 { 6048 expr = instantiate_type (type, expr, tf_none); 6049 if (expr == error_mark_node) 6050 return error_mark_node; 6051 6052 /* [temp.arg.nontype] bullet 1 says the pointer to member 6053 expression must be a pointer-to-member constant. */ 6054 if (!check_valid_ptrmem_cst_expr (type, expr, complain)) 6055 return error_mark_node; 6056 6057 /* There is no way to disable standard conversions in 6058 resolve_address_of_overloaded_function (called by 6059 instantiate_type). It is possible that the call succeeded by 6060 converting &B::I to &D::I (where B is a base of D), so we need 6061 to reject this conversion here. 6062 6063 Actually, even if there was a way to disable standard conversions, 6064 it would still be better to reject them here so that we can 6065 provide a superior diagnostic. */ 6066 if (!same_type_p (TREE_TYPE (expr), type)) 6067 { 6068 error ("%qE is not a valid template argument for type %qT " 6069 "because it is of type %qT", expr, type, 6070 TREE_TYPE (expr)); 6071 /* If we are just one standard conversion off, explain. */ 6072 if (can_convert (type, TREE_TYPE (expr))) 6073 inform (input_location, 6074 "standard conversions are not allowed in this context"); 6075 return NULL_TREE; 6076 } 6077 } 6078 /* [temp.arg.nontype]/5, bullet 7 6079 6080 For a non-type template-parameter of type pointer to data member, 6081 qualification conversions (_conv.qual_) are applied. */ 6082 else if (TYPE_PTRMEM_P (type)) 6083 { 6084 /* [temp.arg.nontype] bullet 1 says the pointer to member 6085 expression must be a pointer-to-member constant. */ 6086 if (!check_valid_ptrmem_cst_expr (type, expr, complain)) 6087 return error_mark_node; 6088 6089 expr = perform_qualification_conversions (type, expr); 6090 if (expr == error_mark_node) 6091 return expr; 6092 } 6093 else if (NULLPTR_TYPE_P (type)) 6094 { 6095 if (expr != nullptr_node) 6096 { 6097 error ("%qE is not a valid template argument for type %qT " 6098 "because it is of type %qT", expr, type, TREE_TYPE (expr)); 6099 return NULL_TREE; 6100 } 6101 return expr; 6102 } 6103 /* A template non-type parameter must be one of the above. */ 6104 else 6105 gcc_unreachable (); 6106 6107 /* Sanity check: did we actually convert the argument to the 6108 right type? */ 6109 gcc_assert (same_type_ignoring_top_level_qualifiers_p 6110 (type, TREE_TYPE (expr))); 6111 return expr; 6112 } 6113 6114 /* Subroutine of coerce_template_template_parms, which returns 1 if 6115 PARM_PARM and ARG_PARM match using the rule for the template 6116 parameters of template template parameters. Both PARM and ARG are 6117 template parameters; the rest of the arguments are the same as for 6118 coerce_template_template_parms. 6119 */ 6120 static int 6121 coerce_template_template_parm (tree parm, 6122 tree arg, 6123 tsubst_flags_t complain, 6124 tree in_decl, 6125 tree outer_args) 6126 { 6127 if (arg == NULL_TREE || arg == error_mark_node 6128 || parm == NULL_TREE || parm == error_mark_node) 6129 return 0; 6130 6131 if (TREE_CODE (arg) != TREE_CODE (parm)) 6132 return 0; 6133 6134 switch (TREE_CODE (parm)) 6135 { 6136 case TEMPLATE_DECL: 6137 /* We encounter instantiations of templates like 6138 template <template <template <class> class> class TT> 6139 class C; */ 6140 { 6141 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm); 6142 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg); 6143 6144 if (!coerce_template_template_parms 6145 (parmparm, argparm, complain, in_decl, outer_args)) 6146 return 0; 6147 } 6148 /* Fall through. */ 6149 6150 case TYPE_DECL: 6151 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg)) 6152 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))) 6153 /* Argument is a parameter pack but parameter is not. */ 6154 return 0; 6155 break; 6156 6157 case PARM_DECL: 6158 /* The tsubst call is used to handle cases such as 6159 6160 template <int> class C {}; 6161 template <class T, template <T> class TT> class D {}; 6162 D<int, C> d; 6163 6164 i.e. the parameter list of TT depends on earlier parameters. */ 6165 if (!uses_template_parms (TREE_TYPE (arg)) 6166 && !same_type_p 6167 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl), 6168 TREE_TYPE (arg))) 6169 return 0; 6170 6171 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg)) 6172 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))) 6173 /* Argument is a parameter pack but parameter is not. */ 6174 return 0; 6175 6176 break; 6177 6178 default: 6179 gcc_unreachable (); 6180 } 6181 6182 return 1; 6183 } 6184 6185 6186 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for 6187 template template parameters. Both PARM_PARMS and ARG_PARMS are 6188 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL 6189 or PARM_DECL. 6190 6191 Consider the example: 6192 template <class T> class A; 6193 template<template <class U> class TT> class B; 6194 6195 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are 6196 the parameters to A, and OUTER_ARGS contains A. */ 6197 6198 static int 6199 coerce_template_template_parms (tree parm_parms, 6200 tree arg_parms, 6201 tsubst_flags_t complain, 6202 tree in_decl, 6203 tree outer_args) 6204 { 6205 int nparms, nargs, i; 6206 tree parm, arg; 6207 int variadic_p = 0; 6208 6209 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC); 6210 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC); 6211 6212 nparms = TREE_VEC_LENGTH (parm_parms); 6213 nargs = TREE_VEC_LENGTH (arg_parms); 6214 6215 /* Determine whether we have a parameter pack at the end of the 6216 template template parameter's template parameter list. */ 6217 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node) 6218 { 6219 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1)); 6220 6221 if (parm == error_mark_node) 6222 return 0; 6223 6224 switch (TREE_CODE (parm)) 6225 { 6226 case TEMPLATE_DECL: 6227 case TYPE_DECL: 6228 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))) 6229 variadic_p = 1; 6230 break; 6231 6232 case PARM_DECL: 6233 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))) 6234 variadic_p = 1; 6235 break; 6236 6237 default: 6238 gcc_unreachable (); 6239 } 6240 } 6241 6242 if (nargs != nparms 6243 && !(variadic_p && nargs >= nparms - 1)) 6244 return 0; 6245 6246 /* Check all of the template parameters except the parameter pack at 6247 the end (if any). */ 6248 for (i = 0; i < nparms - variadic_p; ++i) 6249 { 6250 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node 6251 || TREE_VEC_ELT (arg_parms, i) == error_mark_node) 6252 continue; 6253 6254 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i)); 6255 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i)); 6256 6257 if (!coerce_template_template_parm (parm, arg, complain, in_decl, 6258 outer_args)) 6259 return 0; 6260 6261 } 6262 6263 if (variadic_p) 6264 { 6265 /* Check each of the template parameters in the template 6266 argument against the template parameter pack at the end of 6267 the template template parameter. */ 6268 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node) 6269 return 0; 6270 6271 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i)); 6272 6273 for (; i < nargs; ++i) 6274 { 6275 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node) 6276 continue; 6277 6278 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i)); 6279 6280 if (!coerce_template_template_parm (parm, arg, complain, in_decl, 6281 outer_args)) 6282 return 0; 6283 } 6284 } 6285 6286 return 1; 6287 } 6288 6289 /* Verifies that the deduced template arguments (in TARGS) for the 6290 template template parameters (in TPARMS) represent valid bindings, 6291 by comparing the template parameter list of each template argument 6292 to the template parameter list of its corresponding template 6293 template parameter, in accordance with DR150. This 6294 routine can only be called after all template arguments have been 6295 deduced. It will return TRUE if all of the template template 6296 parameter bindings are okay, FALSE otherwise. */ 6297 bool 6298 template_template_parm_bindings_ok_p (tree tparms, tree targs) 6299 { 6300 int i, ntparms = TREE_VEC_LENGTH (tparms); 6301 bool ret = true; 6302 6303 /* We're dealing with template parms in this process. */ 6304 ++processing_template_decl; 6305 6306 targs = INNERMOST_TEMPLATE_ARGS (targs); 6307 6308 for (i = 0; i < ntparms; ++i) 6309 { 6310 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i)); 6311 tree targ = TREE_VEC_ELT (targs, i); 6312 6313 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ) 6314 { 6315 tree packed_args = NULL_TREE; 6316 int idx, len = 1; 6317 6318 if (ARGUMENT_PACK_P (targ)) 6319 { 6320 /* Look inside the argument pack. */ 6321 packed_args = ARGUMENT_PACK_ARGS (targ); 6322 len = TREE_VEC_LENGTH (packed_args); 6323 } 6324 6325 for (idx = 0; idx < len; ++idx) 6326 { 6327 tree targ_parms = NULL_TREE; 6328 6329 if (packed_args) 6330 /* Extract the next argument from the argument 6331 pack. */ 6332 targ = TREE_VEC_ELT (packed_args, idx); 6333 6334 if (PACK_EXPANSION_P (targ)) 6335 /* Look at the pattern of the pack expansion. */ 6336 targ = PACK_EXPANSION_PATTERN (targ); 6337 6338 /* Extract the template parameters from the template 6339 argument. */ 6340 if (TREE_CODE (targ) == TEMPLATE_DECL) 6341 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ); 6342 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM) 6343 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ)); 6344 6345 /* Verify that we can coerce the template template 6346 parameters from the template argument to the template 6347 parameter. This requires an exact match. */ 6348 if (targ_parms 6349 && !coerce_template_template_parms 6350 (DECL_INNERMOST_TEMPLATE_PARMS (tparm), 6351 targ_parms, 6352 tf_none, 6353 tparm, 6354 targs)) 6355 { 6356 ret = false; 6357 goto out; 6358 } 6359 } 6360 } 6361 } 6362 6363 out: 6364 6365 --processing_template_decl; 6366 return ret; 6367 } 6368 6369 /* Since type attributes aren't mangled, we need to strip them from 6370 template type arguments. */ 6371 6372 static tree 6373 canonicalize_type_argument (tree arg, tsubst_flags_t complain) 6374 { 6375 tree mv; 6376 if (!arg || arg == error_mark_node || arg == TYPE_CANONICAL (arg)) 6377 return arg; 6378 mv = TYPE_MAIN_VARIANT (arg); 6379 arg = strip_typedefs (arg); 6380 if (TYPE_ALIGN (arg) != TYPE_ALIGN (mv) 6381 || TYPE_ATTRIBUTES (arg) != TYPE_ATTRIBUTES (mv)) 6382 { 6383 if (complain & tf_warning) 6384 warning (0, "ignoring attributes on template argument %qT", arg); 6385 arg = build_aligned_type (arg, TYPE_ALIGN (mv)); 6386 arg = cp_build_type_attribute_variant (arg, TYPE_ATTRIBUTES (mv)); 6387 } 6388 return arg; 6389 } 6390 6391 /* Convert the indicated template ARG as necessary to match the 6392 indicated template PARM. Returns the converted ARG, or 6393 error_mark_node if the conversion was unsuccessful. Error and 6394 warning messages are issued under control of COMPLAIN. This 6395 conversion is for the Ith parameter in the parameter list. ARGS is 6396 the full set of template arguments deduced so far. */ 6397 6398 static tree 6399 convert_template_argument (tree parm, 6400 tree arg, 6401 tree args, 6402 tsubst_flags_t complain, 6403 int i, 6404 tree in_decl) 6405 { 6406 tree orig_arg; 6407 tree val; 6408 int is_type, requires_type, is_tmpl_type, requires_tmpl_type; 6409 6410 if (TREE_CODE (arg) == TREE_LIST 6411 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF) 6412 { 6413 /* The template argument was the name of some 6414 member function. That's usually 6415 invalid, but static members are OK. In any 6416 case, grab the underlying fields/functions 6417 and issue an error later if required. */ 6418 orig_arg = TREE_VALUE (arg); 6419 TREE_TYPE (arg) = unknown_type_node; 6420 } 6421 6422 orig_arg = arg; 6423 6424 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL; 6425 requires_type = (TREE_CODE (parm) == TYPE_DECL 6426 || requires_tmpl_type); 6427 6428 /* When determining whether an argument pack expansion is a template, 6429 look at the pattern. */ 6430 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION) 6431 arg = PACK_EXPANSION_PATTERN (arg); 6432 6433 /* Deal with an injected-class-name used as a template template arg. */ 6434 if (requires_tmpl_type && CLASS_TYPE_P (arg)) 6435 { 6436 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg)); 6437 if (TREE_CODE (t) == TEMPLATE_DECL) 6438 { 6439 if (cxx_dialect >= cxx0x) 6440 /* OK under DR 1004. */; 6441 else if (complain & tf_warning_or_error) 6442 pedwarn (input_location, OPT_pedantic, "injected-class-name %qD" 6443 " used as template template argument", TYPE_NAME (arg)); 6444 else if (flag_pedantic_errors) 6445 t = arg; 6446 6447 arg = t; 6448 } 6449 } 6450 6451 is_tmpl_type = 6452 ((TREE_CODE (arg) == TEMPLATE_DECL 6453 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL) 6454 || (requires_tmpl_type && TREE_CODE (arg) == TYPE_ARGUMENT_PACK) 6455 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM 6456 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE); 6457 6458 if (is_tmpl_type 6459 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM 6460 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE)) 6461 arg = TYPE_STUB_DECL (arg); 6462 6463 is_type = TYPE_P (arg) || is_tmpl_type; 6464 6465 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF 6466 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM) 6467 { 6468 if (TREE_CODE (TREE_OPERAND (arg, 1)) == BIT_NOT_EXPR) 6469 { 6470 if (complain & tf_error) 6471 error ("invalid use of destructor %qE as a type", orig_arg); 6472 return error_mark_node; 6473 } 6474 6475 permerror (input_location, 6476 "to refer to a type member of a template parameter, " 6477 "use %<typename %E%>", orig_arg); 6478 6479 orig_arg = make_typename_type (TREE_OPERAND (arg, 0), 6480 TREE_OPERAND (arg, 1), 6481 typename_type, 6482 complain & tf_error); 6483 arg = orig_arg; 6484 is_type = 1; 6485 } 6486 if (is_type != requires_type) 6487 { 6488 if (in_decl) 6489 { 6490 if (complain & tf_error) 6491 { 6492 error ("type/value mismatch at argument %d in template " 6493 "parameter list for %qD", 6494 i + 1, in_decl); 6495 if (is_type) 6496 error (" expected a constant of type %qT, got %qT", 6497 TREE_TYPE (parm), 6498 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg)); 6499 else if (requires_tmpl_type) 6500 error (" expected a class template, got %qE", orig_arg); 6501 else 6502 error (" expected a type, got %qE", orig_arg); 6503 } 6504 } 6505 return error_mark_node; 6506 } 6507 if (is_tmpl_type ^ requires_tmpl_type) 6508 { 6509 if (in_decl && (complain & tf_error)) 6510 { 6511 error ("type/value mismatch at argument %d in template " 6512 "parameter list for %qD", 6513 i + 1, in_decl); 6514 if (is_tmpl_type) 6515 error (" expected a type, got %qT", DECL_NAME (arg)); 6516 else 6517 error (" expected a class template, got %qT", orig_arg); 6518 } 6519 return error_mark_node; 6520 } 6521 6522 if (is_type) 6523 { 6524 if (requires_tmpl_type) 6525 { 6526 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg)) 6527 val = orig_arg; 6528 else if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE) 6529 /* The number of argument required is not known yet. 6530 Just accept it for now. */ 6531 val = TREE_TYPE (arg); 6532 else 6533 { 6534 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm); 6535 tree argparm; 6536 6537 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg); 6538 6539 if (coerce_template_template_parms (parmparm, argparm, 6540 complain, in_decl, 6541 args)) 6542 { 6543 val = arg; 6544 6545 /* TEMPLATE_TEMPLATE_PARM node is preferred over 6546 TEMPLATE_DECL. */ 6547 if (val != error_mark_node) 6548 { 6549 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val)) 6550 val = TREE_TYPE (val); 6551 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION) 6552 val = make_pack_expansion (val); 6553 } 6554 } 6555 else 6556 { 6557 if (in_decl && (complain & tf_error)) 6558 { 6559 error ("type/value mismatch at argument %d in " 6560 "template parameter list for %qD", 6561 i + 1, in_decl); 6562 error (" expected a template of type %qD, got %qT", 6563 parm, orig_arg); 6564 } 6565 6566 val = error_mark_node; 6567 } 6568 } 6569 } 6570 else 6571 val = orig_arg; 6572 /* We only form one instance of each template specialization. 6573 Therefore, if we use a non-canonical variant (i.e., a 6574 typedef), any future messages referring to the type will use 6575 the typedef, which is confusing if those future uses do not 6576 themselves also use the typedef. */ 6577 if (TYPE_P (val)) 6578 val = canonicalize_type_argument (val, complain); 6579 } 6580 else 6581 { 6582 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl); 6583 6584 if (invalid_nontype_parm_type_p (t, complain)) 6585 return error_mark_node; 6586 6587 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg)) 6588 { 6589 if (same_type_p (t, TREE_TYPE (orig_arg))) 6590 val = orig_arg; 6591 else 6592 { 6593 /* Not sure if this is reachable, but it doesn't hurt 6594 to be robust. */ 6595 error ("type mismatch in nontype parameter pack"); 6596 val = error_mark_node; 6597 } 6598 } 6599 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t)) 6600 /* We used to call digest_init here. However, digest_init 6601 will report errors, which we don't want when complain 6602 is zero. More importantly, digest_init will try too 6603 hard to convert things: for example, `0' should not be 6604 converted to pointer type at this point according to 6605 the standard. Accepting this is not merely an 6606 extension, since deciding whether or not these 6607 conversions can occur is part of determining which 6608 function template to call, or whether a given explicit 6609 argument specification is valid. */ 6610 val = convert_nontype_argument (t, orig_arg, complain); 6611 else 6612 val = orig_arg; 6613 6614 if (val == NULL_TREE) 6615 val = error_mark_node; 6616 else if (val == error_mark_node && (complain & tf_error)) 6617 error ("could not convert template argument %qE to %qT", orig_arg, t); 6618 6619 if (TREE_CODE (val) == SCOPE_REF) 6620 { 6621 /* Strip typedefs from the SCOPE_REF. */ 6622 tree type = canonicalize_type_argument (TREE_TYPE (val), complain); 6623 tree scope = canonicalize_type_argument (TREE_OPERAND (val, 0), 6624 complain); 6625 val = build_qualified_name (type, scope, TREE_OPERAND (val, 1), 6626 QUALIFIED_NAME_IS_TEMPLATE (val)); 6627 } 6628 } 6629 6630 return val; 6631 } 6632 6633 /* Coerces the remaining template arguments in INNER_ARGS (from 6634 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS. 6635 Returns the coerced argument pack. PARM_IDX is the position of this 6636 parameter in the template parameter list. ARGS is the original 6637 template argument list. */ 6638 static tree 6639 coerce_template_parameter_pack (tree parms, 6640 int parm_idx, 6641 tree args, 6642 tree inner_args, 6643 int arg_idx, 6644 tree new_args, 6645 int* lost, 6646 tree in_decl, 6647 tsubst_flags_t complain) 6648 { 6649 tree parm = TREE_VEC_ELT (parms, parm_idx); 6650 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0; 6651 tree packed_args; 6652 tree argument_pack; 6653 tree packed_types = NULL_TREE; 6654 6655 if (arg_idx > nargs) 6656 arg_idx = nargs; 6657 6658 packed_args = make_tree_vec (nargs - arg_idx); 6659 6660 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL 6661 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm)))) 6662 { 6663 /* When the template parameter is a non-type template 6664 parameter pack whose type uses parameter packs, we need 6665 to look at each of the template arguments 6666 separately. Build a vector of the types for these 6667 non-type template parameters in PACKED_TYPES. */ 6668 tree expansion 6669 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm))); 6670 packed_types = tsubst_pack_expansion (expansion, args, 6671 complain, in_decl); 6672 6673 if (packed_types == error_mark_node) 6674 return error_mark_node; 6675 6676 /* Check that we have the right number of arguments. */ 6677 if (arg_idx < nargs 6678 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)) 6679 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types)) 6680 { 6681 int needed_parms 6682 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types); 6683 error ("wrong number of template arguments (%d, should be %d)", 6684 nargs, needed_parms); 6685 return error_mark_node; 6686 } 6687 6688 /* If we aren't able to check the actual arguments now 6689 (because they haven't been expanded yet), we can at least 6690 verify that all of the types used for the non-type 6691 template parameter pack are, in fact, valid for non-type 6692 template parameters. */ 6693 if (arg_idx < nargs 6694 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))) 6695 { 6696 int j, len = TREE_VEC_LENGTH (packed_types); 6697 for (j = 0; j < len; ++j) 6698 { 6699 tree t = TREE_VEC_ELT (packed_types, j); 6700 if (invalid_nontype_parm_type_p (t, complain)) 6701 return error_mark_node; 6702 } 6703 } 6704 } 6705 6706 /* Convert the remaining arguments, which will be a part of the 6707 parameter pack "parm". */ 6708 for (; arg_idx < nargs; ++arg_idx) 6709 { 6710 tree arg = TREE_VEC_ELT (inner_args, arg_idx); 6711 tree actual_parm = TREE_VALUE (parm); 6712 6713 if (packed_types && !PACK_EXPANSION_P (arg)) 6714 { 6715 /* When we have a vector of types (corresponding to the 6716 non-type template parameter pack that uses parameter 6717 packs in its type, as mention above), and the 6718 argument is not an expansion (which expands to a 6719 currently unknown number of arguments), clone the 6720 parm and give it the next type in PACKED_TYPES. */ 6721 actual_parm = copy_node (actual_parm); 6722 TREE_TYPE (actual_parm) = 6723 TREE_VEC_ELT (packed_types, arg_idx - parm_idx); 6724 } 6725 6726 if (arg != error_mark_node) 6727 arg = convert_template_argument (actual_parm, 6728 arg, new_args, complain, parm_idx, 6729 in_decl); 6730 if (arg == error_mark_node) 6731 (*lost)++; 6732 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg; 6733 } 6734 6735 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL 6736 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL) 6737 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK); 6738 else 6739 { 6740 argument_pack = make_node (NONTYPE_ARGUMENT_PACK); 6741 TREE_TYPE (argument_pack) 6742 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl); 6743 TREE_CONSTANT (argument_pack) = 1; 6744 } 6745 6746 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args); 6747 #ifdef ENABLE_CHECKING 6748 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args, 6749 TREE_VEC_LENGTH (packed_args)); 6750 #endif 6751 return argument_pack; 6752 } 6753 6754 /* Returns true if the template argument vector ARGS contains 6755 any pack expansions, false otherwise. */ 6756 6757 static bool 6758 any_pack_expanson_args_p (tree args) 6759 { 6760 int i; 6761 if (args) 6762 for (i = 0; i < TREE_VEC_LENGTH (args); ++i) 6763 if (PACK_EXPANSION_P (TREE_VEC_ELT (args, i))) 6764 return true; 6765 return false; 6766 } 6767 6768 /* Convert all template arguments to their appropriate types, and 6769 return a vector containing the innermost resulting template 6770 arguments. If any error occurs, return error_mark_node. Error and 6771 warning messages are issued under control of COMPLAIN. 6772 6773 If REQUIRE_ALL_ARGS is false, argument deduction will be performed 6774 for arguments not specified in ARGS. Otherwise, if 6775 USE_DEFAULT_ARGS is true, default arguments will be used to fill in 6776 unspecified arguments. If REQUIRE_ALL_ARGS is true, but 6777 USE_DEFAULT_ARGS is false, then all arguments must be specified in 6778 ARGS. */ 6779 6780 static tree 6781 coerce_template_parms (tree parms, 6782 tree args, 6783 tree in_decl, 6784 tsubst_flags_t complain, 6785 bool require_all_args, 6786 bool use_default_args) 6787 { 6788 int nparms, nargs, parm_idx, arg_idx, lost = 0; 6789 tree inner_args; 6790 tree new_args; 6791 tree new_inner_args; 6792 int saved_unevaluated_operand; 6793 int saved_inhibit_evaluation_warnings; 6794 6795 /* When used as a boolean value, indicates whether this is a 6796 variadic template parameter list. Since it's an int, we can also 6797 subtract it from nparms to get the number of non-variadic 6798 parameters. */ 6799 int variadic_p = 0; 6800 int post_variadic_parms = 0; 6801 6802 if (args == error_mark_node) 6803 return error_mark_node; 6804 6805 nparms = TREE_VEC_LENGTH (parms); 6806 6807 /* Determine if there are any parameter packs. */ 6808 for (parm_idx = 0; parm_idx < nparms; ++parm_idx) 6809 { 6810 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx)); 6811 if (variadic_p) 6812 ++post_variadic_parms; 6813 if (template_parameter_pack_p (tparm)) 6814 ++variadic_p; 6815 } 6816 6817 inner_args = INNERMOST_TEMPLATE_ARGS (args); 6818 /* If there are no parameters that follow a parameter pack, we need to 6819 expand any argument packs so that we can deduce a parameter pack from 6820 some non-packed args followed by an argument pack, as in variadic85.C. 6821 If there are such parameters, we need to leave argument packs intact 6822 so the arguments are assigned properly. This can happen when dealing 6823 with a nested class inside a partial specialization of a class 6824 template, as in variadic92.C, or when deducing a template parameter pack 6825 from a sub-declarator, as in variadic114.C. */ 6826 if (!post_variadic_parms) 6827 inner_args = expand_template_argument_pack (inner_args); 6828 6829 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0; 6830 if ((nargs > nparms && !variadic_p) 6831 || (nargs < nparms - variadic_p 6832 && require_all_args 6833 && !any_pack_expanson_args_p (inner_args) 6834 && (!use_default_args 6835 || (TREE_VEC_ELT (parms, nargs) != error_mark_node 6836 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs)))))) 6837 { 6838 if (complain & tf_error) 6839 { 6840 if (variadic_p) 6841 { 6842 nparms -= variadic_p; 6843 error ("wrong number of template arguments " 6844 "(%d, should be %d or more)", nargs, nparms); 6845 } 6846 else 6847 error ("wrong number of template arguments " 6848 "(%d, should be %d)", nargs, nparms); 6849 6850 if (in_decl) 6851 error ("provided for %q+D", in_decl); 6852 } 6853 6854 return error_mark_node; 6855 } 6856 6857 /* We need to evaluate the template arguments, even though this 6858 template-id may be nested within a "sizeof". */ 6859 saved_unevaluated_operand = cp_unevaluated_operand; 6860 cp_unevaluated_operand = 0; 6861 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings; 6862 c_inhibit_evaluation_warnings = 0; 6863 new_inner_args = make_tree_vec (nparms); 6864 new_args = add_outermost_template_args (args, new_inner_args); 6865 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++) 6866 { 6867 tree arg; 6868 tree parm; 6869 6870 /* Get the Ith template parameter. */ 6871 parm = TREE_VEC_ELT (parms, parm_idx); 6872 6873 if (parm == error_mark_node) 6874 { 6875 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node; 6876 continue; 6877 } 6878 6879 /* Calculate the next argument. */ 6880 if (arg_idx < nargs) 6881 arg = TREE_VEC_ELT (inner_args, arg_idx); 6882 else 6883 arg = NULL_TREE; 6884 6885 if (template_parameter_pack_p (TREE_VALUE (parm)) 6886 && !(arg && ARGUMENT_PACK_P (arg))) 6887 { 6888 /* All remaining arguments will be placed in the 6889 template parameter pack PARM. */ 6890 arg = coerce_template_parameter_pack (parms, parm_idx, args, 6891 inner_args, arg_idx, 6892 new_args, &lost, 6893 in_decl, complain); 6894 6895 /* Store this argument. */ 6896 if (arg == error_mark_node) 6897 lost++; 6898 TREE_VEC_ELT (new_inner_args, parm_idx) = arg; 6899 6900 /* We are done with all of the arguments. */ 6901 arg_idx = nargs; 6902 6903 continue; 6904 } 6905 else if (arg) 6906 { 6907 if (PACK_EXPANSION_P (arg)) 6908 { 6909 /* We don't know how many args we have yet, just 6910 use the unconverted ones for now. */ 6911 new_inner_args = inner_args; 6912 break; 6913 } 6914 } 6915 else if (require_all_args) 6916 { 6917 /* There must be a default arg in this case. */ 6918 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args, 6919 complain, in_decl); 6920 /* The position of the first default template argument, 6921 is also the number of non-defaulted arguments in NEW_INNER_ARGS. 6922 Record that. */ 6923 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args)) 6924 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, arg_idx); 6925 } 6926 else 6927 break; 6928 6929 if (arg == error_mark_node) 6930 { 6931 if (complain & tf_error) 6932 error ("template argument %d is invalid", arg_idx + 1); 6933 } 6934 else if (!arg) 6935 /* This only occurs if there was an error in the template 6936 parameter list itself (which we would already have 6937 reported) that we are trying to recover from, e.g., a class 6938 template with a parameter list such as 6939 template<typename..., typename>. */ 6940 ++lost; 6941 else 6942 arg = convert_template_argument (TREE_VALUE (parm), 6943 arg, new_args, complain, 6944 parm_idx, in_decl); 6945 6946 if (arg == error_mark_node) 6947 lost++; 6948 TREE_VEC_ELT (new_inner_args, arg_idx) = arg; 6949 } 6950 cp_unevaluated_operand = saved_unevaluated_operand; 6951 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings; 6952 6953 if (lost) 6954 return error_mark_node; 6955 6956 #ifdef ENABLE_CHECKING 6957 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args)) 6958 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, 6959 TREE_VEC_LENGTH (new_inner_args)); 6960 #endif 6961 6962 return new_inner_args; 6963 } 6964 6965 /* Returns 1 if template args OT and NT are equivalent. */ 6966 6967 static int 6968 template_args_equal (tree ot, tree nt) 6969 { 6970 if (nt == ot) 6971 return 1; 6972 if (nt == NULL_TREE || ot == NULL_TREE) 6973 return false; 6974 6975 if (TREE_CODE (nt) == TREE_VEC) 6976 /* For member templates */ 6977 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt); 6978 else if (PACK_EXPANSION_P (ot)) 6979 return (PACK_EXPANSION_P (nt) 6980 && template_args_equal (PACK_EXPANSION_PATTERN (ot), 6981 PACK_EXPANSION_PATTERN (nt)) 6982 && template_args_equal (PACK_EXPANSION_EXTRA_ARGS (ot), 6983 PACK_EXPANSION_EXTRA_ARGS (nt))); 6984 else if (ARGUMENT_PACK_P (ot)) 6985 { 6986 int i, len; 6987 tree opack, npack; 6988 6989 if (!ARGUMENT_PACK_P (nt)) 6990 return 0; 6991 6992 opack = ARGUMENT_PACK_ARGS (ot); 6993 npack = ARGUMENT_PACK_ARGS (nt); 6994 len = TREE_VEC_LENGTH (opack); 6995 if (TREE_VEC_LENGTH (npack) != len) 6996 return 0; 6997 for (i = 0; i < len; ++i) 6998 if (!template_args_equal (TREE_VEC_ELT (opack, i), 6999 TREE_VEC_ELT (npack, i))) 7000 return 0; 7001 return 1; 7002 } 7003 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT) 7004 { 7005 /* We get here probably because we are in the middle of substituting 7006 into the pattern of a pack expansion. In that case the 7007 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are 7008 interested in. So we want to use the initial pack argument for 7009 the comparison. */ 7010 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot); 7011 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT) 7012 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt); 7013 return template_args_equal (ot, nt); 7014 } 7015 else if (TYPE_P (nt)) 7016 return TYPE_P (ot) && same_type_p (ot, nt); 7017 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot)) 7018 return 0; 7019 else 7020 return cp_tree_equal (ot, nt); 7021 } 7022 7023 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of 7024 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and 7025 NEWARG_PTR with the offending arguments if they are non-NULL. */ 7026 7027 static int 7028 comp_template_args_with_info (tree oldargs, tree newargs, 7029 tree *oldarg_ptr, tree *newarg_ptr) 7030 { 7031 int i; 7032 7033 if (oldargs == newargs) 7034 return 1; 7035 7036 if (!oldargs || !newargs) 7037 return 0; 7038 7039 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs)) 7040 return 0; 7041 7042 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i) 7043 { 7044 tree nt = TREE_VEC_ELT (newargs, i); 7045 tree ot = TREE_VEC_ELT (oldargs, i); 7046 7047 if (! template_args_equal (ot, nt)) 7048 { 7049 if (oldarg_ptr != NULL) 7050 *oldarg_ptr = ot; 7051 if (newarg_ptr != NULL) 7052 *newarg_ptr = nt; 7053 return 0; 7054 } 7055 } 7056 return 1; 7057 } 7058 7059 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets 7060 of template arguments. Returns 0 otherwise. */ 7061 7062 int 7063 comp_template_args (tree oldargs, tree newargs) 7064 { 7065 return comp_template_args_with_info (oldargs, newargs, NULL, NULL); 7066 } 7067 7068 static void 7069 add_pending_template (tree d) 7070 { 7071 tree ti = (TYPE_P (d) 7072 ? CLASSTYPE_TEMPLATE_INFO (d) 7073 : DECL_TEMPLATE_INFO (d)); 7074 struct pending_template *pt; 7075 int level; 7076 7077 if (TI_PENDING_TEMPLATE_FLAG (ti)) 7078 return; 7079 7080 /* We are called both from instantiate_decl, where we've already had a 7081 tinst_level pushed, and instantiate_template, where we haven't. 7082 Compensate. */ 7083 level = !current_tinst_level || current_tinst_level->decl != d; 7084 7085 if (level) 7086 push_tinst_level (d); 7087 7088 pt = ggc_alloc_pending_template (); 7089 pt->next = NULL; 7090 pt->tinst = current_tinst_level; 7091 if (last_pending_template) 7092 last_pending_template->next = pt; 7093 else 7094 pending_templates = pt; 7095 7096 last_pending_template = pt; 7097 7098 TI_PENDING_TEMPLATE_FLAG (ti) = 1; 7099 7100 if (level) 7101 pop_tinst_level (); 7102 } 7103 7104 7105 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and 7106 ARGLIST. Valid choices for FNS are given in the cp-tree.def 7107 documentation for TEMPLATE_ID_EXPR. */ 7108 7109 tree 7110 lookup_template_function (tree fns, tree arglist) 7111 { 7112 tree type; 7113 7114 if (fns == error_mark_node || arglist == error_mark_node) 7115 return error_mark_node; 7116 7117 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC); 7118 7119 if (!is_overloaded_fn (fns) && TREE_CODE (fns) != IDENTIFIER_NODE) 7120 { 7121 error ("%q#D is not a function template", fns); 7122 return error_mark_node; 7123 } 7124 7125 if (BASELINK_P (fns)) 7126 { 7127 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR, 7128 unknown_type_node, 7129 BASELINK_FUNCTIONS (fns), 7130 arglist); 7131 return fns; 7132 } 7133 7134 type = TREE_TYPE (fns); 7135 if (TREE_CODE (fns) == OVERLOAD || !type) 7136 type = unknown_type_node; 7137 7138 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist); 7139 } 7140 7141 /* Within the scope of a template class S<T>, the name S gets bound 7142 (in build_self_reference) to a TYPE_DECL for the class, not a 7143 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type, 7144 or one of its enclosing classes, and that type is a template, 7145 return the associated TEMPLATE_DECL. Otherwise, the original 7146 DECL is returned. 7147 7148 Also handle the case when DECL is a TREE_LIST of ambiguous 7149 injected-class-names from different bases. */ 7150 7151 tree 7152 maybe_get_template_decl_from_type_decl (tree decl) 7153 { 7154 if (decl == NULL_TREE) 7155 return decl; 7156 7157 /* DR 176: A lookup that finds an injected-class-name (10.2 7158 [class.member.lookup]) can result in an ambiguity in certain cases 7159 (for example, if it is found in more than one base class). If all of 7160 the injected-class-names that are found refer to specializations of 7161 the same class template, and if the name is followed by a 7162 template-argument-list, the reference refers to the class template 7163 itself and not a specialization thereof, and is not ambiguous. */ 7164 if (TREE_CODE (decl) == TREE_LIST) 7165 { 7166 tree t, tmpl = NULL_TREE; 7167 for (t = decl; t; t = TREE_CHAIN (t)) 7168 { 7169 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t)); 7170 if (!tmpl) 7171 tmpl = elt; 7172 else if (tmpl != elt) 7173 break; 7174 } 7175 if (tmpl && t == NULL_TREE) 7176 return tmpl; 7177 else 7178 return decl; 7179 } 7180 7181 return (decl != NULL_TREE 7182 && DECL_SELF_REFERENCE_P (decl) 7183 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl))) 7184 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl; 7185 } 7186 7187 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of 7188 parameters, find the desired type. 7189 7190 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments. 7191 7192 IN_DECL, if non-NULL, is the template declaration we are trying to 7193 instantiate. 7194 7195 If ENTERING_SCOPE is nonzero, we are about to enter the scope of 7196 the class we are looking up. 7197 7198 Issue error and warning messages under control of COMPLAIN. 7199 7200 If the template class is really a local class in a template 7201 function, then the FUNCTION_CONTEXT is the function in which it is 7202 being instantiated. 7203 7204 ??? Note that this function is currently called *twice* for each 7205 template-id: the first time from the parser, while creating the 7206 incomplete type (finish_template_type), and the second type during the 7207 real instantiation (instantiate_template_class). This is surely something 7208 that we want to avoid. It also causes some problems with argument 7209 coercion (see convert_nontype_argument for more information on this). */ 7210 7211 static tree 7212 lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context, 7213 int entering_scope, tsubst_flags_t complain) 7214 { 7215 tree templ = NULL_TREE, parmlist; 7216 tree t; 7217 void **slot; 7218 spec_entry *entry; 7219 spec_entry elt; 7220 hashval_t hash; 7221 7222 if (TREE_CODE (d1) == IDENTIFIER_NODE) 7223 { 7224 tree value = innermost_non_namespace_value (d1); 7225 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value)) 7226 templ = value; 7227 else 7228 { 7229 if (context) 7230 push_decl_namespace (context); 7231 templ = lookup_name (d1); 7232 templ = maybe_get_template_decl_from_type_decl (templ); 7233 if (context) 7234 pop_decl_namespace (); 7235 } 7236 if (templ) 7237 context = DECL_CONTEXT (templ); 7238 } 7239 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1))) 7240 { 7241 tree type = TREE_TYPE (d1); 7242 7243 /* If we are declaring a constructor, say A<T>::A<T>, we will get 7244 an implicit typename for the second A. Deal with it. */ 7245 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type)) 7246 type = TREE_TYPE (type); 7247 7248 if (CLASSTYPE_TEMPLATE_INFO (type)) 7249 { 7250 templ = CLASSTYPE_TI_TEMPLATE (type); 7251 d1 = DECL_NAME (templ); 7252 } 7253 } 7254 else if (TREE_CODE (d1) == ENUMERAL_TYPE 7255 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1))) 7256 { 7257 templ = TYPE_TI_TEMPLATE (d1); 7258 d1 = DECL_NAME (templ); 7259 } 7260 else if (TREE_CODE (d1) == TEMPLATE_DECL 7261 && DECL_TEMPLATE_RESULT (d1) 7262 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL) 7263 { 7264 templ = d1; 7265 d1 = DECL_NAME (templ); 7266 context = DECL_CONTEXT (templ); 7267 } 7268 7269 /* Issue an error message if we didn't find a template. */ 7270 if (! templ) 7271 { 7272 if (complain & tf_error) 7273 error ("%qT is not a template", d1); 7274 return error_mark_node; 7275 } 7276 7277 if (TREE_CODE (templ) != TEMPLATE_DECL 7278 /* Make sure it's a user visible template, if it was named by 7279 the user. */ 7280 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ) 7281 && !PRIMARY_TEMPLATE_P (templ))) 7282 { 7283 if (complain & tf_error) 7284 { 7285 error ("non-template type %qT used as a template", d1); 7286 if (in_decl) 7287 error ("for template declaration %q+D", in_decl); 7288 } 7289 return error_mark_node; 7290 } 7291 7292 complain &= ~tf_user; 7293 7294 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ)) 7295 { 7296 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store 7297 template arguments */ 7298 7299 tree parm; 7300 tree arglist2; 7301 tree outer; 7302 7303 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ); 7304 7305 /* Consider an example where a template template parameter declared as 7306 7307 template <class T, class U = std::allocator<T> > class TT 7308 7309 The template parameter level of T and U are one level larger than 7310 of TT. To proper process the default argument of U, say when an 7311 instantiation `TT<int>' is seen, we need to build the full 7312 arguments containing {int} as the innermost level. Outer levels, 7313 available when not appearing as default template argument, can be 7314 obtained from the arguments of the enclosing template. 7315 7316 Suppose that TT is later substituted with std::vector. The above 7317 instantiation is `TT<int, std::allocator<T> >' with TT at 7318 level 1, and T at level 2, while the template arguments at level 1 7319 becomes {std::vector} and the inner level 2 is {int}. */ 7320 7321 outer = DECL_CONTEXT (templ); 7322 if (outer) 7323 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer))); 7324 else if (current_template_parms) 7325 /* This is an argument of the current template, so we haven't set 7326 DECL_CONTEXT yet. */ 7327 outer = current_template_args (); 7328 7329 if (outer) 7330 arglist = add_to_template_args (outer, arglist); 7331 7332 arglist2 = coerce_template_parms (parmlist, arglist, templ, 7333 complain, 7334 /*require_all_args=*/true, 7335 /*use_default_args=*/true); 7336 if (arglist2 == error_mark_node 7337 || (!uses_template_parms (arglist2) 7338 && check_instantiated_args (templ, arglist2, complain))) 7339 return error_mark_node; 7340 7341 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2); 7342 return parm; 7343 } 7344 else 7345 { 7346 tree template_type = TREE_TYPE (templ); 7347 tree gen_tmpl; 7348 tree type_decl; 7349 tree found = NULL_TREE; 7350 int arg_depth; 7351 int parm_depth; 7352 int is_dependent_type; 7353 int use_partial_inst_tmpl = false; 7354 7355 if (template_type == error_mark_node) 7356 /* An error occured while building the template TEMPL, and a 7357 diagnostic has most certainly been emitted for that 7358 already. Let's propagate that error. */ 7359 return error_mark_node; 7360 7361 gen_tmpl = most_general_template (templ); 7362 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl); 7363 parm_depth = TMPL_PARMS_DEPTH (parmlist); 7364 arg_depth = TMPL_ARGS_DEPTH (arglist); 7365 7366 if (arg_depth == 1 && parm_depth > 1) 7367 { 7368 /* We've been given an incomplete set of template arguments. 7369 For example, given: 7370 7371 template <class T> struct S1 { 7372 template <class U> struct S2 {}; 7373 template <class U> struct S2<U*> {}; 7374 }; 7375 7376 we will be called with an ARGLIST of `U*', but the 7377 TEMPLATE will be `template <class T> template 7378 <class U> struct S1<T>::S2'. We must fill in the missing 7379 arguments. */ 7380 arglist 7381 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)), 7382 arglist); 7383 arg_depth = TMPL_ARGS_DEPTH (arglist); 7384 } 7385 7386 /* Now we should have enough arguments. */ 7387 gcc_assert (parm_depth == arg_depth); 7388 7389 /* From here on, we're only interested in the most general 7390 template. */ 7391 7392 /* Calculate the BOUND_ARGS. These will be the args that are 7393 actually tsubst'd into the definition to create the 7394 instantiation. */ 7395 if (parm_depth > 1) 7396 { 7397 /* We have multiple levels of arguments to coerce, at once. */ 7398 int i; 7399 int saved_depth = TMPL_ARGS_DEPTH (arglist); 7400 7401 tree bound_args = make_tree_vec (parm_depth); 7402 7403 for (i = saved_depth, 7404 t = DECL_TEMPLATE_PARMS (gen_tmpl); 7405 i > 0 && t != NULL_TREE; 7406 --i, t = TREE_CHAIN (t)) 7407 { 7408 tree a; 7409 if (i == saved_depth) 7410 a = coerce_template_parms (TREE_VALUE (t), 7411 arglist, gen_tmpl, 7412 complain, 7413 /*require_all_args=*/true, 7414 /*use_default_args=*/true); 7415 else 7416 /* Outer levels should have already been coerced. */ 7417 a = TMPL_ARGS_LEVEL (arglist, i); 7418 7419 /* Don't process further if one of the levels fails. */ 7420 if (a == error_mark_node) 7421 { 7422 /* Restore the ARGLIST to its full size. */ 7423 TREE_VEC_LENGTH (arglist) = saved_depth; 7424 return error_mark_node; 7425 } 7426 7427 SET_TMPL_ARGS_LEVEL (bound_args, i, a); 7428 7429 /* We temporarily reduce the length of the ARGLIST so 7430 that coerce_template_parms will see only the arguments 7431 corresponding to the template parameters it is 7432 examining. */ 7433 TREE_VEC_LENGTH (arglist)--; 7434 } 7435 7436 /* Restore the ARGLIST to its full size. */ 7437 TREE_VEC_LENGTH (arglist) = saved_depth; 7438 7439 arglist = bound_args; 7440 } 7441 else 7442 arglist 7443 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist), 7444 INNERMOST_TEMPLATE_ARGS (arglist), 7445 gen_tmpl, 7446 complain, 7447 /*require_all_args=*/true, 7448 /*use_default_args=*/true); 7449 7450 if (arglist == error_mark_node) 7451 /* We were unable to bind the arguments. */ 7452 return error_mark_node; 7453 7454 /* In the scope of a template class, explicit references to the 7455 template class refer to the type of the template, not any 7456 instantiation of it. For example, in: 7457 7458 template <class T> class C { void f(C<T>); } 7459 7460 the `C<T>' is just the same as `C'. Outside of the 7461 class, however, such a reference is an instantiation. */ 7462 if ((entering_scope 7463 || !PRIMARY_TEMPLATE_P (gen_tmpl) 7464 || currently_open_class (template_type)) 7465 /* comp_template_args is expensive, check it last. */ 7466 && comp_template_args (TYPE_TI_ARGS (template_type), 7467 arglist)) 7468 return template_type; 7469 7470 /* If we already have this specialization, return it. */ 7471 elt.tmpl = gen_tmpl; 7472 elt.args = arglist; 7473 hash = hash_specialization (&elt); 7474 entry = (spec_entry *) htab_find_with_hash (type_specializations, 7475 &elt, hash); 7476 7477 if (entry) 7478 return entry->spec; 7479 7480 is_dependent_type = uses_template_parms (arglist); 7481 7482 /* If the deduced arguments are invalid, then the binding 7483 failed. */ 7484 if (!is_dependent_type 7485 && check_instantiated_args (gen_tmpl, 7486 INNERMOST_TEMPLATE_ARGS (arglist), 7487 complain)) 7488 return error_mark_node; 7489 7490 if (!is_dependent_type 7491 && !PRIMARY_TEMPLATE_P (gen_tmpl) 7492 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl)) 7493 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL) 7494 { 7495 found = xref_tag_from_type (TREE_TYPE (gen_tmpl), 7496 DECL_NAME (gen_tmpl), 7497 /*tag_scope=*/ts_global); 7498 return found; 7499 } 7500 7501 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist, 7502 complain, in_decl); 7503 if (context == error_mark_node) 7504 return error_mark_node; 7505 7506 if (!context) 7507 context = global_namespace; 7508 7509 /* Create the type. */ 7510 if (TREE_CODE (template_type) == ENUMERAL_TYPE) 7511 { 7512 if (!is_dependent_type) 7513 { 7514 set_current_access_from_decl (TYPE_NAME (template_type)); 7515 t = start_enum (TYPE_IDENTIFIER (template_type), NULL_TREE, 7516 tsubst (ENUM_UNDERLYING_TYPE (template_type), 7517 arglist, complain, in_decl), 7518 SCOPED_ENUM_P (template_type), NULL); 7519 } 7520 else 7521 { 7522 /* We don't want to call start_enum for this type, since 7523 the values for the enumeration constants may involve 7524 template parameters. And, no one should be interested 7525 in the enumeration constants for such a type. */ 7526 t = cxx_make_type (ENUMERAL_TYPE); 7527 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type)); 7528 } 7529 SET_OPAQUE_ENUM_P (t, OPAQUE_ENUM_P (template_type)); 7530 ENUM_FIXED_UNDERLYING_TYPE_P (t) 7531 = ENUM_FIXED_UNDERLYING_TYPE_P (template_type); 7532 } 7533 else if (DECL_ALIAS_TEMPLATE_P (gen_tmpl)) 7534 { 7535 /* The user referred to a specialization of an alias 7536 template represented by GEN_TMPL. 7537 7538 [temp.alias]/2 says: 7539 7540 When a template-id refers to the specialization of an 7541 alias template, it is equivalent to the associated 7542 type obtained by substitution of its 7543 template-arguments for the template-parameters in the 7544 type-id of the alias template. */ 7545 7546 t = tsubst (TREE_TYPE (gen_tmpl), arglist, complain, in_decl); 7547 /* Note that the call above (by indirectly calling 7548 register_specialization in tsubst_decl) registers the 7549 TYPE_DECL representing the specialization of the alias 7550 template. So next time someone substitutes ARGLIST for 7551 the template parms into the alias template (GEN_TMPL), 7552 she'll get that TYPE_DECL back. */ 7553 7554 if (t == error_mark_node) 7555 return t; 7556 } 7557 else if (CLASS_TYPE_P (template_type)) 7558 { 7559 t = make_class_type (TREE_CODE (template_type)); 7560 CLASSTYPE_DECLARED_CLASS (t) 7561 = CLASSTYPE_DECLARED_CLASS (template_type); 7562 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t); 7563 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type); 7564 7565 /* A local class. Make sure the decl gets registered properly. */ 7566 if (context == current_function_decl) 7567 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_global); 7568 7569 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist)) 7570 /* This instantiation is another name for the primary 7571 template type. Set the TYPE_CANONICAL field 7572 appropriately. */ 7573 TYPE_CANONICAL (t) = template_type; 7574 else if (any_template_arguments_need_structural_equality_p (arglist)) 7575 /* Some of the template arguments require structural 7576 equality testing, so this template class requires 7577 structural equality testing. */ 7578 SET_TYPE_STRUCTURAL_EQUALITY (t); 7579 } 7580 else 7581 gcc_unreachable (); 7582 7583 /* If we called start_enum or pushtag above, this information 7584 will already be set up. */ 7585 if (!TYPE_NAME (t)) 7586 { 7587 TYPE_CONTEXT (t) = FROB_CONTEXT (context); 7588 7589 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t); 7590 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t); 7591 DECL_SOURCE_LOCATION (type_decl) 7592 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type)); 7593 } 7594 else 7595 type_decl = TYPE_NAME (t); 7596 7597 if (CLASS_TYPE_P (template_type)) 7598 { 7599 TREE_PRIVATE (type_decl) 7600 = TREE_PRIVATE (TYPE_STUB_DECL (template_type)); 7601 TREE_PROTECTED (type_decl) 7602 = TREE_PROTECTED (TYPE_STUB_DECL (template_type)); 7603 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type)) 7604 { 7605 DECL_VISIBILITY_SPECIFIED (type_decl) = 1; 7606 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type); 7607 } 7608 } 7609 7610 /* Let's consider the explicit specialization of a member 7611 of a class template specialization that is implicitely instantiated, 7612 e.g.: 7613 template<class T> 7614 struct S 7615 { 7616 template<class U> struct M {}; //#0 7617 }; 7618 7619 template<> 7620 template<> 7621 struct S<int>::M<char> //#1 7622 { 7623 int i; 7624 }; 7625 [temp.expl.spec]/4 says this is valid. 7626 7627 In this case, when we write: 7628 S<int>::M<char> m; 7629 7630 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from 7631 the one of #0. 7632 7633 When we encounter #1, we want to store the partial instantiation 7634 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE. 7635 7636 For all cases other than this "explicit specialization of member of a 7637 class template", we just want to store the most general template into 7638 the CLASSTYPE_TI_TEMPLATE of M. 7639 7640 This case of "explicit specialization of member of a class template" 7641 only happens when: 7642 1/ the enclosing class is an instantiation of, and therefore not 7643 the same as, the context of the most general template, and 7644 2/ we aren't looking at the partial instantiation itself, i.e. 7645 the innermost arguments are not the same as the innermost parms of 7646 the most general template. 7647 7648 So it's only when 1/ and 2/ happens that we want to use the partial 7649 instantiation of the member template in lieu of its most general 7650 template. */ 7651 7652 if (PRIMARY_TEMPLATE_P (gen_tmpl) 7653 && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist) 7654 /* the enclosing class must be an instantiation... */ 7655 && CLASS_TYPE_P (context) 7656 && !same_type_p (context, DECL_CONTEXT (gen_tmpl))) 7657 { 7658 tree partial_inst_args; 7659 TREE_VEC_LENGTH (arglist)--; 7660 ++processing_template_decl; 7661 partial_inst_args = 7662 tsubst (INNERMOST_TEMPLATE_ARGS 7663 (TYPE_TI_ARGS (TREE_TYPE (gen_tmpl))), 7664 arglist, complain, NULL_TREE); 7665 --processing_template_decl; 7666 TREE_VEC_LENGTH (arglist)++; 7667 use_partial_inst_tmpl = 7668 /*...and we must not be looking at the partial instantiation 7669 itself. */ 7670 !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist), 7671 partial_inst_args); 7672 } 7673 7674 if (!use_partial_inst_tmpl) 7675 /* This case is easy; there are no member templates involved. */ 7676 found = gen_tmpl; 7677 else 7678 { 7679 /* This is a full instantiation of a member template. Find 7680 the partial instantiation of which this is an instance. */ 7681 7682 /* Temporarily reduce by one the number of levels in the ARGLIST 7683 so as to avoid comparing the last set of arguments. */ 7684 TREE_VEC_LENGTH (arglist)--; 7685 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE); 7686 TREE_VEC_LENGTH (arglist)++; 7687 /* FOUND is either a proper class type, or an alias 7688 template specialization. In the later case, it's a 7689 TYPE_DECL, resulting from the substituting of arguments 7690 for parameters in the TYPE_DECL of the alias template 7691 done earlier. So be careful while getting the template 7692 of FOUND. */ 7693 found = TREE_CODE (found) == TYPE_DECL 7694 ? TYPE_TI_TEMPLATE (TREE_TYPE (found)) 7695 : CLASSTYPE_TI_TEMPLATE (found); 7696 } 7697 7698 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist)); 7699 7700 elt.spec = t; 7701 slot = htab_find_slot_with_hash (type_specializations, 7702 &elt, hash, INSERT); 7703 entry = ggc_alloc_spec_entry (); 7704 *entry = elt; 7705 *slot = entry; 7706 7707 /* Note this use of the partial instantiation so we can check it 7708 later in maybe_process_partial_specialization. */ 7709 DECL_TEMPLATE_INSTANTIATIONS (templ) 7710 = tree_cons (arglist, t, 7711 DECL_TEMPLATE_INSTANTIATIONS (templ)); 7712 7713 if (TREE_CODE (t) == ENUMERAL_TYPE && !is_dependent_type) 7714 /* Now that the type has been registered on the instantiations 7715 list, we set up the enumerators. Because the enumeration 7716 constants may involve the enumeration type itself, we make 7717 sure to register the type first, and then create the 7718 constants. That way, doing tsubst_expr for the enumeration 7719 constants won't result in recursive calls here; we'll find 7720 the instantiation and exit above. */ 7721 tsubst_enum (template_type, t, arglist); 7722 7723 if (CLASS_TYPE_P (template_type) && is_dependent_type) 7724 /* If the type makes use of template parameters, the 7725 code that generates debugging information will crash. */ 7726 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1; 7727 7728 /* Possibly limit visibility based on template args. */ 7729 TREE_PUBLIC (type_decl) = 1; 7730 determine_visibility (type_decl); 7731 7732 return t; 7733 } 7734 } 7735 7736 /* Wrapper for lookup_template_class_1. */ 7737 7738 tree 7739 lookup_template_class (tree d1, tree arglist, tree in_decl, tree context, 7740 int entering_scope, tsubst_flags_t complain) 7741 { 7742 tree ret; 7743 timevar_push (TV_TEMPLATE_INST); 7744 ret = lookup_template_class_1 (d1, arglist, in_decl, context, 7745 entering_scope, complain); 7746 timevar_pop (TV_TEMPLATE_INST); 7747 return ret; 7748 } 7749 7750 struct pair_fn_data 7751 { 7752 tree_fn_t fn; 7753 void *data; 7754 /* True when we should also visit template parameters that occur in 7755 non-deduced contexts. */ 7756 bool include_nondeduced_p; 7757 struct pointer_set_t *visited; 7758 }; 7759 7760 /* Called from for_each_template_parm via walk_tree. */ 7761 7762 static tree 7763 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d) 7764 { 7765 tree t = *tp; 7766 struct pair_fn_data *pfd = (struct pair_fn_data *) d; 7767 tree_fn_t fn = pfd->fn; 7768 void *data = pfd->data; 7769 7770 if (TYPE_P (t) 7771 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE) 7772 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited, 7773 pfd->include_nondeduced_p)) 7774 return error_mark_node; 7775 7776 switch (TREE_CODE (t)) 7777 { 7778 case RECORD_TYPE: 7779 if (TYPE_PTRMEMFUNC_P (t)) 7780 break; 7781 /* Fall through. */ 7782 7783 case UNION_TYPE: 7784 case ENUMERAL_TYPE: 7785 if (!TYPE_TEMPLATE_INFO (t)) 7786 *walk_subtrees = 0; 7787 else if (for_each_template_parm (TI_ARGS (TYPE_TEMPLATE_INFO (t)), 7788 fn, data, pfd->visited, 7789 pfd->include_nondeduced_p)) 7790 return error_mark_node; 7791 break; 7792 7793 case INTEGER_TYPE: 7794 if (for_each_template_parm (TYPE_MIN_VALUE (t), 7795 fn, data, pfd->visited, 7796 pfd->include_nondeduced_p) 7797 || for_each_template_parm (TYPE_MAX_VALUE (t), 7798 fn, data, pfd->visited, 7799 pfd->include_nondeduced_p)) 7800 return error_mark_node; 7801 break; 7802 7803 case METHOD_TYPE: 7804 /* Since we're not going to walk subtrees, we have to do this 7805 explicitly here. */ 7806 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data, 7807 pfd->visited, pfd->include_nondeduced_p)) 7808 return error_mark_node; 7809 /* Fall through. */ 7810 7811 case FUNCTION_TYPE: 7812 /* Check the return type. */ 7813 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited, 7814 pfd->include_nondeduced_p)) 7815 return error_mark_node; 7816 7817 /* Check the parameter types. Since default arguments are not 7818 instantiated until they are needed, the TYPE_ARG_TYPES may 7819 contain expressions that involve template parameters. But, 7820 no-one should be looking at them yet. And, once they're 7821 instantiated, they don't contain template parameters, so 7822 there's no point in looking at them then, either. */ 7823 { 7824 tree parm; 7825 7826 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm)) 7827 if (for_each_template_parm (TREE_VALUE (parm), fn, data, 7828 pfd->visited, pfd->include_nondeduced_p)) 7829 return error_mark_node; 7830 7831 /* Since we've already handled the TYPE_ARG_TYPES, we don't 7832 want walk_tree walking into them itself. */ 7833 *walk_subtrees = 0; 7834 } 7835 break; 7836 7837 case TYPEOF_TYPE: 7838 case UNDERLYING_TYPE: 7839 if (pfd->include_nondeduced_p 7840 && for_each_template_parm (TYPE_FIELDS (t), fn, data, 7841 pfd->visited, 7842 pfd->include_nondeduced_p)) 7843 return error_mark_node; 7844 break; 7845 7846 case FUNCTION_DECL: 7847 case VAR_DECL: 7848 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t) 7849 && for_each_template_parm (DECL_TI_ARGS (t), fn, data, 7850 pfd->visited, pfd->include_nondeduced_p)) 7851 return error_mark_node; 7852 /* Fall through. */ 7853 7854 case PARM_DECL: 7855 case CONST_DECL: 7856 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t) 7857 && for_each_template_parm (DECL_INITIAL (t), fn, data, 7858 pfd->visited, pfd->include_nondeduced_p)) 7859 return error_mark_node; 7860 if (DECL_CONTEXT (t) 7861 && pfd->include_nondeduced_p 7862 && for_each_template_parm (DECL_CONTEXT (t), fn, data, 7863 pfd->visited, pfd->include_nondeduced_p)) 7864 return error_mark_node; 7865 break; 7866 7867 case BOUND_TEMPLATE_TEMPLATE_PARM: 7868 /* Record template parameters such as `T' inside `TT<T>'. */ 7869 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited, 7870 pfd->include_nondeduced_p)) 7871 return error_mark_node; 7872 /* Fall through. */ 7873 7874 case TEMPLATE_TEMPLATE_PARM: 7875 case TEMPLATE_TYPE_PARM: 7876 case TEMPLATE_PARM_INDEX: 7877 if (fn && (*fn)(t, data)) 7878 return error_mark_node; 7879 else if (!fn) 7880 return error_mark_node; 7881 break; 7882 7883 case TEMPLATE_DECL: 7884 /* A template template parameter is encountered. */ 7885 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t) 7886 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited, 7887 pfd->include_nondeduced_p)) 7888 return error_mark_node; 7889 7890 /* Already substituted template template parameter */ 7891 *walk_subtrees = 0; 7892 break; 7893 7894 case TYPENAME_TYPE: 7895 if (!fn 7896 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn, 7897 data, pfd->visited, 7898 pfd->include_nondeduced_p)) 7899 return error_mark_node; 7900 break; 7901 7902 case CONSTRUCTOR: 7903 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t)) 7904 && pfd->include_nondeduced_p 7905 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE 7906 (TREE_TYPE (t)), fn, data, 7907 pfd->visited, pfd->include_nondeduced_p)) 7908 return error_mark_node; 7909 break; 7910 7911 case INDIRECT_REF: 7912 case COMPONENT_REF: 7913 /* If there's no type, then this thing must be some expression 7914 involving template parameters. */ 7915 if (!fn && !TREE_TYPE (t)) 7916 return error_mark_node; 7917 break; 7918 7919 case MODOP_EXPR: 7920 case CAST_EXPR: 7921 case IMPLICIT_CONV_EXPR: 7922 case REINTERPRET_CAST_EXPR: 7923 case CONST_CAST_EXPR: 7924 case STATIC_CAST_EXPR: 7925 case DYNAMIC_CAST_EXPR: 7926 case ARROW_EXPR: 7927 case DOTSTAR_EXPR: 7928 case TYPEID_EXPR: 7929 case PSEUDO_DTOR_EXPR: 7930 if (!fn) 7931 return error_mark_node; 7932 break; 7933 7934 default: 7935 break; 7936 } 7937 7938 /* We didn't find any template parameters we liked. */ 7939 return NULL_TREE; 7940 } 7941 7942 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM, 7943 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T, 7944 call FN with the parameter and the DATA. 7945 If FN returns nonzero, the iteration is terminated, and 7946 for_each_template_parm returns 1. Otherwise, the iteration 7947 continues. If FN never returns a nonzero value, the value 7948 returned by for_each_template_parm is 0. If FN is NULL, it is 7949 considered to be the function which always returns 1. 7950 7951 If INCLUDE_NONDEDUCED_P, then this routine will also visit template 7952 parameters that occur in non-deduced contexts. When false, only 7953 visits those template parameters that can be deduced. */ 7954 7955 static int 7956 for_each_template_parm (tree t, tree_fn_t fn, void* data, 7957 struct pointer_set_t *visited, 7958 bool include_nondeduced_p) 7959 { 7960 struct pair_fn_data pfd; 7961 int result; 7962 7963 /* Set up. */ 7964 pfd.fn = fn; 7965 pfd.data = data; 7966 pfd.include_nondeduced_p = include_nondeduced_p; 7967 7968 /* Walk the tree. (Conceptually, we would like to walk without 7969 duplicates, but for_each_template_parm_r recursively calls 7970 for_each_template_parm, so we would need to reorganize a fair 7971 bit to use walk_tree_without_duplicates, so we keep our own 7972 visited list.) */ 7973 if (visited) 7974 pfd.visited = visited; 7975 else 7976 pfd.visited = pointer_set_create (); 7977 result = cp_walk_tree (&t, 7978 for_each_template_parm_r, 7979 &pfd, 7980 pfd.visited) != NULL_TREE; 7981 7982 /* Clean up. */ 7983 if (!visited) 7984 { 7985 pointer_set_destroy (pfd.visited); 7986 pfd.visited = 0; 7987 } 7988 7989 return result; 7990 } 7991 7992 /* Returns true if T depends on any template parameter. */ 7993 7994 int 7995 uses_template_parms (tree t) 7996 { 7997 bool dependent_p; 7998 int saved_processing_template_decl; 7999 8000 saved_processing_template_decl = processing_template_decl; 8001 if (!saved_processing_template_decl) 8002 processing_template_decl = 1; 8003 if (TYPE_P (t)) 8004 dependent_p = dependent_type_p (t); 8005 else if (TREE_CODE (t) == TREE_VEC) 8006 dependent_p = any_dependent_template_arguments_p (t); 8007 else if (TREE_CODE (t) == TREE_LIST) 8008 dependent_p = (uses_template_parms (TREE_VALUE (t)) 8009 || uses_template_parms (TREE_CHAIN (t))); 8010 else if (TREE_CODE (t) == TYPE_DECL) 8011 dependent_p = dependent_type_p (TREE_TYPE (t)); 8012 else if (DECL_P (t) 8013 || EXPR_P (t) 8014 || TREE_CODE (t) == TEMPLATE_PARM_INDEX 8015 || TREE_CODE (t) == OVERLOAD 8016 || BASELINK_P (t) 8017 || TREE_CODE (t) == IDENTIFIER_NODE 8018 || TREE_CODE (t) == TRAIT_EXPR 8019 || TREE_CODE (t) == CONSTRUCTOR 8020 || CONSTANT_CLASS_P (t)) 8021 dependent_p = (type_dependent_expression_p (t) 8022 || value_dependent_expression_p (t)); 8023 else 8024 { 8025 gcc_assert (t == error_mark_node); 8026 dependent_p = false; 8027 } 8028 8029 processing_template_decl = saved_processing_template_decl; 8030 8031 return dependent_p; 8032 } 8033 8034 /* Returns true if T depends on any template parameter with level LEVEL. */ 8035 8036 int 8037 uses_template_parms_level (tree t, int level) 8038 { 8039 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL, 8040 /*include_nondeduced_p=*/true); 8041 } 8042 8043 /* Returns TRUE iff INST is an instantiation we don't need to do in an 8044 ill-formed translation unit, i.e. a variable or function that isn't 8045 usable in a constant expression. */ 8046 8047 static inline bool 8048 neglectable_inst_p (tree d) 8049 { 8050 return (DECL_P (d) 8051 && !(TREE_CODE (d) == FUNCTION_DECL ? DECL_DECLARED_CONSTEXPR_P (d) 8052 : decl_maybe_constant_var_p (d))); 8053 } 8054 8055 /* Returns TRUE iff we should refuse to instantiate DECL because it's 8056 neglectable and instantiated from within an erroneous instantiation. */ 8057 8058 static bool 8059 limit_bad_template_recursion (tree decl) 8060 { 8061 struct tinst_level *lev = current_tinst_level; 8062 int errs = errorcount + sorrycount; 8063 if (lev == NULL || errs == 0 || !neglectable_inst_p (decl)) 8064 return false; 8065 8066 for (; lev; lev = lev->next) 8067 if (neglectable_inst_p (lev->decl)) 8068 break; 8069 8070 return (lev && errs > lev->errors); 8071 } 8072 8073 static int tinst_depth; 8074 extern int max_tinst_depth; 8075 #ifdef GATHER_STATISTICS 8076 int depth_reached; 8077 #endif 8078 static GTY(()) struct tinst_level *last_error_tinst_level; 8079 8080 /* We're starting to instantiate D; record the template instantiation context 8081 for diagnostics and to restore it later. */ 8082 8083 int 8084 push_tinst_level (tree d) 8085 { 8086 struct tinst_level *new_level; 8087 8088 if (tinst_depth >= max_tinst_depth) 8089 { 8090 last_error_tinst_level = current_tinst_level; 8091 if (TREE_CODE (d) == TREE_LIST) 8092 error ("template instantiation depth exceeds maximum of %d (use " 8093 "-ftemplate-depth= to increase the maximum) substituting %qS", 8094 max_tinst_depth, d); 8095 else 8096 error ("template instantiation depth exceeds maximum of %d (use " 8097 "-ftemplate-depth= to increase the maximum) instantiating %qD", 8098 max_tinst_depth, d); 8099 8100 print_instantiation_context (); 8101 8102 return 0; 8103 } 8104 8105 /* If the current instantiation caused problems, don't let it instantiate 8106 anything else. Do allow deduction substitution and decls usable in 8107 constant expressions. */ 8108 if (limit_bad_template_recursion (d)) 8109 return 0; 8110 8111 new_level = ggc_alloc_tinst_level (); 8112 new_level->decl = d; 8113 new_level->locus = input_location; 8114 new_level->errors = errorcount+sorrycount; 8115 new_level->in_system_header_p = in_system_header; 8116 new_level->next = current_tinst_level; 8117 current_tinst_level = new_level; 8118 8119 ++tinst_depth; 8120 #ifdef GATHER_STATISTICS 8121 if (tinst_depth > depth_reached) 8122 depth_reached = tinst_depth; 8123 #endif 8124 8125 return 1; 8126 } 8127 8128 /* We're done instantiating this template; return to the instantiation 8129 context. */ 8130 8131 void 8132 pop_tinst_level (void) 8133 { 8134 /* Restore the filename and line number stashed away when we started 8135 this instantiation. */ 8136 input_location = current_tinst_level->locus; 8137 current_tinst_level = current_tinst_level->next; 8138 --tinst_depth; 8139 } 8140 8141 /* We're instantiating a deferred template; restore the template 8142 instantiation context in which the instantiation was requested, which 8143 is one step out from LEVEL. Return the corresponding DECL or TYPE. */ 8144 8145 static tree 8146 reopen_tinst_level (struct tinst_level *level) 8147 { 8148 struct tinst_level *t; 8149 8150 tinst_depth = 0; 8151 for (t = level; t; t = t->next) 8152 ++tinst_depth; 8153 8154 current_tinst_level = level; 8155 pop_tinst_level (); 8156 if (current_tinst_level) 8157 current_tinst_level->errors = errorcount+sorrycount; 8158 return level->decl; 8159 } 8160 8161 /* Returns the TINST_LEVEL which gives the original instantiation 8162 context. */ 8163 8164 struct tinst_level * 8165 outermost_tinst_level (void) 8166 { 8167 struct tinst_level *level = current_tinst_level; 8168 if (level) 8169 while (level->next) 8170 level = level->next; 8171 return level; 8172 } 8173 8174 /* Returns TRUE if PARM is a parameter of the template TEMPL. */ 8175 8176 bool 8177 parameter_of_template_p (tree parm, tree templ) 8178 { 8179 tree parms; 8180 int i; 8181 8182 if (!parm || !templ) 8183 return false; 8184 8185 gcc_assert (DECL_TEMPLATE_PARM_P (parm)); 8186 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL); 8187 8188 parms = DECL_TEMPLATE_PARMS (templ); 8189 parms = INNERMOST_TEMPLATE_PARMS (parms); 8190 8191 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i) 8192 { 8193 tree p = TREE_VALUE (TREE_VEC_ELT (parms, i)); 8194 if (p == error_mark_node) 8195 continue; 8196 8197 if (parm == p 8198 || (DECL_INITIAL (parm) 8199 && DECL_INITIAL (parm) == DECL_INITIAL (p))) 8200 return true; 8201 } 8202 8203 return false; 8204 } 8205 8206 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the 8207 vector of template arguments, as for tsubst. 8208 8209 Returns an appropriate tsubst'd friend declaration. */ 8210 8211 static tree 8212 tsubst_friend_function (tree decl, tree args) 8213 { 8214 tree new_friend; 8215 8216 if (TREE_CODE (decl) == FUNCTION_DECL 8217 && DECL_TEMPLATE_INSTANTIATION (decl) 8218 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL) 8219 /* This was a friend declared with an explicit template 8220 argument list, e.g.: 8221 8222 friend void f<>(T); 8223 8224 to indicate that f was a template instantiation, not a new 8225 function declaration. Now, we have to figure out what 8226 instantiation of what template. */ 8227 { 8228 tree template_id, arglist, fns; 8229 tree new_args; 8230 tree tmpl; 8231 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type)); 8232 8233 /* Friend functions are looked up in the containing namespace scope. 8234 We must enter that scope, to avoid finding member functions of the 8235 current class with same name. */ 8236 push_nested_namespace (ns); 8237 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args, 8238 tf_warning_or_error, NULL_TREE, 8239 /*integral_constant_expression_p=*/false); 8240 pop_nested_namespace (ns); 8241 arglist = tsubst (DECL_TI_ARGS (decl), args, 8242 tf_warning_or_error, NULL_TREE); 8243 template_id = lookup_template_function (fns, arglist); 8244 8245 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE); 8246 tmpl = determine_specialization (template_id, new_friend, 8247 &new_args, 8248 /*need_member_template=*/0, 8249 TREE_VEC_LENGTH (args), 8250 tsk_none); 8251 return instantiate_template (tmpl, new_args, tf_error); 8252 } 8253 8254 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE); 8255 8256 /* The NEW_FRIEND will look like an instantiation, to the 8257 compiler, but is not an instantiation from the point of view of 8258 the language. For example, we might have had: 8259 8260 template <class T> struct S { 8261 template <class U> friend void f(T, U); 8262 }; 8263 8264 Then, in S<int>, template <class U> void f(int, U) is not an 8265 instantiation of anything. */ 8266 if (new_friend == error_mark_node) 8267 return error_mark_node; 8268 8269 DECL_USE_TEMPLATE (new_friend) = 0; 8270 if (TREE_CODE (decl) == TEMPLATE_DECL) 8271 { 8272 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0; 8273 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend)) 8274 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl)); 8275 } 8276 8277 /* The mangled name for the NEW_FRIEND is incorrect. The function 8278 is not a template instantiation and should not be mangled like 8279 one. Therefore, we forget the mangling here; we'll recompute it 8280 later if we need it. */ 8281 if (TREE_CODE (new_friend) != TEMPLATE_DECL) 8282 { 8283 SET_DECL_RTL (new_friend, NULL); 8284 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE); 8285 } 8286 8287 if (DECL_NAMESPACE_SCOPE_P (new_friend)) 8288 { 8289 tree old_decl; 8290 tree new_friend_template_info; 8291 tree new_friend_result_template_info; 8292 tree ns; 8293 int new_friend_is_defn; 8294 8295 /* We must save some information from NEW_FRIEND before calling 8296 duplicate decls since that function will free NEW_FRIEND if 8297 possible. */ 8298 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend); 8299 new_friend_is_defn = 8300 (DECL_INITIAL (DECL_TEMPLATE_RESULT 8301 (template_for_substitution (new_friend))) 8302 != NULL_TREE); 8303 if (TREE_CODE (new_friend) == TEMPLATE_DECL) 8304 { 8305 /* This declaration is a `primary' template. */ 8306 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend; 8307 8308 new_friend_result_template_info 8309 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend)); 8310 } 8311 else 8312 new_friend_result_template_info = NULL_TREE; 8313 8314 /* Make the init_value nonzero so pushdecl knows this is a defn. */ 8315 if (new_friend_is_defn) 8316 DECL_INITIAL (new_friend) = error_mark_node; 8317 8318 /* Inside pushdecl_namespace_level, we will push into the 8319 current namespace. However, the friend function should go 8320 into the namespace of the template. */ 8321 ns = decl_namespace_context (new_friend); 8322 push_nested_namespace (ns); 8323 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true); 8324 pop_nested_namespace (ns); 8325 8326 if (old_decl == error_mark_node) 8327 return error_mark_node; 8328 8329 if (old_decl != new_friend) 8330 { 8331 /* This new friend declaration matched an existing 8332 declaration. For example, given: 8333 8334 template <class T> void f(T); 8335 template <class U> class C { 8336 template <class T> friend void f(T) {} 8337 }; 8338 8339 the friend declaration actually provides the definition 8340 of `f', once C has been instantiated for some type. So, 8341 old_decl will be the out-of-class template declaration, 8342 while new_friend is the in-class definition. 8343 8344 But, if `f' was called before this point, the 8345 instantiation of `f' will have DECL_TI_ARGS corresponding 8346 to `T' but not to `U', references to which might appear 8347 in the definition of `f'. Previously, the most general 8348 template for an instantiation of `f' was the out-of-class 8349 version; now it is the in-class version. Therefore, we 8350 run through all specialization of `f', adding to their 8351 DECL_TI_ARGS appropriately. In particular, they need a 8352 new set of outer arguments, corresponding to the 8353 arguments for this class instantiation. 8354 8355 The same situation can arise with something like this: 8356 8357 friend void f(int); 8358 template <class T> class C { 8359 friend void f(T) {} 8360 }; 8361 8362 when `C<int>' is instantiated. Now, `f(int)' is defined 8363 in the class. */ 8364 8365 if (!new_friend_is_defn) 8366 /* On the other hand, if the in-class declaration does 8367 *not* provide a definition, then we don't want to alter 8368 existing definitions. We can just leave everything 8369 alone. */ 8370 ; 8371 else 8372 { 8373 tree new_template = TI_TEMPLATE (new_friend_template_info); 8374 tree new_args = TI_ARGS (new_friend_template_info); 8375 8376 /* Overwrite whatever template info was there before, if 8377 any, with the new template information pertaining to 8378 the declaration. */ 8379 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info; 8380 8381 if (TREE_CODE (old_decl) != TEMPLATE_DECL) 8382 { 8383 /* We should have called reregister_specialization in 8384 duplicate_decls. */ 8385 gcc_assert (retrieve_specialization (new_template, 8386 new_args, 0) 8387 == old_decl); 8388 8389 /* Instantiate it if the global has already been used. */ 8390 if (DECL_ODR_USED (old_decl)) 8391 instantiate_decl (old_decl, /*defer_ok=*/true, 8392 /*expl_inst_class_mem_p=*/false); 8393 } 8394 else 8395 { 8396 tree t; 8397 8398 /* Indicate that the old function template is a partial 8399 instantiation. */ 8400 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl)) 8401 = new_friend_result_template_info; 8402 8403 gcc_assert (new_template 8404 == most_general_template (new_template)); 8405 gcc_assert (new_template != old_decl); 8406 8407 /* Reassign any specializations already in the hash table 8408 to the new more general template, and add the 8409 additional template args. */ 8410 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl); 8411 t != NULL_TREE; 8412 t = TREE_CHAIN (t)) 8413 { 8414 tree spec = TREE_VALUE (t); 8415 spec_entry elt; 8416 8417 elt.tmpl = old_decl; 8418 elt.args = DECL_TI_ARGS (spec); 8419 elt.spec = NULL_TREE; 8420 8421 htab_remove_elt (decl_specializations, &elt); 8422 8423 DECL_TI_ARGS (spec) 8424 = add_outermost_template_args (new_args, 8425 DECL_TI_ARGS (spec)); 8426 8427 register_specialization 8428 (spec, new_template, DECL_TI_ARGS (spec), true, 0); 8429 8430 } 8431 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE; 8432 } 8433 } 8434 8435 /* The information from NEW_FRIEND has been merged into OLD_DECL 8436 by duplicate_decls. */ 8437 new_friend = old_decl; 8438 } 8439 } 8440 else 8441 { 8442 tree context = DECL_CONTEXT (new_friend); 8443 bool dependent_p; 8444 8445 /* In the code 8446 template <class T> class C { 8447 template <class U> friend void C1<U>::f (); // case 1 8448 friend void C2<T>::f (); // case 2 8449 }; 8450 we only need to make sure CONTEXT is a complete type for 8451 case 2. To distinguish between the two cases, we note that 8452 CONTEXT of case 1 remains dependent type after tsubst while 8453 this isn't true for case 2. */ 8454 ++processing_template_decl; 8455 dependent_p = dependent_type_p (context); 8456 --processing_template_decl; 8457 8458 if (!dependent_p 8459 && !complete_type_or_else (context, NULL_TREE)) 8460 return error_mark_node; 8461 8462 if (COMPLETE_TYPE_P (context)) 8463 { 8464 /* Check to see that the declaration is really present, and, 8465 possibly obtain an improved declaration. */ 8466 tree fn = check_classfn (context, 8467 new_friend, NULL_TREE); 8468 8469 if (fn) 8470 new_friend = fn; 8471 } 8472 } 8473 8474 return new_friend; 8475 } 8476 8477 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of 8478 template arguments, as for tsubst. 8479 8480 Returns an appropriate tsubst'd friend type or error_mark_node on 8481 failure. */ 8482 8483 static tree 8484 tsubst_friend_class (tree friend_tmpl, tree args) 8485 { 8486 tree friend_type; 8487 tree tmpl; 8488 tree context; 8489 8490 context = CP_DECL_CONTEXT (friend_tmpl); 8491 8492 if (context != global_namespace) 8493 { 8494 if (TREE_CODE (context) == NAMESPACE_DECL) 8495 push_nested_namespace (context); 8496 else 8497 push_nested_class (tsubst (context, args, tf_none, NULL_TREE)); 8498 } 8499 8500 /* Look for a class template declaration. We look for hidden names 8501 because two friend declarations of the same template are the 8502 same. For example, in: 8503 8504 struct A { 8505 template <typename> friend class F; 8506 }; 8507 template <typename> struct B { 8508 template <typename> friend class F; 8509 }; 8510 8511 both F templates are the same. */ 8512 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0, 8513 /*block_p=*/true, 0, 8514 LOOKUP_COMPLAIN | LOOKUP_HIDDEN); 8515 8516 /* But, if we don't find one, it might be because we're in a 8517 situation like this: 8518 8519 template <class T> 8520 struct S { 8521 template <class U> 8522 friend struct S; 8523 }; 8524 8525 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL 8526 for `S<int>', not the TEMPLATE_DECL. */ 8527 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl)) 8528 { 8529 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1); 8530 tmpl = maybe_get_template_decl_from_type_decl (tmpl); 8531 } 8532 8533 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl)) 8534 { 8535 /* The friend template has already been declared. Just 8536 check to see that the declarations match, and install any new 8537 default parameters. We must tsubst the default parameters, 8538 of course. We only need the innermost template parameters 8539 because that is all that redeclare_class_template will look 8540 at. */ 8541 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl)) 8542 > TMPL_ARGS_DEPTH (args)) 8543 { 8544 tree parms; 8545 location_t saved_input_location; 8546 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl), 8547 args, tf_warning_or_error); 8548 8549 saved_input_location = input_location; 8550 input_location = DECL_SOURCE_LOCATION (friend_tmpl); 8551 redeclare_class_template (TREE_TYPE (tmpl), parms); 8552 input_location = saved_input_location; 8553 8554 } 8555 8556 friend_type = TREE_TYPE (tmpl); 8557 } 8558 else 8559 { 8560 /* The friend template has not already been declared. In this 8561 case, the instantiation of the template class will cause the 8562 injection of this template into the global scope. */ 8563 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE); 8564 if (tmpl == error_mark_node) 8565 return error_mark_node; 8566 8567 /* The new TMPL is not an instantiation of anything, so we 8568 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for 8569 the new type because that is supposed to be the corresponding 8570 template decl, i.e., TMPL. */ 8571 DECL_USE_TEMPLATE (tmpl) = 0; 8572 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE; 8573 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0; 8574 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)) 8575 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))); 8576 8577 /* Inject this template into the global scope. */ 8578 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true)); 8579 } 8580 8581 if (context != global_namespace) 8582 { 8583 if (TREE_CODE (context) == NAMESPACE_DECL) 8584 pop_nested_namespace (context); 8585 else 8586 pop_nested_class (); 8587 } 8588 8589 return friend_type; 8590 } 8591 8592 /* Returns zero if TYPE cannot be completed later due to circularity. 8593 Otherwise returns one. */ 8594 8595 static int 8596 can_complete_type_without_circularity (tree type) 8597 { 8598 if (type == NULL_TREE || type == error_mark_node) 8599 return 0; 8600 else if (COMPLETE_TYPE_P (type)) 8601 return 1; 8602 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type)) 8603 return can_complete_type_without_circularity (TREE_TYPE (type)); 8604 else if (CLASS_TYPE_P (type) 8605 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type))) 8606 return 0; 8607 else 8608 return 1; 8609 } 8610 8611 /* Apply any attributes which had to be deferred until instantiation 8612 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes; 8613 ARGS, COMPLAIN, IN_DECL are as tsubst. */ 8614 8615 static void 8616 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags, 8617 tree args, tsubst_flags_t complain, tree in_decl) 8618 { 8619 tree last_dep = NULL_TREE; 8620 tree t; 8621 tree *p; 8622 8623 for (t = attributes; t; t = TREE_CHAIN (t)) 8624 if (ATTR_IS_DEPENDENT (t)) 8625 { 8626 last_dep = t; 8627 attributes = copy_list (attributes); 8628 break; 8629 } 8630 8631 if (DECL_P (*decl_p)) 8632 { 8633 if (TREE_TYPE (*decl_p) == error_mark_node) 8634 return; 8635 p = &DECL_ATTRIBUTES (*decl_p); 8636 } 8637 else 8638 p = &TYPE_ATTRIBUTES (*decl_p); 8639 8640 if (last_dep) 8641 { 8642 tree late_attrs = NULL_TREE; 8643 tree *q = &late_attrs; 8644 8645 for (*p = attributes; *p; ) 8646 { 8647 t = *p; 8648 if (ATTR_IS_DEPENDENT (t)) 8649 { 8650 *p = TREE_CHAIN (t); 8651 TREE_CHAIN (t) = NULL_TREE; 8652 /* If the first attribute argument is an identifier, don't 8653 pass it through tsubst. Attributes like mode, format, 8654 cleanup and several target specific attributes expect it 8655 unmodified. */ 8656 if (TREE_VALUE (t) 8657 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST 8658 && TREE_VALUE (TREE_VALUE (t)) 8659 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t))) 8660 == IDENTIFIER_NODE)) 8661 { 8662 tree chain 8663 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain, 8664 in_decl, 8665 /*integral_constant_expression_p=*/false); 8666 if (chain != TREE_CHAIN (TREE_VALUE (t))) 8667 TREE_VALUE (t) 8668 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)), 8669 chain); 8670 } 8671 else 8672 TREE_VALUE (t) 8673 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl, 8674 /*integral_constant_expression_p=*/false); 8675 *q = t; 8676 q = &TREE_CHAIN (t); 8677 } 8678 else 8679 p = &TREE_CHAIN (t); 8680 } 8681 8682 cplus_decl_attributes (decl_p, late_attrs, attr_flags); 8683 } 8684 } 8685 8686 /* Perform (or defer) access check for typedefs that were referenced 8687 from within the template TMPL code. 8688 This is a subroutine of instantiate_template and instantiate_class_template. 8689 TMPL is the template to consider and TARGS is the list of arguments of 8690 that template. */ 8691 8692 static void 8693 perform_typedefs_access_check (tree tmpl, tree targs) 8694 { 8695 location_t saved_location; 8696 int i; 8697 qualified_typedef_usage_t *iter; 8698 8699 if (!tmpl 8700 || (!CLASS_TYPE_P (tmpl) 8701 && TREE_CODE (tmpl) != FUNCTION_DECL)) 8702 return; 8703 8704 saved_location = input_location; 8705 FOR_EACH_VEC_ELT (qualified_typedef_usage_t, 8706 get_types_needing_access_check (tmpl), 8707 i, iter) 8708 { 8709 tree type_decl = iter->typedef_decl; 8710 tree type_scope = iter->context; 8711 8712 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope)) 8713 continue; 8714 8715 if (uses_template_parms (type_decl)) 8716 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE); 8717 if (uses_template_parms (type_scope)) 8718 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE); 8719 8720 /* Make access check error messages point to the location 8721 of the use of the typedef. */ 8722 input_location = iter->locus; 8723 perform_or_defer_access_check (TYPE_BINFO (type_scope), 8724 type_decl, type_decl); 8725 } 8726 input_location = saved_location; 8727 } 8728 8729 static tree 8730 instantiate_class_template_1 (tree type) 8731 { 8732 tree templ, args, pattern, t, member; 8733 tree typedecl; 8734 tree pbinfo; 8735 tree base_list; 8736 unsigned int saved_maximum_field_alignment; 8737 tree fn_context; 8738 8739 if (type == error_mark_node) 8740 return error_mark_node; 8741 8742 if (COMPLETE_OR_OPEN_TYPE_P (type) 8743 || uses_template_parms (type)) 8744 return type; 8745 8746 /* Figure out which template is being instantiated. */ 8747 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type)); 8748 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL); 8749 8750 /* Determine what specialization of the original template to 8751 instantiate. */ 8752 t = most_specialized_class (type, templ, tf_warning_or_error); 8753 if (t == error_mark_node) 8754 { 8755 TYPE_BEING_DEFINED (type) = 1; 8756 return error_mark_node; 8757 } 8758 else if (t) 8759 { 8760 /* This TYPE is actually an instantiation of a partial 8761 specialization. We replace the innermost set of ARGS with 8762 the arguments appropriate for substitution. For example, 8763 given: 8764 8765 template <class T> struct S {}; 8766 template <class T> struct S<T*> {}; 8767 8768 and supposing that we are instantiating S<int*>, ARGS will 8769 presently be {int*} -- but we need {int}. */ 8770 pattern = TREE_TYPE (t); 8771 args = TREE_PURPOSE (t); 8772 } 8773 else 8774 { 8775 pattern = TREE_TYPE (templ); 8776 args = CLASSTYPE_TI_ARGS (type); 8777 } 8778 8779 /* If the template we're instantiating is incomplete, then clearly 8780 there's nothing we can do. */ 8781 if (!COMPLETE_TYPE_P (pattern)) 8782 return type; 8783 8784 /* If we've recursively instantiated too many templates, stop. */ 8785 if (! push_tinst_level (type)) 8786 return type; 8787 8788 /* Now we're really doing the instantiation. Mark the type as in 8789 the process of being defined. */ 8790 TYPE_BEING_DEFINED (type) = 1; 8791 8792 /* We may be in the middle of deferred access check. Disable 8793 it now. */ 8794 push_deferring_access_checks (dk_no_deferred); 8795 8796 fn_context = decl_function_context (TYPE_MAIN_DECL (type)); 8797 if (!fn_context) 8798 push_to_top_level (); 8799 /* Use #pragma pack from the template context. */ 8800 saved_maximum_field_alignment = maximum_field_alignment; 8801 maximum_field_alignment = TYPE_PRECISION (pattern); 8802 8803 SET_CLASSTYPE_INTERFACE_UNKNOWN (type); 8804 8805 /* Set the input location to the most specialized template definition. 8806 This is needed if tsubsting causes an error. */ 8807 typedecl = TYPE_MAIN_DECL (pattern); 8808 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (type)) = 8809 DECL_SOURCE_LOCATION (typedecl); 8810 8811 TYPE_PACKED (type) = TYPE_PACKED (pattern); 8812 TYPE_ALIGN (type) = TYPE_ALIGN (pattern); 8813 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern); 8814 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */ 8815 if (ANON_AGGR_TYPE_P (pattern)) 8816 SET_ANON_AGGR_TYPE_P (type); 8817 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern)) 8818 { 8819 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1; 8820 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern); 8821 /* Adjust visibility for template arguments. */ 8822 determine_visibility (TYPE_MAIN_DECL (type)); 8823 } 8824 CLASSTYPE_FINAL (type) = CLASSTYPE_FINAL (pattern); 8825 8826 pbinfo = TYPE_BINFO (pattern); 8827 8828 /* We should never instantiate a nested class before its enclosing 8829 class; we need to look up the nested class by name before we can 8830 instantiate it, and that lookup should instantiate the enclosing 8831 class. */ 8832 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern)) 8833 || COMPLETE_OR_OPEN_TYPE_P (TYPE_CONTEXT (type))); 8834 8835 base_list = NULL_TREE; 8836 if (BINFO_N_BASE_BINFOS (pbinfo)) 8837 { 8838 tree pbase_binfo; 8839 tree pushed_scope; 8840 int i; 8841 8842 /* We must enter the scope containing the type, as that is where 8843 the accessibility of types named in dependent bases are 8844 looked up from. */ 8845 pushed_scope = push_scope (CP_TYPE_CONTEXT (type)); 8846 8847 /* Substitute into each of the bases to determine the actual 8848 basetypes. */ 8849 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++) 8850 { 8851 tree base; 8852 tree access = BINFO_BASE_ACCESS (pbinfo, i); 8853 tree expanded_bases = NULL_TREE; 8854 int idx, len = 1; 8855 8856 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo))) 8857 { 8858 expanded_bases = 8859 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo), 8860 args, tf_error, NULL_TREE); 8861 if (expanded_bases == error_mark_node) 8862 continue; 8863 8864 len = TREE_VEC_LENGTH (expanded_bases); 8865 } 8866 8867 for (idx = 0; idx < len; idx++) 8868 { 8869 if (expanded_bases) 8870 /* Extract the already-expanded base class. */ 8871 base = TREE_VEC_ELT (expanded_bases, idx); 8872 else 8873 /* Substitute to figure out the base class. */ 8874 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error, 8875 NULL_TREE); 8876 8877 if (base == error_mark_node) 8878 continue; 8879 8880 base_list = tree_cons (access, base, base_list); 8881 if (BINFO_VIRTUAL_P (pbase_binfo)) 8882 TREE_TYPE (base_list) = integer_type_node; 8883 } 8884 } 8885 8886 /* The list is now in reverse order; correct that. */ 8887 base_list = nreverse (base_list); 8888 8889 if (pushed_scope) 8890 pop_scope (pushed_scope); 8891 } 8892 /* Now call xref_basetypes to set up all the base-class 8893 information. */ 8894 xref_basetypes (type, base_list); 8895 8896 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern), 8897 (int) ATTR_FLAG_TYPE_IN_PLACE, 8898 args, tf_error, NULL_TREE); 8899 fixup_attribute_variants (type); 8900 8901 /* Now that our base classes are set up, enter the scope of the 8902 class, so that name lookups into base classes, etc. will work 8903 correctly. This is precisely analogous to what we do in 8904 begin_class_definition when defining an ordinary non-template 8905 class, except we also need to push the enclosing classes. */ 8906 push_nested_class (type); 8907 8908 /* Now members are processed in the order of declaration. */ 8909 for (member = CLASSTYPE_DECL_LIST (pattern); 8910 member; member = TREE_CHAIN (member)) 8911 { 8912 tree t = TREE_VALUE (member); 8913 8914 if (TREE_PURPOSE (member)) 8915 { 8916 if (TYPE_P (t)) 8917 { 8918 /* Build new CLASSTYPE_NESTED_UTDS. */ 8919 8920 tree newtag; 8921 bool class_template_p; 8922 8923 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE 8924 && TYPE_LANG_SPECIFIC (t) 8925 && CLASSTYPE_IS_TEMPLATE (t)); 8926 /* If the member is a class template, then -- even after 8927 substitution -- there may be dependent types in the 8928 template argument list for the class. We increment 8929 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as 8930 that function will assume that no types are dependent 8931 when outside of a template. */ 8932 if (class_template_p) 8933 ++processing_template_decl; 8934 newtag = tsubst (t, args, tf_error, NULL_TREE); 8935 if (class_template_p) 8936 --processing_template_decl; 8937 if (newtag == error_mark_node) 8938 continue; 8939 8940 if (TREE_CODE (newtag) != ENUMERAL_TYPE) 8941 { 8942 tree name = TYPE_IDENTIFIER (t); 8943 8944 if (class_template_p) 8945 /* Unfortunately, lookup_template_class sets 8946 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial 8947 instantiation (i.e., for the type of a member 8948 template class nested within a template class.) 8949 This behavior is required for 8950 maybe_process_partial_specialization to work 8951 correctly, but is not accurate in this case; 8952 the TAG is not an instantiation of anything. 8953 (The corresponding TEMPLATE_DECL is an 8954 instantiation, but the TYPE is not.) */ 8955 CLASSTYPE_USE_TEMPLATE (newtag) = 0; 8956 8957 /* Now, we call pushtag to put this NEWTAG into the scope of 8958 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid 8959 pushtag calling push_template_decl. We don't have to do 8960 this for enums because it will already have been done in 8961 tsubst_enum. */ 8962 if (name) 8963 SET_IDENTIFIER_TYPE_VALUE (name, newtag); 8964 pushtag (name, newtag, /*tag_scope=*/ts_current); 8965 } 8966 } 8967 else if (TREE_CODE (t) == FUNCTION_DECL 8968 || DECL_FUNCTION_TEMPLATE_P (t)) 8969 { 8970 /* Build new TYPE_METHODS. */ 8971 tree r; 8972 8973 if (TREE_CODE (t) == TEMPLATE_DECL) 8974 ++processing_template_decl; 8975 r = tsubst (t, args, tf_error, NULL_TREE); 8976 if (TREE_CODE (t) == TEMPLATE_DECL) 8977 --processing_template_decl; 8978 set_current_access_from_decl (r); 8979 finish_member_declaration (r); 8980 /* Instantiate members marked with attribute used. */ 8981 if (r != error_mark_node && DECL_PRESERVE_P (r)) 8982 mark_used (r); 8983 } 8984 else 8985 { 8986 /* Build new TYPE_FIELDS. */ 8987 if (TREE_CODE (t) == STATIC_ASSERT) 8988 { 8989 tree condition = 8990 tsubst_expr (STATIC_ASSERT_CONDITION (t), args, 8991 tf_warning_or_error, NULL_TREE, 8992 /*integral_constant_expression_p=*/true); 8993 finish_static_assert (condition, 8994 STATIC_ASSERT_MESSAGE (t), 8995 STATIC_ASSERT_SOURCE_LOCATION (t), 8996 /*member_p=*/true); 8997 } 8998 else if (TREE_CODE (t) != CONST_DECL) 8999 { 9000 tree r; 9001 9002 /* The file and line for this declaration, to 9003 assist in error message reporting. Since we 9004 called push_tinst_level above, we don't need to 9005 restore these. */ 9006 input_location = DECL_SOURCE_LOCATION (t); 9007 9008 if (TREE_CODE (t) == TEMPLATE_DECL) 9009 ++processing_template_decl; 9010 r = tsubst (t, args, tf_warning_or_error, NULL_TREE); 9011 if (TREE_CODE (t) == TEMPLATE_DECL) 9012 --processing_template_decl; 9013 if (TREE_CODE (r) == VAR_DECL) 9014 { 9015 /* In [temp.inst]: 9016 9017 [t]he initialization (and any associated 9018 side-effects) of a static data member does 9019 not occur unless the static data member is 9020 itself used in a way that requires the 9021 definition of the static data member to 9022 exist. 9023 9024 Therefore, we do not substitute into the 9025 initialized for the static data member here. */ 9026 finish_static_data_member_decl 9027 (r, 9028 /*init=*/NULL_TREE, 9029 /*init_const_expr_p=*/false, 9030 /*asmspec_tree=*/NULL_TREE, 9031 /*flags=*/0); 9032 /* Instantiate members marked with attribute used. */ 9033 if (r != error_mark_node && DECL_PRESERVE_P (r)) 9034 mark_used (r); 9035 } 9036 else if (TREE_CODE (r) == FIELD_DECL) 9037 { 9038 /* Determine whether R has a valid type and can be 9039 completed later. If R is invalid, then it is 9040 replaced by error_mark_node so that it will not be 9041 added to TYPE_FIELDS. */ 9042 tree rtype = TREE_TYPE (r); 9043 if (can_complete_type_without_circularity (rtype)) 9044 complete_type (rtype); 9045 9046 if (!COMPLETE_TYPE_P (rtype)) 9047 { 9048 cxx_incomplete_type_error (r, rtype); 9049 r = error_mark_node; 9050 } 9051 } 9052 9053 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE, 9054 such a thing will already have been added to the field 9055 list by tsubst_enum in finish_member_declaration in the 9056 CLASSTYPE_NESTED_UTDS case above. */ 9057 if (!(TREE_CODE (r) == TYPE_DECL 9058 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE 9059 && DECL_ARTIFICIAL (r))) 9060 { 9061 set_current_access_from_decl (r); 9062 finish_member_declaration (r); 9063 } 9064 } 9065 } 9066 } 9067 else 9068 { 9069 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t)) 9070 { 9071 /* Build new CLASSTYPE_FRIEND_CLASSES. */ 9072 9073 tree friend_type = t; 9074 bool adjust_processing_template_decl = false; 9075 9076 if (TREE_CODE (friend_type) == TEMPLATE_DECL) 9077 { 9078 /* template <class T> friend class C; */ 9079 friend_type = tsubst_friend_class (friend_type, args); 9080 adjust_processing_template_decl = true; 9081 } 9082 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE) 9083 { 9084 /* template <class T> friend class C::D; */ 9085 friend_type = tsubst (friend_type, args, 9086 tf_warning_or_error, NULL_TREE); 9087 if (TREE_CODE (friend_type) == TEMPLATE_DECL) 9088 friend_type = TREE_TYPE (friend_type); 9089 adjust_processing_template_decl = true; 9090 } 9091 else if (TREE_CODE (friend_type) == TYPENAME_TYPE 9092 || TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM) 9093 { 9094 /* This could be either 9095 9096 friend class T::C; 9097 9098 when dependent_type_p is false or 9099 9100 template <class U> friend class T::C; 9101 9102 otherwise. */ 9103 friend_type = tsubst (friend_type, args, 9104 tf_warning_or_error, NULL_TREE); 9105 /* Bump processing_template_decl for correct 9106 dependent_type_p calculation. */ 9107 ++processing_template_decl; 9108 if (dependent_type_p (friend_type)) 9109 adjust_processing_template_decl = true; 9110 --processing_template_decl; 9111 } 9112 else if (!CLASSTYPE_USE_TEMPLATE (friend_type) 9113 && hidden_name_p (TYPE_NAME (friend_type))) 9114 { 9115 /* friend class C; 9116 9117 where C hasn't been declared yet. Let's lookup name 9118 from namespace scope directly, bypassing any name that 9119 come from dependent base class. */ 9120 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type)); 9121 9122 /* The call to xref_tag_from_type does injection for friend 9123 classes. */ 9124 push_nested_namespace (ns); 9125 friend_type = 9126 xref_tag_from_type (friend_type, NULL_TREE, 9127 /*tag_scope=*/ts_current); 9128 pop_nested_namespace (ns); 9129 } 9130 else if (uses_template_parms (friend_type)) 9131 /* friend class C<T>; */ 9132 friend_type = tsubst (friend_type, args, 9133 tf_warning_or_error, NULL_TREE); 9134 /* Otherwise it's 9135 9136 friend class C; 9137 9138 where C is already declared or 9139 9140 friend class C<int>; 9141 9142 We don't have to do anything in these cases. */ 9143 9144 if (adjust_processing_template_decl) 9145 /* Trick make_friend_class into realizing that the friend 9146 we're adding is a template, not an ordinary class. It's 9147 important that we use make_friend_class since it will 9148 perform some error-checking and output cross-reference 9149 information. */ 9150 ++processing_template_decl; 9151 9152 if (friend_type != error_mark_node) 9153 make_friend_class (type, friend_type, /*complain=*/false); 9154 9155 if (adjust_processing_template_decl) 9156 --processing_template_decl; 9157 } 9158 else 9159 { 9160 /* Build new DECL_FRIENDLIST. */ 9161 tree r; 9162 9163 /* The file and line for this declaration, to 9164 assist in error message reporting. Since we 9165 called push_tinst_level above, we don't need to 9166 restore these. */ 9167 input_location = DECL_SOURCE_LOCATION (t); 9168 9169 if (TREE_CODE (t) == TEMPLATE_DECL) 9170 { 9171 ++processing_template_decl; 9172 push_deferring_access_checks (dk_no_check); 9173 } 9174 9175 r = tsubst_friend_function (t, args); 9176 add_friend (type, r, /*complain=*/false); 9177 if (TREE_CODE (t) == TEMPLATE_DECL) 9178 { 9179 pop_deferring_access_checks (); 9180 --processing_template_decl; 9181 } 9182 } 9183 } 9184 } 9185 9186 if (CLASSTYPE_LAMBDA_EXPR (type)) 9187 { 9188 tree decl = lambda_function (type); 9189 if (decl) 9190 { 9191 tree lambda = CLASSTYPE_LAMBDA_EXPR (type); 9192 if (LAMBDA_EXPR_DEDUCE_RETURN_TYPE_P (lambda)) 9193 { 9194 apply_lambda_return_type (lambda, void_type_node); 9195 LAMBDA_EXPR_RETURN_TYPE (lambda) = NULL_TREE; 9196 } 9197 9198 LAMBDA_EXPR_THIS_CAPTURE (lambda) 9199 = lookup_field_1 (type, get_identifier ("__this"), false); 9200 9201 instantiate_decl (decl, false, false); 9202 maybe_add_lambda_conv_op (type); 9203 9204 LAMBDA_EXPR_THIS_CAPTURE (lambda) = NULL_TREE; 9205 } 9206 else 9207 gcc_assert (errorcount); 9208 } 9209 9210 /* Set the file and line number information to whatever is given for 9211 the class itself. This puts error messages involving generated 9212 implicit functions at a predictable point, and the same point 9213 that would be used for non-template classes. */ 9214 input_location = DECL_SOURCE_LOCATION (typedecl); 9215 9216 unreverse_member_declarations (type); 9217 finish_struct_1 (type); 9218 TYPE_BEING_DEFINED (type) = 0; 9219 9220 /* We don't instantiate default arguments for member functions. 14.7.1: 9221 9222 The implicit instantiation of a class template specialization causes 9223 the implicit instantiation of the declarations, but not of the 9224 definitions or default arguments, of the class member functions, 9225 member classes, static data members and member templates.... */ 9226 9227 /* Some typedefs referenced from within the template code need to be access 9228 checked at template instantiation time, i.e now. These types were 9229 added to the template at parsing time. Let's get those and perform 9230 the access checks then. */ 9231 perform_typedefs_access_check (pattern, args); 9232 perform_deferred_access_checks (); 9233 pop_nested_class (); 9234 maximum_field_alignment = saved_maximum_field_alignment; 9235 if (!fn_context) 9236 pop_from_top_level (); 9237 pop_deferring_access_checks (); 9238 pop_tinst_level (); 9239 9240 /* The vtable for a template class can be emitted in any translation 9241 unit in which the class is instantiated. When there is no key 9242 method, however, finish_struct_1 will already have added TYPE to 9243 the keyed_classes list. */ 9244 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type)) 9245 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes); 9246 9247 return type; 9248 } 9249 9250 /* Wrapper for instantiate_class_template_1. */ 9251 9252 tree 9253 instantiate_class_template (tree type) 9254 { 9255 tree ret; 9256 timevar_push (TV_TEMPLATE_INST); 9257 ret = instantiate_class_template_1 (type); 9258 timevar_pop (TV_TEMPLATE_INST); 9259 return ret; 9260 } 9261 9262 static tree 9263 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl) 9264 { 9265 tree r; 9266 9267 if (!t) 9268 r = t; 9269 else if (TYPE_P (t)) 9270 r = tsubst (t, args, complain, in_decl); 9271 else 9272 { 9273 if (!(complain & tf_warning)) 9274 ++c_inhibit_evaluation_warnings; 9275 r = tsubst_expr (t, args, complain, in_decl, 9276 /*integral_constant_expression_p=*/true); 9277 if (!(complain & tf_warning)) 9278 --c_inhibit_evaluation_warnings; 9279 /* Preserve the raw-reference nature of T. */ 9280 if (TREE_TYPE (t) && TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE 9281 && REFERENCE_REF_P (r)) 9282 r = TREE_OPERAND (r, 0); 9283 } 9284 return r; 9285 } 9286 9287 /* Given a function parameter pack TMPL_PARM and some function parameters 9288 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them 9289 and set *SPEC_P to point at the next point in the list. */ 9290 9291 static tree 9292 extract_fnparm_pack (tree tmpl_parm, tree *spec_p) 9293 { 9294 /* Collect all of the extra "packed" parameters into an 9295 argument pack. */ 9296 tree parmvec; 9297 tree parmtypevec; 9298 tree argpack = make_node (NONTYPE_ARGUMENT_PACK); 9299 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK); 9300 tree spec_parm = *spec_p; 9301 int i, len; 9302 9303 for (len = 0; spec_parm; ++len, spec_parm = TREE_CHAIN (spec_parm)) 9304 if (tmpl_parm 9305 && !function_parameter_expanded_from_pack_p (spec_parm, tmpl_parm)) 9306 break; 9307 9308 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */ 9309 parmvec = make_tree_vec (len); 9310 parmtypevec = make_tree_vec (len); 9311 spec_parm = *spec_p; 9312 for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm)) 9313 { 9314 TREE_VEC_ELT (parmvec, i) = spec_parm; 9315 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm); 9316 } 9317 9318 /* Build the argument packs. */ 9319 SET_ARGUMENT_PACK_ARGS (argpack, parmvec); 9320 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec); 9321 TREE_TYPE (argpack) = argtypepack; 9322 *spec_p = spec_parm; 9323 9324 return argpack; 9325 } 9326 9327 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a 9328 NONTYPE_ARGUMENT_PACK. */ 9329 9330 static tree 9331 make_fnparm_pack (tree spec_parm) 9332 { 9333 return extract_fnparm_pack (NULL_TREE, &spec_parm); 9334 } 9335 9336 /* Substitute ARGS into T, which is an pack expansion 9337 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a 9338 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node 9339 (if only a partial substitution could be performed) or 9340 ERROR_MARK_NODE if there was an error. */ 9341 tree 9342 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain, 9343 tree in_decl) 9344 { 9345 tree pattern; 9346 tree pack, packs = NULL_TREE; 9347 bool unsubstituted_packs = false; 9348 bool real_packs = false; 9349 int missing_level = 0; 9350 int i, len = -1; 9351 tree result; 9352 htab_t saved_local_specializations = NULL; 9353 bool need_local_specializations = false; 9354 int levels; 9355 9356 gcc_assert (PACK_EXPANSION_P (t)); 9357 pattern = PACK_EXPANSION_PATTERN (t); 9358 9359 /* Add in any args remembered from an earlier partial instantiation. */ 9360 args = add_to_template_args (PACK_EXPANSION_EXTRA_ARGS (t), args); 9361 9362 levels = TMPL_ARGS_DEPTH (args); 9363 9364 /* Determine the argument packs that will instantiate the parameter 9365 packs used in the expansion expression. While we're at it, 9366 compute the number of arguments to be expanded and make sure it 9367 is consistent. */ 9368 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack; 9369 pack = TREE_CHAIN (pack)) 9370 { 9371 tree parm_pack = TREE_VALUE (pack); 9372 tree arg_pack = NULL_TREE; 9373 tree orig_arg = NULL_TREE; 9374 int level = 0; 9375 9376 if (TREE_CODE (parm_pack) == BASES) 9377 { 9378 if (BASES_DIRECT (parm_pack)) 9379 return calculate_direct_bases (tsubst_expr (BASES_TYPE (parm_pack), 9380 args, complain, in_decl, false)); 9381 else 9382 return calculate_bases (tsubst_expr (BASES_TYPE (parm_pack), 9383 args, complain, in_decl, false)); 9384 } 9385 if (TREE_CODE (parm_pack) == PARM_DECL) 9386 { 9387 if (PACK_EXPANSION_LOCAL_P (t)) 9388 arg_pack = retrieve_local_specialization (parm_pack); 9389 else 9390 { 9391 /* We can't rely on local_specializations for a parameter 9392 name used later in a function declaration (such as in a 9393 late-specified return type). Even if it exists, it might 9394 have the wrong value for a recursive call. Just make a 9395 dummy decl, since it's only used for its type. */ 9396 /* Copy before tsubsting so that we don't recurse into any 9397 later PARM_DECLs. */ 9398 arg_pack = tsubst_decl (copy_node (parm_pack), args, complain); 9399 if (arg_pack && FUNCTION_PARAMETER_PACK_P (arg_pack)) 9400 /* Partial instantiation of the parm_pack, we can't build 9401 up an argument pack yet. */ 9402 arg_pack = NULL_TREE; 9403 else 9404 arg_pack = make_fnparm_pack (arg_pack); 9405 need_local_specializations = true; 9406 } 9407 } 9408 else 9409 { 9410 int idx; 9411 template_parm_level_and_index (parm_pack, &level, &idx); 9412 9413 if (level <= levels) 9414 arg_pack = TMPL_ARG (args, level, idx); 9415 } 9416 9417 orig_arg = arg_pack; 9418 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT) 9419 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack); 9420 9421 if (arg_pack && !ARGUMENT_PACK_P (arg_pack)) 9422 /* This can only happen if we forget to expand an argument 9423 pack somewhere else. Just return an error, silently. */ 9424 { 9425 result = make_tree_vec (1); 9426 TREE_VEC_ELT (result, 0) = error_mark_node; 9427 return result; 9428 } 9429 9430 if (arg_from_parm_pack_p (arg_pack, parm_pack)) 9431 /* The argument pack that the parameter maps to is just an 9432 expansion of the parameter itself, such as one would find 9433 in the implicit typedef of a class inside the class itself. 9434 Consider this parameter "unsubstituted", so that we will 9435 maintain the outer pack expansion. */ 9436 arg_pack = NULL_TREE; 9437 9438 if (arg_pack) 9439 { 9440 int my_len = 9441 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)); 9442 9443 /* Don't bother trying to do a partial substitution with 9444 incomplete packs; we'll try again after deduction. */ 9445 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack)) 9446 return t; 9447 9448 if (len < 0) 9449 len = my_len; 9450 else if (len != my_len) 9451 { 9452 if (!(complain & tf_error)) 9453 /* Fail quietly. */; 9454 else if (TREE_CODE (t) == TYPE_PACK_EXPANSION) 9455 error ("mismatched argument pack lengths while expanding " 9456 "%<%T%>", 9457 pattern); 9458 else 9459 error ("mismatched argument pack lengths while expanding " 9460 "%<%E%>", 9461 pattern); 9462 return error_mark_node; 9463 } 9464 9465 if (TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1 9466 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 9467 0))) 9468 /* This isn't a real argument pack yet. */; 9469 else 9470 real_packs = true; 9471 9472 /* Keep track of the parameter packs and their corresponding 9473 argument packs. */ 9474 packs = tree_cons (parm_pack, arg_pack, packs); 9475 TREE_TYPE (packs) = orig_arg; 9476 } 9477 else 9478 { 9479 /* We can't substitute for this parameter pack. We use a flag as 9480 well as the missing_level counter because function parameter 9481 packs don't have a level. */ 9482 unsubstituted_packs = true; 9483 if (!missing_level || missing_level > level) 9484 missing_level = level; 9485 } 9486 } 9487 9488 /* We cannot expand this expansion expression, because we don't have 9489 all of the argument packs we need. */ 9490 if (unsubstituted_packs) 9491 { 9492 if (real_packs) 9493 { 9494 /* We got some full packs, but we can't substitute them in until we 9495 have values for all the packs. So remember these until then. */ 9496 tree save_args; 9497 9498 t = make_pack_expansion (pattern); 9499 9500 /* The call to add_to_template_args above assumes no overlap 9501 between saved args and new args, so prune away any fake 9502 args, i.e. those that satisfied arg_from_parm_pack_p above. */ 9503 if (missing_level && levels >= missing_level) 9504 { 9505 gcc_assert (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args) 9506 && missing_level > 1); 9507 TREE_VEC_LENGTH (args) = missing_level - 1; 9508 save_args = copy_node (args); 9509 TREE_VEC_LENGTH (args) = levels; 9510 } 9511 else 9512 save_args = args; 9513 9514 PACK_EXPANSION_EXTRA_ARGS (t) = save_args; 9515 } 9516 else 9517 { 9518 /* There were no real arguments, we're just replacing a parameter 9519 pack with another version of itself. Substitute into the 9520 pattern and return a PACK_EXPANSION_*. The caller will need to 9521 deal with that. */ 9522 if (TREE_CODE (t) == EXPR_PACK_EXPANSION) 9523 t = tsubst_expr (pattern, args, complain, in_decl, 9524 /*integral_constant_expression_p=*/false); 9525 else 9526 t = tsubst (pattern, args, complain, in_decl); 9527 t = make_pack_expansion (t); 9528 } 9529 return t; 9530 } 9531 9532 /* We could not find any argument packs that work. */ 9533 if (len < 0) 9534 return error_mark_node; 9535 9536 if (need_local_specializations) 9537 { 9538 /* We're in a late-specified return type, so create our own local 9539 specializations table; the current table is either NULL or (in the 9540 case of recursive unification) might have bindings that we don't 9541 want to use or alter. */ 9542 saved_local_specializations = local_specializations; 9543 local_specializations = htab_create (37, 9544 hash_local_specialization, 9545 eq_local_specializations, 9546 NULL); 9547 } 9548 9549 /* For each argument in each argument pack, substitute into the 9550 pattern. */ 9551 result = make_tree_vec (len); 9552 for (i = 0; i < len; ++i) 9553 { 9554 /* For parameter pack, change the substitution of the parameter 9555 pack to the ith argument in its argument pack, then expand 9556 the pattern. */ 9557 for (pack = packs; pack; pack = TREE_CHAIN (pack)) 9558 { 9559 tree parm = TREE_PURPOSE (pack); 9560 tree arg; 9561 9562 /* Select the Ith argument from the pack. */ 9563 if (TREE_CODE (parm) == PARM_DECL) 9564 { 9565 if (i == 0) 9566 { 9567 arg = make_node (ARGUMENT_PACK_SELECT); 9568 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack); 9569 mark_used (parm); 9570 register_local_specialization (arg, parm); 9571 } 9572 else 9573 arg = retrieve_local_specialization (parm); 9574 } 9575 else 9576 { 9577 int idx, level; 9578 template_parm_level_and_index (parm, &level, &idx); 9579 9580 if (i == 0) 9581 { 9582 arg = make_node (ARGUMENT_PACK_SELECT); 9583 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack); 9584 /* Update the corresponding argument. */ 9585 TMPL_ARG (args, level, idx) = arg; 9586 } 9587 else 9588 /* Re-use the ARGUMENT_PACK_SELECT. */ 9589 arg = TMPL_ARG (args, level, idx); 9590 } 9591 ARGUMENT_PACK_SELECT_INDEX (arg) = i; 9592 } 9593 9594 /* Substitute into the PATTERN with the altered arguments. */ 9595 if (!TYPE_P (pattern)) 9596 TREE_VEC_ELT (result, i) = 9597 tsubst_expr (pattern, args, complain, in_decl, 9598 /*integral_constant_expression_p=*/false); 9599 else 9600 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl); 9601 9602 if (TREE_VEC_ELT (result, i) == error_mark_node) 9603 { 9604 result = error_mark_node; 9605 break; 9606 } 9607 } 9608 9609 /* Update ARGS to restore the substitution from parameter packs to 9610 their argument packs. */ 9611 for (pack = packs; pack; pack = TREE_CHAIN (pack)) 9612 { 9613 tree parm = TREE_PURPOSE (pack); 9614 9615 if (TREE_CODE (parm) == PARM_DECL) 9616 register_local_specialization (TREE_TYPE (pack), parm); 9617 else 9618 { 9619 int idx, level; 9620 template_parm_level_and_index (parm, &level, &idx); 9621 9622 /* Update the corresponding argument. */ 9623 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args)) 9624 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) = 9625 TREE_TYPE (pack); 9626 else 9627 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack); 9628 } 9629 } 9630 9631 if (need_local_specializations) 9632 { 9633 htab_delete (local_specializations); 9634 local_specializations = saved_local_specializations; 9635 } 9636 9637 return result; 9638 } 9639 9640 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template 9641 TMPL. We do this using DECL_PARM_INDEX, which should work even with 9642 parameter packs; all parms generated from a function parameter pack will 9643 have the same DECL_PARM_INDEX. */ 9644 9645 tree 9646 get_pattern_parm (tree parm, tree tmpl) 9647 { 9648 tree pattern = DECL_TEMPLATE_RESULT (tmpl); 9649 tree patparm; 9650 9651 if (DECL_ARTIFICIAL (parm)) 9652 { 9653 for (patparm = DECL_ARGUMENTS (pattern); 9654 patparm; patparm = DECL_CHAIN (patparm)) 9655 if (DECL_ARTIFICIAL (patparm) 9656 && DECL_NAME (parm) == DECL_NAME (patparm)) 9657 break; 9658 } 9659 else 9660 { 9661 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl)); 9662 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm); 9663 gcc_assert (DECL_PARM_INDEX (patparm) 9664 == DECL_PARM_INDEX (parm)); 9665 } 9666 9667 return patparm; 9668 } 9669 9670 /* Substitute ARGS into the vector or list of template arguments T. */ 9671 9672 static tree 9673 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl) 9674 { 9675 tree orig_t = t; 9676 int len, need_new = 0, i, expanded_len_adjust = 0, out; 9677 tree *elts; 9678 9679 if (t == error_mark_node) 9680 return error_mark_node; 9681 9682 len = TREE_VEC_LENGTH (t); 9683 elts = XALLOCAVEC (tree, len); 9684 9685 for (i = 0; i < len; i++) 9686 { 9687 tree orig_arg = TREE_VEC_ELT (t, i); 9688 tree new_arg; 9689 9690 if (TREE_CODE (orig_arg) == TREE_VEC) 9691 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl); 9692 else if (PACK_EXPANSION_P (orig_arg)) 9693 { 9694 /* Substitute into an expansion expression. */ 9695 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl); 9696 9697 if (TREE_CODE (new_arg) == TREE_VEC) 9698 /* Add to the expanded length adjustment the number of 9699 expanded arguments. We subtract one from this 9700 measurement, because the argument pack expression 9701 itself is already counted as 1 in 9702 LEN. EXPANDED_LEN_ADJUST can actually be negative, if 9703 the argument pack is empty. */ 9704 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1; 9705 } 9706 else if (ARGUMENT_PACK_P (orig_arg)) 9707 { 9708 /* Substitute into each of the arguments. */ 9709 new_arg = TYPE_P (orig_arg) 9710 ? cxx_make_type (TREE_CODE (orig_arg)) 9711 : make_node (TREE_CODE (orig_arg)); 9712 9713 SET_ARGUMENT_PACK_ARGS ( 9714 new_arg, 9715 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg), 9716 args, complain, in_decl)); 9717 9718 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node) 9719 new_arg = error_mark_node; 9720 9721 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) { 9722 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args, 9723 complain, in_decl); 9724 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg); 9725 9726 if (TREE_TYPE (new_arg) == error_mark_node) 9727 new_arg = error_mark_node; 9728 } 9729 } 9730 else 9731 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl); 9732 9733 if (new_arg == error_mark_node) 9734 return error_mark_node; 9735 9736 elts[i] = new_arg; 9737 if (new_arg != orig_arg) 9738 need_new = 1; 9739 } 9740 9741 if (!need_new) 9742 return t; 9743 9744 /* Make space for the expanded arguments coming from template 9745 argument packs. */ 9746 t = make_tree_vec (len + expanded_len_adjust); 9747 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the 9748 arguments for a member template. 9749 In that case each TREE_VEC in ORIG_T represents a level of template 9750 arguments, and ORIG_T won't carry any non defaulted argument count. 9751 It will rather be the nested TREE_VECs that will carry one. 9752 In other words, ORIG_T carries a non defaulted argument count only 9753 if it doesn't contain any nested TREE_VEC. */ 9754 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t)) 9755 { 9756 int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t); 9757 count += expanded_len_adjust; 9758 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count); 9759 } 9760 for (i = 0, out = 0; i < len; i++) 9761 { 9762 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i)) 9763 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i))) 9764 && TREE_CODE (elts[i]) == TREE_VEC) 9765 { 9766 int idx; 9767 9768 /* Now expand the template argument pack "in place". */ 9769 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++) 9770 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx); 9771 } 9772 else 9773 { 9774 TREE_VEC_ELT (t, out) = elts[i]; 9775 out++; 9776 } 9777 } 9778 9779 return t; 9780 } 9781 9782 /* Return the result of substituting ARGS into the template parameters 9783 given by PARMS. If there are m levels of ARGS and m + n levels of 9784 PARMS, then the result will contain n levels of PARMS. For 9785 example, if PARMS is `template <class T> template <class U> 9786 template <T*, U, class V>' and ARGS is {{int}, {double}} then the 9787 result will be `template <int*, double, class V>'. */ 9788 9789 static tree 9790 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain) 9791 { 9792 tree r = NULL_TREE; 9793 tree* new_parms; 9794 9795 /* When substituting into a template, we must set 9796 PROCESSING_TEMPLATE_DECL as the template parameters may be 9797 dependent if they are based on one-another, and the dependency 9798 predicates are short-circuit outside of templates. */ 9799 ++processing_template_decl; 9800 9801 for (new_parms = &r; 9802 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args); 9803 new_parms = &(TREE_CHAIN (*new_parms)), 9804 parms = TREE_CHAIN (parms)) 9805 { 9806 tree new_vec = 9807 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms))); 9808 int i; 9809 9810 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i) 9811 { 9812 tree tuple; 9813 9814 if (parms == error_mark_node) 9815 continue; 9816 9817 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i); 9818 9819 if (tuple == error_mark_node) 9820 continue; 9821 9822 TREE_VEC_ELT (new_vec, i) = 9823 tsubst_template_parm (tuple, args, complain); 9824 } 9825 9826 *new_parms = 9827 tree_cons (size_int (TMPL_PARMS_DEPTH (parms) 9828 - TMPL_ARGS_DEPTH (args)), 9829 new_vec, NULL_TREE); 9830 } 9831 9832 --processing_template_decl; 9833 9834 return r; 9835 } 9836 9837 /* Return the result of substituting ARGS into one template parameter 9838 given by T. T Must be a TREE_LIST which TREE_VALUE is the template 9839 parameter and which TREE_PURPOSE is the default argument of the 9840 template parameter. */ 9841 9842 static tree 9843 tsubst_template_parm (tree t, tree args, tsubst_flags_t complain) 9844 { 9845 tree default_value, parm_decl; 9846 9847 if (args == NULL_TREE 9848 || t == NULL_TREE 9849 || t == error_mark_node) 9850 return t; 9851 9852 gcc_assert (TREE_CODE (t) == TREE_LIST); 9853 9854 default_value = TREE_PURPOSE (t); 9855 parm_decl = TREE_VALUE (t); 9856 9857 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE); 9858 if (TREE_CODE (parm_decl) == PARM_DECL 9859 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain)) 9860 parm_decl = error_mark_node; 9861 default_value = tsubst_template_arg (default_value, args, 9862 complain, NULL_TREE); 9863 9864 return build_tree_list (default_value, parm_decl); 9865 } 9866 9867 /* Substitute the ARGS into the indicated aggregate (or enumeration) 9868 type T. If T is not an aggregate or enumeration type, it is 9869 handled as if by tsubst. IN_DECL is as for tsubst. If 9870 ENTERING_SCOPE is nonzero, T is the context for a template which 9871 we are presently tsubst'ing. Return the substituted value. */ 9872 9873 static tree 9874 tsubst_aggr_type (tree t, 9875 tree args, 9876 tsubst_flags_t complain, 9877 tree in_decl, 9878 int entering_scope) 9879 { 9880 if (t == NULL_TREE) 9881 return NULL_TREE; 9882 9883 switch (TREE_CODE (t)) 9884 { 9885 case RECORD_TYPE: 9886 if (TYPE_PTRMEMFUNC_P (t)) 9887 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl); 9888 9889 /* Else fall through. */ 9890 case ENUMERAL_TYPE: 9891 case UNION_TYPE: 9892 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t)) 9893 { 9894 tree argvec; 9895 tree context; 9896 tree r; 9897 int saved_unevaluated_operand; 9898 int saved_inhibit_evaluation_warnings; 9899 9900 /* In "sizeof(X<I>)" we need to evaluate "I". */ 9901 saved_unevaluated_operand = cp_unevaluated_operand; 9902 cp_unevaluated_operand = 0; 9903 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings; 9904 c_inhibit_evaluation_warnings = 0; 9905 9906 /* First, determine the context for the type we are looking 9907 up. */ 9908 context = TYPE_CONTEXT (t); 9909 if (context && TYPE_P (context)) 9910 { 9911 context = tsubst_aggr_type (context, args, complain, 9912 in_decl, /*entering_scope=*/1); 9913 /* If context is a nested class inside a class template, 9914 it may still need to be instantiated (c++/33959). */ 9915 context = complete_type (context); 9916 } 9917 9918 /* Then, figure out what arguments are appropriate for the 9919 type we are trying to find. For example, given: 9920 9921 template <class T> struct S; 9922 template <class T, class U> void f(T, U) { S<U> su; } 9923 9924 and supposing that we are instantiating f<int, double>, 9925 then our ARGS will be {int, double}, but, when looking up 9926 S we only want {double}. */ 9927 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args, 9928 complain, in_decl); 9929 if (argvec == error_mark_node) 9930 r = error_mark_node; 9931 else 9932 { 9933 r = lookup_template_class (t, argvec, in_decl, context, 9934 entering_scope, complain); 9935 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain); 9936 } 9937 9938 cp_unevaluated_operand = saved_unevaluated_operand; 9939 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings; 9940 9941 return r; 9942 } 9943 else 9944 /* This is not a template type, so there's nothing to do. */ 9945 return t; 9946 9947 default: 9948 return tsubst (t, args, complain, in_decl); 9949 } 9950 } 9951 9952 /* Substitute into the default argument ARG (a default argument for 9953 FN), which has the indicated TYPE. */ 9954 9955 tree 9956 tsubst_default_argument (tree fn, tree type, tree arg) 9957 { 9958 tree saved_class_ptr = NULL_TREE; 9959 tree saved_class_ref = NULL_TREE; 9960 9961 /* This can happen in invalid code. */ 9962 if (TREE_CODE (arg) == DEFAULT_ARG) 9963 return arg; 9964 9965 /* This default argument came from a template. Instantiate the 9966 default argument here, not in tsubst. In the case of 9967 something like: 9968 9969 template <class T> 9970 struct S { 9971 static T t(); 9972 void f(T = t()); 9973 }; 9974 9975 we must be careful to do name lookup in the scope of S<T>, 9976 rather than in the current class. */ 9977 push_access_scope (fn); 9978 /* The "this" pointer is not valid in a default argument. */ 9979 if (cfun) 9980 { 9981 saved_class_ptr = current_class_ptr; 9982 cp_function_chain->x_current_class_ptr = NULL_TREE; 9983 saved_class_ref = current_class_ref; 9984 cp_function_chain->x_current_class_ref = NULL_TREE; 9985 } 9986 9987 push_deferring_access_checks(dk_no_deferred); 9988 /* The default argument expression may cause implicitly defined 9989 member functions to be synthesized, which will result in garbage 9990 collection. We must treat this situation as if we were within 9991 the body of function so as to avoid collecting live data on the 9992 stack. */ 9993 ++function_depth; 9994 arg = tsubst_expr (arg, DECL_TI_ARGS (fn), 9995 tf_warning_or_error, NULL_TREE, 9996 /*integral_constant_expression_p=*/false); 9997 --function_depth; 9998 pop_deferring_access_checks(); 9999 10000 /* Restore the "this" pointer. */ 10001 if (cfun) 10002 { 10003 cp_function_chain->x_current_class_ptr = saved_class_ptr; 10004 cp_function_chain->x_current_class_ref = saved_class_ref; 10005 } 10006 10007 /* Make sure the default argument is reasonable. */ 10008 arg = check_default_argument (type, arg); 10009 10010 pop_access_scope (fn); 10011 10012 return arg; 10013 } 10014 10015 /* Substitute into all the default arguments for FN. */ 10016 10017 static void 10018 tsubst_default_arguments (tree fn) 10019 { 10020 tree arg; 10021 tree tmpl_args; 10022 10023 tmpl_args = DECL_TI_ARGS (fn); 10024 10025 /* If this function is not yet instantiated, we certainly don't need 10026 its default arguments. */ 10027 if (uses_template_parms (tmpl_args)) 10028 return; 10029 /* Don't do this again for clones. */ 10030 if (DECL_CLONED_FUNCTION_P (fn)) 10031 return; 10032 10033 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn)); 10034 arg; 10035 arg = TREE_CHAIN (arg)) 10036 if (TREE_PURPOSE (arg)) 10037 TREE_PURPOSE (arg) = tsubst_default_argument (fn, 10038 TREE_VALUE (arg), 10039 TREE_PURPOSE (arg)); 10040 } 10041 10042 /* Substitute the ARGS into the T, which is a _DECL. Return the 10043 result of the substitution. Issue error and warning messages under 10044 control of COMPLAIN. */ 10045 10046 static tree 10047 tsubst_decl (tree t, tree args, tsubst_flags_t complain) 10048 { 10049 #define RETURN(EXP) do { r = (EXP); goto out; } while(0) 10050 location_t saved_loc; 10051 tree r = NULL_TREE; 10052 tree in_decl = t; 10053 hashval_t hash = 0; 10054 10055 /* Set the filename and linenumber to improve error-reporting. */ 10056 saved_loc = input_location; 10057 input_location = DECL_SOURCE_LOCATION (t); 10058 10059 switch (TREE_CODE (t)) 10060 { 10061 case TEMPLATE_DECL: 10062 { 10063 /* We can get here when processing a member function template, 10064 member class template, or template template parameter. */ 10065 tree decl = DECL_TEMPLATE_RESULT (t); 10066 tree spec; 10067 tree tmpl_args; 10068 tree full_args; 10069 10070 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)) 10071 { 10072 /* Template template parameter is treated here. */ 10073 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl); 10074 if (new_type == error_mark_node) 10075 RETURN (error_mark_node); 10076 10077 r = copy_decl (t); 10078 DECL_CHAIN (r) = NULL_TREE; 10079 TREE_TYPE (r) = new_type; 10080 DECL_TEMPLATE_RESULT (r) 10081 = build_decl (DECL_SOURCE_LOCATION (decl), 10082 TYPE_DECL, DECL_NAME (decl), new_type); 10083 DECL_TEMPLATE_PARMS (r) 10084 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args, 10085 complain); 10086 TYPE_NAME (new_type) = r; 10087 break; 10088 } 10089 10090 /* We might already have an instance of this template. 10091 The ARGS are for the surrounding class type, so the 10092 full args contain the tsubst'd args for the context, 10093 plus the innermost args from the template decl. */ 10094 tmpl_args = DECL_CLASS_TEMPLATE_P (t) 10095 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t)) 10096 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t)); 10097 /* Because this is a template, the arguments will still be 10098 dependent, even after substitution. If 10099 PROCESSING_TEMPLATE_DECL is not set, the dependency 10100 predicates will short-circuit. */ 10101 ++processing_template_decl; 10102 full_args = tsubst_template_args (tmpl_args, args, 10103 complain, in_decl); 10104 --processing_template_decl; 10105 if (full_args == error_mark_node) 10106 RETURN (error_mark_node); 10107 10108 /* If this is a default template template argument, 10109 tsubst might not have changed anything. */ 10110 if (full_args == tmpl_args) 10111 RETURN (t); 10112 10113 hash = hash_tmpl_and_args (t, full_args); 10114 spec = retrieve_specialization (t, full_args, hash); 10115 if (spec != NULL_TREE) 10116 { 10117 r = spec; 10118 break; 10119 } 10120 10121 /* Make a new template decl. It will be similar to the 10122 original, but will record the current template arguments. 10123 We also create a new function declaration, which is just 10124 like the old one, but points to this new template, rather 10125 than the old one. */ 10126 r = copy_decl (t); 10127 gcc_assert (DECL_LANG_SPECIFIC (r) != 0); 10128 DECL_CHAIN (r) = NULL_TREE; 10129 10130 DECL_TEMPLATE_INFO (r) = build_template_info (t, args); 10131 10132 if (TREE_CODE (decl) == TYPE_DECL 10133 && !TYPE_DECL_ALIAS_P (decl)) 10134 { 10135 tree new_type; 10136 ++processing_template_decl; 10137 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl); 10138 --processing_template_decl; 10139 if (new_type == error_mark_node) 10140 RETURN (error_mark_node); 10141 10142 TREE_TYPE (r) = new_type; 10143 CLASSTYPE_TI_TEMPLATE (new_type) = r; 10144 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type); 10145 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type); 10146 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type); 10147 } 10148 else 10149 { 10150 tree new_decl; 10151 ++processing_template_decl; 10152 new_decl = tsubst (decl, args, complain, in_decl); 10153 --processing_template_decl; 10154 if (new_decl == error_mark_node) 10155 RETURN (error_mark_node); 10156 10157 DECL_TEMPLATE_RESULT (r) = new_decl; 10158 DECL_TI_TEMPLATE (new_decl) = r; 10159 TREE_TYPE (r) = TREE_TYPE (new_decl); 10160 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl); 10161 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl); 10162 } 10163 10164 SET_DECL_IMPLICIT_INSTANTIATION (r); 10165 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE; 10166 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE; 10167 10168 /* The template parameters for this new template are all the 10169 template parameters for the old template, except the 10170 outermost level of parameters. */ 10171 DECL_TEMPLATE_PARMS (r) 10172 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args, 10173 complain); 10174 10175 if (PRIMARY_TEMPLATE_P (t)) 10176 DECL_PRIMARY_TEMPLATE (r) = r; 10177 10178 if (TREE_CODE (decl) != TYPE_DECL) 10179 /* Record this non-type partial instantiation. */ 10180 register_specialization (r, t, 10181 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)), 10182 false, hash); 10183 } 10184 break; 10185 10186 case FUNCTION_DECL: 10187 { 10188 tree ctx; 10189 tree argvec = NULL_TREE; 10190 tree *friends; 10191 tree gen_tmpl; 10192 tree type; 10193 int member; 10194 int args_depth; 10195 int parms_depth; 10196 10197 /* Nobody should be tsubst'ing into non-template functions. */ 10198 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE); 10199 10200 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL) 10201 { 10202 tree spec; 10203 bool dependent_p; 10204 10205 /* If T is not dependent, just return it. We have to 10206 increment PROCESSING_TEMPLATE_DECL because 10207 value_dependent_expression_p assumes that nothing is 10208 dependent when PROCESSING_TEMPLATE_DECL is zero. */ 10209 ++processing_template_decl; 10210 dependent_p = value_dependent_expression_p (t); 10211 --processing_template_decl; 10212 if (!dependent_p) 10213 RETURN (t); 10214 10215 /* Calculate the most general template of which R is a 10216 specialization, and the complete set of arguments used to 10217 specialize R. */ 10218 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t)); 10219 argvec = tsubst_template_args (DECL_TI_ARGS 10220 (DECL_TEMPLATE_RESULT 10221 (DECL_TI_TEMPLATE (t))), 10222 args, complain, in_decl); 10223 if (argvec == error_mark_node) 10224 RETURN (error_mark_node); 10225 10226 /* Check to see if we already have this specialization. */ 10227 hash = hash_tmpl_and_args (gen_tmpl, argvec); 10228 spec = retrieve_specialization (gen_tmpl, argvec, hash); 10229 10230 if (spec) 10231 { 10232 r = spec; 10233 break; 10234 } 10235 10236 /* We can see more levels of arguments than parameters if 10237 there was a specialization of a member template, like 10238 this: 10239 10240 template <class T> struct S { template <class U> void f(); } 10241 template <> template <class U> void S<int>::f(U); 10242 10243 Here, we'll be substituting into the specialization, 10244 because that's where we can find the code we actually 10245 want to generate, but we'll have enough arguments for 10246 the most general template. 10247 10248 We also deal with the peculiar case: 10249 10250 template <class T> struct S { 10251 template <class U> friend void f(); 10252 }; 10253 template <class U> void f() {} 10254 template S<int>; 10255 template void f<double>(); 10256 10257 Here, the ARGS for the instantiation of will be {int, 10258 double}. But, we only need as many ARGS as there are 10259 levels of template parameters in CODE_PATTERN. We are 10260 careful not to get fooled into reducing the ARGS in 10261 situations like: 10262 10263 template <class T> struct S { template <class U> void f(U); } 10264 template <class T> template <> void S<T>::f(int) {} 10265 10266 which we can spot because the pattern will be a 10267 specialization in this case. */ 10268 args_depth = TMPL_ARGS_DEPTH (args); 10269 parms_depth = 10270 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t))); 10271 if (args_depth > parms_depth 10272 && !DECL_TEMPLATE_SPECIALIZATION (t)) 10273 args = get_innermost_template_args (args, parms_depth); 10274 } 10275 else 10276 { 10277 /* This special case arises when we have something like this: 10278 10279 template <class T> struct S { 10280 friend void f<int>(int, double); 10281 }; 10282 10283 Here, the DECL_TI_TEMPLATE for the friend declaration 10284 will be an IDENTIFIER_NODE. We are being called from 10285 tsubst_friend_function, and we want only to create a 10286 new decl (R) with appropriate types so that we can call 10287 determine_specialization. */ 10288 gen_tmpl = NULL_TREE; 10289 } 10290 10291 if (DECL_CLASS_SCOPE_P (t)) 10292 { 10293 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t))) 10294 member = 2; 10295 else 10296 member = 1; 10297 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, 10298 complain, t, /*entering_scope=*/1); 10299 } 10300 else 10301 { 10302 member = 0; 10303 ctx = DECL_CONTEXT (t); 10304 } 10305 type = tsubst (TREE_TYPE (t), args, complain, in_decl); 10306 if (type == error_mark_node) 10307 RETURN (error_mark_node); 10308 10309 /* We do NOT check for matching decls pushed separately at this 10310 point, as they may not represent instantiations of this 10311 template, and in any case are considered separate under the 10312 discrete model. */ 10313 r = copy_decl (t); 10314 DECL_USE_TEMPLATE (r) = 0; 10315 TREE_TYPE (r) = type; 10316 /* Clear out the mangled name and RTL for the instantiation. */ 10317 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE); 10318 SET_DECL_RTL (r, NULL); 10319 /* Leave DECL_INITIAL set on deleted instantiations. */ 10320 if (!DECL_DELETED_FN (r)) 10321 DECL_INITIAL (r) = NULL_TREE; 10322 DECL_CONTEXT (r) = ctx; 10323 10324 if (member && DECL_CONV_FN_P (r)) 10325 /* Type-conversion operator. Reconstruct the name, in 10326 case it's the name of one of the template's parameters. */ 10327 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type)); 10328 10329 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args, 10330 complain, t); 10331 DECL_RESULT (r) = NULL_TREE; 10332 10333 TREE_STATIC (r) = 0; 10334 TREE_PUBLIC (r) = TREE_PUBLIC (t); 10335 DECL_EXTERNAL (r) = 1; 10336 /* If this is an instantiation of a function with internal 10337 linkage, we already know what object file linkage will be 10338 assigned to the instantiation. */ 10339 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r); 10340 DECL_DEFER_OUTPUT (r) = 0; 10341 DECL_CHAIN (r) = NULL_TREE; 10342 DECL_PENDING_INLINE_INFO (r) = 0; 10343 DECL_PENDING_INLINE_P (r) = 0; 10344 DECL_SAVED_TREE (r) = NULL_TREE; 10345 DECL_STRUCT_FUNCTION (r) = NULL; 10346 TREE_USED (r) = 0; 10347 /* We'll re-clone as appropriate in instantiate_template. */ 10348 DECL_CLONED_FUNCTION (r) = NULL_TREE; 10349 10350 /* If we aren't complaining now, return on error before we register 10351 the specialization so that we'll complain eventually. */ 10352 if ((complain & tf_error) == 0 10353 && IDENTIFIER_OPNAME_P (DECL_NAME (r)) 10354 && !grok_op_properties (r, /*complain=*/false)) 10355 RETURN (error_mark_node); 10356 10357 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do 10358 this in the special friend case mentioned above where 10359 GEN_TMPL is NULL. */ 10360 if (gen_tmpl) 10361 { 10362 DECL_TEMPLATE_INFO (r) 10363 = build_template_info (gen_tmpl, argvec); 10364 SET_DECL_IMPLICIT_INSTANTIATION (r); 10365 register_specialization (r, gen_tmpl, argvec, false, hash); 10366 10367 /* We're not supposed to instantiate default arguments 10368 until they are called, for a template. But, for a 10369 declaration like: 10370 10371 template <class T> void f () 10372 { extern void g(int i = T()); } 10373 10374 we should do the substitution when the template is 10375 instantiated. We handle the member function case in 10376 instantiate_class_template since the default arguments 10377 might refer to other members of the class. */ 10378 if (!member 10379 && !PRIMARY_TEMPLATE_P (gen_tmpl) 10380 && !uses_template_parms (argvec)) 10381 tsubst_default_arguments (r); 10382 } 10383 else 10384 DECL_TEMPLATE_INFO (r) = NULL_TREE; 10385 10386 /* Copy the list of befriending classes. */ 10387 for (friends = &DECL_BEFRIENDING_CLASSES (r); 10388 *friends; 10389 friends = &TREE_CHAIN (*friends)) 10390 { 10391 *friends = copy_node (*friends); 10392 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends), 10393 args, complain, 10394 in_decl); 10395 } 10396 10397 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r)) 10398 { 10399 maybe_retrofit_in_chrg (r); 10400 if (DECL_CONSTRUCTOR_P (r)) 10401 grok_ctor_properties (ctx, r); 10402 /* If this is an instantiation of a member template, clone it. 10403 If it isn't, that'll be handled by 10404 clone_constructors_and_destructors. */ 10405 if (PRIMARY_TEMPLATE_P (gen_tmpl)) 10406 clone_function_decl (r, /*update_method_vec_p=*/0); 10407 } 10408 else if ((complain & tf_error) != 0 10409 && IDENTIFIER_OPNAME_P (DECL_NAME (r)) 10410 && !grok_op_properties (r, /*complain=*/true)) 10411 RETURN (error_mark_node); 10412 10413 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t)) 10414 SET_DECL_FRIEND_CONTEXT (r, 10415 tsubst (DECL_FRIEND_CONTEXT (t), 10416 args, complain, in_decl)); 10417 10418 /* Possibly limit visibility based on template args. */ 10419 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT; 10420 if (DECL_VISIBILITY_SPECIFIED (t)) 10421 { 10422 DECL_VISIBILITY_SPECIFIED (r) = 0; 10423 DECL_ATTRIBUTES (r) 10424 = remove_attribute ("visibility", DECL_ATTRIBUTES (r)); 10425 } 10426 determine_visibility (r); 10427 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r) 10428 && !processing_template_decl) 10429 defaulted_late_check (r); 10430 10431 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0, 10432 args, complain, in_decl); 10433 } 10434 break; 10435 10436 case PARM_DECL: 10437 { 10438 tree type = NULL_TREE; 10439 int i, len = 1; 10440 tree expanded_types = NULL_TREE; 10441 tree prev_r = NULL_TREE; 10442 tree first_r = NULL_TREE; 10443 10444 if (FUNCTION_PARAMETER_PACK_P (t)) 10445 { 10446 /* If there is a local specialization that isn't a 10447 parameter pack, it means that we're doing a "simple" 10448 substitution from inside tsubst_pack_expansion. Just 10449 return the local specialization (which will be a single 10450 parm). */ 10451 tree spec = retrieve_local_specialization (t); 10452 if (spec 10453 && TREE_CODE (spec) == PARM_DECL 10454 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION) 10455 RETURN (spec); 10456 10457 /* Expand the TYPE_PACK_EXPANSION that provides the types for 10458 the parameters in this function parameter pack. */ 10459 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args, 10460 complain, in_decl); 10461 if (TREE_CODE (expanded_types) == TREE_VEC) 10462 { 10463 len = TREE_VEC_LENGTH (expanded_types); 10464 10465 /* Zero-length parameter packs are boring. Just substitute 10466 into the chain. */ 10467 if (len == 0) 10468 RETURN (tsubst (TREE_CHAIN (t), args, complain, 10469 TREE_CHAIN (t))); 10470 } 10471 else 10472 { 10473 /* All we did was update the type. Make a note of that. */ 10474 type = expanded_types; 10475 expanded_types = NULL_TREE; 10476 } 10477 } 10478 10479 /* Loop through all of the parameter's we'll build. When T is 10480 a function parameter pack, LEN is the number of expanded 10481 types in EXPANDED_TYPES; otherwise, LEN is 1. */ 10482 r = NULL_TREE; 10483 for (i = 0; i < len; ++i) 10484 { 10485 prev_r = r; 10486 r = copy_node (t); 10487 if (DECL_TEMPLATE_PARM_P (t)) 10488 SET_DECL_TEMPLATE_PARM_P (r); 10489 10490 if (expanded_types) 10491 /* We're on the Ith parameter of the function parameter 10492 pack. */ 10493 { 10494 /* An argument of a function parameter pack is not a parameter 10495 pack. */ 10496 FUNCTION_PARAMETER_PACK_P (r) = false; 10497 10498 /* Get the Ith type. */ 10499 type = TREE_VEC_ELT (expanded_types, i); 10500 10501 if (DECL_NAME (r)) 10502 /* Rename the parameter to include the index. */ 10503 DECL_NAME (r) = 10504 make_ith_pack_parameter_name (DECL_NAME (r), i); 10505 } 10506 else if (!type) 10507 /* We're dealing with a normal parameter. */ 10508 type = tsubst (TREE_TYPE (t), args, complain, in_decl); 10509 10510 type = type_decays_to (type); 10511 TREE_TYPE (r) = type; 10512 cp_apply_type_quals_to_decl (cp_type_quals (type), r); 10513 10514 if (DECL_INITIAL (r)) 10515 { 10516 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX) 10517 DECL_INITIAL (r) = TREE_TYPE (r); 10518 else 10519 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args, 10520 complain, in_decl); 10521 } 10522 10523 DECL_CONTEXT (r) = NULL_TREE; 10524 10525 if (!DECL_TEMPLATE_PARM_P (r)) 10526 DECL_ARG_TYPE (r) = type_passed_as (type); 10527 10528 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0, 10529 args, complain, in_decl); 10530 10531 /* Keep track of the first new parameter we 10532 generate. That's what will be returned to the 10533 caller. */ 10534 if (!first_r) 10535 first_r = r; 10536 10537 /* Build a proper chain of parameters when substituting 10538 into a function parameter pack. */ 10539 if (prev_r) 10540 DECL_CHAIN (prev_r) = r; 10541 } 10542 10543 if (DECL_CHAIN (t)) 10544 DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args, 10545 complain, DECL_CHAIN (t)); 10546 10547 /* FIRST_R contains the start of the chain we've built. */ 10548 r = first_r; 10549 } 10550 break; 10551 10552 case FIELD_DECL: 10553 { 10554 tree type; 10555 10556 r = copy_decl (t); 10557 type = tsubst (TREE_TYPE (t), args, complain, in_decl); 10558 if (type == error_mark_node) 10559 RETURN (error_mark_node); 10560 TREE_TYPE (r) = type; 10561 cp_apply_type_quals_to_decl (cp_type_quals (type), r); 10562 10563 if (DECL_C_BIT_FIELD (r)) 10564 /* For bit-fields, DECL_INITIAL gives the number of bits. For 10565 non-bit-fields DECL_INITIAL is a non-static data member 10566 initializer, which gets deferred instantiation. */ 10567 DECL_INITIAL (r) 10568 = tsubst_expr (DECL_INITIAL (t), args, 10569 complain, in_decl, 10570 /*integral_constant_expression_p=*/true); 10571 else if (DECL_INITIAL (t)) 10572 { 10573 /* Set up DECL_TEMPLATE_INFO so that we can get at the 10574 NSDMI in perform_member_init. Still set DECL_INITIAL 10575 so that we know there is one. */ 10576 DECL_INITIAL (r) = void_zero_node; 10577 gcc_assert (DECL_LANG_SPECIFIC (r) == NULL); 10578 retrofit_lang_decl (r); 10579 DECL_TEMPLATE_INFO (r) = build_template_info (t, args); 10580 } 10581 /* We don't have to set DECL_CONTEXT here; it is set by 10582 finish_member_declaration. */ 10583 DECL_CHAIN (r) = NULL_TREE; 10584 if (VOID_TYPE_P (type)) 10585 error ("instantiation of %q+D as type %qT", r, type); 10586 10587 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0, 10588 args, complain, in_decl); 10589 } 10590 break; 10591 10592 case USING_DECL: 10593 /* We reach here only for member using decls. We also need to check 10594 uses_template_parms because DECL_DEPENDENT_P is not set for a 10595 using-declaration that designates a member of the current 10596 instantiation (c++/53549). */ 10597 if (DECL_DEPENDENT_P (t) 10598 || uses_template_parms (USING_DECL_SCOPE (t))) 10599 { 10600 r = do_class_using_decl 10601 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl), 10602 tsubst_copy (DECL_NAME (t), args, complain, in_decl)); 10603 if (!r) 10604 r = error_mark_node; 10605 else 10606 { 10607 TREE_PROTECTED (r) = TREE_PROTECTED (t); 10608 TREE_PRIVATE (r) = TREE_PRIVATE (t); 10609 } 10610 } 10611 else 10612 { 10613 r = copy_node (t); 10614 DECL_CHAIN (r) = NULL_TREE; 10615 } 10616 break; 10617 10618 case TYPE_DECL: 10619 case VAR_DECL: 10620 { 10621 tree argvec = NULL_TREE; 10622 tree gen_tmpl = NULL_TREE; 10623 tree spec; 10624 tree tmpl = NULL_TREE; 10625 tree ctx; 10626 tree type = NULL_TREE; 10627 bool local_p; 10628 10629 if (TREE_CODE (t) == TYPE_DECL 10630 && t == TYPE_MAIN_DECL (TREE_TYPE (t))) 10631 { 10632 /* If this is the canonical decl, we don't have to 10633 mess with instantiations, and often we can't (for 10634 typename, template type parms and such). Note that 10635 TYPE_NAME is not correct for the above test if 10636 we've copied the type for a typedef. */ 10637 type = tsubst (TREE_TYPE (t), args, complain, in_decl); 10638 if (type == error_mark_node) 10639 RETURN (error_mark_node); 10640 r = TYPE_NAME (type); 10641 break; 10642 } 10643 10644 /* Check to see if we already have the specialization we 10645 need. */ 10646 spec = NULL_TREE; 10647 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t)) 10648 { 10649 /* T is a static data member or namespace-scope entity. 10650 We have to substitute into namespace-scope variables 10651 (even though such entities are never templates) because 10652 of cases like: 10653 10654 template <class T> void f() { extern T t; } 10655 10656 where the entity referenced is not known until 10657 instantiation time. */ 10658 local_p = false; 10659 ctx = DECL_CONTEXT (t); 10660 if (DECL_CLASS_SCOPE_P (t)) 10661 { 10662 ctx = tsubst_aggr_type (ctx, args, 10663 complain, 10664 in_decl, /*entering_scope=*/1); 10665 /* If CTX is unchanged, then T is in fact the 10666 specialization we want. That situation occurs when 10667 referencing a static data member within in its own 10668 class. We can use pointer equality, rather than 10669 same_type_p, because DECL_CONTEXT is always 10670 canonical... */ 10671 if (ctx == DECL_CONTEXT (t) 10672 && (TREE_CODE (t) != TYPE_DECL 10673 /* ... unless T is a member template; in which 10674 case our caller can be willing to create a 10675 specialization of that template represented 10676 by T. */ 10677 || !(DECL_TI_TEMPLATE (t) 10678 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (t))))) 10679 spec = t; 10680 } 10681 10682 if (!spec) 10683 { 10684 tmpl = DECL_TI_TEMPLATE (t); 10685 gen_tmpl = most_general_template (tmpl); 10686 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl); 10687 if (argvec == error_mark_node) 10688 RETURN (error_mark_node); 10689 hash = hash_tmpl_and_args (gen_tmpl, argvec); 10690 spec = retrieve_specialization (gen_tmpl, argvec, hash); 10691 } 10692 } 10693 else 10694 { 10695 /* A local variable. */ 10696 local_p = true; 10697 /* Subsequent calls to pushdecl will fill this in. */ 10698 ctx = NULL_TREE; 10699 spec = retrieve_local_specialization (t); 10700 } 10701 /* If we already have the specialization we need, there is 10702 nothing more to do. */ 10703 if (spec) 10704 { 10705 r = spec; 10706 break; 10707 } 10708 10709 if (TREE_CODE (t) == VAR_DECL && DECL_ANON_UNION_VAR_P (t)) 10710 { 10711 /* Just use name lookup to find a member alias for an anonymous 10712 union, but then add it to the hash table. */ 10713 r = lookup_name (DECL_NAME (t)); 10714 gcc_assert (DECL_ANON_UNION_VAR_P (r)); 10715 register_local_specialization (r, t); 10716 break; 10717 } 10718 10719 /* Create a new node for the specialization we need. */ 10720 r = copy_decl (t); 10721 if (type == NULL_TREE) 10722 { 10723 if (is_typedef_decl (t)) 10724 type = DECL_ORIGINAL_TYPE (t); 10725 else 10726 type = TREE_TYPE (t); 10727 if (TREE_CODE (t) == VAR_DECL 10728 && VAR_HAD_UNKNOWN_BOUND (t) 10729 && type != error_mark_node) 10730 type = strip_array_domain (type); 10731 type = tsubst (type, args, complain, in_decl); 10732 } 10733 if (TREE_CODE (r) == VAR_DECL) 10734 { 10735 /* Even if the original location is out of scope, the 10736 newly substituted one is not. */ 10737 DECL_DEAD_FOR_LOCAL (r) = 0; 10738 DECL_INITIALIZED_P (r) = 0; 10739 DECL_TEMPLATE_INSTANTIATED (r) = 0; 10740 if (type == error_mark_node) 10741 RETURN (error_mark_node); 10742 if (TREE_CODE (type) == FUNCTION_TYPE) 10743 { 10744 /* It may seem that this case cannot occur, since: 10745 10746 typedef void f(); 10747 void g() { f x; } 10748 10749 declares a function, not a variable. However: 10750 10751 typedef void f(); 10752 template <typename T> void g() { T t; } 10753 template void g<f>(); 10754 10755 is an attempt to declare a variable with function 10756 type. */ 10757 error ("variable %qD has function type", 10758 /* R is not yet sufficiently initialized, so we 10759 just use its name. */ 10760 DECL_NAME (r)); 10761 RETURN (error_mark_node); 10762 } 10763 type = complete_type (type); 10764 /* Wait until cp_finish_decl to set this again, to handle 10765 circular dependency (template/instantiate6.C). */ 10766 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r) = 0; 10767 type = check_var_type (DECL_NAME (r), type); 10768 10769 if (DECL_HAS_VALUE_EXPR_P (t)) 10770 { 10771 tree ve = DECL_VALUE_EXPR (t); 10772 ve = tsubst_expr (ve, args, complain, in_decl, 10773 /*constant_expression_p=*/false); 10774 if (REFERENCE_REF_P (ve)) 10775 { 10776 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE); 10777 ve = TREE_OPERAND (ve, 0); 10778 } 10779 SET_DECL_VALUE_EXPR (r, ve); 10780 } 10781 } 10782 else if (DECL_SELF_REFERENCE_P (t)) 10783 SET_DECL_SELF_REFERENCE_P (r); 10784 TREE_TYPE (r) = type; 10785 cp_apply_type_quals_to_decl (cp_type_quals (type), r); 10786 DECL_CONTEXT (r) = ctx; 10787 /* Clear out the mangled name and RTL for the instantiation. */ 10788 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE); 10789 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL)) 10790 SET_DECL_RTL (r, NULL); 10791 /* The initializer must not be expanded until it is required; 10792 see [temp.inst]. */ 10793 DECL_INITIAL (r) = NULL_TREE; 10794 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL)) 10795 SET_DECL_RTL (r, NULL); 10796 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0; 10797 if (TREE_CODE (r) == VAR_DECL) 10798 { 10799 /* Possibly limit visibility based on template args. */ 10800 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT; 10801 if (DECL_VISIBILITY_SPECIFIED (t)) 10802 { 10803 DECL_VISIBILITY_SPECIFIED (r) = 0; 10804 DECL_ATTRIBUTES (r) 10805 = remove_attribute ("visibility", DECL_ATTRIBUTES (r)); 10806 } 10807 determine_visibility (r); 10808 } 10809 10810 if (!local_p) 10811 { 10812 /* A static data member declaration is always marked 10813 external when it is declared in-class, even if an 10814 initializer is present. We mimic the non-template 10815 processing here. */ 10816 DECL_EXTERNAL (r) = 1; 10817 10818 register_specialization (r, gen_tmpl, argvec, false, hash); 10819 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec); 10820 SET_DECL_IMPLICIT_INSTANTIATION (r); 10821 } 10822 else if (cp_unevaluated_operand) 10823 { 10824 /* We're substituting this var in a decltype outside of its 10825 scope, such as for a lambda return type. Don't add it to 10826 local_specializations, do perform auto deduction. */ 10827 tree auto_node = type_uses_auto (type); 10828 if (auto_node) 10829 { 10830 tree init 10831 = tsubst_expr (DECL_INITIAL (t), args, complain, in_decl, 10832 /*constant_expression_p=*/false); 10833 init = resolve_nondeduced_context (init); 10834 TREE_TYPE (r) = type 10835 = do_auto_deduction (type, init, auto_node); 10836 } 10837 } 10838 else 10839 register_local_specialization (r, t); 10840 10841 DECL_CHAIN (r) = NULL_TREE; 10842 10843 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 10844 /*flags=*/0, 10845 args, complain, in_decl); 10846 10847 /* Preserve a typedef that names a type. */ 10848 if (is_typedef_decl (r)) 10849 { 10850 DECL_ORIGINAL_TYPE (r) = NULL_TREE; 10851 set_underlying_type (r); 10852 } 10853 10854 layout_decl (r, 0); 10855 } 10856 break; 10857 10858 default: 10859 gcc_unreachable (); 10860 } 10861 #undef RETURN 10862 10863 out: 10864 /* Restore the file and line information. */ 10865 input_location = saved_loc; 10866 10867 return r; 10868 } 10869 10870 /* Substitute into the ARG_TYPES of a function type. */ 10871 10872 static tree 10873 tsubst_arg_types (tree arg_types, 10874 tree args, 10875 tsubst_flags_t complain, 10876 tree in_decl) 10877 { 10878 tree remaining_arg_types; 10879 tree type = NULL_TREE; 10880 int i = 1; 10881 tree expanded_args = NULL_TREE; 10882 tree default_arg; 10883 10884 if (!arg_types || arg_types == void_list_node) 10885 return arg_types; 10886 10887 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types), 10888 args, complain, in_decl); 10889 if (remaining_arg_types == error_mark_node) 10890 return error_mark_node; 10891 10892 if (PACK_EXPANSION_P (TREE_VALUE (arg_types))) 10893 { 10894 /* For a pack expansion, perform substitution on the 10895 entire expression. Later on, we'll handle the arguments 10896 one-by-one. */ 10897 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types), 10898 args, complain, in_decl); 10899 10900 if (TREE_CODE (expanded_args) == TREE_VEC) 10901 /* So that we'll spin through the parameters, one by one. */ 10902 i = TREE_VEC_LENGTH (expanded_args); 10903 else 10904 { 10905 /* We only partially substituted into the parameter 10906 pack. Our type is TYPE_PACK_EXPANSION. */ 10907 type = expanded_args; 10908 expanded_args = NULL_TREE; 10909 } 10910 } 10911 10912 while (i > 0) { 10913 --i; 10914 10915 if (expanded_args) 10916 type = TREE_VEC_ELT (expanded_args, i); 10917 else if (!type) 10918 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl); 10919 10920 if (type == error_mark_node) 10921 return error_mark_node; 10922 if (VOID_TYPE_P (type)) 10923 { 10924 if (complain & tf_error) 10925 { 10926 error ("invalid parameter type %qT", type); 10927 if (in_decl) 10928 error ("in declaration %q+D", in_decl); 10929 } 10930 return error_mark_node; 10931 } 10932 10933 /* Do array-to-pointer, function-to-pointer conversion, and ignore 10934 top-level qualifiers as required. */ 10935 type = cv_unqualified (type_decays_to (type)); 10936 10937 /* We do not substitute into default arguments here. The standard 10938 mandates that they be instantiated only when needed, which is 10939 done in build_over_call. */ 10940 default_arg = TREE_PURPOSE (arg_types); 10941 10942 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG) 10943 { 10944 /* We've instantiated a template before its default arguments 10945 have been parsed. This can happen for a nested template 10946 class, and is not an error unless we require the default 10947 argument in a call of this function. */ 10948 remaining_arg_types = 10949 tree_cons (default_arg, type, remaining_arg_types); 10950 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg), 10951 remaining_arg_types); 10952 } 10953 else 10954 remaining_arg_types = 10955 hash_tree_cons (default_arg, type, remaining_arg_types); 10956 } 10957 10958 return remaining_arg_types; 10959 } 10960 10961 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does 10962 *not* handle the exception-specification for FNTYPE, because the 10963 initial substitution of explicitly provided template parameters 10964 during argument deduction forbids substitution into the 10965 exception-specification: 10966 10967 [temp.deduct] 10968 10969 All references in the function type of the function template to the 10970 corresponding template parameters are replaced by the specified tem- 10971 plate argument values. If a substitution in a template parameter or 10972 in the function type of the function template results in an invalid 10973 type, type deduction fails. [Note: The equivalent substitution in 10974 exception specifications is done only when the function is instanti- 10975 ated, at which point a program is ill-formed if the substitution 10976 results in an invalid type.] */ 10977 10978 static tree 10979 tsubst_function_type (tree t, 10980 tree args, 10981 tsubst_flags_t complain, 10982 tree in_decl) 10983 { 10984 tree return_type; 10985 tree arg_types; 10986 tree fntype; 10987 10988 /* The TYPE_CONTEXT is not used for function/method types. */ 10989 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE); 10990 10991 /* Substitute the return type. */ 10992 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl); 10993 if (return_type == error_mark_node) 10994 return error_mark_node; 10995 /* The standard does not presently indicate that creation of a 10996 function type with an invalid return type is a deduction failure. 10997 However, that is clearly analogous to creating an array of "void" 10998 or a reference to a reference. This is core issue #486. */ 10999 if (TREE_CODE (return_type) == ARRAY_TYPE 11000 || TREE_CODE (return_type) == FUNCTION_TYPE) 11001 { 11002 if (complain & tf_error) 11003 { 11004 if (TREE_CODE (return_type) == ARRAY_TYPE) 11005 error ("function returning an array"); 11006 else 11007 error ("function returning a function"); 11008 } 11009 return error_mark_node; 11010 } 11011 11012 /* Substitute the argument types. */ 11013 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args, 11014 complain, in_decl); 11015 if (arg_types == error_mark_node) 11016 return error_mark_node; 11017 11018 /* Construct a new type node and return it. */ 11019 if (TREE_CODE (t) == FUNCTION_TYPE) 11020 { 11021 fntype = build_function_type (return_type, arg_types); 11022 fntype = apply_memfn_quals (fntype, type_memfn_quals (t)); 11023 } 11024 else 11025 { 11026 tree r = TREE_TYPE (TREE_VALUE (arg_types)); 11027 if (! MAYBE_CLASS_TYPE_P (r)) 11028 { 11029 /* [temp.deduct] 11030 11031 Type deduction may fail for any of the following 11032 reasons: 11033 11034 -- Attempting to create "pointer to member of T" when T 11035 is not a class type. */ 11036 if (complain & tf_error) 11037 error ("creating pointer to member function of non-class type %qT", 11038 r); 11039 return error_mark_node; 11040 } 11041 11042 fntype = build_method_type_directly (r, return_type, 11043 TREE_CHAIN (arg_types)); 11044 } 11045 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t)); 11046 11047 return fntype; 11048 } 11049 11050 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template 11051 ARGS into that specification, and return the substituted 11052 specification. If there is no specification, return NULL_TREE. */ 11053 11054 static tree 11055 tsubst_exception_specification (tree fntype, 11056 tree args, 11057 tsubst_flags_t complain, 11058 tree in_decl, 11059 bool defer_ok) 11060 { 11061 tree specs; 11062 tree new_specs; 11063 11064 specs = TYPE_RAISES_EXCEPTIONS (fntype); 11065 new_specs = NULL_TREE; 11066 if (specs && TREE_PURPOSE (specs)) 11067 { 11068 /* A noexcept-specifier. */ 11069 tree expr = TREE_PURPOSE (specs); 11070 if (expr == boolean_true_node || expr == boolean_false_node) 11071 new_specs = expr; 11072 else if (defer_ok) 11073 { 11074 /* Defer instantiation of noexcept-specifiers to avoid 11075 excessive instantiations (c++/49107). */ 11076 new_specs = make_node (DEFERRED_NOEXCEPT); 11077 if (DEFERRED_NOEXCEPT_SPEC_P (specs)) 11078 { 11079 /* We already partially instantiated this member template, 11080 so combine the new args with the old. */ 11081 DEFERRED_NOEXCEPT_PATTERN (new_specs) 11082 = DEFERRED_NOEXCEPT_PATTERN (expr); 11083 DEFERRED_NOEXCEPT_ARGS (new_specs) 11084 = add_to_template_args (DEFERRED_NOEXCEPT_ARGS (expr), args); 11085 } 11086 else 11087 { 11088 DEFERRED_NOEXCEPT_PATTERN (new_specs) = expr; 11089 DEFERRED_NOEXCEPT_ARGS (new_specs) = args; 11090 } 11091 } 11092 else 11093 new_specs = tsubst_copy_and_build 11094 (expr, args, complain, in_decl, /*function_p=*/false, 11095 /*integral_constant_expression_p=*/true); 11096 new_specs = build_noexcept_spec (new_specs, complain); 11097 } 11098 else if (specs) 11099 { 11100 if (! TREE_VALUE (specs)) 11101 new_specs = specs; 11102 else 11103 while (specs) 11104 { 11105 tree spec; 11106 int i, len = 1; 11107 tree expanded_specs = NULL_TREE; 11108 11109 if (PACK_EXPANSION_P (TREE_VALUE (specs))) 11110 { 11111 /* Expand the pack expansion type. */ 11112 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs), 11113 args, complain, 11114 in_decl); 11115 11116 if (expanded_specs == error_mark_node) 11117 return error_mark_node; 11118 else if (TREE_CODE (expanded_specs) == TREE_VEC) 11119 len = TREE_VEC_LENGTH (expanded_specs); 11120 else 11121 { 11122 /* We're substituting into a member template, so 11123 we got a TYPE_PACK_EXPANSION back. Add that 11124 expansion and move on. */ 11125 gcc_assert (TREE_CODE (expanded_specs) 11126 == TYPE_PACK_EXPANSION); 11127 new_specs = add_exception_specifier (new_specs, 11128 expanded_specs, 11129 complain); 11130 specs = TREE_CHAIN (specs); 11131 continue; 11132 } 11133 } 11134 11135 for (i = 0; i < len; ++i) 11136 { 11137 if (expanded_specs) 11138 spec = TREE_VEC_ELT (expanded_specs, i); 11139 else 11140 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl); 11141 if (spec == error_mark_node) 11142 return spec; 11143 new_specs = add_exception_specifier (new_specs, spec, 11144 complain); 11145 } 11146 11147 specs = TREE_CHAIN (specs); 11148 } 11149 } 11150 return new_specs; 11151 } 11152 11153 /* Take the tree structure T and replace template parameters used 11154 therein with the argument vector ARGS. IN_DECL is an associated 11155 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE. 11156 Issue error and warning messages under control of COMPLAIN. Note 11157 that we must be relatively non-tolerant of extensions here, in 11158 order to preserve conformance; if we allow substitutions that 11159 should not be allowed, we may allow argument deductions that should 11160 not succeed, and therefore report ambiguous overload situations 11161 where there are none. In theory, we could allow the substitution, 11162 but indicate that it should have failed, and allow our caller to 11163 make sure that the right thing happens, but we don't try to do this 11164 yet. 11165 11166 This function is used for dealing with types, decls and the like; 11167 for expressions, use tsubst_expr or tsubst_copy. */ 11168 11169 tree 11170 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl) 11171 { 11172 enum tree_code code; 11173 tree type, r = NULL_TREE; 11174 11175 if (t == NULL_TREE || t == error_mark_node 11176 || t == integer_type_node 11177 || t == void_type_node 11178 || t == char_type_node 11179 || t == unknown_type_node 11180 || TREE_CODE (t) == NAMESPACE_DECL 11181 || TREE_CODE (t) == TRANSLATION_UNIT_DECL) 11182 return t; 11183 11184 if (DECL_P (t)) 11185 return tsubst_decl (t, args, complain); 11186 11187 if (args == NULL_TREE) 11188 return t; 11189 11190 code = TREE_CODE (t); 11191 11192 if (code == IDENTIFIER_NODE) 11193 type = IDENTIFIER_TYPE_VALUE (t); 11194 else 11195 type = TREE_TYPE (t); 11196 11197 gcc_assert (type != unknown_type_node); 11198 11199 /* Reuse typedefs. We need to do this to handle dependent attributes, 11200 such as attribute aligned. */ 11201 if (TYPE_P (t) 11202 && typedef_variant_p (t)) 11203 { 11204 tree decl = TYPE_NAME (t); 11205 11206 if (TYPE_DECL_ALIAS_P (decl) 11207 && DECL_LANG_SPECIFIC (decl) 11208 && DECL_TEMPLATE_INFO (decl) 11209 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl))) 11210 { 11211 /* DECL represents an alias template and we want to 11212 instantiate it. Let's substitute our arguments for the 11213 template parameters into the declaration and get the 11214 resulting type. */ 11215 r = tsubst (decl, args, complain, decl); 11216 } 11217 else if (DECL_CLASS_SCOPE_P (decl) 11218 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl)) 11219 && uses_template_parms (DECL_CONTEXT (decl))) 11220 { 11221 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl)); 11222 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl); 11223 r = retrieve_specialization (tmpl, gen_args, 0); 11224 } 11225 else if (DECL_FUNCTION_SCOPE_P (decl) 11226 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl)) 11227 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl)))) 11228 r = retrieve_local_specialization (decl); 11229 else 11230 /* The typedef is from a non-template context. */ 11231 return t; 11232 11233 if (r) 11234 { 11235 r = TREE_TYPE (r); 11236 r = cp_build_qualified_type_real 11237 (r, cp_type_quals (t) | cp_type_quals (r), 11238 complain | tf_ignore_bad_quals); 11239 return r; 11240 } 11241 else 11242 /* We don't have an instantiation yet, so drop the typedef. */ 11243 t = DECL_ORIGINAL_TYPE (decl); 11244 } 11245 11246 if (type 11247 && code != TYPENAME_TYPE 11248 && code != TEMPLATE_TYPE_PARM 11249 && code != IDENTIFIER_NODE 11250 && code != FUNCTION_TYPE 11251 && code != METHOD_TYPE) 11252 type = tsubst (type, args, complain, in_decl); 11253 if (type == error_mark_node) 11254 return error_mark_node; 11255 11256 switch (code) 11257 { 11258 case RECORD_TYPE: 11259 case UNION_TYPE: 11260 case ENUMERAL_TYPE: 11261 return tsubst_aggr_type (t, args, complain, in_decl, 11262 /*entering_scope=*/0); 11263 11264 case ERROR_MARK: 11265 case IDENTIFIER_NODE: 11266 case VOID_TYPE: 11267 case REAL_TYPE: 11268 case COMPLEX_TYPE: 11269 case VECTOR_TYPE: 11270 case BOOLEAN_TYPE: 11271 case NULLPTR_TYPE: 11272 case LANG_TYPE: 11273 return t; 11274 11275 case INTEGER_TYPE: 11276 if (t == integer_type_node) 11277 return t; 11278 11279 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST 11280 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST) 11281 return t; 11282 11283 { 11284 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0); 11285 11286 max = tsubst_expr (omax, args, complain, in_decl, 11287 /*integral_constant_expression_p=*/false); 11288 11289 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if 11290 needed. */ 11291 if (TREE_CODE (max) == NOP_EXPR 11292 && TREE_SIDE_EFFECTS (omax) 11293 && !TREE_TYPE (max)) 11294 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0)); 11295 11296 /* If we're in a partial instantiation, preserve the magic NOP_EXPR 11297 with TREE_SIDE_EFFECTS that indicates this is not an integral 11298 constant expression. */ 11299 if (processing_template_decl 11300 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR) 11301 { 11302 gcc_assert (TREE_CODE (max) == NOP_EXPR); 11303 TREE_SIDE_EFFECTS (max) = 1; 11304 } 11305 11306 return compute_array_index_type (NULL_TREE, max, complain); 11307 } 11308 11309 case TEMPLATE_TYPE_PARM: 11310 case TEMPLATE_TEMPLATE_PARM: 11311 case BOUND_TEMPLATE_TEMPLATE_PARM: 11312 case TEMPLATE_PARM_INDEX: 11313 { 11314 int idx; 11315 int level; 11316 int levels; 11317 tree arg = NULL_TREE; 11318 11319 r = NULL_TREE; 11320 11321 gcc_assert (TREE_VEC_LENGTH (args) > 0); 11322 template_parm_level_and_index (t, &level, &idx); 11323 11324 levels = TMPL_ARGS_DEPTH (args); 11325 if (level <= levels) 11326 { 11327 arg = TMPL_ARG (args, level, idx); 11328 11329 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT) 11330 /* See through ARGUMENT_PACK_SELECT arguments. */ 11331 arg = ARGUMENT_PACK_SELECT_ARG (arg); 11332 } 11333 11334 if (arg == error_mark_node) 11335 return error_mark_node; 11336 else if (arg != NULL_TREE) 11337 { 11338 if (ARGUMENT_PACK_P (arg)) 11339 /* If ARG is an argument pack, we don't actually want to 11340 perform a substitution here, because substitutions 11341 for argument packs are only done 11342 element-by-element. We can get to this point when 11343 substituting the type of a non-type template 11344 parameter pack, when that type actually contains 11345 template parameter packs from an outer template, e.g., 11346 11347 template<typename... Types> struct A { 11348 template<Types... Values> struct B { }; 11349 }; */ 11350 return t; 11351 11352 if (code == TEMPLATE_TYPE_PARM) 11353 { 11354 int quals; 11355 gcc_assert (TYPE_P (arg)); 11356 11357 quals = cp_type_quals (arg) | cp_type_quals (t); 11358 11359 return cp_build_qualified_type_real 11360 (arg, quals, complain | tf_ignore_bad_quals); 11361 } 11362 else if (code == BOUND_TEMPLATE_TEMPLATE_PARM) 11363 { 11364 /* We are processing a type constructed from a 11365 template template parameter. */ 11366 tree argvec = tsubst (TYPE_TI_ARGS (t), 11367 args, complain, in_decl); 11368 if (argvec == error_mark_node) 11369 return error_mark_node; 11370 11371 gcc_assert (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM 11372 || TREE_CODE (arg) == TEMPLATE_DECL 11373 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE); 11374 11375 if (TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE) 11376 /* Consider this code: 11377 11378 template <template <class> class Template> 11379 struct Internal { 11380 template <class Arg> using Bind = Template<Arg>; 11381 }; 11382 11383 template <template <class> class Template, class Arg> 11384 using Instantiate = Template<Arg>; //#0 11385 11386 template <template <class> class Template, 11387 class Argument> 11388 using Bind = 11389 Instantiate<Internal<Template>::template Bind, 11390 Argument>; //#1 11391 11392 When #1 is parsed, the 11393 BOUND_TEMPLATE_TEMPLATE_PARM representing the 11394 parameter `Template' in #0 matches the 11395 UNBOUND_CLASS_TEMPLATE representing the argument 11396 `Internal<Template>::template Bind'; We then want 11397 to assemble the type `Bind<Argument>' that can't 11398 be fully created right now, because 11399 `Internal<Template>' not being complete, the Bind 11400 template cannot be looked up in that context. So 11401 we need to "store" `Bind<Argument>' for later 11402 when the context of Bind becomes complete. Let's 11403 store that in a TYPENAME_TYPE. */ 11404 return make_typename_type (TYPE_CONTEXT (arg), 11405 build_nt (TEMPLATE_ID_EXPR, 11406 TYPE_IDENTIFIER (arg), 11407 argvec), 11408 typename_type, 11409 complain); 11410 11411 /* We can get a TEMPLATE_TEMPLATE_PARM here when we 11412 are resolving nested-types in the signature of a 11413 member function templates. Otherwise ARG is a 11414 TEMPLATE_DECL and is the real template to be 11415 instantiated. */ 11416 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM) 11417 arg = TYPE_NAME (arg); 11418 11419 r = lookup_template_class (arg, 11420 argvec, in_decl, 11421 DECL_CONTEXT (arg), 11422 /*entering_scope=*/0, 11423 complain); 11424 return cp_build_qualified_type_real 11425 (r, cp_type_quals (t), complain); 11426 } 11427 else 11428 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */ 11429 return convert_from_reference (unshare_expr (arg)); 11430 } 11431 11432 if (level == 1) 11433 /* This can happen during the attempted tsubst'ing in 11434 unify. This means that we don't yet have any information 11435 about the template parameter in question. */ 11436 return t; 11437 11438 /* If we get here, we must have been looking at a parm for a 11439 more deeply nested template. Make a new version of this 11440 template parameter, but with a lower level. */ 11441 switch (code) 11442 { 11443 case TEMPLATE_TYPE_PARM: 11444 case TEMPLATE_TEMPLATE_PARM: 11445 case BOUND_TEMPLATE_TEMPLATE_PARM: 11446 if (cp_type_quals (t)) 11447 { 11448 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl); 11449 r = cp_build_qualified_type_real 11450 (r, cp_type_quals (t), 11451 complain | (code == TEMPLATE_TYPE_PARM 11452 ? tf_ignore_bad_quals : 0)); 11453 } 11454 else 11455 { 11456 r = copy_type (t); 11457 TEMPLATE_TYPE_PARM_INDEX (r) 11458 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t), 11459 r, levels, args, complain); 11460 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r); 11461 TYPE_MAIN_VARIANT (r) = r; 11462 TYPE_POINTER_TO (r) = NULL_TREE; 11463 TYPE_REFERENCE_TO (r) = NULL_TREE; 11464 11465 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM) 11466 /* We have reduced the level of the template 11467 template parameter, but not the levels of its 11468 template parameters, so canonical_type_parameter 11469 will not be able to find the canonical template 11470 template parameter for this level. Thus, we 11471 require structural equality checking to compare 11472 TEMPLATE_TEMPLATE_PARMs. */ 11473 SET_TYPE_STRUCTURAL_EQUALITY (r); 11474 else if (TYPE_STRUCTURAL_EQUALITY_P (t)) 11475 SET_TYPE_STRUCTURAL_EQUALITY (r); 11476 else 11477 TYPE_CANONICAL (r) = canonical_type_parameter (r); 11478 11479 if (code == BOUND_TEMPLATE_TEMPLATE_PARM) 11480 { 11481 tree argvec = tsubst (TYPE_TI_ARGS (t), args, 11482 complain, in_decl); 11483 if (argvec == error_mark_node) 11484 return error_mark_node; 11485 11486 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r) 11487 = build_template_info (TYPE_TI_TEMPLATE (t), argvec); 11488 } 11489 } 11490 break; 11491 11492 case TEMPLATE_PARM_INDEX: 11493 r = reduce_template_parm_level (t, type, levels, args, complain); 11494 break; 11495 11496 default: 11497 gcc_unreachable (); 11498 } 11499 11500 return r; 11501 } 11502 11503 case TREE_LIST: 11504 { 11505 tree purpose, value, chain; 11506 11507 if (t == void_list_node) 11508 return t; 11509 11510 purpose = TREE_PURPOSE (t); 11511 if (purpose) 11512 { 11513 purpose = tsubst (purpose, args, complain, in_decl); 11514 if (purpose == error_mark_node) 11515 return error_mark_node; 11516 } 11517 value = TREE_VALUE (t); 11518 if (value) 11519 { 11520 value = tsubst (value, args, complain, in_decl); 11521 if (value == error_mark_node) 11522 return error_mark_node; 11523 } 11524 chain = TREE_CHAIN (t); 11525 if (chain && chain != void_type_node) 11526 { 11527 chain = tsubst (chain, args, complain, in_decl); 11528 if (chain == error_mark_node) 11529 return error_mark_node; 11530 } 11531 if (purpose == TREE_PURPOSE (t) 11532 && value == TREE_VALUE (t) 11533 && chain == TREE_CHAIN (t)) 11534 return t; 11535 return hash_tree_cons (purpose, value, chain); 11536 } 11537 11538 case TREE_BINFO: 11539 /* We should never be tsubsting a binfo. */ 11540 gcc_unreachable (); 11541 11542 case TREE_VEC: 11543 /* A vector of template arguments. */ 11544 gcc_assert (!type); 11545 return tsubst_template_args (t, args, complain, in_decl); 11546 11547 case POINTER_TYPE: 11548 case REFERENCE_TYPE: 11549 { 11550 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE) 11551 return t; 11552 11553 /* [temp.deduct] 11554 11555 Type deduction may fail for any of the following 11556 reasons: 11557 11558 -- Attempting to create a pointer to reference type. 11559 -- Attempting to create a reference to a reference type or 11560 a reference to void. 11561 11562 Core issue 106 says that creating a reference to a reference 11563 during instantiation is no longer a cause for failure. We 11564 only enforce this check in strict C++98 mode. */ 11565 if ((TREE_CODE (type) == REFERENCE_TYPE 11566 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE)) 11567 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE)) 11568 { 11569 static location_t last_loc; 11570 11571 /* We keep track of the last time we issued this error 11572 message to avoid spewing a ton of messages during a 11573 single bad template instantiation. */ 11574 if (complain & tf_error 11575 && last_loc != input_location) 11576 { 11577 if (TREE_CODE (type) == VOID_TYPE) 11578 error ("forming reference to void"); 11579 else if (code == POINTER_TYPE) 11580 error ("forming pointer to reference type %qT", type); 11581 else 11582 error ("forming reference to reference type %qT", type); 11583 last_loc = input_location; 11584 } 11585 11586 return error_mark_node; 11587 } 11588 else if (code == POINTER_TYPE) 11589 { 11590 r = build_pointer_type (type); 11591 if (TREE_CODE (type) == METHOD_TYPE) 11592 r = build_ptrmemfunc_type (r); 11593 } 11594 else if (TREE_CODE (type) == REFERENCE_TYPE) 11595 /* In C++0x, during template argument substitution, when there is an 11596 attempt to create a reference to a reference type, reference 11597 collapsing is applied as described in [14.3.1/4 temp.arg.type]: 11598 11599 "If a template-argument for a template-parameter T names a type 11600 that is a reference to a type A, an attempt to create the type 11601 'lvalue reference to cv T' creates the type 'lvalue reference to 11602 A,' while an attempt to create the type type rvalue reference to 11603 cv T' creates the type T" 11604 */ 11605 r = cp_build_reference_type 11606 (TREE_TYPE (type), 11607 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type)); 11608 else 11609 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t)); 11610 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain); 11611 11612 if (r != error_mark_node) 11613 /* Will this ever be needed for TYPE_..._TO values? */ 11614 layout_type (r); 11615 11616 return r; 11617 } 11618 case OFFSET_TYPE: 11619 { 11620 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl); 11621 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r)) 11622 { 11623 /* [temp.deduct] 11624 11625 Type deduction may fail for any of the following 11626 reasons: 11627 11628 -- Attempting to create "pointer to member of T" when T 11629 is not a class type. */ 11630 if (complain & tf_error) 11631 error ("creating pointer to member of non-class type %qT", r); 11632 return error_mark_node; 11633 } 11634 if (TREE_CODE (type) == REFERENCE_TYPE) 11635 { 11636 if (complain & tf_error) 11637 error ("creating pointer to member reference type %qT", type); 11638 return error_mark_node; 11639 } 11640 if (TREE_CODE (type) == VOID_TYPE) 11641 { 11642 if (complain & tf_error) 11643 error ("creating pointer to member of type void"); 11644 return error_mark_node; 11645 } 11646 gcc_assert (TREE_CODE (type) != METHOD_TYPE); 11647 if (TREE_CODE (type) == FUNCTION_TYPE) 11648 { 11649 /* The type of the implicit object parameter gets its 11650 cv-qualifiers from the FUNCTION_TYPE. */ 11651 tree memptr; 11652 tree method_type = build_memfn_type (type, r, type_memfn_quals (type)); 11653 memptr = build_ptrmemfunc_type (build_pointer_type (method_type)); 11654 return cp_build_qualified_type_real (memptr, cp_type_quals (t), 11655 complain); 11656 } 11657 else 11658 return cp_build_qualified_type_real (build_ptrmem_type (r, type), 11659 cp_type_quals (t), 11660 complain); 11661 } 11662 case FUNCTION_TYPE: 11663 case METHOD_TYPE: 11664 { 11665 tree fntype; 11666 tree specs; 11667 fntype = tsubst_function_type (t, args, complain, in_decl); 11668 if (fntype == error_mark_node) 11669 return error_mark_node; 11670 11671 /* Substitute the exception specification. */ 11672 specs = tsubst_exception_specification (t, args, complain, 11673 in_decl, /*defer_ok*/true); 11674 if (specs == error_mark_node) 11675 return error_mark_node; 11676 if (specs) 11677 fntype = build_exception_variant (fntype, specs); 11678 return fntype; 11679 } 11680 case ARRAY_TYPE: 11681 { 11682 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl); 11683 if (domain == error_mark_node) 11684 return error_mark_node; 11685 11686 /* As an optimization, we avoid regenerating the array type if 11687 it will obviously be the same as T. */ 11688 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t)) 11689 return t; 11690 11691 /* These checks should match the ones in grokdeclarator. 11692 11693 [temp.deduct] 11694 11695 The deduction may fail for any of the following reasons: 11696 11697 -- Attempting to create an array with an element type that 11698 is void, a function type, or a reference type, or [DR337] 11699 an abstract class type. */ 11700 if (TREE_CODE (type) == VOID_TYPE 11701 || TREE_CODE (type) == FUNCTION_TYPE 11702 || TREE_CODE (type) == REFERENCE_TYPE) 11703 { 11704 if (complain & tf_error) 11705 error ("creating array of %qT", type); 11706 return error_mark_node; 11707 } 11708 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type)) 11709 { 11710 if (complain & tf_error) 11711 error ("creating array of %qT, which is an abstract class type", 11712 type); 11713 return error_mark_node; 11714 } 11715 11716 r = build_cplus_array_type (type, domain); 11717 11718 if (TYPE_USER_ALIGN (t)) 11719 { 11720 TYPE_ALIGN (r) = TYPE_ALIGN (t); 11721 TYPE_USER_ALIGN (r) = 1; 11722 } 11723 11724 return r; 11725 } 11726 11727 case TYPENAME_TYPE: 11728 { 11729 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain, 11730 in_decl, /*entering_scope=*/1); 11731 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args, 11732 complain, in_decl); 11733 11734 if (ctx == error_mark_node || f == error_mark_node) 11735 return error_mark_node; 11736 11737 if (!MAYBE_CLASS_TYPE_P (ctx)) 11738 { 11739 if (complain & tf_error) 11740 error ("%qT is not a class, struct, or union type", ctx); 11741 return error_mark_node; 11742 } 11743 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx)) 11744 { 11745 /* Normally, make_typename_type does not require that the CTX 11746 have complete type in order to allow things like: 11747 11748 template <class T> struct S { typename S<T>::X Y; }; 11749 11750 But, such constructs have already been resolved by this 11751 point, so here CTX really should have complete type, unless 11752 it's a partial instantiation. */ 11753 ctx = complete_type (ctx); 11754 if (!COMPLETE_TYPE_P (ctx)) 11755 { 11756 if (complain & tf_error) 11757 cxx_incomplete_type_error (NULL_TREE, ctx); 11758 return error_mark_node; 11759 } 11760 } 11761 11762 f = make_typename_type (ctx, f, typename_type, 11763 (complain & tf_error) | tf_keep_type_decl); 11764 if (f == error_mark_node) 11765 return f; 11766 if (TREE_CODE (f) == TYPE_DECL) 11767 { 11768 complain |= tf_ignore_bad_quals; 11769 f = TREE_TYPE (f); 11770 } 11771 11772 if (TREE_CODE (f) != TYPENAME_TYPE) 11773 { 11774 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE) 11775 { 11776 if (complain & tf_error) 11777 error ("%qT resolves to %qT, which is not an enumeration type", 11778 t, f); 11779 else 11780 return error_mark_node; 11781 } 11782 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f)) 11783 { 11784 if (complain & tf_error) 11785 error ("%qT resolves to %qT, which is is not a class type", 11786 t, f); 11787 else 11788 return error_mark_node; 11789 } 11790 } 11791 11792 return cp_build_qualified_type_real 11793 (f, cp_type_quals (f) | cp_type_quals (t), complain); 11794 } 11795 11796 case UNBOUND_CLASS_TEMPLATE: 11797 { 11798 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain, 11799 in_decl, /*entering_scope=*/1); 11800 tree name = TYPE_IDENTIFIER (t); 11801 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t)); 11802 11803 if (ctx == error_mark_node || name == error_mark_node) 11804 return error_mark_node; 11805 11806 if (parm_list) 11807 parm_list = tsubst_template_parms (parm_list, args, complain); 11808 return make_unbound_class_template (ctx, name, parm_list, complain); 11809 } 11810 11811 case TYPEOF_TYPE: 11812 { 11813 tree type; 11814 11815 ++cp_unevaluated_operand; 11816 ++c_inhibit_evaluation_warnings; 11817 11818 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args, 11819 complain, in_decl, 11820 /*integral_constant_expression_p=*/false); 11821 11822 --cp_unevaluated_operand; 11823 --c_inhibit_evaluation_warnings; 11824 11825 type = finish_typeof (type); 11826 return cp_build_qualified_type_real (type, 11827 cp_type_quals (t) 11828 | cp_type_quals (type), 11829 complain); 11830 } 11831 11832 case DECLTYPE_TYPE: 11833 { 11834 tree type; 11835 11836 ++cp_unevaluated_operand; 11837 ++c_inhibit_evaluation_warnings; 11838 11839 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args, 11840 complain, in_decl, 11841 /*integral_constant_expression_p=*/false); 11842 11843 --cp_unevaluated_operand; 11844 --c_inhibit_evaluation_warnings; 11845 11846 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t)) 11847 type = lambda_capture_field_type (type); 11848 else if (DECLTYPE_FOR_LAMBDA_PROXY (t)) 11849 type = lambda_proxy_type (type); 11850 else 11851 type = finish_decltype_type 11852 (type, DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t), complain); 11853 return cp_build_qualified_type_real (type, 11854 cp_type_quals (t) 11855 | cp_type_quals (type), 11856 complain); 11857 } 11858 11859 case UNDERLYING_TYPE: 11860 { 11861 tree type = tsubst (UNDERLYING_TYPE_TYPE (t), args, 11862 complain, in_decl); 11863 return finish_underlying_type (type); 11864 } 11865 11866 case TYPE_ARGUMENT_PACK: 11867 case NONTYPE_ARGUMENT_PACK: 11868 { 11869 tree r = TYPE_P (t) ? cxx_make_type (code) : make_node (code); 11870 tree packed_out = 11871 tsubst_template_args (ARGUMENT_PACK_ARGS (t), 11872 args, 11873 complain, 11874 in_decl); 11875 SET_ARGUMENT_PACK_ARGS (r, packed_out); 11876 11877 /* For template nontype argument packs, also substitute into 11878 the type. */ 11879 if (code == NONTYPE_ARGUMENT_PACK) 11880 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl); 11881 11882 return r; 11883 } 11884 break; 11885 11886 case INTEGER_CST: 11887 case REAL_CST: 11888 case STRING_CST: 11889 case PLUS_EXPR: 11890 case MINUS_EXPR: 11891 case NEGATE_EXPR: 11892 case NOP_EXPR: 11893 case INDIRECT_REF: 11894 case ADDR_EXPR: 11895 case CALL_EXPR: 11896 case ARRAY_REF: 11897 case SCOPE_REF: 11898 /* We should use one of the expression tsubsts for these codes. */ 11899 gcc_unreachable (); 11900 11901 default: 11902 sorry ("use of %qs in template", tree_code_name [(int) code]); 11903 return error_mark_node; 11904 } 11905 } 11906 11907 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the 11908 type of the expression on the left-hand side of the "." or "->" 11909 operator. */ 11910 11911 static tree 11912 tsubst_baselink (tree baselink, tree object_type, 11913 tree args, tsubst_flags_t complain, tree in_decl) 11914 { 11915 tree name; 11916 tree qualifying_scope; 11917 tree fns; 11918 tree optype; 11919 tree template_args = 0; 11920 bool template_id_p = false; 11921 bool qualified = BASELINK_QUALIFIED_P (baselink); 11922 11923 /* A baselink indicates a function from a base class. Both the 11924 BASELINK_ACCESS_BINFO and the base class referenced may 11925 indicate bases of the template class, rather than the 11926 instantiated class. In addition, lookups that were not 11927 ambiguous before may be ambiguous now. Therefore, we perform 11928 the lookup again. */ 11929 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink)); 11930 qualifying_scope = tsubst (qualifying_scope, args, 11931 complain, in_decl); 11932 fns = BASELINK_FUNCTIONS (baselink); 11933 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl); 11934 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR) 11935 { 11936 template_id_p = true; 11937 template_args = TREE_OPERAND (fns, 1); 11938 fns = TREE_OPERAND (fns, 0); 11939 if (template_args) 11940 template_args = tsubst_template_args (template_args, args, 11941 complain, in_decl); 11942 } 11943 name = DECL_NAME (get_first_fn (fns)); 11944 if (IDENTIFIER_TYPENAME_P (name)) 11945 name = mangle_conv_op_name_for_type (optype); 11946 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1); 11947 if (!baselink) 11948 return error_mark_node; 11949 11950 /* If lookup found a single function, mark it as used at this 11951 point. (If it lookup found multiple functions the one selected 11952 later by overload resolution will be marked as used at that 11953 point.) */ 11954 if (BASELINK_P (baselink)) 11955 fns = BASELINK_FUNCTIONS (baselink); 11956 if (!template_id_p && !really_overloaded_fn (fns)) 11957 mark_used (OVL_CURRENT (fns)); 11958 11959 /* Add back the template arguments, if present. */ 11960 if (BASELINK_P (baselink) && template_id_p) 11961 BASELINK_FUNCTIONS (baselink) 11962 = build_nt (TEMPLATE_ID_EXPR, 11963 BASELINK_FUNCTIONS (baselink), 11964 template_args); 11965 /* Update the conversion operator type. */ 11966 BASELINK_OPTYPE (baselink) = optype; 11967 11968 if (!object_type) 11969 object_type = current_class_type; 11970 11971 if (qualified) 11972 baselink = adjust_result_of_qualified_name_lookup (baselink, 11973 qualifying_scope, 11974 object_type); 11975 return baselink; 11976 } 11977 11978 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is 11979 true if the qualified-id will be a postfix-expression in-and-of 11980 itself; false if more of the postfix-expression follows the 11981 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand 11982 of "&". */ 11983 11984 static tree 11985 tsubst_qualified_id (tree qualified_id, tree args, 11986 tsubst_flags_t complain, tree in_decl, 11987 bool done, bool address_p) 11988 { 11989 tree expr; 11990 tree scope; 11991 tree name; 11992 bool is_template; 11993 tree template_args; 11994 11995 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF); 11996 11997 /* Figure out what name to look up. */ 11998 name = TREE_OPERAND (qualified_id, 1); 11999 if (TREE_CODE (name) == TEMPLATE_ID_EXPR) 12000 { 12001 is_template = true; 12002 template_args = TREE_OPERAND (name, 1); 12003 if (template_args) 12004 template_args = tsubst_template_args (template_args, args, 12005 complain, in_decl); 12006 name = TREE_OPERAND (name, 0); 12007 } 12008 else 12009 { 12010 is_template = false; 12011 template_args = NULL_TREE; 12012 } 12013 12014 /* Substitute into the qualifying scope. When there are no ARGS, we 12015 are just trying to simplify a non-dependent expression. In that 12016 case the qualifying scope may be dependent, and, in any case, 12017 substituting will not help. */ 12018 scope = TREE_OPERAND (qualified_id, 0); 12019 if (args) 12020 { 12021 scope = tsubst (scope, args, complain, in_decl); 12022 expr = tsubst_copy (name, args, complain, in_decl); 12023 } 12024 else 12025 expr = name; 12026 12027 if (dependent_scope_p (scope)) 12028 { 12029 if (is_template) 12030 expr = build_min_nt (TEMPLATE_ID_EXPR, expr, template_args); 12031 return build_qualified_name (NULL_TREE, scope, expr, 12032 QUALIFIED_NAME_IS_TEMPLATE (qualified_id)); 12033 } 12034 12035 if (!BASELINK_P (name) && !DECL_P (expr)) 12036 { 12037 if (TREE_CODE (expr) == BIT_NOT_EXPR) 12038 { 12039 /* A BIT_NOT_EXPR is used to represent a destructor. */ 12040 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0))) 12041 { 12042 error ("qualifying type %qT does not match destructor name ~%qT", 12043 scope, TREE_OPERAND (expr, 0)); 12044 expr = error_mark_node; 12045 } 12046 else 12047 expr = lookup_qualified_name (scope, complete_dtor_identifier, 12048 /*is_type_p=*/0, false); 12049 } 12050 else 12051 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false); 12052 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL 12053 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL) 12054 { 12055 if (complain & tf_error) 12056 { 12057 error ("dependent-name %qE is parsed as a non-type, but " 12058 "instantiation yields a type", qualified_id); 12059 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id); 12060 } 12061 return error_mark_node; 12062 } 12063 } 12064 12065 if (DECL_P (expr)) 12066 { 12067 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE, 12068 scope); 12069 /* Remember that there was a reference to this entity. */ 12070 mark_used (expr); 12071 } 12072 12073 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST) 12074 { 12075 if (complain & tf_error) 12076 qualified_name_lookup_error (scope, 12077 TREE_OPERAND (qualified_id, 1), 12078 expr, input_location); 12079 return error_mark_node; 12080 } 12081 12082 if (is_template) 12083 expr = lookup_template_function (expr, template_args); 12084 12085 if (expr == error_mark_node && complain & tf_error) 12086 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1), 12087 expr, input_location); 12088 else if (TYPE_P (scope)) 12089 { 12090 expr = (adjust_result_of_qualified_name_lookup 12091 (expr, scope, current_class_type)); 12092 expr = (finish_qualified_id_expr 12093 (scope, expr, done, address_p && PTRMEM_OK_P (qualified_id), 12094 QUALIFIED_NAME_IS_TEMPLATE (qualified_id), 12095 /*template_arg_p=*/false)); 12096 } 12097 12098 /* Expressions do not generally have reference type. */ 12099 if (TREE_CODE (expr) != SCOPE_REF 12100 /* However, if we're about to form a pointer-to-member, we just 12101 want the referenced member referenced. */ 12102 && TREE_CODE (expr) != OFFSET_REF) 12103 expr = convert_from_reference (expr); 12104 12105 return expr; 12106 } 12107 12108 /* Like tsubst, but deals with expressions. This function just replaces 12109 template parms; to finish processing the resultant expression, use 12110 tsubst_copy_and_build or tsubst_expr. */ 12111 12112 static tree 12113 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl) 12114 { 12115 enum tree_code code; 12116 tree r; 12117 12118 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE) 12119 return t; 12120 12121 code = TREE_CODE (t); 12122 12123 switch (code) 12124 { 12125 case PARM_DECL: 12126 r = retrieve_local_specialization (t); 12127 12128 if (r == NULL) 12129 { 12130 tree c; 12131 12132 /* We get here for a use of 'this' in an NSDMI. */ 12133 if (DECL_NAME (t) == this_identifier 12134 && at_function_scope_p () 12135 && DECL_CONSTRUCTOR_P (current_function_decl)) 12136 return current_class_ptr; 12137 12138 /* This can happen for a parameter name used later in a function 12139 declaration (such as in a late-specified return type). Just 12140 make a dummy decl, since it's only used for its type. */ 12141 gcc_assert (cp_unevaluated_operand != 0); 12142 /* We copy T because want to tsubst the PARM_DECL only, 12143 not the following PARM_DECLs that are chained to T. */ 12144 c = copy_node (t); 12145 r = tsubst_decl (c, args, complain); 12146 /* Give it the template pattern as its context; its true context 12147 hasn't been instantiated yet and this is good enough for 12148 mangling. */ 12149 DECL_CONTEXT (r) = DECL_CONTEXT (t); 12150 } 12151 12152 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT) 12153 r = ARGUMENT_PACK_SELECT_ARG (r); 12154 mark_used (r); 12155 return r; 12156 12157 case CONST_DECL: 12158 { 12159 tree enum_type; 12160 tree v; 12161 12162 if (DECL_TEMPLATE_PARM_P (t)) 12163 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl); 12164 /* There is no need to substitute into namespace-scope 12165 enumerators. */ 12166 if (DECL_NAMESPACE_SCOPE_P (t)) 12167 return t; 12168 /* If ARGS is NULL, then T is known to be non-dependent. */ 12169 if (args == NULL_TREE) 12170 return integral_constant_value (t); 12171 12172 /* Unfortunately, we cannot just call lookup_name here. 12173 Consider: 12174 12175 template <int I> int f() { 12176 enum E { a = I }; 12177 struct S { void g() { E e = a; } }; 12178 }; 12179 12180 When we instantiate f<7>::S::g(), say, lookup_name is not 12181 clever enough to find f<7>::a. */ 12182 enum_type 12183 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl, 12184 /*entering_scope=*/0); 12185 12186 for (v = TYPE_VALUES (enum_type); 12187 v != NULL_TREE; 12188 v = TREE_CHAIN (v)) 12189 if (TREE_PURPOSE (v) == DECL_NAME (t)) 12190 return TREE_VALUE (v); 12191 12192 /* We didn't find the name. That should never happen; if 12193 name-lookup found it during preliminary parsing, we 12194 should find it again here during instantiation. */ 12195 gcc_unreachable (); 12196 } 12197 return t; 12198 12199 case FIELD_DECL: 12200 if (DECL_CONTEXT (t)) 12201 { 12202 tree ctx; 12203 12204 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl, 12205 /*entering_scope=*/1); 12206 if (ctx != DECL_CONTEXT (t)) 12207 { 12208 tree r = lookup_field (ctx, DECL_NAME (t), 0, false); 12209 if (!r) 12210 { 12211 if (complain & tf_error) 12212 error ("using invalid field %qD", t); 12213 return error_mark_node; 12214 } 12215 return r; 12216 } 12217 } 12218 12219 return t; 12220 12221 case VAR_DECL: 12222 case FUNCTION_DECL: 12223 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)) 12224 || local_variable_p (t)) 12225 t = tsubst (t, args, complain, in_decl); 12226 mark_used (t); 12227 return t; 12228 12229 case NAMESPACE_DECL: 12230 return t; 12231 12232 case OVERLOAD: 12233 /* An OVERLOAD will always be a non-dependent overload set; an 12234 overload set from function scope will just be represented with an 12235 IDENTIFIER_NODE, and from class scope with a BASELINK. */ 12236 gcc_assert (!uses_template_parms (t)); 12237 return t; 12238 12239 case BASELINK: 12240 return tsubst_baselink (t, current_class_type, args, complain, in_decl); 12241 12242 case TEMPLATE_DECL: 12243 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)) 12244 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)), 12245 args, complain, in_decl); 12246 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t)) 12247 return tsubst (t, args, complain, in_decl); 12248 else if (DECL_CLASS_SCOPE_P (t) 12249 && uses_template_parms (DECL_CONTEXT (t))) 12250 { 12251 /* Template template argument like the following example need 12252 special treatment: 12253 12254 template <template <class> class TT> struct C {}; 12255 template <class T> struct D { 12256 template <class U> struct E {}; 12257 C<E> c; // #1 12258 }; 12259 D<int> d; // #2 12260 12261 We are processing the template argument `E' in #1 for 12262 the template instantiation #2. Originally, `E' is a 12263 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we 12264 have to substitute this with one having context `D<int>'. */ 12265 12266 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl); 12267 return lookup_field (context, DECL_NAME(t), 0, false); 12268 } 12269 else 12270 /* Ordinary template template argument. */ 12271 return t; 12272 12273 case CAST_EXPR: 12274 case REINTERPRET_CAST_EXPR: 12275 case CONST_CAST_EXPR: 12276 case STATIC_CAST_EXPR: 12277 case DYNAMIC_CAST_EXPR: 12278 case IMPLICIT_CONV_EXPR: 12279 case CONVERT_EXPR: 12280 case NOP_EXPR: 12281 return build1 12282 (code, tsubst (TREE_TYPE (t), args, complain, in_decl), 12283 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl)); 12284 12285 case SIZEOF_EXPR: 12286 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0))) 12287 { 12288 12289 tree expanded; 12290 int len = 0; 12291 12292 ++cp_unevaluated_operand; 12293 ++c_inhibit_evaluation_warnings; 12294 /* We only want to compute the number of arguments. */ 12295 expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args, 12296 complain, in_decl); 12297 --cp_unevaluated_operand; 12298 --c_inhibit_evaluation_warnings; 12299 12300 if (TREE_CODE (expanded) == TREE_VEC) 12301 len = TREE_VEC_LENGTH (expanded); 12302 12303 if (expanded == error_mark_node) 12304 return error_mark_node; 12305 else if (PACK_EXPANSION_P (expanded) 12306 || (TREE_CODE (expanded) == TREE_VEC 12307 && len > 0 12308 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1)))) 12309 { 12310 if (TREE_CODE (expanded) == TREE_VEC) 12311 expanded = TREE_VEC_ELT (expanded, len - 1); 12312 12313 if (TYPE_P (expanded)) 12314 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR, 12315 complain & tf_error); 12316 else 12317 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR, 12318 complain & tf_error); 12319 } 12320 else 12321 return build_int_cst (size_type_node, len); 12322 } 12323 /* Fall through */ 12324 12325 case INDIRECT_REF: 12326 case NEGATE_EXPR: 12327 case TRUTH_NOT_EXPR: 12328 case BIT_NOT_EXPR: 12329 case ADDR_EXPR: 12330 case UNARY_PLUS_EXPR: /* Unary + */ 12331 case ALIGNOF_EXPR: 12332 case AT_ENCODE_EXPR: 12333 case ARROW_EXPR: 12334 case THROW_EXPR: 12335 case TYPEID_EXPR: 12336 case REALPART_EXPR: 12337 case IMAGPART_EXPR: 12338 return build1 12339 (code, tsubst (TREE_TYPE (t), args, complain, in_decl), 12340 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl)); 12341 12342 case COMPONENT_REF: 12343 { 12344 tree object; 12345 tree name; 12346 12347 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl); 12348 name = TREE_OPERAND (t, 1); 12349 if (TREE_CODE (name) == BIT_NOT_EXPR) 12350 { 12351 name = tsubst_copy (TREE_OPERAND (name, 0), args, 12352 complain, in_decl); 12353 name = build1 (BIT_NOT_EXPR, NULL_TREE, name); 12354 } 12355 else if (TREE_CODE (name) == SCOPE_REF 12356 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR) 12357 { 12358 tree base = tsubst_copy (TREE_OPERAND (name, 0), args, 12359 complain, in_decl); 12360 name = TREE_OPERAND (name, 1); 12361 name = tsubst_copy (TREE_OPERAND (name, 0), args, 12362 complain, in_decl); 12363 name = build1 (BIT_NOT_EXPR, NULL_TREE, name); 12364 name = build_qualified_name (/*type=*/NULL_TREE, 12365 base, name, 12366 /*template_p=*/false); 12367 } 12368 else if (BASELINK_P (name)) 12369 name = tsubst_baselink (name, 12370 non_reference (TREE_TYPE (object)), 12371 args, complain, 12372 in_decl); 12373 else 12374 name = tsubst_copy (name, args, complain, in_decl); 12375 return build_nt (COMPONENT_REF, object, name, NULL_TREE); 12376 } 12377 12378 case PLUS_EXPR: 12379 case MINUS_EXPR: 12380 case MULT_EXPR: 12381 case TRUNC_DIV_EXPR: 12382 case CEIL_DIV_EXPR: 12383 case FLOOR_DIV_EXPR: 12384 case ROUND_DIV_EXPR: 12385 case EXACT_DIV_EXPR: 12386 case BIT_AND_EXPR: 12387 case BIT_IOR_EXPR: 12388 case BIT_XOR_EXPR: 12389 case TRUNC_MOD_EXPR: 12390 case FLOOR_MOD_EXPR: 12391 case TRUTH_ANDIF_EXPR: 12392 case TRUTH_ORIF_EXPR: 12393 case TRUTH_AND_EXPR: 12394 case TRUTH_OR_EXPR: 12395 case RSHIFT_EXPR: 12396 case LSHIFT_EXPR: 12397 case RROTATE_EXPR: 12398 case LROTATE_EXPR: 12399 case EQ_EXPR: 12400 case NE_EXPR: 12401 case MAX_EXPR: 12402 case MIN_EXPR: 12403 case LE_EXPR: 12404 case GE_EXPR: 12405 case LT_EXPR: 12406 case GT_EXPR: 12407 case COMPOUND_EXPR: 12408 case DOTSTAR_EXPR: 12409 case MEMBER_REF: 12410 case PREDECREMENT_EXPR: 12411 case PREINCREMENT_EXPR: 12412 case POSTDECREMENT_EXPR: 12413 case POSTINCREMENT_EXPR: 12414 return build_nt 12415 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl), 12416 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl)); 12417 12418 case SCOPE_REF: 12419 return build_qualified_name (/*type=*/NULL_TREE, 12420 tsubst_copy (TREE_OPERAND (t, 0), 12421 args, complain, in_decl), 12422 tsubst_copy (TREE_OPERAND (t, 1), 12423 args, complain, in_decl), 12424 QUALIFIED_NAME_IS_TEMPLATE (t)); 12425 12426 case ARRAY_REF: 12427 return build_nt 12428 (ARRAY_REF, 12429 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl), 12430 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl), 12431 NULL_TREE, NULL_TREE); 12432 12433 case CALL_EXPR: 12434 { 12435 int n = VL_EXP_OPERAND_LENGTH (t); 12436 tree result = build_vl_exp (CALL_EXPR, n); 12437 int i; 12438 for (i = 0; i < n; i++) 12439 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args, 12440 complain, in_decl); 12441 return result; 12442 } 12443 12444 case COND_EXPR: 12445 case MODOP_EXPR: 12446 case PSEUDO_DTOR_EXPR: 12447 { 12448 r = build_nt 12449 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl), 12450 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl), 12451 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl)); 12452 TREE_NO_WARNING (r) = TREE_NO_WARNING (t); 12453 return r; 12454 } 12455 12456 case NEW_EXPR: 12457 { 12458 r = build_nt 12459 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl), 12460 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl), 12461 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl)); 12462 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t); 12463 return r; 12464 } 12465 12466 case DELETE_EXPR: 12467 { 12468 r = build_nt 12469 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl), 12470 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl)); 12471 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t); 12472 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t); 12473 return r; 12474 } 12475 12476 case TEMPLATE_ID_EXPR: 12477 { 12478 /* Substituted template arguments */ 12479 tree fn = TREE_OPERAND (t, 0); 12480 tree targs = TREE_OPERAND (t, 1); 12481 12482 fn = tsubst_copy (fn, args, complain, in_decl); 12483 if (targs) 12484 targs = tsubst_template_args (targs, args, complain, in_decl); 12485 12486 return lookup_template_function (fn, targs); 12487 } 12488 12489 case TREE_LIST: 12490 { 12491 tree purpose, value, chain; 12492 12493 if (t == void_list_node) 12494 return t; 12495 12496 purpose = TREE_PURPOSE (t); 12497 if (purpose) 12498 purpose = tsubst_copy (purpose, args, complain, in_decl); 12499 value = TREE_VALUE (t); 12500 if (value) 12501 value = tsubst_copy (value, args, complain, in_decl); 12502 chain = TREE_CHAIN (t); 12503 if (chain && chain != void_type_node) 12504 chain = tsubst_copy (chain, args, complain, in_decl); 12505 if (purpose == TREE_PURPOSE (t) 12506 && value == TREE_VALUE (t) 12507 && chain == TREE_CHAIN (t)) 12508 return t; 12509 return tree_cons (purpose, value, chain); 12510 } 12511 12512 case RECORD_TYPE: 12513 case UNION_TYPE: 12514 case ENUMERAL_TYPE: 12515 case INTEGER_TYPE: 12516 case TEMPLATE_TYPE_PARM: 12517 case TEMPLATE_TEMPLATE_PARM: 12518 case BOUND_TEMPLATE_TEMPLATE_PARM: 12519 case TEMPLATE_PARM_INDEX: 12520 case POINTER_TYPE: 12521 case REFERENCE_TYPE: 12522 case OFFSET_TYPE: 12523 case FUNCTION_TYPE: 12524 case METHOD_TYPE: 12525 case ARRAY_TYPE: 12526 case TYPENAME_TYPE: 12527 case UNBOUND_CLASS_TEMPLATE: 12528 case TYPEOF_TYPE: 12529 case DECLTYPE_TYPE: 12530 case TYPE_DECL: 12531 return tsubst (t, args, complain, in_decl); 12532 12533 case IDENTIFIER_NODE: 12534 if (IDENTIFIER_TYPENAME_P (t)) 12535 { 12536 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl); 12537 return mangle_conv_op_name_for_type (new_type); 12538 } 12539 else 12540 return t; 12541 12542 case CONSTRUCTOR: 12543 /* This is handled by tsubst_copy_and_build. */ 12544 gcc_unreachable (); 12545 12546 case VA_ARG_EXPR: 12547 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain, 12548 in_decl), 12549 tsubst (TREE_TYPE (t), args, complain, in_decl)); 12550 12551 case CLEANUP_POINT_EXPR: 12552 /* We shouldn't have built any of these during initial template 12553 generation. Instead, they should be built during instantiation 12554 in response to the saved STMT_IS_FULL_EXPR_P setting. */ 12555 gcc_unreachable (); 12556 12557 case OFFSET_REF: 12558 r = build2 12559 (code, tsubst (TREE_TYPE (t), args, complain, in_decl), 12560 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl), 12561 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl)); 12562 PTRMEM_OK_P (r) = PTRMEM_OK_P (t); 12563 mark_used (TREE_OPERAND (r, 1)); 12564 return r; 12565 12566 case EXPR_PACK_EXPANSION: 12567 error ("invalid use of pack expansion expression"); 12568 return error_mark_node; 12569 12570 case NONTYPE_ARGUMENT_PACK: 12571 error ("use %<...%> to expand argument pack"); 12572 return error_mark_node; 12573 12574 case INTEGER_CST: 12575 case REAL_CST: 12576 case STRING_CST: 12577 case COMPLEX_CST: 12578 { 12579 /* Instantiate any typedefs in the type. */ 12580 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl); 12581 r = fold_convert (type, t); 12582 gcc_assert (TREE_CODE (r) == code); 12583 return r; 12584 } 12585 12586 case PTRMEM_CST: 12587 /* These can sometimes show up in a partial instantiation, but never 12588 involve template parms. */ 12589 gcc_assert (!uses_template_parms (t)); 12590 return t; 12591 12592 default: 12593 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */ 12594 gcc_checking_assert (false); 12595 return t; 12596 } 12597 } 12598 12599 /* Like tsubst_copy, but specifically for OpenMP clauses. */ 12600 12601 static tree 12602 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain, 12603 tree in_decl) 12604 { 12605 tree new_clauses = NULL, nc, oc; 12606 12607 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc)) 12608 { 12609 nc = copy_node (oc); 12610 OMP_CLAUSE_CHAIN (nc) = new_clauses; 12611 new_clauses = nc; 12612 12613 switch (OMP_CLAUSE_CODE (nc)) 12614 { 12615 case OMP_CLAUSE_LASTPRIVATE: 12616 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc)) 12617 { 12618 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list (); 12619 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain, 12620 in_decl, /*integral_constant_expression_p=*/false); 12621 OMP_CLAUSE_LASTPRIVATE_STMT (nc) 12622 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc)); 12623 } 12624 /* FALLTHRU */ 12625 case OMP_CLAUSE_PRIVATE: 12626 case OMP_CLAUSE_SHARED: 12627 case OMP_CLAUSE_FIRSTPRIVATE: 12628 case OMP_CLAUSE_REDUCTION: 12629 case OMP_CLAUSE_COPYIN: 12630 case OMP_CLAUSE_COPYPRIVATE: 12631 case OMP_CLAUSE_IF: 12632 case OMP_CLAUSE_NUM_THREADS: 12633 case OMP_CLAUSE_SCHEDULE: 12634 case OMP_CLAUSE_COLLAPSE: 12635 case OMP_CLAUSE_FINAL: 12636 OMP_CLAUSE_OPERAND (nc, 0) 12637 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain, 12638 in_decl, /*integral_constant_expression_p=*/false); 12639 break; 12640 case OMP_CLAUSE_NOWAIT: 12641 case OMP_CLAUSE_ORDERED: 12642 case OMP_CLAUSE_DEFAULT: 12643 case OMP_CLAUSE_UNTIED: 12644 case OMP_CLAUSE_MERGEABLE: 12645 break; 12646 default: 12647 gcc_unreachable (); 12648 } 12649 } 12650 12651 return finish_omp_clauses (nreverse (new_clauses)); 12652 } 12653 12654 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */ 12655 12656 static tree 12657 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain, 12658 tree in_decl) 12659 { 12660 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl) 12661 12662 tree purpose, value, chain; 12663 12664 if (t == NULL) 12665 return t; 12666 12667 if (TREE_CODE (t) != TREE_LIST) 12668 return tsubst_copy_and_build (t, args, complain, in_decl, 12669 /*function_p=*/false, 12670 /*integral_constant_expression_p=*/false); 12671 12672 if (t == void_list_node) 12673 return t; 12674 12675 purpose = TREE_PURPOSE (t); 12676 if (purpose) 12677 purpose = RECUR (purpose); 12678 value = TREE_VALUE (t); 12679 if (value) 12680 { 12681 if (TREE_CODE (value) != LABEL_DECL) 12682 value = RECUR (value); 12683 else 12684 { 12685 value = lookup_label (DECL_NAME (value)); 12686 gcc_assert (TREE_CODE (value) == LABEL_DECL); 12687 TREE_USED (value) = 1; 12688 } 12689 } 12690 chain = TREE_CHAIN (t); 12691 if (chain && chain != void_type_node) 12692 chain = RECUR (chain); 12693 return tree_cons (purpose, value, chain); 12694 #undef RECUR 12695 } 12696 12697 /* Substitute one OMP_FOR iterator. */ 12698 12699 static void 12700 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv, 12701 tree condv, tree incrv, tree *clauses, 12702 tree args, tsubst_flags_t complain, tree in_decl, 12703 bool integral_constant_expression_p) 12704 { 12705 #define RECUR(NODE) \ 12706 tsubst_expr ((NODE), args, complain, in_decl, \ 12707 integral_constant_expression_p) 12708 tree decl, init, cond, incr, auto_node; 12709 12710 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i); 12711 gcc_assert (TREE_CODE (init) == MODIFY_EXPR); 12712 decl = RECUR (TREE_OPERAND (init, 0)); 12713 init = TREE_OPERAND (init, 1); 12714 auto_node = type_uses_auto (TREE_TYPE (decl)); 12715 if (auto_node && init) 12716 { 12717 tree init_expr = init; 12718 if (TREE_CODE (init_expr) == DECL_EXPR) 12719 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr)); 12720 init_expr = RECUR (init_expr); 12721 TREE_TYPE (decl) 12722 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node); 12723 } 12724 gcc_assert (!type_dependent_expression_p (decl)); 12725 12726 if (!CLASS_TYPE_P (TREE_TYPE (decl))) 12727 { 12728 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i)); 12729 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i); 12730 if (TREE_CODE (incr) == MODIFY_EXPR) 12731 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR, 12732 RECUR (TREE_OPERAND (incr, 1)), 12733 complain); 12734 else 12735 incr = RECUR (incr); 12736 TREE_VEC_ELT (declv, i) = decl; 12737 TREE_VEC_ELT (initv, i) = init; 12738 TREE_VEC_ELT (condv, i) = cond; 12739 TREE_VEC_ELT (incrv, i) = incr; 12740 return; 12741 } 12742 12743 if (init && TREE_CODE (init) != DECL_EXPR) 12744 { 12745 tree c; 12746 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c)) 12747 { 12748 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE 12749 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE) 12750 && OMP_CLAUSE_DECL (c) == decl) 12751 break; 12752 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE 12753 && OMP_CLAUSE_DECL (c) == decl) 12754 error ("iteration variable %qD should not be firstprivate", decl); 12755 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION 12756 && OMP_CLAUSE_DECL (c) == decl) 12757 error ("iteration variable %qD should not be reduction", decl); 12758 } 12759 if (c == NULL) 12760 { 12761 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE); 12762 OMP_CLAUSE_DECL (c) = decl; 12763 c = finish_omp_clauses (c); 12764 if (c) 12765 { 12766 OMP_CLAUSE_CHAIN (c) = *clauses; 12767 *clauses = c; 12768 } 12769 } 12770 } 12771 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i); 12772 if (COMPARISON_CLASS_P (cond)) 12773 cond = build2 (TREE_CODE (cond), boolean_type_node, 12774 RECUR (TREE_OPERAND (cond, 0)), 12775 RECUR (TREE_OPERAND (cond, 1))); 12776 else 12777 cond = RECUR (cond); 12778 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i); 12779 switch (TREE_CODE (incr)) 12780 { 12781 case PREINCREMENT_EXPR: 12782 case PREDECREMENT_EXPR: 12783 case POSTINCREMENT_EXPR: 12784 case POSTDECREMENT_EXPR: 12785 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl), 12786 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE); 12787 break; 12788 case MODIFY_EXPR: 12789 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR 12790 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR) 12791 { 12792 tree rhs = TREE_OPERAND (incr, 1); 12793 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), 12794 RECUR (TREE_OPERAND (incr, 0)), 12795 build2 (TREE_CODE (rhs), TREE_TYPE (decl), 12796 RECUR (TREE_OPERAND (rhs, 0)), 12797 RECUR (TREE_OPERAND (rhs, 1)))); 12798 } 12799 else 12800 incr = RECUR (incr); 12801 break; 12802 case MODOP_EXPR: 12803 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR 12804 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR) 12805 { 12806 tree lhs = RECUR (TREE_OPERAND (incr, 0)); 12807 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs, 12808 build2 (TREE_CODE (TREE_OPERAND (incr, 1)), 12809 TREE_TYPE (decl), lhs, 12810 RECUR (TREE_OPERAND (incr, 2)))); 12811 } 12812 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR 12813 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR 12814 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR))) 12815 { 12816 tree rhs = TREE_OPERAND (incr, 2); 12817 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), 12818 RECUR (TREE_OPERAND (incr, 0)), 12819 build2 (TREE_CODE (rhs), TREE_TYPE (decl), 12820 RECUR (TREE_OPERAND (rhs, 0)), 12821 RECUR (TREE_OPERAND (rhs, 1)))); 12822 } 12823 else 12824 incr = RECUR (incr); 12825 break; 12826 default: 12827 incr = RECUR (incr); 12828 break; 12829 } 12830 12831 TREE_VEC_ELT (declv, i) = decl; 12832 TREE_VEC_ELT (initv, i) = init; 12833 TREE_VEC_ELT (condv, i) = cond; 12834 TREE_VEC_ELT (incrv, i) = incr; 12835 #undef RECUR 12836 } 12837 12838 /* Like tsubst_copy for expressions, etc. but also does semantic 12839 processing. */ 12840 12841 static tree 12842 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl, 12843 bool integral_constant_expression_p) 12844 { 12845 #define RECUR(NODE) \ 12846 tsubst_expr ((NODE), args, complain, in_decl, \ 12847 integral_constant_expression_p) 12848 12849 tree stmt, tmp; 12850 12851 if (t == NULL_TREE || t == error_mark_node) 12852 return t; 12853 12854 if (EXPR_HAS_LOCATION (t)) 12855 input_location = EXPR_LOCATION (t); 12856 if (STATEMENT_CODE_P (TREE_CODE (t))) 12857 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t); 12858 12859 switch (TREE_CODE (t)) 12860 { 12861 case STATEMENT_LIST: 12862 { 12863 tree_stmt_iterator i; 12864 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) 12865 RECUR (tsi_stmt (i)); 12866 break; 12867 } 12868 12869 case CTOR_INITIALIZER: 12870 finish_mem_initializers (tsubst_initializer_list 12871 (TREE_OPERAND (t, 0), args)); 12872 break; 12873 12874 case RETURN_EXPR: 12875 finish_return_stmt (RECUR (TREE_OPERAND (t, 0))); 12876 break; 12877 12878 case EXPR_STMT: 12879 tmp = RECUR (EXPR_STMT_EXPR (t)); 12880 if (EXPR_STMT_STMT_EXPR_RESULT (t)) 12881 finish_stmt_expr_expr (tmp, cur_stmt_expr); 12882 else 12883 finish_expr_stmt (tmp); 12884 break; 12885 12886 case USING_STMT: 12887 do_using_directive (USING_STMT_NAMESPACE (t)); 12888 break; 12889 12890 case DECL_EXPR: 12891 { 12892 tree decl, pattern_decl; 12893 tree init; 12894 12895 pattern_decl = decl = DECL_EXPR_DECL (t); 12896 if (TREE_CODE (decl) == LABEL_DECL) 12897 finish_label_decl (DECL_NAME (decl)); 12898 else if (TREE_CODE (decl) == USING_DECL) 12899 { 12900 tree scope = USING_DECL_SCOPE (decl); 12901 tree name = DECL_NAME (decl); 12902 tree decl; 12903 12904 scope = tsubst (scope, args, complain, in_decl); 12905 decl = lookup_qualified_name (scope, name, 12906 /*is_type_p=*/false, 12907 /*complain=*/false); 12908 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST) 12909 qualified_name_lookup_error (scope, name, decl, input_location); 12910 else 12911 do_local_using_decl (decl, scope, name); 12912 } 12913 else 12914 { 12915 init = DECL_INITIAL (decl); 12916 decl = tsubst (decl, args, complain, in_decl); 12917 if (decl != error_mark_node) 12918 { 12919 /* By marking the declaration as instantiated, we avoid 12920 trying to instantiate it. Since instantiate_decl can't 12921 handle local variables, and since we've already done 12922 all that needs to be done, that's the right thing to 12923 do. */ 12924 if (TREE_CODE (decl) == VAR_DECL) 12925 DECL_TEMPLATE_INSTANTIATED (decl) = 1; 12926 if (TREE_CODE (decl) == VAR_DECL 12927 && ANON_AGGR_TYPE_P (TREE_TYPE (decl))) 12928 /* Anonymous aggregates are a special case. */ 12929 finish_anon_union (decl); 12930 else if (is_capture_proxy (DECL_EXPR_DECL (t))) 12931 { 12932 DECL_CONTEXT (decl) = current_function_decl; 12933 insert_capture_proxy (decl); 12934 } 12935 else 12936 { 12937 int const_init = false; 12938 maybe_push_decl (decl); 12939 if (TREE_CODE (decl) == VAR_DECL 12940 && DECL_PRETTY_FUNCTION_P (decl)) 12941 { 12942 /* For __PRETTY_FUNCTION__ we have to adjust the 12943 initializer. */ 12944 const char *const name 12945 = cxx_printable_name (current_function_decl, 2); 12946 init = cp_fname_init (name, &TREE_TYPE (decl)); 12947 } 12948 else 12949 { 12950 tree t = RECUR (init); 12951 12952 if (init && !t) 12953 { 12954 /* If we had an initializer but it 12955 instantiated to nothing, 12956 value-initialize the object. This will 12957 only occur when the initializer was a 12958 pack expansion where the parameter packs 12959 used in that expansion were of length 12960 zero. */ 12961 init = build_value_init (TREE_TYPE (decl), 12962 complain); 12963 if (TREE_CODE (init) == AGGR_INIT_EXPR) 12964 init = get_target_expr_sfinae (init, complain); 12965 } 12966 else 12967 init = t; 12968 } 12969 12970 if (TREE_CODE (decl) == VAR_DECL) 12971 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P 12972 (pattern_decl)); 12973 cp_finish_decl (decl, init, const_init, NULL_TREE, 0); 12974 } 12975 } 12976 } 12977 12978 /* A DECL_EXPR can also be used as an expression, in the condition 12979 clause of an if/for/while construct. */ 12980 return decl; 12981 } 12982 12983 case FOR_STMT: 12984 stmt = begin_for_stmt (NULL_TREE, NULL_TREE); 12985 RECUR (FOR_INIT_STMT (t)); 12986 finish_for_init_stmt (stmt); 12987 tmp = RECUR (FOR_COND (t)); 12988 finish_for_cond (tmp, stmt); 12989 tmp = RECUR (FOR_EXPR (t)); 12990 finish_for_expr (tmp, stmt); 12991 RECUR (FOR_BODY (t)); 12992 finish_for_stmt (stmt); 12993 break; 12994 12995 case RANGE_FOR_STMT: 12996 { 12997 tree decl, expr; 12998 stmt = begin_for_stmt (NULL_TREE, NULL_TREE); 12999 decl = RANGE_FOR_DECL (t); 13000 decl = tsubst (decl, args, complain, in_decl); 13001 maybe_push_decl (decl); 13002 expr = RECUR (RANGE_FOR_EXPR (t)); 13003 stmt = cp_convert_range_for (stmt, decl, expr); 13004 RECUR (RANGE_FOR_BODY (t)); 13005 finish_for_stmt (stmt); 13006 } 13007 break; 13008 13009 case WHILE_STMT: 13010 stmt = begin_while_stmt (); 13011 tmp = RECUR (WHILE_COND (t)); 13012 finish_while_stmt_cond (tmp, stmt); 13013 RECUR (WHILE_BODY (t)); 13014 finish_while_stmt (stmt); 13015 break; 13016 13017 case DO_STMT: 13018 stmt = begin_do_stmt (); 13019 RECUR (DO_BODY (t)); 13020 finish_do_body (stmt); 13021 tmp = RECUR (DO_COND (t)); 13022 finish_do_stmt (tmp, stmt); 13023 break; 13024 13025 case IF_STMT: 13026 stmt = begin_if_stmt (); 13027 tmp = RECUR (IF_COND (t)); 13028 finish_if_stmt_cond (tmp, stmt); 13029 RECUR (THEN_CLAUSE (t)); 13030 finish_then_clause (stmt); 13031 13032 if (ELSE_CLAUSE (t)) 13033 { 13034 begin_else_clause (stmt); 13035 RECUR (ELSE_CLAUSE (t)); 13036 finish_else_clause (stmt); 13037 } 13038 13039 finish_if_stmt (stmt); 13040 break; 13041 13042 case BIND_EXPR: 13043 if (BIND_EXPR_BODY_BLOCK (t)) 13044 stmt = begin_function_body (); 13045 else 13046 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t) 13047 ? BCS_TRY_BLOCK : 0); 13048 13049 RECUR (BIND_EXPR_BODY (t)); 13050 13051 if (BIND_EXPR_BODY_BLOCK (t)) 13052 finish_function_body (stmt); 13053 else 13054 finish_compound_stmt (stmt); 13055 break; 13056 13057 case BREAK_STMT: 13058 finish_break_stmt (); 13059 break; 13060 13061 case CONTINUE_STMT: 13062 finish_continue_stmt (); 13063 break; 13064 13065 case SWITCH_STMT: 13066 stmt = begin_switch_stmt (); 13067 tmp = RECUR (SWITCH_STMT_COND (t)); 13068 finish_switch_cond (tmp, stmt); 13069 RECUR (SWITCH_STMT_BODY (t)); 13070 finish_switch_stmt (stmt); 13071 break; 13072 13073 case CASE_LABEL_EXPR: 13074 finish_case_label (EXPR_LOCATION (t), 13075 RECUR (CASE_LOW (t)), 13076 RECUR (CASE_HIGH (t))); 13077 break; 13078 13079 case LABEL_EXPR: 13080 { 13081 tree decl = LABEL_EXPR_LABEL (t); 13082 tree label; 13083 13084 label = finish_label_stmt (DECL_NAME (decl)); 13085 if (DECL_ATTRIBUTES (decl) != NULL_TREE) 13086 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0); 13087 } 13088 break; 13089 13090 case GOTO_EXPR: 13091 tmp = GOTO_DESTINATION (t); 13092 if (TREE_CODE (tmp) != LABEL_DECL) 13093 /* Computed goto's must be tsubst'd into. On the other hand, 13094 non-computed gotos must not be; the identifier in question 13095 will have no binding. */ 13096 tmp = RECUR (tmp); 13097 else 13098 tmp = DECL_NAME (tmp); 13099 finish_goto_stmt (tmp); 13100 break; 13101 13102 case ASM_EXPR: 13103 tmp = finish_asm_stmt 13104 (ASM_VOLATILE_P (t), 13105 RECUR (ASM_STRING (t)), 13106 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl), 13107 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl), 13108 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl), 13109 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl)); 13110 { 13111 tree asm_expr = tmp; 13112 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR) 13113 asm_expr = TREE_OPERAND (asm_expr, 0); 13114 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t); 13115 } 13116 break; 13117 13118 case TRY_BLOCK: 13119 if (CLEANUP_P (t)) 13120 { 13121 stmt = begin_try_block (); 13122 RECUR (TRY_STMTS (t)); 13123 finish_cleanup_try_block (stmt); 13124 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt); 13125 } 13126 else 13127 { 13128 tree compound_stmt = NULL_TREE; 13129 13130 if (FN_TRY_BLOCK_P (t)) 13131 stmt = begin_function_try_block (&compound_stmt); 13132 else 13133 stmt = begin_try_block (); 13134 13135 RECUR (TRY_STMTS (t)); 13136 13137 if (FN_TRY_BLOCK_P (t)) 13138 finish_function_try_block (stmt); 13139 else 13140 finish_try_block (stmt); 13141 13142 RECUR (TRY_HANDLERS (t)); 13143 if (FN_TRY_BLOCK_P (t)) 13144 finish_function_handler_sequence (stmt, compound_stmt); 13145 else 13146 finish_handler_sequence (stmt); 13147 } 13148 break; 13149 13150 case HANDLER: 13151 { 13152 tree decl = HANDLER_PARMS (t); 13153 13154 if (decl) 13155 { 13156 decl = tsubst (decl, args, complain, in_decl); 13157 /* Prevent instantiate_decl from trying to instantiate 13158 this variable. We've already done all that needs to be 13159 done. */ 13160 if (decl != error_mark_node) 13161 DECL_TEMPLATE_INSTANTIATED (decl) = 1; 13162 } 13163 stmt = begin_handler (); 13164 finish_handler_parms (decl, stmt); 13165 RECUR (HANDLER_BODY (t)); 13166 finish_handler (stmt); 13167 } 13168 break; 13169 13170 case TAG_DEFN: 13171 tsubst (TREE_TYPE (t), args, complain, NULL_TREE); 13172 break; 13173 13174 case STATIC_ASSERT: 13175 { 13176 tree condition = 13177 tsubst_expr (STATIC_ASSERT_CONDITION (t), 13178 args, 13179 complain, in_decl, 13180 /*integral_constant_expression_p=*/true); 13181 finish_static_assert (condition, 13182 STATIC_ASSERT_MESSAGE (t), 13183 STATIC_ASSERT_SOURCE_LOCATION (t), 13184 /*member_p=*/false); 13185 } 13186 break; 13187 13188 case OMP_PARALLEL: 13189 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t), 13190 args, complain, in_decl); 13191 stmt = begin_omp_parallel (); 13192 RECUR (OMP_PARALLEL_BODY (t)); 13193 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt)) 13194 = OMP_PARALLEL_COMBINED (t); 13195 break; 13196 13197 case OMP_TASK: 13198 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t), 13199 args, complain, in_decl); 13200 stmt = begin_omp_task (); 13201 RECUR (OMP_TASK_BODY (t)); 13202 finish_omp_task (tmp, stmt); 13203 break; 13204 13205 case OMP_FOR: 13206 { 13207 tree clauses, body, pre_body; 13208 tree declv, initv, condv, incrv; 13209 int i; 13210 13211 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t), 13212 args, complain, in_decl); 13213 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t))); 13214 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t))); 13215 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t))); 13216 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t))); 13217 13218 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++) 13219 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv, 13220 &clauses, args, complain, in_decl, 13221 integral_constant_expression_p); 13222 13223 stmt = begin_omp_structured_block (); 13224 13225 for (i = 0; i < TREE_VEC_LENGTH (initv); i++) 13226 if (TREE_VEC_ELT (initv, i) == NULL 13227 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR) 13228 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i)); 13229 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i)))) 13230 { 13231 tree init = RECUR (TREE_VEC_ELT (initv, i)); 13232 gcc_assert (init == TREE_VEC_ELT (declv, i)); 13233 TREE_VEC_ELT (initv, i) = NULL_TREE; 13234 } 13235 else 13236 { 13237 tree decl_expr = TREE_VEC_ELT (initv, i); 13238 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr)); 13239 gcc_assert (init != NULL); 13240 TREE_VEC_ELT (initv, i) = RECUR (init); 13241 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL; 13242 RECUR (decl_expr); 13243 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init; 13244 } 13245 13246 pre_body = push_stmt_list (); 13247 RECUR (OMP_FOR_PRE_BODY (t)); 13248 pre_body = pop_stmt_list (pre_body); 13249 13250 body = push_stmt_list (); 13251 RECUR (OMP_FOR_BODY (t)); 13252 body = pop_stmt_list (body); 13253 13254 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv, 13255 body, pre_body, clauses); 13256 13257 add_stmt (finish_omp_structured_block (stmt)); 13258 } 13259 break; 13260 13261 case OMP_SECTIONS: 13262 case OMP_SINGLE: 13263 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl); 13264 stmt = push_stmt_list (); 13265 RECUR (OMP_BODY (t)); 13266 stmt = pop_stmt_list (stmt); 13267 13268 t = copy_node (t); 13269 OMP_BODY (t) = stmt; 13270 OMP_CLAUSES (t) = tmp; 13271 add_stmt (t); 13272 break; 13273 13274 case OMP_SECTION: 13275 case OMP_CRITICAL: 13276 case OMP_MASTER: 13277 case OMP_ORDERED: 13278 stmt = push_stmt_list (); 13279 RECUR (OMP_BODY (t)); 13280 stmt = pop_stmt_list (stmt); 13281 13282 t = copy_node (t); 13283 OMP_BODY (t) = stmt; 13284 add_stmt (t); 13285 break; 13286 13287 case OMP_ATOMIC: 13288 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t)); 13289 if (TREE_CODE (TREE_OPERAND (t, 1)) != MODIFY_EXPR) 13290 { 13291 tree op1 = TREE_OPERAND (t, 1); 13292 tree rhs1 = NULL_TREE; 13293 tree lhs, rhs; 13294 if (TREE_CODE (op1) == COMPOUND_EXPR) 13295 { 13296 rhs1 = RECUR (TREE_OPERAND (op1, 0)); 13297 op1 = TREE_OPERAND (op1, 1); 13298 } 13299 lhs = RECUR (TREE_OPERAND (op1, 0)); 13300 rhs = RECUR (TREE_OPERAND (op1, 1)); 13301 finish_omp_atomic (OMP_ATOMIC, TREE_CODE (op1), lhs, rhs, 13302 NULL_TREE, NULL_TREE, rhs1); 13303 } 13304 else 13305 { 13306 tree op1 = TREE_OPERAND (t, 1); 13307 tree v = NULL_TREE, lhs, rhs = NULL_TREE, lhs1 = NULL_TREE; 13308 tree rhs1 = NULL_TREE; 13309 enum tree_code code = TREE_CODE (TREE_OPERAND (op1, 1)); 13310 enum tree_code opcode = NOP_EXPR; 13311 if (code == OMP_ATOMIC_READ) 13312 { 13313 v = RECUR (TREE_OPERAND (op1, 0)); 13314 lhs = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0)); 13315 } 13316 else if (code == OMP_ATOMIC_CAPTURE_OLD 13317 || code == OMP_ATOMIC_CAPTURE_NEW) 13318 { 13319 tree op11 = TREE_OPERAND (TREE_OPERAND (op1, 1), 1); 13320 v = RECUR (TREE_OPERAND (op1, 0)); 13321 lhs1 = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0)); 13322 if (TREE_CODE (op11) == COMPOUND_EXPR) 13323 { 13324 rhs1 = RECUR (TREE_OPERAND (op11, 0)); 13325 op11 = TREE_OPERAND (op11, 1); 13326 } 13327 lhs = RECUR (TREE_OPERAND (op11, 0)); 13328 rhs = RECUR (TREE_OPERAND (op11, 1)); 13329 opcode = TREE_CODE (op11); 13330 } 13331 else 13332 { 13333 code = OMP_ATOMIC; 13334 lhs = RECUR (TREE_OPERAND (op1, 0)); 13335 rhs = RECUR (TREE_OPERAND (op1, 1)); 13336 } 13337 finish_omp_atomic (code, opcode, lhs, rhs, v, lhs1, rhs1); 13338 } 13339 break; 13340 13341 case TRANSACTION_EXPR: 13342 { 13343 int flags = 0; 13344 flags |= (TRANSACTION_EXPR_OUTER (t) ? TM_STMT_ATTR_OUTER : 0); 13345 flags |= (TRANSACTION_EXPR_RELAXED (t) ? TM_STMT_ATTR_RELAXED : 0); 13346 13347 if (TRANSACTION_EXPR_IS_STMT (t)) 13348 { 13349 tree body = TRANSACTION_EXPR_BODY (t); 13350 tree noex = NULL_TREE; 13351 if (TREE_CODE (body) == MUST_NOT_THROW_EXPR) 13352 { 13353 noex = MUST_NOT_THROW_COND (body); 13354 if (noex == NULL_TREE) 13355 noex = boolean_true_node; 13356 body = TREE_OPERAND (body, 0); 13357 } 13358 stmt = begin_transaction_stmt (input_location, NULL, flags); 13359 RECUR (body); 13360 finish_transaction_stmt (stmt, NULL, flags, RECUR (noex)); 13361 } 13362 else 13363 { 13364 stmt = build_transaction_expr (EXPR_LOCATION (t), 13365 RECUR (TRANSACTION_EXPR_BODY (t)), 13366 flags, NULL_TREE); 13367 return stmt; 13368 } 13369 } 13370 break; 13371 13372 case MUST_NOT_THROW_EXPR: 13373 return build_must_not_throw_expr (RECUR (TREE_OPERAND (t, 0)), 13374 RECUR (MUST_NOT_THROW_COND (t))); 13375 13376 case EXPR_PACK_EXPANSION: 13377 error ("invalid use of pack expansion expression"); 13378 return error_mark_node; 13379 13380 case NONTYPE_ARGUMENT_PACK: 13381 error ("use %<...%> to expand argument pack"); 13382 return error_mark_node; 13383 13384 default: 13385 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t))); 13386 13387 return tsubst_copy_and_build (t, args, complain, in_decl, 13388 /*function_p=*/false, 13389 integral_constant_expression_p); 13390 } 13391 13392 return NULL_TREE; 13393 #undef RECUR 13394 } 13395 13396 /* T is a postfix-expression that is not being used in a function 13397 call. Return the substituted version of T. */ 13398 13399 static tree 13400 tsubst_non_call_postfix_expression (tree t, tree args, 13401 tsubst_flags_t complain, 13402 tree in_decl) 13403 { 13404 if (TREE_CODE (t) == SCOPE_REF) 13405 t = tsubst_qualified_id (t, args, complain, in_decl, 13406 /*done=*/false, /*address_p=*/false); 13407 else 13408 t = tsubst_copy_and_build (t, args, complain, in_decl, 13409 /*function_p=*/false, 13410 /*integral_constant_expression_p=*/false); 13411 13412 return t; 13413 } 13414 13415 /* Like tsubst but deals with expressions and performs semantic 13416 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */ 13417 13418 tree 13419 tsubst_copy_and_build (tree t, 13420 tree args, 13421 tsubst_flags_t complain, 13422 tree in_decl, 13423 bool function_p, 13424 bool integral_constant_expression_p) 13425 { 13426 #define RECUR(NODE) \ 13427 tsubst_copy_and_build (NODE, args, complain, in_decl, \ 13428 /*function_p=*/false, \ 13429 integral_constant_expression_p) 13430 13431 tree op1; 13432 13433 if (t == NULL_TREE || t == error_mark_node) 13434 return t; 13435 13436 switch (TREE_CODE (t)) 13437 { 13438 case USING_DECL: 13439 t = DECL_NAME (t); 13440 /* Fall through. */ 13441 case IDENTIFIER_NODE: 13442 { 13443 tree decl; 13444 cp_id_kind idk; 13445 bool non_integral_constant_expression_p; 13446 const char *error_msg; 13447 13448 if (IDENTIFIER_TYPENAME_P (t)) 13449 { 13450 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl); 13451 t = mangle_conv_op_name_for_type (new_type); 13452 } 13453 13454 /* Look up the name. */ 13455 decl = lookup_name (t); 13456 13457 /* By convention, expressions use ERROR_MARK_NODE to indicate 13458 failure, not NULL_TREE. */ 13459 if (decl == NULL_TREE) 13460 decl = error_mark_node; 13461 13462 decl = finish_id_expression (t, decl, NULL_TREE, 13463 &idk, 13464 integral_constant_expression_p, 13465 /*allow_non_integral_constant_expression_p=*/(cxx_dialect >= cxx0x), 13466 &non_integral_constant_expression_p, 13467 /*template_p=*/false, 13468 /*done=*/true, 13469 /*address_p=*/false, 13470 /*template_arg_p=*/false, 13471 &error_msg, 13472 input_location); 13473 if (error_msg) 13474 error (error_msg); 13475 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE) 13476 { 13477 if (complain & tf_error) 13478 unqualified_name_lookup_error (decl); 13479 decl = error_mark_node; 13480 } 13481 return decl; 13482 } 13483 13484 case TEMPLATE_ID_EXPR: 13485 { 13486 tree object; 13487 tree templ = RECUR (TREE_OPERAND (t, 0)); 13488 tree targs = TREE_OPERAND (t, 1); 13489 13490 if (targs) 13491 targs = tsubst_template_args (targs, args, complain, in_decl); 13492 13493 if (TREE_CODE (templ) == COMPONENT_REF) 13494 { 13495 object = TREE_OPERAND (templ, 0); 13496 templ = TREE_OPERAND (templ, 1); 13497 } 13498 else 13499 object = NULL_TREE; 13500 templ = lookup_template_function (templ, targs); 13501 13502 if (object) 13503 return build3 (COMPONENT_REF, TREE_TYPE (templ), 13504 object, templ, NULL_TREE); 13505 else 13506 return baselink_for_fns (templ); 13507 } 13508 13509 case INDIRECT_REF: 13510 { 13511 tree r = RECUR (TREE_OPERAND (t, 0)); 13512 13513 if (REFERENCE_REF_P (t)) 13514 { 13515 /* A type conversion to reference type will be enclosed in 13516 such an indirect ref, but the substitution of the cast 13517 will have also added such an indirect ref. */ 13518 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE) 13519 r = convert_from_reference (r); 13520 } 13521 else 13522 r = build_x_indirect_ref (r, RO_UNARY_STAR, complain); 13523 return r; 13524 } 13525 13526 case NOP_EXPR: 13527 return build_nop 13528 (tsubst (TREE_TYPE (t), args, complain, in_decl), 13529 RECUR (TREE_OPERAND (t, 0))); 13530 13531 case IMPLICIT_CONV_EXPR: 13532 { 13533 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl); 13534 tree expr = RECUR (TREE_OPERAND (t, 0)); 13535 int flags = LOOKUP_IMPLICIT; 13536 if (IMPLICIT_CONV_EXPR_DIRECT_INIT (t)) 13537 flags = LOOKUP_NORMAL; 13538 return perform_implicit_conversion_flags (type, expr, complain, 13539 flags); 13540 } 13541 13542 case CONVERT_EXPR: 13543 return build1 13544 (CONVERT_EXPR, 13545 tsubst (TREE_TYPE (t), args, complain, in_decl), 13546 RECUR (TREE_OPERAND (t, 0))); 13547 13548 case CAST_EXPR: 13549 case REINTERPRET_CAST_EXPR: 13550 case CONST_CAST_EXPR: 13551 case DYNAMIC_CAST_EXPR: 13552 case STATIC_CAST_EXPR: 13553 { 13554 tree type; 13555 tree op; 13556 13557 type = tsubst (TREE_TYPE (t), args, complain, in_decl); 13558 if (integral_constant_expression_p 13559 && !cast_valid_in_integral_constant_expression_p (type)) 13560 { 13561 if (complain & tf_error) 13562 error ("a cast to a type other than an integral or " 13563 "enumeration type cannot appear in a constant-expression"); 13564 return error_mark_node; 13565 } 13566 13567 op = RECUR (TREE_OPERAND (t, 0)); 13568 13569 switch (TREE_CODE (t)) 13570 { 13571 case CAST_EXPR: 13572 return build_functional_cast (type, op, complain); 13573 case REINTERPRET_CAST_EXPR: 13574 return build_reinterpret_cast (type, op, complain); 13575 case CONST_CAST_EXPR: 13576 return build_const_cast (type, op, complain); 13577 case DYNAMIC_CAST_EXPR: 13578 return build_dynamic_cast (type, op, complain); 13579 case STATIC_CAST_EXPR: 13580 return build_static_cast (type, op, complain); 13581 default: 13582 gcc_unreachable (); 13583 } 13584 } 13585 13586 case POSTDECREMENT_EXPR: 13587 case POSTINCREMENT_EXPR: 13588 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0), 13589 args, complain, in_decl); 13590 return build_x_unary_op (TREE_CODE (t), op1, complain); 13591 13592 case PREDECREMENT_EXPR: 13593 case PREINCREMENT_EXPR: 13594 case NEGATE_EXPR: 13595 case BIT_NOT_EXPR: 13596 case ABS_EXPR: 13597 case TRUTH_NOT_EXPR: 13598 case UNARY_PLUS_EXPR: /* Unary + */ 13599 case REALPART_EXPR: 13600 case IMAGPART_EXPR: 13601 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)), 13602 complain); 13603 13604 case FIX_TRUNC_EXPR: 13605 return cp_build_unary_op (FIX_TRUNC_EXPR, RECUR (TREE_OPERAND (t, 0)), 13606 0, complain); 13607 13608 case ADDR_EXPR: 13609 op1 = TREE_OPERAND (t, 0); 13610 if (TREE_CODE (op1) == LABEL_DECL) 13611 return finish_label_address_expr (DECL_NAME (op1), 13612 EXPR_LOCATION (op1)); 13613 if (TREE_CODE (op1) == SCOPE_REF) 13614 op1 = tsubst_qualified_id (op1, args, complain, in_decl, 13615 /*done=*/true, /*address_p=*/true); 13616 else 13617 op1 = tsubst_non_call_postfix_expression (op1, args, complain, 13618 in_decl); 13619 return build_x_unary_op (ADDR_EXPR, op1, complain); 13620 13621 case PLUS_EXPR: 13622 case MINUS_EXPR: 13623 case MULT_EXPR: 13624 case TRUNC_DIV_EXPR: 13625 case CEIL_DIV_EXPR: 13626 case FLOOR_DIV_EXPR: 13627 case ROUND_DIV_EXPR: 13628 case EXACT_DIV_EXPR: 13629 case BIT_AND_EXPR: 13630 case BIT_IOR_EXPR: 13631 case BIT_XOR_EXPR: 13632 case TRUNC_MOD_EXPR: 13633 case FLOOR_MOD_EXPR: 13634 case TRUTH_ANDIF_EXPR: 13635 case TRUTH_ORIF_EXPR: 13636 case TRUTH_AND_EXPR: 13637 case TRUTH_OR_EXPR: 13638 case RSHIFT_EXPR: 13639 case LSHIFT_EXPR: 13640 case RROTATE_EXPR: 13641 case LROTATE_EXPR: 13642 case EQ_EXPR: 13643 case NE_EXPR: 13644 case MAX_EXPR: 13645 case MIN_EXPR: 13646 case LE_EXPR: 13647 case GE_EXPR: 13648 case LT_EXPR: 13649 case GT_EXPR: 13650 case MEMBER_REF: 13651 case DOTSTAR_EXPR: 13652 { 13653 tree r = build_x_binary_op 13654 (TREE_CODE (t), 13655 RECUR (TREE_OPERAND (t, 0)), 13656 (TREE_NO_WARNING (TREE_OPERAND (t, 0)) 13657 ? ERROR_MARK 13658 : TREE_CODE (TREE_OPERAND (t, 0))), 13659 RECUR (TREE_OPERAND (t, 1)), 13660 (TREE_NO_WARNING (TREE_OPERAND (t, 1)) 13661 ? ERROR_MARK 13662 : TREE_CODE (TREE_OPERAND (t, 1))), 13663 /*overload=*/NULL, 13664 complain); 13665 if (EXPR_P (r) && TREE_NO_WARNING (t)) 13666 TREE_NO_WARNING (r) = TREE_NO_WARNING (t); 13667 return r; 13668 } 13669 13670 case SCOPE_REF: 13671 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true, 13672 /*address_p=*/false); 13673 case ARRAY_REF: 13674 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0), 13675 args, complain, in_decl); 13676 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain); 13677 13678 case SIZEOF_EXPR: 13679 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0))) 13680 return tsubst_copy (t, args, complain, in_decl); 13681 /* Fall through */ 13682 13683 case ALIGNOF_EXPR: 13684 op1 = TREE_OPERAND (t, 0); 13685 if (!args) 13686 { 13687 /* When there are no ARGS, we are trying to evaluate a 13688 non-dependent expression from the parser. Trying to do 13689 the substitutions may not work. */ 13690 if (!TYPE_P (op1)) 13691 op1 = TREE_TYPE (op1); 13692 } 13693 else 13694 { 13695 ++cp_unevaluated_operand; 13696 ++c_inhibit_evaluation_warnings; 13697 op1 = tsubst_copy_and_build (op1, args, complain, in_decl, 13698 /*function_p=*/false, 13699 /*integral_constant_expression_p=*/false); 13700 --cp_unevaluated_operand; 13701 --c_inhibit_evaluation_warnings; 13702 } 13703 if (TYPE_P (op1)) 13704 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t), 13705 complain & tf_error); 13706 else 13707 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t), 13708 complain & tf_error); 13709 13710 case AT_ENCODE_EXPR: 13711 { 13712 op1 = TREE_OPERAND (t, 0); 13713 ++cp_unevaluated_operand; 13714 ++c_inhibit_evaluation_warnings; 13715 op1 = tsubst_copy_and_build (op1, args, complain, in_decl, 13716 /*function_p=*/false, 13717 /*integral_constant_expression_p=*/false); 13718 --cp_unevaluated_operand; 13719 --c_inhibit_evaluation_warnings; 13720 return objc_build_encode_expr (op1); 13721 } 13722 13723 case NOEXCEPT_EXPR: 13724 op1 = TREE_OPERAND (t, 0); 13725 ++cp_unevaluated_operand; 13726 ++c_inhibit_evaluation_warnings; 13727 op1 = tsubst_copy_and_build (op1, args, complain, in_decl, 13728 /*function_p=*/false, 13729 /*integral_constant_expression_p=*/false); 13730 --cp_unevaluated_operand; 13731 --c_inhibit_evaluation_warnings; 13732 return finish_noexcept_expr (op1, complain); 13733 13734 case MODOP_EXPR: 13735 { 13736 tree r = build_x_modify_expr 13737 (RECUR (TREE_OPERAND (t, 0)), 13738 TREE_CODE (TREE_OPERAND (t, 1)), 13739 RECUR (TREE_OPERAND (t, 2)), 13740 complain); 13741 /* TREE_NO_WARNING must be set if either the expression was 13742 parenthesized or it uses an operator such as >>= rather 13743 than plain assignment. In the former case, it was already 13744 set and must be copied. In the latter case, 13745 build_x_modify_expr sets it and it must not be reset 13746 here. */ 13747 if (TREE_NO_WARNING (t)) 13748 TREE_NO_WARNING (r) = TREE_NO_WARNING (t); 13749 return r; 13750 } 13751 13752 case ARROW_EXPR: 13753 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0), 13754 args, complain, in_decl); 13755 /* Remember that there was a reference to this entity. */ 13756 if (DECL_P (op1)) 13757 mark_used (op1); 13758 return build_x_arrow (op1); 13759 13760 case NEW_EXPR: 13761 { 13762 tree placement = RECUR (TREE_OPERAND (t, 0)); 13763 tree init = RECUR (TREE_OPERAND (t, 3)); 13764 VEC(tree,gc) *placement_vec; 13765 VEC(tree,gc) *init_vec; 13766 tree ret; 13767 13768 if (placement == NULL_TREE) 13769 placement_vec = NULL; 13770 else 13771 { 13772 placement_vec = make_tree_vector (); 13773 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement)) 13774 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement)); 13775 } 13776 13777 /* If there was an initializer in the original tree, but it 13778 instantiated to an empty list, then we should pass a 13779 non-NULL empty vector to tell build_new that it was an 13780 empty initializer() rather than no initializer. This can 13781 only happen when the initializer is a pack expansion whose 13782 parameter packs are of length zero. */ 13783 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE) 13784 init_vec = NULL; 13785 else 13786 { 13787 init_vec = make_tree_vector (); 13788 if (init == void_zero_node) 13789 gcc_assert (init_vec != NULL); 13790 else 13791 { 13792 for (; init != NULL_TREE; init = TREE_CHAIN (init)) 13793 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init)); 13794 } 13795 } 13796 13797 ret = build_new (&placement_vec, 13798 tsubst (TREE_OPERAND (t, 1), args, complain, in_decl), 13799 RECUR (TREE_OPERAND (t, 2)), 13800 &init_vec, 13801 NEW_EXPR_USE_GLOBAL (t), 13802 complain); 13803 13804 if (placement_vec != NULL) 13805 release_tree_vector (placement_vec); 13806 if (init_vec != NULL) 13807 release_tree_vector (init_vec); 13808 13809 return ret; 13810 } 13811 13812 case DELETE_EXPR: 13813 return delete_sanity 13814 (RECUR (TREE_OPERAND (t, 0)), 13815 RECUR (TREE_OPERAND (t, 1)), 13816 DELETE_EXPR_USE_VEC (t), 13817 DELETE_EXPR_USE_GLOBAL (t), 13818 complain); 13819 13820 case COMPOUND_EXPR: 13821 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)), 13822 RECUR (TREE_OPERAND (t, 1)), 13823 complain); 13824 13825 case CALL_EXPR: 13826 { 13827 tree function; 13828 VEC(tree,gc) *call_args; 13829 unsigned int nargs, i; 13830 bool qualified_p; 13831 bool koenig_p; 13832 tree ret; 13833 13834 function = CALL_EXPR_FN (t); 13835 /* When we parsed the expression, we determined whether or 13836 not Koenig lookup should be performed. */ 13837 koenig_p = KOENIG_LOOKUP_P (t); 13838 if (TREE_CODE (function) == SCOPE_REF) 13839 { 13840 qualified_p = true; 13841 function = tsubst_qualified_id (function, args, complain, in_decl, 13842 /*done=*/false, 13843 /*address_p=*/false); 13844 } 13845 else if (koenig_p && TREE_CODE (function) == IDENTIFIER_NODE) 13846 { 13847 /* Do nothing; calling tsubst_copy_and_build on an identifier 13848 would incorrectly perform unqualified lookup again. 13849 13850 Note that we can also have an IDENTIFIER_NODE if the earlier 13851 unqualified lookup found a member function; in that case 13852 koenig_p will be false and we do want to do the lookup 13853 again to find the instantiated member function. 13854 13855 FIXME but doing that causes c++/15272, so we need to stop 13856 using IDENTIFIER_NODE in that situation. */ 13857 qualified_p = false; 13858 } 13859 else 13860 { 13861 if (TREE_CODE (function) == COMPONENT_REF) 13862 { 13863 tree op = TREE_OPERAND (function, 1); 13864 13865 qualified_p = (TREE_CODE (op) == SCOPE_REF 13866 || (BASELINK_P (op) 13867 && BASELINK_QUALIFIED_P (op))); 13868 } 13869 else 13870 qualified_p = false; 13871 13872 function = tsubst_copy_and_build (function, args, complain, 13873 in_decl, 13874 !qualified_p, 13875 integral_constant_expression_p); 13876 13877 if (BASELINK_P (function)) 13878 qualified_p = true; 13879 } 13880 13881 nargs = call_expr_nargs (t); 13882 call_args = make_tree_vector (); 13883 for (i = 0; i < nargs; ++i) 13884 { 13885 tree arg = CALL_EXPR_ARG (t, i); 13886 13887 if (!PACK_EXPANSION_P (arg)) 13888 VEC_safe_push (tree, gc, call_args, 13889 RECUR (CALL_EXPR_ARG (t, i))); 13890 else 13891 { 13892 /* Expand the pack expansion and push each entry onto 13893 CALL_ARGS. */ 13894 arg = tsubst_pack_expansion (arg, args, complain, in_decl); 13895 if (TREE_CODE (arg) == TREE_VEC) 13896 { 13897 unsigned int len, j; 13898 13899 len = TREE_VEC_LENGTH (arg); 13900 for (j = 0; j < len; ++j) 13901 { 13902 tree value = TREE_VEC_ELT (arg, j); 13903 if (value != NULL_TREE) 13904 value = convert_from_reference (value); 13905 VEC_safe_push (tree, gc, call_args, value); 13906 } 13907 } 13908 else 13909 { 13910 /* A partial substitution. Add one entry. */ 13911 VEC_safe_push (tree, gc, call_args, arg); 13912 } 13913 } 13914 } 13915 13916 /* We do not perform argument-dependent lookup if normal 13917 lookup finds a non-function, in accordance with the 13918 expected resolution of DR 218. */ 13919 if (koenig_p 13920 && ((is_overloaded_fn (function) 13921 /* If lookup found a member function, the Koenig lookup is 13922 not appropriate, even if an unqualified-name was used 13923 to denote the function. */ 13924 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function))) 13925 || TREE_CODE (function) == IDENTIFIER_NODE) 13926 /* Only do this when substitution turns a dependent call 13927 into a non-dependent call. */ 13928 && type_dependent_expression_p_push (t) 13929 && !any_type_dependent_arguments_p (call_args)) 13930 function = perform_koenig_lookup (function, call_args, false, 13931 tf_none); 13932 13933 if (TREE_CODE (function) == IDENTIFIER_NODE 13934 && !any_type_dependent_arguments_p (call_args)) 13935 { 13936 if (koenig_p && (complain & tf_warning_or_error)) 13937 { 13938 /* For backwards compatibility and good diagnostics, try 13939 the unqualified lookup again if we aren't in SFINAE 13940 context. */ 13941 tree unq = (tsubst_copy_and_build 13942 (function, args, complain, in_decl, true, 13943 integral_constant_expression_p)); 13944 if (unq == error_mark_node) 13945 return error_mark_node; 13946 13947 if (unq != function) 13948 { 13949 tree fn = unq; 13950 if (TREE_CODE (fn) == INDIRECT_REF) 13951 fn = TREE_OPERAND (fn, 0); 13952 if (TREE_CODE (fn) == COMPONENT_REF) 13953 fn = TREE_OPERAND (fn, 1); 13954 if (is_overloaded_fn (fn)) 13955 fn = get_first_fn (fn); 13956 permerror (EXPR_LOC_OR_HERE (t), 13957 "%qD was not declared in this scope, " 13958 "and no declarations were found by " 13959 "argument-dependent lookup at the point " 13960 "of instantiation", function); 13961 if (!DECL_P (fn)) 13962 /* Can't say anything more. */; 13963 else if (DECL_CLASS_SCOPE_P (fn)) 13964 { 13965 inform (EXPR_LOC_OR_HERE (t), 13966 "declarations in dependent base %qT are " 13967 "not found by unqualified lookup", 13968 DECL_CLASS_CONTEXT (fn)); 13969 if (current_class_ptr) 13970 inform (EXPR_LOC_OR_HERE (t), 13971 "use %<this->%D%> instead", function); 13972 else 13973 inform (EXPR_LOC_OR_HERE (t), 13974 "use %<%T::%D%> instead", 13975 current_class_name, function); 13976 } 13977 else 13978 inform (0, "%q+D declared here, later in the " 13979 "translation unit", fn); 13980 function = unq; 13981 } 13982 } 13983 if (TREE_CODE (function) == IDENTIFIER_NODE) 13984 { 13985 unqualified_name_lookup_error (function); 13986 release_tree_vector (call_args); 13987 return error_mark_node; 13988 } 13989 } 13990 13991 /* Remember that there was a reference to this entity. */ 13992 if (DECL_P (function)) 13993 mark_used (function); 13994 13995 if (TREE_CODE (function) == OFFSET_REF) 13996 ret = build_offset_ref_call_from_tree (function, &call_args); 13997 else if (TREE_CODE (function) == COMPONENT_REF) 13998 { 13999 tree instance = TREE_OPERAND (function, 0); 14000 tree fn = TREE_OPERAND (function, 1); 14001 14002 if (processing_template_decl 14003 && (type_dependent_expression_p (instance) 14004 || (!BASELINK_P (fn) 14005 && TREE_CODE (fn) != FIELD_DECL) 14006 || type_dependent_expression_p (fn) 14007 || any_type_dependent_arguments_p (call_args))) 14008 ret = build_nt_call_vec (function, call_args); 14009 else if (!BASELINK_P (fn)) 14010 ret = finish_call_expr (function, &call_args, 14011 /*disallow_virtual=*/false, 14012 /*koenig_p=*/false, 14013 complain); 14014 else 14015 ret = (build_new_method_call 14016 (instance, fn, 14017 &call_args, NULL_TREE, 14018 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL, 14019 /*fn_p=*/NULL, 14020 complain)); 14021 } 14022 else 14023 ret = finish_call_expr (function, &call_args, 14024 /*disallow_virtual=*/qualified_p, 14025 koenig_p, 14026 complain); 14027 14028 release_tree_vector (call_args); 14029 14030 return ret; 14031 } 14032 14033 case COND_EXPR: 14034 return build_x_conditional_expr 14035 (RECUR (TREE_OPERAND (t, 0)), 14036 RECUR (TREE_OPERAND (t, 1)), 14037 RECUR (TREE_OPERAND (t, 2)), 14038 complain); 14039 14040 case PSEUDO_DTOR_EXPR: 14041 return finish_pseudo_destructor_expr 14042 (RECUR (TREE_OPERAND (t, 0)), 14043 RECUR (TREE_OPERAND (t, 1)), 14044 tsubst (TREE_OPERAND (t, 2), args, complain, in_decl)); 14045 14046 case TREE_LIST: 14047 { 14048 tree purpose, value, chain; 14049 14050 if (t == void_list_node) 14051 return t; 14052 14053 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t))) 14054 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t)))) 14055 { 14056 /* We have pack expansions, so expand those and 14057 create a new list out of it. */ 14058 tree purposevec = NULL_TREE; 14059 tree valuevec = NULL_TREE; 14060 tree chain; 14061 int i, len = -1; 14062 14063 /* Expand the argument expressions. */ 14064 if (TREE_PURPOSE (t)) 14065 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args, 14066 complain, in_decl); 14067 if (TREE_VALUE (t)) 14068 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args, 14069 complain, in_decl); 14070 14071 /* Build the rest of the list. */ 14072 chain = TREE_CHAIN (t); 14073 if (chain && chain != void_type_node) 14074 chain = RECUR (chain); 14075 14076 /* Determine the number of arguments. */ 14077 if (purposevec && TREE_CODE (purposevec) == TREE_VEC) 14078 { 14079 len = TREE_VEC_LENGTH (purposevec); 14080 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec)); 14081 } 14082 else if (TREE_CODE (valuevec) == TREE_VEC) 14083 len = TREE_VEC_LENGTH (valuevec); 14084 else 14085 { 14086 /* Since we only performed a partial substitution into 14087 the argument pack, we only return a single list 14088 node. */ 14089 if (purposevec == TREE_PURPOSE (t) 14090 && valuevec == TREE_VALUE (t) 14091 && chain == TREE_CHAIN (t)) 14092 return t; 14093 14094 return tree_cons (purposevec, valuevec, chain); 14095 } 14096 14097 /* Convert the argument vectors into a TREE_LIST */ 14098 i = len; 14099 while (i > 0) 14100 { 14101 /* Grab the Ith values. */ 14102 i--; 14103 purpose = purposevec ? TREE_VEC_ELT (purposevec, i) 14104 : NULL_TREE; 14105 value 14106 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i)) 14107 : NULL_TREE; 14108 14109 /* Build the list (backwards). */ 14110 chain = tree_cons (purpose, value, chain); 14111 } 14112 14113 return chain; 14114 } 14115 14116 purpose = TREE_PURPOSE (t); 14117 if (purpose) 14118 purpose = RECUR (purpose); 14119 value = TREE_VALUE (t); 14120 if (value) 14121 value = RECUR (value); 14122 chain = TREE_CHAIN (t); 14123 if (chain && chain != void_type_node) 14124 chain = RECUR (chain); 14125 if (purpose == TREE_PURPOSE (t) 14126 && value == TREE_VALUE (t) 14127 && chain == TREE_CHAIN (t)) 14128 return t; 14129 return tree_cons (purpose, value, chain); 14130 } 14131 14132 case COMPONENT_REF: 14133 { 14134 tree object; 14135 tree object_type; 14136 tree member; 14137 14138 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0), 14139 args, complain, in_decl); 14140 /* Remember that there was a reference to this entity. */ 14141 if (DECL_P (object)) 14142 mark_used (object); 14143 object_type = TREE_TYPE (object); 14144 14145 member = TREE_OPERAND (t, 1); 14146 if (BASELINK_P (member)) 14147 member = tsubst_baselink (member, 14148 non_reference (TREE_TYPE (object)), 14149 args, complain, in_decl); 14150 else 14151 member = tsubst_copy (member, args, complain, in_decl); 14152 if (member == error_mark_node) 14153 return error_mark_node; 14154 14155 if (type_dependent_expression_p (object)) 14156 /* We can't do much here. */; 14157 else if (!CLASS_TYPE_P (object_type)) 14158 { 14159 if (SCALAR_TYPE_P (object_type)) 14160 { 14161 tree s = NULL_TREE; 14162 tree dtor = member; 14163 14164 if (TREE_CODE (dtor) == SCOPE_REF) 14165 { 14166 s = TREE_OPERAND (dtor, 0); 14167 dtor = TREE_OPERAND (dtor, 1); 14168 } 14169 if (TREE_CODE (dtor) == BIT_NOT_EXPR) 14170 { 14171 dtor = TREE_OPERAND (dtor, 0); 14172 if (TYPE_P (dtor)) 14173 return finish_pseudo_destructor_expr (object, s, dtor); 14174 } 14175 } 14176 } 14177 else if (TREE_CODE (member) == SCOPE_REF 14178 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR) 14179 { 14180 /* Lookup the template functions now that we know what the 14181 scope is. */ 14182 tree scope = TREE_OPERAND (member, 0); 14183 tree tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0); 14184 tree args = TREE_OPERAND (TREE_OPERAND (member, 1), 1); 14185 member = lookup_qualified_name (scope, tmpl, 14186 /*is_type_p=*/false, 14187 /*complain=*/false); 14188 if (BASELINK_P (member)) 14189 { 14190 BASELINK_FUNCTIONS (member) 14191 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member), 14192 args); 14193 member = (adjust_result_of_qualified_name_lookup 14194 (member, BINFO_TYPE (BASELINK_BINFO (member)), 14195 object_type)); 14196 } 14197 else 14198 { 14199 qualified_name_lookup_error (scope, tmpl, member, 14200 input_location); 14201 return error_mark_node; 14202 } 14203 } 14204 else if (TREE_CODE (member) == SCOPE_REF 14205 && !CLASS_TYPE_P (TREE_OPERAND (member, 0)) 14206 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL) 14207 { 14208 if (complain & tf_error) 14209 { 14210 if (TYPE_P (TREE_OPERAND (member, 0))) 14211 error ("%qT is not a class or namespace", 14212 TREE_OPERAND (member, 0)); 14213 else 14214 error ("%qD is not a class or namespace", 14215 TREE_OPERAND (member, 0)); 14216 } 14217 return error_mark_node; 14218 } 14219 else if (TREE_CODE (member) == FIELD_DECL) 14220 return finish_non_static_data_member (member, object, NULL_TREE); 14221 14222 return finish_class_member_access_expr (object, member, 14223 /*template_p=*/false, 14224 complain); 14225 } 14226 14227 case THROW_EXPR: 14228 return build_throw 14229 (RECUR (TREE_OPERAND (t, 0))); 14230 14231 case CONSTRUCTOR: 14232 { 14233 VEC(constructor_elt,gc) *n; 14234 constructor_elt *ce; 14235 unsigned HOST_WIDE_INT idx; 14236 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl); 14237 bool process_index_p; 14238 int newlen; 14239 bool need_copy_p = false; 14240 tree r; 14241 14242 if (type == error_mark_node) 14243 return error_mark_node; 14244 14245 /* digest_init will do the wrong thing if we let it. */ 14246 if (type && TYPE_PTRMEMFUNC_P (type)) 14247 return t; 14248 14249 /* We do not want to process the index of aggregate 14250 initializers as they are identifier nodes which will be 14251 looked up by digest_init. */ 14252 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type)); 14253 14254 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t)); 14255 newlen = VEC_length (constructor_elt, n); 14256 FOR_EACH_VEC_ELT (constructor_elt, n, idx, ce) 14257 { 14258 if (ce->index && process_index_p) 14259 ce->index = RECUR (ce->index); 14260 14261 if (PACK_EXPANSION_P (ce->value)) 14262 { 14263 /* Substitute into the pack expansion. */ 14264 ce->value = tsubst_pack_expansion (ce->value, args, complain, 14265 in_decl); 14266 14267 if (ce->value == error_mark_node 14268 || PACK_EXPANSION_P (ce->value)) 14269 ; 14270 else if (TREE_VEC_LENGTH (ce->value) == 1) 14271 /* Just move the argument into place. */ 14272 ce->value = TREE_VEC_ELT (ce->value, 0); 14273 else 14274 { 14275 /* Update the length of the final CONSTRUCTOR 14276 arguments vector, and note that we will need to 14277 copy.*/ 14278 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1; 14279 need_copy_p = true; 14280 } 14281 } 14282 else 14283 ce->value = RECUR (ce->value); 14284 } 14285 14286 if (need_copy_p) 14287 { 14288 VEC(constructor_elt,gc) *old_n = n; 14289 14290 n = VEC_alloc (constructor_elt, gc, newlen); 14291 FOR_EACH_VEC_ELT (constructor_elt, old_n, idx, ce) 14292 { 14293 if (TREE_CODE (ce->value) == TREE_VEC) 14294 { 14295 int i, len = TREE_VEC_LENGTH (ce->value); 14296 for (i = 0; i < len; ++i) 14297 CONSTRUCTOR_APPEND_ELT (n, 0, 14298 TREE_VEC_ELT (ce->value, i)); 14299 } 14300 else 14301 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value); 14302 } 14303 } 14304 14305 r = build_constructor (init_list_type_node, n); 14306 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t); 14307 14308 if (TREE_HAS_CONSTRUCTOR (t)) 14309 return finish_compound_literal (type, r, complain); 14310 14311 TREE_TYPE (r) = type; 14312 return r; 14313 } 14314 14315 case TYPEID_EXPR: 14316 { 14317 tree operand_0 = TREE_OPERAND (t, 0); 14318 if (TYPE_P (operand_0)) 14319 { 14320 operand_0 = tsubst (operand_0, args, complain, in_decl); 14321 return get_typeid (operand_0); 14322 } 14323 else 14324 { 14325 operand_0 = RECUR (operand_0); 14326 return build_typeid (operand_0); 14327 } 14328 } 14329 14330 case VAR_DECL: 14331 if (!args) 14332 return t; 14333 /* Fall through */ 14334 14335 case PARM_DECL: 14336 { 14337 tree r = tsubst_copy (t, args, complain, in_decl); 14338 14339 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE) 14340 /* If the original type was a reference, we'll be wrapped in 14341 the appropriate INDIRECT_REF. */ 14342 r = convert_from_reference (r); 14343 return r; 14344 } 14345 14346 case VA_ARG_EXPR: 14347 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)), 14348 tsubst (TREE_TYPE (t), args, complain, in_decl)); 14349 14350 case OFFSETOF_EXPR: 14351 return finish_offsetof (RECUR (TREE_OPERAND (t, 0))); 14352 14353 case TRAIT_EXPR: 14354 { 14355 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args, 14356 complain, in_decl); 14357 14358 tree type2 = TRAIT_EXPR_TYPE2 (t); 14359 if (type2) 14360 type2 = tsubst_copy (type2, args, complain, in_decl); 14361 14362 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2); 14363 } 14364 14365 case STMT_EXPR: 14366 { 14367 tree old_stmt_expr = cur_stmt_expr; 14368 tree stmt_expr = begin_stmt_expr (); 14369 14370 cur_stmt_expr = stmt_expr; 14371 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl, 14372 integral_constant_expression_p); 14373 stmt_expr = finish_stmt_expr (stmt_expr, false); 14374 cur_stmt_expr = old_stmt_expr; 14375 14376 /* If the resulting list of expression statement is empty, 14377 fold it further into void_zero_node. */ 14378 if (empty_expr_stmt_p (stmt_expr)) 14379 stmt_expr = void_zero_node; 14380 14381 return stmt_expr; 14382 } 14383 14384 case CONST_DECL: 14385 t = tsubst_copy (t, args, complain, in_decl); 14386 /* As in finish_id_expression, we resolve enumeration constants 14387 to their underlying values. */ 14388 if (TREE_CODE (t) == CONST_DECL && !processing_template_decl) 14389 { 14390 used_types_insert (TREE_TYPE (t)); 14391 return DECL_INITIAL (t); 14392 } 14393 return t; 14394 14395 case LAMBDA_EXPR: 14396 { 14397 tree r = build_lambda_expr (); 14398 14399 tree type = tsubst (LAMBDA_EXPR_CLOSURE (t), args, complain, NULL_TREE); 14400 LAMBDA_EXPR_CLOSURE (r) = type; 14401 CLASSTYPE_LAMBDA_EXPR (type) = r; 14402 14403 LAMBDA_EXPR_LOCATION (r) 14404 = LAMBDA_EXPR_LOCATION (t); 14405 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r) 14406 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t); 14407 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t); 14408 LAMBDA_EXPR_DISCRIMINATOR (r) 14409 = (LAMBDA_EXPR_DISCRIMINATOR (t)); 14410 LAMBDA_EXPR_EXTRA_SCOPE (r) 14411 = RECUR (LAMBDA_EXPR_EXTRA_SCOPE (t)); 14412 if (LAMBDA_EXPR_RETURN_TYPE (t) == dependent_lambda_return_type_node) 14413 { 14414 LAMBDA_EXPR_RETURN_TYPE (r) = dependent_lambda_return_type_node; 14415 LAMBDA_EXPR_DEDUCE_RETURN_TYPE_P (r) = true; 14416 } 14417 else 14418 LAMBDA_EXPR_RETURN_TYPE (r) 14419 = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl); 14420 14421 gcc_assert (LAMBDA_EXPR_THIS_CAPTURE (t) == NULL_TREE 14422 && LAMBDA_EXPR_PENDING_PROXIES (t) == NULL); 14423 14424 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */ 14425 determine_visibility (TYPE_NAME (type)); 14426 /* Now that we know visibility, instantiate the type so we have a 14427 declaration of the op() for later calls to lambda_function. */ 14428 complete_type (type); 14429 14430 /* The capture list refers to closure members, so this needs to 14431 wait until after we finish instantiating the type. */ 14432 LAMBDA_EXPR_CAPTURE_LIST (r) 14433 = RECUR (LAMBDA_EXPR_CAPTURE_LIST (t)); 14434 14435 return build_lambda_object (r); 14436 } 14437 14438 case TARGET_EXPR: 14439 /* We can get here for a constant initializer of non-dependent type. 14440 FIXME stop folding in cp_parser_initializer_clause. */ 14441 gcc_assert (TREE_CONSTANT (t)); 14442 { 14443 tree r = get_target_expr (RECUR (TARGET_EXPR_INITIAL (t))); 14444 TREE_CONSTANT (r) = true; 14445 return r; 14446 } 14447 14448 case TRANSACTION_EXPR: 14449 return tsubst_expr(t, args, complain, in_decl, 14450 integral_constant_expression_p); 14451 14452 default: 14453 /* Handle Objective-C++ constructs, if appropriate. */ 14454 { 14455 tree subst 14456 = objcp_tsubst_copy_and_build (t, args, complain, 14457 in_decl, /*function_p=*/false); 14458 if (subst) 14459 return subst; 14460 } 14461 return tsubst_copy (t, args, complain, in_decl); 14462 } 14463 14464 #undef RECUR 14465 } 14466 14467 /* Verify that the instantiated ARGS are valid. For type arguments, 14468 make sure that the type's linkage is ok. For non-type arguments, 14469 make sure they are constants if they are integral or enumerations. 14470 Emit an error under control of COMPLAIN, and return TRUE on error. */ 14471 14472 static bool 14473 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain) 14474 { 14475 if (ARGUMENT_PACK_P (t)) 14476 { 14477 tree vec = ARGUMENT_PACK_ARGS (t); 14478 int len = TREE_VEC_LENGTH (vec); 14479 bool result = false; 14480 int i; 14481 14482 for (i = 0; i < len; ++i) 14483 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain)) 14484 result = true; 14485 return result; 14486 } 14487 else if (TYPE_P (t)) 14488 { 14489 /* [basic.link]: A name with no linkage (notably, the name 14490 of a class or enumeration declared in a local scope) 14491 shall not be used to declare an entity with linkage. 14492 This implies that names with no linkage cannot be used as 14493 template arguments 14494 14495 DR 757 relaxes this restriction for C++0x. */ 14496 tree nt = (cxx_dialect > cxx98 ? NULL_TREE 14497 : no_linkage_check (t, /*relaxed_p=*/false)); 14498 14499 if (nt) 14500 { 14501 /* DR 488 makes use of a type with no linkage cause 14502 type deduction to fail. */ 14503 if (complain & tf_error) 14504 { 14505 if (TYPE_ANONYMOUS_P (nt)) 14506 error ("%qT is/uses anonymous type", t); 14507 else 14508 error ("template argument for %qD uses local type %qT", 14509 tmpl, t); 14510 } 14511 return true; 14512 } 14513 /* In order to avoid all sorts of complications, we do not 14514 allow variably-modified types as template arguments. */ 14515 else if (variably_modified_type_p (t, NULL_TREE)) 14516 { 14517 if (complain & tf_error) 14518 error ("%qT is a variably modified type", t); 14519 return true; 14520 } 14521 } 14522 /* A non-type argument of integral or enumerated type must be a 14523 constant. */ 14524 else if (TREE_TYPE (t) 14525 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t)) 14526 && !TREE_CONSTANT (t)) 14527 { 14528 if (complain & tf_error) 14529 error ("integral expression %qE is not constant", t); 14530 return true; 14531 } 14532 return false; 14533 } 14534 14535 static bool 14536 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain) 14537 { 14538 int ix, len = DECL_NTPARMS (tmpl); 14539 bool result = false; 14540 14541 for (ix = 0; ix != len; ix++) 14542 { 14543 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain)) 14544 result = true; 14545 } 14546 if (result && (complain & tf_error)) 14547 error (" trying to instantiate %qD", tmpl); 14548 return result; 14549 } 14550 14551 /* In C++0x, it's possible to have a function template whose type depends 14552 on itself recursively. This is most obvious with decltype, but can also 14553 occur with enumeration scope (c++/48969). So we need to catch infinite 14554 recursion and reject the substitution at deduction time; this function 14555 will return error_mark_node for any repeated substitution. 14556 14557 This also catches excessive recursion such as when f<N> depends on 14558 f<N-1> across all integers, and returns error_mark_node for all the 14559 substitutions back up to the initial one. 14560 14561 This is, of course, not reentrant. */ 14562 14563 static tree 14564 deduction_tsubst_fntype (tree fn, tree targs, tsubst_flags_t complain) 14565 { 14566 static bool excessive_deduction_depth; 14567 static int deduction_depth; 14568 struct pending_template *old_last_pend = last_pending_template; 14569 struct tinst_level *old_error_tinst = last_error_tinst_level; 14570 14571 tree fntype = TREE_TYPE (fn); 14572 tree tinst; 14573 tree r; 14574 14575 if (excessive_deduction_depth) 14576 return error_mark_node; 14577 14578 tinst = build_tree_list (fn, targs); 14579 if (!push_tinst_level (tinst)) 14580 { 14581 excessive_deduction_depth = true; 14582 ggc_free (tinst); 14583 return error_mark_node; 14584 } 14585 14586 input_location = DECL_SOURCE_LOCATION (fn); 14587 ++deduction_depth; 14588 push_deduction_access_scope (fn); 14589 r = tsubst (fntype, targs, complain, NULL_TREE); 14590 pop_deduction_access_scope (fn); 14591 --deduction_depth; 14592 14593 if (excessive_deduction_depth) 14594 { 14595 r = error_mark_node; 14596 if (deduction_depth == 0) 14597 /* Reset once we're all the way out. */ 14598 excessive_deduction_depth = false; 14599 } 14600 14601 pop_tinst_level (); 14602 /* We can't free this if a pending_template entry or last_error_tinst_level 14603 is pointing at it. */ 14604 if (last_pending_template == old_last_pend 14605 && last_error_tinst_level == old_error_tinst) 14606 ggc_free (tinst); 14607 return r; 14608 } 14609 14610 /* Instantiate the indicated variable or function template TMPL with 14611 the template arguments in TARG_PTR. */ 14612 14613 static tree 14614 instantiate_template_1 (tree tmpl, tree orig_args, tsubst_flags_t complain) 14615 { 14616 tree targ_ptr = orig_args; 14617 tree fndecl; 14618 tree gen_tmpl; 14619 tree spec; 14620 14621 if (tmpl == error_mark_node) 14622 return error_mark_node; 14623 14624 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL); 14625 14626 /* If this function is a clone, handle it specially. */ 14627 if (DECL_CLONED_FUNCTION_P (tmpl)) 14628 { 14629 tree spec; 14630 tree clone; 14631 14632 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have 14633 DECL_CLONED_FUNCTION. */ 14634 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl), 14635 targ_ptr, complain); 14636 if (spec == error_mark_node) 14637 return error_mark_node; 14638 14639 /* Look for the clone. */ 14640 FOR_EACH_CLONE (clone, spec) 14641 if (DECL_NAME (clone) == DECL_NAME (tmpl)) 14642 return clone; 14643 /* We should always have found the clone by now. */ 14644 gcc_unreachable (); 14645 return NULL_TREE; 14646 } 14647 14648 /* Check to see if we already have this specialization. */ 14649 gen_tmpl = most_general_template (tmpl); 14650 if (tmpl != gen_tmpl) 14651 /* The TMPL is a partial instantiation. To get a full set of 14652 arguments we must add the arguments used to perform the 14653 partial instantiation. */ 14654 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl), 14655 targ_ptr); 14656 14657 /* It would be nice to avoid hashing here and then again in tsubst_decl, 14658 but it doesn't seem to be on the hot path. */ 14659 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0); 14660 14661 gcc_assert (tmpl == gen_tmpl 14662 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0)) 14663 == spec) 14664 || fndecl == NULL_TREE); 14665 14666 if (spec != NULL_TREE) 14667 return spec; 14668 14669 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr), 14670 complain)) 14671 return error_mark_node; 14672 14673 /* We are building a FUNCTION_DECL, during which the access of its 14674 parameters and return types have to be checked. However this 14675 FUNCTION_DECL which is the desired context for access checking 14676 is not built yet. We solve this chicken-and-egg problem by 14677 deferring all checks until we have the FUNCTION_DECL. */ 14678 push_deferring_access_checks (dk_deferred); 14679 14680 /* Instantiation of the function happens in the context of the function 14681 template, not the context of the overload resolution we're doing. */ 14682 push_to_top_level (); 14683 if (DECL_CLASS_SCOPE_P (gen_tmpl)) 14684 { 14685 tree ctx = tsubst (DECL_CONTEXT (gen_tmpl), targ_ptr, 14686 complain, gen_tmpl); 14687 push_nested_class (ctx); 14688 } 14689 /* Substitute template parameters to obtain the specialization. */ 14690 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl), 14691 targ_ptr, complain, gen_tmpl); 14692 if (DECL_CLASS_SCOPE_P (gen_tmpl)) 14693 pop_nested_class (); 14694 pop_from_top_level (); 14695 14696 if (fndecl == error_mark_node) 14697 return error_mark_node; 14698 14699 /* Now we know the specialization, compute access previously 14700 deferred. */ 14701 push_access_scope (fndecl); 14702 14703 /* Some typedefs referenced from within the template code need to be access 14704 checked at template instantiation time, i.e now. These types were 14705 added to the template at parsing time. Let's get those and perfom 14706 the acces checks then. */ 14707 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr); 14708 perform_deferred_access_checks (); 14709 pop_access_scope (fndecl); 14710 pop_deferring_access_checks (); 14711 14712 /* The DECL_TI_TEMPLATE should always be the immediate parent 14713 template, not the most general template. */ 14714 DECL_TI_TEMPLATE (fndecl) = tmpl; 14715 14716 /* If we've just instantiated the main entry point for a function, 14717 instantiate all the alternate entry points as well. We do this 14718 by cloning the instantiation of the main entry point, not by 14719 instantiating the template clones. */ 14720 if (DECL_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (DECL_CHAIN (gen_tmpl))) 14721 clone_function_decl (fndecl, /*update_method_vec_p=*/0); 14722 14723 return fndecl; 14724 } 14725 14726 /* Wrapper for instantiate_template_1. */ 14727 14728 tree 14729 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain) 14730 { 14731 tree ret; 14732 timevar_push (TV_TEMPLATE_INST); 14733 ret = instantiate_template_1 (tmpl, orig_args, complain); 14734 timevar_pop (TV_TEMPLATE_INST); 14735 return ret; 14736 } 14737 14738 /* We're going to do deduction substitution on the type of TMPL, a function 14739 template. In C++11 mode, push into that access scope. In C++03 mode, 14740 disable access checking. */ 14741 14742 static void 14743 push_deduction_access_scope (tree tmpl) 14744 { 14745 if (cxx_dialect >= cxx0x) 14746 { 14747 int ptd = processing_template_decl; 14748 push_access_scope (DECL_TEMPLATE_RESULT (tmpl)); 14749 /* Preserve processing_template_decl across push_to_top_level. */ 14750 if (ptd && !processing_template_decl) 14751 ++processing_template_decl; 14752 } 14753 else 14754 push_deferring_access_checks (dk_no_check); 14755 } 14756 14757 /* And pop back out. */ 14758 14759 static void 14760 pop_deduction_access_scope (tree tmpl) 14761 { 14762 if (cxx_dialect >= cxx0x) 14763 pop_access_scope (DECL_TEMPLATE_RESULT (tmpl)); 14764 else 14765 pop_deferring_access_checks (); 14766 } 14767 14768 /* PARM is a template parameter pack for FN. Returns true iff 14769 PARM is used in a deducible way in the argument list of FN. */ 14770 14771 static bool 14772 pack_deducible_p (tree parm, tree fn) 14773 { 14774 tree t = FUNCTION_FIRST_USER_PARMTYPE (fn); 14775 for (; t; t = TREE_CHAIN (t)) 14776 { 14777 tree type = TREE_VALUE (t); 14778 tree packs; 14779 if (!PACK_EXPANSION_P (type)) 14780 continue; 14781 for (packs = PACK_EXPANSION_PARAMETER_PACKS (type); 14782 packs; packs = TREE_CHAIN (packs)) 14783 if (TREE_VALUE (packs) == parm) 14784 { 14785 /* The template parameter pack is used in a function parameter 14786 pack. If this is the end of the parameter list, the 14787 template parameter pack is deducible. */ 14788 if (TREE_CHAIN (t) == void_list_node) 14789 return true; 14790 else 14791 /* Otherwise, not. Well, it could be deduced from 14792 a non-pack parameter, but doing so would end up with 14793 a deduction mismatch, so don't bother. */ 14794 return false; 14795 } 14796 } 14797 /* The template parameter pack isn't used in any function parameter 14798 packs, but it might be used deeper, e.g. tuple<Args...>. */ 14799 return true; 14800 } 14801 14802 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with 14803 NARGS elements of the arguments that are being used when calling 14804 it. TARGS is a vector into which the deduced template arguments 14805 are placed. 14806 14807 Return zero for success, 2 for an incomplete match that doesn't resolve 14808 all the types, and 1 for complete failure. An error message will be 14809 printed only for an incomplete match. 14810 14811 If FN is a conversion operator, or we are trying to produce a specific 14812 specialization, RETURN_TYPE is the return type desired. 14813 14814 The EXPLICIT_TARGS are explicit template arguments provided via a 14815 template-id. 14816 14817 The parameter STRICT is one of: 14818 14819 DEDUCE_CALL: 14820 We are deducing arguments for a function call, as in 14821 [temp.deduct.call]. 14822 14823 DEDUCE_CONV: 14824 We are deducing arguments for a conversion function, as in 14825 [temp.deduct.conv]. 14826 14827 DEDUCE_EXACT: 14828 We are deducing arguments when doing an explicit instantiation 14829 as in [temp.explicit], when determining an explicit specialization 14830 as in [temp.expl.spec], or when taking the address of a function 14831 template, as in [temp.deduct.funcaddr]. */ 14832 14833 int 14834 fn_type_unification (tree fn, 14835 tree explicit_targs, 14836 tree targs, 14837 const tree *args, 14838 unsigned int nargs, 14839 tree return_type, 14840 unification_kind_t strict, 14841 int flags, 14842 bool explain_p) 14843 { 14844 tree parms; 14845 tree fntype; 14846 int result; 14847 14848 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL); 14849 14850 fntype = TREE_TYPE (fn); 14851 if (explicit_targs) 14852 { 14853 /* [temp.deduct] 14854 14855 The specified template arguments must match the template 14856 parameters in kind (i.e., type, nontype, template), and there 14857 must not be more arguments than there are parameters; 14858 otherwise type deduction fails. 14859 14860 Nontype arguments must match the types of the corresponding 14861 nontype template parameters, or must be convertible to the 14862 types of the corresponding nontype parameters as specified in 14863 _temp.arg.nontype_, otherwise type deduction fails. 14864 14865 All references in the function type of the function template 14866 to the corresponding template parameters are replaced by the 14867 specified template argument values. If a substitution in a 14868 template parameter or in the function type of the function 14869 template results in an invalid type, type deduction fails. */ 14870 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn); 14871 int i, len = TREE_VEC_LENGTH (tparms); 14872 tree converted_args; 14873 bool incomplete = false; 14874 14875 if (explicit_targs == error_mark_node) 14876 return unify_invalid (explain_p); 14877 14878 converted_args 14879 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE, 14880 (explain_p 14881 ? tf_warning_or_error 14882 : tf_none), 14883 /*require_all_args=*/false, 14884 /*use_default_args=*/false)); 14885 if (converted_args == error_mark_node) 14886 return 1; 14887 14888 /* Substitute the explicit args into the function type. This is 14889 necessary so that, for instance, explicitly declared function 14890 arguments can match null pointed constants. If we were given 14891 an incomplete set of explicit args, we must not do semantic 14892 processing during substitution as we could create partial 14893 instantiations. */ 14894 for (i = 0; i < len; i++) 14895 { 14896 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i)); 14897 bool parameter_pack = false; 14898 tree targ = TREE_VEC_ELT (converted_args, i); 14899 14900 /* Dig out the actual parm. */ 14901 if (TREE_CODE (parm) == TYPE_DECL 14902 || TREE_CODE (parm) == TEMPLATE_DECL) 14903 { 14904 parm = TREE_TYPE (parm); 14905 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm); 14906 } 14907 else if (TREE_CODE (parm) == PARM_DECL) 14908 { 14909 parm = DECL_INITIAL (parm); 14910 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm); 14911 } 14912 14913 if (!parameter_pack && targ == NULL_TREE) 14914 /* No explicit argument for this template parameter. */ 14915 incomplete = true; 14916 14917 if (parameter_pack && pack_deducible_p (parm, fn)) 14918 { 14919 /* Mark the argument pack as "incomplete". We could 14920 still deduce more arguments during unification. 14921 We remove this mark in type_unification_real. */ 14922 if (targ) 14923 { 14924 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1; 14925 ARGUMENT_PACK_EXPLICIT_ARGS (targ) 14926 = ARGUMENT_PACK_ARGS (targ); 14927 } 14928 14929 /* We have some incomplete argument packs. */ 14930 incomplete = true; 14931 } 14932 } 14933 14934 processing_template_decl += incomplete; 14935 fntype = deduction_tsubst_fntype (fn, converted_args, 14936 (explain_p 14937 ? tf_warning_or_error 14938 : tf_none)); 14939 processing_template_decl -= incomplete; 14940 14941 if (fntype == error_mark_node) 14942 return 1; 14943 14944 /* Place the explicitly specified arguments in TARGS. */ 14945 for (i = NUM_TMPL_ARGS (converted_args); i--;) 14946 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i); 14947 } 14948 14949 /* Never do unification on the 'this' parameter. */ 14950 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype)); 14951 14952 if (return_type) 14953 { 14954 tree *new_args; 14955 14956 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms); 14957 new_args = XALLOCAVEC (tree, nargs + 1); 14958 new_args[0] = return_type; 14959 memcpy (new_args + 1, args, nargs * sizeof (tree)); 14960 args = new_args; 14961 ++nargs; 14962 } 14963 14964 /* We allow incomplete unification without an error message here 14965 because the standard doesn't seem to explicitly prohibit it. Our 14966 callers must be ready to deal with unification failures in any 14967 event. */ 14968 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn), 14969 targs, parms, args, nargs, /*subr=*/0, 14970 strict, flags, explain_p); 14971 14972 /* Now that we have bindings for all of the template arguments, 14973 ensure that the arguments deduced for the template template 14974 parameters have compatible template parameter lists. We cannot 14975 check this property before we have deduced all template 14976 arguments, because the template parameter types of a template 14977 template parameter might depend on prior template parameters 14978 deduced after the template template parameter. The following 14979 ill-formed example illustrates this issue: 14980 14981 template<typename T, template<T> class C> void f(C<5>, T); 14982 14983 template<int N> struct X {}; 14984 14985 void g() { 14986 f(X<5>(), 5l); // error: template argument deduction fails 14987 } 14988 14989 The template parameter list of 'C' depends on the template type 14990 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to 14991 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the 14992 time that we deduce 'C'. */ 14993 if (result == 0 14994 && !template_template_parm_bindings_ok_p 14995 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs)) 14996 return unify_inconsistent_template_template_parameters (explain_p); 14997 14998 if (result == 0) 14999 /* All is well so far. Now, check: 15000 15001 [temp.deduct] 15002 15003 When all template arguments have been deduced, all uses of 15004 template parameters in nondeduced contexts are replaced with 15005 the corresponding deduced argument values. If the 15006 substitution results in an invalid type, as described above, 15007 type deduction fails. */ 15008 { 15009 tree substed = deduction_tsubst_fntype (fn, targs, 15010 (explain_p 15011 ? tf_warning_or_error 15012 : tf_none)); 15013 if (substed == error_mark_node) 15014 return 1; 15015 15016 /* If we're looking for an exact match, check that what we got 15017 is indeed an exact match. It might not be if some template 15018 parameters are used in non-deduced contexts. */ 15019 if (strict == DEDUCE_EXACT) 15020 { 15021 unsigned int i; 15022 15023 tree sarg 15024 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed)); 15025 if (return_type) 15026 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg); 15027 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg)) 15028 if (!same_type_p (args[i], TREE_VALUE (sarg))) 15029 return unify_type_mismatch (explain_p, args[i], 15030 TREE_VALUE (sarg)); 15031 } 15032 } 15033 15034 return result; 15035 } 15036 15037 /* Adjust types before performing type deduction, as described in 15038 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two 15039 sections are symmetric. PARM is the type of a function parameter 15040 or the return type of the conversion function. ARG is the type of 15041 the argument passed to the call, or the type of the value 15042 initialized with the result of the conversion function. 15043 ARG_EXPR is the original argument expression, which may be null. */ 15044 15045 static int 15046 maybe_adjust_types_for_deduction (unification_kind_t strict, 15047 tree* parm, 15048 tree* arg, 15049 tree arg_expr) 15050 { 15051 int result = 0; 15052 15053 switch (strict) 15054 { 15055 case DEDUCE_CALL: 15056 break; 15057 15058 case DEDUCE_CONV: 15059 { 15060 /* Swap PARM and ARG throughout the remainder of this 15061 function; the handling is precisely symmetric since PARM 15062 will initialize ARG rather than vice versa. */ 15063 tree* temp = parm; 15064 parm = arg; 15065 arg = temp; 15066 break; 15067 } 15068 15069 case DEDUCE_EXACT: 15070 /* Core issue #873: Do the DR606 thing (see below) for these cases, 15071 too, but here handle it by stripping the reference from PARM 15072 rather than by adding it to ARG. */ 15073 if (TREE_CODE (*parm) == REFERENCE_TYPE 15074 && TYPE_REF_IS_RVALUE (*parm) 15075 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM 15076 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED 15077 && TREE_CODE (*arg) == REFERENCE_TYPE 15078 && !TYPE_REF_IS_RVALUE (*arg)) 15079 *parm = TREE_TYPE (*parm); 15080 /* Nothing else to do in this case. */ 15081 return 0; 15082 15083 default: 15084 gcc_unreachable (); 15085 } 15086 15087 if (TREE_CODE (*parm) != REFERENCE_TYPE) 15088 { 15089 /* [temp.deduct.call] 15090 15091 If P is not a reference type: 15092 15093 --If A is an array type, the pointer type produced by the 15094 array-to-pointer standard conversion (_conv.array_) is 15095 used in place of A for type deduction; otherwise, 15096 15097 --If A is a function type, the pointer type produced by 15098 the function-to-pointer standard conversion 15099 (_conv.func_) is used in place of A for type deduction; 15100 otherwise, 15101 15102 --If A is a cv-qualified type, the top level 15103 cv-qualifiers of A's type are ignored for type 15104 deduction. */ 15105 if (TREE_CODE (*arg) == ARRAY_TYPE) 15106 *arg = build_pointer_type (TREE_TYPE (*arg)); 15107 else if (TREE_CODE (*arg) == FUNCTION_TYPE) 15108 *arg = build_pointer_type (*arg); 15109 else 15110 *arg = TYPE_MAIN_VARIANT (*arg); 15111 } 15112 15113 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is 15114 of the form T&&, where T is a template parameter, and the argument 15115 is an lvalue, T is deduced as A& */ 15116 if (TREE_CODE (*parm) == REFERENCE_TYPE 15117 && TYPE_REF_IS_RVALUE (*parm) 15118 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM 15119 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED 15120 && (arg_expr ? real_lvalue_p (arg_expr) 15121 /* try_one_overload doesn't provide an arg_expr, but 15122 functions are always lvalues. */ 15123 : TREE_CODE (*arg) == FUNCTION_TYPE)) 15124 *arg = build_reference_type (*arg); 15125 15126 /* [temp.deduct.call] 15127 15128 If P is a cv-qualified type, the top level cv-qualifiers 15129 of P's type are ignored for type deduction. If P is a 15130 reference type, the type referred to by P is used for 15131 type deduction. */ 15132 *parm = TYPE_MAIN_VARIANT (*parm); 15133 if (TREE_CODE (*parm) == REFERENCE_TYPE) 15134 { 15135 *parm = TREE_TYPE (*parm); 15136 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL; 15137 } 15138 15139 /* DR 322. For conversion deduction, remove a reference type on parm 15140 too (which has been swapped into ARG). */ 15141 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE) 15142 *arg = TREE_TYPE (*arg); 15143 15144 return result; 15145 } 15146 15147 /* Subroutine of unify_one_argument. PARM is a function parameter of a 15148 template which does contain any deducible template parameters; check if 15149 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in 15150 unify_one_argument. */ 15151 15152 static int 15153 check_non_deducible_conversion (tree parm, tree arg, int strict, 15154 int flags, bool explain_p) 15155 { 15156 tree type; 15157 15158 if (!TYPE_P (arg)) 15159 type = TREE_TYPE (arg); 15160 else 15161 type = arg; 15162 15163 if (same_type_p (parm, type)) 15164 return unify_success (explain_p); 15165 15166 if (strict == DEDUCE_CONV) 15167 { 15168 if (can_convert_arg (type, parm, NULL_TREE, flags)) 15169 return unify_success (explain_p); 15170 } 15171 else if (strict != DEDUCE_EXACT) 15172 { 15173 if (can_convert_arg (parm, type, 15174 TYPE_P (arg) ? NULL_TREE : arg, 15175 flags)) 15176 return unify_success (explain_p); 15177 } 15178 15179 if (strict == DEDUCE_EXACT) 15180 return unify_type_mismatch (explain_p, parm, arg); 15181 else 15182 return unify_arg_conversion (explain_p, parm, type, arg); 15183 } 15184 15185 /* Subroutine of type_unification_real and unify_pack_expansion to 15186 handle unification of a single P/A pair. Parameters are as 15187 for those functions. */ 15188 15189 static int 15190 unify_one_argument (tree tparms, tree targs, tree parm, tree arg, 15191 int subr, unification_kind_t strict, int flags, 15192 bool explain_p) 15193 { 15194 tree arg_expr = NULL_TREE; 15195 int arg_strict; 15196 15197 if (arg == error_mark_node || parm == error_mark_node) 15198 return unify_invalid (explain_p); 15199 if (arg == unknown_type_node) 15200 /* We can't deduce anything from this, but we might get all the 15201 template args from other function args. */ 15202 return unify_success (explain_p); 15203 15204 /* FIXME uses_deducible_template_parms */ 15205 if (TYPE_P (parm) && !uses_template_parms (parm)) 15206 return check_non_deducible_conversion (parm, arg, strict, flags, 15207 explain_p); 15208 15209 switch (strict) 15210 { 15211 case DEDUCE_CALL: 15212 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL 15213 | UNIFY_ALLOW_MORE_CV_QUAL 15214 | UNIFY_ALLOW_DERIVED); 15215 break; 15216 15217 case DEDUCE_CONV: 15218 arg_strict = UNIFY_ALLOW_LESS_CV_QUAL; 15219 break; 15220 15221 case DEDUCE_EXACT: 15222 arg_strict = UNIFY_ALLOW_NONE; 15223 break; 15224 15225 default: 15226 gcc_unreachable (); 15227 } 15228 15229 /* We only do these transformations if this is the top-level 15230 parameter_type_list in a call or declaration matching; in other 15231 situations (nested function declarators, template argument lists) we 15232 won't be comparing a type to an expression, and we don't do any type 15233 adjustments. */ 15234 if (!subr) 15235 { 15236 if (!TYPE_P (arg)) 15237 { 15238 gcc_assert (TREE_TYPE (arg) != NULL_TREE); 15239 if (type_unknown_p (arg)) 15240 { 15241 /* [temp.deduct.type] A template-argument can be 15242 deduced from a pointer to function or pointer 15243 to member function argument if the set of 15244 overloaded functions does not contain function 15245 templates and at most one of a set of 15246 overloaded functions provides a unique 15247 match. */ 15248 15249 if (resolve_overloaded_unification 15250 (tparms, targs, parm, arg, strict, 15251 arg_strict, explain_p)) 15252 return unify_success (explain_p); 15253 return unify_overload_resolution_failure (explain_p, arg); 15254 } 15255 15256 arg_expr = arg; 15257 arg = unlowered_expr_type (arg); 15258 if (arg == error_mark_node) 15259 return unify_invalid (explain_p); 15260 } 15261 15262 arg_strict |= 15263 maybe_adjust_types_for_deduction (strict, &parm, &arg, arg_expr); 15264 } 15265 else 15266 gcc_assert ((TYPE_P (parm) || TREE_CODE (parm) == TEMPLATE_DECL) 15267 == (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)); 15268 15269 /* For deduction from an init-list we need the actual list. */ 15270 if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr)) 15271 arg = arg_expr; 15272 return unify (tparms, targs, parm, arg, arg_strict, explain_p); 15273 } 15274 15275 /* Most parms like fn_type_unification. 15276 15277 If SUBR is 1, we're being called recursively (to unify the 15278 arguments of a function or method parameter of a function 15279 template). */ 15280 15281 static int 15282 type_unification_real (tree tparms, 15283 tree targs, 15284 tree xparms, 15285 const tree *xargs, 15286 unsigned int xnargs, 15287 int subr, 15288 unification_kind_t strict, 15289 int flags, 15290 bool explain_p) 15291 { 15292 tree parm, arg; 15293 int i; 15294 int ntparms = TREE_VEC_LENGTH (tparms); 15295 int saw_undeduced = 0; 15296 tree parms; 15297 const tree *args; 15298 unsigned int nargs; 15299 unsigned int ia; 15300 15301 gcc_assert (TREE_CODE (tparms) == TREE_VEC); 15302 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST); 15303 gcc_assert (ntparms > 0); 15304 15305 /* Reset the number of non-defaulted template arguments contained 15306 in TARGS. */ 15307 NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE; 15308 15309 again: 15310 parms = xparms; 15311 args = xargs; 15312 nargs = xnargs; 15313 15314 ia = 0; 15315 while (parms && parms != void_list_node 15316 && ia < nargs) 15317 { 15318 parm = TREE_VALUE (parms); 15319 15320 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION 15321 && (!TREE_CHAIN (parms) || TREE_CHAIN (parms) == void_list_node)) 15322 /* For a function parameter pack that occurs at the end of the 15323 parameter-declaration-list, the type A of each remaining 15324 argument of the call is compared with the type P of the 15325 declarator-id of the function parameter pack. */ 15326 break; 15327 15328 parms = TREE_CHAIN (parms); 15329 15330 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION) 15331 /* For a function parameter pack that does not occur at the 15332 end of the parameter-declaration-list, the type of the 15333 parameter pack is a non-deduced context. */ 15334 continue; 15335 15336 arg = args[ia]; 15337 ++ia; 15338 15339 if (unify_one_argument (tparms, targs, parm, arg, subr, strict, 15340 flags, explain_p)) 15341 return 1; 15342 } 15343 15344 if (parms 15345 && parms != void_list_node 15346 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION) 15347 { 15348 /* Unify the remaining arguments with the pack expansion type. */ 15349 tree argvec; 15350 tree parmvec = make_tree_vec (1); 15351 15352 /* Allocate a TREE_VEC and copy in all of the arguments */ 15353 argvec = make_tree_vec (nargs - ia); 15354 for (i = 0; ia < nargs; ++ia, ++i) 15355 TREE_VEC_ELT (argvec, i) = args[ia]; 15356 15357 /* Copy the parameter into parmvec. */ 15358 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms); 15359 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict, 15360 /*subr=*/subr, explain_p)) 15361 return 1; 15362 15363 /* Advance to the end of the list of parameters. */ 15364 parms = TREE_CHAIN (parms); 15365 } 15366 15367 /* Fail if we've reached the end of the parm list, and more args 15368 are present, and the parm list isn't variadic. */ 15369 if (ia < nargs && parms == void_list_node) 15370 return unify_too_many_arguments (explain_p, nargs, ia); 15371 /* Fail if parms are left and they don't have default values. */ 15372 if (parms && parms != void_list_node 15373 && TREE_PURPOSE (parms) == NULL_TREE) 15374 { 15375 unsigned int count = nargs; 15376 tree p = parms; 15377 while (p && p != void_list_node) 15378 { 15379 count++; 15380 p = TREE_CHAIN (p); 15381 } 15382 return unify_too_few_arguments (explain_p, ia, count); 15383 } 15384 15385 if (!subr) 15386 { 15387 tsubst_flags_t complain = (explain_p 15388 ? tf_warning_or_error 15389 : tf_none); 15390 15391 /* Check to see if we need another pass before we start clearing 15392 ARGUMENT_PACK_INCOMPLETE_P. */ 15393 for (i = 0; i < ntparms; i++) 15394 { 15395 tree targ = TREE_VEC_ELT (targs, i); 15396 tree tparm = TREE_VEC_ELT (tparms, i); 15397 15398 if (targ || tparm == error_mark_node) 15399 continue; 15400 tparm = TREE_VALUE (tparm); 15401 15402 /* If this is an undeduced nontype parameter that depends on 15403 a type parameter, try another pass; its type may have been 15404 deduced from a later argument than the one from which 15405 this parameter can be deduced. */ 15406 if (TREE_CODE (tparm) == PARM_DECL 15407 && uses_template_parms (TREE_TYPE (tparm)) 15408 && !saw_undeduced++) 15409 goto again; 15410 } 15411 15412 for (i = 0; i < ntparms; i++) 15413 { 15414 tree targ = TREE_VEC_ELT (targs, i); 15415 tree tparm = TREE_VEC_ELT (tparms, i); 15416 15417 /* Clear the "incomplete" flags on all argument packs now so that 15418 substituting them into later default arguments works. */ 15419 if (targ && ARGUMENT_PACK_P (targ)) 15420 { 15421 ARGUMENT_PACK_INCOMPLETE_P (targ) = 0; 15422 ARGUMENT_PACK_EXPLICIT_ARGS (targ) = NULL_TREE; 15423 } 15424 15425 if (targ || tparm == error_mark_node) 15426 continue; 15427 tparm = TREE_VALUE (tparm); 15428 15429 /* Core issue #226 (C++0x) [temp.deduct]: 15430 15431 If a template argument has not been deduced, its 15432 default template argument, if any, is used. 15433 15434 When we are in C++98 mode, TREE_PURPOSE will either 15435 be NULL_TREE or ERROR_MARK_NODE, so we do not need 15436 to explicitly check cxx_dialect here. */ 15437 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i))) 15438 { 15439 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i)); 15440 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i)); 15441 location_t save_loc = input_location; 15442 if (DECL_P (parm)) 15443 input_location = DECL_SOURCE_LOCATION (parm); 15444 arg = tsubst_template_arg (arg, targs, complain, NULL_TREE); 15445 arg = convert_template_argument (parm, arg, targs, complain, 15446 i, NULL_TREE); 15447 input_location = save_loc; 15448 if (arg == error_mark_node) 15449 return 1; 15450 else 15451 { 15452 TREE_VEC_ELT (targs, i) = arg; 15453 /* The position of the first default template argument, 15454 is also the number of non-defaulted arguments in TARGS. 15455 Record that. */ 15456 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs)) 15457 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i); 15458 continue; 15459 } 15460 } 15461 15462 /* If the type parameter is a parameter pack, then it will 15463 be deduced to an empty parameter pack. */ 15464 if (template_parameter_pack_p (tparm)) 15465 { 15466 tree arg; 15467 15468 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX) 15469 { 15470 arg = make_node (NONTYPE_ARGUMENT_PACK); 15471 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm)); 15472 TREE_CONSTANT (arg) = 1; 15473 } 15474 else 15475 arg = cxx_make_type (TYPE_ARGUMENT_PACK); 15476 15477 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0)); 15478 15479 TREE_VEC_ELT (targs, i) = arg; 15480 continue; 15481 } 15482 15483 return unify_parameter_deduction_failure (explain_p, tparm); 15484 } 15485 } 15486 #ifdef ENABLE_CHECKING 15487 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs)) 15488 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs)); 15489 #endif 15490 15491 return unify_success (explain_p); 15492 } 15493 15494 /* Subroutine of type_unification_real. Args are like the variables 15495 at the call site. ARG is an overloaded function (or template-id); 15496 we try deducing template args from each of the overloads, and if 15497 only one succeeds, we go with that. Modifies TARGS and returns 15498 true on success. */ 15499 15500 static bool 15501 resolve_overloaded_unification (tree tparms, 15502 tree targs, 15503 tree parm, 15504 tree arg, 15505 unification_kind_t strict, 15506 int sub_strict, 15507 bool explain_p) 15508 { 15509 tree tempargs = copy_node (targs); 15510 int good = 0; 15511 tree goodfn = NULL_TREE; 15512 bool addr_p; 15513 15514 if (TREE_CODE (arg) == ADDR_EXPR) 15515 { 15516 arg = TREE_OPERAND (arg, 0); 15517 addr_p = true; 15518 } 15519 else 15520 addr_p = false; 15521 15522 if (TREE_CODE (arg) == COMPONENT_REF) 15523 /* Handle `&x' where `x' is some static or non-static member 15524 function name. */ 15525 arg = TREE_OPERAND (arg, 1); 15526 15527 if (TREE_CODE (arg) == OFFSET_REF) 15528 arg = TREE_OPERAND (arg, 1); 15529 15530 /* Strip baselink information. */ 15531 if (BASELINK_P (arg)) 15532 arg = BASELINK_FUNCTIONS (arg); 15533 15534 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR) 15535 { 15536 /* If we got some explicit template args, we need to plug them into 15537 the affected templates before we try to unify, in case the 15538 explicit args will completely resolve the templates in question. */ 15539 15540 int ok = 0; 15541 tree expl_subargs = TREE_OPERAND (arg, 1); 15542 arg = TREE_OPERAND (arg, 0); 15543 15544 for (; arg; arg = OVL_NEXT (arg)) 15545 { 15546 tree fn = OVL_CURRENT (arg); 15547 tree subargs, elem; 15548 15549 if (TREE_CODE (fn) != TEMPLATE_DECL) 15550 continue; 15551 15552 ++processing_template_decl; 15553 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn), 15554 expl_subargs, /*check_ret=*/false); 15555 if (subargs && !any_dependent_template_arguments_p (subargs)) 15556 { 15557 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE); 15558 if (try_one_overload (tparms, targs, tempargs, parm, 15559 elem, strict, sub_strict, addr_p, explain_p) 15560 && (!goodfn || !same_type_p (goodfn, elem))) 15561 { 15562 goodfn = elem; 15563 ++good; 15564 } 15565 } 15566 else if (subargs) 15567 ++ok; 15568 --processing_template_decl; 15569 } 15570 /* If no templates (or more than one) are fully resolved by the 15571 explicit arguments, this template-id is a non-deduced context; it 15572 could still be OK if we deduce all template arguments for the 15573 enclosing call through other arguments. */ 15574 if (good != 1) 15575 good = ok; 15576 } 15577 else if (TREE_CODE (arg) != OVERLOAD 15578 && TREE_CODE (arg) != FUNCTION_DECL) 15579 /* If ARG is, for example, "(0, &f)" then its type will be unknown 15580 -- but the deduction does not succeed because the expression is 15581 not just the function on its own. */ 15582 return false; 15583 else 15584 for (; arg; arg = OVL_NEXT (arg)) 15585 if (try_one_overload (tparms, targs, tempargs, parm, 15586 TREE_TYPE (OVL_CURRENT (arg)), 15587 strict, sub_strict, addr_p, explain_p) 15588 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg)))) 15589 { 15590 goodfn = OVL_CURRENT (arg); 15591 ++good; 15592 } 15593 15594 /* [temp.deduct.type] A template-argument can be deduced from a pointer 15595 to function or pointer to member function argument if the set of 15596 overloaded functions does not contain function templates and at most 15597 one of a set of overloaded functions provides a unique match. 15598 15599 So if we found multiple possibilities, we return success but don't 15600 deduce anything. */ 15601 15602 if (good == 1) 15603 { 15604 int i = TREE_VEC_LENGTH (targs); 15605 for (; i--; ) 15606 if (TREE_VEC_ELT (tempargs, i)) 15607 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i); 15608 } 15609 if (good) 15610 return true; 15611 15612 return false; 15613 } 15614 15615 /* Core DR 115: In contexts where deduction is done and fails, or in 15616 contexts where deduction is not done, if a template argument list is 15617 specified and it, along with any default template arguments, identifies 15618 a single function template specialization, then the template-id is an 15619 lvalue for the function template specialization. */ 15620 15621 tree 15622 resolve_nondeduced_context (tree orig_expr) 15623 { 15624 tree expr, offset, baselink; 15625 bool addr; 15626 15627 if (!type_unknown_p (orig_expr)) 15628 return orig_expr; 15629 15630 expr = orig_expr; 15631 addr = false; 15632 offset = NULL_TREE; 15633 baselink = NULL_TREE; 15634 15635 if (TREE_CODE (expr) == ADDR_EXPR) 15636 { 15637 expr = TREE_OPERAND (expr, 0); 15638 addr = true; 15639 } 15640 if (TREE_CODE (expr) == OFFSET_REF) 15641 { 15642 offset = expr; 15643 expr = TREE_OPERAND (expr, 1); 15644 } 15645 if (BASELINK_P (expr)) 15646 { 15647 baselink = expr; 15648 expr = BASELINK_FUNCTIONS (expr); 15649 } 15650 15651 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR) 15652 { 15653 int good = 0; 15654 tree goodfn = NULL_TREE; 15655 15656 /* If we got some explicit template args, we need to plug them into 15657 the affected templates before we try to unify, in case the 15658 explicit args will completely resolve the templates in question. */ 15659 15660 tree expl_subargs = TREE_OPERAND (expr, 1); 15661 tree arg = TREE_OPERAND (expr, 0); 15662 tree badfn = NULL_TREE; 15663 tree badargs = NULL_TREE; 15664 15665 for (; arg; arg = OVL_NEXT (arg)) 15666 { 15667 tree fn = OVL_CURRENT (arg); 15668 tree subargs, elem; 15669 15670 if (TREE_CODE (fn) != TEMPLATE_DECL) 15671 continue; 15672 15673 ++processing_template_decl; 15674 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn), 15675 expl_subargs, /*check_ret=*/false); 15676 if (subargs && !any_dependent_template_arguments_p (subargs)) 15677 { 15678 elem = instantiate_template (fn, subargs, tf_none); 15679 if (elem == error_mark_node) 15680 { 15681 badfn = fn; 15682 badargs = subargs; 15683 } 15684 else if (elem && (!goodfn || !decls_match (goodfn, elem))) 15685 { 15686 goodfn = elem; 15687 ++good; 15688 } 15689 } 15690 --processing_template_decl; 15691 } 15692 if (good == 1) 15693 { 15694 mark_used (goodfn); 15695 expr = goodfn; 15696 if (baselink) 15697 expr = build_baselink (BASELINK_BINFO (baselink), 15698 BASELINK_ACCESS_BINFO (baselink), 15699 expr, BASELINK_OPTYPE (baselink)); 15700 if (offset) 15701 { 15702 tree base 15703 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (offset, 0))); 15704 expr = build_offset_ref (base, expr, addr); 15705 } 15706 if (addr) 15707 expr = cp_build_addr_expr (expr, tf_warning_or_error); 15708 return expr; 15709 } 15710 else if (good == 0 && badargs) 15711 /* There were no good options and at least one bad one, so let the 15712 user know what the problem is. */ 15713 instantiate_template (badfn, badargs, tf_warning_or_error); 15714 } 15715 return orig_expr; 15716 } 15717 15718 /* Subroutine of resolve_overloaded_unification; does deduction for a single 15719 overload. Fills TARGS with any deduced arguments, or error_mark_node if 15720 different overloads deduce different arguments for a given parm. 15721 ADDR_P is true if the expression for which deduction is being 15722 performed was of the form "& fn" rather than simply "fn". 15723 15724 Returns 1 on success. */ 15725 15726 static int 15727 try_one_overload (tree tparms, 15728 tree orig_targs, 15729 tree targs, 15730 tree parm, 15731 tree arg, 15732 unification_kind_t strict, 15733 int sub_strict, 15734 bool addr_p, 15735 bool explain_p) 15736 { 15737 int nargs; 15738 tree tempargs; 15739 int i; 15740 15741 /* [temp.deduct.type] A template-argument can be deduced from a pointer 15742 to function or pointer to member function argument if the set of 15743 overloaded functions does not contain function templates and at most 15744 one of a set of overloaded functions provides a unique match. 15745 15746 So if this is a template, just return success. */ 15747 15748 if (uses_template_parms (arg)) 15749 return 1; 15750 15751 if (TREE_CODE (arg) == METHOD_TYPE) 15752 arg = build_ptrmemfunc_type (build_pointer_type (arg)); 15753 else if (addr_p) 15754 arg = build_pointer_type (arg); 15755 15756 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL); 15757 15758 /* We don't copy orig_targs for this because if we have already deduced 15759 some template args from previous args, unify would complain when we 15760 try to deduce a template parameter for the same argument, even though 15761 there isn't really a conflict. */ 15762 nargs = TREE_VEC_LENGTH (targs); 15763 tempargs = make_tree_vec (nargs); 15764 15765 if (unify (tparms, tempargs, parm, arg, sub_strict, explain_p)) 15766 return 0; 15767 15768 /* First make sure we didn't deduce anything that conflicts with 15769 explicitly specified args. */ 15770 for (i = nargs; i--; ) 15771 { 15772 tree elt = TREE_VEC_ELT (tempargs, i); 15773 tree oldelt = TREE_VEC_ELT (orig_targs, i); 15774 15775 if (!elt) 15776 /*NOP*/; 15777 else if (uses_template_parms (elt)) 15778 /* Since we're unifying against ourselves, we will fill in 15779 template args used in the function parm list with our own 15780 template parms. Discard them. */ 15781 TREE_VEC_ELT (tempargs, i) = NULL_TREE; 15782 else if (oldelt && !template_args_equal (oldelt, elt)) 15783 return 0; 15784 } 15785 15786 for (i = nargs; i--; ) 15787 { 15788 tree elt = TREE_VEC_ELT (tempargs, i); 15789 15790 if (elt) 15791 TREE_VEC_ELT (targs, i) = elt; 15792 } 15793 15794 return 1; 15795 } 15796 15797 /* PARM is a template class (perhaps with unbound template 15798 parameters). ARG is a fully instantiated type. If ARG can be 15799 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and 15800 TARGS are as for unify. */ 15801 15802 static tree 15803 try_class_unification (tree tparms, tree targs, tree parm, tree arg, 15804 bool explain_p) 15805 { 15806 tree copy_of_targs; 15807 15808 if (!CLASSTYPE_TEMPLATE_INFO (arg) 15809 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg)) 15810 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm)))) 15811 return NULL_TREE; 15812 15813 /* We need to make a new template argument vector for the call to 15814 unify. If we used TARGS, we'd clutter it up with the result of 15815 the attempted unification, even if this class didn't work out. 15816 We also don't want to commit ourselves to all the unifications 15817 we've already done, since unification is supposed to be done on 15818 an argument-by-argument basis. In other words, consider the 15819 following pathological case: 15820 15821 template <int I, int J, int K> 15822 struct S {}; 15823 15824 template <int I, int J> 15825 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {}; 15826 15827 template <int I, int J, int K> 15828 void f(S<I, J, K>, S<I, I, I>); 15829 15830 void g() { 15831 S<0, 0, 0> s0; 15832 S<0, 1, 2> s2; 15833 15834 f(s0, s2); 15835 } 15836 15837 Now, by the time we consider the unification involving `s2', we 15838 already know that we must have `f<0, 0, 0>'. But, even though 15839 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid 15840 because there are two ways to unify base classes of S<0, 1, 2> 15841 with S<I, I, I>. If we kept the already deduced knowledge, we 15842 would reject the possibility I=1. */ 15843 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs)); 15844 15845 /* If unification failed, we're done. */ 15846 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm), 15847 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE, explain_p)) 15848 return NULL_TREE; 15849 15850 return arg; 15851 } 15852 15853 /* Given a template type PARM and a class type ARG, find the unique 15854 base type in ARG that is an instance of PARM. We do not examine 15855 ARG itself; only its base-classes. If there is not exactly one 15856 appropriate base class, return NULL_TREE. PARM may be the type of 15857 a partial specialization, as well as a plain template type. Used 15858 by unify. */ 15859 15860 static enum template_base_result 15861 get_template_base (tree tparms, tree targs, tree parm, tree arg, 15862 bool explain_p, tree *result) 15863 { 15864 tree rval = NULL_TREE; 15865 tree binfo; 15866 15867 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg))); 15868 15869 binfo = TYPE_BINFO (complete_type (arg)); 15870 if (!binfo) 15871 { 15872 /* The type could not be completed. */ 15873 *result = NULL_TREE; 15874 return tbr_incomplete_type; 15875 } 15876 15877 /* Walk in inheritance graph order. The search order is not 15878 important, and this avoids multiple walks of virtual bases. */ 15879 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo)) 15880 { 15881 tree r = try_class_unification (tparms, targs, parm, 15882 BINFO_TYPE (binfo), explain_p); 15883 15884 if (r) 15885 { 15886 /* If there is more than one satisfactory baseclass, then: 15887 15888 [temp.deduct.call] 15889 15890 If they yield more than one possible deduced A, the type 15891 deduction fails. 15892 15893 applies. */ 15894 if (rval && !same_type_p (r, rval)) 15895 { 15896 *result = NULL_TREE; 15897 return tbr_ambiguous_baseclass; 15898 } 15899 15900 rval = r; 15901 } 15902 } 15903 15904 *result = rval; 15905 return tbr_success; 15906 } 15907 15908 /* Returns the level of DECL, which declares a template parameter. */ 15909 15910 static int 15911 template_decl_level (tree decl) 15912 { 15913 switch (TREE_CODE (decl)) 15914 { 15915 case TYPE_DECL: 15916 case TEMPLATE_DECL: 15917 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl)); 15918 15919 case PARM_DECL: 15920 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl)); 15921 15922 default: 15923 gcc_unreachable (); 15924 } 15925 return 0; 15926 } 15927 15928 /* Decide whether ARG can be unified with PARM, considering only the 15929 cv-qualifiers of each type, given STRICT as documented for unify. 15930 Returns nonzero iff the unification is OK on that basis. */ 15931 15932 static int 15933 check_cv_quals_for_unify (int strict, tree arg, tree parm) 15934 { 15935 int arg_quals = cp_type_quals (arg); 15936 int parm_quals = cp_type_quals (parm); 15937 15938 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM 15939 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL)) 15940 { 15941 /* Although a CVR qualifier is ignored when being applied to a 15942 substituted template parameter ([8.3.2]/1 for example), that 15943 does not allow us to unify "const T" with "int&" because both 15944 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type]. 15945 It is ok when we're allowing additional CV qualifiers 15946 at the outer level [14.8.2.1]/3,1st bullet. */ 15947 if ((TREE_CODE (arg) == REFERENCE_TYPE 15948 || TREE_CODE (arg) == FUNCTION_TYPE 15949 || TREE_CODE (arg) == METHOD_TYPE) 15950 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE))) 15951 return 0; 15952 15953 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM) 15954 && (parm_quals & TYPE_QUAL_RESTRICT)) 15955 return 0; 15956 } 15957 15958 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL)) 15959 && (arg_quals & parm_quals) != parm_quals) 15960 return 0; 15961 15962 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL)) 15963 && (parm_quals & arg_quals) != arg_quals) 15964 return 0; 15965 15966 return 1; 15967 } 15968 15969 /* Determines the LEVEL and INDEX for the template parameter PARM. */ 15970 void 15971 template_parm_level_and_index (tree parm, int* level, int* index) 15972 { 15973 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM 15974 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM 15975 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM) 15976 { 15977 *index = TEMPLATE_TYPE_IDX (parm); 15978 *level = TEMPLATE_TYPE_LEVEL (parm); 15979 } 15980 else 15981 { 15982 *index = TEMPLATE_PARM_IDX (parm); 15983 *level = TEMPLATE_PARM_LEVEL (parm); 15984 } 15985 } 15986 15987 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \ 15988 do { \ 15989 if (unify (TP, TA, P, A, S, EP)) \ 15990 return 1; \ 15991 } while (0); 15992 15993 /* Unifies the remaining arguments in PACKED_ARGS with the pack 15994 expansion at the end of PACKED_PARMS. Returns 0 if the type 15995 deduction succeeds, 1 otherwise. STRICT is the same as in 15996 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function 15997 call argument list. We'll need to adjust the arguments to make them 15998 types. SUBR tells us if this is from a recursive call to 15999 type_unification_real, or for comparing two template argument 16000 lists. */ 16001 16002 static int 16003 unify_pack_expansion (tree tparms, tree targs, tree packed_parms, 16004 tree packed_args, unification_kind_t strict, 16005 bool subr, bool explain_p) 16006 { 16007 tree parm 16008 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1); 16009 tree pattern = PACK_EXPANSION_PATTERN (parm); 16010 tree pack, packs = NULL_TREE; 16011 int i, start = TREE_VEC_LENGTH (packed_parms) - 1; 16012 int len = TREE_VEC_LENGTH (packed_args); 16013 16014 /* Determine the parameter packs we will be deducing from the 16015 pattern, and record their current deductions. */ 16016 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm); 16017 pack; pack = TREE_CHAIN (pack)) 16018 { 16019 tree parm_pack = TREE_VALUE (pack); 16020 int idx, level; 16021 16022 /* Determine the index and level of this parameter pack. */ 16023 template_parm_level_and_index (parm_pack, &level, &idx); 16024 16025 /* Keep track of the parameter packs and their corresponding 16026 argument packs. */ 16027 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs); 16028 TREE_TYPE (packs) = make_tree_vec (len - start); 16029 } 16030 16031 /* Loop through all of the arguments that have not yet been 16032 unified and unify each with the pattern. */ 16033 for (i = start; i < len; i++) 16034 { 16035 tree parm; 16036 bool any_explicit = false; 16037 tree arg = TREE_VEC_ELT (packed_args, i); 16038 16039 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE 16040 or the element of its argument pack at the current index if 16041 this argument was explicitly specified. */ 16042 for (pack = packs; pack; pack = TREE_CHAIN (pack)) 16043 { 16044 int idx, level; 16045 tree arg, pargs; 16046 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx); 16047 16048 arg = NULL_TREE; 16049 if (TREE_VALUE (pack) 16050 && (pargs = ARGUMENT_PACK_EXPLICIT_ARGS (TREE_VALUE (pack))) 16051 && (i < TREE_VEC_LENGTH (pargs))) 16052 { 16053 any_explicit = true; 16054 arg = TREE_VEC_ELT (pargs, i); 16055 } 16056 TMPL_ARG (targs, level, idx) = arg; 16057 } 16058 16059 /* If we had explicit template arguments, substitute them into the 16060 pattern before deduction. */ 16061 if (any_explicit) 16062 { 16063 /* Some arguments might still be unspecified or dependent. */ 16064 bool dependent; 16065 ++processing_template_decl; 16066 dependent = any_dependent_template_arguments_p (targs); 16067 if (!dependent) 16068 --processing_template_decl; 16069 parm = tsubst (pattern, targs, 16070 explain_p ? tf_warning_or_error : tf_none, 16071 NULL_TREE); 16072 if (dependent) 16073 --processing_template_decl; 16074 if (parm == error_mark_node) 16075 return 1; 16076 } 16077 else 16078 parm = pattern; 16079 16080 /* Unify the pattern with the current argument. */ 16081 if (unify_one_argument (tparms, targs, parm, arg, subr, strict, 16082 LOOKUP_IMPLICIT, explain_p)) 16083 return 1; 16084 16085 /* For each parameter pack, collect the deduced value. */ 16086 for (pack = packs; pack; pack = TREE_CHAIN (pack)) 16087 { 16088 int idx, level; 16089 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx); 16090 16091 TREE_VEC_ELT (TREE_TYPE (pack), i - start) = 16092 TMPL_ARG (targs, level, idx); 16093 } 16094 } 16095 16096 /* Verify that the results of unification with the parameter packs 16097 produce results consistent with what we've seen before, and make 16098 the deduced argument packs available. */ 16099 for (pack = packs; pack; pack = TREE_CHAIN (pack)) 16100 { 16101 tree old_pack = TREE_VALUE (pack); 16102 tree new_args = TREE_TYPE (pack); 16103 int i, len = TREE_VEC_LENGTH (new_args); 16104 int idx, level; 16105 bool nondeduced_p = false; 16106 16107 /* By default keep the original deduced argument pack. 16108 If necessary, more specific code is going to update the 16109 resulting deduced argument later down in this function. */ 16110 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx); 16111 TMPL_ARG (targs, level, idx) = old_pack; 16112 16113 /* If NEW_ARGS contains any NULL_TREE entries, we didn't 16114 actually deduce anything. */ 16115 for (i = 0; i < len && !nondeduced_p; ++i) 16116 if (TREE_VEC_ELT (new_args, i) == NULL_TREE) 16117 nondeduced_p = true; 16118 if (nondeduced_p) 16119 continue; 16120 16121 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack)) 16122 { 16123 /* If we had fewer function args than explicit template args, 16124 just use the explicits. */ 16125 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack); 16126 int explicit_len = TREE_VEC_LENGTH (explicit_args); 16127 if (len < explicit_len) 16128 new_args = explicit_args; 16129 } 16130 16131 if (!old_pack) 16132 { 16133 tree result; 16134 /* Build the deduced *_ARGUMENT_PACK. */ 16135 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX) 16136 { 16137 result = make_node (NONTYPE_ARGUMENT_PACK); 16138 TREE_TYPE (result) = 16139 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack))); 16140 TREE_CONSTANT (result) = 1; 16141 } 16142 else 16143 result = cxx_make_type (TYPE_ARGUMENT_PACK); 16144 16145 SET_ARGUMENT_PACK_ARGS (result, new_args); 16146 16147 /* Note the deduced argument packs for this parameter 16148 pack. */ 16149 TMPL_ARG (targs, level, idx) = result; 16150 } 16151 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack) 16152 && (ARGUMENT_PACK_ARGS (old_pack) 16153 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack))) 16154 { 16155 /* We only had the explicitly-provided arguments before, but 16156 now we have a complete set of arguments. */ 16157 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack); 16158 16159 SET_ARGUMENT_PACK_ARGS (old_pack, new_args); 16160 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1; 16161 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args; 16162 } 16163 else 16164 { 16165 tree bad_old_arg = NULL_TREE, bad_new_arg = NULL_TREE; 16166 tree old_args = ARGUMENT_PACK_ARGS (old_pack); 16167 16168 if (!comp_template_args_with_info (old_args, new_args, 16169 &bad_old_arg, &bad_new_arg)) 16170 /* Inconsistent unification of this parameter pack. */ 16171 return unify_parameter_pack_inconsistent (explain_p, 16172 bad_old_arg, 16173 bad_new_arg); 16174 } 16175 } 16176 16177 return unify_success (explain_p); 16178 } 16179 16180 /* Deduce the value of template parameters. TPARMS is the (innermost) 16181 set of template parameters to a template. TARGS is the bindings 16182 for those template parameters, as determined thus far; TARGS may 16183 include template arguments for outer levels of template parameters 16184 as well. PARM is a parameter to a template function, or a 16185 subcomponent of that parameter; ARG is the corresponding argument. 16186 This function attempts to match PARM with ARG in a manner 16187 consistent with the existing assignments in TARGS. If more values 16188 are deduced, then TARGS is updated. 16189 16190 Returns 0 if the type deduction succeeds, 1 otherwise. The 16191 parameter STRICT is a bitwise or of the following flags: 16192 16193 UNIFY_ALLOW_NONE: 16194 Require an exact match between PARM and ARG. 16195 UNIFY_ALLOW_MORE_CV_QUAL: 16196 Allow the deduced ARG to be more cv-qualified (by qualification 16197 conversion) than ARG. 16198 UNIFY_ALLOW_LESS_CV_QUAL: 16199 Allow the deduced ARG to be less cv-qualified than ARG. 16200 UNIFY_ALLOW_DERIVED: 16201 Allow the deduced ARG to be a template base class of ARG, 16202 or a pointer to a template base class of the type pointed to by 16203 ARG. 16204 UNIFY_ALLOW_INTEGER: 16205 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX 16206 case for more information. 16207 UNIFY_ALLOW_OUTER_LEVEL: 16208 This is the outermost level of a deduction. Used to determine validity 16209 of qualification conversions. A valid qualification conversion must 16210 have const qualified pointers leading up to the inner type which 16211 requires additional CV quals, except at the outer level, where const 16212 is not required [conv.qual]. It would be normal to set this flag in 16213 addition to setting UNIFY_ALLOW_MORE_CV_QUAL. 16214 UNIFY_ALLOW_OUTER_MORE_CV_QUAL: 16215 This is the outermost level of a deduction, and PARM can be more CV 16216 qualified at this point. 16217 UNIFY_ALLOW_OUTER_LESS_CV_QUAL: 16218 This is the outermost level of a deduction, and PARM can be less CV 16219 qualified at this point. */ 16220 16221 static int 16222 unify (tree tparms, tree targs, tree parm, tree arg, int strict, 16223 bool explain_p) 16224 { 16225 int idx; 16226 tree targ; 16227 tree tparm; 16228 int strict_in = strict; 16229 16230 /* I don't think this will do the right thing with respect to types. 16231 But the only case I've seen it in so far has been array bounds, where 16232 signedness is the only information lost, and I think that will be 16233 okay. */ 16234 while (TREE_CODE (parm) == NOP_EXPR) 16235 parm = TREE_OPERAND (parm, 0); 16236 16237 if (arg == error_mark_node) 16238 return unify_invalid (explain_p); 16239 if (arg == unknown_type_node 16240 || arg == init_list_type_node) 16241 /* We can't deduce anything from this, but we might get all the 16242 template args from other function args. */ 16243 return unify_success (explain_p); 16244 16245 /* If PARM uses template parameters, then we can't bail out here, 16246 even if ARG == PARM, since we won't record unifications for the 16247 template parameters. We might need them if we're trying to 16248 figure out which of two things is more specialized. */ 16249 if (arg == parm && !uses_template_parms (parm)) 16250 return unify_success (explain_p); 16251 16252 /* Handle init lists early, so the rest of the function can assume 16253 we're dealing with a type. */ 16254 if (BRACE_ENCLOSED_INITIALIZER_P (arg)) 16255 { 16256 tree elt, elttype; 16257 unsigned i; 16258 tree orig_parm = parm; 16259 16260 /* Replace T with std::initializer_list<T> for deduction. */ 16261 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM 16262 && flag_deduce_init_list) 16263 parm = listify (parm); 16264 16265 if (!is_std_init_list (parm)) 16266 /* We can only deduce from an initializer list argument if the 16267 parameter is std::initializer_list; otherwise this is a 16268 non-deduced context. */ 16269 return unify_success (explain_p); 16270 16271 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0); 16272 16273 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt) 16274 { 16275 int elt_strict = strict; 16276 16277 if (elt == error_mark_node) 16278 return unify_invalid (explain_p); 16279 16280 if (!BRACE_ENCLOSED_INITIALIZER_P (elt)) 16281 { 16282 tree type = TREE_TYPE (elt); 16283 /* It should only be possible to get here for a call. */ 16284 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL); 16285 elt_strict |= maybe_adjust_types_for_deduction 16286 (DEDUCE_CALL, &elttype, &type, elt); 16287 elt = type; 16288 } 16289 16290 RECUR_AND_CHECK_FAILURE (tparms, targs, elttype, elt, elt_strict, 16291 explain_p); 16292 } 16293 16294 /* If the std::initializer_list<T> deduction worked, replace the 16295 deduced A with std::initializer_list<A>. */ 16296 if (orig_parm != parm) 16297 { 16298 idx = TEMPLATE_TYPE_IDX (orig_parm); 16299 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx); 16300 targ = listify (targ); 16301 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ; 16302 } 16303 return unify_success (explain_p); 16304 } 16305 16306 /* Immediately reject some pairs that won't unify because of 16307 cv-qualification mismatches. */ 16308 if (TREE_CODE (arg) == TREE_CODE (parm) 16309 && TYPE_P (arg) 16310 /* It is the elements of the array which hold the cv quals of an array 16311 type, and the elements might be template type parms. We'll check 16312 when we recurse. */ 16313 && TREE_CODE (arg) != ARRAY_TYPE 16314 /* We check the cv-qualifiers when unifying with template type 16315 parameters below. We want to allow ARG `const T' to unify with 16316 PARM `T' for example, when computing which of two templates 16317 is more specialized, for example. */ 16318 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM 16319 && !check_cv_quals_for_unify (strict_in, arg, parm)) 16320 return unify_cv_qual_mismatch (explain_p, parm, arg); 16321 16322 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL) 16323 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm)) 16324 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL; 16325 strict &= ~UNIFY_ALLOW_OUTER_LEVEL; 16326 strict &= ~UNIFY_ALLOW_DERIVED; 16327 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL; 16328 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL; 16329 16330 switch (TREE_CODE (parm)) 16331 { 16332 case TYPENAME_TYPE: 16333 case SCOPE_REF: 16334 case UNBOUND_CLASS_TEMPLATE: 16335 /* In a type which contains a nested-name-specifier, template 16336 argument values cannot be deduced for template parameters used 16337 within the nested-name-specifier. */ 16338 return unify_success (explain_p); 16339 16340 case TEMPLATE_TYPE_PARM: 16341 case TEMPLATE_TEMPLATE_PARM: 16342 case BOUND_TEMPLATE_TEMPLATE_PARM: 16343 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0)); 16344 if (tparm == error_mark_node) 16345 return unify_invalid (explain_p); 16346 16347 if (TEMPLATE_TYPE_LEVEL (parm) 16348 != template_decl_level (tparm)) 16349 /* The PARM is not one we're trying to unify. Just check 16350 to see if it matches ARG. */ 16351 { 16352 if (TREE_CODE (arg) == TREE_CODE (parm) 16353 && same_type_p (parm, arg)) 16354 return unify_success (explain_p); 16355 else 16356 return unify_type_mismatch (explain_p, parm, arg); 16357 } 16358 idx = TEMPLATE_TYPE_IDX (parm); 16359 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx); 16360 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx)); 16361 if (tparm == error_mark_node) 16362 return unify_invalid (explain_p); 16363 16364 /* Check for mixed types and values. */ 16365 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM 16366 && TREE_CODE (tparm) != TYPE_DECL) 16367 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM 16368 && TREE_CODE (tparm) != TEMPLATE_DECL)) 16369 gcc_unreachable (); 16370 16371 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM) 16372 { 16373 /* ARG must be constructed from a template class or a template 16374 template parameter. */ 16375 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM 16376 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg)) 16377 return unify_template_deduction_failure (explain_p, parm, arg); 16378 16379 { 16380 tree parmvec = TYPE_TI_ARGS (parm); 16381 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg)); 16382 tree full_argvec = add_to_template_args (targs, argvec); 16383 tree parm_parms 16384 = DECL_INNERMOST_TEMPLATE_PARMS 16385 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm)); 16386 int i, len; 16387 int parm_variadic_p = 0; 16388 16389 /* The resolution to DR150 makes clear that default 16390 arguments for an N-argument may not be used to bind T 16391 to a template template parameter with fewer than N 16392 parameters. It is not safe to permit the binding of 16393 default arguments as an extension, as that may change 16394 the meaning of a conforming program. Consider: 16395 16396 struct Dense { static const unsigned int dim = 1; }; 16397 16398 template <template <typename> class View, 16399 typename Block> 16400 void operator+(float, View<Block> const&); 16401 16402 template <typename Block, 16403 unsigned int Dim = Block::dim> 16404 struct Lvalue_proxy { operator float() const; }; 16405 16406 void 16407 test_1d (void) { 16408 Lvalue_proxy<Dense> p; 16409 float b; 16410 b + p; 16411 } 16412 16413 Here, if Lvalue_proxy is permitted to bind to View, then 16414 the global operator+ will be used; if they are not, the 16415 Lvalue_proxy will be converted to float. */ 16416 if (coerce_template_parms (parm_parms, 16417 full_argvec, 16418 TYPE_TI_TEMPLATE (parm), 16419 (explain_p 16420 ? tf_warning_or_error 16421 : tf_none), 16422 /*require_all_args=*/true, 16423 /*use_default_args=*/false) 16424 == error_mark_node) 16425 return 1; 16426 16427 /* Deduce arguments T, i from TT<T> or TT<i>. 16428 We check each element of PARMVEC and ARGVEC individually 16429 rather than the whole TREE_VEC since they can have 16430 different number of elements. */ 16431 16432 parmvec = expand_template_argument_pack (parmvec); 16433 argvec = expand_template_argument_pack (argvec); 16434 16435 len = TREE_VEC_LENGTH (parmvec); 16436 16437 /* Check if the parameters end in a pack, making them 16438 variadic. */ 16439 if (len > 0 16440 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1))) 16441 parm_variadic_p = 1; 16442 16443 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p) 16444 return unify_too_few_arguments (explain_p, 16445 TREE_VEC_LENGTH (argvec), len); 16446 16447 for (i = 0; i < len - parm_variadic_p; ++i) 16448 { 16449 RECUR_AND_CHECK_FAILURE (tparms, targs, 16450 TREE_VEC_ELT (parmvec, i), 16451 TREE_VEC_ELT (argvec, i), 16452 UNIFY_ALLOW_NONE, explain_p); 16453 } 16454 16455 if (parm_variadic_p 16456 && unify_pack_expansion (tparms, targs, 16457 parmvec, argvec, 16458 DEDUCE_EXACT, 16459 /*subr=*/true, explain_p)) 16460 return 1; 16461 } 16462 arg = TYPE_TI_TEMPLATE (arg); 16463 16464 /* Fall through to deduce template name. */ 16465 } 16466 16467 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM 16468 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM) 16469 { 16470 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */ 16471 16472 /* Simple cases: Value already set, does match or doesn't. */ 16473 if (targ != NULL_TREE && template_args_equal (targ, arg)) 16474 return unify_success (explain_p); 16475 else if (targ) 16476 return unify_inconsistency (explain_p, parm, targ, arg); 16477 } 16478 else 16479 { 16480 /* If PARM is `const T' and ARG is only `int', we don't have 16481 a match unless we are allowing additional qualification. 16482 If ARG is `const int' and PARM is just `T' that's OK; 16483 that binds `const int' to `T'. */ 16484 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL, 16485 arg, parm)) 16486 return unify_cv_qual_mismatch (explain_p, parm, arg); 16487 16488 /* Consider the case where ARG is `const volatile int' and 16489 PARM is `const T'. Then, T should be `volatile int'. */ 16490 arg = cp_build_qualified_type_real 16491 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none); 16492 if (arg == error_mark_node) 16493 return unify_invalid (explain_p); 16494 16495 /* Simple cases: Value already set, does match or doesn't. */ 16496 if (targ != NULL_TREE && same_type_p (targ, arg)) 16497 return unify_success (explain_p); 16498 else if (targ) 16499 return unify_inconsistency (explain_p, parm, targ, arg); 16500 16501 /* Make sure that ARG is not a variable-sized array. (Note 16502 that were talking about variable-sized arrays (like 16503 `int[n]'), rather than arrays of unknown size (like 16504 `int[]').) We'll get very confused by such a type since 16505 the bound of the array is not constant, and therefore 16506 not mangleable. Besides, such types are not allowed in 16507 ISO C++, so we can do as we please here. We do allow 16508 them for 'auto' deduction, since that isn't ABI-exposed. */ 16509 if (!is_auto (parm) && variably_modified_type_p (arg, NULL_TREE)) 16510 return unify_vla_arg (explain_p, arg); 16511 16512 /* Strip typedefs as in convert_template_argument. */ 16513 arg = canonicalize_type_argument (arg, tf_none); 16514 } 16515 16516 /* If ARG is a parameter pack or an expansion, we cannot unify 16517 against it unless PARM is also a parameter pack. */ 16518 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg)) 16519 && !template_parameter_pack_p (parm)) 16520 return unify_parameter_pack_mismatch (explain_p, parm, arg); 16521 16522 /* If the argument deduction results is a METHOD_TYPE, 16523 then there is a problem. 16524 METHOD_TYPE doesn't map to any real C++ type the result of 16525 the deduction can not be of that type. */ 16526 if (TREE_CODE (arg) == METHOD_TYPE) 16527 return unify_method_type_error (explain_p, arg); 16528 16529 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg; 16530 return unify_success (explain_p); 16531 16532 case TEMPLATE_PARM_INDEX: 16533 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0)); 16534 if (tparm == error_mark_node) 16535 return unify_invalid (explain_p); 16536 16537 if (TEMPLATE_PARM_LEVEL (parm) 16538 != template_decl_level (tparm)) 16539 { 16540 /* The PARM is not one we're trying to unify. Just check 16541 to see if it matches ARG. */ 16542 int result = !(TREE_CODE (arg) == TREE_CODE (parm) 16543 && cp_tree_equal (parm, arg)); 16544 if (result) 16545 unify_expression_unequal (explain_p, parm, arg); 16546 return result; 16547 } 16548 16549 idx = TEMPLATE_PARM_IDX (parm); 16550 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx); 16551 16552 if (targ) 16553 { 16554 int x = !cp_tree_equal (targ, arg); 16555 if (x) 16556 unify_inconsistency (explain_p, parm, targ, arg); 16557 return x; 16558 } 16559 16560 /* [temp.deduct.type] If, in the declaration of a function template 16561 with a non-type template-parameter, the non-type 16562 template-parameter is used in an expression in the function 16563 parameter-list and, if the corresponding template-argument is 16564 deduced, the template-argument type shall match the type of the 16565 template-parameter exactly, except that a template-argument 16566 deduced from an array bound may be of any integral type. 16567 The non-type parameter might use already deduced type parameters. */ 16568 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE); 16569 if (!TREE_TYPE (arg)) 16570 /* Template-parameter dependent expression. Just accept it for now. 16571 It will later be processed in convert_template_argument. */ 16572 ; 16573 else if (same_type_p (TREE_TYPE (arg), tparm)) 16574 /* OK */; 16575 else if ((strict & UNIFY_ALLOW_INTEGER) 16576 && (TREE_CODE (tparm) == INTEGER_TYPE 16577 || TREE_CODE (tparm) == BOOLEAN_TYPE)) 16578 /* Convert the ARG to the type of PARM; the deduced non-type 16579 template argument must exactly match the types of the 16580 corresponding parameter. */ 16581 arg = fold (build_nop (tparm, arg)); 16582 else if (uses_template_parms (tparm)) 16583 /* We haven't deduced the type of this parameter yet. Try again 16584 later. */ 16585 return unify_success (explain_p); 16586 else 16587 return unify_type_mismatch (explain_p, tparm, arg); 16588 16589 /* If ARG is a parameter pack or an expansion, we cannot unify 16590 against it unless PARM is also a parameter pack. */ 16591 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg)) 16592 && !TEMPLATE_PARM_PARAMETER_PACK (parm)) 16593 return unify_parameter_pack_mismatch (explain_p, parm, arg); 16594 16595 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg; 16596 return unify_success (explain_p); 16597 16598 case PTRMEM_CST: 16599 { 16600 /* A pointer-to-member constant can be unified only with 16601 another constant. */ 16602 if (TREE_CODE (arg) != PTRMEM_CST) 16603 return unify_ptrmem_cst_mismatch (explain_p, parm, arg); 16604 16605 /* Just unify the class member. It would be useless (and possibly 16606 wrong, depending on the strict flags) to unify also 16607 PTRMEM_CST_CLASS, because we want to be sure that both parm and 16608 arg refer to the same variable, even if through different 16609 classes. For instance: 16610 16611 struct A { int x; }; 16612 struct B : A { }; 16613 16614 Unification of &A::x and &B::x must succeed. */ 16615 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm), 16616 PTRMEM_CST_MEMBER (arg), strict, explain_p); 16617 } 16618 16619 case POINTER_TYPE: 16620 { 16621 if (TREE_CODE (arg) != POINTER_TYPE) 16622 return unify_type_mismatch (explain_p, parm, arg); 16623 16624 /* [temp.deduct.call] 16625 16626 A can be another pointer or pointer to member type that can 16627 be converted to the deduced A via a qualification 16628 conversion (_conv.qual_). 16629 16630 We pass down STRICT here rather than UNIFY_ALLOW_NONE. 16631 This will allow for additional cv-qualification of the 16632 pointed-to types if appropriate. */ 16633 16634 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE) 16635 /* The derived-to-base conversion only persists through one 16636 level of pointers. */ 16637 strict |= (strict_in & UNIFY_ALLOW_DERIVED); 16638 16639 return unify (tparms, targs, TREE_TYPE (parm), 16640 TREE_TYPE (arg), strict, explain_p); 16641 } 16642 16643 case REFERENCE_TYPE: 16644 if (TREE_CODE (arg) != REFERENCE_TYPE) 16645 return unify_type_mismatch (explain_p, parm, arg); 16646 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg), 16647 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p); 16648 16649 case ARRAY_TYPE: 16650 if (TREE_CODE (arg) != ARRAY_TYPE) 16651 return unify_type_mismatch (explain_p, parm, arg); 16652 if ((TYPE_DOMAIN (parm) == NULL_TREE) 16653 != (TYPE_DOMAIN (arg) == NULL_TREE)) 16654 return unify_type_mismatch (explain_p, parm, arg); 16655 if (TYPE_DOMAIN (parm) != NULL_TREE) 16656 { 16657 tree parm_max; 16658 tree arg_max; 16659 bool parm_cst; 16660 bool arg_cst; 16661 16662 /* Our representation of array types uses "N - 1" as the 16663 TYPE_MAX_VALUE for an array with "N" elements, if "N" is 16664 not an integer constant. We cannot unify arbitrarily 16665 complex expressions, so we eliminate the MINUS_EXPRs 16666 here. */ 16667 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm)); 16668 parm_cst = TREE_CODE (parm_max) == INTEGER_CST; 16669 if (!parm_cst) 16670 { 16671 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR); 16672 parm_max = TREE_OPERAND (parm_max, 0); 16673 } 16674 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg)); 16675 arg_cst = TREE_CODE (arg_max) == INTEGER_CST; 16676 if (!arg_cst) 16677 { 16678 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are 16679 trying to unify the type of a variable with the type 16680 of a template parameter. For example: 16681 16682 template <unsigned int N> 16683 void f (char (&) [N]); 16684 int g(); 16685 void h(int i) { 16686 char a[g(i)]; 16687 f(a); 16688 } 16689 16690 Here, the type of the ARG will be "int [g(i)]", and 16691 may be a SAVE_EXPR, etc. */ 16692 if (TREE_CODE (arg_max) != MINUS_EXPR) 16693 return unify_vla_arg (explain_p, arg); 16694 arg_max = TREE_OPERAND (arg_max, 0); 16695 } 16696 16697 /* If only one of the bounds used a MINUS_EXPR, compensate 16698 by adding one to the other bound. */ 16699 if (parm_cst && !arg_cst) 16700 parm_max = fold_build2_loc (input_location, PLUS_EXPR, 16701 integer_type_node, 16702 parm_max, 16703 integer_one_node); 16704 else if (arg_cst && !parm_cst) 16705 arg_max = fold_build2_loc (input_location, PLUS_EXPR, 16706 integer_type_node, 16707 arg_max, 16708 integer_one_node); 16709 16710 RECUR_AND_CHECK_FAILURE (tparms, targs, parm_max, arg_max, 16711 UNIFY_ALLOW_INTEGER, explain_p); 16712 } 16713 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg), 16714 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p); 16715 16716 case REAL_TYPE: 16717 case COMPLEX_TYPE: 16718 case VECTOR_TYPE: 16719 case INTEGER_TYPE: 16720 case BOOLEAN_TYPE: 16721 case ENUMERAL_TYPE: 16722 case VOID_TYPE: 16723 case NULLPTR_TYPE: 16724 if (TREE_CODE (arg) != TREE_CODE (parm)) 16725 return unify_type_mismatch (explain_p, parm, arg); 16726 16727 /* We have already checked cv-qualification at the top of the 16728 function. */ 16729 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm)) 16730 return unify_type_mismatch (explain_p, parm, arg); 16731 16732 /* As far as unification is concerned, this wins. Later checks 16733 will invalidate it if necessary. */ 16734 return unify_success (explain_p); 16735 16736 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */ 16737 /* Type INTEGER_CST can come from ordinary constant template args. */ 16738 case INTEGER_CST: 16739 while (TREE_CODE (arg) == NOP_EXPR) 16740 arg = TREE_OPERAND (arg, 0); 16741 16742 if (TREE_CODE (arg) != INTEGER_CST) 16743 return unify_template_argument_mismatch (explain_p, parm, arg); 16744 return (tree_int_cst_equal (parm, arg) 16745 ? unify_success (explain_p) 16746 : unify_template_argument_mismatch (explain_p, parm, arg)); 16747 16748 case TREE_VEC: 16749 { 16750 int i, len, argslen; 16751 int parm_variadic_p = 0; 16752 16753 if (TREE_CODE (arg) != TREE_VEC) 16754 return unify_template_argument_mismatch (explain_p, parm, arg); 16755 16756 len = TREE_VEC_LENGTH (parm); 16757 argslen = TREE_VEC_LENGTH (arg); 16758 16759 /* Check for pack expansions in the parameters. */ 16760 for (i = 0; i < len; ++i) 16761 { 16762 if (PACK_EXPANSION_P (TREE_VEC_ELT (parm, i))) 16763 { 16764 if (i == len - 1) 16765 /* We can unify against something with a trailing 16766 parameter pack. */ 16767 parm_variadic_p = 1; 16768 else 16769 /* [temp.deduct.type]/9: If the template argument list of 16770 P contains a pack expansion that is not the last 16771 template argument, the entire template argument list 16772 is a non-deduced context. */ 16773 return unify_success (explain_p); 16774 } 16775 } 16776 16777 /* If we don't have enough arguments to satisfy the parameters 16778 (not counting the pack expression at the end), or we have 16779 too many arguments for a parameter list that doesn't end in 16780 a pack expression, we can't unify. */ 16781 if (parm_variadic_p 16782 ? argslen < len - parm_variadic_p 16783 : argslen != len) 16784 return unify_arity (explain_p, TREE_VEC_LENGTH (arg), len); 16785 16786 /* Unify all of the parameters that precede the (optional) 16787 pack expression. */ 16788 for (i = 0; i < len - parm_variadic_p; ++i) 16789 { 16790 RECUR_AND_CHECK_FAILURE (tparms, targs, 16791 TREE_VEC_ELT (parm, i), 16792 TREE_VEC_ELT (arg, i), 16793 UNIFY_ALLOW_NONE, explain_p); 16794 } 16795 if (parm_variadic_p) 16796 return unify_pack_expansion (tparms, targs, parm, arg, 16797 DEDUCE_EXACT, 16798 /*subr=*/true, explain_p); 16799 return unify_success (explain_p); 16800 } 16801 16802 case RECORD_TYPE: 16803 case UNION_TYPE: 16804 if (TREE_CODE (arg) != TREE_CODE (parm)) 16805 return unify_type_mismatch (explain_p, parm, arg); 16806 16807 if (TYPE_PTRMEMFUNC_P (parm)) 16808 { 16809 if (!TYPE_PTRMEMFUNC_P (arg)) 16810 return unify_type_mismatch (explain_p, parm, arg); 16811 16812 return unify (tparms, targs, 16813 TYPE_PTRMEMFUNC_FN_TYPE (parm), 16814 TYPE_PTRMEMFUNC_FN_TYPE (arg), 16815 strict, explain_p); 16816 } 16817 16818 if (CLASSTYPE_TEMPLATE_INFO (parm)) 16819 { 16820 tree t = NULL_TREE; 16821 16822 if (strict_in & UNIFY_ALLOW_DERIVED) 16823 { 16824 /* First, we try to unify the PARM and ARG directly. */ 16825 t = try_class_unification (tparms, targs, 16826 parm, arg, explain_p); 16827 16828 if (!t) 16829 { 16830 /* Fallback to the special case allowed in 16831 [temp.deduct.call]: 16832 16833 If P is a class, and P has the form 16834 template-id, then A can be a derived class of 16835 the deduced A. Likewise, if P is a pointer to 16836 a class of the form template-id, A can be a 16837 pointer to a derived class pointed to by the 16838 deduced A. */ 16839 enum template_base_result r; 16840 r = get_template_base (tparms, targs, parm, arg, 16841 explain_p, &t); 16842 16843 if (!t) 16844 return unify_no_common_base (explain_p, r, parm, arg); 16845 } 16846 } 16847 else if (CLASSTYPE_TEMPLATE_INFO (arg) 16848 && (CLASSTYPE_TI_TEMPLATE (parm) 16849 == CLASSTYPE_TI_TEMPLATE (arg))) 16850 /* Perhaps PARM is something like S<U> and ARG is S<int>. 16851 Then, we should unify `int' and `U'. */ 16852 t = arg; 16853 else 16854 /* There's no chance of unification succeeding. */ 16855 return unify_type_mismatch (explain_p, parm, arg); 16856 16857 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm), 16858 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE, explain_p); 16859 } 16860 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg)) 16861 return unify_type_mismatch (explain_p, parm, arg); 16862 return unify_success (explain_p); 16863 16864 case METHOD_TYPE: 16865 case FUNCTION_TYPE: 16866 { 16867 unsigned int nargs; 16868 tree *args; 16869 tree a; 16870 unsigned int i; 16871 16872 if (TREE_CODE (arg) != TREE_CODE (parm)) 16873 return unify_type_mismatch (explain_p, parm, arg); 16874 16875 /* CV qualifications for methods can never be deduced, they must 16876 match exactly. We need to check them explicitly here, 16877 because type_unification_real treats them as any other 16878 cv-qualified parameter. */ 16879 if (TREE_CODE (parm) == METHOD_TYPE 16880 && (!check_cv_quals_for_unify 16881 (UNIFY_ALLOW_NONE, 16882 class_of_this_parm (arg), 16883 class_of_this_parm (parm)))) 16884 return unify_cv_qual_mismatch (explain_p, parm, arg); 16885 16886 RECUR_AND_CHECK_FAILURE (tparms, targs, TREE_TYPE (parm), 16887 TREE_TYPE (arg), UNIFY_ALLOW_NONE, explain_p); 16888 16889 nargs = list_length (TYPE_ARG_TYPES (arg)); 16890 args = XALLOCAVEC (tree, nargs); 16891 for (a = TYPE_ARG_TYPES (arg), i = 0; 16892 a != NULL_TREE && a != void_list_node; 16893 a = TREE_CHAIN (a), ++i) 16894 args[i] = TREE_VALUE (a); 16895 nargs = i; 16896 16897 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm), 16898 args, nargs, 1, DEDUCE_EXACT, 16899 LOOKUP_NORMAL, explain_p); 16900 } 16901 16902 case OFFSET_TYPE: 16903 /* Unify a pointer to member with a pointer to member function, which 16904 deduces the type of the member as a function type. */ 16905 if (TYPE_PTRMEMFUNC_P (arg)) 16906 { 16907 tree method_type; 16908 tree fntype; 16909 16910 /* Check top-level cv qualifiers */ 16911 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm)) 16912 return unify_cv_qual_mismatch (explain_p, parm, arg); 16913 16914 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm), 16915 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg), 16916 UNIFY_ALLOW_NONE, explain_p); 16917 16918 /* Determine the type of the function we are unifying against. */ 16919 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg)); 16920 fntype = 16921 build_function_type (TREE_TYPE (method_type), 16922 TREE_CHAIN (TYPE_ARG_TYPES (method_type))); 16923 16924 /* Extract the cv-qualifiers of the member function from the 16925 implicit object parameter and place them on the function 16926 type to be restored later. */ 16927 fntype = apply_memfn_quals (fntype, type_memfn_quals (method_type)); 16928 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict, explain_p); 16929 } 16930 16931 if (TREE_CODE (arg) != OFFSET_TYPE) 16932 return unify_type_mismatch (explain_p, parm, arg); 16933 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm), 16934 TYPE_OFFSET_BASETYPE (arg), 16935 UNIFY_ALLOW_NONE, explain_p); 16936 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg), 16937 strict, explain_p); 16938 16939 case CONST_DECL: 16940 if (DECL_TEMPLATE_PARM_P (parm)) 16941 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict, explain_p); 16942 if (arg != integral_constant_value (parm)) 16943 return unify_template_argument_mismatch (explain_p, parm, arg); 16944 return unify_success (explain_p); 16945 16946 case FIELD_DECL: 16947 case TEMPLATE_DECL: 16948 /* Matched cases are handled by the ARG == PARM test above. */ 16949 return unify_template_argument_mismatch (explain_p, parm, arg); 16950 16951 case VAR_DECL: 16952 /* A non-type template parameter that is a variable should be a 16953 an integral constant, in which case, it whould have been 16954 folded into its (constant) value. So we should not be getting 16955 a variable here. */ 16956 gcc_unreachable (); 16957 16958 case TYPE_ARGUMENT_PACK: 16959 case NONTYPE_ARGUMENT_PACK: 16960 return unify (tparms, targs, ARGUMENT_PACK_ARGS (parm), 16961 ARGUMENT_PACK_ARGS (arg), strict, explain_p); 16962 16963 case TYPEOF_TYPE: 16964 case DECLTYPE_TYPE: 16965 case UNDERLYING_TYPE: 16966 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE, 16967 or UNDERLYING_TYPE nodes. */ 16968 return unify_success (explain_p); 16969 16970 case ERROR_MARK: 16971 /* Unification fails if we hit an error node. */ 16972 return unify_invalid (explain_p); 16973 16974 default: 16975 /* An unresolved overload is a nondeduced context. */ 16976 if (is_overloaded_fn (parm) || type_unknown_p (parm)) 16977 return unify_success (explain_p); 16978 gcc_assert (EXPR_P (parm)); 16979 16980 /* We must be looking at an expression. This can happen with 16981 something like: 16982 16983 template <int I> 16984 void foo(S<I>, S<I + 2>); 16985 16986 This is a "nondeduced context": 16987 16988 [deduct.type] 16989 16990 The nondeduced contexts are: 16991 16992 --A type that is a template-id in which one or more of 16993 the template-arguments is an expression that references 16994 a template-parameter. 16995 16996 In these cases, we assume deduction succeeded, but don't 16997 actually infer any unifications. */ 16998 16999 if (!uses_template_parms (parm) 17000 && !template_args_equal (parm, arg)) 17001 return unify_expression_unequal (explain_p, parm, arg); 17002 else 17003 return unify_success (explain_p); 17004 } 17005 } 17006 #undef RECUR_AND_CHECK_FAILURE 17007 17008 /* Note that DECL can be defined in this translation unit, if 17009 required. */ 17010 17011 static void 17012 mark_definable (tree decl) 17013 { 17014 tree clone; 17015 DECL_NOT_REALLY_EXTERN (decl) = 1; 17016 FOR_EACH_CLONE (clone, decl) 17017 DECL_NOT_REALLY_EXTERN (clone) = 1; 17018 } 17019 17020 /* Called if RESULT is explicitly instantiated, or is a member of an 17021 explicitly instantiated class. */ 17022 17023 void 17024 mark_decl_instantiated (tree result, int extern_p) 17025 { 17026 SET_DECL_EXPLICIT_INSTANTIATION (result); 17027 17028 /* If this entity has already been written out, it's too late to 17029 make any modifications. */ 17030 if (TREE_ASM_WRITTEN (result)) 17031 return; 17032 17033 if (TREE_CODE (result) != FUNCTION_DECL) 17034 /* The TREE_PUBLIC flag for function declarations will have been 17035 set correctly by tsubst. */ 17036 TREE_PUBLIC (result) = 1; 17037 17038 /* This might have been set by an earlier implicit instantiation. */ 17039 DECL_COMDAT (result) = 0; 17040 17041 if (extern_p) 17042 DECL_NOT_REALLY_EXTERN (result) = 0; 17043 else 17044 { 17045 mark_definable (result); 17046 /* Always make artificials weak. */ 17047 if (DECL_ARTIFICIAL (result) && flag_weak) 17048 comdat_linkage (result); 17049 /* For WIN32 we also want to put explicit instantiations in 17050 linkonce sections. */ 17051 else if (TREE_PUBLIC (result)) 17052 maybe_make_one_only (result); 17053 } 17054 17055 /* If EXTERN_P, then this function will not be emitted -- unless 17056 followed by an explicit instantiation, at which point its linkage 17057 will be adjusted. If !EXTERN_P, then this function will be 17058 emitted here. In neither circumstance do we want 17059 import_export_decl to adjust the linkage. */ 17060 DECL_INTERFACE_KNOWN (result) = 1; 17061 } 17062 17063 /* Subroutine of more_specialized_fn: check whether TARGS is missing any 17064 important template arguments. If any are missing, we check whether 17065 they're important by using error_mark_node for substituting into any 17066 args that were used for partial ordering (the ones between ARGS and END) 17067 and seeing if it bubbles up. */ 17068 17069 static bool 17070 check_undeduced_parms (tree targs, tree args, tree end) 17071 { 17072 bool found = false; 17073 int i; 17074 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i) 17075 if (TREE_VEC_ELT (targs, i) == NULL_TREE) 17076 { 17077 found = true; 17078 TREE_VEC_ELT (targs, i) = error_mark_node; 17079 } 17080 if (found) 17081 { 17082 for (; args != end; args = TREE_CHAIN (args)) 17083 { 17084 tree substed = tsubst (TREE_VALUE (args), targs, tf_none, NULL_TREE); 17085 if (substed == error_mark_node) 17086 return true; 17087 } 17088 } 17089 return false; 17090 } 17091 17092 /* Given two function templates PAT1 and PAT2, return: 17093 17094 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order]. 17095 -1 if PAT2 is more specialized than PAT1. 17096 0 if neither is more specialized. 17097 17098 LEN indicates the number of parameters we should consider 17099 (defaulted parameters should not be considered). 17100 17101 The 1998 std underspecified function template partial ordering, and 17102 DR214 addresses the issue. We take pairs of arguments, one from 17103 each of the templates, and deduce them against each other. One of 17104 the templates will be more specialized if all the *other* 17105 template's arguments deduce against its arguments and at least one 17106 of its arguments *does* *not* deduce against the other template's 17107 corresponding argument. Deduction is done as for class templates. 17108 The arguments used in deduction have reference and top level cv 17109 qualifiers removed. Iff both arguments were originally reference 17110 types *and* deduction succeeds in both directions, the template 17111 with the more cv-qualified argument wins for that pairing (if 17112 neither is more cv-qualified, they both are equal). Unlike regular 17113 deduction, after all the arguments have been deduced in this way, 17114 we do *not* verify the deduced template argument values can be 17115 substituted into non-deduced contexts. 17116 17117 The logic can be a bit confusing here, because we look at deduce1 and 17118 targs1 to see if pat2 is at least as specialized, and vice versa; if we 17119 can find template arguments for pat1 to make arg1 look like arg2, that 17120 means that arg2 is at least as specialized as arg1. */ 17121 17122 int 17123 more_specialized_fn (tree pat1, tree pat2, int len) 17124 { 17125 tree decl1 = DECL_TEMPLATE_RESULT (pat1); 17126 tree decl2 = DECL_TEMPLATE_RESULT (pat2); 17127 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1)); 17128 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2)); 17129 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1); 17130 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2); 17131 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1)); 17132 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2)); 17133 tree origs1, origs2; 17134 bool lose1 = false; 17135 bool lose2 = false; 17136 17137 /* Remove the this parameter from non-static member functions. If 17138 one is a non-static member function and the other is not a static 17139 member function, remove the first parameter from that function 17140 also. This situation occurs for operator functions where we 17141 locate both a member function (with this pointer) and non-member 17142 operator (with explicit first operand). */ 17143 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1)) 17144 { 17145 len--; /* LEN is the number of significant arguments for DECL1 */ 17146 args1 = TREE_CHAIN (args1); 17147 if (!DECL_STATIC_FUNCTION_P (decl2)) 17148 args2 = TREE_CHAIN (args2); 17149 } 17150 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2)) 17151 { 17152 args2 = TREE_CHAIN (args2); 17153 if (!DECL_STATIC_FUNCTION_P (decl1)) 17154 { 17155 len--; 17156 args1 = TREE_CHAIN (args1); 17157 } 17158 } 17159 17160 /* If only one is a conversion operator, they are unordered. */ 17161 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2)) 17162 return 0; 17163 17164 /* Consider the return type for a conversion function */ 17165 if (DECL_CONV_FN_P (decl1)) 17166 { 17167 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1); 17168 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2); 17169 len++; 17170 } 17171 17172 processing_template_decl++; 17173 17174 origs1 = args1; 17175 origs2 = args2; 17176 17177 while (len-- 17178 /* Stop when an ellipsis is seen. */ 17179 && args1 != NULL_TREE && args2 != NULL_TREE) 17180 { 17181 tree arg1 = TREE_VALUE (args1); 17182 tree arg2 = TREE_VALUE (args2); 17183 int deduce1, deduce2; 17184 int quals1 = -1; 17185 int quals2 = -1; 17186 17187 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION 17188 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION) 17189 { 17190 /* When both arguments are pack expansions, we need only 17191 unify the patterns themselves. */ 17192 arg1 = PACK_EXPANSION_PATTERN (arg1); 17193 arg2 = PACK_EXPANSION_PATTERN (arg2); 17194 17195 /* This is the last comparison we need to do. */ 17196 len = 0; 17197 } 17198 17199 if (TREE_CODE (arg1) == REFERENCE_TYPE) 17200 { 17201 arg1 = TREE_TYPE (arg1); 17202 quals1 = cp_type_quals (arg1); 17203 } 17204 17205 if (TREE_CODE (arg2) == REFERENCE_TYPE) 17206 { 17207 arg2 = TREE_TYPE (arg2); 17208 quals2 = cp_type_quals (arg2); 17209 } 17210 17211 if ((quals1 < 0) != (quals2 < 0)) 17212 { 17213 /* Only of the args is a reference, see if we should apply 17214 array/function pointer decay to it. This is not part of 17215 DR214, but is, IMHO, consistent with the deduction rules 17216 for the function call itself, and with our earlier 17217 implementation of the underspecified partial ordering 17218 rules. (nathan). */ 17219 if (quals1 >= 0) 17220 { 17221 switch (TREE_CODE (arg1)) 17222 { 17223 case ARRAY_TYPE: 17224 arg1 = TREE_TYPE (arg1); 17225 /* FALLTHROUGH. */ 17226 case FUNCTION_TYPE: 17227 arg1 = build_pointer_type (arg1); 17228 break; 17229 17230 default: 17231 break; 17232 } 17233 } 17234 else 17235 { 17236 switch (TREE_CODE (arg2)) 17237 { 17238 case ARRAY_TYPE: 17239 arg2 = TREE_TYPE (arg2); 17240 /* FALLTHROUGH. */ 17241 case FUNCTION_TYPE: 17242 arg2 = build_pointer_type (arg2); 17243 break; 17244 17245 default: 17246 break; 17247 } 17248 } 17249 } 17250 17251 arg1 = TYPE_MAIN_VARIANT (arg1); 17252 arg2 = TYPE_MAIN_VARIANT (arg2); 17253 17254 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION) 17255 { 17256 int i, len2 = list_length (args2); 17257 tree parmvec = make_tree_vec (1); 17258 tree argvec = make_tree_vec (len2); 17259 tree ta = args2; 17260 17261 /* Setup the parameter vector, which contains only ARG1. */ 17262 TREE_VEC_ELT (parmvec, 0) = arg1; 17263 17264 /* Setup the argument vector, which contains the remaining 17265 arguments. */ 17266 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta)) 17267 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta); 17268 17269 deduce1 = (unify_pack_expansion (tparms1, targs1, parmvec, 17270 argvec, DEDUCE_EXACT, 17271 /*subr=*/true, /*explain_p=*/false) 17272 == 0); 17273 17274 /* We cannot deduce in the other direction, because ARG1 is 17275 a pack expansion but ARG2 is not. */ 17276 deduce2 = 0; 17277 } 17278 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION) 17279 { 17280 int i, len1 = list_length (args1); 17281 tree parmvec = make_tree_vec (1); 17282 tree argvec = make_tree_vec (len1); 17283 tree ta = args1; 17284 17285 /* Setup the parameter vector, which contains only ARG1. */ 17286 TREE_VEC_ELT (parmvec, 0) = arg2; 17287 17288 /* Setup the argument vector, which contains the remaining 17289 arguments. */ 17290 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta)) 17291 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta); 17292 17293 deduce2 = (unify_pack_expansion (tparms2, targs2, parmvec, 17294 argvec, DEDUCE_EXACT, 17295 /*subr=*/true, /*explain_p=*/false) 17296 == 0); 17297 17298 /* We cannot deduce in the other direction, because ARG2 is 17299 a pack expansion but ARG1 is not.*/ 17300 deduce1 = 0; 17301 } 17302 17303 else 17304 { 17305 /* The normal case, where neither argument is a pack 17306 expansion. */ 17307 deduce1 = (unify (tparms1, targs1, arg1, arg2, 17308 UNIFY_ALLOW_NONE, /*explain_p=*/false) 17309 == 0); 17310 deduce2 = (unify (tparms2, targs2, arg2, arg1, 17311 UNIFY_ALLOW_NONE, /*explain_p=*/false) 17312 == 0); 17313 } 17314 17315 /* If we couldn't deduce arguments for tparms1 to make arg1 match 17316 arg2, then arg2 is not as specialized as arg1. */ 17317 if (!deduce1) 17318 lose2 = true; 17319 if (!deduce2) 17320 lose1 = true; 17321 17322 /* "If, for a given type, deduction succeeds in both directions 17323 (i.e., the types are identical after the transformations above) 17324 and if the type from the argument template is more cv-qualified 17325 than the type from the parameter template (as described above) 17326 that type is considered to be more specialized than the other. If 17327 neither type is more cv-qualified than the other then neither type 17328 is more specialized than the other." */ 17329 17330 if (deduce1 && deduce2 17331 && quals1 != quals2 && quals1 >= 0 && quals2 >= 0) 17332 { 17333 if ((quals1 & quals2) == quals2) 17334 lose2 = true; 17335 if ((quals1 & quals2) == quals1) 17336 lose1 = true; 17337 } 17338 17339 if (lose1 && lose2) 17340 /* We've failed to deduce something in either direction. 17341 These must be unordered. */ 17342 break; 17343 17344 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION 17345 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION) 17346 /* We have already processed all of the arguments in our 17347 handing of the pack expansion type. */ 17348 len = 0; 17349 17350 args1 = TREE_CHAIN (args1); 17351 args2 = TREE_CHAIN (args2); 17352 } 17353 17354 /* "In most cases, all template parameters must have values in order for 17355 deduction to succeed, but for partial ordering purposes a template 17356 parameter may remain without a value provided it is not used in the 17357 types being used for partial ordering." 17358 17359 Thus, if we are missing any of the targs1 we need to substitute into 17360 origs1, then pat2 is not as specialized as pat1. This can happen when 17361 there is a nondeduced context. */ 17362 if (!lose2 && check_undeduced_parms (targs1, origs1, args1)) 17363 lose2 = true; 17364 if (!lose1 && check_undeduced_parms (targs2, origs2, args2)) 17365 lose1 = true; 17366 17367 processing_template_decl--; 17368 17369 /* All things being equal, if the next argument is a pack expansion 17370 for one function but not for the other, prefer the 17371 non-variadic function. FIXME this is bogus; see c++/41958. */ 17372 if (lose1 == lose2 17373 && args1 && TREE_VALUE (args1) 17374 && args2 && TREE_VALUE (args2)) 17375 { 17376 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION; 17377 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION; 17378 } 17379 17380 if (lose1 == lose2) 17381 return 0; 17382 else if (!lose1) 17383 return 1; 17384 else 17385 return -1; 17386 } 17387 17388 /* Determine which of two partial specializations is more specialized. 17389 17390 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding 17391 to the first partial specialization. The TREE_VALUE is the 17392 innermost set of template parameters for the partial 17393 specialization. PAT2 is similar, but for the second template. 17394 17395 Return 1 if the first partial specialization is more specialized; 17396 -1 if the second is more specialized; 0 if neither is more 17397 specialized. 17398 17399 See [temp.class.order] for information about determining which of 17400 two templates is more specialized. */ 17401 17402 static int 17403 more_specialized_class (tree pat1, tree pat2) 17404 { 17405 tree targs; 17406 tree tmpl1, tmpl2; 17407 int winner = 0; 17408 bool any_deductions = false; 17409 17410 tmpl1 = TREE_TYPE (pat1); 17411 tmpl2 = TREE_TYPE (pat2); 17412 17413 /* Just like what happens for functions, if we are ordering between 17414 different class template specializations, we may encounter dependent 17415 types in the arguments, and we need our dependency check functions 17416 to behave correctly. */ 17417 ++processing_template_decl; 17418 targs = get_class_bindings (TREE_VALUE (pat1), 17419 CLASSTYPE_TI_ARGS (tmpl1), 17420 CLASSTYPE_TI_ARGS (tmpl2)); 17421 if (targs) 17422 { 17423 --winner; 17424 any_deductions = true; 17425 } 17426 17427 targs = get_class_bindings (TREE_VALUE (pat2), 17428 CLASSTYPE_TI_ARGS (tmpl2), 17429 CLASSTYPE_TI_ARGS (tmpl1)); 17430 if (targs) 17431 { 17432 ++winner; 17433 any_deductions = true; 17434 } 17435 --processing_template_decl; 17436 17437 /* In the case of a tie where at least one of the class templates 17438 has a parameter pack at the end, the template with the most 17439 non-packed parameters wins. */ 17440 if (winner == 0 17441 && any_deductions 17442 && (template_args_variadic_p (TREE_PURPOSE (pat1)) 17443 || template_args_variadic_p (TREE_PURPOSE (pat2)))) 17444 { 17445 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1)); 17446 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2)); 17447 int len1 = TREE_VEC_LENGTH (args1); 17448 int len2 = TREE_VEC_LENGTH (args2); 17449 17450 /* We don't count the pack expansion at the end. */ 17451 if (template_args_variadic_p (TREE_PURPOSE (pat1))) 17452 --len1; 17453 if (template_args_variadic_p (TREE_PURPOSE (pat2))) 17454 --len2; 17455 17456 if (len1 > len2) 17457 return 1; 17458 else if (len1 < len2) 17459 return -1; 17460 } 17461 17462 return winner; 17463 } 17464 17465 /* Return the template arguments that will produce the function signature 17466 DECL from the function template FN, with the explicit template 17467 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must 17468 also match. Return NULL_TREE if no satisfactory arguments could be 17469 found. */ 17470 17471 static tree 17472 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype) 17473 { 17474 int ntparms = DECL_NTPARMS (fn); 17475 tree targs = make_tree_vec (ntparms); 17476 tree decl_type; 17477 tree decl_arg_types; 17478 tree *args; 17479 unsigned int nargs, ix; 17480 tree arg; 17481 17482 /* Substitute the explicit template arguments into the type of DECL. 17483 The call to fn_type_unification will handle substitution into the 17484 FN. */ 17485 decl_type = TREE_TYPE (decl); 17486 if (explicit_args && uses_template_parms (decl_type)) 17487 { 17488 tree tmpl; 17489 tree converted_args; 17490 17491 if (DECL_TEMPLATE_INFO (decl)) 17492 tmpl = DECL_TI_TEMPLATE (decl); 17493 else 17494 /* We can get here for some invalid specializations. */ 17495 return NULL_TREE; 17496 17497 converted_args 17498 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl), 17499 explicit_args, NULL_TREE, 17500 tf_none, 17501 /*require_all_args=*/false, 17502 /*use_default_args=*/false); 17503 if (converted_args == error_mark_node) 17504 return NULL_TREE; 17505 17506 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE); 17507 if (decl_type == error_mark_node) 17508 return NULL_TREE; 17509 } 17510 17511 /* Never do unification on the 'this' parameter. */ 17512 decl_arg_types = skip_artificial_parms_for (decl, 17513 TYPE_ARG_TYPES (decl_type)); 17514 17515 nargs = list_length (decl_arg_types); 17516 args = XALLOCAVEC (tree, nargs); 17517 for (arg = decl_arg_types, ix = 0; 17518 arg != NULL_TREE && arg != void_list_node; 17519 arg = TREE_CHAIN (arg), ++ix) 17520 args[ix] = TREE_VALUE (arg); 17521 17522 if (fn_type_unification (fn, explicit_args, targs, 17523 args, ix, 17524 (check_rettype || DECL_CONV_FN_P (fn) 17525 ? TREE_TYPE (decl_type) : NULL_TREE), 17526 DEDUCE_EXACT, LOOKUP_NORMAL, /*explain_p=*/false)) 17527 return NULL_TREE; 17528 17529 return targs; 17530 } 17531 17532 /* Return the innermost template arguments that, when applied to a 17533 template specialization whose innermost template parameters are 17534 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the 17535 ARGS. 17536 17537 For example, suppose we have: 17538 17539 template <class T, class U> struct S {}; 17540 template <class T> struct S<T*, int> {}; 17541 17542 Then, suppose we want to get `S<double*, int>'. The TPARMS will be 17543 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*, 17544 int}. The resulting vector will be {double}, indicating that `T' 17545 is bound to `double'. */ 17546 17547 static tree 17548 get_class_bindings (tree tparms, tree spec_args, tree args) 17549 { 17550 int i, ntparms = TREE_VEC_LENGTH (tparms); 17551 tree deduced_args; 17552 tree innermost_deduced_args; 17553 17554 innermost_deduced_args = make_tree_vec (ntparms); 17555 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args)) 17556 { 17557 deduced_args = copy_node (args); 17558 SET_TMPL_ARGS_LEVEL (deduced_args, 17559 TMPL_ARGS_DEPTH (deduced_args), 17560 innermost_deduced_args); 17561 } 17562 else 17563 deduced_args = innermost_deduced_args; 17564 17565 if (unify (tparms, deduced_args, 17566 INNERMOST_TEMPLATE_ARGS (spec_args), 17567 INNERMOST_TEMPLATE_ARGS (args), 17568 UNIFY_ALLOW_NONE, /*explain_p=*/false)) 17569 return NULL_TREE; 17570 17571 for (i = 0; i < ntparms; ++i) 17572 if (! TREE_VEC_ELT (innermost_deduced_args, i)) 17573 return NULL_TREE; 17574 17575 /* Verify that nondeduced template arguments agree with the type 17576 obtained from argument deduction. 17577 17578 For example: 17579 17580 struct A { typedef int X; }; 17581 template <class T, class U> struct C {}; 17582 template <class T> struct C<T, typename T::X> {}; 17583 17584 Then with the instantiation `C<A, int>', we can deduce that 17585 `T' is `A' but unify () does not check whether `typename T::X' 17586 is `int'. */ 17587 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE); 17588 if (spec_args == error_mark_node 17589 /* We only need to check the innermost arguments; the other 17590 arguments will always agree. */ 17591 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args), 17592 INNERMOST_TEMPLATE_ARGS (args))) 17593 return NULL_TREE; 17594 17595 /* Now that we have bindings for all of the template arguments, 17596 ensure that the arguments deduced for the template template 17597 parameters have compatible template parameter lists. See the use 17598 of template_template_parm_bindings_ok_p in fn_type_unification 17599 for more information. */ 17600 if (!template_template_parm_bindings_ok_p (tparms, deduced_args)) 17601 return NULL_TREE; 17602 17603 return deduced_args; 17604 } 17605 17606 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL. 17607 Return the TREE_LIST node with the most specialized template, if 17608 any. If there is no most specialized template, the error_mark_node 17609 is returned. 17610 17611 Note that this function does not look at, or modify, the 17612 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node 17613 returned is one of the elements of INSTANTIATIONS, callers may 17614 store information in the TREE_PURPOSE or TREE_TYPE of the nodes, 17615 and retrieve it from the value returned. */ 17616 17617 tree 17618 most_specialized_instantiation (tree templates) 17619 { 17620 tree fn, champ; 17621 17622 ++processing_template_decl; 17623 17624 champ = templates; 17625 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn)) 17626 { 17627 int fate = 0; 17628 17629 if (get_bindings (TREE_VALUE (champ), 17630 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)), 17631 NULL_TREE, /*check_ret=*/true)) 17632 fate--; 17633 17634 if (get_bindings (TREE_VALUE (fn), 17635 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)), 17636 NULL_TREE, /*check_ret=*/true)) 17637 fate++; 17638 17639 if (fate == -1) 17640 champ = fn; 17641 else if (!fate) 17642 { 17643 /* Equally specialized, move to next function. If there 17644 is no next function, nothing's most specialized. */ 17645 fn = TREE_CHAIN (fn); 17646 champ = fn; 17647 if (!fn) 17648 break; 17649 } 17650 } 17651 17652 if (champ) 17653 /* Now verify that champ is better than everything earlier in the 17654 instantiation list. */ 17655 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn)) 17656 if (get_bindings (TREE_VALUE (champ), 17657 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)), 17658 NULL_TREE, /*check_ret=*/true) 17659 || !get_bindings (TREE_VALUE (fn), 17660 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)), 17661 NULL_TREE, /*check_ret=*/true)) 17662 { 17663 champ = NULL_TREE; 17664 break; 17665 } 17666 17667 processing_template_decl--; 17668 17669 if (!champ) 17670 return error_mark_node; 17671 17672 return champ; 17673 } 17674 17675 /* If DECL is a specialization of some template, return the most 17676 general such template. Otherwise, returns NULL_TREE. 17677 17678 For example, given: 17679 17680 template <class T> struct S { template <class U> void f(U); }; 17681 17682 if TMPL is `template <class U> void S<int>::f(U)' this will return 17683 the full template. This function will not trace past partial 17684 specializations, however. For example, given in addition: 17685 17686 template <class T> struct S<T*> { template <class U> void f(U); }; 17687 17688 if TMPL is `template <class U> void S<int*>::f(U)' this will return 17689 `template <class T> template <class U> S<T*>::f(U)'. */ 17690 17691 tree 17692 most_general_template (tree decl) 17693 { 17694 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is 17695 an immediate specialization. */ 17696 if (TREE_CODE (decl) == FUNCTION_DECL) 17697 { 17698 if (DECL_TEMPLATE_INFO (decl)) { 17699 decl = DECL_TI_TEMPLATE (decl); 17700 17701 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a 17702 template friend. */ 17703 if (TREE_CODE (decl) != TEMPLATE_DECL) 17704 return NULL_TREE; 17705 } else 17706 return NULL_TREE; 17707 } 17708 17709 /* Look for more and more general templates. */ 17710 while (DECL_TEMPLATE_INFO (decl)) 17711 { 17712 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases. 17713 (See cp-tree.h for details.) */ 17714 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL) 17715 break; 17716 17717 if (CLASS_TYPE_P (TREE_TYPE (decl)) 17718 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl))) 17719 break; 17720 17721 /* Stop if we run into an explicitly specialized class template. */ 17722 if (!DECL_NAMESPACE_SCOPE_P (decl) 17723 && DECL_CONTEXT (decl) 17724 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl))) 17725 break; 17726 17727 decl = DECL_TI_TEMPLATE (decl); 17728 } 17729 17730 return decl; 17731 } 17732 17733 /* Return the most specialized of the class template partial 17734 specializations of TMPL which can produce TYPE, a specialization of 17735 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is 17736 a _TYPE node corresponding to the partial specialization, while the 17737 TREE_PURPOSE is the set of template arguments that must be 17738 substituted into the TREE_TYPE in order to generate TYPE. 17739 17740 If the choice of partial specialization is ambiguous, a diagnostic 17741 is issued, and the error_mark_node is returned. If there are no 17742 partial specializations of TMPL matching TYPE, then NULL_TREE is 17743 returned. */ 17744 17745 static tree 17746 most_specialized_class (tree type, tree tmpl, tsubst_flags_t complain) 17747 { 17748 tree list = NULL_TREE; 17749 tree t; 17750 tree champ; 17751 int fate; 17752 bool ambiguous_p; 17753 tree args; 17754 tree outer_args = NULL_TREE; 17755 17756 tmpl = most_general_template (tmpl); 17757 args = CLASSTYPE_TI_ARGS (type); 17758 17759 /* For determining which partial specialization to use, only the 17760 innermost args are interesting. */ 17761 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args)) 17762 { 17763 outer_args = strip_innermost_template_args (args, 1); 17764 args = INNERMOST_TEMPLATE_ARGS (args); 17765 } 17766 17767 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t)) 17768 { 17769 tree partial_spec_args; 17770 tree spec_args; 17771 tree parms = TREE_VALUE (t); 17772 17773 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t)); 17774 17775 ++processing_template_decl; 17776 17777 if (outer_args) 17778 { 17779 int i; 17780 17781 /* Discard the outer levels of args, and then substitute in the 17782 template args from the enclosing class. */ 17783 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args); 17784 partial_spec_args = tsubst_template_args 17785 (partial_spec_args, outer_args, tf_none, NULL_TREE); 17786 17787 /* PARMS already refers to just the innermost parms, but the 17788 template parms in partial_spec_args had their levels lowered 17789 by tsubst, so we need to do the same for the parm list. We 17790 can't just tsubst the TREE_VEC itself, as tsubst wants to 17791 treat a TREE_VEC as an argument vector. */ 17792 parms = copy_node (parms); 17793 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i) 17794 TREE_VEC_ELT (parms, i) = 17795 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE); 17796 17797 } 17798 17799 partial_spec_args = 17800 coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl), 17801 add_to_template_args (outer_args, 17802 partial_spec_args), 17803 tmpl, tf_none, 17804 /*require_all_args=*/true, 17805 /*use_default_args=*/true); 17806 17807 --processing_template_decl; 17808 17809 if (partial_spec_args == error_mark_node) 17810 return error_mark_node; 17811 17812 spec_args = get_class_bindings (parms, 17813 partial_spec_args, 17814 args); 17815 if (spec_args) 17816 { 17817 if (outer_args) 17818 spec_args = add_to_template_args (outer_args, spec_args); 17819 list = tree_cons (spec_args, TREE_VALUE (t), list); 17820 TREE_TYPE (list) = TREE_TYPE (t); 17821 } 17822 } 17823 17824 if (! list) 17825 return NULL_TREE; 17826 17827 ambiguous_p = false; 17828 t = list; 17829 champ = t; 17830 t = TREE_CHAIN (t); 17831 for (; t; t = TREE_CHAIN (t)) 17832 { 17833 fate = more_specialized_class (champ, t); 17834 if (fate == 1) 17835 ; 17836 else 17837 { 17838 if (fate == 0) 17839 { 17840 t = TREE_CHAIN (t); 17841 if (! t) 17842 { 17843 ambiguous_p = true; 17844 break; 17845 } 17846 } 17847 champ = t; 17848 } 17849 } 17850 17851 if (!ambiguous_p) 17852 for (t = list; t && t != champ; t = TREE_CHAIN (t)) 17853 { 17854 fate = more_specialized_class (champ, t); 17855 if (fate != 1) 17856 { 17857 ambiguous_p = true; 17858 break; 17859 } 17860 } 17861 17862 if (ambiguous_p) 17863 { 17864 const char *str; 17865 char *spaces = NULL; 17866 if (!(complain & tf_error)) 17867 return error_mark_node; 17868 error ("ambiguous class template instantiation for %q#T", type); 17869 str = ngettext ("candidate is:", "candidates are:", list_length (list)); 17870 for (t = list; t; t = TREE_CHAIN (t)) 17871 { 17872 error ("%s %+#T", spaces ? spaces : str, TREE_TYPE (t)); 17873 spaces = spaces ? spaces : get_spaces (str); 17874 } 17875 free (spaces); 17876 return error_mark_node; 17877 } 17878 17879 return champ; 17880 } 17881 17882 /* Explicitly instantiate DECL. */ 17883 17884 void 17885 do_decl_instantiation (tree decl, tree storage) 17886 { 17887 tree result = NULL_TREE; 17888 int extern_p = 0; 17889 17890 if (!decl || decl == error_mark_node) 17891 /* An error occurred, for which grokdeclarator has already issued 17892 an appropriate message. */ 17893 return; 17894 else if (! DECL_LANG_SPECIFIC (decl)) 17895 { 17896 error ("explicit instantiation of non-template %q#D", decl); 17897 return; 17898 } 17899 else if (TREE_CODE (decl) == VAR_DECL) 17900 { 17901 /* There is an asymmetry here in the way VAR_DECLs and 17902 FUNCTION_DECLs are handled by grokdeclarator. In the case of 17903 the latter, the DECL we get back will be marked as a 17904 template instantiation, and the appropriate 17905 DECL_TEMPLATE_INFO will be set up. This does not happen for 17906 VAR_DECLs so we do the lookup here. Probably, grokdeclarator 17907 should handle VAR_DECLs as it currently handles 17908 FUNCTION_DECLs. */ 17909 if (!DECL_CLASS_SCOPE_P (decl)) 17910 { 17911 error ("%qD is not a static data member of a class template", decl); 17912 return; 17913 } 17914 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false); 17915 if (!result || TREE_CODE (result) != VAR_DECL) 17916 { 17917 error ("no matching template for %qD found", decl); 17918 return; 17919 } 17920 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl))) 17921 { 17922 error ("type %qT for explicit instantiation %qD does not match " 17923 "declared type %qT", TREE_TYPE (result), decl, 17924 TREE_TYPE (decl)); 17925 return; 17926 } 17927 } 17928 else if (TREE_CODE (decl) != FUNCTION_DECL) 17929 { 17930 error ("explicit instantiation of %q#D", decl); 17931 return; 17932 } 17933 else 17934 result = decl; 17935 17936 /* Check for various error cases. Note that if the explicit 17937 instantiation is valid the RESULT will currently be marked as an 17938 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set 17939 until we get here. */ 17940 17941 if (DECL_TEMPLATE_SPECIALIZATION (result)) 17942 { 17943 /* DR 259 [temp.spec]. 17944 17945 Both an explicit instantiation and a declaration of an explicit 17946 specialization shall not appear in a program unless the explicit 17947 instantiation follows a declaration of the explicit specialization. 17948 17949 For a given set of template parameters, if an explicit 17950 instantiation of a template appears after a declaration of an 17951 explicit specialization for that template, the explicit 17952 instantiation has no effect. */ 17953 return; 17954 } 17955 else if (DECL_EXPLICIT_INSTANTIATION (result)) 17956 { 17957 /* [temp.spec] 17958 17959 No program shall explicitly instantiate any template more 17960 than once. 17961 17962 We check DECL_NOT_REALLY_EXTERN so as not to complain when 17963 the first instantiation was `extern' and the second is not, 17964 and EXTERN_P for the opposite case. */ 17965 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p) 17966 permerror (input_location, "duplicate explicit instantiation of %q#D", result); 17967 /* If an "extern" explicit instantiation follows an ordinary 17968 explicit instantiation, the template is instantiated. */ 17969 if (extern_p) 17970 return; 17971 } 17972 else if (!DECL_IMPLICIT_INSTANTIATION (result)) 17973 { 17974 error ("no matching template for %qD found", result); 17975 return; 17976 } 17977 else if (!DECL_TEMPLATE_INFO (result)) 17978 { 17979 permerror (input_location, "explicit instantiation of non-template %q#D", result); 17980 return; 17981 } 17982 17983 if (storage == NULL_TREE) 17984 ; 17985 else if (storage == ridpointers[(int) RID_EXTERN]) 17986 { 17987 if (!in_system_header && (cxx_dialect == cxx98)) 17988 pedwarn (input_location, OPT_pedantic, 17989 "ISO C++ 1998 forbids the use of %<extern%> on explicit " 17990 "instantiations"); 17991 extern_p = 1; 17992 } 17993 else 17994 error ("storage class %qD applied to template instantiation", storage); 17995 17996 check_explicit_instantiation_namespace (result); 17997 mark_decl_instantiated (result, extern_p); 17998 if (! extern_p) 17999 instantiate_decl (result, /*defer_ok=*/1, 18000 /*expl_inst_class_mem_p=*/false); 18001 } 18002 18003 static void 18004 mark_class_instantiated (tree t, int extern_p) 18005 { 18006 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t); 18007 SET_CLASSTYPE_INTERFACE_KNOWN (t); 18008 CLASSTYPE_INTERFACE_ONLY (t) = extern_p; 18009 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p; 18010 if (! extern_p) 18011 { 18012 CLASSTYPE_DEBUG_REQUESTED (t) = 1; 18013 rest_of_type_compilation (t, 1); 18014 } 18015 } 18016 18017 /* Called from do_type_instantiation through binding_table_foreach to 18018 do recursive instantiation for the type bound in ENTRY. */ 18019 static void 18020 bt_instantiate_type_proc (binding_entry entry, void *data) 18021 { 18022 tree storage = *(tree *) data; 18023 18024 if (MAYBE_CLASS_TYPE_P (entry->type) 18025 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type))) 18026 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0); 18027 } 18028 18029 /* Called from do_type_instantiation to instantiate a member 18030 (a member function or a static member variable) of an 18031 explicitly instantiated class template. */ 18032 static void 18033 instantiate_class_member (tree decl, int extern_p) 18034 { 18035 mark_decl_instantiated (decl, extern_p); 18036 if (! extern_p) 18037 instantiate_decl (decl, /*defer_ok=*/1, 18038 /*expl_inst_class_mem_p=*/true); 18039 } 18040 18041 /* Perform an explicit instantiation of template class T. STORAGE, if 18042 non-null, is the RID for extern, inline or static. COMPLAIN is 18043 nonzero if this is called from the parser, zero if called recursively, 18044 since the standard is unclear (as detailed below). */ 18045 18046 void 18047 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain) 18048 { 18049 int extern_p = 0; 18050 int nomem_p = 0; 18051 int static_p = 0; 18052 int previous_instantiation_extern_p = 0; 18053 18054 if (TREE_CODE (t) == TYPE_DECL) 18055 t = TREE_TYPE (t); 18056 18057 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t)) 18058 { 18059 tree tmpl = 18060 (TYPE_TEMPLATE_INFO (t)) ? TYPE_TI_TEMPLATE (t) : NULL; 18061 if (tmpl) 18062 error ("explicit instantiation of non-class template %qD", tmpl); 18063 else 18064 error ("explicit instantiation of non-template type %qT", t); 18065 return; 18066 } 18067 18068 complete_type (t); 18069 18070 if (!COMPLETE_TYPE_P (t)) 18071 { 18072 if (complain & tf_error) 18073 error ("explicit instantiation of %q#T before definition of template", 18074 t); 18075 return; 18076 } 18077 18078 if (storage != NULL_TREE) 18079 { 18080 if (!in_system_header) 18081 { 18082 if (storage == ridpointers[(int) RID_EXTERN]) 18083 { 18084 if (cxx_dialect == cxx98) 18085 pedwarn (input_location, OPT_pedantic, 18086 "ISO C++ 1998 forbids the use of %<extern%> on " 18087 "explicit instantiations"); 18088 } 18089 else 18090 pedwarn (input_location, OPT_pedantic, 18091 "ISO C++ forbids the use of %qE" 18092 " on explicit instantiations", storage); 18093 } 18094 18095 if (storage == ridpointers[(int) RID_INLINE]) 18096 nomem_p = 1; 18097 else if (storage == ridpointers[(int) RID_EXTERN]) 18098 extern_p = 1; 18099 else if (storage == ridpointers[(int) RID_STATIC]) 18100 static_p = 1; 18101 else 18102 { 18103 error ("storage class %qD applied to template instantiation", 18104 storage); 18105 extern_p = 0; 18106 } 18107 } 18108 18109 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t)) 18110 { 18111 /* DR 259 [temp.spec]. 18112 18113 Both an explicit instantiation and a declaration of an explicit 18114 specialization shall not appear in a program unless the explicit 18115 instantiation follows a declaration of the explicit specialization. 18116 18117 For a given set of template parameters, if an explicit 18118 instantiation of a template appears after a declaration of an 18119 explicit specialization for that template, the explicit 18120 instantiation has no effect. */ 18121 return; 18122 } 18123 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t)) 18124 { 18125 /* [temp.spec] 18126 18127 No program shall explicitly instantiate any template more 18128 than once. 18129 18130 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit 18131 instantiation was `extern'. If EXTERN_P then the second is. 18132 These cases are OK. */ 18133 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t); 18134 18135 if (!previous_instantiation_extern_p && !extern_p 18136 && (complain & tf_error)) 18137 permerror (input_location, "duplicate explicit instantiation of %q#T", t); 18138 18139 /* If we've already instantiated the template, just return now. */ 18140 if (!CLASSTYPE_INTERFACE_ONLY (t)) 18141 return; 18142 } 18143 18144 check_explicit_instantiation_namespace (TYPE_NAME (t)); 18145 mark_class_instantiated (t, extern_p); 18146 18147 if (nomem_p) 18148 return; 18149 18150 { 18151 tree tmp; 18152 18153 /* In contrast to implicit instantiation, where only the 18154 declarations, and not the definitions, of members are 18155 instantiated, we have here: 18156 18157 [temp.explicit] 18158 18159 The explicit instantiation of a class template specialization 18160 implies the instantiation of all of its members not 18161 previously explicitly specialized in the translation unit 18162 containing the explicit instantiation. 18163 18164 Of course, we can't instantiate member template classes, since 18165 we don't have any arguments for them. Note that the standard 18166 is unclear on whether the instantiation of the members are 18167 *explicit* instantiations or not. However, the most natural 18168 interpretation is that it should be an explicit instantiation. */ 18169 18170 if (! static_p) 18171 for (tmp = TYPE_METHODS (t); tmp; tmp = DECL_CHAIN (tmp)) 18172 if (TREE_CODE (tmp) == FUNCTION_DECL 18173 && DECL_TEMPLATE_INSTANTIATION (tmp)) 18174 instantiate_class_member (tmp, extern_p); 18175 18176 for (tmp = TYPE_FIELDS (t); tmp; tmp = DECL_CHAIN (tmp)) 18177 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp)) 18178 instantiate_class_member (tmp, extern_p); 18179 18180 if (CLASSTYPE_NESTED_UTDS (t)) 18181 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t), 18182 bt_instantiate_type_proc, &storage); 18183 } 18184 } 18185 18186 /* Given a function DECL, which is a specialization of TMPL, modify 18187 DECL to be a re-instantiation of TMPL with the same template 18188 arguments. TMPL should be the template into which tsubst'ing 18189 should occur for DECL, not the most general template. 18190 18191 One reason for doing this is a scenario like this: 18192 18193 template <class T> 18194 void f(const T&, int i); 18195 18196 void g() { f(3, 7); } 18197 18198 template <class T> 18199 void f(const T& t, const int i) { } 18200 18201 Note that when the template is first instantiated, with 18202 instantiate_template, the resulting DECL will have no name for the 18203 first parameter, and the wrong type for the second. So, when we go 18204 to instantiate the DECL, we regenerate it. */ 18205 18206 static void 18207 regenerate_decl_from_template (tree decl, tree tmpl) 18208 { 18209 /* The arguments used to instantiate DECL, from the most general 18210 template. */ 18211 tree args; 18212 tree code_pattern; 18213 18214 args = DECL_TI_ARGS (decl); 18215 code_pattern = DECL_TEMPLATE_RESULT (tmpl); 18216 18217 /* Make sure that we can see identifiers, and compute access 18218 correctly. */ 18219 push_access_scope (decl); 18220 18221 if (TREE_CODE (decl) == FUNCTION_DECL) 18222 { 18223 tree decl_parm; 18224 tree pattern_parm; 18225 tree specs; 18226 int args_depth; 18227 int parms_depth; 18228 18229 args_depth = TMPL_ARGS_DEPTH (args); 18230 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)); 18231 if (args_depth > parms_depth) 18232 args = get_innermost_template_args (args, parms_depth); 18233 18234 specs = tsubst_exception_specification (TREE_TYPE (code_pattern), 18235 args, tf_error, NULL_TREE, 18236 /*defer_ok*/false); 18237 if (specs && specs != error_mark_node) 18238 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl), 18239 specs); 18240 18241 /* Merge parameter declarations. */ 18242 decl_parm = skip_artificial_parms_for (decl, 18243 DECL_ARGUMENTS (decl)); 18244 pattern_parm 18245 = skip_artificial_parms_for (code_pattern, 18246 DECL_ARGUMENTS (code_pattern)); 18247 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm)) 18248 { 18249 tree parm_type; 18250 tree attributes; 18251 18252 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm)) 18253 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm); 18254 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error, 18255 NULL_TREE); 18256 parm_type = type_decays_to (parm_type); 18257 if (!same_type_p (TREE_TYPE (decl_parm), parm_type)) 18258 TREE_TYPE (decl_parm) = parm_type; 18259 attributes = DECL_ATTRIBUTES (pattern_parm); 18260 if (DECL_ATTRIBUTES (decl_parm) != attributes) 18261 { 18262 DECL_ATTRIBUTES (decl_parm) = attributes; 18263 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0); 18264 } 18265 decl_parm = DECL_CHAIN (decl_parm); 18266 pattern_parm = DECL_CHAIN (pattern_parm); 18267 } 18268 /* Merge any parameters that match with the function parameter 18269 pack. */ 18270 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm)) 18271 { 18272 int i, len; 18273 tree expanded_types; 18274 /* Expand the TYPE_PACK_EXPANSION that provides the types for 18275 the parameters in this function parameter pack. */ 18276 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm), 18277 args, tf_error, NULL_TREE); 18278 len = TREE_VEC_LENGTH (expanded_types); 18279 for (i = 0; i < len; i++) 18280 { 18281 tree parm_type; 18282 tree attributes; 18283 18284 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm)) 18285 /* Rename the parameter to include the index. */ 18286 DECL_NAME (decl_parm) = 18287 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i); 18288 parm_type = TREE_VEC_ELT (expanded_types, i); 18289 parm_type = type_decays_to (parm_type); 18290 if (!same_type_p (TREE_TYPE (decl_parm), parm_type)) 18291 TREE_TYPE (decl_parm) = parm_type; 18292 attributes = DECL_ATTRIBUTES (pattern_parm); 18293 if (DECL_ATTRIBUTES (decl_parm) != attributes) 18294 { 18295 DECL_ATTRIBUTES (decl_parm) = attributes; 18296 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0); 18297 } 18298 decl_parm = DECL_CHAIN (decl_parm); 18299 } 18300 } 18301 /* Merge additional specifiers from the CODE_PATTERN. */ 18302 if (DECL_DECLARED_INLINE_P (code_pattern) 18303 && !DECL_DECLARED_INLINE_P (decl)) 18304 DECL_DECLARED_INLINE_P (decl) = 1; 18305 } 18306 else if (TREE_CODE (decl) == VAR_DECL) 18307 { 18308 DECL_INITIAL (decl) = 18309 tsubst_expr (DECL_INITIAL (code_pattern), args, 18310 tf_error, DECL_TI_TEMPLATE (decl), 18311 /*integral_constant_expression_p=*/false); 18312 if (VAR_HAD_UNKNOWN_BOUND (decl)) 18313 TREE_TYPE (decl) = tsubst (TREE_TYPE (code_pattern), args, 18314 tf_error, DECL_TI_TEMPLATE (decl)); 18315 } 18316 else 18317 gcc_unreachable (); 18318 18319 pop_access_scope (decl); 18320 } 18321 18322 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be 18323 substituted to get DECL. */ 18324 18325 tree 18326 template_for_substitution (tree decl) 18327 { 18328 tree tmpl = DECL_TI_TEMPLATE (decl); 18329 18330 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern 18331 for the instantiation. This is not always the most general 18332 template. Consider, for example: 18333 18334 template <class T> 18335 struct S { template <class U> void f(); 18336 template <> void f<int>(); }; 18337 18338 and an instantiation of S<double>::f<int>. We want TD to be the 18339 specialization S<T>::f<int>, not the more general S<T>::f<U>. */ 18340 while (/* An instantiation cannot have a definition, so we need a 18341 more general template. */ 18342 DECL_TEMPLATE_INSTANTIATION (tmpl) 18343 /* We must also deal with friend templates. Given: 18344 18345 template <class T> struct S { 18346 template <class U> friend void f() {}; 18347 }; 18348 18349 S<int>::f<U> say, is not an instantiation of S<T>::f<U>, 18350 so far as the language is concerned, but that's still 18351 where we get the pattern for the instantiation from. On 18352 other hand, if the definition comes outside the class, say: 18353 18354 template <class T> struct S { 18355 template <class U> friend void f(); 18356 }; 18357 template <class U> friend void f() {} 18358 18359 we don't need to look any further. That's what the check for 18360 DECL_INITIAL is for. */ 18361 || (TREE_CODE (decl) == FUNCTION_DECL 18362 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl) 18363 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl)))) 18364 { 18365 /* The present template, TD, should not be a definition. If it 18366 were a definition, we should be using it! Note that we 18367 cannot restructure the loop to just keep going until we find 18368 a template with a definition, since that might go too far if 18369 a specialization was declared, but not defined. */ 18370 gcc_assert (TREE_CODE (decl) != VAR_DECL 18371 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl))); 18372 18373 /* Fetch the more general template. */ 18374 tmpl = DECL_TI_TEMPLATE (tmpl); 18375 } 18376 18377 return tmpl; 18378 } 18379 18380 /* Returns true if we need to instantiate this template instance even if we 18381 know we aren't going to emit it.. */ 18382 18383 bool 18384 always_instantiate_p (tree decl) 18385 { 18386 /* We always instantiate inline functions so that we can inline them. An 18387 explicit instantiation declaration prohibits implicit instantiation of 18388 non-inline functions. With high levels of optimization, we would 18389 normally inline non-inline functions -- but we're not allowed to do 18390 that for "extern template" functions. Therefore, we check 18391 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */ 18392 return ((TREE_CODE (decl) == FUNCTION_DECL 18393 && DECL_DECLARED_INLINE_P (decl)) 18394 /* And we need to instantiate static data members so that 18395 their initializers are available in integral constant 18396 expressions. */ 18397 || (TREE_CODE (decl) == VAR_DECL 18398 && decl_maybe_constant_var_p (decl))); 18399 } 18400 18401 /* If FN has a noexcept-specifier that hasn't been instantiated yet, 18402 instantiate it now, modifying TREE_TYPE (fn). */ 18403 18404 void 18405 maybe_instantiate_noexcept (tree fn) 18406 { 18407 tree fntype, spec, noex, clone; 18408 18409 if (DECL_CLONED_FUNCTION_P (fn)) 18410 fn = DECL_CLONED_FUNCTION (fn); 18411 fntype = TREE_TYPE (fn); 18412 spec = TYPE_RAISES_EXCEPTIONS (fntype); 18413 18414 if (!DEFERRED_NOEXCEPT_SPEC_P (spec)) 18415 return; 18416 18417 noex = TREE_PURPOSE (spec); 18418 18419 if (TREE_CODE (noex) == DEFERRED_NOEXCEPT) 18420 { 18421 if (push_tinst_level (fn)) 18422 { 18423 push_access_scope (fn); 18424 input_location = DECL_SOURCE_LOCATION (fn); 18425 noex = tsubst_copy_and_build (DEFERRED_NOEXCEPT_PATTERN (noex), 18426 DEFERRED_NOEXCEPT_ARGS (noex), 18427 tf_warning_or_error, fn, 18428 /*function_p=*/false, 18429 /*integral_constant_expression_p=*/true); 18430 pop_access_scope (fn); 18431 pop_tinst_level (); 18432 spec = build_noexcept_spec (noex, tf_warning_or_error); 18433 if (spec == error_mark_node) 18434 spec = noexcept_false_spec; 18435 } 18436 else 18437 spec = noexcept_false_spec; 18438 } 18439 else 18440 { 18441 /* This is an implicitly declared function, so NOEX is a list of 18442 other functions to evaluate and merge. */ 18443 tree elt; 18444 spec = noexcept_true_spec; 18445 for (elt = noex; elt; elt = OVL_NEXT (elt)) 18446 { 18447 tree fn = OVL_CURRENT (elt); 18448 tree subspec; 18449 maybe_instantiate_noexcept (fn); 18450 subspec = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn)); 18451 spec = merge_exception_specifiers (spec, subspec, NULL_TREE); 18452 } 18453 } 18454 18455 TREE_TYPE (fn) = build_exception_variant (fntype, spec); 18456 18457 FOR_EACH_CLONE (clone, fn) 18458 { 18459 if (TREE_TYPE (clone) == fntype) 18460 TREE_TYPE (clone) = TREE_TYPE (fn); 18461 else 18462 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), spec); 18463 } 18464 } 18465 18466 /* Produce the definition of D, a _DECL generated from a template. If 18467 DEFER_OK is nonzero, then we don't have to actually do the 18468 instantiation now; we just have to do it sometime. Normally it is 18469 an error if this is an explicit instantiation but D is undefined. 18470 EXPL_INST_CLASS_MEM_P is true iff D is a member of an 18471 explicitly instantiated class template. */ 18472 18473 tree 18474 instantiate_decl (tree d, int defer_ok, 18475 bool expl_inst_class_mem_p) 18476 { 18477 tree tmpl = DECL_TI_TEMPLATE (d); 18478 tree gen_args; 18479 tree args; 18480 tree td; 18481 tree code_pattern; 18482 tree spec; 18483 tree gen_tmpl; 18484 bool pattern_defined; 18485 location_t saved_loc = input_location; 18486 bool external_p; 18487 tree fn_context; 18488 bool nested; 18489 18490 /* This function should only be used to instantiate templates for 18491 functions and static member variables. */ 18492 gcc_assert (TREE_CODE (d) == FUNCTION_DECL 18493 || TREE_CODE (d) == VAR_DECL); 18494 18495 /* Variables are never deferred; if instantiation is required, they 18496 are instantiated right away. That allows for better code in the 18497 case that an expression refers to the value of the variable -- 18498 if the variable has a constant value the referring expression can 18499 take advantage of that fact. */ 18500 if (TREE_CODE (d) == VAR_DECL 18501 || DECL_DECLARED_CONSTEXPR_P (d)) 18502 defer_ok = 0; 18503 18504 /* Don't instantiate cloned functions. Instead, instantiate the 18505 functions they cloned. */ 18506 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d)) 18507 d = DECL_CLONED_FUNCTION (d); 18508 18509 if (DECL_TEMPLATE_INSTANTIATED (d) 18510 || (TREE_CODE (d) == FUNCTION_DECL 18511 && DECL_DEFAULTED_FN (d) && DECL_INITIAL (d)) 18512 || DECL_TEMPLATE_SPECIALIZATION (d)) 18513 /* D has already been instantiated or explicitly specialized, so 18514 there's nothing for us to do here. 18515 18516 It might seem reasonable to check whether or not D is an explicit 18517 instantiation, and, if so, stop here. But when an explicit 18518 instantiation is deferred until the end of the compilation, 18519 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do 18520 the instantiation. */ 18521 return d; 18522 18523 /* Check to see whether we know that this template will be 18524 instantiated in some other file, as with "extern template" 18525 extension. */ 18526 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d)); 18527 18528 /* In general, we do not instantiate such templates. */ 18529 if (external_p && !always_instantiate_p (d)) 18530 return d; 18531 18532 gen_tmpl = most_general_template (tmpl); 18533 gen_args = DECL_TI_ARGS (d); 18534 18535 if (tmpl != gen_tmpl) 18536 /* We should already have the extra args. */ 18537 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl)) 18538 == TMPL_ARGS_DEPTH (gen_args)); 18539 /* And what's in the hash table should match D. */ 18540 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d 18541 || spec == NULL_TREE); 18542 18543 /* This needs to happen before any tsubsting. */ 18544 if (! push_tinst_level (d)) 18545 return d; 18546 18547 timevar_push (TV_TEMPLATE_INST); 18548 18549 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern 18550 for the instantiation. */ 18551 td = template_for_substitution (d); 18552 code_pattern = DECL_TEMPLATE_RESULT (td); 18553 18554 /* We should never be trying to instantiate a member of a class 18555 template or partial specialization. */ 18556 gcc_assert (d != code_pattern); 18557 18558 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d)) 18559 || DECL_TEMPLATE_SPECIALIZATION (td)) 18560 /* In the case of a friend template whose definition is provided 18561 outside the class, we may have too many arguments. Drop the 18562 ones we don't need. The same is true for specializations. */ 18563 args = get_innermost_template_args 18564 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td))); 18565 else 18566 args = gen_args; 18567 18568 if (TREE_CODE (d) == FUNCTION_DECL) 18569 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE 18570 || DECL_DEFAULTED_OUTSIDE_CLASS_P (code_pattern)); 18571 else 18572 pattern_defined = ! DECL_IN_AGGR_P (code_pattern); 18573 18574 /* We may be in the middle of deferred access check. Disable it now. */ 18575 push_deferring_access_checks (dk_no_deferred); 18576 18577 /* Unless an explicit instantiation directive has already determined 18578 the linkage of D, remember that a definition is available for 18579 this entity. */ 18580 if (pattern_defined 18581 && !DECL_INTERFACE_KNOWN (d) 18582 && !DECL_NOT_REALLY_EXTERN (d)) 18583 mark_definable (d); 18584 18585 DECL_SOURCE_LOCATION (td) = DECL_SOURCE_LOCATION (code_pattern); 18586 DECL_SOURCE_LOCATION (d) = DECL_SOURCE_LOCATION (code_pattern); 18587 input_location = DECL_SOURCE_LOCATION (d); 18588 18589 /* If D is a member of an explicitly instantiated class template, 18590 and no definition is available, treat it like an implicit 18591 instantiation. */ 18592 if (!pattern_defined && expl_inst_class_mem_p 18593 && DECL_EXPLICIT_INSTANTIATION (d)) 18594 { 18595 /* Leave linkage flags alone on instantiations with anonymous 18596 visibility. */ 18597 if (TREE_PUBLIC (d)) 18598 { 18599 DECL_NOT_REALLY_EXTERN (d) = 0; 18600 DECL_INTERFACE_KNOWN (d) = 0; 18601 } 18602 SET_DECL_IMPLICIT_INSTANTIATION (d); 18603 } 18604 18605 if (TREE_CODE (d) == FUNCTION_DECL) 18606 maybe_instantiate_noexcept (d); 18607 18608 /* Recheck the substitutions to obtain any warning messages 18609 about ignoring cv qualifiers. Don't do this for artificial decls, 18610 as it breaks the context-sensitive substitution for lambda op(). */ 18611 if (!defer_ok && !DECL_ARTIFICIAL (d)) 18612 { 18613 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl); 18614 tree type = TREE_TYPE (gen); 18615 18616 /* Make sure that we can see identifiers, and compute access 18617 correctly. D is already the target FUNCTION_DECL with the 18618 right context. */ 18619 push_access_scope (d); 18620 18621 if (TREE_CODE (gen) == FUNCTION_DECL) 18622 { 18623 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d); 18624 tsubst_exception_specification (type, gen_args, tf_warning_or_error, 18625 d, /*defer_ok*/true); 18626 /* Don't simply tsubst the function type, as that will give 18627 duplicate warnings about poor parameter qualifications. 18628 The function arguments are the same as the decl_arguments 18629 without the top level cv qualifiers. */ 18630 type = TREE_TYPE (type); 18631 } 18632 tsubst (type, gen_args, tf_warning_or_error, d); 18633 18634 pop_access_scope (d); 18635 } 18636 18637 /* Defer all other templates, unless we have been explicitly 18638 forbidden from doing so. */ 18639 if (/* If there is no definition, we cannot instantiate the 18640 template. */ 18641 ! pattern_defined 18642 /* If it's OK to postpone instantiation, do so. */ 18643 || defer_ok 18644 /* If this is a static data member that will be defined 18645 elsewhere, we don't want to instantiate the entire data 18646 member, but we do want to instantiate the initializer so that 18647 we can substitute that elsewhere. */ 18648 || (external_p && TREE_CODE (d) == VAR_DECL)) 18649 { 18650 /* The definition of the static data member is now required so 18651 we must substitute the initializer. */ 18652 if (TREE_CODE (d) == VAR_DECL 18653 && !DECL_INITIAL (d) 18654 && DECL_INITIAL (code_pattern)) 18655 { 18656 tree ns; 18657 tree init; 18658 bool const_init = false; 18659 18660 ns = decl_namespace_context (d); 18661 push_nested_namespace (ns); 18662 push_nested_class (DECL_CONTEXT (d)); 18663 init = tsubst_expr (DECL_INITIAL (code_pattern), 18664 args, 18665 tf_warning_or_error, NULL_TREE, 18666 /*integral_constant_expression_p=*/false); 18667 /* Make sure the initializer is still constant, in case of 18668 circular dependency (template/instantiate6.C). */ 18669 const_init 18670 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern); 18671 cp_finish_decl (d, init, /*init_const_expr_p=*/const_init, 18672 /*asmspec_tree=*/NULL_TREE, 18673 LOOKUP_ONLYCONVERTING); 18674 pop_nested_class (); 18675 pop_nested_namespace (ns); 18676 } 18677 18678 /* We restore the source position here because it's used by 18679 add_pending_template. */ 18680 input_location = saved_loc; 18681 18682 if (at_eof && !pattern_defined 18683 && DECL_EXPLICIT_INSTANTIATION (d) 18684 && DECL_NOT_REALLY_EXTERN (d)) 18685 /* [temp.explicit] 18686 18687 The definition of a non-exported function template, a 18688 non-exported member function template, or a non-exported 18689 member function or static data member of a class template 18690 shall be present in every translation unit in which it is 18691 explicitly instantiated. */ 18692 permerror (input_location, "explicit instantiation of %qD " 18693 "but no definition available", d); 18694 18695 /* If we're in unevaluated context, we just wanted to get the 18696 constant value; this isn't an odr use, so don't queue 18697 a full instantiation. */ 18698 if (cp_unevaluated_operand != 0) 18699 goto out; 18700 /* ??? Historically, we have instantiated inline functions, even 18701 when marked as "extern template". */ 18702 if (!(external_p && TREE_CODE (d) == VAR_DECL)) 18703 add_pending_template (d); 18704 goto out; 18705 } 18706 /* Tell the repository that D is available in this translation unit 18707 -- and see if it is supposed to be instantiated here. */ 18708 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d)) 18709 { 18710 /* In a PCH file, despite the fact that the repository hasn't 18711 requested instantiation in the PCH it is still possible that 18712 an instantiation will be required in a file that includes the 18713 PCH. */ 18714 if (pch_file) 18715 add_pending_template (d); 18716 /* Instantiate inline functions so that the inliner can do its 18717 job, even though we'll not be emitting a copy of this 18718 function. */ 18719 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d))) 18720 goto out; 18721 } 18722 18723 fn_context = decl_function_context (d); 18724 nested = (current_function_decl != NULL_TREE); 18725 if (!fn_context) 18726 push_to_top_level (); 18727 else if (nested) 18728 push_function_context (); 18729 18730 /* Mark D as instantiated so that recursive calls to 18731 instantiate_decl do not try to instantiate it again. */ 18732 DECL_TEMPLATE_INSTANTIATED (d) = 1; 18733 18734 /* Regenerate the declaration in case the template has been modified 18735 by a subsequent redeclaration. */ 18736 regenerate_decl_from_template (d, td); 18737 18738 /* We already set the file and line above. Reset them now in case 18739 they changed as a result of calling regenerate_decl_from_template. */ 18740 input_location = DECL_SOURCE_LOCATION (d); 18741 18742 if (TREE_CODE (d) == VAR_DECL) 18743 { 18744 tree init; 18745 bool const_init = false; 18746 18747 /* Clear out DECL_RTL; whatever was there before may not be right 18748 since we've reset the type of the declaration. */ 18749 SET_DECL_RTL (d, NULL); 18750 DECL_IN_AGGR_P (d) = 0; 18751 18752 /* The initializer is placed in DECL_INITIAL by 18753 regenerate_decl_from_template so we don't need to 18754 push/pop_access_scope again here. Pull it out so that 18755 cp_finish_decl can process it. */ 18756 init = DECL_INITIAL (d); 18757 DECL_INITIAL (d) = NULL_TREE; 18758 DECL_INITIALIZED_P (d) = 0; 18759 18760 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the 18761 initializer. That function will defer actual emission until 18762 we have a chance to determine linkage. */ 18763 DECL_EXTERNAL (d) = 0; 18764 18765 /* Enter the scope of D so that access-checking works correctly. */ 18766 push_nested_class (DECL_CONTEXT (d)); 18767 const_init = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern); 18768 cp_finish_decl (d, init, const_init, NULL_TREE, 0); 18769 pop_nested_class (); 18770 } 18771 else if (TREE_CODE (d) == FUNCTION_DECL && DECL_DEFAULTED_FN (code_pattern)) 18772 synthesize_method (d); 18773 else if (TREE_CODE (d) == FUNCTION_DECL) 18774 { 18775 htab_t saved_local_specializations; 18776 tree subst_decl; 18777 tree tmpl_parm; 18778 tree spec_parm; 18779 18780 /* Save away the current list, in case we are instantiating one 18781 template from within the body of another. */ 18782 saved_local_specializations = local_specializations; 18783 18784 /* Set up the list of local specializations. */ 18785 local_specializations = htab_create (37, 18786 hash_local_specialization, 18787 eq_local_specializations, 18788 NULL); 18789 18790 /* Set up context. */ 18791 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED); 18792 18793 /* Create substitution entries for the parameters. */ 18794 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d)); 18795 tmpl_parm = DECL_ARGUMENTS (subst_decl); 18796 spec_parm = DECL_ARGUMENTS (d); 18797 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d)) 18798 { 18799 register_local_specialization (spec_parm, tmpl_parm); 18800 spec_parm = skip_artificial_parms_for (d, spec_parm); 18801 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm); 18802 } 18803 for (; tmpl_parm; tmpl_parm = DECL_CHAIN (tmpl_parm)) 18804 { 18805 if (!FUNCTION_PARAMETER_PACK_P (tmpl_parm)) 18806 { 18807 register_local_specialization (spec_parm, tmpl_parm); 18808 spec_parm = DECL_CHAIN (spec_parm); 18809 } 18810 else 18811 { 18812 /* Register the (value) argument pack as a specialization of 18813 TMPL_PARM, then move on. */ 18814 tree argpack = extract_fnparm_pack (tmpl_parm, &spec_parm); 18815 register_local_specialization (argpack, tmpl_parm); 18816 } 18817 } 18818 gcc_assert (!spec_parm); 18819 18820 /* Substitute into the body of the function. */ 18821 tsubst_expr (DECL_SAVED_TREE (code_pattern), args, 18822 tf_warning_or_error, tmpl, 18823 /*integral_constant_expression_p=*/false); 18824 18825 /* Set the current input_location to the end of the function 18826 so that finish_function knows where we are. */ 18827 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus; 18828 18829 /* We don't need the local specializations any more. */ 18830 htab_delete (local_specializations); 18831 local_specializations = saved_local_specializations; 18832 18833 /* Finish the function. */ 18834 d = finish_function (0); 18835 expand_or_defer_fn (d); 18836 } 18837 18838 /* We're not deferring instantiation any more. */ 18839 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0; 18840 18841 if (!fn_context) 18842 pop_from_top_level (); 18843 else if (nested) 18844 pop_function_context (); 18845 18846 out: 18847 input_location = saved_loc; 18848 pop_deferring_access_checks (); 18849 pop_tinst_level (); 18850 18851 timevar_pop (TV_TEMPLATE_INST); 18852 18853 return d; 18854 } 18855 18856 /* Run through the list of templates that we wish we could 18857 instantiate, and instantiate any we can. RETRIES is the 18858 number of times we retry pending template instantiation. */ 18859 18860 void 18861 instantiate_pending_templates (int retries) 18862 { 18863 int reconsider; 18864 location_t saved_loc = input_location; 18865 18866 /* Instantiating templates may trigger vtable generation. This in turn 18867 may require further template instantiations. We place a limit here 18868 to avoid infinite loop. */ 18869 if (pending_templates && retries >= max_tinst_depth) 18870 { 18871 tree decl = pending_templates->tinst->decl; 18872 18873 error ("template instantiation depth exceeds maximum of %d" 18874 " instantiating %q+D, possibly from virtual table generation" 18875 " (use -ftemplate-depth= to increase the maximum)", 18876 max_tinst_depth, decl); 18877 if (TREE_CODE (decl) == FUNCTION_DECL) 18878 /* Pretend that we defined it. */ 18879 DECL_INITIAL (decl) = error_mark_node; 18880 return; 18881 } 18882 18883 do 18884 { 18885 struct pending_template **t = &pending_templates; 18886 struct pending_template *last = NULL; 18887 reconsider = 0; 18888 while (*t) 18889 { 18890 tree instantiation = reopen_tinst_level ((*t)->tinst); 18891 bool complete = false; 18892 18893 if (TYPE_P (instantiation)) 18894 { 18895 tree fn; 18896 18897 if (!COMPLETE_TYPE_P (instantiation)) 18898 { 18899 instantiate_class_template (instantiation); 18900 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation)) 18901 for (fn = TYPE_METHODS (instantiation); 18902 fn; 18903 fn = TREE_CHAIN (fn)) 18904 if (! DECL_ARTIFICIAL (fn)) 18905 instantiate_decl (fn, 18906 /*defer_ok=*/0, 18907 /*expl_inst_class_mem_p=*/false); 18908 if (COMPLETE_TYPE_P (instantiation)) 18909 reconsider = 1; 18910 } 18911 18912 complete = COMPLETE_TYPE_P (instantiation); 18913 } 18914 else 18915 { 18916 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation) 18917 && !DECL_TEMPLATE_INSTANTIATED (instantiation)) 18918 { 18919 instantiation 18920 = instantiate_decl (instantiation, 18921 /*defer_ok=*/0, 18922 /*expl_inst_class_mem_p=*/false); 18923 if (DECL_TEMPLATE_INSTANTIATED (instantiation)) 18924 reconsider = 1; 18925 } 18926 18927 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation) 18928 || DECL_TEMPLATE_INSTANTIATED (instantiation)); 18929 } 18930 18931 if (complete) 18932 /* If INSTANTIATION has been instantiated, then we don't 18933 need to consider it again in the future. */ 18934 *t = (*t)->next; 18935 else 18936 { 18937 last = *t; 18938 t = &(*t)->next; 18939 } 18940 tinst_depth = 0; 18941 current_tinst_level = NULL; 18942 } 18943 last_pending_template = last; 18944 } 18945 while (reconsider); 18946 18947 input_location = saved_loc; 18948 } 18949 18950 /* Substitute ARGVEC into T, which is a list of initializers for 18951 either base class or a non-static data member. The TREE_PURPOSEs 18952 are DECLs, and the TREE_VALUEs are the initializer values. Used by 18953 instantiate_decl. */ 18954 18955 static tree 18956 tsubst_initializer_list (tree t, tree argvec) 18957 { 18958 tree inits = NULL_TREE; 18959 18960 for (; t; t = TREE_CHAIN (t)) 18961 { 18962 tree decl; 18963 tree init; 18964 tree expanded_bases = NULL_TREE; 18965 tree expanded_arguments = NULL_TREE; 18966 int i, len = 1; 18967 18968 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION) 18969 { 18970 tree expr; 18971 tree arg; 18972 18973 /* Expand the base class expansion type into separate base 18974 classes. */ 18975 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec, 18976 tf_warning_or_error, 18977 NULL_TREE); 18978 if (expanded_bases == error_mark_node) 18979 continue; 18980 18981 /* We'll be building separate TREE_LISTs of arguments for 18982 each base. */ 18983 len = TREE_VEC_LENGTH (expanded_bases); 18984 expanded_arguments = make_tree_vec (len); 18985 for (i = 0; i < len; i++) 18986 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE; 18987 18988 /* Build a dummy EXPR_PACK_EXPANSION that will be used to 18989 expand each argument in the TREE_VALUE of t. */ 18990 expr = make_node (EXPR_PACK_EXPANSION); 18991 PACK_EXPANSION_LOCAL_P (expr) = true; 18992 PACK_EXPANSION_PARAMETER_PACKS (expr) = 18993 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t)); 18994 18995 if (TREE_VALUE (t) == void_type_node) 18996 /* VOID_TYPE_NODE is used to indicate 18997 value-initialization. */ 18998 { 18999 for (i = 0; i < len; i++) 19000 TREE_VEC_ELT (expanded_arguments, i) = void_type_node; 19001 } 19002 else 19003 { 19004 /* Substitute parameter packs into each argument in the 19005 TREE_LIST. */ 19006 in_base_initializer = 1; 19007 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg)) 19008 { 19009 tree expanded_exprs; 19010 19011 /* Expand the argument. */ 19012 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg)); 19013 expanded_exprs 19014 = tsubst_pack_expansion (expr, argvec, 19015 tf_warning_or_error, 19016 NULL_TREE); 19017 if (expanded_exprs == error_mark_node) 19018 continue; 19019 19020 /* Prepend each of the expanded expressions to the 19021 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */ 19022 for (i = 0; i < len; i++) 19023 { 19024 TREE_VEC_ELT (expanded_arguments, i) = 19025 tree_cons (NULL_TREE, 19026 TREE_VEC_ELT (expanded_exprs, i), 19027 TREE_VEC_ELT (expanded_arguments, i)); 19028 } 19029 } 19030 in_base_initializer = 0; 19031 19032 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS, 19033 since we built them backwards. */ 19034 for (i = 0; i < len; i++) 19035 { 19036 TREE_VEC_ELT (expanded_arguments, i) = 19037 nreverse (TREE_VEC_ELT (expanded_arguments, i)); 19038 } 19039 } 19040 } 19041 19042 for (i = 0; i < len; ++i) 19043 { 19044 if (expanded_bases) 19045 { 19046 decl = TREE_VEC_ELT (expanded_bases, i); 19047 decl = expand_member_init (decl); 19048 init = TREE_VEC_ELT (expanded_arguments, i); 19049 } 19050 else 19051 { 19052 tree tmp; 19053 decl = tsubst_copy (TREE_PURPOSE (t), argvec, 19054 tf_warning_or_error, NULL_TREE); 19055 19056 decl = expand_member_init (decl); 19057 if (decl && !DECL_P (decl)) 19058 in_base_initializer = 1; 19059 19060 init = TREE_VALUE (t); 19061 tmp = init; 19062 if (init != void_type_node) 19063 init = tsubst_expr (init, argvec, 19064 tf_warning_or_error, NULL_TREE, 19065 /*integral_constant_expression_p=*/false); 19066 if (init == NULL_TREE && tmp != NULL_TREE) 19067 /* If we had an initializer but it instantiated to nothing, 19068 value-initialize the object. This will only occur when 19069 the initializer was a pack expansion where the parameter 19070 packs used in that expansion were of length zero. */ 19071 init = void_type_node; 19072 in_base_initializer = 0; 19073 } 19074 19075 if (decl) 19076 { 19077 init = build_tree_list (decl, init); 19078 TREE_CHAIN (init) = inits; 19079 inits = init; 19080 } 19081 } 19082 } 19083 return inits; 19084 } 19085 19086 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */ 19087 19088 static void 19089 set_current_access_from_decl (tree decl) 19090 { 19091 if (TREE_PRIVATE (decl)) 19092 current_access_specifier = access_private_node; 19093 else if (TREE_PROTECTED (decl)) 19094 current_access_specifier = access_protected_node; 19095 else 19096 current_access_specifier = access_public_node; 19097 } 19098 19099 /* Instantiate an enumerated type. TAG is the template type, NEWTAG 19100 is the instantiation (which should have been created with 19101 start_enum) and ARGS are the template arguments to use. */ 19102 19103 static void 19104 tsubst_enum (tree tag, tree newtag, tree args) 19105 { 19106 tree e; 19107 19108 if (SCOPED_ENUM_P (newtag)) 19109 begin_scope (sk_scoped_enum, newtag); 19110 19111 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e)) 19112 { 19113 tree value; 19114 tree decl; 19115 19116 decl = TREE_VALUE (e); 19117 /* Note that in a template enum, the TREE_VALUE is the 19118 CONST_DECL, not the corresponding INTEGER_CST. */ 19119 value = tsubst_expr (DECL_INITIAL (decl), 19120 args, tf_warning_or_error, NULL_TREE, 19121 /*integral_constant_expression_p=*/true); 19122 19123 /* Give this enumeration constant the correct access. */ 19124 set_current_access_from_decl (decl); 19125 19126 /* Actually build the enumerator itself. */ 19127 build_enumerator 19128 (DECL_NAME (decl), value, newtag, DECL_SOURCE_LOCATION (decl)); 19129 } 19130 19131 if (SCOPED_ENUM_P (newtag)) 19132 finish_scope (); 19133 19134 finish_enum_value_list (newtag); 19135 finish_enum (newtag); 19136 19137 DECL_SOURCE_LOCATION (TYPE_NAME (newtag)) 19138 = DECL_SOURCE_LOCATION (TYPE_NAME (tag)); 19139 } 19140 19141 /* DECL is a FUNCTION_DECL that is a template specialization. Return 19142 its type -- but without substituting the innermost set of template 19143 arguments. So, innermost set of template parameters will appear in 19144 the type. */ 19145 19146 tree 19147 get_mostly_instantiated_function_type (tree decl) 19148 { 19149 tree fn_type; 19150 tree tmpl; 19151 tree targs; 19152 tree tparms; 19153 int parm_depth; 19154 19155 tmpl = most_general_template (DECL_TI_TEMPLATE (decl)); 19156 targs = DECL_TI_ARGS (decl); 19157 tparms = DECL_TEMPLATE_PARMS (tmpl); 19158 parm_depth = TMPL_PARMS_DEPTH (tparms); 19159 19160 /* There should be as many levels of arguments as there are levels 19161 of parameters. */ 19162 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs)); 19163 19164 fn_type = TREE_TYPE (tmpl); 19165 19166 if (parm_depth == 1) 19167 /* No substitution is necessary. */ 19168 ; 19169 else 19170 { 19171 int i; 19172 tree partial_args; 19173 19174 /* Replace the innermost level of the TARGS with NULL_TREEs to 19175 let tsubst know not to substitute for those parameters. */ 19176 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs)); 19177 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i) 19178 SET_TMPL_ARGS_LEVEL (partial_args, i, 19179 TMPL_ARGS_LEVEL (targs, i)); 19180 SET_TMPL_ARGS_LEVEL (partial_args, 19181 TMPL_ARGS_DEPTH (targs), 19182 make_tree_vec (DECL_NTPARMS (tmpl))); 19183 19184 /* Make sure that we can see identifiers, and compute access 19185 correctly. */ 19186 push_access_scope (decl); 19187 19188 ++processing_template_decl; 19189 /* Now, do the (partial) substitution to figure out the 19190 appropriate function type. */ 19191 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE); 19192 --processing_template_decl; 19193 19194 /* Substitute into the template parameters to obtain the real 19195 innermost set of parameters. This step is important if the 19196 innermost set of template parameters contains value 19197 parameters whose types depend on outer template parameters. */ 19198 TREE_VEC_LENGTH (partial_args)--; 19199 tparms = tsubst_template_parms (tparms, partial_args, tf_error); 19200 19201 pop_access_scope (decl); 19202 } 19203 19204 return fn_type; 19205 } 19206 19207 /* Return truthvalue if we're processing a template different from 19208 the last one involved in diagnostics. */ 19209 int 19210 problematic_instantiation_changed (void) 19211 { 19212 return current_tinst_level != last_error_tinst_level; 19213 } 19214 19215 /* Remember current template involved in diagnostics. */ 19216 void 19217 record_last_problematic_instantiation (void) 19218 { 19219 last_error_tinst_level = current_tinst_level; 19220 } 19221 19222 struct tinst_level * 19223 current_instantiation (void) 19224 { 19225 return current_tinst_level; 19226 } 19227 19228 /* [temp.param] Check that template non-type parm TYPE is of an allowable 19229 type. Return zero for ok, nonzero for disallowed. Issue error and 19230 warning messages under control of COMPLAIN. */ 19231 19232 static int 19233 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain) 19234 { 19235 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type)) 19236 return 0; 19237 else if (POINTER_TYPE_P (type)) 19238 return 0; 19239 else if (TYPE_PTR_TO_MEMBER_P (type)) 19240 return 0; 19241 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM) 19242 return 0; 19243 else if (TREE_CODE (type) == TYPENAME_TYPE) 19244 return 0; 19245 else if (TREE_CODE (type) == DECLTYPE_TYPE) 19246 return 0; 19247 else if (TREE_CODE (type) == NULLPTR_TYPE) 19248 return 0; 19249 19250 if (complain & tf_error) 19251 { 19252 if (type == error_mark_node) 19253 inform (input_location, "invalid template non-type parameter"); 19254 else 19255 error ("%q#T is not a valid type for a template non-type parameter", 19256 type); 19257 } 19258 return 1; 19259 } 19260 19261 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type]. 19262 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/ 19263 19264 static bool 19265 dependent_type_p_r (tree type) 19266 { 19267 tree scope; 19268 19269 /* [temp.dep.type] 19270 19271 A type is dependent if it is: 19272 19273 -- a template parameter. Template template parameters are types 19274 for us (since TYPE_P holds true for them) so we handle 19275 them here. */ 19276 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM 19277 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM) 19278 return true; 19279 /* -- a qualified-id with a nested-name-specifier which contains a 19280 class-name that names a dependent type or whose unqualified-id 19281 names a dependent type. */ 19282 if (TREE_CODE (type) == TYPENAME_TYPE) 19283 return true; 19284 /* -- a cv-qualified type where the cv-unqualified type is 19285 dependent. */ 19286 type = TYPE_MAIN_VARIANT (type); 19287 /* -- a compound type constructed from any dependent type. */ 19288 if (TYPE_PTR_TO_MEMBER_P (type)) 19289 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type)) 19290 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE 19291 (type))); 19292 else if (TREE_CODE (type) == POINTER_TYPE 19293 || TREE_CODE (type) == REFERENCE_TYPE) 19294 return dependent_type_p (TREE_TYPE (type)); 19295 else if (TREE_CODE (type) == FUNCTION_TYPE 19296 || TREE_CODE (type) == METHOD_TYPE) 19297 { 19298 tree arg_type; 19299 19300 if (dependent_type_p (TREE_TYPE (type))) 19301 return true; 19302 for (arg_type = TYPE_ARG_TYPES (type); 19303 arg_type; 19304 arg_type = TREE_CHAIN (arg_type)) 19305 if (dependent_type_p (TREE_VALUE (arg_type))) 19306 return true; 19307 return false; 19308 } 19309 /* -- an array type constructed from any dependent type or whose 19310 size is specified by a constant expression that is 19311 value-dependent. 19312 19313 We checked for type- and value-dependence of the bounds in 19314 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */ 19315 if (TREE_CODE (type) == ARRAY_TYPE) 19316 { 19317 if (TYPE_DOMAIN (type) 19318 && dependent_type_p (TYPE_DOMAIN (type))) 19319 return true; 19320 return dependent_type_p (TREE_TYPE (type)); 19321 } 19322 19323 /* -- a template-id in which either the template name is a template 19324 parameter ... */ 19325 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM) 19326 return true; 19327 /* ... or any of the template arguments is a dependent type or 19328 an expression that is type-dependent or value-dependent. */ 19329 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type) 19330 && (any_dependent_template_arguments_p 19331 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type))))) 19332 return true; 19333 19334 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are 19335 dependent; if the argument of the `typeof' expression is not 19336 type-dependent, then it should already been have resolved. */ 19337 if (TREE_CODE (type) == TYPEOF_TYPE 19338 || TREE_CODE (type) == DECLTYPE_TYPE 19339 || TREE_CODE (type) == UNDERLYING_TYPE) 19340 return true; 19341 19342 /* A template argument pack is dependent if any of its packed 19343 arguments are. */ 19344 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK) 19345 { 19346 tree args = ARGUMENT_PACK_ARGS (type); 19347 int i, len = TREE_VEC_LENGTH (args); 19348 for (i = 0; i < len; ++i) 19349 if (dependent_template_arg_p (TREE_VEC_ELT (args, i))) 19350 return true; 19351 } 19352 19353 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must 19354 be template parameters. */ 19355 if (TREE_CODE (type) == TYPE_PACK_EXPANSION) 19356 return true; 19357 19358 /* The standard does not specifically mention types that are local 19359 to template functions or local classes, but they should be 19360 considered dependent too. For example: 19361 19362 template <int I> void f() { 19363 enum E { a = I }; 19364 S<sizeof (E)> s; 19365 } 19366 19367 The size of `E' cannot be known until the value of `I' has been 19368 determined. Therefore, `E' must be considered dependent. */ 19369 scope = TYPE_CONTEXT (type); 19370 if (scope && TYPE_P (scope)) 19371 return dependent_type_p (scope); 19372 /* Don't use type_dependent_expression_p here, as it can lead 19373 to infinite recursion trying to determine whether a lambda 19374 nested in a lambda is dependent (c++/47687). */ 19375 else if (scope && TREE_CODE (scope) == FUNCTION_DECL 19376 && DECL_LANG_SPECIFIC (scope) 19377 && DECL_TEMPLATE_INFO (scope) 19378 && (any_dependent_template_arguments_p 19379 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (scope))))) 19380 return true; 19381 19382 /* Other types are non-dependent. */ 19383 return false; 19384 } 19385 19386 /* Returns TRUE if TYPE is dependent, in the sense of 19387 [temp.dep.type]. Note that a NULL type is considered dependent. */ 19388 19389 bool 19390 dependent_type_p (tree type) 19391 { 19392 /* If there are no template parameters in scope, then there can't be 19393 any dependent types. */ 19394 if (!processing_template_decl) 19395 { 19396 /* If we are not processing a template, then nobody should be 19397 providing us with a dependent type. */ 19398 gcc_assert (type); 19399 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type)); 19400 return false; 19401 } 19402 19403 /* If the type is NULL, we have not computed a type for the entity 19404 in question; in that case, the type is dependent. */ 19405 if (!type) 19406 return true; 19407 19408 /* Erroneous types can be considered non-dependent. */ 19409 if (type == error_mark_node) 19410 return false; 19411 19412 /* If we have not already computed the appropriate value for TYPE, 19413 do so now. */ 19414 if (!TYPE_DEPENDENT_P_VALID (type)) 19415 { 19416 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type); 19417 TYPE_DEPENDENT_P_VALID (type) = 1; 19418 } 19419 19420 return TYPE_DEPENDENT_P (type); 19421 } 19422 19423 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any 19424 lookup. In other words, a dependent type that is not the current 19425 instantiation. */ 19426 19427 bool 19428 dependent_scope_p (tree scope) 19429 { 19430 return (scope && TYPE_P (scope) && dependent_type_p (scope) 19431 && !currently_open_class (scope)); 19432 } 19433 19434 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of 19435 [temp.dep.constexpr]. EXPRESSION is already known to be a constant 19436 expression. */ 19437 19438 /* Note that this predicate is not appropriate for general expressions; 19439 only constant expressions (that satisfy potential_constant_expression) 19440 can be tested for value dependence. 19441 19442 We should really also have a predicate for "instantiation-dependent". 19443 19444 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent. 19445 (what about instantiation-dependent constant-expressions?) 19446 is_late_template_attribute: defer if instantiation-dependent. 19447 compute_array_index_type: proceed if constant and not t- or v-dependent 19448 if instantiation-dependent, need to remember full expression 19449 uses_template_parms: FIXME - need to audit callers 19450 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p? 19451 dependent_type_p [array_type]: dependent if index type is dependent 19452 (or non-constant?) 19453 static_assert - instantiation-dependent */ 19454 19455 bool 19456 value_dependent_expression_p (tree expression) 19457 { 19458 if (!processing_template_decl) 19459 return false; 19460 19461 /* A name declared with a dependent type. */ 19462 if (DECL_P (expression) && type_dependent_expression_p (expression)) 19463 return true; 19464 19465 switch (TREE_CODE (expression)) 19466 { 19467 case IDENTIFIER_NODE: 19468 /* A name that has not been looked up -- must be dependent. */ 19469 return true; 19470 19471 case TEMPLATE_PARM_INDEX: 19472 /* A non-type template parm. */ 19473 return true; 19474 19475 case CONST_DECL: 19476 /* A non-type template parm. */ 19477 if (DECL_TEMPLATE_PARM_P (expression)) 19478 return true; 19479 return value_dependent_expression_p (DECL_INITIAL (expression)); 19480 19481 case VAR_DECL: 19482 /* A constant with literal type and is initialized 19483 with an expression that is value-dependent. 19484 19485 Note that a non-dependent parenthesized initializer will have 19486 already been replaced with its constant value, so if we see 19487 a TREE_LIST it must be dependent. */ 19488 if (DECL_INITIAL (expression) 19489 && decl_constant_var_p (expression) 19490 && (TREE_CODE (DECL_INITIAL (expression)) == TREE_LIST 19491 || value_dependent_expression_p (DECL_INITIAL (expression)))) 19492 return true; 19493 return false; 19494 19495 case DYNAMIC_CAST_EXPR: 19496 case STATIC_CAST_EXPR: 19497 case CONST_CAST_EXPR: 19498 case REINTERPRET_CAST_EXPR: 19499 case CAST_EXPR: 19500 /* These expressions are value-dependent if the type to which 19501 the cast occurs is dependent or the expression being casted 19502 is value-dependent. */ 19503 { 19504 tree type = TREE_TYPE (expression); 19505 19506 if (dependent_type_p (type)) 19507 return true; 19508 19509 /* A functional cast has a list of operands. */ 19510 expression = TREE_OPERAND (expression, 0); 19511 if (!expression) 19512 { 19513 /* If there are no operands, it must be an expression such 19514 as "int()". This should not happen for aggregate types 19515 because it would form non-constant expressions. */ 19516 gcc_assert (cxx_dialect >= cxx0x 19517 || INTEGRAL_OR_ENUMERATION_TYPE_P (type)); 19518 19519 return false; 19520 } 19521 19522 if (TREE_CODE (expression) == TREE_LIST) 19523 return any_value_dependent_elements_p (expression); 19524 19525 return value_dependent_expression_p (expression); 19526 } 19527 19528 case SIZEOF_EXPR: 19529 case ALIGNOF_EXPR: 19530 case TYPEID_EXPR: 19531 /* A `sizeof' expression is value-dependent if the operand is 19532 type-dependent or is a pack expansion. */ 19533 expression = TREE_OPERAND (expression, 0); 19534 if (PACK_EXPANSION_P (expression)) 19535 return true; 19536 else if (TYPE_P (expression)) 19537 return dependent_type_p (expression); 19538 return type_dependent_expression_p (expression); 19539 19540 case AT_ENCODE_EXPR: 19541 /* An 'encode' expression is value-dependent if the operand is 19542 type-dependent. */ 19543 expression = TREE_OPERAND (expression, 0); 19544 return dependent_type_p (expression); 19545 19546 case NOEXCEPT_EXPR: 19547 expression = TREE_OPERAND (expression, 0); 19548 return type_dependent_expression_p (expression); 19549 19550 case SCOPE_REF: 19551 { 19552 tree name = TREE_OPERAND (expression, 1); 19553 return value_dependent_expression_p (name); 19554 } 19555 19556 case COMPONENT_REF: 19557 return (value_dependent_expression_p (TREE_OPERAND (expression, 0)) 19558 || value_dependent_expression_p (TREE_OPERAND (expression, 1))); 19559 19560 case NONTYPE_ARGUMENT_PACK: 19561 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument 19562 is value-dependent. */ 19563 { 19564 tree values = ARGUMENT_PACK_ARGS (expression); 19565 int i, len = TREE_VEC_LENGTH (values); 19566 19567 for (i = 0; i < len; ++i) 19568 if (value_dependent_expression_p (TREE_VEC_ELT (values, i))) 19569 return true; 19570 19571 return false; 19572 } 19573 19574 case TRAIT_EXPR: 19575 { 19576 tree type2 = TRAIT_EXPR_TYPE2 (expression); 19577 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression)) 19578 || (type2 ? dependent_type_p (type2) : false)); 19579 } 19580 19581 case MODOP_EXPR: 19582 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0))) 19583 || (value_dependent_expression_p (TREE_OPERAND (expression, 2)))); 19584 19585 case ARRAY_REF: 19586 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0))) 19587 || (value_dependent_expression_p (TREE_OPERAND (expression, 1)))); 19588 19589 case ADDR_EXPR: 19590 { 19591 tree op = TREE_OPERAND (expression, 0); 19592 return (value_dependent_expression_p (op) 19593 || has_value_dependent_address (op)); 19594 } 19595 19596 case CALL_EXPR: 19597 { 19598 tree fn = get_callee_fndecl (expression); 19599 int i, nargs; 19600 if (!fn && value_dependent_expression_p (CALL_EXPR_FN (expression))) 19601 return true; 19602 nargs = call_expr_nargs (expression); 19603 for (i = 0; i < nargs; ++i) 19604 { 19605 tree op = CALL_EXPR_ARG (expression, i); 19606 /* In a call to a constexpr member function, look through the 19607 implicit ADDR_EXPR on the object argument so that it doesn't 19608 cause the call to be considered value-dependent. We also 19609 look through it in potential_constant_expression. */ 19610 if (i == 0 && fn && DECL_DECLARED_CONSTEXPR_P (fn) 19611 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) 19612 && TREE_CODE (op) == ADDR_EXPR) 19613 op = TREE_OPERAND (op, 0); 19614 if (value_dependent_expression_p (op)) 19615 return true; 19616 } 19617 return false; 19618 } 19619 19620 case TEMPLATE_ID_EXPR: 19621 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be 19622 type-dependent. */ 19623 return type_dependent_expression_p (expression); 19624 19625 case CONSTRUCTOR: 19626 { 19627 unsigned ix; 19628 tree val; 19629 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), ix, val) 19630 if (value_dependent_expression_p (val)) 19631 return true; 19632 return false; 19633 } 19634 19635 case STMT_EXPR: 19636 /* Treat a GNU statement expression as dependent to avoid crashing 19637 under fold_non_dependent_expr; it can't be constant. */ 19638 return true; 19639 19640 default: 19641 /* A constant expression is value-dependent if any subexpression is 19642 value-dependent. */ 19643 switch (TREE_CODE_CLASS (TREE_CODE (expression))) 19644 { 19645 case tcc_reference: 19646 case tcc_unary: 19647 case tcc_comparison: 19648 case tcc_binary: 19649 case tcc_expression: 19650 case tcc_vl_exp: 19651 { 19652 int i, len = cp_tree_operand_length (expression); 19653 19654 for (i = 0; i < len; i++) 19655 { 19656 tree t = TREE_OPERAND (expression, i); 19657 19658 /* In some cases, some of the operands may be missing.l 19659 (For example, in the case of PREDECREMENT_EXPR, the 19660 amount to increment by may be missing.) That doesn't 19661 make the expression dependent. */ 19662 if (t && value_dependent_expression_p (t)) 19663 return true; 19664 } 19665 } 19666 break; 19667 default: 19668 break; 19669 } 19670 break; 19671 } 19672 19673 /* The expression is not value-dependent. */ 19674 return false; 19675 } 19676 19677 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of 19678 [temp.dep.expr]. Note that an expression with no type is 19679 considered dependent. Other parts of the compiler arrange for an 19680 expression with type-dependent subexpressions to have no type, so 19681 this function doesn't have to be fully recursive. */ 19682 19683 bool 19684 type_dependent_expression_p (tree expression) 19685 { 19686 if (!processing_template_decl) 19687 return false; 19688 19689 if (expression == error_mark_node) 19690 return false; 19691 19692 /* An unresolved name is always dependent. */ 19693 if (TREE_CODE (expression) == IDENTIFIER_NODE 19694 || TREE_CODE (expression) == USING_DECL) 19695 return true; 19696 19697 /* Some expression forms are never type-dependent. */ 19698 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR 19699 || TREE_CODE (expression) == SIZEOF_EXPR 19700 || TREE_CODE (expression) == ALIGNOF_EXPR 19701 || TREE_CODE (expression) == AT_ENCODE_EXPR 19702 || TREE_CODE (expression) == NOEXCEPT_EXPR 19703 || TREE_CODE (expression) == TRAIT_EXPR 19704 || TREE_CODE (expression) == TYPEID_EXPR 19705 || TREE_CODE (expression) == DELETE_EXPR 19706 || TREE_CODE (expression) == VEC_DELETE_EXPR 19707 || TREE_CODE (expression) == THROW_EXPR) 19708 return false; 19709 19710 /* The types of these expressions depends only on the type to which 19711 the cast occurs. */ 19712 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR 19713 || TREE_CODE (expression) == STATIC_CAST_EXPR 19714 || TREE_CODE (expression) == CONST_CAST_EXPR 19715 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR 19716 || TREE_CODE (expression) == IMPLICIT_CONV_EXPR 19717 || TREE_CODE (expression) == CAST_EXPR) 19718 return dependent_type_p (TREE_TYPE (expression)); 19719 19720 /* The types of these expressions depends only on the type created 19721 by the expression. */ 19722 if (TREE_CODE (expression) == NEW_EXPR 19723 || TREE_CODE (expression) == VEC_NEW_EXPR) 19724 { 19725 /* For NEW_EXPR tree nodes created inside a template, either 19726 the object type itself or a TREE_LIST may appear as the 19727 operand 1. */ 19728 tree type = TREE_OPERAND (expression, 1); 19729 if (TREE_CODE (type) == TREE_LIST) 19730 /* This is an array type. We need to check array dimensions 19731 as well. */ 19732 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type))) 19733 || value_dependent_expression_p 19734 (TREE_OPERAND (TREE_VALUE (type), 1)); 19735 else 19736 return dependent_type_p (type); 19737 } 19738 19739 if (TREE_CODE (expression) == SCOPE_REF) 19740 { 19741 tree scope = TREE_OPERAND (expression, 0); 19742 tree name = TREE_OPERAND (expression, 1); 19743 19744 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it 19745 contains an identifier associated by name lookup with one or more 19746 declarations declared with a dependent type, or...a 19747 nested-name-specifier or qualified-id that names a member of an 19748 unknown specialization. */ 19749 return (type_dependent_expression_p (name) 19750 || dependent_scope_p (scope)); 19751 } 19752 19753 if (TREE_CODE (expression) == FUNCTION_DECL 19754 && DECL_LANG_SPECIFIC (expression) 19755 && DECL_TEMPLATE_INFO (expression) 19756 && (any_dependent_template_arguments_p 19757 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression))))) 19758 return true; 19759 19760 if (TREE_CODE (expression) == TEMPLATE_DECL 19761 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression)) 19762 return false; 19763 19764 if (TREE_CODE (expression) == STMT_EXPR) 19765 expression = stmt_expr_value_expr (expression); 19766 19767 if (BRACE_ENCLOSED_INITIALIZER_P (expression)) 19768 { 19769 tree elt; 19770 unsigned i; 19771 19772 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt) 19773 { 19774 if (type_dependent_expression_p (elt)) 19775 return true; 19776 } 19777 return false; 19778 } 19779 19780 /* A static data member of the current instantiation with incomplete 19781 array type is type-dependent, as the definition and specializations 19782 can have different bounds. */ 19783 if (TREE_CODE (expression) == VAR_DECL 19784 && DECL_CLASS_SCOPE_P (expression) 19785 && dependent_type_p (DECL_CONTEXT (expression)) 19786 && VAR_HAD_UNKNOWN_BOUND (expression)) 19787 return true; 19788 19789 if (TREE_TYPE (expression) == unknown_type_node) 19790 { 19791 if (TREE_CODE (expression) == ADDR_EXPR) 19792 return type_dependent_expression_p (TREE_OPERAND (expression, 0)); 19793 if (TREE_CODE (expression) == COMPONENT_REF 19794 || TREE_CODE (expression) == OFFSET_REF) 19795 { 19796 if (type_dependent_expression_p (TREE_OPERAND (expression, 0))) 19797 return true; 19798 expression = TREE_OPERAND (expression, 1); 19799 if (TREE_CODE (expression) == IDENTIFIER_NODE) 19800 return false; 19801 } 19802 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */ 19803 if (TREE_CODE (expression) == SCOPE_REF) 19804 return false; 19805 19806 if (BASELINK_P (expression)) 19807 expression = BASELINK_FUNCTIONS (expression); 19808 19809 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR) 19810 { 19811 if (any_dependent_template_arguments_p 19812 (TREE_OPERAND (expression, 1))) 19813 return true; 19814 expression = TREE_OPERAND (expression, 0); 19815 } 19816 gcc_assert (TREE_CODE (expression) == OVERLOAD 19817 || TREE_CODE (expression) == FUNCTION_DECL); 19818 19819 while (expression) 19820 { 19821 if (type_dependent_expression_p (OVL_CURRENT (expression))) 19822 return true; 19823 expression = OVL_NEXT (expression); 19824 } 19825 return false; 19826 } 19827 19828 gcc_assert (TREE_CODE (expression) != TYPE_DECL); 19829 19830 return (dependent_type_p (TREE_TYPE (expression))); 19831 } 19832 19833 /* Like type_dependent_expression_p, but it also works while not processing 19834 a template definition, i.e. during substitution or mangling. */ 19835 19836 bool 19837 type_dependent_expression_p_push (tree expr) 19838 { 19839 bool b; 19840 ++processing_template_decl; 19841 b = type_dependent_expression_p (expr); 19842 --processing_template_decl; 19843 return b; 19844 } 19845 19846 /* Returns TRUE if ARGS contains a type-dependent expression. */ 19847 19848 bool 19849 any_type_dependent_arguments_p (const VEC(tree,gc) *args) 19850 { 19851 unsigned int i; 19852 tree arg; 19853 19854 FOR_EACH_VEC_ELT (tree, args, i, arg) 19855 { 19856 if (type_dependent_expression_p (arg)) 19857 return true; 19858 } 19859 return false; 19860 } 19861 19862 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are 19863 expressions) contains any type-dependent expressions. */ 19864 19865 bool 19866 any_type_dependent_elements_p (const_tree list) 19867 { 19868 for (; list; list = TREE_CHAIN (list)) 19869 if (value_dependent_expression_p (TREE_VALUE (list))) 19870 return true; 19871 19872 return false; 19873 } 19874 19875 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are 19876 expressions) contains any value-dependent expressions. */ 19877 19878 bool 19879 any_value_dependent_elements_p (const_tree list) 19880 { 19881 for (; list; list = TREE_CHAIN (list)) 19882 if (value_dependent_expression_p (TREE_VALUE (list))) 19883 return true; 19884 19885 return false; 19886 } 19887 19888 /* Returns TRUE if the ARG (a template argument) is dependent. */ 19889 19890 bool 19891 dependent_template_arg_p (tree arg) 19892 { 19893 if (!processing_template_decl) 19894 return false; 19895 19896 /* Assume a template argument that was wrongly written by the user 19897 is dependent. This is consistent with what 19898 any_dependent_template_arguments_p [that calls this function] 19899 does. */ 19900 if (!arg || arg == error_mark_node) 19901 return true; 19902 19903 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT) 19904 arg = ARGUMENT_PACK_SELECT_ARG (arg); 19905 19906 if (TREE_CODE (arg) == TEMPLATE_DECL 19907 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM) 19908 return dependent_template_p (arg); 19909 else if (ARGUMENT_PACK_P (arg)) 19910 { 19911 tree args = ARGUMENT_PACK_ARGS (arg); 19912 int i, len = TREE_VEC_LENGTH (args); 19913 for (i = 0; i < len; ++i) 19914 { 19915 if (dependent_template_arg_p (TREE_VEC_ELT (args, i))) 19916 return true; 19917 } 19918 19919 return false; 19920 } 19921 else if (TYPE_P (arg)) 19922 return dependent_type_p (arg); 19923 else 19924 return (type_dependent_expression_p (arg) 19925 || value_dependent_expression_p (arg)); 19926 } 19927 19928 /* Returns true if ARGS (a collection of template arguments) contains 19929 any types that require structural equality testing. */ 19930 19931 bool 19932 any_template_arguments_need_structural_equality_p (tree args) 19933 { 19934 int i; 19935 int j; 19936 19937 if (!args) 19938 return false; 19939 if (args == error_mark_node) 19940 return true; 19941 19942 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i) 19943 { 19944 tree level = TMPL_ARGS_LEVEL (args, i + 1); 19945 for (j = 0; j < TREE_VEC_LENGTH (level); ++j) 19946 { 19947 tree arg = TREE_VEC_ELT (level, j); 19948 tree packed_args = NULL_TREE; 19949 int k, len = 1; 19950 19951 if (ARGUMENT_PACK_P (arg)) 19952 { 19953 /* Look inside the argument pack. */ 19954 packed_args = ARGUMENT_PACK_ARGS (arg); 19955 len = TREE_VEC_LENGTH (packed_args); 19956 } 19957 19958 for (k = 0; k < len; ++k) 19959 { 19960 if (packed_args) 19961 arg = TREE_VEC_ELT (packed_args, k); 19962 19963 if (error_operand_p (arg)) 19964 return true; 19965 else if (TREE_CODE (arg) == TEMPLATE_DECL 19966 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM) 19967 continue; 19968 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg)) 19969 return true; 19970 else if (!TYPE_P (arg) && TREE_TYPE (arg) 19971 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg))) 19972 return true; 19973 } 19974 } 19975 } 19976 19977 return false; 19978 } 19979 19980 /* Returns true if ARGS (a collection of template arguments) contains 19981 any dependent arguments. */ 19982 19983 bool 19984 any_dependent_template_arguments_p (const_tree args) 19985 { 19986 int i; 19987 int j; 19988 19989 if (!args) 19990 return false; 19991 if (args == error_mark_node) 19992 return true; 19993 19994 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i) 19995 { 19996 const_tree level = TMPL_ARGS_LEVEL (args, i + 1); 19997 for (j = 0; j < TREE_VEC_LENGTH (level); ++j) 19998 if (dependent_template_arg_p (TREE_VEC_ELT (level, j))) 19999 return true; 20000 } 20001 20002 return false; 20003 } 20004 20005 /* Returns TRUE if the template TMPL is dependent. */ 20006 20007 bool 20008 dependent_template_p (tree tmpl) 20009 { 20010 if (TREE_CODE (tmpl) == OVERLOAD) 20011 { 20012 while (tmpl) 20013 { 20014 if (dependent_template_p (OVL_CURRENT (tmpl))) 20015 return true; 20016 tmpl = OVL_NEXT (tmpl); 20017 } 20018 return false; 20019 } 20020 20021 /* Template template parameters are dependent. */ 20022 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl) 20023 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM) 20024 return true; 20025 /* So are names that have not been looked up. */ 20026 if (TREE_CODE (tmpl) == SCOPE_REF 20027 || TREE_CODE (tmpl) == IDENTIFIER_NODE) 20028 return true; 20029 /* So are member templates of dependent classes. */ 20030 if (TYPE_P (CP_DECL_CONTEXT (tmpl))) 20031 return dependent_type_p (DECL_CONTEXT (tmpl)); 20032 return false; 20033 } 20034 20035 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */ 20036 20037 bool 20038 dependent_template_id_p (tree tmpl, tree args) 20039 { 20040 return (dependent_template_p (tmpl) 20041 || any_dependent_template_arguments_p (args)); 20042 } 20043 20044 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors 20045 is dependent. */ 20046 20047 bool 20048 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv) 20049 { 20050 int i; 20051 20052 if (!processing_template_decl) 20053 return false; 20054 20055 for (i = 0; i < TREE_VEC_LENGTH (declv); i++) 20056 { 20057 tree decl = TREE_VEC_ELT (declv, i); 20058 tree init = TREE_VEC_ELT (initv, i); 20059 tree cond = TREE_VEC_ELT (condv, i); 20060 tree incr = TREE_VEC_ELT (incrv, i); 20061 20062 if (type_dependent_expression_p (decl)) 20063 return true; 20064 20065 if (init && type_dependent_expression_p (init)) 20066 return true; 20067 20068 if (type_dependent_expression_p (cond)) 20069 return true; 20070 20071 if (COMPARISON_CLASS_P (cond) 20072 && (type_dependent_expression_p (TREE_OPERAND (cond, 0)) 20073 || type_dependent_expression_p (TREE_OPERAND (cond, 1)))) 20074 return true; 20075 20076 if (TREE_CODE (incr) == MODOP_EXPR) 20077 { 20078 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)) 20079 || type_dependent_expression_p (TREE_OPERAND (incr, 2))) 20080 return true; 20081 } 20082 else if (type_dependent_expression_p (incr)) 20083 return true; 20084 else if (TREE_CODE (incr) == MODIFY_EXPR) 20085 { 20086 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))) 20087 return true; 20088 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1))) 20089 { 20090 tree t = TREE_OPERAND (incr, 1); 20091 if (type_dependent_expression_p (TREE_OPERAND (t, 0)) 20092 || type_dependent_expression_p (TREE_OPERAND (t, 1))) 20093 return true; 20094 } 20095 } 20096 } 20097 20098 return false; 20099 } 20100 20101 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the 20102 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if 20103 no such TYPE can be found. Note that this function peers inside 20104 uninstantiated templates and therefore should be used only in 20105 extremely limited situations. ONLY_CURRENT_P restricts this 20106 peering to the currently open classes hierarchy (which is required 20107 when comparing types). */ 20108 20109 tree 20110 resolve_typename_type (tree type, bool only_current_p) 20111 { 20112 tree scope; 20113 tree name; 20114 tree decl; 20115 int quals; 20116 tree pushed_scope; 20117 tree result; 20118 20119 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE); 20120 20121 scope = TYPE_CONTEXT (type); 20122 /* Usually the non-qualified identifier of a TYPENAME_TYPE is 20123 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of 20124 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing 20125 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified 20126 identifier of the TYPENAME_TYPE anymore. 20127 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the 20128 TYPENAME_TYPE instead, we avoid messing up with a possible 20129 typedef variant case. */ 20130 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type)); 20131 20132 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve 20133 it first before we can figure out what NAME refers to. */ 20134 if (TREE_CODE (scope) == TYPENAME_TYPE) 20135 scope = resolve_typename_type (scope, only_current_p); 20136 /* If we don't know what SCOPE refers to, then we cannot resolve the 20137 TYPENAME_TYPE. */ 20138 if (TREE_CODE (scope) == TYPENAME_TYPE) 20139 return type; 20140 /* If the SCOPE is a template type parameter, we have no way of 20141 resolving the name. */ 20142 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM) 20143 return type; 20144 /* If the SCOPE is not the current instantiation, there's no reason 20145 to look inside it. */ 20146 if (only_current_p && !currently_open_class (scope)) 20147 return type; 20148 /* If this is a typedef, we don't want to look inside (c++/11987). */ 20149 if (typedef_variant_p (type)) 20150 return type; 20151 /* If SCOPE isn't the template itself, it will not have a valid 20152 TYPE_FIELDS list. */ 20153 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope))) 20154 /* scope is either the template itself or a compatible instantiation 20155 like X<T>, so look up the name in the original template. */ 20156 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope); 20157 else 20158 /* scope is a partial instantiation, so we can't do the lookup or we 20159 will lose the template arguments. */ 20160 return type; 20161 /* Enter the SCOPE so that name lookup will be resolved as if we 20162 were in the class definition. In particular, SCOPE will no 20163 longer be considered a dependent type. */ 20164 pushed_scope = push_scope (scope); 20165 /* Look up the declaration. */ 20166 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true, 20167 tf_warning_or_error); 20168 20169 result = NULL_TREE; 20170 20171 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to 20172 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */ 20173 if (!decl) 20174 /*nop*/; 20175 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE 20176 && TREE_CODE (decl) == TYPE_DECL) 20177 { 20178 result = TREE_TYPE (decl); 20179 if (result == error_mark_node) 20180 result = NULL_TREE; 20181 } 20182 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR 20183 && DECL_CLASS_TEMPLATE_P (decl)) 20184 { 20185 tree tmpl; 20186 tree args; 20187 /* Obtain the template and the arguments. */ 20188 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0); 20189 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1); 20190 /* Instantiate the template. */ 20191 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE, 20192 /*entering_scope=*/0, 20193 tf_error | tf_user); 20194 if (result == error_mark_node) 20195 result = NULL_TREE; 20196 } 20197 20198 /* Leave the SCOPE. */ 20199 if (pushed_scope) 20200 pop_scope (pushed_scope); 20201 20202 /* If we failed to resolve it, return the original typename. */ 20203 if (!result) 20204 return type; 20205 20206 /* If lookup found a typename type, resolve that too. */ 20207 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result)) 20208 { 20209 /* Ill-formed programs can cause infinite recursion here, so we 20210 must catch that. */ 20211 TYPENAME_IS_RESOLVING_P (type) = 1; 20212 result = resolve_typename_type (result, only_current_p); 20213 TYPENAME_IS_RESOLVING_P (type) = 0; 20214 } 20215 20216 /* Qualify the resulting type. */ 20217 quals = cp_type_quals (type); 20218 if (quals) 20219 result = cp_build_qualified_type (result, cp_type_quals (result) | quals); 20220 20221 return result; 20222 } 20223 20224 /* EXPR is an expression which is not type-dependent. Return a proxy 20225 for EXPR that can be used to compute the types of larger 20226 expressions containing EXPR. */ 20227 20228 tree 20229 build_non_dependent_expr (tree expr) 20230 { 20231 tree inner_expr; 20232 20233 #ifdef ENABLE_CHECKING 20234 /* Try to get a constant value for all non-type-dependent expressions in 20235 order to expose bugs in *_dependent_expression_p and constexpr. */ 20236 if (cxx_dialect >= cxx0x) 20237 maybe_constant_value (fold_non_dependent_expr_sfinae (expr, tf_none)); 20238 #endif 20239 20240 /* Preserve OVERLOADs; the functions must be available to resolve 20241 types. */ 20242 inner_expr = expr; 20243 if (TREE_CODE (inner_expr) == STMT_EXPR) 20244 inner_expr = stmt_expr_value_expr (inner_expr); 20245 if (TREE_CODE (inner_expr) == ADDR_EXPR) 20246 inner_expr = TREE_OPERAND (inner_expr, 0); 20247 if (TREE_CODE (inner_expr) == COMPONENT_REF) 20248 inner_expr = TREE_OPERAND (inner_expr, 1); 20249 if (is_overloaded_fn (inner_expr) 20250 || TREE_CODE (inner_expr) == OFFSET_REF) 20251 return expr; 20252 /* There is no need to return a proxy for a variable. */ 20253 if (TREE_CODE (expr) == VAR_DECL) 20254 return expr; 20255 /* Preserve string constants; conversions from string constants to 20256 "char *" are allowed, even though normally a "const char *" 20257 cannot be used to initialize a "char *". */ 20258 if (TREE_CODE (expr) == STRING_CST) 20259 return expr; 20260 /* Preserve arithmetic constants, as an optimization -- there is no 20261 reason to create a new node. */ 20262 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST) 20263 return expr; 20264 /* Preserve THROW_EXPRs -- all throw-expressions have type "void". 20265 There is at least one place where we want to know that a 20266 particular expression is a throw-expression: when checking a ?: 20267 expression, there are special rules if the second or third 20268 argument is a throw-expression. */ 20269 if (TREE_CODE (expr) == THROW_EXPR) 20270 return expr; 20271 20272 /* Don't wrap an initializer list, we need to be able to look inside. */ 20273 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 20274 return expr; 20275 20276 if (TREE_CODE (expr) == COND_EXPR) 20277 return build3 (COND_EXPR, 20278 TREE_TYPE (expr), 20279 TREE_OPERAND (expr, 0), 20280 (TREE_OPERAND (expr, 1) 20281 ? build_non_dependent_expr (TREE_OPERAND (expr, 1)) 20282 : build_non_dependent_expr (TREE_OPERAND (expr, 0))), 20283 build_non_dependent_expr (TREE_OPERAND (expr, 2))); 20284 if (TREE_CODE (expr) == COMPOUND_EXPR 20285 && !COMPOUND_EXPR_OVERLOADED (expr)) 20286 return build2 (COMPOUND_EXPR, 20287 TREE_TYPE (expr), 20288 TREE_OPERAND (expr, 0), 20289 build_non_dependent_expr (TREE_OPERAND (expr, 1))); 20290 20291 /* If the type is unknown, it can't really be non-dependent */ 20292 gcc_assert (TREE_TYPE (expr) != unknown_type_node); 20293 20294 /* Otherwise, build a NON_DEPENDENT_EXPR. */ 20295 return build1 (NON_DEPENDENT_EXPR, TREE_TYPE (expr), expr); 20296 } 20297 20298 /* ARGS is a vector of expressions as arguments to a function call. 20299 Replace the arguments with equivalent non-dependent expressions. 20300 This modifies ARGS in place. */ 20301 20302 void 20303 make_args_non_dependent (VEC(tree,gc) *args) 20304 { 20305 unsigned int ix; 20306 tree arg; 20307 20308 FOR_EACH_VEC_ELT (tree, args, ix, arg) 20309 { 20310 tree newarg = build_non_dependent_expr (arg); 20311 if (newarg != arg) 20312 VEC_replace (tree, args, ix, newarg); 20313 } 20314 } 20315 20316 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM 20317 with a level one deeper than the actual template parms. */ 20318 20319 tree 20320 make_auto (void) 20321 { 20322 tree au = cxx_make_type (TEMPLATE_TYPE_PARM); 20323 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION, 20324 TYPE_DECL, get_identifier ("auto"), au); 20325 TYPE_STUB_DECL (au) = TYPE_NAME (au); 20326 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index 20327 (0, processing_template_decl + 1, processing_template_decl + 1, 20328 0, TYPE_NAME (au), NULL_TREE); 20329 TYPE_CANONICAL (au) = canonical_type_parameter (au); 20330 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1; 20331 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au)); 20332 20333 return au; 20334 } 20335 20336 /* Given type ARG, return std::initializer_list<ARG>. */ 20337 20338 static tree 20339 listify (tree arg) 20340 { 20341 tree std_init_list = namespace_binding 20342 (get_identifier ("initializer_list"), std_node); 20343 tree argvec; 20344 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list)) 20345 { 20346 error ("deducing from brace-enclosed initializer list requires " 20347 "#include <initializer_list>"); 20348 return error_mark_node; 20349 } 20350 argvec = make_tree_vec (1); 20351 TREE_VEC_ELT (argvec, 0) = arg; 20352 return lookup_template_class (std_init_list, argvec, NULL_TREE, 20353 NULL_TREE, 0, tf_warning_or_error); 20354 } 20355 20356 /* Replace auto in TYPE with std::initializer_list<auto>. */ 20357 20358 static tree 20359 listify_autos (tree type, tree auto_node) 20360 { 20361 tree init_auto = listify (auto_node); 20362 tree argvec = make_tree_vec (1); 20363 TREE_VEC_ELT (argvec, 0) = init_auto; 20364 if (processing_template_decl) 20365 argvec = add_to_template_args (current_template_args (), argvec); 20366 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE); 20367 } 20368 20369 /* walk_tree helper for do_auto_deduction. */ 20370 20371 static tree 20372 contains_auto_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED, 20373 void *type) 20374 { 20375 /* Is this a variable with the type we're looking for? */ 20376 if (DECL_P (*tp) 20377 && TREE_TYPE (*tp) == type) 20378 return *tp; 20379 else 20380 return NULL_TREE; 20381 } 20382 20383 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced 20384 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */ 20385 20386 tree 20387 do_auto_deduction (tree type, tree init, tree auto_node) 20388 { 20389 tree parms, tparms, targs; 20390 tree args[1]; 20391 tree decl; 20392 int val; 20393 20394 if (type_dependent_expression_p (init)) 20395 /* Defining a subset of type-dependent expressions that we can deduce 20396 from ahead of time isn't worth the trouble. */ 20397 return type; 20398 20399 /* The name of the object being declared shall not appear in the 20400 initializer expression. */ 20401 decl = cp_walk_tree_without_duplicates (&init, contains_auto_r, type); 20402 if (decl) 20403 { 20404 error ("variable %q#D with %<auto%> type used in its own " 20405 "initializer", decl); 20406 return error_mark_node; 20407 } 20408 20409 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto 20410 with either a new invented type template parameter U or, if the 20411 initializer is a braced-init-list (8.5.4), with 20412 std::initializer_list<U>. */ 20413 if (BRACE_ENCLOSED_INITIALIZER_P (init)) 20414 type = listify_autos (type, auto_node); 20415 20416 init = resolve_nondeduced_context (init); 20417 20418 parms = build_tree_list (NULL_TREE, type); 20419 args[0] = init; 20420 tparms = make_tree_vec (1); 20421 targs = make_tree_vec (1); 20422 TREE_VEC_ELT (tparms, 0) 20423 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node)); 20424 val = type_unification_real (tparms, targs, parms, args, 1, 0, 20425 DEDUCE_CALL, LOOKUP_NORMAL, 20426 /*explain_p=*/false); 20427 if (val > 0) 20428 { 20429 if (processing_template_decl) 20430 /* Try again at instantiation time. */ 20431 return type; 20432 if (type && type != error_mark_node) 20433 /* If type is error_mark_node a diagnostic must have been 20434 emitted by now. Also, having a mention to '<type error>' 20435 in the diagnostic is not really useful to the user. */ 20436 error ("unable to deduce %qT from %qE", type, init); 20437 return error_mark_node; 20438 } 20439 20440 /* If the list of declarators contains more than one declarator, the type 20441 of each declared variable is determined as described above. If the 20442 type deduced for the template parameter U is not the same in each 20443 deduction, the program is ill-formed. */ 20444 if (TREE_TYPE (auto_node) 20445 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0))) 20446 { 20447 error ("inconsistent deduction for %qT: %qT and then %qT", 20448 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)); 20449 return error_mark_node; 20450 } 20451 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0); 20452 20453 if (processing_template_decl) 20454 targs = add_to_template_args (current_template_args (), targs); 20455 return tsubst (type, targs, tf_warning_or_error, NULL_TREE); 20456 } 20457 20458 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the 20459 result. */ 20460 20461 tree 20462 splice_late_return_type (tree type, tree late_return_type) 20463 { 20464 tree argvec; 20465 20466 if (late_return_type == NULL_TREE) 20467 return type; 20468 argvec = make_tree_vec (1); 20469 TREE_VEC_ELT (argvec, 0) = late_return_type; 20470 if (processing_template_parmlist) 20471 /* For a late-specified return type in a template type-parameter, we 20472 need to add a dummy argument level for its parmlist. */ 20473 argvec = add_to_template_args 20474 (make_tree_vec (processing_template_parmlist), argvec); 20475 if (current_template_parms) 20476 argvec = add_to_template_args (current_template_args (), argvec); 20477 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE); 20478 } 20479 20480 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */ 20481 20482 bool 20483 is_auto (const_tree type) 20484 { 20485 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM 20486 && TYPE_IDENTIFIER (type) == get_identifier ("auto")) 20487 return true; 20488 else 20489 return false; 20490 } 20491 20492 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only 20493 appear as a type-specifier for the declaration in question, we don't 20494 have to look through the whole type. */ 20495 20496 tree 20497 type_uses_auto (tree type) 20498 { 20499 enum tree_code code; 20500 if (is_auto (type)) 20501 return type; 20502 20503 code = TREE_CODE (type); 20504 20505 if (code == POINTER_TYPE || code == REFERENCE_TYPE 20506 || code == OFFSET_TYPE || code == FUNCTION_TYPE 20507 || code == METHOD_TYPE || code == ARRAY_TYPE) 20508 return type_uses_auto (TREE_TYPE (type)); 20509 20510 if (TYPE_PTRMEMFUNC_P (type)) 20511 return type_uses_auto (TREE_TYPE (TREE_TYPE 20512 (TYPE_PTRMEMFUNC_FN_TYPE (type)))); 20513 20514 return NULL_TREE; 20515 } 20516 20517 /* For a given template T, return the vector of typedefs referenced 20518 in T for which access check is needed at T instantiation time. 20519 T is either a FUNCTION_DECL or a RECORD_TYPE. 20520 Those typedefs were added to T by the function 20521 append_type_to_template_for_access_check. */ 20522 20523 VEC(qualified_typedef_usage_t,gc)* 20524 get_types_needing_access_check (tree t) 20525 { 20526 tree ti; 20527 VEC(qualified_typedef_usage_t,gc) *result = NULL; 20528 20529 if (!t || t == error_mark_node) 20530 return NULL; 20531 20532 if (!(ti = get_template_info (t))) 20533 return NULL; 20534 20535 if (CLASS_TYPE_P (t) 20536 || TREE_CODE (t) == FUNCTION_DECL) 20537 { 20538 if (!TI_TEMPLATE (ti)) 20539 return NULL; 20540 20541 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti); 20542 } 20543 20544 return result; 20545 } 20546 20547 /* Append the typedef TYPE_DECL used in template T to a list of typedefs 20548 tied to T. That list of typedefs will be access checked at 20549 T instantiation time. 20550 T is either a FUNCTION_DECL or a RECORD_TYPE. 20551 TYPE_DECL is a TYPE_DECL node representing a typedef. 20552 SCOPE is the scope through which TYPE_DECL is accessed. 20553 LOCATION is the location of the usage point of TYPE_DECL. 20554 20555 This function is a subroutine of 20556 append_type_to_template_for_access_check. */ 20557 20558 static void 20559 append_type_to_template_for_access_check_1 (tree t, 20560 tree type_decl, 20561 tree scope, 20562 location_t location) 20563 { 20564 qualified_typedef_usage_t typedef_usage; 20565 tree ti; 20566 20567 if (!t || t == error_mark_node) 20568 return; 20569 20570 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL 20571 || CLASS_TYPE_P (t)) 20572 && type_decl 20573 && TREE_CODE (type_decl) == TYPE_DECL 20574 && scope); 20575 20576 if (!(ti = get_template_info (t))) 20577 return; 20578 20579 gcc_assert (TI_TEMPLATE (ti)); 20580 20581 typedef_usage.typedef_decl = type_decl; 20582 typedef_usage.context = scope; 20583 typedef_usage.locus = location; 20584 20585 VEC_safe_push (qualified_typedef_usage_t, gc, 20586 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti), 20587 &typedef_usage); 20588 } 20589 20590 /* Append TYPE_DECL to the template TEMPL. 20591 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL. 20592 At TEMPL instanciation time, TYPE_DECL will be checked to see 20593 if it can be accessed through SCOPE. 20594 LOCATION is the location of the usage point of TYPE_DECL. 20595 20596 e.g. consider the following code snippet: 20597 20598 class C 20599 { 20600 typedef int myint; 20601 }; 20602 20603 template<class U> struct S 20604 { 20605 C::myint mi; // <-- usage point of the typedef C::myint 20606 }; 20607 20608 S<char> s; 20609 20610 At S<char> instantiation time, we need to check the access of C::myint 20611 In other words, we need to check the access of the myint typedef through 20612 the C scope. For that purpose, this function will add the myint typedef 20613 and the scope C through which its being accessed to a list of typedefs 20614 tied to the template S. That list will be walked at template instantiation 20615 time and access check performed on each typedefs it contains. 20616 Note that this particular code snippet should yield an error because 20617 myint is private to C. */ 20618 20619 void 20620 append_type_to_template_for_access_check (tree templ, 20621 tree type_decl, 20622 tree scope, 20623 location_t location) 20624 { 20625 qualified_typedef_usage_t *iter; 20626 int i; 20627 20628 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL)); 20629 20630 /* Make sure we don't append the type to the template twice. */ 20631 FOR_EACH_VEC_ELT (qualified_typedef_usage_t, 20632 get_types_needing_access_check (templ), 20633 i, iter) 20634 if (iter->typedef_decl == type_decl && scope == iter->context) 20635 return; 20636 20637 append_type_to_template_for_access_check_1 (templ, type_decl, 20638 scope, location); 20639 } 20640 20641 /* Set up the hash tables for template instantiations. */ 20642 20643 void 20644 init_template_processing (void) 20645 { 20646 decl_specializations = htab_create_ggc (37, 20647 hash_specialization, 20648 eq_specializations, 20649 ggc_free); 20650 type_specializations = htab_create_ggc (37, 20651 hash_specialization, 20652 eq_specializations, 20653 ggc_free); 20654 } 20655 20656 /* Print stats about the template hash tables for -fstats. */ 20657 20658 void 20659 print_template_statistics (void) 20660 { 20661 fprintf (stderr, "decl_specializations: size %ld, %ld elements, " 20662 "%f collisions\n", (long) htab_size (decl_specializations), 20663 (long) htab_elements (decl_specializations), 20664 htab_collisions (decl_specializations)); 20665 fprintf (stderr, "type_specializations: size %ld, %ld elements, " 20666 "%f collisions\n", (long) htab_size (type_specializations), 20667 (long) htab_elements (type_specializations), 20668 htab_collisions (type_specializations)); 20669 } 20670 20671 #include "gt-cp-pt.h" 20672