1 /* Functions related to building classes and their related objects. 2 Copyright (C) 1987-2018 Free Software Foundation, Inc. 3 Contributed by Michael Tiemann (tiemann@cygnus.com) 4 5 This file is part of GCC. 6 7 GCC is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3, or (at your option) 10 any later version. 11 12 GCC is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with GCC; see the file COPYING3. If not see 19 <http://www.gnu.org/licenses/>. */ 20 21 22 /* High-level class interface. */ 23 24 #include "config.h" 25 #include "system.h" 26 #include "coretypes.h" 27 #include "target.h" 28 #include "cp-tree.h" 29 #include "stringpool.h" 30 #include "cgraph.h" 31 #include "stor-layout.h" 32 #include "attribs.h" 33 #include "flags.h" 34 #include "toplev.h" 35 #include "convert.h" 36 #include "dumpfile.h" 37 #include "gimplify.h" 38 #include "intl.h" 39 #include "asan.h" 40 41 /* Id for dumping the class hierarchy. */ 42 int class_dump_id; 43 44 /* The number of nested classes being processed. If we are not in the 45 scope of any class, this is zero. */ 46 47 int current_class_depth; 48 49 /* In order to deal with nested classes, we keep a stack of classes. 50 The topmost entry is the innermost class, and is the entry at index 51 CURRENT_CLASS_DEPTH */ 52 53 typedef struct class_stack_node { 54 /* The name of the class. */ 55 tree name; 56 57 /* The _TYPE node for the class. */ 58 tree type; 59 60 /* The access specifier pending for new declarations in the scope of 61 this class. */ 62 tree access; 63 64 /* If were defining TYPE, the names used in this class. */ 65 splay_tree names_used; 66 67 /* Nonzero if this class is no longer open, because of a call to 68 push_to_top_level. */ 69 size_t hidden; 70 }* class_stack_node_t; 71 72 struct vtbl_init_data 73 { 74 /* The base for which we're building initializers. */ 75 tree binfo; 76 /* The type of the most-derived type. */ 77 tree derived; 78 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived), 79 unless ctor_vtbl_p is true. */ 80 tree rtti_binfo; 81 /* The negative-index vtable initializers built up so far. These 82 are in order from least negative index to most negative index. */ 83 vec<constructor_elt, va_gc> *inits; 84 /* The binfo for the virtual base for which we're building 85 vcall offset initializers. */ 86 tree vbase; 87 /* The functions in vbase for which we have already provided vcall 88 offsets. */ 89 vec<tree, va_gc> *fns; 90 /* The vtable index of the next vcall or vbase offset. */ 91 tree index; 92 /* Nonzero if we are building the initializer for the primary 93 vtable. */ 94 int primary_vtbl_p; 95 /* Nonzero if we are building the initializer for a construction 96 vtable. */ 97 int ctor_vtbl_p; 98 /* True when adding vcall offset entries to the vtable. False when 99 merely computing the indices. */ 100 bool generate_vcall_entries; 101 }; 102 103 /* The type of a function passed to walk_subobject_offsets. */ 104 typedef int (*subobject_offset_fn) (tree, tree, splay_tree); 105 106 /* The stack itself. This is a dynamically resized array. The 107 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */ 108 static int current_class_stack_size; 109 static class_stack_node_t current_class_stack; 110 111 /* The size of the largest empty class seen in this translation unit. */ 112 static GTY (()) tree sizeof_biggest_empty_class; 113 114 /* An array of all local classes present in this translation unit, in 115 declaration order. */ 116 vec<tree, va_gc> *local_classes; 117 118 static tree get_vfield_name (tree); 119 static void finish_struct_anon (tree); 120 static tree get_vtable_name (tree); 121 static void get_basefndecls (tree, tree, vec<tree> *); 122 static int build_primary_vtable (tree, tree); 123 static int build_secondary_vtable (tree); 124 static void finish_vtbls (tree); 125 static void modify_vtable_entry (tree, tree, tree, tree, tree *); 126 static void finish_struct_bits (tree); 127 static int alter_access (tree, tree, tree); 128 static void handle_using_decl (tree, tree); 129 static tree dfs_modify_vtables (tree, void *); 130 static tree modify_all_vtables (tree, tree); 131 static void determine_primary_bases (tree); 132 static void maybe_warn_about_overly_private_class (tree); 133 static void add_implicitly_declared_members (tree, tree*, int, int); 134 static tree fixed_type_or_null (tree, int *, int *); 135 static tree build_simple_base_path (tree expr, tree binfo); 136 static tree build_vtbl_ref_1 (tree, tree); 137 static void build_vtbl_initializer (tree, tree, tree, tree, int *, 138 vec<constructor_elt, va_gc> **); 139 static bool check_bitfield_decl (tree); 140 static bool check_field_decl (tree, tree, int *, int *); 141 static void check_field_decls (tree, tree *, int *, int *); 142 static tree *build_base_field (record_layout_info, tree, splay_tree, tree *); 143 static void build_base_fields (record_layout_info, splay_tree, tree *); 144 static void check_methods (tree); 145 static void remove_zero_width_bit_fields (tree); 146 static bool accessible_nvdtor_p (tree); 147 148 /* Used by find_flexarrays and related functions. */ 149 struct flexmems_t; 150 static void diagnose_flexarrays (tree, const flexmems_t *); 151 static void find_flexarrays (tree, flexmems_t *, bool = false, 152 tree = NULL_TREE, tree = NULL_TREE); 153 static void check_flexarrays (tree, flexmems_t * = NULL, bool = false); 154 static void check_bases (tree, int *, int *); 155 static void check_bases_and_members (tree); 156 static tree create_vtable_ptr (tree, tree *); 157 static void include_empty_classes (record_layout_info); 158 static void layout_class_type (tree, tree *); 159 static void propagate_binfo_offsets (tree, tree); 160 static void layout_virtual_bases (record_layout_info, splay_tree); 161 static void build_vbase_offset_vtbl_entries (tree, vtbl_init_data *); 162 static void add_vcall_offset_vtbl_entries_r (tree, vtbl_init_data *); 163 static void add_vcall_offset_vtbl_entries_1 (tree, vtbl_init_data *); 164 static void build_vcall_offset_vtbl_entries (tree, vtbl_init_data *); 165 static void add_vcall_offset (tree, tree, vtbl_init_data *); 166 static void layout_vtable_decl (tree, int); 167 static tree dfs_find_final_overrider_pre (tree, void *); 168 static tree dfs_find_final_overrider_post (tree, void *); 169 static tree find_final_overrider (tree, tree, tree); 170 static int make_new_vtable (tree, tree); 171 static tree get_primary_binfo (tree); 172 static int maybe_indent_hierarchy (FILE *, int, int); 173 static tree dump_class_hierarchy_r (FILE *, dump_flags_t, tree, tree, int); 174 static void dump_class_hierarchy (tree); 175 static void dump_class_hierarchy_1 (FILE *, dump_flags_t, tree); 176 static void dump_array (FILE *, tree); 177 static void dump_vtable (tree, tree, tree); 178 static void dump_vtt (tree, tree); 179 static void dump_thunk (FILE *, int, tree); 180 static tree build_vtable (tree, tree, tree); 181 static void initialize_vtable (tree, vec<constructor_elt, va_gc> *); 182 static void layout_nonempty_base_or_field (record_layout_info, 183 tree, tree, splay_tree); 184 static tree end_of_class (tree, int); 185 static bool layout_empty_base (record_layout_info, tree, tree, splay_tree); 186 static void accumulate_vtbl_inits (tree, tree, tree, tree, tree, 187 vec<constructor_elt, va_gc> **); 188 static void dfs_accumulate_vtbl_inits (tree, tree, tree, tree, tree, 189 vec<constructor_elt, va_gc> **); 190 static void build_rtti_vtbl_entries (tree, vtbl_init_data *); 191 static void build_vcall_and_vbase_vtbl_entries (tree, vtbl_init_data *); 192 static void clone_constructors_and_destructors (tree); 193 static tree build_clone (tree, tree); 194 static void update_vtable_entry_for_fn (tree, tree, tree, tree *, unsigned); 195 static void build_ctor_vtbl_group (tree, tree); 196 static void build_vtt (tree); 197 static tree binfo_ctor_vtable (tree); 198 static void build_vtt_inits (tree, tree, vec<constructor_elt, va_gc> **, 199 tree *); 200 static tree dfs_build_secondary_vptr_vtt_inits (tree, void *); 201 static tree dfs_fixup_binfo_vtbls (tree, void *); 202 static int record_subobject_offset (tree, tree, splay_tree); 203 static int check_subobject_offset (tree, tree, splay_tree); 204 static int walk_subobject_offsets (tree, subobject_offset_fn, 205 tree, splay_tree, tree, int); 206 static void record_subobject_offsets (tree, tree, splay_tree, bool); 207 static int layout_conflict_p (tree, tree, splay_tree, int); 208 static int splay_tree_compare_integer_csts (splay_tree_key k1, 209 splay_tree_key k2); 210 static void warn_about_ambiguous_bases (tree); 211 static bool type_requires_array_cookie (tree); 212 static bool base_derived_from (tree, tree); 213 static int empty_base_at_nonzero_offset_p (tree, tree, splay_tree); 214 static tree end_of_base (tree); 215 static tree get_vcall_index (tree, tree); 216 static bool type_maybe_constexpr_default_constructor (tree); 217 218 /* Return a COND_EXPR that executes TRUE_STMT if this execution of the 219 'structor is in charge of 'structing virtual bases, or FALSE_STMT 220 otherwise. */ 221 222 tree 223 build_if_in_charge (tree true_stmt, tree false_stmt) 224 { 225 gcc_assert (DECL_HAS_IN_CHARGE_PARM_P (current_function_decl)); 226 tree cmp = build2 (NE_EXPR, boolean_type_node, 227 current_in_charge_parm, integer_zero_node); 228 tree type = unlowered_expr_type (true_stmt); 229 if (VOID_TYPE_P (type)) 230 type = unlowered_expr_type (false_stmt); 231 tree cond = build3 (COND_EXPR, type, 232 cmp, true_stmt, false_stmt); 233 return cond; 234 } 235 236 /* Convert to or from a base subobject. EXPR is an expression of type 237 `A' or `A*', an expression of type `B' or `B*' is returned. To 238 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for 239 the B base instance within A. To convert base A to derived B, CODE 240 is MINUS_EXPR and BINFO is the binfo for the A instance within B. 241 In this latter case, A must not be a morally virtual base of B. 242 NONNULL is true if EXPR is known to be non-NULL (this is only 243 needed when EXPR is of pointer type). CV qualifiers are preserved 244 from EXPR. */ 245 246 tree 247 build_base_path (enum tree_code code, 248 tree expr, 249 tree binfo, 250 int nonnull, 251 tsubst_flags_t complain) 252 { 253 tree v_binfo = NULL_TREE; 254 tree d_binfo = NULL_TREE; 255 tree probe; 256 tree offset; 257 tree target_type; 258 tree null_test = NULL; 259 tree ptr_target_type; 260 int fixed_type_p; 261 int want_pointer = TYPE_PTR_P (TREE_TYPE (expr)); 262 bool has_empty = false; 263 bool virtual_access; 264 bool rvalue = false; 265 266 if (expr == error_mark_node || binfo == error_mark_node || !binfo) 267 return error_mark_node; 268 269 for (probe = binfo; probe; probe = BINFO_INHERITANCE_CHAIN (probe)) 270 { 271 d_binfo = probe; 272 if (is_empty_class (BINFO_TYPE (probe))) 273 has_empty = true; 274 if (!v_binfo && BINFO_VIRTUAL_P (probe)) 275 v_binfo = probe; 276 } 277 278 probe = TYPE_MAIN_VARIANT (TREE_TYPE (expr)); 279 if (want_pointer) 280 probe = TYPE_MAIN_VARIANT (TREE_TYPE (probe)); 281 if (dependent_type_p (probe)) 282 if (tree open = currently_open_class (probe)) 283 probe = open; 284 285 if (code == PLUS_EXPR 286 && !SAME_BINFO_TYPE_P (BINFO_TYPE (d_binfo), probe)) 287 { 288 /* This can happen when adjust_result_of_qualified_name_lookup can't 289 find a unique base binfo in a call to a member function. We 290 couldn't give the diagnostic then since we might have been calling 291 a static member function, so we do it now. In other cases, eg. 292 during error recovery (c++/71979), we may not have a base at all. */ 293 if (complain & tf_error) 294 { 295 tree base = lookup_base (probe, BINFO_TYPE (d_binfo), 296 ba_unique, NULL, complain); 297 gcc_assert (base == error_mark_node || !base); 298 } 299 return error_mark_node; 300 } 301 302 gcc_assert ((code == MINUS_EXPR 303 && SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), probe)) 304 || code == PLUS_EXPR); 305 306 if (binfo == d_binfo) 307 /* Nothing to do. */ 308 return expr; 309 310 if (code == MINUS_EXPR && v_binfo) 311 { 312 if (complain & tf_error) 313 { 314 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (v_binfo))) 315 { 316 if (want_pointer) 317 error ("cannot convert from pointer to base class %qT to " 318 "pointer to derived class %qT because the base is " 319 "virtual", BINFO_TYPE (binfo), BINFO_TYPE (d_binfo)); 320 else 321 error ("cannot convert from base class %qT to derived " 322 "class %qT because the base is virtual", 323 BINFO_TYPE (binfo), BINFO_TYPE (d_binfo)); 324 } 325 else 326 { 327 if (want_pointer) 328 error ("cannot convert from pointer to base class %qT to " 329 "pointer to derived class %qT via virtual base %qT", 330 BINFO_TYPE (binfo), BINFO_TYPE (d_binfo), 331 BINFO_TYPE (v_binfo)); 332 else 333 error ("cannot convert from base class %qT to derived " 334 "class %qT via virtual base %qT", BINFO_TYPE (binfo), 335 BINFO_TYPE (d_binfo), BINFO_TYPE (v_binfo)); 336 } 337 } 338 return error_mark_node; 339 } 340 341 if (!want_pointer) 342 { 343 rvalue = !lvalue_p (expr); 344 /* This must happen before the call to save_expr. */ 345 expr = cp_build_addr_expr (expr, complain); 346 } 347 else 348 expr = mark_rvalue_use (expr); 349 350 offset = BINFO_OFFSET (binfo); 351 fixed_type_p = resolves_to_fixed_type_p (expr, &nonnull); 352 target_type = code == PLUS_EXPR ? BINFO_TYPE (binfo) : BINFO_TYPE (d_binfo); 353 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always 354 cv-unqualified. Extract the cv-qualifiers from EXPR so that the 355 expression returned matches the input. */ 356 target_type = cp_build_qualified_type 357 (target_type, cp_type_quals (TREE_TYPE (TREE_TYPE (expr)))); 358 ptr_target_type = build_pointer_type (target_type); 359 360 /* Do we need to look in the vtable for the real offset? */ 361 virtual_access = (v_binfo && fixed_type_p <= 0); 362 363 /* Don't bother with the calculations inside sizeof; they'll ICE if the 364 source type is incomplete and the pointer value doesn't matter. In a 365 template (even in instantiate_non_dependent_expr), we don't have vtables 366 set up properly yet, and the value doesn't matter there either; we're 367 just interested in the result of overload resolution. */ 368 if (cp_unevaluated_operand != 0 369 || processing_template_decl 370 || in_template_function ()) 371 { 372 expr = build_nop (ptr_target_type, expr); 373 goto indout; 374 } 375 376 /* If we're in an NSDMI, we don't have the full constructor context yet 377 that we need for converting to a virtual base, so just build a stub 378 CONVERT_EXPR and expand it later in bot_replace. */ 379 if (virtual_access && fixed_type_p < 0 380 && current_scope () != current_function_decl) 381 { 382 expr = build1 (CONVERT_EXPR, ptr_target_type, expr); 383 CONVERT_EXPR_VBASE_PATH (expr) = true; 384 goto indout; 385 } 386 387 /* Do we need to check for a null pointer? */ 388 if (want_pointer && !nonnull) 389 { 390 /* If we know the conversion will not actually change the value 391 of EXPR, then we can avoid testing the expression for NULL. 392 We have to avoid generating a COMPONENT_REF for a base class 393 field, because other parts of the compiler know that such 394 expressions are always non-NULL. */ 395 if (!virtual_access && integer_zerop (offset)) 396 return build_nop (ptr_target_type, expr); 397 null_test = error_mark_node; 398 } 399 400 /* Protect against multiple evaluation if necessary. */ 401 if (TREE_SIDE_EFFECTS (expr) && (null_test || virtual_access)) 402 expr = save_expr (expr); 403 404 /* Now that we've saved expr, build the real null test. */ 405 if (null_test) 406 { 407 tree zero = cp_convert (TREE_TYPE (expr), nullptr_node, complain); 408 null_test = build2_loc (input_location, NE_EXPR, boolean_type_node, 409 expr, zero); 410 /* This is a compiler generated comparison, don't emit 411 e.g. -Wnonnull-compare warning for it. */ 412 TREE_NO_WARNING (null_test) = 1; 413 } 414 415 /* If this is a simple base reference, express it as a COMPONENT_REF. */ 416 if (code == PLUS_EXPR && !virtual_access 417 /* We don't build base fields for empty bases, and they aren't very 418 interesting to the optimizers anyway. */ 419 && !has_empty) 420 { 421 expr = cp_build_fold_indirect_ref (expr); 422 expr = build_simple_base_path (expr, binfo); 423 if (rvalue && lvalue_p (expr)) 424 expr = move (expr); 425 if (want_pointer) 426 expr = build_address (expr); 427 target_type = TREE_TYPE (expr); 428 goto out; 429 } 430 431 if (virtual_access) 432 { 433 /* Going via virtual base V_BINFO. We need the static offset 434 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to 435 V_BINFO. That offset is an entry in D_BINFO's vtable. */ 436 tree v_offset; 437 438 if (fixed_type_p < 0 && in_base_initializer) 439 { 440 /* In a base member initializer, we cannot rely on the 441 vtable being set up. We have to indirect via the 442 vtt_parm. */ 443 tree t; 444 445 t = TREE_TYPE (TYPE_VFIELD (current_class_type)); 446 t = build_pointer_type (t); 447 v_offset = fold_convert (t, current_vtt_parm); 448 v_offset = cp_build_fold_indirect_ref (v_offset); 449 } 450 else 451 { 452 tree t = expr; 453 if (sanitize_flags_p (SANITIZE_VPTR) 454 && fixed_type_p == 0) 455 { 456 t = cp_ubsan_maybe_instrument_cast_to_vbase (input_location, 457 probe, expr); 458 if (t == NULL_TREE) 459 t = expr; 460 } 461 v_offset = build_vfield_ref (cp_build_fold_indirect_ref (t), 462 TREE_TYPE (TREE_TYPE (expr))); 463 } 464 465 if (v_offset == error_mark_node) 466 return error_mark_node; 467 468 v_offset = fold_build_pointer_plus (v_offset, BINFO_VPTR_FIELD (v_binfo)); 469 v_offset = build1 (NOP_EXPR, 470 build_pointer_type (ptrdiff_type_node), 471 v_offset); 472 v_offset = cp_build_fold_indirect_ref (v_offset); 473 TREE_CONSTANT (v_offset) = 1; 474 475 offset = convert_to_integer (ptrdiff_type_node, 476 size_diffop_loc (input_location, offset, 477 BINFO_OFFSET (v_binfo))); 478 479 if (!integer_zerop (offset)) 480 v_offset = build2 (code, ptrdiff_type_node, v_offset, offset); 481 482 if (fixed_type_p < 0) 483 /* Negative fixed_type_p means this is a constructor or destructor; 484 virtual base layout is fixed in in-charge [cd]tors, but not in 485 base [cd]tors. */ 486 offset = build_if_in_charge 487 (convert_to_integer (ptrdiff_type_node, BINFO_OFFSET (binfo)), 488 v_offset); 489 else 490 offset = v_offset; 491 } 492 493 if (want_pointer) 494 target_type = ptr_target_type; 495 496 expr = build1 (NOP_EXPR, ptr_target_type, expr); 497 498 if (!integer_zerop (offset)) 499 { 500 offset = fold_convert (sizetype, offset); 501 if (code == MINUS_EXPR) 502 offset = fold_build1_loc (input_location, NEGATE_EXPR, sizetype, offset); 503 expr = fold_build_pointer_plus (expr, offset); 504 } 505 else 506 null_test = NULL; 507 508 indout: 509 if (!want_pointer) 510 { 511 expr = cp_build_fold_indirect_ref (expr); 512 if (rvalue) 513 expr = move (expr); 514 } 515 516 out: 517 if (null_test) 518 expr = fold_build3_loc (input_location, COND_EXPR, target_type, null_test, expr, 519 build_zero_cst (target_type)); 520 521 return expr; 522 } 523 524 /* Subroutine of build_base_path; EXPR and BINFO are as in that function. 525 Perform a derived-to-base conversion by recursively building up a 526 sequence of COMPONENT_REFs to the appropriate base fields. */ 527 528 static tree 529 build_simple_base_path (tree expr, tree binfo) 530 { 531 tree type = BINFO_TYPE (binfo); 532 tree d_binfo = BINFO_INHERITANCE_CHAIN (binfo); 533 tree field; 534 535 if (d_binfo == NULL_TREE) 536 { 537 tree temp; 538 539 gcc_assert (TYPE_MAIN_VARIANT (TREE_TYPE (expr)) == type); 540 541 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' 542 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only 543 an lvalue in the front end; only _DECLs and _REFs are lvalues 544 in the back end. */ 545 temp = unary_complex_lvalue (ADDR_EXPR, expr); 546 if (temp) 547 expr = cp_build_fold_indirect_ref (temp); 548 549 return expr; 550 } 551 552 /* Recurse. */ 553 expr = build_simple_base_path (expr, d_binfo); 554 555 for (field = TYPE_FIELDS (BINFO_TYPE (d_binfo)); 556 field; field = DECL_CHAIN (field)) 557 /* Is this the base field created by build_base_field? */ 558 if (TREE_CODE (field) == FIELD_DECL 559 && DECL_FIELD_IS_BASE (field) 560 && TREE_TYPE (field) == type 561 /* If we're looking for a field in the most-derived class, 562 also check the field offset; we can have two base fields 563 of the same type if one is an indirect virtual base and one 564 is a direct non-virtual base. */ 565 && (BINFO_INHERITANCE_CHAIN (d_binfo) 566 || tree_int_cst_equal (byte_position (field), 567 BINFO_OFFSET (binfo)))) 568 { 569 /* We don't use build_class_member_access_expr here, as that 570 has unnecessary checks, and more importantly results in 571 recursive calls to dfs_walk_once. */ 572 int type_quals = cp_type_quals (TREE_TYPE (expr)); 573 574 expr = build3 (COMPONENT_REF, 575 cp_build_qualified_type (type, type_quals), 576 expr, field, NULL_TREE); 577 /* Mark the expression const or volatile, as appropriate. 578 Even though we've dealt with the type above, we still have 579 to mark the expression itself. */ 580 if (type_quals & TYPE_QUAL_CONST) 581 TREE_READONLY (expr) = 1; 582 if (type_quals & TYPE_QUAL_VOLATILE) 583 TREE_THIS_VOLATILE (expr) = 1; 584 585 return expr; 586 } 587 588 /* Didn't find the base field?!? */ 589 gcc_unreachable (); 590 } 591 592 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose 593 type is a class type or a pointer to a class type. In the former 594 case, TYPE is also a class type; in the latter it is another 595 pointer type. If CHECK_ACCESS is true, an error message is emitted 596 if TYPE is inaccessible. If OBJECT has pointer type, the value is 597 assumed to be non-NULL. */ 598 599 tree 600 convert_to_base (tree object, tree type, bool check_access, bool nonnull, 601 tsubst_flags_t complain) 602 { 603 tree binfo; 604 tree object_type; 605 606 if (TYPE_PTR_P (TREE_TYPE (object))) 607 { 608 object_type = TREE_TYPE (TREE_TYPE (object)); 609 type = TREE_TYPE (type); 610 } 611 else 612 object_type = TREE_TYPE (object); 613 614 binfo = lookup_base (object_type, type, check_access ? ba_check : ba_unique, 615 NULL, complain); 616 if (!binfo || binfo == error_mark_node) 617 return error_mark_node; 618 619 return build_base_path (PLUS_EXPR, object, binfo, nonnull, complain); 620 } 621 622 /* EXPR is an expression with unqualified class type. BASE is a base 623 binfo of that class type. Returns EXPR, converted to the BASE 624 type. This function assumes that EXPR is the most derived class; 625 therefore virtual bases can be found at their static offsets. */ 626 627 tree 628 convert_to_base_statically (tree expr, tree base) 629 { 630 tree expr_type; 631 632 expr_type = TREE_TYPE (expr); 633 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (base), expr_type)) 634 { 635 /* If this is a non-empty base, use a COMPONENT_REF. */ 636 if (!is_empty_class (BINFO_TYPE (base))) 637 return build_simple_base_path (expr, base); 638 639 /* We use fold_build2 and fold_convert below to simplify the trees 640 provided to the optimizers. It is not safe to call these functions 641 when processing a template because they do not handle C++-specific 642 trees. */ 643 gcc_assert (!processing_template_decl); 644 expr = cp_build_addr_expr (expr, tf_warning_or_error); 645 if (!integer_zerop (BINFO_OFFSET (base))) 646 expr = fold_build_pointer_plus_loc (input_location, 647 expr, BINFO_OFFSET (base)); 648 expr = fold_convert (build_pointer_type (BINFO_TYPE (base)), expr); 649 expr = build_fold_indirect_ref_loc (input_location, expr); 650 } 651 652 return expr; 653 } 654 655 656 tree 657 build_vfield_ref (tree datum, tree type) 658 { 659 tree vfield, vcontext; 660 661 if (datum == error_mark_node 662 /* Can happen in case of duplicate base types (c++/59082). */ 663 || !TYPE_VFIELD (type)) 664 return error_mark_node; 665 666 /* First, convert to the requested type. */ 667 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (datum), type)) 668 datum = convert_to_base (datum, type, /*check_access=*/false, 669 /*nonnull=*/true, tf_warning_or_error); 670 671 /* Second, the requested type may not be the owner of its own vptr. 672 If not, convert to the base class that owns it. We cannot use 673 convert_to_base here, because VCONTEXT may appear more than once 674 in the inheritance hierarchy of TYPE, and thus direct conversion 675 between the types may be ambiguous. Following the path back up 676 one step at a time via primary bases avoids the problem. */ 677 vfield = TYPE_VFIELD (type); 678 vcontext = DECL_CONTEXT (vfield); 679 while (!same_type_ignoring_top_level_qualifiers_p (vcontext, type)) 680 { 681 datum = build_simple_base_path (datum, CLASSTYPE_PRIMARY_BINFO (type)); 682 type = TREE_TYPE (datum); 683 } 684 685 return build3 (COMPONENT_REF, TREE_TYPE (vfield), datum, vfield, NULL_TREE); 686 } 687 688 /* Given an object INSTANCE, return an expression which yields the 689 vtable element corresponding to INDEX. There are many special 690 cases for INSTANCE which we take care of here, mainly to avoid 691 creating extra tree nodes when we don't have to. */ 692 693 static tree 694 build_vtbl_ref_1 (tree instance, tree idx) 695 { 696 tree aref; 697 tree vtbl = NULL_TREE; 698 699 /* Try to figure out what a reference refers to, and 700 access its virtual function table directly. */ 701 702 int cdtorp = 0; 703 tree fixed_type = fixed_type_or_null (instance, NULL, &cdtorp); 704 705 tree basetype = non_reference (TREE_TYPE (instance)); 706 707 if (fixed_type && !cdtorp) 708 { 709 tree binfo = lookup_base (fixed_type, basetype, 710 ba_unique, NULL, tf_none); 711 if (binfo && binfo != error_mark_node) 712 vtbl = unshare_expr (BINFO_VTABLE (binfo)); 713 } 714 715 if (!vtbl) 716 vtbl = build_vfield_ref (instance, basetype); 717 718 aref = build_array_ref (input_location, vtbl, idx); 719 TREE_CONSTANT (aref) |= TREE_CONSTANT (vtbl) && TREE_CONSTANT (idx); 720 721 return aref; 722 } 723 724 tree 725 build_vtbl_ref (tree instance, tree idx) 726 { 727 tree aref = build_vtbl_ref_1 (instance, idx); 728 729 return aref; 730 } 731 732 /* Given a stable object pointer INSTANCE_PTR, return an expression which 733 yields a function pointer corresponding to vtable element INDEX. */ 734 735 tree 736 build_vfn_ref (tree instance_ptr, tree idx) 737 { 738 tree aref; 739 740 aref = build_vtbl_ref_1 (cp_build_fold_indirect_ref (instance_ptr), 741 idx); 742 743 /* When using function descriptors, the address of the 744 vtable entry is treated as a function pointer. */ 745 if (TARGET_VTABLE_USES_DESCRIPTORS) 746 aref = build1 (NOP_EXPR, TREE_TYPE (aref), 747 cp_build_addr_expr (aref, tf_warning_or_error)); 748 749 /* Remember this as a method reference, for later devirtualization. */ 750 aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr, idx); 751 752 return aref; 753 } 754 755 /* Return the name of the virtual function table (as an IDENTIFIER_NODE) 756 for the given TYPE. */ 757 758 static tree 759 get_vtable_name (tree type) 760 { 761 return mangle_vtbl_for_type (type); 762 } 763 764 /* DECL is an entity associated with TYPE, like a virtual table or an 765 implicitly generated constructor. Determine whether or not DECL 766 should have external or internal linkage at the object file 767 level. This routine does not deal with COMDAT linkage and other 768 similar complexities; it simply sets TREE_PUBLIC if it possible for 769 entities in other translation units to contain copies of DECL, in 770 the abstract. */ 771 772 void 773 set_linkage_according_to_type (tree /*type*/, tree decl) 774 { 775 TREE_PUBLIC (decl) = 1; 776 determine_visibility (decl); 777 } 778 779 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE. 780 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.) 781 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */ 782 783 static tree 784 build_vtable (tree class_type, tree name, tree vtable_type) 785 { 786 tree decl; 787 788 decl = build_lang_decl (VAR_DECL, name, vtable_type); 789 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME 790 now to avoid confusion in mangle_decl. */ 791 SET_DECL_ASSEMBLER_NAME (decl, name); 792 DECL_CONTEXT (decl) = class_type; 793 DECL_ARTIFICIAL (decl) = 1; 794 TREE_STATIC (decl) = 1; 795 TREE_READONLY (decl) = 1; 796 DECL_VIRTUAL_P (decl) = 1; 797 SET_DECL_ALIGN (decl, TARGET_VTABLE_ENTRY_ALIGN); 798 DECL_USER_ALIGN (decl) = true; 799 DECL_VTABLE_OR_VTT_P (decl) = 1; 800 set_linkage_according_to_type (class_type, decl); 801 /* The vtable has not been defined -- yet. */ 802 DECL_EXTERNAL (decl) = 1; 803 DECL_NOT_REALLY_EXTERN (decl) = 1; 804 805 /* Mark the VAR_DECL node representing the vtable itself as a 806 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It 807 is rather important that such things be ignored because any 808 effort to actually generate DWARF for them will run into 809 trouble when/if we encounter code like: 810 811 #pragma interface 812 struct S { virtual void member (); }; 813 814 because the artificial declaration of the vtable itself (as 815 manufactured by the g++ front end) will say that the vtable is 816 a static member of `S' but only *after* the debug output for 817 the definition of `S' has already been output. This causes 818 grief because the DWARF entry for the definition of the vtable 819 will try to refer back to an earlier *declaration* of the 820 vtable as a static member of `S' and there won't be one. We 821 might be able to arrange to have the "vtable static member" 822 attached to the member list for `S' before the debug info for 823 `S' get written (which would solve the problem) but that would 824 require more intrusive changes to the g++ front end. */ 825 DECL_IGNORED_P (decl) = 1; 826 827 return decl; 828 } 829 830 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic, 831 or even complete. If this does not exist, create it. If COMPLETE is 832 nonzero, then complete the definition of it -- that will render it 833 impossible to actually build the vtable, but is useful to get at those 834 which are known to exist in the runtime. */ 835 836 tree 837 get_vtable_decl (tree type, int complete) 838 { 839 tree decl; 840 841 if (CLASSTYPE_VTABLES (type)) 842 return CLASSTYPE_VTABLES (type); 843 844 decl = build_vtable (type, get_vtable_name (type), vtbl_type_node); 845 CLASSTYPE_VTABLES (type) = decl; 846 847 if (complete) 848 { 849 DECL_EXTERNAL (decl) = 1; 850 cp_finish_decl (decl, NULL_TREE, false, NULL_TREE, 0); 851 } 852 853 return decl; 854 } 855 856 /* Build the primary virtual function table for TYPE. If BINFO is 857 non-NULL, build the vtable starting with the initial approximation 858 that it is the same as the one which is the head of the association 859 list. Returns a nonzero value if a new vtable is actually 860 created. */ 861 862 static int 863 build_primary_vtable (tree binfo, tree type) 864 { 865 tree decl; 866 tree virtuals; 867 868 decl = get_vtable_decl (type, /*complete=*/0); 869 870 if (binfo) 871 { 872 if (BINFO_NEW_VTABLE_MARKED (binfo)) 873 /* We have already created a vtable for this base, so there's 874 no need to do it again. */ 875 return 0; 876 877 virtuals = copy_list (BINFO_VIRTUALS (binfo)); 878 TREE_TYPE (decl) = TREE_TYPE (get_vtbl_decl_for_binfo (binfo)); 879 DECL_SIZE (decl) = TYPE_SIZE (TREE_TYPE (decl)); 880 DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (TREE_TYPE (decl)); 881 } 882 else 883 { 884 gcc_assert (TREE_TYPE (decl) == vtbl_type_node); 885 virtuals = NULL_TREE; 886 } 887 888 /* Initialize the association list for this type, based 889 on our first approximation. */ 890 BINFO_VTABLE (TYPE_BINFO (type)) = decl; 891 BINFO_VIRTUALS (TYPE_BINFO (type)) = virtuals; 892 SET_BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (type)); 893 return 1; 894 } 895 896 /* Give BINFO a new virtual function table which is initialized 897 with a skeleton-copy of its original initialization. The only 898 entry that changes is the `delta' entry, so we can really 899 share a lot of structure. 900 901 FOR_TYPE is the most derived type which caused this table to 902 be needed. 903 904 Returns nonzero if we haven't met BINFO before. 905 906 The order in which vtables are built (by calling this function) for 907 an object must remain the same, otherwise a binary incompatibility 908 can result. */ 909 910 static int 911 build_secondary_vtable (tree binfo) 912 { 913 if (BINFO_NEW_VTABLE_MARKED (binfo)) 914 /* We already created a vtable for this base. There's no need to 915 do it again. */ 916 return 0; 917 918 /* Remember that we've created a vtable for this BINFO, so that we 919 don't try to do so again. */ 920 SET_BINFO_NEW_VTABLE_MARKED (binfo); 921 922 /* Make fresh virtual list, so we can smash it later. */ 923 BINFO_VIRTUALS (binfo) = copy_list (BINFO_VIRTUALS (binfo)); 924 925 /* Secondary vtables are laid out as part of the same structure as 926 the primary vtable. */ 927 BINFO_VTABLE (binfo) = NULL_TREE; 928 return 1; 929 } 930 931 /* Create a new vtable for BINFO which is the hierarchy dominated by 932 T. Return nonzero if we actually created a new vtable. */ 933 934 static int 935 make_new_vtable (tree t, tree binfo) 936 { 937 if (binfo == TYPE_BINFO (t)) 938 /* In this case, it is *type*'s vtable we are modifying. We start 939 with the approximation that its vtable is that of the 940 immediate base class. */ 941 return build_primary_vtable (binfo, t); 942 else 943 /* This is our very own copy of `basetype' to play with. Later, 944 we will fill in all the virtual functions that override the 945 virtual functions in these base classes which are not defined 946 by the current type. */ 947 return build_secondary_vtable (binfo); 948 } 949 950 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO 951 (which is in the hierarchy dominated by T) list FNDECL as its 952 BV_FN. DELTA is the required constant adjustment from the `this' 953 pointer where the vtable entry appears to the `this' required when 954 the function is actually called. */ 955 956 static void 957 modify_vtable_entry (tree t, 958 tree binfo, 959 tree fndecl, 960 tree delta, 961 tree *virtuals) 962 { 963 tree v; 964 965 v = *virtuals; 966 967 if (fndecl != BV_FN (v) 968 || !tree_int_cst_equal (delta, BV_DELTA (v))) 969 { 970 /* We need a new vtable for BINFO. */ 971 if (make_new_vtable (t, binfo)) 972 { 973 /* If we really did make a new vtable, we also made a copy 974 of the BINFO_VIRTUALS list. Now, we have to find the 975 corresponding entry in that list. */ 976 *virtuals = BINFO_VIRTUALS (binfo); 977 while (BV_FN (*virtuals) != BV_FN (v)) 978 *virtuals = TREE_CHAIN (*virtuals); 979 v = *virtuals; 980 } 981 982 BV_DELTA (v) = delta; 983 BV_VCALL_INDEX (v) = NULL_TREE; 984 BV_FN (v) = fndecl; 985 } 986 } 987 988 989 /* Add method METHOD to class TYPE. If VIA_USING indicates whether 990 METHOD is being injected via a using_decl. Returns true if the 991 method could be added to the method vec. */ 992 993 bool 994 add_method (tree type, tree method, bool via_using) 995 { 996 if (method == error_mark_node) 997 return false; 998 999 gcc_assert (!DECL_EXTERN_C_P (method)); 1000 1001 tree *slot = find_member_slot (type, DECL_NAME (method)); 1002 tree current_fns = slot ? *slot : NULL_TREE; 1003 1004 /* Check to see if we've already got this method. */ 1005 for (ovl_iterator iter (current_fns); iter; ++iter) 1006 { 1007 tree fn = *iter; 1008 tree fn_type; 1009 tree method_type; 1010 tree parms1; 1011 tree parms2; 1012 1013 if (TREE_CODE (fn) != TREE_CODE (method)) 1014 continue; 1015 1016 /* Two using-declarations can coexist, we'll complain about ambiguity in 1017 overload resolution. */ 1018 if (via_using && iter.using_p () 1019 /* Except handle inherited constructors specially. */ 1020 && ! DECL_CONSTRUCTOR_P (fn)) 1021 continue; 1022 1023 /* [over.load] Member function declarations with the 1024 same name and the same parameter types cannot be 1025 overloaded if any of them is a static member 1026 function declaration. 1027 1028 [over.load] Member function declarations with the same name and 1029 the same parameter-type-list as well as member function template 1030 declarations with the same name, the same parameter-type-list, and 1031 the same template parameter lists cannot be overloaded if any of 1032 them, but not all, have a ref-qualifier. 1033 1034 [namespace.udecl] When a using-declaration brings names 1035 from a base class into a derived class scope, member 1036 functions in the derived class override and/or hide member 1037 functions with the same name and parameter types in a base 1038 class (rather than conflicting). */ 1039 fn_type = TREE_TYPE (fn); 1040 method_type = TREE_TYPE (method); 1041 parms1 = TYPE_ARG_TYPES (fn_type); 1042 parms2 = TYPE_ARG_TYPES (method_type); 1043 1044 /* Compare the quals on the 'this' parm. Don't compare 1045 the whole types, as used functions are treated as 1046 coming from the using class in overload resolution. */ 1047 if (! DECL_STATIC_FUNCTION_P (fn) 1048 && ! DECL_STATIC_FUNCTION_P (method) 1049 /* Either both or neither need to be ref-qualified for 1050 differing quals to allow overloading. */ 1051 && (FUNCTION_REF_QUALIFIED (fn_type) 1052 == FUNCTION_REF_QUALIFIED (method_type)) 1053 && (type_memfn_quals (fn_type) != type_memfn_quals (method_type) 1054 || type_memfn_rqual (fn_type) != type_memfn_rqual (method_type))) 1055 continue; 1056 1057 /* For templates, the return type and template parameters 1058 must be identical. */ 1059 if (TREE_CODE (fn) == TEMPLATE_DECL 1060 && (!same_type_p (TREE_TYPE (fn_type), 1061 TREE_TYPE (method_type)) 1062 || !comp_template_parms (DECL_TEMPLATE_PARMS (fn), 1063 DECL_TEMPLATE_PARMS (method)))) 1064 continue; 1065 1066 if (! DECL_STATIC_FUNCTION_P (fn)) 1067 parms1 = TREE_CHAIN (parms1); 1068 if (! DECL_STATIC_FUNCTION_P (method)) 1069 parms2 = TREE_CHAIN (parms2); 1070 1071 /* Bring back parameters omitted from an inherited ctor. */ 1072 if (ctor_omit_inherited_parms (fn)) 1073 parms1 = FUNCTION_FIRST_USER_PARMTYPE (DECL_ORIGIN (fn)); 1074 if (ctor_omit_inherited_parms (method)) 1075 parms2 = FUNCTION_FIRST_USER_PARMTYPE (DECL_ORIGIN (method)); 1076 1077 if (compparms (parms1, parms2) 1078 && (!DECL_CONV_FN_P (fn) 1079 || same_type_p (TREE_TYPE (fn_type), 1080 TREE_TYPE (method_type))) 1081 && equivalently_constrained (fn, method)) 1082 { 1083 /* If these are versions of the same function, process and 1084 move on. */ 1085 if (TREE_CODE (fn) == FUNCTION_DECL 1086 && maybe_version_functions (method, fn, true)) 1087 continue; 1088 1089 if (DECL_INHERITED_CTOR (method)) 1090 { 1091 if (DECL_INHERITED_CTOR (fn)) 1092 { 1093 tree basem = DECL_INHERITED_CTOR_BASE (method); 1094 tree basef = DECL_INHERITED_CTOR_BASE (fn); 1095 if (flag_new_inheriting_ctors) 1096 { 1097 if (basem == basef) 1098 { 1099 /* Inheriting the same constructor along different 1100 paths, combine them. */ 1101 SET_DECL_INHERITED_CTOR 1102 (fn, ovl_make (DECL_INHERITED_CTOR (method), 1103 DECL_INHERITED_CTOR (fn))); 1104 /* And discard the new one. */ 1105 return false; 1106 } 1107 else 1108 /* Inherited ctors can coexist until overload 1109 resolution. */ 1110 continue; 1111 } 1112 error_at (DECL_SOURCE_LOCATION (method), 1113 "%q#D conflicts with version inherited from %qT", 1114 method, basef); 1115 inform (DECL_SOURCE_LOCATION (fn), 1116 "version inherited from %qT declared here", 1117 basef); 1118 } 1119 /* Otherwise defer to the other function. */ 1120 return false; 1121 } 1122 1123 if (via_using) 1124 /* Defer to the local function. */ 1125 return false; 1126 else if (flag_new_inheriting_ctors 1127 && DECL_INHERITED_CTOR (fn)) 1128 { 1129 /* Remove the inherited constructor. */ 1130 current_fns = iter.remove_node (current_fns); 1131 continue; 1132 } 1133 else 1134 { 1135 error_at (DECL_SOURCE_LOCATION (method), 1136 "%q#D cannot be overloaded with %q#D", method, fn); 1137 inform (DECL_SOURCE_LOCATION (fn), 1138 "previous declaration %q#D", fn); 1139 return false; 1140 } 1141 } 1142 } 1143 1144 current_fns = ovl_insert (method, current_fns, via_using); 1145 1146 if (!COMPLETE_TYPE_P (type) && !DECL_CONV_FN_P (method) 1147 && !push_class_level_binding (DECL_NAME (method), current_fns)) 1148 return false; 1149 1150 if (!slot) 1151 slot = add_member_slot (type, DECL_NAME (method)); 1152 1153 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */ 1154 grok_special_member_properties (method); 1155 1156 *slot = current_fns; 1157 1158 return true; 1159 } 1160 1161 /* Subroutines of finish_struct. */ 1162 1163 /* Change the access of FDECL to ACCESS in T. Return 1 if change was 1164 legit, otherwise return 0. */ 1165 1166 static int 1167 alter_access (tree t, tree fdecl, tree access) 1168 { 1169 tree elem; 1170 1171 retrofit_lang_decl (fdecl); 1172 1173 gcc_assert (!DECL_DISCRIMINATOR_P (fdecl)); 1174 1175 elem = purpose_member (t, DECL_ACCESS (fdecl)); 1176 if (elem) 1177 { 1178 if (TREE_VALUE (elem) != access) 1179 { 1180 if (TREE_CODE (TREE_TYPE (fdecl)) == FUNCTION_DECL) 1181 error ("conflicting access specifications for method" 1182 " %q+D, ignored", TREE_TYPE (fdecl)); 1183 else 1184 error ("conflicting access specifications for field %qE, ignored", 1185 DECL_NAME (fdecl)); 1186 } 1187 else 1188 { 1189 /* They're changing the access to the same thing they changed 1190 it to before. That's OK. */ 1191 ; 1192 } 1193 } 1194 else 1195 { 1196 perform_or_defer_access_check (TYPE_BINFO (t), fdecl, fdecl, 1197 tf_warning_or_error); 1198 DECL_ACCESS (fdecl) = tree_cons (t, access, DECL_ACCESS (fdecl)); 1199 return 1; 1200 } 1201 return 0; 1202 } 1203 1204 /* Return the access node for DECL's access in its enclosing class. */ 1205 1206 tree 1207 declared_access (tree decl) 1208 { 1209 return (TREE_PRIVATE (decl) ? access_private_node 1210 : TREE_PROTECTED (decl) ? access_protected_node 1211 : access_public_node); 1212 } 1213 1214 /* Process the USING_DECL, which is a member of T. */ 1215 1216 static void 1217 handle_using_decl (tree using_decl, tree t) 1218 { 1219 tree decl = USING_DECL_DECLS (using_decl); 1220 tree name = DECL_NAME (using_decl); 1221 tree access = declared_access (using_decl); 1222 tree flist = NULL_TREE; 1223 tree old_value; 1224 1225 gcc_assert (!processing_template_decl && decl); 1226 1227 old_value = lookup_member (t, name, /*protect=*/0, /*want_type=*/false, 1228 tf_warning_or_error); 1229 if (old_value) 1230 { 1231 old_value = OVL_FIRST (old_value); 1232 1233 if (DECL_P (old_value) && DECL_CONTEXT (old_value) == t) 1234 /* OK */; 1235 else 1236 old_value = NULL_TREE; 1237 } 1238 1239 cp_emit_debug_info_for_using (decl, t); 1240 1241 if (is_overloaded_fn (decl)) 1242 flist = decl; 1243 1244 if (! old_value) 1245 ; 1246 else if (is_overloaded_fn (old_value)) 1247 { 1248 if (flist) 1249 /* It's OK to use functions from a base when there are functions with 1250 the same name already present in the current class. */; 1251 else 1252 { 1253 error_at (DECL_SOURCE_LOCATION (using_decl), "%qD invalid in %q#T " 1254 "because of local method %q#D with same name", 1255 using_decl, t, old_value); 1256 inform (DECL_SOURCE_LOCATION (old_value), 1257 "local method %q#D declared here", old_value); 1258 return; 1259 } 1260 } 1261 else if (!DECL_ARTIFICIAL (old_value)) 1262 { 1263 error_at (DECL_SOURCE_LOCATION (using_decl), "%qD invalid in %q#T " 1264 "because of local member %q#D with same name", 1265 using_decl, t, old_value); 1266 inform (DECL_SOURCE_LOCATION (old_value), 1267 "local member %q#D declared here", old_value); 1268 return; 1269 } 1270 1271 /* Make type T see field decl FDECL with access ACCESS. */ 1272 if (flist) 1273 for (ovl_iterator iter (flist); iter; ++iter) 1274 { 1275 add_method (t, *iter, true); 1276 alter_access (t, *iter, access); 1277 } 1278 else 1279 alter_access (t, decl, access); 1280 } 1281 1282 /* Data structure for find_abi_tags_r, below. */ 1283 1284 struct abi_tag_data 1285 { 1286 tree t; // The type that we're checking for missing tags. 1287 tree subob; // The subobject of T that we're getting tags from. 1288 tree tags; // error_mark_node for diagnostics, or a list of missing tags. 1289 }; 1290 1291 /* Subroutine of find_abi_tags_r. Handle a single TAG found on the class TP 1292 in the context of P. TAG can be either an identifier (the DECL_NAME of 1293 a tag NAMESPACE_DECL) or a STRING_CST (a tag attribute). */ 1294 1295 static void 1296 check_tag (tree tag, tree id, tree *tp, abi_tag_data *p) 1297 { 1298 if (!IDENTIFIER_MARKED (id)) 1299 { 1300 if (p->tags != error_mark_node) 1301 { 1302 /* We're collecting tags from template arguments or from 1303 the type of a variable or function return type. */ 1304 p->tags = tree_cons (NULL_TREE, tag, p->tags); 1305 1306 /* Don't inherit this tag multiple times. */ 1307 IDENTIFIER_MARKED (id) = true; 1308 1309 if (TYPE_P (p->t)) 1310 { 1311 /* Tags inherited from type template arguments are only used 1312 to avoid warnings. */ 1313 ABI_TAG_IMPLICIT (p->tags) = true; 1314 return; 1315 } 1316 /* For functions and variables we want to warn, too. */ 1317 } 1318 1319 /* Otherwise we're diagnosing missing tags. */ 1320 if (TREE_CODE (p->t) == FUNCTION_DECL) 1321 { 1322 if (warning (OPT_Wabi_tag, "%qD inherits the %E ABI tag " 1323 "that %qT (used in its return type) has", 1324 p->t, tag, *tp)) 1325 inform (location_of (*tp), "%qT declared here", *tp); 1326 } 1327 else if (VAR_P (p->t)) 1328 { 1329 if (warning (OPT_Wabi_tag, "%qD inherits the %E ABI tag " 1330 "that %qT (used in its type) has", p->t, tag, *tp)) 1331 inform (location_of (*tp), "%qT declared here", *tp); 1332 } 1333 else if (TYPE_P (p->subob)) 1334 { 1335 if (warning (OPT_Wabi_tag, "%qT does not have the %E ABI tag " 1336 "that base %qT has", p->t, tag, p->subob)) 1337 inform (location_of (p->subob), "%qT declared here", 1338 p->subob); 1339 } 1340 else 1341 { 1342 if (warning (OPT_Wabi_tag, "%qT does not have the %E ABI tag " 1343 "that %qT (used in the type of %qD) has", 1344 p->t, tag, *tp, p->subob)) 1345 { 1346 inform (location_of (p->subob), "%qD declared here", 1347 p->subob); 1348 inform (location_of (*tp), "%qT declared here", *tp); 1349 } 1350 } 1351 } 1352 } 1353 1354 /* Find all the ABI tags in the attribute list ATTR and either call 1355 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */ 1356 1357 static void 1358 mark_or_check_attr_tags (tree attr, tree *tp, abi_tag_data *p, bool val) 1359 { 1360 if (!attr) 1361 return; 1362 for (; (attr = lookup_attribute ("abi_tag", attr)); 1363 attr = TREE_CHAIN (attr)) 1364 for (tree list = TREE_VALUE (attr); list; 1365 list = TREE_CHAIN (list)) 1366 { 1367 tree tag = TREE_VALUE (list); 1368 tree id = get_identifier (TREE_STRING_POINTER (tag)); 1369 if (tp) 1370 check_tag (tag, id, tp, p); 1371 else 1372 IDENTIFIER_MARKED (id) = val; 1373 } 1374 } 1375 1376 /* Find all the ABI tags on T and its enclosing scopes and either call 1377 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */ 1378 1379 static void 1380 mark_or_check_tags (tree t, tree *tp, abi_tag_data *p, bool val) 1381 { 1382 while (t != global_namespace) 1383 { 1384 tree attr; 1385 if (TYPE_P (t)) 1386 { 1387 attr = TYPE_ATTRIBUTES (t); 1388 t = CP_TYPE_CONTEXT (t); 1389 } 1390 else 1391 { 1392 attr = DECL_ATTRIBUTES (t); 1393 t = CP_DECL_CONTEXT (t); 1394 } 1395 mark_or_check_attr_tags (attr, tp, p, val); 1396 } 1397 } 1398 1399 /* walk_tree callback for check_abi_tags: if the type at *TP involves any 1400 types with ABI tags, add the corresponding identifiers to the VEC in 1401 *DATA and set IDENTIFIER_MARKED. */ 1402 1403 static tree 1404 find_abi_tags_r (tree *tp, int *walk_subtrees, void *data) 1405 { 1406 if (!OVERLOAD_TYPE_P (*tp)) 1407 return NULL_TREE; 1408 1409 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE 1410 anyway, but let's make sure of it. */ 1411 *walk_subtrees = false; 1412 1413 abi_tag_data *p = static_cast<struct abi_tag_data*>(data); 1414 1415 mark_or_check_tags (*tp, tp, p, false); 1416 1417 return NULL_TREE; 1418 } 1419 1420 /* walk_tree callback for mark_abi_tags: if *TP is a class, set 1421 IDENTIFIER_MARKED on its ABI tags. */ 1422 1423 static tree 1424 mark_abi_tags_r (tree *tp, int *walk_subtrees, void *data) 1425 { 1426 if (!OVERLOAD_TYPE_P (*tp)) 1427 return NULL_TREE; 1428 1429 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE 1430 anyway, but let's make sure of it. */ 1431 *walk_subtrees = false; 1432 1433 bool *valp = static_cast<bool*>(data); 1434 1435 mark_or_check_tags (*tp, NULL, NULL, *valp); 1436 1437 return NULL_TREE; 1438 } 1439 1440 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its enclosing 1441 scopes. */ 1442 1443 static void 1444 mark_abi_tags (tree t, bool val) 1445 { 1446 mark_or_check_tags (t, NULL, NULL, val); 1447 if (DECL_P (t)) 1448 { 1449 if (DECL_LANG_SPECIFIC (t) && DECL_USE_TEMPLATE (t) 1450 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t))) 1451 { 1452 /* Template arguments are part of the signature. */ 1453 tree level = INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (t)); 1454 for (int j = 0; j < TREE_VEC_LENGTH (level); ++j) 1455 { 1456 tree arg = TREE_VEC_ELT (level, j); 1457 cp_walk_tree_without_duplicates (&arg, mark_abi_tags_r, &val); 1458 } 1459 } 1460 if (TREE_CODE (t) == FUNCTION_DECL) 1461 /* A function's parameter types are part of the signature, so 1462 we don't need to inherit any tags that are also in them. */ 1463 for (tree arg = FUNCTION_FIRST_USER_PARMTYPE (t); arg; 1464 arg = TREE_CHAIN (arg)) 1465 cp_walk_tree_without_duplicates (&TREE_VALUE (arg), 1466 mark_abi_tags_r, &val); 1467 } 1468 } 1469 1470 /* Check that T has all the ABI tags that subobject SUBOB has, or 1471 warn if not. If T is a (variable or function) declaration, also 1472 return any missing tags, and add them to T if JUST_CHECKING is false. */ 1473 1474 static tree 1475 check_abi_tags (tree t, tree subob, bool just_checking = false) 1476 { 1477 bool inherit = DECL_P (t); 1478 1479 if (!inherit && !warn_abi_tag) 1480 return NULL_TREE; 1481 1482 tree decl = TYPE_P (t) ? TYPE_NAME (t) : t; 1483 if (!TREE_PUBLIC (decl)) 1484 /* No need to worry about things local to this TU. */ 1485 return NULL_TREE; 1486 1487 mark_abi_tags (t, true); 1488 1489 tree subtype = TYPE_P (subob) ? subob : TREE_TYPE (subob); 1490 struct abi_tag_data data = { t, subob, error_mark_node }; 1491 if (inherit) 1492 data.tags = NULL_TREE; 1493 1494 cp_walk_tree_without_duplicates (&subtype, find_abi_tags_r, &data); 1495 1496 if (!(inherit && data.tags)) 1497 /* We don't need to do anything with data.tags. */; 1498 else if (just_checking) 1499 for (tree t = data.tags; t; t = TREE_CHAIN (t)) 1500 { 1501 tree id = get_identifier (TREE_STRING_POINTER (TREE_VALUE (t))); 1502 IDENTIFIER_MARKED (id) = false; 1503 } 1504 else 1505 { 1506 tree attr = lookup_attribute ("abi_tag", DECL_ATTRIBUTES (t)); 1507 if (attr) 1508 TREE_VALUE (attr) = chainon (data.tags, TREE_VALUE (attr)); 1509 else 1510 DECL_ATTRIBUTES (t) 1511 = tree_cons (get_identifier ("abi_tag"), data.tags, 1512 DECL_ATTRIBUTES (t)); 1513 } 1514 1515 mark_abi_tags (t, false); 1516 1517 return data.tags; 1518 } 1519 1520 /* Check that DECL has all the ABI tags that are used in parts of its type 1521 that are not reflected in its mangled name. */ 1522 1523 void 1524 check_abi_tags (tree decl) 1525 { 1526 if (VAR_P (decl)) 1527 check_abi_tags (decl, TREE_TYPE (decl)); 1528 else if (TREE_CODE (decl) == FUNCTION_DECL 1529 && !DECL_CONV_FN_P (decl) 1530 && !mangle_return_type_p (decl)) 1531 check_abi_tags (decl, TREE_TYPE (TREE_TYPE (decl))); 1532 } 1533 1534 /* Return any ABI tags that are used in parts of the type of DECL 1535 that are not reflected in its mangled name. This function is only 1536 used in backward-compatible mangling for ABI <11. */ 1537 1538 tree 1539 missing_abi_tags (tree decl) 1540 { 1541 if (VAR_P (decl)) 1542 return check_abi_tags (decl, TREE_TYPE (decl), true); 1543 else if (TREE_CODE (decl) == FUNCTION_DECL 1544 /* Don't check DECL_CONV_FN_P here like we do in check_abi_tags, so 1545 that we can use this function for setting need_abi_warning 1546 regardless of the current flag_abi_version. */ 1547 && !mangle_return_type_p (decl)) 1548 return check_abi_tags (decl, TREE_TYPE (TREE_TYPE (decl)), true); 1549 else 1550 return NULL_TREE; 1551 } 1552 1553 void 1554 inherit_targ_abi_tags (tree t) 1555 { 1556 if (!CLASS_TYPE_P (t) 1557 || CLASSTYPE_TEMPLATE_INFO (t) == NULL_TREE) 1558 return; 1559 1560 mark_abi_tags (t, true); 1561 1562 tree args = CLASSTYPE_TI_ARGS (t); 1563 struct abi_tag_data data = { t, NULL_TREE, NULL_TREE }; 1564 for (int i = 0; i < TMPL_ARGS_DEPTH (args); ++i) 1565 { 1566 tree level = TMPL_ARGS_LEVEL (args, i+1); 1567 for (int j = 0; j < TREE_VEC_LENGTH (level); ++j) 1568 { 1569 tree arg = TREE_VEC_ELT (level, j); 1570 data.subob = arg; 1571 cp_walk_tree_without_duplicates (&arg, find_abi_tags_r, &data); 1572 } 1573 } 1574 1575 // If we found some tags on our template arguments, add them to our 1576 // abi_tag attribute. 1577 if (data.tags) 1578 { 1579 tree attr = lookup_attribute ("abi_tag", TYPE_ATTRIBUTES (t)); 1580 if (attr) 1581 TREE_VALUE (attr) = chainon (data.tags, TREE_VALUE (attr)); 1582 else 1583 TYPE_ATTRIBUTES (t) 1584 = tree_cons (get_identifier ("abi_tag"), data.tags, 1585 TYPE_ATTRIBUTES (t)); 1586 } 1587 1588 mark_abi_tags (t, false); 1589 } 1590 1591 /* Return true, iff class T has a non-virtual destructor that is 1592 accessible from outside the class heirarchy (i.e. is public, or 1593 there's a suitable friend. */ 1594 1595 static bool 1596 accessible_nvdtor_p (tree t) 1597 { 1598 tree dtor = CLASSTYPE_DESTRUCTOR (t); 1599 1600 /* An implicitly declared destructor is always public. And, 1601 if it were virtual, we would have created it by now. */ 1602 if (!dtor) 1603 return true; 1604 1605 if (DECL_VINDEX (dtor)) 1606 return false; /* Virtual */ 1607 1608 if (!TREE_PRIVATE (dtor) && !TREE_PROTECTED (dtor)) 1609 return true; /* Public */ 1610 1611 if (CLASSTYPE_FRIEND_CLASSES (t) 1612 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t))) 1613 return true; /* Has friends */ 1614 1615 return false; 1616 } 1617 1618 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P, 1619 and NO_CONST_ASN_REF_P. Also set flag bits in T based on 1620 properties of the bases. */ 1621 1622 static void 1623 check_bases (tree t, 1624 int* cant_have_const_ctor_p, 1625 int* no_const_asn_ref_p) 1626 { 1627 int i; 1628 bool seen_non_virtual_nearly_empty_base_p = 0; 1629 int seen_tm_mask = 0; 1630 tree base_binfo; 1631 tree binfo; 1632 tree field = NULL_TREE; 1633 1634 if (!CLASSTYPE_NON_STD_LAYOUT (t)) 1635 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) 1636 if (TREE_CODE (field) == FIELD_DECL) 1637 break; 1638 1639 for (binfo = TYPE_BINFO (t), i = 0; 1640 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 1641 { 1642 tree basetype = TREE_TYPE (base_binfo); 1643 1644 gcc_assert (COMPLETE_TYPE_P (basetype)); 1645 1646 if (CLASSTYPE_FINAL (basetype)) 1647 error ("cannot derive from %<final%> base %qT in derived type %qT", 1648 basetype, t); 1649 1650 /* If any base class is non-literal, so is the derived class. */ 1651 if (!CLASSTYPE_LITERAL_P (basetype)) 1652 CLASSTYPE_LITERAL_P (t) = false; 1653 1654 /* If the base class doesn't have copy constructors or 1655 assignment operators that take const references, then the 1656 derived class cannot have such a member automatically 1657 generated. */ 1658 if (TYPE_HAS_COPY_CTOR (basetype) 1659 && ! TYPE_HAS_CONST_COPY_CTOR (basetype)) 1660 *cant_have_const_ctor_p = 1; 1661 if (TYPE_HAS_COPY_ASSIGN (basetype) 1662 && !TYPE_HAS_CONST_COPY_ASSIGN (basetype)) 1663 *no_const_asn_ref_p = 1; 1664 1665 if (BINFO_VIRTUAL_P (base_binfo)) 1666 /* A virtual base does not effect nearly emptiness. */ 1667 ; 1668 else if (CLASSTYPE_NEARLY_EMPTY_P (basetype)) 1669 { 1670 if (seen_non_virtual_nearly_empty_base_p) 1671 /* And if there is more than one nearly empty base, then the 1672 derived class is not nearly empty either. */ 1673 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 1674 else 1675 /* Remember we've seen one. */ 1676 seen_non_virtual_nearly_empty_base_p = 1; 1677 } 1678 else if (!is_empty_class (basetype)) 1679 /* If the base class is not empty or nearly empty, then this 1680 class cannot be nearly empty. */ 1681 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 1682 1683 /* A lot of properties from the bases also apply to the derived 1684 class. */ 1685 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (basetype); 1686 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) 1687 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype); 1688 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) 1689 |= (TYPE_HAS_COMPLEX_COPY_ASSIGN (basetype) 1690 || !TYPE_HAS_COPY_ASSIGN (basetype)); 1691 TYPE_HAS_COMPLEX_COPY_CTOR (t) |= (TYPE_HAS_COMPLEX_COPY_CTOR (basetype) 1692 || !TYPE_HAS_COPY_CTOR (basetype)); 1693 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) 1694 |= TYPE_HAS_COMPLEX_MOVE_ASSIGN (basetype); 1695 TYPE_HAS_COMPLEX_MOVE_CTOR (t) |= TYPE_HAS_COMPLEX_MOVE_CTOR (basetype); 1696 TYPE_POLYMORPHIC_P (t) |= TYPE_POLYMORPHIC_P (basetype); 1697 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) 1698 |= CLASSTYPE_CONTAINS_EMPTY_CLASS_P (basetype); 1699 TYPE_HAS_COMPLEX_DFLT (t) |= (!TYPE_HAS_DEFAULT_CONSTRUCTOR (basetype) 1700 || TYPE_HAS_COMPLEX_DFLT (basetype)); 1701 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT 1702 (t, CLASSTYPE_READONLY_FIELDS_NEED_INIT (t) 1703 | CLASSTYPE_READONLY_FIELDS_NEED_INIT (basetype)); 1704 SET_CLASSTYPE_REF_FIELDS_NEED_INIT 1705 (t, CLASSTYPE_REF_FIELDS_NEED_INIT (t) 1706 | CLASSTYPE_REF_FIELDS_NEED_INIT (basetype)); 1707 if (TYPE_HAS_MUTABLE_P (basetype)) 1708 CLASSTYPE_HAS_MUTABLE (t) = 1; 1709 1710 /* A standard-layout class is a class that: 1711 ... 1712 * has no non-standard-layout base classes, */ 1713 CLASSTYPE_NON_STD_LAYOUT (t) |= CLASSTYPE_NON_STD_LAYOUT (basetype); 1714 if (!CLASSTYPE_NON_STD_LAYOUT (t)) 1715 { 1716 tree basefield; 1717 /* ...has no base classes of the same type as the first non-static 1718 data member... */ 1719 if (field && DECL_CONTEXT (field) == t 1720 && (same_type_ignoring_top_level_qualifiers_p 1721 (TREE_TYPE (field), basetype))) 1722 CLASSTYPE_NON_STD_LAYOUT (t) = 1; 1723 else 1724 /* ...either has no non-static data members in the most-derived 1725 class and at most one base class with non-static data 1726 members, or has no base classes with non-static data 1727 members */ 1728 for (basefield = TYPE_FIELDS (basetype); basefield; 1729 basefield = DECL_CHAIN (basefield)) 1730 if (TREE_CODE (basefield) == FIELD_DECL 1731 && !(DECL_FIELD_IS_BASE (basefield) 1732 && integer_zerop (DECL_SIZE (basefield)))) 1733 { 1734 if (field) 1735 CLASSTYPE_NON_STD_LAYOUT (t) = 1; 1736 else 1737 field = basefield; 1738 break; 1739 } 1740 } 1741 1742 /* Don't bother collecting tm attributes if transactional memory 1743 support is not enabled. */ 1744 if (flag_tm) 1745 { 1746 tree tm_attr = find_tm_attribute (TYPE_ATTRIBUTES (basetype)); 1747 if (tm_attr) 1748 seen_tm_mask |= tm_attr_to_mask (tm_attr); 1749 } 1750 1751 check_abi_tags (t, basetype); 1752 } 1753 1754 /* If one of the base classes had TM attributes, and the current class 1755 doesn't define its own, then the current class inherits one. */ 1756 if (seen_tm_mask && !find_tm_attribute (TYPE_ATTRIBUTES (t))) 1757 { 1758 tree tm_attr = tm_mask_to_attr (least_bit_hwi (seen_tm_mask)); 1759 TYPE_ATTRIBUTES (t) = tree_cons (tm_attr, NULL, TYPE_ATTRIBUTES (t)); 1760 } 1761 } 1762 1763 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for 1764 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those 1765 that have had a nearly-empty virtual primary base stolen by some 1766 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for 1767 T. */ 1768 1769 static void 1770 determine_primary_bases (tree t) 1771 { 1772 unsigned i; 1773 tree primary = NULL_TREE; 1774 tree type_binfo = TYPE_BINFO (t); 1775 tree base_binfo; 1776 1777 /* Determine the primary bases of our bases. */ 1778 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo; 1779 base_binfo = TREE_CHAIN (base_binfo)) 1780 { 1781 tree primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (base_binfo)); 1782 1783 /* See if we're the non-virtual primary of our inheritance 1784 chain. */ 1785 if (!BINFO_VIRTUAL_P (base_binfo)) 1786 { 1787 tree parent = BINFO_INHERITANCE_CHAIN (base_binfo); 1788 tree parent_primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (parent)); 1789 1790 if (parent_primary 1791 && SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo), 1792 BINFO_TYPE (parent_primary))) 1793 /* We are the primary binfo. */ 1794 BINFO_PRIMARY_P (base_binfo) = 1; 1795 } 1796 /* Determine if we have a virtual primary base, and mark it so. 1797 */ 1798 if (primary && BINFO_VIRTUAL_P (primary)) 1799 { 1800 tree this_primary = copied_binfo (primary, base_binfo); 1801 1802 if (BINFO_PRIMARY_P (this_primary)) 1803 /* Someone already claimed this base. */ 1804 BINFO_LOST_PRIMARY_P (base_binfo) = 1; 1805 else 1806 { 1807 tree delta; 1808 1809 BINFO_PRIMARY_P (this_primary) = 1; 1810 BINFO_INHERITANCE_CHAIN (this_primary) = base_binfo; 1811 1812 /* A virtual binfo might have been copied from within 1813 another hierarchy. As we're about to use it as a 1814 primary base, make sure the offsets match. */ 1815 delta = size_diffop_loc (input_location, 1816 fold_convert (ssizetype, 1817 BINFO_OFFSET (base_binfo)), 1818 fold_convert (ssizetype, 1819 BINFO_OFFSET (this_primary))); 1820 1821 propagate_binfo_offsets (this_primary, delta); 1822 } 1823 } 1824 } 1825 1826 /* First look for a dynamic direct non-virtual base. */ 1827 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, base_binfo); i++) 1828 { 1829 tree basetype = BINFO_TYPE (base_binfo); 1830 1831 if (TYPE_CONTAINS_VPTR_P (basetype) && !BINFO_VIRTUAL_P (base_binfo)) 1832 { 1833 primary = base_binfo; 1834 goto found; 1835 } 1836 } 1837 1838 /* A "nearly-empty" virtual base class can be the primary base 1839 class, if no non-virtual polymorphic base can be found. Look for 1840 a nearly-empty virtual dynamic base that is not already a primary 1841 base of something in the hierarchy. If there is no such base, 1842 just pick the first nearly-empty virtual base. */ 1843 1844 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo; 1845 base_binfo = TREE_CHAIN (base_binfo)) 1846 if (BINFO_VIRTUAL_P (base_binfo) 1847 && CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (base_binfo))) 1848 { 1849 if (!BINFO_PRIMARY_P (base_binfo)) 1850 { 1851 /* Found one that is not primary. */ 1852 primary = base_binfo; 1853 goto found; 1854 } 1855 else if (!primary) 1856 /* Remember the first candidate. */ 1857 primary = base_binfo; 1858 } 1859 1860 found: 1861 /* If we've got a primary base, use it. */ 1862 if (primary) 1863 { 1864 tree basetype = BINFO_TYPE (primary); 1865 1866 CLASSTYPE_PRIMARY_BINFO (t) = primary; 1867 if (BINFO_PRIMARY_P (primary)) 1868 /* We are stealing a primary base. */ 1869 BINFO_LOST_PRIMARY_P (BINFO_INHERITANCE_CHAIN (primary)) = 1; 1870 BINFO_PRIMARY_P (primary) = 1; 1871 if (BINFO_VIRTUAL_P (primary)) 1872 { 1873 tree delta; 1874 1875 BINFO_INHERITANCE_CHAIN (primary) = type_binfo; 1876 /* A virtual binfo might have been copied from within 1877 another hierarchy. As we're about to use it as a primary 1878 base, make sure the offsets match. */ 1879 delta = size_diffop_loc (input_location, ssize_int (0), 1880 fold_convert (ssizetype, BINFO_OFFSET (primary))); 1881 1882 propagate_binfo_offsets (primary, delta); 1883 } 1884 1885 primary = TYPE_BINFO (basetype); 1886 1887 TYPE_VFIELD (t) = TYPE_VFIELD (basetype); 1888 BINFO_VTABLE (type_binfo) = BINFO_VTABLE (primary); 1889 BINFO_VIRTUALS (type_binfo) = BINFO_VIRTUALS (primary); 1890 } 1891 } 1892 1893 /* Update the variant types of T. */ 1894 1895 void 1896 fixup_type_variants (tree t) 1897 { 1898 tree variants; 1899 1900 if (!t) 1901 return; 1902 1903 for (variants = TYPE_NEXT_VARIANT (t); 1904 variants; 1905 variants = TYPE_NEXT_VARIANT (variants)) 1906 { 1907 /* These fields are in the _TYPE part of the node, not in 1908 the TYPE_LANG_SPECIFIC component, so they are not shared. */ 1909 TYPE_HAS_USER_CONSTRUCTOR (variants) = TYPE_HAS_USER_CONSTRUCTOR (t); 1910 TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t); 1911 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variants) 1912 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t); 1913 1914 TYPE_POLYMORPHIC_P (variants) = TYPE_POLYMORPHIC_P (t); 1915 1916 TYPE_BINFO (variants) = TYPE_BINFO (t); 1917 1918 /* Copy whatever these are holding today. */ 1919 TYPE_VFIELD (variants) = TYPE_VFIELD (t); 1920 TYPE_FIELDS (variants) = TYPE_FIELDS (t); 1921 } 1922 } 1923 1924 /* KLASS is a class that we're applying may_alias to after the body is 1925 parsed. Fixup any POINTER_TO and REFERENCE_TO types. The 1926 canonical type(s) will be implicitly updated. */ 1927 1928 static void 1929 fixup_may_alias (tree klass) 1930 { 1931 tree t, v; 1932 1933 for (t = TYPE_POINTER_TO (klass); t; t = TYPE_NEXT_PTR_TO (t)) 1934 for (v = TYPE_MAIN_VARIANT (t); v; v = TYPE_NEXT_VARIANT (v)) 1935 TYPE_REF_CAN_ALIAS_ALL (v) = true; 1936 for (t = TYPE_REFERENCE_TO (klass); t; t = TYPE_NEXT_REF_TO (t)) 1937 for (v = TYPE_MAIN_VARIANT (t); v; v = TYPE_NEXT_VARIANT (v)) 1938 TYPE_REF_CAN_ALIAS_ALL (v) = true; 1939 } 1940 1941 /* Early variant fixups: we apply attributes at the beginning of the class 1942 definition, and we need to fix up any variants that have already been 1943 made via elaborated-type-specifier so that check_qualified_type works. */ 1944 1945 void 1946 fixup_attribute_variants (tree t) 1947 { 1948 tree variants; 1949 1950 if (!t) 1951 return; 1952 1953 tree attrs = TYPE_ATTRIBUTES (t); 1954 unsigned align = TYPE_ALIGN (t); 1955 bool user_align = TYPE_USER_ALIGN (t); 1956 bool may_alias = lookup_attribute ("may_alias", attrs); 1957 bool packed = TYPE_PACKED (t); 1958 1959 if (may_alias) 1960 fixup_may_alias (t); 1961 1962 for (variants = TYPE_NEXT_VARIANT (t); 1963 variants; 1964 variants = TYPE_NEXT_VARIANT (variants)) 1965 { 1966 /* These are the two fields that check_qualified_type looks at and 1967 are affected by attributes. */ 1968 TYPE_ATTRIBUTES (variants) = attrs; 1969 unsigned valign = align; 1970 if (TYPE_USER_ALIGN (variants)) 1971 valign = MAX (valign, TYPE_ALIGN (variants)); 1972 else 1973 TYPE_USER_ALIGN (variants) = user_align; 1974 SET_TYPE_ALIGN (variants, valign); 1975 TYPE_PACKED (variants) = packed; 1976 if (may_alias) 1977 fixup_may_alias (variants); 1978 } 1979 } 1980 1981 /* Set memoizing fields and bits of T (and its variants) for later 1982 use. */ 1983 1984 static void 1985 finish_struct_bits (tree t) 1986 { 1987 /* Fix up variants (if any). */ 1988 fixup_type_variants (t); 1989 1990 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) && TYPE_POLYMORPHIC_P (t)) 1991 /* For a class w/o baseclasses, 'finish_struct' has set 1992 CLASSTYPE_PURE_VIRTUALS correctly (by definition). 1993 Similarly for a class whose base classes do not have vtables. 1994 When neither of these is true, we might have removed abstract 1995 virtuals (by providing a definition), added some (by declaring 1996 new ones), or redeclared ones from a base class. We need to 1997 recalculate what's really an abstract virtual at this point (by 1998 looking in the vtables). */ 1999 get_pure_virtuals (t); 2000 2001 /* If this type has a copy constructor or a destructor, force its 2002 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be 2003 nonzero. This will cause it to be passed by invisible reference 2004 and prevent it from being returned in a register. */ 2005 if (type_has_nontrivial_copy_init (t) 2006 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)) 2007 { 2008 tree variants; 2009 SET_DECL_MODE (TYPE_MAIN_DECL (t), BLKmode); 2010 for (variants = t; variants; variants = TYPE_NEXT_VARIANT (variants)) 2011 { 2012 SET_TYPE_MODE (variants, BLKmode); 2013 TREE_ADDRESSABLE (variants) = 1; 2014 } 2015 } 2016 } 2017 2018 /* Issue warnings about T having private constructors, but no friends, 2019 and so forth. 2020 2021 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or 2022 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any 2023 non-private static member functions. */ 2024 2025 static void 2026 maybe_warn_about_overly_private_class (tree t) 2027 { 2028 int has_member_fn = 0; 2029 int has_nonprivate_method = 0; 2030 bool nonprivate_ctor = false; 2031 2032 if (!warn_ctor_dtor_privacy 2033 /* If the class has friends, those entities might create and 2034 access instances, so we should not warn. */ 2035 || (CLASSTYPE_FRIEND_CLASSES (t) 2036 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t))) 2037 /* We will have warned when the template was declared; there's 2038 no need to warn on every instantiation. */ 2039 || CLASSTYPE_TEMPLATE_INSTANTIATION (t)) 2040 /* There's no reason to even consider warning about this 2041 class. */ 2042 return; 2043 2044 /* We only issue one warning, if more than one applies, because 2045 otherwise, on code like: 2046 2047 class A { 2048 // Oops - forgot `public:' 2049 A(); 2050 A(const A&); 2051 ~A(); 2052 }; 2053 2054 we warn several times about essentially the same problem. */ 2055 2056 /* Check to see if all (non-constructor, non-destructor) member 2057 functions are private. (Since there are no friends or 2058 non-private statics, we can't ever call any of the private member 2059 functions.) */ 2060 for (tree fn = TYPE_FIELDS (t); fn; fn = DECL_CHAIN (fn)) 2061 if (TREE_CODE (fn) == USING_DECL 2062 && DECL_NAME (fn) == ctor_identifier 2063 && !TREE_PRIVATE (fn)) 2064 nonprivate_ctor = true; 2065 else if (!DECL_DECLARES_FUNCTION_P (fn)) 2066 /* Not a function. */; 2067 else if (DECL_ARTIFICIAL (fn)) 2068 /* We're not interested in compiler-generated methods; they don't 2069 provide any way to call private members. */; 2070 else if (!TREE_PRIVATE (fn)) 2071 { 2072 if (DECL_STATIC_FUNCTION_P (fn)) 2073 /* A non-private static member function is just like a 2074 friend; it can create and invoke private member 2075 functions, and be accessed without a class 2076 instance. */ 2077 return; 2078 2079 has_nonprivate_method = 1; 2080 /* Keep searching for a static member function. */ 2081 } 2082 else if (!DECL_CONSTRUCTOR_P (fn) && !DECL_DESTRUCTOR_P (fn)) 2083 has_member_fn = 1; 2084 2085 if (!has_nonprivate_method && has_member_fn) 2086 { 2087 /* There are no non-private methods, and there's at least one 2088 private member function that isn't a constructor or 2089 destructor. (If all the private members are 2090 constructors/destructors we want to use the code below that 2091 issues error messages specifically referring to 2092 constructors/destructors.) */ 2093 unsigned i; 2094 tree binfo = TYPE_BINFO (t); 2095 2096 for (i = 0; i != BINFO_N_BASE_BINFOS (binfo); i++) 2097 if (BINFO_BASE_ACCESS (binfo, i) != access_private_node) 2098 { 2099 has_nonprivate_method = 1; 2100 break; 2101 } 2102 if (!has_nonprivate_method) 2103 { 2104 warning (OPT_Wctor_dtor_privacy, 2105 "all member functions in class %qT are private", t); 2106 return; 2107 } 2108 } 2109 2110 /* Even if some of the member functions are non-private, the class 2111 won't be useful for much if all the constructors or destructors 2112 are private: such an object can never be created or destroyed. */ 2113 if (tree dtor = CLASSTYPE_DESTRUCTOR (t)) 2114 if (TREE_PRIVATE (dtor)) 2115 { 2116 warning (OPT_Wctor_dtor_privacy, 2117 "%q#T only defines a private destructor and has no friends", 2118 t); 2119 return; 2120 } 2121 2122 /* Warn about classes that have private constructors and no friends. */ 2123 if (TYPE_HAS_USER_CONSTRUCTOR (t) 2124 /* Implicitly generated constructors are always public. */ 2125 && !CLASSTYPE_LAZY_DEFAULT_CTOR (t)) 2126 { 2127 tree copy_or_move = NULL_TREE; 2128 2129 /* If a non-template class does not define a copy 2130 constructor, one is defined for it, enabling it to avoid 2131 this warning. For a template class, this does not 2132 happen, and so we would normally get a warning on: 2133 2134 template <class T> class C { private: C(); }; 2135 2136 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All 2137 complete non-template or fully instantiated classes have this 2138 flag set. */ 2139 if (!TYPE_HAS_COPY_CTOR (t)) 2140 nonprivate_ctor = true; 2141 else 2142 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); 2143 !nonprivate_ctor && iter; ++iter) 2144 if (TREE_PRIVATE (*iter)) 2145 continue; 2146 else if (copy_fn_p (*iter) || move_fn_p (*iter)) 2147 /* Ideally, we wouldn't count any constructor that takes 2148 an argument of the class type as a parameter, because 2149 such things cannot be used to construct an instance of 2150 the class unless you already have one. */ 2151 copy_or_move = *iter; 2152 else 2153 nonprivate_ctor = true; 2154 2155 if (!nonprivate_ctor) 2156 { 2157 warning (OPT_Wctor_dtor_privacy, 2158 "%q#T only defines private constructors and has no friends", 2159 t); 2160 if (copy_or_move) 2161 inform (DECL_SOURCE_LOCATION (copy_or_move), 2162 "%q#D is public, but requires an existing %q#T object", 2163 copy_or_move, t); 2164 return; 2165 } 2166 } 2167 } 2168 2169 /* Make BINFO's vtable have N entries, including RTTI entries, 2170 vbase and vcall offsets, etc. Set its type and call the back end 2171 to lay it out. */ 2172 2173 static void 2174 layout_vtable_decl (tree binfo, int n) 2175 { 2176 tree atype; 2177 tree vtable; 2178 2179 atype = build_array_of_n_type (vtable_entry_type, n); 2180 layout_type (atype); 2181 2182 /* We may have to grow the vtable. */ 2183 vtable = get_vtbl_decl_for_binfo (binfo); 2184 if (!same_type_p (TREE_TYPE (vtable), atype)) 2185 { 2186 TREE_TYPE (vtable) = atype; 2187 DECL_SIZE (vtable) = DECL_SIZE_UNIT (vtable) = NULL_TREE; 2188 layout_decl (vtable, 0); 2189 } 2190 } 2191 2192 /* True iff FNDECL and BASE_FNDECL (both non-static member functions) 2193 have the same signature. */ 2194 2195 int 2196 same_signature_p (const_tree fndecl, const_tree base_fndecl) 2197 { 2198 /* One destructor overrides another if they are the same kind of 2199 destructor. */ 2200 if (DECL_DESTRUCTOR_P (base_fndecl) && DECL_DESTRUCTOR_P (fndecl) 2201 && special_function_p (base_fndecl) == special_function_p (fndecl)) 2202 return 1; 2203 /* But a non-destructor never overrides a destructor, nor vice 2204 versa, nor do different kinds of destructors override 2205 one-another. For example, a complete object destructor does not 2206 override a deleting destructor. */ 2207 if (DECL_DESTRUCTOR_P (base_fndecl) || DECL_DESTRUCTOR_P (fndecl)) 2208 return 0; 2209 2210 if (DECL_NAME (fndecl) == DECL_NAME (base_fndecl) 2211 || (DECL_CONV_FN_P (fndecl) 2212 && DECL_CONV_FN_P (base_fndecl) 2213 && same_type_p (DECL_CONV_FN_TYPE (fndecl), 2214 DECL_CONV_FN_TYPE (base_fndecl)))) 2215 { 2216 tree fntype = TREE_TYPE (fndecl); 2217 tree base_fntype = TREE_TYPE (base_fndecl); 2218 if (type_memfn_quals (fntype) == type_memfn_quals (base_fntype) 2219 && type_memfn_rqual (fntype) == type_memfn_rqual (base_fntype) 2220 && compparms (FUNCTION_FIRST_USER_PARMTYPE (fndecl), 2221 FUNCTION_FIRST_USER_PARMTYPE (base_fndecl))) 2222 return 1; 2223 } 2224 return 0; 2225 } 2226 2227 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a 2228 subobject. */ 2229 2230 static bool 2231 base_derived_from (tree derived, tree base) 2232 { 2233 tree probe; 2234 2235 for (probe = base; probe; probe = BINFO_INHERITANCE_CHAIN (probe)) 2236 { 2237 if (probe == derived) 2238 return true; 2239 else if (BINFO_VIRTUAL_P (probe)) 2240 /* If we meet a virtual base, we can't follow the inheritance 2241 any more. See if the complete type of DERIVED contains 2242 such a virtual base. */ 2243 return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (derived)) 2244 != NULL_TREE); 2245 } 2246 return false; 2247 } 2248 2249 struct find_final_overrider_data { 2250 /* The function for which we are trying to find a final overrider. */ 2251 tree fn; 2252 /* The base class in which the function was declared. */ 2253 tree declaring_base; 2254 /* The candidate overriders. */ 2255 tree candidates; 2256 /* Path to most derived. */ 2257 vec<tree> path; 2258 }; 2259 2260 /* Add the overrider along the current path to FFOD->CANDIDATES. 2261 Returns true if an overrider was found; false otherwise. */ 2262 2263 static bool 2264 dfs_find_final_overrider_1 (tree binfo, 2265 find_final_overrider_data *ffod, 2266 unsigned depth) 2267 { 2268 tree method; 2269 2270 /* If BINFO is not the most derived type, try a more derived class. 2271 A definition there will overrider a definition here. */ 2272 if (depth) 2273 { 2274 depth--; 2275 if (dfs_find_final_overrider_1 2276 (ffod->path[depth], ffod, depth)) 2277 return true; 2278 } 2279 2280 method = look_for_overrides_here (BINFO_TYPE (binfo), ffod->fn); 2281 if (method) 2282 { 2283 tree *candidate = &ffod->candidates; 2284 2285 /* Remove any candidates overridden by this new function. */ 2286 while (*candidate) 2287 { 2288 /* If *CANDIDATE overrides METHOD, then METHOD 2289 cannot override anything else on the list. */ 2290 if (base_derived_from (TREE_VALUE (*candidate), binfo)) 2291 return true; 2292 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */ 2293 if (base_derived_from (binfo, TREE_VALUE (*candidate))) 2294 *candidate = TREE_CHAIN (*candidate); 2295 else 2296 candidate = &TREE_CHAIN (*candidate); 2297 } 2298 2299 /* Add the new function. */ 2300 ffod->candidates = tree_cons (method, binfo, ffod->candidates); 2301 return true; 2302 } 2303 2304 return false; 2305 } 2306 2307 /* Called from find_final_overrider via dfs_walk. */ 2308 2309 static tree 2310 dfs_find_final_overrider_pre (tree binfo, void *data) 2311 { 2312 find_final_overrider_data *ffod = (find_final_overrider_data *) data; 2313 2314 if (binfo == ffod->declaring_base) 2315 dfs_find_final_overrider_1 (binfo, ffod, ffod->path.length ()); 2316 ffod->path.safe_push (binfo); 2317 2318 return NULL_TREE; 2319 } 2320 2321 static tree 2322 dfs_find_final_overrider_post (tree /*binfo*/, void *data) 2323 { 2324 find_final_overrider_data *ffod = (find_final_overrider_data *) data; 2325 ffod->path.pop (); 2326 2327 return NULL_TREE; 2328 } 2329 2330 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for 2331 FN and whose TREE_VALUE is the binfo for the base where the 2332 overriding occurs. BINFO (in the hierarchy dominated by the binfo 2333 DERIVED) is the base object in which FN is declared. */ 2334 2335 static tree 2336 find_final_overrider (tree derived, tree binfo, tree fn) 2337 { 2338 find_final_overrider_data ffod; 2339 2340 /* Getting this right is a little tricky. This is valid: 2341 2342 struct S { virtual void f (); }; 2343 struct T { virtual void f (); }; 2344 struct U : public S, public T { }; 2345 2346 even though calling `f' in `U' is ambiguous. But, 2347 2348 struct R { virtual void f(); }; 2349 struct S : virtual public R { virtual void f (); }; 2350 struct T : virtual public R { virtual void f (); }; 2351 struct U : public S, public T { }; 2352 2353 is not -- there's no way to decide whether to put `S::f' or 2354 `T::f' in the vtable for `R'. 2355 2356 The solution is to look at all paths to BINFO. If we find 2357 different overriders along any two, then there is a problem. */ 2358 if (DECL_THUNK_P (fn)) 2359 fn = THUNK_TARGET (fn); 2360 2361 /* Determine the depth of the hierarchy. */ 2362 ffod.fn = fn; 2363 ffod.declaring_base = binfo; 2364 ffod.candidates = NULL_TREE; 2365 ffod.path.create (30); 2366 2367 dfs_walk_all (derived, dfs_find_final_overrider_pre, 2368 dfs_find_final_overrider_post, &ffod); 2369 2370 ffod.path.release (); 2371 2372 /* If there was no winner, issue an error message. */ 2373 if (!ffod.candidates || TREE_CHAIN (ffod.candidates)) 2374 return error_mark_node; 2375 2376 return ffod.candidates; 2377 } 2378 2379 /* Return the index of the vcall offset for FN when TYPE is used as a 2380 virtual base. */ 2381 2382 static tree 2383 get_vcall_index (tree fn, tree type) 2384 { 2385 vec<tree_pair_s, va_gc> *indices = CLASSTYPE_VCALL_INDICES (type); 2386 tree_pair_p p; 2387 unsigned ix; 2388 2389 FOR_EACH_VEC_SAFE_ELT (indices, ix, p) 2390 if ((DECL_DESTRUCTOR_P (fn) && DECL_DESTRUCTOR_P (p->purpose)) 2391 || same_signature_p (fn, p->purpose)) 2392 return p->value; 2393 2394 /* There should always be an appropriate index. */ 2395 gcc_unreachable (); 2396 } 2397 2398 /* Update an entry in the vtable for BINFO, which is in the hierarchy 2399 dominated by T. FN is the old function; VIRTUALS points to the 2400 corresponding position in the new BINFO_VIRTUALS list. IX is the index 2401 of that entry in the list. */ 2402 2403 static void 2404 update_vtable_entry_for_fn (tree t, tree binfo, tree fn, tree* virtuals, 2405 unsigned ix) 2406 { 2407 tree b; 2408 tree overrider; 2409 tree delta; 2410 tree virtual_base; 2411 tree first_defn; 2412 tree overrider_fn, overrider_target; 2413 tree target_fn = DECL_THUNK_P (fn) ? THUNK_TARGET (fn) : fn; 2414 tree over_return, base_return; 2415 bool lost = false; 2416 2417 /* Find the nearest primary base (possibly binfo itself) which defines 2418 this function; this is the class the caller will convert to when 2419 calling FN through BINFO. */ 2420 for (b = binfo; ; b = get_primary_binfo (b)) 2421 { 2422 gcc_assert (b); 2423 if (look_for_overrides_here (BINFO_TYPE (b), target_fn)) 2424 break; 2425 2426 /* The nearest definition is from a lost primary. */ 2427 if (BINFO_LOST_PRIMARY_P (b)) 2428 lost = true; 2429 } 2430 first_defn = b; 2431 2432 /* Find the final overrider. */ 2433 overrider = find_final_overrider (TYPE_BINFO (t), b, target_fn); 2434 if (overrider == error_mark_node) 2435 { 2436 error ("no unique final overrider for %qD in %qT", target_fn, t); 2437 return; 2438 } 2439 overrider_target = overrider_fn = TREE_PURPOSE (overrider); 2440 2441 /* Check for adjusting covariant return types. */ 2442 over_return = TREE_TYPE (TREE_TYPE (overrider_target)); 2443 base_return = TREE_TYPE (TREE_TYPE (target_fn)); 2444 2445 if (POINTER_TYPE_P (over_return) 2446 && TREE_CODE (over_return) == TREE_CODE (base_return) 2447 && CLASS_TYPE_P (TREE_TYPE (over_return)) 2448 && CLASS_TYPE_P (TREE_TYPE (base_return)) 2449 /* If the overrider is invalid, don't even try. */ 2450 && !DECL_INVALID_OVERRIDER_P (overrider_target)) 2451 { 2452 /* If FN is a covariant thunk, we must figure out the adjustment 2453 to the final base FN was converting to. As OVERRIDER_TARGET might 2454 also be converting to the return type of FN, we have to 2455 combine the two conversions here. */ 2456 tree fixed_offset, virtual_offset; 2457 2458 over_return = TREE_TYPE (over_return); 2459 base_return = TREE_TYPE (base_return); 2460 2461 if (DECL_THUNK_P (fn)) 2462 { 2463 gcc_assert (DECL_RESULT_THUNK_P (fn)); 2464 fixed_offset = ssize_int (THUNK_FIXED_OFFSET (fn)); 2465 virtual_offset = THUNK_VIRTUAL_OFFSET (fn); 2466 } 2467 else 2468 fixed_offset = virtual_offset = NULL_TREE; 2469 2470 if (virtual_offset) 2471 /* Find the equivalent binfo within the return type of the 2472 overriding function. We will want the vbase offset from 2473 there. */ 2474 virtual_offset = binfo_for_vbase (BINFO_TYPE (virtual_offset), 2475 over_return); 2476 else if (!same_type_ignoring_top_level_qualifiers_p 2477 (over_return, base_return)) 2478 { 2479 /* There was no existing virtual thunk (which takes 2480 precedence). So find the binfo of the base function's 2481 return type within the overriding function's return type. 2482 Fortunately we know the covariancy is valid (it 2483 has already been checked), so we can just iterate along 2484 the binfos, which have been chained in inheritance graph 2485 order. Of course it is lame that we have to repeat the 2486 search here anyway -- we should really be caching pieces 2487 of the vtable and avoiding this repeated work. */ 2488 tree thunk_binfo = NULL_TREE; 2489 tree base_binfo = TYPE_BINFO (base_return); 2490 2491 /* Find the base binfo within the overriding function's 2492 return type. We will always find a thunk_binfo, except 2493 when the covariancy is invalid (which we will have 2494 already diagnosed). */ 2495 if (base_binfo) 2496 for (thunk_binfo = TYPE_BINFO (over_return); thunk_binfo; 2497 thunk_binfo = TREE_CHAIN (thunk_binfo)) 2498 if (SAME_BINFO_TYPE_P (BINFO_TYPE (thunk_binfo), 2499 BINFO_TYPE (base_binfo))) 2500 break; 2501 gcc_assert (thunk_binfo || errorcount); 2502 2503 /* See if virtual inheritance is involved. */ 2504 for (virtual_offset = thunk_binfo; 2505 virtual_offset; 2506 virtual_offset = BINFO_INHERITANCE_CHAIN (virtual_offset)) 2507 if (BINFO_VIRTUAL_P (virtual_offset)) 2508 break; 2509 2510 if (virtual_offset 2511 || (thunk_binfo && !BINFO_OFFSET_ZEROP (thunk_binfo))) 2512 { 2513 tree offset = fold_convert (ssizetype, BINFO_OFFSET (thunk_binfo)); 2514 2515 if (virtual_offset) 2516 { 2517 /* We convert via virtual base. Adjust the fixed 2518 offset to be from there. */ 2519 offset = 2520 size_diffop (offset, 2521 fold_convert (ssizetype, 2522 BINFO_OFFSET (virtual_offset))); 2523 } 2524 if (fixed_offset) 2525 /* There was an existing fixed offset, this must be 2526 from the base just converted to, and the base the 2527 FN was thunking to. */ 2528 fixed_offset = size_binop (PLUS_EXPR, fixed_offset, offset); 2529 else 2530 fixed_offset = offset; 2531 } 2532 } 2533 2534 if (fixed_offset || virtual_offset) 2535 /* Replace the overriding function with a covariant thunk. We 2536 will emit the overriding function in its own slot as 2537 well. */ 2538 overrider_fn = make_thunk (overrider_target, /*this_adjusting=*/0, 2539 fixed_offset, virtual_offset); 2540 } 2541 else 2542 gcc_assert (DECL_INVALID_OVERRIDER_P (overrider_target) || 2543 !DECL_THUNK_P (fn)); 2544 2545 /* If we need a covariant thunk, then we may need to adjust first_defn. 2546 The ABI specifies that the thunks emitted with a function are 2547 determined by which bases the function overrides, so we need to be 2548 sure that we're using a thunk for some overridden base; even if we 2549 know that the necessary this adjustment is zero, there may not be an 2550 appropriate zero-this-adjustment thunk for us to use since thunks for 2551 overriding virtual bases always use the vcall offset. 2552 2553 Furthermore, just choosing any base that overrides this function isn't 2554 quite right, as this slot won't be used for calls through a type that 2555 puts a covariant thunk here. Calling the function through such a type 2556 will use a different slot, and that slot is the one that determines 2557 the thunk emitted for that base. 2558 2559 So, keep looking until we find the base that we're really overriding 2560 in this slot: the nearest primary base that doesn't use a covariant 2561 thunk in this slot. */ 2562 if (overrider_target != overrider_fn) 2563 { 2564 if (BINFO_TYPE (b) == DECL_CONTEXT (overrider_target)) 2565 /* We already know that the overrider needs a covariant thunk. */ 2566 b = get_primary_binfo (b); 2567 for (; ; b = get_primary_binfo (b)) 2568 { 2569 tree main_binfo = TYPE_BINFO (BINFO_TYPE (b)); 2570 tree bv = chain_index (ix, BINFO_VIRTUALS (main_binfo)); 2571 if (!DECL_THUNK_P (TREE_VALUE (bv))) 2572 break; 2573 if (BINFO_LOST_PRIMARY_P (b)) 2574 lost = true; 2575 } 2576 first_defn = b; 2577 } 2578 2579 /* Assume that we will produce a thunk that convert all the way to 2580 the final overrider, and not to an intermediate virtual base. */ 2581 virtual_base = NULL_TREE; 2582 2583 /* See if we can convert to an intermediate virtual base first, and then 2584 use the vcall offset located there to finish the conversion. */ 2585 for (; b; b = BINFO_INHERITANCE_CHAIN (b)) 2586 { 2587 /* If we find the final overrider, then we can stop 2588 walking. */ 2589 if (SAME_BINFO_TYPE_P (BINFO_TYPE (b), 2590 BINFO_TYPE (TREE_VALUE (overrider)))) 2591 break; 2592 2593 /* If we find a virtual base, and we haven't yet found the 2594 overrider, then there is a virtual base between the 2595 declaring base (first_defn) and the final overrider. */ 2596 if (BINFO_VIRTUAL_P (b)) 2597 { 2598 virtual_base = b; 2599 break; 2600 } 2601 } 2602 2603 /* Compute the constant adjustment to the `this' pointer. The 2604 `this' pointer, when this function is called, will point at BINFO 2605 (or one of its primary bases, which are at the same offset). */ 2606 if (virtual_base) 2607 /* The `this' pointer needs to be adjusted from the declaration to 2608 the nearest virtual base. */ 2609 delta = size_diffop_loc (input_location, 2610 fold_convert (ssizetype, BINFO_OFFSET (virtual_base)), 2611 fold_convert (ssizetype, BINFO_OFFSET (first_defn))); 2612 else if (lost) 2613 /* If the nearest definition is in a lost primary, we don't need an 2614 entry in our vtable. Except possibly in a constructor vtable, 2615 if we happen to get our primary back. In that case, the offset 2616 will be zero, as it will be a primary base. */ 2617 delta = size_zero_node; 2618 else 2619 /* The `this' pointer needs to be adjusted from pointing to 2620 BINFO to pointing at the base where the final overrider 2621 appears. */ 2622 delta = size_diffop_loc (input_location, 2623 fold_convert (ssizetype, 2624 BINFO_OFFSET (TREE_VALUE (overrider))), 2625 fold_convert (ssizetype, BINFO_OFFSET (binfo))); 2626 2627 modify_vtable_entry (t, binfo, overrider_fn, delta, virtuals); 2628 2629 if (virtual_base) 2630 BV_VCALL_INDEX (*virtuals) 2631 = get_vcall_index (overrider_target, BINFO_TYPE (virtual_base)); 2632 else 2633 BV_VCALL_INDEX (*virtuals) = NULL_TREE; 2634 2635 BV_LOST_PRIMARY (*virtuals) = lost; 2636 } 2637 2638 /* Called from modify_all_vtables via dfs_walk. */ 2639 2640 static tree 2641 dfs_modify_vtables (tree binfo, void* data) 2642 { 2643 tree t = (tree) data; 2644 tree virtuals; 2645 tree old_virtuals; 2646 unsigned ix; 2647 2648 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) 2649 /* A base without a vtable needs no modification, and its bases 2650 are uninteresting. */ 2651 return dfs_skip_bases; 2652 2653 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t) 2654 && !CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 2655 /* Don't do the primary vtable, if it's new. */ 2656 return NULL_TREE; 2657 2658 if (BINFO_PRIMARY_P (binfo) && !BINFO_VIRTUAL_P (binfo)) 2659 /* There's no need to modify the vtable for a non-virtual primary 2660 base; we're not going to use that vtable anyhow. We do still 2661 need to do this for virtual primary bases, as they could become 2662 non-primary in a construction vtable. */ 2663 return NULL_TREE; 2664 2665 make_new_vtable (t, binfo); 2666 2667 /* Now, go through each of the virtual functions in the virtual 2668 function table for BINFO. Find the final overrider, and update 2669 the BINFO_VIRTUALS list appropriately. */ 2670 for (ix = 0, virtuals = BINFO_VIRTUALS (binfo), 2671 old_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo))); 2672 virtuals; 2673 ix++, virtuals = TREE_CHAIN (virtuals), 2674 old_virtuals = TREE_CHAIN (old_virtuals)) 2675 update_vtable_entry_for_fn (t, 2676 binfo, 2677 BV_FN (old_virtuals), 2678 &virtuals, ix); 2679 2680 return NULL_TREE; 2681 } 2682 2683 /* Update all of the primary and secondary vtables for T. Create new 2684 vtables as required, and initialize their RTTI information. Each 2685 of the functions in VIRTUALS is declared in T and may override a 2686 virtual function from a base class; find and modify the appropriate 2687 entries to point to the overriding functions. Returns a list, in 2688 declaration order, of the virtual functions that are declared in T, 2689 but do not appear in the primary base class vtable, and which 2690 should therefore be appended to the end of the vtable for T. */ 2691 2692 static tree 2693 modify_all_vtables (tree t, tree virtuals) 2694 { 2695 tree binfo = TYPE_BINFO (t); 2696 tree *fnsp; 2697 2698 /* Mangle the vtable name before entering dfs_walk (c++/51884). */ 2699 if (TYPE_CONTAINS_VPTR_P (t)) 2700 get_vtable_decl (t, false); 2701 2702 /* Update all of the vtables. */ 2703 dfs_walk_once (binfo, dfs_modify_vtables, NULL, t); 2704 2705 /* Add virtual functions not already in our primary vtable. These 2706 will be both those introduced by this class, and those overridden 2707 from secondary bases. It does not include virtuals merely 2708 inherited from secondary bases. */ 2709 for (fnsp = &virtuals; *fnsp; ) 2710 { 2711 tree fn = TREE_VALUE (*fnsp); 2712 2713 if (!value_member (fn, BINFO_VIRTUALS (binfo)) 2714 || DECL_VINDEX (fn) == error_mark_node) 2715 { 2716 /* We don't need to adjust the `this' pointer when 2717 calling this function. */ 2718 BV_DELTA (*fnsp) = integer_zero_node; 2719 BV_VCALL_INDEX (*fnsp) = NULL_TREE; 2720 2721 /* This is a function not already in our vtable. Keep it. */ 2722 fnsp = &TREE_CHAIN (*fnsp); 2723 } 2724 else 2725 /* We've already got an entry for this function. Skip it. */ 2726 *fnsp = TREE_CHAIN (*fnsp); 2727 } 2728 2729 return virtuals; 2730 } 2731 2732 /* Get the base virtual function declarations in T that have the 2733 indicated NAME. */ 2734 2735 static void 2736 get_basefndecls (tree name, tree t, vec<tree> *base_fndecls) 2737 { 2738 bool found_decls = false; 2739 2740 /* Find virtual functions in T with the indicated NAME. */ 2741 for (ovl_iterator iter (get_class_binding (t, name)); iter; ++iter) 2742 { 2743 tree method = *iter; 2744 2745 if (TREE_CODE (method) == FUNCTION_DECL && DECL_VINDEX (method)) 2746 { 2747 base_fndecls->safe_push (method); 2748 found_decls = true; 2749 } 2750 } 2751 2752 if (found_decls) 2753 return; 2754 2755 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t)); 2756 for (int i = 0; i < n_baseclasses; i++) 2757 { 2758 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (t), i)); 2759 get_basefndecls (name, basetype, base_fndecls); 2760 } 2761 } 2762 2763 /* If this declaration supersedes the declaration of 2764 a method declared virtual in the base class, then 2765 mark this field as being virtual as well. */ 2766 2767 void 2768 check_for_override (tree decl, tree ctype) 2769 { 2770 bool overrides_found = false; 2771 if (TREE_CODE (decl) == TEMPLATE_DECL) 2772 /* In [temp.mem] we have: 2773 2774 A specialization of a member function template does not 2775 override a virtual function from a base class. */ 2776 return; 2777 if ((DECL_DESTRUCTOR_P (decl) 2778 || IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) 2779 || DECL_CONV_FN_P (decl)) 2780 && look_for_overrides (ctype, decl) 2781 && !DECL_STATIC_FUNCTION_P (decl)) 2782 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor 2783 the error_mark_node so that we know it is an overriding 2784 function. */ 2785 { 2786 DECL_VINDEX (decl) = decl; 2787 overrides_found = true; 2788 if (warn_override && !DECL_OVERRIDE_P (decl) 2789 && !DECL_DESTRUCTOR_P (decl)) 2790 warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wsuggest_override, 2791 "%qD can be marked override", decl); 2792 } 2793 2794 if (DECL_VIRTUAL_P (decl)) 2795 { 2796 if (!DECL_VINDEX (decl)) 2797 DECL_VINDEX (decl) = error_mark_node; 2798 IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) = 1; 2799 if (DECL_DESTRUCTOR_P (decl)) 2800 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (ctype) = true; 2801 } 2802 else if (DECL_FINAL_P (decl)) 2803 error ("%q+#D marked %<final%>, but is not virtual", decl); 2804 if (DECL_OVERRIDE_P (decl) && !overrides_found) 2805 error ("%q+#D marked %<override%>, but does not override", decl); 2806 } 2807 2808 /* Warn about hidden virtual functions that are not overridden in t. 2809 We know that constructors and destructors don't apply. */ 2810 2811 static void 2812 warn_hidden (tree t) 2813 { 2814 if (vec<tree, va_gc> *member_vec = CLASSTYPE_MEMBER_VEC (t)) 2815 for (unsigned ix = member_vec->length (); ix--;) 2816 { 2817 tree fns = (*member_vec)[ix]; 2818 2819 if (!OVL_P (fns)) 2820 continue; 2821 2822 tree name = OVL_NAME (fns); 2823 auto_vec<tree, 20> base_fndecls; 2824 tree base_binfo; 2825 tree binfo; 2826 unsigned j; 2827 2828 /* Iterate through all of the base classes looking for possibly 2829 hidden functions. */ 2830 for (binfo = TYPE_BINFO (t), j = 0; 2831 BINFO_BASE_ITERATE (binfo, j, base_binfo); j++) 2832 { 2833 tree basetype = BINFO_TYPE (base_binfo); 2834 get_basefndecls (name, basetype, &base_fndecls); 2835 } 2836 2837 /* If there are no functions to hide, continue. */ 2838 if (base_fndecls.is_empty ()) 2839 continue; 2840 2841 /* Remove any overridden functions. */ 2842 for (ovl_iterator iter (fns); iter; ++iter) 2843 { 2844 tree fndecl = *iter; 2845 if (TREE_CODE (fndecl) == FUNCTION_DECL 2846 && DECL_VINDEX (fndecl)) 2847 { 2848 /* If the method from the base class has the same 2849 signature as the method from the derived class, it 2850 has been overridden. */ 2851 for (size_t k = 0; k < base_fndecls.length (); k++) 2852 if (base_fndecls[k] 2853 && same_signature_p (fndecl, base_fndecls[k])) 2854 base_fndecls[k] = NULL_TREE; 2855 } 2856 } 2857 2858 /* Now give a warning for all base functions without overriders, 2859 as they are hidden. */ 2860 tree base_fndecl; 2861 FOR_EACH_VEC_ELT (base_fndecls, j, base_fndecl) 2862 if (base_fndecl) 2863 { 2864 /* Here we know it is a hider, and no overrider exists. */ 2865 warning_at (location_of (base_fndecl), 2866 OPT_Woverloaded_virtual, 2867 "%qD was hidden", base_fndecl); 2868 warning_at (location_of (fns), 2869 OPT_Woverloaded_virtual, " by %qD", fns); 2870 } 2871 } 2872 } 2873 2874 /* Recursive helper for finish_struct_anon. */ 2875 2876 static void 2877 finish_struct_anon_r (tree field, bool complain) 2878 { 2879 for (tree elt = TYPE_FIELDS (TREE_TYPE (field)); elt; elt = DECL_CHAIN (elt)) 2880 { 2881 /* We're generally only interested in entities the user 2882 declared, but we also find nested classes by noticing 2883 the TYPE_DECL that we create implicitly. You're 2884 allowed to put one anonymous union inside another, 2885 though, so we explicitly tolerate that. We use 2886 TYPE_UNNAMED_P rather than ANON_AGGR_TYPE_P so that 2887 we also allow unnamed types used for defining fields. */ 2888 if (DECL_ARTIFICIAL (elt) 2889 && (!DECL_IMPLICIT_TYPEDEF_P (elt) 2890 || TYPE_UNNAMED_P (TREE_TYPE (elt)))) 2891 continue; 2892 2893 if (complain 2894 && (TREE_CODE (elt) != FIELD_DECL 2895 || (TREE_PRIVATE (elt) || TREE_PROTECTED (elt)))) 2896 { 2897 /* We already complained about static data members in 2898 finish_static_data_member_decl. */ 2899 if (!VAR_P (elt) 2900 && permerror (DECL_SOURCE_LOCATION (elt), 2901 TREE_CODE (TREE_TYPE (field)) == UNION_TYPE 2902 ? "%q#D invalid; an anonymous union may " 2903 "only have public non-static data members" 2904 : "%q#D invalid; an anonymous struct may " 2905 "only have public non-static data members", elt)) 2906 { 2907 static bool hint; 2908 if (flag_permissive && !hint) 2909 { 2910 hint = true; 2911 inform (DECL_SOURCE_LOCATION (elt), 2912 "this flexibility is deprecated and will be removed"); 2913 } 2914 } 2915 } 2916 2917 TREE_PRIVATE (elt) = TREE_PRIVATE (field); 2918 TREE_PROTECTED (elt) = TREE_PROTECTED (field); 2919 2920 /* Recurse into the anonymous aggregates to correctly handle 2921 access control (c++/24926): 2922 2923 class A { 2924 union { 2925 union { 2926 int i; 2927 }; 2928 }; 2929 }; 2930 2931 int j=A().i; */ 2932 if (DECL_NAME (elt) == NULL_TREE 2933 && ANON_AGGR_TYPE_P (TREE_TYPE (elt))) 2934 finish_struct_anon_r (elt, /*complain=*/false); 2935 } 2936 } 2937 2938 /* Check for things that are invalid. There are probably plenty of other 2939 things we should check for also. */ 2940 2941 static void 2942 finish_struct_anon (tree t) 2943 { 2944 for (tree field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) 2945 { 2946 if (TREE_STATIC (field)) 2947 continue; 2948 if (TREE_CODE (field) != FIELD_DECL) 2949 continue; 2950 2951 if (DECL_NAME (field) == NULL_TREE 2952 && ANON_AGGR_TYPE_P (TREE_TYPE (field))) 2953 finish_struct_anon_r (field, /*complain=*/true); 2954 } 2955 } 2956 2957 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which 2958 will be used later during class template instantiation. 2959 When FRIEND_P is zero, T can be a static member data (VAR_DECL), 2960 a non-static member data (FIELD_DECL), a member function 2961 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE), 2962 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL) 2963 When FRIEND_P is nonzero, T is either a friend class 2964 (RECORD_TYPE, TEMPLATE_DECL) or a friend function 2965 (FUNCTION_DECL, TEMPLATE_DECL). */ 2966 2967 void 2968 maybe_add_class_template_decl_list (tree type, tree t, int friend_p) 2969 { 2970 /* Save some memory by not creating TREE_LIST if TYPE is not template. */ 2971 if (CLASSTYPE_TEMPLATE_INFO (type)) 2972 CLASSTYPE_DECL_LIST (type) 2973 = tree_cons (friend_p ? NULL_TREE : type, 2974 t, CLASSTYPE_DECL_LIST (type)); 2975 } 2976 2977 /* This function is called from declare_virt_assop_and_dtor via 2978 dfs_walk_all. 2979 2980 DATA is a type that direcly or indirectly inherits the base 2981 represented by BINFO. If BINFO contains a virtual assignment [copy 2982 assignment or move assigment] operator or a virtual constructor, 2983 declare that function in DATA if it hasn't been already declared. */ 2984 2985 static tree 2986 dfs_declare_virt_assop_and_dtor (tree binfo, void *data) 2987 { 2988 tree bv, fn, t = (tree)data; 2989 tree opname = assign_op_identifier; 2990 2991 gcc_assert (t && CLASS_TYPE_P (t)); 2992 gcc_assert (binfo && TREE_CODE (binfo) == TREE_BINFO); 2993 2994 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) 2995 /* A base without a vtable needs no modification, and its bases 2996 are uninteresting. */ 2997 return dfs_skip_bases; 2998 2999 if (BINFO_PRIMARY_P (binfo)) 3000 /* If this is a primary base, then we have already looked at the 3001 virtual functions of its vtable. */ 3002 return NULL_TREE; 3003 3004 for (bv = BINFO_VIRTUALS (binfo); bv; bv = TREE_CHAIN (bv)) 3005 { 3006 fn = BV_FN (bv); 3007 3008 if (DECL_NAME (fn) == opname) 3009 { 3010 if (CLASSTYPE_LAZY_COPY_ASSIGN (t)) 3011 lazily_declare_fn (sfk_copy_assignment, t); 3012 if (CLASSTYPE_LAZY_MOVE_ASSIGN (t)) 3013 lazily_declare_fn (sfk_move_assignment, t); 3014 } 3015 else if (DECL_DESTRUCTOR_P (fn) 3016 && CLASSTYPE_LAZY_DESTRUCTOR (t)) 3017 lazily_declare_fn (sfk_destructor, t); 3018 } 3019 3020 return NULL_TREE; 3021 } 3022 3023 /* If the class type T has a direct or indirect base that contains a 3024 virtual assignment operator or a virtual destructor, declare that 3025 function in T if it hasn't been already declared. */ 3026 3027 static void 3028 declare_virt_assop_and_dtor (tree t) 3029 { 3030 if (!(TYPE_POLYMORPHIC_P (t) 3031 && (CLASSTYPE_LAZY_COPY_ASSIGN (t) 3032 || CLASSTYPE_LAZY_MOVE_ASSIGN (t) 3033 || CLASSTYPE_LAZY_DESTRUCTOR (t)))) 3034 return; 3035 3036 dfs_walk_all (TYPE_BINFO (t), 3037 dfs_declare_virt_assop_and_dtor, 3038 NULL, t); 3039 } 3040 3041 /* Declare the inheriting constructor for class T inherited from base 3042 constructor CTOR with the parameter array PARMS of size NPARMS. */ 3043 3044 static void 3045 one_inheriting_sig (tree t, tree ctor, tree *parms, int nparms) 3046 { 3047 gcc_assert (TYPE_MAIN_VARIANT (t) == t); 3048 3049 /* We don't declare an inheriting ctor that would be a default, 3050 copy or move ctor for derived or base. */ 3051 if (nparms == 0) 3052 return; 3053 if (nparms == 1 3054 && TREE_CODE (parms[0]) == REFERENCE_TYPE) 3055 { 3056 tree parm = TYPE_MAIN_VARIANT (TREE_TYPE (parms[0])); 3057 if (parm == t || parm == DECL_CONTEXT (ctor)) 3058 return; 3059 } 3060 3061 tree parmlist = void_list_node; 3062 for (int i = nparms - 1; i >= 0; i--) 3063 parmlist = tree_cons (NULL_TREE, parms[i], parmlist); 3064 tree fn = implicitly_declare_fn (sfk_inheriting_constructor, 3065 t, false, ctor, parmlist); 3066 3067 if (add_method (t, fn, false)) 3068 { 3069 DECL_CHAIN (fn) = TYPE_FIELDS (t); 3070 TYPE_FIELDS (t) = fn; 3071 } 3072 } 3073 3074 /* Declare all the inheriting constructors for class T inherited from base 3075 constructor CTOR. */ 3076 3077 static void 3078 one_inherited_ctor (tree ctor, tree t, tree using_decl) 3079 { 3080 tree parms = FUNCTION_FIRST_USER_PARMTYPE (ctor); 3081 3082 if (flag_new_inheriting_ctors) 3083 { 3084 ctor = implicitly_declare_fn (sfk_inheriting_constructor, 3085 t, /*const*/false, ctor, parms); 3086 add_method (t, ctor, using_decl != NULL_TREE); 3087 TYPE_HAS_USER_CONSTRUCTOR (t) = true; 3088 return; 3089 } 3090 3091 tree *new_parms = XALLOCAVEC (tree, list_length (parms)); 3092 int i = 0; 3093 for (; parms && parms != void_list_node; parms = TREE_CHAIN (parms)) 3094 { 3095 if (TREE_PURPOSE (parms)) 3096 one_inheriting_sig (t, ctor, new_parms, i); 3097 new_parms[i++] = TREE_VALUE (parms); 3098 } 3099 one_inheriting_sig (t, ctor, new_parms, i); 3100 if (parms == NULL_TREE) 3101 { 3102 if (warning (OPT_Winherited_variadic_ctor, 3103 "the ellipsis in %qD is not inherited", ctor)) 3104 inform (DECL_SOURCE_LOCATION (ctor), "%qD declared here", ctor); 3105 } 3106 } 3107 3108 /* Create default constructors, assignment operators, and so forth for 3109 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR, 3110 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason, 3111 the class cannot have a default constructor, copy constructor 3112 taking a const reference argument, or an assignment operator taking 3113 a const reference, respectively. */ 3114 3115 static void 3116 add_implicitly_declared_members (tree t, tree* access_decls, 3117 int cant_have_const_cctor, 3118 int cant_have_const_assignment) 3119 { 3120 /* Destructor. */ 3121 if (!CLASSTYPE_DESTRUCTOR (t)) 3122 /* In general, we create destructors lazily. */ 3123 CLASSTYPE_LAZY_DESTRUCTOR (t) = 1; 3124 3125 bool move_ok = false; 3126 if (cxx_dialect >= cxx11 && CLASSTYPE_LAZY_DESTRUCTOR (t) 3127 && !TYPE_HAS_COPY_CTOR (t) && !TYPE_HAS_COPY_ASSIGN (t) 3128 && !classtype_has_move_assign_or_move_ctor_p (t, false)) 3129 move_ok = true; 3130 3131 /* [class.ctor] 3132 3133 If there is no user-declared constructor for a class, a default 3134 constructor is implicitly declared. */ 3135 if (! TYPE_HAS_USER_CONSTRUCTOR (t)) 3136 { 3137 TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 1; 3138 CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 1; 3139 if (cxx_dialect >= cxx11) 3140 TYPE_HAS_CONSTEXPR_CTOR (t) 3141 /* Don't force the declaration to get a hard answer; if the 3142 definition would have made the class non-literal, it will still be 3143 non-literal because of the base or member in question, and that 3144 gives a better diagnostic. */ 3145 = type_maybe_constexpr_default_constructor (t); 3146 } 3147 3148 /* [class.ctor] 3149 3150 If a class definition does not explicitly declare a copy 3151 constructor, one is declared implicitly. */ 3152 if (! TYPE_HAS_COPY_CTOR (t)) 3153 { 3154 TYPE_HAS_COPY_CTOR (t) = 1; 3155 TYPE_HAS_CONST_COPY_CTOR (t) = !cant_have_const_cctor; 3156 CLASSTYPE_LAZY_COPY_CTOR (t) = 1; 3157 if (move_ok) 3158 CLASSTYPE_LAZY_MOVE_CTOR (t) = 1; 3159 } 3160 3161 /* If there is no assignment operator, one will be created if and 3162 when it is needed. For now, just record whether or not the type 3163 of the parameter to the assignment operator will be a const or 3164 non-const reference. */ 3165 if (!TYPE_HAS_COPY_ASSIGN (t)) 3166 { 3167 TYPE_HAS_COPY_ASSIGN (t) = 1; 3168 TYPE_HAS_CONST_COPY_ASSIGN (t) = !cant_have_const_assignment; 3169 CLASSTYPE_LAZY_COPY_ASSIGN (t) = 1; 3170 if (move_ok && !LAMBDA_TYPE_P (t)) 3171 CLASSTYPE_LAZY_MOVE_ASSIGN (t) = 1; 3172 } 3173 3174 /* We can't be lazy about declaring functions that might override 3175 a virtual function from a base class. */ 3176 declare_virt_assop_and_dtor (t); 3177 3178 while (*access_decls) 3179 { 3180 tree using_decl = TREE_VALUE (*access_decls); 3181 tree decl = USING_DECL_DECLS (using_decl); 3182 if (DECL_NAME (using_decl) == ctor_identifier) 3183 { 3184 /* declare, then remove the decl */ 3185 tree ctor_list = decl; 3186 location_t loc = input_location; 3187 input_location = DECL_SOURCE_LOCATION (using_decl); 3188 for (ovl_iterator iter (ctor_list); iter; ++iter) 3189 one_inherited_ctor (*iter, t, using_decl); 3190 *access_decls = TREE_CHAIN (*access_decls); 3191 input_location = loc; 3192 } 3193 else 3194 access_decls = &TREE_CHAIN (*access_decls); 3195 } 3196 } 3197 3198 /* Cache of enum_min_precision values. */ 3199 static GTY((deletable)) hash_map<tree, int> *enum_to_min_precision; 3200 3201 /* Return the minimum precision of a bit-field needed to store all 3202 enumerators of ENUMERAL_TYPE TYPE. */ 3203 3204 static int 3205 enum_min_precision (tree type) 3206 { 3207 type = TYPE_MAIN_VARIANT (type); 3208 /* For unscoped enums without fixed underlying type and without mode 3209 attribute we can just use precision of the underlying type. */ 3210 if (UNSCOPED_ENUM_P (type) 3211 && !ENUM_FIXED_UNDERLYING_TYPE_P (type) 3212 && !lookup_attribute ("mode", TYPE_ATTRIBUTES (type))) 3213 return TYPE_PRECISION (ENUM_UNDERLYING_TYPE (type)); 3214 3215 if (enum_to_min_precision == NULL) 3216 enum_to_min_precision = hash_map<tree, int>::create_ggc (37); 3217 3218 bool existed; 3219 int &prec = enum_to_min_precision->get_or_insert (type, &existed); 3220 if (existed) 3221 return prec; 3222 3223 tree minnode, maxnode; 3224 if (TYPE_VALUES (type)) 3225 { 3226 minnode = maxnode = NULL_TREE; 3227 for (tree values = TYPE_VALUES (type); 3228 values; values = TREE_CHAIN (values)) 3229 { 3230 tree decl = TREE_VALUE (values); 3231 tree value = DECL_INITIAL (decl); 3232 if (value == error_mark_node) 3233 value = integer_zero_node; 3234 if (!minnode) 3235 minnode = maxnode = value; 3236 else if (tree_int_cst_lt (maxnode, value)) 3237 maxnode = value; 3238 else if (tree_int_cst_lt (value, minnode)) 3239 minnode = value; 3240 } 3241 } 3242 else 3243 minnode = maxnode = integer_zero_node; 3244 3245 signop sgn = tree_int_cst_sgn (minnode) >= 0 ? UNSIGNED : SIGNED; 3246 int lowprec = tree_int_cst_min_precision (minnode, sgn); 3247 int highprec = tree_int_cst_min_precision (maxnode, sgn); 3248 prec = MAX (lowprec, highprec); 3249 return prec; 3250 } 3251 3252 /* FIELD is a bit-field. We are finishing the processing for its 3253 enclosing type. Issue any appropriate messages and set appropriate 3254 flags. Returns false if an error has been diagnosed. */ 3255 3256 static bool 3257 check_bitfield_decl (tree field) 3258 { 3259 tree type = TREE_TYPE (field); 3260 tree w; 3261 3262 /* Extract the declared width of the bitfield, which has been 3263 temporarily stashed in DECL_BIT_FIELD_REPRESENTATIVE by grokbitfield. */ 3264 w = DECL_BIT_FIELD_REPRESENTATIVE (field); 3265 gcc_assert (w != NULL_TREE); 3266 /* Remove the bit-field width indicator so that the rest of the 3267 compiler does not treat that value as a qualifier. */ 3268 DECL_BIT_FIELD_REPRESENTATIVE (field) = NULL_TREE; 3269 3270 /* Detect invalid bit-field type. */ 3271 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (type)) 3272 { 3273 error ("bit-field %q+#D with non-integral type", field); 3274 w = error_mark_node; 3275 } 3276 else 3277 { 3278 location_t loc = input_location; 3279 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */ 3280 STRIP_NOPS (w); 3281 3282 /* detect invalid field size. */ 3283 input_location = DECL_SOURCE_LOCATION (field); 3284 w = cxx_constant_value (w); 3285 input_location = loc; 3286 3287 if (TREE_CODE (w) != INTEGER_CST) 3288 { 3289 error ("bit-field %q+D width not an integer constant", field); 3290 w = error_mark_node; 3291 } 3292 else if (tree_int_cst_sgn (w) < 0) 3293 { 3294 error ("negative width in bit-field %q+D", field); 3295 w = error_mark_node; 3296 } 3297 else if (integer_zerop (w) && DECL_NAME (field) != 0) 3298 { 3299 error ("zero width for bit-field %q+D", field); 3300 w = error_mark_node; 3301 } 3302 else if ((TREE_CODE (type) != ENUMERAL_TYPE 3303 && TREE_CODE (type) != BOOLEAN_TYPE 3304 && compare_tree_int (w, TYPE_PRECISION (type)) > 0) 3305 || ((TREE_CODE (type) == ENUMERAL_TYPE 3306 || TREE_CODE (type) == BOOLEAN_TYPE) 3307 && tree_int_cst_lt (TYPE_SIZE (type), w))) 3308 warning_at (DECL_SOURCE_LOCATION (field), 0, 3309 "width of %qD exceeds its type", field); 3310 else if (TREE_CODE (type) == ENUMERAL_TYPE) 3311 { 3312 int prec = enum_min_precision (type); 3313 if (compare_tree_int (w, prec) < 0) 3314 warning_at (DECL_SOURCE_LOCATION (field), 0, 3315 "%qD is too small to hold all values of %q#T", 3316 field, type); 3317 } 3318 } 3319 3320 if (w != error_mark_node) 3321 { 3322 DECL_SIZE (field) = fold_convert (bitsizetype, w); 3323 DECL_BIT_FIELD (field) = 1; 3324 return true; 3325 } 3326 else 3327 { 3328 /* Non-bit-fields are aligned for their type. */ 3329 DECL_BIT_FIELD (field) = 0; 3330 CLEAR_DECL_C_BIT_FIELD (field); 3331 return false; 3332 } 3333 } 3334 3335 /* FIELD is a non bit-field. We are finishing the processing for its 3336 enclosing type T. Issue any appropriate messages and set appropriate 3337 flags. */ 3338 3339 static bool 3340 check_field_decl (tree field, 3341 tree t, 3342 int* cant_have_const_ctor, 3343 int* no_const_asn_ref) 3344 { 3345 tree type = strip_array_types (TREE_TYPE (field)); 3346 bool any_default_members = false; 3347 3348 /* In C++98 an anonymous union cannot contain any fields which would change 3349 the settings of CANT_HAVE_CONST_CTOR and friends. */ 3350 if (ANON_UNION_TYPE_P (type) && cxx_dialect < cxx11) 3351 ; 3352 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous 3353 structs. So, we recurse through their fields here. */ 3354 else if (ANON_AGGR_TYPE_P (type)) 3355 { 3356 for (tree fields = TYPE_FIELDS (type); fields; 3357 fields = DECL_CHAIN (fields)) 3358 if (TREE_CODE (fields) == FIELD_DECL) 3359 any_default_members |= check_field_decl (fields, t, 3360 cant_have_const_ctor, 3361 no_const_asn_ref); 3362 } 3363 /* Check members with class type for constructors, destructors, 3364 etc. */ 3365 else if (CLASS_TYPE_P (type)) 3366 { 3367 /* Never let anything with uninheritable virtuals 3368 make it through without complaint. */ 3369 abstract_virtuals_error (field, type); 3370 3371 if (TREE_CODE (t) == UNION_TYPE && cxx_dialect < cxx11) 3372 { 3373 static bool warned; 3374 int oldcount = errorcount; 3375 if (TYPE_NEEDS_CONSTRUCTING (type)) 3376 error ("member %q+#D with constructor not allowed in union", 3377 field); 3378 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 3379 error ("member %q+#D with destructor not allowed in union", field); 3380 if (TYPE_HAS_COMPLEX_COPY_ASSIGN (type)) 3381 error ("member %q+#D with copy assignment operator not allowed in union", 3382 field); 3383 if (!warned && errorcount > oldcount) 3384 { 3385 inform (DECL_SOURCE_LOCATION (field), "unrestricted unions " 3386 "only available with -std=c++11 or -std=gnu++11"); 3387 warned = true; 3388 } 3389 } 3390 else 3391 { 3392 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (type); 3393 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) 3394 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type); 3395 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) 3396 |= (TYPE_HAS_COMPLEX_COPY_ASSIGN (type) 3397 || !TYPE_HAS_COPY_ASSIGN (type)); 3398 TYPE_HAS_COMPLEX_COPY_CTOR (t) |= (TYPE_HAS_COMPLEX_COPY_CTOR (type) 3399 || !TYPE_HAS_COPY_CTOR (type)); 3400 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) |= TYPE_HAS_COMPLEX_MOVE_ASSIGN (type); 3401 TYPE_HAS_COMPLEX_MOVE_CTOR (t) |= TYPE_HAS_COMPLEX_MOVE_CTOR (type); 3402 TYPE_HAS_COMPLEX_DFLT (t) |= (!TYPE_HAS_DEFAULT_CONSTRUCTOR (type) 3403 || TYPE_HAS_COMPLEX_DFLT (type)); 3404 } 3405 3406 if (TYPE_HAS_COPY_CTOR (type) 3407 && !TYPE_HAS_CONST_COPY_CTOR (type)) 3408 *cant_have_const_ctor = 1; 3409 3410 if (TYPE_HAS_COPY_ASSIGN (type) 3411 && !TYPE_HAS_CONST_COPY_ASSIGN (type)) 3412 *no_const_asn_ref = 1; 3413 } 3414 3415 check_abi_tags (t, field); 3416 3417 if (DECL_INITIAL (field) != NULL_TREE) 3418 /* `build_class_init_list' does not recognize 3419 non-FIELD_DECLs. */ 3420 any_default_members = true; 3421 3422 return any_default_members; 3423 } 3424 3425 /* Check the data members (both static and non-static), class-scoped 3426 typedefs, etc., appearing in the declaration of T. Issue 3427 appropriate diagnostics. Sets ACCESS_DECLS to a list (in 3428 declaration order) of access declarations; each TREE_VALUE in this 3429 list is a USING_DECL. 3430 3431 In addition, set the following flags: 3432 3433 EMPTY_P 3434 The class is empty, i.e., contains no non-static data members. 3435 3436 CANT_HAVE_CONST_CTOR_P 3437 This class cannot have an implicitly generated copy constructor 3438 taking a const reference. 3439 3440 CANT_HAVE_CONST_ASN_REF 3441 This class cannot have an implicitly generated assignment 3442 operator taking a const reference. 3443 3444 All of these flags should be initialized before calling this 3445 function. 3446 3447 Returns a pointer to the end of the TYPE_FIELDs chain; additional 3448 fields can be added by adding to this chain. */ 3449 3450 static void 3451 check_field_decls (tree t, tree *access_decls, 3452 int *cant_have_const_ctor_p, 3453 int *no_const_asn_ref_p) 3454 { 3455 tree *field; 3456 tree *next; 3457 bool has_pointers; 3458 bool any_default_members; 3459 int cant_pack = 0; 3460 int field_access = -1; 3461 3462 /* Assume there are no access declarations. */ 3463 *access_decls = NULL_TREE; 3464 /* Assume this class has no pointer members. */ 3465 has_pointers = false; 3466 /* Assume none of the members of this class have default 3467 initializations. */ 3468 any_default_members = false; 3469 3470 for (field = &TYPE_FIELDS (t); *field; field = next) 3471 { 3472 tree x = *field; 3473 tree type = TREE_TYPE (x); 3474 int this_field_access; 3475 3476 next = &DECL_CHAIN (x); 3477 3478 if (TREE_CODE (x) == USING_DECL) 3479 { 3480 /* Save the access declarations for our caller. */ 3481 *access_decls = tree_cons (NULL_TREE, x, *access_decls); 3482 continue; 3483 } 3484 3485 if (TREE_CODE (x) == TYPE_DECL 3486 || TREE_CODE (x) == TEMPLATE_DECL) 3487 continue; 3488 3489 if (TREE_CODE (x) == FUNCTION_DECL) 3490 /* FIXME: We should fold in the checking from check_methods. */ 3491 continue; 3492 3493 /* If we've gotten this far, it's a data member, possibly static, 3494 or an enumerator. */ 3495 if (TREE_CODE (x) != CONST_DECL) 3496 DECL_CONTEXT (x) = t; 3497 3498 /* When this goes into scope, it will be a non-local reference. */ 3499 DECL_NONLOCAL (x) = 1; 3500 3501 if (TREE_CODE (t) == UNION_TYPE) 3502 { 3503 /* [class.union] (C++98) 3504 3505 If a union contains a static data member, or a member of 3506 reference type, the program is ill-formed. 3507 3508 In C++11 [class.union] says: 3509 If a union contains a non-static data member of reference type 3510 the program is ill-formed. */ 3511 if (VAR_P (x) && cxx_dialect < cxx11) 3512 { 3513 error ("in C++98 %q+D may not be static because it is " 3514 "a member of a union", x); 3515 continue; 3516 } 3517 if (TREE_CODE (type) == REFERENCE_TYPE 3518 && TREE_CODE (x) == FIELD_DECL) 3519 { 3520 error ("non-static data member %q+D in a union may not " 3521 "have reference type %qT", x, type); 3522 continue; 3523 } 3524 } 3525 3526 /* Perform error checking that did not get done in 3527 grokdeclarator. */ 3528 if (TREE_CODE (type) == FUNCTION_TYPE) 3529 { 3530 error ("field %q+D invalidly declared function type", x); 3531 type = build_pointer_type (type); 3532 TREE_TYPE (x) = type; 3533 } 3534 else if (TREE_CODE (type) == METHOD_TYPE) 3535 { 3536 error ("field %q+D invalidly declared method type", x); 3537 type = build_pointer_type (type); 3538 TREE_TYPE (x) = type; 3539 } 3540 3541 if (type == error_mark_node) 3542 continue; 3543 3544 if (TREE_CODE (x) == CONST_DECL || VAR_P (x)) 3545 continue; 3546 3547 /* Now it can only be a FIELD_DECL. */ 3548 3549 if (TREE_PRIVATE (x) || TREE_PROTECTED (x)) 3550 CLASSTYPE_NON_AGGREGATE (t) = 1; 3551 3552 /* If at least one non-static data member is non-literal, the whole 3553 class becomes non-literal. Per Core/1453, volatile non-static 3554 data members and base classes are also not allowed. 3555 Note: if the type is incomplete we will complain later on. */ 3556 if (COMPLETE_TYPE_P (type) 3557 && (!literal_type_p (type) || CP_TYPE_VOLATILE_P (type))) 3558 CLASSTYPE_LITERAL_P (t) = false; 3559 3560 /* A standard-layout class is a class that: 3561 ... 3562 has the same access control (Clause 11) for all non-static data members, 3563 ... */ 3564 this_field_access = TREE_PROTECTED (x) ? 1 : TREE_PRIVATE (x) ? 2 : 0; 3565 if (field_access == -1) 3566 field_access = this_field_access; 3567 else if (this_field_access != field_access) 3568 CLASSTYPE_NON_STD_LAYOUT (t) = 1; 3569 3570 /* If this is of reference type, check if it needs an init. */ 3571 if (TREE_CODE (type) == REFERENCE_TYPE) 3572 { 3573 CLASSTYPE_NON_LAYOUT_POD_P (t) = 1; 3574 CLASSTYPE_NON_STD_LAYOUT (t) = 1; 3575 if (DECL_INITIAL (x) == NULL_TREE) 3576 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1); 3577 if (cxx_dialect < cxx11) 3578 { 3579 /* ARM $12.6.2: [A member initializer list] (or, for an 3580 aggregate, initialization by a brace-enclosed list) is the 3581 only way to initialize nonstatic const and reference 3582 members. */ 3583 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) = 1; 3584 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) = 1; 3585 } 3586 } 3587 3588 type = strip_array_types (type); 3589 3590 if (TYPE_PACKED (t)) 3591 { 3592 if (!layout_pod_type_p (type) && !TYPE_PACKED (type)) 3593 { 3594 warning_at 3595 (DECL_SOURCE_LOCATION (x), 0, 3596 "ignoring packed attribute because of unpacked non-POD field %q#D", 3597 x); 3598 cant_pack = 1; 3599 } 3600 else if (DECL_C_BIT_FIELD (x) 3601 || TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT) 3602 DECL_PACKED (x) = 1; 3603 } 3604 3605 if (DECL_C_BIT_FIELD (x) 3606 && integer_zerop (DECL_BIT_FIELD_REPRESENTATIVE (x))) 3607 /* We don't treat zero-width bitfields as making a class 3608 non-empty. */ 3609 ; 3610 else 3611 { 3612 /* The class is non-empty. */ 3613 CLASSTYPE_EMPTY_P (t) = 0; 3614 /* The class is not even nearly empty. */ 3615 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 3616 /* If one of the data members contains an empty class, 3617 so does T. */ 3618 if (CLASS_TYPE_P (type) 3619 && CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type)) 3620 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1; 3621 } 3622 3623 /* This is used by -Weffc++ (see below). Warn only for pointers 3624 to members which might hold dynamic memory. So do not warn 3625 for pointers to functions or pointers to members. */ 3626 if (TYPE_PTR_P (type) 3627 && !TYPE_PTRFN_P (type)) 3628 has_pointers = true; 3629 3630 if (CLASS_TYPE_P (type)) 3631 { 3632 if (CLASSTYPE_REF_FIELDS_NEED_INIT (type)) 3633 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1); 3634 if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (type)) 3635 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1); 3636 } 3637 3638 if (DECL_MUTABLE_P (x) || TYPE_HAS_MUTABLE_P (type)) 3639 CLASSTYPE_HAS_MUTABLE (t) = 1; 3640 3641 if (DECL_MUTABLE_P (x)) 3642 { 3643 if (CP_TYPE_CONST_P (type)) 3644 { 3645 error ("member %q+D cannot be declared both %<const%> " 3646 "and %<mutable%>", x); 3647 continue; 3648 } 3649 if (TREE_CODE (type) == REFERENCE_TYPE) 3650 { 3651 error ("member %q+D cannot be declared as a %<mutable%> " 3652 "reference", x); 3653 continue; 3654 } 3655 } 3656 3657 if (! layout_pod_type_p (type)) 3658 /* DR 148 now allows pointers to members (which are POD themselves), 3659 to be allowed in POD structs. */ 3660 CLASSTYPE_NON_LAYOUT_POD_P (t) = 1; 3661 3662 if (!std_layout_type_p (type)) 3663 CLASSTYPE_NON_STD_LAYOUT (t) = 1; 3664 3665 if (! zero_init_p (type)) 3666 CLASSTYPE_NON_ZERO_INIT_P (t) = 1; 3667 3668 /* We set DECL_C_BIT_FIELD in grokbitfield. 3669 If the type and width are valid, we'll also set DECL_BIT_FIELD. */ 3670 if (DECL_C_BIT_FIELD (x)) 3671 check_bitfield_decl (x); 3672 3673 if (check_field_decl (x, t, cant_have_const_ctor_p, no_const_asn_ref_p)) 3674 { 3675 if (any_default_members 3676 && TREE_CODE (t) == UNION_TYPE) 3677 error ("multiple fields in union %qT initialized", t); 3678 any_default_members = true; 3679 } 3680 3681 /* Now that we've removed bit-field widths from DECL_INITIAL, 3682 anything left in DECL_INITIAL is an NSDMI that makes the class 3683 non-aggregate in C++11. */ 3684 if (DECL_INITIAL (x) && cxx_dialect < cxx14) 3685 CLASSTYPE_NON_AGGREGATE (t) = true; 3686 3687 /* If any field is const, the structure type is pseudo-const. */ 3688 if (CP_TYPE_CONST_P (type)) 3689 { 3690 C_TYPE_FIELDS_READONLY (t) = 1; 3691 if (DECL_INITIAL (x) == NULL_TREE) 3692 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1); 3693 if (cxx_dialect < cxx11) 3694 { 3695 /* ARM $12.6.2: [A member initializer list] (or, for an 3696 aggregate, initialization by a brace-enclosed list) is the 3697 only way to initialize nonstatic const and reference 3698 members. */ 3699 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) = 1; 3700 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) = 1; 3701 } 3702 } 3703 /* A field that is pseudo-const makes the structure likewise. */ 3704 else if (CLASS_TYPE_P (type)) 3705 { 3706 C_TYPE_FIELDS_READONLY (t) |= C_TYPE_FIELDS_READONLY (type); 3707 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 3708 CLASSTYPE_READONLY_FIELDS_NEED_INIT (t) 3709 | CLASSTYPE_READONLY_FIELDS_NEED_INIT (type)); 3710 } 3711 3712 /* Core issue 80: A nonstatic data member is required to have a 3713 different name from the class iff the class has a 3714 user-declared constructor. */ 3715 if (constructor_name_p (DECL_NAME (x), t) 3716 && TYPE_HAS_USER_CONSTRUCTOR (t)) 3717 permerror (DECL_SOURCE_LOCATION (x), 3718 "field %q#D with same name as class", x); 3719 } 3720 3721 /* Effective C++ rule 11: if a class has dynamic memory held by pointers, 3722 it should also define a copy constructor and an assignment operator to 3723 implement the correct copy semantic (deep vs shallow, etc.). As it is 3724 not feasible to check whether the constructors do allocate dynamic memory 3725 and store it within members, we approximate the warning like this: 3726 3727 -- Warn only if there are members which are pointers 3728 -- Warn only if there is a non-trivial constructor (otherwise, 3729 there cannot be memory allocated). 3730 -- Warn only if there is a non-trivial destructor. We assume that the 3731 user at least implemented the cleanup correctly, and a destructor 3732 is needed to free dynamic memory. 3733 3734 This seems enough for practical purposes. */ 3735 if (warn_ecpp 3736 && has_pointers 3737 && TYPE_HAS_USER_CONSTRUCTOR (t) 3738 && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) 3739 && !(TYPE_HAS_COPY_CTOR (t) && TYPE_HAS_COPY_ASSIGN (t))) 3740 { 3741 warning (OPT_Weffc__, "%q#T has pointer data members", t); 3742 3743 if (! TYPE_HAS_COPY_CTOR (t)) 3744 { 3745 warning (OPT_Weffc__, 3746 " but does not override %<%T(const %T&)%>", t, t); 3747 if (!TYPE_HAS_COPY_ASSIGN (t)) 3748 warning (OPT_Weffc__, " or %<operator=(const %T&)%>", t); 3749 } 3750 else if (! TYPE_HAS_COPY_ASSIGN (t)) 3751 warning (OPT_Weffc__, 3752 " but does not override %<operator=(const %T&)%>", t); 3753 } 3754 3755 /* Non-static data member initializers make the default constructor 3756 non-trivial. */ 3757 if (any_default_members) 3758 { 3759 TYPE_NEEDS_CONSTRUCTING (t) = true; 3760 TYPE_HAS_COMPLEX_DFLT (t) = true; 3761 } 3762 3763 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */ 3764 if (cant_pack) 3765 TYPE_PACKED (t) = 0; 3766 3767 /* Check anonymous struct/anonymous union fields. */ 3768 finish_struct_anon (t); 3769 3770 /* We've built up the list of access declarations in reverse order. 3771 Fix that now. */ 3772 *access_decls = nreverse (*access_decls); 3773 } 3774 3775 /* If TYPE is an empty class type, records its OFFSET in the table of 3776 OFFSETS. */ 3777 3778 static int 3779 record_subobject_offset (tree type, tree offset, splay_tree offsets) 3780 { 3781 splay_tree_node n; 3782 3783 if (!is_empty_class (type)) 3784 return 0; 3785 3786 /* Record the location of this empty object in OFFSETS. */ 3787 n = splay_tree_lookup (offsets, (splay_tree_key) offset); 3788 if (!n) 3789 n = splay_tree_insert (offsets, 3790 (splay_tree_key) offset, 3791 (splay_tree_value) NULL_TREE); 3792 n->value = ((splay_tree_value) 3793 tree_cons (NULL_TREE, 3794 type, 3795 (tree) n->value)); 3796 3797 return 0; 3798 } 3799 3800 /* Returns nonzero if TYPE is an empty class type and there is 3801 already an entry in OFFSETS for the same TYPE as the same OFFSET. */ 3802 3803 static int 3804 check_subobject_offset (tree type, tree offset, splay_tree offsets) 3805 { 3806 splay_tree_node n; 3807 tree t; 3808 3809 if (!is_empty_class (type)) 3810 return 0; 3811 3812 /* Record the location of this empty object in OFFSETS. */ 3813 n = splay_tree_lookup (offsets, (splay_tree_key) offset); 3814 if (!n) 3815 return 0; 3816 3817 for (t = (tree) n->value; t; t = TREE_CHAIN (t)) 3818 if (same_type_p (TREE_VALUE (t), type)) 3819 return 1; 3820 3821 return 0; 3822 } 3823 3824 /* Walk through all the subobjects of TYPE (located at OFFSET). Call 3825 F for every subobject, passing it the type, offset, and table of 3826 OFFSETS. If VBASES_P is one, then virtual non-primary bases should 3827 be traversed. 3828 3829 If MAX_OFFSET is non-NULL, then subobjects with an offset greater 3830 than MAX_OFFSET will not be walked. 3831 3832 If F returns a nonzero value, the traversal ceases, and that value 3833 is returned. Otherwise, returns zero. */ 3834 3835 static int 3836 walk_subobject_offsets (tree type, 3837 subobject_offset_fn f, 3838 tree offset, 3839 splay_tree offsets, 3840 tree max_offset, 3841 int vbases_p) 3842 { 3843 int r = 0; 3844 tree type_binfo = NULL_TREE; 3845 3846 /* If this OFFSET is bigger than the MAX_OFFSET, then we should 3847 stop. */ 3848 if (max_offset && tree_int_cst_lt (max_offset, offset)) 3849 return 0; 3850 3851 if (type == error_mark_node) 3852 return 0; 3853 3854 if (!TYPE_P (type)) 3855 { 3856 type_binfo = type; 3857 type = BINFO_TYPE (type); 3858 } 3859 3860 if (CLASS_TYPE_P (type)) 3861 { 3862 tree field; 3863 tree binfo; 3864 int i; 3865 3866 /* Avoid recursing into objects that are not interesting. */ 3867 if (!CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type)) 3868 return 0; 3869 3870 /* Record the location of TYPE. */ 3871 r = (*f) (type, offset, offsets); 3872 if (r) 3873 return r; 3874 3875 /* Iterate through the direct base classes of TYPE. */ 3876 if (!type_binfo) 3877 type_binfo = TYPE_BINFO (type); 3878 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, binfo); i++) 3879 { 3880 tree binfo_offset; 3881 3882 if (BINFO_VIRTUAL_P (binfo)) 3883 continue; 3884 3885 tree orig_binfo; 3886 /* We cannot rely on BINFO_OFFSET being set for the base 3887 class yet, but the offsets for direct non-virtual 3888 bases can be calculated by going back to the TYPE. */ 3889 orig_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), i); 3890 binfo_offset = size_binop (PLUS_EXPR, 3891 offset, 3892 BINFO_OFFSET (orig_binfo)); 3893 3894 r = walk_subobject_offsets (binfo, 3895 f, 3896 binfo_offset, 3897 offsets, 3898 max_offset, 3899 /*vbases_p=*/0); 3900 if (r) 3901 return r; 3902 } 3903 3904 if (CLASSTYPE_VBASECLASSES (type)) 3905 { 3906 unsigned ix; 3907 vec<tree, va_gc> *vbases; 3908 3909 /* Iterate through the virtual base classes of TYPE. In G++ 3910 3.2, we included virtual bases in the direct base class 3911 loop above, which results in incorrect results; the 3912 correct offsets for virtual bases are only known when 3913 working with the most derived type. */ 3914 if (vbases_p) 3915 for (vbases = CLASSTYPE_VBASECLASSES (type), ix = 0; 3916 vec_safe_iterate (vbases, ix, &binfo); ix++) 3917 { 3918 r = walk_subobject_offsets (binfo, 3919 f, 3920 size_binop (PLUS_EXPR, 3921 offset, 3922 BINFO_OFFSET (binfo)), 3923 offsets, 3924 max_offset, 3925 /*vbases_p=*/0); 3926 if (r) 3927 return r; 3928 } 3929 else 3930 { 3931 /* We still have to walk the primary base, if it is 3932 virtual. (If it is non-virtual, then it was walked 3933 above.) */ 3934 tree vbase = get_primary_binfo (type_binfo); 3935 3936 if (vbase && BINFO_VIRTUAL_P (vbase) 3937 && BINFO_PRIMARY_P (vbase) 3938 && BINFO_INHERITANCE_CHAIN (vbase) == type_binfo) 3939 { 3940 r = (walk_subobject_offsets 3941 (vbase, f, offset, 3942 offsets, max_offset, /*vbases_p=*/0)); 3943 if (r) 3944 return r; 3945 } 3946 } 3947 } 3948 3949 /* Iterate through the fields of TYPE. */ 3950 for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) 3951 if (TREE_CODE (field) == FIELD_DECL 3952 && TREE_TYPE (field) != error_mark_node 3953 && !DECL_ARTIFICIAL (field)) 3954 { 3955 tree field_offset; 3956 3957 field_offset = byte_position (field); 3958 3959 r = walk_subobject_offsets (TREE_TYPE (field), 3960 f, 3961 size_binop (PLUS_EXPR, 3962 offset, 3963 field_offset), 3964 offsets, 3965 max_offset, 3966 /*vbases_p=*/1); 3967 if (r) 3968 return r; 3969 } 3970 } 3971 else if (TREE_CODE (type) == ARRAY_TYPE) 3972 { 3973 tree element_type = strip_array_types (type); 3974 tree domain = TYPE_DOMAIN (type); 3975 tree index; 3976 3977 /* Avoid recursing into objects that are not interesting. */ 3978 if (!CLASS_TYPE_P (element_type) 3979 || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type) 3980 || !domain 3981 || integer_minus_onep (TYPE_MAX_VALUE (domain))) 3982 return 0; 3983 3984 /* Step through each of the elements in the array. */ 3985 for (index = size_zero_node; 3986 !tree_int_cst_lt (TYPE_MAX_VALUE (domain), index); 3987 index = size_binop (PLUS_EXPR, index, size_one_node)) 3988 { 3989 r = walk_subobject_offsets (TREE_TYPE (type), 3990 f, 3991 offset, 3992 offsets, 3993 max_offset, 3994 /*vbases_p=*/1); 3995 if (r) 3996 return r; 3997 offset = size_binop (PLUS_EXPR, offset, 3998 TYPE_SIZE_UNIT (TREE_TYPE (type))); 3999 /* If this new OFFSET is bigger than the MAX_OFFSET, then 4000 there's no point in iterating through the remaining 4001 elements of the array. */ 4002 if (max_offset && tree_int_cst_lt (max_offset, offset)) 4003 break; 4004 } 4005 } 4006 4007 return 0; 4008 } 4009 4010 /* Record all of the empty subobjects of TYPE (either a type or a 4011 binfo). If IS_DATA_MEMBER is true, then a non-static data member 4012 is being placed at OFFSET; otherwise, it is a base class that is 4013 being placed at OFFSET. */ 4014 4015 static void 4016 record_subobject_offsets (tree type, 4017 tree offset, 4018 splay_tree offsets, 4019 bool is_data_member) 4020 { 4021 tree max_offset; 4022 /* If recording subobjects for a non-static data member or a 4023 non-empty base class , we do not need to record offsets beyond 4024 the size of the biggest empty class. Additional data members 4025 will go at the end of the class. Additional base classes will go 4026 either at offset zero (if empty, in which case they cannot 4027 overlap with offsets past the size of the biggest empty class) or 4028 at the end of the class. 4029 4030 However, if we are placing an empty base class, then we must record 4031 all offsets, as either the empty class is at offset zero (where 4032 other empty classes might later be placed) or at the end of the 4033 class (where other objects might then be placed, so other empty 4034 subobjects might later overlap). */ 4035 if (is_data_member 4036 || !is_empty_class (BINFO_TYPE (type))) 4037 max_offset = sizeof_biggest_empty_class; 4038 else 4039 max_offset = NULL_TREE; 4040 walk_subobject_offsets (type, record_subobject_offset, offset, 4041 offsets, max_offset, is_data_member); 4042 } 4043 4044 /* Returns nonzero if any of the empty subobjects of TYPE (located at 4045 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero, 4046 virtual bases of TYPE are examined. */ 4047 4048 static int 4049 layout_conflict_p (tree type, 4050 tree offset, 4051 splay_tree offsets, 4052 int vbases_p) 4053 { 4054 splay_tree_node max_node; 4055 4056 /* Get the node in OFFSETS that indicates the maximum offset where 4057 an empty subobject is located. */ 4058 max_node = splay_tree_max (offsets); 4059 /* If there aren't any empty subobjects, then there's no point in 4060 performing this check. */ 4061 if (!max_node) 4062 return 0; 4063 4064 return walk_subobject_offsets (type, check_subobject_offset, offset, 4065 offsets, (tree) (max_node->key), 4066 vbases_p); 4067 } 4068 4069 /* DECL is a FIELD_DECL corresponding either to a base subobject of a 4070 non-static data member of the type indicated by RLI. BINFO is the 4071 binfo corresponding to the base subobject, OFFSETS maps offsets to 4072 types already located at those offsets. This function determines 4073 the position of the DECL. */ 4074 4075 static void 4076 layout_nonempty_base_or_field (record_layout_info rli, 4077 tree decl, 4078 tree binfo, 4079 splay_tree offsets) 4080 { 4081 tree offset = NULL_TREE; 4082 bool field_p; 4083 tree type; 4084 4085 if (binfo) 4086 { 4087 /* For the purposes of determining layout conflicts, we want to 4088 use the class type of BINFO; TREE_TYPE (DECL) will be the 4089 CLASSTYPE_AS_BASE version, which does not contain entries for 4090 zero-sized bases. */ 4091 type = TREE_TYPE (binfo); 4092 field_p = false; 4093 } 4094 else 4095 { 4096 type = TREE_TYPE (decl); 4097 field_p = true; 4098 } 4099 4100 /* Try to place the field. It may take more than one try if we have 4101 a hard time placing the field without putting two objects of the 4102 same type at the same address. */ 4103 while (1) 4104 { 4105 struct record_layout_info_s old_rli = *rli; 4106 4107 /* Place this field. */ 4108 place_field (rli, decl); 4109 offset = byte_position (decl); 4110 4111 /* We have to check to see whether or not there is already 4112 something of the same type at the offset we're about to use. 4113 For example, consider: 4114 4115 struct S {}; 4116 struct T : public S { int i; }; 4117 struct U : public S, public T {}; 4118 4119 Here, we put S at offset zero in U. Then, we can't put T at 4120 offset zero -- its S component would be at the same address 4121 as the S we already allocated. So, we have to skip ahead. 4122 Since all data members, including those whose type is an 4123 empty class, have nonzero size, any overlap can happen only 4124 with a direct or indirect base-class -- it can't happen with 4125 a data member. */ 4126 /* In a union, overlap is permitted; all members are placed at 4127 offset zero. */ 4128 if (TREE_CODE (rli->t) == UNION_TYPE) 4129 break; 4130 if (layout_conflict_p (field_p ? type : binfo, offset, 4131 offsets, field_p)) 4132 { 4133 /* Strip off the size allocated to this field. That puts us 4134 at the first place we could have put the field with 4135 proper alignment. */ 4136 *rli = old_rli; 4137 4138 /* Bump up by the alignment required for the type. */ 4139 rli->bitpos 4140 = size_binop (PLUS_EXPR, rli->bitpos, 4141 bitsize_int (binfo 4142 ? CLASSTYPE_ALIGN (type) 4143 : TYPE_ALIGN (type))); 4144 normalize_rli (rli); 4145 } 4146 else if (TREE_CODE (type) == NULLPTR_TYPE 4147 && warn_abi && abi_version_crosses (9)) 4148 { 4149 /* Before ABI v9, we were giving nullptr_t alignment of 1; if 4150 the offset wasn't aligned like a pointer when we started to 4151 layout this field, that affects its position. */ 4152 tree pos = rli_size_unit_so_far (&old_rli); 4153 if (int_cst_value (pos) % TYPE_ALIGN_UNIT (ptr_type_node) != 0) 4154 { 4155 if (abi_version_at_least (9)) 4156 warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wabi, 4157 "alignment of %qD increased in -fabi-version=9 " 4158 "(GCC 5.2)", decl); 4159 else 4160 warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wabi, "alignment " 4161 "of %qD will increase in -fabi-version=9", decl); 4162 } 4163 break; 4164 } 4165 else 4166 /* There was no conflict. We're done laying out this field. */ 4167 break; 4168 } 4169 4170 /* Now that we know where it will be placed, update its 4171 BINFO_OFFSET. */ 4172 if (binfo && CLASS_TYPE_P (BINFO_TYPE (binfo))) 4173 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at 4174 this point because their BINFO_OFFSET is copied from another 4175 hierarchy. Therefore, we may not need to add the entire 4176 OFFSET. */ 4177 propagate_binfo_offsets (binfo, 4178 size_diffop_loc (input_location, 4179 fold_convert (ssizetype, offset), 4180 fold_convert (ssizetype, 4181 BINFO_OFFSET (binfo)))); 4182 } 4183 4184 /* Returns true if TYPE is empty and OFFSET is nonzero. */ 4185 4186 static int 4187 empty_base_at_nonzero_offset_p (tree type, 4188 tree offset, 4189 splay_tree /*offsets*/) 4190 { 4191 return is_empty_class (type) && !integer_zerop (offset); 4192 } 4193 4194 /* Layout the empty base BINFO. EOC indicates the byte currently just 4195 past the end of the class, and should be correctly aligned for a 4196 class of the type indicated by BINFO; OFFSETS gives the offsets of 4197 the empty bases allocated so far. T is the most derived 4198 type. Return nonzero iff we added it at the end. */ 4199 4200 static bool 4201 layout_empty_base (record_layout_info rli, tree binfo, 4202 tree eoc, splay_tree offsets) 4203 { 4204 tree alignment; 4205 tree basetype = BINFO_TYPE (binfo); 4206 bool atend = false; 4207 4208 /* This routine should only be used for empty classes. */ 4209 gcc_assert (is_empty_class (basetype)); 4210 alignment = ssize_int (CLASSTYPE_ALIGN_UNIT (basetype)); 4211 4212 if (!integer_zerop (BINFO_OFFSET (binfo))) 4213 propagate_binfo_offsets 4214 (binfo, size_diffop_loc (input_location, 4215 size_zero_node, BINFO_OFFSET (binfo))); 4216 4217 /* This is an empty base class. We first try to put it at offset 4218 zero. */ 4219 if (layout_conflict_p (binfo, 4220 BINFO_OFFSET (binfo), 4221 offsets, 4222 /*vbases_p=*/0)) 4223 { 4224 /* That didn't work. Now, we move forward from the next 4225 available spot in the class. */ 4226 atend = true; 4227 propagate_binfo_offsets (binfo, fold_convert (ssizetype, eoc)); 4228 while (1) 4229 { 4230 if (!layout_conflict_p (binfo, 4231 BINFO_OFFSET (binfo), 4232 offsets, 4233 /*vbases_p=*/0)) 4234 /* We finally found a spot where there's no overlap. */ 4235 break; 4236 4237 /* There's overlap here, too. Bump along to the next spot. */ 4238 propagate_binfo_offsets (binfo, alignment); 4239 } 4240 } 4241 4242 if (CLASSTYPE_USER_ALIGN (basetype)) 4243 { 4244 rli->record_align = MAX (rli->record_align, CLASSTYPE_ALIGN (basetype)); 4245 if (warn_packed) 4246 rli->unpacked_align = MAX (rli->unpacked_align, CLASSTYPE_ALIGN (basetype)); 4247 TYPE_USER_ALIGN (rli->t) = 1; 4248 } 4249 4250 return atend; 4251 } 4252 4253 /* Build the FIELD_DECL for BASETYPE as a base of T, add it to the chain of 4254 fields at NEXT_FIELD, and return it. */ 4255 4256 static tree 4257 build_base_field_1 (tree t, tree basetype, tree *&next_field) 4258 { 4259 /* Create the FIELD_DECL. */ 4260 gcc_assert (CLASSTYPE_AS_BASE (basetype)); 4261 tree decl = build_decl (input_location, 4262 FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype)); 4263 DECL_ARTIFICIAL (decl) = 1; 4264 DECL_IGNORED_P (decl) = 1; 4265 DECL_FIELD_CONTEXT (decl) = t; 4266 if (is_empty_class (basetype)) 4267 /* CLASSTYPE_SIZE is one byte, but the field needs to have size zero. */ 4268 DECL_SIZE (decl) = DECL_SIZE_UNIT (decl) = size_zero_node; 4269 else 4270 { 4271 DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype); 4272 DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype); 4273 } 4274 SET_DECL_ALIGN (decl, CLASSTYPE_ALIGN (basetype)); 4275 DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype); 4276 SET_DECL_MODE (decl, TYPE_MODE (basetype)); 4277 DECL_FIELD_IS_BASE (decl) = 1; 4278 4279 /* Add the new FIELD_DECL to the list of fields for T. */ 4280 DECL_CHAIN (decl) = *next_field; 4281 *next_field = decl; 4282 next_field = &DECL_CHAIN (decl); 4283 4284 return decl; 4285 } 4286 4287 /* Layout the base given by BINFO in the class indicated by RLI. 4288 *BASE_ALIGN is a running maximum of the alignments of 4289 any base class. OFFSETS gives the location of empty base 4290 subobjects. T is the most derived type. Return nonzero if the new 4291 object cannot be nearly-empty. A new FIELD_DECL is inserted at 4292 *NEXT_FIELD, unless BINFO is for an empty base class. 4293 4294 Returns the location at which the next field should be inserted. */ 4295 4296 static tree * 4297 build_base_field (record_layout_info rli, tree binfo, 4298 splay_tree offsets, tree *next_field) 4299 { 4300 tree t = rli->t; 4301 tree basetype = BINFO_TYPE (binfo); 4302 4303 if (!COMPLETE_TYPE_P (basetype)) 4304 /* This error is now reported in xref_tag, thus giving better 4305 location information. */ 4306 return next_field; 4307 4308 /* Place the base class. */ 4309 if (!is_empty_class (basetype)) 4310 { 4311 tree decl; 4312 4313 /* The containing class is non-empty because it has a non-empty 4314 base class. */ 4315 CLASSTYPE_EMPTY_P (t) = 0; 4316 4317 /* Create the FIELD_DECL. */ 4318 decl = build_base_field_1 (t, basetype, next_field); 4319 4320 /* Try to place the field. It may take more than one try if we 4321 have a hard time placing the field without putting two 4322 objects of the same type at the same address. */ 4323 layout_nonempty_base_or_field (rli, decl, binfo, offsets); 4324 } 4325 else 4326 { 4327 tree eoc; 4328 bool atend; 4329 4330 /* On some platforms (ARM), even empty classes will not be 4331 byte-aligned. */ 4332 eoc = round_up_loc (input_location, 4333 rli_size_unit_so_far (rli), 4334 CLASSTYPE_ALIGN_UNIT (basetype)); 4335 atend = layout_empty_base (rli, binfo, eoc, offsets); 4336 /* A nearly-empty class "has no proper base class that is empty, 4337 not morally virtual, and at an offset other than zero." */ 4338 if (!BINFO_VIRTUAL_P (binfo) && CLASSTYPE_NEARLY_EMPTY_P (t)) 4339 { 4340 if (atend) 4341 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 4342 /* The check above (used in G++ 3.2) is insufficient because 4343 an empty class placed at offset zero might itself have an 4344 empty base at a nonzero offset. */ 4345 else if (walk_subobject_offsets (basetype, 4346 empty_base_at_nonzero_offset_p, 4347 size_zero_node, 4348 /*offsets=*/NULL, 4349 /*max_offset=*/NULL_TREE, 4350 /*vbases_p=*/true)) 4351 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 4352 } 4353 4354 /* We used to not create a FIELD_DECL for empty base classes because of 4355 back end issues with overlapping FIELD_DECLs, but that doesn't seem to 4356 be a problem anymore. We need them to handle initialization of C++17 4357 aggregate bases. */ 4358 if (cxx_dialect >= cxx17 && !BINFO_VIRTUAL_P (binfo)) 4359 { 4360 tree decl = build_base_field_1 (t, basetype, next_field); 4361 DECL_FIELD_OFFSET (decl) = BINFO_OFFSET (binfo); 4362 DECL_FIELD_BIT_OFFSET (decl) = bitsize_zero_node; 4363 SET_DECL_OFFSET_ALIGN (decl, BITS_PER_UNIT); 4364 } 4365 4366 /* An empty virtual base causes a class to be non-empty 4367 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P 4368 here because that was already done when the virtual table 4369 pointer was created. */ 4370 } 4371 4372 /* Record the offsets of BINFO and its base subobjects. */ 4373 record_subobject_offsets (binfo, 4374 BINFO_OFFSET (binfo), 4375 offsets, 4376 /*is_data_member=*/false); 4377 4378 return next_field; 4379 } 4380 4381 /* Layout all of the non-virtual base classes. Record empty 4382 subobjects in OFFSETS. T is the most derived type. Return nonzero 4383 if the type cannot be nearly empty. The fields created 4384 corresponding to the base classes will be inserted at 4385 *NEXT_FIELD. */ 4386 4387 static void 4388 build_base_fields (record_layout_info rli, 4389 splay_tree offsets, tree *next_field) 4390 { 4391 /* Chain to hold all the new FIELD_DECLs which stand in for base class 4392 subobjects. */ 4393 tree t = rli->t; 4394 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t)); 4395 int i; 4396 4397 /* The primary base class is always allocated first. */ 4398 if (CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 4399 next_field = build_base_field (rli, CLASSTYPE_PRIMARY_BINFO (t), 4400 offsets, next_field); 4401 4402 /* Now allocate the rest of the bases. */ 4403 for (i = 0; i < n_baseclasses; ++i) 4404 { 4405 tree base_binfo; 4406 4407 base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i); 4408 4409 /* The primary base was already allocated above, so we don't 4410 need to allocate it again here. */ 4411 if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t)) 4412 continue; 4413 4414 /* Virtual bases are added at the end (a primary virtual base 4415 will have already been added). */ 4416 if (BINFO_VIRTUAL_P (base_binfo)) 4417 continue; 4418 4419 next_field = build_base_field (rli, base_binfo, 4420 offsets, next_field); 4421 } 4422 } 4423 4424 /* Go through the TYPE_FIELDS of T issuing any appropriate 4425 diagnostics, figuring out which methods override which other 4426 methods, and so forth. */ 4427 4428 static void 4429 check_methods (tree t) 4430 { 4431 for (tree x = TYPE_FIELDS (t); x; x = DECL_CHAIN (x)) 4432 if (DECL_DECLARES_FUNCTION_P (x)) 4433 { 4434 check_for_override (x, t); 4435 4436 if (DECL_PURE_VIRTUAL_P (x) 4437 && (TREE_CODE (x) != FUNCTION_DECL || ! DECL_VINDEX (x))) 4438 error ("initializer specified for non-virtual method %q+D", x); 4439 /* The name of the field is the original field name 4440 Save this in auxiliary field for later overloading. */ 4441 if (TREE_CODE (x) == FUNCTION_DECL && DECL_VINDEX (x)) 4442 { 4443 TYPE_POLYMORPHIC_P (t) = 1; 4444 if (DECL_PURE_VIRTUAL_P (x)) 4445 vec_safe_push (CLASSTYPE_PURE_VIRTUALS (t), x); 4446 } 4447 4448 /* All user-provided destructors are non-trivial. 4449 Constructors and assignment ops are handled in 4450 grok_special_member_properties. */ 4451 if (DECL_DESTRUCTOR_P (x) && user_provided_p (x)) 4452 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = 1; 4453 if (!DECL_VIRTUAL_P (x) 4454 && lookup_attribute ("transaction_safe_dynamic", 4455 DECL_ATTRIBUTES (x))) 4456 error_at (DECL_SOURCE_LOCATION (x), 4457 "%<transaction_safe_dynamic%> may only be specified for " 4458 "a virtual function"); 4459 } 4460 } 4461 4462 /* FN is a constructor or destructor. Clone the declaration to create 4463 a specialized in-charge or not-in-charge version, as indicated by 4464 NAME. */ 4465 4466 static tree 4467 build_clone (tree fn, tree name) 4468 { 4469 tree parms; 4470 tree clone; 4471 4472 /* Copy the function. */ 4473 clone = copy_decl (fn); 4474 /* Reset the function name. */ 4475 DECL_NAME (clone) = name; 4476 /* Remember where this function came from. */ 4477 DECL_ABSTRACT_ORIGIN (clone) = fn; 4478 /* Make it easy to find the CLONE given the FN. */ 4479 DECL_CHAIN (clone) = DECL_CHAIN (fn); 4480 DECL_CHAIN (fn) = clone; 4481 4482 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */ 4483 if (TREE_CODE (clone) == TEMPLATE_DECL) 4484 { 4485 tree result = build_clone (DECL_TEMPLATE_RESULT (clone), name); 4486 DECL_TEMPLATE_RESULT (clone) = result; 4487 DECL_TEMPLATE_INFO (result) = copy_node (DECL_TEMPLATE_INFO (result)); 4488 DECL_TI_TEMPLATE (result) = clone; 4489 TREE_TYPE (clone) = TREE_TYPE (result); 4490 return clone; 4491 } 4492 else 4493 { 4494 // Clone constraints. 4495 if (flag_concepts) 4496 if (tree ci = get_constraints (fn)) 4497 set_constraints (clone, copy_node (ci)); 4498 } 4499 4500 4501 SET_DECL_ASSEMBLER_NAME (clone, NULL_TREE); 4502 DECL_CLONED_FUNCTION (clone) = fn; 4503 /* There's no pending inline data for this function. */ 4504 DECL_PENDING_INLINE_INFO (clone) = NULL; 4505 DECL_PENDING_INLINE_P (clone) = 0; 4506 4507 /* The base-class destructor is not virtual. */ 4508 if (name == base_dtor_identifier) 4509 { 4510 DECL_VIRTUAL_P (clone) = 0; 4511 if (TREE_CODE (clone) != TEMPLATE_DECL) 4512 DECL_VINDEX (clone) = NULL_TREE; 4513 } 4514 4515 bool ctor_omit_inherited_parms_p = ctor_omit_inherited_parms (clone); 4516 if (ctor_omit_inherited_parms_p) 4517 gcc_assert (DECL_HAS_IN_CHARGE_PARM_P (clone)); 4518 4519 /* If there was an in-charge parameter, drop it from the function 4520 type. */ 4521 if (DECL_HAS_IN_CHARGE_PARM_P (clone)) 4522 { 4523 tree basetype; 4524 tree parmtypes; 4525 tree exceptions; 4526 4527 exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone)); 4528 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone)); 4529 parmtypes = TYPE_ARG_TYPES (TREE_TYPE (clone)); 4530 /* Skip the `this' parameter. */ 4531 parmtypes = TREE_CHAIN (parmtypes); 4532 /* Skip the in-charge parameter. */ 4533 parmtypes = TREE_CHAIN (parmtypes); 4534 /* And the VTT parm, in a complete [cd]tor. */ 4535 if (DECL_HAS_VTT_PARM_P (fn) 4536 && ! DECL_NEEDS_VTT_PARM_P (clone)) 4537 parmtypes = TREE_CHAIN (parmtypes); 4538 if (ctor_omit_inherited_parms_p) 4539 { 4540 /* If we're omitting inherited parms, that just leaves the VTT. */ 4541 gcc_assert (DECL_NEEDS_VTT_PARM_P (clone)); 4542 parmtypes = tree_cons (NULL_TREE, vtt_parm_type, void_list_node); 4543 } 4544 TREE_TYPE (clone) 4545 = build_method_type_directly (basetype, 4546 TREE_TYPE (TREE_TYPE (clone)), 4547 parmtypes); 4548 if (exceptions) 4549 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), 4550 exceptions); 4551 TREE_TYPE (clone) 4552 = cp_build_type_attribute_variant (TREE_TYPE (clone), 4553 TYPE_ATTRIBUTES (TREE_TYPE (fn))); 4554 } 4555 4556 /* Copy the function parameters. */ 4557 DECL_ARGUMENTS (clone) = copy_list (DECL_ARGUMENTS (clone)); 4558 /* Remove the in-charge parameter. */ 4559 if (DECL_HAS_IN_CHARGE_PARM_P (clone)) 4560 { 4561 DECL_CHAIN (DECL_ARGUMENTS (clone)) 4562 = DECL_CHAIN (DECL_CHAIN (DECL_ARGUMENTS (clone))); 4563 DECL_HAS_IN_CHARGE_PARM_P (clone) = 0; 4564 } 4565 /* And the VTT parm, in a complete [cd]tor. */ 4566 if (DECL_HAS_VTT_PARM_P (fn)) 4567 { 4568 if (DECL_NEEDS_VTT_PARM_P (clone)) 4569 DECL_HAS_VTT_PARM_P (clone) = 1; 4570 else 4571 { 4572 DECL_CHAIN (DECL_ARGUMENTS (clone)) 4573 = DECL_CHAIN (DECL_CHAIN (DECL_ARGUMENTS (clone))); 4574 DECL_HAS_VTT_PARM_P (clone) = 0; 4575 } 4576 } 4577 4578 /* A base constructor inheriting from a virtual base doesn't get the 4579 arguments. */ 4580 if (ctor_omit_inherited_parms_p) 4581 DECL_CHAIN (DECL_CHAIN (DECL_ARGUMENTS (clone))) = NULL_TREE; 4582 4583 for (parms = DECL_ARGUMENTS (clone); parms; parms = DECL_CHAIN (parms)) 4584 { 4585 DECL_CONTEXT (parms) = clone; 4586 cxx_dup_lang_specific_decl (parms); 4587 } 4588 4589 /* Create the RTL for this function. */ 4590 SET_DECL_RTL (clone, NULL); 4591 rest_of_decl_compilation (clone, /*top_level=*/1, at_eof); 4592 4593 return clone; 4594 } 4595 4596 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do 4597 not invoke this function directly. 4598 4599 For a non-thunk function, returns the address of the slot for storing 4600 the function it is a clone of. Otherwise returns NULL_TREE. 4601 4602 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if 4603 cloned_function is unset. This is to support the separate 4604 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter 4605 on a template makes sense, but not the former. */ 4606 4607 tree * 4608 decl_cloned_function_p (const_tree decl, bool just_testing) 4609 { 4610 tree *ptr; 4611 if (just_testing) 4612 decl = STRIP_TEMPLATE (decl); 4613 4614 if (TREE_CODE (decl) != FUNCTION_DECL 4615 || !DECL_LANG_SPECIFIC (decl) 4616 || DECL_LANG_SPECIFIC (decl)->u.fn.thunk_p) 4617 { 4618 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007) 4619 if (!just_testing) 4620 lang_check_failed (__FILE__, __LINE__, __FUNCTION__); 4621 else 4622 #endif 4623 return NULL; 4624 } 4625 4626 ptr = &DECL_LANG_SPECIFIC (decl)->u.fn.u5.cloned_function; 4627 if (just_testing && *ptr == NULL_TREE) 4628 return NULL; 4629 else 4630 return ptr; 4631 } 4632 4633 /* Produce declarations for all appropriate clones of FN. If 4634 UPDATE_METHODS is true, the clones are added to the 4635 CLASSTYPE_MEMBER_VEC. */ 4636 4637 void 4638 clone_function_decl (tree fn, bool update_methods) 4639 { 4640 tree clone; 4641 4642 /* Avoid inappropriate cloning. */ 4643 if (DECL_CHAIN (fn) 4644 && DECL_CLONED_FUNCTION_P (DECL_CHAIN (fn))) 4645 return; 4646 4647 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)) 4648 { 4649 /* For each constructor, we need two variants: an in-charge version 4650 and a not-in-charge version. */ 4651 clone = build_clone (fn, complete_ctor_identifier); 4652 if (update_methods) 4653 add_method (DECL_CONTEXT (clone), clone, false); 4654 clone = build_clone (fn, base_ctor_identifier); 4655 if (update_methods) 4656 add_method (DECL_CONTEXT (clone), clone, false); 4657 } 4658 else 4659 { 4660 gcc_assert (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)); 4661 4662 /* For each destructor, we need three variants: an in-charge 4663 version, a not-in-charge version, and an in-charge deleting 4664 version. We clone the deleting version first because that 4665 means it will go second on the TYPE_FIELDS list -- and that 4666 corresponds to the correct layout order in the virtual 4667 function table. 4668 4669 For a non-virtual destructor, we do not build a deleting 4670 destructor. */ 4671 if (DECL_VIRTUAL_P (fn)) 4672 { 4673 clone = build_clone (fn, deleting_dtor_identifier); 4674 if (update_methods) 4675 add_method (DECL_CONTEXT (clone), clone, false); 4676 } 4677 clone = build_clone (fn, complete_dtor_identifier); 4678 if (update_methods) 4679 add_method (DECL_CONTEXT (clone), clone, false); 4680 clone = build_clone (fn, base_dtor_identifier); 4681 if (update_methods) 4682 add_method (DECL_CONTEXT (clone), clone, false); 4683 } 4684 4685 /* Note that this is an abstract function that is never emitted. */ 4686 DECL_ABSTRACT_P (fn) = true; 4687 } 4688 4689 /* DECL is an in charge constructor, which is being defined. This will 4690 have had an in class declaration, from whence clones were 4691 declared. An out-of-class definition can specify additional default 4692 arguments. As it is the clones that are involved in overload 4693 resolution, we must propagate the information from the DECL to its 4694 clones. */ 4695 4696 void 4697 adjust_clone_args (tree decl) 4698 { 4699 tree clone; 4700 4701 for (clone = DECL_CHAIN (decl); clone && DECL_CLONED_FUNCTION_P (clone); 4702 clone = DECL_CHAIN (clone)) 4703 { 4704 tree orig_clone_parms = TYPE_ARG_TYPES (TREE_TYPE (clone)); 4705 tree orig_decl_parms = TYPE_ARG_TYPES (TREE_TYPE (decl)); 4706 tree decl_parms, clone_parms; 4707 4708 clone_parms = orig_clone_parms; 4709 4710 /* Skip the 'this' parameter. */ 4711 orig_clone_parms = TREE_CHAIN (orig_clone_parms); 4712 orig_decl_parms = TREE_CHAIN (orig_decl_parms); 4713 4714 if (DECL_HAS_IN_CHARGE_PARM_P (decl)) 4715 orig_decl_parms = TREE_CHAIN (orig_decl_parms); 4716 if (DECL_HAS_VTT_PARM_P (decl)) 4717 orig_decl_parms = TREE_CHAIN (orig_decl_parms); 4718 4719 clone_parms = orig_clone_parms; 4720 if (DECL_HAS_VTT_PARM_P (clone)) 4721 clone_parms = TREE_CHAIN (clone_parms); 4722 4723 for (decl_parms = orig_decl_parms; decl_parms; 4724 decl_parms = TREE_CHAIN (decl_parms), 4725 clone_parms = TREE_CHAIN (clone_parms)) 4726 { 4727 if (clone_parms == void_list_node) 4728 { 4729 gcc_assert (decl_parms == clone_parms 4730 || ctor_omit_inherited_parms (clone)); 4731 break; 4732 } 4733 4734 gcc_assert (same_type_p (TREE_TYPE (decl_parms), 4735 TREE_TYPE (clone_parms))); 4736 4737 if (TREE_PURPOSE (decl_parms) && !TREE_PURPOSE (clone_parms)) 4738 { 4739 /* A default parameter has been added. Adjust the 4740 clone's parameters. */ 4741 tree exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone)); 4742 tree attrs = TYPE_ATTRIBUTES (TREE_TYPE (clone)); 4743 tree basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone)); 4744 tree type; 4745 4746 clone_parms = orig_decl_parms; 4747 4748 if (DECL_HAS_VTT_PARM_P (clone)) 4749 { 4750 clone_parms = tree_cons (TREE_PURPOSE (orig_clone_parms), 4751 TREE_VALUE (orig_clone_parms), 4752 clone_parms); 4753 TREE_TYPE (clone_parms) = TREE_TYPE (orig_clone_parms); 4754 } 4755 type = build_method_type_directly (basetype, 4756 TREE_TYPE (TREE_TYPE (clone)), 4757 clone_parms); 4758 if (exceptions) 4759 type = build_exception_variant (type, exceptions); 4760 if (attrs) 4761 type = cp_build_type_attribute_variant (type, attrs); 4762 TREE_TYPE (clone) = type; 4763 4764 clone_parms = NULL_TREE; 4765 break; 4766 } 4767 } 4768 gcc_assert (!clone_parms || clone_parms == void_list_node); 4769 } 4770 } 4771 4772 /* For each of the constructors and destructors in T, create an 4773 in-charge and not-in-charge variant. */ 4774 4775 static void 4776 clone_constructors_and_destructors (tree t) 4777 { 4778 /* While constructors can be via a using declaration, at this point 4779 we no longer need to know that. */ 4780 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 4781 clone_function_decl (*iter, /*update_methods=*/true); 4782 4783 if (tree dtor = CLASSTYPE_DESTRUCTOR (t)) 4784 clone_function_decl (dtor, /*update_methods=*/true); 4785 } 4786 4787 /* Deduce noexcept for a destructor DTOR. */ 4788 4789 void 4790 deduce_noexcept_on_destructor (tree dtor) 4791 { 4792 if (!TYPE_RAISES_EXCEPTIONS (TREE_TYPE (dtor))) 4793 TREE_TYPE (dtor) = build_exception_variant (TREE_TYPE (dtor), 4794 noexcept_deferred_spec); 4795 } 4796 4797 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes 4798 of TYPE for virtual functions which FNDECL overrides. Return a 4799 mask of the tm attributes found therein. */ 4800 4801 static int 4802 look_for_tm_attr_overrides (tree type, tree fndecl) 4803 { 4804 tree binfo = TYPE_BINFO (type); 4805 tree base_binfo; 4806 int ix, found = 0; 4807 4808 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ++ix) 4809 { 4810 tree o, basetype = BINFO_TYPE (base_binfo); 4811 4812 if (!TYPE_POLYMORPHIC_P (basetype)) 4813 continue; 4814 4815 o = look_for_overrides_here (basetype, fndecl); 4816 if (o) 4817 { 4818 if (lookup_attribute ("transaction_safe_dynamic", 4819 DECL_ATTRIBUTES (o))) 4820 /* transaction_safe_dynamic is not inherited. */; 4821 else 4822 found |= tm_attr_to_mask (find_tm_attribute 4823 (TYPE_ATTRIBUTES (TREE_TYPE (o)))); 4824 } 4825 else 4826 found |= look_for_tm_attr_overrides (basetype, fndecl); 4827 } 4828 4829 return found; 4830 } 4831 4832 /* Subroutine of set_method_tm_attributes. Handle the checks and 4833 inheritance for one virtual method FNDECL. */ 4834 4835 static void 4836 set_one_vmethod_tm_attributes (tree type, tree fndecl) 4837 { 4838 tree tm_attr; 4839 int found, have; 4840 4841 found = look_for_tm_attr_overrides (type, fndecl); 4842 4843 /* If FNDECL doesn't actually override anything (i.e. T is the 4844 class that first declares FNDECL virtual), then we're done. */ 4845 if (found == 0) 4846 return; 4847 4848 tm_attr = find_tm_attribute (TYPE_ATTRIBUTES (TREE_TYPE (fndecl))); 4849 have = tm_attr_to_mask (tm_attr); 4850 4851 /* Intel STM Language Extension 3.0, Section 4.2 table 4: 4852 tm_pure must match exactly, otherwise no weakening of 4853 tm_safe > tm_callable > nothing. */ 4854 /* ??? The tm_pure attribute didn't make the transition to the 4855 multivendor language spec. */ 4856 if (have == TM_ATTR_PURE) 4857 { 4858 if (found != TM_ATTR_PURE) 4859 { 4860 found &= -found; 4861 goto err_override; 4862 } 4863 } 4864 /* If the overridden function is tm_pure, then FNDECL must be. */ 4865 else if (found == TM_ATTR_PURE && tm_attr) 4866 goto err_override; 4867 /* Look for base class combinations that cannot be satisfied. */ 4868 else if (found != TM_ATTR_PURE && (found & TM_ATTR_PURE)) 4869 { 4870 found &= ~TM_ATTR_PURE; 4871 found &= -found; 4872 error_at (DECL_SOURCE_LOCATION (fndecl), 4873 "method overrides both %<transaction_pure%> and %qE methods", 4874 tm_mask_to_attr (found)); 4875 } 4876 /* If FNDECL did not declare an attribute, then inherit the most 4877 restrictive one. */ 4878 else if (tm_attr == NULL) 4879 { 4880 apply_tm_attr (fndecl, tm_mask_to_attr (least_bit_hwi (found))); 4881 } 4882 /* Otherwise validate that we're not weaker than a function 4883 that is being overridden. */ 4884 else 4885 { 4886 found &= -found; 4887 if (found <= TM_ATTR_CALLABLE && have > found) 4888 goto err_override; 4889 } 4890 return; 4891 4892 err_override: 4893 error_at (DECL_SOURCE_LOCATION (fndecl), 4894 "method declared %qE overriding %qE method", 4895 tm_attr, tm_mask_to_attr (found)); 4896 } 4897 4898 /* For each of the methods in T, propagate a class-level tm attribute. */ 4899 4900 static void 4901 set_method_tm_attributes (tree t) 4902 { 4903 tree class_tm_attr, fndecl; 4904 4905 /* Don't bother collecting tm attributes if transactional memory 4906 support is not enabled. */ 4907 if (!flag_tm) 4908 return; 4909 4910 /* Process virtual methods first, as they inherit directly from the 4911 base virtual function and also require validation of new attributes. */ 4912 if (TYPE_CONTAINS_VPTR_P (t)) 4913 { 4914 tree vchain; 4915 for (vchain = BINFO_VIRTUALS (TYPE_BINFO (t)); vchain; 4916 vchain = TREE_CHAIN (vchain)) 4917 { 4918 fndecl = BV_FN (vchain); 4919 if (DECL_THUNK_P (fndecl)) 4920 fndecl = THUNK_TARGET (fndecl); 4921 set_one_vmethod_tm_attributes (t, fndecl); 4922 } 4923 } 4924 4925 /* If the class doesn't have an attribute, nothing more to do. */ 4926 class_tm_attr = find_tm_attribute (TYPE_ATTRIBUTES (t)); 4927 if (class_tm_attr == NULL) 4928 return; 4929 4930 /* Any method that does not yet have a tm attribute inherits 4931 the one from the class. */ 4932 for (fndecl = TYPE_FIELDS (t); fndecl; fndecl = DECL_CHAIN (fndecl)) 4933 if (DECL_DECLARES_FUNCTION_P (fndecl) 4934 && !find_tm_attribute (TYPE_ATTRIBUTES (TREE_TYPE (fndecl)))) 4935 apply_tm_attr (fndecl, class_tm_attr); 4936 } 4937 4938 /* Returns true if FN is a default constructor. */ 4939 4940 bool 4941 default_ctor_p (tree fn) 4942 { 4943 return (DECL_CONSTRUCTOR_P (fn) 4944 && sufficient_parms_p (FUNCTION_FIRST_USER_PARMTYPE (fn))); 4945 } 4946 4947 /* Returns true iff class T has a user-defined constructor that can be called 4948 with more than zero arguments. */ 4949 4950 bool 4951 type_has_user_nondefault_constructor (tree t) 4952 { 4953 if (!TYPE_HAS_USER_CONSTRUCTOR (t)) 4954 return false; 4955 4956 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 4957 { 4958 tree fn = *iter; 4959 if (!DECL_ARTIFICIAL (fn) 4960 && (TREE_CODE (fn) == TEMPLATE_DECL 4961 || (skip_artificial_parms_for (fn, DECL_ARGUMENTS (fn)) 4962 != NULL_TREE))) 4963 return true; 4964 } 4965 4966 return false; 4967 } 4968 4969 /* Returns the defaulted constructor if T has one. Otherwise, returns 4970 NULL_TREE. */ 4971 4972 tree 4973 in_class_defaulted_default_constructor (tree t) 4974 { 4975 if (!TYPE_HAS_USER_CONSTRUCTOR (t)) 4976 return NULL_TREE; 4977 4978 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 4979 { 4980 tree fn = *iter; 4981 4982 if (DECL_DEFAULTED_IN_CLASS_P (fn) 4983 && default_ctor_p (fn)) 4984 return fn; 4985 } 4986 4987 return NULL_TREE; 4988 } 4989 4990 /* Returns true iff FN is a user-provided function, i.e. user-declared 4991 and not defaulted at its first declaration. */ 4992 4993 bool 4994 user_provided_p (tree fn) 4995 { 4996 if (TREE_CODE (fn) == TEMPLATE_DECL) 4997 return true; 4998 else 4999 return (!DECL_ARTIFICIAL (fn) 5000 && !(DECL_INITIALIZED_IN_CLASS_P (fn) 5001 && (DECL_DEFAULTED_FN (fn) || DECL_DELETED_FN (fn)))); 5002 } 5003 5004 /* Returns true iff class T has a user-provided constructor. */ 5005 5006 bool 5007 type_has_user_provided_constructor (tree t) 5008 { 5009 if (!CLASS_TYPE_P (t)) 5010 return false; 5011 5012 if (!TYPE_HAS_USER_CONSTRUCTOR (t)) 5013 return false; 5014 5015 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 5016 if (user_provided_p (*iter)) 5017 return true; 5018 5019 return false; 5020 } 5021 5022 /* Returns true iff class T has a user-provided or explicit constructor. */ 5023 5024 bool 5025 type_has_user_provided_or_explicit_constructor (tree t) 5026 { 5027 if (!CLASS_TYPE_P (t)) 5028 return false; 5029 5030 if (!TYPE_HAS_USER_CONSTRUCTOR (t)) 5031 return false; 5032 5033 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 5034 { 5035 tree fn = *iter; 5036 if (user_provided_p (fn) || DECL_NONCONVERTING_P (fn)) 5037 return true; 5038 } 5039 5040 return false; 5041 } 5042 5043 /* Returns true iff class T has a non-user-provided (i.e. implicitly 5044 declared or explicitly defaulted in the class body) default 5045 constructor. */ 5046 5047 bool 5048 type_has_non_user_provided_default_constructor (tree t) 5049 { 5050 if (!TYPE_HAS_DEFAULT_CONSTRUCTOR (t)) 5051 return false; 5052 if (CLASSTYPE_LAZY_DEFAULT_CTOR (t)) 5053 return true; 5054 5055 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 5056 { 5057 tree fn = *iter; 5058 if (TREE_CODE (fn) == FUNCTION_DECL 5059 && default_ctor_p (fn) 5060 && !user_provided_p (fn)) 5061 return true; 5062 } 5063 5064 return false; 5065 } 5066 5067 /* TYPE is being used as a virtual base, and has a non-trivial move 5068 assignment. Return true if this is due to there being a user-provided 5069 move assignment in TYPE or one of its subobjects; if there isn't, then 5070 multiple move assignment can't cause any harm. */ 5071 5072 bool 5073 vbase_has_user_provided_move_assign (tree type) 5074 { 5075 /* Does the type itself have a user-provided move assignment operator? */ 5076 if (!CLASSTYPE_LAZY_MOVE_ASSIGN (type)) 5077 for (ovl_iterator iter (get_class_binding_direct 5078 (type, assign_op_identifier)); 5079 iter; ++iter) 5080 if (!DECL_ARTIFICIAL (*iter) && move_fn_p (*iter)) 5081 return true; 5082 5083 /* Do any of its bases? */ 5084 tree binfo = TYPE_BINFO (type); 5085 tree base_binfo; 5086 for (int i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 5087 if (vbase_has_user_provided_move_assign (BINFO_TYPE (base_binfo))) 5088 return true; 5089 5090 /* Or non-static data members? */ 5091 for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) 5092 { 5093 if (TREE_CODE (field) == FIELD_DECL 5094 && CLASS_TYPE_P (TREE_TYPE (field)) 5095 && vbase_has_user_provided_move_assign (TREE_TYPE (field))) 5096 return true; 5097 } 5098 5099 /* Seems not. */ 5100 return false; 5101 } 5102 5103 /* If default-initialization leaves part of TYPE uninitialized, returns 5104 a DECL for the field or TYPE itself (DR 253). */ 5105 5106 tree 5107 default_init_uninitialized_part (tree type) 5108 { 5109 tree t, r, binfo; 5110 int i; 5111 5112 type = strip_array_types (type); 5113 if (!CLASS_TYPE_P (type)) 5114 return type; 5115 if (!type_has_non_user_provided_default_constructor (type)) 5116 return NULL_TREE; 5117 for (binfo = TYPE_BINFO (type), i = 0; 5118 BINFO_BASE_ITERATE (binfo, i, t); ++i) 5119 { 5120 r = default_init_uninitialized_part (BINFO_TYPE (t)); 5121 if (r) 5122 return r; 5123 } 5124 for (t = TYPE_FIELDS (type); t; t = DECL_CHAIN (t)) 5125 if (TREE_CODE (t) == FIELD_DECL 5126 && !DECL_ARTIFICIAL (t) 5127 && !DECL_INITIAL (t)) 5128 { 5129 r = default_init_uninitialized_part (TREE_TYPE (t)); 5130 if (r) 5131 return DECL_P (r) ? r : t; 5132 } 5133 5134 return NULL_TREE; 5135 } 5136 5137 /* Returns true iff for class T, a trivial synthesized default constructor 5138 would be constexpr. */ 5139 5140 bool 5141 trivial_default_constructor_is_constexpr (tree t) 5142 { 5143 /* A defaulted trivial default constructor is constexpr 5144 if there is nothing to initialize. */ 5145 gcc_assert (!TYPE_HAS_COMPLEX_DFLT (t)); 5146 return is_really_empty_class (t); 5147 } 5148 5149 /* Returns true iff class T has a constexpr default constructor. */ 5150 5151 bool 5152 type_has_constexpr_default_constructor (tree t) 5153 { 5154 tree fns; 5155 5156 if (!CLASS_TYPE_P (t)) 5157 { 5158 /* The caller should have stripped an enclosing array. */ 5159 gcc_assert (TREE_CODE (t) != ARRAY_TYPE); 5160 return false; 5161 } 5162 if (CLASSTYPE_LAZY_DEFAULT_CTOR (t)) 5163 { 5164 if (!TYPE_HAS_COMPLEX_DFLT (t)) 5165 return trivial_default_constructor_is_constexpr (t); 5166 /* Non-trivial, we need to check subobject constructors. */ 5167 lazily_declare_fn (sfk_constructor, t); 5168 } 5169 fns = locate_ctor (t); 5170 return (fns && DECL_DECLARED_CONSTEXPR_P (fns)); 5171 } 5172 5173 /* Returns true iff class T has a constexpr default constructor or has an 5174 implicitly declared default constructor that we can't tell if it's constexpr 5175 without forcing a lazy declaration (which might cause undesired 5176 instantiations). */ 5177 5178 bool 5179 type_maybe_constexpr_default_constructor (tree t) 5180 { 5181 if (CLASS_TYPE_P (t) && CLASSTYPE_LAZY_DEFAULT_CTOR (t) 5182 && TYPE_HAS_COMPLEX_DFLT (t)) 5183 /* Assume it's constexpr. */ 5184 return true; 5185 return type_has_constexpr_default_constructor (t); 5186 } 5187 5188 /* Returns true iff class TYPE has a virtual destructor. */ 5189 5190 bool 5191 type_has_virtual_destructor (tree type) 5192 { 5193 tree dtor; 5194 5195 if (!CLASS_TYPE_P (type)) 5196 return false; 5197 5198 gcc_assert (COMPLETE_TYPE_P (type)); 5199 dtor = CLASSTYPE_DESTRUCTOR (type); 5200 return (dtor && DECL_VIRTUAL_P (dtor)); 5201 } 5202 5203 /* Returns true iff T, a class, has a move-assignment or 5204 move-constructor. Does not lazily declare either. 5205 If USER_P is false, any move function will do. If it is true, the 5206 move function must be user-declared. 5207 5208 Note that user-declared here is different from "user-provided", 5209 which doesn't include functions that are defaulted in the 5210 class. */ 5211 5212 bool 5213 classtype_has_move_assign_or_move_ctor_p (tree t, bool user_p) 5214 { 5215 gcc_assert (user_p 5216 || (!CLASSTYPE_LAZY_MOVE_CTOR (t) 5217 && !CLASSTYPE_LAZY_MOVE_ASSIGN (t))); 5218 5219 if (!CLASSTYPE_LAZY_MOVE_CTOR (t)) 5220 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 5221 if ((!user_p || !DECL_ARTIFICIAL (*iter)) && move_fn_p (*iter)) 5222 return true; 5223 5224 if (!CLASSTYPE_LAZY_MOVE_ASSIGN (t)) 5225 for (ovl_iterator iter (get_class_binding_direct 5226 (t, assign_op_identifier)); 5227 iter; ++iter) 5228 if ((!user_p || !DECL_ARTIFICIAL (*iter)) 5229 && DECL_CONTEXT (*iter) == t 5230 && move_fn_p (*iter)) 5231 return true; 5232 5233 return false; 5234 } 5235 5236 /* True iff T has a move constructor that is not deleted. */ 5237 5238 bool 5239 classtype_has_non_deleted_move_ctor (tree t) 5240 { 5241 if (CLASSTYPE_LAZY_MOVE_CTOR (t)) 5242 lazily_declare_fn (sfk_move_constructor, t); 5243 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 5244 if (move_fn_p (*iter) && !DECL_DELETED_FN (*iter)) 5245 return true; 5246 return false; 5247 } 5248 5249 /* Nonzero if we need to build up a constructor call when initializing an 5250 object of this class, either because it has a user-declared constructor 5251 or because it doesn't have a default constructor (so we need to give an 5252 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when 5253 what you care about is whether or not an object can be produced by a 5254 constructor (e.g. so we don't set TREE_READONLY on const variables of 5255 such type); use this function when what you care about is whether or not 5256 to try to call a constructor to create an object. The latter case is 5257 the former plus some cases of constructors that cannot be called. */ 5258 5259 bool 5260 type_build_ctor_call (tree t) 5261 { 5262 tree inner; 5263 if (TYPE_NEEDS_CONSTRUCTING (t)) 5264 return true; 5265 inner = strip_array_types (t); 5266 if (!CLASS_TYPE_P (inner) || ANON_AGGR_TYPE_P (inner)) 5267 return false; 5268 if (!TYPE_HAS_DEFAULT_CONSTRUCTOR (inner)) 5269 return true; 5270 if (cxx_dialect < cxx11) 5271 return false; 5272 /* A user-declared constructor might be private, and a constructor might 5273 be trivial but deleted. */ 5274 for (ovl_iterator iter (get_class_binding (inner, complete_ctor_identifier)); 5275 iter; ++iter) 5276 { 5277 tree fn = *iter; 5278 if (!DECL_ARTIFICIAL (fn) 5279 || DECL_DELETED_FN (fn)) 5280 return true; 5281 } 5282 return false; 5283 } 5284 5285 /* Like type_build_ctor_call, but for destructors. */ 5286 5287 bool 5288 type_build_dtor_call (tree t) 5289 { 5290 tree inner; 5291 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)) 5292 return true; 5293 inner = strip_array_types (t); 5294 if (!CLASS_TYPE_P (inner) || ANON_AGGR_TYPE_P (inner) 5295 || !COMPLETE_TYPE_P (inner)) 5296 return false; 5297 if (cxx_dialect < cxx11) 5298 return false; 5299 /* A user-declared destructor might be private, and a destructor might 5300 be trivial but deleted. */ 5301 for (ovl_iterator iter (get_class_binding (inner, complete_dtor_identifier)); 5302 iter; ++iter) 5303 { 5304 tree fn = *iter; 5305 if (!DECL_ARTIFICIAL (fn) 5306 || DECL_DELETED_FN (fn)) 5307 return true; 5308 } 5309 return false; 5310 } 5311 5312 /* Remove all zero-width bit-fields from T. */ 5313 5314 static void 5315 remove_zero_width_bit_fields (tree t) 5316 { 5317 tree *fieldsp; 5318 5319 fieldsp = &TYPE_FIELDS (t); 5320 while (*fieldsp) 5321 { 5322 if (TREE_CODE (*fieldsp) == FIELD_DECL 5323 && DECL_C_BIT_FIELD (*fieldsp) 5324 /* We should not be confused by the fact that grokbitfield 5325 temporarily sets the width of the bit field into 5326 DECL_BIT_FIELD_REPRESENTATIVE (*fieldsp). 5327 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp) 5328 to that width. */ 5329 && (DECL_SIZE (*fieldsp) == NULL_TREE 5330 || integer_zerop (DECL_SIZE (*fieldsp)))) 5331 *fieldsp = DECL_CHAIN (*fieldsp); 5332 else 5333 fieldsp = &DECL_CHAIN (*fieldsp); 5334 } 5335 } 5336 5337 /* Returns TRUE iff we need a cookie when dynamically allocating an 5338 array whose elements have the indicated class TYPE. */ 5339 5340 static bool 5341 type_requires_array_cookie (tree type) 5342 { 5343 tree fns; 5344 bool has_two_argument_delete_p = false; 5345 5346 gcc_assert (CLASS_TYPE_P (type)); 5347 5348 /* If there's a non-trivial destructor, we need a cookie. In order 5349 to iterate through the array calling the destructor for each 5350 element, we'll have to know how many elements there are. */ 5351 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 5352 return true; 5353 5354 /* If the usual deallocation function is a two-argument whose second 5355 argument is of type `size_t', then we have to pass the size of 5356 the array to the deallocation function, so we will need to store 5357 a cookie. */ 5358 fns = lookup_fnfields (TYPE_BINFO (type), 5359 ovl_op_identifier (false, VEC_DELETE_EXPR), 5360 /*protect=*/0); 5361 /* If there are no `operator []' members, or the lookup is 5362 ambiguous, then we don't need a cookie. */ 5363 if (!fns || fns == error_mark_node) 5364 return false; 5365 /* Loop through all of the functions. */ 5366 for (lkp_iterator iter (BASELINK_FUNCTIONS (fns)); iter; ++iter) 5367 { 5368 tree fn = *iter; 5369 5370 /* See if this function is a one-argument delete function. If 5371 it is, then it will be the usual deallocation function. */ 5372 tree second_parm = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fn))); 5373 if (second_parm == void_list_node) 5374 return false; 5375 /* Do not consider this function if its second argument is an 5376 ellipsis. */ 5377 if (!second_parm) 5378 continue; 5379 /* Otherwise, if we have a two-argument function and the second 5380 argument is `size_t', it will be the usual deallocation 5381 function -- unless there is one-argument function, too. */ 5382 if (TREE_CHAIN (second_parm) == void_list_node 5383 && same_type_p (TREE_VALUE (second_parm), size_type_node)) 5384 has_two_argument_delete_p = true; 5385 } 5386 5387 return has_two_argument_delete_p; 5388 } 5389 5390 /* Finish computing the `literal type' property of class type T. 5391 5392 At this point, we have already processed base classes and 5393 non-static data members. We need to check whether the copy 5394 constructor is trivial, the destructor is trivial, and there 5395 is a trivial default constructor or at least one constexpr 5396 constructor other than the copy constructor. */ 5397 5398 static void 5399 finalize_literal_type_property (tree t) 5400 { 5401 tree fn; 5402 5403 if (cxx_dialect < cxx11 5404 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)) 5405 CLASSTYPE_LITERAL_P (t) = false; 5406 else if (CLASSTYPE_LITERAL_P (t) && LAMBDA_TYPE_P (t)) 5407 CLASSTYPE_LITERAL_P (t) = (cxx_dialect >= cxx17); 5408 else if (CLASSTYPE_LITERAL_P (t) && !TYPE_HAS_TRIVIAL_DFLT (t) 5409 && CLASSTYPE_NON_AGGREGATE (t) 5410 && !TYPE_HAS_CONSTEXPR_CTOR (t)) 5411 CLASSTYPE_LITERAL_P (t) = false; 5412 5413 /* C++14 DR 1684 removed this restriction. */ 5414 if (cxx_dialect < cxx14 5415 && !CLASSTYPE_LITERAL_P (t) && !LAMBDA_TYPE_P (t)) 5416 for (fn = TYPE_FIELDS (t); fn; fn = DECL_CHAIN (fn)) 5417 if (TREE_CODE (fn) == FUNCTION_DECL 5418 && DECL_DECLARED_CONSTEXPR_P (fn) 5419 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) 5420 && !DECL_CONSTRUCTOR_P (fn)) 5421 { 5422 DECL_DECLARED_CONSTEXPR_P (fn) = false; 5423 if (!DECL_GENERATED_P (fn) 5424 && pedwarn (DECL_SOURCE_LOCATION (fn), OPT_Wpedantic, 5425 "enclosing class of %<constexpr%> non-static member " 5426 "function %q+#D is not a literal type", fn)) 5427 explain_non_literal_class (t); 5428 } 5429 } 5430 5431 /* T is a non-literal type used in a context which requires a constant 5432 expression. Explain why it isn't literal. */ 5433 5434 void 5435 explain_non_literal_class (tree t) 5436 { 5437 static hash_set<tree> *diagnosed; 5438 5439 if (!CLASS_TYPE_P (t)) 5440 return; 5441 t = TYPE_MAIN_VARIANT (t); 5442 5443 if (diagnosed == NULL) 5444 diagnosed = new hash_set<tree>; 5445 if (diagnosed->add (t)) 5446 /* Already explained. */ 5447 return; 5448 5449 inform (UNKNOWN_LOCATION, "%q+T is not literal because:", t); 5450 if (cxx_dialect < cxx17 && LAMBDA_TYPE_P (t)) 5451 inform (UNKNOWN_LOCATION, 5452 " %qT is a closure type, which is only literal in " 5453 "C++17 and later", t); 5454 else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)) 5455 inform (UNKNOWN_LOCATION, " %q+T has a non-trivial destructor", t); 5456 else if (CLASSTYPE_NON_AGGREGATE (t) 5457 && !TYPE_HAS_TRIVIAL_DFLT (t) 5458 && !LAMBDA_TYPE_P (t) 5459 && !TYPE_HAS_CONSTEXPR_CTOR (t)) 5460 { 5461 inform (UNKNOWN_LOCATION, 5462 " %q+T is not an aggregate, does not have a trivial " 5463 "default constructor, and has no %<constexpr%> constructor that " 5464 "is not a copy or move constructor", t); 5465 if (type_has_non_user_provided_default_constructor (t)) 5466 /* Note that we can't simply call locate_ctor because when the 5467 constructor is deleted it just returns NULL_TREE. */ 5468 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 5469 { 5470 tree fn = *iter; 5471 tree parms = TYPE_ARG_TYPES (TREE_TYPE (fn)); 5472 5473 parms = skip_artificial_parms_for (fn, parms); 5474 5475 if (sufficient_parms_p (parms)) 5476 { 5477 if (DECL_DELETED_FN (fn)) 5478 maybe_explain_implicit_delete (fn); 5479 else 5480 explain_invalid_constexpr_fn (fn); 5481 break; 5482 } 5483 } 5484 } 5485 else 5486 { 5487 tree binfo, base_binfo, field; int i; 5488 for (binfo = TYPE_BINFO (t), i = 0; 5489 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 5490 { 5491 tree basetype = TREE_TYPE (base_binfo); 5492 if (!CLASSTYPE_LITERAL_P (basetype)) 5493 { 5494 inform (UNKNOWN_LOCATION, 5495 " base class %qT of %q+T is non-literal", 5496 basetype, t); 5497 explain_non_literal_class (basetype); 5498 return; 5499 } 5500 } 5501 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field)) 5502 { 5503 tree ftype; 5504 if (TREE_CODE (field) != FIELD_DECL) 5505 continue; 5506 ftype = TREE_TYPE (field); 5507 if (!literal_type_p (ftype)) 5508 { 5509 inform (DECL_SOURCE_LOCATION (field), 5510 " non-static data member %qD has non-literal type", 5511 field); 5512 if (CLASS_TYPE_P (ftype)) 5513 explain_non_literal_class (ftype); 5514 } 5515 if (CP_TYPE_VOLATILE_P (ftype)) 5516 inform (DECL_SOURCE_LOCATION (field), 5517 " non-static data member %qD has volatile type", field); 5518 } 5519 } 5520 } 5521 5522 /* Check the validity of the bases and members declared in T. Add any 5523 implicitly-generated functions (like copy-constructors and 5524 assignment operators). Compute various flag bits (like 5525 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++ 5526 level: i.e., independently of the ABI in use. */ 5527 5528 static void 5529 check_bases_and_members (tree t) 5530 { 5531 /* Nonzero if the implicitly generated copy constructor should take 5532 a non-const reference argument. */ 5533 int cant_have_const_ctor; 5534 /* Nonzero if the implicitly generated assignment operator 5535 should take a non-const reference argument. */ 5536 int no_const_asn_ref; 5537 tree access_decls; 5538 bool saved_complex_asn_ref; 5539 bool saved_nontrivial_dtor; 5540 tree fn; 5541 5542 /* By default, we use const reference arguments and generate default 5543 constructors. */ 5544 cant_have_const_ctor = 0; 5545 no_const_asn_ref = 0; 5546 5547 /* Check all the base-classes and set FMEM members to point to arrays 5548 of potential interest. */ 5549 check_bases (t, &cant_have_const_ctor, &no_const_asn_ref); 5550 5551 /* Deduce noexcept on destructor. This needs to happen after we've set 5552 triviality flags appropriately for our bases. */ 5553 if (cxx_dialect >= cxx11) 5554 if (tree dtor = CLASSTYPE_DESTRUCTOR (t)) 5555 deduce_noexcept_on_destructor (dtor); 5556 5557 /* Check all the method declarations. */ 5558 check_methods (t); 5559 5560 /* Save the initial values of these flags which only indicate whether 5561 or not the class has user-provided functions. As we analyze the 5562 bases and members we can set these flags for other reasons. */ 5563 saved_complex_asn_ref = TYPE_HAS_COMPLEX_COPY_ASSIGN (t); 5564 saved_nontrivial_dtor = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t); 5565 5566 /* Check all the data member declarations. We cannot call 5567 check_field_decls until we have called check_bases check_methods, 5568 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR 5569 being set appropriately. */ 5570 check_field_decls (t, &access_decls, 5571 &cant_have_const_ctor, 5572 &no_const_asn_ref); 5573 5574 /* A nearly-empty class has to be vptr-containing; a nearly empty 5575 class contains just a vptr. */ 5576 if (!TYPE_CONTAINS_VPTR_P (t)) 5577 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 5578 5579 /* Do some bookkeeping that will guide the generation of implicitly 5580 declared member functions. */ 5581 TYPE_HAS_COMPLEX_COPY_CTOR (t) |= TYPE_CONTAINS_VPTR_P (t); 5582 TYPE_HAS_COMPLEX_MOVE_CTOR (t) |= TYPE_CONTAINS_VPTR_P (t); 5583 /* We need to call a constructor for this class if it has a 5584 user-provided constructor, or if the default constructor is going 5585 to initialize the vptr. (This is not an if-and-only-if; 5586 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members 5587 themselves need constructing.) */ 5588 TYPE_NEEDS_CONSTRUCTING (t) 5589 |= (type_has_user_provided_constructor (t) || TYPE_CONTAINS_VPTR_P (t)); 5590 /* [dcl.init.aggr] 5591 5592 An aggregate is an array or a class with no user-provided 5593 constructors ... and no virtual functions. 5594 5595 Again, other conditions for being an aggregate are checked 5596 elsewhere. */ 5597 CLASSTYPE_NON_AGGREGATE (t) 5598 |= (type_has_user_provided_or_explicit_constructor (t) 5599 || TYPE_POLYMORPHIC_P (t)); 5600 /* This is the C++98/03 definition of POD; it changed in C++0x, but we 5601 retain the old definition internally for ABI reasons. */ 5602 CLASSTYPE_NON_LAYOUT_POD_P (t) 5603 |= (CLASSTYPE_NON_AGGREGATE (t) 5604 || saved_nontrivial_dtor || saved_complex_asn_ref); 5605 CLASSTYPE_NON_STD_LAYOUT (t) |= TYPE_CONTAINS_VPTR_P (t); 5606 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) |= TYPE_CONTAINS_VPTR_P (t); 5607 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) |= TYPE_CONTAINS_VPTR_P (t); 5608 TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_CONTAINS_VPTR_P (t); 5609 5610 /* If the only explicitly declared default constructor is user-provided, 5611 set TYPE_HAS_COMPLEX_DFLT. */ 5612 if (!TYPE_HAS_COMPLEX_DFLT (t) 5613 && TYPE_HAS_DEFAULT_CONSTRUCTOR (t) 5614 && !type_has_non_user_provided_default_constructor (t)) 5615 TYPE_HAS_COMPLEX_DFLT (t) = true; 5616 5617 /* Warn if a public base of a polymorphic type has an accessible 5618 non-virtual destructor. It is only now that we know the class is 5619 polymorphic. Although a polymorphic base will have a already 5620 been diagnosed during its definition, we warn on use too. */ 5621 if (TYPE_POLYMORPHIC_P (t) && warn_nonvdtor) 5622 { 5623 tree binfo = TYPE_BINFO (t); 5624 vec<tree, va_gc> *accesses = BINFO_BASE_ACCESSES (binfo); 5625 tree base_binfo; 5626 unsigned i; 5627 5628 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 5629 { 5630 tree basetype = TREE_TYPE (base_binfo); 5631 5632 if ((*accesses)[i] == access_public_node 5633 && (TYPE_POLYMORPHIC_P (basetype) || warn_ecpp) 5634 && accessible_nvdtor_p (basetype)) 5635 warning (OPT_Wnon_virtual_dtor, 5636 "base class %q#T has accessible non-virtual destructor", 5637 basetype); 5638 } 5639 } 5640 5641 /* If the class has no user-declared constructor, but does have 5642 non-static const or reference data members that can never be 5643 initialized, issue a warning. */ 5644 if (warn_uninitialized 5645 /* Classes with user-declared constructors are presumed to 5646 initialize these members. */ 5647 && !TYPE_HAS_USER_CONSTRUCTOR (t) 5648 /* Aggregates can be initialized with brace-enclosed 5649 initializers. */ 5650 && CLASSTYPE_NON_AGGREGATE (t)) 5651 { 5652 tree field; 5653 5654 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) 5655 { 5656 tree type; 5657 5658 if (TREE_CODE (field) != FIELD_DECL 5659 || DECL_INITIAL (field) != NULL_TREE) 5660 continue; 5661 5662 type = TREE_TYPE (field); 5663 if (TREE_CODE (type) == REFERENCE_TYPE) 5664 warning_at (DECL_SOURCE_LOCATION (field), 5665 OPT_Wuninitialized, "non-static reference %q#D " 5666 "in class without a constructor", field); 5667 else if (CP_TYPE_CONST_P (type) 5668 && (!CLASS_TYPE_P (type) 5669 || !TYPE_HAS_DEFAULT_CONSTRUCTOR (type))) 5670 warning_at (DECL_SOURCE_LOCATION (field), 5671 OPT_Wuninitialized, "non-static const member %q#D " 5672 "in class without a constructor", field); 5673 } 5674 } 5675 5676 /* Synthesize any needed methods. */ 5677 add_implicitly_declared_members (t, &access_decls, 5678 cant_have_const_ctor, 5679 no_const_asn_ref); 5680 5681 /* Check defaulted declarations here so we have cant_have_const_ctor 5682 and don't need to worry about clones. */ 5683 for (fn = TYPE_FIELDS (t); fn; fn = DECL_CHAIN (fn)) 5684 if (DECL_DECLARES_FUNCTION_P (fn) 5685 && !DECL_ARTIFICIAL (fn) 5686 && DECL_DEFAULTED_IN_CLASS_P (fn)) 5687 { 5688 int copy = copy_fn_p (fn); 5689 if (copy > 0) 5690 { 5691 bool imp_const_p 5692 = (DECL_CONSTRUCTOR_P (fn) ? !cant_have_const_ctor 5693 : !no_const_asn_ref); 5694 bool fn_const_p = (copy == 2); 5695 5696 if (fn_const_p && !imp_const_p) 5697 /* If the function is defaulted outside the class, we just 5698 give the synthesis error. */ 5699 error ("%q+D declared to take const reference, but implicit " 5700 "declaration would take non-const", fn); 5701 } 5702 defaulted_late_check (fn); 5703 } 5704 5705 if (LAMBDA_TYPE_P (t)) 5706 { 5707 /* "This class type is not an aggregate." */ 5708 CLASSTYPE_NON_AGGREGATE (t) = 1; 5709 } 5710 5711 /* Compute the 'literal type' property before we 5712 do anything with non-static member functions. */ 5713 finalize_literal_type_property (t); 5714 5715 /* Create the in-charge and not-in-charge variants of constructors 5716 and destructors. */ 5717 clone_constructors_and_destructors (t); 5718 5719 /* Process the using-declarations. */ 5720 for (; access_decls; access_decls = TREE_CHAIN (access_decls)) 5721 handle_using_decl (TREE_VALUE (access_decls), t); 5722 5723 /* Figure out whether or not we will need a cookie when dynamically 5724 allocating an array of this type. */ 5725 LANG_TYPE_CLASS_CHECK (t)->vec_new_uses_cookie 5726 = type_requires_array_cookie (t); 5727 } 5728 5729 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD 5730 accordingly. If a new vfield was created (because T doesn't have a 5731 primary base class), then the newly created field is returned. It 5732 is not added to the TYPE_FIELDS list; it is the caller's 5733 responsibility to do that. Accumulate declared virtual functions 5734 on VIRTUALS_P. */ 5735 5736 static tree 5737 create_vtable_ptr (tree t, tree* virtuals_p) 5738 { 5739 tree fn; 5740 5741 /* Collect the virtual functions declared in T. */ 5742 for (fn = TYPE_FIELDS (t); fn; fn = DECL_CHAIN (fn)) 5743 if (TREE_CODE (fn) == FUNCTION_DECL 5744 && DECL_VINDEX (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn) 5745 && TREE_CODE (DECL_VINDEX (fn)) != INTEGER_CST) 5746 { 5747 tree new_virtual = make_node (TREE_LIST); 5748 5749 BV_FN (new_virtual) = fn; 5750 BV_DELTA (new_virtual) = integer_zero_node; 5751 BV_VCALL_INDEX (new_virtual) = NULL_TREE; 5752 5753 TREE_CHAIN (new_virtual) = *virtuals_p; 5754 *virtuals_p = new_virtual; 5755 } 5756 5757 /* If we couldn't find an appropriate base class, create a new field 5758 here. Even if there weren't any new virtual functions, we might need a 5759 new virtual function table if we're supposed to include vptrs in 5760 all classes that need them. */ 5761 if (!TYPE_VFIELD (t) && (*virtuals_p || TYPE_CONTAINS_VPTR_P (t))) 5762 { 5763 /* We build this decl with vtbl_ptr_type_node, which is a 5764 `vtable_entry_type*'. It might seem more precise to use 5765 `vtable_entry_type (*)[N]' where N is the number of virtual 5766 functions. However, that would require the vtable pointer in 5767 base classes to have a different type than the vtable pointer 5768 in derived classes. We could make that happen, but that 5769 still wouldn't solve all the problems. In particular, the 5770 type-based alias analysis code would decide that assignments 5771 to the base class vtable pointer can't alias assignments to 5772 the derived class vtable pointer, since they have different 5773 types. Thus, in a derived class destructor, where the base 5774 class constructor was inlined, we could generate bad code for 5775 setting up the vtable pointer. 5776 5777 Therefore, we use one type for all vtable pointers. We still 5778 use a type-correct type; it's just doesn't indicate the array 5779 bounds. That's better than using `void*' or some such; it's 5780 cleaner, and it let's the alias analysis code know that these 5781 stores cannot alias stores to void*! */ 5782 tree field; 5783 5784 field = build_decl (input_location, 5785 FIELD_DECL, get_vfield_name (t), vtbl_ptr_type_node); 5786 DECL_VIRTUAL_P (field) = 1; 5787 DECL_ARTIFICIAL (field) = 1; 5788 DECL_FIELD_CONTEXT (field) = t; 5789 DECL_FCONTEXT (field) = t; 5790 if (TYPE_PACKED (t)) 5791 DECL_PACKED (field) = 1; 5792 5793 TYPE_VFIELD (t) = field; 5794 5795 /* This class is non-empty. */ 5796 CLASSTYPE_EMPTY_P (t) = 0; 5797 5798 return field; 5799 } 5800 5801 return NULL_TREE; 5802 } 5803 5804 /* Add OFFSET to all base types of BINFO which is a base in the 5805 hierarchy dominated by T. 5806 5807 OFFSET, which is a type offset, is number of bytes. */ 5808 5809 static void 5810 propagate_binfo_offsets (tree binfo, tree offset) 5811 { 5812 int i; 5813 tree primary_binfo; 5814 tree base_binfo; 5815 5816 /* Update BINFO's offset. */ 5817 BINFO_OFFSET (binfo) 5818 = fold_convert (sizetype, 5819 size_binop (PLUS_EXPR, 5820 fold_convert (ssizetype, BINFO_OFFSET (binfo)), 5821 offset)); 5822 5823 /* Find the primary base class. */ 5824 primary_binfo = get_primary_binfo (binfo); 5825 5826 if (primary_binfo && BINFO_INHERITANCE_CHAIN (primary_binfo) == binfo) 5827 propagate_binfo_offsets (primary_binfo, offset); 5828 5829 /* Scan all of the bases, pushing the BINFO_OFFSET adjust 5830 downwards. */ 5831 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 5832 { 5833 /* Don't do the primary base twice. */ 5834 if (base_binfo == primary_binfo) 5835 continue; 5836 5837 if (BINFO_VIRTUAL_P (base_binfo)) 5838 continue; 5839 5840 propagate_binfo_offsets (base_binfo, offset); 5841 } 5842 } 5843 5844 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update 5845 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of 5846 empty subobjects of T. */ 5847 5848 static void 5849 layout_virtual_bases (record_layout_info rli, splay_tree offsets) 5850 { 5851 tree vbase; 5852 tree t = rli->t; 5853 tree *next_field; 5854 5855 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) == 0) 5856 return; 5857 5858 /* Find the last field. The artificial fields created for virtual 5859 bases will go after the last extant field to date. */ 5860 next_field = &TYPE_FIELDS (t); 5861 while (*next_field) 5862 next_field = &DECL_CHAIN (*next_field); 5863 5864 /* Go through the virtual bases, allocating space for each virtual 5865 base that is not already a primary base class. These are 5866 allocated in inheritance graph order. */ 5867 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase)) 5868 { 5869 if (!BINFO_VIRTUAL_P (vbase)) 5870 continue; 5871 5872 if (!BINFO_PRIMARY_P (vbase)) 5873 { 5874 /* This virtual base is not a primary base of any class in the 5875 hierarchy, so we have to add space for it. */ 5876 next_field = build_base_field (rli, vbase, 5877 offsets, next_field); 5878 } 5879 } 5880 } 5881 5882 /* Returns the offset of the byte just past the end of the base class 5883 BINFO. */ 5884 5885 static tree 5886 end_of_base (tree binfo) 5887 { 5888 tree size; 5889 5890 if (!CLASSTYPE_AS_BASE (BINFO_TYPE (binfo))) 5891 size = TYPE_SIZE_UNIT (char_type_node); 5892 else if (is_empty_class (BINFO_TYPE (binfo))) 5893 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to 5894 allocate some space for it. It cannot have virtual bases, so 5895 TYPE_SIZE_UNIT is fine. */ 5896 size = TYPE_SIZE_UNIT (BINFO_TYPE (binfo)); 5897 else 5898 size = CLASSTYPE_SIZE_UNIT (BINFO_TYPE (binfo)); 5899 5900 return size_binop (PLUS_EXPR, BINFO_OFFSET (binfo), size); 5901 } 5902 5903 /* Returns the offset of the byte just past the end of the base class 5904 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then 5905 only non-virtual bases are included. */ 5906 5907 static tree 5908 end_of_class (tree t, int include_virtuals_p) 5909 { 5910 tree result = size_zero_node; 5911 vec<tree, va_gc> *vbases; 5912 tree binfo; 5913 tree base_binfo; 5914 tree offset; 5915 int i; 5916 5917 for (binfo = TYPE_BINFO (t), i = 0; 5918 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 5919 { 5920 if (!include_virtuals_p 5921 && BINFO_VIRTUAL_P (base_binfo) 5922 && (!BINFO_PRIMARY_P (base_binfo) 5923 || BINFO_INHERITANCE_CHAIN (base_binfo) != TYPE_BINFO (t))) 5924 continue; 5925 5926 offset = end_of_base (base_binfo); 5927 if (tree_int_cst_lt (result, offset)) 5928 result = offset; 5929 } 5930 5931 if (include_virtuals_p) 5932 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0; 5933 vec_safe_iterate (vbases, i, &base_binfo); i++) 5934 { 5935 offset = end_of_base (base_binfo); 5936 if (tree_int_cst_lt (result, offset)) 5937 result = offset; 5938 } 5939 5940 return result; 5941 } 5942 5943 /* Warn about bases of T that are inaccessible because they are 5944 ambiguous. For example: 5945 5946 struct S {}; 5947 struct T : public S {}; 5948 struct U : public S, public T {}; 5949 5950 Here, `(S*) new U' is not allowed because there are two `S' 5951 subobjects of U. */ 5952 5953 static void 5954 warn_about_ambiguous_bases (tree t) 5955 { 5956 int i; 5957 vec<tree, va_gc> *vbases; 5958 tree basetype; 5959 tree binfo; 5960 tree base_binfo; 5961 5962 /* If there are no repeated bases, nothing can be ambiguous. */ 5963 if (!CLASSTYPE_REPEATED_BASE_P (t)) 5964 return; 5965 5966 /* Check direct bases. */ 5967 for (binfo = TYPE_BINFO (t), i = 0; 5968 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 5969 { 5970 basetype = BINFO_TYPE (base_binfo); 5971 5972 if (!uniquely_derived_from_p (basetype, t)) 5973 warning (0, "direct base %qT inaccessible in %qT due to ambiguity", 5974 basetype, t); 5975 } 5976 5977 /* Check for ambiguous virtual bases. */ 5978 if (extra_warnings) 5979 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0; 5980 vec_safe_iterate (vbases, i, &binfo); i++) 5981 { 5982 basetype = BINFO_TYPE (binfo); 5983 5984 if (!uniquely_derived_from_p (basetype, t)) 5985 warning (OPT_Wextra, "virtual base %qT inaccessible in %qT due " 5986 "to ambiguity", basetype, t); 5987 } 5988 } 5989 5990 /* Compare two INTEGER_CSTs K1 and K2. */ 5991 5992 static int 5993 splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2) 5994 { 5995 return tree_int_cst_compare ((tree) k1, (tree) k2); 5996 } 5997 5998 /* Increase the size indicated in RLI to account for empty classes 5999 that are "off the end" of the class. */ 6000 6001 static void 6002 include_empty_classes (record_layout_info rli) 6003 { 6004 tree eoc; 6005 tree rli_size; 6006 6007 /* It might be the case that we grew the class to allocate a 6008 zero-sized base class. That won't be reflected in RLI, yet, 6009 because we are willing to overlay multiple bases at the same 6010 offset. However, now we need to make sure that RLI is big enough 6011 to reflect the entire class. */ 6012 eoc = end_of_class (rli->t, CLASSTYPE_AS_BASE (rli->t) != NULL_TREE); 6013 rli_size = rli_size_unit_so_far (rli); 6014 if (TREE_CODE (rli_size) == INTEGER_CST 6015 && tree_int_cst_lt (rli_size, eoc)) 6016 { 6017 /* The size should have been rounded to a whole byte. */ 6018 gcc_assert (tree_int_cst_equal 6019 (rli->bitpos, round_down (rli->bitpos, BITS_PER_UNIT))); 6020 rli->bitpos 6021 = size_binop (PLUS_EXPR, 6022 rli->bitpos, 6023 size_binop (MULT_EXPR, 6024 fold_convert (bitsizetype, 6025 size_binop (MINUS_EXPR, 6026 eoc, rli_size)), 6027 bitsize_int (BITS_PER_UNIT))); 6028 normalize_rli (rli); 6029 } 6030 } 6031 6032 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate 6033 BINFO_OFFSETs for all of the base-classes. Position the vtable 6034 pointer. Accumulate declared virtual functions on VIRTUALS_P. */ 6035 6036 static void 6037 layout_class_type (tree t, tree *virtuals_p) 6038 { 6039 tree non_static_data_members; 6040 tree field; 6041 tree vptr; 6042 record_layout_info rli; 6043 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of 6044 types that appear at that offset. */ 6045 splay_tree empty_base_offsets; 6046 /* True if the last field laid out was a bit-field. */ 6047 bool last_field_was_bitfield = false; 6048 /* The location at which the next field should be inserted. */ 6049 tree *next_field; 6050 6051 /* Keep track of the first non-static data member. */ 6052 non_static_data_members = TYPE_FIELDS (t); 6053 6054 /* Start laying out the record. */ 6055 rli = start_record_layout (t); 6056 6057 /* Mark all the primary bases in the hierarchy. */ 6058 determine_primary_bases (t); 6059 6060 /* Create a pointer to our virtual function table. */ 6061 vptr = create_vtable_ptr (t, virtuals_p); 6062 6063 /* The vptr is always the first thing in the class. */ 6064 if (vptr) 6065 { 6066 DECL_CHAIN (vptr) = TYPE_FIELDS (t); 6067 TYPE_FIELDS (t) = vptr; 6068 next_field = &DECL_CHAIN (vptr); 6069 place_field (rli, vptr); 6070 } 6071 else 6072 next_field = &TYPE_FIELDS (t); 6073 6074 /* Build FIELD_DECLs for all of the non-virtual base-types. */ 6075 empty_base_offsets = splay_tree_new (splay_tree_compare_integer_csts, 6076 NULL, NULL); 6077 build_base_fields (rli, empty_base_offsets, next_field); 6078 6079 /* Layout the non-static data members. */ 6080 for (field = non_static_data_members; field; field = DECL_CHAIN (field)) 6081 { 6082 tree type; 6083 tree padding; 6084 6085 /* We still pass things that aren't non-static data members to 6086 the back end, in case it wants to do something with them. */ 6087 if (TREE_CODE (field) != FIELD_DECL) 6088 { 6089 place_field (rli, field); 6090 /* If the static data member has incomplete type, keep track 6091 of it so that it can be completed later. (The handling 6092 of pending statics in finish_record_layout is 6093 insufficient; consider: 6094 6095 struct S1; 6096 struct S2 { static S1 s1; }; 6097 6098 At this point, finish_record_layout will be called, but 6099 S1 is still incomplete.) */ 6100 if (VAR_P (field)) 6101 { 6102 maybe_register_incomplete_var (field); 6103 /* The visibility of static data members is determined 6104 at their point of declaration, not their point of 6105 definition. */ 6106 determine_visibility (field); 6107 } 6108 continue; 6109 } 6110 6111 type = TREE_TYPE (field); 6112 if (type == error_mark_node) 6113 continue; 6114 6115 padding = NULL_TREE; 6116 6117 /* If this field is a bit-field whose width is greater than its 6118 type, then there are some special rules for allocating 6119 it. */ 6120 if (DECL_C_BIT_FIELD (field) 6121 && tree_int_cst_lt (TYPE_SIZE (type), DECL_SIZE (field))) 6122 { 6123 bool was_unnamed_p = false; 6124 /* We must allocate the bits as if suitably aligned for the 6125 longest integer type that fits in this many bits. Then, 6126 we are supposed to use the left over bits as additional 6127 padding. */ 6128 6129 /* Do not pick a type bigger than MAX_FIXED_MODE_SIZE. */ 6130 tree limit = size_int (MAX_FIXED_MODE_SIZE); 6131 if (tree_int_cst_lt (DECL_SIZE (field), limit)) 6132 limit = DECL_SIZE (field); 6133 6134 tree integer_type = integer_types[itk_char]; 6135 for (unsigned itk = itk_char; itk != itk_none; itk++) 6136 if (tree next = integer_types[itk]) 6137 { 6138 if (tree_int_cst_lt (limit, TYPE_SIZE (next))) 6139 /* Too big, so our current guess is what we want. */ 6140 break; 6141 /* Not bigger than limit, ok */ 6142 integer_type = next; 6143 } 6144 6145 /* Figure out how much additional padding is required. */ 6146 if (TREE_CODE (t) == UNION_TYPE) 6147 /* In a union, the padding field must have the full width 6148 of the bit-field; all fields start at offset zero. */ 6149 padding = DECL_SIZE (field); 6150 else 6151 padding = size_binop (MINUS_EXPR, DECL_SIZE (field), 6152 TYPE_SIZE (integer_type)); 6153 6154 if (integer_zerop (padding)) 6155 padding = NULL_TREE; 6156 6157 /* An unnamed bitfield does not normally affect the 6158 alignment of the containing class on a target where 6159 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not 6160 make any exceptions for unnamed bitfields when the 6161 bitfields are longer than their types. Therefore, we 6162 temporarily give the field a name. */ 6163 if (PCC_BITFIELD_TYPE_MATTERS && !DECL_NAME (field)) 6164 { 6165 was_unnamed_p = true; 6166 DECL_NAME (field) = make_anon_name (); 6167 } 6168 6169 DECL_SIZE (field) = TYPE_SIZE (integer_type); 6170 SET_DECL_ALIGN (field, TYPE_ALIGN (integer_type)); 6171 DECL_USER_ALIGN (field) = TYPE_USER_ALIGN (integer_type); 6172 layout_nonempty_base_or_field (rli, field, NULL_TREE, 6173 empty_base_offsets); 6174 if (was_unnamed_p) 6175 DECL_NAME (field) = NULL_TREE; 6176 /* Now that layout has been performed, set the size of the 6177 field to the size of its declared type; the rest of the 6178 field is effectively invisible. */ 6179 DECL_SIZE (field) = TYPE_SIZE (type); 6180 /* We must also reset the DECL_MODE of the field. */ 6181 SET_DECL_MODE (field, TYPE_MODE (type)); 6182 } 6183 else 6184 layout_nonempty_base_or_field (rli, field, NULL_TREE, 6185 empty_base_offsets); 6186 6187 /* Remember the location of any empty classes in FIELD. */ 6188 record_subobject_offsets (TREE_TYPE (field), 6189 byte_position(field), 6190 empty_base_offsets, 6191 /*is_data_member=*/true); 6192 6193 /* If a bit-field does not immediately follow another bit-field, 6194 and yet it starts in the middle of a byte, we have failed to 6195 comply with the ABI. */ 6196 if (warn_abi 6197 && DECL_C_BIT_FIELD (field) 6198 /* The TREE_NO_WARNING flag gets set by Objective-C when 6199 laying out an Objective-C class. The ObjC ABI differs 6200 from the C++ ABI, and so we do not want a warning 6201 here. */ 6202 && !TREE_NO_WARNING (field) 6203 && !last_field_was_bitfield 6204 && !integer_zerop (size_binop (TRUNC_MOD_EXPR, 6205 DECL_FIELD_BIT_OFFSET (field), 6206 bitsize_unit_node))) 6207 warning_at (DECL_SOURCE_LOCATION (field), OPT_Wabi, 6208 "offset of %qD is not ABI-compliant and may " 6209 "change in a future version of GCC", field); 6210 6211 /* The middle end uses the type of expressions to determine the 6212 possible range of expression values. In order to optimize 6213 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end 6214 must be made aware of the width of "i", via its type. 6215 6216 Because C++ does not have integer types of arbitrary width, 6217 we must (for the purposes of the front end) convert from the 6218 type assigned here to the declared type of the bitfield 6219 whenever a bitfield expression is used as an rvalue. 6220 Similarly, when assigning a value to a bitfield, the value 6221 must be converted to the type given the bitfield here. */ 6222 if (DECL_C_BIT_FIELD (field)) 6223 { 6224 unsigned HOST_WIDE_INT width; 6225 tree ftype = TREE_TYPE (field); 6226 width = tree_to_uhwi (DECL_SIZE (field)); 6227 if (width != TYPE_PRECISION (ftype)) 6228 { 6229 TREE_TYPE (field) 6230 = c_build_bitfield_integer_type (width, 6231 TYPE_UNSIGNED (ftype)); 6232 TREE_TYPE (field) 6233 = cp_build_qualified_type (TREE_TYPE (field), 6234 cp_type_quals (ftype)); 6235 } 6236 } 6237 6238 /* If we needed additional padding after this field, add it 6239 now. */ 6240 if (padding) 6241 { 6242 tree padding_field; 6243 6244 padding_field = build_decl (input_location, 6245 FIELD_DECL, 6246 NULL_TREE, 6247 char_type_node); 6248 DECL_BIT_FIELD (padding_field) = 1; 6249 DECL_SIZE (padding_field) = padding; 6250 DECL_CONTEXT (padding_field) = t; 6251 DECL_ARTIFICIAL (padding_field) = 1; 6252 DECL_IGNORED_P (padding_field) = 1; 6253 DECL_PADDING_P (padding_field) = 1; 6254 layout_nonempty_base_or_field (rli, padding_field, 6255 NULL_TREE, 6256 empty_base_offsets); 6257 } 6258 6259 last_field_was_bitfield = DECL_C_BIT_FIELD (field); 6260 } 6261 6262 if (!integer_zerop (rli->bitpos)) 6263 { 6264 /* Make sure that we are on a byte boundary so that the size of 6265 the class without virtual bases will always be a round number 6266 of bytes. */ 6267 rli->bitpos = round_up_loc (input_location, rli->bitpos, BITS_PER_UNIT); 6268 normalize_rli (rli); 6269 } 6270 6271 /* Delete all zero-width bit-fields from the list of fields. Now 6272 that the type is laid out they are no longer important. */ 6273 remove_zero_width_bit_fields (t); 6274 6275 if (CLASSTYPE_NON_LAYOUT_POD_P (t) || CLASSTYPE_EMPTY_P (t)) 6276 { 6277 /* T needs a different layout as a base (eliding virtual bases 6278 or whatever). Create that version. */ 6279 tree base_t = make_node (TREE_CODE (t)); 6280 6281 /* If the ABI version is not at least two, and the last 6282 field was a bit-field, RLI may not be on a byte 6283 boundary. In particular, rli_size_unit_so_far might 6284 indicate the last complete byte, while rli_size_so_far 6285 indicates the total number of bits used. Therefore, 6286 rli_size_so_far, rather than rli_size_unit_so_far, is 6287 used to compute TYPE_SIZE_UNIT. */ 6288 tree eoc = end_of_class (t, /*include_virtuals_p=*/0); 6289 TYPE_SIZE_UNIT (base_t) 6290 = size_binop (MAX_EXPR, 6291 fold_convert (sizetype, 6292 size_binop (CEIL_DIV_EXPR, 6293 rli_size_so_far (rli), 6294 bitsize_int (BITS_PER_UNIT))), 6295 eoc); 6296 TYPE_SIZE (base_t) 6297 = size_binop (MAX_EXPR, 6298 rli_size_so_far (rli), 6299 size_binop (MULT_EXPR, 6300 fold_convert (bitsizetype, eoc), 6301 bitsize_int (BITS_PER_UNIT))); 6302 SET_TYPE_ALIGN (base_t, rli->record_align); 6303 TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t); 6304 TYPE_TYPELESS_STORAGE (base_t) = TYPE_TYPELESS_STORAGE (t); 6305 6306 /* Copy the non-static data members of T. This will include its 6307 direct non-virtual bases & vtable. */ 6308 next_field = &TYPE_FIELDS (base_t); 6309 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) 6310 if (TREE_CODE (field) == FIELD_DECL) 6311 { 6312 *next_field = copy_node (field); 6313 DECL_CONTEXT (*next_field) = base_t; 6314 next_field = &DECL_CHAIN (*next_field); 6315 } 6316 *next_field = NULL_TREE; 6317 6318 /* We use the base type for trivial assignments, and hence it 6319 needs a mode. */ 6320 compute_record_mode (base_t); 6321 6322 TYPE_CONTEXT (base_t) = t; 6323 6324 /* Record the base version of the type. */ 6325 CLASSTYPE_AS_BASE (t) = base_t; 6326 } 6327 else 6328 CLASSTYPE_AS_BASE (t) = t; 6329 6330 /* Every empty class contains an empty class. */ 6331 if (CLASSTYPE_EMPTY_P (t)) 6332 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1; 6333 6334 /* Set the TYPE_DECL for this type to contain the right 6335 value for DECL_OFFSET, so that we can use it as part 6336 of a COMPONENT_REF for multiple inheritance. */ 6337 layout_decl (TYPE_MAIN_DECL (t), 0); 6338 6339 /* Now fix up any virtual base class types that we left lying 6340 around. We must get these done before we try to lay out the 6341 virtual function table. As a side-effect, this will remove the 6342 base subobject fields. */ 6343 layout_virtual_bases (rli, empty_base_offsets); 6344 6345 /* Make sure that empty classes are reflected in RLI at this 6346 point. */ 6347 include_empty_classes (rli); 6348 6349 /* Make sure not to create any structures with zero size. */ 6350 if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t)) 6351 place_field (rli, 6352 build_decl (input_location, 6353 FIELD_DECL, NULL_TREE, char_type_node)); 6354 6355 /* If this is a non-POD, declaring it packed makes a difference to how it 6356 can be used as a field; don't let finalize_record_size undo it. */ 6357 if (TYPE_PACKED (t) && !layout_pod_type_p (t)) 6358 rli->packed_maybe_necessary = true; 6359 6360 /* Let the back end lay out the type. */ 6361 finish_record_layout (rli, /*free_p=*/true); 6362 6363 if (TYPE_SIZE_UNIT (t) 6364 && TREE_CODE (TYPE_SIZE_UNIT (t)) == INTEGER_CST 6365 && !TREE_OVERFLOW (TYPE_SIZE_UNIT (t)) 6366 && !valid_constant_size_p (TYPE_SIZE_UNIT (t))) 6367 error ("size of type %qT is too large (%qE bytes)", t, TYPE_SIZE_UNIT (t)); 6368 6369 /* Warn about bases that can't be talked about due to ambiguity. */ 6370 warn_about_ambiguous_bases (t); 6371 6372 /* Now that we're done with layout, give the base fields the real types. */ 6373 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) 6374 if (DECL_ARTIFICIAL (field) && IS_FAKE_BASE_TYPE (TREE_TYPE (field))) 6375 TREE_TYPE (field) = TYPE_CONTEXT (TREE_TYPE (field)); 6376 6377 /* Clean up. */ 6378 splay_tree_delete (empty_base_offsets); 6379 6380 if (CLASSTYPE_EMPTY_P (t) 6381 && tree_int_cst_lt (sizeof_biggest_empty_class, 6382 TYPE_SIZE_UNIT (t))) 6383 sizeof_biggest_empty_class = TYPE_SIZE_UNIT (t); 6384 } 6385 6386 /* Determine the "key method" for the class type indicated by TYPE, 6387 and set CLASSTYPE_KEY_METHOD accordingly. */ 6388 6389 void 6390 determine_key_method (tree type) 6391 { 6392 tree method; 6393 6394 if (processing_template_decl 6395 || CLASSTYPE_TEMPLATE_INSTANTIATION (type) 6396 || CLASSTYPE_INTERFACE_KNOWN (type)) 6397 return; 6398 6399 /* The key method is the first non-pure virtual function that is not 6400 inline at the point of class definition. On some targets the 6401 key function may not be inline; those targets should not call 6402 this function until the end of the translation unit. */ 6403 for (method = TYPE_FIELDS (type); method; method = DECL_CHAIN (method)) 6404 if (TREE_CODE (method) == FUNCTION_DECL 6405 && DECL_VINDEX (method) != NULL_TREE 6406 && ! DECL_DECLARED_INLINE_P (method) 6407 && ! DECL_PURE_VIRTUAL_P (method)) 6408 { 6409 CLASSTYPE_KEY_METHOD (type) = method; 6410 break; 6411 } 6412 6413 return; 6414 } 6415 6416 /* Helper of find_flexarrays. Return true when FLD refers to a non-static 6417 class data member of non-zero size, otherwise false. */ 6418 6419 static inline bool 6420 field_nonempty_p (const_tree fld) 6421 { 6422 if (TREE_CODE (fld) == ERROR_MARK) 6423 return false; 6424 6425 tree type = TREE_TYPE (fld); 6426 if (TREE_CODE (fld) == FIELD_DECL 6427 && TREE_CODE (type) != ERROR_MARK 6428 && (DECL_NAME (fld) || RECORD_OR_UNION_TYPE_P (type))) 6429 { 6430 return TYPE_SIZE (type) 6431 && (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST 6432 || !tree_int_cst_equal (size_zero_node, TYPE_SIZE (type))); 6433 } 6434 6435 return false; 6436 } 6437 6438 /* Used by find_flexarrays and related functions. */ 6439 6440 struct flexmems_t 6441 { 6442 /* The first flexible array member or non-zero array member found 6443 in the order of layout. */ 6444 tree array; 6445 /* First non-static non-empty data member in the class or its bases. */ 6446 tree first; 6447 /* The first non-static non-empty data member following either 6448 the flexible array member, if found, or the zero-length array member 6449 otherwise. AFTER[1] refers to the first such data member of a union 6450 of which the struct containing the flexible array member or zero-length 6451 array is a member, or NULL when no such union exists. This element is 6452 only used during searching, not for diagnosing problems. AFTER[0] 6453 refers to the first such data member that is not a member of such 6454 a union. */ 6455 tree after[2]; 6456 6457 /* Refers to a struct (not union) in which the struct of which the flexible 6458 array is member is defined. Used to diagnose strictly (according to C) 6459 invalid uses of the latter structs. */ 6460 tree enclosing; 6461 }; 6462 6463 /* Find either the first flexible array member or the first zero-length 6464 array, in that order of preference, among members of class T (but not 6465 its base classes), and set members of FMEM accordingly. 6466 BASE_P is true if T is a base class of another class. 6467 PUN is set to the outermost union in which the flexible array member 6468 (or zero-length array) is defined if one such union exists, otherwise 6469 to NULL. 6470 Similarly, PSTR is set to a data member of the outermost struct of 6471 which the flexible array is a member if one such struct exists, 6472 otherwise to NULL. */ 6473 6474 static void 6475 find_flexarrays (tree t, flexmems_t *fmem, bool base_p, 6476 tree pun /* = NULL_TREE */, 6477 tree pstr /* = NULL_TREE */) 6478 { 6479 /* Set the "pointer" to the outermost enclosing union if not set 6480 yet and maintain it for the remainder of the recursion. */ 6481 if (!pun && TREE_CODE (t) == UNION_TYPE) 6482 pun = t; 6483 6484 for (tree fld = TYPE_FIELDS (t); fld; fld = DECL_CHAIN (fld)) 6485 { 6486 if (fld == error_mark_node) 6487 return; 6488 6489 /* Is FLD a typedef for an anonymous struct? */ 6490 6491 /* FIXME: Note that typedefs (as well as arrays) need to be fully 6492 handled elsewhere so that errors like the following are detected 6493 as well: 6494 typedef struct { int i, a[], j; } S; // bug c++/72753 6495 S s [2]; // bug c++/68489 6496 */ 6497 if (TREE_CODE (fld) == TYPE_DECL 6498 && DECL_IMPLICIT_TYPEDEF_P (fld) 6499 && CLASS_TYPE_P (TREE_TYPE (fld)) 6500 && anon_aggrname_p (DECL_NAME (fld))) 6501 { 6502 /* Check the nested unnamed type referenced via a typedef 6503 independently of FMEM (since it's not a data member of 6504 the enclosing class). */ 6505 check_flexarrays (TREE_TYPE (fld)); 6506 continue; 6507 } 6508 6509 /* Skip anything that's GCC-generated or not a (non-static) data 6510 member. */ 6511 if (DECL_ARTIFICIAL (fld) || TREE_CODE (fld) != FIELD_DECL) 6512 continue; 6513 6514 /* Type of the member. */ 6515 tree fldtype = TREE_TYPE (fld); 6516 if (fldtype == error_mark_node) 6517 return; 6518 6519 /* Determine the type of the array element or object referenced 6520 by the member so that it can be checked for flexible array 6521 members if it hasn't been yet. */ 6522 tree eltype = fldtype; 6523 while (TREE_CODE (eltype) == ARRAY_TYPE 6524 || TREE_CODE (eltype) == POINTER_TYPE 6525 || TREE_CODE (eltype) == REFERENCE_TYPE) 6526 eltype = TREE_TYPE (eltype); 6527 6528 if (RECORD_OR_UNION_TYPE_P (eltype)) 6529 { 6530 if (fmem->array && !fmem->after[bool (pun)]) 6531 { 6532 /* Once the member after the flexible array has been found 6533 we're done. */ 6534 fmem->after[bool (pun)] = fld; 6535 break; 6536 } 6537 6538 if (eltype == fldtype || TYPE_UNNAMED_P (eltype)) 6539 { 6540 /* Descend into the non-static member struct or union and try 6541 to find a flexible array member or zero-length array among 6542 its members. This is only necessary for anonymous types 6543 and types in whose context the current type T has not been 6544 defined (the latter must not be checked again because they 6545 are already in the process of being checked by one of the 6546 recursive calls). */ 6547 6548 tree first = fmem->first; 6549 tree array = fmem->array; 6550 6551 /* If this member isn't anonymous and a prior non-flexible array 6552 member has been seen in one of the enclosing structs, clear 6553 the FIRST member since it doesn't contribute to the flexible 6554 array struct's members. */ 6555 if (first && !array && !ANON_AGGR_TYPE_P (eltype)) 6556 fmem->first = NULL_TREE; 6557 6558 find_flexarrays (eltype, fmem, false, pun, 6559 !pstr && TREE_CODE (t) == RECORD_TYPE ? fld : pstr); 6560 6561 if (fmem->array != array) 6562 continue; 6563 6564 if (first && !array && !ANON_AGGR_TYPE_P (eltype)) 6565 { 6566 /* Restore the FIRST member reset above if no flexible 6567 array member has been found in this member's struct. */ 6568 fmem->first = first; 6569 } 6570 6571 /* If the member struct contains the first flexible array 6572 member, or if this member is a base class, continue to 6573 the next member and avoid setting the FMEM->NEXT pointer 6574 to point to it. */ 6575 if (base_p) 6576 continue; 6577 } 6578 } 6579 6580 if (field_nonempty_p (fld)) 6581 { 6582 /* Remember the first non-static data member. */ 6583 if (!fmem->first) 6584 fmem->first = fld; 6585 6586 /* Remember the first non-static data member after the flexible 6587 array member, if one has been found, or the zero-length array 6588 if it has been found. */ 6589 if (fmem->array && !fmem->after[bool (pun)]) 6590 fmem->after[bool (pun)] = fld; 6591 } 6592 6593 /* Skip non-arrays. */ 6594 if (TREE_CODE (fldtype) != ARRAY_TYPE) 6595 continue; 6596 6597 /* Determine the upper bound of the array if it has one. */ 6598 if (TYPE_DOMAIN (fldtype)) 6599 { 6600 if (fmem->array) 6601 { 6602 /* Make a record of the zero-length array if either one 6603 such field or a flexible array member has been seen to 6604 handle the pathological and unlikely case of multiple 6605 such members. */ 6606 if (!fmem->after[bool (pun)]) 6607 fmem->after[bool (pun)] = fld; 6608 } 6609 else if (integer_all_onesp (TYPE_MAX_VALUE (TYPE_DOMAIN (fldtype)))) 6610 { 6611 /* Remember the first zero-length array unless a flexible array 6612 member has already been seen. */ 6613 fmem->array = fld; 6614 fmem->enclosing = pstr; 6615 } 6616 } 6617 else 6618 { 6619 /* Flexible array members have no upper bound. */ 6620 if (fmem->array) 6621 { 6622 if (TYPE_DOMAIN (TREE_TYPE (fmem->array))) 6623 { 6624 /* Replace the zero-length array if it's been stored and 6625 reset the after pointer. */ 6626 fmem->after[bool (pun)] = NULL_TREE; 6627 fmem->array = fld; 6628 fmem->enclosing = pstr; 6629 } 6630 else if (!fmem->after[bool (pun)]) 6631 /* Make a record of another flexible array member. */ 6632 fmem->after[bool (pun)] = fld; 6633 } 6634 else 6635 { 6636 fmem->array = fld; 6637 fmem->enclosing = pstr; 6638 } 6639 } 6640 } 6641 } 6642 6643 /* Diagnose a strictly (by the C standard) invalid use of a struct with 6644 a flexible array member (or the zero-length array extension). */ 6645 6646 static void 6647 diagnose_invalid_flexarray (const flexmems_t *fmem) 6648 { 6649 if (fmem->array && fmem->enclosing 6650 && pedwarn (location_of (fmem->enclosing), OPT_Wpedantic, 6651 TYPE_DOMAIN (TREE_TYPE (fmem->array)) 6652 ? G_("invalid use of %q#T with a zero-size array " 6653 "in %q#D") 6654 : G_("invalid use of %q#T with a flexible array member " 6655 "in %q#T"), 6656 DECL_CONTEXT (fmem->array), 6657 DECL_CONTEXT (fmem->enclosing))) 6658 inform (DECL_SOURCE_LOCATION (fmem->array), 6659 "array member %q#D declared here", fmem->array); 6660 } 6661 6662 /* Issue diagnostics for invalid flexible array members or zero-length 6663 arrays that are not the last elements of the containing class or its 6664 base classes or that are its sole members. */ 6665 6666 static void 6667 diagnose_flexarrays (tree t, const flexmems_t *fmem) 6668 { 6669 if (!fmem->array) 6670 return; 6671 6672 if (fmem->first && !fmem->after[0]) 6673 { 6674 diagnose_invalid_flexarray (fmem); 6675 return; 6676 } 6677 6678 /* Has a diagnostic been issued? */ 6679 bool diagd = false; 6680 6681 const char *msg = 0; 6682 6683 if (TYPE_DOMAIN (TREE_TYPE (fmem->array))) 6684 { 6685 if (fmem->after[0]) 6686 msg = G_("zero-size array member %qD not at end of %q#T"); 6687 else if (!fmem->first) 6688 msg = G_("zero-size array member %qD in an otherwise empty %q#T"); 6689 6690 if (msg) 6691 { 6692 location_t loc = DECL_SOURCE_LOCATION (fmem->array); 6693 6694 if (pedwarn (loc, OPT_Wpedantic, msg, fmem->array, t)) 6695 { 6696 inform (location_of (t), "in the definition of %q#T", t); 6697 diagd = true; 6698 } 6699 } 6700 } 6701 else 6702 { 6703 if (fmem->after[0]) 6704 msg = G_("flexible array member %qD not at end of %q#T"); 6705 else if (!fmem->first) 6706 msg = G_("flexible array member %qD in an otherwise empty %q#T"); 6707 6708 if (msg) 6709 { 6710 location_t loc = DECL_SOURCE_LOCATION (fmem->array); 6711 diagd = true; 6712 6713 error_at (loc, msg, fmem->array, t); 6714 6715 /* In the unlikely event that the member following the flexible 6716 array member is declared in a different class, or the member 6717 overlaps another member of a common union, point to it. 6718 Otherwise it should be obvious. */ 6719 if (fmem->after[0] 6720 && ((DECL_CONTEXT (fmem->after[0]) 6721 != DECL_CONTEXT (fmem->array)))) 6722 { 6723 inform (DECL_SOURCE_LOCATION (fmem->after[0]), 6724 "next member %q#D declared here", 6725 fmem->after[0]); 6726 inform (location_of (t), "in the definition of %q#T", t); 6727 } 6728 } 6729 } 6730 6731 if (!diagd && fmem->array && fmem->enclosing) 6732 diagnose_invalid_flexarray (fmem); 6733 } 6734 6735 6736 /* Recursively check to make sure that any flexible array or zero-length 6737 array members of class T or its bases are valid (i.e., not the sole 6738 non-static data member of T and, if one exists, that it is the last 6739 non-static data member of T and its base classes. FMEM is expected 6740 to be initially null and is used internally by recursive calls to 6741 the function. Issue the appropriate diagnostics for the array member 6742 that fails the checks. */ 6743 6744 static void 6745 check_flexarrays (tree t, flexmems_t *fmem /* = NULL */, 6746 bool base_p /* = false */) 6747 { 6748 /* Initialize the result of a search for flexible array and zero-length 6749 array members. Avoid doing any work if the most interesting FMEM data 6750 have already been populated. */ 6751 flexmems_t flexmems = flexmems_t (); 6752 if (!fmem) 6753 fmem = &flexmems; 6754 else if (fmem->array && fmem->first && fmem->after[0]) 6755 return; 6756 6757 tree fam = fmem->array; 6758 6759 /* Recursively check the primary base class first. */ 6760 if (CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 6761 { 6762 tree basetype = BINFO_TYPE (CLASSTYPE_PRIMARY_BINFO (t)); 6763 check_flexarrays (basetype, fmem, true); 6764 } 6765 6766 /* Recursively check the base classes. */ 6767 int nbases = TYPE_BINFO (t) ? BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) : 0; 6768 for (int i = 0; i < nbases; ++i) 6769 { 6770 tree base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i); 6771 6772 /* The primary base class was already checked above. */ 6773 if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t)) 6774 continue; 6775 6776 /* Virtual base classes are at the end. */ 6777 if (BINFO_VIRTUAL_P (base_binfo)) 6778 continue; 6779 6780 /* Check the base class. */ 6781 check_flexarrays (BINFO_TYPE (base_binfo), fmem, /*base_p=*/true); 6782 } 6783 6784 if (fmem == &flexmems) 6785 { 6786 /* Check virtual base classes only once per derived class. 6787 I.e., this check is not performed recursively for base 6788 classes. */ 6789 int i; 6790 tree base_binfo; 6791 vec<tree, va_gc> *vbases; 6792 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0; 6793 vec_safe_iterate (vbases, i, &base_binfo); i++) 6794 { 6795 /* Check the virtual base class. */ 6796 tree basetype = TREE_TYPE (base_binfo); 6797 6798 check_flexarrays (basetype, fmem, /*base_p=*/true); 6799 } 6800 } 6801 6802 /* Is the type unnamed (and therefore a member of it potentially 6803 an anonymous struct or union)? */ 6804 bool maybe_anon_p = TYPE_UNNAMED_P (t); 6805 6806 /* Search the members of the current (possibly derived) class, skipping 6807 unnamed structs and unions since those could be anonymous. */ 6808 if (fmem != &flexmems || !maybe_anon_p) 6809 find_flexarrays (t, fmem, base_p || fam != fmem->array); 6810 6811 if (fmem == &flexmems && !maybe_anon_p) 6812 { 6813 /* Issue diagnostics for invalid flexible and zero-length array 6814 members found in base classes or among the members of the current 6815 class. Ignore anonymous structs and unions whose members are 6816 considered to be members of the enclosing class and thus will 6817 be diagnosed when checking it. */ 6818 diagnose_flexarrays (t, fmem); 6819 } 6820 } 6821 6822 /* Perform processing required when the definition of T (a class type) 6823 is complete. Diagnose invalid definitions of flexible array members 6824 and zero-size arrays. */ 6825 6826 void 6827 finish_struct_1 (tree t) 6828 { 6829 tree x; 6830 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */ 6831 tree virtuals = NULL_TREE; 6832 6833 if (COMPLETE_TYPE_P (t)) 6834 { 6835 gcc_assert (MAYBE_CLASS_TYPE_P (t)); 6836 error ("redefinition of %q#T", t); 6837 popclass (); 6838 return; 6839 } 6840 6841 /* If this type was previously laid out as a forward reference, 6842 make sure we lay it out again. */ 6843 TYPE_SIZE (t) = NULL_TREE; 6844 CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE; 6845 6846 /* Make assumptions about the class; we'll reset the flags if 6847 necessary. */ 6848 CLASSTYPE_EMPTY_P (t) = 1; 6849 CLASSTYPE_NEARLY_EMPTY_P (t) = 1; 6850 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 0; 6851 CLASSTYPE_LITERAL_P (t) = true; 6852 6853 /* Do end-of-class semantic processing: checking the validity of the 6854 bases and members and add implicitly generated methods. */ 6855 check_bases_and_members (t); 6856 6857 /* Find the key method. */ 6858 if (TYPE_CONTAINS_VPTR_P (t)) 6859 { 6860 /* The Itanium C++ ABI permits the key method to be chosen when 6861 the class is defined -- even though the key method so 6862 selected may later turn out to be an inline function. On 6863 some systems (such as ARM Symbian OS) the key method cannot 6864 be determined until the end of the translation unit. On such 6865 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which 6866 will cause the class to be added to KEYED_CLASSES. Then, in 6867 finish_file we will determine the key method. */ 6868 if (targetm.cxx.key_method_may_be_inline ()) 6869 determine_key_method (t); 6870 6871 /* If a polymorphic class has no key method, we may emit the vtable 6872 in every translation unit where the class definition appears. If 6873 we're devirtualizing, we can look into the vtable even if we 6874 aren't emitting it. */ 6875 if (!CLASSTYPE_KEY_METHOD (t)) 6876 vec_safe_push (keyed_classes, t); 6877 } 6878 6879 /* Layout the class itself. */ 6880 layout_class_type (t, &virtuals); 6881 /* COMPLETE_TYPE_P is now true. */ 6882 6883 set_class_bindings (t); 6884 6885 /* With the layout complete, check for flexible array members and 6886 zero-length arrays that might overlap other members in the final 6887 layout. */ 6888 check_flexarrays (t); 6889 6890 virtuals = modify_all_vtables (t, nreverse (virtuals)); 6891 6892 /* If necessary, create the primary vtable for this class. */ 6893 if (virtuals || TYPE_CONTAINS_VPTR_P (t)) 6894 { 6895 /* We must enter these virtuals into the table. */ 6896 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 6897 build_primary_vtable (NULL_TREE, t); 6898 else if (! BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (t))) 6899 /* Here we know enough to change the type of our virtual 6900 function table, but we will wait until later this function. */ 6901 build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t); 6902 6903 /* If we're warning about ABI tags, check the types of the new 6904 virtual functions. */ 6905 if (warn_abi_tag) 6906 for (tree v = virtuals; v; v = TREE_CHAIN (v)) 6907 check_abi_tags (t, TREE_VALUE (v)); 6908 } 6909 6910 if (TYPE_CONTAINS_VPTR_P (t)) 6911 { 6912 int vindex; 6913 tree fn; 6914 6915 if (BINFO_VTABLE (TYPE_BINFO (t))) 6916 gcc_assert (DECL_VIRTUAL_P (BINFO_VTABLE (TYPE_BINFO (t)))); 6917 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 6918 gcc_assert (BINFO_VIRTUALS (TYPE_BINFO (t)) == NULL_TREE); 6919 6920 /* Add entries for virtual functions introduced by this class. */ 6921 BINFO_VIRTUALS (TYPE_BINFO (t)) 6922 = chainon (BINFO_VIRTUALS (TYPE_BINFO (t)), virtuals); 6923 6924 /* Set DECL_VINDEX for all functions declared in this class. */ 6925 for (vindex = 0, fn = BINFO_VIRTUALS (TYPE_BINFO (t)); 6926 fn; 6927 fn = TREE_CHAIN (fn), 6928 vindex += (TARGET_VTABLE_USES_DESCRIPTORS 6929 ? TARGET_VTABLE_USES_DESCRIPTORS : 1)) 6930 { 6931 tree fndecl = BV_FN (fn); 6932 6933 if (DECL_THUNK_P (fndecl)) 6934 /* A thunk. We should never be calling this entry directly 6935 from this vtable -- we'd use the entry for the non 6936 thunk base function. */ 6937 DECL_VINDEX (fndecl) = NULL_TREE; 6938 else if (TREE_CODE (DECL_VINDEX (fndecl)) != INTEGER_CST) 6939 DECL_VINDEX (fndecl) = build_int_cst (NULL_TREE, vindex); 6940 } 6941 } 6942 6943 finish_struct_bits (t); 6944 6945 set_method_tm_attributes (t); 6946 if (flag_openmp || flag_openmp_simd) 6947 finish_omp_declare_simd_methods (t); 6948 6949 /* Clear DECL_IN_AGGR_P for all member functions. Complete the rtl 6950 for any static member objects of the type we're working on. */ 6951 for (x = TYPE_FIELDS (t); x; x = DECL_CHAIN (x)) 6952 if (DECL_DECLARES_FUNCTION_P (x)) 6953 DECL_IN_AGGR_P (x) = false; 6954 else if (VAR_P (x) && TREE_STATIC (x) 6955 && TREE_TYPE (x) != error_mark_node 6956 && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t)) 6957 SET_DECL_MODE (x, TYPE_MODE (t)); 6958 6959 /* Complain if one of the field types requires lower visibility. */ 6960 constrain_class_visibility (t); 6961 6962 /* Make the rtl for any new vtables we have created, and unmark 6963 the base types we marked. */ 6964 finish_vtbls (t); 6965 6966 /* Build the VTT for T. */ 6967 build_vtt (t); 6968 6969 if (warn_nonvdtor 6970 && TYPE_POLYMORPHIC_P (t) && accessible_nvdtor_p (t) 6971 && !CLASSTYPE_FINAL (t)) 6972 warning (OPT_Wnon_virtual_dtor, 6973 "%q#T has virtual functions and accessible" 6974 " non-virtual destructor", t); 6975 6976 complete_vars (t); 6977 6978 if (warn_overloaded_virtual) 6979 warn_hidden (t); 6980 6981 /* Class layout, assignment of virtual table slots, etc., is now 6982 complete. Give the back end a chance to tweak the visibility of 6983 the class or perform any other required target modifications. */ 6984 targetm.cxx.adjust_class_at_definition (t); 6985 6986 maybe_suppress_debug_info (t); 6987 6988 if (flag_vtable_verify) 6989 vtv_save_class_info (t); 6990 6991 dump_class_hierarchy (t); 6992 6993 /* Finish debugging output for this type. */ 6994 rest_of_type_compilation (t, ! LOCAL_CLASS_P (t)); 6995 6996 if (TYPE_TRANSPARENT_AGGR (t)) 6997 { 6998 tree field = first_field (t); 6999 if (field == NULL_TREE || error_operand_p (field)) 7000 { 7001 error ("type transparent %q#T does not have any fields", t); 7002 TYPE_TRANSPARENT_AGGR (t) = 0; 7003 } 7004 else if (DECL_ARTIFICIAL (field)) 7005 { 7006 if (DECL_FIELD_IS_BASE (field)) 7007 error ("type transparent class %qT has base classes", t); 7008 else 7009 { 7010 gcc_checking_assert (DECL_VIRTUAL_P (field)); 7011 error ("type transparent class %qT has virtual functions", t); 7012 } 7013 TYPE_TRANSPARENT_AGGR (t) = 0; 7014 } 7015 else if (TYPE_MODE (t) != DECL_MODE (field)) 7016 { 7017 error ("type transparent %q#T cannot be made transparent because " 7018 "the type of the first field has a different ABI from the " 7019 "class overall", t); 7020 TYPE_TRANSPARENT_AGGR (t) = 0; 7021 } 7022 } 7023 } 7024 7025 /* When T was built up, the member declarations were added in reverse 7026 order. Rearrange them to declaration order. */ 7027 7028 void 7029 unreverse_member_declarations (tree t) 7030 { 7031 tree next; 7032 tree prev; 7033 tree x; 7034 7035 /* The following lists are all in reverse order. Put them in 7036 declaration order now. */ 7037 CLASSTYPE_DECL_LIST (t) = nreverse (CLASSTYPE_DECL_LIST (t)); 7038 7039 /* For the TYPE_FIELDS, only the non TYPE_DECLs are in reverse 7040 order, so we can't just use nreverse. Due to stat_hack 7041 chicanery in finish_member_declaration. */ 7042 prev = NULL_TREE; 7043 for (x = TYPE_FIELDS (t); 7044 x && TREE_CODE (x) != TYPE_DECL; 7045 x = next) 7046 { 7047 next = DECL_CHAIN (x); 7048 DECL_CHAIN (x) = prev; 7049 prev = x; 7050 } 7051 7052 if (prev) 7053 { 7054 DECL_CHAIN (TYPE_FIELDS (t)) = x; 7055 TYPE_FIELDS (t) = prev; 7056 } 7057 } 7058 7059 tree 7060 finish_struct (tree t, tree attributes) 7061 { 7062 location_t saved_loc = input_location; 7063 7064 /* Now that we've got all the field declarations, reverse everything 7065 as necessary. */ 7066 unreverse_member_declarations (t); 7067 7068 cplus_decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 7069 fixup_attribute_variants (t); 7070 7071 /* Nadger the current location so that diagnostics point to the start of 7072 the struct, not the end. */ 7073 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (t)); 7074 7075 if (processing_template_decl) 7076 { 7077 tree x; 7078 7079 /* We need to add the target functions of USING_DECLS, so that 7080 they can be found when the using declaration is not 7081 instantiated yet. */ 7082 for (x = TYPE_FIELDS (t); x; x = DECL_CHAIN (x)) 7083 if (TREE_CODE (x) == USING_DECL) 7084 { 7085 tree fn = strip_using_decl (x); 7086 if (OVL_P (fn)) 7087 for (lkp_iterator iter (fn); iter; ++iter) 7088 add_method (t, *iter, true); 7089 } 7090 else if (DECL_DECLARES_FUNCTION_P (x)) 7091 DECL_IN_AGGR_P (x) = false; 7092 7093 /* Also add a USING_DECL for operator=. We know there'll be (at 7094 least) one, but we don't know the signature(s). We want name 7095 lookup not to fail or recurse into bases. This isn't added 7096 to the template decl list so we drop this at instantiation 7097 time. */ 7098 tree ass_op = build_lang_decl (USING_DECL, assign_op_identifier, 7099 NULL_TREE); 7100 DECL_CONTEXT (ass_op) = t; 7101 USING_DECL_SCOPE (ass_op) = t; 7102 DECL_DEPENDENT_P (ass_op) = true; 7103 DECL_ARTIFICIAL (ass_op) = true; 7104 DECL_CHAIN (ass_op) = TYPE_FIELDS (t); 7105 TYPE_FIELDS (t) = ass_op; 7106 7107 TYPE_SIZE (t) = bitsize_zero_node; 7108 TYPE_SIZE_UNIT (t) = size_zero_node; 7109 /* COMPLETE_TYPE_P is now true. */ 7110 7111 set_class_bindings (t); 7112 7113 /* We need to emit an error message if this type was used as a parameter 7114 and it is an abstract type, even if it is a template. We construct 7115 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into 7116 account and we call complete_vars with this type, which will check 7117 the PARM_DECLS. Note that while the type is being defined, 7118 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends 7119 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */ 7120 CLASSTYPE_PURE_VIRTUALS (t) = NULL; 7121 for (x = TYPE_FIELDS (t); x; x = DECL_CHAIN (x)) 7122 if (TREE_CODE (x) == FUNCTION_DECL && DECL_PURE_VIRTUAL_P (x)) 7123 vec_safe_push (CLASSTYPE_PURE_VIRTUALS (t), x); 7124 complete_vars (t); 7125 7126 /* Remember current #pragma pack value. */ 7127 TYPE_PRECISION (t) = maximum_field_alignment; 7128 7129 /* Fix up any variants we've already built. */ 7130 for (x = TYPE_NEXT_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x)) 7131 { 7132 TYPE_SIZE (x) = TYPE_SIZE (t); 7133 TYPE_SIZE_UNIT (x) = TYPE_SIZE_UNIT (t); 7134 TYPE_FIELDS (x) = TYPE_FIELDS (t); 7135 } 7136 } 7137 else 7138 finish_struct_1 (t); 7139 /* COMPLETE_TYPE_P is now true. */ 7140 7141 maybe_warn_about_overly_private_class (t); 7142 7143 if (is_std_init_list (t)) 7144 { 7145 /* People keep complaining that the compiler crashes on an invalid 7146 definition of initializer_list, so I guess we should explicitly 7147 reject it. What the compiler internals care about is that it's a 7148 template and has a pointer field followed by size_type field. */ 7149 bool ok = false; 7150 if (processing_template_decl) 7151 { 7152 tree f = next_initializable_field (TYPE_FIELDS (t)); 7153 if (f && TREE_CODE (TREE_TYPE (f)) == POINTER_TYPE) 7154 { 7155 f = next_initializable_field (DECL_CHAIN (f)); 7156 if (f && same_type_p (TREE_TYPE (f), size_type_node)) 7157 ok = true; 7158 } 7159 } 7160 if (!ok) 7161 fatal_error (input_location, "definition of %qD does not match " 7162 "%<#include <initializer_list>%>", TYPE_NAME (t)); 7163 } 7164 7165 input_location = saved_loc; 7166 7167 TYPE_BEING_DEFINED (t) = 0; 7168 7169 if (current_class_type) 7170 popclass (); 7171 else 7172 error ("trying to finish struct, but kicked out due to previous parse errors"); 7173 7174 if (processing_template_decl && at_function_scope_p () 7175 /* Lambdas are defined by the LAMBDA_EXPR. */ 7176 && !LAMBDA_TYPE_P (t)) 7177 add_stmt (build_min (TAG_DEFN, t)); 7178 7179 return t; 7180 } 7181 7182 /* Hash table to avoid endless recursion when handling references. */ 7183 static hash_table<nofree_ptr_hash<tree_node> > *fixed_type_or_null_ref_ht; 7184 7185 /* Return the dynamic type of INSTANCE, if known. 7186 Used to determine whether the virtual function table is needed 7187 or not. 7188 7189 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless 7190 of our knowledge of its type. *NONNULL should be initialized 7191 before this function is called. */ 7192 7193 static tree 7194 fixed_type_or_null (tree instance, int *nonnull, int *cdtorp) 7195 { 7196 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp) 7197 7198 switch (TREE_CODE (instance)) 7199 { 7200 case INDIRECT_REF: 7201 if (POINTER_TYPE_P (TREE_TYPE (instance))) 7202 return NULL_TREE; 7203 else 7204 return RECUR (TREE_OPERAND (instance, 0)); 7205 7206 case CALL_EXPR: 7207 /* This is a call to a constructor, hence it's never zero. */ 7208 if (CALL_EXPR_FN (instance) 7209 && TREE_HAS_CONSTRUCTOR (instance)) 7210 { 7211 if (nonnull) 7212 *nonnull = 1; 7213 return TREE_TYPE (instance); 7214 } 7215 return NULL_TREE; 7216 7217 case SAVE_EXPR: 7218 /* This is a call to a constructor, hence it's never zero. */ 7219 if (TREE_HAS_CONSTRUCTOR (instance)) 7220 { 7221 if (nonnull) 7222 *nonnull = 1; 7223 return TREE_TYPE (instance); 7224 } 7225 return RECUR (TREE_OPERAND (instance, 0)); 7226 7227 case POINTER_PLUS_EXPR: 7228 case PLUS_EXPR: 7229 case MINUS_EXPR: 7230 if (TREE_CODE (TREE_OPERAND (instance, 0)) == ADDR_EXPR) 7231 return RECUR (TREE_OPERAND (instance, 0)); 7232 if (TREE_CODE (TREE_OPERAND (instance, 1)) == INTEGER_CST) 7233 /* Propagate nonnull. */ 7234 return RECUR (TREE_OPERAND (instance, 0)); 7235 7236 return NULL_TREE; 7237 7238 CASE_CONVERT: 7239 return RECUR (TREE_OPERAND (instance, 0)); 7240 7241 case ADDR_EXPR: 7242 instance = TREE_OPERAND (instance, 0); 7243 if (nonnull) 7244 { 7245 /* Just because we see an ADDR_EXPR doesn't mean we're dealing 7246 with a real object -- given &p->f, p can still be null. */ 7247 tree t = get_base_address (instance); 7248 /* ??? Probably should check DECL_WEAK here. */ 7249 if (t && DECL_P (t)) 7250 *nonnull = 1; 7251 } 7252 return RECUR (instance); 7253 7254 case COMPONENT_REF: 7255 /* If this component is really a base class reference, then the field 7256 itself isn't definitive. */ 7257 if (DECL_FIELD_IS_BASE (TREE_OPERAND (instance, 1))) 7258 return RECUR (TREE_OPERAND (instance, 0)); 7259 return RECUR (TREE_OPERAND (instance, 1)); 7260 7261 case VAR_DECL: 7262 case FIELD_DECL: 7263 if (TREE_CODE (TREE_TYPE (instance)) == ARRAY_TYPE 7264 && MAYBE_CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (instance)))) 7265 { 7266 if (nonnull) 7267 *nonnull = 1; 7268 return TREE_TYPE (TREE_TYPE (instance)); 7269 } 7270 /* fall through. */ 7271 case TARGET_EXPR: 7272 case PARM_DECL: 7273 case RESULT_DECL: 7274 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (instance))) 7275 { 7276 if (nonnull) 7277 *nonnull = 1; 7278 return TREE_TYPE (instance); 7279 } 7280 else if (instance == current_class_ptr) 7281 { 7282 if (nonnull) 7283 *nonnull = 1; 7284 7285 /* if we're in a ctor or dtor, we know our type. If 7286 current_class_ptr is set but we aren't in a function, we're in 7287 an NSDMI (and therefore a constructor). */ 7288 if (current_scope () != current_function_decl 7289 || (DECL_LANG_SPECIFIC (current_function_decl) 7290 && (DECL_CONSTRUCTOR_P (current_function_decl) 7291 || DECL_DESTRUCTOR_P (current_function_decl)))) 7292 { 7293 if (cdtorp) 7294 *cdtorp = 1; 7295 return TREE_TYPE (TREE_TYPE (instance)); 7296 } 7297 } 7298 else if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE) 7299 { 7300 /* We only need one hash table because it is always left empty. */ 7301 if (!fixed_type_or_null_ref_ht) 7302 fixed_type_or_null_ref_ht 7303 = new hash_table<nofree_ptr_hash<tree_node> > (37); 7304 7305 /* Reference variables should be references to objects. */ 7306 if (nonnull) 7307 *nonnull = 1; 7308 7309 /* Enter the INSTANCE in a table to prevent recursion; a 7310 variable's initializer may refer to the variable 7311 itself. */ 7312 if (VAR_P (instance) 7313 && DECL_INITIAL (instance) 7314 && !type_dependent_expression_p_push (DECL_INITIAL (instance)) 7315 && !fixed_type_or_null_ref_ht->find (instance)) 7316 { 7317 tree type; 7318 tree_node **slot; 7319 7320 slot = fixed_type_or_null_ref_ht->find_slot (instance, INSERT); 7321 *slot = instance; 7322 type = RECUR (DECL_INITIAL (instance)); 7323 fixed_type_or_null_ref_ht->remove_elt (instance); 7324 7325 return type; 7326 } 7327 } 7328 return NULL_TREE; 7329 7330 default: 7331 return NULL_TREE; 7332 } 7333 #undef RECUR 7334 } 7335 7336 /* Return nonzero if the dynamic type of INSTANCE is known, and 7337 equivalent to the static type. We also handle the case where 7338 INSTANCE is really a pointer. Return negative if this is a 7339 ctor/dtor. There the dynamic type is known, but this might not be 7340 the most derived base of the original object, and hence virtual 7341 bases may not be laid out according to this type. 7342 7343 Used to determine whether the virtual function table is needed 7344 or not. 7345 7346 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless 7347 of our knowledge of its type. *NONNULL should be initialized 7348 before this function is called. */ 7349 7350 int 7351 resolves_to_fixed_type_p (tree instance, int* nonnull) 7352 { 7353 tree t = TREE_TYPE (instance); 7354 int cdtorp = 0; 7355 tree fixed; 7356 7357 /* processing_template_decl can be false in a template if we're in 7358 instantiate_non_dependent_expr, but we still want to suppress 7359 this check. */ 7360 if (in_template_function ()) 7361 { 7362 /* In a template we only care about the type of the result. */ 7363 if (nonnull) 7364 *nonnull = true; 7365 return true; 7366 } 7367 7368 fixed = fixed_type_or_null (instance, nonnull, &cdtorp); 7369 if (fixed == NULL_TREE) 7370 return 0; 7371 if (POINTER_TYPE_P (t)) 7372 t = TREE_TYPE (t); 7373 if (!same_type_ignoring_top_level_qualifiers_p (t, fixed)) 7374 return 0; 7375 return cdtorp ? -1 : 1; 7376 } 7377 7378 7379 void 7380 init_class_processing (void) 7381 { 7382 current_class_depth = 0; 7383 current_class_stack_size = 10; 7384 current_class_stack 7385 = XNEWVEC (struct class_stack_node, current_class_stack_size); 7386 vec_alloc (local_classes, 8); 7387 sizeof_biggest_empty_class = size_zero_node; 7388 7389 ridpointers[(int) RID_PUBLIC] = access_public_node; 7390 ridpointers[(int) RID_PRIVATE] = access_private_node; 7391 ridpointers[(int) RID_PROTECTED] = access_protected_node; 7392 } 7393 7394 /* Restore the cached PREVIOUS_CLASS_LEVEL. */ 7395 7396 static void 7397 restore_class_cache (void) 7398 { 7399 tree type; 7400 7401 /* We are re-entering the same class we just left, so we don't 7402 have to search the whole inheritance matrix to find all the 7403 decls to bind again. Instead, we install the cached 7404 class_shadowed list and walk through it binding names. */ 7405 push_binding_level (previous_class_level); 7406 class_binding_level = previous_class_level; 7407 /* Restore IDENTIFIER_TYPE_VALUE. */ 7408 for (type = class_binding_level->type_shadowed; 7409 type; 7410 type = TREE_CHAIN (type)) 7411 SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (type), TREE_TYPE (type)); 7412 } 7413 7414 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as 7415 appropriate for TYPE. 7416 7417 So that we may avoid calls to lookup_name, we cache the _TYPE 7418 nodes of local TYPE_DECLs in the TREE_TYPE field of the name. 7419 7420 For multiple inheritance, we perform a two-pass depth-first search 7421 of the type lattice. */ 7422 7423 void 7424 pushclass (tree type) 7425 { 7426 class_stack_node_t csn; 7427 7428 type = TYPE_MAIN_VARIANT (type); 7429 7430 /* Make sure there is enough room for the new entry on the stack. */ 7431 if (current_class_depth + 1 >= current_class_stack_size) 7432 { 7433 current_class_stack_size *= 2; 7434 current_class_stack 7435 = XRESIZEVEC (struct class_stack_node, current_class_stack, 7436 current_class_stack_size); 7437 } 7438 7439 /* Insert a new entry on the class stack. */ 7440 csn = current_class_stack + current_class_depth; 7441 csn->name = current_class_name; 7442 csn->type = current_class_type; 7443 csn->access = current_access_specifier; 7444 csn->names_used = 0; 7445 csn->hidden = 0; 7446 current_class_depth++; 7447 7448 /* Now set up the new type. */ 7449 current_class_name = TYPE_NAME (type); 7450 if (TREE_CODE (current_class_name) == TYPE_DECL) 7451 current_class_name = DECL_NAME (current_class_name); 7452 current_class_type = type; 7453 7454 /* By default, things in classes are private, while things in 7455 structures or unions are public. */ 7456 current_access_specifier = (CLASSTYPE_DECLARED_CLASS (type) 7457 ? access_private_node 7458 : access_public_node); 7459 7460 if (previous_class_level 7461 && type != previous_class_level->this_entity 7462 && current_class_depth == 1) 7463 { 7464 /* Forcibly remove any old class remnants. */ 7465 invalidate_class_lookup_cache (); 7466 } 7467 7468 if (!previous_class_level 7469 || type != previous_class_level->this_entity 7470 || current_class_depth > 1) 7471 pushlevel_class (); 7472 else 7473 restore_class_cache (); 7474 } 7475 7476 /* When we exit a toplevel class scope, we save its binding level so 7477 that we can restore it quickly. Here, we've entered some other 7478 class, so we must invalidate our cache. */ 7479 7480 void 7481 invalidate_class_lookup_cache (void) 7482 { 7483 previous_class_level = NULL; 7484 } 7485 7486 /* Get out of the current class scope. If we were in a class scope 7487 previously, that is the one popped to. */ 7488 7489 void 7490 popclass (void) 7491 { 7492 poplevel_class (); 7493 7494 current_class_depth--; 7495 current_class_name = current_class_stack[current_class_depth].name; 7496 current_class_type = current_class_stack[current_class_depth].type; 7497 current_access_specifier = current_class_stack[current_class_depth].access; 7498 if (current_class_stack[current_class_depth].names_used) 7499 splay_tree_delete (current_class_stack[current_class_depth].names_used); 7500 } 7501 7502 /* Mark the top of the class stack as hidden. */ 7503 7504 void 7505 push_class_stack (void) 7506 { 7507 if (current_class_depth) 7508 ++current_class_stack[current_class_depth - 1].hidden; 7509 } 7510 7511 /* Mark the top of the class stack as un-hidden. */ 7512 7513 void 7514 pop_class_stack (void) 7515 { 7516 if (current_class_depth) 7517 --current_class_stack[current_class_depth - 1].hidden; 7518 } 7519 7520 /* If the class type currently being defined is either T or 7521 a nested type of T, returns the type from the current_class_stack, 7522 which might be equivalent to but not equal to T in case of 7523 constrained partial specializations. */ 7524 7525 tree 7526 currently_open_class (tree t) 7527 { 7528 int i; 7529 7530 if (!CLASS_TYPE_P (t)) 7531 return NULL_TREE; 7532 7533 t = TYPE_MAIN_VARIANT (t); 7534 7535 /* We start looking from 1 because entry 0 is from global scope, 7536 and has no type. */ 7537 for (i = current_class_depth; i > 0; --i) 7538 { 7539 tree c; 7540 if (i == current_class_depth) 7541 c = current_class_type; 7542 else 7543 { 7544 if (current_class_stack[i].hidden) 7545 break; 7546 c = current_class_stack[i].type; 7547 } 7548 if (!c) 7549 continue; 7550 if (same_type_p (c, t)) 7551 return c; 7552 } 7553 return NULL_TREE; 7554 } 7555 7556 /* If either current_class_type or one of its enclosing classes are derived 7557 from T, return the appropriate type. Used to determine how we found 7558 something via unqualified lookup. */ 7559 7560 tree 7561 currently_open_derived_class (tree t) 7562 { 7563 int i; 7564 7565 /* The bases of a dependent type are unknown. */ 7566 if (dependent_type_p (t)) 7567 return NULL_TREE; 7568 7569 if (!current_class_type) 7570 return NULL_TREE; 7571 7572 if (DERIVED_FROM_P (t, current_class_type)) 7573 return current_class_type; 7574 7575 for (i = current_class_depth - 1; i > 0; --i) 7576 { 7577 if (current_class_stack[i].hidden) 7578 break; 7579 if (DERIVED_FROM_P (t, current_class_stack[i].type)) 7580 return current_class_stack[i].type; 7581 } 7582 7583 return NULL_TREE; 7584 } 7585 7586 /* Return the outermost enclosing class type that is still open, or 7587 NULL_TREE. */ 7588 7589 tree 7590 outermost_open_class (void) 7591 { 7592 if (!current_class_type) 7593 return NULL_TREE; 7594 tree r = NULL_TREE; 7595 if (TYPE_BEING_DEFINED (current_class_type)) 7596 r = current_class_type; 7597 for (int i = current_class_depth - 1; i > 0; --i) 7598 { 7599 if (current_class_stack[i].hidden) 7600 break; 7601 tree t = current_class_stack[i].type; 7602 if (!TYPE_BEING_DEFINED (t)) 7603 break; 7604 r = t; 7605 } 7606 return r; 7607 } 7608 7609 /* Returns the innermost class type which is not a lambda closure type. */ 7610 7611 tree 7612 current_nonlambda_class_type (void) 7613 { 7614 tree type = current_class_type; 7615 while (type && LAMBDA_TYPE_P (type)) 7616 type = decl_type_context (TYPE_NAME (type)); 7617 return type; 7618 } 7619 7620 /* When entering a class scope, all enclosing class scopes' names with 7621 static meaning (static variables, static functions, types and 7622 enumerators) have to be visible. This recursive function calls 7623 pushclass for all enclosing class contexts until global or a local 7624 scope is reached. TYPE is the enclosed class. */ 7625 7626 void 7627 push_nested_class (tree type) 7628 { 7629 /* A namespace might be passed in error cases, like A::B:C. */ 7630 if (type == NULL_TREE 7631 || !CLASS_TYPE_P (type)) 7632 return; 7633 7634 push_nested_class (DECL_CONTEXT (TYPE_MAIN_DECL (type))); 7635 7636 pushclass (type); 7637 } 7638 7639 /* Undoes a push_nested_class call. */ 7640 7641 void 7642 pop_nested_class (void) 7643 { 7644 tree context = DECL_CONTEXT (TYPE_MAIN_DECL (current_class_type)); 7645 7646 popclass (); 7647 if (context && CLASS_TYPE_P (context)) 7648 pop_nested_class (); 7649 } 7650 7651 /* Returns the number of extern "LANG" blocks we are nested within. */ 7652 7653 int 7654 current_lang_depth (void) 7655 { 7656 return vec_safe_length (current_lang_base); 7657 } 7658 7659 /* Set global variables CURRENT_LANG_NAME to appropriate value 7660 so that behavior of name-mangling machinery is correct. */ 7661 7662 void 7663 push_lang_context (tree name) 7664 { 7665 vec_safe_push (current_lang_base, current_lang_name); 7666 7667 if (name == lang_name_cplusplus) 7668 current_lang_name = name; 7669 else if (name == lang_name_c) 7670 current_lang_name = name; 7671 else 7672 error ("language string %<\"%E\"%> not recognized", name); 7673 } 7674 7675 /* Get out of the current language scope. */ 7676 7677 void 7678 pop_lang_context (void) 7679 { 7680 current_lang_name = current_lang_base->pop (); 7681 } 7682 7683 /* Type instantiation routines. */ 7684 7685 /* Given an OVERLOAD and a TARGET_TYPE, return the function that 7686 matches the TARGET_TYPE. If there is no satisfactory match, return 7687 error_mark_node, and issue an error & warning messages under 7688 control of FLAGS. Permit pointers to member function if FLAGS 7689 permits. If TEMPLATE_ONLY, the name of the overloaded function was 7690 a template-id, and EXPLICIT_TARGS are the explicitly provided 7691 template arguments. 7692 7693 If OVERLOAD is for one or more member functions, then ACCESS_PATH 7694 is the base path used to reference those member functions. If 7695 the address is resolved to a member function, access checks will be 7696 performed and errors issued if appropriate. */ 7697 7698 static tree 7699 resolve_address_of_overloaded_function (tree target_type, 7700 tree overload, 7701 tsubst_flags_t complain, 7702 bool template_only, 7703 tree explicit_targs, 7704 tree access_path) 7705 { 7706 /* Here's what the standard says: 7707 7708 [over.over] 7709 7710 If the name is a function template, template argument deduction 7711 is done, and if the argument deduction succeeds, the deduced 7712 arguments are used to generate a single template function, which 7713 is added to the set of overloaded functions considered. 7714 7715 Non-member functions and static member functions match targets of 7716 type "pointer-to-function" or "reference-to-function." Nonstatic 7717 member functions match targets of type "pointer-to-member 7718 function;" the function type of the pointer to member is used to 7719 select the member function from the set of overloaded member 7720 functions. If a nonstatic member function is selected, the 7721 reference to the overloaded function name is required to have the 7722 form of a pointer to member as described in 5.3.1. 7723 7724 If more than one function is selected, any template functions in 7725 the set are eliminated if the set also contains a non-template 7726 function, and any given template function is eliminated if the 7727 set contains a second template function that is more specialized 7728 than the first according to the partial ordering rules 14.5.5.2. 7729 After such eliminations, if any, there shall remain exactly one 7730 selected function. */ 7731 7732 int is_ptrmem = 0; 7733 /* We store the matches in a TREE_LIST rooted here. The functions 7734 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy 7735 interoperability with most_specialized_instantiation. */ 7736 tree matches = NULL_TREE; 7737 tree fn; 7738 tree target_fn_type; 7739 7740 /* By the time we get here, we should be seeing only real 7741 pointer-to-member types, not the internal POINTER_TYPE to 7742 METHOD_TYPE representation. */ 7743 gcc_assert (!TYPE_PTR_P (target_type) 7744 || TREE_CODE (TREE_TYPE (target_type)) != METHOD_TYPE); 7745 7746 gcc_assert (is_overloaded_fn (overload)); 7747 7748 /* Check that the TARGET_TYPE is reasonable. */ 7749 if (TYPE_PTRFN_P (target_type) 7750 || TYPE_REFFN_P (target_type)) 7751 /* This is OK. */; 7752 else if (TYPE_PTRMEMFUNC_P (target_type)) 7753 /* This is OK, too. */ 7754 is_ptrmem = 1; 7755 else if (TREE_CODE (target_type) == FUNCTION_TYPE) 7756 /* This is OK, too. This comes from a conversion to reference 7757 type. */ 7758 target_type = build_reference_type (target_type); 7759 else 7760 { 7761 if (complain & tf_error) 7762 error ("cannot resolve overloaded function %qD based on" 7763 " conversion to type %qT", 7764 OVL_NAME (overload), target_type); 7765 return error_mark_node; 7766 } 7767 7768 /* Non-member functions and static member functions match targets of type 7769 "pointer-to-function" or "reference-to-function." Nonstatic member 7770 functions match targets of type "pointer-to-member-function;" the 7771 function type of the pointer to member is used to select the member 7772 function from the set of overloaded member functions. 7773 7774 So figure out the FUNCTION_TYPE that we want to match against. */ 7775 target_fn_type = static_fn_type (target_type); 7776 7777 /* If we can find a non-template function that matches, we can just 7778 use it. There's no point in generating template instantiations 7779 if we're just going to throw them out anyhow. But, of course, we 7780 can only do this when we don't *need* a template function. */ 7781 if (!template_only) 7782 for (lkp_iterator iter (overload); iter; ++iter) 7783 { 7784 tree fn = *iter; 7785 7786 if (TREE_CODE (fn) == TEMPLATE_DECL) 7787 /* We're not looking for templates just yet. */ 7788 continue; 7789 7790 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) != is_ptrmem) 7791 /* We're looking for a non-static member, and this isn't 7792 one, or vice versa. */ 7793 continue; 7794 7795 /* In C++17 we need the noexcept-qualifier to compare types. */ 7796 if (flag_noexcept_type 7797 && !maybe_instantiate_noexcept (fn, complain)) 7798 continue; 7799 7800 /* See if there's a match. */ 7801 tree fntype = static_fn_type (fn); 7802 if (same_type_p (target_fn_type, fntype) 7803 || fnptr_conv_p (target_fn_type, fntype)) 7804 matches = tree_cons (fn, NULL_TREE, matches); 7805 } 7806 7807 /* Now, if we've already got a match (or matches), there's no need 7808 to proceed to the template functions. But, if we don't have a 7809 match we need to look at them, too. */ 7810 if (!matches) 7811 { 7812 tree target_arg_types; 7813 tree target_ret_type; 7814 tree *args; 7815 unsigned int nargs, ia; 7816 tree arg; 7817 7818 target_arg_types = TYPE_ARG_TYPES (target_fn_type); 7819 target_ret_type = TREE_TYPE (target_fn_type); 7820 7821 nargs = list_length (target_arg_types); 7822 args = XALLOCAVEC (tree, nargs); 7823 for (arg = target_arg_types, ia = 0; 7824 arg != NULL_TREE && arg != void_list_node; 7825 arg = TREE_CHAIN (arg), ++ia) 7826 args[ia] = TREE_VALUE (arg); 7827 nargs = ia; 7828 7829 for (lkp_iterator iter (overload); iter; ++iter) 7830 { 7831 tree fn = *iter; 7832 tree instantiation; 7833 tree targs; 7834 7835 if (TREE_CODE (fn) != TEMPLATE_DECL) 7836 /* We're only looking for templates. */ 7837 continue; 7838 7839 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) 7840 != is_ptrmem) 7841 /* We're not looking for a non-static member, and this is 7842 one, or vice versa. */ 7843 continue; 7844 7845 tree ret = target_ret_type; 7846 7847 /* If the template has a deduced return type, don't expose it to 7848 template argument deduction. */ 7849 if (undeduced_auto_decl (fn)) 7850 ret = NULL_TREE; 7851 7852 /* Try to do argument deduction. */ 7853 targs = make_tree_vec (DECL_NTPARMS (fn)); 7854 instantiation = fn_type_unification (fn, explicit_targs, targs, args, 7855 nargs, ret, 7856 DEDUCE_EXACT, LOOKUP_NORMAL, 7857 false, false); 7858 if (instantiation == error_mark_node) 7859 /* Instantiation failed. */ 7860 continue; 7861 7862 /* Constraints must be satisfied. This is done before 7863 return type deduction since that instantiates the 7864 function. */ 7865 if (flag_concepts && !constraints_satisfied_p (instantiation)) 7866 continue; 7867 7868 /* And now force instantiation to do return type deduction. */ 7869 if (undeduced_auto_decl (instantiation)) 7870 { 7871 ++function_depth; 7872 instantiate_decl (instantiation, /*defer*/false, /*class*/false); 7873 --function_depth; 7874 7875 require_deduced_type (instantiation); 7876 } 7877 7878 /* In C++17 we need the noexcept-qualifier to compare types. */ 7879 if (flag_noexcept_type) 7880 maybe_instantiate_noexcept (instantiation, complain); 7881 7882 /* See if there's a match. */ 7883 tree fntype = static_fn_type (instantiation); 7884 if (same_type_p (target_fn_type, fntype) 7885 || fnptr_conv_p (target_fn_type, fntype)) 7886 matches = tree_cons (instantiation, fn, matches); 7887 } 7888 7889 /* Now, remove all but the most specialized of the matches. */ 7890 if (matches) 7891 { 7892 tree match = most_specialized_instantiation (matches); 7893 7894 if (match != error_mark_node) 7895 matches = tree_cons (TREE_PURPOSE (match), 7896 NULL_TREE, 7897 NULL_TREE); 7898 } 7899 } 7900 7901 /* Now we should have exactly one function in MATCHES. */ 7902 if (matches == NULL_TREE) 7903 { 7904 /* There were *no* matches. */ 7905 if (complain & tf_error) 7906 { 7907 error ("no matches converting function %qD to type %q#T", 7908 OVL_NAME (overload), target_type); 7909 7910 print_candidates (overload); 7911 } 7912 return error_mark_node; 7913 } 7914 else if (TREE_CHAIN (matches)) 7915 { 7916 /* There were too many matches. First check if they're all 7917 the same function. */ 7918 tree match = NULL_TREE; 7919 7920 fn = TREE_PURPOSE (matches); 7921 7922 /* For multi-versioned functions, more than one match is just fine and 7923 decls_match will return false as they are different. */ 7924 for (match = TREE_CHAIN (matches); match; match = TREE_CHAIN (match)) 7925 if (!decls_match (fn, TREE_PURPOSE (match)) 7926 && !targetm.target_option.function_versions 7927 (fn, TREE_PURPOSE (match))) 7928 break; 7929 7930 if (match) 7931 { 7932 if (complain & tf_error) 7933 { 7934 error ("converting overloaded function %qD to type %q#T is ambiguous", 7935 OVL_NAME (overload), target_type); 7936 7937 /* Since print_candidates expects the functions in the 7938 TREE_VALUE slot, we flip them here. */ 7939 for (match = matches; match; match = TREE_CHAIN (match)) 7940 TREE_VALUE (match) = TREE_PURPOSE (match); 7941 7942 print_candidates (matches); 7943 } 7944 7945 return error_mark_node; 7946 } 7947 } 7948 7949 /* Good, exactly one match. Now, convert it to the correct type. */ 7950 fn = TREE_PURPOSE (matches); 7951 7952 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) 7953 && !(complain & tf_ptrmem_ok) && !flag_ms_extensions) 7954 { 7955 static int explained; 7956 7957 if (!(complain & tf_error)) 7958 return error_mark_node; 7959 7960 permerror (input_location, "assuming pointer to member %qD", fn); 7961 if (!explained) 7962 { 7963 inform (input_location, "(a pointer to member can only be formed with %<&%E%>)", fn); 7964 explained = 1; 7965 } 7966 } 7967 7968 /* If a pointer to a function that is multi-versioned is requested, the 7969 pointer to the dispatcher function is returned instead. This works 7970 well because indirectly calling the function will dispatch the right 7971 function version at run-time. */ 7972 if (DECL_FUNCTION_VERSIONED (fn)) 7973 { 7974 fn = get_function_version_dispatcher (fn); 7975 if (fn == NULL) 7976 return error_mark_node; 7977 /* Mark all the versions corresponding to the dispatcher as used. */ 7978 if (!(complain & tf_conv)) 7979 mark_versions_used (fn); 7980 } 7981 7982 /* If we're doing overload resolution purely for the purpose of 7983 determining conversion sequences, we should not consider the 7984 function used. If this conversion sequence is selected, the 7985 function will be marked as used at this point. */ 7986 if (!(complain & tf_conv)) 7987 { 7988 /* Make =delete work with SFINAE. */ 7989 if (DECL_DELETED_FN (fn) && !(complain & tf_error)) 7990 return error_mark_node; 7991 if (!mark_used (fn, complain) && !(complain & tf_error)) 7992 return error_mark_node; 7993 } 7994 7995 /* We could not check access to member functions when this 7996 expression was originally created since we did not know at that 7997 time to which function the expression referred. */ 7998 if (DECL_FUNCTION_MEMBER_P (fn)) 7999 { 8000 gcc_assert (access_path); 8001 perform_or_defer_access_check (access_path, fn, fn, complain); 8002 } 8003 8004 if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type)) 8005 return cp_build_addr_expr (fn, complain); 8006 else 8007 { 8008 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op 8009 will mark the function as addressed, but here we must do it 8010 explicitly. */ 8011 cxx_mark_addressable (fn); 8012 8013 return fn; 8014 } 8015 } 8016 8017 /* This function will instantiate the type of the expression given in 8018 RHS to match the type of LHSTYPE. If errors exist, then return 8019 error_mark_node. COMPLAIN is a bit mask. If TF_ERROR is set, then 8020 we complain on errors. If we are not complaining, never modify rhs, 8021 as overload resolution wants to try many possible instantiations, in 8022 the hope that at least one will work. 8023 8024 For non-recursive calls, LHSTYPE should be a function, pointer to 8025 function, or a pointer to member function. */ 8026 8027 tree 8028 instantiate_type (tree lhstype, tree rhs, tsubst_flags_t complain) 8029 { 8030 tsubst_flags_t complain_in = complain; 8031 tree access_path = NULL_TREE; 8032 8033 complain &= ~tf_ptrmem_ok; 8034 8035 if (lhstype == unknown_type_node) 8036 { 8037 if (complain & tf_error) 8038 error ("not enough type information"); 8039 return error_mark_node; 8040 } 8041 8042 if (TREE_TYPE (rhs) != NULL_TREE && ! (type_unknown_p (rhs))) 8043 { 8044 tree fntype = non_reference (lhstype); 8045 if (same_type_p (fntype, TREE_TYPE (rhs))) 8046 return rhs; 8047 if (fnptr_conv_p (fntype, TREE_TYPE (rhs))) 8048 return rhs; 8049 if (flag_ms_extensions 8050 && TYPE_PTRMEMFUNC_P (fntype) 8051 && !TYPE_PTRMEMFUNC_P (TREE_TYPE (rhs))) 8052 /* Microsoft allows `A::f' to be resolved to a 8053 pointer-to-member. */ 8054 ; 8055 else 8056 { 8057 if (complain & tf_error) 8058 error ("cannot convert %qE from type %qT to type %qT", 8059 rhs, TREE_TYPE (rhs), fntype); 8060 return error_mark_node; 8061 } 8062 } 8063 8064 /* If we instantiate a template, and it is a A ?: C expression 8065 with omitted B, look through the SAVE_EXPR. */ 8066 if (TREE_CODE (rhs) == SAVE_EXPR) 8067 rhs = TREE_OPERAND (rhs, 0); 8068 8069 if (BASELINK_P (rhs)) 8070 { 8071 access_path = BASELINK_ACCESS_BINFO (rhs); 8072 rhs = BASELINK_FUNCTIONS (rhs); 8073 } 8074 8075 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot 8076 deduce any type information. */ 8077 if (TREE_CODE (rhs) == NON_DEPENDENT_EXPR) 8078 { 8079 if (complain & tf_error) 8080 error ("not enough type information"); 8081 return error_mark_node; 8082 } 8083 8084 /* There are only a few kinds of expressions that may have a type 8085 dependent on overload resolution. */ 8086 gcc_assert (TREE_CODE (rhs) == ADDR_EXPR 8087 || TREE_CODE (rhs) == COMPONENT_REF 8088 || is_overloaded_fn (rhs) 8089 || (flag_ms_extensions && TREE_CODE (rhs) == FUNCTION_DECL)); 8090 8091 /* This should really only be used when attempting to distinguish 8092 what sort of a pointer to function we have. For now, any 8093 arithmetic operation which is not supported on pointers 8094 is rejected as an error. */ 8095 8096 switch (TREE_CODE (rhs)) 8097 { 8098 case COMPONENT_REF: 8099 { 8100 tree member = TREE_OPERAND (rhs, 1); 8101 8102 member = instantiate_type (lhstype, member, complain); 8103 if (member != error_mark_node 8104 && TREE_SIDE_EFFECTS (TREE_OPERAND (rhs, 0))) 8105 /* Do not lose object's side effects. */ 8106 return build2 (COMPOUND_EXPR, TREE_TYPE (member), 8107 TREE_OPERAND (rhs, 0), member); 8108 return member; 8109 } 8110 8111 case OFFSET_REF: 8112 rhs = TREE_OPERAND (rhs, 1); 8113 if (BASELINK_P (rhs)) 8114 return instantiate_type (lhstype, rhs, complain_in); 8115 8116 /* This can happen if we are forming a pointer-to-member for a 8117 member template. */ 8118 gcc_assert (TREE_CODE (rhs) == TEMPLATE_ID_EXPR); 8119 8120 /* Fall through. */ 8121 8122 case TEMPLATE_ID_EXPR: 8123 { 8124 tree fns = TREE_OPERAND (rhs, 0); 8125 tree args = TREE_OPERAND (rhs, 1); 8126 8127 return 8128 resolve_address_of_overloaded_function (lhstype, fns, complain_in, 8129 /*template_only=*/true, 8130 args, access_path); 8131 } 8132 8133 case OVERLOAD: 8134 case FUNCTION_DECL: 8135 return 8136 resolve_address_of_overloaded_function (lhstype, rhs, complain_in, 8137 /*template_only=*/false, 8138 /*explicit_targs=*/NULL_TREE, 8139 access_path); 8140 8141 case ADDR_EXPR: 8142 { 8143 if (PTRMEM_OK_P (rhs)) 8144 complain |= tf_ptrmem_ok; 8145 8146 return instantiate_type (lhstype, TREE_OPERAND (rhs, 0), complain); 8147 } 8148 8149 case ERROR_MARK: 8150 return error_mark_node; 8151 8152 default: 8153 gcc_unreachable (); 8154 } 8155 return error_mark_node; 8156 } 8157 8158 /* Return the name of the virtual function pointer field 8159 (as an IDENTIFIER_NODE) for the given TYPE. Note that 8160 this may have to look back through base types to find the 8161 ultimate field name. (For single inheritance, these could 8162 all be the same name. Who knows for multiple inheritance). */ 8163 8164 static tree 8165 get_vfield_name (tree type) 8166 { 8167 tree binfo, base_binfo; 8168 8169 for (binfo = TYPE_BINFO (type); 8170 BINFO_N_BASE_BINFOS (binfo); 8171 binfo = base_binfo) 8172 { 8173 base_binfo = BINFO_BASE_BINFO (binfo, 0); 8174 8175 if (BINFO_VIRTUAL_P (base_binfo) 8176 || !TYPE_CONTAINS_VPTR_P (BINFO_TYPE (base_binfo))) 8177 break; 8178 } 8179 8180 type = BINFO_TYPE (binfo); 8181 tree ctor_name = constructor_name (type); 8182 char *buf = (char *) alloca (sizeof (VFIELD_NAME_FORMAT) 8183 + IDENTIFIER_LENGTH (ctor_name) + 2); 8184 sprintf (buf, VFIELD_NAME_FORMAT, IDENTIFIER_POINTER (ctor_name)); 8185 return get_identifier (buf); 8186 } 8187 8188 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works, 8189 according to [class]: 8190 The class-name is also inserted 8191 into the scope of the class itself. For purposes of access checking, 8192 the inserted class name is treated as if it were a public member name. */ 8193 8194 void 8195 build_self_reference (void) 8196 { 8197 tree name = DECL_NAME (TYPE_NAME (current_class_type)); 8198 tree value = build_lang_decl (TYPE_DECL, name, current_class_type); 8199 8200 DECL_NONLOCAL (value) = 1; 8201 DECL_CONTEXT (value) = current_class_type; 8202 DECL_ARTIFICIAL (value) = 1; 8203 SET_DECL_SELF_REFERENCE_P (value); 8204 set_underlying_type (value); 8205 8206 if (processing_template_decl) 8207 value = push_template_decl (value); 8208 8209 tree saved_cas = current_access_specifier; 8210 current_access_specifier = access_public_node; 8211 finish_member_declaration (value); 8212 current_access_specifier = saved_cas; 8213 } 8214 8215 /* Returns 1 if TYPE contains only padding bytes. */ 8216 8217 int 8218 is_empty_class (tree type) 8219 { 8220 if (type == error_mark_node) 8221 return 0; 8222 8223 if (! CLASS_TYPE_P (type)) 8224 return 0; 8225 8226 return CLASSTYPE_EMPTY_P (type); 8227 } 8228 8229 /* Returns true if TYPE contains no actual data, just various 8230 possible combinations of empty classes and possibly a vptr. */ 8231 8232 bool 8233 is_really_empty_class (tree type) 8234 { 8235 if (CLASS_TYPE_P (type)) 8236 { 8237 tree field; 8238 tree binfo; 8239 tree base_binfo; 8240 int i; 8241 8242 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid 8243 out, but we'd like to be able to check this before then. */ 8244 if (COMPLETE_TYPE_P (type) && is_empty_class (type)) 8245 return true; 8246 8247 for (binfo = TYPE_BINFO (type), i = 0; 8248 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 8249 if (!is_really_empty_class (BINFO_TYPE (base_binfo))) 8250 return false; 8251 for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) 8252 if (TREE_CODE (field) == FIELD_DECL 8253 && !DECL_ARTIFICIAL (field) 8254 /* An unnamed bit-field is not a data member. */ 8255 && !DECL_UNNAMED_BIT_FIELD (field) 8256 && !is_really_empty_class (TREE_TYPE (field))) 8257 return false; 8258 return true; 8259 } 8260 else if (TREE_CODE (type) == ARRAY_TYPE) 8261 return (integer_zerop (array_type_nelts_top (type)) 8262 || is_really_empty_class (TREE_TYPE (type))); 8263 return false; 8264 } 8265 8266 /* Note that NAME was looked up while the current class was being 8267 defined and that the result of that lookup was DECL. */ 8268 8269 void 8270 maybe_note_name_used_in_class (tree name, tree decl) 8271 { 8272 splay_tree names_used; 8273 8274 /* If we're not defining a class, there's nothing to do. */ 8275 if (!(innermost_scope_kind() == sk_class 8276 && TYPE_BEING_DEFINED (current_class_type) 8277 && !LAMBDA_TYPE_P (current_class_type))) 8278 return; 8279 8280 /* If there's already a binding for this NAME, then we don't have 8281 anything to worry about. */ 8282 if (lookup_member (current_class_type, name, 8283 /*protect=*/0, /*want_type=*/false, tf_warning_or_error)) 8284 return; 8285 8286 if (!current_class_stack[current_class_depth - 1].names_used) 8287 current_class_stack[current_class_depth - 1].names_used 8288 = splay_tree_new (splay_tree_compare_pointers, 0, 0); 8289 names_used = current_class_stack[current_class_depth - 1].names_used; 8290 8291 splay_tree_insert (names_used, 8292 (splay_tree_key) name, 8293 (splay_tree_value) decl); 8294 } 8295 8296 /* Note that NAME was declared (as DECL) in the current class. Check 8297 to see that the declaration is valid. */ 8298 8299 void 8300 note_name_declared_in_class (tree name, tree decl) 8301 { 8302 splay_tree names_used; 8303 splay_tree_node n; 8304 8305 /* Look to see if we ever used this name. */ 8306 names_used 8307 = current_class_stack[current_class_depth - 1].names_used; 8308 if (!names_used) 8309 return; 8310 /* The C language allows members to be declared with a type of the same 8311 name, and the C++ standard says this diagnostic is not required. So 8312 allow it in extern "C" blocks unless predantic is specified. 8313 Allow it in all cases if -ms-extensions is specified. */ 8314 if ((!pedantic && current_lang_name == lang_name_c) 8315 || flag_ms_extensions) 8316 return; 8317 n = splay_tree_lookup (names_used, (splay_tree_key) name); 8318 if (n) 8319 { 8320 /* [basic.scope.class] 8321 8322 A name N used in a class S shall refer to the same declaration 8323 in its context and when re-evaluated in the completed scope of 8324 S. */ 8325 permerror (input_location, "declaration of %q#D", decl); 8326 permerror (location_of ((tree) n->value), 8327 "changes meaning of %qD from %q#D", 8328 OVL_NAME (decl), (tree) n->value); 8329 } 8330 } 8331 8332 /* Returns the VAR_DECL for the complete vtable associated with BINFO. 8333 Secondary vtables are merged with primary vtables; this function 8334 will return the VAR_DECL for the primary vtable. */ 8335 8336 tree 8337 get_vtbl_decl_for_binfo (tree binfo) 8338 { 8339 tree decl; 8340 8341 decl = BINFO_VTABLE (binfo); 8342 if (decl && TREE_CODE (decl) == POINTER_PLUS_EXPR) 8343 { 8344 gcc_assert (TREE_CODE (TREE_OPERAND (decl, 0)) == ADDR_EXPR); 8345 decl = TREE_OPERAND (TREE_OPERAND (decl, 0), 0); 8346 } 8347 if (decl) 8348 gcc_assert (VAR_P (decl)); 8349 return decl; 8350 } 8351 8352 8353 /* Returns the binfo for the primary base of BINFO. If the resulting 8354 BINFO is a virtual base, and it is inherited elsewhere in the 8355 hierarchy, then the returned binfo might not be the primary base of 8356 BINFO in the complete object. Check BINFO_PRIMARY_P or 8357 BINFO_LOST_PRIMARY_P to be sure. */ 8358 8359 static tree 8360 get_primary_binfo (tree binfo) 8361 { 8362 tree primary_base; 8363 8364 primary_base = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (binfo)); 8365 if (!primary_base) 8366 return NULL_TREE; 8367 8368 return copied_binfo (primary_base, binfo); 8369 } 8370 8371 /* As above, but iterate until we reach the binfo that actually provides the 8372 vptr for BINFO. */ 8373 8374 static tree 8375 most_primary_binfo (tree binfo) 8376 { 8377 tree b = binfo; 8378 while (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (b)) 8379 && !BINFO_LOST_PRIMARY_P (b)) 8380 { 8381 tree primary_base = get_primary_binfo (b); 8382 gcc_assert (BINFO_PRIMARY_P (primary_base) 8383 && BINFO_INHERITANCE_CHAIN (primary_base) == b); 8384 b = primary_base; 8385 } 8386 return b; 8387 } 8388 8389 /* Returns true if BINFO gets its vptr from a virtual base of the most derived 8390 type. Note that the virtual inheritance might be above or below BINFO in 8391 the hierarchy. */ 8392 8393 bool 8394 vptr_via_virtual_p (tree binfo) 8395 { 8396 if (TYPE_P (binfo)) 8397 binfo = TYPE_BINFO (binfo); 8398 tree primary = most_primary_binfo (binfo); 8399 /* Don't limit binfo_via_virtual, we want to return true when BINFO itself is 8400 a morally virtual base. */ 8401 tree virt = binfo_via_virtual (primary, NULL_TREE); 8402 return virt != NULL_TREE; 8403 } 8404 8405 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */ 8406 8407 static int 8408 maybe_indent_hierarchy (FILE * stream, int indent, int indented_p) 8409 { 8410 if (!indented_p) 8411 fprintf (stream, "%*s", indent, ""); 8412 return 1; 8413 } 8414 8415 /* Dump the offsets of all the bases rooted at BINFO to STREAM. 8416 INDENT should be zero when called from the top level; it is 8417 incremented recursively. IGO indicates the next expected BINFO in 8418 inheritance graph ordering. */ 8419 8420 static tree 8421 dump_class_hierarchy_r (FILE *stream, 8422 dump_flags_t flags, 8423 tree binfo, 8424 tree igo, 8425 int indent) 8426 { 8427 int indented = 0; 8428 tree base_binfo; 8429 int i; 8430 8431 indented = maybe_indent_hierarchy (stream, indent, 0); 8432 fprintf (stream, "%s (0x" HOST_WIDE_INT_PRINT_HEX ") ", 8433 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER), 8434 (HOST_WIDE_INT) (uintptr_t) binfo); 8435 if (binfo != igo) 8436 { 8437 fprintf (stream, "alternative-path\n"); 8438 return igo; 8439 } 8440 igo = TREE_CHAIN (binfo); 8441 8442 fprintf (stream, HOST_WIDE_INT_PRINT_DEC, 8443 tree_to_shwi (BINFO_OFFSET (binfo))); 8444 if (is_empty_class (BINFO_TYPE (binfo))) 8445 fprintf (stream, " empty"); 8446 else if (CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (binfo))) 8447 fprintf (stream, " nearly-empty"); 8448 if (BINFO_VIRTUAL_P (binfo)) 8449 fprintf (stream, " virtual"); 8450 fprintf (stream, "\n"); 8451 8452 indented = 0; 8453 if (BINFO_PRIMARY_P (binfo)) 8454 { 8455 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8456 fprintf (stream, " primary-for %s (0x" HOST_WIDE_INT_PRINT_HEX ")", 8457 type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)), 8458 TFF_PLAIN_IDENTIFIER), 8459 (HOST_WIDE_INT) (uintptr_t) BINFO_INHERITANCE_CHAIN (binfo)); 8460 } 8461 if (BINFO_LOST_PRIMARY_P (binfo)) 8462 { 8463 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8464 fprintf (stream, " lost-primary"); 8465 } 8466 if (indented) 8467 fprintf (stream, "\n"); 8468 8469 if (!(flags & TDF_SLIM)) 8470 { 8471 int indented = 0; 8472 8473 if (BINFO_SUBVTT_INDEX (binfo)) 8474 { 8475 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8476 fprintf (stream, " subvttidx=%s", 8477 expr_as_string (BINFO_SUBVTT_INDEX (binfo), 8478 TFF_PLAIN_IDENTIFIER)); 8479 } 8480 if (BINFO_VPTR_INDEX (binfo)) 8481 { 8482 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8483 fprintf (stream, " vptridx=%s", 8484 expr_as_string (BINFO_VPTR_INDEX (binfo), 8485 TFF_PLAIN_IDENTIFIER)); 8486 } 8487 if (BINFO_VPTR_FIELD (binfo)) 8488 { 8489 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8490 fprintf (stream, " vbaseoffset=%s", 8491 expr_as_string (BINFO_VPTR_FIELD (binfo), 8492 TFF_PLAIN_IDENTIFIER)); 8493 } 8494 if (BINFO_VTABLE (binfo)) 8495 { 8496 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8497 fprintf (stream, " vptr=%s", 8498 expr_as_string (BINFO_VTABLE (binfo), 8499 TFF_PLAIN_IDENTIFIER)); 8500 } 8501 8502 if (indented) 8503 fprintf (stream, "\n"); 8504 } 8505 8506 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 8507 igo = dump_class_hierarchy_r (stream, flags, base_binfo, igo, indent + 2); 8508 8509 return igo; 8510 } 8511 8512 /* Dump the BINFO hierarchy for T. */ 8513 8514 static void 8515 dump_class_hierarchy_1 (FILE *stream, dump_flags_t flags, tree t) 8516 { 8517 fprintf (stream, "Class %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER)); 8518 fprintf (stream, " size=%lu align=%lu\n", 8519 (unsigned long)(tree_to_shwi (TYPE_SIZE (t)) / BITS_PER_UNIT), 8520 (unsigned long)(TYPE_ALIGN (t) / BITS_PER_UNIT)); 8521 fprintf (stream, " base size=%lu base align=%lu\n", 8522 (unsigned long)(tree_to_shwi (TYPE_SIZE (CLASSTYPE_AS_BASE (t))) 8523 / BITS_PER_UNIT), 8524 (unsigned long)(TYPE_ALIGN (CLASSTYPE_AS_BASE (t)) 8525 / BITS_PER_UNIT)); 8526 dump_class_hierarchy_r (stream, flags, TYPE_BINFO (t), TYPE_BINFO (t), 0); 8527 fprintf (stream, "\n"); 8528 } 8529 8530 /* Debug interface to hierarchy dumping. */ 8531 8532 void 8533 debug_class (tree t) 8534 { 8535 dump_class_hierarchy_1 (stderr, TDF_SLIM, t); 8536 } 8537 8538 static void 8539 dump_class_hierarchy (tree t) 8540 { 8541 dump_flags_t flags; 8542 if (FILE *stream = dump_begin (class_dump_id, &flags)) 8543 { 8544 dump_class_hierarchy_1 (stream, flags, t); 8545 dump_end (class_dump_id, stream); 8546 } 8547 } 8548 8549 static void 8550 dump_array (FILE * stream, tree decl) 8551 { 8552 tree value; 8553 unsigned HOST_WIDE_INT ix; 8554 HOST_WIDE_INT elt; 8555 tree size = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (decl))); 8556 8557 elt = (tree_to_shwi (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl)))) 8558 / BITS_PER_UNIT); 8559 fprintf (stream, "%s:", decl_as_string (decl, TFF_PLAIN_IDENTIFIER)); 8560 fprintf (stream, " %s entries", 8561 expr_as_string (size_binop (PLUS_EXPR, size, size_one_node), 8562 TFF_PLAIN_IDENTIFIER)); 8563 fprintf (stream, "\n"); 8564 8565 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (DECL_INITIAL (decl)), 8566 ix, value) 8567 fprintf (stream, "%-4ld %s\n", (long)(ix * elt), 8568 expr_as_string (value, TFF_PLAIN_IDENTIFIER)); 8569 } 8570 8571 static void 8572 dump_vtable (tree t, tree binfo, tree vtable) 8573 { 8574 dump_flags_t flags; 8575 FILE *stream = dump_begin (class_dump_id, &flags); 8576 8577 if (!stream) 8578 return; 8579 8580 if (!(flags & TDF_SLIM)) 8581 { 8582 int ctor_vtbl_p = TYPE_BINFO (t) != binfo; 8583 8584 fprintf (stream, "%s for %s", 8585 ctor_vtbl_p ? "Construction vtable" : "Vtable", 8586 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER)); 8587 if (ctor_vtbl_p) 8588 { 8589 if (!BINFO_VIRTUAL_P (binfo)) 8590 fprintf (stream, " (0x" HOST_WIDE_INT_PRINT_HEX " instance)", 8591 (HOST_WIDE_INT) (uintptr_t) binfo); 8592 fprintf (stream, " in %s", type_as_string (t, TFF_PLAIN_IDENTIFIER)); 8593 } 8594 fprintf (stream, "\n"); 8595 dump_array (stream, vtable); 8596 fprintf (stream, "\n"); 8597 } 8598 8599 dump_end (class_dump_id, stream); 8600 } 8601 8602 static void 8603 dump_vtt (tree t, tree vtt) 8604 { 8605 dump_flags_t flags; 8606 FILE *stream = dump_begin (class_dump_id, &flags); 8607 8608 if (!stream) 8609 return; 8610 8611 if (!(flags & TDF_SLIM)) 8612 { 8613 fprintf (stream, "VTT for %s\n", 8614 type_as_string (t, TFF_PLAIN_IDENTIFIER)); 8615 dump_array (stream, vtt); 8616 fprintf (stream, "\n"); 8617 } 8618 8619 dump_end (class_dump_id, stream); 8620 } 8621 8622 /* Dump a function or thunk and its thunkees. */ 8623 8624 static void 8625 dump_thunk (FILE *stream, int indent, tree thunk) 8626 { 8627 static const char spaces[] = " "; 8628 tree name = DECL_NAME (thunk); 8629 tree thunks; 8630 8631 fprintf (stream, "%.*s%p %s %s", indent, spaces, 8632 (void *)thunk, 8633 !DECL_THUNK_P (thunk) ? "function" 8634 : DECL_THIS_THUNK_P (thunk) ? "this-thunk" : "covariant-thunk", 8635 name ? IDENTIFIER_POINTER (name) : "<unset>"); 8636 if (DECL_THUNK_P (thunk)) 8637 { 8638 HOST_WIDE_INT fixed_adjust = THUNK_FIXED_OFFSET (thunk); 8639 tree virtual_adjust = THUNK_VIRTUAL_OFFSET (thunk); 8640 8641 fprintf (stream, " fixed=" HOST_WIDE_INT_PRINT_DEC, fixed_adjust); 8642 if (!virtual_adjust) 8643 /*NOP*/; 8644 else if (DECL_THIS_THUNK_P (thunk)) 8645 fprintf (stream, " vcall=" HOST_WIDE_INT_PRINT_DEC, 8646 tree_to_shwi (virtual_adjust)); 8647 else 8648 fprintf (stream, " vbase=" HOST_WIDE_INT_PRINT_DEC "(%s)", 8649 tree_to_shwi (BINFO_VPTR_FIELD (virtual_adjust)), 8650 type_as_string (BINFO_TYPE (virtual_adjust), TFF_SCOPE)); 8651 if (THUNK_ALIAS (thunk)) 8652 fprintf (stream, " alias to %p", (void *)THUNK_ALIAS (thunk)); 8653 } 8654 fprintf (stream, "\n"); 8655 for (thunks = DECL_THUNKS (thunk); thunks; thunks = TREE_CHAIN (thunks)) 8656 dump_thunk (stream, indent + 2, thunks); 8657 } 8658 8659 /* Dump the thunks for FN. */ 8660 8661 void 8662 debug_thunks (tree fn) 8663 { 8664 dump_thunk (stderr, 0, fn); 8665 } 8666 8667 /* Virtual function table initialization. */ 8668 8669 /* Create all the necessary vtables for T and its base classes. */ 8670 8671 static void 8672 finish_vtbls (tree t) 8673 { 8674 tree vbase; 8675 vec<constructor_elt, va_gc> *v = NULL; 8676 tree vtable = BINFO_VTABLE (TYPE_BINFO (t)); 8677 8678 /* We lay out the primary and secondary vtables in one contiguous 8679 vtable. The primary vtable is first, followed by the non-virtual 8680 secondary vtables in inheritance graph order. */ 8681 accumulate_vtbl_inits (TYPE_BINFO (t), TYPE_BINFO (t), TYPE_BINFO (t), 8682 vtable, t, &v); 8683 8684 /* Then come the virtual bases, also in inheritance graph order. */ 8685 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase)) 8686 { 8687 if (!BINFO_VIRTUAL_P (vbase)) 8688 continue; 8689 accumulate_vtbl_inits (vbase, vbase, TYPE_BINFO (t), vtable, t, &v); 8690 } 8691 8692 if (BINFO_VTABLE (TYPE_BINFO (t))) 8693 initialize_vtable (TYPE_BINFO (t), v); 8694 } 8695 8696 /* Initialize the vtable for BINFO with the INITS. */ 8697 8698 static void 8699 initialize_vtable (tree binfo, vec<constructor_elt, va_gc> *inits) 8700 { 8701 tree decl; 8702 8703 layout_vtable_decl (binfo, vec_safe_length (inits)); 8704 decl = get_vtbl_decl_for_binfo (binfo); 8705 initialize_artificial_var (decl, inits); 8706 dump_vtable (BINFO_TYPE (binfo), binfo, decl); 8707 } 8708 8709 /* Build the VTT (virtual table table) for T. 8710 A class requires a VTT if it has virtual bases. 8711 8712 This holds 8713 1 - primary virtual pointer for complete object T 8714 2 - secondary VTTs for each direct non-virtual base of T which requires a 8715 VTT 8716 3 - secondary virtual pointers for each direct or indirect base of T which 8717 has virtual bases or is reachable via a virtual path from T. 8718 4 - secondary VTTs for each direct or indirect virtual base of T. 8719 8720 Secondary VTTs look like complete object VTTs without part 4. */ 8721 8722 static void 8723 build_vtt (tree t) 8724 { 8725 tree type; 8726 tree vtt; 8727 tree index; 8728 vec<constructor_elt, va_gc> *inits; 8729 8730 /* Build up the initializers for the VTT. */ 8731 inits = NULL; 8732 index = size_zero_node; 8733 build_vtt_inits (TYPE_BINFO (t), t, &inits, &index); 8734 8735 /* If we didn't need a VTT, we're done. */ 8736 if (!inits) 8737 return; 8738 8739 /* Figure out the type of the VTT. */ 8740 type = build_array_of_n_type (const_ptr_type_node, 8741 inits->length ()); 8742 8743 /* Now, build the VTT object itself. */ 8744 vtt = build_vtable (t, mangle_vtt_for_type (t), type); 8745 initialize_artificial_var (vtt, inits); 8746 /* Add the VTT to the vtables list. */ 8747 DECL_CHAIN (vtt) = DECL_CHAIN (CLASSTYPE_VTABLES (t)); 8748 DECL_CHAIN (CLASSTYPE_VTABLES (t)) = vtt; 8749 8750 dump_vtt (t, vtt); 8751 } 8752 8753 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with 8754 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo, 8755 and CHAIN the vtable pointer for this binfo after construction is 8756 complete. VALUE can also be another BINFO, in which case we recurse. */ 8757 8758 static tree 8759 binfo_ctor_vtable (tree binfo) 8760 { 8761 tree vt; 8762 8763 while (1) 8764 { 8765 vt = BINFO_VTABLE (binfo); 8766 if (TREE_CODE (vt) == TREE_LIST) 8767 vt = TREE_VALUE (vt); 8768 if (TREE_CODE (vt) == TREE_BINFO) 8769 binfo = vt; 8770 else 8771 break; 8772 } 8773 8774 return vt; 8775 } 8776 8777 /* Data for secondary VTT initialization. */ 8778 struct secondary_vptr_vtt_init_data 8779 { 8780 /* Is this the primary VTT? */ 8781 bool top_level_p; 8782 8783 /* Current index into the VTT. */ 8784 tree index; 8785 8786 /* Vector of initializers built up. */ 8787 vec<constructor_elt, va_gc> *inits; 8788 8789 /* The type being constructed by this secondary VTT. */ 8790 tree type_being_constructed; 8791 }; 8792 8793 /* Recursively build the VTT-initializer for BINFO (which is in the 8794 hierarchy dominated by T). INITS points to the end of the initializer 8795 list to date. INDEX is the VTT index where the next element will be 8796 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e. 8797 not a subvtt for some base of T). When that is so, we emit the sub-VTTs 8798 for virtual bases of T. When it is not so, we build the constructor 8799 vtables for the BINFO-in-T variant. */ 8800 8801 static void 8802 build_vtt_inits (tree binfo, tree t, vec<constructor_elt, va_gc> **inits, 8803 tree *index) 8804 { 8805 int i; 8806 tree b; 8807 tree init; 8808 secondary_vptr_vtt_init_data data; 8809 int top_level_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t); 8810 8811 /* We only need VTTs for subobjects with virtual bases. */ 8812 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))) 8813 return; 8814 8815 /* We need to use a construction vtable if this is not the primary 8816 VTT. */ 8817 if (!top_level_p) 8818 { 8819 build_ctor_vtbl_group (binfo, t); 8820 8821 /* Record the offset in the VTT where this sub-VTT can be found. */ 8822 BINFO_SUBVTT_INDEX (binfo) = *index; 8823 } 8824 8825 /* Add the address of the primary vtable for the complete object. */ 8826 init = binfo_ctor_vtable (binfo); 8827 CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, init); 8828 if (top_level_p) 8829 { 8830 gcc_assert (!BINFO_VPTR_INDEX (binfo)); 8831 BINFO_VPTR_INDEX (binfo) = *index; 8832 } 8833 *index = size_binop (PLUS_EXPR, *index, TYPE_SIZE_UNIT (ptr_type_node)); 8834 8835 /* Recursively add the secondary VTTs for non-virtual bases. */ 8836 for (i = 0; BINFO_BASE_ITERATE (binfo, i, b); ++i) 8837 if (!BINFO_VIRTUAL_P (b)) 8838 build_vtt_inits (b, t, inits, index); 8839 8840 /* Add secondary virtual pointers for all subobjects of BINFO with 8841 either virtual bases or reachable along a virtual path, except 8842 subobjects that are non-virtual primary bases. */ 8843 data.top_level_p = top_level_p; 8844 data.index = *index; 8845 data.inits = *inits; 8846 data.type_being_constructed = BINFO_TYPE (binfo); 8847 8848 dfs_walk_once (binfo, dfs_build_secondary_vptr_vtt_inits, NULL, &data); 8849 8850 *index = data.index; 8851 8852 /* data.inits might have grown as we added secondary virtual pointers. 8853 Make sure our caller knows about the new vector. */ 8854 *inits = data.inits; 8855 8856 if (top_level_p) 8857 /* Add the secondary VTTs for virtual bases in inheritance graph 8858 order. */ 8859 for (b = TYPE_BINFO (BINFO_TYPE (binfo)); b; b = TREE_CHAIN (b)) 8860 { 8861 if (!BINFO_VIRTUAL_P (b)) 8862 continue; 8863 8864 build_vtt_inits (b, t, inits, index); 8865 } 8866 else 8867 /* Remove the ctor vtables we created. */ 8868 dfs_walk_all (binfo, dfs_fixup_binfo_vtbls, NULL, binfo); 8869 } 8870 8871 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base 8872 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */ 8873 8874 static tree 8875 dfs_build_secondary_vptr_vtt_inits (tree binfo, void *data_) 8876 { 8877 secondary_vptr_vtt_init_data *data = (secondary_vptr_vtt_init_data *)data_; 8878 8879 /* We don't care about bases that don't have vtables. */ 8880 if (!TYPE_VFIELD (BINFO_TYPE (binfo))) 8881 return dfs_skip_bases; 8882 8883 /* We're only interested in proper subobjects of the type being 8884 constructed. */ 8885 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->type_being_constructed)) 8886 return NULL_TREE; 8887 8888 /* We're only interested in bases with virtual bases or reachable 8889 via a virtual path from the type being constructed. */ 8890 if (!(CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)) 8891 || binfo_via_virtual (binfo, data->type_being_constructed))) 8892 return dfs_skip_bases; 8893 8894 /* We're not interested in non-virtual primary bases. */ 8895 if (!BINFO_VIRTUAL_P (binfo) && BINFO_PRIMARY_P (binfo)) 8896 return NULL_TREE; 8897 8898 /* Record the index where this secondary vptr can be found. */ 8899 if (data->top_level_p) 8900 { 8901 gcc_assert (!BINFO_VPTR_INDEX (binfo)); 8902 BINFO_VPTR_INDEX (binfo) = data->index; 8903 8904 if (BINFO_VIRTUAL_P (binfo)) 8905 { 8906 /* It's a primary virtual base, and this is not a 8907 construction vtable. Find the base this is primary of in 8908 the inheritance graph, and use that base's vtable 8909 now. */ 8910 while (BINFO_PRIMARY_P (binfo)) 8911 binfo = BINFO_INHERITANCE_CHAIN (binfo); 8912 } 8913 } 8914 8915 /* Add the initializer for the secondary vptr itself. */ 8916 CONSTRUCTOR_APPEND_ELT (data->inits, NULL_TREE, binfo_ctor_vtable (binfo)); 8917 8918 /* Advance the vtt index. */ 8919 data->index = size_binop (PLUS_EXPR, data->index, 8920 TYPE_SIZE_UNIT (ptr_type_node)); 8921 8922 return NULL_TREE; 8923 } 8924 8925 /* Called from build_vtt_inits via dfs_walk. After building 8926 constructor vtables and generating the sub-vtt from them, we need 8927 to restore the BINFO_VTABLES that were scribbled on. DATA is the 8928 binfo of the base whose sub vtt was generated. */ 8929 8930 static tree 8931 dfs_fixup_binfo_vtbls (tree binfo, void* data) 8932 { 8933 tree vtable = BINFO_VTABLE (binfo); 8934 8935 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) 8936 /* If this class has no vtable, none of its bases do. */ 8937 return dfs_skip_bases; 8938 8939 if (!vtable) 8940 /* This might be a primary base, so have no vtable in this 8941 hierarchy. */ 8942 return NULL_TREE; 8943 8944 /* If we scribbled the construction vtable vptr into BINFO, clear it 8945 out now. */ 8946 if (TREE_CODE (vtable) == TREE_LIST 8947 && (TREE_PURPOSE (vtable) == (tree) data)) 8948 BINFO_VTABLE (binfo) = TREE_CHAIN (vtable); 8949 8950 return NULL_TREE; 8951 } 8952 8953 /* Build the construction vtable group for BINFO which is in the 8954 hierarchy dominated by T. */ 8955 8956 static void 8957 build_ctor_vtbl_group (tree binfo, tree t) 8958 { 8959 tree type; 8960 tree vtbl; 8961 tree id; 8962 tree vbase; 8963 vec<constructor_elt, va_gc> *v; 8964 8965 /* See if we've already created this construction vtable group. */ 8966 id = mangle_ctor_vtbl_for_type (t, binfo); 8967 if (get_global_binding (id)) 8968 return; 8969 8970 gcc_assert (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t)); 8971 /* Build a version of VTBL (with the wrong type) for use in 8972 constructing the addresses of secondary vtables in the 8973 construction vtable group. */ 8974 vtbl = build_vtable (t, id, ptr_type_node); 8975 DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1; 8976 /* Don't export construction vtables from shared libraries. Even on 8977 targets that don't support hidden visibility, this tells 8978 can_refer_decl_in_current_unit_p not to assume that it's safe to 8979 access from a different compilation unit (bz 54314). */ 8980 DECL_VISIBILITY (vtbl) = VISIBILITY_HIDDEN; 8981 DECL_VISIBILITY_SPECIFIED (vtbl) = true; 8982 8983 v = NULL; 8984 accumulate_vtbl_inits (binfo, TYPE_BINFO (TREE_TYPE (binfo)), 8985 binfo, vtbl, t, &v); 8986 8987 /* Add the vtables for each of our virtual bases using the vbase in T 8988 binfo. */ 8989 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo)); 8990 vbase; 8991 vbase = TREE_CHAIN (vbase)) 8992 { 8993 tree b; 8994 8995 if (!BINFO_VIRTUAL_P (vbase)) 8996 continue; 8997 b = copied_binfo (vbase, binfo); 8998 8999 accumulate_vtbl_inits (b, vbase, binfo, vtbl, t, &v); 9000 } 9001 9002 /* Figure out the type of the construction vtable. */ 9003 type = build_array_of_n_type (vtable_entry_type, v->length ()); 9004 layout_type (type); 9005 TREE_TYPE (vtbl) = type; 9006 DECL_SIZE (vtbl) = DECL_SIZE_UNIT (vtbl) = NULL_TREE; 9007 layout_decl (vtbl, 0); 9008 9009 /* Initialize the construction vtable. */ 9010 CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl); 9011 initialize_artificial_var (vtbl, v); 9012 dump_vtable (t, binfo, vtbl); 9013 } 9014 9015 /* Add the vtbl initializers for BINFO (and its bases other than 9016 non-virtual primaries) to the list of INITS. BINFO is in the 9017 hierarchy dominated by T. RTTI_BINFO is the binfo within T of 9018 the constructor the vtbl inits should be accumulated for. (If this 9019 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).) 9020 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO). 9021 BINFO is the active base equivalent of ORIG_BINFO in the inheritance 9022 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE, 9023 but are not necessarily the same in terms of layout. */ 9024 9025 static void 9026 accumulate_vtbl_inits (tree binfo, 9027 tree orig_binfo, 9028 tree rtti_binfo, 9029 tree vtbl, 9030 tree t, 9031 vec<constructor_elt, va_gc> **inits) 9032 { 9033 int i; 9034 tree base_binfo; 9035 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); 9036 9037 gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (orig_binfo))); 9038 9039 /* If it doesn't have a vptr, we don't do anything. */ 9040 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) 9041 return; 9042 9043 /* If we're building a construction vtable, we're not interested in 9044 subobjects that don't require construction vtables. */ 9045 if (ctor_vtbl_p 9046 && !CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)) 9047 && !binfo_via_virtual (orig_binfo, BINFO_TYPE (rtti_binfo))) 9048 return; 9049 9050 /* Build the initializers for the BINFO-in-T vtable. */ 9051 dfs_accumulate_vtbl_inits (binfo, orig_binfo, rtti_binfo, vtbl, t, inits); 9052 9053 /* Walk the BINFO and its bases. We walk in preorder so that as we 9054 initialize each vtable we can figure out at what offset the 9055 secondary vtable lies from the primary vtable. We can't use 9056 dfs_walk here because we need to iterate through bases of BINFO 9057 and RTTI_BINFO simultaneously. */ 9058 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 9059 { 9060 /* Skip virtual bases. */ 9061 if (BINFO_VIRTUAL_P (base_binfo)) 9062 continue; 9063 accumulate_vtbl_inits (base_binfo, 9064 BINFO_BASE_BINFO (orig_binfo, i), 9065 rtti_binfo, vtbl, t, 9066 inits); 9067 } 9068 } 9069 9070 /* Called from accumulate_vtbl_inits. Adds the initializers for the 9071 BINFO vtable to L. */ 9072 9073 static void 9074 dfs_accumulate_vtbl_inits (tree binfo, 9075 tree orig_binfo, 9076 tree rtti_binfo, 9077 tree orig_vtbl, 9078 tree t, 9079 vec<constructor_elt, va_gc> **l) 9080 { 9081 tree vtbl = NULL_TREE; 9082 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); 9083 int n_inits; 9084 9085 if (ctor_vtbl_p 9086 && BINFO_VIRTUAL_P (orig_binfo) && BINFO_PRIMARY_P (orig_binfo)) 9087 { 9088 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a 9089 primary virtual base. If it is not the same primary in 9090 the hierarchy of T, we'll need to generate a ctor vtable 9091 for it, to place at its location in T. If it is the same 9092 primary, we still need a VTT entry for the vtable, but it 9093 should point to the ctor vtable for the base it is a 9094 primary for within the sub-hierarchy of RTTI_BINFO. 9095 9096 There are three possible cases: 9097 9098 1) We are in the same place. 9099 2) We are a primary base within a lost primary virtual base of 9100 RTTI_BINFO. 9101 3) We are primary to something not a base of RTTI_BINFO. */ 9102 9103 tree b; 9104 tree last = NULL_TREE; 9105 9106 /* First, look through the bases we are primary to for RTTI_BINFO 9107 or a virtual base. */ 9108 b = binfo; 9109 while (BINFO_PRIMARY_P (b)) 9110 { 9111 b = BINFO_INHERITANCE_CHAIN (b); 9112 last = b; 9113 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo) 9114 goto found; 9115 } 9116 /* If we run out of primary links, keep looking down our 9117 inheritance chain; we might be an indirect primary. */ 9118 for (b = last; b; b = BINFO_INHERITANCE_CHAIN (b)) 9119 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo) 9120 break; 9121 found: 9122 9123 /* If we found RTTI_BINFO, this is case 1. If we found a virtual 9124 base B and it is a base of RTTI_BINFO, this is case 2. In 9125 either case, we share our vtable with LAST, i.e. the 9126 derived-most base within B of which we are a primary. */ 9127 if (b == rtti_binfo 9128 || (b && binfo_for_vbase (BINFO_TYPE (b), BINFO_TYPE (rtti_binfo)))) 9129 /* Just set our BINFO_VTABLE to point to LAST, as we may not have 9130 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in 9131 binfo_ctor_vtable after everything's been set up. */ 9132 vtbl = last; 9133 9134 /* Otherwise, this is case 3 and we get our own. */ 9135 } 9136 else if (!BINFO_NEW_VTABLE_MARKED (orig_binfo)) 9137 return; 9138 9139 n_inits = vec_safe_length (*l); 9140 9141 if (!vtbl) 9142 { 9143 tree index; 9144 int non_fn_entries; 9145 9146 /* Add the initializer for this vtable. */ 9147 build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo, 9148 &non_fn_entries, l); 9149 9150 /* Figure out the position to which the VPTR should point. */ 9151 vtbl = build1 (ADDR_EXPR, vtbl_ptr_type_node, orig_vtbl); 9152 index = size_binop (MULT_EXPR, 9153 TYPE_SIZE_UNIT (vtable_entry_type), 9154 size_int (non_fn_entries + n_inits)); 9155 vtbl = fold_build_pointer_plus (vtbl, index); 9156 } 9157 9158 if (ctor_vtbl_p) 9159 /* For a construction vtable, we can't overwrite BINFO_VTABLE. 9160 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will 9161 straighten this out. */ 9162 BINFO_VTABLE (binfo) = tree_cons (rtti_binfo, vtbl, BINFO_VTABLE (binfo)); 9163 else if (BINFO_PRIMARY_P (binfo) && BINFO_VIRTUAL_P (binfo)) 9164 /* Throw away any unneeded intializers. */ 9165 (*l)->truncate (n_inits); 9166 else 9167 /* For an ordinary vtable, set BINFO_VTABLE. */ 9168 BINFO_VTABLE (binfo) = vtbl; 9169 } 9170 9171 static GTY(()) tree abort_fndecl_addr; 9172 static GTY(()) tree dvirt_fn; 9173 9174 /* Construct the initializer for BINFO's virtual function table. BINFO 9175 is part of the hierarchy dominated by T. If we're building a 9176 construction vtable, the ORIG_BINFO is the binfo we should use to 9177 find the actual function pointers to put in the vtable - but they 9178 can be overridden on the path to most-derived in the graph that 9179 ORIG_BINFO belongs. Otherwise, 9180 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the 9181 BINFO that should be indicated by the RTTI information in the 9182 vtable; it will be a base class of T, rather than T itself, if we 9183 are building a construction vtable. 9184 9185 The value returned is a TREE_LIST suitable for wrapping in a 9186 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If 9187 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the 9188 number of non-function entries in the vtable. 9189 9190 It might seem that this function should never be called with a 9191 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a 9192 base is always subsumed by a derived class vtable. However, when 9193 we are building construction vtables, we do build vtables for 9194 primary bases; we need these while the primary base is being 9195 constructed. */ 9196 9197 static void 9198 build_vtbl_initializer (tree binfo, 9199 tree orig_binfo, 9200 tree t, 9201 tree rtti_binfo, 9202 int* non_fn_entries_p, 9203 vec<constructor_elt, va_gc> **inits) 9204 { 9205 tree v; 9206 vtbl_init_data vid; 9207 unsigned ix, jx; 9208 tree vbinfo; 9209 vec<tree, va_gc> *vbases; 9210 constructor_elt *e; 9211 9212 /* Initialize VID. */ 9213 memset (&vid, 0, sizeof (vid)); 9214 vid.binfo = binfo; 9215 vid.derived = t; 9216 vid.rtti_binfo = rtti_binfo; 9217 vid.primary_vtbl_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t); 9218 vid.ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); 9219 vid.generate_vcall_entries = true; 9220 /* The first vbase or vcall offset is at index -3 in the vtable. */ 9221 vid.index = ssize_int(-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE); 9222 9223 /* Add entries to the vtable for RTTI. */ 9224 build_rtti_vtbl_entries (binfo, &vid); 9225 9226 /* Create an array for keeping track of the functions we've 9227 processed. When we see multiple functions with the same 9228 signature, we share the vcall offsets. */ 9229 vec_alloc (vid.fns, 32); 9230 /* Add the vcall and vbase offset entries. */ 9231 build_vcall_and_vbase_vtbl_entries (binfo, &vid); 9232 9233 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by 9234 build_vbase_offset_vtbl_entries. */ 9235 for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0; 9236 vec_safe_iterate (vbases, ix, &vbinfo); ix++) 9237 BINFO_VTABLE_PATH_MARKED (vbinfo) = 0; 9238 9239 /* If the target requires padding between data entries, add that now. */ 9240 if (TARGET_VTABLE_DATA_ENTRY_DISTANCE > 1) 9241 { 9242 int n_entries = vec_safe_length (vid.inits); 9243 9244 vec_safe_grow (vid.inits, TARGET_VTABLE_DATA_ENTRY_DISTANCE * n_entries); 9245 9246 /* Move data entries into their new positions and add padding 9247 after the new positions. Iterate backwards so we don't 9248 overwrite entries that we would need to process later. */ 9249 for (ix = n_entries - 1; 9250 vid.inits->iterate (ix, &e); 9251 ix--) 9252 { 9253 int j; 9254 int new_position = (TARGET_VTABLE_DATA_ENTRY_DISTANCE * ix 9255 + (TARGET_VTABLE_DATA_ENTRY_DISTANCE - 1)); 9256 9257 (*vid.inits)[new_position] = *e; 9258 9259 for (j = 1; j < TARGET_VTABLE_DATA_ENTRY_DISTANCE; ++j) 9260 { 9261 constructor_elt *f = &(*vid.inits)[new_position - j]; 9262 f->index = NULL_TREE; 9263 f->value = build1 (NOP_EXPR, vtable_entry_type, 9264 null_pointer_node); 9265 } 9266 } 9267 } 9268 9269 if (non_fn_entries_p) 9270 *non_fn_entries_p = vec_safe_length (vid.inits); 9271 9272 /* The initializers for virtual functions were built up in reverse 9273 order. Straighten them out and add them to the running list in one 9274 step. */ 9275 jx = vec_safe_length (*inits); 9276 vec_safe_grow (*inits, jx + vid.inits->length ()); 9277 9278 for (ix = vid.inits->length () - 1; 9279 vid.inits->iterate (ix, &e); 9280 ix--, jx++) 9281 (**inits)[jx] = *e; 9282 9283 /* Go through all the ordinary virtual functions, building up 9284 initializers. */ 9285 for (v = BINFO_VIRTUALS (orig_binfo); v; v = TREE_CHAIN (v)) 9286 { 9287 tree delta; 9288 tree vcall_index; 9289 tree fn, fn_original; 9290 tree init = NULL_TREE; 9291 9292 fn = BV_FN (v); 9293 fn_original = fn; 9294 if (DECL_THUNK_P (fn)) 9295 { 9296 if (!DECL_NAME (fn)) 9297 finish_thunk (fn); 9298 if (THUNK_ALIAS (fn)) 9299 { 9300 fn = THUNK_ALIAS (fn); 9301 BV_FN (v) = fn; 9302 } 9303 fn_original = THUNK_TARGET (fn); 9304 } 9305 9306 /* If the only definition of this function signature along our 9307 primary base chain is from a lost primary, this vtable slot will 9308 never be used, so just zero it out. This is important to avoid 9309 requiring extra thunks which cannot be generated with the function. 9310 9311 We first check this in update_vtable_entry_for_fn, so we handle 9312 restored primary bases properly; we also need to do it here so we 9313 zero out unused slots in ctor vtables, rather than filling them 9314 with erroneous values (though harmless, apart from relocation 9315 costs). */ 9316 if (BV_LOST_PRIMARY (v)) 9317 init = size_zero_node; 9318 9319 if (! init) 9320 { 9321 /* Pull the offset for `this', and the function to call, out of 9322 the list. */ 9323 delta = BV_DELTA (v); 9324 vcall_index = BV_VCALL_INDEX (v); 9325 9326 gcc_assert (TREE_CODE (delta) == INTEGER_CST); 9327 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); 9328 9329 /* You can't call an abstract virtual function; it's abstract. 9330 So, we replace these functions with __pure_virtual. */ 9331 if (DECL_PURE_VIRTUAL_P (fn_original)) 9332 { 9333 fn = abort_fndecl; 9334 if (!TARGET_VTABLE_USES_DESCRIPTORS) 9335 { 9336 if (abort_fndecl_addr == NULL) 9337 abort_fndecl_addr 9338 = fold_convert (vfunc_ptr_type_node, 9339 build_fold_addr_expr (fn)); 9340 init = abort_fndecl_addr; 9341 } 9342 } 9343 /* Likewise for deleted virtuals. */ 9344 else if (DECL_DELETED_FN (fn_original)) 9345 { 9346 if (!dvirt_fn) 9347 { 9348 tree name = get_identifier ("__cxa_deleted_virtual"); 9349 dvirt_fn = get_global_binding (name); 9350 if (!dvirt_fn) 9351 dvirt_fn = push_library_fn 9352 (name, 9353 build_function_type_list (void_type_node, NULL_TREE), 9354 NULL_TREE, ECF_NORETURN | ECF_COLD); 9355 } 9356 fn = dvirt_fn; 9357 if (!TARGET_VTABLE_USES_DESCRIPTORS) 9358 init = fold_convert (vfunc_ptr_type_node, 9359 build_fold_addr_expr (fn)); 9360 } 9361 else 9362 { 9363 if (!integer_zerop (delta) || vcall_index) 9364 { 9365 fn = make_thunk (fn, /*this_adjusting=*/1, 9366 delta, vcall_index); 9367 if (!DECL_NAME (fn)) 9368 finish_thunk (fn); 9369 } 9370 /* Take the address of the function, considering it to be of an 9371 appropriate generic type. */ 9372 if (!TARGET_VTABLE_USES_DESCRIPTORS) 9373 init = fold_convert (vfunc_ptr_type_node, 9374 build_fold_addr_expr (fn)); 9375 /* Don't refer to a virtual destructor from a constructor 9376 vtable or a vtable for an abstract class, since destroying 9377 an object under construction is undefined behavior and we 9378 don't want it to be considered a candidate for speculative 9379 devirtualization. But do create the thunk for ABI 9380 compliance. */ 9381 if (DECL_DESTRUCTOR_P (fn_original) 9382 && (CLASSTYPE_PURE_VIRTUALS (DECL_CONTEXT (fn_original)) 9383 || orig_binfo != binfo)) 9384 init = size_zero_node; 9385 } 9386 } 9387 9388 /* And add it to the chain of initializers. */ 9389 if (TARGET_VTABLE_USES_DESCRIPTORS) 9390 { 9391 int i; 9392 if (init == size_zero_node) 9393 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i) 9394 CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, init); 9395 else 9396 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i) 9397 { 9398 tree fdesc = build2 (FDESC_EXPR, vfunc_ptr_type_node, 9399 fn, build_int_cst (NULL_TREE, i)); 9400 TREE_CONSTANT (fdesc) = 1; 9401 9402 CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, fdesc); 9403 } 9404 } 9405 else 9406 CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, init); 9407 } 9408 } 9409 9410 /* Adds to vid->inits the initializers for the vbase and vcall 9411 offsets in BINFO, which is in the hierarchy dominated by T. */ 9412 9413 static void 9414 build_vcall_and_vbase_vtbl_entries (tree binfo, vtbl_init_data* vid) 9415 { 9416 tree b; 9417 9418 /* If this is a derived class, we must first create entries 9419 corresponding to the primary base class. */ 9420 b = get_primary_binfo (binfo); 9421 if (b) 9422 build_vcall_and_vbase_vtbl_entries (b, vid); 9423 9424 /* Add the vbase entries for this base. */ 9425 build_vbase_offset_vtbl_entries (binfo, vid); 9426 /* Add the vcall entries for this base. */ 9427 build_vcall_offset_vtbl_entries (binfo, vid); 9428 } 9429 9430 /* Returns the initializers for the vbase offset entries in the vtable 9431 for BINFO (which is part of the class hierarchy dominated by T), in 9432 reverse order. VBASE_OFFSET_INDEX gives the vtable index 9433 where the next vbase offset will go. */ 9434 9435 static void 9436 build_vbase_offset_vtbl_entries (tree binfo, vtbl_init_data* vid) 9437 { 9438 tree vbase; 9439 tree t; 9440 tree non_primary_binfo; 9441 9442 /* If there are no virtual baseclasses, then there is nothing to 9443 do. */ 9444 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))) 9445 return; 9446 9447 t = vid->derived; 9448 9449 /* We might be a primary base class. Go up the inheritance hierarchy 9450 until we find the most derived class of which we are a primary base: 9451 it is the offset of that which we need to use. */ 9452 non_primary_binfo = binfo; 9453 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo)) 9454 { 9455 tree b; 9456 9457 /* If we have reached a virtual base, then it must be a primary 9458 base (possibly multi-level) of vid->binfo, or we wouldn't 9459 have called build_vcall_and_vbase_vtbl_entries for it. But it 9460 might be a lost primary, so just skip down to vid->binfo. */ 9461 if (BINFO_VIRTUAL_P (non_primary_binfo)) 9462 { 9463 non_primary_binfo = vid->binfo; 9464 break; 9465 } 9466 9467 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo); 9468 if (get_primary_binfo (b) != non_primary_binfo) 9469 break; 9470 non_primary_binfo = b; 9471 } 9472 9473 /* Go through the virtual bases, adding the offsets. */ 9474 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo)); 9475 vbase; 9476 vbase = TREE_CHAIN (vbase)) 9477 { 9478 tree b; 9479 tree delta; 9480 9481 if (!BINFO_VIRTUAL_P (vbase)) 9482 continue; 9483 9484 /* Find the instance of this virtual base in the complete 9485 object. */ 9486 b = copied_binfo (vbase, binfo); 9487 9488 /* If we've already got an offset for this virtual base, we 9489 don't need another one. */ 9490 if (BINFO_VTABLE_PATH_MARKED (b)) 9491 continue; 9492 BINFO_VTABLE_PATH_MARKED (b) = 1; 9493 9494 /* Figure out where we can find this vbase offset. */ 9495 delta = size_binop (MULT_EXPR, 9496 vid->index, 9497 fold_convert (ssizetype, 9498 TYPE_SIZE_UNIT (vtable_entry_type))); 9499 if (vid->primary_vtbl_p) 9500 BINFO_VPTR_FIELD (b) = delta; 9501 9502 if (binfo != TYPE_BINFO (t)) 9503 /* The vbase offset had better be the same. */ 9504 gcc_assert (tree_int_cst_equal (delta, BINFO_VPTR_FIELD (vbase))); 9505 9506 /* The next vbase will come at a more negative offset. */ 9507 vid->index = size_binop (MINUS_EXPR, vid->index, 9508 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE)); 9509 9510 /* The initializer is the delta from BINFO to this virtual base. 9511 The vbase offsets go in reverse inheritance-graph order, and 9512 we are walking in inheritance graph order so these end up in 9513 the right order. */ 9514 delta = size_diffop_loc (input_location, 9515 BINFO_OFFSET (b), BINFO_OFFSET (non_primary_binfo)); 9516 9517 CONSTRUCTOR_APPEND_ELT (vid->inits, NULL_TREE, 9518 fold_build1_loc (input_location, NOP_EXPR, 9519 vtable_entry_type, delta)); 9520 } 9521 } 9522 9523 /* Adds the initializers for the vcall offset entries in the vtable 9524 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED) 9525 to VID->INITS. */ 9526 9527 static void 9528 build_vcall_offset_vtbl_entries (tree binfo, vtbl_init_data* vid) 9529 { 9530 /* We only need these entries if this base is a virtual base. We 9531 compute the indices -- but do not add to the vtable -- when 9532 building the main vtable for a class. */ 9533 if (binfo == TYPE_BINFO (vid->derived) 9534 || (BINFO_VIRTUAL_P (binfo) 9535 /* If BINFO is RTTI_BINFO, then (since BINFO does not 9536 correspond to VID->DERIVED), we are building a primary 9537 construction virtual table. Since this is a primary 9538 virtual table, we do not need the vcall offsets for 9539 BINFO. */ 9540 && binfo != vid->rtti_binfo)) 9541 { 9542 /* We need a vcall offset for each of the virtual functions in this 9543 vtable. For example: 9544 9545 class A { virtual void f (); }; 9546 class B1 : virtual public A { virtual void f (); }; 9547 class B2 : virtual public A { virtual void f (); }; 9548 class C: public B1, public B2 { virtual void f (); }; 9549 9550 A C object has a primary base of B1, which has a primary base of A. A 9551 C also has a secondary base of B2, which no longer has a primary base 9552 of A. So the B2-in-C construction vtable needs a secondary vtable for 9553 A, which will adjust the A* to a B2* to call f. We have no way of 9554 knowing what (or even whether) this offset will be when we define B2, 9555 so we store this "vcall offset" in the A sub-vtable and look it up in 9556 a "virtual thunk" for B2::f. 9557 9558 We need entries for all the functions in our primary vtable and 9559 in our non-virtual bases' secondary vtables. */ 9560 vid->vbase = binfo; 9561 /* If we are just computing the vcall indices -- but do not need 9562 the actual entries -- not that. */ 9563 if (!BINFO_VIRTUAL_P (binfo)) 9564 vid->generate_vcall_entries = false; 9565 /* Now, walk through the non-virtual bases, adding vcall offsets. */ 9566 add_vcall_offset_vtbl_entries_r (binfo, vid); 9567 } 9568 } 9569 9570 /* Build vcall offsets, starting with those for BINFO. */ 9571 9572 static void 9573 add_vcall_offset_vtbl_entries_r (tree binfo, vtbl_init_data* vid) 9574 { 9575 int i; 9576 tree primary_binfo; 9577 tree base_binfo; 9578 9579 /* Don't walk into virtual bases -- except, of course, for the 9580 virtual base for which we are building vcall offsets. Any 9581 primary virtual base will have already had its offsets generated 9582 through the recursion in build_vcall_and_vbase_vtbl_entries. */ 9583 if (BINFO_VIRTUAL_P (binfo) && vid->vbase != binfo) 9584 return; 9585 9586 /* If BINFO has a primary base, process it first. */ 9587 primary_binfo = get_primary_binfo (binfo); 9588 if (primary_binfo) 9589 add_vcall_offset_vtbl_entries_r (primary_binfo, vid); 9590 9591 /* Add BINFO itself to the list. */ 9592 add_vcall_offset_vtbl_entries_1 (binfo, vid); 9593 9594 /* Scan the non-primary bases of BINFO. */ 9595 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 9596 if (base_binfo != primary_binfo) 9597 add_vcall_offset_vtbl_entries_r (base_binfo, vid); 9598 } 9599 9600 /* Called from build_vcall_offset_vtbl_entries_r. */ 9601 9602 static void 9603 add_vcall_offset_vtbl_entries_1 (tree binfo, vtbl_init_data* vid) 9604 { 9605 /* Make entries for the rest of the virtuals. */ 9606 tree orig_fn; 9607 9608 /* The ABI requires that the methods be processed in declaration 9609 order. */ 9610 for (orig_fn = TYPE_FIELDS (BINFO_TYPE (binfo)); 9611 orig_fn; 9612 orig_fn = DECL_CHAIN (orig_fn)) 9613 if (TREE_CODE (orig_fn) == FUNCTION_DECL && DECL_VINDEX (orig_fn)) 9614 add_vcall_offset (orig_fn, binfo, vid); 9615 } 9616 9617 /* Add a vcall offset entry for ORIG_FN to the vtable. */ 9618 9619 static void 9620 add_vcall_offset (tree orig_fn, tree binfo, vtbl_init_data *vid) 9621 { 9622 size_t i; 9623 tree vcall_offset; 9624 tree derived_entry; 9625 9626 /* If there is already an entry for a function with the same 9627 signature as FN, then we do not need a second vcall offset. 9628 Check the list of functions already present in the derived 9629 class vtable. */ 9630 FOR_EACH_VEC_SAFE_ELT (vid->fns, i, derived_entry) 9631 { 9632 if (same_signature_p (derived_entry, orig_fn) 9633 /* We only use one vcall offset for virtual destructors, 9634 even though there are two virtual table entries. */ 9635 || (DECL_DESTRUCTOR_P (derived_entry) 9636 && DECL_DESTRUCTOR_P (orig_fn))) 9637 return; 9638 } 9639 9640 /* If we are building these vcall offsets as part of building 9641 the vtable for the most derived class, remember the vcall 9642 offset. */ 9643 if (vid->binfo == TYPE_BINFO (vid->derived)) 9644 { 9645 tree_pair_s elt = {orig_fn, vid->index}; 9646 vec_safe_push (CLASSTYPE_VCALL_INDICES (vid->derived), elt); 9647 } 9648 9649 /* The next vcall offset will be found at a more negative 9650 offset. */ 9651 vid->index = size_binop (MINUS_EXPR, vid->index, 9652 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE)); 9653 9654 /* Keep track of this function. */ 9655 vec_safe_push (vid->fns, orig_fn); 9656 9657 if (vid->generate_vcall_entries) 9658 { 9659 tree base; 9660 tree fn; 9661 9662 /* Find the overriding function. */ 9663 fn = find_final_overrider (vid->rtti_binfo, binfo, orig_fn); 9664 if (fn == error_mark_node) 9665 vcall_offset = build_zero_cst (vtable_entry_type); 9666 else 9667 { 9668 base = TREE_VALUE (fn); 9669 9670 /* The vbase we're working on is a primary base of 9671 vid->binfo. But it might be a lost primary, so its 9672 BINFO_OFFSET might be wrong, so we just use the 9673 BINFO_OFFSET from vid->binfo. */ 9674 vcall_offset = size_diffop_loc (input_location, 9675 BINFO_OFFSET (base), 9676 BINFO_OFFSET (vid->binfo)); 9677 vcall_offset = fold_build1_loc (input_location, 9678 NOP_EXPR, vtable_entry_type, 9679 vcall_offset); 9680 } 9681 /* Add the initializer to the vtable. */ 9682 CONSTRUCTOR_APPEND_ELT (vid->inits, NULL_TREE, vcall_offset); 9683 } 9684 } 9685 9686 /* Return vtbl initializers for the RTTI entries corresponding to the 9687 BINFO's vtable. The RTTI entries should indicate the object given 9688 by VID->rtti_binfo. */ 9689 9690 static void 9691 build_rtti_vtbl_entries (tree binfo, vtbl_init_data* vid) 9692 { 9693 tree b; 9694 tree t; 9695 tree offset; 9696 tree decl; 9697 tree init; 9698 9699 t = BINFO_TYPE (vid->rtti_binfo); 9700 9701 /* To find the complete object, we will first convert to our most 9702 primary base, and then add the offset in the vtbl to that value. */ 9703 b = most_primary_binfo (binfo); 9704 offset = size_diffop_loc (input_location, 9705 BINFO_OFFSET (vid->rtti_binfo), BINFO_OFFSET (b)); 9706 9707 /* The second entry is the address of the typeinfo object. */ 9708 if (flag_rtti) 9709 decl = build_address (get_tinfo_decl (t)); 9710 else 9711 decl = integer_zero_node; 9712 9713 /* Convert the declaration to a type that can be stored in the 9714 vtable. */ 9715 init = build_nop (vfunc_ptr_type_node, decl); 9716 CONSTRUCTOR_APPEND_ELT (vid->inits, NULL_TREE, init); 9717 9718 /* Add the offset-to-top entry. It comes earlier in the vtable than 9719 the typeinfo entry. Convert the offset to look like a 9720 function pointer, so that we can put it in the vtable. */ 9721 init = build_nop (vfunc_ptr_type_node, offset); 9722 CONSTRUCTOR_APPEND_ELT (vid->inits, NULL_TREE, init); 9723 } 9724 9725 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores 9726 accessibility. */ 9727 9728 bool 9729 uniquely_derived_from_p (tree parent, tree type) 9730 { 9731 tree base = lookup_base (type, parent, ba_unique, NULL, tf_none); 9732 return base && base != error_mark_node; 9733 } 9734 9735 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */ 9736 9737 bool 9738 publicly_uniquely_derived_p (tree parent, tree type) 9739 { 9740 tree base = lookup_base (type, parent, ba_ignore_scope | ba_check, 9741 NULL, tf_none); 9742 return base && base != error_mark_node; 9743 } 9744 9745 /* CTX1 and CTX2 are declaration contexts. Return the innermost common 9746 class between them, if any. */ 9747 9748 tree 9749 common_enclosing_class (tree ctx1, tree ctx2) 9750 { 9751 if (!TYPE_P (ctx1) || !TYPE_P (ctx2)) 9752 return NULL_TREE; 9753 gcc_assert (ctx1 == TYPE_MAIN_VARIANT (ctx1) 9754 && ctx2 == TYPE_MAIN_VARIANT (ctx2)); 9755 if (ctx1 == ctx2) 9756 return ctx1; 9757 for (tree t = ctx1; TYPE_P (t); t = TYPE_CONTEXT (t)) 9758 TYPE_MARKED_P (t) = true; 9759 tree found = NULL_TREE; 9760 for (tree t = ctx2; TYPE_P (t); t = TYPE_CONTEXT (t)) 9761 if (TYPE_MARKED_P (t)) 9762 { 9763 found = t; 9764 break; 9765 } 9766 for (tree t = ctx1; TYPE_P (t); t = TYPE_CONTEXT (t)) 9767 TYPE_MARKED_P (t) = false; 9768 return found; 9769 } 9770 9771 #include "gt-cp-class.h" 9772