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 /* FIELD is a bit-field. We are finishing the processing for its 3199 enclosing type. Issue any appropriate messages and set appropriate 3200 flags. Returns false if an error has been diagnosed. */ 3201 3202 static bool 3203 check_bitfield_decl (tree field) 3204 { 3205 tree type = TREE_TYPE (field); 3206 tree w; 3207 3208 /* Extract the declared width of the bitfield, which has been 3209 temporarily stashed in DECL_BIT_FIELD_REPRESENTATIVE by grokbitfield. */ 3210 w = DECL_BIT_FIELD_REPRESENTATIVE (field); 3211 gcc_assert (w != NULL_TREE); 3212 /* Remove the bit-field width indicator so that the rest of the 3213 compiler does not treat that value as a qualifier. */ 3214 DECL_BIT_FIELD_REPRESENTATIVE (field) = NULL_TREE; 3215 3216 /* Detect invalid bit-field type. */ 3217 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (type)) 3218 { 3219 error ("bit-field %q+#D with non-integral type", field); 3220 w = error_mark_node; 3221 } 3222 else 3223 { 3224 location_t loc = input_location; 3225 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */ 3226 STRIP_NOPS (w); 3227 3228 /* detect invalid field size. */ 3229 input_location = DECL_SOURCE_LOCATION (field); 3230 w = cxx_constant_value (w); 3231 input_location = loc; 3232 3233 if (TREE_CODE (w) != INTEGER_CST) 3234 { 3235 error ("bit-field %q+D width not an integer constant", field); 3236 w = error_mark_node; 3237 } 3238 else if (tree_int_cst_sgn (w) < 0) 3239 { 3240 error ("negative width in bit-field %q+D", field); 3241 w = error_mark_node; 3242 } 3243 else if (integer_zerop (w) && DECL_NAME (field) != 0) 3244 { 3245 error ("zero width for bit-field %q+D", field); 3246 w = error_mark_node; 3247 } 3248 else if ((TREE_CODE (type) != ENUMERAL_TYPE 3249 && TREE_CODE (type) != BOOLEAN_TYPE 3250 && compare_tree_int (w, TYPE_PRECISION (type)) > 0) 3251 || ((TREE_CODE (type) == ENUMERAL_TYPE 3252 || TREE_CODE (type) == BOOLEAN_TYPE) 3253 && tree_int_cst_lt (TYPE_SIZE (type), w))) 3254 warning_at (DECL_SOURCE_LOCATION (field), 0, 3255 "width of %qD exceeds its type", field); 3256 else if (TREE_CODE (type) == ENUMERAL_TYPE) 3257 { 3258 int prec = TYPE_PRECISION (ENUM_UNDERLYING_TYPE (type)); 3259 if (compare_tree_int (w, prec) < 0) 3260 warning_at (DECL_SOURCE_LOCATION (field), 0, 3261 "%qD is too small to hold all values of %q#T", 3262 field, type); 3263 } 3264 } 3265 3266 if (w != error_mark_node) 3267 { 3268 DECL_SIZE (field) = fold_convert (bitsizetype, w); 3269 DECL_BIT_FIELD (field) = 1; 3270 return true; 3271 } 3272 else 3273 { 3274 /* Non-bit-fields are aligned for their type. */ 3275 DECL_BIT_FIELD (field) = 0; 3276 CLEAR_DECL_C_BIT_FIELD (field); 3277 return false; 3278 } 3279 } 3280 3281 /* FIELD is a non bit-field. We are finishing the processing for its 3282 enclosing type T. Issue any appropriate messages and set appropriate 3283 flags. */ 3284 3285 static bool 3286 check_field_decl (tree field, 3287 tree t, 3288 int* cant_have_const_ctor, 3289 int* no_const_asn_ref) 3290 { 3291 tree type = strip_array_types (TREE_TYPE (field)); 3292 bool any_default_members = false; 3293 3294 /* In C++98 an anonymous union cannot contain any fields which would change 3295 the settings of CANT_HAVE_CONST_CTOR and friends. */ 3296 if (ANON_UNION_TYPE_P (type) && cxx_dialect < cxx11) 3297 ; 3298 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous 3299 structs. So, we recurse through their fields here. */ 3300 else if (ANON_AGGR_TYPE_P (type)) 3301 { 3302 for (tree fields = TYPE_FIELDS (type); fields; 3303 fields = DECL_CHAIN (fields)) 3304 if (TREE_CODE (fields) == FIELD_DECL) 3305 any_default_members |= check_field_decl (fields, t, 3306 cant_have_const_ctor, 3307 no_const_asn_ref); 3308 } 3309 /* Check members with class type for constructors, destructors, 3310 etc. */ 3311 else if (CLASS_TYPE_P (type)) 3312 { 3313 /* Never let anything with uninheritable virtuals 3314 make it through without complaint. */ 3315 abstract_virtuals_error (field, type); 3316 3317 if (TREE_CODE (t) == UNION_TYPE && cxx_dialect < cxx11) 3318 { 3319 static bool warned; 3320 int oldcount = errorcount; 3321 if (TYPE_NEEDS_CONSTRUCTING (type)) 3322 error ("member %q+#D with constructor not allowed in union", 3323 field); 3324 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 3325 error ("member %q+#D with destructor not allowed in union", field); 3326 if (TYPE_HAS_COMPLEX_COPY_ASSIGN (type)) 3327 error ("member %q+#D with copy assignment operator not allowed in union", 3328 field); 3329 if (!warned && errorcount > oldcount) 3330 { 3331 inform (DECL_SOURCE_LOCATION (field), "unrestricted unions " 3332 "only available with -std=c++11 or -std=gnu++11"); 3333 warned = true; 3334 } 3335 } 3336 else 3337 { 3338 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (type); 3339 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) 3340 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type); 3341 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) 3342 |= (TYPE_HAS_COMPLEX_COPY_ASSIGN (type) 3343 || !TYPE_HAS_COPY_ASSIGN (type)); 3344 TYPE_HAS_COMPLEX_COPY_CTOR (t) |= (TYPE_HAS_COMPLEX_COPY_CTOR (type) 3345 || !TYPE_HAS_COPY_CTOR (type)); 3346 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) |= TYPE_HAS_COMPLEX_MOVE_ASSIGN (type); 3347 TYPE_HAS_COMPLEX_MOVE_CTOR (t) |= TYPE_HAS_COMPLEX_MOVE_CTOR (type); 3348 TYPE_HAS_COMPLEX_DFLT (t) |= (!TYPE_HAS_DEFAULT_CONSTRUCTOR (type) 3349 || TYPE_HAS_COMPLEX_DFLT (type)); 3350 } 3351 3352 if (TYPE_HAS_COPY_CTOR (type) 3353 && !TYPE_HAS_CONST_COPY_CTOR (type)) 3354 *cant_have_const_ctor = 1; 3355 3356 if (TYPE_HAS_COPY_ASSIGN (type) 3357 && !TYPE_HAS_CONST_COPY_ASSIGN (type)) 3358 *no_const_asn_ref = 1; 3359 } 3360 3361 check_abi_tags (t, field); 3362 3363 if (DECL_INITIAL (field) != NULL_TREE) 3364 /* `build_class_init_list' does not recognize 3365 non-FIELD_DECLs. */ 3366 any_default_members = true; 3367 3368 return any_default_members; 3369 } 3370 3371 /* Check the data members (both static and non-static), class-scoped 3372 typedefs, etc., appearing in the declaration of T. Issue 3373 appropriate diagnostics. Sets ACCESS_DECLS to a list (in 3374 declaration order) of access declarations; each TREE_VALUE in this 3375 list is a USING_DECL. 3376 3377 In addition, set the following flags: 3378 3379 EMPTY_P 3380 The class is empty, i.e., contains no non-static data members. 3381 3382 CANT_HAVE_CONST_CTOR_P 3383 This class cannot have an implicitly generated copy constructor 3384 taking a const reference. 3385 3386 CANT_HAVE_CONST_ASN_REF 3387 This class cannot have an implicitly generated assignment 3388 operator taking a const reference. 3389 3390 All of these flags should be initialized before calling this 3391 function. 3392 3393 Returns a pointer to the end of the TYPE_FIELDs chain; additional 3394 fields can be added by adding to this chain. */ 3395 3396 static void 3397 check_field_decls (tree t, tree *access_decls, 3398 int *cant_have_const_ctor_p, 3399 int *no_const_asn_ref_p) 3400 { 3401 tree *field; 3402 tree *next; 3403 bool has_pointers; 3404 bool any_default_members; 3405 int cant_pack = 0; 3406 int field_access = -1; 3407 3408 /* Assume there are no access declarations. */ 3409 *access_decls = NULL_TREE; 3410 /* Assume this class has no pointer members. */ 3411 has_pointers = false; 3412 /* Assume none of the members of this class have default 3413 initializations. */ 3414 any_default_members = false; 3415 3416 for (field = &TYPE_FIELDS (t); *field; field = next) 3417 { 3418 tree x = *field; 3419 tree type = TREE_TYPE (x); 3420 int this_field_access; 3421 3422 next = &DECL_CHAIN (x); 3423 3424 if (TREE_CODE (x) == USING_DECL) 3425 { 3426 /* Save the access declarations for our caller. */ 3427 *access_decls = tree_cons (NULL_TREE, x, *access_decls); 3428 continue; 3429 } 3430 3431 if (TREE_CODE (x) == TYPE_DECL 3432 || TREE_CODE (x) == TEMPLATE_DECL) 3433 continue; 3434 3435 if (TREE_CODE (x) == FUNCTION_DECL) 3436 /* FIXME: We should fold in the checking from check_methods. */ 3437 continue; 3438 3439 /* If we've gotten this far, it's a data member, possibly static, 3440 or an enumerator. */ 3441 if (TREE_CODE (x) != CONST_DECL) 3442 DECL_CONTEXT (x) = t; 3443 3444 /* When this goes into scope, it will be a non-local reference. */ 3445 DECL_NONLOCAL (x) = 1; 3446 3447 if (TREE_CODE (t) == UNION_TYPE) 3448 { 3449 /* [class.union] (C++98) 3450 3451 If a union contains a static data member, or a member of 3452 reference type, the program is ill-formed. 3453 3454 In C++11 [class.union] says: 3455 If a union contains a non-static data member of reference type 3456 the program is ill-formed. */ 3457 if (VAR_P (x) && cxx_dialect < cxx11) 3458 { 3459 error ("in C++98 %q+D may not be static because it is " 3460 "a member of a union", x); 3461 continue; 3462 } 3463 if (TREE_CODE (type) == REFERENCE_TYPE 3464 && TREE_CODE (x) == FIELD_DECL) 3465 { 3466 error ("non-static data member %q+D in a union may not " 3467 "have reference type %qT", x, type); 3468 continue; 3469 } 3470 } 3471 3472 /* Perform error checking that did not get done in 3473 grokdeclarator. */ 3474 if (TREE_CODE (type) == FUNCTION_TYPE) 3475 { 3476 error ("field %q+D invalidly declared function type", x); 3477 type = build_pointer_type (type); 3478 TREE_TYPE (x) = type; 3479 } 3480 else if (TREE_CODE (type) == METHOD_TYPE) 3481 { 3482 error ("field %q+D invalidly declared method type", x); 3483 type = build_pointer_type (type); 3484 TREE_TYPE (x) = type; 3485 } 3486 3487 if (type == error_mark_node) 3488 continue; 3489 3490 if (TREE_CODE (x) == CONST_DECL || VAR_P (x)) 3491 continue; 3492 3493 /* Now it can only be a FIELD_DECL. */ 3494 3495 if (TREE_PRIVATE (x) || TREE_PROTECTED (x)) 3496 CLASSTYPE_NON_AGGREGATE (t) = 1; 3497 3498 /* If at least one non-static data member is non-literal, the whole 3499 class becomes non-literal. Per Core/1453, volatile non-static 3500 data members and base classes are also not allowed. 3501 Note: if the type is incomplete we will complain later on. */ 3502 if (COMPLETE_TYPE_P (type) 3503 && (!literal_type_p (type) || CP_TYPE_VOLATILE_P (type))) 3504 CLASSTYPE_LITERAL_P (t) = false; 3505 3506 /* A standard-layout class is a class that: 3507 ... 3508 has the same access control (Clause 11) for all non-static data members, 3509 ... */ 3510 this_field_access = TREE_PROTECTED (x) ? 1 : TREE_PRIVATE (x) ? 2 : 0; 3511 if (field_access == -1) 3512 field_access = this_field_access; 3513 else if (this_field_access != field_access) 3514 CLASSTYPE_NON_STD_LAYOUT (t) = 1; 3515 3516 /* If this is of reference type, check if it needs an init. */ 3517 if (TREE_CODE (type) == REFERENCE_TYPE) 3518 { 3519 CLASSTYPE_NON_LAYOUT_POD_P (t) = 1; 3520 CLASSTYPE_NON_STD_LAYOUT (t) = 1; 3521 if (DECL_INITIAL (x) == NULL_TREE) 3522 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1); 3523 if (cxx_dialect < cxx11) 3524 { 3525 /* ARM $12.6.2: [A member initializer list] (or, for an 3526 aggregate, initialization by a brace-enclosed list) is the 3527 only way to initialize nonstatic const and reference 3528 members. */ 3529 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) = 1; 3530 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) = 1; 3531 } 3532 } 3533 3534 type = strip_array_types (type); 3535 3536 if (TYPE_PACKED (t)) 3537 { 3538 if (!layout_pod_type_p (type) && !TYPE_PACKED (type)) 3539 { 3540 warning_at 3541 (DECL_SOURCE_LOCATION (x), 0, 3542 "ignoring packed attribute because of unpacked non-POD field %q#D", 3543 x); 3544 cant_pack = 1; 3545 } 3546 else if (DECL_C_BIT_FIELD (x) 3547 || TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT) 3548 DECL_PACKED (x) = 1; 3549 } 3550 3551 if (DECL_C_BIT_FIELD (x) 3552 && integer_zerop (DECL_BIT_FIELD_REPRESENTATIVE (x))) 3553 /* We don't treat zero-width bitfields as making a class 3554 non-empty. */ 3555 ; 3556 else 3557 { 3558 /* The class is non-empty. */ 3559 CLASSTYPE_EMPTY_P (t) = 0; 3560 /* The class is not even nearly empty. */ 3561 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 3562 /* If one of the data members contains an empty class, 3563 so does T. */ 3564 if (CLASS_TYPE_P (type) 3565 && CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type)) 3566 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1; 3567 } 3568 3569 /* This is used by -Weffc++ (see below). Warn only for pointers 3570 to members which might hold dynamic memory. So do not warn 3571 for pointers to functions or pointers to members. */ 3572 if (TYPE_PTR_P (type) 3573 && !TYPE_PTRFN_P (type)) 3574 has_pointers = true; 3575 3576 if (CLASS_TYPE_P (type)) 3577 { 3578 if (CLASSTYPE_REF_FIELDS_NEED_INIT (type)) 3579 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1); 3580 if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (type)) 3581 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1); 3582 } 3583 3584 if (DECL_MUTABLE_P (x) || TYPE_HAS_MUTABLE_P (type)) 3585 CLASSTYPE_HAS_MUTABLE (t) = 1; 3586 3587 if (DECL_MUTABLE_P (x)) 3588 { 3589 if (CP_TYPE_CONST_P (type)) 3590 { 3591 error ("member %q+D cannot be declared both %<const%> " 3592 "and %<mutable%>", x); 3593 continue; 3594 } 3595 if (TREE_CODE (type) == REFERENCE_TYPE) 3596 { 3597 error ("member %q+D cannot be declared as a %<mutable%> " 3598 "reference", x); 3599 continue; 3600 } 3601 } 3602 3603 if (! layout_pod_type_p (type)) 3604 /* DR 148 now allows pointers to members (which are POD themselves), 3605 to be allowed in POD structs. */ 3606 CLASSTYPE_NON_LAYOUT_POD_P (t) = 1; 3607 3608 if (!std_layout_type_p (type)) 3609 CLASSTYPE_NON_STD_LAYOUT (t) = 1; 3610 3611 if (! zero_init_p (type)) 3612 CLASSTYPE_NON_ZERO_INIT_P (t) = 1; 3613 3614 /* We set DECL_C_BIT_FIELD in grokbitfield. 3615 If the type and width are valid, we'll also set DECL_BIT_FIELD. */ 3616 if (DECL_C_BIT_FIELD (x)) 3617 check_bitfield_decl (x); 3618 3619 if (check_field_decl (x, t, cant_have_const_ctor_p, no_const_asn_ref_p)) 3620 { 3621 if (any_default_members 3622 && TREE_CODE (t) == UNION_TYPE) 3623 error ("multiple fields in union %qT initialized", t); 3624 any_default_members = true; 3625 } 3626 3627 /* Now that we've removed bit-field widths from DECL_INITIAL, 3628 anything left in DECL_INITIAL is an NSDMI that makes the class 3629 non-aggregate in C++11. */ 3630 if (DECL_INITIAL (x) && cxx_dialect < cxx14) 3631 CLASSTYPE_NON_AGGREGATE (t) = true; 3632 3633 /* If any field is const, the structure type is pseudo-const. */ 3634 if (CP_TYPE_CONST_P (type)) 3635 { 3636 C_TYPE_FIELDS_READONLY (t) = 1; 3637 if (DECL_INITIAL (x) == NULL_TREE) 3638 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1); 3639 if (cxx_dialect < cxx11) 3640 { 3641 /* ARM $12.6.2: [A member initializer list] (or, for an 3642 aggregate, initialization by a brace-enclosed list) is the 3643 only way to initialize nonstatic const and reference 3644 members. */ 3645 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) = 1; 3646 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) = 1; 3647 } 3648 } 3649 /* A field that is pseudo-const makes the structure likewise. */ 3650 else if (CLASS_TYPE_P (type)) 3651 { 3652 C_TYPE_FIELDS_READONLY (t) |= C_TYPE_FIELDS_READONLY (type); 3653 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 3654 CLASSTYPE_READONLY_FIELDS_NEED_INIT (t) 3655 | CLASSTYPE_READONLY_FIELDS_NEED_INIT (type)); 3656 } 3657 3658 /* Core issue 80: A nonstatic data member is required to have a 3659 different name from the class iff the class has a 3660 user-declared constructor. */ 3661 if (constructor_name_p (DECL_NAME (x), t) 3662 && TYPE_HAS_USER_CONSTRUCTOR (t)) 3663 permerror (DECL_SOURCE_LOCATION (x), 3664 "field %q#D with same name as class", x); 3665 } 3666 3667 /* Effective C++ rule 11: if a class has dynamic memory held by pointers, 3668 it should also define a copy constructor and an assignment operator to 3669 implement the correct copy semantic (deep vs shallow, etc.). As it is 3670 not feasible to check whether the constructors do allocate dynamic memory 3671 and store it within members, we approximate the warning like this: 3672 3673 -- Warn only if there are members which are pointers 3674 -- Warn only if there is a non-trivial constructor (otherwise, 3675 there cannot be memory allocated). 3676 -- Warn only if there is a non-trivial destructor. We assume that the 3677 user at least implemented the cleanup correctly, and a destructor 3678 is needed to free dynamic memory. 3679 3680 This seems enough for practical purposes. */ 3681 if (warn_ecpp 3682 && has_pointers 3683 && TYPE_HAS_USER_CONSTRUCTOR (t) 3684 && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) 3685 && !(TYPE_HAS_COPY_CTOR (t) && TYPE_HAS_COPY_ASSIGN (t))) 3686 { 3687 warning (OPT_Weffc__, "%q#T has pointer data members", t); 3688 3689 if (! TYPE_HAS_COPY_CTOR (t)) 3690 { 3691 warning (OPT_Weffc__, 3692 " but does not override %<%T(const %T&)%>", t, t); 3693 if (!TYPE_HAS_COPY_ASSIGN (t)) 3694 warning (OPT_Weffc__, " or %<operator=(const %T&)%>", t); 3695 } 3696 else if (! TYPE_HAS_COPY_ASSIGN (t)) 3697 warning (OPT_Weffc__, 3698 " but does not override %<operator=(const %T&)%>", t); 3699 } 3700 3701 /* Non-static data member initializers make the default constructor 3702 non-trivial. */ 3703 if (any_default_members) 3704 { 3705 TYPE_NEEDS_CONSTRUCTING (t) = true; 3706 TYPE_HAS_COMPLEX_DFLT (t) = true; 3707 } 3708 3709 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */ 3710 if (cant_pack) 3711 TYPE_PACKED (t) = 0; 3712 3713 /* Check anonymous struct/anonymous union fields. */ 3714 finish_struct_anon (t); 3715 3716 /* We've built up the list of access declarations in reverse order. 3717 Fix that now. */ 3718 *access_decls = nreverse (*access_decls); 3719 } 3720 3721 /* If TYPE is an empty class type, records its OFFSET in the table of 3722 OFFSETS. */ 3723 3724 static int 3725 record_subobject_offset (tree type, tree offset, splay_tree offsets) 3726 { 3727 splay_tree_node n; 3728 3729 if (!is_empty_class (type)) 3730 return 0; 3731 3732 /* Record the location of this empty object in OFFSETS. */ 3733 n = splay_tree_lookup (offsets, (splay_tree_key) offset); 3734 if (!n) 3735 n = splay_tree_insert (offsets, 3736 (splay_tree_key) offset, 3737 (splay_tree_value) NULL_TREE); 3738 n->value = ((splay_tree_value) 3739 tree_cons (NULL_TREE, 3740 type, 3741 (tree) n->value)); 3742 3743 return 0; 3744 } 3745 3746 /* Returns nonzero if TYPE is an empty class type and there is 3747 already an entry in OFFSETS for the same TYPE as the same OFFSET. */ 3748 3749 static int 3750 check_subobject_offset (tree type, tree offset, splay_tree offsets) 3751 { 3752 splay_tree_node n; 3753 tree t; 3754 3755 if (!is_empty_class (type)) 3756 return 0; 3757 3758 /* Record the location of this empty object in OFFSETS. */ 3759 n = splay_tree_lookup (offsets, (splay_tree_key) offset); 3760 if (!n) 3761 return 0; 3762 3763 for (t = (tree) n->value; t; t = TREE_CHAIN (t)) 3764 if (same_type_p (TREE_VALUE (t), type)) 3765 return 1; 3766 3767 return 0; 3768 } 3769 3770 /* Walk through all the subobjects of TYPE (located at OFFSET). Call 3771 F for every subobject, passing it the type, offset, and table of 3772 OFFSETS. If VBASES_P is one, then virtual non-primary bases should 3773 be traversed. 3774 3775 If MAX_OFFSET is non-NULL, then subobjects with an offset greater 3776 than MAX_OFFSET will not be walked. 3777 3778 If F returns a nonzero value, the traversal ceases, and that value 3779 is returned. Otherwise, returns zero. */ 3780 3781 static int 3782 walk_subobject_offsets (tree type, 3783 subobject_offset_fn f, 3784 tree offset, 3785 splay_tree offsets, 3786 tree max_offset, 3787 int vbases_p) 3788 { 3789 int r = 0; 3790 tree type_binfo = NULL_TREE; 3791 3792 /* If this OFFSET is bigger than the MAX_OFFSET, then we should 3793 stop. */ 3794 if (max_offset && tree_int_cst_lt (max_offset, offset)) 3795 return 0; 3796 3797 if (type == error_mark_node) 3798 return 0; 3799 3800 if (!TYPE_P (type)) 3801 { 3802 type_binfo = type; 3803 type = BINFO_TYPE (type); 3804 } 3805 3806 if (CLASS_TYPE_P (type)) 3807 { 3808 tree field; 3809 tree binfo; 3810 int i; 3811 3812 /* Avoid recursing into objects that are not interesting. */ 3813 if (!CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type)) 3814 return 0; 3815 3816 /* Record the location of TYPE. */ 3817 r = (*f) (type, offset, offsets); 3818 if (r) 3819 return r; 3820 3821 /* Iterate through the direct base classes of TYPE. */ 3822 if (!type_binfo) 3823 type_binfo = TYPE_BINFO (type); 3824 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, binfo); i++) 3825 { 3826 tree binfo_offset; 3827 3828 if (BINFO_VIRTUAL_P (binfo)) 3829 continue; 3830 3831 tree orig_binfo; 3832 /* We cannot rely on BINFO_OFFSET being set for the base 3833 class yet, but the offsets for direct non-virtual 3834 bases can be calculated by going back to the TYPE. */ 3835 orig_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), i); 3836 binfo_offset = size_binop (PLUS_EXPR, 3837 offset, 3838 BINFO_OFFSET (orig_binfo)); 3839 3840 r = walk_subobject_offsets (binfo, 3841 f, 3842 binfo_offset, 3843 offsets, 3844 max_offset, 3845 /*vbases_p=*/0); 3846 if (r) 3847 return r; 3848 } 3849 3850 if (CLASSTYPE_VBASECLASSES (type)) 3851 { 3852 unsigned ix; 3853 vec<tree, va_gc> *vbases; 3854 3855 /* Iterate through the virtual base classes of TYPE. In G++ 3856 3.2, we included virtual bases in the direct base class 3857 loop above, which results in incorrect results; the 3858 correct offsets for virtual bases are only known when 3859 working with the most derived type. */ 3860 if (vbases_p) 3861 for (vbases = CLASSTYPE_VBASECLASSES (type), ix = 0; 3862 vec_safe_iterate (vbases, ix, &binfo); ix++) 3863 { 3864 r = walk_subobject_offsets (binfo, 3865 f, 3866 size_binop (PLUS_EXPR, 3867 offset, 3868 BINFO_OFFSET (binfo)), 3869 offsets, 3870 max_offset, 3871 /*vbases_p=*/0); 3872 if (r) 3873 return r; 3874 } 3875 else 3876 { 3877 /* We still have to walk the primary base, if it is 3878 virtual. (If it is non-virtual, then it was walked 3879 above.) */ 3880 tree vbase = get_primary_binfo (type_binfo); 3881 3882 if (vbase && BINFO_VIRTUAL_P (vbase) 3883 && BINFO_PRIMARY_P (vbase) 3884 && BINFO_INHERITANCE_CHAIN (vbase) == type_binfo) 3885 { 3886 r = (walk_subobject_offsets 3887 (vbase, f, offset, 3888 offsets, max_offset, /*vbases_p=*/0)); 3889 if (r) 3890 return r; 3891 } 3892 } 3893 } 3894 3895 /* Iterate through the fields of TYPE. */ 3896 for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) 3897 if (TREE_CODE (field) == FIELD_DECL 3898 && TREE_TYPE (field) != error_mark_node 3899 && !DECL_ARTIFICIAL (field)) 3900 { 3901 tree field_offset; 3902 3903 field_offset = byte_position (field); 3904 3905 r = walk_subobject_offsets (TREE_TYPE (field), 3906 f, 3907 size_binop (PLUS_EXPR, 3908 offset, 3909 field_offset), 3910 offsets, 3911 max_offset, 3912 /*vbases_p=*/1); 3913 if (r) 3914 return r; 3915 } 3916 } 3917 else if (TREE_CODE (type) == ARRAY_TYPE) 3918 { 3919 tree element_type = strip_array_types (type); 3920 tree domain = TYPE_DOMAIN (type); 3921 tree index; 3922 3923 /* Avoid recursing into objects that are not interesting. */ 3924 if (!CLASS_TYPE_P (element_type) 3925 || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type) 3926 || !domain 3927 || integer_minus_onep (TYPE_MAX_VALUE (domain))) 3928 return 0; 3929 3930 /* Step through each of the elements in the array. */ 3931 for (index = size_zero_node; 3932 !tree_int_cst_lt (TYPE_MAX_VALUE (domain), index); 3933 index = size_binop (PLUS_EXPR, index, size_one_node)) 3934 { 3935 r = walk_subobject_offsets (TREE_TYPE (type), 3936 f, 3937 offset, 3938 offsets, 3939 max_offset, 3940 /*vbases_p=*/1); 3941 if (r) 3942 return r; 3943 offset = size_binop (PLUS_EXPR, offset, 3944 TYPE_SIZE_UNIT (TREE_TYPE (type))); 3945 /* If this new OFFSET is bigger than the MAX_OFFSET, then 3946 there's no point in iterating through the remaining 3947 elements of the array. */ 3948 if (max_offset && tree_int_cst_lt (max_offset, offset)) 3949 break; 3950 } 3951 } 3952 3953 return 0; 3954 } 3955 3956 /* Record all of the empty subobjects of TYPE (either a type or a 3957 binfo). If IS_DATA_MEMBER is true, then a non-static data member 3958 is being placed at OFFSET; otherwise, it is a base class that is 3959 being placed at OFFSET. */ 3960 3961 static void 3962 record_subobject_offsets (tree type, 3963 tree offset, 3964 splay_tree offsets, 3965 bool is_data_member) 3966 { 3967 tree max_offset; 3968 /* If recording subobjects for a non-static data member or a 3969 non-empty base class , we do not need to record offsets beyond 3970 the size of the biggest empty class. Additional data members 3971 will go at the end of the class. Additional base classes will go 3972 either at offset zero (if empty, in which case they cannot 3973 overlap with offsets past the size of the biggest empty class) or 3974 at the end of the class. 3975 3976 However, if we are placing an empty base class, then we must record 3977 all offsets, as either the empty class is at offset zero (where 3978 other empty classes might later be placed) or at the end of the 3979 class (where other objects might then be placed, so other empty 3980 subobjects might later overlap). */ 3981 if (is_data_member 3982 || !is_empty_class (BINFO_TYPE (type))) 3983 max_offset = sizeof_biggest_empty_class; 3984 else 3985 max_offset = NULL_TREE; 3986 walk_subobject_offsets (type, record_subobject_offset, offset, 3987 offsets, max_offset, is_data_member); 3988 } 3989 3990 /* Returns nonzero if any of the empty subobjects of TYPE (located at 3991 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero, 3992 virtual bases of TYPE are examined. */ 3993 3994 static int 3995 layout_conflict_p (tree type, 3996 tree offset, 3997 splay_tree offsets, 3998 int vbases_p) 3999 { 4000 splay_tree_node max_node; 4001 4002 /* Get the node in OFFSETS that indicates the maximum offset where 4003 an empty subobject is located. */ 4004 max_node = splay_tree_max (offsets); 4005 /* If there aren't any empty subobjects, then there's no point in 4006 performing this check. */ 4007 if (!max_node) 4008 return 0; 4009 4010 return walk_subobject_offsets (type, check_subobject_offset, offset, 4011 offsets, (tree) (max_node->key), 4012 vbases_p); 4013 } 4014 4015 /* DECL is a FIELD_DECL corresponding either to a base subobject of a 4016 non-static data member of the type indicated by RLI. BINFO is the 4017 binfo corresponding to the base subobject, OFFSETS maps offsets to 4018 types already located at those offsets. This function determines 4019 the position of the DECL. */ 4020 4021 static void 4022 layout_nonempty_base_or_field (record_layout_info rli, 4023 tree decl, 4024 tree binfo, 4025 splay_tree offsets) 4026 { 4027 tree offset = NULL_TREE; 4028 bool field_p; 4029 tree type; 4030 4031 if (binfo) 4032 { 4033 /* For the purposes of determining layout conflicts, we want to 4034 use the class type of BINFO; TREE_TYPE (DECL) will be the 4035 CLASSTYPE_AS_BASE version, which does not contain entries for 4036 zero-sized bases. */ 4037 type = TREE_TYPE (binfo); 4038 field_p = false; 4039 } 4040 else 4041 { 4042 type = TREE_TYPE (decl); 4043 field_p = true; 4044 } 4045 4046 /* Try to place the field. It may take more than one try if we have 4047 a hard time placing the field without putting two objects of the 4048 same type at the same address. */ 4049 while (1) 4050 { 4051 struct record_layout_info_s old_rli = *rli; 4052 4053 /* Place this field. */ 4054 place_field (rli, decl); 4055 offset = byte_position (decl); 4056 4057 /* We have to check to see whether or not there is already 4058 something of the same type at the offset we're about to use. 4059 For example, consider: 4060 4061 struct S {}; 4062 struct T : public S { int i; }; 4063 struct U : public S, public T {}; 4064 4065 Here, we put S at offset zero in U. Then, we can't put T at 4066 offset zero -- its S component would be at the same address 4067 as the S we already allocated. So, we have to skip ahead. 4068 Since all data members, including those whose type is an 4069 empty class, have nonzero size, any overlap can happen only 4070 with a direct or indirect base-class -- it can't happen with 4071 a data member. */ 4072 /* In a union, overlap is permitted; all members are placed at 4073 offset zero. */ 4074 if (TREE_CODE (rli->t) == UNION_TYPE) 4075 break; 4076 if (layout_conflict_p (field_p ? type : binfo, offset, 4077 offsets, field_p)) 4078 { 4079 /* Strip off the size allocated to this field. That puts us 4080 at the first place we could have put the field with 4081 proper alignment. */ 4082 *rli = old_rli; 4083 4084 /* Bump up by the alignment required for the type. */ 4085 rli->bitpos 4086 = size_binop (PLUS_EXPR, rli->bitpos, 4087 bitsize_int (binfo 4088 ? CLASSTYPE_ALIGN (type) 4089 : TYPE_ALIGN (type))); 4090 normalize_rli (rli); 4091 } 4092 else if (TREE_CODE (type) == NULLPTR_TYPE 4093 && warn_abi && abi_version_crosses (9)) 4094 { 4095 /* Before ABI v9, we were giving nullptr_t alignment of 1; if 4096 the offset wasn't aligned like a pointer when we started to 4097 layout this field, that affects its position. */ 4098 tree pos = rli_size_unit_so_far (&old_rli); 4099 if (int_cst_value (pos) % TYPE_ALIGN_UNIT (ptr_type_node) != 0) 4100 { 4101 if (abi_version_at_least (9)) 4102 warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wabi, 4103 "alignment of %qD increased in -fabi-version=9 " 4104 "(GCC 5.2)", decl); 4105 else 4106 warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wabi, "alignment " 4107 "of %qD will increase in -fabi-version=9", decl); 4108 } 4109 break; 4110 } 4111 else 4112 /* There was no conflict. We're done laying out this field. */ 4113 break; 4114 } 4115 4116 /* Now that we know where it will be placed, update its 4117 BINFO_OFFSET. */ 4118 if (binfo && CLASS_TYPE_P (BINFO_TYPE (binfo))) 4119 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at 4120 this point because their BINFO_OFFSET is copied from another 4121 hierarchy. Therefore, we may not need to add the entire 4122 OFFSET. */ 4123 propagate_binfo_offsets (binfo, 4124 size_diffop_loc (input_location, 4125 fold_convert (ssizetype, offset), 4126 fold_convert (ssizetype, 4127 BINFO_OFFSET (binfo)))); 4128 } 4129 4130 /* Returns true if TYPE is empty and OFFSET is nonzero. */ 4131 4132 static int 4133 empty_base_at_nonzero_offset_p (tree type, 4134 tree offset, 4135 splay_tree /*offsets*/) 4136 { 4137 return is_empty_class (type) && !integer_zerop (offset); 4138 } 4139 4140 /* Layout the empty base BINFO. EOC indicates the byte currently just 4141 past the end of the class, and should be correctly aligned for a 4142 class of the type indicated by BINFO; OFFSETS gives the offsets of 4143 the empty bases allocated so far. T is the most derived 4144 type. Return nonzero iff we added it at the end. */ 4145 4146 static bool 4147 layout_empty_base (record_layout_info rli, tree binfo, 4148 tree eoc, splay_tree offsets) 4149 { 4150 tree alignment; 4151 tree basetype = BINFO_TYPE (binfo); 4152 bool atend = false; 4153 4154 /* This routine should only be used for empty classes. */ 4155 gcc_assert (is_empty_class (basetype)); 4156 alignment = ssize_int (CLASSTYPE_ALIGN_UNIT (basetype)); 4157 4158 if (!integer_zerop (BINFO_OFFSET (binfo))) 4159 propagate_binfo_offsets 4160 (binfo, size_diffop_loc (input_location, 4161 size_zero_node, BINFO_OFFSET (binfo))); 4162 4163 /* This is an empty base class. We first try to put it at offset 4164 zero. */ 4165 if (layout_conflict_p (binfo, 4166 BINFO_OFFSET (binfo), 4167 offsets, 4168 /*vbases_p=*/0)) 4169 { 4170 /* That didn't work. Now, we move forward from the next 4171 available spot in the class. */ 4172 atend = true; 4173 propagate_binfo_offsets (binfo, fold_convert (ssizetype, eoc)); 4174 while (1) 4175 { 4176 if (!layout_conflict_p (binfo, 4177 BINFO_OFFSET (binfo), 4178 offsets, 4179 /*vbases_p=*/0)) 4180 /* We finally found a spot where there's no overlap. */ 4181 break; 4182 4183 /* There's overlap here, too. Bump along to the next spot. */ 4184 propagate_binfo_offsets (binfo, alignment); 4185 } 4186 } 4187 4188 if (CLASSTYPE_USER_ALIGN (basetype)) 4189 { 4190 rli->record_align = MAX (rli->record_align, CLASSTYPE_ALIGN (basetype)); 4191 if (warn_packed) 4192 rli->unpacked_align = MAX (rli->unpacked_align, CLASSTYPE_ALIGN (basetype)); 4193 TYPE_USER_ALIGN (rli->t) = 1; 4194 } 4195 4196 return atend; 4197 } 4198 4199 /* Build the FIELD_DECL for BASETYPE as a base of T, add it to the chain of 4200 fields at NEXT_FIELD, and return it. */ 4201 4202 static tree 4203 build_base_field_1 (tree t, tree basetype, tree *&next_field) 4204 { 4205 /* Create the FIELD_DECL. */ 4206 gcc_assert (CLASSTYPE_AS_BASE (basetype)); 4207 tree decl = build_decl (input_location, 4208 FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype)); 4209 DECL_ARTIFICIAL (decl) = 1; 4210 DECL_IGNORED_P (decl) = 1; 4211 DECL_FIELD_CONTEXT (decl) = t; 4212 if (is_empty_class (basetype)) 4213 /* CLASSTYPE_SIZE is one byte, but the field needs to have size zero. */ 4214 DECL_SIZE (decl) = DECL_SIZE_UNIT (decl) = size_zero_node; 4215 else 4216 { 4217 DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype); 4218 DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype); 4219 } 4220 SET_DECL_ALIGN (decl, CLASSTYPE_ALIGN (basetype)); 4221 DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype); 4222 SET_DECL_MODE (decl, TYPE_MODE (basetype)); 4223 DECL_FIELD_IS_BASE (decl) = 1; 4224 4225 /* Add the new FIELD_DECL to the list of fields for T. */ 4226 DECL_CHAIN (decl) = *next_field; 4227 *next_field = decl; 4228 next_field = &DECL_CHAIN (decl); 4229 4230 return decl; 4231 } 4232 4233 /* Layout the base given by BINFO in the class indicated by RLI. 4234 *BASE_ALIGN is a running maximum of the alignments of 4235 any base class. OFFSETS gives the location of empty base 4236 subobjects. T is the most derived type. Return nonzero if the new 4237 object cannot be nearly-empty. A new FIELD_DECL is inserted at 4238 *NEXT_FIELD, unless BINFO is for an empty base class. 4239 4240 Returns the location at which the next field should be inserted. */ 4241 4242 static tree * 4243 build_base_field (record_layout_info rli, tree binfo, 4244 splay_tree offsets, tree *next_field) 4245 { 4246 tree t = rli->t; 4247 tree basetype = BINFO_TYPE (binfo); 4248 4249 if (!COMPLETE_TYPE_P (basetype)) 4250 /* This error is now reported in xref_tag, thus giving better 4251 location information. */ 4252 return next_field; 4253 4254 /* Place the base class. */ 4255 if (!is_empty_class (basetype)) 4256 { 4257 tree decl; 4258 4259 /* The containing class is non-empty because it has a non-empty 4260 base class. */ 4261 CLASSTYPE_EMPTY_P (t) = 0; 4262 4263 /* Create the FIELD_DECL. */ 4264 decl = build_base_field_1 (t, basetype, next_field); 4265 4266 /* Try to place the field. It may take more than one try if we 4267 have a hard time placing the field without putting two 4268 objects of the same type at the same address. */ 4269 layout_nonempty_base_or_field (rli, decl, binfo, offsets); 4270 } 4271 else 4272 { 4273 tree eoc; 4274 bool atend; 4275 4276 /* On some platforms (ARM), even empty classes will not be 4277 byte-aligned. */ 4278 eoc = round_up_loc (input_location, 4279 rli_size_unit_so_far (rli), 4280 CLASSTYPE_ALIGN_UNIT (basetype)); 4281 atend = layout_empty_base (rli, binfo, eoc, offsets); 4282 /* A nearly-empty class "has no proper base class that is empty, 4283 not morally virtual, and at an offset other than zero." */ 4284 if (!BINFO_VIRTUAL_P (binfo) && CLASSTYPE_NEARLY_EMPTY_P (t)) 4285 { 4286 if (atend) 4287 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 4288 /* The check above (used in G++ 3.2) is insufficient because 4289 an empty class placed at offset zero might itself have an 4290 empty base at a nonzero offset. */ 4291 else if (walk_subobject_offsets (basetype, 4292 empty_base_at_nonzero_offset_p, 4293 size_zero_node, 4294 /*offsets=*/NULL, 4295 /*max_offset=*/NULL_TREE, 4296 /*vbases_p=*/true)) 4297 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 4298 } 4299 4300 /* We used to not create a FIELD_DECL for empty base classes because of 4301 back end issues with overlapping FIELD_DECLs, but that doesn't seem to 4302 be a problem anymore. We need them to handle initialization of C++17 4303 aggregate bases. */ 4304 if (cxx_dialect >= cxx17 && !BINFO_VIRTUAL_P (binfo)) 4305 { 4306 tree decl = build_base_field_1 (t, basetype, next_field); 4307 DECL_FIELD_OFFSET (decl) = BINFO_OFFSET (binfo); 4308 DECL_FIELD_BIT_OFFSET (decl) = bitsize_zero_node; 4309 SET_DECL_OFFSET_ALIGN (decl, BITS_PER_UNIT); 4310 } 4311 4312 /* An empty virtual base causes a class to be non-empty 4313 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P 4314 here because that was already done when the virtual table 4315 pointer was created. */ 4316 } 4317 4318 /* Record the offsets of BINFO and its base subobjects. */ 4319 record_subobject_offsets (binfo, 4320 BINFO_OFFSET (binfo), 4321 offsets, 4322 /*is_data_member=*/false); 4323 4324 return next_field; 4325 } 4326 4327 /* Layout all of the non-virtual base classes. Record empty 4328 subobjects in OFFSETS. T is the most derived type. Return nonzero 4329 if the type cannot be nearly empty. The fields created 4330 corresponding to the base classes will be inserted at 4331 *NEXT_FIELD. */ 4332 4333 static void 4334 build_base_fields (record_layout_info rli, 4335 splay_tree offsets, tree *next_field) 4336 { 4337 /* Chain to hold all the new FIELD_DECLs which stand in for base class 4338 subobjects. */ 4339 tree t = rli->t; 4340 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t)); 4341 int i; 4342 4343 /* The primary base class is always allocated first. */ 4344 if (CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 4345 next_field = build_base_field (rli, CLASSTYPE_PRIMARY_BINFO (t), 4346 offsets, next_field); 4347 4348 /* Now allocate the rest of the bases. */ 4349 for (i = 0; i < n_baseclasses; ++i) 4350 { 4351 tree base_binfo; 4352 4353 base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i); 4354 4355 /* The primary base was already allocated above, so we don't 4356 need to allocate it again here. */ 4357 if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t)) 4358 continue; 4359 4360 /* Virtual bases are added at the end (a primary virtual base 4361 will have already been added). */ 4362 if (BINFO_VIRTUAL_P (base_binfo)) 4363 continue; 4364 4365 next_field = build_base_field (rli, base_binfo, 4366 offsets, next_field); 4367 } 4368 } 4369 4370 /* Go through the TYPE_FIELDS of T issuing any appropriate 4371 diagnostics, figuring out which methods override which other 4372 methods, and so forth. */ 4373 4374 static void 4375 check_methods (tree t) 4376 { 4377 for (tree x = TYPE_FIELDS (t); x; x = DECL_CHAIN (x)) 4378 if (DECL_DECLARES_FUNCTION_P (x)) 4379 { 4380 check_for_override (x, t); 4381 4382 if (DECL_PURE_VIRTUAL_P (x) 4383 && (TREE_CODE (x) != FUNCTION_DECL || ! DECL_VINDEX (x))) 4384 error ("initializer specified for non-virtual method %q+D", x); 4385 /* The name of the field is the original field name 4386 Save this in auxiliary field for later overloading. */ 4387 if (TREE_CODE (x) == FUNCTION_DECL && DECL_VINDEX (x)) 4388 { 4389 TYPE_POLYMORPHIC_P (t) = 1; 4390 if (DECL_PURE_VIRTUAL_P (x)) 4391 vec_safe_push (CLASSTYPE_PURE_VIRTUALS (t), x); 4392 } 4393 4394 /* All user-provided destructors are non-trivial. 4395 Constructors and assignment ops are handled in 4396 grok_special_member_properties. */ 4397 if (DECL_DESTRUCTOR_P (x) && user_provided_p (x)) 4398 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = 1; 4399 if (!DECL_VIRTUAL_P (x) 4400 && lookup_attribute ("transaction_safe_dynamic", 4401 DECL_ATTRIBUTES (x))) 4402 error_at (DECL_SOURCE_LOCATION (x), 4403 "%<transaction_safe_dynamic%> may only be specified for " 4404 "a virtual function"); 4405 } 4406 } 4407 4408 /* FN is a constructor or destructor. Clone the declaration to create 4409 a specialized in-charge or not-in-charge version, as indicated by 4410 NAME. */ 4411 4412 static tree 4413 build_clone (tree fn, tree name) 4414 { 4415 tree parms; 4416 tree clone; 4417 4418 /* Copy the function. */ 4419 clone = copy_decl (fn); 4420 /* Reset the function name. */ 4421 DECL_NAME (clone) = name; 4422 /* Remember where this function came from. */ 4423 DECL_ABSTRACT_ORIGIN (clone) = fn; 4424 /* Make it easy to find the CLONE given the FN. */ 4425 DECL_CHAIN (clone) = DECL_CHAIN (fn); 4426 DECL_CHAIN (fn) = clone; 4427 4428 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */ 4429 if (TREE_CODE (clone) == TEMPLATE_DECL) 4430 { 4431 tree result = build_clone (DECL_TEMPLATE_RESULT (clone), name); 4432 DECL_TEMPLATE_RESULT (clone) = result; 4433 DECL_TEMPLATE_INFO (result) = copy_node (DECL_TEMPLATE_INFO (result)); 4434 DECL_TI_TEMPLATE (result) = clone; 4435 TREE_TYPE (clone) = TREE_TYPE (result); 4436 return clone; 4437 } 4438 else 4439 { 4440 // Clone constraints. 4441 if (flag_concepts) 4442 if (tree ci = get_constraints (fn)) 4443 set_constraints (clone, copy_node (ci)); 4444 } 4445 4446 4447 SET_DECL_ASSEMBLER_NAME (clone, NULL_TREE); 4448 DECL_CLONED_FUNCTION (clone) = fn; 4449 /* There's no pending inline data for this function. */ 4450 DECL_PENDING_INLINE_INFO (clone) = NULL; 4451 DECL_PENDING_INLINE_P (clone) = 0; 4452 4453 /* The base-class destructor is not virtual. */ 4454 if (name == base_dtor_identifier) 4455 { 4456 DECL_VIRTUAL_P (clone) = 0; 4457 if (TREE_CODE (clone) != TEMPLATE_DECL) 4458 DECL_VINDEX (clone) = NULL_TREE; 4459 } 4460 4461 bool ctor_omit_inherited_parms_p = ctor_omit_inherited_parms (clone); 4462 if (ctor_omit_inherited_parms_p) 4463 gcc_assert (DECL_HAS_IN_CHARGE_PARM_P (clone)); 4464 4465 /* If there was an in-charge parameter, drop it from the function 4466 type. */ 4467 if (DECL_HAS_IN_CHARGE_PARM_P (clone)) 4468 { 4469 tree basetype; 4470 tree parmtypes; 4471 tree exceptions; 4472 4473 exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone)); 4474 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone)); 4475 parmtypes = TYPE_ARG_TYPES (TREE_TYPE (clone)); 4476 /* Skip the `this' parameter. */ 4477 parmtypes = TREE_CHAIN (parmtypes); 4478 /* Skip the in-charge parameter. */ 4479 parmtypes = TREE_CHAIN (parmtypes); 4480 /* And the VTT parm, in a complete [cd]tor. */ 4481 if (DECL_HAS_VTT_PARM_P (fn) 4482 && ! DECL_NEEDS_VTT_PARM_P (clone)) 4483 parmtypes = TREE_CHAIN (parmtypes); 4484 if (ctor_omit_inherited_parms_p) 4485 { 4486 /* If we're omitting inherited parms, that just leaves the VTT. */ 4487 gcc_assert (DECL_NEEDS_VTT_PARM_P (clone)); 4488 parmtypes = tree_cons (NULL_TREE, vtt_parm_type, void_list_node); 4489 } 4490 TREE_TYPE (clone) 4491 = build_method_type_directly (basetype, 4492 TREE_TYPE (TREE_TYPE (clone)), 4493 parmtypes); 4494 if (exceptions) 4495 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), 4496 exceptions); 4497 TREE_TYPE (clone) 4498 = cp_build_type_attribute_variant (TREE_TYPE (clone), 4499 TYPE_ATTRIBUTES (TREE_TYPE (fn))); 4500 } 4501 4502 /* Copy the function parameters. */ 4503 DECL_ARGUMENTS (clone) = copy_list (DECL_ARGUMENTS (clone)); 4504 /* Remove the in-charge parameter. */ 4505 if (DECL_HAS_IN_CHARGE_PARM_P (clone)) 4506 { 4507 DECL_CHAIN (DECL_ARGUMENTS (clone)) 4508 = DECL_CHAIN (DECL_CHAIN (DECL_ARGUMENTS (clone))); 4509 DECL_HAS_IN_CHARGE_PARM_P (clone) = 0; 4510 } 4511 /* And the VTT parm, in a complete [cd]tor. */ 4512 if (DECL_HAS_VTT_PARM_P (fn)) 4513 { 4514 if (DECL_NEEDS_VTT_PARM_P (clone)) 4515 DECL_HAS_VTT_PARM_P (clone) = 1; 4516 else 4517 { 4518 DECL_CHAIN (DECL_ARGUMENTS (clone)) 4519 = DECL_CHAIN (DECL_CHAIN (DECL_ARGUMENTS (clone))); 4520 DECL_HAS_VTT_PARM_P (clone) = 0; 4521 } 4522 } 4523 4524 /* A base constructor inheriting from a virtual base doesn't get the 4525 arguments. */ 4526 if (ctor_omit_inherited_parms_p) 4527 DECL_CHAIN (DECL_CHAIN (DECL_ARGUMENTS (clone))) = NULL_TREE; 4528 4529 for (parms = DECL_ARGUMENTS (clone); parms; parms = DECL_CHAIN (parms)) 4530 { 4531 DECL_CONTEXT (parms) = clone; 4532 cxx_dup_lang_specific_decl (parms); 4533 } 4534 4535 /* Create the RTL for this function. */ 4536 SET_DECL_RTL (clone, NULL); 4537 rest_of_decl_compilation (clone, /*top_level=*/1, at_eof); 4538 4539 return clone; 4540 } 4541 4542 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do 4543 not invoke this function directly. 4544 4545 For a non-thunk function, returns the address of the slot for storing 4546 the function it is a clone of. Otherwise returns NULL_TREE. 4547 4548 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if 4549 cloned_function is unset. This is to support the separate 4550 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter 4551 on a template makes sense, but not the former. */ 4552 4553 tree * 4554 decl_cloned_function_p (const_tree decl, bool just_testing) 4555 { 4556 tree *ptr; 4557 if (just_testing) 4558 decl = STRIP_TEMPLATE (decl); 4559 4560 if (TREE_CODE (decl) != FUNCTION_DECL 4561 || !DECL_LANG_SPECIFIC (decl) 4562 || DECL_LANG_SPECIFIC (decl)->u.fn.thunk_p) 4563 { 4564 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007) 4565 if (!just_testing) 4566 lang_check_failed (__FILE__, __LINE__, __FUNCTION__); 4567 else 4568 #endif 4569 return NULL; 4570 } 4571 4572 ptr = &DECL_LANG_SPECIFIC (decl)->u.fn.u5.cloned_function; 4573 if (just_testing && *ptr == NULL_TREE) 4574 return NULL; 4575 else 4576 return ptr; 4577 } 4578 4579 /* Produce declarations for all appropriate clones of FN. If 4580 UPDATE_METHODS is true, the clones are added to the 4581 CLASSTYPE_MEMBER_VEC. */ 4582 4583 void 4584 clone_function_decl (tree fn, bool update_methods) 4585 { 4586 tree clone; 4587 4588 /* Avoid inappropriate cloning. */ 4589 if (DECL_CHAIN (fn) 4590 && DECL_CLONED_FUNCTION_P (DECL_CHAIN (fn))) 4591 return; 4592 4593 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)) 4594 { 4595 /* For each constructor, we need two variants: an in-charge version 4596 and a not-in-charge version. */ 4597 clone = build_clone (fn, complete_ctor_identifier); 4598 if (update_methods) 4599 add_method (DECL_CONTEXT (clone), clone, false); 4600 clone = build_clone (fn, base_ctor_identifier); 4601 if (update_methods) 4602 add_method (DECL_CONTEXT (clone), clone, false); 4603 } 4604 else 4605 { 4606 gcc_assert (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)); 4607 4608 /* For each destructor, we need three variants: an in-charge 4609 version, a not-in-charge version, and an in-charge deleting 4610 version. We clone the deleting version first because that 4611 means it will go second on the TYPE_FIELDS list -- and that 4612 corresponds to the correct layout order in the virtual 4613 function table. 4614 4615 For a non-virtual destructor, we do not build a deleting 4616 destructor. */ 4617 if (DECL_VIRTUAL_P (fn)) 4618 { 4619 clone = build_clone (fn, deleting_dtor_identifier); 4620 if (update_methods) 4621 add_method (DECL_CONTEXT (clone), clone, false); 4622 } 4623 clone = build_clone (fn, complete_dtor_identifier); 4624 if (update_methods) 4625 add_method (DECL_CONTEXT (clone), clone, false); 4626 clone = build_clone (fn, base_dtor_identifier); 4627 if (update_methods) 4628 add_method (DECL_CONTEXT (clone), clone, false); 4629 } 4630 4631 /* Note that this is an abstract function that is never emitted. */ 4632 DECL_ABSTRACT_P (fn) = true; 4633 } 4634 4635 /* DECL is an in charge constructor, which is being defined. This will 4636 have had an in class declaration, from whence clones were 4637 declared. An out-of-class definition can specify additional default 4638 arguments. As it is the clones that are involved in overload 4639 resolution, we must propagate the information from the DECL to its 4640 clones. */ 4641 4642 void 4643 adjust_clone_args (tree decl) 4644 { 4645 tree clone; 4646 4647 for (clone = DECL_CHAIN (decl); clone && DECL_CLONED_FUNCTION_P (clone); 4648 clone = DECL_CHAIN (clone)) 4649 { 4650 tree orig_clone_parms = TYPE_ARG_TYPES (TREE_TYPE (clone)); 4651 tree orig_decl_parms = TYPE_ARG_TYPES (TREE_TYPE (decl)); 4652 tree decl_parms, clone_parms; 4653 4654 clone_parms = orig_clone_parms; 4655 4656 /* Skip the 'this' parameter. */ 4657 orig_clone_parms = TREE_CHAIN (orig_clone_parms); 4658 orig_decl_parms = TREE_CHAIN (orig_decl_parms); 4659 4660 if (DECL_HAS_IN_CHARGE_PARM_P (decl)) 4661 orig_decl_parms = TREE_CHAIN (orig_decl_parms); 4662 if (DECL_HAS_VTT_PARM_P (decl)) 4663 orig_decl_parms = TREE_CHAIN (orig_decl_parms); 4664 4665 clone_parms = orig_clone_parms; 4666 if (DECL_HAS_VTT_PARM_P (clone)) 4667 clone_parms = TREE_CHAIN (clone_parms); 4668 4669 for (decl_parms = orig_decl_parms; decl_parms; 4670 decl_parms = TREE_CHAIN (decl_parms), 4671 clone_parms = TREE_CHAIN (clone_parms)) 4672 { 4673 if (clone_parms == void_list_node) 4674 { 4675 gcc_assert (decl_parms == clone_parms 4676 || ctor_omit_inherited_parms (clone)); 4677 break; 4678 } 4679 4680 gcc_assert (same_type_p (TREE_TYPE (decl_parms), 4681 TREE_TYPE (clone_parms))); 4682 4683 if (TREE_PURPOSE (decl_parms) && !TREE_PURPOSE (clone_parms)) 4684 { 4685 /* A default parameter has been added. Adjust the 4686 clone's parameters. */ 4687 tree exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone)); 4688 tree attrs = TYPE_ATTRIBUTES (TREE_TYPE (clone)); 4689 tree basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone)); 4690 tree type; 4691 4692 clone_parms = orig_decl_parms; 4693 4694 if (DECL_HAS_VTT_PARM_P (clone)) 4695 { 4696 clone_parms = tree_cons (TREE_PURPOSE (orig_clone_parms), 4697 TREE_VALUE (orig_clone_parms), 4698 clone_parms); 4699 TREE_TYPE (clone_parms) = TREE_TYPE (orig_clone_parms); 4700 } 4701 type = build_method_type_directly (basetype, 4702 TREE_TYPE (TREE_TYPE (clone)), 4703 clone_parms); 4704 if (exceptions) 4705 type = build_exception_variant (type, exceptions); 4706 if (attrs) 4707 type = cp_build_type_attribute_variant (type, attrs); 4708 TREE_TYPE (clone) = type; 4709 4710 clone_parms = NULL_TREE; 4711 break; 4712 } 4713 } 4714 gcc_assert (!clone_parms || clone_parms == void_list_node); 4715 } 4716 } 4717 4718 /* For each of the constructors and destructors in T, create an 4719 in-charge and not-in-charge variant. */ 4720 4721 static void 4722 clone_constructors_and_destructors (tree t) 4723 { 4724 /* While constructors can be via a using declaration, at this point 4725 we no longer need to know that. */ 4726 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 4727 clone_function_decl (*iter, /*update_methods=*/true); 4728 4729 if (tree dtor = CLASSTYPE_DESTRUCTOR (t)) 4730 clone_function_decl (dtor, /*update_methods=*/true); 4731 } 4732 4733 /* Deduce noexcept for a destructor DTOR. */ 4734 4735 void 4736 deduce_noexcept_on_destructor (tree dtor) 4737 { 4738 if (!TYPE_RAISES_EXCEPTIONS (TREE_TYPE (dtor))) 4739 TREE_TYPE (dtor) = build_exception_variant (TREE_TYPE (dtor), 4740 noexcept_deferred_spec); 4741 } 4742 4743 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes 4744 of TYPE for virtual functions which FNDECL overrides. Return a 4745 mask of the tm attributes found therein. */ 4746 4747 static int 4748 look_for_tm_attr_overrides (tree type, tree fndecl) 4749 { 4750 tree binfo = TYPE_BINFO (type); 4751 tree base_binfo; 4752 int ix, found = 0; 4753 4754 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ++ix) 4755 { 4756 tree o, basetype = BINFO_TYPE (base_binfo); 4757 4758 if (!TYPE_POLYMORPHIC_P (basetype)) 4759 continue; 4760 4761 o = look_for_overrides_here (basetype, fndecl); 4762 if (o) 4763 { 4764 if (lookup_attribute ("transaction_safe_dynamic", 4765 DECL_ATTRIBUTES (o))) 4766 /* transaction_safe_dynamic is not inherited. */; 4767 else 4768 found |= tm_attr_to_mask (find_tm_attribute 4769 (TYPE_ATTRIBUTES (TREE_TYPE (o)))); 4770 } 4771 else 4772 found |= look_for_tm_attr_overrides (basetype, fndecl); 4773 } 4774 4775 return found; 4776 } 4777 4778 /* Subroutine of set_method_tm_attributes. Handle the checks and 4779 inheritance for one virtual method FNDECL. */ 4780 4781 static void 4782 set_one_vmethod_tm_attributes (tree type, tree fndecl) 4783 { 4784 tree tm_attr; 4785 int found, have; 4786 4787 found = look_for_tm_attr_overrides (type, fndecl); 4788 4789 /* If FNDECL doesn't actually override anything (i.e. T is the 4790 class that first declares FNDECL virtual), then we're done. */ 4791 if (found == 0) 4792 return; 4793 4794 tm_attr = find_tm_attribute (TYPE_ATTRIBUTES (TREE_TYPE (fndecl))); 4795 have = tm_attr_to_mask (tm_attr); 4796 4797 /* Intel STM Language Extension 3.0, Section 4.2 table 4: 4798 tm_pure must match exactly, otherwise no weakening of 4799 tm_safe > tm_callable > nothing. */ 4800 /* ??? The tm_pure attribute didn't make the transition to the 4801 multivendor language spec. */ 4802 if (have == TM_ATTR_PURE) 4803 { 4804 if (found != TM_ATTR_PURE) 4805 { 4806 found &= -found; 4807 goto err_override; 4808 } 4809 } 4810 /* If the overridden function is tm_pure, then FNDECL must be. */ 4811 else if (found == TM_ATTR_PURE && tm_attr) 4812 goto err_override; 4813 /* Look for base class combinations that cannot be satisfied. */ 4814 else if (found != TM_ATTR_PURE && (found & TM_ATTR_PURE)) 4815 { 4816 found &= ~TM_ATTR_PURE; 4817 found &= -found; 4818 error_at (DECL_SOURCE_LOCATION (fndecl), 4819 "method overrides both %<transaction_pure%> and %qE methods", 4820 tm_mask_to_attr (found)); 4821 } 4822 /* If FNDECL did not declare an attribute, then inherit the most 4823 restrictive one. */ 4824 else if (tm_attr == NULL) 4825 { 4826 apply_tm_attr (fndecl, tm_mask_to_attr (least_bit_hwi (found))); 4827 } 4828 /* Otherwise validate that we're not weaker than a function 4829 that is being overridden. */ 4830 else 4831 { 4832 found &= -found; 4833 if (found <= TM_ATTR_CALLABLE && have > found) 4834 goto err_override; 4835 } 4836 return; 4837 4838 err_override: 4839 error_at (DECL_SOURCE_LOCATION (fndecl), 4840 "method declared %qE overriding %qE method", 4841 tm_attr, tm_mask_to_attr (found)); 4842 } 4843 4844 /* For each of the methods in T, propagate a class-level tm attribute. */ 4845 4846 static void 4847 set_method_tm_attributes (tree t) 4848 { 4849 tree class_tm_attr, fndecl; 4850 4851 /* Don't bother collecting tm attributes if transactional memory 4852 support is not enabled. */ 4853 if (!flag_tm) 4854 return; 4855 4856 /* Process virtual methods first, as they inherit directly from the 4857 base virtual function and also require validation of new attributes. */ 4858 if (TYPE_CONTAINS_VPTR_P (t)) 4859 { 4860 tree vchain; 4861 for (vchain = BINFO_VIRTUALS (TYPE_BINFO (t)); vchain; 4862 vchain = TREE_CHAIN (vchain)) 4863 { 4864 fndecl = BV_FN (vchain); 4865 if (DECL_THUNK_P (fndecl)) 4866 fndecl = THUNK_TARGET (fndecl); 4867 set_one_vmethod_tm_attributes (t, fndecl); 4868 } 4869 } 4870 4871 /* If the class doesn't have an attribute, nothing more to do. */ 4872 class_tm_attr = find_tm_attribute (TYPE_ATTRIBUTES (t)); 4873 if (class_tm_attr == NULL) 4874 return; 4875 4876 /* Any method that does not yet have a tm attribute inherits 4877 the one from the class. */ 4878 for (fndecl = TYPE_FIELDS (t); fndecl; fndecl = DECL_CHAIN (fndecl)) 4879 if (DECL_DECLARES_FUNCTION_P (fndecl) 4880 && !find_tm_attribute (TYPE_ATTRIBUTES (TREE_TYPE (fndecl)))) 4881 apply_tm_attr (fndecl, class_tm_attr); 4882 } 4883 4884 /* Returns true if FN is a default constructor. */ 4885 4886 bool 4887 default_ctor_p (tree fn) 4888 { 4889 return (DECL_CONSTRUCTOR_P (fn) 4890 && sufficient_parms_p (FUNCTION_FIRST_USER_PARMTYPE (fn))); 4891 } 4892 4893 /* Returns true iff class T has a user-defined constructor that can be called 4894 with more than zero arguments. */ 4895 4896 bool 4897 type_has_user_nondefault_constructor (tree t) 4898 { 4899 if (!TYPE_HAS_USER_CONSTRUCTOR (t)) 4900 return false; 4901 4902 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 4903 { 4904 tree fn = *iter; 4905 if (!DECL_ARTIFICIAL (fn) 4906 && (TREE_CODE (fn) == TEMPLATE_DECL 4907 || (skip_artificial_parms_for (fn, DECL_ARGUMENTS (fn)) 4908 != NULL_TREE))) 4909 return true; 4910 } 4911 4912 return false; 4913 } 4914 4915 /* Returns the defaulted constructor if T has one. Otherwise, returns 4916 NULL_TREE. */ 4917 4918 tree 4919 in_class_defaulted_default_constructor (tree t) 4920 { 4921 if (!TYPE_HAS_USER_CONSTRUCTOR (t)) 4922 return NULL_TREE; 4923 4924 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 4925 { 4926 tree fn = *iter; 4927 4928 if (DECL_DEFAULTED_IN_CLASS_P (fn) 4929 && default_ctor_p (fn)) 4930 return fn; 4931 } 4932 4933 return NULL_TREE; 4934 } 4935 4936 /* Returns true iff FN is a user-provided function, i.e. user-declared 4937 and not defaulted at its first declaration. */ 4938 4939 bool 4940 user_provided_p (tree fn) 4941 { 4942 if (TREE_CODE (fn) == TEMPLATE_DECL) 4943 return true; 4944 else 4945 return (!DECL_ARTIFICIAL (fn) 4946 && !(DECL_INITIALIZED_IN_CLASS_P (fn) 4947 && (DECL_DEFAULTED_FN (fn) || DECL_DELETED_FN (fn)))); 4948 } 4949 4950 /* Returns true iff class T has a user-provided constructor. */ 4951 4952 bool 4953 type_has_user_provided_constructor (tree t) 4954 { 4955 if (!CLASS_TYPE_P (t)) 4956 return false; 4957 4958 if (!TYPE_HAS_USER_CONSTRUCTOR (t)) 4959 return false; 4960 4961 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 4962 if (user_provided_p (*iter)) 4963 return true; 4964 4965 return false; 4966 } 4967 4968 /* Returns true iff class T has a user-provided or explicit constructor. */ 4969 4970 bool 4971 type_has_user_provided_or_explicit_constructor (tree t) 4972 { 4973 if (!CLASS_TYPE_P (t)) 4974 return false; 4975 4976 if (!TYPE_HAS_USER_CONSTRUCTOR (t)) 4977 return false; 4978 4979 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 4980 { 4981 tree fn = *iter; 4982 if (user_provided_p (fn) || DECL_NONCONVERTING_P (fn)) 4983 return true; 4984 } 4985 4986 return false; 4987 } 4988 4989 /* Returns true iff class T has a non-user-provided (i.e. implicitly 4990 declared or explicitly defaulted in the class body) default 4991 constructor. */ 4992 4993 bool 4994 type_has_non_user_provided_default_constructor (tree t) 4995 { 4996 if (!TYPE_HAS_DEFAULT_CONSTRUCTOR (t)) 4997 return false; 4998 if (CLASSTYPE_LAZY_DEFAULT_CTOR (t)) 4999 return true; 5000 5001 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 5002 { 5003 tree fn = *iter; 5004 if (TREE_CODE (fn) == FUNCTION_DECL 5005 && default_ctor_p (fn) 5006 && !user_provided_p (fn)) 5007 return true; 5008 } 5009 5010 return false; 5011 } 5012 5013 /* TYPE is being used as a virtual base, and has a non-trivial move 5014 assignment. Return true if this is due to there being a user-provided 5015 move assignment in TYPE or one of its subobjects; if there isn't, then 5016 multiple move assignment can't cause any harm. */ 5017 5018 bool 5019 vbase_has_user_provided_move_assign (tree type) 5020 { 5021 /* Does the type itself have a user-provided move assignment operator? */ 5022 if (!CLASSTYPE_LAZY_MOVE_ASSIGN (type)) 5023 for (ovl_iterator iter (get_class_binding_direct 5024 (type, assign_op_identifier)); 5025 iter; ++iter) 5026 if (!DECL_ARTIFICIAL (*iter) && move_fn_p (*iter)) 5027 return true; 5028 5029 /* Do any of its bases? */ 5030 tree binfo = TYPE_BINFO (type); 5031 tree base_binfo; 5032 for (int i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 5033 if (vbase_has_user_provided_move_assign (BINFO_TYPE (base_binfo))) 5034 return true; 5035 5036 /* Or non-static data members? */ 5037 for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) 5038 { 5039 if (TREE_CODE (field) == FIELD_DECL 5040 && CLASS_TYPE_P (TREE_TYPE (field)) 5041 && vbase_has_user_provided_move_assign (TREE_TYPE (field))) 5042 return true; 5043 } 5044 5045 /* Seems not. */ 5046 return false; 5047 } 5048 5049 /* If default-initialization leaves part of TYPE uninitialized, returns 5050 a DECL for the field or TYPE itself (DR 253). */ 5051 5052 tree 5053 default_init_uninitialized_part (tree type) 5054 { 5055 tree t, r, binfo; 5056 int i; 5057 5058 type = strip_array_types (type); 5059 if (!CLASS_TYPE_P (type)) 5060 return type; 5061 if (!type_has_non_user_provided_default_constructor (type)) 5062 return NULL_TREE; 5063 for (binfo = TYPE_BINFO (type), i = 0; 5064 BINFO_BASE_ITERATE (binfo, i, t); ++i) 5065 { 5066 r = default_init_uninitialized_part (BINFO_TYPE (t)); 5067 if (r) 5068 return r; 5069 } 5070 for (t = TYPE_FIELDS (type); t; t = DECL_CHAIN (t)) 5071 if (TREE_CODE (t) == FIELD_DECL 5072 && !DECL_ARTIFICIAL (t) 5073 && !DECL_INITIAL (t)) 5074 { 5075 r = default_init_uninitialized_part (TREE_TYPE (t)); 5076 if (r) 5077 return DECL_P (r) ? r : t; 5078 } 5079 5080 return NULL_TREE; 5081 } 5082 5083 /* Returns true iff for class T, a trivial synthesized default constructor 5084 would be constexpr. */ 5085 5086 bool 5087 trivial_default_constructor_is_constexpr (tree t) 5088 { 5089 /* A defaulted trivial default constructor is constexpr 5090 if there is nothing to initialize. */ 5091 gcc_assert (!TYPE_HAS_COMPLEX_DFLT (t)); 5092 return is_really_empty_class (t); 5093 } 5094 5095 /* Returns true iff class T has a constexpr default constructor. */ 5096 5097 bool 5098 type_has_constexpr_default_constructor (tree t) 5099 { 5100 tree fns; 5101 5102 if (!CLASS_TYPE_P (t)) 5103 { 5104 /* The caller should have stripped an enclosing array. */ 5105 gcc_assert (TREE_CODE (t) != ARRAY_TYPE); 5106 return false; 5107 } 5108 if (CLASSTYPE_LAZY_DEFAULT_CTOR (t)) 5109 { 5110 if (!TYPE_HAS_COMPLEX_DFLT (t)) 5111 return trivial_default_constructor_is_constexpr (t); 5112 /* Non-trivial, we need to check subobject constructors. */ 5113 lazily_declare_fn (sfk_constructor, t); 5114 } 5115 fns = locate_ctor (t); 5116 return (fns && DECL_DECLARED_CONSTEXPR_P (fns)); 5117 } 5118 5119 /* Returns true iff class T has a constexpr default constructor or has an 5120 implicitly declared default constructor that we can't tell if it's constexpr 5121 without forcing a lazy declaration (which might cause undesired 5122 instantiations). */ 5123 5124 bool 5125 type_maybe_constexpr_default_constructor (tree t) 5126 { 5127 if (CLASS_TYPE_P (t) && CLASSTYPE_LAZY_DEFAULT_CTOR (t) 5128 && TYPE_HAS_COMPLEX_DFLT (t)) 5129 /* Assume it's constexpr. */ 5130 return true; 5131 return type_has_constexpr_default_constructor (t); 5132 } 5133 5134 /* Returns true iff class TYPE has a virtual destructor. */ 5135 5136 bool 5137 type_has_virtual_destructor (tree type) 5138 { 5139 tree dtor; 5140 5141 if (!CLASS_TYPE_P (type)) 5142 return false; 5143 5144 gcc_assert (COMPLETE_TYPE_P (type)); 5145 dtor = CLASSTYPE_DESTRUCTOR (type); 5146 return (dtor && DECL_VIRTUAL_P (dtor)); 5147 } 5148 5149 /* Returns true iff T, a class, has a move-assignment or 5150 move-constructor. Does not lazily declare either. 5151 If USER_P is false, any move function will do. If it is true, the 5152 move function must be user-declared. 5153 5154 Note that user-declared here is different from "user-provided", 5155 which doesn't include functions that are defaulted in the 5156 class. */ 5157 5158 bool 5159 classtype_has_move_assign_or_move_ctor_p (tree t, bool user_p) 5160 { 5161 gcc_assert (user_p 5162 || (!CLASSTYPE_LAZY_MOVE_CTOR (t) 5163 && !CLASSTYPE_LAZY_MOVE_ASSIGN (t))); 5164 5165 if (!CLASSTYPE_LAZY_MOVE_CTOR (t)) 5166 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 5167 if ((!user_p || !DECL_ARTIFICIAL (*iter)) && move_fn_p (*iter)) 5168 return true; 5169 5170 if (!CLASSTYPE_LAZY_MOVE_ASSIGN (t)) 5171 for (ovl_iterator iter (get_class_binding_direct 5172 (t, assign_op_identifier)); 5173 iter; ++iter) 5174 if ((!user_p || !DECL_ARTIFICIAL (*iter)) && move_fn_p (*iter)) 5175 return true; 5176 5177 return false; 5178 } 5179 5180 /* True iff T has a move constructor that is not deleted. */ 5181 5182 bool 5183 classtype_has_non_deleted_move_ctor (tree t) 5184 { 5185 if (CLASSTYPE_LAZY_MOVE_CTOR (t)) 5186 lazily_declare_fn (sfk_move_constructor, t); 5187 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 5188 if (move_fn_p (*iter) && !DECL_DELETED_FN (*iter)) 5189 return true; 5190 return false; 5191 } 5192 5193 /* Nonzero if we need to build up a constructor call when initializing an 5194 object of this class, either because it has a user-declared constructor 5195 or because it doesn't have a default constructor (so we need to give an 5196 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when 5197 what you care about is whether or not an object can be produced by a 5198 constructor (e.g. so we don't set TREE_READONLY on const variables of 5199 such type); use this function when what you care about is whether or not 5200 to try to call a constructor to create an object. The latter case is 5201 the former plus some cases of constructors that cannot be called. */ 5202 5203 bool 5204 type_build_ctor_call (tree t) 5205 { 5206 tree inner; 5207 if (TYPE_NEEDS_CONSTRUCTING (t)) 5208 return true; 5209 inner = strip_array_types (t); 5210 if (!CLASS_TYPE_P (inner) || ANON_AGGR_TYPE_P (inner)) 5211 return false; 5212 if (!TYPE_HAS_DEFAULT_CONSTRUCTOR (inner)) 5213 return true; 5214 if (cxx_dialect < cxx11) 5215 return false; 5216 /* A user-declared constructor might be private, and a constructor might 5217 be trivial but deleted. */ 5218 for (ovl_iterator iter (get_class_binding (inner, complete_ctor_identifier)); 5219 iter; ++iter) 5220 { 5221 tree fn = *iter; 5222 if (!DECL_ARTIFICIAL (fn) 5223 || DECL_DELETED_FN (fn)) 5224 return true; 5225 } 5226 return false; 5227 } 5228 5229 /* Like type_build_ctor_call, but for destructors. */ 5230 5231 bool 5232 type_build_dtor_call (tree t) 5233 { 5234 tree inner; 5235 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)) 5236 return true; 5237 inner = strip_array_types (t); 5238 if (!CLASS_TYPE_P (inner) || ANON_AGGR_TYPE_P (inner) 5239 || !COMPLETE_TYPE_P (inner)) 5240 return false; 5241 if (cxx_dialect < cxx11) 5242 return false; 5243 /* A user-declared destructor might be private, and a destructor might 5244 be trivial but deleted. */ 5245 for (ovl_iterator iter (get_class_binding (inner, complete_dtor_identifier)); 5246 iter; ++iter) 5247 { 5248 tree fn = *iter; 5249 if (!DECL_ARTIFICIAL (fn) 5250 || DECL_DELETED_FN (fn)) 5251 return true; 5252 } 5253 return false; 5254 } 5255 5256 /* Remove all zero-width bit-fields from T. */ 5257 5258 static void 5259 remove_zero_width_bit_fields (tree t) 5260 { 5261 tree *fieldsp; 5262 5263 fieldsp = &TYPE_FIELDS (t); 5264 while (*fieldsp) 5265 { 5266 if (TREE_CODE (*fieldsp) == FIELD_DECL 5267 && DECL_C_BIT_FIELD (*fieldsp) 5268 /* We should not be confused by the fact that grokbitfield 5269 temporarily sets the width of the bit field into 5270 DECL_BIT_FIELD_REPRESENTATIVE (*fieldsp). 5271 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp) 5272 to that width. */ 5273 && (DECL_SIZE (*fieldsp) == NULL_TREE 5274 || integer_zerop (DECL_SIZE (*fieldsp)))) 5275 *fieldsp = DECL_CHAIN (*fieldsp); 5276 else 5277 fieldsp = &DECL_CHAIN (*fieldsp); 5278 } 5279 } 5280 5281 /* Returns TRUE iff we need a cookie when dynamically allocating an 5282 array whose elements have the indicated class TYPE. */ 5283 5284 static bool 5285 type_requires_array_cookie (tree type) 5286 { 5287 tree fns; 5288 bool has_two_argument_delete_p = false; 5289 5290 gcc_assert (CLASS_TYPE_P (type)); 5291 5292 /* If there's a non-trivial destructor, we need a cookie. In order 5293 to iterate through the array calling the destructor for each 5294 element, we'll have to know how many elements there are. */ 5295 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 5296 return true; 5297 5298 /* If the usual deallocation function is a two-argument whose second 5299 argument is of type `size_t', then we have to pass the size of 5300 the array to the deallocation function, so we will need to store 5301 a cookie. */ 5302 fns = lookup_fnfields (TYPE_BINFO (type), 5303 ovl_op_identifier (false, VEC_DELETE_EXPR), 5304 /*protect=*/0); 5305 /* If there are no `operator []' members, or the lookup is 5306 ambiguous, then we don't need a cookie. */ 5307 if (!fns || fns == error_mark_node) 5308 return false; 5309 /* Loop through all of the functions. */ 5310 for (lkp_iterator iter (BASELINK_FUNCTIONS (fns)); iter; ++iter) 5311 { 5312 tree fn = *iter; 5313 5314 /* See if this function is a one-argument delete function. If 5315 it is, then it will be the usual deallocation function. */ 5316 tree second_parm = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fn))); 5317 if (second_parm == void_list_node) 5318 return false; 5319 /* Do not consider this function if its second argument is an 5320 ellipsis. */ 5321 if (!second_parm) 5322 continue; 5323 /* Otherwise, if we have a two-argument function and the second 5324 argument is `size_t', it will be the usual deallocation 5325 function -- unless there is one-argument function, too. */ 5326 if (TREE_CHAIN (second_parm) == void_list_node 5327 && same_type_p (TREE_VALUE (second_parm), size_type_node)) 5328 has_two_argument_delete_p = true; 5329 } 5330 5331 return has_two_argument_delete_p; 5332 } 5333 5334 /* Finish computing the `literal type' property of class type T. 5335 5336 At this point, we have already processed base classes and 5337 non-static data members. We need to check whether the copy 5338 constructor is trivial, the destructor is trivial, and there 5339 is a trivial default constructor or at least one constexpr 5340 constructor other than the copy constructor. */ 5341 5342 static void 5343 finalize_literal_type_property (tree t) 5344 { 5345 tree fn; 5346 5347 if (cxx_dialect < cxx11 5348 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)) 5349 CLASSTYPE_LITERAL_P (t) = false; 5350 else if (CLASSTYPE_LITERAL_P (t) && LAMBDA_TYPE_P (t)) 5351 CLASSTYPE_LITERAL_P (t) = (cxx_dialect >= cxx17); 5352 else if (CLASSTYPE_LITERAL_P (t) && !TYPE_HAS_TRIVIAL_DFLT (t) 5353 && CLASSTYPE_NON_AGGREGATE (t) 5354 && !TYPE_HAS_CONSTEXPR_CTOR (t)) 5355 CLASSTYPE_LITERAL_P (t) = false; 5356 5357 /* C++14 DR 1684 removed this restriction. */ 5358 if (cxx_dialect < cxx14 5359 && !CLASSTYPE_LITERAL_P (t) && !LAMBDA_TYPE_P (t)) 5360 for (fn = TYPE_FIELDS (t); fn; fn = DECL_CHAIN (fn)) 5361 if (TREE_CODE (fn) == FUNCTION_DECL 5362 && DECL_DECLARED_CONSTEXPR_P (fn) 5363 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) 5364 && !DECL_CONSTRUCTOR_P (fn)) 5365 { 5366 DECL_DECLARED_CONSTEXPR_P (fn) = false; 5367 if (!DECL_GENERATED_P (fn) 5368 && pedwarn (DECL_SOURCE_LOCATION (fn), OPT_Wpedantic, 5369 "enclosing class of %<constexpr%> non-static member " 5370 "function %q+#D is not a literal type", fn)) 5371 explain_non_literal_class (t); 5372 } 5373 } 5374 5375 /* T is a non-literal type used in a context which requires a constant 5376 expression. Explain why it isn't literal. */ 5377 5378 void 5379 explain_non_literal_class (tree t) 5380 { 5381 static hash_set<tree> *diagnosed; 5382 5383 if (!CLASS_TYPE_P (t)) 5384 return; 5385 t = TYPE_MAIN_VARIANT (t); 5386 5387 if (diagnosed == NULL) 5388 diagnosed = new hash_set<tree>; 5389 if (diagnosed->add (t)) 5390 /* Already explained. */ 5391 return; 5392 5393 inform (UNKNOWN_LOCATION, "%q+T is not literal because:", t); 5394 if (cxx_dialect < cxx17 && LAMBDA_TYPE_P (t)) 5395 inform (UNKNOWN_LOCATION, 5396 " %qT is a closure type, which is only literal in " 5397 "C++17 and later", t); 5398 else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)) 5399 inform (UNKNOWN_LOCATION, " %q+T has a non-trivial destructor", t); 5400 else if (CLASSTYPE_NON_AGGREGATE (t) 5401 && !TYPE_HAS_TRIVIAL_DFLT (t) 5402 && !LAMBDA_TYPE_P (t) 5403 && !TYPE_HAS_CONSTEXPR_CTOR (t)) 5404 { 5405 inform (UNKNOWN_LOCATION, 5406 " %q+T is not an aggregate, does not have a trivial " 5407 "default constructor, and has no %<constexpr%> constructor that " 5408 "is not a copy or move constructor", t); 5409 if (type_has_non_user_provided_default_constructor (t)) 5410 /* Note that we can't simply call locate_ctor because when the 5411 constructor is deleted it just returns NULL_TREE. */ 5412 for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter) 5413 { 5414 tree fn = *iter; 5415 tree parms = TYPE_ARG_TYPES (TREE_TYPE (fn)); 5416 5417 parms = skip_artificial_parms_for (fn, parms); 5418 5419 if (sufficient_parms_p (parms)) 5420 { 5421 if (DECL_DELETED_FN (fn)) 5422 maybe_explain_implicit_delete (fn); 5423 else 5424 explain_invalid_constexpr_fn (fn); 5425 break; 5426 } 5427 } 5428 } 5429 else 5430 { 5431 tree binfo, base_binfo, field; int i; 5432 for (binfo = TYPE_BINFO (t), i = 0; 5433 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 5434 { 5435 tree basetype = TREE_TYPE (base_binfo); 5436 if (!CLASSTYPE_LITERAL_P (basetype)) 5437 { 5438 inform (UNKNOWN_LOCATION, 5439 " base class %qT of %q+T is non-literal", 5440 basetype, t); 5441 explain_non_literal_class (basetype); 5442 return; 5443 } 5444 } 5445 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field)) 5446 { 5447 tree ftype; 5448 if (TREE_CODE (field) != FIELD_DECL) 5449 continue; 5450 ftype = TREE_TYPE (field); 5451 if (!literal_type_p (ftype)) 5452 { 5453 inform (DECL_SOURCE_LOCATION (field), 5454 " non-static data member %qD has non-literal type", 5455 field); 5456 if (CLASS_TYPE_P (ftype)) 5457 explain_non_literal_class (ftype); 5458 } 5459 if (CP_TYPE_VOLATILE_P (ftype)) 5460 inform (DECL_SOURCE_LOCATION (field), 5461 " non-static data member %qD has volatile type", field); 5462 } 5463 } 5464 } 5465 5466 /* Check the validity of the bases and members declared in T. Add any 5467 implicitly-generated functions (like copy-constructors and 5468 assignment operators). Compute various flag bits (like 5469 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++ 5470 level: i.e., independently of the ABI in use. */ 5471 5472 static void 5473 check_bases_and_members (tree t) 5474 { 5475 /* Nonzero if the implicitly generated copy constructor should take 5476 a non-const reference argument. */ 5477 int cant_have_const_ctor; 5478 /* Nonzero if the implicitly generated assignment operator 5479 should take a non-const reference argument. */ 5480 int no_const_asn_ref; 5481 tree access_decls; 5482 bool saved_complex_asn_ref; 5483 bool saved_nontrivial_dtor; 5484 tree fn; 5485 5486 /* By default, we use const reference arguments and generate default 5487 constructors. */ 5488 cant_have_const_ctor = 0; 5489 no_const_asn_ref = 0; 5490 5491 /* Check all the base-classes and set FMEM members to point to arrays 5492 of potential interest. */ 5493 check_bases (t, &cant_have_const_ctor, &no_const_asn_ref); 5494 5495 /* Deduce noexcept on destructor. This needs to happen after we've set 5496 triviality flags appropriately for our bases. */ 5497 if (cxx_dialect >= cxx11) 5498 if (tree dtor = CLASSTYPE_DESTRUCTOR (t)) 5499 deduce_noexcept_on_destructor (dtor); 5500 5501 /* Check all the method declarations. */ 5502 check_methods (t); 5503 5504 /* Save the initial values of these flags which only indicate whether 5505 or not the class has user-provided functions. As we analyze the 5506 bases and members we can set these flags for other reasons. */ 5507 saved_complex_asn_ref = TYPE_HAS_COMPLEX_COPY_ASSIGN (t); 5508 saved_nontrivial_dtor = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t); 5509 5510 /* Check all the data member declarations. We cannot call 5511 check_field_decls until we have called check_bases check_methods, 5512 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR 5513 being set appropriately. */ 5514 check_field_decls (t, &access_decls, 5515 &cant_have_const_ctor, 5516 &no_const_asn_ref); 5517 5518 /* A nearly-empty class has to be vptr-containing; a nearly empty 5519 class contains just a vptr. */ 5520 if (!TYPE_CONTAINS_VPTR_P (t)) 5521 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 5522 5523 /* Do some bookkeeping that will guide the generation of implicitly 5524 declared member functions. */ 5525 TYPE_HAS_COMPLEX_COPY_CTOR (t) |= TYPE_CONTAINS_VPTR_P (t); 5526 TYPE_HAS_COMPLEX_MOVE_CTOR (t) |= TYPE_CONTAINS_VPTR_P (t); 5527 /* We need to call a constructor for this class if it has a 5528 user-provided constructor, or if the default constructor is going 5529 to initialize the vptr. (This is not an if-and-only-if; 5530 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members 5531 themselves need constructing.) */ 5532 TYPE_NEEDS_CONSTRUCTING (t) 5533 |= (type_has_user_provided_constructor (t) || TYPE_CONTAINS_VPTR_P (t)); 5534 /* [dcl.init.aggr] 5535 5536 An aggregate is an array or a class with no user-provided 5537 constructors ... and no virtual functions. 5538 5539 Again, other conditions for being an aggregate are checked 5540 elsewhere. */ 5541 CLASSTYPE_NON_AGGREGATE (t) 5542 |= (type_has_user_provided_or_explicit_constructor (t) 5543 || TYPE_POLYMORPHIC_P (t)); 5544 /* This is the C++98/03 definition of POD; it changed in C++0x, but we 5545 retain the old definition internally for ABI reasons. */ 5546 CLASSTYPE_NON_LAYOUT_POD_P (t) 5547 |= (CLASSTYPE_NON_AGGREGATE (t) 5548 || saved_nontrivial_dtor || saved_complex_asn_ref); 5549 CLASSTYPE_NON_STD_LAYOUT (t) |= TYPE_CONTAINS_VPTR_P (t); 5550 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) |= TYPE_CONTAINS_VPTR_P (t); 5551 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) |= TYPE_CONTAINS_VPTR_P (t); 5552 TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_CONTAINS_VPTR_P (t); 5553 5554 /* If the only explicitly declared default constructor is user-provided, 5555 set TYPE_HAS_COMPLEX_DFLT. */ 5556 if (!TYPE_HAS_COMPLEX_DFLT (t) 5557 && TYPE_HAS_DEFAULT_CONSTRUCTOR (t) 5558 && !type_has_non_user_provided_default_constructor (t)) 5559 TYPE_HAS_COMPLEX_DFLT (t) = true; 5560 5561 /* Warn if a public base of a polymorphic type has an accessible 5562 non-virtual destructor. It is only now that we know the class is 5563 polymorphic. Although a polymorphic base will have a already 5564 been diagnosed during its definition, we warn on use too. */ 5565 if (TYPE_POLYMORPHIC_P (t) && warn_nonvdtor) 5566 { 5567 tree binfo = TYPE_BINFO (t); 5568 vec<tree, va_gc> *accesses = BINFO_BASE_ACCESSES (binfo); 5569 tree base_binfo; 5570 unsigned i; 5571 5572 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 5573 { 5574 tree basetype = TREE_TYPE (base_binfo); 5575 5576 if ((*accesses)[i] == access_public_node 5577 && (TYPE_POLYMORPHIC_P (basetype) || warn_ecpp) 5578 && accessible_nvdtor_p (basetype)) 5579 warning (OPT_Wnon_virtual_dtor, 5580 "base class %q#T has accessible non-virtual destructor", 5581 basetype); 5582 } 5583 } 5584 5585 /* If the class has no user-declared constructor, but does have 5586 non-static const or reference data members that can never be 5587 initialized, issue a warning. */ 5588 if (warn_uninitialized 5589 /* Classes with user-declared constructors are presumed to 5590 initialize these members. */ 5591 && !TYPE_HAS_USER_CONSTRUCTOR (t) 5592 /* Aggregates can be initialized with brace-enclosed 5593 initializers. */ 5594 && CLASSTYPE_NON_AGGREGATE (t)) 5595 { 5596 tree field; 5597 5598 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) 5599 { 5600 tree type; 5601 5602 if (TREE_CODE (field) != FIELD_DECL 5603 || DECL_INITIAL (field) != NULL_TREE) 5604 continue; 5605 5606 type = TREE_TYPE (field); 5607 if (TREE_CODE (type) == REFERENCE_TYPE) 5608 warning_at (DECL_SOURCE_LOCATION (field), 5609 OPT_Wuninitialized, "non-static reference %q#D " 5610 "in class without a constructor", field); 5611 else if (CP_TYPE_CONST_P (type) 5612 && (!CLASS_TYPE_P (type) 5613 || !TYPE_HAS_DEFAULT_CONSTRUCTOR (type))) 5614 warning_at (DECL_SOURCE_LOCATION (field), 5615 OPT_Wuninitialized, "non-static const member %q#D " 5616 "in class without a constructor", field); 5617 } 5618 } 5619 5620 /* Synthesize any needed methods. */ 5621 add_implicitly_declared_members (t, &access_decls, 5622 cant_have_const_ctor, 5623 no_const_asn_ref); 5624 5625 /* Check defaulted declarations here so we have cant_have_const_ctor 5626 and don't need to worry about clones. */ 5627 for (fn = TYPE_FIELDS (t); fn; fn = DECL_CHAIN (fn)) 5628 if (DECL_DECLARES_FUNCTION_P (fn) 5629 && !DECL_ARTIFICIAL (fn) 5630 && DECL_DEFAULTED_IN_CLASS_P (fn)) 5631 { 5632 int copy = copy_fn_p (fn); 5633 if (copy > 0) 5634 { 5635 bool imp_const_p 5636 = (DECL_CONSTRUCTOR_P (fn) ? !cant_have_const_ctor 5637 : !no_const_asn_ref); 5638 bool fn_const_p = (copy == 2); 5639 5640 if (fn_const_p && !imp_const_p) 5641 /* If the function is defaulted outside the class, we just 5642 give the synthesis error. */ 5643 error ("%q+D declared to take const reference, but implicit " 5644 "declaration would take non-const", fn); 5645 } 5646 defaulted_late_check (fn); 5647 } 5648 5649 if (LAMBDA_TYPE_P (t)) 5650 { 5651 /* "This class type is not an aggregate." */ 5652 CLASSTYPE_NON_AGGREGATE (t) = 1; 5653 } 5654 5655 /* Compute the 'literal type' property before we 5656 do anything with non-static member functions. */ 5657 finalize_literal_type_property (t); 5658 5659 /* Create the in-charge and not-in-charge variants of constructors 5660 and destructors. */ 5661 clone_constructors_and_destructors (t); 5662 5663 /* Process the using-declarations. */ 5664 for (; access_decls; access_decls = TREE_CHAIN (access_decls)) 5665 handle_using_decl (TREE_VALUE (access_decls), t); 5666 5667 /* Figure out whether or not we will need a cookie when dynamically 5668 allocating an array of this type. */ 5669 LANG_TYPE_CLASS_CHECK (t)->vec_new_uses_cookie 5670 = type_requires_array_cookie (t); 5671 } 5672 5673 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD 5674 accordingly. If a new vfield was created (because T doesn't have a 5675 primary base class), then the newly created field is returned. It 5676 is not added to the TYPE_FIELDS list; it is the caller's 5677 responsibility to do that. Accumulate declared virtual functions 5678 on VIRTUALS_P. */ 5679 5680 static tree 5681 create_vtable_ptr (tree t, tree* virtuals_p) 5682 { 5683 tree fn; 5684 5685 /* Collect the virtual functions declared in T. */ 5686 for (fn = TYPE_FIELDS (t); fn; fn = DECL_CHAIN (fn)) 5687 if (TREE_CODE (fn) == FUNCTION_DECL 5688 && DECL_VINDEX (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn) 5689 && TREE_CODE (DECL_VINDEX (fn)) != INTEGER_CST) 5690 { 5691 tree new_virtual = make_node (TREE_LIST); 5692 5693 BV_FN (new_virtual) = fn; 5694 BV_DELTA (new_virtual) = integer_zero_node; 5695 BV_VCALL_INDEX (new_virtual) = NULL_TREE; 5696 5697 TREE_CHAIN (new_virtual) = *virtuals_p; 5698 *virtuals_p = new_virtual; 5699 } 5700 5701 /* If we couldn't find an appropriate base class, create a new field 5702 here. Even if there weren't any new virtual functions, we might need a 5703 new virtual function table if we're supposed to include vptrs in 5704 all classes that need them. */ 5705 if (!TYPE_VFIELD (t) && (*virtuals_p || TYPE_CONTAINS_VPTR_P (t))) 5706 { 5707 /* We build this decl with vtbl_ptr_type_node, which is a 5708 `vtable_entry_type*'. It might seem more precise to use 5709 `vtable_entry_type (*)[N]' where N is the number of virtual 5710 functions. However, that would require the vtable pointer in 5711 base classes to have a different type than the vtable pointer 5712 in derived classes. We could make that happen, but that 5713 still wouldn't solve all the problems. In particular, the 5714 type-based alias analysis code would decide that assignments 5715 to the base class vtable pointer can't alias assignments to 5716 the derived class vtable pointer, since they have different 5717 types. Thus, in a derived class destructor, where the base 5718 class constructor was inlined, we could generate bad code for 5719 setting up the vtable pointer. 5720 5721 Therefore, we use one type for all vtable pointers. We still 5722 use a type-correct type; it's just doesn't indicate the array 5723 bounds. That's better than using `void*' or some such; it's 5724 cleaner, and it let's the alias analysis code know that these 5725 stores cannot alias stores to void*! */ 5726 tree field; 5727 5728 field = build_decl (input_location, 5729 FIELD_DECL, get_vfield_name (t), vtbl_ptr_type_node); 5730 DECL_VIRTUAL_P (field) = 1; 5731 DECL_ARTIFICIAL (field) = 1; 5732 DECL_FIELD_CONTEXT (field) = t; 5733 DECL_FCONTEXT (field) = t; 5734 if (TYPE_PACKED (t)) 5735 DECL_PACKED (field) = 1; 5736 5737 TYPE_VFIELD (t) = field; 5738 5739 /* This class is non-empty. */ 5740 CLASSTYPE_EMPTY_P (t) = 0; 5741 5742 return field; 5743 } 5744 5745 return NULL_TREE; 5746 } 5747 5748 /* Add OFFSET to all base types of BINFO which is a base in the 5749 hierarchy dominated by T. 5750 5751 OFFSET, which is a type offset, is number of bytes. */ 5752 5753 static void 5754 propagate_binfo_offsets (tree binfo, tree offset) 5755 { 5756 int i; 5757 tree primary_binfo; 5758 tree base_binfo; 5759 5760 /* Update BINFO's offset. */ 5761 BINFO_OFFSET (binfo) 5762 = fold_convert (sizetype, 5763 size_binop (PLUS_EXPR, 5764 fold_convert (ssizetype, BINFO_OFFSET (binfo)), 5765 offset)); 5766 5767 /* Find the primary base class. */ 5768 primary_binfo = get_primary_binfo (binfo); 5769 5770 if (primary_binfo && BINFO_INHERITANCE_CHAIN (primary_binfo) == binfo) 5771 propagate_binfo_offsets (primary_binfo, offset); 5772 5773 /* Scan all of the bases, pushing the BINFO_OFFSET adjust 5774 downwards. */ 5775 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 5776 { 5777 /* Don't do the primary base twice. */ 5778 if (base_binfo == primary_binfo) 5779 continue; 5780 5781 if (BINFO_VIRTUAL_P (base_binfo)) 5782 continue; 5783 5784 propagate_binfo_offsets (base_binfo, offset); 5785 } 5786 } 5787 5788 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update 5789 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of 5790 empty subobjects of T. */ 5791 5792 static void 5793 layout_virtual_bases (record_layout_info rli, splay_tree offsets) 5794 { 5795 tree vbase; 5796 tree t = rli->t; 5797 tree *next_field; 5798 5799 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) == 0) 5800 return; 5801 5802 /* Find the last field. The artificial fields created for virtual 5803 bases will go after the last extant field to date. */ 5804 next_field = &TYPE_FIELDS (t); 5805 while (*next_field) 5806 next_field = &DECL_CHAIN (*next_field); 5807 5808 /* Go through the virtual bases, allocating space for each virtual 5809 base that is not already a primary base class. These are 5810 allocated in inheritance graph order. */ 5811 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase)) 5812 { 5813 if (!BINFO_VIRTUAL_P (vbase)) 5814 continue; 5815 5816 if (!BINFO_PRIMARY_P (vbase)) 5817 { 5818 /* This virtual base is not a primary base of any class in the 5819 hierarchy, so we have to add space for it. */ 5820 next_field = build_base_field (rli, vbase, 5821 offsets, next_field); 5822 } 5823 } 5824 } 5825 5826 /* Returns the offset of the byte just past the end of the base class 5827 BINFO. */ 5828 5829 static tree 5830 end_of_base (tree binfo) 5831 { 5832 tree size; 5833 5834 if (!CLASSTYPE_AS_BASE (BINFO_TYPE (binfo))) 5835 size = TYPE_SIZE_UNIT (char_type_node); 5836 else if (is_empty_class (BINFO_TYPE (binfo))) 5837 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to 5838 allocate some space for it. It cannot have virtual bases, so 5839 TYPE_SIZE_UNIT is fine. */ 5840 size = TYPE_SIZE_UNIT (BINFO_TYPE (binfo)); 5841 else 5842 size = CLASSTYPE_SIZE_UNIT (BINFO_TYPE (binfo)); 5843 5844 return size_binop (PLUS_EXPR, BINFO_OFFSET (binfo), size); 5845 } 5846 5847 /* Returns the offset of the byte just past the end of the base class 5848 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then 5849 only non-virtual bases are included. */ 5850 5851 static tree 5852 end_of_class (tree t, int include_virtuals_p) 5853 { 5854 tree result = size_zero_node; 5855 vec<tree, va_gc> *vbases; 5856 tree binfo; 5857 tree base_binfo; 5858 tree offset; 5859 int i; 5860 5861 for (binfo = TYPE_BINFO (t), i = 0; 5862 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 5863 { 5864 if (!include_virtuals_p 5865 && BINFO_VIRTUAL_P (base_binfo) 5866 && (!BINFO_PRIMARY_P (base_binfo) 5867 || BINFO_INHERITANCE_CHAIN (base_binfo) != TYPE_BINFO (t))) 5868 continue; 5869 5870 offset = end_of_base (base_binfo); 5871 if (tree_int_cst_lt (result, offset)) 5872 result = offset; 5873 } 5874 5875 if (include_virtuals_p) 5876 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0; 5877 vec_safe_iterate (vbases, i, &base_binfo); i++) 5878 { 5879 offset = end_of_base (base_binfo); 5880 if (tree_int_cst_lt (result, offset)) 5881 result = offset; 5882 } 5883 5884 return result; 5885 } 5886 5887 /* Warn about bases of T that are inaccessible because they are 5888 ambiguous. For example: 5889 5890 struct S {}; 5891 struct T : public S {}; 5892 struct U : public S, public T {}; 5893 5894 Here, `(S*) new U' is not allowed because there are two `S' 5895 subobjects of U. */ 5896 5897 static void 5898 warn_about_ambiguous_bases (tree t) 5899 { 5900 int i; 5901 vec<tree, va_gc> *vbases; 5902 tree basetype; 5903 tree binfo; 5904 tree base_binfo; 5905 5906 /* If there are no repeated bases, nothing can be ambiguous. */ 5907 if (!CLASSTYPE_REPEATED_BASE_P (t)) 5908 return; 5909 5910 /* Check direct bases. */ 5911 for (binfo = TYPE_BINFO (t), i = 0; 5912 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 5913 { 5914 basetype = BINFO_TYPE (base_binfo); 5915 5916 if (!uniquely_derived_from_p (basetype, t)) 5917 warning (0, "direct base %qT inaccessible in %qT due to ambiguity", 5918 basetype, t); 5919 } 5920 5921 /* Check for ambiguous virtual bases. */ 5922 if (extra_warnings) 5923 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0; 5924 vec_safe_iterate (vbases, i, &binfo); i++) 5925 { 5926 basetype = BINFO_TYPE (binfo); 5927 5928 if (!uniquely_derived_from_p (basetype, t)) 5929 warning (OPT_Wextra, "virtual base %qT inaccessible in %qT due " 5930 "to ambiguity", basetype, t); 5931 } 5932 } 5933 5934 /* Compare two INTEGER_CSTs K1 and K2. */ 5935 5936 static int 5937 splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2) 5938 { 5939 return tree_int_cst_compare ((tree) k1, (tree) k2); 5940 } 5941 5942 /* Increase the size indicated in RLI to account for empty classes 5943 that are "off the end" of the class. */ 5944 5945 static void 5946 include_empty_classes (record_layout_info rli) 5947 { 5948 tree eoc; 5949 tree rli_size; 5950 5951 /* It might be the case that we grew the class to allocate a 5952 zero-sized base class. That won't be reflected in RLI, yet, 5953 because we are willing to overlay multiple bases at the same 5954 offset. However, now we need to make sure that RLI is big enough 5955 to reflect the entire class. */ 5956 eoc = end_of_class (rli->t, CLASSTYPE_AS_BASE (rli->t) != NULL_TREE); 5957 rli_size = rli_size_unit_so_far (rli); 5958 if (TREE_CODE (rli_size) == INTEGER_CST 5959 && tree_int_cst_lt (rli_size, eoc)) 5960 { 5961 /* The size should have been rounded to a whole byte. */ 5962 gcc_assert (tree_int_cst_equal 5963 (rli->bitpos, round_down (rli->bitpos, BITS_PER_UNIT))); 5964 rli->bitpos 5965 = size_binop (PLUS_EXPR, 5966 rli->bitpos, 5967 size_binop (MULT_EXPR, 5968 fold_convert (bitsizetype, 5969 size_binop (MINUS_EXPR, 5970 eoc, rli_size)), 5971 bitsize_int (BITS_PER_UNIT))); 5972 normalize_rli (rli); 5973 } 5974 } 5975 5976 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate 5977 BINFO_OFFSETs for all of the base-classes. Position the vtable 5978 pointer. Accumulate declared virtual functions on VIRTUALS_P. */ 5979 5980 static void 5981 layout_class_type (tree t, tree *virtuals_p) 5982 { 5983 tree non_static_data_members; 5984 tree field; 5985 tree vptr; 5986 record_layout_info rli; 5987 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of 5988 types that appear at that offset. */ 5989 splay_tree empty_base_offsets; 5990 /* True if the last field laid out was a bit-field. */ 5991 bool last_field_was_bitfield = false; 5992 /* The location at which the next field should be inserted. */ 5993 tree *next_field; 5994 5995 /* Keep track of the first non-static data member. */ 5996 non_static_data_members = TYPE_FIELDS (t); 5997 5998 /* Start laying out the record. */ 5999 rli = start_record_layout (t); 6000 6001 /* Mark all the primary bases in the hierarchy. */ 6002 determine_primary_bases (t); 6003 6004 /* Create a pointer to our virtual function table. */ 6005 vptr = create_vtable_ptr (t, virtuals_p); 6006 6007 /* The vptr is always the first thing in the class. */ 6008 if (vptr) 6009 { 6010 DECL_CHAIN (vptr) = TYPE_FIELDS (t); 6011 TYPE_FIELDS (t) = vptr; 6012 next_field = &DECL_CHAIN (vptr); 6013 place_field (rli, vptr); 6014 } 6015 else 6016 next_field = &TYPE_FIELDS (t); 6017 6018 /* Build FIELD_DECLs for all of the non-virtual base-types. */ 6019 empty_base_offsets = splay_tree_new (splay_tree_compare_integer_csts, 6020 NULL, NULL); 6021 build_base_fields (rli, empty_base_offsets, next_field); 6022 6023 /* Layout the non-static data members. */ 6024 for (field = non_static_data_members; field; field = DECL_CHAIN (field)) 6025 { 6026 tree type; 6027 tree padding; 6028 6029 /* We still pass things that aren't non-static data members to 6030 the back end, in case it wants to do something with them. */ 6031 if (TREE_CODE (field) != FIELD_DECL) 6032 { 6033 place_field (rli, field); 6034 /* If the static data member has incomplete type, keep track 6035 of it so that it can be completed later. (The handling 6036 of pending statics in finish_record_layout is 6037 insufficient; consider: 6038 6039 struct S1; 6040 struct S2 { static S1 s1; }; 6041 6042 At this point, finish_record_layout will be called, but 6043 S1 is still incomplete.) */ 6044 if (VAR_P (field)) 6045 { 6046 maybe_register_incomplete_var (field); 6047 /* The visibility of static data members is determined 6048 at their point of declaration, not their point of 6049 definition. */ 6050 determine_visibility (field); 6051 } 6052 continue; 6053 } 6054 6055 type = TREE_TYPE (field); 6056 if (type == error_mark_node) 6057 continue; 6058 6059 padding = NULL_TREE; 6060 6061 /* If this field is a bit-field whose width is greater than its 6062 type, then there are some special rules for allocating 6063 it. */ 6064 if (DECL_C_BIT_FIELD (field) 6065 && tree_int_cst_lt (TYPE_SIZE (type), DECL_SIZE (field))) 6066 { 6067 bool was_unnamed_p = false; 6068 /* We must allocate the bits as if suitably aligned for the 6069 longest integer type that fits in this many bits. Then, 6070 we are supposed to use the left over bits as additional 6071 padding. */ 6072 6073 /* Do not pick a type bigger than MAX_FIXED_MODE_SIZE. */ 6074 tree limit = size_int (MAX_FIXED_MODE_SIZE); 6075 if (tree_int_cst_lt (DECL_SIZE (field), limit)) 6076 limit = DECL_SIZE (field); 6077 6078 tree integer_type = integer_types[itk_char]; 6079 for (unsigned itk = itk_char; itk != itk_none; itk++) 6080 if (tree next = integer_types[itk]) 6081 { 6082 if (tree_int_cst_lt (limit, TYPE_SIZE (next))) 6083 /* Too big, so our current guess is what we want. */ 6084 break; 6085 /* Not bigger than limit, ok */ 6086 integer_type = next; 6087 } 6088 6089 /* Figure out how much additional padding is required. */ 6090 if (TREE_CODE (t) == UNION_TYPE) 6091 /* In a union, the padding field must have the full width 6092 of the bit-field; all fields start at offset zero. */ 6093 padding = DECL_SIZE (field); 6094 else 6095 padding = size_binop (MINUS_EXPR, DECL_SIZE (field), 6096 TYPE_SIZE (integer_type)); 6097 6098 if (integer_zerop (padding)) 6099 padding = NULL_TREE; 6100 6101 /* An unnamed bitfield does not normally affect the 6102 alignment of the containing class on a target where 6103 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not 6104 make any exceptions for unnamed bitfields when the 6105 bitfields are longer than their types. Therefore, we 6106 temporarily give the field a name. */ 6107 if (PCC_BITFIELD_TYPE_MATTERS && !DECL_NAME (field)) 6108 { 6109 was_unnamed_p = true; 6110 DECL_NAME (field) = make_anon_name (); 6111 } 6112 6113 DECL_SIZE (field) = TYPE_SIZE (integer_type); 6114 SET_DECL_ALIGN (field, TYPE_ALIGN (integer_type)); 6115 DECL_USER_ALIGN (field) = TYPE_USER_ALIGN (integer_type); 6116 layout_nonempty_base_or_field (rli, field, NULL_TREE, 6117 empty_base_offsets); 6118 if (was_unnamed_p) 6119 DECL_NAME (field) = NULL_TREE; 6120 /* Now that layout has been performed, set the size of the 6121 field to the size of its declared type; the rest of the 6122 field is effectively invisible. */ 6123 DECL_SIZE (field) = TYPE_SIZE (type); 6124 /* We must also reset the DECL_MODE of the field. */ 6125 SET_DECL_MODE (field, TYPE_MODE (type)); 6126 } 6127 else 6128 layout_nonempty_base_or_field (rli, field, NULL_TREE, 6129 empty_base_offsets); 6130 6131 /* Remember the location of any empty classes in FIELD. */ 6132 record_subobject_offsets (TREE_TYPE (field), 6133 byte_position(field), 6134 empty_base_offsets, 6135 /*is_data_member=*/true); 6136 6137 /* If a bit-field does not immediately follow another bit-field, 6138 and yet it starts in the middle of a byte, we have failed to 6139 comply with the ABI. */ 6140 if (warn_abi 6141 && DECL_C_BIT_FIELD (field) 6142 /* The TREE_NO_WARNING flag gets set by Objective-C when 6143 laying out an Objective-C class. The ObjC ABI differs 6144 from the C++ ABI, and so we do not want a warning 6145 here. */ 6146 && !TREE_NO_WARNING (field) 6147 && !last_field_was_bitfield 6148 && !integer_zerop (size_binop (TRUNC_MOD_EXPR, 6149 DECL_FIELD_BIT_OFFSET (field), 6150 bitsize_unit_node))) 6151 warning_at (DECL_SOURCE_LOCATION (field), OPT_Wabi, 6152 "offset of %qD is not ABI-compliant and may " 6153 "change in a future version of GCC", field); 6154 6155 /* The middle end uses the type of expressions to determine the 6156 possible range of expression values. In order to optimize 6157 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end 6158 must be made aware of the width of "i", via its type. 6159 6160 Because C++ does not have integer types of arbitrary width, 6161 we must (for the purposes of the front end) convert from the 6162 type assigned here to the declared type of the bitfield 6163 whenever a bitfield expression is used as an rvalue. 6164 Similarly, when assigning a value to a bitfield, the value 6165 must be converted to the type given the bitfield here. */ 6166 if (DECL_C_BIT_FIELD (field)) 6167 { 6168 unsigned HOST_WIDE_INT width; 6169 tree ftype = TREE_TYPE (field); 6170 width = tree_to_uhwi (DECL_SIZE (field)); 6171 if (width != TYPE_PRECISION (ftype)) 6172 { 6173 TREE_TYPE (field) 6174 = c_build_bitfield_integer_type (width, 6175 TYPE_UNSIGNED (ftype)); 6176 TREE_TYPE (field) 6177 = cp_build_qualified_type (TREE_TYPE (field), 6178 cp_type_quals (ftype)); 6179 } 6180 } 6181 6182 /* If we needed additional padding after this field, add it 6183 now. */ 6184 if (padding) 6185 { 6186 tree padding_field; 6187 6188 padding_field = build_decl (input_location, 6189 FIELD_DECL, 6190 NULL_TREE, 6191 char_type_node); 6192 DECL_BIT_FIELD (padding_field) = 1; 6193 DECL_SIZE (padding_field) = padding; 6194 DECL_CONTEXT (padding_field) = t; 6195 DECL_ARTIFICIAL (padding_field) = 1; 6196 DECL_IGNORED_P (padding_field) = 1; 6197 DECL_PADDING_P (padding_field) = 1; 6198 layout_nonempty_base_or_field (rli, padding_field, 6199 NULL_TREE, 6200 empty_base_offsets); 6201 } 6202 6203 last_field_was_bitfield = DECL_C_BIT_FIELD (field); 6204 } 6205 6206 if (!integer_zerop (rli->bitpos)) 6207 { 6208 /* Make sure that we are on a byte boundary so that the size of 6209 the class without virtual bases will always be a round number 6210 of bytes. */ 6211 rli->bitpos = round_up_loc (input_location, rli->bitpos, BITS_PER_UNIT); 6212 normalize_rli (rli); 6213 } 6214 6215 /* Delete all zero-width bit-fields from the list of fields. Now 6216 that the type is laid out they are no longer important. */ 6217 remove_zero_width_bit_fields (t); 6218 6219 if (CLASSTYPE_NON_LAYOUT_POD_P (t) || CLASSTYPE_EMPTY_P (t)) 6220 { 6221 /* T needs a different layout as a base (eliding virtual bases 6222 or whatever). Create that version. */ 6223 tree base_t = make_node (TREE_CODE (t)); 6224 6225 /* If the ABI version is not at least two, and the last 6226 field was a bit-field, RLI may not be on a byte 6227 boundary. In particular, rli_size_unit_so_far might 6228 indicate the last complete byte, while rli_size_so_far 6229 indicates the total number of bits used. Therefore, 6230 rli_size_so_far, rather than rli_size_unit_so_far, is 6231 used to compute TYPE_SIZE_UNIT. */ 6232 tree eoc = end_of_class (t, /*include_virtuals_p=*/0); 6233 TYPE_SIZE_UNIT (base_t) 6234 = size_binop (MAX_EXPR, 6235 fold_convert (sizetype, 6236 size_binop (CEIL_DIV_EXPR, 6237 rli_size_so_far (rli), 6238 bitsize_int (BITS_PER_UNIT))), 6239 eoc); 6240 TYPE_SIZE (base_t) 6241 = size_binop (MAX_EXPR, 6242 rli_size_so_far (rli), 6243 size_binop (MULT_EXPR, 6244 fold_convert (bitsizetype, eoc), 6245 bitsize_int (BITS_PER_UNIT))); 6246 SET_TYPE_ALIGN (base_t, rli->record_align); 6247 TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t); 6248 TYPE_TYPELESS_STORAGE (base_t) = TYPE_TYPELESS_STORAGE (t); 6249 6250 /* Copy the non-static data members of T. This will include its 6251 direct non-virtual bases & vtable. */ 6252 next_field = &TYPE_FIELDS (base_t); 6253 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) 6254 if (TREE_CODE (field) == FIELD_DECL) 6255 { 6256 *next_field = copy_node (field); 6257 DECL_CONTEXT (*next_field) = base_t; 6258 next_field = &DECL_CHAIN (*next_field); 6259 } 6260 *next_field = NULL_TREE; 6261 6262 /* We use the base type for trivial assignments, and hence it 6263 needs a mode. */ 6264 compute_record_mode (base_t); 6265 6266 TYPE_CONTEXT (base_t) = t; 6267 6268 /* Record the base version of the type. */ 6269 CLASSTYPE_AS_BASE (t) = base_t; 6270 } 6271 else 6272 CLASSTYPE_AS_BASE (t) = t; 6273 6274 /* Every empty class contains an empty class. */ 6275 if (CLASSTYPE_EMPTY_P (t)) 6276 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1; 6277 6278 /* Set the TYPE_DECL for this type to contain the right 6279 value for DECL_OFFSET, so that we can use it as part 6280 of a COMPONENT_REF for multiple inheritance. */ 6281 layout_decl (TYPE_MAIN_DECL (t), 0); 6282 6283 /* Now fix up any virtual base class types that we left lying 6284 around. We must get these done before we try to lay out the 6285 virtual function table. As a side-effect, this will remove the 6286 base subobject fields. */ 6287 layout_virtual_bases (rli, empty_base_offsets); 6288 6289 /* Make sure that empty classes are reflected in RLI at this 6290 point. */ 6291 include_empty_classes (rli); 6292 6293 /* Make sure not to create any structures with zero size. */ 6294 if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t)) 6295 place_field (rli, 6296 build_decl (input_location, 6297 FIELD_DECL, NULL_TREE, char_type_node)); 6298 6299 /* If this is a non-POD, declaring it packed makes a difference to how it 6300 can be used as a field; don't let finalize_record_size undo it. */ 6301 if (TYPE_PACKED (t) && !layout_pod_type_p (t)) 6302 rli->packed_maybe_necessary = true; 6303 6304 /* Let the back end lay out the type. */ 6305 finish_record_layout (rli, /*free_p=*/true); 6306 6307 if (TYPE_SIZE_UNIT (t) 6308 && TREE_CODE (TYPE_SIZE_UNIT (t)) == INTEGER_CST 6309 && !TREE_OVERFLOW (TYPE_SIZE_UNIT (t)) 6310 && !valid_constant_size_p (TYPE_SIZE_UNIT (t))) 6311 error ("size of type %qT is too large (%qE bytes)", t, TYPE_SIZE_UNIT (t)); 6312 6313 /* Warn about bases that can't be talked about due to ambiguity. */ 6314 warn_about_ambiguous_bases (t); 6315 6316 /* Now that we're done with layout, give the base fields the real types. */ 6317 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) 6318 if (DECL_ARTIFICIAL (field) && IS_FAKE_BASE_TYPE (TREE_TYPE (field))) 6319 TREE_TYPE (field) = TYPE_CONTEXT (TREE_TYPE (field)); 6320 6321 /* Clean up. */ 6322 splay_tree_delete (empty_base_offsets); 6323 6324 if (CLASSTYPE_EMPTY_P (t) 6325 && tree_int_cst_lt (sizeof_biggest_empty_class, 6326 TYPE_SIZE_UNIT (t))) 6327 sizeof_biggest_empty_class = TYPE_SIZE_UNIT (t); 6328 } 6329 6330 /* Determine the "key method" for the class type indicated by TYPE, 6331 and set CLASSTYPE_KEY_METHOD accordingly. */ 6332 6333 void 6334 determine_key_method (tree type) 6335 { 6336 tree method; 6337 6338 if (processing_template_decl 6339 || CLASSTYPE_TEMPLATE_INSTANTIATION (type) 6340 || CLASSTYPE_INTERFACE_KNOWN (type)) 6341 return; 6342 6343 /* The key method is the first non-pure virtual function that is not 6344 inline at the point of class definition. On some targets the 6345 key function may not be inline; those targets should not call 6346 this function until the end of the translation unit. */ 6347 for (method = TYPE_FIELDS (type); method; method = DECL_CHAIN (method)) 6348 if (TREE_CODE (method) == FUNCTION_DECL 6349 && DECL_VINDEX (method) != NULL_TREE 6350 && ! DECL_DECLARED_INLINE_P (method) 6351 && ! DECL_PURE_VIRTUAL_P (method)) 6352 { 6353 CLASSTYPE_KEY_METHOD (type) = method; 6354 break; 6355 } 6356 6357 return; 6358 } 6359 6360 /* Helper of find_flexarrays. Return true when FLD refers to a non-static 6361 class data member of non-zero size, otherwise false. */ 6362 6363 static inline bool 6364 field_nonempty_p (const_tree fld) 6365 { 6366 if (TREE_CODE (fld) == ERROR_MARK) 6367 return false; 6368 6369 tree type = TREE_TYPE (fld); 6370 if (TREE_CODE (fld) == FIELD_DECL 6371 && TREE_CODE (type) != ERROR_MARK 6372 && (DECL_NAME (fld) || RECORD_OR_UNION_TYPE_P (type))) 6373 { 6374 return TYPE_SIZE (type) 6375 && (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST 6376 || !tree_int_cst_equal (size_zero_node, TYPE_SIZE (type))); 6377 } 6378 6379 return false; 6380 } 6381 6382 /* Used by find_flexarrays and related functions. */ 6383 6384 struct flexmems_t 6385 { 6386 /* The first flexible array member or non-zero array member found 6387 in the order of layout. */ 6388 tree array; 6389 /* First non-static non-empty data member in the class or its bases. */ 6390 tree first; 6391 /* The first non-static non-empty data member following either 6392 the flexible array member, if found, or the zero-length array member 6393 otherwise. AFTER[1] refers to the first such data member of a union 6394 of which the struct containing the flexible array member or zero-length 6395 array is a member, or NULL when no such union exists. This element is 6396 only used during searching, not for diagnosing problems. AFTER[0] 6397 refers to the first such data member that is not a member of such 6398 a union. */ 6399 tree after[2]; 6400 6401 /* Refers to a struct (not union) in which the struct of which the flexible 6402 array is member is defined. Used to diagnose strictly (according to C) 6403 invalid uses of the latter structs. */ 6404 tree enclosing; 6405 }; 6406 6407 /* Find either the first flexible array member or the first zero-length 6408 array, in that order of preference, among members of class T (but not 6409 its base classes), and set members of FMEM accordingly. 6410 BASE_P is true if T is a base class of another class. 6411 PUN is set to the outermost union in which the flexible array member 6412 (or zero-length array) is defined if one such union exists, otherwise 6413 to NULL. 6414 Similarly, PSTR is set to a data member of the outermost struct of 6415 which the flexible array is a member if one such struct exists, 6416 otherwise to NULL. */ 6417 6418 static void 6419 find_flexarrays (tree t, flexmems_t *fmem, bool base_p, 6420 tree pun /* = NULL_TREE */, 6421 tree pstr /* = NULL_TREE */) 6422 { 6423 /* Set the "pointer" to the outermost enclosing union if not set 6424 yet and maintain it for the remainder of the recursion. */ 6425 if (!pun && TREE_CODE (t) == UNION_TYPE) 6426 pun = t; 6427 6428 for (tree fld = TYPE_FIELDS (t); fld; fld = DECL_CHAIN (fld)) 6429 { 6430 if (fld == error_mark_node) 6431 return; 6432 6433 /* Is FLD a typedef for an anonymous struct? */ 6434 6435 /* FIXME: Note that typedefs (as well as arrays) need to be fully 6436 handled elsewhere so that errors like the following are detected 6437 as well: 6438 typedef struct { int i, a[], j; } S; // bug c++/72753 6439 S s [2]; // bug c++/68489 6440 */ 6441 if (TREE_CODE (fld) == TYPE_DECL 6442 && DECL_IMPLICIT_TYPEDEF_P (fld) 6443 && CLASS_TYPE_P (TREE_TYPE (fld)) 6444 && anon_aggrname_p (DECL_NAME (fld))) 6445 { 6446 /* Check the nested unnamed type referenced via a typedef 6447 independently of FMEM (since it's not a data member of 6448 the enclosing class). */ 6449 check_flexarrays (TREE_TYPE (fld)); 6450 continue; 6451 } 6452 6453 /* Skip anything that's GCC-generated or not a (non-static) data 6454 member. */ 6455 if (DECL_ARTIFICIAL (fld) || TREE_CODE (fld) != FIELD_DECL) 6456 continue; 6457 6458 /* Type of the member. */ 6459 tree fldtype = TREE_TYPE (fld); 6460 if (fldtype == error_mark_node) 6461 return; 6462 6463 /* Determine the type of the array element or object referenced 6464 by the member so that it can be checked for flexible array 6465 members if it hasn't been yet. */ 6466 tree eltype = fldtype; 6467 while (TREE_CODE (eltype) == ARRAY_TYPE 6468 || TREE_CODE (eltype) == POINTER_TYPE 6469 || TREE_CODE (eltype) == REFERENCE_TYPE) 6470 eltype = TREE_TYPE (eltype); 6471 6472 if (RECORD_OR_UNION_TYPE_P (eltype)) 6473 { 6474 if (fmem->array && !fmem->after[bool (pun)]) 6475 { 6476 /* Once the member after the flexible array has been found 6477 we're done. */ 6478 fmem->after[bool (pun)] = fld; 6479 break; 6480 } 6481 6482 if (eltype == fldtype || TYPE_UNNAMED_P (eltype)) 6483 { 6484 /* Descend into the non-static member struct or union and try 6485 to find a flexible array member or zero-length array among 6486 its members. This is only necessary for anonymous types 6487 and types in whose context the current type T has not been 6488 defined (the latter must not be checked again because they 6489 are already in the process of being checked by one of the 6490 recursive calls). */ 6491 6492 tree first = fmem->first; 6493 tree array = fmem->array; 6494 6495 /* If this member isn't anonymous and a prior non-flexible array 6496 member has been seen in one of the enclosing structs, clear 6497 the FIRST member since it doesn't contribute to the flexible 6498 array struct's members. */ 6499 if (first && !array && !ANON_AGGR_TYPE_P (eltype)) 6500 fmem->first = NULL_TREE; 6501 6502 find_flexarrays (eltype, fmem, false, pun, 6503 !pstr && TREE_CODE (t) == RECORD_TYPE ? fld : pstr); 6504 6505 if (fmem->array != array) 6506 continue; 6507 6508 if (first && !array && !ANON_AGGR_TYPE_P (eltype)) 6509 { 6510 /* Restore the FIRST member reset above if no flexible 6511 array member has been found in this member's struct. */ 6512 fmem->first = first; 6513 } 6514 6515 /* If the member struct contains the first flexible array 6516 member, or if this member is a base class, continue to 6517 the next member and avoid setting the FMEM->NEXT pointer 6518 to point to it. */ 6519 if (base_p) 6520 continue; 6521 } 6522 } 6523 6524 if (field_nonempty_p (fld)) 6525 { 6526 /* Remember the first non-static data member. */ 6527 if (!fmem->first) 6528 fmem->first = fld; 6529 6530 /* Remember the first non-static data member after the flexible 6531 array member, if one has been found, or the zero-length array 6532 if it has been found. */ 6533 if (fmem->array && !fmem->after[bool (pun)]) 6534 fmem->after[bool (pun)] = fld; 6535 } 6536 6537 /* Skip non-arrays. */ 6538 if (TREE_CODE (fldtype) != ARRAY_TYPE) 6539 continue; 6540 6541 /* Determine the upper bound of the array if it has one. */ 6542 if (TYPE_DOMAIN (fldtype)) 6543 { 6544 if (fmem->array) 6545 { 6546 /* Make a record of the zero-length array if either one 6547 such field or a flexible array member has been seen to 6548 handle the pathological and unlikely case of multiple 6549 such members. */ 6550 if (!fmem->after[bool (pun)]) 6551 fmem->after[bool (pun)] = fld; 6552 } 6553 else if (integer_all_onesp (TYPE_MAX_VALUE (TYPE_DOMAIN (fldtype)))) 6554 { 6555 /* Remember the first zero-length array unless a flexible array 6556 member has already been seen. */ 6557 fmem->array = fld; 6558 fmem->enclosing = pstr; 6559 } 6560 } 6561 else 6562 { 6563 /* Flexible array members have no upper bound. */ 6564 if (fmem->array) 6565 { 6566 if (TYPE_DOMAIN (TREE_TYPE (fmem->array))) 6567 { 6568 /* Replace the zero-length array if it's been stored and 6569 reset the after pointer. */ 6570 fmem->after[bool (pun)] = NULL_TREE; 6571 fmem->array = fld; 6572 fmem->enclosing = pstr; 6573 } 6574 else if (!fmem->after[bool (pun)]) 6575 /* Make a record of another flexible array member. */ 6576 fmem->after[bool (pun)] = fld; 6577 } 6578 else 6579 { 6580 fmem->array = fld; 6581 fmem->enclosing = pstr; 6582 } 6583 } 6584 } 6585 } 6586 6587 /* Diagnose a strictly (by the C standard) invalid use of a struct with 6588 a flexible array member (or the zero-length array extension). */ 6589 6590 static void 6591 diagnose_invalid_flexarray (const flexmems_t *fmem) 6592 { 6593 if (fmem->array && fmem->enclosing 6594 && pedwarn (location_of (fmem->enclosing), OPT_Wpedantic, 6595 TYPE_DOMAIN (TREE_TYPE (fmem->array)) 6596 ? G_("invalid use of %q#T with a zero-size array " 6597 "in %q#D") 6598 : G_("invalid use of %q#T with a flexible array member " 6599 "in %q#T"), 6600 DECL_CONTEXT (fmem->array), 6601 DECL_CONTEXT (fmem->enclosing))) 6602 inform (DECL_SOURCE_LOCATION (fmem->array), 6603 "array member %q#D declared here", fmem->array); 6604 } 6605 6606 /* Issue diagnostics for invalid flexible array members or zero-length 6607 arrays that are not the last elements of the containing class or its 6608 base classes or that are its sole members. */ 6609 6610 static void 6611 diagnose_flexarrays (tree t, const flexmems_t *fmem) 6612 { 6613 if (!fmem->array) 6614 return; 6615 6616 if (fmem->first && !fmem->after[0]) 6617 { 6618 diagnose_invalid_flexarray (fmem); 6619 return; 6620 } 6621 6622 /* Has a diagnostic been issued? */ 6623 bool diagd = false; 6624 6625 const char *msg = 0; 6626 6627 if (TYPE_DOMAIN (TREE_TYPE (fmem->array))) 6628 { 6629 if (fmem->after[0]) 6630 msg = G_("zero-size array member %qD not at end of %q#T"); 6631 else if (!fmem->first) 6632 msg = G_("zero-size array member %qD in an otherwise empty %q#T"); 6633 6634 if (msg) 6635 { 6636 location_t loc = DECL_SOURCE_LOCATION (fmem->array); 6637 6638 if (pedwarn (loc, OPT_Wpedantic, msg, fmem->array, t)) 6639 { 6640 inform (location_of (t), "in the definition of %q#T", t); 6641 diagd = true; 6642 } 6643 } 6644 } 6645 else 6646 { 6647 if (fmem->after[0]) 6648 msg = G_("flexible array member %qD not at end of %q#T"); 6649 else if (!fmem->first) 6650 msg = G_("flexible array member %qD in an otherwise empty %q#T"); 6651 6652 if (msg) 6653 { 6654 location_t loc = DECL_SOURCE_LOCATION (fmem->array); 6655 diagd = true; 6656 6657 error_at (loc, msg, fmem->array, t); 6658 6659 /* In the unlikely event that the member following the flexible 6660 array member is declared in a different class, or the member 6661 overlaps another member of a common union, point to it. 6662 Otherwise it should be obvious. */ 6663 if (fmem->after[0] 6664 && ((DECL_CONTEXT (fmem->after[0]) 6665 != DECL_CONTEXT (fmem->array)))) 6666 { 6667 inform (DECL_SOURCE_LOCATION (fmem->after[0]), 6668 "next member %q#D declared here", 6669 fmem->after[0]); 6670 inform (location_of (t), "in the definition of %q#T", t); 6671 } 6672 } 6673 } 6674 6675 if (!diagd && fmem->array && fmem->enclosing) 6676 diagnose_invalid_flexarray (fmem); 6677 } 6678 6679 6680 /* Recursively check to make sure that any flexible array or zero-length 6681 array members of class T or its bases are valid (i.e., not the sole 6682 non-static data member of T and, if one exists, that it is the last 6683 non-static data member of T and its base classes. FMEM is expected 6684 to be initially null and is used internally by recursive calls to 6685 the function. Issue the appropriate diagnostics for the array member 6686 that fails the checks. */ 6687 6688 static void 6689 check_flexarrays (tree t, flexmems_t *fmem /* = NULL */, 6690 bool base_p /* = false */) 6691 { 6692 /* Initialize the result of a search for flexible array and zero-length 6693 array members. Avoid doing any work if the most interesting FMEM data 6694 have already been populated. */ 6695 flexmems_t flexmems = flexmems_t (); 6696 if (!fmem) 6697 fmem = &flexmems; 6698 else if (fmem->array && fmem->first && fmem->after[0]) 6699 return; 6700 6701 tree fam = fmem->array; 6702 6703 /* Recursively check the primary base class first. */ 6704 if (CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 6705 { 6706 tree basetype = BINFO_TYPE (CLASSTYPE_PRIMARY_BINFO (t)); 6707 check_flexarrays (basetype, fmem, true); 6708 } 6709 6710 /* Recursively check the base classes. */ 6711 int nbases = TYPE_BINFO (t) ? BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) : 0; 6712 for (int i = 0; i < nbases; ++i) 6713 { 6714 tree base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i); 6715 6716 /* The primary base class was already checked above. */ 6717 if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t)) 6718 continue; 6719 6720 /* Virtual base classes are at the end. */ 6721 if (BINFO_VIRTUAL_P (base_binfo)) 6722 continue; 6723 6724 /* Check the base class. */ 6725 check_flexarrays (BINFO_TYPE (base_binfo), fmem, /*base_p=*/true); 6726 } 6727 6728 if (fmem == &flexmems) 6729 { 6730 /* Check virtual base classes only once per derived class. 6731 I.e., this check is not performed recursively for base 6732 classes. */ 6733 int i; 6734 tree base_binfo; 6735 vec<tree, va_gc> *vbases; 6736 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0; 6737 vec_safe_iterate (vbases, i, &base_binfo); i++) 6738 { 6739 /* Check the virtual base class. */ 6740 tree basetype = TREE_TYPE (base_binfo); 6741 6742 check_flexarrays (basetype, fmem, /*base_p=*/true); 6743 } 6744 } 6745 6746 /* Is the type unnamed (and therefore a member of it potentially 6747 an anonymous struct or union)? */ 6748 bool maybe_anon_p = TYPE_UNNAMED_P (t); 6749 6750 /* Search the members of the current (possibly derived) class, skipping 6751 unnamed structs and unions since those could be anonymous. */ 6752 if (fmem != &flexmems || !maybe_anon_p) 6753 find_flexarrays (t, fmem, base_p || fam != fmem->array); 6754 6755 if (fmem == &flexmems && !maybe_anon_p) 6756 { 6757 /* Issue diagnostics for invalid flexible and zero-length array 6758 members found in base classes or among the members of the current 6759 class. Ignore anonymous structs and unions whose members are 6760 considered to be members of the enclosing class and thus will 6761 be diagnosed when checking it. */ 6762 diagnose_flexarrays (t, fmem); 6763 } 6764 } 6765 6766 /* Perform processing required when the definition of T (a class type) 6767 is complete. Diagnose invalid definitions of flexible array members 6768 and zero-size arrays. */ 6769 6770 void 6771 finish_struct_1 (tree t) 6772 { 6773 tree x; 6774 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */ 6775 tree virtuals = NULL_TREE; 6776 6777 if (COMPLETE_TYPE_P (t)) 6778 { 6779 gcc_assert (MAYBE_CLASS_TYPE_P (t)); 6780 error ("redefinition of %q#T", t); 6781 popclass (); 6782 return; 6783 } 6784 6785 /* If this type was previously laid out as a forward reference, 6786 make sure we lay it out again. */ 6787 TYPE_SIZE (t) = NULL_TREE; 6788 CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE; 6789 6790 /* Make assumptions about the class; we'll reset the flags if 6791 necessary. */ 6792 CLASSTYPE_EMPTY_P (t) = 1; 6793 CLASSTYPE_NEARLY_EMPTY_P (t) = 1; 6794 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 0; 6795 CLASSTYPE_LITERAL_P (t) = true; 6796 6797 /* Do end-of-class semantic processing: checking the validity of the 6798 bases and members and add implicitly generated methods. */ 6799 check_bases_and_members (t); 6800 6801 /* Find the key method. */ 6802 if (TYPE_CONTAINS_VPTR_P (t)) 6803 { 6804 /* The Itanium C++ ABI permits the key method to be chosen when 6805 the class is defined -- even though the key method so 6806 selected may later turn out to be an inline function. On 6807 some systems (such as ARM Symbian OS) the key method cannot 6808 be determined until the end of the translation unit. On such 6809 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which 6810 will cause the class to be added to KEYED_CLASSES. Then, in 6811 finish_file we will determine the key method. */ 6812 if (targetm.cxx.key_method_may_be_inline ()) 6813 determine_key_method (t); 6814 6815 /* If a polymorphic class has no key method, we may emit the vtable 6816 in every translation unit where the class definition appears. If 6817 we're devirtualizing, we can look into the vtable even if we 6818 aren't emitting it. */ 6819 if (!CLASSTYPE_KEY_METHOD (t)) 6820 vec_safe_push (keyed_classes, t); 6821 } 6822 6823 /* Layout the class itself. */ 6824 layout_class_type (t, &virtuals); 6825 /* COMPLETE_TYPE_P is now true. */ 6826 6827 set_class_bindings (t); 6828 6829 /* With the layout complete, check for flexible array members and 6830 zero-length arrays that might overlap other members in the final 6831 layout. */ 6832 check_flexarrays (t); 6833 6834 virtuals = modify_all_vtables (t, nreverse (virtuals)); 6835 6836 /* If necessary, create the primary vtable for this class. */ 6837 if (virtuals || TYPE_CONTAINS_VPTR_P (t)) 6838 { 6839 /* We must enter these virtuals into the table. */ 6840 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 6841 build_primary_vtable (NULL_TREE, t); 6842 else if (! BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (t))) 6843 /* Here we know enough to change the type of our virtual 6844 function table, but we will wait until later this function. */ 6845 build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t); 6846 6847 /* If we're warning about ABI tags, check the types of the new 6848 virtual functions. */ 6849 if (warn_abi_tag) 6850 for (tree v = virtuals; v; v = TREE_CHAIN (v)) 6851 check_abi_tags (t, TREE_VALUE (v)); 6852 } 6853 6854 if (TYPE_CONTAINS_VPTR_P (t)) 6855 { 6856 int vindex; 6857 tree fn; 6858 6859 if (BINFO_VTABLE (TYPE_BINFO (t))) 6860 gcc_assert (DECL_VIRTUAL_P (BINFO_VTABLE (TYPE_BINFO (t)))); 6861 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 6862 gcc_assert (BINFO_VIRTUALS (TYPE_BINFO (t)) == NULL_TREE); 6863 6864 /* Add entries for virtual functions introduced by this class. */ 6865 BINFO_VIRTUALS (TYPE_BINFO (t)) 6866 = chainon (BINFO_VIRTUALS (TYPE_BINFO (t)), virtuals); 6867 6868 /* Set DECL_VINDEX for all functions declared in this class. */ 6869 for (vindex = 0, fn = BINFO_VIRTUALS (TYPE_BINFO (t)); 6870 fn; 6871 fn = TREE_CHAIN (fn), 6872 vindex += (TARGET_VTABLE_USES_DESCRIPTORS 6873 ? TARGET_VTABLE_USES_DESCRIPTORS : 1)) 6874 { 6875 tree fndecl = BV_FN (fn); 6876 6877 if (DECL_THUNK_P (fndecl)) 6878 /* A thunk. We should never be calling this entry directly 6879 from this vtable -- we'd use the entry for the non 6880 thunk base function. */ 6881 DECL_VINDEX (fndecl) = NULL_TREE; 6882 else if (TREE_CODE (DECL_VINDEX (fndecl)) != INTEGER_CST) 6883 DECL_VINDEX (fndecl) = build_int_cst (NULL_TREE, vindex); 6884 } 6885 } 6886 6887 finish_struct_bits (t); 6888 6889 set_method_tm_attributes (t); 6890 if (flag_openmp || flag_openmp_simd) 6891 finish_omp_declare_simd_methods (t); 6892 6893 /* Clear DECL_IN_AGGR_P for all member functions. Complete the rtl 6894 for any static member objects of the type we're working on. */ 6895 for (x = TYPE_FIELDS (t); x; x = DECL_CHAIN (x)) 6896 if (DECL_DECLARES_FUNCTION_P (x)) 6897 DECL_IN_AGGR_P (x) = false; 6898 else if (VAR_P (x) && TREE_STATIC (x) 6899 && TREE_TYPE (x) != error_mark_node 6900 && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t)) 6901 SET_DECL_MODE (x, TYPE_MODE (t)); 6902 6903 /* Complain if one of the field types requires lower visibility. */ 6904 constrain_class_visibility (t); 6905 6906 /* Make the rtl for any new vtables we have created, and unmark 6907 the base types we marked. */ 6908 finish_vtbls (t); 6909 6910 /* Build the VTT for T. */ 6911 build_vtt (t); 6912 6913 if (warn_nonvdtor 6914 && TYPE_POLYMORPHIC_P (t) && accessible_nvdtor_p (t) 6915 && !CLASSTYPE_FINAL (t)) 6916 warning (OPT_Wnon_virtual_dtor, 6917 "%q#T has virtual functions and accessible" 6918 " non-virtual destructor", t); 6919 6920 complete_vars (t); 6921 6922 if (warn_overloaded_virtual) 6923 warn_hidden (t); 6924 6925 /* Class layout, assignment of virtual table slots, etc., is now 6926 complete. Give the back end a chance to tweak the visibility of 6927 the class or perform any other required target modifications. */ 6928 targetm.cxx.adjust_class_at_definition (t); 6929 6930 maybe_suppress_debug_info (t); 6931 6932 if (flag_vtable_verify) 6933 vtv_save_class_info (t); 6934 6935 dump_class_hierarchy (t); 6936 6937 /* Finish debugging output for this type. */ 6938 rest_of_type_compilation (t, ! LOCAL_CLASS_P (t)); 6939 6940 if (TYPE_TRANSPARENT_AGGR (t)) 6941 { 6942 tree field = first_field (t); 6943 if (field == NULL_TREE || error_operand_p (field)) 6944 { 6945 error ("type transparent %q#T does not have any fields", t); 6946 TYPE_TRANSPARENT_AGGR (t) = 0; 6947 } 6948 else if (DECL_ARTIFICIAL (field)) 6949 { 6950 if (DECL_FIELD_IS_BASE (field)) 6951 error ("type transparent class %qT has base classes", t); 6952 else 6953 { 6954 gcc_checking_assert (DECL_VIRTUAL_P (field)); 6955 error ("type transparent class %qT has virtual functions", t); 6956 } 6957 TYPE_TRANSPARENT_AGGR (t) = 0; 6958 } 6959 else if (TYPE_MODE (t) != DECL_MODE (field)) 6960 { 6961 error ("type transparent %q#T cannot be made transparent because " 6962 "the type of the first field has a different ABI from the " 6963 "class overall", t); 6964 TYPE_TRANSPARENT_AGGR (t) = 0; 6965 } 6966 } 6967 } 6968 6969 /* When T was built up, the member declarations were added in reverse 6970 order. Rearrange them to declaration order. */ 6971 6972 void 6973 unreverse_member_declarations (tree t) 6974 { 6975 tree next; 6976 tree prev; 6977 tree x; 6978 6979 /* The following lists are all in reverse order. Put them in 6980 declaration order now. */ 6981 CLASSTYPE_DECL_LIST (t) = nreverse (CLASSTYPE_DECL_LIST (t)); 6982 6983 /* For the TYPE_FIELDS, only the non TYPE_DECLs are in reverse 6984 order, so we can't just use nreverse. Due to stat_hack 6985 chicanery in finish_member_declaration. */ 6986 prev = NULL_TREE; 6987 for (x = TYPE_FIELDS (t); 6988 x && TREE_CODE (x) != TYPE_DECL; 6989 x = next) 6990 { 6991 next = DECL_CHAIN (x); 6992 DECL_CHAIN (x) = prev; 6993 prev = x; 6994 } 6995 6996 if (prev) 6997 { 6998 DECL_CHAIN (TYPE_FIELDS (t)) = x; 6999 TYPE_FIELDS (t) = prev; 7000 } 7001 } 7002 7003 tree 7004 finish_struct (tree t, tree attributes) 7005 { 7006 location_t saved_loc = input_location; 7007 7008 /* Now that we've got all the field declarations, reverse everything 7009 as necessary. */ 7010 unreverse_member_declarations (t); 7011 7012 cplus_decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 7013 fixup_attribute_variants (t); 7014 7015 /* Nadger the current location so that diagnostics point to the start of 7016 the struct, not the end. */ 7017 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (t)); 7018 7019 if (processing_template_decl) 7020 { 7021 tree x; 7022 7023 /* We need to add the target functions of USING_DECLS, so that 7024 they can be found when the using declaration is not 7025 instantiated yet. */ 7026 for (x = TYPE_FIELDS (t); x; x = DECL_CHAIN (x)) 7027 if (TREE_CODE (x) == USING_DECL) 7028 { 7029 tree fn = strip_using_decl (x); 7030 if (OVL_P (fn)) 7031 for (lkp_iterator iter (fn); iter; ++iter) 7032 add_method (t, *iter, true); 7033 } 7034 else if (DECL_DECLARES_FUNCTION_P (x)) 7035 DECL_IN_AGGR_P (x) = false; 7036 7037 /* Also add a USING_DECL for operator=. We know there'll be (at 7038 least) one, but we don't know the signature(s). We want name 7039 lookup not to fail or recurse into bases. This isn't added 7040 to the template decl list so we drop this at instantiation 7041 time. */ 7042 tree ass_op = build_lang_decl (USING_DECL, assign_op_identifier, 7043 NULL_TREE); 7044 DECL_CONTEXT (ass_op) = t; 7045 USING_DECL_SCOPE (ass_op) = t; 7046 DECL_DEPENDENT_P (ass_op) = true; 7047 DECL_ARTIFICIAL (ass_op) = true; 7048 DECL_CHAIN (ass_op) = TYPE_FIELDS (t); 7049 TYPE_FIELDS (t) = ass_op; 7050 7051 TYPE_SIZE (t) = bitsize_zero_node; 7052 TYPE_SIZE_UNIT (t) = size_zero_node; 7053 /* COMPLETE_TYPE_P is now true. */ 7054 7055 set_class_bindings (t); 7056 7057 /* We need to emit an error message if this type was used as a parameter 7058 and it is an abstract type, even if it is a template. We construct 7059 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into 7060 account and we call complete_vars with this type, which will check 7061 the PARM_DECLS. Note that while the type is being defined, 7062 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends 7063 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */ 7064 CLASSTYPE_PURE_VIRTUALS (t) = NULL; 7065 for (x = TYPE_FIELDS (t); x; x = DECL_CHAIN (x)) 7066 if (TREE_CODE (x) == FUNCTION_DECL && DECL_PURE_VIRTUAL_P (x)) 7067 vec_safe_push (CLASSTYPE_PURE_VIRTUALS (t), x); 7068 complete_vars (t); 7069 7070 /* Remember current #pragma pack value. */ 7071 TYPE_PRECISION (t) = maximum_field_alignment; 7072 7073 /* Fix up any variants we've already built. */ 7074 for (x = TYPE_NEXT_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x)) 7075 { 7076 TYPE_SIZE (x) = TYPE_SIZE (t); 7077 TYPE_SIZE_UNIT (x) = TYPE_SIZE_UNIT (t); 7078 TYPE_FIELDS (x) = TYPE_FIELDS (t); 7079 } 7080 } 7081 else 7082 finish_struct_1 (t); 7083 /* COMPLETE_TYPE_P is now true. */ 7084 7085 maybe_warn_about_overly_private_class (t); 7086 7087 if (is_std_init_list (t)) 7088 { 7089 /* People keep complaining that the compiler crashes on an invalid 7090 definition of initializer_list, so I guess we should explicitly 7091 reject it. What the compiler internals care about is that it's a 7092 template and has a pointer field followed by size_type field. */ 7093 bool ok = false; 7094 if (processing_template_decl) 7095 { 7096 tree f = next_initializable_field (TYPE_FIELDS (t)); 7097 if (f && TREE_CODE (TREE_TYPE (f)) == POINTER_TYPE) 7098 { 7099 f = next_initializable_field (DECL_CHAIN (f)); 7100 if (f && same_type_p (TREE_TYPE (f), size_type_node)) 7101 ok = true; 7102 } 7103 } 7104 if (!ok) 7105 fatal_error (input_location, "definition of %qD does not match " 7106 "%<#include <initializer_list>%>", TYPE_NAME (t)); 7107 } 7108 7109 input_location = saved_loc; 7110 7111 TYPE_BEING_DEFINED (t) = 0; 7112 7113 if (current_class_type) 7114 popclass (); 7115 else 7116 error ("trying to finish struct, but kicked out due to previous parse errors"); 7117 7118 if (processing_template_decl && at_function_scope_p () 7119 /* Lambdas are defined by the LAMBDA_EXPR. */ 7120 && !LAMBDA_TYPE_P (t)) 7121 add_stmt (build_min (TAG_DEFN, t)); 7122 7123 return t; 7124 } 7125 7126 /* Hash table to avoid endless recursion when handling references. */ 7127 static hash_table<nofree_ptr_hash<tree_node> > *fixed_type_or_null_ref_ht; 7128 7129 /* Return the dynamic type of INSTANCE, if known. 7130 Used to determine whether the virtual function table is needed 7131 or not. 7132 7133 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless 7134 of our knowledge of its type. *NONNULL should be initialized 7135 before this function is called. */ 7136 7137 static tree 7138 fixed_type_or_null (tree instance, int *nonnull, int *cdtorp) 7139 { 7140 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp) 7141 7142 switch (TREE_CODE (instance)) 7143 { 7144 case INDIRECT_REF: 7145 if (POINTER_TYPE_P (TREE_TYPE (instance))) 7146 return NULL_TREE; 7147 else 7148 return RECUR (TREE_OPERAND (instance, 0)); 7149 7150 case CALL_EXPR: 7151 /* This is a call to a constructor, hence it's never zero. */ 7152 if (CALL_EXPR_FN (instance) 7153 && TREE_HAS_CONSTRUCTOR (instance)) 7154 { 7155 if (nonnull) 7156 *nonnull = 1; 7157 return TREE_TYPE (instance); 7158 } 7159 return NULL_TREE; 7160 7161 case SAVE_EXPR: 7162 /* This is a call to a constructor, hence it's never zero. */ 7163 if (TREE_HAS_CONSTRUCTOR (instance)) 7164 { 7165 if (nonnull) 7166 *nonnull = 1; 7167 return TREE_TYPE (instance); 7168 } 7169 return RECUR (TREE_OPERAND (instance, 0)); 7170 7171 case POINTER_PLUS_EXPR: 7172 case PLUS_EXPR: 7173 case MINUS_EXPR: 7174 if (TREE_CODE (TREE_OPERAND (instance, 0)) == ADDR_EXPR) 7175 return RECUR (TREE_OPERAND (instance, 0)); 7176 if (TREE_CODE (TREE_OPERAND (instance, 1)) == INTEGER_CST) 7177 /* Propagate nonnull. */ 7178 return RECUR (TREE_OPERAND (instance, 0)); 7179 7180 return NULL_TREE; 7181 7182 CASE_CONVERT: 7183 return RECUR (TREE_OPERAND (instance, 0)); 7184 7185 case ADDR_EXPR: 7186 instance = TREE_OPERAND (instance, 0); 7187 if (nonnull) 7188 { 7189 /* Just because we see an ADDR_EXPR doesn't mean we're dealing 7190 with a real object -- given &p->f, p can still be null. */ 7191 tree t = get_base_address (instance); 7192 /* ??? Probably should check DECL_WEAK here. */ 7193 if (t && DECL_P (t)) 7194 *nonnull = 1; 7195 } 7196 return RECUR (instance); 7197 7198 case COMPONENT_REF: 7199 /* If this component is really a base class reference, then the field 7200 itself isn't definitive. */ 7201 if (DECL_FIELD_IS_BASE (TREE_OPERAND (instance, 1))) 7202 return RECUR (TREE_OPERAND (instance, 0)); 7203 return RECUR (TREE_OPERAND (instance, 1)); 7204 7205 case VAR_DECL: 7206 case FIELD_DECL: 7207 if (TREE_CODE (TREE_TYPE (instance)) == ARRAY_TYPE 7208 && MAYBE_CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (instance)))) 7209 { 7210 if (nonnull) 7211 *nonnull = 1; 7212 return TREE_TYPE (TREE_TYPE (instance)); 7213 } 7214 /* fall through. */ 7215 case TARGET_EXPR: 7216 case PARM_DECL: 7217 case RESULT_DECL: 7218 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (instance))) 7219 { 7220 if (nonnull) 7221 *nonnull = 1; 7222 return TREE_TYPE (instance); 7223 } 7224 else if (instance == current_class_ptr) 7225 { 7226 if (nonnull) 7227 *nonnull = 1; 7228 7229 /* if we're in a ctor or dtor, we know our type. If 7230 current_class_ptr is set but we aren't in a function, we're in 7231 an NSDMI (and therefore a constructor). */ 7232 if (current_scope () != current_function_decl 7233 || (DECL_LANG_SPECIFIC (current_function_decl) 7234 && (DECL_CONSTRUCTOR_P (current_function_decl) 7235 || DECL_DESTRUCTOR_P (current_function_decl)))) 7236 { 7237 if (cdtorp) 7238 *cdtorp = 1; 7239 return TREE_TYPE (TREE_TYPE (instance)); 7240 } 7241 } 7242 else if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE) 7243 { 7244 /* We only need one hash table because it is always left empty. */ 7245 if (!fixed_type_or_null_ref_ht) 7246 fixed_type_or_null_ref_ht 7247 = new hash_table<nofree_ptr_hash<tree_node> > (37); 7248 7249 /* Reference variables should be references to objects. */ 7250 if (nonnull) 7251 *nonnull = 1; 7252 7253 /* Enter the INSTANCE in a table to prevent recursion; a 7254 variable's initializer may refer to the variable 7255 itself. */ 7256 if (VAR_P (instance) 7257 && DECL_INITIAL (instance) 7258 && !type_dependent_expression_p_push (DECL_INITIAL (instance)) 7259 && !fixed_type_or_null_ref_ht->find (instance)) 7260 { 7261 tree type; 7262 tree_node **slot; 7263 7264 slot = fixed_type_or_null_ref_ht->find_slot (instance, INSERT); 7265 *slot = instance; 7266 type = RECUR (DECL_INITIAL (instance)); 7267 fixed_type_or_null_ref_ht->remove_elt (instance); 7268 7269 return type; 7270 } 7271 } 7272 return NULL_TREE; 7273 7274 default: 7275 return NULL_TREE; 7276 } 7277 #undef RECUR 7278 } 7279 7280 /* Return nonzero if the dynamic type of INSTANCE is known, and 7281 equivalent to the static type. We also handle the case where 7282 INSTANCE is really a pointer. Return negative if this is a 7283 ctor/dtor. There the dynamic type is known, but this might not be 7284 the most derived base of the original object, and hence virtual 7285 bases may not be laid out according to this type. 7286 7287 Used to determine whether the virtual function table is needed 7288 or not. 7289 7290 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless 7291 of our knowledge of its type. *NONNULL should be initialized 7292 before this function is called. */ 7293 7294 int 7295 resolves_to_fixed_type_p (tree instance, int* nonnull) 7296 { 7297 tree t = TREE_TYPE (instance); 7298 int cdtorp = 0; 7299 tree fixed; 7300 7301 /* processing_template_decl can be false in a template if we're in 7302 instantiate_non_dependent_expr, but we still want to suppress 7303 this check. */ 7304 if (in_template_function ()) 7305 { 7306 /* In a template we only care about the type of the result. */ 7307 if (nonnull) 7308 *nonnull = true; 7309 return true; 7310 } 7311 7312 fixed = fixed_type_or_null (instance, nonnull, &cdtorp); 7313 if (fixed == NULL_TREE) 7314 return 0; 7315 if (POINTER_TYPE_P (t)) 7316 t = TREE_TYPE (t); 7317 if (!same_type_ignoring_top_level_qualifiers_p (t, fixed)) 7318 return 0; 7319 return cdtorp ? -1 : 1; 7320 } 7321 7322 7323 void 7324 init_class_processing (void) 7325 { 7326 current_class_depth = 0; 7327 current_class_stack_size = 10; 7328 current_class_stack 7329 = XNEWVEC (struct class_stack_node, current_class_stack_size); 7330 vec_alloc (local_classes, 8); 7331 sizeof_biggest_empty_class = size_zero_node; 7332 7333 ridpointers[(int) RID_PUBLIC] = access_public_node; 7334 ridpointers[(int) RID_PRIVATE] = access_private_node; 7335 ridpointers[(int) RID_PROTECTED] = access_protected_node; 7336 } 7337 7338 /* Restore the cached PREVIOUS_CLASS_LEVEL. */ 7339 7340 static void 7341 restore_class_cache (void) 7342 { 7343 tree type; 7344 7345 /* We are re-entering the same class we just left, so we don't 7346 have to search the whole inheritance matrix to find all the 7347 decls to bind again. Instead, we install the cached 7348 class_shadowed list and walk through it binding names. */ 7349 push_binding_level (previous_class_level); 7350 class_binding_level = previous_class_level; 7351 /* Restore IDENTIFIER_TYPE_VALUE. */ 7352 for (type = class_binding_level->type_shadowed; 7353 type; 7354 type = TREE_CHAIN (type)) 7355 SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (type), TREE_TYPE (type)); 7356 } 7357 7358 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as 7359 appropriate for TYPE. 7360 7361 So that we may avoid calls to lookup_name, we cache the _TYPE 7362 nodes of local TYPE_DECLs in the TREE_TYPE field of the name. 7363 7364 For multiple inheritance, we perform a two-pass depth-first search 7365 of the type lattice. */ 7366 7367 void 7368 pushclass (tree type) 7369 { 7370 class_stack_node_t csn; 7371 7372 type = TYPE_MAIN_VARIANT (type); 7373 7374 /* Make sure there is enough room for the new entry on the stack. */ 7375 if (current_class_depth + 1 >= current_class_stack_size) 7376 { 7377 current_class_stack_size *= 2; 7378 current_class_stack 7379 = XRESIZEVEC (struct class_stack_node, current_class_stack, 7380 current_class_stack_size); 7381 } 7382 7383 /* Insert a new entry on the class stack. */ 7384 csn = current_class_stack + current_class_depth; 7385 csn->name = current_class_name; 7386 csn->type = current_class_type; 7387 csn->access = current_access_specifier; 7388 csn->names_used = 0; 7389 csn->hidden = 0; 7390 current_class_depth++; 7391 7392 /* Now set up the new type. */ 7393 current_class_name = TYPE_NAME (type); 7394 if (TREE_CODE (current_class_name) == TYPE_DECL) 7395 current_class_name = DECL_NAME (current_class_name); 7396 current_class_type = type; 7397 7398 /* By default, things in classes are private, while things in 7399 structures or unions are public. */ 7400 current_access_specifier = (CLASSTYPE_DECLARED_CLASS (type) 7401 ? access_private_node 7402 : access_public_node); 7403 7404 if (previous_class_level 7405 && type != previous_class_level->this_entity 7406 && current_class_depth == 1) 7407 { 7408 /* Forcibly remove any old class remnants. */ 7409 invalidate_class_lookup_cache (); 7410 } 7411 7412 if (!previous_class_level 7413 || type != previous_class_level->this_entity 7414 || current_class_depth > 1) 7415 pushlevel_class (); 7416 else 7417 restore_class_cache (); 7418 } 7419 7420 /* When we exit a toplevel class scope, we save its binding level so 7421 that we can restore it quickly. Here, we've entered some other 7422 class, so we must invalidate our cache. */ 7423 7424 void 7425 invalidate_class_lookup_cache (void) 7426 { 7427 previous_class_level = NULL; 7428 } 7429 7430 /* Get out of the current class scope. If we were in a class scope 7431 previously, that is the one popped to. */ 7432 7433 void 7434 popclass (void) 7435 { 7436 poplevel_class (); 7437 7438 current_class_depth--; 7439 current_class_name = current_class_stack[current_class_depth].name; 7440 current_class_type = current_class_stack[current_class_depth].type; 7441 current_access_specifier = current_class_stack[current_class_depth].access; 7442 if (current_class_stack[current_class_depth].names_used) 7443 splay_tree_delete (current_class_stack[current_class_depth].names_used); 7444 } 7445 7446 /* Mark the top of the class stack as hidden. */ 7447 7448 void 7449 push_class_stack (void) 7450 { 7451 if (current_class_depth) 7452 ++current_class_stack[current_class_depth - 1].hidden; 7453 } 7454 7455 /* Mark the top of the class stack as un-hidden. */ 7456 7457 void 7458 pop_class_stack (void) 7459 { 7460 if (current_class_depth) 7461 --current_class_stack[current_class_depth - 1].hidden; 7462 } 7463 7464 /* If the class type currently being defined is either T or 7465 a nested type of T, returns the type from the current_class_stack, 7466 which might be equivalent to but not equal to T in case of 7467 constrained partial specializations. */ 7468 7469 tree 7470 currently_open_class (tree t) 7471 { 7472 int i; 7473 7474 if (!CLASS_TYPE_P (t)) 7475 return NULL_TREE; 7476 7477 t = TYPE_MAIN_VARIANT (t); 7478 7479 /* We start looking from 1 because entry 0 is from global scope, 7480 and has no type. */ 7481 for (i = current_class_depth; i > 0; --i) 7482 { 7483 tree c; 7484 if (i == current_class_depth) 7485 c = current_class_type; 7486 else 7487 { 7488 if (current_class_stack[i].hidden) 7489 break; 7490 c = current_class_stack[i].type; 7491 } 7492 if (!c) 7493 continue; 7494 if (same_type_p (c, t)) 7495 return c; 7496 } 7497 return NULL_TREE; 7498 } 7499 7500 /* If either current_class_type or one of its enclosing classes are derived 7501 from T, return the appropriate type. Used to determine how we found 7502 something via unqualified lookup. */ 7503 7504 tree 7505 currently_open_derived_class (tree t) 7506 { 7507 int i; 7508 7509 /* The bases of a dependent type are unknown. */ 7510 if (dependent_type_p (t)) 7511 return NULL_TREE; 7512 7513 if (!current_class_type) 7514 return NULL_TREE; 7515 7516 if (DERIVED_FROM_P (t, current_class_type)) 7517 return current_class_type; 7518 7519 for (i = current_class_depth - 1; i > 0; --i) 7520 { 7521 if (current_class_stack[i].hidden) 7522 break; 7523 if (DERIVED_FROM_P (t, current_class_stack[i].type)) 7524 return current_class_stack[i].type; 7525 } 7526 7527 return NULL_TREE; 7528 } 7529 7530 /* Return the outermost enclosing class type that is still open, or 7531 NULL_TREE. */ 7532 7533 tree 7534 outermost_open_class (void) 7535 { 7536 if (!current_class_type) 7537 return NULL_TREE; 7538 tree r = NULL_TREE; 7539 if (TYPE_BEING_DEFINED (current_class_type)) 7540 r = current_class_type; 7541 for (int i = current_class_depth - 1; i > 0; --i) 7542 { 7543 if (current_class_stack[i].hidden) 7544 break; 7545 tree t = current_class_stack[i].type; 7546 if (!TYPE_BEING_DEFINED (t)) 7547 break; 7548 r = t; 7549 } 7550 return r; 7551 } 7552 7553 /* Returns the innermost class type which is not a lambda closure type. */ 7554 7555 tree 7556 current_nonlambda_class_type (void) 7557 { 7558 tree type = current_class_type; 7559 while (type && LAMBDA_TYPE_P (type)) 7560 type = decl_type_context (TYPE_NAME (type)); 7561 return type; 7562 } 7563 7564 /* When entering a class scope, all enclosing class scopes' names with 7565 static meaning (static variables, static functions, types and 7566 enumerators) have to be visible. This recursive function calls 7567 pushclass for all enclosing class contexts until global or a local 7568 scope is reached. TYPE is the enclosed class. */ 7569 7570 void 7571 push_nested_class (tree type) 7572 { 7573 /* A namespace might be passed in error cases, like A::B:C. */ 7574 if (type == NULL_TREE 7575 || !CLASS_TYPE_P (type)) 7576 return; 7577 7578 push_nested_class (DECL_CONTEXT (TYPE_MAIN_DECL (type))); 7579 7580 pushclass (type); 7581 } 7582 7583 /* Undoes a push_nested_class call. */ 7584 7585 void 7586 pop_nested_class (void) 7587 { 7588 tree context = DECL_CONTEXT (TYPE_MAIN_DECL (current_class_type)); 7589 7590 popclass (); 7591 if (context && CLASS_TYPE_P (context)) 7592 pop_nested_class (); 7593 } 7594 7595 /* Returns the number of extern "LANG" blocks we are nested within. */ 7596 7597 int 7598 current_lang_depth (void) 7599 { 7600 return vec_safe_length (current_lang_base); 7601 } 7602 7603 /* Set global variables CURRENT_LANG_NAME to appropriate value 7604 so that behavior of name-mangling machinery is correct. */ 7605 7606 void 7607 push_lang_context (tree name) 7608 { 7609 vec_safe_push (current_lang_base, current_lang_name); 7610 7611 if (name == lang_name_cplusplus) 7612 current_lang_name = name; 7613 else if (name == lang_name_c) 7614 current_lang_name = name; 7615 else 7616 error ("language string %<\"%E\"%> not recognized", name); 7617 } 7618 7619 /* Get out of the current language scope. */ 7620 7621 void 7622 pop_lang_context (void) 7623 { 7624 current_lang_name = current_lang_base->pop (); 7625 } 7626 7627 /* Type instantiation routines. */ 7628 7629 /* Given an OVERLOAD and a TARGET_TYPE, return the function that 7630 matches the TARGET_TYPE. If there is no satisfactory match, return 7631 error_mark_node, and issue an error & warning messages under 7632 control of FLAGS. Permit pointers to member function if FLAGS 7633 permits. If TEMPLATE_ONLY, the name of the overloaded function was 7634 a template-id, and EXPLICIT_TARGS are the explicitly provided 7635 template arguments. 7636 7637 If OVERLOAD is for one or more member functions, then ACCESS_PATH 7638 is the base path used to reference those member functions. If 7639 the address is resolved to a member function, access checks will be 7640 performed and errors issued if appropriate. */ 7641 7642 static tree 7643 resolve_address_of_overloaded_function (tree target_type, 7644 tree overload, 7645 tsubst_flags_t complain, 7646 bool template_only, 7647 tree explicit_targs, 7648 tree access_path) 7649 { 7650 /* Here's what the standard says: 7651 7652 [over.over] 7653 7654 If the name is a function template, template argument deduction 7655 is done, and if the argument deduction succeeds, the deduced 7656 arguments are used to generate a single template function, which 7657 is added to the set of overloaded functions considered. 7658 7659 Non-member functions and static member functions match targets of 7660 type "pointer-to-function" or "reference-to-function." Nonstatic 7661 member functions match targets of type "pointer-to-member 7662 function;" the function type of the pointer to member is used to 7663 select the member function from the set of overloaded member 7664 functions. If a nonstatic member function is selected, the 7665 reference to the overloaded function name is required to have the 7666 form of a pointer to member as described in 5.3.1. 7667 7668 If more than one function is selected, any template functions in 7669 the set are eliminated if the set also contains a non-template 7670 function, and any given template function is eliminated if the 7671 set contains a second template function that is more specialized 7672 than the first according to the partial ordering rules 14.5.5.2. 7673 After such eliminations, if any, there shall remain exactly one 7674 selected function. */ 7675 7676 int is_ptrmem = 0; 7677 /* We store the matches in a TREE_LIST rooted here. The functions 7678 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy 7679 interoperability with most_specialized_instantiation. */ 7680 tree matches = NULL_TREE; 7681 tree fn; 7682 tree target_fn_type; 7683 7684 /* By the time we get here, we should be seeing only real 7685 pointer-to-member types, not the internal POINTER_TYPE to 7686 METHOD_TYPE representation. */ 7687 gcc_assert (!TYPE_PTR_P (target_type) 7688 || TREE_CODE (TREE_TYPE (target_type)) != METHOD_TYPE); 7689 7690 gcc_assert (is_overloaded_fn (overload)); 7691 7692 /* Check that the TARGET_TYPE is reasonable. */ 7693 if (TYPE_PTRFN_P (target_type) 7694 || TYPE_REFFN_P (target_type)) 7695 /* This is OK. */; 7696 else if (TYPE_PTRMEMFUNC_P (target_type)) 7697 /* This is OK, too. */ 7698 is_ptrmem = 1; 7699 else if (TREE_CODE (target_type) == FUNCTION_TYPE) 7700 /* This is OK, too. This comes from a conversion to reference 7701 type. */ 7702 target_type = build_reference_type (target_type); 7703 else 7704 { 7705 if (complain & tf_error) 7706 error ("cannot resolve overloaded function %qD based on" 7707 " conversion to type %qT", 7708 OVL_NAME (overload), target_type); 7709 return error_mark_node; 7710 } 7711 7712 /* Non-member functions and static member functions match targets of type 7713 "pointer-to-function" or "reference-to-function." Nonstatic member 7714 functions match targets of type "pointer-to-member-function;" the 7715 function type of the pointer to member is used to select the member 7716 function from the set of overloaded member functions. 7717 7718 So figure out the FUNCTION_TYPE that we want to match against. */ 7719 target_fn_type = static_fn_type (target_type); 7720 7721 /* If we can find a non-template function that matches, we can just 7722 use it. There's no point in generating template instantiations 7723 if we're just going to throw them out anyhow. But, of course, we 7724 can only do this when we don't *need* a template function. */ 7725 if (!template_only) 7726 for (lkp_iterator iter (overload); iter; ++iter) 7727 { 7728 tree fn = *iter; 7729 7730 if (TREE_CODE (fn) == TEMPLATE_DECL) 7731 /* We're not looking for templates just yet. */ 7732 continue; 7733 7734 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) != is_ptrmem) 7735 /* We're looking for a non-static member, and this isn't 7736 one, or vice versa. */ 7737 continue; 7738 7739 /* In C++17 we need the noexcept-qualifier to compare types. */ 7740 if (flag_noexcept_type 7741 && !maybe_instantiate_noexcept (fn, complain)) 7742 continue; 7743 7744 /* See if there's a match. */ 7745 tree fntype = static_fn_type (fn); 7746 if (same_type_p (target_fn_type, fntype) 7747 || fnptr_conv_p (target_fn_type, fntype)) 7748 matches = tree_cons (fn, NULL_TREE, matches); 7749 } 7750 7751 /* Now, if we've already got a match (or matches), there's no need 7752 to proceed to the template functions. But, if we don't have a 7753 match we need to look at them, too. */ 7754 if (!matches) 7755 { 7756 tree target_arg_types; 7757 tree target_ret_type; 7758 tree *args; 7759 unsigned int nargs, ia; 7760 tree arg; 7761 7762 target_arg_types = TYPE_ARG_TYPES (target_fn_type); 7763 target_ret_type = TREE_TYPE (target_fn_type); 7764 7765 nargs = list_length (target_arg_types); 7766 args = XALLOCAVEC (tree, nargs); 7767 for (arg = target_arg_types, ia = 0; 7768 arg != NULL_TREE && arg != void_list_node; 7769 arg = TREE_CHAIN (arg), ++ia) 7770 args[ia] = TREE_VALUE (arg); 7771 nargs = ia; 7772 7773 for (lkp_iterator iter (overload); iter; ++iter) 7774 { 7775 tree fn = *iter; 7776 tree instantiation; 7777 tree targs; 7778 7779 if (TREE_CODE (fn) != TEMPLATE_DECL) 7780 /* We're only looking for templates. */ 7781 continue; 7782 7783 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) 7784 != is_ptrmem) 7785 /* We're not looking for a non-static member, and this is 7786 one, or vice versa. */ 7787 continue; 7788 7789 tree ret = target_ret_type; 7790 7791 /* If the template has a deduced return type, don't expose it to 7792 template argument deduction. */ 7793 if (undeduced_auto_decl (fn)) 7794 ret = NULL_TREE; 7795 7796 /* Try to do argument deduction. */ 7797 targs = make_tree_vec (DECL_NTPARMS (fn)); 7798 instantiation = fn_type_unification (fn, explicit_targs, targs, args, 7799 nargs, ret, 7800 DEDUCE_EXACT, LOOKUP_NORMAL, 7801 false, false); 7802 if (instantiation == error_mark_node) 7803 /* Instantiation failed. */ 7804 continue; 7805 7806 /* Constraints must be satisfied. This is done before 7807 return type deduction since that instantiates the 7808 function. */ 7809 if (flag_concepts && !constraints_satisfied_p (instantiation)) 7810 continue; 7811 7812 /* And now force instantiation to do return type deduction. */ 7813 if (undeduced_auto_decl (instantiation)) 7814 { 7815 ++function_depth; 7816 instantiate_decl (instantiation, /*defer*/false, /*class*/false); 7817 --function_depth; 7818 7819 require_deduced_type (instantiation); 7820 } 7821 7822 /* In C++17 we need the noexcept-qualifier to compare types. */ 7823 if (flag_noexcept_type) 7824 maybe_instantiate_noexcept (instantiation, complain); 7825 7826 /* See if there's a match. */ 7827 tree fntype = static_fn_type (instantiation); 7828 if (same_type_p (target_fn_type, fntype) 7829 || fnptr_conv_p (target_fn_type, fntype)) 7830 matches = tree_cons (instantiation, fn, matches); 7831 } 7832 7833 /* Now, remove all but the most specialized of the matches. */ 7834 if (matches) 7835 { 7836 tree match = most_specialized_instantiation (matches); 7837 7838 if (match != error_mark_node) 7839 matches = tree_cons (TREE_PURPOSE (match), 7840 NULL_TREE, 7841 NULL_TREE); 7842 } 7843 } 7844 7845 /* Now we should have exactly one function in MATCHES. */ 7846 if (matches == NULL_TREE) 7847 { 7848 /* There were *no* matches. */ 7849 if (complain & tf_error) 7850 { 7851 error ("no matches converting function %qD to type %q#T", 7852 OVL_NAME (overload), target_type); 7853 7854 print_candidates (overload); 7855 } 7856 return error_mark_node; 7857 } 7858 else if (TREE_CHAIN (matches)) 7859 { 7860 /* There were too many matches. First check if they're all 7861 the same function. */ 7862 tree match = NULL_TREE; 7863 7864 fn = TREE_PURPOSE (matches); 7865 7866 /* For multi-versioned functions, more than one match is just fine and 7867 decls_match will return false as they are different. */ 7868 for (match = TREE_CHAIN (matches); match; match = TREE_CHAIN (match)) 7869 if (!decls_match (fn, TREE_PURPOSE (match)) 7870 && !targetm.target_option.function_versions 7871 (fn, TREE_PURPOSE (match))) 7872 break; 7873 7874 if (match) 7875 { 7876 if (complain & tf_error) 7877 { 7878 error ("converting overloaded function %qD to type %q#T is ambiguous", 7879 OVL_NAME (overload), target_type); 7880 7881 /* Since print_candidates expects the functions in the 7882 TREE_VALUE slot, we flip them here. */ 7883 for (match = matches; match; match = TREE_CHAIN (match)) 7884 TREE_VALUE (match) = TREE_PURPOSE (match); 7885 7886 print_candidates (matches); 7887 } 7888 7889 return error_mark_node; 7890 } 7891 } 7892 7893 /* Good, exactly one match. Now, convert it to the correct type. */ 7894 fn = TREE_PURPOSE (matches); 7895 7896 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) 7897 && !(complain & tf_ptrmem_ok) && !flag_ms_extensions) 7898 { 7899 static int explained; 7900 7901 if (!(complain & tf_error)) 7902 return error_mark_node; 7903 7904 permerror (input_location, "assuming pointer to member %qD", fn); 7905 if (!explained) 7906 { 7907 inform (input_location, "(a pointer to member can only be formed with %<&%E%>)", fn); 7908 explained = 1; 7909 } 7910 } 7911 7912 /* If a pointer to a function that is multi-versioned is requested, the 7913 pointer to the dispatcher function is returned instead. This works 7914 well because indirectly calling the function will dispatch the right 7915 function version at run-time. */ 7916 if (DECL_FUNCTION_VERSIONED (fn)) 7917 { 7918 fn = get_function_version_dispatcher (fn); 7919 if (fn == NULL) 7920 return error_mark_node; 7921 /* Mark all the versions corresponding to the dispatcher as used. */ 7922 if (!(complain & tf_conv)) 7923 mark_versions_used (fn); 7924 } 7925 7926 /* If we're doing overload resolution purely for the purpose of 7927 determining conversion sequences, we should not consider the 7928 function used. If this conversion sequence is selected, the 7929 function will be marked as used at this point. */ 7930 if (!(complain & tf_conv)) 7931 { 7932 /* Make =delete work with SFINAE. */ 7933 if (DECL_DELETED_FN (fn) && !(complain & tf_error)) 7934 return error_mark_node; 7935 if (!mark_used (fn, complain) && !(complain & tf_error)) 7936 return error_mark_node; 7937 } 7938 7939 /* We could not check access to member functions when this 7940 expression was originally created since we did not know at that 7941 time to which function the expression referred. */ 7942 if (DECL_FUNCTION_MEMBER_P (fn)) 7943 { 7944 gcc_assert (access_path); 7945 perform_or_defer_access_check (access_path, fn, fn, complain); 7946 } 7947 7948 if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type)) 7949 return cp_build_addr_expr (fn, complain); 7950 else 7951 { 7952 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op 7953 will mark the function as addressed, but here we must do it 7954 explicitly. */ 7955 cxx_mark_addressable (fn); 7956 7957 return fn; 7958 } 7959 } 7960 7961 /* This function will instantiate the type of the expression given in 7962 RHS to match the type of LHSTYPE. If errors exist, then return 7963 error_mark_node. COMPLAIN is a bit mask. If TF_ERROR is set, then 7964 we complain on errors. If we are not complaining, never modify rhs, 7965 as overload resolution wants to try many possible instantiations, in 7966 the hope that at least one will work. 7967 7968 For non-recursive calls, LHSTYPE should be a function, pointer to 7969 function, or a pointer to member function. */ 7970 7971 tree 7972 instantiate_type (tree lhstype, tree rhs, tsubst_flags_t complain) 7973 { 7974 tsubst_flags_t complain_in = complain; 7975 tree access_path = NULL_TREE; 7976 7977 complain &= ~tf_ptrmem_ok; 7978 7979 if (lhstype == unknown_type_node) 7980 { 7981 if (complain & tf_error) 7982 error ("not enough type information"); 7983 return error_mark_node; 7984 } 7985 7986 if (TREE_TYPE (rhs) != NULL_TREE && ! (type_unknown_p (rhs))) 7987 { 7988 tree fntype = non_reference (lhstype); 7989 if (same_type_p (fntype, TREE_TYPE (rhs))) 7990 return rhs; 7991 if (fnptr_conv_p (fntype, TREE_TYPE (rhs))) 7992 return rhs; 7993 if (flag_ms_extensions 7994 && TYPE_PTRMEMFUNC_P (fntype) 7995 && !TYPE_PTRMEMFUNC_P (TREE_TYPE (rhs))) 7996 /* Microsoft allows `A::f' to be resolved to a 7997 pointer-to-member. */ 7998 ; 7999 else 8000 { 8001 if (complain & tf_error) 8002 error ("cannot convert %qE from type %qT to type %qT", 8003 rhs, TREE_TYPE (rhs), fntype); 8004 return error_mark_node; 8005 } 8006 } 8007 8008 /* If we instantiate a template, and it is a A ?: C expression 8009 with omitted B, look through the SAVE_EXPR. */ 8010 if (TREE_CODE (rhs) == SAVE_EXPR) 8011 rhs = TREE_OPERAND (rhs, 0); 8012 8013 if (BASELINK_P (rhs)) 8014 { 8015 access_path = BASELINK_ACCESS_BINFO (rhs); 8016 rhs = BASELINK_FUNCTIONS (rhs); 8017 } 8018 8019 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot 8020 deduce any type information. */ 8021 if (TREE_CODE (rhs) == NON_DEPENDENT_EXPR) 8022 { 8023 if (complain & tf_error) 8024 error ("not enough type information"); 8025 return error_mark_node; 8026 } 8027 8028 /* There are only a few kinds of expressions that may have a type 8029 dependent on overload resolution. */ 8030 gcc_assert (TREE_CODE (rhs) == ADDR_EXPR 8031 || TREE_CODE (rhs) == COMPONENT_REF 8032 || is_overloaded_fn (rhs) 8033 || (flag_ms_extensions && TREE_CODE (rhs) == FUNCTION_DECL)); 8034 8035 /* This should really only be used when attempting to distinguish 8036 what sort of a pointer to function we have. For now, any 8037 arithmetic operation which is not supported on pointers 8038 is rejected as an error. */ 8039 8040 switch (TREE_CODE (rhs)) 8041 { 8042 case COMPONENT_REF: 8043 { 8044 tree member = TREE_OPERAND (rhs, 1); 8045 8046 member = instantiate_type (lhstype, member, complain); 8047 if (member != error_mark_node 8048 && TREE_SIDE_EFFECTS (TREE_OPERAND (rhs, 0))) 8049 /* Do not lose object's side effects. */ 8050 return build2 (COMPOUND_EXPR, TREE_TYPE (member), 8051 TREE_OPERAND (rhs, 0), member); 8052 return member; 8053 } 8054 8055 case OFFSET_REF: 8056 rhs = TREE_OPERAND (rhs, 1); 8057 if (BASELINK_P (rhs)) 8058 return instantiate_type (lhstype, rhs, complain_in); 8059 8060 /* This can happen if we are forming a pointer-to-member for a 8061 member template. */ 8062 gcc_assert (TREE_CODE (rhs) == TEMPLATE_ID_EXPR); 8063 8064 /* Fall through. */ 8065 8066 case TEMPLATE_ID_EXPR: 8067 { 8068 tree fns = TREE_OPERAND (rhs, 0); 8069 tree args = TREE_OPERAND (rhs, 1); 8070 8071 return 8072 resolve_address_of_overloaded_function (lhstype, fns, complain_in, 8073 /*template_only=*/true, 8074 args, access_path); 8075 } 8076 8077 case OVERLOAD: 8078 case FUNCTION_DECL: 8079 return 8080 resolve_address_of_overloaded_function (lhstype, rhs, complain_in, 8081 /*template_only=*/false, 8082 /*explicit_targs=*/NULL_TREE, 8083 access_path); 8084 8085 case ADDR_EXPR: 8086 { 8087 if (PTRMEM_OK_P (rhs)) 8088 complain |= tf_ptrmem_ok; 8089 8090 return instantiate_type (lhstype, TREE_OPERAND (rhs, 0), complain); 8091 } 8092 8093 case ERROR_MARK: 8094 return error_mark_node; 8095 8096 default: 8097 gcc_unreachable (); 8098 } 8099 return error_mark_node; 8100 } 8101 8102 /* Return the name of the virtual function pointer field 8103 (as an IDENTIFIER_NODE) for the given TYPE. Note that 8104 this may have to look back through base types to find the 8105 ultimate field name. (For single inheritance, these could 8106 all be the same name. Who knows for multiple inheritance). */ 8107 8108 static tree 8109 get_vfield_name (tree type) 8110 { 8111 tree binfo, base_binfo; 8112 8113 for (binfo = TYPE_BINFO (type); 8114 BINFO_N_BASE_BINFOS (binfo); 8115 binfo = base_binfo) 8116 { 8117 base_binfo = BINFO_BASE_BINFO (binfo, 0); 8118 8119 if (BINFO_VIRTUAL_P (base_binfo) 8120 || !TYPE_CONTAINS_VPTR_P (BINFO_TYPE (base_binfo))) 8121 break; 8122 } 8123 8124 type = BINFO_TYPE (binfo); 8125 tree ctor_name = constructor_name (type); 8126 char *buf = (char *) alloca (sizeof (VFIELD_NAME_FORMAT) 8127 + IDENTIFIER_LENGTH (ctor_name) + 2); 8128 sprintf (buf, VFIELD_NAME_FORMAT, IDENTIFIER_POINTER (ctor_name)); 8129 return get_identifier (buf); 8130 } 8131 8132 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works, 8133 according to [class]: 8134 The class-name is also inserted 8135 into the scope of the class itself. For purposes of access checking, 8136 the inserted class name is treated as if it were a public member name. */ 8137 8138 void 8139 build_self_reference (void) 8140 { 8141 tree name = DECL_NAME (TYPE_NAME (current_class_type)); 8142 tree value = build_lang_decl (TYPE_DECL, name, current_class_type); 8143 8144 DECL_NONLOCAL (value) = 1; 8145 DECL_CONTEXT (value) = current_class_type; 8146 DECL_ARTIFICIAL (value) = 1; 8147 SET_DECL_SELF_REFERENCE_P (value); 8148 set_underlying_type (value); 8149 8150 if (processing_template_decl) 8151 value = push_template_decl (value); 8152 8153 tree saved_cas = current_access_specifier; 8154 current_access_specifier = access_public_node; 8155 finish_member_declaration (value); 8156 current_access_specifier = saved_cas; 8157 } 8158 8159 /* Returns 1 if TYPE contains only padding bytes. */ 8160 8161 int 8162 is_empty_class (tree type) 8163 { 8164 if (type == error_mark_node) 8165 return 0; 8166 8167 if (! CLASS_TYPE_P (type)) 8168 return 0; 8169 8170 return CLASSTYPE_EMPTY_P (type); 8171 } 8172 8173 /* Returns true if TYPE contains no actual data, just various 8174 possible combinations of empty classes and possibly a vptr. */ 8175 8176 bool 8177 is_really_empty_class (tree type) 8178 { 8179 if (CLASS_TYPE_P (type)) 8180 { 8181 tree field; 8182 tree binfo; 8183 tree base_binfo; 8184 int i; 8185 8186 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid 8187 out, but we'd like to be able to check this before then. */ 8188 if (COMPLETE_TYPE_P (type) && is_empty_class (type)) 8189 return true; 8190 8191 for (binfo = TYPE_BINFO (type), i = 0; 8192 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 8193 if (!is_really_empty_class (BINFO_TYPE (base_binfo))) 8194 return false; 8195 for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) 8196 if (TREE_CODE (field) == FIELD_DECL 8197 && !DECL_ARTIFICIAL (field) 8198 /* An unnamed bit-field is not a data member. */ 8199 && !DECL_UNNAMED_BIT_FIELD (field) 8200 && !is_really_empty_class (TREE_TYPE (field))) 8201 return false; 8202 return true; 8203 } 8204 else if (TREE_CODE (type) == ARRAY_TYPE) 8205 return (integer_zerop (array_type_nelts_top (type)) 8206 || is_really_empty_class (TREE_TYPE (type))); 8207 return false; 8208 } 8209 8210 /* Note that NAME was looked up while the current class was being 8211 defined and that the result of that lookup was DECL. */ 8212 8213 void 8214 maybe_note_name_used_in_class (tree name, tree decl) 8215 { 8216 splay_tree names_used; 8217 8218 /* If we're not defining a class, there's nothing to do. */ 8219 if (!(innermost_scope_kind() == sk_class 8220 && TYPE_BEING_DEFINED (current_class_type) 8221 && !LAMBDA_TYPE_P (current_class_type))) 8222 return; 8223 8224 /* If there's already a binding for this NAME, then we don't have 8225 anything to worry about. */ 8226 if (lookup_member (current_class_type, name, 8227 /*protect=*/0, /*want_type=*/false, tf_warning_or_error)) 8228 return; 8229 8230 if (!current_class_stack[current_class_depth - 1].names_used) 8231 current_class_stack[current_class_depth - 1].names_used 8232 = splay_tree_new (splay_tree_compare_pointers, 0, 0); 8233 names_used = current_class_stack[current_class_depth - 1].names_used; 8234 8235 splay_tree_insert (names_used, 8236 (splay_tree_key) name, 8237 (splay_tree_value) decl); 8238 } 8239 8240 /* Note that NAME was declared (as DECL) in the current class. Check 8241 to see that the declaration is valid. */ 8242 8243 void 8244 note_name_declared_in_class (tree name, tree decl) 8245 { 8246 splay_tree names_used; 8247 splay_tree_node n; 8248 8249 /* Look to see if we ever used this name. */ 8250 names_used 8251 = current_class_stack[current_class_depth - 1].names_used; 8252 if (!names_used) 8253 return; 8254 /* The C language allows members to be declared with a type of the same 8255 name, and the C++ standard says this diagnostic is not required. So 8256 allow it in extern "C" blocks unless predantic is specified. 8257 Allow it in all cases if -ms-extensions is specified. */ 8258 if ((!pedantic && current_lang_name == lang_name_c) 8259 || flag_ms_extensions) 8260 return; 8261 n = splay_tree_lookup (names_used, (splay_tree_key) name); 8262 if (n) 8263 { 8264 /* [basic.scope.class] 8265 8266 A name N used in a class S shall refer to the same declaration 8267 in its context and when re-evaluated in the completed scope of 8268 S. */ 8269 permerror (input_location, "declaration of %q#D", decl); 8270 permerror (location_of ((tree) n->value), 8271 "changes meaning of %qD from %q#D", 8272 OVL_NAME (decl), (tree) n->value); 8273 } 8274 } 8275 8276 /* Returns the VAR_DECL for the complete vtable associated with BINFO. 8277 Secondary vtables are merged with primary vtables; this function 8278 will return the VAR_DECL for the primary vtable. */ 8279 8280 tree 8281 get_vtbl_decl_for_binfo (tree binfo) 8282 { 8283 tree decl; 8284 8285 decl = BINFO_VTABLE (binfo); 8286 if (decl && TREE_CODE (decl) == POINTER_PLUS_EXPR) 8287 { 8288 gcc_assert (TREE_CODE (TREE_OPERAND (decl, 0)) == ADDR_EXPR); 8289 decl = TREE_OPERAND (TREE_OPERAND (decl, 0), 0); 8290 } 8291 if (decl) 8292 gcc_assert (VAR_P (decl)); 8293 return decl; 8294 } 8295 8296 8297 /* Returns the binfo for the primary base of BINFO. If the resulting 8298 BINFO is a virtual base, and it is inherited elsewhere in the 8299 hierarchy, then the returned binfo might not be the primary base of 8300 BINFO in the complete object. Check BINFO_PRIMARY_P or 8301 BINFO_LOST_PRIMARY_P to be sure. */ 8302 8303 static tree 8304 get_primary_binfo (tree binfo) 8305 { 8306 tree primary_base; 8307 8308 primary_base = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (binfo)); 8309 if (!primary_base) 8310 return NULL_TREE; 8311 8312 return copied_binfo (primary_base, binfo); 8313 } 8314 8315 /* As above, but iterate until we reach the binfo that actually provides the 8316 vptr for BINFO. */ 8317 8318 static tree 8319 most_primary_binfo (tree binfo) 8320 { 8321 tree b = binfo; 8322 while (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (b)) 8323 && !BINFO_LOST_PRIMARY_P (b)) 8324 { 8325 tree primary_base = get_primary_binfo (b); 8326 gcc_assert (BINFO_PRIMARY_P (primary_base) 8327 && BINFO_INHERITANCE_CHAIN (primary_base) == b); 8328 b = primary_base; 8329 } 8330 return b; 8331 } 8332 8333 /* Returns true if BINFO gets its vptr from a virtual base of the most derived 8334 type. Note that the virtual inheritance might be above or below BINFO in 8335 the hierarchy. */ 8336 8337 bool 8338 vptr_via_virtual_p (tree binfo) 8339 { 8340 if (TYPE_P (binfo)) 8341 binfo = TYPE_BINFO (binfo); 8342 tree primary = most_primary_binfo (binfo); 8343 /* Don't limit binfo_via_virtual, we want to return true when BINFO itself is 8344 a morally virtual base. */ 8345 tree virt = binfo_via_virtual (primary, NULL_TREE); 8346 return virt != NULL_TREE; 8347 } 8348 8349 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */ 8350 8351 static int 8352 maybe_indent_hierarchy (FILE * stream, int indent, int indented_p) 8353 { 8354 if (!indented_p) 8355 fprintf (stream, "%*s", indent, ""); 8356 return 1; 8357 } 8358 8359 /* Dump the offsets of all the bases rooted at BINFO to STREAM. 8360 INDENT should be zero when called from the top level; it is 8361 incremented recursively. IGO indicates the next expected BINFO in 8362 inheritance graph ordering. */ 8363 8364 static tree 8365 dump_class_hierarchy_r (FILE *stream, 8366 dump_flags_t flags, 8367 tree binfo, 8368 tree igo, 8369 int indent) 8370 { 8371 int indented = 0; 8372 tree base_binfo; 8373 int i; 8374 8375 indented = maybe_indent_hierarchy (stream, indent, 0); 8376 fprintf (stream, "%s (0x" HOST_WIDE_INT_PRINT_HEX ") ", 8377 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER), 8378 (HOST_WIDE_INT) (uintptr_t) binfo); 8379 if (binfo != igo) 8380 { 8381 fprintf (stream, "alternative-path\n"); 8382 return igo; 8383 } 8384 igo = TREE_CHAIN (binfo); 8385 8386 fprintf (stream, HOST_WIDE_INT_PRINT_DEC, 8387 tree_to_shwi (BINFO_OFFSET (binfo))); 8388 if (is_empty_class (BINFO_TYPE (binfo))) 8389 fprintf (stream, " empty"); 8390 else if (CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (binfo))) 8391 fprintf (stream, " nearly-empty"); 8392 if (BINFO_VIRTUAL_P (binfo)) 8393 fprintf (stream, " virtual"); 8394 fprintf (stream, "\n"); 8395 8396 indented = 0; 8397 if (BINFO_PRIMARY_P (binfo)) 8398 { 8399 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8400 fprintf (stream, " primary-for %s (0x" HOST_WIDE_INT_PRINT_HEX ")", 8401 type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)), 8402 TFF_PLAIN_IDENTIFIER), 8403 (HOST_WIDE_INT) (uintptr_t) BINFO_INHERITANCE_CHAIN (binfo)); 8404 } 8405 if (BINFO_LOST_PRIMARY_P (binfo)) 8406 { 8407 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8408 fprintf (stream, " lost-primary"); 8409 } 8410 if (indented) 8411 fprintf (stream, "\n"); 8412 8413 if (!(flags & TDF_SLIM)) 8414 { 8415 int indented = 0; 8416 8417 if (BINFO_SUBVTT_INDEX (binfo)) 8418 { 8419 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8420 fprintf (stream, " subvttidx=%s", 8421 expr_as_string (BINFO_SUBVTT_INDEX (binfo), 8422 TFF_PLAIN_IDENTIFIER)); 8423 } 8424 if (BINFO_VPTR_INDEX (binfo)) 8425 { 8426 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8427 fprintf (stream, " vptridx=%s", 8428 expr_as_string (BINFO_VPTR_INDEX (binfo), 8429 TFF_PLAIN_IDENTIFIER)); 8430 } 8431 if (BINFO_VPTR_FIELD (binfo)) 8432 { 8433 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8434 fprintf (stream, " vbaseoffset=%s", 8435 expr_as_string (BINFO_VPTR_FIELD (binfo), 8436 TFF_PLAIN_IDENTIFIER)); 8437 } 8438 if (BINFO_VTABLE (binfo)) 8439 { 8440 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8441 fprintf (stream, " vptr=%s", 8442 expr_as_string (BINFO_VTABLE (binfo), 8443 TFF_PLAIN_IDENTIFIER)); 8444 } 8445 8446 if (indented) 8447 fprintf (stream, "\n"); 8448 } 8449 8450 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 8451 igo = dump_class_hierarchy_r (stream, flags, base_binfo, igo, indent + 2); 8452 8453 return igo; 8454 } 8455 8456 /* Dump the BINFO hierarchy for T. */ 8457 8458 static void 8459 dump_class_hierarchy_1 (FILE *stream, dump_flags_t flags, tree t) 8460 { 8461 fprintf (stream, "Class %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER)); 8462 fprintf (stream, " size=%lu align=%lu\n", 8463 (unsigned long)(tree_to_shwi (TYPE_SIZE (t)) / BITS_PER_UNIT), 8464 (unsigned long)(TYPE_ALIGN (t) / BITS_PER_UNIT)); 8465 fprintf (stream, " base size=%lu base align=%lu\n", 8466 (unsigned long)(tree_to_shwi (TYPE_SIZE (CLASSTYPE_AS_BASE (t))) 8467 / BITS_PER_UNIT), 8468 (unsigned long)(TYPE_ALIGN (CLASSTYPE_AS_BASE (t)) 8469 / BITS_PER_UNIT)); 8470 dump_class_hierarchy_r (stream, flags, TYPE_BINFO (t), TYPE_BINFO (t), 0); 8471 fprintf (stream, "\n"); 8472 } 8473 8474 /* Debug interface to hierarchy dumping. */ 8475 8476 void 8477 debug_class (tree t) 8478 { 8479 dump_class_hierarchy_1 (stderr, TDF_SLIM, t); 8480 } 8481 8482 static void 8483 dump_class_hierarchy (tree t) 8484 { 8485 dump_flags_t flags; 8486 if (FILE *stream = dump_begin (class_dump_id, &flags)) 8487 { 8488 dump_class_hierarchy_1 (stream, flags, t); 8489 dump_end (class_dump_id, stream); 8490 } 8491 } 8492 8493 static void 8494 dump_array (FILE * stream, tree decl) 8495 { 8496 tree value; 8497 unsigned HOST_WIDE_INT ix; 8498 HOST_WIDE_INT elt; 8499 tree size = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (decl))); 8500 8501 elt = (tree_to_shwi (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl)))) 8502 / BITS_PER_UNIT); 8503 fprintf (stream, "%s:", decl_as_string (decl, TFF_PLAIN_IDENTIFIER)); 8504 fprintf (stream, " %s entries", 8505 expr_as_string (size_binop (PLUS_EXPR, size, size_one_node), 8506 TFF_PLAIN_IDENTIFIER)); 8507 fprintf (stream, "\n"); 8508 8509 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (DECL_INITIAL (decl)), 8510 ix, value) 8511 fprintf (stream, "%-4ld %s\n", (long)(ix * elt), 8512 expr_as_string (value, TFF_PLAIN_IDENTIFIER)); 8513 } 8514 8515 static void 8516 dump_vtable (tree t, tree binfo, tree vtable) 8517 { 8518 dump_flags_t flags; 8519 FILE *stream = dump_begin (class_dump_id, &flags); 8520 8521 if (!stream) 8522 return; 8523 8524 if (!(flags & TDF_SLIM)) 8525 { 8526 int ctor_vtbl_p = TYPE_BINFO (t) != binfo; 8527 8528 fprintf (stream, "%s for %s", 8529 ctor_vtbl_p ? "Construction vtable" : "Vtable", 8530 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER)); 8531 if (ctor_vtbl_p) 8532 { 8533 if (!BINFO_VIRTUAL_P (binfo)) 8534 fprintf (stream, " (0x" HOST_WIDE_INT_PRINT_HEX " instance)", 8535 (HOST_WIDE_INT) (uintptr_t) binfo); 8536 fprintf (stream, " in %s", type_as_string (t, TFF_PLAIN_IDENTIFIER)); 8537 } 8538 fprintf (stream, "\n"); 8539 dump_array (stream, vtable); 8540 fprintf (stream, "\n"); 8541 } 8542 8543 dump_end (class_dump_id, stream); 8544 } 8545 8546 static void 8547 dump_vtt (tree t, tree vtt) 8548 { 8549 dump_flags_t flags; 8550 FILE *stream = dump_begin (class_dump_id, &flags); 8551 8552 if (!stream) 8553 return; 8554 8555 if (!(flags & TDF_SLIM)) 8556 { 8557 fprintf (stream, "VTT for %s\n", 8558 type_as_string (t, TFF_PLAIN_IDENTIFIER)); 8559 dump_array (stream, vtt); 8560 fprintf (stream, "\n"); 8561 } 8562 8563 dump_end (class_dump_id, stream); 8564 } 8565 8566 /* Dump a function or thunk and its thunkees. */ 8567 8568 static void 8569 dump_thunk (FILE *stream, int indent, tree thunk) 8570 { 8571 static const char spaces[] = " "; 8572 tree name = DECL_NAME (thunk); 8573 tree thunks; 8574 8575 fprintf (stream, "%.*s%p %s %s", indent, spaces, 8576 (void *)thunk, 8577 !DECL_THUNK_P (thunk) ? "function" 8578 : DECL_THIS_THUNK_P (thunk) ? "this-thunk" : "covariant-thunk", 8579 name ? IDENTIFIER_POINTER (name) : "<unset>"); 8580 if (DECL_THUNK_P (thunk)) 8581 { 8582 HOST_WIDE_INT fixed_adjust = THUNK_FIXED_OFFSET (thunk); 8583 tree virtual_adjust = THUNK_VIRTUAL_OFFSET (thunk); 8584 8585 fprintf (stream, " fixed=" HOST_WIDE_INT_PRINT_DEC, fixed_adjust); 8586 if (!virtual_adjust) 8587 /*NOP*/; 8588 else if (DECL_THIS_THUNK_P (thunk)) 8589 fprintf (stream, " vcall=" HOST_WIDE_INT_PRINT_DEC, 8590 tree_to_shwi (virtual_adjust)); 8591 else 8592 fprintf (stream, " vbase=" HOST_WIDE_INT_PRINT_DEC "(%s)", 8593 tree_to_shwi (BINFO_VPTR_FIELD (virtual_adjust)), 8594 type_as_string (BINFO_TYPE (virtual_adjust), TFF_SCOPE)); 8595 if (THUNK_ALIAS (thunk)) 8596 fprintf (stream, " alias to %p", (void *)THUNK_ALIAS (thunk)); 8597 } 8598 fprintf (stream, "\n"); 8599 for (thunks = DECL_THUNKS (thunk); thunks; thunks = TREE_CHAIN (thunks)) 8600 dump_thunk (stream, indent + 2, thunks); 8601 } 8602 8603 /* Dump the thunks for FN. */ 8604 8605 void 8606 debug_thunks (tree fn) 8607 { 8608 dump_thunk (stderr, 0, fn); 8609 } 8610 8611 /* Virtual function table initialization. */ 8612 8613 /* Create all the necessary vtables for T and its base classes. */ 8614 8615 static void 8616 finish_vtbls (tree t) 8617 { 8618 tree vbase; 8619 vec<constructor_elt, va_gc> *v = NULL; 8620 tree vtable = BINFO_VTABLE (TYPE_BINFO (t)); 8621 8622 /* We lay out the primary and secondary vtables in one contiguous 8623 vtable. The primary vtable is first, followed by the non-virtual 8624 secondary vtables in inheritance graph order. */ 8625 accumulate_vtbl_inits (TYPE_BINFO (t), TYPE_BINFO (t), TYPE_BINFO (t), 8626 vtable, t, &v); 8627 8628 /* Then come the virtual bases, also in inheritance graph order. */ 8629 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase)) 8630 { 8631 if (!BINFO_VIRTUAL_P (vbase)) 8632 continue; 8633 accumulate_vtbl_inits (vbase, vbase, TYPE_BINFO (t), vtable, t, &v); 8634 } 8635 8636 if (BINFO_VTABLE (TYPE_BINFO (t))) 8637 initialize_vtable (TYPE_BINFO (t), v); 8638 } 8639 8640 /* Initialize the vtable for BINFO with the INITS. */ 8641 8642 static void 8643 initialize_vtable (tree binfo, vec<constructor_elt, va_gc> *inits) 8644 { 8645 tree decl; 8646 8647 layout_vtable_decl (binfo, vec_safe_length (inits)); 8648 decl = get_vtbl_decl_for_binfo (binfo); 8649 initialize_artificial_var (decl, inits); 8650 dump_vtable (BINFO_TYPE (binfo), binfo, decl); 8651 } 8652 8653 /* Build the VTT (virtual table table) for T. 8654 A class requires a VTT if it has virtual bases. 8655 8656 This holds 8657 1 - primary virtual pointer for complete object T 8658 2 - secondary VTTs for each direct non-virtual base of T which requires a 8659 VTT 8660 3 - secondary virtual pointers for each direct or indirect base of T which 8661 has virtual bases or is reachable via a virtual path from T. 8662 4 - secondary VTTs for each direct or indirect virtual base of T. 8663 8664 Secondary VTTs look like complete object VTTs without part 4. */ 8665 8666 static void 8667 build_vtt (tree t) 8668 { 8669 tree type; 8670 tree vtt; 8671 tree index; 8672 vec<constructor_elt, va_gc> *inits; 8673 8674 /* Build up the initializers for the VTT. */ 8675 inits = NULL; 8676 index = size_zero_node; 8677 build_vtt_inits (TYPE_BINFO (t), t, &inits, &index); 8678 8679 /* If we didn't need a VTT, we're done. */ 8680 if (!inits) 8681 return; 8682 8683 /* Figure out the type of the VTT. */ 8684 type = build_array_of_n_type (const_ptr_type_node, 8685 inits->length ()); 8686 8687 /* Now, build the VTT object itself. */ 8688 vtt = build_vtable (t, mangle_vtt_for_type (t), type); 8689 initialize_artificial_var (vtt, inits); 8690 /* Add the VTT to the vtables list. */ 8691 DECL_CHAIN (vtt) = DECL_CHAIN (CLASSTYPE_VTABLES (t)); 8692 DECL_CHAIN (CLASSTYPE_VTABLES (t)) = vtt; 8693 8694 dump_vtt (t, vtt); 8695 } 8696 8697 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with 8698 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo, 8699 and CHAIN the vtable pointer for this binfo after construction is 8700 complete. VALUE can also be another BINFO, in which case we recurse. */ 8701 8702 static tree 8703 binfo_ctor_vtable (tree binfo) 8704 { 8705 tree vt; 8706 8707 while (1) 8708 { 8709 vt = BINFO_VTABLE (binfo); 8710 if (TREE_CODE (vt) == TREE_LIST) 8711 vt = TREE_VALUE (vt); 8712 if (TREE_CODE (vt) == TREE_BINFO) 8713 binfo = vt; 8714 else 8715 break; 8716 } 8717 8718 return vt; 8719 } 8720 8721 /* Data for secondary VTT initialization. */ 8722 struct secondary_vptr_vtt_init_data 8723 { 8724 /* Is this the primary VTT? */ 8725 bool top_level_p; 8726 8727 /* Current index into the VTT. */ 8728 tree index; 8729 8730 /* Vector of initializers built up. */ 8731 vec<constructor_elt, va_gc> *inits; 8732 8733 /* The type being constructed by this secondary VTT. */ 8734 tree type_being_constructed; 8735 }; 8736 8737 /* Recursively build the VTT-initializer for BINFO (which is in the 8738 hierarchy dominated by T). INITS points to the end of the initializer 8739 list to date. INDEX is the VTT index where the next element will be 8740 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e. 8741 not a subvtt for some base of T). When that is so, we emit the sub-VTTs 8742 for virtual bases of T. When it is not so, we build the constructor 8743 vtables for the BINFO-in-T variant. */ 8744 8745 static void 8746 build_vtt_inits (tree binfo, tree t, vec<constructor_elt, va_gc> **inits, 8747 tree *index) 8748 { 8749 int i; 8750 tree b; 8751 tree init; 8752 secondary_vptr_vtt_init_data data; 8753 int top_level_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t); 8754 8755 /* We only need VTTs for subobjects with virtual bases. */ 8756 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))) 8757 return; 8758 8759 /* We need to use a construction vtable if this is not the primary 8760 VTT. */ 8761 if (!top_level_p) 8762 { 8763 build_ctor_vtbl_group (binfo, t); 8764 8765 /* Record the offset in the VTT where this sub-VTT can be found. */ 8766 BINFO_SUBVTT_INDEX (binfo) = *index; 8767 } 8768 8769 /* Add the address of the primary vtable for the complete object. */ 8770 init = binfo_ctor_vtable (binfo); 8771 CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, init); 8772 if (top_level_p) 8773 { 8774 gcc_assert (!BINFO_VPTR_INDEX (binfo)); 8775 BINFO_VPTR_INDEX (binfo) = *index; 8776 } 8777 *index = size_binop (PLUS_EXPR, *index, TYPE_SIZE_UNIT (ptr_type_node)); 8778 8779 /* Recursively add the secondary VTTs for non-virtual bases. */ 8780 for (i = 0; BINFO_BASE_ITERATE (binfo, i, b); ++i) 8781 if (!BINFO_VIRTUAL_P (b)) 8782 build_vtt_inits (b, t, inits, index); 8783 8784 /* Add secondary virtual pointers for all subobjects of BINFO with 8785 either virtual bases or reachable along a virtual path, except 8786 subobjects that are non-virtual primary bases. */ 8787 data.top_level_p = top_level_p; 8788 data.index = *index; 8789 data.inits = *inits; 8790 data.type_being_constructed = BINFO_TYPE (binfo); 8791 8792 dfs_walk_once (binfo, dfs_build_secondary_vptr_vtt_inits, NULL, &data); 8793 8794 *index = data.index; 8795 8796 /* data.inits might have grown as we added secondary virtual pointers. 8797 Make sure our caller knows about the new vector. */ 8798 *inits = data.inits; 8799 8800 if (top_level_p) 8801 /* Add the secondary VTTs for virtual bases in inheritance graph 8802 order. */ 8803 for (b = TYPE_BINFO (BINFO_TYPE (binfo)); b; b = TREE_CHAIN (b)) 8804 { 8805 if (!BINFO_VIRTUAL_P (b)) 8806 continue; 8807 8808 build_vtt_inits (b, t, inits, index); 8809 } 8810 else 8811 /* Remove the ctor vtables we created. */ 8812 dfs_walk_all (binfo, dfs_fixup_binfo_vtbls, NULL, binfo); 8813 } 8814 8815 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base 8816 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */ 8817 8818 static tree 8819 dfs_build_secondary_vptr_vtt_inits (tree binfo, void *data_) 8820 { 8821 secondary_vptr_vtt_init_data *data = (secondary_vptr_vtt_init_data *)data_; 8822 8823 /* We don't care about bases that don't have vtables. */ 8824 if (!TYPE_VFIELD (BINFO_TYPE (binfo))) 8825 return dfs_skip_bases; 8826 8827 /* We're only interested in proper subobjects of the type being 8828 constructed. */ 8829 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->type_being_constructed)) 8830 return NULL_TREE; 8831 8832 /* We're only interested in bases with virtual bases or reachable 8833 via a virtual path from the type being constructed. */ 8834 if (!(CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)) 8835 || binfo_via_virtual (binfo, data->type_being_constructed))) 8836 return dfs_skip_bases; 8837 8838 /* We're not interested in non-virtual primary bases. */ 8839 if (!BINFO_VIRTUAL_P (binfo) && BINFO_PRIMARY_P (binfo)) 8840 return NULL_TREE; 8841 8842 /* Record the index where this secondary vptr can be found. */ 8843 if (data->top_level_p) 8844 { 8845 gcc_assert (!BINFO_VPTR_INDEX (binfo)); 8846 BINFO_VPTR_INDEX (binfo) = data->index; 8847 8848 if (BINFO_VIRTUAL_P (binfo)) 8849 { 8850 /* It's a primary virtual base, and this is not a 8851 construction vtable. Find the base this is primary of in 8852 the inheritance graph, and use that base's vtable 8853 now. */ 8854 while (BINFO_PRIMARY_P (binfo)) 8855 binfo = BINFO_INHERITANCE_CHAIN (binfo); 8856 } 8857 } 8858 8859 /* Add the initializer for the secondary vptr itself. */ 8860 CONSTRUCTOR_APPEND_ELT (data->inits, NULL_TREE, binfo_ctor_vtable (binfo)); 8861 8862 /* Advance the vtt index. */ 8863 data->index = size_binop (PLUS_EXPR, data->index, 8864 TYPE_SIZE_UNIT (ptr_type_node)); 8865 8866 return NULL_TREE; 8867 } 8868 8869 /* Called from build_vtt_inits via dfs_walk. After building 8870 constructor vtables and generating the sub-vtt from them, we need 8871 to restore the BINFO_VTABLES that were scribbled on. DATA is the 8872 binfo of the base whose sub vtt was generated. */ 8873 8874 static tree 8875 dfs_fixup_binfo_vtbls (tree binfo, void* data) 8876 { 8877 tree vtable = BINFO_VTABLE (binfo); 8878 8879 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) 8880 /* If this class has no vtable, none of its bases do. */ 8881 return dfs_skip_bases; 8882 8883 if (!vtable) 8884 /* This might be a primary base, so have no vtable in this 8885 hierarchy. */ 8886 return NULL_TREE; 8887 8888 /* If we scribbled the construction vtable vptr into BINFO, clear it 8889 out now. */ 8890 if (TREE_CODE (vtable) == TREE_LIST 8891 && (TREE_PURPOSE (vtable) == (tree) data)) 8892 BINFO_VTABLE (binfo) = TREE_CHAIN (vtable); 8893 8894 return NULL_TREE; 8895 } 8896 8897 /* Build the construction vtable group for BINFO which is in the 8898 hierarchy dominated by T. */ 8899 8900 static void 8901 build_ctor_vtbl_group (tree binfo, tree t) 8902 { 8903 tree type; 8904 tree vtbl; 8905 tree id; 8906 tree vbase; 8907 vec<constructor_elt, va_gc> *v; 8908 8909 /* See if we've already created this construction vtable group. */ 8910 id = mangle_ctor_vtbl_for_type (t, binfo); 8911 if (get_global_binding (id)) 8912 return; 8913 8914 gcc_assert (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t)); 8915 /* Build a version of VTBL (with the wrong type) for use in 8916 constructing the addresses of secondary vtables in the 8917 construction vtable group. */ 8918 vtbl = build_vtable (t, id, ptr_type_node); 8919 DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1; 8920 /* Don't export construction vtables from shared libraries. Even on 8921 targets that don't support hidden visibility, this tells 8922 can_refer_decl_in_current_unit_p not to assume that it's safe to 8923 access from a different compilation unit (bz 54314). */ 8924 DECL_VISIBILITY (vtbl) = VISIBILITY_HIDDEN; 8925 DECL_VISIBILITY_SPECIFIED (vtbl) = true; 8926 8927 v = NULL; 8928 accumulate_vtbl_inits (binfo, TYPE_BINFO (TREE_TYPE (binfo)), 8929 binfo, vtbl, t, &v); 8930 8931 /* Add the vtables for each of our virtual bases using the vbase in T 8932 binfo. */ 8933 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo)); 8934 vbase; 8935 vbase = TREE_CHAIN (vbase)) 8936 { 8937 tree b; 8938 8939 if (!BINFO_VIRTUAL_P (vbase)) 8940 continue; 8941 b = copied_binfo (vbase, binfo); 8942 8943 accumulate_vtbl_inits (b, vbase, binfo, vtbl, t, &v); 8944 } 8945 8946 /* Figure out the type of the construction vtable. */ 8947 type = build_array_of_n_type (vtable_entry_type, v->length ()); 8948 layout_type (type); 8949 TREE_TYPE (vtbl) = type; 8950 DECL_SIZE (vtbl) = DECL_SIZE_UNIT (vtbl) = NULL_TREE; 8951 layout_decl (vtbl, 0); 8952 8953 /* Initialize the construction vtable. */ 8954 CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl); 8955 initialize_artificial_var (vtbl, v); 8956 dump_vtable (t, binfo, vtbl); 8957 } 8958 8959 /* Add the vtbl initializers for BINFO (and its bases other than 8960 non-virtual primaries) to the list of INITS. BINFO is in the 8961 hierarchy dominated by T. RTTI_BINFO is the binfo within T of 8962 the constructor the vtbl inits should be accumulated for. (If this 8963 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).) 8964 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO). 8965 BINFO is the active base equivalent of ORIG_BINFO in the inheritance 8966 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE, 8967 but are not necessarily the same in terms of layout. */ 8968 8969 static void 8970 accumulate_vtbl_inits (tree binfo, 8971 tree orig_binfo, 8972 tree rtti_binfo, 8973 tree vtbl, 8974 tree t, 8975 vec<constructor_elt, va_gc> **inits) 8976 { 8977 int i; 8978 tree base_binfo; 8979 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); 8980 8981 gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (orig_binfo))); 8982 8983 /* If it doesn't have a vptr, we don't do anything. */ 8984 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) 8985 return; 8986 8987 /* If we're building a construction vtable, we're not interested in 8988 subobjects that don't require construction vtables. */ 8989 if (ctor_vtbl_p 8990 && !CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)) 8991 && !binfo_via_virtual (orig_binfo, BINFO_TYPE (rtti_binfo))) 8992 return; 8993 8994 /* Build the initializers for the BINFO-in-T vtable. */ 8995 dfs_accumulate_vtbl_inits (binfo, orig_binfo, rtti_binfo, vtbl, t, inits); 8996 8997 /* Walk the BINFO and its bases. We walk in preorder so that as we 8998 initialize each vtable we can figure out at what offset the 8999 secondary vtable lies from the primary vtable. We can't use 9000 dfs_walk here because we need to iterate through bases of BINFO 9001 and RTTI_BINFO simultaneously. */ 9002 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 9003 { 9004 /* Skip virtual bases. */ 9005 if (BINFO_VIRTUAL_P (base_binfo)) 9006 continue; 9007 accumulate_vtbl_inits (base_binfo, 9008 BINFO_BASE_BINFO (orig_binfo, i), 9009 rtti_binfo, vtbl, t, 9010 inits); 9011 } 9012 } 9013 9014 /* Called from accumulate_vtbl_inits. Adds the initializers for the 9015 BINFO vtable to L. */ 9016 9017 static void 9018 dfs_accumulate_vtbl_inits (tree binfo, 9019 tree orig_binfo, 9020 tree rtti_binfo, 9021 tree orig_vtbl, 9022 tree t, 9023 vec<constructor_elt, va_gc> **l) 9024 { 9025 tree vtbl = NULL_TREE; 9026 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); 9027 int n_inits; 9028 9029 if (ctor_vtbl_p 9030 && BINFO_VIRTUAL_P (orig_binfo) && BINFO_PRIMARY_P (orig_binfo)) 9031 { 9032 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a 9033 primary virtual base. If it is not the same primary in 9034 the hierarchy of T, we'll need to generate a ctor vtable 9035 for it, to place at its location in T. If it is the same 9036 primary, we still need a VTT entry for the vtable, but it 9037 should point to the ctor vtable for the base it is a 9038 primary for within the sub-hierarchy of RTTI_BINFO. 9039 9040 There are three possible cases: 9041 9042 1) We are in the same place. 9043 2) We are a primary base within a lost primary virtual base of 9044 RTTI_BINFO. 9045 3) We are primary to something not a base of RTTI_BINFO. */ 9046 9047 tree b; 9048 tree last = NULL_TREE; 9049 9050 /* First, look through the bases we are primary to for RTTI_BINFO 9051 or a virtual base. */ 9052 b = binfo; 9053 while (BINFO_PRIMARY_P (b)) 9054 { 9055 b = BINFO_INHERITANCE_CHAIN (b); 9056 last = b; 9057 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo) 9058 goto found; 9059 } 9060 /* If we run out of primary links, keep looking down our 9061 inheritance chain; we might be an indirect primary. */ 9062 for (b = last; b; b = BINFO_INHERITANCE_CHAIN (b)) 9063 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo) 9064 break; 9065 found: 9066 9067 /* If we found RTTI_BINFO, this is case 1. If we found a virtual 9068 base B and it is a base of RTTI_BINFO, this is case 2. In 9069 either case, we share our vtable with LAST, i.e. the 9070 derived-most base within B of which we are a primary. */ 9071 if (b == rtti_binfo 9072 || (b && binfo_for_vbase (BINFO_TYPE (b), BINFO_TYPE (rtti_binfo)))) 9073 /* Just set our BINFO_VTABLE to point to LAST, as we may not have 9074 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in 9075 binfo_ctor_vtable after everything's been set up. */ 9076 vtbl = last; 9077 9078 /* Otherwise, this is case 3 and we get our own. */ 9079 } 9080 else if (!BINFO_NEW_VTABLE_MARKED (orig_binfo)) 9081 return; 9082 9083 n_inits = vec_safe_length (*l); 9084 9085 if (!vtbl) 9086 { 9087 tree index; 9088 int non_fn_entries; 9089 9090 /* Add the initializer for this vtable. */ 9091 build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo, 9092 &non_fn_entries, l); 9093 9094 /* Figure out the position to which the VPTR should point. */ 9095 vtbl = build1 (ADDR_EXPR, vtbl_ptr_type_node, orig_vtbl); 9096 index = size_binop (MULT_EXPR, 9097 TYPE_SIZE_UNIT (vtable_entry_type), 9098 size_int (non_fn_entries + n_inits)); 9099 vtbl = fold_build_pointer_plus (vtbl, index); 9100 } 9101 9102 if (ctor_vtbl_p) 9103 /* For a construction vtable, we can't overwrite BINFO_VTABLE. 9104 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will 9105 straighten this out. */ 9106 BINFO_VTABLE (binfo) = tree_cons (rtti_binfo, vtbl, BINFO_VTABLE (binfo)); 9107 else if (BINFO_PRIMARY_P (binfo) && BINFO_VIRTUAL_P (binfo)) 9108 /* Throw away any unneeded intializers. */ 9109 (*l)->truncate (n_inits); 9110 else 9111 /* For an ordinary vtable, set BINFO_VTABLE. */ 9112 BINFO_VTABLE (binfo) = vtbl; 9113 } 9114 9115 static GTY(()) tree abort_fndecl_addr; 9116 static GTY(()) tree dvirt_fn; 9117 9118 /* Construct the initializer for BINFO's virtual function table. BINFO 9119 is part of the hierarchy dominated by T. If we're building a 9120 construction vtable, the ORIG_BINFO is the binfo we should use to 9121 find the actual function pointers to put in the vtable - but they 9122 can be overridden on the path to most-derived in the graph that 9123 ORIG_BINFO belongs. Otherwise, 9124 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the 9125 BINFO that should be indicated by the RTTI information in the 9126 vtable; it will be a base class of T, rather than T itself, if we 9127 are building a construction vtable. 9128 9129 The value returned is a TREE_LIST suitable for wrapping in a 9130 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If 9131 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the 9132 number of non-function entries in the vtable. 9133 9134 It might seem that this function should never be called with a 9135 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a 9136 base is always subsumed by a derived class vtable. However, when 9137 we are building construction vtables, we do build vtables for 9138 primary bases; we need these while the primary base is being 9139 constructed. */ 9140 9141 static void 9142 build_vtbl_initializer (tree binfo, 9143 tree orig_binfo, 9144 tree t, 9145 tree rtti_binfo, 9146 int* non_fn_entries_p, 9147 vec<constructor_elt, va_gc> **inits) 9148 { 9149 tree v; 9150 vtbl_init_data vid; 9151 unsigned ix, jx; 9152 tree vbinfo; 9153 vec<tree, va_gc> *vbases; 9154 constructor_elt *e; 9155 9156 /* Initialize VID. */ 9157 memset (&vid, 0, sizeof (vid)); 9158 vid.binfo = binfo; 9159 vid.derived = t; 9160 vid.rtti_binfo = rtti_binfo; 9161 vid.primary_vtbl_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t); 9162 vid.ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); 9163 vid.generate_vcall_entries = true; 9164 /* The first vbase or vcall offset is at index -3 in the vtable. */ 9165 vid.index = ssize_int(-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE); 9166 9167 /* Add entries to the vtable for RTTI. */ 9168 build_rtti_vtbl_entries (binfo, &vid); 9169 9170 /* Create an array for keeping track of the functions we've 9171 processed. When we see multiple functions with the same 9172 signature, we share the vcall offsets. */ 9173 vec_alloc (vid.fns, 32); 9174 /* Add the vcall and vbase offset entries. */ 9175 build_vcall_and_vbase_vtbl_entries (binfo, &vid); 9176 9177 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by 9178 build_vbase_offset_vtbl_entries. */ 9179 for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0; 9180 vec_safe_iterate (vbases, ix, &vbinfo); ix++) 9181 BINFO_VTABLE_PATH_MARKED (vbinfo) = 0; 9182 9183 /* If the target requires padding between data entries, add that now. */ 9184 if (TARGET_VTABLE_DATA_ENTRY_DISTANCE > 1) 9185 { 9186 int n_entries = vec_safe_length (vid.inits); 9187 9188 vec_safe_grow (vid.inits, TARGET_VTABLE_DATA_ENTRY_DISTANCE * n_entries); 9189 9190 /* Move data entries into their new positions and add padding 9191 after the new positions. Iterate backwards so we don't 9192 overwrite entries that we would need to process later. */ 9193 for (ix = n_entries - 1; 9194 vid.inits->iterate (ix, &e); 9195 ix--) 9196 { 9197 int j; 9198 int new_position = (TARGET_VTABLE_DATA_ENTRY_DISTANCE * ix 9199 + (TARGET_VTABLE_DATA_ENTRY_DISTANCE - 1)); 9200 9201 (*vid.inits)[new_position] = *e; 9202 9203 for (j = 1; j < TARGET_VTABLE_DATA_ENTRY_DISTANCE; ++j) 9204 { 9205 constructor_elt *f = &(*vid.inits)[new_position - j]; 9206 f->index = NULL_TREE; 9207 f->value = build1 (NOP_EXPR, vtable_entry_type, 9208 null_pointer_node); 9209 } 9210 } 9211 } 9212 9213 if (non_fn_entries_p) 9214 *non_fn_entries_p = vec_safe_length (vid.inits); 9215 9216 /* The initializers for virtual functions were built up in reverse 9217 order. Straighten them out and add them to the running list in one 9218 step. */ 9219 jx = vec_safe_length (*inits); 9220 vec_safe_grow (*inits, jx + vid.inits->length ()); 9221 9222 for (ix = vid.inits->length () - 1; 9223 vid.inits->iterate (ix, &e); 9224 ix--, jx++) 9225 (**inits)[jx] = *e; 9226 9227 /* Go through all the ordinary virtual functions, building up 9228 initializers. */ 9229 for (v = BINFO_VIRTUALS (orig_binfo); v; v = TREE_CHAIN (v)) 9230 { 9231 tree delta; 9232 tree vcall_index; 9233 tree fn, fn_original; 9234 tree init = NULL_TREE; 9235 9236 fn = BV_FN (v); 9237 fn_original = fn; 9238 if (DECL_THUNK_P (fn)) 9239 { 9240 if (!DECL_NAME (fn)) 9241 finish_thunk (fn); 9242 if (THUNK_ALIAS (fn)) 9243 { 9244 fn = THUNK_ALIAS (fn); 9245 BV_FN (v) = fn; 9246 } 9247 fn_original = THUNK_TARGET (fn); 9248 } 9249 9250 /* If the only definition of this function signature along our 9251 primary base chain is from a lost primary, this vtable slot will 9252 never be used, so just zero it out. This is important to avoid 9253 requiring extra thunks which cannot be generated with the function. 9254 9255 We first check this in update_vtable_entry_for_fn, so we handle 9256 restored primary bases properly; we also need to do it here so we 9257 zero out unused slots in ctor vtables, rather than filling them 9258 with erroneous values (though harmless, apart from relocation 9259 costs). */ 9260 if (BV_LOST_PRIMARY (v)) 9261 init = size_zero_node; 9262 9263 if (! init) 9264 { 9265 /* Pull the offset for `this', and the function to call, out of 9266 the list. */ 9267 delta = BV_DELTA (v); 9268 vcall_index = BV_VCALL_INDEX (v); 9269 9270 gcc_assert (TREE_CODE (delta) == INTEGER_CST); 9271 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); 9272 9273 /* You can't call an abstract virtual function; it's abstract. 9274 So, we replace these functions with __pure_virtual. */ 9275 if (DECL_PURE_VIRTUAL_P (fn_original)) 9276 { 9277 fn = abort_fndecl; 9278 if (!TARGET_VTABLE_USES_DESCRIPTORS) 9279 { 9280 if (abort_fndecl_addr == NULL) 9281 abort_fndecl_addr 9282 = fold_convert (vfunc_ptr_type_node, 9283 build_fold_addr_expr (fn)); 9284 init = abort_fndecl_addr; 9285 } 9286 } 9287 /* Likewise for deleted virtuals. */ 9288 else if (DECL_DELETED_FN (fn_original)) 9289 { 9290 if (!dvirt_fn) 9291 { 9292 tree name = get_identifier ("__cxa_deleted_virtual"); 9293 dvirt_fn = get_global_binding (name); 9294 if (!dvirt_fn) 9295 dvirt_fn = push_library_fn 9296 (name, 9297 build_function_type_list (void_type_node, NULL_TREE), 9298 NULL_TREE, ECF_NORETURN | ECF_COLD); 9299 } 9300 fn = dvirt_fn; 9301 if (!TARGET_VTABLE_USES_DESCRIPTORS) 9302 init = fold_convert (vfunc_ptr_type_node, 9303 build_fold_addr_expr (fn)); 9304 } 9305 else 9306 { 9307 if (!integer_zerop (delta) || vcall_index) 9308 { 9309 fn = make_thunk (fn, /*this_adjusting=*/1, 9310 delta, vcall_index); 9311 if (!DECL_NAME (fn)) 9312 finish_thunk (fn); 9313 } 9314 /* Take the address of the function, considering it to be of an 9315 appropriate generic type. */ 9316 if (!TARGET_VTABLE_USES_DESCRIPTORS) 9317 init = fold_convert (vfunc_ptr_type_node, 9318 build_fold_addr_expr (fn)); 9319 /* Don't refer to a virtual destructor from a constructor 9320 vtable or a vtable for an abstract class, since destroying 9321 an object under construction is undefined behavior and we 9322 don't want it to be considered a candidate for speculative 9323 devirtualization. But do create the thunk for ABI 9324 compliance. */ 9325 if (DECL_DESTRUCTOR_P (fn_original) 9326 && (CLASSTYPE_PURE_VIRTUALS (DECL_CONTEXT (fn_original)) 9327 || orig_binfo != binfo)) 9328 init = size_zero_node; 9329 } 9330 } 9331 9332 /* And add it to the chain of initializers. */ 9333 if (TARGET_VTABLE_USES_DESCRIPTORS) 9334 { 9335 int i; 9336 if (init == size_zero_node) 9337 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i) 9338 CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, init); 9339 else 9340 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i) 9341 { 9342 tree fdesc = build2 (FDESC_EXPR, vfunc_ptr_type_node, 9343 fn, build_int_cst (NULL_TREE, i)); 9344 TREE_CONSTANT (fdesc) = 1; 9345 9346 CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, fdesc); 9347 } 9348 } 9349 else 9350 CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, init); 9351 } 9352 } 9353 9354 /* Adds to vid->inits the initializers for the vbase and vcall 9355 offsets in BINFO, which is in the hierarchy dominated by T. */ 9356 9357 static void 9358 build_vcall_and_vbase_vtbl_entries (tree binfo, vtbl_init_data* vid) 9359 { 9360 tree b; 9361 9362 /* If this is a derived class, we must first create entries 9363 corresponding to the primary base class. */ 9364 b = get_primary_binfo (binfo); 9365 if (b) 9366 build_vcall_and_vbase_vtbl_entries (b, vid); 9367 9368 /* Add the vbase entries for this base. */ 9369 build_vbase_offset_vtbl_entries (binfo, vid); 9370 /* Add the vcall entries for this base. */ 9371 build_vcall_offset_vtbl_entries (binfo, vid); 9372 } 9373 9374 /* Returns the initializers for the vbase offset entries in the vtable 9375 for BINFO (which is part of the class hierarchy dominated by T), in 9376 reverse order. VBASE_OFFSET_INDEX gives the vtable index 9377 where the next vbase offset will go. */ 9378 9379 static void 9380 build_vbase_offset_vtbl_entries (tree binfo, vtbl_init_data* vid) 9381 { 9382 tree vbase; 9383 tree t; 9384 tree non_primary_binfo; 9385 9386 /* If there are no virtual baseclasses, then there is nothing to 9387 do. */ 9388 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))) 9389 return; 9390 9391 t = vid->derived; 9392 9393 /* We might be a primary base class. Go up the inheritance hierarchy 9394 until we find the most derived class of which we are a primary base: 9395 it is the offset of that which we need to use. */ 9396 non_primary_binfo = binfo; 9397 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo)) 9398 { 9399 tree b; 9400 9401 /* If we have reached a virtual base, then it must be a primary 9402 base (possibly multi-level) of vid->binfo, or we wouldn't 9403 have called build_vcall_and_vbase_vtbl_entries for it. But it 9404 might be a lost primary, so just skip down to vid->binfo. */ 9405 if (BINFO_VIRTUAL_P (non_primary_binfo)) 9406 { 9407 non_primary_binfo = vid->binfo; 9408 break; 9409 } 9410 9411 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo); 9412 if (get_primary_binfo (b) != non_primary_binfo) 9413 break; 9414 non_primary_binfo = b; 9415 } 9416 9417 /* Go through the virtual bases, adding the offsets. */ 9418 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo)); 9419 vbase; 9420 vbase = TREE_CHAIN (vbase)) 9421 { 9422 tree b; 9423 tree delta; 9424 9425 if (!BINFO_VIRTUAL_P (vbase)) 9426 continue; 9427 9428 /* Find the instance of this virtual base in the complete 9429 object. */ 9430 b = copied_binfo (vbase, binfo); 9431 9432 /* If we've already got an offset for this virtual base, we 9433 don't need another one. */ 9434 if (BINFO_VTABLE_PATH_MARKED (b)) 9435 continue; 9436 BINFO_VTABLE_PATH_MARKED (b) = 1; 9437 9438 /* Figure out where we can find this vbase offset. */ 9439 delta = size_binop (MULT_EXPR, 9440 vid->index, 9441 fold_convert (ssizetype, 9442 TYPE_SIZE_UNIT (vtable_entry_type))); 9443 if (vid->primary_vtbl_p) 9444 BINFO_VPTR_FIELD (b) = delta; 9445 9446 if (binfo != TYPE_BINFO (t)) 9447 /* The vbase offset had better be the same. */ 9448 gcc_assert (tree_int_cst_equal (delta, BINFO_VPTR_FIELD (vbase))); 9449 9450 /* The next vbase will come at a more negative offset. */ 9451 vid->index = size_binop (MINUS_EXPR, vid->index, 9452 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE)); 9453 9454 /* The initializer is the delta from BINFO to this virtual base. 9455 The vbase offsets go in reverse inheritance-graph order, and 9456 we are walking in inheritance graph order so these end up in 9457 the right order. */ 9458 delta = size_diffop_loc (input_location, 9459 BINFO_OFFSET (b), BINFO_OFFSET (non_primary_binfo)); 9460 9461 CONSTRUCTOR_APPEND_ELT (vid->inits, NULL_TREE, 9462 fold_build1_loc (input_location, NOP_EXPR, 9463 vtable_entry_type, delta)); 9464 } 9465 } 9466 9467 /* Adds the initializers for the vcall offset entries in the vtable 9468 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED) 9469 to VID->INITS. */ 9470 9471 static void 9472 build_vcall_offset_vtbl_entries (tree binfo, vtbl_init_data* vid) 9473 { 9474 /* We only need these entries if this base is a virtual base. We 9475 compute the indices -- but do not add to the vtable -- when 9476 building the main vtable for a class. */ 9477 if (binfo == TYPE_BINFO (vid->derived) 9478 || (BINFO_VIRTUAL_P (binfo) 9479 /* If BINFO is RTTI_BINFO, then (since BINFO does not 9480 correspond to VID->DERIVED), we are building a primary 9481 construction virtual table. Since this is a primary 9482 virtual table, we do not need the vcall offsets for 9483 BINFO. */ 9484 && binfo != vid->rtti_binfo)) 9485 { 9486 /* We need a vcall offset for each of the virtual functions in this 9487 vtable. For example: 9488 9489 class A { virtual void f (); }; 9490 class B1 : virtual public A { virtual void f (); }; 9491 class B2 : virtual public A { virtual void f (); }; 9492 class C: public B1, public B2 { virtual void f (); }; 9493 9494 A C object has a primary base of B1, which has a primary base of A. A 9495 C also has a secondary base of B2, which no longer has a primary base 9496 of A. So the B2-in-C construction vtable needs a secondary vtable for 9497 A, which will adjust the A* to a B2* to call f. We have no way of 9498 knowing what (or even whether) this offset will be when we define B2, 9499 so we store this "vcall offset" in the A sub-vtable and look it up in 9500 a "virtual thunk" for B2::f. 9501 9502 We need entries for all the functions in our primary vtable and 9503 in our non-virtual bases' secondary vtables. */ 9504 vid->vbase = binfo; 9505 /* If we are just computing the vcall indices -- but do not need 9506 the actual entries -- not that. */ 9507 if (!BINFO_VIRTUAL_P (binfo)) 9508 vid->generate_vcall_entries = false; 9509 /* Now, walk through the non-virtual bases, adding vcall offsets. */ 9510 add_vcall_offset_vtbl_entries_r (binfo, vid); 9511 } 9512 } 9513 9514 /* Build vcall offsets, starting with those for BINFO. */ 9515 9516 static void 9517 add_vcall_offset_vtbl_entries_r (tree binfo, vtbl_init_data* vid) 9518 { 9519 int i; 9520 tree primary_binfo; 9521 tree base_binfo; 9522 9523 /* Don't walk into virtual bases -- except, of course, for the 9524 virtual base for which we are building vcall offsets. Any 9525 primary virtual base will have already had its offsets generated 9526 through the recursion in build_vcall_and_vbase_vtbl_entries. */ 9527 if (BINFO_VIRTUAL_P (binfo) && vid->vbase != binfo) 9528 return; 9529 9530 /* If BINFO has a primary base, process it first. */ 9531 primary_binfo = get_primary_binfo (binfo); 9532 if (primary_binfo) 9533 add_vcall_offset_vtbl_entries_r (primary_binfo, vid); 9534 9535 /* Add BINFO itself to the list. */ 9536 add_vcall_offset_vtbl_entries_1 (binfo, vid); 9537 9538 /* Scan the non-primary bases of BINFO. */ 9539 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 9540 if (base_binfo != primary_binfo) 9541 add_vcall_offset_vtbl_entries_r (base_binfo, vid); 9542 } 9543 9544 /* Called from build_vcall_offset_vtbl_entries_r. */ 9545 9546 static void 9547 add_vcall_offset_vtbl_entries_1 (tree binfo, vtbl_init_data* vid) 9548 { 9549 /* Make entries for the rest of the virtuals. */ 9550 tree orig_fn; 9551 9552 /* The ABI requires that the methods be processed in declaration 9553 order. */ 9554 for (orig_fn = TYPE_FIELDS (BINFO_TYPE (binfo)); 9555 orig_fn; 9556 orig_fn = DECL_CHAIN (orig_fn)) 9557 if (TREE_CODE (orig_fn) == FUNCTION_DECL && DECL_VINDEX (orig_fn)) 9558 add_vcall_offset (orig_fn, binfo, vid); 9559 } 9560 9561 /* Add a vcall offset entry for ORIG_FN to the vtable. */ 9562 9563 static void 9564 add_vcall_offset (tree orig_fn, tree binfo, vtbl_init_data *vid) 9565 { 9566 size_t i; 9567 tree vcall_offset; 9568 tree derived_entry; 9569 9570 /* If there is already an entry for a function with the same 9571 signature as FN, then we do not need a second vcall offset. 9572 Check the list of functions already present in the derived 9573 class vtable. */ 9574 FOR_EACH_VEC_SAFE_ELT (vid->fns, i, derived_entry) 9575 { 9576 if (same_signature_p (derived_entry, orig_fn) 9577 /* We only use one vcall offset for virtual destructors, 9578 even though there are two virtual table entries. */ 9579 || (DECL_DESTRUCTOR_P (derived_entry) 9580 && DECL_DESTRUCTOR_P (orig_fn))) 9581 return; 9582 } 9583 9584 /* If we are building these vcall offsets as part of building 9585 the vtable for the most derived class, remember the vcall 9586 offset. */ 9587 if (vid->binfo == TYPE_BINFO (vid->derived)) 9588 { 9589 tree_pair_s elt = {orig_fn, vid->index}; 9590 vec_safe_push (CLASSTYPE_VCALL_INDICES (vid->derived), elt); 9591 } 9592 9593 /* The next vcall offset will be found at a more negative 9594 offset. */ 9595 vid->index = size_binop (MINUS_EXPR, vid->index, 9596 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE)); 9597 9598 /* Keep track of this function. */ 9599 vec_safe_push (vid->fns, orig_fn); 9600 9601 if (vid->generate_vcall_entries) 9602 { 9603 tree base; 9604 tree fn; 9605 9606 /* Find the overriding function. */ 9607 fn = find_final_overrider (vid->rtti_binfo, binfo, orig_fn); 9608 if (fn == error_mark_node) 9609 vcall_offset = build_zero_cst (vtable_entry_type); 9610 else 9611 { 9612 base = TREE_VALUE (fn); 9613 9614 /* The vbase we're working on is a primary base of 9615 vid->binfo. But it might be a lost primary, so its 9616 BINFO_OFFSET might be wrong, so we just use the 9617 BINFO_OFFSET from vid->binfo. */ 9618 vcall_offset = size_diffop_loc (input_location, 9619 BINFO_OFFSET (base), 9620 BINFO_OFFSET (vid->binfo)); 9621 vcall_offset = fold_build1_loc (input_location, 9622 NOP_EXPR, vtable_entry_type, 9623 vcall_offset); 9624 } 9625 /* Add the initializer to the vtable. */ 9626 CONSTRUCTOR_APPEND_ELT (vid->inits, NULL_TREE, vcall_offset); 9627 } 9628 } 9629 9630 /* Return vtbl initializers for the RTTI entries corresponding to the 9631 BINFO's vtable. The RTTI entries should indicate the object given 9632 by VID->rtti_binfo. */ 9633 9634 static void 9635 build_rtti_vtbl_entries (tree binfo, vtbl_init_data* vid) 9636 { 9637 tree b; 9638 tree t; 9639 tree offset; 9640 tree decl; 9641 tree init; 9642 9643 t = BINFO_TYPE (vid->rtti_binfo); 9644 9645 /* To find the complete object, we will first convert to our most 9646 primary base, and then add the offset in the vtbl to that value. */ 9647 b = most_primary_binfo (binfo); 9648 offset = size_diffop_loc (input_location, 9649 BINFO_OFFSET (vid->rtti_binfo), BINFO_OFFSET (b)); 9650 9651 /* The second entry is the address of the typeinfo object. */ 9652 if (flag_rtti) 9653 decl = build_address (get_tinfo_decl (t)); 9654 else 9655 decl = integer_zero_node; 9656 9657 /* Convert the declaration to a type that can be stored in the 9658 vtable. */ 9659 init = build_nop (vfunc_ptr_type_node, decl); 9660 CONSTRUCTOR_APPEND_ELT (vid->inits, NULL_TREE, init); 9661 9662 /* Add the offset-to-top entry. It comes earlier in the vtable than 9663 the typeinfo entry. Convert the offset to look like a 9664 function pointer, so that we can put it in the vtable. */ 9665 init = build_nop (vfunc_ptr_type_node, offset); 9666 CONSTRUCTOR_APPEND_ELT (vid->inits, NULL_TREE, init); 9667 } 9668 9669 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores 9670 accessibility. */ 9671 9672 bool 9673 uniquely_derived_from_p (tree parent, tree type) 9674 { 9675 tree base = lookup_base (type, parent, ba_unique, NULL, tf_none); 9676 return base && base != error_mark_node; 9677 } 9678 9679 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */ 9680 9681 bool 9682 publicly_uniquely_derived_p (tree parent, tree type) 9683 { 9684 tree base = lookup_base (type, parent, ba_ignore_scope | ba_check, 9685 NULL, tf_none); 9686 return base && base != error_mark_node; 9687 } 9688 9689 /* CTX1 and CTX2 are declaration contexts. Return the innermost common 9690 class between them, if any. */ 9691 9692 tree 9693 common_enclosing_class (tree ctx1, tree ctx2) 9694 { 9695 if (!TYPE_P (ctx1) || !TYPE_P (ctx2)) 9696 return NULL_TREE; 9697 gcc_assert (ctx1 == TYPE_MAIN_VARIANT (ctx1) 9698 && ctx2 == TYPE_MAIN_VARIANT (ctx2)); 9699 if (ctx1 == ctx2) 9700 return ctx1; 9701 for (tree t = ctx1; TYPE_P (t); t = TYPE_CONTEXT (t)) 9702 TYPE_MARKED_P (t) = true; 9703 tree found = NULL_TREE; 9704 for (tree t = ctx2; TYPE_P (t); t = TYPE_CONTEXT (t)) 9705 if (TYPE_MARKED_P (t)) 9706 { 9707 found = t; 9708 break; 9709 } 9710 for (tree t = ctx1; TYPE_P (t); t = TYPE_CONTEXT (t)) 9711 TYPE_MARKED_P (t) = false; 9712 return found; 9713 } 9714 9715 #include "gt-cp-class.h" 9716