1 /* Functions related to building classes and their related objects. 2 Copyright (C) 1987-2017 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 40 /* The number of nested classes being processed. If we are not in the 41 scope of any class, this is zero. */ 42 43 int current_class_depth; 44 45 /* In order to deal with nested classes, we keep a stack of classes. 46 The topmost entry is the innermost class, and is the entry at index 47 CURRENT_CLASS_DEPTH */ 48 49 typedef struct class_stack_node { 50 /* The name of the class. */ 51 tree name; 52 53 /* The _TYPE node for the class. */ 54 tree type; 55 56 /* The access specifier pending for new declarations in the scope of 57 this class. */ 58 tree access; 59 60 /* If were defining TYPE, the names used in this class. */ 61 splay_tree names_used; 62 63 /* Nonzero if this class is no longer open, because of a call to 64 push_to_top_level. */ 65 size_t hidden; 66 }* class_stack_node_t; 67 68 struct vtbl_init_data 69 { 70 /* The base for which we're building initializers. */ 71 tree binfo; 72 /* The type of the most-derived type. */ 73 tree derived; 74 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived), 75 unless ctor_vtbl_p is true. */ 76 tree rtti_binfo; 77 /* The negative-index vtable initializers built up so far. These 78 are in order from least negative index to most negative index. */ 79 vec<constructor_elt, va_gc> *inits; 80 /* The binfo for the virtual base for which we're building 81 vcall offset initializers. */ 82 tree vbase; 83 /* The functions in vbase for which we have already provided vcall 84 offsets. */ 85 vec<tree, va_gc> *fns; 86 /* The vtable index of the next vcall or vbase offset. */ 87 tree index; 88 /* Nonzero if we are building the initializer for the primary 89 vtable. */ 90 int primary_vtbl_p; 91 /* Nonzero if we are building the initializer for a construction 92 vtable. */ 93 int ctor_vtbl_p; 94 /* True when adding vcall offset entries to the vtable. False when 95 merely computing the indices. */ 96 bool generate_vcall_entries; 97 }; 98 99 /* The type of a function passed to walk_subobject_offsets. */ 100 typedef int (*subobject_offset_fn) (tree, tree, splay_tree); 101 102 /* The stack itself. This is a dynamically resized array. The 103 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */ 104 static int current_class_stack_size; 105 static class_stack_node_t current_class_stack; 106 107 /* The size of the largest empty class seen in this translation unit. */ 108 static GTY (()) tree sizeof_biggest_empty_class; 109 110 /* An array of all local classes present in this translation unit, in 111 declaration order. */ 112 vec<tree, va_gc> *local_classes; 113 114 static tree get_vfield_name (tree); 115 static void finish_struct_anon (tree); 116 static tree get_vtable_name (tree); 117 static void get_basefndecls (tree, tree, vec<tree> *); 118 static int build_primary_vtable (tree, tree); 119 static int build_secondary_vtable (tree); 120 static void finish_vtbls (tree); 121 static void modify_vtable_entry (tree, tree, tree, tree, tree *); 122 static void finish_struct_bits (tree); 123 static int alter_access (tree, tree, tree); 124 static void handle_using_decl (tree, tree); 125 static tree dfs_modify_vtables (tree, void *); 126 static tree modify_all_vtables (tree, tree); 127 static void determine_primary_bases (tree); 128 static void finish_struct_methods (tree); 129 static void maybe_warn_about_overly_private_class (tree); 130 static int method_name_cmp (const void *, const void *); 131 static int resort_method_name_cmp (const void *, const void *); 132 static void add_implicitly_declared_members (tree, tree*, int, int); 133 static tree fixed_type_or_null (tree, int *, int *); 134 static tree build_simple_base_path (tree expr, tree binfo); 135 static tree build_vtbl_ref_1 (tree, tree); 136 static void build_vtbl_initializer (tree, tree, tree, tree, int *, 137 vec<constructor_elt, va_gc> **); 138 static int count_fields (tree); 139 static int add_fields_to_record_type (tree, struct sorted_fields_type*, int); 140 static void insert_into_classtype_sorted_fields (tree, tree, int); 141 static bool check_bitfield_decl (tree); 142 static bool check_field_decl (tree, tree, int *, int *); 143 static void check_field_decls (tree, tree *, int *, int *); 144 static tree *build_base_field (record_layout_info, tree, splay_tree, tree *); 145 static void build_base_fields (record_layout_info, splay_tree, tree *); 146 static void check_methods (tree); 147 static void remove_zero_width_bit_fields (tree); 148 static bool accessible_nvdtor_p (tree); 149 150 /* Used by find_flexarrays and related functions. */ 151 struct flexmems_t; 152 static void diagnose_flexarrays (tree, const flexmems_t *); 153 static void find_flexarrays (tree, flexmems_t *, bool = false, 154 tree = NULL_TREE, tree = NULL_TREE); 155 static void check_flexarrays (tree, flexmems_t * = NULL, bool = false); 156 static void check_bases (tree, int *, int *); 157 static void check_bases_and_members (tree); 158 static tree create_vtable_ptr (tree, tree *); 159 static void include_empty_classes (record_layout_info); 160 static void layout_class_type (tree, tree *); 161 static void propagate_binfo_offsets (tree, tree); 162 static void layout_virtual_bases (record_layout_info, splay_tree); 163 static void build_vbase_offset_vtbl_entries (tree, vtbl_init_data *); 164 static void add_vcall_offset_vtbl_entries_r (tree, vtbl_init_data *); 165 static void add_vcall_offset_vtbl_entries_1 (tree, vtbl_init_data *); 166 static void build_vcall_offset_vtbl_entries (tree, vtbl_init_data *); 167 static void add_vcall_offset (tree, tree, vtbl_init_data *); 168 static void layout_vtable_decl (tree, int); 169 static tree dfs_find_final_overrider_pre (tree, void *); 170 static tree dfs_find_final_overrider_post (tree, void *); 171 static tree find_final_overrider (tree, tree, tree); 172 static int make_new_vtable (tree, tree); 173 static tree get_primary_binfo (tree); 174 static int maybe_indent_hierarchy (FILE *, int, int); 175 static tree dump_class_hierarchy_r (FILE *, int, tree, tree, int); 176 static void dump_class_hierarchy (tree); 177 static void dump_class_hierarchy_1 (FILE *, int, tree); 178 static void dump_array (FILE *, tree); 179 static void dump_vtable (tree, tree, tree); 180 static void dump_vtt (tree, tree); 181 static void dump_thunk (FILE *, int, tree); 182 static tree build_vtable (tree, tree, tree); 183 static void initialize_vtable (tree, vec<constructor_elt, va_gc> *); 184 static void layout_nonempty_base_or_field (record_layout_info, 185 tree, tree, splay_tree); 186 static tree end_of_class (tree, int); 187 static bool layout_empty_base (record_layout_info, tree, tree, splay_tree); 188 static void accumulate_vtbl_inits (tree, tree, tree, tree, tree, 189 vec<constructor_elt, va_gc> **); 190 static void dfs_accumulate_vtbl_inits (tree, tree, tree, tree, tree, 191 vec<constructor_elt, va_gc> **); 192 static void build_rtti_vtbl_entries (tree, vtbl_init_data *); 193 static void build_vcall_and_vbase_vtbl_entries (tree, vtbl_init_data *); 194 static void clone_constructors_and_destructors (tree); 195 static tree build_clone (tree, tree); 196 static void update_vtable_entry_for_fn (tree, tree, tree, tree *, unsigned); 197 static void build_ctor_vtbl_group (tree, tree); 198 static void build_vtt (tree); 199 static tree binfo_ctor_vtable (tree); 200 static void build_vtt_inits (tree, tree, vec<constructor_elt, va_gc> **, 201 tree *); 202 static tree dfs_build_secondary_vptr_vtt_inits (tree, void *); 203 static tree dfs_fixup_binfo_vtbls (tree, void *); 204 static int record_subobject_offset (tree, tree, splay_tree); 205 static int check_subobject_offset (tree, tree, splay_tree); 206 static int walk_subobject_offsets (tree, subobject_offset_fn, 207 tree, splay_tree, tree, int); 208 static void record_subobject_offsets (tree, tree, splay_tree, bool); 209 static int layout_conflict_p (tree, tree, splay_tree, int); 210 static int splay_tree_compare_integer_csts (splay_tree_key k1, 211 splay_tree_key k2); 212 static void warn_about_ambiguous_bases (tree); 213 static bool type_requires_array_cookie (tree); 214 static bool base_derived_from (tree, tree); 215 static int empty_base_at_nonzero_offset_p (tree, tree, splay_tree); 216 static tree end_of_base (tree); 217 static tree get_vcall_index (tree, tree); 218 static bool type_maybe_constexpr_default_constructor (tree); 219 220 /* Variables shared between class.c and call.c. */ 221 222 int n_vtables = 0; 223 int n_vtable_entries = 0; 224 int n_vtable_searches = 0; 225 int n_vtable_elems = 0; 226 int n_convert_harshness = 0; 227 int n_compute_conversion_costs = 0; 228 int n_inner_fields_searched = 0; 229 230 /* Return a COND_EXPR that executes TRUE_STMT if this execution of the 231 'structor is in charge of 'structing virtual bases, or FALSE_STMT 232 otherwise. */ 233 234 tree 235 build_if_in_charge (tree true_stmt, tree false_stmt) 236 { 237 gcc_assert (DECL_HAS_IN_CHARGE_PARM_P (current_function_decl)); 238 tree cmp = build2 (NE_EXPR, boolean_type_node, 239 current_in_charge_parm, integer_zero_node); 240 tree type = unlowered_expr_type (true_stmt); 241 if (VOID_TYPE_P (type)) 242 type = unlowered_expr_type (false_stmt); 243 tree cond = build3 (COND_EXPR, type, 244 cmp, true_stmt, false_stmt); 245 return cond; 246 } 247 248 /* Convert to or from a base subobject. EXPR is an expression of type 249 `A' or `A*', an expression of type `B' or `B*' is returned. To 250 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for 251 the B base instance within A. To convert base A to derived B, CODE 252 is MINUS_EXPR and BINFO is the binfo for the A instance within B. 253 In this latter case, A must not be a morally virtual base of B. 254 NONNULL is true if EXPR is known to be non-NULL (this is only 255 needed when EXPR is of pointer type). CV qualifiers are preserved 256 from EXPR. */ 257 258 tree 259 build_base_path (enum tree_code code, 260 tree expr, 261 tree binfo, 262 int nonnull, 263 tsubst_flags_t complain) 264 { 265 tree v_binfo = NULL_TREE; 266 tree d_binfo = NULL_TREE; 267 tree probe; 268 tree offset; 269 tree target_type; 270 tree null_test = NULL; 271 tree ptr_target_type; 272 int fixed_type_p; 273 int want_pointer = TYPE_PTR_P (TREE_TYPE (expr)); 274 bool has_empty = false; 275 bool virtual_access; 276 bool rvalue = false; 277 278 if (expr == error_mark_node || binfo == error_mark_node || !binfo) 279 return error_mark_node; 280 281 for (probe = binfo; probe; probe = BINFO_INHERITANCE_CHAIN (probe)) 282 { 283 d_binfo = probe; 284 if (is_empty_class (BINFO_TYPE (probe))) 285 has_empty = true; 286 if (!v_binfo && BINFO_VIRTUAL_P (probe)) 287 v_binfo = probe; 288 } 289 290 probe = TYPE_MAIN_VARIANT (TREE_TYPE (expr)); 291 if (want_pointer) 292 probe = TYPE_MAIN_VARIANT (TREE_TYPE (probe)); 293 294 if (code == PLUS_EXPR 295 && !SAME_BINFO_TYPE_P (BINFO_TYPE (d_binfo), probe)) 296 { 297 /* This can happen when adjust_result_of_qualified_name_lookup can't 298 find a unique base binfo in a call to a member function. We 299 couldn't give the diagnostic then since we might have been calling 300 a static member function, so we do it now. In other cases, eg. 301 during error recovery (c++/71979), we may not have a base at all. */ 302 if (complain & tf_error) 303 { 304 tree base = lookup_base (probe, BINFO_TYPE (d_binfo), 305 ba_unique, NULL, complain); 306 gcc_assert (base == error_mark_node || !base); 307 } 308 return error_mark_node; 309 } 310 311 gcc_assert ((code == MINUS_EXPR 312 && SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), probe)) 313 || code == PLUS_EXPR); 314 315 if (binfo == d_binfo) 316 /* Nothing to do. */ 317 return expr; 318 319 if (code == MINUS_EXPR && v_binfo) 320 { 321 if (complain & tf_error) 322 { 323 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (v_binfo))) 324 { 325 if (want_pointer) 326 error ("cannot convert from pointer to base class %qT to " 327 "pointer to derived class %qT because the base is " 328 "virtual", BINFO_TYPE (binfo), BINFO_TYPE (d_binfo)); 329 else 330 error ("cannot convert from base class %qT to derived " 331 "class %qT because the base is virtual", 332 BINFO_TYPE (binfo), BINFO_TYPE (d_binfo)); 333 } 334 else 335 { 336 if (want_pointer) 337 error ("cannot convert from pointer to base class %qT to " 338 "pointer to derived class %qT via virtual base %qT", 339 BINFO_TYPE (binfo), BINFO_TYPE (d_binfo), 340 BINFO_TYPE (v_binfo)); 341 else 342 error ("cannot convert from base class %qT to derived " 343 "class %qT via virtual base %qT", BINFO_TYPE (binfo), 344 BINFO_TYPE (d_binfo), BINFO_TYPE (v_binfo)); 345 } 346 } 347 return error_mark_node; 348 } 349 350 if (!want_pointer) 351 { 352 rvalue = !lvalue_p (expr); 353 /* This must happen before the call to save_expr. */ 354 expr = cp_build_addr_expr (expr, complain); 355 } 356 else 357 expr = mark_rvalue_use (expr); 358 359 offset = BINFO_OFFSET (binfo); 360 fixed_type_p = resolves_to_fixed_type_p (expr, &nonnull); 361 target_type = code == PLUS_EXPR ? BINFO_TYPE (binfo) : BINFO_TYPE (d_binfo); 362 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always 363 cv-unqualified. Extract the cv-qualifiers from EXPR so that the 364 expression returned matches the input. */ 365 target_type = cp_build_qualified_type 366 (target_type, cp_type_quals (TREE_TYPE (TREE_TYPE (expr)))); 367 ptr_target_type = build_pointer_type (target_type); 368 369 /* Do we need to look in the vtable for the real offset? */ 370 virtual_access = (v_binfo && fixed_type_p <= 0); 371 372 /* Don't bother with the calculations inside sizeof; they'll ICE if the 373 source type is incomplete and the pointer value doesn't matter. In a 374 template (even in instantiate_non_dependent_expr), we don't have vtables 375 set up properly yet, and the value doesn't matter there either; we're 376 just interested in the result of overload resolution. */ 377 if (cp_unevaluated_operand != 0 378 || processing_template_decl 379 || in_template_function ()) 380 { 381 expr = build_nop (ptr_target_type, expr); 382 goto indout; 383 } 384 385 /* If we're in an NSDMI, we don't have the full constructor context yet 386 that we need for converting to a virtual base, so just build a stub 387 CONVERT_EXPR and expand it later in bot_replace. */ 388 if (virtual_access && fixed_type_p < 0 389 && current_scope () != current_function_decl) 390 { 391 expr = build1 (CONVERT_EXPR, ptr_target_type, expr); 392 CONVERT_EXPR_VBASE_PATH (expr) = true; 393 goto indout; 394 } 395 396 /* Do we need to check for a null pointer? */ 397 if (want_pointer && !nonnull) 398 { 399 /* If we know the conversion will not actually change the value 400 of EXPR, then we can avoid testing the expression for NULL. 401 We have to avoid generating a COMPONENT_REF for a base class 402 field, because other parts of the compiler know that such 403 expressions are always non-NULL. */ 404 if (!virtual_access && integer_zerop (offset)) 405 return build_nop (ptr_target_type, expr); 406 null_test = error_mark_node; 407 } 408 409 /* Protect against multiple evaluation if necessary. */ 410 if (TREE_SIDE_EFFECTS (expr) && (null_test || virtual_access)) 411 expr = save_expr (expr); 412 413 /* Now that we've saved expr, build the real null test. */ 414 if (null_test) 415 { 416 tree zero = cp_convert (TREE_TYPE (expr), nullptr_node, complain); 417 null_test = build2_loc (input_location, NE_EXPR, boolean_type_node, 418 expr, zero); 419 /* This is a compiler generated comparison, don't emit 420 e.g. -Wnonnull-compare warning for it. */ 421 TREE_NO_WARNING (null_test) = 1; 422 } 423 424 /* If this is a simple base reference, express it as a COMPONENT_REF. */ 425 if (code == PLUS_EXPR && !virtual_access 426 /* We don't build base fields for empty bases, and they aren't very 427 interesting to the optimizers anyway. */ 428 && !has_empty) 429 { 430 expr = cp_build_indirect_ref (expr, RO_NULL, complain); 431 expr = build_simple_base_path (expr, binfo); 432 if (rvalue) 433 expr = move (expr); 434 if (want_pointer) 435 expr = build_address (expr); 436 target_type = TREE_TYPE (expr); 437 goto out; 438 } 439 440 if (virtual_access) 441 { 442 /* Going via virtual base V_BINFO. We need the static offset 443 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to 444 V_BINFO. That offset is an entry in D_BINFO's vtable. */ 445 tree v_offset; 446 447 if (fixed_type_p < 0 && in_base_initializer) 448 { 449 /* In a base member initializer, we cannot rely on the 450 vtable being set up. We have to indirect via the 451 vtt_parm. */ 452 tree t; 453 454 t = TREE_TYPE (TYPE_VFIELD (current_class_type)); 455 t = build_pointer_type (t); 456 v_offset = fold_convert (t, current_vtt_parm); 457 v_offset = cp_build_indirect_ref (v_offset, RO_NULL, complain); 458 } 459 else 460 { 461 tree t = expr; 462 if ((flag_sanitize & SANITIZE_VPTR) && fixed_type_p == 0) 463 { 464 t = cp_ubsan_maybe_instrument_cast_to_vbase (input_location, 465 probe, expr); 466 if (t == NULL_TREE) 467 t = expr; 468 } 469 v_offset = build_vfield_ref (cp_build_indirect_ref (t, RO_NULL, 470 complain), 471 TREE_TYPE (TREE_TYPE (expr))); 472 } 473 474 if (v_offset == error_mark_node) 475 return error_mark_node; 476 477 v_offset = fold_build_pointer_plus (v_offset, BINFO_VPTR_FIELD (v_binfo)); 478 v_offset = build1 (NOP_EXPR, 479 build_pointer_type (ptrdiff_type_node), 480 v_offset); 481 v_offset = cp_build_indirect_ref (v_offset, RO_NULL, complain); 482 TREE_CONSTANT (v_offset) = 1; 483 484 offset = convert_to_integer (ptrdiff_type_node, 485 size_diffop_loc (input_location, offset, 486 BINFO_OFFSET (v_binfo))); 487 488 if (!integer_zerop (offset)) 489 v_offset = build2 (code, ptrdiff_type_node, v_offset, offset); 490 491 if (fixed_type_p < 0) 492 /* Negative fixed_type_p means this is a constructor or destructor; 493 virtual base layout is fixed in in-charge [cd]tors, but not in 494 base [cd]tors. */ 495 offset = build_if_in_charge 496 (convert_to_integer (ptrdiff_type_node, BINFO_OFFSET (binfo)), 497 v_offset); 498 else 499 offset = v_offset; 500 } 501 502 if (want_pointer) 503 target_type = ptr_target_type; 504 505 expr = build1 (NOP_EXPR, ptr_target_type, expr); 506 507 if (!integer_zerop (offset)) 508 { 509 offset = fold_convert (sizetype, offset); 510 if (code == MINUS_EXPR) 511 offset = fold_build1_loc (input_location, NEGATE_EXPR, sizetype, offset); 512 expr = fold_build_pointer_plus (expr, offset); 513 } 514 else 515 null_test = NULL; 516 517 indout: 518 if (!want_pointer) 519 { 520 expr = cp_build_indirect_ref (expr, RO_NULL, complain); 521 if (rvalue) 522 expr = move (expr); 523 } 524 525 out: 526 if (null_test) 527 expr = fold_build3_loc (input_location, COND_EXPR, target_type, null_test, expr, 528 build_zero_cst (target_type)); 529 530 return expr; 531 } 532 533 /* Subroutine of build_base_path; EXPR and BINFO are as in that function. 534 Perform a derived-to-base conversion by recursively building up a 535 sequence of COMPONENT_REFs to the appropriate base fields. */ 536 537 static tree 538 build_simple_base_path (tree expr, tree binfo) 539 { 540 tree type = BINFO_TYPE (binfo); 541 tree d_binfo = BINFO_INHERITANCE_CHAIN (binfo); 542 tree field; 543 544 if (d_binfo == NULL_TREE) 545 { 546 tree temp; 547 548 gcc_assert (TYPE_MAIN_VARIANT (TREE_TYPE (expr)) == type); 549 550 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' 551 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only 552 an lvalue in the front end; only _DECLs and _REFs are lvalues 553 in the back end. */ 554 temp = unary_complex_lvalue (ADDR_EXPR, expr); 555 if (temp) 556 expr = cp_build_indirect_ref (temp, RO_NULL, tf_warning_or_error); 557 558 return expr; 559 } 560 561 /* Recurse. */ 562 expr = build_simple_base_path (expr, d_binfo); 563 564 for (field = TYPE_FIELDS (BINFO_TYPE (d_binfo)); 565 field; field = DECL_CHAIN (field)) 566 /* Is this the base field created by build_base_field? */ 567 if (TREE_CODE (field) == FIELD_DECL 568 && DECL_FIELD_IS_BASE (field) 569 && TREE_TYPE (field) == type 570 /* If we're looking for a field in the most-derived class, 571 also check the field offset; we can have two base fields 572 of the same type if one is an indirect virtual base and one 573 is a direct non-virtual base. */ 574 && (BINFO_INHERITANCE_CHAIN (d_binfo) 575 || tree_int_cst_equal (byte_position (field), 576 BINFO_OFFSET (binfo)))) 577 { 578 /* We don't use build_class_member_access_expr here, as that 579 has unnecessary checks, and more importantly results in 580 recursive calls to dfs_walk_once. */ 581 int type_quals = cp_type_quals (TREE_TYPE (expr)); 582 583 expr = build3 (COMPONENT_REF, 584 cp_build_qualified_type (type, type_quals), 585 expr, field, NULL_TREE); 586 /* Mark the expression const or volatile, as appropriate. 587 Even though we've dealt with the type above, we still have 588 to mark the expression itself. */ 589 if (type_quals & TYPE_QUAL_CONST) 590 TREE_READONLY (expr) = 1; 591 if (type_quals & TYPE_QUAL_VOLATILE) 592 TREE_THIS_VOLATILE (expr) = 1; 593 594 return expr; 595 } 596 597 /* Didn't find the base field?!? */ 598 gcc_unreachable (); 599 } 600 601 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose 602 type is a class type or a pointer to a class type. In the former 603 case, TYPE is also a class type; in the latter it is another 604 pointer type. If CHECK_ACCESS is true, an error message is emitted 605 if TYPE is inaccessible. If OBJECT has pointer type, the value is 606 assumed to be non-NULL. */ 607 608 tree 609 convert_to_base (tree object, tree type, bool check_access, bool nonnull, 610 tsubst_flags_t complain) 611 { 612 tree binfo; 613 tree object_type; 614 615 if (TYPE_PTR_P (TREE_TYPE (object))) 616 { 617 object_type = TREE_TYPE (TREE_TYPE (object)); 618 type = TREE_TYPE (type); 619 } 620 else 621 object_type = TREE_TYPE (object); 622 623 binfo = lookup_base (object_type, type, check_access ? ba_check : ba_unique, 624 NULL, complain); 625 if (!binfo || binfo == error_mark_node) 626 return error_mark_node; 627 628 return build_base_path (PLUS_EXPR, object, binfo, nonnull, complain); 629 } 630 631 /* EXPR is an expression with unqualified class type. BASE is a base 632 binfo of that class type. Returns EXPR, converted to the BASE 633 type. This function assumes that EXPR is the most derived class; 634 therefore virtual bases can be found at their static offsets. */ 635 636 tree 637 convert_to_base_statically (tree expr, tree base) 638 { 639 tree expr_type; 640 641 expr_type = TREE_TYPE (expr); 642 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (base), expr_type)) 643 { 644 /* If this is a non-empty base, use a COMPONENT_REF. */ 645 if (!is_empty_class (BINFO_TYPE (base))) 646 return build_simple_base_path (expr, base); 647 648 /* We use fold_build2 and fold_convert below to simplify the trees 649 provided to the optimizers. It is not safe to call these functions 650 when processing a template because they do not handle C++-specific 651 trees. */ 652 gcc_assert (!processing_template_decl); 653 expr = cp_build_addr_expr (expr, tf_warning_or_error); 654 if (!integer_zerop (BINFO_OFFSET (base))) 655 expr = fold_build_pointer_plus_loc (input_location, 656 expr, BINFO_OFFSET (base)); 657 expr = fold_convert (build_pointer_type (BINFO_TYPE (base)), expr); 658 expr = build_fold_indirect_ref_loc (input_location, expr); 659 } 660 661 return expr; 662 } 663 664 665 tree 666 build_vfield_ref (tree datum, tree type) 667 { 668 tree vfield, vcontext; 669 670 if (datum == error_mark_node 671 /* Can happen in case of duplicate base types (c++/59082). */ 672 || !TYPE_VFIELD (type)) 673 return error_mark_node; 674 675 /* First, convert to the requested type. */ 676 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (datum), type)) 677 datum = convert_to_base (datum, type, /*check_access=*/false, 678 /*nonnull=*/true, tf_warning_or_error); 679 680 /* Second, the requested type may not be the owner of its own vptr. 681 If not, convert to the base class that owns it. We cannot use 682 convert_to_base here, because VCONTEXT may appear more than once 683 in the inheritance hierarchy of TYPE, and thus direct conversion 684 between the types may be ambiguous. Following the path back up 685 one step at a time via primary bases avoids the problem. */ 686 vfield = TYPE_VFIELD (type); 687 vcontext = DECL_CONTEXT (vfield); 688 while (!same_type_ignoring_top_level_qualifiers_p (vcontext, type)) 689 { 690 datum = build_simple_base_path (datum, CLASSTYPE_PRIMARY_BINFO (type)); 691 type = TREE_TYPE (datum); 692 } 693 694 return build3 (COMPONENT_REF, TREE_TYPE (vfield), datum, vfield, NULL_TREE); 695 } 696 697 /* Given an object INSTANCE, return an expression which yields the 698 vtable element corresponding to INDEX. There are many special 699 cases for INSTANCE which we take care of here, mainly to avoid 700 creating extra tree nodes when we don't have to. */ 701 702 static tree 703 build_vtbl_ref_1 (tree instance, tree idx) 704 { 705 tree aref; 706 tree vtbl = NULL_TREE; 707 708 /* Try to figure out what a reference refers to, and 709 access its virtual function table directly. */ 710 711 int cdtorp = 0; 712 tree fixed_type = fixed_type_or_null (instance, NULL, &cdtorp); 713 714 tree basetype = non_reference (TREE_TYPE (instance)); 715 716 if (fixed_type && !cdtorp) 717 { 718 tree binfo = lookup_base (fixed_type, basetype, 719 ba_unique, NULL, tf_none); 720 if (binfo && binfo != error_mark_node) 721 vtbl = unshare_expr (BINFO_VTABLE (binfo)); 722 } 723 724 if (!vtbl) 725 vtbl = build_vfield_ref (instance, basetype); 726 727 aref = build_array_ref (input_location, vtbl, idx); 728 TREE_CONSTANT (aref) |= TREE_CONSTANT (vtbl) && TREE_CONSTANT (idx); 729 730 return aref; 731 } 732 733 tree 734 build_vtbl_ref (tree instance, tree idx) 735 { 736 tree aref = build_vtbl_ref_1 (instance, idx); 737 738 return aref; 739 } 740 741 /* Given a stable object pointer INSTANCE_PTR, return an expression which 742 yields a function pointer corresponding to vtable element INDEX. */ 743 744 tree 745 build_vfn_ref (tree instance_ptr, tree idx) 746 { 747 tree aref; 748 749 aref = build_vtbl_ref_1 (cp_build_indirect_ref (instance_ptr, RO_NULL, 750 tf_warning_or_error), 751 idx); 752 753 /* When using function descriptors, the address of the 754 vtable entry is treated as a function pointer. */ 755 if (TARGET_VTABLE_USES_DESCRIPTORS) 756 aref = build1 (NOP_EXPR, TREE_TYPE (aref), 757 cp_build_addr_expr (aref, tf_warning_or_error)); 758 759 /* Remember this as a method reference, for later devirtualization. */ 760 aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr, idx); 761 762 return aref; 763 } 764 765 /* Return the name of the virtual function table (as an IDENTIFIER_NODE) 766 for the given TYPE. */ 767 768 static tree 769 get_vtable_name (tree type) 770 { 771 return mangle_vtbl_for_type (type); 772 } 773 774 /* DECL is an entity associated with TYPE, like a virtual table or an 775 implicitly generated constructor. Determine whether or not DECL 776 should have external or internal linkage at the object file 777 level. This routine does not deal with COMDAT linkage and other 778 similar complexities; it simply sets TREE_PUBLIC if it possible for 779 entities in other translation units to contain copies of DECL, in 780 the abstract. */ 781 782 void 783 set_linkage_according_to_type (tree /*type*/, tree decl) 784 { 785 TREE_PUBLIC (decl) = 1; 786 determine_visibility (decl); 787 } 788 789 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE. 790 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.) 791 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */ 792 793 static tree 794 build_vtable (tree class_type, tree name, tree vtable_type) 795 { 796 tree decl; 797 798 decl = build_lang_decl (VAR_DECL, name, vtable_type); 799 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME 800 now to avoid confusion in mangle_decl. */ 801 SET_DECL_ASSEMBLER_NAME (decl, name); 802 DECL_CONTEXT (decl) = class_type; 803 DECL_ARTIFICIAL (decl) = 1; 804 TREE_STATIC (decl) = 1; 805 TREE_READONLY (decl) = 1; 806 DECL_VIRTUAL_P (decl) = 1; 807 SET_DECL_ALIGN (decl, TARGET_VTABLE_ENTRY_ALIGN); 808 DECL_USER_ALIGN (decl) = true; 809 DECL_VTABLE_OR_VTT_P (decl) = 1; 810 set_linkage_according_to_type (class_type, decl); 811 /* The vtable has not been defined -- yet. */ 812 DECL_EXTERNAL (decl) = 1; 813 DECL_NOT_REALLY_EXTERN (decl) = 1; 814 815 /* Mark the VAR_DECL node representing the vtable itself as a 816 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It 817 is rather important that such things be ignored because any 818 effort to actually generate DWARF for them will run into 819 trouble when/if we encounter code like: 820 821 #pragma interface 822 struct S { virtual void member (); }; 823 824 because the artificial declaration of the vtable itself (as 825 manufactured by the g++ front end) will say that the vtable is 826 a static member of `S' but only *after* the debug output for 827 the definition of `S' has already been output. This causes 828 grief because the DWARF entry for the definition of the vtable 829 will try to refer back to an earlier *declaration* of the 830 vtable as a static member of `S' and there won't be one. We 831 might be able to arrange to have the "vtable static member" 832 attached to the member list for `S' before the debug info for 833 `S' get written (which would solve the problem) but that would 834 require more intrusive changes to the g++ front end. */ 835 DECL_IGNORED_P (decl) = 1; 836 837 return decl; 838 } 839 840 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic, 841 or even complete. If this does not exist, create it. If COMPLETE is 842 nonzero, then complete the definition of it -- that will render it 843 impossible to actually build the vtable, but is useful to get at those 844 which are known to exist in the runtime. */ 845 846 tree 847 get_vtable_decl (tree type, int complete) 848 { 849 tree decl; 850 851 if (CLASSTYPE_VTABLES (type)) 852 return CLASSTYPE_VTABLES (type); 853 854 decl = build_vtable (type, get_vtable_name (type), vtbl_type_node); 855 CLASSTYPE_VTABLES (type) = decl; 856 857 if (complete) 858 { 859 DECL_EXTERNAL (decl) = 1; 860 cp_finish_decl (decl, NULL_TREE, false, NULL_TREE, 0); 861 } 862 863 return decl; 864 } 865 866 /* Build the primary virtual function table for TYPE. If BINFO is 867 non-NULL, build the vtable starting with the initial approximation 868 that it is the same as the one which is the head of the association 869 list. Returns a nonzero value if a new vtable is actually 870 created. */ 871 872 static int 873 build_primary_vtable (tree binfo, tree type) 874 { 875 tree decl; 876 tree virtuals; 877 878 decl = get_vtable_decl (type, /*complete=*/0); 879 880 if (binfo) 881 { 882 if (BINFO_NEW_VTABLE_MARKED (binfo)) 883 /* We have already created a vtable for this base, so there's 884 no need to do it again. */ 885 return 0; 886 887 virtuals = copy_list (BINFO_VIRTUALS (binfo)); 888 TREE_TYPE (decl) = TREE_TYPE (get_vtbl_decl_for_binfo (binfo)); 889 DECL_SIZE (decl) = TYPE_SIZE (TREE_TYPE (decl)); 890 DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (TREE_TYPE (decl)); 891 } 892 else 893 { 894 gcc_assert (TREE_TYPE (decl) == vtbl_type_node); 895 virtuals = NULL_TREE; 896 } 897 898 if (GATHER_STATISTICS) 899 { 900 n_vtables += 1; 901 n_vtable_elems += list_length (virtuals); 902 } 903 904 /* Initialize the association list for this type, based 905 on our first approximation. */ 906 BINFO_VTABLE (TYPE_BINFO (type)) = decl; 907 BINFO_VIRTUALS (TYPE_BINFO (type)) = virtuals; 908 SET_BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (type)); 909 return 1; 910 } 911 912 /* Give BINFO a new virtual function table which is initialized 913 with a skeleton-copy of its original initialization. The only 914 entry that changes is the `delta' entry, so we can really 915 share a lot of structure. 916 917 FOR_TYPE is the most derived type which caused this table to 918 be needed. 919 920 Returns nonzero if we haven't met BINFO before. 921 922 The order in which vtables are built (by calling this function) for 923 an object must remain the same, otherwise a binary incompatibility 924 can result. */ 925 926 static int 927 build_secondary_vtable (tree binfo) 928 { 929 if (BINFO_NEW_VTABLE_MARKED (binfo)) 930 /* We already created a vtable for this base. There's no need to 931 do it again. */ 932 return 0; 933 934 /* Remember that we've created a vtable for this BINFO, so that we 935 don't try to do so again. */ 936 SET_BINFO_NEW_VTABLE_MARKED (binfo); 937 938 /* Make fresh virtual list, so we can smash it later. */ 939 BINFO_VIRTUALS (binfo) = copy_list (BINFO_VIRTUALS (binfo)); 940 941 /* Secondary vtables are laid out as part of the same structure as 942 the primary vtable. */ 943 BINFO_VTABLE (binfo) = NULL_TREE; 944 return 1; 945 } 946 947 /* Create a new vtable for BINFO which is the hierarchy dominated by 948 T. Return nonzero if we actually created a new vtable. */ 949 950 static int 951 make_new_vtable (tree t, tree binfo) 952 { 953 if (binfo == TYPE_BINFO (t)) 954 /* In this case, it is *type*'s vtable we are modifying. We start 955 with the approximation that its vtable is that of the 956 immediate base class. */ 957 return build_primary_vtable (binfo, t); 958 else 959 /* This is our very own copy of `basetype' to play with. Later, 960 we will fill in all the virtual functions that override the 961 virtual functions in these base classes which are not defined 962 by the current type. */ 963 return build_secondary_vtable (binfo); 964 } 965 966 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO 967 (which is in the hierarchy dominated by T) list FNDECL as its 968 BV_FN. DELTA is the required constant adjustment from the `this' 969 pointer where the vtable entry appears to the `this' required when 970 the function is actually called. */ 971 972 static void 973 modify_vtable_entry (tree t, 974 tree binfo, 975 tree fndecl, 976 tree delta, 977 tree *virtuals) 978 { 979 tree v; 980 981 v = *virtuals; 982 983 if (fndecl != BV_FN (v) 984 || !tree_int_cst_equal (delta, BV_DELTA (v))) 985 { 986 /* We need a new vtable for BINFO. */ 987 if (make_new_vtable (t, binfo)) 988 { 989 /* If we really did make a new vtable, we also made a copy 990 of the BINFO_VIRTUALS list. Now, we have to find the 991 corresponding entry in that list. */ 992 *virtuals = BINFO_VIRTUALS (binfo); 993 while (BV_FN (*virtuals) != BV_FN (v)) 994 *virtuals = TREE_CHAIN (*virtuals); 995 v = *virtuals; 996 } 997 998 BV_DELTA (v) = delta; 999 BV_VCALL_INDEX (v) = NULL_TREE; 1000 BV_FN (v) = fndecl; 1001 } 1002 } 1003 1004 1005 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is 1006 the USING_DECL naming METHOD. Returns true if the method could be 1007 added to the method vec. */ 1008 1009 bool 1010 add_method (tree type, tree method, tree using_decl) 1011 { 1012 unsigned slot; 1013 tree overload; 1014 bool template_conv_p = false; 1015 bool conv_p; 1016 vec<tree, va_gc> *method_vec; 1017 bool complete_p; 1018 bool insert_p = false; 1019 tree current_fns; 1020 1021 if (method == error_mark_node) 1022 return false; 1023 1024 complete_p = COMPLETE_TYPE_P (type); 1025 conv_p = DECL_CONV_FN_P (method); 1026 if (conv_p) 1027 template_conv_p = (TREE_CODE (method) == TEMPLATE_DECL 1028 && DECL_TEMPLATE_CONV_FN_P (method)); 1029 1030 method_vec = CLASSTYPE_METHOD_VEC (type); 1031 if (!method_vec) 1032 { 1033 /* Make a new method vector. We start with 8 entries. We must 1034 allocate at least two (for constructors and destructors), and 1035 we're going to end up with an assignment operator at some 1036 point as well. */ 1037 vec_alloc (method_vec, 8); 1038 /* Create slots for constructors and destructors. */ 1039 method_vec->quick_push (NULL_TREE); 1040 method_vec->quick_push (NULL_TREE); 1041 CLASSTYPE_METHOD_VEC (type) = method_vec; 1042 } 1043 1044 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */ 1045 grok_special_member_properties (method); 1046 1047 /* Constructors and destructors go in special slots. */ 1048 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (method)) 1049 slot = CLASSTYPE_CONSTRUCTOR_SLOT; 1050 else if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method)) 1051 slot = CLASSTYPE_DESTRUCTOR_SLOT; 1052 else 1053 { 1054 tree m; 1055 1056 insert_p = true; 1057 /* See if we already have an entry with this name. */ 1058 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT; 1059 vec_safe_iterate (method_vec, slot, &m); 1060 ++slot) 1061 { 1062 m = OVL_CURRENT (m); 1063 if (template_conv_p) 1064 { 1065 if (TREE_CODE (m) == TEMPLATE_DECL 1066 && DECL_TEMPLATE_CONV_FN_P (m)) 1067 insert_p = false; 1068 break; 1069 } 1070 if (conv_p && !DECL_CONV_FN_P (m)) 1071 break; 1072 if (DECL_NAME (m) == DECL_NAME (method)) 1073 { 1074 insert_p = false; 1075 break; 1076 } 1077 if (complete_p 1078 && !DECL_CONV_FN_P (m) 1079 && DECL_NAME (m) > DECL_NAME (method)) 1080 break; 1081 } 1082 } 1083 current_fns = insert_p ? NULL_TREE : (*method_vec)[slot]; 1084 1085 /* Check to see if we've already got this method. */ 1086 for (tree *p = ¤t_fns; *p; ) 1087 { 1088 tree fns = *p; 1089 tree fn = OVL_CURRENT (fns); 1090 tree fn_type; 1091 tree method_type; 1092 tree parms1; 1093 tree parms2; 1094 1095 if (TREE_CODE (fn) != TREE_CODE (method)) 1096 goto cont; 1097 1098 /* Two using-declarations can coexist, we'll complain about ambiguity in 1099 overload resolution. */ 1100 if (using_decl && TREE_CODE (fns) == OVERLOAD && OVL_USED (fns) 1101 /* Except handle inherited constructors specially. */ 1102 && ! DECL_CONSTRUCTOR_P (fn)) 1103 goto cont; 1104 1105 /* [over.load] Member function declarations with the 1106 same name and the same parameter types cannot be 1107 overloaded if any of them is a static member 1108 function declaration. 1109 1110 [over.load] Member function declarations with the same name and 1111 the same parameter-type-list as well as member function template 1112 declarations with the same name, the same parameter-type-list, and 1113 the same template parameter lists cannot be overloaded if any of 1114 them, but not all, have a ref-qualifier. 1115 1116 [namespace.udecl] When a using-declaration brings names 1117 from a base class into a derived class scope, member 1118 functions in the derived class override and/or hide member 1119 functions with the same name and parameter types in a base 1120 class (rather than conflicting). */ 1121 fn_type = TREE_TYPE (fn); 1122 method_type = TREE_TYPE (method); 1123 parms1 = TYPE_ARG_TYPES (fn_type); 1124 parms2 = TYPE_ARG_TYPES (method_type); 1125 1126 /* Compare the quals on the 'this' parm. Don't compare 1127 the whole types, as used functions are treated as 1128 coming from the using class in overload resolution. */ 1129 if (! DECL_STATIC_FUNCTION_P (fn) 1130 && ! DECL_STATIC_FUNCTION_P (method) 1131 /* Either both or neither need to be ref-qualified for 1132 differing quals to allow overloading. */ 1133 && (FUNCTION_REF_QUALIFIED (fn_type) 1134 == FUNCTION_REF_QUALIFIED (method_type)) 1135 && (type_memfn_quals (fn_type) != type_memfn_quals (method_type) 1136 || type_memfn_rqual (fn_type) != type_memfn_rqual (method_type))) 1137 goto cont; 1138 1139 /* For templates, the return type and template parameters 1140 must be identical. */ 1141 if (TREE_CODE (fn) == TEMPLATE_DECL 1142 && (!same_type_p (TREE_TYPE (fn_type), 1143 TREE_TYPE (method_type)) 1144 || !comp_template_parms (DECL_TEMPLATE_PARMS (fn), 1145 DECL_TEMPLATE_PARMS (method)))) 1146 goto cont; 1147 1148 if (! DECL_STATIC_FUNCTION_P (fn)) 1149 parms1 = TREE_CHAIN (parms1); 1150 if (! DECL_STATIC_FUNCTION_P (method)) 1151 parms2 = TREE_CHAIN (parms2); 1152 1153 /* Bring back parameters omitted from an inherited ctor. */ 1154 if (ctor_omit_inherited_parms (fn)) 1155 parms1 = FUNCTION_FIRST_USER_PARMTYPE (DECL_ORIGIN (fn)); 1156 if (ctor_omit_inherited_parms (method)) 1157 parms2 = FUNCTION_FIRST_USER_PARMTYPE (DECL_ORIGIN (method)); 1158 1159 if (compparms (parms1, parms2) 1160 && (!DECL_CONV_FN_P (fn) 1161 || same_type_p (TREE_TYPE (fn_type), 1162 TREE_TYPE (method_type))) 1163 && equivalently_constrained (fn, method)) 1164 { 1165 /* For function versions, their parms and types match 1166 but they are not duplicates. Record function versions 1167 as and when they are found. extern "C" functions are 1168 not treated as versions. */ 1169 if (TREE_CODE (fn) == FUNCTION_DECL 1170 && TREE_CODE (method) == FUNCTION_DECL 1171 && !DECL_EXTERN_C_P (fn) 1172 && !DECL_EXTERN_C_P (method) 1173 && targetm.target_option.function_versions (fn, method)) 1174 { 1175 /* Mark functions as versions if necessary. Modify the mangled 1176 decl name if necessary. */ 1177 if (!DECL_FUNCTION_VERSIONED (fn)) 1178 { 1179 DECL_FUNCTION_VERSIONED (fn) = 1; 1180 if (DECL_ASSEMBLER_NAME_SET_P (fn)) 1181 mangle_decl (fn); 1182 } 1183 if (!DECL_FUNCTION_VERSIONED (method)) 1184 { 1185 DECL_FUNCTION_VERSIONED (method) = 1; 1186 if (DECL_ASSEMBLER_NAME_SET_P (method)) 1187 mangle_decl (method); 1188 } 1189 cgraph_node::record_function_versions (fn, method); 1190 goto cont; 1191 } 1192 if (DECL_INHERITED_CTOR (method)) 1193 { 1194 if (DECL_INHERITED_CTOR (fn)) 1195 { 1196 tree basem = DECL_INHERITED_CTOR_BASE (method); 1197 tree basef = DECL_INHERITED_CTOR_BASE (fn); 1198 if (flag_new_inheriting_ctors) 1199 { 1200 if (basem == basef) 1201 { 1202 /* Inheriting the same constructor along different 1203 paths, combine them. */ 1204 SET_DECL_INHERITED_CTOR 1205 (fn, ovl_cons (DECL_INHERITED_CTOR (method), 1206 DECL_INHERITED_CTOR (fn))); 1207 /* And discard the new one. */ 1208 return false; 1209 } 1210 else 1211 /* Inherited ctors can coexist until overload 1212 resolution. */ 1213 goto cont; 1214 } 1215 error_at (DECL_SOURCE_LOCATION (method), 1216 "%q#D", method); 1217 error_at (DECL_SOURCE_LOCATION (fn), 1218 "conflicts with version inherited from %qT", 1219 basef); 1220 } 1221 /* Otherwise defer to the other function. */ 1222 return false; 1223 } 1224 if (using_decl) 1225 { 1226 if (DECL_CONTEXT (fn) == type) 1227 /* Defer to the local function. */ 1228 return false; 1229 } 1230 else if (flag_new_inheriting_ctors 1231 && DECL_INHERITED_CTOR (fn)) 1232 { 1233 /* Hide the inherited constructor. */ 1234 *p = OVL_NEXT (fns); 1235 continue; 1236 } 1237 else 1238 { 1239 error ("%q+#D cannot be overloaded", method); 1240 error ("with %q+#D", fn); 1241 } 1242 1243 /* We don't call duplicate_decls here to merge the 1244 declarations because that will confuse things if the 1245 methods have inline definitions. In particular, we 1246 will crash while processing the definitions. */ 1247 return false; 1248 } 1249 1250 cont: 1251 if (TREE_CODE (fns) == OVERLOAD) 1252 p = &OVL_CHAIN (fns); 1253 else 1254 break; 1255 } 1256 1257 /* A class should never have more than one destructor. */ 1258 if (current_fns && DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method)) 1259 return false; 1260 1261 /* Add the new binding. */ 1262 if (using_decl) 1263 { 1264 overload = ovl_cons (method, current_fns); 1265 OVL_USED (overload) = true; 1266 } 1267 else 1268 overload = build_overload (method, current_fns); 1269 1270 if (conv_p) 1271 TYPE_HAS_CONVERSION (type) = 1; 1272 else if (slot >= CLASSTYPE_FIRST_CONVERSION_SLOT && !complete_p) 1273 push_class_level_binding (DECL_NAME (method), overload); 1274 1275 if (insert_p) 1276 { 1277 bool reallocated; 1278 1279 /* We only expect to add few methods in the COMPLETE_P case, so 1280 just make room for one more method in that case. */ 1281 if (complete_p) 1282 reallocated = vec_safe_reserve_exact (method_vec, 1); 1283 else 1284 reallocated = vec_safe_reserve (method_vec, 1); 1285 if (reallocated) 1286 CLASSTYPE_METHOD_VEC (type) = method_vec; 1287 if (slot == method_vec->length ()) 1288 method_vec->quick_push (overload); 1289 else 1290 method_vec->quick_insert (slot, overload); 1291 } 1292 else 1293 /* Replace the current slot. */ 1294 (*method_vec)[slot] = overload; 1295 return true; 1296 } 1297 1298 /* Subroutines of finish_struct. */ 1299 1300 /* Change the access of FDECL to ACCESS in T. Return 1 if change was 1301 legit, otherwise return 0. */ 1302 1303 static int 1304 alter_access (tree t, tree fdecl, tree access) 1305 { 1306 tree elem; 1307 1308 if (!DECL_LANG_SPECIFIC (fdecl)) 1309 retrofit_lang_decl (fdecl); 1310 1311 gcc_assert (!DECL_DISCRIMINATOR_P (fdecl)); 1312 1313 elem = purpose_member (t, DECL_ACCESS (fdecl)); 1314 if (elem) 1315 { 1316 if (TREE_VALUE (elem) != access) 1317 { 1318 if (TREE_CODE (TREE_TYPE (fdecl)) == FUNCTION_DECL) 1319 error ("conflicting access specifications for method" 1320 " %q+D, ignored", TREE_TYPE (fdecl)); 1321 else 1322 error ("conflicting access specifications for field %qE, ignored", 1323 DECL_NAME (fdecl)); 1324 } 1325 else 1326 { 1327 /* They're changing the access to the same thing they changed 1328 it to before. That's OK. */ 1329 ; 1330 } 1331 } 1332 else 1333 { 1334 perform_or_defer_access_check (TYPE_BINFO (t), fdecl, fdecl, 1335 tf_warning_or_error); 1336 DECL_ACCESS (fdecl) = tree_cons (t, access, DECL_ACCESS (fdecl)); 1337 return 1; 1338 } 1339 return 0; 1340 } 1341 1342 /* Return the access node for DECL's access in its enclosing class. */ 1343 1344 tree 1345 declared_access (tree decl) 1346 { 1347 return (TREE_PRIVATE (decl) ? access_private_node 1348 : TREE_PROTECTED (decl) ? access_protected_node 1349 : access_public_node); 1350 } 1351 1352 /* Process the USING_DECL, which is a member of T. */ 1353 1354 static void 1355 handle_using_decl (tree using_decl, tree t) 1356 { 1357 tree decl = USING_DECL_DECLS (using_decl); 1358 tree name = DECL_NAME (using_decl); 1359 tree access = declared_access (using_decl); 1360 tree flist = NULL_TREE; 1361 tree old_value; 1362 1363 gcc_assert (!processing_template_decl && decl); 1364 1365 old_value = lookup_member (t, name, /*protect=*/0, /*want_type=*/false, 1366 tf_warning_or_error); 1367 if (old_value) 1368 { 1369 if (is_overloaded_fn (old_value)) 1370 old_value = OVL_CURRENT (old_value); 1371 1372 if (DECL_P (old_value) && DECL_CONTEXT (old_value) == t) 1373 /* OK */; 1374 else 1375 old_value = NULL_TREE; 1376 } 1377 1378 cp_emit_debug_info_for_using (decl, t); 1379 1380 if (is_overloaded_fn (decl)) 1381 flist = decl; 1382 1383 if (! old_value) 1384 ; 1385 else if (is_overloaded_fn (old_value)) 1386 { 1387 if (flist) 1388 /* It's OK to use functions from a base when there are functions with 1389 the same name already present in the current class. */; 1390 else 1391 { 1392 error ("%q+D invalid in %q#T", using_decl, t); 1393 error (" because of local method %q+#D with same name", 1394 OVL_CURRENT (old_value)); 1395 return; 1396 } 1397 } 1398 else if (!DECL_ARTIFICIAL (old_value)) 1399 { 1400 error ("%q+D invalid in %q#T", using_decl, t); 1401 error (" because of local member %q+#D with same name", old_value); 1402 return; 1403 } 1404 1405 /* Make type T see field decl FDECL with access ACCESS. */ 1406 if (flist) 1407 for (; flist; flist = OVL_NEXT (flist)) 1408 { 1409 add_method (t, OVL_CURRENT (flist), using_decl); 1410 alter_access (t, OVL_CURRENT (flist), access); 1411 } 1412 else 1413 alter_access (t, decl, access); 1414 } 1415 1416 /* Data structure for find_abi_tags_r, below. */ 1417 1418 struct abi_tag_data 1419 { 1420 tree t; // The type that we're checking for missing tags. 1421 tree subob; // The subobject of T that we're getting tags from. 1422 tree tags; // error_mark_node for diagnostics, or a list of missing tags. 1423 }; 1424 1425 /* Subroutine of find_abi_tags_r. Handle a single TAG found on the class TP 1426 in the context of P. TAG can be either an identifier (the DECL_NAME of 1427 a tag NAMESPACE_DECL) or a STRING_CST (a tag attribute). */ 1428 1429 static void 1430 check_tag (tree tag, tree id, tree *tp, abi_tag_data *p) 1431 { 1432 if (!IDENTIFIER_MARKED (id)) 1433 { 1434 if (p->tags != error_mark_node) 1435 { 1436 /* We're collecting tags from template arguments or from 1437 the type of a variable or function return type. */ 1438 p->tags = tree_cons (NULL_TREE, tag, p->tags); 1439 1440 /* Don't inherit this tag multiple times. */ 1441 IDENTIFIER_MARKED (id) = true; 1442 1443 if (TYPE_P (p->t)) 1444 { 1445 /* Tags inherited from type template arguments are only used 1446 to avoid warnings. */ 1447 ABI_TAG_IMPLICIT (p->tags) = true; 1448 return; 1449 } 1450 /* For functions and variables we want to warn, too. */ 1451 } 1452 1453 /* Otherwise we're diagnosing missing tags. */ 1454 if (TREE_CODE (p->t) == FUNCTION_DECL) 1455 { 1456 if (warning (OPT_Wabi_tag, "%qD inherits the %E ABI tag " 1457 "that %qT (used in its return type) has", 1458 p->t, tag, *tp)) 1459 inform (location_of (*tp), "%qT declared here", *tp); 1460 } 1461 else if (VAR_P (p->t)) 1462 { 1463 if (warning (OPT_Wabi_tag, "%qD inherits the %E ABI tag " 1464 "that %qT (used in its type) has", p->t, tag, *tp)) 1465 inform (location_of (*tp), "%qT declared here", *tp); 1466 } 1467 else if (TYPE_P (p->subob)) 1468 { 1469 if (warning (OPT_Wabi_tag, "%qT does not have the %E ABI tag " 1470 "that base %qT has", p->t, tag, p->subob)) 1471 inform (location_of (p->subob), "%qT declared here", 1472 p->subob); 1473 } 1474 else 1475 { 1476 if (warning (OPT_Wabi_tag, "%qT does not have the %E ABI tag " 1477 "that %qT (used in the type of %qD) has", 1478 p->t, tag, *tp, p->subob)) 1479 { 1480 inform (location_of (p->subob), "%qD declared here", 1481 p->subob); 1482 inform (location_of (*tp), "%qT declared here", *tp); 1483 } 1484 } 1485 } 1486 } 1487 1488 /* Find all the ABI tags in the attribute list ATTR and either call 1489 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */ 1490 1491 static void 1492 mark_or_check_attr_tags (tree attr, tree *tp, abi_tag_data *p, bool val) 1493 { 1494 if (!attr) 1495 return; 1496 for (; (attr = lookup_attribute ("abi_tag", attr)); 1497 attr = TREE_CHAIN (attr)) 1498 for (tree list = TREE_VALUE (attr); list; 1499 list = TREE_CHAIN (list)) 1500 { 1501 tree tag = TREE_VALUE (list); 1502 tree id = get_identifier (TREE_STRING_POINTER (tag)); 1503 if (tp) 1504 check_tag (tag, id, tp, p); 1505 else 1506 IDENTIFIER_MARKED (id) = val; 1507 } 1508 } 1509 1510 /* Find all the ABI tags on T and its enclosing scopes and either call 1511 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */ 1512 1513 static void 1514 mark_or_check_tags (tree t, tree *tp, abi_tag_data *p, bool val) 1515 { 1516 while (t != global_namespace) 1517 { 1518 tree attr; 1519 if (TYPE_P (t)) 1520 { 1521 attr = TYPE_ATTRIBUTES (t); 1522 t = CP_TYPE_CONTEXT (t); 1523 } 1524 else 1525 { 1526 attr = DECL_ATTRIBUTES (t); 1527 t = CP_DECL_CONTEXT (t); 1528 } 1529 mark_or_check_attr_tags (attr, tp, p, val); 1530 } 1531 } 1532 1533 /* walk_tree callback for check_abi_tags: if the type at *TP involves any 1534 types with ABI tags, add the corresponding identifiers to the VEC in 1535 *DATA and set IDENTIFIER_MARKED. */ 1536 1537 static tree 1538 find_abi_tags_r (tree *tp, int *walk_subtrees, void *data) 1539 { 1540 if (!OVERLOAD_TYPE_P (*tp)) 1541 return NULL_TREE; 1542 1543 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE 1544 anyway, but let's make sure of it. */ 1545 *walk_subtrees = false; 1546 1547 abi_tag_data *p = static_cast<struct abi_tag_data*>(data); 1548 1549 mark_or_check_tags (*tp, tp, p, false); 1550 1551 return NULL_TREE; 1552 } 1553 1554 /* walk_tree callback for mark_abi_tags: if *TP is a class, set 1555 IDENTIFIER_MARKED on its ABI tags. */ 1556 1557 static tree 1558 mark_abi_tags_r (tree *tp, int *walk_subtrees, void *data) 1559 { 1560 if (!OVERLOAD_TYPE_P (*tp)) 1561 return NULL_TREE; 1562 1563 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE 1564 anyway, but let's make sure of it. */ 1565 *walk_subtrees = false; 1566 1567 bool *valp = static_cast<bool*>(data); 1568 1569 mark_or_check_tags (*tp, NULL, NULL, *valp); 1570 1571 return NULL_TREE; 1572 } 1573 1574 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its enclosing 1575 scopes. */ 1576 1577 static void 1578 mark_abi_tags (tree t, bool val) 1579 { 1580 mark_or_check_tags (t, NULL, NULL, val); 1581 if (DECL_P (t)) 1582 { 1583 if (DECL_LANG_SPECIFIC (t) && DECL_USE_TEMPLATE (t) 1584 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t))) 1585 { 1586 /* Template arguments are part of the signature. */ 1587 tree level = INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (t)); 1588 for (int j = 0; j < TREE_VEC_LENGTH (level); ++j) 1589 { 1590 tree arg = TREE_VEC_ELT (level, j); 1591 cp_walk_tree_without_duplicates (&arg, mark_abi_tags_r, &val); 1592 } 1593 } 1594 if (TREE_CODE (t) == FUNCTION_DECL) 1595 /* A function's parameter types are part of the signature, so 1596 we don't need to inherit any tags that are also in them. */ 1597 for (tree arg = FUNCTION_FIRST_USER_PARMTYPE (t); arg; 1598 arg = TREE_CHAIN (arg)) 1599 cp_walk_tree_without_duplicates (&TREE_VALUE (arg), 1600 mark_abi_tags_r, &val); 1601 } 1602 } 1603 1604 /* Check that T has all the ABI tags that subobject SUBOB has, or 1605 warn if not. If T is a (variable or function) declaration, also 1606 return any missing tags, and add them to T if JUST_CHECKING is false. */ 1607 1608 static tree 1609 check_abi_tags (tree t, tree subob, bool just_checking = false) 1610 { 1611 bool inherit = DECL_P (t); 1612 1613 if (!inherit && !warn_abi_tag) 1614 return NULL_TREE; 1615 1616 tree decl = TYPE_P (t) ? TYPE_NAME (t) : t; 1617 if (!TREE_PUBLIC (decl)) 1618 /* No need to worry about things local to this TU. */ 1619 return NULL_TREE; 1620 1621 mark_abi_tags (t, true); 1622 1623 tree subtype = TYPE_P (subob) ? subob : TREE_TYPE (subob); 1624 struct abi_tag_data data = { t, subob, error_mark_node }; 1625 if (inherit) 1626 data.tags = NULL_TREE; 1627 1628 cp_walk_tree_without_duplicates (&subtype, find_abi_tags_r, &data); 1629 1630 if (!(inherit && data.tags)) 1631 /* We don't need to do anything with data.tags. */; 1632 else if (just_checking) 1633 for (tree t = data.tags; t; t = TREE_CHAIN (t)) 1634 { 1635 tree id = get_identifier (TREE_STRING_POINTER (TREE_VALUE (t))); 1636 IDENTIFIER_MARKED (id) = false; 1637 } 1638 else 1639 { 1640 tree attr = lookup_attribute ("abi_tag", DECL_ATTRIBUTES (t)); 1641 if (attr) 1642 TREE_VALUE (attr) = chainon (data.tags, TREE_VALUE (attr)); 1643 else 1644 DECL_ATTRIBUTES (t) 1645 = tree_cons (get_identifier ("abi_tag"), data.tags, 1646 DECL_ATTRIBUTES (t)); 1647 } 1648 1649 mark_abi_tags (t, false); 1650 1651 return data.tags; 1652 } 1653 1654 /* Check that DECL has all the ABI tags that are used in parts of its type 1655 that are not reflected in its mangled name. */ 1656 1657 void 1658 check_abi_tags (tree decl) 1659 { 1660 if (VAR_P (decl)) 1661 check_abi_tags (decl, TREE_TYPE (decl)); 1662 else if (TREE_CODE (decl) == FUNCTION_DECL 1663 && !DECL_CONV_FN_P (decl) 1664 && !mangle_return_type_p (decl)) 1665 check_abi_tags (decl, TREE_TYPE (TREE_TYPE (decl))); 1666 } 1667 1668 /* Return any ABI tags that are used in parts of the type of DECL 1669 that are not reflected in its mangled name. This function is only 1670 used in backward-compatible mangling for ABI <11. */ 1671 1672 tree 1673 missing_abi_tags (tree decl) 1674 { 1675 if (VAR_P (decl)) 1676 return check_abi_tags (decl, TREE_TYPE (decl), true); 1677 else if (TREE_CODE (decl) == FUNCTION_DECL 1678 /* Don't check DECL_CONV_FN_P here like we do in check_abi_tags, so 1679 that we can use this function for setting need_abi_warning 1680 regardless of the current flag_abi_version. */ 1681 && !mangle_return_type_p (decl)) 1682 return check_abi_tags (decl, TREE_TYPE (TREE_TYPE (decl)), true); 1683 else 1684 return NULL_TREE; 1685 } 1686 1687 void 1688 inherit_targ_abi_tags (tree t) 1689 { 1690 if (!CLASS_TYPE_P (t) 1691 || CLASSTYPE_TEMPLATE_INFO (t) == NULL_TREE) 1692 return; 1693 1694 mark_abi_tags (t, true); 1695 1696 tree args = CLASSTYPE_TI_ARGS (t); 1697 struct abi_tag_data data = { t, NULL_TREE, NULL_TREE }; 1698 for (int i = 0; i < TMPL_ARGS_DEPTH (args); ++i) 1699 { 1700 tree level = TMPL_ARGS_LEVEL (args, i+1); 1701 for (int j = 0; j < TREE_VEC_LENGTH (level); ++j) 1702 { 1703 tree arg = TREE_VEC_ELT (level, j); 1704 data.subob = arg; 1705 cp_walk_tree_without_duplicates (&arg, find_abi_tags_r, &data); 1706 } 1707 } 1708 1709 // If we found some tags on our template arguments, add them to our 1710 // abi_tag attribute. 1711 if (data.tags) 1712 { 1713 tree attr = lookup_attribute ("abi_tag", TYPE_ATTRIBUTES (t)); 1714 if (attr) 1715 TREE_VALUE (attr) = chainon (data.tags, TREE_VALUE (attr)); 1716 else 1717 TYPE_ATTRIBUTES (t) 1718 = tree_cons (get_identifier ("abi_tag"), data.tags, 1719 TYPE_ATTRIBUTES (t)); 1720 } 1721 1722 mark_abi_tags (t, false); 1723 } 1724 1725 /* Return true, iff class T has a non-virtual destructor that is 1726 accessible from outside the class heirarchy (i.e. is public, or 1727 there's a suitable friend. */ 1728 1729 static bool 1730 accessible_nvdtor_p (tree t) 1731 { 1732 tree dtor = CLASSTYPE_DESTRUCTORS (t); 1733 1734 /* An implicitly declared destructor is always public. And, 1735 if it were virtual, we would have created it by now. */ 1736 if (!dtor) 1737 return true; 1738 1739 if (DECL_VINDEX (dtor)) 1740 return false; /* Virtual */ 1741 1742 if (!TREE_PRIVATE (dtor) && !TREE_PROTECTED (dtor)) 1743 return true; /* Public */ 1744 1745 if (CLASSTYPE_FRIEND_CLASSES (t) 1746 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t))) 1747 return true; /* Has friends */ 1748 1749 return false; 1750 } 1751 1752 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P, 1753 and NO_CONST_ASN_REF_P. Also set flag bits in T based on 1754 properties of the bases. */ 1755 1756 static void 1757 check_bases (tree t, 1758 int* cant_have_const_ctor_p, 1759 int* no_const_asn_ref_p) 1760 { 1761 int i; 1762 bool seen_non_virtual_nearly_empty_base_p = 0; 1763 int seen_tm_mask = 0; 1764 tree base_binfo; 1765 tree binfo; 1766 tree field = NULL_TREE; 1767 1768 if (!CLASSTYPE_NON_STD_LAYOUT (t)) 1769 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) 1770 if (TREE_CODE (field) == FIELD_DECL) 1771 break; 1772 1773 for (binfo = TYPE_BINFO (t), i = 0; 1774 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 1775 { 1776 tree basetype = TREE_TYPE (base_binfo); 1777 1778 gcc_assert (COMPLETE_TYPE_P (basetype)); 1779 1780 if (CLASSTYPE_FINAL (basetype)) 1781 error ("cannot derive from %<final%> base %qT in derived type %qT", 1782 basetype, t); 1783 1784 /* If any base class is non-literal, so is the derived class. */ 1785 if (!CLASSTYPE_LITERAL_P (basetype)) 1786 CLASSTYPE_LITERAL_P (t) = false; 1787 1788 /* If the base class doesn't have copy constructors or 1789 assignment operators that take const references, then the 1790 derived class cannot have such a member automatically 1791 generated. */ 1792 if (TYPE_HAS_COPY_CTOR (basetype) 1793 && ! TYPE_HAS_CONST_COPY_CTOR (basetype)) 1794 *cant_have_const_ctor_p = 1; 1795 if (TYPE_HAS_COPY_ASSIGN (basetype) 1796 && !TYPE_HAS_CONST_COPY_ASSIGN (basetype)) 1797 *no_const_asn_ref_p = 1; 1798 1799 if (BINFO_VIRTUAL_P (base_binfo)) 1800 /* A virtual base does not effect nearly emptiness. */ 1801 ; 1802 else if (CLASSTYPE_NEARLY_EMPTY_P (basetype)) 1803 { 1804 if (seen_non_virtual_nearly_empty_base_p) 1805 /* And if there is more than one nearly empty base, then the 1806 derived class is not nearly empty either. */ 1807 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 1808 else 1809 /* Remember we've seen one. */ 1810 seen_non_virtual_nearly_empty_base_p = 1; 1811 } 1812 else if (!is_empty_class (basetype)) 1813 /* If the base class is not empty or nearly empty, then this 1814 class cannot be nearly empty. */ 1815 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 1816 1817 /* A lot of properties from the bases also apply to the derived 1818 class. */ 1819 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (basetype); 1820 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) 1821 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype); 1822 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) 1823 |= (TYPE_HAS_COMPLEX_COPY_ASSIGN (basetype) 1824 || !TYPE_HAS_COPY_ASSIGN (basetype)); 1825 TYPE_HAS_COMPLEX_COPY_CTOR (t) |= (TYPE_HAS_COMPLEX_COPY_CTOR (basetype) 1826 || !TYPE_HAS_COPY_CTOR (basetype)); 1827 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) 1828 |= TYPE_HAS_COMPLEX_MOVE_ASSIGN (basetype); 1829 TYPE_HAS_COMPLEX_MOVE_CTOR (t) |= TYPE_HAS_COMPLEX_MOVE_CTOR (basetype); 1830 TYPE_POLYMORPHIC_P (t) |= TYPE_POLYMORPHIC_P (basetype); 1831 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) 1832 |= CLASSTYPE_CONTAINS_EMPTY_CLASS_P (basetype); 1833 TYPE_HAS_COMPLEX_DFLT (t) |= (!TYPE_HAS_DEFAULT_CONSTRUCTOR (basetype) 1834 || TYPE_HAS_COMPLEX_DFLT (basetype)); 1835 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT 1836 (t, CLASSTYPE_READONLY_FIELDS_NEED_INIT (t) 1837 | CLASSTYPE_READONLY_FIELDS_NEED_INIT (basetype)); 1838 SET_CLASSTYPE_REF_FIELDS_NEED_INIT 1839 (t, CLASSTYPE_REF_FIELDS_NEED_INIT (t) 1840 | CLASSTYPE_REF_FIELDS_NEED_INIT (basetype)); 1841 if (TYPE_HAS_MUTABLE_P (basetype)) 1842 CLASSTYPE_HAS_MUTABLE (t) = 1; 1843 1844 /* A standard-layout class is a class that: 1845 ... 1846 * has no non-standard-layout base classes, */ 1847 CLASSTYPE_NON_STD_LAYOUT (t) |= CLASSTYPE_NON_STD_LAYOUT (basetype); 1848 if (!CLASSTYPE_NON_STD_LAYOUT (t)) 1849 { 1850 tree basefield; 1851 /* ...has no base classes of the same type as the first non-static 1852 data member... */ 1853 if (field && DECL_CONTEXT (field) == t 1854 && (same_type_ignoring_top_level_qualifiers_p 1855 (TREE_TYPE (field), basetype))) 1856 CLASSTYPE_NON_STD_LAYOUT (t) = 1; 1857 else 1858 /* ...either has no non-static data members in the most-derived 1859 class and at most one base class with non-static data 1860 members, or has no base classes with non-static data 1861 members */ 1862 for (basefield = TYPE_FIELDS (basetype); basefield; 1863 basefield = DECL_CHAIN (basefield)) 1864 if (TREE_CODE (basefield) == FIELD_DECL 1865 && !(DECL_FIELD_IS_BASE (basefield) 1866 && integer_zerop (DECL_SIZE (basefield)))) 1867 { 1868 if (field) 1869 CLASSTYPE_NON_STD_LAYOUT (t) = 1; 1870 else 1871 field = basefield; 1872 break; 1873 } 1874 } 1875 1876 /* Don't bother collecting tm attributes if transactional memory 1877 support is not enabled. */ 1878 if (flag_tm) 1879 { 1880 tree tm_attr = find_tm_attribute (TYPE_ATTRIBUTES (basetype)); 1881 if (tm_attr) 1882 seen_tm_mask |= tm_attr_to_mask (tm_attr); 1883 } 1884 1885 check_abi_tags (t, basetype); 1886 } 1887 1888 /* If one of the base classes had TM attributes, and the current class 1889 doesn't define its own, then the current class inherits one. */ 1890 if (seen_tm_mask && !find_tm_attribute (TYPE_ATTRIBUTES (t))) 1891 { 1892 tree tm_attr = tm_mask_to_attr (least_bit_hwi (seen_tm_mask)); 1893 TYPE_ATTRIBUTES (t) = tree_cons (tm_attr, NULL, TYPE_ATTRIBUTES (t)); 1894 } 1895 } 1896 1897 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for 1898 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those 1899 that have had a nearly-empty virtual primary base stolen by some 1900 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for 1901 T. */ 1902 1903 static void 1904 determine_primary_bases (tree t) 1905 { 1906 unsigned i; 1907 tree primary = NULL_TREE; 1908 tree type_binfo = TYPE_BINFO (t); 1909 tree base_binfo; 1910 1911 /* Determine the primary bases of our bases. */ 1912 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo; 1913 base_binfo = TREE_CHAIN (base_binfo)) 1914 { 1915 tree primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (base_binfo)); 1916 1917 /* See if we're the non-virtual primary of our inheritance 1918 chain. */ 1919 if (!BINFO_VIRTUAL_P (base_binfo)) 1920 { 1921 tree parent = BINFO_INHERITANCE_CHAIN (base_binfo); 1922 tree parent_primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (parent)); 1923 1924 if (parent_primary 1925 && SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo), 1926 BINFO_TYPE (parent_primary))) 1927 /* We are the primary binfo. */ 1928 BINFO_PRIMARY_P (base_binfo) = 1; 1929 } 1930 /* Determine if we have a virtual primary base, and mark it so. 1931 */ 1932 if (primary && BINFO_VIRTUAL_P (primary)) 1933 { 1934 tree this_primary = copied_binfo (primary, base_binfo); 1935 1936 if (BINFO_PRIMARY_P (this_primary)) 1937 /* Someone already claimed this base. */ 1938 BINFO_LOST_PRIMARY_P (base_binfo) = 1; 1939 else 1940 { 1941 tree delta; 1942 1943 BINFO_PRIMARY_P (this_primary) = 1; 1944 BINFO_INHERITANCE_CHAIN (this_primary) = base_binfo; 1945 1946 /* A virtual binfo might have been copied from within 1947 another hierarchy. As we're about to use it as a 1948 primary base, make sure the offsets match. */ 1949 delta = size_diffop_loc (input_location, 1950 fold_convert (ssizetype, 1951 BINFO_OFFSET (base_binfo)), 1952 fold_convert (ssizetype, 1953 BINFO_OFFSET (this_primary))); 1954 1955 propagate_binfo_offsets (this_primary, delta); 1956 } 1957 } 1958 } 1959 1960 /* First look for a dynamic direct non-virtual base. */ 1961 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, base_binfo); i++) 1962 { 1963 tree basetype = BINFO_TYPE (base_binfo); 1964 1965 if (TYPE_CONTAINS_VPTR_P (basetype) && !BINFO_VIRTUAL_P (base_binfo)) 1966 { 1967 primary = base_binfo; 1968 goto found; 1969 } 1970 } 1971 1972 /* A "nearly-empty" virtual base class can be the primary base 1973 class, if no non-virtual polymorphic base can be found. Look for 1974 a nearly-empty virtual dynamic base that is not already a primary 1975 base of something in the hierarchy. If there is no such base, 1976 just pick the first nearly-empty virtual base. */ 1977 1978 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo; 1979 base_binfo = TREE_CHAIN (base_binfo)) 1980 if (BINFO_VIRTUAL_P (base_binfo) 1981 && CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (base_binfo))) 1982 { 1983 if (!BINFO_PRIMARY_P (base_binfo)) 1984 { 1985 /* Found one that is not primary. */ 1986 primary = base_binfo; 1987 goto found; 1988 } 1989 else if (!primary) 1990 /* Remember the first candidate. */ 1991 primary = base_binfo; 1992 } 1993 1994 found: 1995 /* If we've got a primary base, use it. */ 1996 if (primary) 1997 { 1998 tree basetype = BINFO_TYPE (primary); 1999 2000 CLASSTYPE_PRIMARY_BINFO (t) = primary; 2001 if (BINFO_PRIMARY_P (primary)) 2002 /* We are stealing a primary base. */ 2003 BINFO_LOST_PRIMARY_P (BINFO_INHERITANCE_CHAIN (primary)) = 1; 2004 BINFO_PRIMARY_P (primary) = 1; 2005 if (BINFO_VIRTUAL_P (primary)) 2006 { 2007 tree delta; 2008 2009 BINFO_INHERITANCE_CHAIN (primary) = type_binfo; 2010 /* A virtual binfo might have been copied from within 2011 another hierarchy. As we're about to use it as a primary 2012 base, make sure the offsets match. */ 2013 delta = size_diffop_loc (input_location, ssize_int (0), 2014 fold_convert (ssizetype, BINFO_OFFSET (primary))); 2015 2016 propagate_binfo_offsets (primary, delta); 2017 } 2018 2019 primary = TYPE_BINFO (basetype); 2020 2021 TYPE_VFIELD (t) = TYPE_VFIELD (basetype); 2022 BINFO_VTABLE (type_binfo) = BINFO_VTABLE (primary); 2023 BINFO_VIRTUALS (type_binfo) = BINFO_VIRTUALS (primary); 2024 } 2025 } 2026 2027 /* Update the variant types of T. */ 2028 2029 void 2030 fixup_type_variants (tree t) 2031 { 2032 tree variants; 2033 2034 if (!t) 2035 return; 2036 2037 for (variants = TYPE_NEXT_VARIANT (t); 2038 variants; 2039 variants = TYPE_NEXT_VARIANT (variants)) 2040 { 2041 /* These fields are in the _TYPE part of the node, not in 2042 the TYPE_LANG_SPECIFIC component, so they are not shared. */ 2043 TYPE_HAS_USER_CONSTRUCTOR (variants) = TYPE_HAS_USER_CONSTRUCTOR (t); 2044 TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t); 2045 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variants) 2046 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t); 2047 2048 TYPE_POLYMORPHIC_P (variants) = TYPE_POLYMORPHIC_P (t); 2049 2050 TYPE_BINFO (variants) = TYPE_BINFO (t); 2051 2052 /* Copy whatever these are holding today. */ 2053 TYPE_VFIELD (variants) = TYPE_VFIELD (t); 2054 TYPE_FIELDS (variants) = TYPE_FIELDS (t); 2055 } 2056 } 2057 2058 /* KLASS is a class that we're applying may_alias to after the body is 2059 parsed. Fixup any POINTER_TO and REFERENCE_TO types. The 2060 canonical type(s) will be implicitly updated. */ 2061 2062 static void 2063 fixup_may_alias (tree klass) 2064 { 2065 tree t, v; 2066 2067 for (t = TYPE_POINTER_TO (klass); t; t = TYPE_NEXT_PTR_TO (t)) 2068 for (v = TYPE_MAIN_VARIANT (t); v; v = TYPE_NEXT_VARIANT (v)) 2069 TYPE_REF_CAN_ALIAS_ALL (v) = true; 2070 for (t = TYPE_REFERENCE_TO (klass); t; t = TYPE_NEXT_REF_TO (t)) 2071 for (v = TYPE_MAIN_VARIANT (t); v; v = TYPE_NEXT_VARIANT (v)) 2072 TYPE_REF_CAN_ALIAS_ALL (v) = true; 2073 } 2074 2075 /* Early variant fixups: we apply attributes at the beginning of the class 2076 definition, and we need to fix up any variants that have already been 2077 made via elaborated-type-specifier so that check_qualified_type works. */ 2078 2079 void 2080 fixup_attribute_variants (tree t) 2081 { 2082 tree variants; 2083 2084 if (!t) 2085 return; 2086 2087 tree attrs = TYPE_ATTRIBUTES (t); 2088 unsigned align = TYPE_ALIGN (t); 2089 bool user_align = TYPE_USER_ALIGN (t); 2090 bool may_alias = lookup_attribute ("may_alias", attrs); 2091 2092 if (may_alias) 2093 fixup_may_alias (t); 2094 2095 for (variants = TYPE_NEXT_VARIANT (t); 2096 variants; 2097 variants = TYPE_NEXT_VARIANT (variants)) 2098 { 2099 /* These are the two fields that check_qualified_type looks at and 2100 are affected by attributes. */ 2101 TYPE_ATTRIBUTES (variants) = attrs; 2102 unsigned valign = align; 2103 if (TYPE_USER_ALIGN (variants)) 2104 valign = MAX (valign, TYPE_ALIGN (variants)); 2105 else 2106 TYPE_USER_ALIGN (variants) = user_align; 2107 SET_TYPE_ALIGN (variants, valign); 2108 if (may_alias) 2109 fixup_may_alias (variants); 2110 } 2111 } 2112 2113 /* Set memoizing fields and bits of T (and its variants) for later 2114 use. */ 2115 2116 static void 2117 finish_struct_bits (tree t) 2118 { 2119 /* Fix up variants (if any). */ 2120 fixup_type_variants (t); 2121 2122 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) && TYPE_POLYMORPHIC_P (t)) 2123 /* For a class w/o baseclasses, 'finish_struct' has set 2124 CLASSTYPE_PURE_VIRTUALS correctly (by definition). 2125 Similarly for a class whose base classes do not have vtables. 2126 When neither of these is true, we might have removed abstract 2127 virtuals (by providing a definition), added some (by declaring 2128 new ones), or redeclared ones from a base class. We need to 2129 recalculate what's really an abstract virtual at this point (by 2130 looking in the vtables). */ 2131 get_pure_virtuals (t); 2132 2133 /* If this type has a copy constructor or a destructor, force its 2134 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be 2135 nonzero. This will cause it to be passed by invisible reference 2136 and prevent it from being returned in a register. */ 2137 if (type_has_nontrivial_copy_init (t) 2138 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)) 2139 { 2140 tree variants; 2141 SET_DECL_MODE (TYPE_MAIN_DECL (t), BLKmode); 2142 for (variants = t; variants; variants = TYPE_NEXT_VARIANT (variants)) 2143 { 2144 SET_TYPE_MODE (variants, BLKmode); 2145 TREE_ADDRESSABLE (variants) = 1; 2146 } 2147 } 2148 } 2149 2150 /* Issue warnings about T having private constructors, but no friends, 2151 and so forth. 2152 2153 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or 2154 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any 2155 non-private static member functions. */ 2156 2157 static void 2158 maybe_warn_about_overly_private_class (tree t) 2159 { 2160 int has_member_fn = 0; 2161 int has_nonprivate_method = 0; 2162 tree fn; 2163 2164 if (!warn_ctor_dtor_privacy 2165 /* If the class has friends, those entities might create and 2166 access instances, so we should not warn. */ 2167 || (CLASSTYPE_FRIEND_CLASSES (t) 2168 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t))) 2169 /* We will have warned when the template was declared; there's 2170 no need to warn on every instantiation. */ 2171 || CLASSTYPE_TEMPLATE_INSTANTIATION (t)) 2172 /* There's no reason to even consider warning about this 2173 class. */ 2174 return; 2175 2176 /* We only issue one warning, if more than one applies, because 2177 otherwise, on code like: 2178 2179 class A { 2180 // Oops - forgot `public:' 2181 A(); 2182 A(const A&); 2183 ~A(); 2184 }; 2185 2186 we warn several times about essentially the same problem. */ 2187 2188 /* Check to see if all (non-constructor, non-destructor) member 2189 functions are private. (Since there are no friends or 2190 non-private statics, we can't ever call any of the private member 2191 functions.) */ 2192 for (fn = TYPE_METHODS (t); fn; fn = DECL_CHAIN (fn)) 2193 /* We're not interested in compiler-generated methods; they don't 2194 provide any way to call private members. */ 2195 if (!DECL_ARTIFICIAL (fn)) 2196 { 2197 if (!TREE_PRIVATE (fn)) 2198 { 2199 if (DECL_STATIC_FUNCTION_P (fn)) 2200 /* A non-private static member function is just like a 2201 friend; it can create and invoke private member 2202 functions, and be accessed without a class 2203 instance. */ 2204 return; 2205 2206 has_nonprivate_method = 1; 2207 /* Keep searching for a static member function. */ 2208 } 2209 else if (!DECL_CONSTRUCTOR_P (fn) && !DECL_DESTRUCTOR_P (fn)) 2210 has_member_fn = 1; 2211 } 2212 2213 if (!has_nonprivate_method && has_member_fn) 2214 { 2215 /* There are no non-private methods, and there's at least one 2216 private member function that isn't a constructor or 2217 destructor. (If all the private members are 2218 constructors/destructors we want to use the code below that 2219 issues error messages specifically referring to 2220 constructors/destructors.) */ 2221 unsigned i; 2222 tree binfo = TYPE_BINFO (t); 2223 2224 for (i = 0; i != BINFO_N_BASE_BINFOS (binfo); i++) 2225 if (BINFO_BASE_ACCESS (binfo, i) != access_private_node) 2226 { 2227 has_nonprivate_method = 1; 2228 break; 2229 } 2230 if (!has_nonprivate_method) 2231 { 2232 warning (OPT_Wctor_dtor_privacy, 2233 "all member functions in class %qT are private", t); 2234 return; 2235 } 2236 } 2237 2238 /* Even if some of the member functions are non-private, the class 2239 won't be useful for much if all the constructors or destructors 2240 are private: such an object can never be created or destroyed. */ 2241 fn = CLASSTYPE_DESTRUCTORS (t); 2242 if (fn && TREE_PRIVATE (fn)) 2243 { 2244 warning (OPT_Wctor_dtor_privacy, 2245 "%q#T only defines a private destructor and has no friends", 2246 t); 2247 return; 2248 } 2249 2250 /* Warn about classes that have private constructors and no friends. */ 2251 if (TYPE_HAS_USER_CONSTRUCTOR (t) 2252 /* Implicitly generated constructors are always public. */ 2253 && (!CLASSTYPE_LAZY_DEFAULT_CTOR (t) 2254 || !CLASSTYPE_LAZY_COPY_CTOR (t))) 2255 { 2256 int nonprivate_ctor = 0; 2257 2258 /* If a non-template class does not define a copy 2259 constructor, one is defined for it, enabling it to avoid 2260 this warning. For a template class, this does not 2261 happen, and so we would normally get a warning on: 2262 2263 template <class T> class C { private: C(); }; 2264 2265 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All 2266 complete non-template or fully instantiated classes have this 2267 flag set. */ 2268 if (!TYPE_HAS_COPY_CTOR (t)) 2269 nonprivate_ctor = 1; 2270 else 2271 for (fn = CLASSTYPE_CONSTRUCTORS (t); fn; fn = OVL_NEXT (fn)) 2272 { 2273 tree ctor = OVL_CURRENT (fn); 2274 /* Ideally, we wouldn't count copy constructors (or, in 2275 fact, any constructor that takes an argument of the 2276 class type as a parameter) because such things cannot 2277 be used to construct an instance of the class unless 2278 you already have one. But, for now at least, we're 2279 more generous. */ 2280 if (! TREE_PRIVATE (ctor)) 2281 { 2282 nonprivate_ctor = 1; 2283 break; 2284 } 2285 } 2286 2287 if (nonprivate_ctor == 0) 2288 { 2289 warning (OPT_Wctor_dtor_privacy, 2290 "%q#T only defines private constructors and has no friends", 2291 t); 2292 return; 2293 } 2294 } 2295 } 2296 2297 static struct { 2298 gt_pointer_operator new_value; 2299 void *cookie; 2300 } resort_data; 2301 2302 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */ 2303 2304 static int 2305 method_name_cmp (const void* m1_p, const void* m2_p) 2306 { 2307 const tree *const m1 = (const tree *) m1_p; 2308 const tree *const m2 = (const tree *) m2_p; 2309 2310 if (*m1 == NULL_TREE && *m2 == NULL_TREE) 2311 return 0; 2312 if (*m1 == NULL_TREE) 2313 return -1; 2314 if (*m2 == NULL_TREE) 2315 return 1; 2316 if (DECL_NAME (OVL_CURRENT (*m1)) < DECL_NAME (OVL_CURRENT (*m2))) 2317 return -1; 2318 return 1; 2319 } 2320 2321 /* This routine compares two fields like method_name_cmp but using the 2322 pointer operator in resort_field_decl_data. */ 2323 2324 static int 2325 resort_method_name_cmp (const void* m1_p, const void* m2_p) 2326 { 2327 const tree *const m1 = (const tree *) m1_p; 2328 const tree *const m2 = (const tree *) m2_p; 2329 if (*m1 == NULL_TREE && *m2 == NULL_TREE) 2330 return 0; 2331 if (*m1 == NULL_TREE) 2332 return -1; 2333 if (*m2 == NULL_TREE) 2334 return 1; 2335 { 2336 tree d1 = DECL_NAME (OVL_CURRENT (*m1)); 2337 tree d2 = DECL_NAME (OVL_CURRENT (*m2)); 2338 resort_data.new_value (&d1, resort_data.cookie); 2339 resort_data.new_value (&d2, resort_data.cookie); 2340 if (d1 < d2) 2341 return -1; 2342 } 2343 return 1; 2344 } 2345 2346 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */ 2347 2348 void 2349 resort_type_method_vec (void* obj, 2350 void* /*orig_obj*/, 2351 gt_pointer_operator new_value, 2352 void* cookie) 2353 { 2354 vec<tree, va_gc> *method_vec = (vec<tree, va_gc> *) obj; 2355 int len = vec_safe_length (method_vec); 2356 size_t slot; 2357 tree fn; 2358 2359 /* The type conversion ops have to live at the front of the vec, so we 2360 can't sort them. */ 2361 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT; 2362 vec_safe_iterate (method_vec, slot, &fn); 2363 ++slot) 2364 if (!DECL_CONV_FN_P (OVL_CURRENT (fn))) 2365 break; 2366 2367 if (len - slot > 1) 2368 { 2369 resort_data.new_value = new_value; 2370 resort_data.cookie = cookie; 2371 qsort (method_vec->address () + slot, len - slot, sizeof (tree), 2372 resort_method_name_cmp); 2373 } 2374 } 2375 2376 /* Warn about duplicate methods in fn_fields. 2377 2378 Sort methods that are not special (i.e., constructors, destructors, 2379 and type conversion operators) so that we can find them faster in 2380 search. */ 2381 2382 static void 2383 finish_struct_methods (tree t) 2384 { 2385 tree fn_fields; 2386 vec<tree, va_gc> *method_vec; 2387 int slot, len; 2388 2389 method_vec = CLASSTYPE_METHOD_VEC (t); 2390 if (!method_vec) 2391 return; 2392 2393 len = method_vec->length (); 2394 2395 /* Clear DECL_IN_AGGR_P for all functions. */ 2396 for (fn_fields = TYPE_METHODS (t); fn_fields; 2397 fn_fields = DECL_CHAIN (fn_fields)) 2398 DECL_IN_AGGR_P (fn_fields) = 0; 2399 2400 /* Issue warnings about private constructors and such. If there are 2401 no methods, then some public defaults are generated. */ 2402 maybe_warn_about_overly_private_class (t); 2403 2404 /* The type conversion ops have to live at the front of the vec, so we 2405 can't sort them. */ 2406 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT; 2407 method_vec->iterate (slot, &fn_fields); 2408 ++slot) 2409 if (!DECL_CONV_FN_P (OVL_CURRENT (fn_fields))) 2410 break; 2411 if (len - slot > 1) 2412 qsort (method_vec->address () + slot, 2413 len-slot, sizeof (tree), method_name_cmp); 2414 } 2415 2416 /* Make BINFO's vtable have N entries, including RTTI entries, 2417 vbase and vcall offsets, etc. Set its type and call the back end 2418 to lay it out. */ 2419 2420 static void 2421 layout_vtable_decl (tree binfo, int n) 2422 { 2423 tree atype; 2424 tree vtable; 2425 2426 atype = build_array_of_n_type (vtable_entry_type, n); 2427 layout_type (atype); 2428 2429 /* We may have to grow the vtable. */ 2430 vtable = get_vtbl_decl_for_binfo (binfo); 2431 if (!same_type_p (TREE_TYPE (vtable), atype)) 2432 { 2433 TREE_TYPE (vtable) = atype; 2434 DECL_SIZE (vtable) = DECL_SIZE_UNIT (vtable) = NULL_TREE; 2435 layout_decl (vtable, 0); 2436 } 2437 } 2438 2439 /* True iff FNDECL and BASE_FNDECL (both non-static member functions) 2440 have the same signature. */ 2441 2442 int 2443 same_signature_p (const_tree fndecl, const_tree base_fndecl) 2444 { 2445 /* One destructor overrides another if they are the same kind of 2446 destructor. */ 2447 if (DECL_DESTRUCTOR_P (base_fndecl) && DECL_DESTRUCTOR_P (fndecl) 2448 && special_function_p (base_fndecl) == special_function_p (fndecl)) 2449 return 1; 2450 /* But a non-destructor never overrides a destructor, nor vice 2451 versa, nor do different kinds of destructors override 2452 one-another. For example, a complete object destructor does not 2453 override a deleting destructor. */ 2454 if (DECL_DESTRUCTOR_P (base_fndecl) || DECL_DESTRUCTOR_P (fndecl)) 2455 return 0; 2456 2457 if (DECL_NAME (fndecl) == DECL_NAME (base_fndecl) 2458 || (DECL_CONV_FN_P (fndecl) 2459 && DECL_CONV_FN_P (base_fndecl) 2460 && same_type_p (DECL_CONV_FN_TYPE (fndecl), 2461 DECL_CONV_FN_TYPE (base_fndecl)))) 2462 { 2463 tree fntype = TREE_TYPE (fndecl); 2464 tree base_fntype = TREE_TYPE (base_fndecl); 2465 if (type_memfn_quals (fntype) == type_memfn_quals (base_fntype) 2466 && type_memfn_rqual (fntype) == type_memfn_rqual (base_fntype) 2467 && compparms (FUNCTION_FIRST_USER_PARMTYPE (fndecl), 2468 FUNCTION_FIRST_USER_PARMTYPE (base_fndecl))) 2469 return 1; 2470 } 2471 return 0; 2472 } 2473 2474 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a 2475 subobject. */ 2476 2477 static bool 2478 base_derived_from (tree derived, tree base) 2479 { 2480 tree probe; 2481 2482 for (probe = base; probe; probe = BINFO_INHERITANCE_CHAIN (probe)) 2483 { 2484 if (probe == derived) 2485 return true; 2486 else if (BINFO_VIRTUAL_P (probe)) 2487 /* If we meet a virtual base, we can't follow the inheritance 2488 any more. See if the complete type of DERIVED contains 2489 such a virtual base. */ 2490 return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (derived)) 2491 != NULL_TREE); 2492 } 2493 return false; 2494 } 2495 2496 struct find_final_overrider_data { 2497 /* The function for which we are trying to find a final overrider. */ 2498 tree fn; 2499 /* The base class in which the function was declared. */ 2500 tree declaring_base; 2501 /* The candidate overriders. */ 2502 tree candidates; 2503 /* Path to most derived. */ 2504 vec<tree> path; 2505 }; 2506 2507 /* Add the overrider along the current path to FFOD->CANDIDATES. 2508 Returns true if an overrider was found; false otherwise. */ 2509 2510 static bool 2511 dfs_find_final_overrider_1 (tree binfo, 2512 find_final_overrider_data *ffod, 2513 unsigned depth) 2514 { 2515 tree method; 2516 2517 /* If BINFO is not the most derived type, try a more derived class. 2518 A definition there will overrider a definition here. */ 2519 if (depth) 2520 { 2521 depth--; 2522 if (dfs_find_final_overrider_1 2523 (ffod->path[depth], ffod, depth)) 2524 return true; 2525 } 2526 2527 method = look_for_overrides_here (BINFO_TYPE (binfo), ffod->fn); 2528 if (method) 2529 { 2530 tree *candidate = &ffod->candidates; 2531 2532 /* Remove any candidates overridden by this new function. */ 2533 while (*candidate) 2534 { 2535 /* If *CANDIDATE overrides METHOD, then METHOD 2536 cannot override anything else on the list. */ 2537 if (base_derived_from (TREE_VALUE (*candidate), binfo)) 2538 return true; 2539 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */ 2540 if (base_derived_from (binfo, TREE_VALUE (*candidate))) 2541 *candidate = TREE_CHAIN (*candidate); 2542 else 2543 candidate = &TREE_CHAIN (*candidate); 2544 } 2545 2546 /* Add the new function. */ 2547 ffod->candidates = tree_cons (method, binfo, ffod->candidates); 2548 return true; 2549 } 2550 2551 return false; 2552 } 2553 2554 /* Called from find_final_overrider via dfs_walk. */ 2555 2556 static tree 2557 dfs_find_final_overrider_pre (tree binfo, void *data) 2558 { 2559 find_final_overrider_data *ffod = (find_final_overrider_data *) data; 2560 2561 if (binfo == ffod->declaring_base) 2562 dfs_find_final_overrider_1 (binfo, ffod, ffod->path.length ()); 2563 ffod->path.safe_push (binfo); 2564 2565 return NULL_TREE; 2566 } 2567 2568 static tree 2569 dfs_find_final_overrider_post (tree /*binfo*/, void *data) 2570 { 2571 find_final_overrider_data *ffod = (find_final_overrider_data *) data; 2572 ffod->path.pop (); 2573 2574 return NULL_TREE; 2575 } 2576 2577 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for 2578 FN and whose TREE_VALUE is the binfo for the base where the 2579 overriding occurs. BINFO (in the hierarchy dominated by the binfo 2580 DERIVED) is the base object in which FN is declared. */ 2581 2582 static tree 2583 find_final_overrider (tree derived, tree binfo, tree fn) 2584 { 2585 find_final_overrider_data ffod; 2586 2587 /* Getting this right is a little tricky. This is valid: 2588 2589 struct S { virtual void f (); }; 2590 struct T { virtual void f (); }; 2591 struct U : public S, public T { }; 2592 2593 even though calling `f' in `U' is ambiguous. But, 2594 2595 struct R { virtual void f(); }; 2596 struct S : virtual public R { virtual void f (); }; 2597 struct T : virtual public R { virtual void f (); }; 2598 struct U : public S, public T { }; 2599 2600 is not -- there's no way to decide whether to put `S::f' or 2601 `T::f' in the vtable for `R'. 2602 2603 The solution is to look at all paths to BINFO. If we find 2604 different overriders along any two, then there is a problem. */ 2605 if (DECL_THUNK_P (fn)) 2606 fn = THUNK_TARGET (fn); 2607 2608 /* Determine the depth of the hierarchy. */ 2609 ffod.fn = fn; 2610 ffod.declaring_base = binfo; 2611 ffod.candidates = NULL_TREE; 2612 ffod.path.create (30); 2613 2614 dfs_walk_all (derived, dfs_find_final_overrider_pre, 2615 dfs_find_final_overrider_post, &ffod); 2616 2617 ffod.path.release (); 2618 2619 /* If there was no winner, issue an error message. */ 2620 if (!ffod.candidates || TREE_CHAIN (ffod.candidates)) 2621 return error_mark_node; 2622 2623 return ffod.candidates; 2624 } 2625 2626 /* Return the index of the vcall offset for FN when TYPE is used as a 2627 virtual base. */ 2628 2629 static tree 2630 get_vcall_index (tree fn, tree type) 2631 { 2632 vec<tree_pair_s, va_gc> *indices = CLASSTYPE_VCALL_INDICES (type); 2633 tree_pair_p p; 2634 unsigned ix; 2635 2636 FOR_EACH_VEC_SAFE_ELT (indices, ix, p) 2637 if ((DECL_DESTRUCTOR_P (fn) && DECL_DESTRUCTOR_P (p->purpose)) 2638 || same_signature_p (fn, p->purpose)) 2639 return p->value; 2640 2641 /* There should always be an appropriate index. */ 2642 gcc_unreachable (); 2643 } 2644 2645 /* Update an entry in the vtable for BINFO, which is in the hierarchy 2646 dominated by T. FN is the old function; VIRTUALS points to the 2647 corresponding position in the new BINFO_VIRTUALS list. IX is the index 2648 of that entry in the list. */ 2649 2650 static void 2651 update_vtable_entry_for_fn (tree t, tree binfo, tree fn, tree* virtuals, 2652 unsigned ix) 2653 { 2654 tree b; 2655 tree overrider; 2656 tree delta; 2657 tree virtual_base; 2658 tree first_defn; 2659 tree overrider_fn, overrider_target; 2660 tree target_fn = DECL_THUNK_P (fn) ? THUNK_TARGET (fn) : fn; 2661 tree over_return, base_return; 2662 bool lost = false; 2663 2664 /* Find the nearest primary base (possibly binfo itself) which defines 2665 this function; this is the class the caller will convert to when 2666 calling FN through BINFO. */ 2667 for (b = binfo; ; b = get_primary_binfo (b)) 2668 { 2669 gcc_assert (b); 2670 if (look_for_overrides_here (BINFO_TYPE (b), target_fn)) 2671 break; 2672 2673 /* The nearest definition is from a lost primary. */ 2674 if (BINFO_LOST_PRIMARY_P (b)) 2675 lost = true; 2676 } 2677 first_defn = b; 2678 2679 /* Find the final overrider. */ 2680 overrider = find_final_overrider (TYPE_BINFO (t), b, target_fn); 2681 if (overrider == error_mark_node) 2682 { 2683 error ("no unique final overrider for %qD in %qT", target_fn, t); 2684 return; 2685 } 2686 overrider_target = overrider_fn = TREE_PURPOSE (overrider); 2687 2688 /* Check for adjusting covariant return types. */ 2689 over_return = TREE_TYPE (TREE_TYPE (overrider_target)); 2690 base_return = TREE_TYPE (TREE_TYPE (target_fn)); 2691 2692 if (POINTER_TYPE_P (over_return) 2693 && TREE_CODE (over_return) == TREE_CODE (base_return) 2694 && CLASS_TYPE_P (TREE_TYPE (over_return)) 2695 && CLASS_TYPE_P (TREE_TYPE (base_return)) 2696 /* If the overrider is invalid, don't even try. */ 2697 && !DECL_INVALID_OVERRIDER_P (overrider_target)) 2698 { 2699 /* If FN is a covariant thunk, we must figure out the adjustment 2700 to the final base FN was converting to. As OVERRIDER_TARGET might 2701 also be converting to the return type of FN, we have to 2702 combine the two conversions here. */ 2703 tree fixed_offset, virtual_offset; 2704 2705 over_return = TREE_TYPE (over_return); 2706 base_return = TREE_TYPE (base_return); 2707 2708 if (DECL_THUNK_P (fn)) 2709 { 2710 gcc_assert (DECL_RESULT_THUNK_P (fn)); 2711 fixed_offset = ssize_int (THUNK_FIXED_OFFSET (fn)); 2712 virtual_offset = THUNK_VIRTUAL_OFFSET (fn); 2713 } 2714 else 2715 fixed_offset = virtual_offset = NULL_TREE; 2716 2717 if (virtual_offset) 2718 /* Find the equivalent binfo within the return type of the 2719 overriding function. We will want the vbase offset from 2720 there. */ 2721 virtual_offset = binfo_for_vbase (BINFO_TYPE (virtual_offset), 2722 over_return); 2723 else if (!same_type_ignoring_top_level_qualifiers_p 2724 (over_return, base_return)) 2725 { 2726 /* There was no existing virtual thunk (which takes 2727 precedence). So find the binfo of the base function's 2728 return type within the overriding function's return type. 2729 Fortunately we know the covariancy is valid (it 2730 has already been checked), so we can just iterate along 2731 the binfos, which have been chained in inheritance graph 2732 order. Of course it is lame that we have to repeat the 2733 search here anyway -- we should really be caching pieces 2734 of the vtable and avoiding this repeated work. */ 2735 tree thunk_binfo = NULL_TREE; 2736 tree base_binfo = TYPE_BINFO (base_return); 2737 2738 /* Find the base binfo within the overriding function's 2739 return type. We will always find a thunk_binfo, except 2740 when the covariancy is invalid (which we will have 2741 already diagnosed). */ 2742 if (base_binfo) 2743 for (thunk_binfo = TYPE_BINFO (over_return); thunk_binfo; 2744 thunk_binfo = TREE_CHAIN (thunk_binfo)) 2745 if (SAME_BINFO_TYPE_P (BINFO_TYPE (thunk_binfo), 2746 BINFO_TYPE (base_binfo))) 2747 break; 2748 gcc_assert (thunk_binfo || errorcount); 2749 2750 /* See if virtual inheritance is involved. */ 2751 for (virtual_offset = thunk_binfo; 2752 virtual_offset; 2753 virtual_offset = BINFO_INHERITANCE_CHAIN (virtual_offset)) 2754 if (BINFO_VIRTUAL_P (virtual_offset)) 2755 break; 2756 2757 if (virtual_offset 2758 || (thunk_binfo && !BINFO_OFFSET_ZEROP (thunk_binfo))) 2759 { 2760 tree offset = fold_convert (ssizetype, BINFO_OFFSET (thunk_binfo)); 2761 2762 if (virtual_offset) 2763 { 2764 /* We convert via virtual base. Adjust the fixed 2765 offset to be from there. */ 2766 offset = 2767 size_diffop (offset, 2768 fold_convert (ssizetype, 2769 BINFO_OFFSET (virtual_offset))); 2770 } 2771 if (fixed_offset) 2772 /* There was an existing fixed offset, this must be 2773 from the base just converted to, and the base the 2774 FN was thunking to. */ 2775 fixed_offset = size_binop (PLUS_EXPR, fixed_offset, offset); 2776 else 2777 fixed_offset = offset; 2778 } 2779 } 2780 2781 if (fixed_offset || virtual_offset) 2782 /* Replace the overriding function with a covariant thunk. We 2783 will emit the overriding function in its own slot as 2784 well. */ 2785 overrider_fn = make_thunk (overrider_target, /*this_adjusting=*/0, 2786 fixed_offset, virtual_offset); 2787 } 2788 else 2789 gcc_assert (DECL_INVALID_OVERRIDER_P (overrider_target) || 2790 !DECL_THUNK_P (fn)); 2791 2792 /* If we need a covariant thunk, then we may need to adjust first_defn. 2793 The ABI specifies that the thunks emitted with a function are 2794 determined by which bases the function overrides, so we need to be 2795 sure that we're using a thunk for some overridden base; even if we 2796 know that the necessary this adjustment is zero, there may not be an 2797 appropriate zero-this-adjustment thunk for us to use since thunks for 2798 overriding virtual bases always use the vcall offset. 2799 2800 Furthermore, just choosing any base that overrides this function isn't 2801 quite right, as this slot won't be used for calls through a type that 2802 puts a covariant thunk here. Calling the function through such a type 2803 will use a different slot, and that slot is the one that determines 2804 the thunk emitted for that base. 2805 2806 So, keep looking until we find the base that we're really overriding 2807 in this slot: the nearest primary base that doesn't use a covariant 2808 thunk in this slot. */ 2809 if (overrider_target != overrider_fn) 2810 { 2811 if (BINFO_TYPE (b) == DECL_CONTEXT (overrider_target)) 2812 /* We already know that the overrider needs a covariant thunk. */ 2813 b = get_primary_binfo (b); 2814 for (; ; b = get_primary_binfo (b)) 2815 { 2816 tree main_binfo = TYPE_BINFO (BINFO_TYPE (b)); 2817 tree bv = chain_index (ix, BINFO_VIRTUALS (main_binfo)); 2818 if (!DECL_THUNK_P (TREE_VALUE (bv))) 2819 break; 2820 if (BINFO_LOST_PRIMARY_P (b)) 2821 lost = true; 2822 } 2823 first_defn = b; 2824 } 2825 2826 /* Assume that we will produce a thunk that convert all the way to 2827 the final overrider, and not to an intermediate virtual base. */ 2828 virtual_base = NULL_TREE; 2829 2830 /* See if we can convert to an intermediate virtual base first, and then 2831 use the vcall offset located there to finish the conversion. */ 2832 for (; b; b = BINFO_INHERITANCE_CHAIN (b)) 2833 { 2834 /* If we find the final overrider, then we can stop 2835 walking. */ 2836 if (SAME_BINFO_TYPE_P (BINFO_TYPE (b), 2837 BINFO_TYPE (TREE_VALUE (overrider)))) 2838 break; 2839 2840 /* If we find a virtual base, and we haven't yet found the 2841 overrider, then there is a virtual base between the 2842 declaring base (first_defn) and the final overrider. */ 2843 if (BINFO_VIRTUAL_P (b)) 2844 { 2845 virtual_base = b; 2846 break; 2847 } 2848 } 2849 2850 /* Compute the constant adjustment to the `this' pointer. The 2851 `this' pointer, when this function is called, will point at BINFO 2852 (or one of its primary bases, which are at the same offset). */ 2853 if (virtual_base) 2854 /* The `this' pointer needs to be adjusted from the declaration to 2855 the nearest virtual base. */ 2856 delta = size_diffop_loc (input_location, 2857 fold_convert (ssizetype, BINFO_OFFSET (virtual_base)), 2858 fold_convert (ssizetype, BINFO_OFFSET (first_defn))); 2859 else if (lost) 2860 /* If the nearest definition is in a lost primary, we don't need an 2861 entry in our vtable. Except possibly in a constructor vtable, 2862 if we happen to get our primary back. In that case, the offset 2863 will be zero, as it will be a primary base. */ 2864 delta = size_zero_node; 2865 else 2866 /* The `this' pointer needs to be adjusted from pointing to 2867 BINFO to pointing at the base where the final overrider 2868 appears. */ 2869 delta = size_diffop_loc (input_location, 2870 fold_convert (ssizetype, 2871 BINFO_OFFSET (TREE_VALUE (overrider))), 2872 fold_convert (ssizetype, BINFO_OFFSET (binfo))); 2873 2874 modify_vtable_entry (t, binfo, overrider_fn, delta, virtuals); 2875 2876 if (virtual_base) 2877 BV_VCALL_INDEX (*virtuals) 2878 = get_vcall_index (overrider_target, BINFO_TYPE (virtual_base)); 2879 else 2880 BV_VCALL_INDEX (*virtuals) = NULL_TREE; 2881 2882 BV_LOST_PRIMARY (*virtuals) = lost; 2883 } 2884 2885 /* Called from modify_all_vtables via dfs_walk. */ 2886 2887 static tree 2888 dfs_modify_vtables (tree binfo, void* data) 2889 { 2890 tree t = (tree) data; 2891 tree virtuals; 2892 tree old_virtuals; 2893 unsigned ix; 2894 2895 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) 2896 /* A base without a vtable needs no modification, and its bases 2897 are uninteresting. */ 2898 return dfs_skip_bases; 2899 2900 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t) 2901 && !CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 2902 /* Don't do the primary vtable, if it's new. */ 2903 return NULL_TREE; 2904 2905 if (BINFO_PRIMARY_P (binfo) && !BINFO_VIRTUAL_P (binfo)) 2906 /* There's no need to modify the vtable for a non-virtual primary 2907 base; we're not going to use that vtable anyhow. We do still 2908 need to do this for virtual primary bases, as they could become 2909 non-primary in a construction vtable. */ 2910 return NULL_TREE; 2911 2912 make_new_vtable (t, binfo); 2913 2914 /* Now, go through each of the virtual functions in the virtual 2915 function table for BINFO. Find the final overrider, and update 2916 the BINFO_VIRTUALS list appropriately. */ 2917 for (ix = 0, virtuals = BINFO_VIRTUALS (binfo), 2918 old_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo))); 2919 virtuals; 2920 ix++, virtuals = TREE_CHAIN (virtuals), 2921 old_virtuals = TREE_CHAIN (old_virtuals)) 2922 update_vtable_entry_for_fn (t, 2923 binfo, 2924 BV_FN (old_virtuals), 2925 &virtuals, ix); 2926 2927 return NULL_TREE; 2928 } 2929 2930 /* Update all of the primary and secondary vtables for T. Create new 2931 vtables as required, and initialize their RTTI information. Each 2932 of the functions in VIRTUALS is declared in T and may override a 2933 virtual function from a base class; find and modify the appropriate 2934 entries to point to the overriding functions. Returns a list, in 2935 declaration order, of the virtual functions that are declared in T, 2936 but do not appear in the primary base class vtable, and which 2937 should therefore be appended to the end of the vtable for T. */ 2938 2939 static tree 2940 modify_all_vtables (tree t, tree virtuals) 2941 { 2942 tree binfo = TYPE_BINFO (t); 2943 tree *fnsp; 2944 2945 /* Mangle the vtable name before entering dfs_walk (c++/51884). */ 2946 if (TYPE_CONTAINS_VPTR_P (t)) 2947 get_vtable_decl (t, false); 2948 2949 /* Update all of the vtables. */ 2950 dfs_walk_once (binfo, dfs_modify_vtables, NULL, t); 2951 2952 /* Add virtual functions not already in our primary vtable. These 2953 will be both those introduced by this class, and those overridden 2954 from secondary bases. It does not include virtuals merely 2955 inherited from secondary bases. */ 2956 for (fnsp = &virtuals; *fnsp; ) 2957 { 2958 tree fn = TREE_VALUE (*fnsp); 2959 2960 if (!value_member (fn, BINFO_VIRTUALS (binfo)) 2961 || DECL_VINDEX (fn) == error_mark_node) 2962 { 2963 /* We don't need to adjust the `this' pointer when 2964 calling this function. */ 2965 BV_DELTA (*fnsp) = integer_zero_node; 2966 BV_VCALL_INDEX (*fnsp) = NULL_TREE; 2967 2968 /* This is a function not already in our vtable. Keep it. */ 2969 fnsp = &TREE_CHAIN (*fnsp); 2970 } 2971 else 2972 /* We've already got an entry for this function. Skip it. */ 2973 *fnsp = TREE_CHAIN (*fnsp); 2974 } 2975 2976 return virtuals; 2977 } 2978 2979 /* Get the base virtual function declarations in T that have the 2980 indicated NAME. */ 2981 2982 static void 2983 get_basefndecls (tree name, tree t, vec<tree> *base_fndecls) 2984 { 2985 tree methods; 2986 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t)); 2987 int i; 2988 2989 /* Find virtual functions in T with the indicated NAME. */ 2990 i = lookup_fnfields_1 (t, name); 2991 bool found_decls = false; 2992 if (i != -1) 2993 for (methods = (*CLASSTYPE_METHOD_VEC (t))[i]; 2994 methods; 2995 methods = OVL_NEXT (methods)) 2996 { 2997 tree method = OVL_CURRENT (methods); 2998 2999 if (TREE_CODE (method) == FUNCTION_DECL 3000 && DECL_VINDEX (method)) 3001 { 3002 base_fndecls->safe_push (method); 3003 found_decls = true; 3004 } 3005 } 3006 3007 if (found_decls) 3008 return; 3009 3010 for (i = 0; i < n_baseclasses; i++) 3011 { 3012 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (t), i)); 3013 get_basefndecls (name, basetype, base_fndecls); 3014 } 3015 } 3016 3017 /* If this declaration supersedes the declaration of 3018 a method declared virtual in the base class, then 3019 mark this field as being virtual as well. */ 3020 3021 void 3022 check_for_override (tree decl, tree ctype) 3023 { 3024 bool overrides_found = false; 3025 if (TREE_CODE (decl) == TEMPLATE_DECL) 3026 /* In [temp.mem] we have: 3027 3028 A specialization of a member function template does not 3029 override a virtual function from a base class. */ 3030 return; 3031 if ((DECL_DESTRUCTOR_P (decl) 3032 || IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) 3033 || DECL_CONV_FN_P (decl)) 3034 && look_for_overrides (ctype, decl) 3035 && !DECL_STATIC_FUNCTION_P (decl)) 3036 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor 3037 the error_mark_node so that we know it is an overriding 3038 function. */ 3039 { 3040 DECL_VINDEX (decl) = decl; 3041 overrides_found = true; 3042 if (warn_override && !DECL_OVERRIDE_P (decl) 3043 && !DECL_DESTRUCTOR_P (decl)) 3044 warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wsuggest_override, 3045 "%qD can be marked override", decl); 3046 } 3047 3048 if (DECL_VIRTUAL_P (decl)) 3049 { 3050 if (!DECL_VINDEX (decl)) 3051 DECL_VINDEX (decl) = error_mark_node; 3052 IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) = 1; 3053 if (DECL_DESTRUCTOR_P (decl)) 3054 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (ctype) = true; 3055 } 3056 else if (DECL_FINAL_P (decl)) 3057 error ("%q+#D marked %<final%>, but is not virtual", decl); 3058 if (DECL_OVERRIDE_P (decl) && !overrides_found) 3059 error ("%q+#D marked %<override%>, but does not override", decl); 3060 } 3061 3062 /* Warn about hidden virtual functions that are not overridden in t. 3063 We know that constructors and destructors don't apply. */ 3064 3065 static void 3066 warn_hidden (tree t) 3067 { 3068 vec<tree, va_gc> *method_vec = CLASSTYPE_METHOD_VEC (t); 3069 tree fns; 3070 size_t i; 3071 3072 /* We go through each separately named virtual function. */ 3073 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT; 3074 vec_safe_iterate (method_vec, i, &fns); 3075 ++i) 3076 { 3077 tree fn; 3078 tree name; 3079 tree fndecl; 3080 tree base_binfo; 3081 tree binfo; 3082 int j; 3083 3084 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will 3085 have the same name. Figure out what name that is. */ 3086 name = DECL_NAME (OVL_CURRENT (fns)); 3087 /* There are no possibly hidden functions yet. */ 3088 auto_vec<tree, 20> base_fndecls; 3089 /* Iterate through all of the base classes looking for possibly 3090 hidden functions. */ 3091 for (binfo = TYPE_BINFO (t), j = 0; 3092 BINFO_BASE_ITERATE (binfo, j, base_binfo); j++) 3093 { 3094 tree basetype = BINFO_TYPE (base_binfo); 3095 get_basefndecls (name, basetype, &base_fndecls); 3096 } 3097 3098 /* If there are no functions to hide, continue. */ 3099 if (base_fndecls.is_empty ()) 3100 continue; 3101 3102 /* Remove any overridden functions. */ 3103 for (fn = fns; fn; fn = OVL_NEXT (fn)) 3104 { 3105 fndecl = OVL_CURRENT (fn); 3106 if (TREE_CODE (fndecl) == FUNCTION_DECL 3107 && DECL_VINDEX (fndecl)) 3108 { 3109 /* If the method from the base class has the same 3110 signature as the method from the derived class, it 3111 has been overridden. */ 3112 for (size_t k = 0; k < base_fndecls.length (); k++) 3113 if (base_fndecls[k] 3114 && same_signature_p (fndecl, base_fndecls[k])) 3115 base_fndecls[k] = NULL_TREE; 3116 } 3117 } 3118 3119 /* Now give a warning for all base functions without overriders, 3120 as they are hidden. */ 3121 size_t k; 3122 tree base_fndecl; 3123 FOR_EACH_VEC_ELT (base_fndecls, k, base_fndecl) 3124 if (base_fndecl) 3125 { 3126 /* Here we know it is a hider, and no overrider exists. */ 3127 warning_at (location_of (base_fndecl), 3128 OPT_Woverloaded_virtual, 3129 "%qD was hidden", base_fndecl); 3130 warning_at (location_of (fns), 3131 OPT_Woverloaded_virtual, " by %qD", fns); 3132 } 3133 } 3134 } 3135 3136 /* Recursive helper for finish_struct_anon. */ 3137 3138 static void 3139 finish_struct_anon_r (tree field, bool complain) 3140 { 3141 bool is_union = TREE_CODE (TREE_TYPE (field)) == UNION_TYPE; 3142 tree elt = TYPE_FIELDS (TREE_TYPE (field)); 3143 for (; elt; elt = DECL_CHAIN (elt)) 3144 { 3145 /* We're generally only interested in entities the user 3146 declared, but we also find nested classes by noticing 3147 the TYPE_DECL that we create implicitly. You're 3148 allowed to put one anonymous union inside another, 3149 though, so we explicitly tolerate that. We use 3150 TYPE_UNNAMED_P rather than ANON_AGGR_TYPE_P so that 3151 we also allow unnamed types used for defining fields. */ 3152 if (DECL_ARTIFICIAL (elt) 3153 && (!DECL_IMPLICIT_TYPEDEF_P (elt) 3154 || TYPE_UNNAMED_P (TREE_TYPE (elt)))) 3155 continue; 3156 3157 if (TREE_CODE (elt) != FIELD_DECL) 3158 { 3159 /* We already complained about static data members in 3160 finish_static_data_member_decl. */ 3161 if (complain && !VAR_P (elt)) 3162 { 3163 if (is_union) 3164 permerror (DECL_SOURCE_LOCATION (elt), 3165 "%q#D invalid; an anonymous union can " 3166 "only have non-static data members", elt); 3167 else 3168 permerror (DECL_SOURCE_LOCATION (elt), 3169 "%q#D invalid; an anonymous struct can " 3170 "only have non-static data members", elt); 3171 } 3172 continue; 3173 } 3174 3175 if (complain) 3176 { 3177 if (TREE_PRIVATE (elt)) 3178 { 3179 if (is_union) 3180 permerror (DECL_SOURCE_LOCATION (elt), 3181 "private member %q#D in anonymous union", elt); 3182 else 3183 permerror (DECL_SOURCE_LOCATION (elt), 3184 "private member %q#D in anonymous struct", elt); 3185 } 3186 else if (TREE_PROTECTED (elt)) 3187 { 3188 if (is_union) 3189 permerror (DECL_SOURCE_LOCATION (elt), 3190 "protected member %q#D in anonymous union", elt); 3191 else 3192 permerror (DECL_SOURCE_LOCATION (elt), 3193 "protected member %q#D in anonymous struct", elt); 3194 } 3195 } 3196 3197 TREE_PRIVATE (elt) = TREE_PRIVATE (field); 3198 TREE_PROTECTED (elt) = TREE_PROTECTED (field); 3199 3200 /* Recurse into the anonymous aggregates to handle correctly 3201 access control (c++/24926): 3202 3203 class A { 3204 union { 3205 union { 3206 int i; 3207 }; 3208 }; 3209 }; 3210 3211 int j=A().i; */ 3212 if (DECL_NAME (elt) == NULL_TREE 3213 && ANON_AGGR_TYPE_P (TREE_TYPE (elt))) 3214 finish_struct_anon_r (elt, /*complain=*/false); 3215 } 3216 } 3217 3218 /* Check for things that are invalid. There are probably plenty of other 3219 things we should check for also. */ 3220 3221 static void 3222 finish_struct_anon (tree t) 3223 { 3224 for (tree field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) 3225 { 3226 if (TREE_STATIC (field)) 3227 continue; 3228 if (TREE_CODE (field) != FIELD_DECL) 3229 continue; 3230 3231 if (DECL_NAME (field) == NULL_TREE 3232 && ANON_AGGR_TYPE_P (TREE_TYPE (field))) 3233 finish_struct_anon_r (field, /*complain=*/true); 3234 } 3235 } 3236 3237 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which 3238 will be used later during class template instantiation. 3239 When FRIEND_P is zero, T can be a static member data (VAR_DECL), 3240 a non-static member data (FIELD_DECL), a member function 3241 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE), 3242 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL) 3243 When FRIEND_P is nonzero, T is either a friend class 3244 (RECORD_TYPE, TEMPLATE_DECL) or a friend function 3245 (FUNCTION_DECL, TEMPLATE_DECL). */ 3246 3247 void 3248 maybe_add_class_template_decl_list (tree type, tree t, int friend_p) 3249 { 3250 /* Save some memory by not creating TREE_LIST if TYPE is not template. */ 3251 if (CLASSTYPE_TEMPLATE_INFO (type)) 3252 CLASSTYPE_DECL_LIST (type) 3253 = tree_cons (friend_p ? NULL_TREE : type, 3254 t, CLASSTYPE_DECL_LIST (type)); 3255 } 3256 3257 /* This function is called from declare_virt_assop_and_dtor via 3258 dfs_walk_all. 3259 3260 DATA is a type that direcly or indirectly inherits the base 3261 represented by BINFO. If BINFO contains a virtual assignment [copy 3262 assignment or move assigment] operator or a virtual constructor, 3263 declare that function in DATA if it hasn't been already declared. */ 3264 3265 static tree 3266 dfs_declare_virt_assop_and_dtor (tree binfo, void *data) 3267 { 3268 tree bv, fn, t = (tree)data; 3269 tree opname = cp_assignment_operator_id (NOP_EXPR); 3270 3271 gcc_assert (t && CLASS_TYPE_P (t)); 3272 gcc_assert (binfo && TREE_CODE (binfo) == TREE_BINFO); 3273 3274 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) 3275 /* A base without a vtable needs no modification, and its bases 3276 are uninteresting. */ 3277 return dfs_skip_bases; 3278 3279 if (BINFO_PRIMARY_P (binfo)) 3280 /* If this is a primary base, then we have already looked at the 3281 virtual functions of its vtable. */ 3282 return NULL_TREE; 3283 3284 for (bv = BINFO_VIRTUALS (binfo); bv; bv = TREE_CHAIN (bv)) 3285 { 3286 fn = BV_FN (bv); 3287 3288 if (DECL_NAME (fn) == opname) 3289 { 3290 if (CLASSTYPE_LAZY_COPY_ASSIGN (t)) 3291 lazily_declare_fn (sfk_copy_assignment, t); 3292 if (CLASSTYPE_LAZY_MOVE_ASSIGN (t)) 3293 lazily_declare_fn (sfk_move_assignment, t); 3294 } 3295 else if (DECL_DESTRUCTOR_P (fn) 3296 && CLASSTYPE_LAZY_DESTRUCTOR (t)) 3297 lazily_declare_fn (sfk_destructor, t); 3298 } 3299 3300 return NULL_TREE; 3301 } 3302 3303 /* If the class type T has a direct or indirect base that contains a 3304 virtual assignment operator or a virtual destructor, declare that 3305 function in T if it hasn't been already declared. */ 3306 3307 static void 3308 declare_virt_assop_and_dtor (tree t) 3309 { 3310 if (!(TYPE_POLYMORPHIC_P (t) 3311 && (CLASSTYPE_LAZY_COPY_ASSIGN (t) 3312 || CLASSTYPE_LAZY_MOVE_ASSIGN (t) 3313 || CLASSTYPE_LAZY_DESTRUCTOR (t)))) 3314 return; 3315 3316 dfs_walk_all (TYPE_BINFO (t), 3317 dfs_declare_virt_assop_and_dtor, 3318 NULL, t); 3319 } 3320 3321 /* Declare the inheriting constructor for class T inherited from base 3322 constructor CTOR with the parameter array PARMS of size NPARMS. */ 3323 3324 static void 3325 one_inheriting_sig (tree t, tree ctor, tree *parms, int nparms) 3326 { 3327 /* We don't declare an inheriting ctor that would be a default, 3328 copy or move ctor for derived or base. */ 3329 if (nparms == 0) 3330 return; 3331 if (nparms == 1 3332 && TREE_CODE (parms[0]) == REFERENCE_TYPE) 3333 { 3334 tree parm = TYPE_MAIN_VARIANT (TREE_TYPE (parms[0])); 3335 if (parm == t || parm == DECL_CONTEXT (ctor)) 3336 return; 3337 } 3338 3339 tree parmlist = void_list_node; 3340 for (int i = nparms - 1; i >= 0; i--) 3341 parmlist = tree_cons (NULL_TREE, parms[i], parmlist); 3342 tree fn = implicitly_declare_fn (sfk_inheriting_constructor, 3343 t, false, ctor, parmlist); 3344 gcc_assert (TYPE_MAIN_VARIANT (t) == t); 3345 if (add_method (t, fn, NULL_TREE)) 3346 { 3347 DECL_CHAIN (fn) = TYPE_METHODS (t); 3348 TYPE_METHODS (t) = fn; 3349 } 3350 } 3351 3352 /* Declare all the inheriting constructors for class T inherited from base 3353 constructor CTOR. */ 3354 3355 static void 3356 one_inherited_ctor (tree ctor, tree t, tree using_decl) 3357 { 3358 tree parms = FUNCTION_FIRST_USER_PARMTYPE (ctor); 3359 3360 if (flag_new_inheriting_ctors) 3361 { 3362 ctor = implicitly_declare_fn (sfk_inheriting_constructor, 3363 t, /*const*/false, ctor, parms); 3364 add_method (t, ctor, using_decl); 3365 TYPE_HAS_USER_CONSTRUCTOR (t) = true; 3366 return; 3367 } 3368 3369 tree *new_parms = XALLOCAVEC (tree, list_length (parms)); 3370 int i = 0; 3371 for (; parms && parms != void_list_node; parms = TREE_CHAIN (parms)) 3372 { 3373 if (TREE_PURPOSE (parms)) 3374 one_inheriting_sig (t, ctor, new_parms, i); 3375 new_parms[i++] = TREE_VALUE (parms); 3376 } 3377 one_inheriting_sig (t, ctor, new_parms, i); 3378 if (parms == NULL_TREE) 3379 { 3380 if (warning (OPT_Winherited_variadic_ctor, 3381 "the ellipsis in %qD is not inherited", ctor)) 3382 inform (DECL_SOURCE_LOCATION (ctor), "%qD declared here", ctor); 3383 } 3384 } 3385 3386 /* Create default constructors, assignment operators, and so forth for 3387 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR, 3388 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason, 3389 the class cannot have a default constructor, copy constructor 3390 taking a const reference argument, or an assignment operator taking 3391 a const reference, respectively. */ 3392 3393 static void 3394 add_implicitly_declared_members (tree t, tree* access_decls, 3395 int cant_have_const_cctor, 3396 int cant_have_const_assignment) 3397 { 3398 bool move_ok = false; 3399 3400 if (cxx_dialect >= cxx11 && !CLASSTYPE_DESTRUCTORS (t) 3401 && !TYPE_HAS_COPY_CTOR (t) && !TYPE_HAS_COPY_ASSIGN (t) 3402 && !type_has_move_constructor (t) && !type_has_move_assign (t)) 3403 move_ok = true; 3404 3405 /* Destructor. */ 3406 if (!CLASSTYPE_DESTRUCTORS (t)) 3407 /* In general, we create destructors lazily. */ 3408 CLASSTYPE_LAZY_DESTRUCTOR (t) = 1; 3409 3410 /* [class.ctor] 3411 3412 If there is no user-declared constructor for a class, a default 3413 constructor is implicitly declared. */ 3414 if (! TYPE_HAS_USER_CONSTRUCTOR (t)) 3415 { 3416 TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 1; 3417 CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 1; 3418 if (cxx_dialect >= cxx11) 3419 TYPE_HAS_CONSTEXPR_CTOR (t) 3420 /* Don't force the declaration to get a hard answer; if the 3421 definition would have made the class non-literal, it will still be 3422 non-literal because of the base or member in question, and that 3423 gives a better diagnostic. */ 3424 = type_maybe_constexpr_default_constructor (t); 3425 } 3426 3427 /* [class.ctor] 3428 3429 If a class definition does not explicitly declare a copy 3430 constructor, one is declared implicitly. */ 3431 if (! TYPE_HAS_COPY_CTOR (t)) 3432 { 3433 TYPE_HAS_COPY_CTOR (t) = 1; 3434 TYPE_HAS_CONST_COPY_CTOR (t) = !cant_have_const_cctor; 3435 CLASSTYPE_LAZY_COPY_CTOR (t) = 1; 3436 if (move_ok) 3437 CLASSTYPE_LAZY_MOVE_CTOR (t) = 1; 3438 } 3439 3440 /* If there is no assignment operator, one will be created if and 3441 when it is needed. For now, just record whether or not the type 3442 of the parameter to the assignment operator will be a const or 3443 non-const reference. */ 3444 if (!TYPE_HAS_COPY_ASSIGN (t)) 3445 { 3446 TYPE_HAS_COPY_ASSIGN (t) = 1; 3447 TYPE_HAS_CONST_COPY_ASSIGN (t) = !cant_have_const_assignment; 3448 CLASSTYPE_LAZY_COPY_ASSIGN (t) = 1; 3449 if (move_ok && !LAMBDA_TYPE_P (t)) 3450 CLASSTYPE_LAZY_MOVE_ASSIGN (t) = 1; 3451 } 3452 3453 /* We can't be lazy about declaring functions that might override 3454 a virtual function from a base class. */ 3455 declare_virt_assop_and_dtor (t); 3456 3457 while (*access_decls) 3458 { 3459 tree using_decl = TREE_VALUE (*access_decls); 3460 tree decl = USING_DECL_DECLS (using_decl); 3461 if (DECL_NAME (using_decl) == ctor_identifier) 3462 { 3463 /* declare, then remove the decl */ 3464 tree ctor_list = decl; 3465 location_t loc = input_location; 3466 input_location = DECL_SOURCE_LOCATION (using_decl); 3467 if (ctor_list) 3468 for (; ctor_list; ctor_list = OVL_NEXT (ctor_list)) 3469 one_inherited_ctor (OVL_CURRENT (ctor_list), t, using_decl); 3470 *access_decls = TREE_CHAIN (*access_decls); 3471 input_location = loc; 3472 } 3473 else 3474 access_decls = &TREE_CHAIN (*access_decls); 3475 } 3476 } 3477 3478 /* Subroutine of insert_into_classtype_sorted_fields. Recursively 3479 count the number of fields in TYPE, including anonymous union 3480 members. */ 3481 3482 static int 3483 count_fields (tree fields) 3484 { 3485 tree x; 3486 int n_fields = 0; 3487 for (x = fields; x; x = DECL_CHAIN (x)) 3488 { 3489 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x))) 3490 n_fields += count_fields (TYPE_FIELDS (TREE_TYPE (x))); 3491 else 3492 n_fields += 1; 3493 } 3494 return n_fields; 3495 } 3496 3497 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add 3498 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE 3499 elts, starting at offset IDX. */ 3500 3501 static int 3502 add_fields_to_record_type (tree fields, struct sorted_fields_type *field_vec, int idx) 3503 { 3504 tree x; 3505 for (x = fields; x; x = DECL_CHAIN (x)) 3506 { 3507 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x))) 3508 idx = add_fields_to_record_type (TYPE_FIELDS (TREE_TYPE (x)), field_vec, idx); 3509 else 3510 field_vec->elts[idx++] = x; 3511 } 3512 return idx; 3513 } 3514 3515 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts, 3516 starting at offset IDX. */ 3517 3518 static int 3519 add_enum_fields_to_record_type (tree enumtype, 3520 struct sorted_fields_type *field_vec, 3521 int idx) 3522 { 3523 tree values; 3524 for (values = TYPE_VALUES (enumtype); values; values = TREE_CHAIN (values)) 3525 field_vec->elts[idx++] = TREE_VALUE (values); 3526 return idx; 3527 } 3528 3529 /* FIELD is a bit-field. We are finishing the processing for its 3530 enclosing type. Issue any appropriate messages and set appropriate 3531 flags. Returns false if an error has been diagnosed. */ 3532 3533 static bool 3534 check_bitfield_decl (tree field) 3535 { 3536 tree type = TREE_TYPE (field); 3537 tree w; 3538 3539 /* Extract the declared width of the bitfield, which has been 3540 temporarily stashed in DECL_INITIAL. */ 3541 w = DECL_INITIAL (field); 3542 gcc_assert (w != NULL_TREE); 3543 /* Remove the bit-field width indicator so that the rest of the 3544 compiler does not treat that value as an initializer. */ 3545 DECL_INITIAL (field) = NULL_TREE; 3546 3547 /* Detect invalid bit-field type. */ 3548 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (type)) 3549 { 3550 error ("bit-field %q+#D with non-integral type", field); 3551 w = error_mark_node; 3552 } 3553 else 3554 { 3555 location_t loc = input_location; 3556 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */ 3557 STRIP_NOPS (w); 3558 3559 /* detect invalid field size. */ 3560 input_location = DECL_SOURCE_LOCATION (field); 3561 w = cxx_constant_value (w); 3562 input_location = loc; 3563 3564 if (TREE_CODE (w) != INTEGER_CST) 3565 { 3566 error ("bit-field %q+D width not an integer constant", field); 3567 w = error_mark_node; 3568 } 3569 else if (tree_int_cst_sgn (w) < 0) 3570 { 3571 error ("negative width in bit-field %q+D", field); 3572 w = error_mark_node; 3573 } 3574 else if (integer_zerop (w) && DECL_NAME (field) != 0) 3575 { 3576 error ("zero width for bit-field %q+D", field); 3577 w = error_mark_node; 3578 } 3579 else if ((TREE_CODE (type) != ENUMERAL_TYPE 3580 && TREE_CODE (type) != BOOLEAN_TYPE 3581 && compare_tree_int (w, TYPE_PRECISION (type)) > 0) 3582 || ((TREE_CODE (type) == ENUMERAL_TYPE 3583 || TREE_CODE (type) == BOOLEAN_TYPE) 3584 && tree_int_cst_lt (TYPE_SIZE (type), w))) 3585 warning_at (DECL_SOURCE_LOCATION (field), 0, 3586 "width of %qD exceeds its type", field); 3587 else if (TREE_CODE (type) == ENUMERAL_TYPE 3588 && (0 > (compare_tree_int 3589 (w, TYPE_PRECISION (ENUM_UNDERLYING_TYPE (type)))))) 3590 warning_at (DECL_SOURCE_LOCATION (field), 0, 3591 "%qD is too small to hold all values of %q#T", 3592 field, type); 3593 } 3594 3595 if (w != error_mark_node) 3596 { 3597 DECL_SIZE (field) = fold_convert (bitsizetype, w); 3598 DECL_BIT_FIELD (field) = 1; 3599 return true; 3600 } 3601 else 3602 { 3603 /* Non-bit-fields are aligned for their type. */ 3604 DECL_BIT_FIELD (field) = 0; 3605 CLEAR_DECL_C_BIT_FIELD (field); 3606 return false; 3607 } 3608 } 3609 3610 /* FIELD is a non bit-field. We are finishing the processing for its 3611 enclosing type T. Issue any appropriate messages and set appropriate 3612 flags. */ 3613 3614 static bool 3615 check_field_decl (tree field, 3616 tree t, 3617 int* cant_have_const_ctor, 3618 int* no_const_asn_ref) 3619 { 3620 tree type = strip_array_types (TREE_TYPE (field)); 3621 bool any_default_members = false; 3622 3623 /* In C++98 an anonymous union cannot contain any fields which would change 3624 the settings of CANT_HAVE_CONST_CTOR and friends. */ 3625 if (ANON_UNION_TYPE_P (type) && cxx_dialect < cxx11) 3626 ; 3627 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous 3628 structs. So, we recurse through their fields here. */ 3629 else if (ANON_AGGR_TYPE_P (type)) 3630 { 3631 for (tree fields = TYPE_FIELDS (type); fields; 3632 fields = DECL_CHAIN (fields)) 3633 if (TREE_CODE (fields) == FIELD_DECL && !DECL_C_BIT_FIELD (field)) 3634 any_default_members |= check_field_decl (fields, t, 3635 cant_have_const_ctor, 3636 no_const_asn_ref); 3637 } 3638 /* Check members with class type for constructors, destructors, 3639 etc. */ 3640 else if (CLASS_TYPE_P (type)) 3641 { 3642 /* Never let anything with uninheritable virtuals 3643 make it through without complaint. */ 3644 abstract_virtuals_error (field, type); 3645 3646 if (TREE_CODE (t) == UNION_TYPE && cxx_dialect < cxx11) 3647 { 3648 static bool warned; 3649 int oldcount = errorcount; 3650 if (TYPE_NEEDS_CONSTRUCTING (type)) 3651 error ("member %q+#D with constructor not allowed in union", 3652 field); 3653 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 3654 error ("member %q+#D with destructor not allowed in union", field); 3655 if (TYPE_HAS_COMPLEX_COPY_ASSIGN (type)) 3656 error ("member %q+#D with copy assignment operator not allowed in union", 3657 field); 3658 if (!warned && errorcount > oldcount) 3659 { 3660 inform (DECL_SOURCE_LOCATION (field), "unrestricted unions " 3661 "only available with -std=c++11 or -std=gnu++11"); 3662 warned = true; 3663 } 3664 } 3665 else 3666 { 3667 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (type); 3668 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) 3669 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type); 3670 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) 3671 |= (TYPE_HAS_COMPLEX_COPY_ASSIGN (type) 3672 || !TYPE_HAS_COPY_ASSIGN (type)); 3673 TYPE_HAS_COMPLEX_COPY_CTOR (t) |= (TYPE_HAS_COMPLEX_COPY_CTOR (type) 3674 || !TYPE_HAS_COPY_CTOR (type)); 3675 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) |= TYPE_HAS_COMPLEX_MOVE_ASSIGN (type); 3676 TYPE_HAS_COMPLEX_MOVE_CTOR (t) |= TYPE_HAS_COMPLEX_MOVE_CTOR (type); 3677 TYPE_HAS_COMPLEX_DFLT (t) |= (!TYPE_HAS_DEFAULT_CONSTRUCTOR (type) 3678 || TYPE_HAS_COMPLEX_DFLT (type)); 3679 } 3680 3681 if (TYPE_HAS_COPY_CTOR (type) 3682 && !TYPE_HAS_CONST_COPY_CTOR (type)) 3683 *cant_have_const_ctor = 1; 3684 3685 if (TYPE_HAS_COPY_ASSIGN (type) 3686 && !TYPE_HAS_CONST_COPY_ASSIGN (type)) 3687 *no_const_asn_ref = 1; 3688 } 3689 3690 check_abi_tags (t, field); 3691 3692 if (DECL_INITIAL (field) != NULL_TREE) 3693 /* `build_class_init_list' does not recognize 3694 non-FIELD_DECLs. */ 3695 any_default_members = true; 3696 3697 return any_default_members; 3698 } 3699 3700 /* Check the data members (both static and non-static), class-scoped 3701 typedefs, etc., appearing in the declaration of T. Issue 3702 appropriate diagnostics. Sets ACCESS_DECLS to a list (in 3703 declaration order) of access declarations; each TREE_VALUE in this 3704 list is a USING_DECL. 3705 3706 In addition, set the following flags: 3707 3708 EMPTY_P 3709 The class is empty, i.e., contains no non-static data members. 3710 3711 CANT_HAVE_CONST_CTOR_P 3712 This class cannot have an implicitly generated copy constructor 3713 taking a const reference. 3714 3715 CANT_HAVE_CONST_ASN_REF 3716 This class cannot have an implicitly generated assignment 3717 operator taking a const reference. 3718 3719 All of these flags should be initialized before calling this 3720 function. 3721 3722 Returns a pointer to the end of the TYPE_FIELDs chain; additional 3723 fields can be added by adding to this chain. */ 3724 3725 static void 3726 check_field_decls (tree t, tree *access_decls, 3727 int *cant_have_const_ctor_p, 3728 int *no_const_asn_ref_p) 3729 { 3730 tree *field; 3731 tree *next; 3732 bool has_pointers; 3733 bool any_default_members; 3734 int cant_pack = 0; 3735 int field_access = -1; 3736 3737 /* Assume there are no access declarations. */ 3738 *access_decls = NULL_TREE; 3739 /* Assume this class has no pointer members. */ 3740 has_pointers = false; 3741 /* Assume none of the members of this class have default 3742 initializations. */ 3743 any_default_members = false; 3744 3745 for (field = &TYPE_FIELDS (t); *field; field = next) 3746 { 3747 tree x = *field; 3748 tree type = TREE_TYPE (x); 3749 int this_field_access; 3750 3751 next = &DECL_CHAIN (x); 3752 3753 if (TREE_CODE (x) == USING_DECL) 3754 { 3755 /* Save the access declarations for our caller. */ 3756 *access_decls = tree_cons (NULL_TREE, x, *access_decls); 3757 continue; 3758 } 3759 3760 if (TREE_CODE (x) == TYPE_DECL 3761 || TREE_CODE (x) == TEMPLATE_DECL) 3762 continue; 3763 3764 /* If we've gotten this far, it's a data member, possibly static, 3765 or an enumerator. */ 3766 if (TREE_CODE (x) != CONST_DECL) 3767 DECL_CONTEXT (x) = t; 3768 3769 /* When this goes into scope, it will be a non-local reference. */ 3770 DECL_NONLOCAL (x) = 1; 3771 3772 if (TREE_CODE (t) == UNION_TYPE) 3773 { 3774 /* [class.union] (C++98) 3775 3776 If a union contains a static data member, or a member of 3777 reference type, the program is ill-formed. 3778 3779 In C++11 [class.union] says: 3780 If a union contains a non-static data member of reference type 3781 the program is ill-formed. */ 3782 if (VAR_P (x) && cxx_dialect < cxx11) 3783 { 3784 error ("in C++98 %q+D may not be static because it is " 3785 "a member of a union", x); 3786 continue; 3787 } 3788 if (TREE_CODE (type) == REFERENCE_TYPE 3789 && TREE_CODE (x) == FIELD_DECL) 3790 { 3791 error ("non-static data member %q+D in a union may not " 3792 "have reference type %qT", x, type); 3793 continue; 3794 } 3795 } 3796 3797 /* Perform error checking that did not get done in 3798 grokdeclarator. */ 3799 if (TREE_CODE (type) == FUNCTION_TYPE) 3800 { 3801 error ("field %q+D invalidly declared function type", x); 3802 type = build_pointer_type (type); 3803 TREE_TYPE (x) = type; 3804 } 3805 else if (TREE_CODE (type) == METHOD_TYPE) 3806 { 3807 error ("field %q+D invalidly declared method type", x); 3808 type = build_pointer_type (type); 3809 TREE_TYPE (x) = type; 3810 } 3811 3812 if (type == error_mark_node) 3813 continue; 3814 3815 if (TREE_CODE (x) == CONST_DECL || VAR_P (x)) 3816 continue; 3817 3818 /* Now it can only be a FIELD_DECL. */ 3819 3820 if (TREE_PRIVATE (x) || TREE_PROTECTED (x)) 3821 CLASSTYPE_NON_AGGREGATE (t) = 1; 3822 3823 /* If at least one non-static data member is non-literal, the whole 3824 class becomes non-literal. Per Core/1453, volatile non-static 3825 data members and base classes are also not allowed. 3826 Note: if the type is incomplete we will complain later on. */ 3827 if (COMPLETE_TYPE_P (type) 3828 && (!literal_type_p (type) || CP_TYPE_VOLATILE_P (type))) 3829 CLASSTYPE_LITERAL_P (t) = false; 3830 3831 /* A standard-layout class is a class that: 3832 ... 3833 has the same access control (Clause 11) for all non-static data members, 3834 ... */ 3835 this_field_access = TREE_PROTECTED (x) ? 1 : TREE_PRIVATE (x) ? 2 : 0; 3836 if (field_access == -1) 3837 field_access = this_field_access; 3838 else if (this_field_access != field_access) 3839 CLASSTYPE_NON_STD_LAYOUT (t) = 1; 3840 3841 /* If this is of reference type, check if it needs an init. */ 3842 if (TREE_CODE (type) == REFERENCE_TYPE) 3843 { 3844 CLASSTYPE_NON_LAYOUT_POD_P (t) = 1; 3845 CLASSTYPE_NON_STD_LAYOUT (t) = 1; 3846 if (DECL_INITIAL (x) == NULL_TREE) 3847 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1); 3848 if (cxx_dialect < cxx11) 3849 { 3850 /* ARM $12.6.2: [A member initializer list] (or, for an 3851 aggregate, initialization by a brace-enclosed list) is the 3852 only way to initialize nonstatic const and reference 3853 members. */ 3854 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) = 1; 3855 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) = 1; 3856 } 3857 } 3858 3859 type = strip_array_types (type); 3860 3861 if (TYPE_PACKED (t)) 3862 { 3863 if (!layout_pod_type_p (type) && !TYPE_PACKED (type)) 3864 { 3865 warning_at 3866 (DECL_SOURCE_LOCATION (x), 0, 3867 "ignoring packed attribute because of unpacked non-POD field %q#D", 3868 x); 3869 cant_pack = 1; 3870 } 3871 else if (DECL_C_BIT_FIELD (x) 3872 || TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT) 3873 DECL_PACKED (x) = 1; 3874 } 3875 3876 if (DECL_C_BIT_FIELD (x) && integer_zerop (DECL_INITIAL (x))) 3877 /* We don't treat zero-width bitfields as making a class 3878 non-empty. */ 3879 ; 3880 else 3881 { 3882 /* The class is non-empty. */ 3883 CLASSTYPE_EMPTY_P (t) = 0; 3884 /* The class is not even nearly empty. */ 3885 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 3886 /* If one of the data members contains an empty class, 3887 so does T. */ 3888 if (CLASS_TYPE_P (type) 3889 && CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type)) 3890 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1; 3891 } 3892 3893 /* This is used by -Weffc++ (see below). Warn only for pointers 3894 to members which might hold dynamic memory. So do not warn 3895 for pointers to functions or pointers to members. */ 3896 if (TYPE_PTR_P (type) 3897 && !TYPE_PTRFN_P (type)) 3898 has_pointers = true; 3899 3900 if (CLASS_TYPE_P (type)) 3901 { 3902 if (CLASSTYPE_REF_FIELDS_NEED_INIT (type)) 3903 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1); 3904 if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (type)) 3905 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1); 3906 } 3907 3908 if (DECL_MUTABLE_P (x) || TYPE_HAS_MUTABLE_P (type)) 3909 CLASSTYPE_HAS_MUTABLE (t) = 1; 3910 3911 if (DECL_MUTABLE_P (x)) 3912 { 3913 if (CP_TYPE_CONST_P (type)) 3914 { 3915 error ("member %q+D cannot be declared both %<const%> " 3916 "and %<mutable%>", x); 3917 continue; 3918 } 3919 if (TREE_CODE (type) == REFERENCE_TYPE) 3920 { 3921 error ("member %q+D cannot be declared as a %<mutable%> " 3922 "reference", x); 3923 continue; 3924 } 3925 } 3926 3927 if (! layout_pod_type_p (type)) 3928 /* DR 148 now allows pointers to members (which are POD themselves), 3929 to be allowed in POD structs. */ 3930 CLASSTYPE_NON_LAYOUT_POD_P (t) = 1; 3931 3932 if (!std_layout_type_p (type)) 3933 CLASSTYPE_NON_STD_LAYOUT (t) = 1; 3934 3935 if (! zero_init_p (type)) 3936 CLASSTYPE_NON_ZERO_INIT_P (t) = 1; 3937 3938 /* We set DECL_C_BIT_FIELD in grokbitfield. 3939 If the type and width are valid, we'll also set DECL_BIT_FIELD. */ 3940 if ((! DECL_C_BIT_FIELD (x) || ! check_bitfield_decl (x)) 3941 && check_field_decl (x, t, 3942 cant_have_const_ctor_p, 3943 no_const_asn_ref_p)) 3944 { 3945 if (any_default_members 3946 && TREE_CODE (t) == UNION_TYPE) 3947 error ("multiple fields in union %qT initialized", t); 3948 any_default_members = true; 3949 } 3950 3951 /* Now that we've removed bit-field widths from DECL_INITIAL, 3952 anything left in DECL_INITIAL is an NSDMI that makes the class 3953 non-aggregate in C++11. */ 3954 if (DECL_INITIAL (x) && cxx_dialect < cxx14) 3955 CLASSTYPE_NON_AGGREGATE (t) = true; 3956 3957 /* If any field is const, the structure type is pseudo-const. */ 3958 if (CP_TYPE_CONST_P (type)) 3959 { 3960 C_TYPE_FIELDS_READONLY (t) = 1; 3961 if (DECL_INITIAL (x) == NULL_TREE) 3962 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1); 3963 if (cxx_dialect < cxx11) 3964 { 3965 /* ARM $12.6.2: [A member initializer list] (or, for an 3966 aggregate, initialization by a brace-enclosed list) is the 3967 only way to initialize nonstatic const and reference 3968 members. */ 3969 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) = 1; 3970 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) = 1; 3971 } 3972 } 3973 /* A field that is pseudo-const makes the structure likewise. */ 3974 else if (CLASS_TYPE_P (type)) 3975 { 3976 C_TYPE_FIELDS_READONLY (t) |= C_TYPE_FIELDS_READONLY (type); 3977 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 3978 CLASSTYPE_READONLY_FIELDS_NEED_INIT (t) 3979 | CLASSTYPE_READONLY_FIELDS_NEED_INIT (type)); 3980 } 3981 3982 /* Core issue 80: A nonstatic data member is required to have a 3983 different name from the class iff the class has a 3984 user-declared constructor. */ 3985 if (constructor_name_p (DECL_NAME (x), t) 3986 && TYPE_HAS_USER_CONSTRUCTOR (t)) 3987 permerror (DECL_SOURCE_LOCATION (x), 3988 "field %q#D with same name as class", x); 3989 } 3990 3991 /* Effective C++ rule 11: if a class has dynamic memory held by pointers, 3992 it should also define a copy constructor and an assignment operator to 3993 implement the correct copy semantic (deep vs shallow, etc.). As it is 3994 not feasible to check whether the constructors do allocate dynamic memory 3995 and store it within members, we approximate the warning like this: 3996 3997 -- Warn only if there are members which are pointers 3998 -- Warn only if there is a non-trivial constructor (otherwise, 3999 there cannot be memory allocated). 4000 -- Warn only if there is a non-trivial destructor. We assume that the 4001 user at least implemented the cleanup correctly, and a destructor 4002 is needed to free dynamic memory. 4003 4004 This seems enough for practical purposes. */ 4005 if (warn_ecpp 4006 && has_pointers 4007 && TYPE_HAS_USER_CONSTRUCTOR (t) 4008 && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) 4009 && !(TYPE_HAS_COPY_CTOR (t) && TYPE_HAS_COPY_ASSIGN (t))) 4010 { 4011 warning (OPT_Weffc__, "%q#T has pointer data members", t); 4012 4013 if (! TYPE_HAS_COPY_CTOR (t)) 4014 { 4015 warning (OPT_Weffc__, 4016 " but does not override %<%T(const %T&)%>", t, t); 4017 if (!TYPE_HAS_COPY_ASSIGN (t)) 4018 warning (OPT_Weffc__, " or %<operator=(const %T&)%>", t); 4019 } 4020 else if (! TYPE_HAS_COPY_ASSIGN (t)) 4021 warning (OPT_Weffc__, 4022 " but does not override %<operator=(const %T&)%>", t); 4023 } 4024 4025 /* Non-static data member initializers make the default constructor 4026 non-trivial. */ 4027 if (any_default_members) 4028 { 4029 TYPE_NEEDS_CONSTRUCTING (t) = true; 4030 TYPE_HAS_COMPLEX_DFLT (t) = true; 4031 } 4032 4033 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */ 4034 if (cant_pack) 4035 TYPE_PACKED (t) = 0; 4036 4037 /* Check anonymous struct/anonymous union fields. */ 4038 finish_struct_anon (t); 4039 4040 /* We've built up the list of access declarations in reverse order. 4041 Fix that now. */ 4042 *access_decls = nreverse (*access_decls); 4043 } 4044 4045 /* If TYPE is an empty class type, records its OFFSET in the table of 4046 OFFSETS. */ 4047 4048 static int 4049 record_subobject_offset (tree type, tree offset, splay_tree offsets) 4050 { 4051 splay_tree_node n; 4052 4053 if (!is_empty_class (type)) 4054 return 0; 4055 4056 /* Record the location of this empty object in OFFSETS. */ 4057 n = splay_tree_lookup (offsets, (splay_tree_key) offset); 4058 if (!n) 4059 n = splay_tree_insert (offsets, 4060 (splay_tree_key) offset, 4061 (splay_tree_value) NULL_TREE); 4062 n->value = ((splay_tree_value) 4063 tree_cons (NULL_TREE, 4064 type, 4065 (tree) n->value)); 4066 4067 return 0; 4068 } 4069 4070 /* Returns nonzero if TYPE is an empty class type and there is 4071 already an entry in OFFSETS for the same TYPE as the same OFFSET. */ 4072 4073 static int 4074 check_subobject_offset (tree type, tree offset, splay_tree offsets) 4075 { 4076 splay_tree_node n; 4077 tree t; 4078 4079 if (!is_empty_class (type)) 4080 return 0; 4081 4082 /* Record the location of this empty object in OFFSETS. */ 4083 n = splay_tree_lookup (offsets, (splay_tree_key) offset); 4084 if (!n) 4085 return 0; 4086 4087 for (t = (tree) n->value; t; t = TREE_CHAIN (t)) 4088 if (same_type_p (TREE_VALUE (t), type)) 4089 return 1; 4090 4091 return 0; 4092 } 4093 4094 /* Walk through all the subobjects of TYPE (located at OFFSET). Call 4095 F for every subobject, passing it the type, offset, and table of 4096 OFFSETS. If VBASES_P is one, then virtual non-primary bases should 4097 be traversed. 4098 4099 If MAX_OFFSET is non-NULL, then subobjects with an offset greater 4100 than MAX_OFFSET will not be walked. 4101 4102 If F returns a nonzero value, the traversal ceases, and that value 4103 is returned. Otherwise, returns zero. */ 4104 4105 static int 4106 walk_subobject_offsets (tree type, 4107 subobject_offset_fn f, 4108 tree offset, 4109 splay_tree offsets, 4110 tree max_offset, 4111 int vbases_p) 4112 { 4113 int r = 0; 4114 tree type_binfo = NULL_TREE; 4115 4116 /* If this OFFSET is bigger than the MAX_OFFSET, then we should 4117 stop. */ 4118 if (max_offset && tree_int_cst_lt (max_offset, offset)) 4119 return 0; 4120 4121 if (type == error_mark_node) 4122 return 0; 4123 4124 if (!TYPE_P (type)) 4125 { 4126 type_binfo = type; 4127 type = BINFO_TYPE (type); 4128 } 4129 4130 if (CLASS_TYPE_P (type)) 4131 { 4132 tree field; 4133 tree binfo; 4134 int i; 4135 4136 /* Avoid recursing into objects that are not interesting. */ 4137 if (!CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type)) 4138 return 0; 4139 4140 /* Record the location of TYPE. */ 4141 r = (*f) (type, offset, offsets); 4142 if (r) 4143 return r; 4144 4145 /* Iterate through the direct base classes of TYPE. */ 4146 if (!type_binfo) 4147 type_binfo = TYPE_BINFO (type); 4148 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, binfo); i++) 4149 { 4150 tree binfo_offset; 4151 4152 if (BINFO_VIRTUAL_P (binfo)) 4153 continue; 4154 4155 tree orig_binfo; 4156 /* We cannot rely on BINFO_OFFSET being set for the base 4157 class yet, but the offsets for direct non-virtual 4158 bases can be calculated by going back to the TYPE. */ 4159 orig_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), i); 4160 binfo_offset = size_binop (PLUS_EXPR, 4161 offset, 4162 BINFO_OFFSET (orig_binfo)); 4163 4164 r = walk_subobject_offsets (binfo, 4165 f, 4166 binfo_offset, 4167 offsets, 4168 max_offset, 4169 /*vbases_p=*/0); 4170 if (r) 4171 return r; 4172 } 4173 4174 if (CLASSTYPE_VBASECLASSES (type)) 4175 { 4176 unsigned ix; 4177 vec<tree, va_gc> *vbases; 4178 4179 /* Iterate through the virtual base classes of TYPE. In G++ 4180 3.2, we included virtual bases in the direct base class 4181 loop above, which results in incorrect results; the 4182 correct offsets for virtual bases are only known when 4183 working with the most derived type. */ 4184 if (vbases_p) 4185 for (vbases = CLASSTYPE_VBASECLASSES (type), ix = 0; 4186 vec_safe_iterate (vbases, ix, &binfo); ix++) 4187 { 4188 r = walk_subobject_offsets (binfo, 4189 f, 4190 size_binop (PLUS_EXPR, 4191 offset, 4192 BINFO_OFFSET (binfo)), 4193 offsets, 4194 max_offset, 4195 /*vbases_p=*/0); 4196 if (r) 4197 return r; 4198 } 4199 else 4200 { 4201 /* We still have to walk the primary base, if it is 4202 virtual. (If it is non-virtual, then it was walked 4203 above.) */ 4204 tree vbase = get_primary_binfo (type_binfo); 4205 4206 if (vbase && BINFO_VIRTUAL_P (vbase) 4207 && BINFO_PRIMARY_P (vbase) 4208 && BINFO_INHERITANCE_CHAIN (vbase) == type_binfo) 4209 { 4210 r = (walk_subobject_offsets 4211 (vbase, f, offset, 4212 offsets, max_offset, /*vbases_p=*/0)); 4213 if (r) 4214 return r; 4215 } 4216 } 4217 } 4218 4219 /* Iterate through the fields of TYPE. */ 4220 for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) 4221 if (TREE_CODE (field) == FIELD_DECL 4222 && TREE_TYPE (field) != error_mark_node 4223 && !DECL_ARTIFICIAL (field)) 4224 { 4225 tree field_offset; 4226 4227 field_offset = byte_position (field); 4228 4229 r = walk_subobject_offsets (TREE_TYPE (field), 4230 f, 4231 size_binop (PLUS_EXPR, 4232 offset, 4233 field_offset), 4234 offsets, 4235 max_offset, 4236 /*vbases_p=*/1); 4237 if (r) 4238 return r; 4239 } 4240 } 4241 else if (TREE_CODE (type) == ARRAY_TYPE) 4242 { 4243 tree element_type = strip_array_types (type); 4244 tree domain = TYPE_DOMAIN (type); 4245 tree index; 4246 4247 /* Avoid recursing into objects that are not interesting. */ 4248 if (!CLASS_TYPE_P (element_type) 4249 || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type) 4250 || !domain 4251 || integer_minus_onep (TYPE_MAX_VALUE (domain))) 4252 return 0; 4253 4254 /* Step through each of the elements in the array. */ 4255 for (index = size_zero_node; 4256 !tree_int_cst_lt (TYPE_MAX_VALUE (domain), index); 4257 index = size_binop (PLUS_EXPR, index, size_one_node)) 4258 { 4259 r = walk_subobject_offsets (TREE_TYPE (type), 4260 f, 4261 offset, 4262 offsets, 4263 max_offset, 4264 /*vbases_p=*/1); 4265 if (r) 4266 return r; 4267 offset = size_binop (PLUS_EXPR, offset, 4268 TYPE_SIZE_UNIT (TREE_TYPE (type))); 4269 /* If this new OFFSET is bigger than the MAX_OFFSET, then 4270 there's no point in iterating through the remaining 4271 elements of the array. */ 4272 if (max_offset && tree_int_cst_lt (max_offset, offset)) 4273 break; 4274 } 4275 } 4276 4277 return 0; 4278 } 4279 4280 /* Record all of the empty subobjects of TYPE (either a type or a 4281 binfo). If IS_DATA_MEMBER is true, then a non-static data member 4282 is being placed at OFFSET; otherwise, it is a base class that is 4283 being placed at OFFSET. */ 4284 4285 static void 4286 record_subobject_offsets (tree type, 4287 tree offset, 4288 splay_tree offsets, 4289 bool is_data_member) 4290 { 4291 tree max_offset; 4292 /* If recording subobjects for a non-static data member or a 4293 non-empty base class , we do not need to record offsets beyond 4294 the size of the biggest empty class. Additional data members 4295 will go at the end of the class. Additional base classes will go 4296 either at offset zero (if empty, in which case they cannot 4297 overlap with offsets past the size of the biggest empty class) or 4298 at the end of the class. 4299 4300 However, if we are placing an empty base class, then we must record 4301 all offsets, as either the empty class is at offset zero (where 4302 other empty classes might later be placed) or at the end of the 4303 class (where other objects might then be placed, so other empty 4304 subobjects might later overlap). */ 4305 if (is_data_member 4306 || !is_empty_class (BINFO_TYPE (type))) 4307 max_offset = sizeof_biggest_empty_class; 4308 else 4309 max_offset = NULL_TREE; 4310 walk_subobject_offsets (type, record_subobject_offset, offset, 4311 offsets, max_offset, is_data_member); 4312 } 4313 4314 /* Returns nonzero if any of the empty subobjects of TYPE (located at 4315 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero, 4316 virtual bases of TYPE are examined. */ 4317 4318 static int 4319 layout_conflict_p (tree type, 4320 tree offset, 4321 splay_tree offsets, 4322 int vbases_p) 4323 { 4324 splay_tree_node max_node; 4325 4326 /* Get the node in OFFSETS that indicates the maximum offset where 4327 an empty subobject is located. */ 4328 max_node = splay_tree_max (offsets); 4329 /* If there aren't any empty subobjects, then there's no point in 4330 performing this check. */ 4331 if (!max_node) 4332 return 0; 4333 4334 return walk_subobject_offsets (type, check_subobject_offset, offset, 4335 offsets, (tree) (max_node->key), 4336 vbases_p); 4337 } 4338 4339 /* DECL is a FIELD_DECL corresponding either to a base subobject of a 4340 non-static data member of the type indicated by RLI. BINFO is the 4341 binfo corresponding to the base subobject, OFFSETS maps offsets to 4342 types already located at those offsets. This function determines 4343 the position of the DECL. */ 4344 4345 static void 4346 layout_nonempty_base_or_field (record_layout_info rli, 4347 tree decl, 4348 tree binfo, 4349 splay_tree offsets) 4350 { 4351 tree offset = NULL_TREE; 4352 bool field_p; 4353 tree type; 4354 4355 if (binfo) 4356 { 4357 /* For the purposes of determining layout conflicts, we want to 4358 use the class type of BINFO; TREE_TYPE (DECL) will be the 4359 CLASSTYPE_AS_BASE version, which does not contain entries for 4360 zero-sized bases. */ 4361 type = TREE_TYPE (binfo); 4362 field_p = false; 4363 } 4364 else 4365 { 4366 type = TREE_TYPE (decl); 4367 field_p = true; 4368 } 4369 4370 /* Try to place the field. It may take more than one try if we have 4371 a hard time placing the field without putting two objects of the 4372 same type at the same address. */ 4373 while (1) 4374 { 4375 struct record_layout_info_s old_rli = *rli; 4376 4377 /* Place this field. */ 4378 place_field (rli, decl); 4379 offset = byte_position (decl); 4380 4381 /* We have to check to see whether or not there is already 4382 something of the same type at the offset we're about to use. 4383 For example, consider: 4384 4385 struct S {}; 4386 struct T : public S { int i; }; 4387 struct U : public S, public T {}; 4388 4389 Here, we put S at offset zero in U. Then, we can't put T at 4390 offset zero -- its S component would be at the same address 4391 as the S we already allocated. So, we have to skip ahead. 4392 Since all data members, including those whose type is an 4393 empty class, have nonzero size, any overlap can happen only 4394 with a direct or indirect base-class -- it can't happen with 4395 a data member. */ 4396 /* In a union, overlap is permitted; all members are placed at 4397 offset zero. */ 4398 if (TREE_CODE (rli->t) == UNION_TYPE) 4399 break; 4400 if (layout_conflict_p (field_p ? type : binfo, offset, 4401 offsets, field_p)) 4402 { 4403 /* Strip off the size allocated to this field. That puts us 4404 at the first place we could have put the field with 4405 proper alignment. */ 4406 *rli = old_rli; 4407 4408 /* Bump up by the alignment required for the type. */ 4409 rli->bitpos 4410 = size_binop (PLUS_EXPR, rli->bitpos, 4411 bitsize_int (binfo 4412 ? CLASSTYPE_ALIGN (type) 4413 : TYPE_ALIGN (type))); 4414 normalize_rli (rli); 4415 } 4416 else if (TREE_CODE (type) == NULLPTR_TYPE 4417 && warn_abi && abi_version_crosses (9)) 4418 { 4419 /* Before ABI v9, we were giving nullptr_t alignment of 1; if 4420 the offset wasn't aligned like a pointer when we started to 4421 layout this field, that affects its position. */ 4422 tree pos = rli_size_unit_so_far (&old_rli); 4423 if (int_cst_value (pos) % TYPE_ALIGN_UNIT (ptr_type_node) != 0) 4424 { 4425 if (abi_version_at_least (9)) 4426 warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wabi, 4427 "alignment of %qD increased in -fabi-version=9 " 4428 "(GCC 5.2)", decl); 4429 else 4430 warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wabi, "alignment " 4431 "of %qD will increase in -fabi-version=9", decl); 4432 } 4433 break; 4434 } 4435 else 4436 /* There was no conflict. We're done laying out this field. */ 4437 break; 4438 } 4439 4440 /* Now that we know where it will be placed, update its 4441 BINFO_OFFSET. */ 4442 if (binfo && CLASS_TYPE_P (BINFO_TYPE (binfo))) 4443 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at 4444 this point because their BINFO_OFFSET is copied from another 4445 hierarchy. Therefore, we may not need to add the entire 4446 OFFSET. */ 4447 propagate_binfo_offsets (binfo, 4448 size_diffop_loc (input_location, 4449 fold_convert (ssizetype, offset), 4450 fold_convert (ssizetype, 4451 BINFO_OFFSET (binfo)))); 4452 } 4453 4454 /* Returns true if TYPE is empty and OFFSET is nonzero. */ 4455 4456 static int 4457 empty_base_at_nonzero_offset_p (tree type, 4458 tree offset, 4459 splay_tree /*offsets*/) 4460 { 4461 return is_empty_class (type) && !integer_zerop (offset); 4462 } 4463 4464 /* Layout the empty base BINFO. EOC indicates the byte currently just 4465 past the end of the class, and should be correctly aligned for a 4466 class of the type indicated by BINFO; OFFSETS gives the offsets of 4467 the empty bases allocated so far. T is the most derived 4468 type. Return nonzero iff we added it at the end. */ 4469 4470 static bool 4471 layout_empty_base (record_layout_info rli, tree binfo, 4472 tree eoc, splay_tree offsets) 4473 { 4474 tree alignment; 4475 tree basetype = BINFO_TYPE (binfo); 4476 bool atend = false; 4477 4478 /* This routine should only be used for empty classes. */ 4479 gcc_assert (is_empty_class (basetype)); 4480 alignment = ssize_int (CLASSTYPE_ALIGN_UNIT (basetype)); 4481 4482 if (!integer_zerop (BINFO_OFFSET (binfo))) 4483 propagate_binfo_offsets 4484 (binfo, size_diffop_loc (input_location, 4485 size_zero_node, BINFO_OFFSET (binfo))); 4486 4487 /* This is an empty base class. We first try to put it at offset 4488 zero. */ 4489 if (layout_conflict_p (binfo, 4490 BINFO_OFFSET (binfo), 4491 offsets, 4492 /*vbases_p=*/0)) 4493 { 4494 /* That didn't work. Now, we move forward from the next 4495 available spot in the class. */ 4496 atend = true; 4497 propagate_binfo_offsets (binfo, fold_convert (ssizetype, eoc)); 4498 while (1) 4499 { 4500 if (!layout_conflict_p (binfo, 4501 BINFO_OFFSET (binfo), 4502 offsets, 4503 /*vbases_p=*/0)) 4504 /* We finally found a spot where there's no overlap. */ 4505 break; 4506 4507 /* There's overlap here, too. Bump along to the next spot. */ 4508 propagate_binfo_offsets (binfo, alignment); 4509 } 4510 } 4511 4512 if (CLASSTYPE_USER_ALIGN (basetype)) 4513 { 4514 rli->record_align = MAX (rli->record_align, CLASSTYPE_ALIGN (basetype)); 4515 if (warn_packed) 4516 rli->unpacked_align = MAX (rli->unpacked_align, CLASSTYPE_ALIGN (basetype)); 4517 TYPE_USER_ALIGN (rli->t) = 1; 4518 } 4519 4520 return atend; 4521 } 4522 4523 /* Build the FIELD_DECL for BASETYPE as a base of T, add it to the chain of 4524 fields at NEXT_FIELD, and return it. */ 4525 4526 static tree 4527 build_base_field_1 (tree t, tree basetype, tree *&next_field) 4528 { 4529 /* Create the FIELD_DECL. */ 4530 gcc_assert (CLASSTYPE_AS_BASE (basetype)); 4531 tree decl = build_decl (input_location, 4532 FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype)); 4533 DECL_ARTIFICIAL (decl) = 1; 4534 DECL_IGNORED_P (decl) = 1; 4535 DECL_FIELD_CONTEXT (decl) = t; 4536 if (is_empty_class (basetype)) 4537 /* CLASSTYPE_SIZE is one byte, but the field needs to have size zero. */ 4538 DECL_SIZE (decl) = DECL_SIZE_UNIT (decl) = size_zero_node; 4539 else 4540 { 4541 DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype); 4542 DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype); 4543 } 4544 SET_DECL_ALIGN (decl, CLASSTYPE_ALIGN (basetype)); 4545 DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype); 4546 SET_DECL_MODE (decl, TYPE_MODE (basetype)); 4547 DECL_FIELD_IS_BASE (decl) = 1; 4548 4549 /* Add the new FIELD_DECL to the list of fields for T. */ 4550 DECL_CHAIN (decl) = *next_field; 4551 *next_field = decl; 4552 next_field = &DECL_CHAIN (decl); 4553 4554 return decl; 4555 } 4556 4557 /* Layout the base given by BINFO in the class indicated by RLI. 4558 *BASE_ALIGN is a running maximum of the alignments of 4559 any base class. OFFSETS gives the location of empty base 4560 subobjects. T is the most derived type. Return nonzero if the new 4561 object cannot be nearly-empty. A new FIELD_DECL is inserted at 4562 *NEXT_FIELD, unless BINFO is for an empty base class. 4563 4564 Returns the location at which the next field should be inserted. */ 4565 4566 static tree * 4567 build_base_field (record_layout_info rli, tree binfo, 4568 splay_tree offsets, tree *next_field) 4569 { 4570 tree t = rli->t; 4571 tree basetype = BINFO_TYPE (binfo); 4572 4573 if (!COMPLETE_TYPE_P (basetype)) 4574 /* This error is now reported in xref_tag, thus giving better 4575 location information. */ 4576 return next_field; 4577 4578 /* Place the base class. */ 4579 if (!is_empty_class (basetype)) 4580 { 4581 tree decl; 4582 4583 /* The containing class is non-empty because it has a non-empty 4584 base class. */ 4585 CLASSTYPE_EMPTY_P (t) = 0; 4586 4587 /* Create the FIELD_DECL. */ 4588 decl = build_base_field_1 (t, basetype, next_field); 4589 4590 /* Try to place the field. It may take more than one try if we 4591 have a hard time placing the field without putting two 4592 objects of the same type at the same address. */ 4593 layout_nonempty_base_or_field (rli, decl, binfo, offsets); 4594 } 4595 else 4596 { 4597 tree eoc; 4598 bool atend; 4599 4600 /* On some platforms (ARM), even empty classes will not be 4601 byte-aligned. */ 4602 eoc = round_up_loc (input_location, 4603 rli_size_unit_so_far (rli), 4604 CLASSTYPE_ALIGN_UNIT (basetype)); 4605 atend = layout_empty_base (rli, binfo, eoc, offsets); 4606 /* A nearly-empty class "has no proper base class that is empty, 4607 not morally virtual, and at an offset other than zero." */ 4608 if (!BINFO_VIRTUAL_P (binfo) && CLASSTYPE_NEARLY_EMPTY_P (t)) 4609 { 4610 if (atend) 4611 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 4612 /* The check above (used in G++ 3.2) is insufficient because 4613 an empty class placed at offset zero might itself have an 4614 empty base at a nonzero offset. */ 4615 else if (walk_subobject_offsets (basetype, 4616 empty_base_at_nonzero_offset_p, 4617 size_zero_node, 4618 /*offsets=*/NULL, 4619 /*max_offset=*/NULL_TREE, 4620 /*vbases_p=*/true)) 4621 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 4622 } 4623 4624 /* We used to not create a FIELD_DECL for empty base classes because of 4625 back end issues with overlapping FIELD_DECLs, but that doesn't seem to 4626 be a problem anymore. We need them to handle initialization of C++17 4627 aggregate bases. */ 4628 if (cxx_dialect >= cxx1z && !BINFO_VIRTUAL_P (binfo)) 4629 { 4630 tree decl = build_base_field_1 (t, basetype, next_field); 4631 DECL_FIELD_OFFSET (decl) = BINFO_OFFSET (binfo); 4632 DECL_FIELD_BIT_OFFSET (decl) = bitsize_zero_node; 4633 SET_DECL_OFFSET_ALIGN (decl, BITS_PER_UNIT); 4634 } 4635 4636 /* An empty virtual base causes a class to be non-empty 4637 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P 4638 here because that was already done when the virtual table 4639 pointer was created. */ 4640 } 4641 4642 /* Record the offsets of BINFO and its base subobjects. */ 4643 record_subobject_offsets (binfo, 4644 BINFO_OFFSET (binfo), 4645 offsets, 4646 /*is_data_member=*/false); 4647 4648 return next_field; 4649 } 4650 4651 /* Layout all of the non-virtual base classes. Record empty 4652 subobjects in OFFSETS. T is the most derived type. Return nonzero 4653 if the type cannot be nearly empty. The fields created 4654 corresponding to the base classes will be inserted at 4655 *NEXT_FIELD. */ 4656 4657 static void 4658 build_base_fields (record_layout_info rli, 4659 splay_tree offsets, tree *next_field) 4660 { 4661 /* Chain to hold all the new FIELD_DECLs which stand in for base class 4662 subobjects. */ 4663 tree t = rli->t; 4664 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t)); 4665 int i; 4666 4667 /* The primary base class is always allocated first. */ 4668 if (CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 4669 next_field = build_base_field (rli, CLASSTYPE_PRIMARY_BINFO (t), 4670 offsets, next_field); 4671 4672 /* Now allocate the rest of the bases. */ 4673 for (i = 0; i < n_baseclasses; ++i) 4674 { 4675 tree base_binfo; 4676 4677 base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i); 4678 4679 /* The primary base was already allocated above, so we don't 4680 need to allocate it again here. */ 4681 if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t)) 4682 continue; 4683 4684 /* Virtual bases are added at the end (a primary virtual base 4685 will have already been added). */ 4686 if (BINFO_VIRTUAL_P (base_binfo)) 4687 continue; 4688 4689 next_field = build_base_field (rli, base_binfo, 4690 offsets, next_field); 4691 } 4692 } 4693 4694 /* Go through the TYPE_METHODS of T issuing any appropriate 4695 diagnostics, figuring out which methods override which other 4696 methods, and so forth. */ 4697 4698 static void 4699 check_methods (tree t) 4700 { 4701 tree x; 4702 4703 for (x = TYPE_METHODS (t); x; x = DECL_CHAIN (x)) 4704 { 4705 check_for_override (x, t); 4706 if (DECL_PURE_VIRTUAL_P (x) && (TREE_CODE (x) != FUNCTION_DECL || ! DECL_VINDEX (x))) 4707 error ("initializer specified for non-virtual method %q+D", x); 4708 /* The name of the field is the original field name 4709 Save this in auxiliary field for later overloading. */ 4710 if (TREE_CODE (x) == FUNCTION_DECL && DECL_VINDEX (x)) 4711 { 4712 TYPE_POLYMORPHIC_P (t) = 1; 4713 if (DECL_PURE_VIRTUAL_P (x)) 4714 vec_safe_push (CLASSTYPE_PURE_VIRTUALS (t), x); 4715 } 4716 /* All user-provided destructors are non-trivial. 4717 Constructors and assignment ops are handled in 4718 grok_special_member_properties. */ 4719 if (DECL_DESTRUCTOR_P (x) && user_provided_p (x)) 4720 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = 1; 4721 if (!DECL_VIRTUAL_P (x) 4722 && lookup_attribute ("transaction_safe_dynamic", DECL_ATTRIBUTES (x))) 4723 error_at (DECL_SOURCE_LOCATION (x), 4724 "%<transaction_safe_dynamic%> may only be specified for " 4725 "a virtual function"); 4726 } 4727 } 4728 4729 /* FN is a constructor or destructor. Clone the declaration to create 4730 a specialized in-charge or not-in-charge version, as indicated by 4731 NAME. */ 4732 4733 static tree 4734 build_clone (tree fn, tree name) 4735 { 4736 tree parms; 4737 tree clone; 4738 4739 /* Copy the function. */ 4740 clone = copy_decl (fn); 4741 /* Reset the function name. */ 4742 DECL_NAME (clone) = name; 4743 /* Remember where this function came from. */ 4744 DECL_ABSTRACT_ORIGIN (clone) = fn; 4745 /* Make it easy to find the CLONE given the FN. */ 4746 DECL_CHAIN (clone) = DECL_CHAIN (fn); 4747 DECL_CHAIN (fn) = clone; 4748 4749 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */ 4750 if (TREE_CODE (clone) == TEMPLATE_DECL) 4751 { 4752 tree result = build_clone (DECL_TEMPLATE_RESULT (clone), name); 4753 DECL_TEMPLATE_RESULT (clone) = result; 4754 DECL_TEMPLATE_INFO (result) = copy_node (DECL_TEMPLATE_INFO (result)); 4755 DECL_TI_TEMPLATE (result) = clone; 4756 TREE_TYPE (clone) = TREE_TYPE (result); 4757 return clone; 4758 } 4759 else 4760 { 4761 // Clone constraints. 4762 if (flag_concepts) 4763 if (tree ci = get_constraints (fn)) 4764 set_constraints (clone, copy_node (ci)); 4765 } 4766 4767 4768 SET_DECL_ASSEMBLER_NAME (clone, NULL_TREE); 4769 DECL_CLONED_FUNCTION (clone) = fn; 4770 /* There's no pending inline data for this function. */ 4771 DECL_PENDING_INLINE_INFO (clone) = NULL; 4772 DECL_PENDING_INLINE_P (clone) = 0; 4773 4774 /* The base-class destructor is not virtual. */ 4775 if (name == base_dtor_identifier) 4776 { 4777 DECL_VIRTUAL_P (clone) = 0; 4778 if (TREE_CODE (clone) != TEMPLATE_DECL) 4779 DECL_VINDEX (clone) = NULL_TREE; 4780 } 4781 4782 bool ctor_omit_inherited_parms_p = ctor_omit_inherited_parms (clone); 4783 if (ctor_omit_inherited_parms_p) 4784 gcc_assert (DECL_HAS_IN_CHARGE_PARM_P (clone)); 4785 4786 /* If there was an in-charge parameter, drop it from the function 4787 type. */ 4788 if (DECL_HAS_IN_CHARGE_PARM_P (clone)) 4789 { 4790 tree basetype; 4791 tree parmtypes; 4792 tree exceptions; 4793 4794 exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone)); 4795 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone)); 4796 parmtypes = TYPE_ARG_TYPES (TREE_TYPE (clone)); 4797 /* Skip the `this' parameter. */ 4798 parmtypes = TREE_CHAIN (parmtypes); 4799 /* Skip the in-charge parameter. */ 4800 parmtypes = TREE_CHAIN (parmtypes); 4801 /* And the VTT parm, in a complete [cd]tor. */ 4802 if (DECL_HAS_VTT_PARM_P (fn) 4803 && ! DECL_NEEDS_VTT_PARM_P (clone)) 4804 parmtypes = TREE_CHAIN (parmtypes); 4805 if (ctor_omit_inherited_parms_p) 4806 { 4807 /* If we're omitting inherited parms, that just leaves the VTT. */ 4808 gcc_assert (DECL_NEEDS_VTT_PARM_P (clone)); 4809 parmtypes = tree_cons (NULL_TREE, vtt_parm_type, void_list_node); 4810 } 4811 TREE_TYPE (clone) 4812 = build_method_type_directly (basetype, 4813 TREE_TYPE (TREE_TYPE (clone)), 4814 parmtypes); 4815 if (exceptions) 4816 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), 4817 exceptions); 4818 TREE_TYPE (clone) 4819 = cp_build_type_attribute_variant (TREE_TYPE (clone), 4820 TYPE_ATTRIBUTES (TREE_TYPE (fn))); 4821 } 4822 4823 /* Copy the function parameters. */ 4824 DECL_ARGUMENTS (clone) = copy_list (DECL_ARGUMENTS (clone)); 4825 /* Remove the in-charge parameter. */ 4826 if (DECL_HAS_IN_CHARGE_PARM_P (clone)) 4827 { 4828 DECL_CHAIN (DECL_ARGUMENTS (clone)) 4829 = DECL_CHAIN (DECL_CHAIN (DECL_ARGUMENTS (clone))); 4830 DECL_HAS_IN_CHARGE_PARM_P (clone) = 0; 4831 } 4832 /* And the VTT parm, in a complete [cd]tor. */ 4833 if (DECL_HAS_VTT_PARM_P (fn)) 4834 { 4835 if (DECL_NEEDS_VTT_PARM_P (clone)) 4836 DECL_HAS_VTT_PARM_P (clone) = 1; 4837 else 4838 { 4839 DECL_CHAIN (DECL_ARGUMENTS (clone)) 4840 = DECL_CHAIN (DECL_CHAIN (DECL_ARGUMENTS (clone))); 4841 DECL_HAS_VTT_PARM_P (clone) = 0; 4842 } 4843 } 4844 4845 /* A base constructor inheriting from a virtual base doesn't get the 4846 arguments. */ 4847 if (ctor_omit_inherited_parms_p) 4848 DECL_CHAIN (DECL_CHAIN (DECL_ARGUMENTS (clone))) = NULL_TREE; 4849 4850 for (parms = DECL_ARGUMENTS (clone); parms; parms = DECL_CHAIN (parms)) 4851 { 4852 DECL_CONTEXT (parms) = clone; 4853 cxx_dup_lang_specific_decl (parms); 4854 } 4855 4856 /* Create the RTL for this function. */ 4857 SET_DECL_RTL (clone, NULL); 4858 rest_of_decl_compilation (clone, /*top_level=*/1, at_eof); 4859 4860 return clone; 4861 } 4862 4863 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do 4864 not invoke this function directly. 4865 4866 For a non-thunk function, returns the address of the slot for storing 4867 the function it is a clone of. Otherwise returns NULL_TREE. 4868 4869 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if 4870 cloned_function is unset. This is to support the separate 4871 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter 4872 on a template makes sense, but not the former. */ 4873 4874 tree * 4875 decl_cloned_function_p (const_tree decl, bool just_testing) 4876 { 4877 tree *ptr; 4878 if (just_testing) 4879 decl = STRIP_TEMPLATE (decl); 4880 4881 if (TREE_CODE (decl) != FUNCTION_DECL 4882 || !DECL_LANG_SPECIFIC (decl) 4883 || DECL_LANG_SPECIFIC (decl)->u.fn.thunk_p) 4884 { 4885 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007) 4886 if (!just_testing) 4887 lang_check_failed (__FILE__, __LINE__, __FUNCTION__); 4888 else 4889 #endif 4890 return NULL; 4891 } 4892 4893 ptr = &DECL_LANG_SPECIFIC (decl)->u.fn.u5.cloned_function; 4894 if (just_testing && *ptr == NULL_TREE) 4895 return NULL; 4896 else 4897 return ptr; 4898 } 4899 4900 /* Produce declarations for all appropriate clones of FN. If 4901 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the 4902 CLASTYPE_METHOD_VEC as well. */ 4903 4904 void 4905 clone_function_decl (tree fn, int update_method_vec_p) 4906 { 4907 tree clone; 4908 4909 /* Avoid inappropriate cloning. */ 4910 if (DECL_CHAIN (fn) 4911 && DECL_CLONED_FUNCTION_P (DECL_CHAIN (fn))) 4912 return; 4913 4914 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)) 4915 { 4916 /* For each constructor, we need two variants: an in-charge version 4917 and a not-in-charge version. */ 4918 clone = build_clone (fn, complete_ctor_identifier); 4919 if (update_method_vec_p) 4920 add_method (DECL_CONTEXT (clone), clone, NULL_TREE); 4921 clone = build_clone (fn, base_ctor_identifier); 4922 if (update_method_vec_p) 4923 add_method (DECL_CONTEXT (clone), clone, NULL_TREE); 4924 } 4925 else 4926 { 4927 gcc_assert (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)); 4928 4929 /* For each destructor, we need three variants: an in-charge 4930 version, a not-in-charge version, and an in-charge deleting 4931 version. We clone the deleting version first because that 4932 means it will go second on the TYPE_METHODS list -- and that 4933 corresponds to the correct layout order in the virtual 4934 function table. 4935 4936 For a non-virtual destructor, we do not build a deleting 4937 destructor. */ 4938 if (DECL_VIRTUAL_P (fn)) 4939 { 4940 clone = build_clone (fn, deleting_dtor_identifier); 4941 if (update_method_vec_p) 4942 add_method (DECL_CONTEXT (clone), clone, NULL_TREE); 4943 } 4944 clone = build_clone (fn, complete_dtor_identifier); 4945 if (update_method_vec_p) 4946 add_method (DECL_CONTEXT (clone), clone, NULL_TREE); 4947 clone = build_clone (fn, base_dtor_identifier); 4948 if (update_method_vec_p) 4949 add_method (DECL_CONTEXT (clone), clone, NULL_TREE); 4950 } 4951 4952 /* Note that this is an abstract function that is never emitted. */ 4953 DECL_ABSTRACT_P (fn) = true; 4954 } 4955 4956 /* DECL is an in charge constructor, which is being defined. This will 4957 have had an in class declaration, from whence clones were 4958 declared. An out-of-class definition can specify additional default 4959 arguments. As it is the clones that are involved in overload 4960 resolution, we must propagate the information from the DECL to its 4961 clones. */ 4962 4963 void 4964 adjust_clone_args (tree decl) 4965 { 4966 tree clone; 4967 4968 for (clone = DECL_CHAIN (decl); clone && DECL_CLONED_FUNCTION_P (clone); 4969 clone = DECL_CHAIN (clone)) 4970 { 4971 tree orig_clone_parms = TYPE_ARG_TYPES (TREE_TYPE (clone)); 4972 tree orig_decl_parms = TYPE_ARG_TYPES (TREE_TYPE (decl)); 4973 tree decl_parms, clone_parms; 4974 4975 clone_parms = orig_clone_parms; 4976 4977 /* Skip the 'this' parameter. */ 4978 orig_clone_parms = TREE_CHAIN (orig_clone_parms); 4979 orig_decl_parms = TREE_CHAIN (orig_decl_parms); 4980 4981 if (DECL_HAS_IN_CHARGE_PARM_P (decl)) 4982 orig_decl_parms = TREE_CHAIN (orig_decl_parms); 4983 if (DECL_HAS_VTT_PARM_P (decl)) 4984 orig_decl_parms = TREE_CHAIN (orig_decl_parms); 4985 4986 clone_parms = orig_clone_parms; 4987 if (DECL_HAS_VTT_PARM_P (clone)) 4988 clone_parms = TREE_CHAIN (clone_parms); 4989 4990 for (decl_parms = orig_decl_parms; decl_parms; 4991 decl_parms = TREE_CHAIN (decl_parms), 4992 clone_parms = TREE_CHAIN (clone_parms)) 4993 { 4994 if (clone_parms == void_list_node) 4995 { 4996 gcc_assert (decl_parms == clone_parms 4997 || ctor_omit_inherited_parms (clone)); 4998 break; 4999 } 5000 5001 gcc_assert (same_type_p (TREE_TYPE (decl_parms), 5002 TREE_TYPE (clone_parms))); 5003 5004 if (TREE_PURPOSE (decl_parms) && !TREE_PURPOSE (clone_parms)) 5005 { 5006 /* A default parameter has been added. Adjust the 5007 clone's parameters. */ 5008 tree exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone)); 5009 tree attrs = TYPE_ATTRIBUTES (TREE_TYPE (clone)); 5010 tree basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone)); 5011 tree type; 5012 5013 clone_parms = orig_decl_parms; 5014 5015 if (DECL_HAS_VTT_PARM_P (clone)) 5016 { 5017 clone_parms = tree_cons (TREE_PURPOSE (orig_clone_parms), 5018 TREE_VALUE (orig_clone_parms), 5019 clone_parms); 5020 TREE_TYPE (clone_parms) = TREE_TYPE (orig_clone_parms); 5021 } 5022 type = build_method_type_directly (basetype, 5023 TREE_TYPE (TREE_TYPE (clone)), 5024 clone_parms); 5025 if (exceptions) 5026 type = build_exception_variant (type, exceptions); 5027 if (attrs) 5028 type = cp_build_type_attribute_variant (type, attrs); 5029 TREE_TYPE (clone) = type; 5030 5031 clone_parms = NULL_TREE; 5032 break; 5033 } 5034 } 5035 gcc_assert (!clone_parms || clone_parms == void_list_node); 5036 } 5037 } 5038 5039 /* For each of the constructors and destructors in T, create an 5040 in-charge and not-in-charge variant. */ 5041 5042 static void 5043 clone_constructors_and_destructors (tree t) 5044 { 5045 tree fns; 5046 5047 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail 5048 out now. */ 5049 if (!CLASSTYPE_METHOD_VEC (t)) 5050 return; 5051 5052 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns)) 5053 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1); 5054 for (fns = CLASSTYPE_DESTRUCTORS (t); fns; fns = OVL_NEXT (fns)) 5055 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1); 5056 } 5057 5058 /* Deduce noexcept for a destructor DTOR. */ 5059 5060 void 5061 deduce_noexcept_on_destructor (tree dtor) 5062 { 5063 if (!TYPE_RAISES_EXCEPTIONS (TREE_TYPE (dtor))) 5064 { 5065 tree eh_spec = unevaluated_noexcept_spec (); 5066 TREE_TYPE (dtor) = build_exception_variant (TREE_TYPE (dtor), eh_spec); 5067 } 5068 } 5069 5070 /* For each destructor in T, deduce noexcept: 5071 5072 12.4/3: A declaration of a destructor that does not have an 5073 exception-specification is implicitly considered to have the 5074 same exception-specification as an implicit declaration (15.4). */ 5075 5076 static void 5077 deduce_noexcept_on_destructors (tree t) 5078 { 5079 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail 5080 out now. */ 5081 if (!CLASSTYPE_METHOD_VEC (t)) 5082 return; 5083 5084 for (tree fns = CLASSTYPE_DESTRUCTORS (t); fns; fns = OVL_NEXT (fns)) 5085 deduce_noexcept_on_destructor (OVL_CURRENT (fns)); 5086 } 5087 5088 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes 5089 of TYPE for virtual functions which FNDECL overrides. Return a 5090 mask of the tm attributes found therein. */ 5091 5092 static int 5093 look_for_tm_attr_overrides (tree type, tree fndecl) 5094 { 5095 tree binfo = TYPE_BINFO (type); 5096 tree base_binfo; 5097 int ix, found = 0; 5098 5099 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ++ix) 5100 { 5101 tree o, basetype = BINFO_TYPE (base_binfo); 5102 5103 if (!TYPE_POLYMORPHIC_P (basetype)) 5104 continue; 5105 5106 o = look_for_overrides_here (basetype, fndecl); 5107 if (o) 5108 { 5109 if (lookup_attribute ("transaction_safe_dynamic", 5110 DECL_ATTRIBUTES (o))) 5111 /* transaction_safe_dynamic is not inherited. */; 5112 else 5113 found |= tm_attr_to_mask (find_tm_attribute 5114 (TYPE_ATTRIBUTES (TREE_TYPE (o)))); 5115 } 5116 else 5117 found |= look_for_tm_attr_overrides (basetype, fndecl); 5118 } 5119 5120 return found; 5121 } 5122 5123 /* Subroutine of set_method_tm_attributes. Handle the checks and 5124 inheritance for one virtual method FNDECL. */ 5125 5126 static void 5127 set_one_vmethod_tm_attributes (tree type, tree fndecl) 5128 { 5129 tree tm_attr; 5130 int found, have; 5131 5132 found = look_for_tm_attr_overrides (type, fndecl); 5133 5134 /* If FNDECL doesn't actually override anything (i.e. T is the 5135 class that first declares FNDECL virtual), then we're done. */ 5136 if (found == 0) 5137 return; 5138 5139 tm_attr = find_tm_attribute (TYPE_ATTRIBUTES (TREE_TYPE (fndecl))); 5140 have = tm_attr_to_mask (tm_attr); 5141 5142 /* Intel STM Language Extension 3.0, Section 4.2 table 4: 5143 tm_pure must match exactly, otherwise no weakening of 5144 tm_safe > tm_callable > nothing. */ 5145 /* ??? The tm_pure attribute didn't make the transition to the 5146 multivendor language spec. */ 5147 if (have == TM_ATTR_PURE) 5148 { 5149 if (found != TM_ATTR_PURE) 5150 { 5151 found &= -found; 5152 goto err_override; 5153 } 5154 } 5155 /* If the overridden function is tm_pure, then FNDECL must be. */ 5156 else if (found == TM_ATTR_PURE && tm_attr) 5157 goto err_override; 5158 /* Look for base class combinations that cannot be satisfied. */ 5159 else if (found != TM_ATTR_PURE && (found & TM_ATTR_PURE)) 5160 { 5161 found &= ~TM_ATTR_PURE; 5162 found &= -found; 5163 error_at (DECL_SOURCE_LOCATION (fndecl), 5164 "method overrides both %<transaction_pure%> and %qE methods", 5165 tm_mask_to_attr (found)); 5166 } 5167 /* If FNDECL did not declare an attribute, then inherit the most 5168 restrictive one. */ 5169 else if (tm_attr == NULL) 5170 { 5171 apply_tm_attr (fndecl, tm_mask_to_attr (least_bit_hwi (found))); 5172 } 5173 /* Otherwise validate that we're not weaker than a function 5174 that is being overridden. */ 5175 else 5176 { 5177 found &= -found; 5178 if (found <= TM_ATTR_CALLABLE && have > found) 5179 goto err_override; 5180 } 5181 return; 5182 5183 err_override: 5184 error_at (DECL_SOURCE_LOCATION (fndecl), 5185 "method declared %qE overriding %qE method", 5186 tm_attr, tm_mask_to_attr (found)); 5187 } 5188 5189 /* For each of the methods in T, propagate a class-level tm attribute. */ 5190 5191 static void 5192 set_method_tm_attributes (tree t) 5193 { 5194 tree class_tm_attr, fndecl; 5195 5196 /* Don't bother collecting tm attributes if transactional memory 5197 support is not enabled. */ 5198 if (!flag_tm) 5199 return; 5200 5201 /* Process virtual methods first, as they inherit directly from the 5202 base virtual function and also require validation of new attributes. */ 5203 if (TYPE_CONTAINS_VPTR_P (t)) 5204 { 5205 tree vchain; 5206 for (vchain = BINFO_VIRTUALS (TYPE_BINFO (t)); vchain; 5207 vchain = TREE_CHAIN (vchain)) 5208 { 5209 fndecl = BV_FN (vchain); 5210 if (DECL_THUNK_P (fndecl)) 5211 fndecl = THUNK_TARGET (fndecl); 5212 set_one_vmethod_tm_attributes (t, fndecl); 5213 } 5214 } 5215 5216 /* If the class doesn't have an attribute, nothing more to do. */ 5217 class_tm_attr = find_tm_attribute (TYPE_ATTRIBUTES (t)); 5218 if (class_tm_attr == NULL) 5219 return; 5220 5221 /* Any method that does not yet have a tm attribute inherits 5222 the one from the class. */ 5223 for (fndecl = TYPE_METHODS (t); fndecl; fndecl = TREE_CHAIN (fndecl)) 5224 { 5225 if (!find_tm_attribute (TYPE_ATTRIBUTES (TREE_TYPE (fndecl)))) 5226 apply_tm_attr (fndecl, class_tm_attr); 5227 } 5228 } 5229 5230 /* Returns true if FN is a default constructor. */ 5231 5232 bool 5233 default_ctor_p (tree fn) 5234 { 5235 return (DECL_CONSTRUCTOR_P (fn) 5236 && sufficient_parms_p (FUNCTION_FIRST_USER_PARMTYPE (fn))); 5237 } 5238 5239 /* Returns true iff class T has a user-defined constructor that can be called 5240 with more than zero arguments. */ 5241 5242 bool 5243 type_has_user_nondefault_constructor (tree t) 5244 { 5245 tree fns; 5246 5247 if (!TYPE_HAS_USER_CONSTRUCTOR (t)) 5248 return false; 5249 5250 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns)) 5251 { 5252 tree fn = OVL_CURRENT (fns); 5253 if (!DECL_ARTIFICIAL (fn) 5254 && (TREE_CODE (fn) == TEMPLATE_DECL 5255 || (skip_artificial_parms_for (fn, DECL_ARGUMENTS (fn)) 5256 != NULL_TREE))) 5257 return true; 5258 } 5259 5260 return false; 5261 } 5262 5263 /* Returns the defaulted constructor if T has one. Otherwise, returns 5264 NULL_TREE. */ 5265 5266 tree 5267 in_class_defaulted_default_constructor (tree t) 5268 { 5269 if (!TYPE_HAS_USER_CONSTRUCTOR (t)) 5270 return NULL_TREE; 5271 5272 for (tree fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns)) 5273 { 5274 tree fn = OVL_CURRENT (fns); 5275 5276 if (DECL_DEFAULTED_IN_CLASS_P (fn) 5277 && default_ctor_p (fn)) 5278 return fn; 5279 } 5280 5281 return NULL_TREE; 5282 } 5283 5284 /* Returns true iff FN is a user-provided function, i.e. user-declared 5285 and not defaulted at its first declaration. */ 5286 5287 bool 5288 user_provided_p (tree fn) 5289 { 5290 if (TREE_CODE (fn) == TEMPLATE_DECL) 5291 return true; 5292 else 5293 return (!DECL_ARTIFICIAL (fn) 5294 && !(DECL_INITIALIZED_IN_CLASS_P (fn) 5295 && (DECL_DEFAULTED_FN (fn) || DECL_DELETED_FN (fn)))); 5296 } 5297 5298 /* Returns true iff class T has a user-provided constructor. */ 5299 5300 bool 5301 type_has_user_provided_constructor (tree t) 5302 { 5303 tree fns; 5304 5305 if (!CLASS_TYPE_P (t)) 5306 return false; 5307 5308 if (!TYPE_HAS_USER_CONSTRUCTOR (t)) 5309 return false; 5310 5311 /* This can happen in error cases; avoid crashing. */ 5312 if (!CLASSTYPE_METHOD_VEC (t)) 5313 return false; 5314 5315 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns)) 5316 if (user_provided_p (OVL_CURRENT (fns))) 5317 return true; 5318 5319 return false; 5320 } 5321 5322 /* Returns true iff class T has a user-provided or explicit constructor. */ 5323 5324 bool 5325 type_has_user_provided_or_explicit_constructor (tree t) 5326 { 5327 tree fns; 5328 5329 if (!CLASS_TYPE_P (t)) 5330 return false; 5331 5332 if (!TYPE_HAS_USER_CONSTRUCTOR (t)) 5333 return false; 5334 5335 /* This can happen in error cases; avoid crashing. */ 5336 if (!CLASSTYPE_METHOD_VEC (t)) 5337 return false; 5338 5339 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns)) 5340 { 5341 tree fn = OVL_CURRENT (fns); 5342 if (user_provided_p (fn) || DECL_NONCONVERTING_P (fn)) 5343 return true; 5344 } 5345 5346 return false; 5347 } 5348 5349 /* Returns true iff class T has a non-user-provided (i.e. implicitly 5350 declared or explicitly defaulted in the class body) default 5351 constructor. */ 5352 5353 bool 5354 type_has_non_user_provided_default_constructor (tree t) 5355 { 5356 tree fns; 5357 5358 if (!TYPE_HAS_DEFAULT_CONSTRUCTOR (t)) 5359 return false; 5360 if (CLASSTYPE_LAZY_DEFAULT_CTOR (t)) 5361 return true; 5362 5363 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns)) 5364 { 5365 tree fn = OVL_CURRENT (fns); 5366 if (TREE_CODE (fn) == FUNCTION_DECL 5367 && default_ctor_p (fn) 5368 && !user_provided_p (fn)) 5369 return true; 5370 } 5371 5372 return false; 5373 } 5374 5375 /* TYPE is being used as a virtual base, and has a non-trivial move 5376 assignment. Return true if this is due to there being a user-provided 5377 move assignment in TYPE or one of its subobjects; if there isn't, then 5378 multiple move assignment can't cause any harm. */ 5379 5380 bool 5381 vbase_has_user_provided_move_assign (tree type) 5382 { 5383 /* Does the type itself have a user-provided move assignment operator? */ 5384 for (tree fns 5385 = lookup_fnfields_slot_nolazy (type, cp_assignment_operator_id (NOP_EXPR)); 5386 fns; fns = OVL_NEXT (fns)) 5387 { 5388 tree fn = OVL_CURRENT (fns); 5389 if (move_fn_p (fn) && user_provided_p (fn)) 5390 return true; 5391 } 5392 5393 /* Do any of its bases? */ 5394 tree binfo = TYPE_BINFO (type); 5395 tree base_binfo; 5396 for (int i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 5397 if (vbase_has_user_provided_move_assign (BINFO_TYPE (base_binfo))) 5398 return true; 5399 5400 /* Or non-static data members? */ 5401 for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) 5402 { 5403 if (TREE_CODE (field) == FIELD_DECL 5404 && CLASS_TYPE_P (TREE_TYPE (field)) 5405 && vbase_has_user_provided_move_assign (TREE_TYPE (field))) 5406 return true; 5407 } 5408 5409 /* Seems not. */ 5410 return false; 5411 } 5412 5413 /* If default-initialization leaves part of TYPE uninitialized, returns 5414 a DECL for the field or TYPE itself (DR 253). */ 5415 5416 tree 5417 default_init_uninitialized_part (tree type) 5418 { 5419 tree t, r, binfo; 5420 int i; 5421 5422 type = strip_array_types (type); 5423 if (!CLASS_TYPE_P (type)) 5424 return type; 5425 if (!type_has_non_user_provided_default_constructor (type)) 5426 return NULL_TREE; 5427 for (binfo = TYPE_BINFO (type), i = 0; 5428 BINFO_BASE_ITERATE (binfo, i, t); ++i) 5429 { 5430 r = default_init_uninitialized_part (BINFO_TYPE (t)); 5431 if (r) 5432 return r; 5433 } 5434 for (t = TYPE_FIELDS (type); t; t = DECL_CHAIN (t)) 5435 if (TREE_CODE (t) == FIELD_DECL 5436 && !DECL_ARTIFICIAL (t) 5437 && !DECL_INITIAL (t)) 5438 { 5439 r = default_init_uninitialized_part (TREE_TYPE (t)); 5440 if (r) 5441 return DECL_P (r) ? r : t; 5442 } 5443 5444 return NULL_TREE; 5445 } 5446 5447 /* Returns true iff for class T, a trivial synthesized default constructor 5448 would be constexpr. */ 5449 5450 bool 5451 trivial_default_constructor_is_constexpr (tree t) 5452 { 5453 /* A defaulted trivial default constructor is constexpr 5454 if there is nothing to initialize. */ 5455 gcc_assert (!TYPE_HAS_COMPLEX_DFLT (t)); 5456 return is_really_empty_class (t); 5457 } 5458 5459 /* Returns true iff class T has a constexpr default constructor. */ 5460 5461 bool 5462 type_has_constexpr_default_constructor (tree t) 5463 { 5464 tree fns; 5465 5466 if (!CLASS_TYPE_P (t)) 5467 { 5468 /* The caller should have stripped an enclosing array. */ 5469 gcc_assert (TREE_CODE (t) != ARRAY_TYPE); 5470 return false; 5471 } 5472 if (CLASSTYPE_LAZY_DEFAULT_CTOR (t)) 5473 { 5474 if (!TYPE_HAS_COMPLEX_DFLT (t)) 5475 return trivial_default_constructor_is_constexpr (t); 5476 /* Non-trivial, we need to check subobject constructors. */ 5477 lazily_declare_fn (sfk_constructor, t); 5478 } 5479 fns = locate_ctor (t); 5480 return (fns && DECL_DECLARED_CONSTEXPR_P (fns)); 5481 } 5482 5483 /* Returns true iff class T has a constexpr default constructor or has an 5484 implicitly declared default constructor that we can't tell if it's constexpr 5485 without forcing a lazy declaration (which might cause undesired 5486 instantiations). */ 5487 5488 bool 5489 type_maybe_constexpr_default_constructor (tree t) 5490 { 5491 if (CLASS_TYPE_P (t) && CLASSTYPE_LAZY_DEFAULT_CTOR (t) 5492 && TYPE_HAS_COMPLEX_DFLT (t)) 5493 /* Assume it's constexpr. */ 5494 return true; 5495 return type_has_constexpr_default_constructor (t); 5496 } 5497 5498 /* Returns true iff class TYPE has a virtual destructor. */ 5499 5500 bool 5501 type_has_virtual_destructor (tree type) 5502 { 5503 tree dtor; 5504 5505 if (!CLASS_TYPE_P (type)) 5506 return false; 5507 5508 gcc_assert (COMPLETE_TYPE_P (type)); 5509 dtor = CLASSTYPE_DESTRUCTORS (type); 5510 return (dtor && DECL_VIRTUAL_P (dtor)); 5511 } 5512 5513 /* Returns true iff class T has a move constructor. */ 5514 5515 bool 5516 type_has_move_constructor (tree t) 5517 { 5518 tree fns; 5519 5520 if (CLASSTYPE_LAZY_MOVE_CTOR (t)) 5521 { 5522 gcc_assert (COMPLETE_TYPE_P (t)); 5523 lazily_declare_fn (sfk_move_constructor, t); 5524 } 5525 5526 if (!CLASSTYPE_METHOD_VEC (t)) 5527 return false; 5528 5529 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns)) 5530 if (move_fn_p (OVL_CURRENT (fns))) 5531 return true; 5532 5533 return false; 5534 } 5535 5536 /* Returns true iff class T has a move assignment operator. */ 5537 5538 bool 5539 type_has_move_assign (tree t) 5540 { 5541 tree fns; 5542 5543 if (CLASSTYPE_LAZY_MOVE_ASSIGN (t)) 5544 { 5545 gcc_assert (COMPLETE_TYPE_P (t)); 5546 lazily_declare_fn (sfk_move_assignment, t); 5547 } 5548 5549 for (fns = lookup_fnfields_slot_nolazy (t, cp_assignment_operator_id (NOP_EXPR)); 5550 fns; fns = OVL_NEXT (fns)) 5551 if (move_fn_p (OVL_CURRENT (fns))) 5552 return true; 5553 5554 return false; 5555 } 5556 5557 /* Returns true iff class T has a move constructor that was explicitly 5558 declared in the class body. Note that this is different from 5559 "user-provided", which doesn't include functions that are defaulted in 5560 the class. */ 5561 5562 bool 5563 type_has_user_declared_move_constructor (tree t) 5564 { 5565 tree fns; 5566 5567 if (CLASSTYPE_LAZY_MOVE_CTOR (t)) 5568 return false; 5569 5570 if (!CLASSTYPE_METHOD_VEC (t)) 5571 return false; 5572 5573 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns)) 5574 { 5575 tree fn = OVL_CURRENT (fns); 5576 if (move_fn_p (fn) && !DECL_ARTIFICIAL (fn)) 5577 return true; 5578 } 5579 5580 return false; 5581 } 5582 5583 /* Returns true iff class T has a move assignment operator that was 5584 explicitly declared in the class body. */ 5585 5586 bool 5587 type_has_user_declared_move_assign (tree t) 5588 { 5589 tree fns; 5590 5591 if (CLASSTYPE_LAZY_MOVE_ASSIGN (t)) 5592 return false; 5593 5594 for (fns = lookup_fnfields_slot_nolazy (t, cp_assignment_operator_id (NOP_EXPR)); 5595 fns; fns = OVL_NEXT (fns)) 5596 { 5597 tree fn = OVL_CURRENT (fns); 5598 if (move_fn_p (fn) && !DECL_ARTIFICIAL (fn)) 5599 return true; 5600 } 5601 5602 return false; 5603 } 5604 5605 /* Nonzero if we need to build up a constructor call when initializing an 5606 object of this class, either because it has a user-declared constructor 5607 or because it doesn't have a default constructor (so we need to give an 5608 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when 5609 what you care about is whether or not an object can be produced by a 5610 constructor (e.g. so we don't set TREE_READONLY on const variables of 5611 such type); use this function when what you care about is whether or not 5612 to try to call a constructor to create an object. The latter case is 5613 the former plus some cases of constructors that cannot be called. */ 5614 5615 bool 5616 type_build_ctor_call (tree t) 5617 { 5618 tree inner; 5619 if (TYPE_NEEDS_CONSTRUCTING (t)) 5620 return true; 5621 inner = strip_array_types (t); 5622 if (!CLASS_TYPE_P (inner) || ANON_AGGR_TYPE_P (inner)) 5623 return false; 5624 if (!TYPE_HAS_DEFAULT_CONSTRUCTOR (inner)) 5625 return true; 5626 if (cxx_dialect < cxx11) 5627 return false; 5628 /* A user-declared constructor might be private, and a constructor might 5629 be trivial but deleted. */ 5630 for (tree fns = lookup_fnfields_slot (inner, complete_ctor_identifier); 5631 fns; fns = OVL_NEXT (fns)) 5632 { 5633 tree fn = OVL_CURRENT (fns); 5634 if (!DECL_ARTIFICIAL (fn) 5635 || DECL_DELETED_FN (fn)) 5636 return true; 5637 } 5638 return false; 5639 } 5640 5641 /* Like type_build_ctor_call, but for destructors. */ 5642 5643 bool 5644 type_build_dtor_call (tree t) 5645 { 5646 tree inner; 5647 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)) 5648 return true; 5649 inner = strip_array_types (t); 5650 if (!CLASS_TYPE_P (inner) || ANON_AGGR_TYPE_P (inner) 5651 || !COMPLETE_TYPE_P (inner)) 5652 return false; 5653 if (cxx_dialect < cxx11) 5654 return false; 5655 /* A user-declared destructor might be private, and a destructor might 5656 be trivial but deleted. */ 5657 for (tree fns = lookup_fnfields_slot (inner, complete_dtor_identifier); 5658 fns; fns = OVL_NEXT (fns)) 5659 { 5660 tree fn = OVL_CURRENT (fns); 5661 if (!DECL_ARTIFICIAL (fn) 5662 || DECL_DELETED_FN (fn)) 5663 return true; 5664 } 5665 return false; 5666 } 5667 5668 /* Remove all zero-width bit-fields from T. */ 5669 5670 static void 5671 remove_zero_width_bit_fields (tree t) 5672 { 5673 tree *fieldsp; 5674 5675 fieldsp = &TYPE_FIELDS (t); 5676 while (*fieldsp) 5677 { 5678 if (TREE_CODE (*fieldsp) == FIELD_DECL 5679 && DECL_C_BIT_FIELD (*fieldsp) 5680 /* We should not be confused by the fact that grokbitfield 5681 temporarily sets the width of the bit field into 5682 DECL_INITIAL (*fieldsp). 5683 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp) 5684 to that width. */ 5685 && (DECL_SIZE (*fieldsp) == NULL_TREE 5686 || integer_zerop (DECL_SIZE (*fieldsp)))) 5687 *fieldsp = DECL_CHAIN (*fieldsp); 5688 else 5689 fieldsp = &DECL_CHAIN (*fieldsp); 5690 } 5691 } 5692 5693 /* Returns TRUE iff we need a cookie when dynamically allocating an 5694 array whose elements have the indicated class TYPE. */ 5695 5696 static bool 5697 type_requires_array_cookie (tree type) 5698 { 5699 tree fns; 5700 bool has_two_argument_delete_p = false; 5701 5702 gcc_assert (CLASS_TYPE_P (type)); 5703 5704 /* If there's a non-trivial destructor, we need a cookie. In order 5705 to iterate through the array calling the destructor for each 5706 element, we'll have to know how many elements there are. */ 5707 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 5708 return true; 5709 5710 /* If the usual deallocation function is a two-argument whose second 5711 argument is of type `size_t', then we have to pass the size of 5712 the array to the deallocation function, so we will need to store 5713 a cookie. */ 5714 fns = lookup_fnfields (TYPE_BINFO (type), 5715 cp_operator_id (VEC_DELETE_EXPR), 5716 /*protect=*/0); 5717 /* If there are no `operator []' members, or the lookup is 5718 ambiguous, then we don't need a cookie. */ 5719 if (!fns || fns == error_mark_node) 5720 return false; 5721 /* Loop through all of the functions. */ 5722 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns)) 5723 { 5724 tree fn; 5725 tree second_parm; 5726 5727 /* Select the current function. */ 5728 fn = OVL_CURRENT (fns); 5729 /* See if this function is a one-argument delete function. If 5730 it is, then it will be the usual deallocation function. */ 5731 second_parm = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fn))); 5732 if (second_parm == void_list_node) 5733 return false; 5734 /* Do not consider this function if its second argument is an 5735 ellipsis. */ 5736 if (!second_parm) 5737 continue; 5738 /* Otherwise, if we have a two-argument function and the second 5739 argument is `size_t', it will be the usual deallocation 5740 function -- unless there is one-argument function, too. */ 5741 if (TREE_CHAIN (second_parm) == void_list_node 5742 && same_type_p (TREE_VALUE (second_parm), size_type_node)) 5743 has_two_argument_delete_p = true; 5744 } 5745 5746 return has_two_argument_delete_p; 5747 } 5748 5749 /* Finish computing the `literal type' property of class type T. 5750 5751 At this point, we have already processed base classes and 5752 non-static data members. We need to check whether the copy 5753 constructor is trivial, the destructor is trivial, and there 5754 is a trivial default constructor or at least one constexpr 5755 constructor other than the copy constructor. */ 5756 5757 static void 5758 finalize_literal_type_property (tree t) 5759 { 5760 tree fn; 5761 5762 if (cxx_dialect < cxx11 5763 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)) 5764 CLASSTYPE_LITERAL_P (t) = false; 5765 else if (CLASSTYPE_LITERAL_P (t) && !TYPE_HAS_TRIVIAL_DFLT (t) 5766 && CLASSTYPE_NON_AGGREGATE (t) 5767 && !TYPE_HAS_CONSTEXPR_CTOR (t)) 5768 CLASSTYPE_LITERAL_P (t) = false; 5769 5770 /* C++14 DR 1684 removed this restriction. */ 5771 if (cxx_dialect < cxx14 5772 && !CLASSTYPE_LITERAL_P (t) && !LAMBDA_TYPE_P (t)) 5773 for (fn = TYPE_METHODS (t); fn; fn = DECL_CHAIN (fn)) 5774 if (DECL_DECLARED_CONSTEXPR_P (fn) 5775 && TREE_CODE (fn) != TEMPLATE_DECL 5776 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) 5777 && !DECL_CONSTRUCTOR_P (fn)) 5778 { 5779 DECL_DECLARED_CONSTEXPR_P (fn) = false; 5780 if (!DECL_GENERATED_P (fn) 5781 && pedwarn (DECL_SOURCE_LOCATION (fn), OPT_Wpedantic, 5782 "enclosing class of constexpr non-static member " 5783 "function %q+#D is not a literal type", fn)) 5784 explain_non_literal_class (t); 5785 } 5786 } 5787 5788 /* T is a non-literal type used in a context which requires a constant 5789 expression. Explain why it isn't literal. */ 5790 5791 void 5792 explain_non_literal_class (tree t) 5793 { 5794 static hash_set<tree> *diagnosed; 5795 5796 if (!CLASS_TYPE_P (t)) 5797 return; 5798 t = TYPE_MAIN_VARIANT (t); 5799 5800 if (diagnosed == NULL) 5801 diagnosed = new hash_set<tree>; 5802 if (diagnosed->add (t)) 5803 /* Already explained. */ 5804 return; 5805 5806 inform (0, "%q+T is not literal because:", t); 5807 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)) 5808 inform (0, " %q+T has a non-trivial destructor", t); 5809 else if (CLASSTYPE_NON_AGGREGATE (t) 5810 && !TYPE_HAS_TRIVIAL_DFLT (t) 5811 && !TYPE_HAS_CONSTEXPR_CTOR (t)) 5812 { 5813 inform (0, " %q+T is not an aggregate, does not have a trivial " 5814 "default constructor, and has no constexpr constructor that " 5815 "is not a copy or move constructor", t); 5816 if (type_has_non_user_provided_default_constructor (t)) 5817 { 5818 /* Note that we can't simply call locate_ctor because when the 5819 constructor is deleted it just returns NULL_TREE. */ 5820 tree fns; 5821 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns)) 5822 { 5823 tree fn = OVL_CURRENT (fns); 5824 tree parms = TYPE_ARG_TYPES (TREE_TYPE (fn)); 5825 5826 parms = skip_artificial_parms_for (fn, parms); 5827 5828 if (sufficient_parms_p (parms)) 5829 { 5830 if (DECL_DELETED_FN (fn)) 5831 maybe_explain_implicit_delete (fn); 5832 else 5833 explain_invalid_constexpr_fn (fn); 5834 break; 5835 } 5836 } 5837 } 5838 } 5839 else 5840 { 5841 tree binfo, base_binfo, field; int i; 5842 for (binfo = TYPE_BINFO (t), i = 0; 5843 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 5844 { 5845 tree basetype = TREE_TYPE (base_binfo); 5846 if (!CLASSTYPE_LITERAL_P (basetype)) 5847 { 5848 inform (0, " base class %qT of %q+T is non-literal", 5849 basetype, t); 5850 explain_non_literal_class (basetype); 5851 return; 5852 } 5853 } 5854 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field)) 5855 { 5856 tree ftype; 5857 if (TREE_CODE (field) != FIELD_DECL) 5858 continue; 5859 ftype = TREE_TYPE (field); 5860 if (!literal_type_p (ftype)) 5861 { 5862 inform (DECL_SOURCE_LOCATION (field), 5863 " non-static data member %qD has non-literal type", 5864 field); 5865 if (CLASS_TYPE_P (ftype)) 5866 explain_non_literal_class (ftype); 5867 } 5868 if (CP_TYPE_VOLATILE_P (ftype)) 5869 inform (DECL_SOURCE_LOCATION (field), 5870 " non-static data member %qD has volatile type", field); 5871 } 5872 } 5873 } 5874 5875 /* Check the validity of the bases and members declared in T. Add any 5876 implicitly-generated functions (like copy-constructors and 5877 assignment operators). Compute various flag bits (like 5878 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++ 5879 level: i.e., independently of the ABI in use. */ 5880 5881 static void 5882 check_bases_and_members (tree t) 5883 { 5884 /* Nonzero if the implicitly generated copy constructor should take 5885 a non-const reference argument. */ 5886 int cant_have_const_ctor; 5887 /* Nonzero if the implicitly generated assignment operator 5888 should take a non-const reference argument. */ 5889 int no_const_asn_ref; 5890 tree access_decls; 5891 bool saved_complex_asn_ref; 5892 bool saved_nontrivial_dtor; 5893 tree fn; 5894 5895 /* By default, we use const reference arguments and generate default 5896 constructors. */ 5897 cant_have_const_ctor = 0; 5898 no_const_asn_ref = 0; 5899 5900 /* Check all the base-classes and set FMEM members to point to arrays 5901 of potential interest. */ 5902 check_bases (t, &cant_have_const_ctor, &no_const_asn_ref); 5903 5904 /* Deduce noexcept on destructors. This needs to happen after we've set 5905 triviality flags appropriately for our bases. */ 5906 if (cxx_dialect >= cxx11) 5907 deduce_noexcept_on_destructors (t); 5908 5909 /* Check all the method declarations. */ 5910 check_methods (t); 5911 5912 /* Save the initial values of these flags which only indicate whether 5913 or not the class has user-provided functions. As we analyze the 5914 bases and members we can set these flags for other reasons. */ 5915 saved_complex_asn_ref = TYPE_HAS_COMPLEX_COPY_ASSIGN (t); 5916 saved_nontrivial_dtor = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t); 5917 5918 /* Check all the data member declarations. We cannot call 5919 check_field_decls until we have called check_bases check_methods, 5920 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR 5921 being set appropriately. */ 5922 check_field_decls (t, &access_decls, 5923 &cant_have_const_ctor, 5924 &no_const_asn_ref); 5925 5926 /* A nearly-empty class has to be vptr-containing; a nearly empty 5927 class contains just a vptr. */ 5928 if (!TYPE_CONTAINS_VPTR_P (t)) 5929 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 5930 5931 /* Do some bookkeeping that will guide the generation of implicitly 5932 declared member functions. */ 5933 TYPE_HAS_COMPLEX_COPY_CTOR (t) |= TYPE_CONTAINS_VPTR_P (t); 5934 TYPE_HAS_COMPLEX_MOVE_CTOR (t) |= TYPE_CONTAINS_VPTR_P (t); 5935 /* We need to call a constructor for this class if it has a 5936 user-provided constructor, or if the default constructor is going 5937 to initialize the vptr. (This is not an if-and-only-if; 5938 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members 5939 themselves need constructing.) */ 5940 TYPE_NEEDS_CONSTRUCTING (t) 5941 |= (type_has_user_provided_constructor (t) || TYPE_CONTAINS_VPTR_P (t)); 5942 /* [dcl.init.aggr] 5943 5944 An aggregate is an array or a class with no user-provided 5945 constructors ... and no virtual functions. 5946 5947 Again, other conditions for being an aggregate are checked 5948 elsewhere. */ 5949 CLASSTYPE_NON_AGGREGATE (t) 5950 |= (type_has_user_provided_or_explicit_constructor (t) 5951 || TYPE_POLYMORPHIC_P (t)); 5952 /* This is the C++98/03 definition of POD; it changed in C++0x, but we 5953 retain the old definition internally for ABI reasons. */ 5954 CLASSTYPE_NON_LAYOUT_POD_P (t) 5955 |= (CLASSTYPE_NON_AGGREGATE (t) 5956 || saved_nontrivial_dtor || saved_complex_asn_ref); 5957 CLASSTYPE_NON_STD_LAYOUT (t) |= TYPE_CONTAINS_VPTR_P (t); 5958 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) |= TYPE_CONTAINS_VPTR_P (t); 5959 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) |= TYPE_CONTAINS_VPTR_P (t); 5960 TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_CONTAINS_VPTR_P (t); 5961 5962 /* If the only explicitly declared default constructor is user-provided, 5963 set TYPE_HAS_COMPLEX_DFLT. */ 5964 if (!TYPE_HAS_COMPLEX_DFLT (t) 5965 && TYPE_HAS_DEFAULT_CONSTRUCTOR (t) 5966 && !type_has_non_user_provided_default_constructor (t)) 5967 TYPE_HAS_COMPLEX_DFLT (t) = true; 5968 5969 /* Warn if a public base of a polymorphic type has an accessible 5970 non-virtual destructor. It is only now that we know the class is 5971 polymorphic. Although a polymorphic base will have a already 5972 been diagnosed during its definition, we warn on use too. */ 5973 if (TYPE_POLYMORPHIC_P (t) && warn_nonvdtor) 5974 { 5975 tree binfo = TYPE_BINFO (t); 5976 vec<tree, va_gc> *accesses = BINFO_BASE_ACCESSES (binfo); 5977 tree base_binfo; 5978 unsigned i; 5979 5980 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 5981 { 5982 tree basetype = TREE_TYPE (base_binfo); 5983 5984 if ((*accesses)[i] == access_public_node 5985 && (TYPE_POLYMORPHIC_P (basetype) || warn_ecpp) 5986 && accessible_nvdtor_p (basetype)) 5987 warning (OPT_Wnon_virtual_dtor, 5988 "base class %q#T has accessible non-virtual destructor", 5989 basetype); 5990 } 5991 } 5992 5993 /* If the class has no user-declared constructor, but does have 5994 non-static const or reference data members that can never be 5995 initialized, issue a warning. */ 5996 if (warn_uninitialized 5997 /* Classes with user-declared constructors are presumed to 5998 initialize these members. */ 5999 && !TYPE_HAS_USER_CONSTRUCTOR (t) 6000 /* Aggregates can be initialized with brace-enclosed 6001 initializers. */ 6002 && CLASSTYPE_NON_AGGREGATE (t)) 6003 { 6004 tree field; 6005 6006 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) 6007 { 6008 tree type; 6009 6010 if (TREE_CODE (field) != FIELD_DECL 6011 || DECL_INITIAL (field) != NULL_TREE) 6012 continue; 6013 6014 type = TREE_TYPE (field); 6015 if (TREE_CODE (type) == REFERENCE_TYPE) 6016 warning_at (DECL_SOURCE_LOCATION (field), 6017 OPT_Wuninitialized, "non-static reference %q#D " 6018 "in class without a constructor", field); 6019 else if (CP_TYPE_CONST_P (type) 6020 && (!CLASS_TYPE_P (type) 6021 || !TYPE_HAS_DEFAULT_CONSTRUCTOR (type))) 6022 warning_at (DECL_SOURCE_LOCATION (field), 6023 OPT_Wuninitialized, "non-static const member %q#D " 6024 "in class without a constructor", field); 6025 } 6026 } 6027 6028 /* Synthesize any needed methods. */ 6029 add_implicitly_declared_members (t, &access_decls, 6030 cant_have_const_ctor, 6031 no_const_asn_ref); 6032 6033 /* Check defaulted declarations here so we have cant_have_const_ctor 6034 and don't need to worry about clones. */ 6035 for (fn = TYPE_METHODS (t); fn; fn = DECL_CHAIN (fn)) 6036 if (!DECL_ARTIFICIAL (fn) && DECL_DEFAULTED_IN_CLASS_P (fn)) 6037 { 6038 int copy = copy_fn_p (fn); 6039 if (copy > 0) 6040 { 6041 bool imp_const_p 6042 = (DECL_CONSTRUCTOR_P (fn) ? !cant_have_const_ctor 6043 : !no_const_asn_ref); 6044 bool fn_const_p = (copy == 2); 6045 6046 if (fn_const_p && !imp_const_p) 6047 /* If the function is defaulted outside the class, we just 6048 give the synthesis error. */ 6049 error ("%q+D declared to take const reference, but implicit " 6050 "declaration would take non-const", fn); 6051 } 6052 defaulted_late_check (fn); 6053 } 6054 6055 if (LAMBDA_TYPE_P (t)) 6056 { 6057 /* "This class type is not an aggregate." */ 6058 CLASSTYPE_NON_AGGREGATE (t) = 1; 6059 } 6060 6061 /* Compute the 'literal type' property before we 6062 do anything with non-static member functions. */ 6063 finalize_literal_type_property (t); 6064 6065 /* Create the in-charge and not-in-charge variants of constructors 6066 and destructors. */ 6067 clone_constructors_and_destructors (t); 6068 6069 /* Process the using-declarations. */ 6070 for (; access_decls; access_decls = TREE_CHAIN (access_decls)) 6071 handle_using_decl (TREE_VALUE (access_decls), t); 6072 6073 /* Build and sort the CLASSTYPE_METHOD_VEC. */ 6074 finish_struct_methods (t); 6075 6076 /* Figure out whether or not we will need a cookie when dynamically 6077 allocating an array of this type. */ 6078 TYPE_LANG_SPECIFIC (t)->u.c.vec_new_uses_cookie 6079 = type_requires_array_cookie (t); 6080 } 6081 6082 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD 6083 accordingly. If a new vfield was created (because T doesn't have a 6084 primary base class), then the newly created field is returned. It 6085 is not added to the TYPE_FIELDS list; it is the caller's 6086 responsibility to do that. Accumulate declared virtual functions 6087 on VIRTUALS_P. */ 6088 6089 static tree 6090 create_vtable_ptr (tree t, tree* virtuals_p) 6091 { 6092 tree fn; 6093 6094 /* Collect the virtual functions declared in T. */ 6095 for (fn = TYPE_METHODS (t); fn; fn = DECL_CHAIN (fn)) 6096 if (TREE_CODE (fn) == FUNCTION_DECL 6097 && DECL_VINDEX (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn) 6098 && TREE_CODE (DECL_VINDEX (fn)) != INTEGER_CST) 6099 { 6100 tree new_virtual = make_node (TREE_LIST); 6101 6102 BV_FN (new_virtual) = fn; 6103 BV_DELTA (new_virtual) = integer_zero_node; 6104 BV_VCALL_INDEX (new_virtual) = NULL_TREE; 6105 6106 TREE_CHAIN (new_virtual) = *virtuals_p; 6107 *virtuals_p = new_virtual; 6108 } 6109 6110 /* If we couldn't find an appropriate base class, create a new field 6111 here. Even if there weren't any new virtual functions, we might need a 6112 new virtual function table if we're supposed to include vptrs in 6113 all classes that need them. */ 6114 if (!TYPE_VFIELD (t) && (*virtuals_p || TYPE_CONTAINS_VPTR_P (t))) 6115 { 6116 /* We build this decl with vtbl_ptr_type_node, which is a 6117 `vtable_entry_type*'. It might seem more precise to use 6118 `vtable_entry_type (*)[N]' where N is the number of virtual 6119 functions. However, that would require the vtable pointer in 6120 base classes to have a different type than the vtable pointer 6121 in derived classes. We could make that happen, but that 6122 still wouldn't solve all the problems. In particular, the 6123 type-based alias analysis code would decide that assignments 6124 to the base class vtable pointer can't alias assignments to 6125 the derived class vtable pointer, since they have different 6126 types. Thus, in a derived class destructor, where the base 6127 class constructor was inlined, we could generate bad code for 6128 setting up the vtable pointer. 6129 6130 Therefore, we use one type for all vtable pointers. We still 6131 use a type-correct type; it's just doesn't indicate the array 6132 bounds. That's better than using `void*' or some such; it's 6133 cleaner, and it let's the alias analysis code know that these 6134 stores cannot alias stores to void*! */ 6135 tree field; 6136 6137 field = build_decl (input_location, 6138 FIELD_DECL, get_vfield_name (t), vtbl_ptr_type_node); 6139 DECL_VIRTUAL_P (field) = 1; 6140 DECL_ARTIFICIAL (field) = 1; 6141 DECL_FIELD_CONTEXT (field) = t; 6142 DECL_FCONTEXT (field) = t; 6143 if (TYPE_PACKED (t)) 6144 DECL_PACKED (field) = 1; 6145 6146 TYPE_VFIELD (t) = field; 6147 6148 /* This class is non-empty. */ 6149 CLASSTYPE_EMPTY_P (t) = 0; 6150 6151 return field; 6152 } 6153 6154 return NULL_TREE; 6155 } 6156 6157 /* Add OFFSET to all base types of BINFO which is a base in the 6158 hierarchy dominated by T. 6159 6160 OFFSET, which is a type offset, is number of bytes. */ 6161 6162 static void 6163 propagate_binfo_offsets (tree binfo, tree offset) 6164 { 6165 int i; 6166 tree primary_binfo; 6167 tree base_binfo; 6168 6169 /* Update BINFO's offset. */ 6170 BINFO_OFFSET (binfo) 6171 = fold_convert (sizetype, 6172 size_binop (PLUS_EXPR, 6173 fold_convert (ssizetype, BINFO_OFFSET (binfo)), 6174 offset)); 6175 6176 /* Find the primary base class. */ 6177 primary_binfo = get_primary_binfo (binfo); 6178 6179 if (primary_binfo && BINFO_INHERITANCE_CHAIN (primary_binfo) == binfo) 6180 propagate_binfo_offsets (primary_binfo, offset); 6181 6182 /* Scan all of the bases, pushing the BINFO_OFFSET adjust 6183 downwards. */ 6184 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 6185 { 6186 /* Don't do the primary base twice. */ 6187 if (base_binfo == primary_binfo) 6188 continue; 6189 6190 if (BINFO_VIRTUAL_P (base_binfo)) 6191 continue; 6192 6193 propagate_binfo_offsets (base_binfo, offset); 6194 } 6195 } 6196 6197 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update 6198 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of 6199 empty subobjects of T. */ 6200 6201 static void 6202 layout_virtual_bases (record_layout_info rli, splay_tree offsets) 6203 { 6204 tree vbase; 6205 tree t = rli->t; 6206 tree *next_field; 6207 6208 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) == 0) 6209 return; 6210 6211 /* Find the last field. The artificial fields created for virtual 6212 bases will go after the last extant field to date. */ 6213 next_field = &TYPE_FIELDS (t); 6214 while (*next_field) 6215 next_field = &DECL_CHAIN (*next_field); 6216 6217 /* Go through the virtual bases, allocating space for each virtual 6218 base that is not already a primary base class. These are 6219 allocated in inheritance graph order. */ 6220 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase)) 6221 { 6222 if (!BINFO_VIRTUAL_P (vbase)) 6223 continue; 6224 6225 if (!BINFO_PRIMARY_P (vbase)) 6226 { 6227 /* This virtual base is not a primary base of any class in the 6228 hierarchy, so we have to add space for it. */ 6229 next_field = build_base_field (rli, vbase, 6230 offsets, next_field); 6231 } 6232 } 6233 } 6234 6235 /* Returns the offset of the byte just past the end of the base class 6236 BINFO. */ 6237 6238 static tree 6239 end_of_base (tree binfo) 6240 { 6241 tree size; 6242 6243 if (!CLASSTYPE_AS_BASE (BINFO_TYPE (binfo))) 6244 size = TYPE_SIZE_UNIT (char_type_node); 6245 else if (is_empty_class (BINFO_TYPE (binfo))) 6246 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to 6247 allocate some space for it. It cannot have virtual bases, so 6248 TYPE_SIZE_UNIT is fine. */ 6249 size = TYPE_SIZE_UNIT (BINFO_TYPE (binfo)); 6250 else 6251 size = CLASSTYPE_SIZE_UNIT (BINFO_TYPE (binfo)); 6252 6253 return size_binop (PLUS_EXPR, BINFO_OFFSET (binfo), size); 6254 } 6255 6256 /* Returns the offset of the byte just past the end of the base class 6257 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then 6258 only non-virtual bases are included. */ 6259 6260 static tree 6261 end_of_class (tree t, int include_virtuals_p) 6262 { 6263 tree result = size_zero_node; 6264 vec<tree, va_gc> *vbases; 6265 tree binfo; 6266 tree base_binfo; 6267 tree offset; 6268 int i; 6269 6270 for (binfo = TYPE_BINFO (t), i = 0; 6271 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 6272 { 6273 if (!include_virtuals_p 6274 && BINFO_VIRTUAL_P (base_binfo) 6275 && (!BINFO_PRIMARY_P (base_binfo) 6276 || BINFO_INHERITANCE_CHAIN (base_binfo) != TYPE_BINFO (t))) 6277 continue; 6278 6279 offset = end_of_base (base_binfo); 6280 if (tree_int_cst_lt (result, offset)) 6281 result = offset; 6282 } 6283 6284 if (include_virtuals_p) 6285 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0; 6286 vec_safe_iterate (vbases, i, &base_binfo); i++) 6287 { 6288 offset = end_of_base (base_binfo); 6289 if (tree_int_cst_lt (result, offset)) 6290 result = offset; 6291 } 6292 6293 return result; 6294 } 6295 6296 /* Warn about bases of T that are inaccessible because they are 6297 ambiguous. For example: 6298 6299 struct S {}; 6300 struct T : public S {}; 6301 struct U : public S, public T {}; 6302 6303 Here, `(S*) new U' is not allowed because there are two `S' 6304 subobjects of U. */ 6305 6306 static void 6307 warn_about_ambiguous_bases (tree t) 6308 { 6309 int i; 6310 vec<tree, va_gc> *vbases; 6311 tree basetype; 6312 tree binfo; 6313 tree base_binfo; 6314 6315 /* If there are no repeated bases, nothing can be ambiguous. */ 6316 if (!CLASSTYPE_REPEATED_BASE_P (t)) 6317 return; 6318 6319 /* Check direct bases. */ 6320 for (binfo = TYPE_BINFO (t), i = 0; 6321 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 6322 { 6323 basetype = BINFO_TYPE (base_binfo); 6324 6325 if (!uniquely_derived_from_p (basetype, t)) 6326 warning (0, "direct base %qT inaccessible in %qT due to ambiguity", 6327 basetype, t); 6328 } 6329 6330 /* Check for ambiguous virtual bases. */ 6331 if (extra_warnings) 6332 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0; 6333 vec_safe_iterate (vbases, i, &binfo); i++) 6334 { 6335 basetype = BINFO_TYPE (binfo); 6336 6337 if (!uniquely_derived_from_p (basetype, t)) 6338 warning (OPT_Wextra, "virtual base %qT inaccessible in %qT due " 6339 "to ambiguity", basetype, t); 6340 } 6341 } 6342 6343 /* Compare two INTEGER_CSTs K1 and K2. */ 6344 6345 static int 6346 splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2) 6347 { 6348 return tree_int_cst_compare ((tree) k1, (tree) k2); 6349 } 6350 6351 /* Increase the size indicated in RLI to account for empty classes 6352 that are "off the end" of the class. */ 6353 6354 static void 6355 include_empty_classes (record_layout_info rli) 6356 { 6357 tree eoc; 6358 tree rli_size; 6359 6360 /* It might be the case that we grew the class to allocate a 6361 zero-sized base class. That won't be reflected in RLI, yet, 6362 because we are willing to overlay multiple bases at the same 6363 offset. However, now we need to make sure that RLI is big enough 6364 to reflect the entire class. */ 6365 eoc = end_of_class (rli->t, 6366 CLASSTYPE_AS_BASE (rli->t) != NULL_TREE); 6367 rli_size = rli_size_unit_so_far (rli); 6368 if (TREE_CODE (rli_size) == INTEGER_CST 6369 && tree_int_cst_lt (rli_size, eoc)) 6370 { 6371 /* The size should have been rounded to a whole byte. */ 6372 gcc_assert (tree_int_cst_equal 6373 (rli->bitpos, round_down (rli->bitpos, BITS_PER_UNIT))); 6374 rli->bitpos 6375 = size_binop (PLUS_EXPR, 6376 rli->bitpos, 6377 size_binop (MULT_EXPR, 6378 fold_convert (bitsizetype, 6379 size_binop (MINUS_EXPR, 6380 eoc, rli_size)), 6381 bitsize_int (BITS_PER_UNIT))); 6382 normalize_rli (rli); 6383 } 6384 } 6385 6386 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate 6387 BINFO_OFFSETs for all of the base-classes. Position the vtable 6388 pointer. Accumulate declared virtual functions on VIRTUALS_P. */ 6389 6390 static void 6391 layout_class_type (tree t, tree *virtuals_p) 6392 { 6393 tree non_static_data_members; 6394 tree field; 6395 tree vptr; 6396 record_layout_info rli; 6397 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of 6398 types that appear at that offset. */ 6399 splay_tree empty_base_offsets; 6400 /* True if the last field laid out was a bit-field. */ 6401 bool last_field_was_bitfield = false; 6402 /* The location at which the next field should be inserted. */ 6403 tree *next_field; 6404 /* T, as a base class. */ 6405 tree base_t; 6406 6407 /* Keep track of the first non-static data member. */ 6408 non_static_data_members = TYPE_FIELDS (t); 6409 6410 /* Start laying out the record. */ 6411 rli = start_record_layout (t); 6412 6413 /* Mark all the primary bases in the hierarchy. */ 6414 determine_primary_bases (t); 6415 6416 /* Create a pointer to our virtual function table. */ 6417 vptr = create_vtable_ptr (t, virtuals_p); 6418 6419 /* The vptr is always the first thing in the class. */ 6420 if (vptr) 6421 { 6422 DECL_CHAIN (vptr) = TYPE_FIELDS (t); 6423 TYPE_FIELDS (t) = vptr; 6424 next_field = &DECL_CHAIN (vptr); 6425 place_field (rli, vptr); 6426 } 6427 else 6428 next_field = &TYPE_FIELDS (t); 6429 6430 /* Build FIELD_DECLs for all of the non-virtual base-types. */ 6431 empty_base_offsets = splay_tree_new (splay_tree_compare_integer_csts, 6432 NULL, NULL); 6433 build_base_fields (rli, empty_base_offsets, next_field); 6434 6435 /* Layout the non-static data members. */ 6436 for (field = non_static_data_members; field; field = DECL_CHAIN (field)) 6437 { 6438 tree type; 6439 tree padding; 6440 6441 /* We still pass things that aren't non-static data members to 6442 the back end, in case it wants to do something with them. */ 6443 if (TREE_CODE (field) != FIELD_DECL) 6444 { 6445 place_field (rli, field); 6446 /* If the static data member has incomplete type, keep track 6447 of it so that it can be completed later. (The handling 6448 of pending statics in finish_record_layout is 6449 insufficient; consider: 6450 6451 struct S1; 6452 struct S2 { static S1 s1; }; 6453 6454 At this point, finish_record_layout will be called, but 6455 S1 is still incomplete.) */ 6456 if (VAR_P (field)) 6457 { 6458 maybe_register_incomplete_var (field); 6459 /* The visibility of static data members is determined 6460 at their point of declaration, not their point of 6461 definition. */ 6462 determine_visibility (field); 6463 } 6464 continue; 6465 } 6466 6467 type = TREE_TYPE (field); 6468 if (type == error_mark_node) 6469 continue; 6470 6471 padding = NULL_TREE; 6472 6473 /* If this field is a bit-field whose width is greater than its 6474 type, then there are some special rules for allocating 6475 it. */ 6476 if (DECL_C_BIT_FIELD (field) 6477 && tree_int_cst_lt (TYPE_SIZE (type), DECL_SIZE (field))) 6478 { 6479 unsigned int itk; 6480 tree integer_type; 6481 bool was_unnamed_p = false; 6482 /* We must allocate the bits as if suitably aligned for the 6483 longest integer type that fits in this many bits. type 6484 of the field. Then, we are supposed to use the left over 6485 bits as additional padding. */ 6486 for (itk = itk_char; itk != itk_none; ++itk) 6487 if (integer_types[itk] != NULL_TREE 6488 && (tree_int_cst_lt (size_int (MAX_FIXED_MODE_SIZE), 6489 TYPE_SIZE (integer_types[itk])) 6490 || tree_int_cst_lt (DECL_SIZE (field), 6491 TYPE_SIZE (integer_types[itk])))) 6492 break; 6493 6494 /* ITK now indicates a type that is too large for the 6495 field. We have to back up by one to find the largest 6496 type that fits. */ 6497 do 6498 { 6499 --itk; 6500 integer_type = integer_types[itk]; 6501 } while (itk > 0 && integer_type == NULL_TREE); 6502 6503 /* Figure out how much additional padding is required. */ 6504 if (tree_int_cst_lt (TYPE_SIZE (integer_type), DECL_SIZE (field))) 6505 { 6506 if (TREE_CODE (t) == UNION_TYPE) 6507 /* In a union, the padding field must have the full width 6508 of the bit-field; all fields start at offset zero. */ 6509 padding = DECL_SIZE (field); 6510 else 6511 padding = size_binop (MINUS_EXPR, DECL_SIZE (field), 6512 TYPE_SIZE (integer_type)); 6513 } 6514 6515 /* An unnamed bitfield does not normally affect the 6516 alignment of the containing class on a target where 6517 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not 6518 make any exceptions for unnamed bitfields when the 6519 bitfields are longer than their types. Therefore, we 6520 temporarily give the field a name. */ 6521 if (PCC_BITFIELD_TYPE_MATTERS && !DECL_NAME (field)) 6522 { 6523 was_unnamed_p = true; 6524 DECL_NAME (field) = make_anon_name (); 6525 } 6526 6527 DECL_SIZE (field) = TYPE_SIZE (integer_type); 6528 SET_DECL_ALIGN (field, TYPE_ALIGN (integer_type)); 6529 DECL_USER_ALIGN (field) = TYPE_USER_ALIGN (integer_type); 6530 layout_nonempty_base_or_field (rli, field, NULL_TREE, 6531 empty_base_offsets); 6532 if (was_unnamed_p) 6533 DECL_NAME (field) = NULL_TREE; 6534 /* Now that layout has been performed, set the size of the 6535 field to the size of its declared type; the rest of the 6536 field is effectively invisible. */ 6537 DECL_SIZE (field) = TYPE_SIZE (type); 6538 /* We must also reset the DECL_MODE of the field. */ 6539 SET_DECL_MODE (field, TYPE_MODE (type)); 6540 } 6541 else 6542 layout_nonempty_base_or_field (rli, field, NULL_TREE, 6543 empty_base_offsets); 6544 6545 /* Remember the location of any empty classes in FIELD. */ 6546 record_subobject_offsets (TREE_TYPE (field), 6547 byte_position(field), 6548 empty_base_offsets, 6549 /*is_data_member=*/true); 6550 6551 /* If a bit-field does not immediately follow another bit-field, 6552 and yet it starts in the middle of a byte, we have failed to 6553 comply with the ABI. */ 6554 if (warn_abi 6555 && DECL_C_BIT_FIELD (field) 6556 /* The TREE_NO_WARNING flag gets set by Objective-C when 6557 laying out an Objective-C class. The ObjC ABI differs 6558 from the C++ ABI, and so we do not want a warning 6559 here. */ 6560 && !TREE_NO_WARNING (field) 6561 && !last_field_was_bitfield 6562 && !integer_zerop (size_binop (TRUNC_MOD_EXPR, 6563 DECL_FIELD_BIT_OFFSET (field), 6564 bitsize_unit_node))) 6565 warning_at (DECL_SOURCE_LOCATION (field), OPT_Wabi, 6566 "offset of %qD is not ABI-compliant and may " 6567 "change in a future version of GCC", field); 6568 6569 /* The middle end uses the type of expressions to determine the 6570 possible range of expression values. In order to optimize 6571 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end 6572 must be made aware of the width of "i", via its type. 6573 6574 Because C++ does not have integer types of arbitrary width, 6575 we must (for the purposes of the front end) convert from the 6576 type assigned here to the declared type of the bitfield 6577 whenever a bitfield expression is used as an rvalue. 6578 Similarly, when assigning a value to a bitfield, the value 6579 must be converted to the type given the bitfield here. */ 6580 if (DECL_C_BIT_FIELD (field)) 6581 { 6582 unsigned HOST_WIDE_INT width; 6583 tree ftype = TREE_TYPE (field); 6584 width = tree_to_uhwi (DECL_SIZE (field)); 6585 if (width != TYPE_PRECISION (ftype)) 6586 { 6587 TREE_TYPE (field) 6588 = c_build_bitfield_integer_type (width, 6589 TYPE_UNSIGNED (ftype)); 6590 TREE_TYPE (field) 6591 = cp_build_qualified_type (TREE_TYPE (field), 6592 cp_type_quals (ftype)); 6593 } 6594 } 6595 6596 /* If we needed additional padding after this field, add it 6597 now. */ 6598 if (padding) 6599 { 6600 tree padding_field; 6601 6602 padding_field = build_decl (input_location, 6603 FIELD_DECL, 6604 NULL_TREE, 6605 char_type_node); 6606 DECL_BIT_FIELD (padding_field) = 1; 6607 DECL_SIZE (padding_field) = padding; 6608 DECL_CONTEXT (padding_field) = t; 6609 DECL_ARTIFICIAL (padding_field) = 1; 6610 DECL_IGNORED_P (padding_field) = 1; 6611 layout_nonempty_base_or_field (rli, padding_field, 6612 NULL_TREE, 6613 empty_base_offsets); 6614 } 6615 6616 last_field_was_bitfield = DECL_C_BIT_FIELD (field); 6617 } 6618 6619 if (!integer_zerop (rli->bitpos)) 6620 { 6621 /* Make sure that we are on a byte boundary so that the size of 6622 the class without virtual bases will always be a round number 6623 of bytes. */ 6624 rli->bitpos = round_up_loc (input_location, rli->bitpos, BITS_PER_UNIT); 6625 normalize_rli (rli); 6626 } 6627 6628 /* Delete all zero-width bit-fields from the list of fields. Now 6629 that the type is laid out they are no longer important. */ 6630 remove_zero_width_bit_fields (t); 6631 6632 /* Create the version of T used for virtual bases. We do not use 6633 make_class_type for this version; this is an artificial type. For 6634 a POD type, we just reuse T. */ 6635 if (CLASSTYPE_NON_LAYOUT_POD_P (t) || CLASSTYPE_EMPTY_P (t)) 6636 { 6637 base_t = make_node (TREE_CODE (t)); 6638 6639 /* Set the size and alignment for the new type. */ 6640 tree eoc; 6641 6642 /* If the ABI version is not at least two, and the last 6643 field was a bit-field, RLI may not be on a byte 6644 boundary. In particular, rli_size_unit_so_far might 6645 indicate the last complete byte, while rli_size_so_far 6646 indicates the total number of bits used. Therefore, 6647 rli_size_so_far, rather than rli_size_unit_so_far, is 6648 used to compute TYPE_SIZE_UNIT. */ 6649 eoc = end_of_class (t, /*include_virtuals_p=*/0); 6650 TYPE_SIZE_UNIT (base_t) 6651 = size_binop (MAX_EXPR, 6652 fold_convert (sizetype, 6653 size_binop (CEIL_DIV_EXPR, 6654 rli_size_so_far (rli), 6655 bitsize_int (BITS_PER_UNIT))), 6656 eoc); 6657 TYPE_SIZE (base_t) 6658 = size_binop (MAX_EXPR, 6659 rli_size_so_far (rli), 6660 size_binop (MULT_EXPR, 6661 fold_convert (bitsizetype, eoc), 6662 bitsize_int (BITS_PER_UNIT))); 6663 SET_TYPE_ALIGN (base_t, rli->record_align); 6664 TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t); 6665 TYPE_TYPELESS_STORAGE (base_t) = TYPE_TYPELESS_STORAGE (t); 6666 6667 /* Copy the fields from T. */ 6668 next_field = &TYPE_FIELDS (base_t); 6669 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) 6670 if (TREE_CODE (field) == FIELD_DECL) 6671 { 6672 *next_field = copy_node (field); 6673 DECL_CONTEXT (*next_field) = base_t; 6674 next_field = &DECL_CHAIN (*next_field); 6675 } 6676 *next_field = NULL_TREE; 6677 6678 /* Record the base version of the type. */ 6679 CLASSTYPE_AS_BASE (t) = base_t; 6680 TYPE_CONTEXT (base_t) = t; 6681 } 6682 else 6683 CLASSTYPE_AS_BASE (t) = t; 6684 6685 /* Every empty class contains an empty class. */ 6686 if (CLASSTYPE_EMPTY_P (t)) 6687 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1; 6688 6689 /* Set the TYPE_DECL for this type to contain the right 6690 value for DECL_OFFSET, so that we can use it as part 6691 of a COMPONENT_REF for multiple inheritance. */ 6692 layout_decl (TYPE_MAIN_DECL (t), 0); 6693 6694 /* Now fix up any virtual base class types that we left lying 6695 around. We must get these done before we try to lay out the 6696 virtual function table. As a side-effect, this will remove the 6697 base subobject fields. */ 6698 layout_virtual_bases (rli, empty_base_offsets); 6699 6700 /* Make sure that empty classes are reflected in RLI at this 6701 point. */ 6702 include_empty_classes (rli); 6703 6704 /* Make sure not to create any structures with zero size. */ 6705 if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t)) 6706 place_field (rli, 6707 build_decl (input_location, 6708 FIELD_DECL, NULL_TREE, char_type_node)); 6709 6710 /* If this is a non-POD, declaring it packed makes a difference to how it 6711 can be used as a field; don't let finalize_record_size undo it. */ 6712 if (TYPE_PACKED (t) && !layout_pod_type_p (t)) 6713 rli->packed_maybe_necessary = true; 6714 6715 /* Let the back end lay out the type. */ 6716 finish_record_layout (rli, /*free_p=*/true); 6717 6718 if (TYPE_SIZE_UNIT (t) 6719 && TREE_CODE (TYPE_SIZE_UNIT (t)) == INTEGER_CST 6720 && !TREE_OVERFLOW (TYPE_SIZE_UNIT (t)) 6721 && !valid_constant_size_p (TYPE_SIZE_UNIT (t))) 6722 error ("size of type %qT is too large (%qE bytes)", t, TYPE_SIZE_UNIT (t)); 6723 6724 /* Warn about bases that can't be talked about due to ambiguity. */ 6725 warn_about_ambiguous_bases (t); 6726 6727 /* Now that we're done with layout, give the base fields the real types. */ 6728 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) 6729 if (DECL_ARTIFICIAL (field) && IS_FAKE_BASE_TYPE (TREE_TYPE (field))) 6730 TREE_TYPE (field) = TYPE_CONTEXT (TREE_TYPE (field)); 6731 6732 /* Clean up. */ 6733 splay_tree_delete (empty_base_offsets); 6734 6735 if (CLASSTYPE_EMPTY_P (t) 6736 && tree_int_cst_lt (sizeof_biggest_empty_class, 6737 TYPE_SIZE_UNIT (t))) 6738 sizeof_biggest_empty_class = TYPE_SIZE_UNIT (t); 6739 } 6740 6741 /* Determine the "key method" for the class type indicated by TYPE, 6742 and set CLASSTYPE_KEY_METHOD accordingly. */ 6743 6744 void 6745 determine_key_method (tree type) 6746 { 6747 tree method; 6748 6749 if (processing_template_decl 6750 || CLASSTYPE_TEMPLATE_INSTANTIATION (type) 6751 || CLASSTYPE_INTERFACE_KNOWN (type)) 6752 return; 6753 6754 /* The key method is the first non-pure virtual function that is not 6755 inline at the point of class definition. On some targets the 6756 key function may not be inline; those targets should not call 6757 this function until the end of the translation unit. */ 6758 for (method = TYPE_METHODS (type); method != NULL_TREE; 6759 method = DECL_CHAIN (method)) 6760 if (TREE_CODE (method) == FUNCTION_DECL 6761 && DECL_VINDEX (method) != NULL_TREE 6762 && ! DECL_DECLARED_INLINE_P (method) 6763 && ! DECL_PURE_VIRTUAL_P (method)) 6764 { 6765 CLASSTYPE_KEY_METHOD (type) = method; 6766 break; 6767 } 6768 6769 return; 6770 } 6771 6772 6773 /* Allocate and return an instance of struct sorted_fields_type with 6774 N fields. */ 6775 6776 static struct sorted_fields_type * 6777 sorted_fields_type_new (int n) 6778 { 6779 struct sorted_fields_type *sft; 6780 sft = (sorted_fields_type *) ggc_internal_alloc (sizeof (sorted_fields_type) 6781 + n * sizeof (tree)); 6782 sft->len = n; 6783 6784 return sft; 6785 } 6786 6787 /* Helper of find_flexarrays. Return true when FLD refers to a non-static 6788 class data member of non-zero size, otherwise false. */ 6789 6790 static inline bool 6791 field_nonempty_p (const_tree fld) 6792 { 6793 if (TREE_CODE (fld) == ERROR_MARK) 6794 return false; 6795 6796 tree type = TREE_TYPE (fld); 6797 if (TREE_CODE (fld) == FIELD_DECL 6798 && TREE_CODE (type) != ERROR_MARK 6799 && (DECL_NAME (fld) || RECORD_OR_UNION_TYPE_P (type))) 6800 { 6801 return TYPE_SIZE (type) 6802 && (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST 6803 || !tree_int_cst_equal (size_zero_node, TYPE_SIZE (type))); 6804 } 6805 6806 return false; 6807 } 6808 6809 /* Used by find_flexarrays and related functions. */ 6810 6811 struct flexmems_t 6812 { 6813 /* The first flexible array member or non-zero array member found 6814 in the order of layout. */ 6815 tree array; 6816 /* First non-static non-empty data member in the class or its bases. */ 6817 tree first; 6818 /* The first non-static non-empty data member following either 6819 the flexible array member, if found, or the zero-length array member 6820 otherwise. AFTER[1] refers to the first such data member of a union 6821 of which the struct containing the flexible array member or zero-length 6822 array is a member, or NULL when no such union exists. This element is 6823 only used during searching, not for diagnosing problems. AFTER[0] 6824 refers to the first such data member that is not a member of such 6825 a union. */ 6826 tree after[2]; 6827 6828 /* Refers to a struct (not union) in which the struct of which the flexible 6829 array is member is defined. Used to diagnose strictly (according to C) 6830 invalid uses of the latter structs. */ 6831 tree enclosing; 6832 }; 6833 6834 /* Find either the first flexible array member or the first zero-length 6835 array, in that order of preference, among members of class T (but not 6836 its base classes), and set members of FMEM accordingly. 6837 BASE_P is true if T is a base class of another class. 6838 PUN is set to the outermost union in which the flexible array member 6839 (or zero-length array) is defined if one such union exists, otherwise 6840 to NULL. 6841 Similarly, PSTR is set to a data member of the outermost struct of 6842 which the flexible array is a member if one such struct exists, 6843 otherwise to NULL. */ 6844 6845 static void 6846 find_flexarrays (tree t, flexmems_t *fmem, bool base_p, 6847 tree pun /* = NULL_TREE */, 6848 tree pstr /* = NULL_TREE */) 6849 { 6850 /* Set the "pointer" to the outermost enclosing union if not set 6851 yet and maintain it for the remainder of the recursion. */ 6852 if (!pun && TREE_CODE (t) == UNION_TYPE) 6853 pun = t; 6854 6855 for (tree fld = TYPE_FIELDS (t); fld; fld = DECL_CHAIN (fld)) 6856 { 6857 if (fld == error_mark_node) 6858 return; 6859 6860 /* Is FLD a typedef for an anonymous struct? */ 6861 6862 /* FIXME: Note that typedefs (as well as arrays) need to be fully 6863 handled elsewhere so that errors like the following are detected 6864 as well: 6865 typedef struct { int i, a[], j; } S; // bug c++/72753 6866 S s [2]; // bug c++/68489 6867 */ 6868 if (TREE_CODE (fld) == TYPE_DECL 6869 && DECL_IMPLICIT_TYPEDEF_P (fld) 6870 && CLASS_TYPE_P (TREE_TYPE (fld)) 6871 && anon_aggrname_p (DECL_NAME (fld))) 6872 { 6873 /* Check the nested unnamed type referenced via a typedef 6874 independently of FMEM (since it's not a data member of 6875 the enclosing class). */ 6876 check_flexarrays (TREE_TYPE (fld)); 6877 continue; 6878 } 6879 6880 /* Skip anything that's GCC-generated or not a (non-static) data 6881 member. */ 6882 if (DECL_ARTIFICIAL (fld) || TREE_CODE (fld) != FIELD_DECL) 6883 continue; 6884 6885 /* Type of the member. */ 6886 tree fldtype = TREE_TYPE (fld); 6887 if (fldtype == error_mark_node) 6888 return; 6889 6890 /* Determine the type of the array element or object referenced 6891 by the member so that it can be checked for flexible array 6892 members if it hasn't been yet. */ 6893 tree eltype = fldtype; 6894 while (TREE_CODE (eltype) == ARRAY_TYPE 6895 || TREE_CODE (eltype) == POINTER_TYPE 6896 || TREE_CODE (eltype) == REFERENCE_TYPE) 6897 eltype = TREE_TYPE (eltype); 6898 6899 if (RECORD_OR_UNION_TYPE_P (eltype)) 6900 { 6901 if (fmem->array && !fmem->after[bool (pun)]) 6902 { 6903 /* Once the member after the flexible array has been found 6904 we're done. */ 6905 fmem->after[bool (pun)] = fld; 6906 break; 6907 } 6908 6909 if (eltype == fldtype || TYPE_UNNAMED_P (eltype)) 6910 { 6911 /* Descend into the non-static member struct or union and try 6912 to find a flexible array member or zero-length array among 6913 its members. This is only necessary for anonymous types 6914 and types in whose context the current type T has not been 6915 defined (the latter must not be checked again because they 6916 are already in the process of being checked by one of the 6917 recursive calls). */ 6918 6919 tree first = fmem->first; 6920 tree array = fmem->array; 6921 6922 /* If this member isn't anonymous and a prior non-flexible array 6923 member has been seen in one of the enclosing structs, clear 6924 the FIRST member since it doesn't contribute to the flexible 6925 array struct's members. */ 6926 if (first && !array && !ANON_AGGR_TYPE_P (eltype)) 6927 fmem->first = NULL_TREE; 6928 6929 find_flexarrays (eltype, fmem, false, pun, 6930 !pstr && TREE_CODE (t) == RECORD_TYPE ? fld : pstr); 6931 6932 if (fmem->array != array) 6933 continue; 6934 6935 if (first && !array && !ANON_AGGR_TYPE_P (eltype)) 6936 { 6937 /* Restore the FIRST member reset above if no flexible 6938 array member has been found in this member's struct. */ 6939 fmem->first = first; 6940 } 6941 6942 /* If the member struct contains the first flexible array 6943 member, or if this member is a base class, continue to 6944 the next member and avoid setting the FMEM->NEXT pointer 6945 to point to it. */ 6946 if (base_p) 6947 continue; 6948 } 6949 } 6950 6951 if (field_nonempty_p (fld)) 6952 { 6953 /* Remember the first non-static data member. */ 6954 if (!fmem->first) 6955 fmem->first = fld; 6956 6957 /* Remember the first non-static data member after the flexible 6958 array member, if one has been found, or the zero-length array 6959 if it has been found. */ 6960 if (fmem->array && !fmem->after[bool (pun)]) 6961 fmem->after[bool (pun)] = fld; 6962 } 6963 6964 /* Skip non-arrays. */ 6965 if (TREE_CODE (fldtype) != ARRAY_TYPE) 6966 continue; 6967 6968 /* Determine the upper bound of the array if it has one. */ 6969 if (TYPE_DOMAIN (fldtype)) 6970 { 6971 if (fmem->array) 6972 { 6973 /* Make a record of the zero-length array if either one 6974 such field or a flexible array member has been seen to 6975 handle the pathological and unlikely case of multiple 6976 such members. */ 6977 if (!fmem->after[bool (pun)]) 6978 fmem->after[bool (pun)] = fld; 6979 } 6980 else if (integer_all_onesp (TYPE_MAX_VALUE (TYPE_DOMAIN (fldtype)))) 6981 { 6982 /* Remember the first zero-length array unless a flexible array 6983 member has already been seen. */ 6984 fmem->array = fld; 6985 fmem->enclosing = pstr; 6986 } 6987 } 6988 else 6989 { 6990 /* Flexible array members have no upper bound. */ 6991 if (fmem->array) 6992 { 6993 /* Replace the zero-length array if it's been stored and 6994 reset the after pointer. */ 6995 if (TYPE_DOMAIN (TREE_TYPE (fmem->array))) 6996 { 6997 fmem->after[bool (pun)] = NULL_TREE; 6998 fmem->array = fld; 6999 fmem->enclosing = pstr; 7000 } 7001 } 7002 else 7003 { 7004 fmem->array = fld; 7005 fmem->enclosing = pstr; 7006 } 7007 } 7008 } 7009 } 7010 7011 /* Diagnose a strictly (by the C standard) invalid use of a struct with 7012 a flexible array member (or the zero-length array extension). */ 7013 7014 static void 7015 diagnose_invalid_flexarray (const flexmems_t *fmem) 7016 { 7017 if (fmem->array && fmem->enclosing 7018 && pedwarn (location_of (fmem->enclosing), OPT_Wpedantic, 7019 TYPE_DOMAIN (TREE_TYPE (fmem->array)) 7020 ? G_("invalid use of %q#T with a zero-size array " 7021 "in %q#D") 7022 : G_("invalid use of %q#T with a flexible array member " 7023 "in %q#T"), 7024 DECL_CONTEXT (fmem->array), 7025 DECL_CONTEXT (fmem->enclosing))) 7026 inform (DECL_SOURCE_LOCATION (fmem->array), 7027 "array member %q#D declared here", fmem->array); 7028 } 7029 7030 /* Issue diagnostics for invalid flexible array members or zero-length 7031 arrays that are not the last elements of the containing class or its 7032 base classes or that are its sole members. */ 7033 7034 static void 7035 diagnose_flexarrays (tree t, const flexmems_t *fmem) 7036 { 7037 if (!fmem->array) 7038 return; 7039 7040 if (fmem->first && !fmem->after[0]) 7041 { 7042 diagnose_invalid_flexarray (fmem); 7043 return; 7044 } 7045 7046 /* Has a diagnostic been issued? */ 7047 bool diagd = false; 7048 7049 const char *msg = 0; 7050 7051 if (TYPE_DOMAIN (TREE_TYPE (fmem->array))) 7052 { 7053 if (fmem->after[0]) 7054 msg = G_("zero-size array member %qD not at end of %q#T"); 7055 else if (!fmem->first) 7056 msg = G_("zero-size array member %qD in an otherwise empty %q#T"); 7057 7058 if (msg) 7059 { 7060 location_t loc = DECL_SOURCE_LOCATION (fmem->array); 7061 7062 if (pedwarn (loc, OPT_Wpedantic, msg, fmem->array, t)) 7063 { 7064 inform (location_of (t), "in the definition of %q#T", t); 7065 diagd = true; 7066 } 7067 } 7068 } 7069 else 7070 { 7071 if (fmem->after[0]) 7072 msg = G_("flexible array member %qD not at end of %q#T"); 7073 else if (!fmem->first) 7074 msg = G_("flexible array member %qD in an otherwise empty %q#T"); 7075 7076 if (msg) 7077 { 7078 location_t loc = DECL_SOURCE_LOCATION (fmem->array); 7079 diagd = true; 7080 7081 error_at (loc, msg, fmem->array, t); 7082 7083 /* In the unlikely event that the member following the flexible 7084 array member is declared in a different class, or the member 7085 overlaps another member of a common union, point to it. 7086 Otherwise it should be obvious. */ 7087 if (fmem->after[0] 7088 && ((DECL_CONTEXT (fmem->after[0]) 7089 != DECL_CONTEXT (fmem->array)))) 7090 { 7091 inform (DECL_SOURCE_LOCATION (fmem->after[0]), 7092 "next member %q#D declared here", 7093 fmem->after[0]); 7094 inform (location_of (t), "in the definition of %q#T", t); 7095 } 7096 } 7097 } 7098 7099 if (!diagd && fmem->array && fmem->enclosing) 7100 diagnose_invalid_flexarray (fmem); 7101 } 7102 7103 7104 /* Recursively check to make sure that any flexible array or zero-length 7105 array members of class T or its bases are valid (i.e., not the sole 7106 non-static data member of T and, if one exists, that it is the last 7107 non-static data member of T and its base classes. FMEM is expected 7108 to be initially null and is used internally by recursive calls to 7109 the function. Issue the appropriate diagnostics for the array member 7110 that fails the checks. */ 7111 7112 static void 7113 check_flexarrays (tree t, flexmems_t *fmem /* = NULL */, 7114 bool base_p /* = false */) 7115 { 7116 /* Initialize the result of a search for flexible array and zero-length 7117 array members. Avoid doing any work if the most interesting FMEM data 7118 have already been populated. */ 7119 flexmems_t flexmems = flexmems_t (); 7120 if (!fmem) 7121 fmem = &flexmems; 7122 else if (fmem->array && fmem->first && fmem->after[0]) 7123 return; 7124 7125 tree fam = fmem->array; 7126 7127 /* Recursively check the primary base class first. */ 7128 if (CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 7129 { 7130 tree basetype = BINFO_TYPE (CLASSTYPE_PRIMARY_BINFO (t)); 7131 check_flexarrays (basetype, fmem, true); 7132 } 7133 7134 /* Recursively check the base classes. */ 7135 int nbases = TYPE_BINFO (t) ? BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) : 0; 7136 for (int i = 0; i < nbases; ++i) 7137 { 7138 tree base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i); 7139 7140 /* The primary base class was already checked above. */ 7141 if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t)) 7142 continue; 7143 7144 /* Virtual base classes are at the end. */ 7145 if (BINFO_VIRTUAL_P (base_binfo)) 7146 continue; 7147 7148 /* Check the base class. */ 7149 check_flexarrays (BINFO_TYPE (base_binfo), fmem, /*base_p=*/true); 7150 } 7151 7152 if (fmem == &flexmems) 7153 { 7154 /* Check virtual base classes only once per derived class. 7155 I.e., this check is not performed recursively for base 7156 classes. */ 7157 int i; 7158 tree base_binfo; 7159 vec<tree, va_gc> *vbases; 7160 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0; 7161 vec_safe_iterate (vbases, i, &base_binfo); i++) 7162 { 7163 /* Check the virtual base class. */ 7164 tree basetype = TREE_TYPE (base_binfo); 7165 7166 check_flexarrays (basetype, fmem, /*base_p=*/true); 7167 } 7168 } 7169 7170 /* Is the type unnamed (and therefore a member of it potentially 7171 an anonymous struct or union)? */ 7172 bool maybe_anon_p = TYPE_UNNAMED_P (t); 7173 7174 /* Search the members of the current (possibly derived) class, skipping 7175 unnamed structs and unions since those could be anonymous. */ 7176 if (fmem != &flexmems || !maybe_anon_p) 7177 find_flexarrays (t, fmem, base_p || fam != fmem->array); 7178 7179 if (fmem == &flexmems && !maybe_anon_p) 7180 { 7181 /* Issue diagnostics for invalid flexible and zero-length array 7182 members found in base classes or among the members of the current 7183 class. Ignore anonymous structs and unions whose members are 7184 considered to be members of the enclosing class and thus will 7185 be diagnosed when checking it. */ 7186 diagnose_flexarrays (t, fmem); 7187 } 7188 } 7189 7190 /* Perform processing required when the definition of T (a class type) 7191 is complete. Diagnose invalid definitions of flexible array members 7192 and zero-size arrays. */ 7193 7194 void 7195 finish_struct_1 (tree t) 7196 { 7197 tree x; 7198 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */ 7199 tree virtuals = NULL_TREE; 7200 7201 if (COMPLETE_TYPE_P (t)) 7202 { 7203 gcc_assert (MAYBE_CLASS_TYPE_P (t)); 7204 error ("redefinition of %q#T", t); 7205 popclass (); 7206 return; 7207 } 7208 7209 /* If this type was previously laid out as a forward reference, 7210 make sure we lay it out again. */ 7211 TYPE_SIZE (t) = NULL_TREE; 7212 CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE; 7213 7214 /* Make assumptions about the class; we'll reset the flags if 7215 necessary. */ 7216 CLASSTYPE_EMPTY_P (t) = 1; 7217 CLASSTYPE_NEARLY_EMPTY_P (t) = 1; 7218 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 0; 7219 CLASSTYPE_LITERAL_P (t) = true; 7220 7221 /* Do end-of-class semantic processing: checking the validity of the 7222 bases and members and add implicitly generated methods. */ 7223 check_bases_and_members (t); 7224 7225 /* Find the key method. */ 7226 if (TYPE_CONTAINS_VPTR_P (t)) 7227 { 7228 /* The Itanium C++ ABI permits the key method to be chosen when 7229 the class is defined -- even though the key method so 7230 selected may later turn out to be an inline function. On 7231 some systems (such as ARM Symbian OS) the key method cannot 7232 be determined until the end of the translation unit. On such 7233 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which 7234 will cause the class to be added to KEYED_CLASSES. Then, in 7235 finish_file we will determine the key method. */ 7236 if (targetm.cxx.key_method_may_be_inline ()) 7237 determine_key_method (t); 7238 7239 /* If a polymorphic class has no key method, we may emit the vtable 7240 in every translation unit where the class definition appears. If 7241 we're devirtualizing, we can look into the vtable even if we 7242 aren't emitting it. */ 7243 if (CLASSTYPE_KEY_METHOD (t) == NULL_TREE) 7244 keyed_classes = tree_cons (NULL_TREE, t, keyed_classes); 7245 } 7246 7247 /* Layout the class itself. */ 7248 layout_class_type (t, &virtuals); 7249 if (CLASSTYPE_AS_BASE (t) != t) 7250 /* We use the base type for trivial assignments, and hence it 7251 needs a mode. */ 7252 compute_record_mode (CLASSTYPE_AS_BASE (t)); 7253 7254 /* With the layout complete, check for flexible array members and 7255 zero-length arrays that might overlap other members in the final 7256 layout. */ 7257 check_flexarrays (t); 7258 7259 virtuals = modify_all_vtables (t, nreverse (virtuals)); 7260 7261 /* If necessary, create the primary vtable for this class. */ 7262 if (virtuals || TYPE_CONTAINS_VPTR_P (t)) 7263 { 7264 /* We must enter these virtuals into the table. */ 7265 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 7266 build_primary_vtable (NULL_TREE, t); 7267 else if (! BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (t))) 7268 /* Here we know enough to change the type of our virtual 7269 function table, but we will wait until later this function. */ 7270 build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t); 7271 7272 /* If we're warning about ABI tags, check the types of the new 7273 virtual functions. */ 7274 if (warn_abi_tag) 7275 for (tree v = virtuals; v; v = TREE_CHAIN (v)) 7276 check_abi_tags (t, TREE_VALUE (v)); 7277 } 7278 7279 if (TYPE_CONTAINS_VPTR_P (t)) 7280 { 7281 int vindex; 7282 tree fn; 7283 7284 if (BINFO_VTABLE (TYPE_BINFO (t))) 7285 gcc_assert (DECL_VIRTUAL_P (BINFO_VTABLE (TYPE_BINFO (t)))); 7286 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 7287 gcc_assert (BINFO_VIRTUALS (TYPE_BINFO (t)) == NULL_TREE); 7288 7289 /* Add entries for virtual functions introduced by this class. */ 7290 BINFO_VIRTUALS (TYPE_BINFO (t)) 7291 = chainon (BINFO_VIRTUALS (TYPE_BINFO (t)), virtuals); 7292 7293 /* Set DECL_VINDEX for all functions declared in this class. */ 7294 for (vindex = 0, fn = BINFO_VIRTUALS (TYPE_BINFO (t)); 7295 fn; 7296 fn = TREE_CHAIN (fn), 7297 vindex += (TARGET_VTABLE_USES_DESCRIPTORS 7298 ? TARGET_VTABLE_USES_DESCRIPTORS : 1)) 7299 { 7300 tree fndecl = BV_FN (fn); 7301 7302 if (DECL_THUNK_P (fndecl)) 7303 /* A thunk. We should never be calling this entry directly 7304 from this vtable -- we'd use the entry for the non 7305 thunk base function. */ 7306 DECL_VINDEX (fndecl) = NULL_TREE; 7307 else if (TREE_CODE (DECL_VINDEX (fndecl)) != INTEGER_CST) 7308 DECL_VINDEX (fndecl) = build_int_cst (NULL_TREE, vindex); 7309 } 7310 } 7311 7312 finish_struct_bits (t); 7313 set_method_tm_attributes (t); 7314 if (flag_openmp || flag_openmp_simd) 7315 finish_omp_declare_simd_methods (t); 7316 7317 /* Complete the rtl for any static member objects of the type we're 7318 working on. */ 7319 for (x = TYPE_FIELDS (t); x; x = DECL_CHAIN (x)) 7320 if (VAR_P (x) && TREE_STATIC (x) 7321 && TREE_TYPE (x) != error_mark_node 7322 && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t)) 7323 SET_DECL_MODE (x, TYPE_MODE (t)); 7324 7325 /* Done with FIELDS...now decide whether to sort these for 7326 faster lookups later. 7327 7328 We use a small number because most searches fail (succeeding 7329 ultimately as the search bores through the inheritance 7330 hierarchy), and we want this failure to occur quickly. */ 7331 7332 insert_into_classtype_sorted_fields (TYPE_FIELDS (t), t, 8); 7333 7334 /* Complain if one of the field types requires lower visibility. */ 7335 constrain_class_visibility (t); 7336 7337 /* Make the rtl for any new vtables we have created, and unmark 7338 the base types we marked. */ 7339 finish_vtbls (t); 7340 7341 /* Build the VTT for T. */ 7342 build_vtt (t); 7343 7344 if (warn_nonvdtor 7345 && TYPE_POLYMORPHIC_P (t) && accessible_nvdtor_p (t) 7346 && !CLASSTYPE_FINAL (t)) 7347 warning (OPT_Wnon_virtual_dtor, 7348 "%q#T has virtual functions and accessible" 7349 " non-virtual destructor", t); 7350 7351 complete_vars (t); 7352 7353 if (warn_overloaded_virtual) 7354 warn_hidden (t); 7355 7356 /* Class layout, assignment of virtual table slots, etc., is now 7357 complete. Give the back end a chance to tweak the visibility of 7358 the class or perform any other required target modifications. */ 7359 targetm.cxx.adjust_class_at_definition (t); 7360 7361 maybe_suppress_debug_info (t); 7362 7363 if (flag_vtable_verify) 7364 vtv_save_class_info (t); 7365 7366 dump_class_hierarchy (t); 7367 7368 /* Finish debugging output for this type. */ 7369 rest_of_type_compilation (t, ! LOCAL_CLASS_P (t)); 7370 7371 if (TYPE_TRANSPARENT_AGGR (t)) 7372 { 7373 tree field = first_field (t); 7374 if (field == NULL_TREE || error_operand_p (field)) 7375 { 7376 error ("type transparent %q#T does not have any fields", t); 7377 TYPE_TRANSPARENT_AGGR (t) = 0; 7378 } 7379 else if (DECL_ARTIFICIAL (field)) 7380 { 7381 if (DECL_FIELD_IS_BASE (field)) 7382 error ("type transparent class %qT has base classes", t); 7383 else 7384 { 7385 gcc_checking_assert (DECL_VIRTUAL_P (field)); 7386 error ("type transparent class %qT has virtual functions", t); 7387 } 7388 TYPE_TRANSPARENT_AGGR (t) = 0; 7389 } 7390 else if (TYPE_MODE (t) != DECL_MODE (field)) 7391 { 7392 error ("type transparent %q#T cannot be made transparent because " 7393 "the type of the first field has a different ABI from the " 7394 "class overall", t); 7395 TYPE_TRANSPARENT_AGGR (t) = 0; 7396 } 7397 } 7398 } 7399 7400 /* Insert FIELDS into T for the sorted case if the FIELDS count is 7401 equal to THRESHOLD or greater than THRESHOLD. */ 7402 7403 static void 7404 insert_into_classtype_sorted_fields (tree fields, tree t, int threshold) 7405 { 7406 int n_fields = count_fields (fields); 7407 if (n_fields >= threshold) 7408 { 7409 struct sorted_fields_type *field_vec = sorted_fields_type_new (n_fields); 7410 add_fields_to_record_type (fields, field_vec, 0); 7411 qsort (field_vec->elts, n_fields, sizeof (tree), field_decl_cmp); 7412 CLASSTYPE_SORTED_FIELDS (t) = field_vec; 7413 } 7414 } 7415 7416 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */ 7417 7418 void 7419 insert_late_enum_def_into_classtype_sorted_fields (tree enumtype, tree t) 7420 { 7421 struct sorted_fields_type *sorted_fields = CLASSTYPE_SORTED_FIELDS (t); 7422 if (sorted_fields) 7423 { 7424 int i; 7425 int n_fields 7426 = list_length (TYPE_VALUES (enumtype)) + sorted_fields->len; 7427 struct sorted_fields_type *field_vec = sorted_fields_type_new (n_fields); 7428 7429 for (i = 0; i < sorted_fields->len; ++i) 7430 field_vec->elts[i] = sorted_fields->elts[i]; 7431 7432 add_enum_fields_to_record_type (enumtype, field_vec, 7433 sorted_fields->len); 7434 qsort (field_vec->elts, n_fields, sizeof (tree), field_decl_cmp); 7435 CLASSTYPE_SORTED_FIELDS (t) = field_vec; 7436 } 7437 } 7438 7439 /* When T was built up, the member declarations were added in reverse 7440 order. Rearrange them to declaration order. */ 7441 7442 void 7443 unreverse_member_declarations (tree t) 7444 { 7445 tree next; 7446 tree prev; 7447 tree x; 7448 7449 /* The following lists are all in reverse order. Put them in 7450 declaration order now. */ 7451 TYPE_METHODS (t) = nreverse (TYPE_METHODS (t)); 7452 CLASSTYPE_DECL_LIST (t) = nreverse (CLASSTYPE_DECL_LIST (t)); 7453 7454 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in 7455 reverse order, so we can't just use nreverse. */ 7456 prev = NULL_TREE; 7457 for (x = TYPE_FIELDS (t); 7458 x && TREE_CODE (x) != TYPE_DECL; 7459 x = next) 7460 { 7461 next = DECL_CHAIN (x); 7462 DECL_CHAIN (x) = prev; 7463 prev = x; 7464 } 7465 if (prev) 7466 { 7467 DECL_CHAIN (TYPE_FIELDS (t)) = x; 7468 if (prev) 7469 TYPE_FIELDS (t) = prev; 7470 } 7471 } 7472 7473 tree 7474 finish_struct (tree t, tree attributes) 7475 { 7476 location_t saved_loc = input_location; 7477 7478 /* Now that we've got all the field declarations, reverse everything 7479 as necessary. */ 7480 unreverse_member_declarations (t); 7481 7482 cplus_decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 7483 fixup_attribute_variants (t); 7484 7485 /* Nadger the current location so that diagnostics point to the start of 7486 the struct, not the end. */ 7487 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (t)); 7488 7489 if (processing_template_decl) 7490 { 7491 tree x; 7492 7493 finish_struct_methods (t); 7494 TYPE_SIZE (t) = bitsize_zero_node; 7495 TYPE_SIZE_UNIT (t) = size_zero_node; 7496 7497 /* We need to emit an error message if this type was used as a parameter 7498 and it is an abstract type, even if it is a template. We construct 7499 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into 7500 account and we call complete_vars with this type, which will check 7501 the PARM_DECLS. Note that while the type is being defined, 7502 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends 7503 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */ 7504 CLASSTYPE_PURE_VIRTUALS (t) = NULL; 7505 for (x = TYPE_METHODS (t); x; x = DECL_CHAIN (x)) 7506 if (DECL_PURE_VIRTUAL_P (x)) 7507 vec_safe_push (CLASSTYPE_PURE_VIRTUALS (t), x); 7508 complete_vars (t); 7509 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if 7510 an enclosing scope is a template class, so that this function be 7511 found by lookup_fnfields_1 when the using declaration is not 7512 instantiated yet. */ 7513 for (x = TYPE_FIELDS (t); x; x = DECL_CHAIN (x)) 7514 if (TREE_CODE (x) == USING_DECL) 7515 { 7516 tree fn = strip_using_decl (x); 7517 if (is_overloaded_fn (fn)) 7518 for (; fn; fn = OVL_NEXT (fn)) 7519 add_method (t, OVL_CURRENT (fn), x); 7520 } 7521 7522 /* Remember current #pragma pack value. */ 7523 TYPE_PRECISION (t) = maximum_field_alignment; 7524 7525 /* Fix up any variants we've already built. */ 7526 for (x = TYPE_NEXT_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x)) 7527 { 7528 TYPE_SIZE (x) = TYPE_SIZE (t); 7529 TYPE_SIZE_UNIT (x) = TYPE_SIZE_UNIT (t); 7530 TYPE_FIELDS (x) = TYPE_FIELDS (t); 7531 TYPE_METHODS (x) = TYPE_METHODS (t); 7532 } 7533 } 7534 else 7535 finish_struct_1 (t); 7536 7537 if (is_std_init_list (t)) 7538 { 7539 /* People keep complaining that the compiler crashes on an invalid 7540 definition of initializer_list, so I guess we should explicitly 7541 reject it. What the compiler internals care about is that it's a 7542 template and has a pointer field followed by an integer field. */ 7543 bool ok = false; 7544 if (processing_template_decl) 7545 { 7546 tree f = next_initializable_field (TYPE_FIELDS (t)); 7547 if (f && TREE_CODE (TREE_TYPE (f)) == POINTER_TYPE) 7548 { 7549 f = next_initializable_field (DECL_CHAIN (f)); 7550 if (f && same_type_p (TREE_TYPE (f), size_type_node)) 7551 ok = true; 7552 } 7553 } 7554 if (!ok) 7555 fatal_error (input_location, 7556 "definition of std::initializer_list does not match " 7557 "#include <initializer_list>"); 7558 } 7559 7560 input_location = saved_loc; 7561 7562 TYPE_BEING_DEFINED (t) = 0; 7563 7564 if (current_class_type) 7565 popclass (); 7566 else 7567 error ("trying to finish struct, but kicked out due to previous parse errors"); 7568 7569 if (processing_template_decl && at_function_scope_p () 7570 /* Lambdas are defined by the LAMBDA_EXPR. */ 7571 && !LAMBDA_TYPE_P (t)) 7572 add_stmt (build_min (TAG_DEFN, t)); 7573 7574 return t; 7575 } 7576 7577 /* Hash table to avoid endless recursion when handling references. */ 7578 static hash_table<nofree_ptr_hash<tree_node> > *fixed_type_or_null_ref_ht; 7579 7580 /* Return the dynamic type of INSTANCE, if known. 7581 Used to determine whether the virtual function table is needed 7582 or not. 7583 7584 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless 7585 of our knowledge of its type. *NONNULL should be initialized 7586 before this function is called. */ 7587 7588 static tree 7589 fixed_type_or_null (tree instance, int *nonnull, int *cdtorp) 7590 { 7591 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp) 7592 7593 switch (TREE_CODE (instance)) 7594 { 7595 case INDIRECT_REF: 7596 if (POINTER_TYPE_P (TREE_TYPE (instance))) 7597 return NULL_TREE; 7598 else 7599 return RECUR (TREE_OPERAND (instance, 0)); 7600 7601 case CALL_EXPR: 7602 /* This is a call to a constructor, hence it's never zero. */ 7603 if (CALL_EXPR_FN (instance) 7604 && TREE_HAS_CONSTRUCTOR (instance)) 7605 { 7606 if (nonnull) 7607 *nonnull = 1; 7608 return TREE_TYPE (instance); 7609 } 7610 return NULL_TREE; 7611 7612 case SAVE_EXPR: 7613 /* This is a call to a constructor, hence it's never zero. */ 7614 if (TREE_HAS_CONSTRUCTOR (instance)) 7615 { 7616 if (nonnull) 7617 *nonnull = 1; 7618 return TREE_TYPE (instance); 7619 } 7620 return RECUR (TREE_OPERAND (instance, 0)); 7621 7622 case POINTER_PLUS_EXPR: 7623 case PLUS_EXPR: 7624 case MINUS_EXPR: 7625 if (TREE_CODE (TREE_OPERAND (instance, 0)) == ADDR_EXPR) 7626 return RECUR (TREE_OPERAND (instance, 0)); 7627 if (TREE_CODE (TREE_OPERAND (instance, 1)) == INTEGER_CST) 7628 /* Propagate nonnull. */ 7629 return RECUR (TREE_OPERAND (instance, 0)); 7630 7631 return NULL_TREE; 7632 7633 CASE_CONVERT: 7634 return RECUR (TREE_OPERAND (instance, 0)); 7635 7636 case ADDR_EXPR: 7637 instance = TREE_OPERAND (instance, 0); 7638 if (nonnull) 7639 { 7640 /* Just because we see an ADDR_EXPR doesn't mean we're dealing 7641 with a real object -- given &p->f, p can still be null. */ 7642 tree t = get_base_address (instance); 7643 /* ??? Probably should check DECL_WEAK here. */ 7644 if (t && DECL_P (t)) 7645 *nonnull = 1; 7646 } 7647 return RECUR (instance); 7648 7649 case COMPONENT_REF: 7650 /* If this component is really a base class reference, then the field 7651 itself isn't definitive. */ 7652 if (DECL_FIELD_IS_BASE (TREE_OPERAND (instance, 1))) 7653 return RECUR (TREE_OPERAND (instance, 0)); 7654 return RECUR (TREE_OPERAND (instance, 1)); 7655 7656 case VAR_DECL: 7657 case FIELD_DECL: 7658 if (TREE_CODE (TREE_TYPE (instance)) == ARRAY_TYPE 7659 && MAYBE_CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (instance)))) 7660 { 7661 if (nonnull) 7662 *nonnull = 1; 7663 return TREE_TYPE (TREE_TYPE (instance)); 7664 } 7665 /* fall through. */ 7666 case TARGET_EXPR: 7667 case PARM_DECL: 7668 case RESULT_DECL: 7669 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (instance))) 7670 { 7671 if (nonnull) 7672 *nonnull = 1; 7673 return TREE_TYPE (instance); 7674 } 7675 else if (instance == current_class_ptr) 7676 { 7677 if (nonnull) 7678 *nonnull = 1; 7679 7680 /* if we're in a ctor or dtor, we know our type. If 7681 current_class_ptr is set but we aren't in a function, we're in 7682 an NSDMI (and therefore a constructor). */ 7683 if (current_scope () != current_function_decl 7684 || (DECL_LANG_SPECIFIC (current_function_decl) 7685 && (DECL_CONSTRUCTOR_P (current_function_decl) 7686 || DECL_DESTRUCTOR_P (current_function_decl)))) 7687 { 7688 if (cdtorp) 7689 *cdtorp = 1; 7690 return TREE_TYPE (TREE_TYPE (instance)); 7691 } 7692 } 7693 else if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE) 7694 { 7695 /* We only need one hash table because it is always left empty. */ 7696 if (!fixed_type_or_null_ref_ht) 7697 fixed_type_or_null_ref_ht 7698 = new hash_table<nofree_ptr_hash<tree_node> > (37); 7699 7700 /* Reference variables should be references to objects. */ 7701 if (nonnull) 7702 *nonnull = 1; 7703 7704 /* Enter the INSTANCE in a table to prevent recursion; a 7705 variable's initializer may refer to the variable 7706 itself. */ 7707 if (VAR_P (instance) 7708 && DECL_INITIAL (instance) 7709 && !type_dependent_expression_p_push (DECL_INITIAL (instance)) 7710 && !fixed_type_or_null_ref_ht->find (instance)) 7711 { 7712 tree type; 7713 tree_node **slot; 7714 7715 slot = fixed_type_or_null_ref_ht->find_slot (instance, INSERT); 7716 *slot = instance; 7717 type = RECUR (DECL_INITIAL (instance)); 7718 fixed_type_or_null_ref_ht->remove_elt (instance); 7719 7720 return type; 7721 } 7722 } 7723 return NULL_TREE; 7724 7725 default: 7726 return NULL_TREE; 7727 } 7728 #undef RECUR 7729 } 7730 7731 /* Return nonzero if the dynamic type of INSTANCE is known, and 7732 equivalent to the static type. We also handle the case where 7733 INSTANCE is really a pointer. Return negative if this is a 7734 ctor/dtor. There the dynamic type is known, but this might not be 7735 the most derived base of the original object, and hence virtual 7736 bases may not be laid out according to this type. 7737 7738 Used to determine whether the virtual function table is needed 7739 or not. 7740 7741 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless 7742 of our knowledge of its type. *NONNULL should be initialized 7743 before this function is called. */ 7744 7745 int 7746 resolves_to_fixed_type_p (tree instance, int* nonnull) 7747 { 7748 tree t = TREE_TYPE (instance); 7749 int cdtorp = 0; 7750 tree fixed; 7751 7752 /* processing_template_decl can be false in a template if we're in 7753 instantiate_non_dependent_expr, but we still want to suppress 7754 this check. */ 7755 if (in_template_function ()) 7756 { 7757 /* In a template we only care about the type of the result. */ 7758 if (nonnull) 7759 *nonnull = true; 7760 return true; 7761 } 7762 7763 fixed = fixed_type_or_null (instance, nonnull, &cdtorp); 7764 if (fixed == NULL_TREE) 7765 return 0; 7766 if (POINTER_TYPE_P (t)) 7767 t = TREE_TYPE (t); 7768 if (!same_type_ignoring_top_level_qualifiers_p (t, fixed)) 7769 return 0; 7770 return cdtorp ? -1 : 1; 7771 } 7772 7773 7774 void 7775 init_class_processing (void) 7776 { 7777 current_class_depth = 0; 7778 current_class_stack_size = 10; 7779 current_class_stack 7780 = XNEWVEC (struct class_stack_node, current_class_stack_size); 7781 vec_alloc (local_classes, 8); 7782 sizeof_biggest_empty_class = size_zero_node; 7783 7784 ridpointers[(int) RID_PUBLIC] = access_public_node; 7785 ridpointers[(int) RID_PRIVATE] = access_private_node; 7786 ridpointers[(int) RID_PROTECTED] = access_protected_node; 7787 } 7788 7789 /* Restore the cached PREVIOUS_CLASS_LEVEL. */ 7790 7791 static void 7792 restore_class_cache (void) 7793 { 7794 tree type; 7795 7796 /* We are re-entering the same class we just left, so we don't 7797 have to search the whole inheritance matrix to find all the 7798 decls to bind again. Instead, we install the cached 7799 class_shadowed list and walk through it binding names. */ 7800 push_binding_level (previous_class_level); 7801 class_binding_level = previous_class_level; 7802 /* Restore IDENTIFIER_TYPE_VALUE. */ 7803 for (type = class_binding_level->type_shadowed; 7804 type; 7805 type = TREE_CHAIN (type)) 7806 SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (type), TREE_TYPE (type)); 7807 } 7808 7809 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as 7810 appropriate for TYPE. 7811 7812 So that we may avoid calls to lookup_name, we cache the _TYPE 7813 nodes of local TYPE_DECLs in the TREE_TYPE field of the name. 7814 7815 For multiple inheritance, we perform a two-pass depth-first search 7816 of the type lattice. */ 7817 7818 void 7819 pushclass (tree type) 7820 { 7821 class_stack_node_t csn; 7822 7823 type = TYPE_MAIN_VARIANT (type); 7824 7825 /* Make sure there is enough room for the new entry on the stack. */ 7826 if (current_class_depth + 1 >= current_class_stack_size) 7827 { 7828 current_class_stack_size *= 2; 7829 current_class_stack 7830 = XRESIZEVEC (struct class_stack_node, current_class_stack, 7831 current_class_stack_size); 7832 } 7833 7834 /* Insert a new entry on the class stack. */ 7835 csn = current_class_stack + current_class_depth; 7836 csn->name = current_class_name; 7837 csn->type = current_class_type; 7838 csn->access = current_access_specifier; 7839 csn->names_used = 0; 7840 csn->hidden = 0; 7841 current_class_depth++; 7842 7843 /* Now set up the new type. */ 7844 current_class_name = TYPE_NAME (type); 7845 if (TREE_CODE (current_class_name) == TYPE_DECL) 7846 current_class_name = DECL_NAME (current_class_name); 7847 current_class_type = type; 7848 7849 /* By default, things in classes are private, while things in 7850 structures or unions are public. */ 7851 current_access_specifier = (CLASSTYPE_DECLARED_CLASS (type) 7852 ? access_private_node 7853 : access_public_node); 7854 7855 if (previous_class_level 7856 && type != previous_class_level->this_entity 7857 && current_class_depth == 1) 7858 { 7859 /* Forcibly remove any old class remnants. */ 7860 invalidate_class_lookup_cache (); 7861 } 7862 7863 if (!previous_class_level 7864 || type != previous_class_level->this_entity 7865 || current_class_depth > 1) 7866 pushlevel_class (); 7867 else 7868 restore_class_cache (); 7869 } 7870 7871 /* When we exit a toplevel class scope, we save its binding level so 7872 that we can restore it quickly. Here, we've entered some other 7873 class, so we must invalidate our cache. */ 7874 7875 void 7876 invalidate_class_lookup_cache (void) 7877 { 7878 previous_class_level = NULL; 7879 } 7880 7881 /* Get out of the current class scope. If we were in a class scope 7882 previously, that is the one popped to. */ 7883 7884 void 7885 popclass (void) 7886 { 7887 poplevel_class (); 7888 7889 current_class_depth--; 7890 current_class_name = current_class_stack[current_class_depth].name; 7891 current_class_type = current_class_stack[current_class_depth].type; 7892 current_access_specifier = current_class_stack[current_class_depth].access; 7893 if (current_class_stack[current_class_depth].names_used) 7894 splay_tree_delete (current_class_stack[current_class_depth].names_used); 7895 } 7896 7897 /* Mark the top of the class stack as hidden. */ 7898 7899 void 7900 push_class_stack (void) 7901 { 7902 if (current_class_depth) 7903 ++current_class_stack[current_class_depth - 1].hidden; 7904 } 7905 7906 /* Mark the top of the class stack as un-hidden. */ 7907 7908 void 7909 pop_class_stack (void) 7910 { 7911 if (current_class_depth) 7912 --current_class_stack[current_class_depth - 1].hidden; 7913 } 7914 7915 /* Returns 1 if the class type currently being defined is either T or 7916 a nested type of T. Returns the type from the current_class_stack, 7917 which might be equivalent to but not equal to T in case of 7918 constrained partial specializations. */ 7919 7920 tree 7921 currently_open_class (tree t) 7922 { 7923 int i; 7924 7925 if (!CLASS_TYPE_P (t)) 7926 return NULL_TREE; 7927 7928 t = TYPE_MAIN_VARIANT (t); 7929 7930 /* We start looking from 1 because entry 0 is from global scope, 7931 and has no type. */ 7932 for (i = current_class_depth; i > 0; --i) 7933 { 7934 tree c; 7935 if (i == current_class_depth) 7936 c = current_class_type; 7937 else 7938 { 7939 if (current_class_stack[i].hidden) 7940 break; 7941 c = current_class_stack[i].type; 7942 } 7943 if (!c) 7944 continue; 7945 if (same_type_p (c, t)) 7946 return c; 7947 } 7948 return NULL_TREE; 7949 } 7950 7951 /* If either current_class_type or one of its enclosing classes are derived 7952 from T, return the appropriate type. Used to determine how we found 7953 something via unqualified lookup. */ 7954 7955 tree 7956 currently_open_derived_class (tree t) 7957 { 7958 int i; 7959 7960 /* The bases of a dependent type are unknown. */ 7961 if (dependent_type_p (t)) 7962 return NULL_TREE; 7963 7964 if (!current_class_type) 7965 return NULL_TREE; 7966 7967 if (DERIVED_FROM_P (t, current_class_type)) 7968 return current_class_type; 7969 7970 for (i = current_class_depth - 1; i > 0; --i) 7971 { 7972 if (current_class_stack[i].hidden) 7973 break; 7974 if (DERIVED_FROM_P (t, current_class_stack[i].type)) 7975 return current_class_stack[i].type; 7976 } 7977 7978 return NULL_TREE; 7979 } 7980 7981 /* Return the outermost enclosing class type that is still open, or 7982 NULL_TREE. */ 7983 7984 tree 7985 outermost_open_class (void) 7986 { 7987 if (!current_class_type) 7988 return NULL_TREE; 7989 tree r = NULL_TREE; 7990 if (TYPE_BEING_DEFINED (current_class_type)) 7991 r = current_class_type; 7992 for (int i = current_class_depth - 1; i > 0; --i) 7993 { 7994 if (current_class_stack[i].hidden) 7995 break; 7996 tree t = current_class_stack[i].type; 7997 if (!TYPE_BEING_DEFINED (t)) 7998 break; 7999 r = t; 8000 } 8001 return r; 8002 } 8003 8004 /* Returns the innermost class type which is not a lambda closure type. */ 8005 8006 tree 8007 current_nonlambda_class_type (void) 8008 { 8009 int i; 8010 8011 /* We start looking from 1 because entry 0 is from global scope, 8012 and has no type. */ 8013 for (i = current_class_depth; i > 0; --i) 8014 { 8015 tree c; 8016 if (i == current_class_depth) 8017 c = current_class_type; 8018 else 8019 { 8020 if (current_class_stack[i].hidden) 8021 break; 8022 c = current_class_stack[i].type; 8023 } 8024 if (!c) 8025 continue; 8026 if (!LAMBDA_TYPE_P (c)) 8027 return c; 8028 } 8029 return NULL_TREE; 8030 } 8031 8032 /* When entering a class scope, all enclosing class scopes' names with 8033 static meaning (static variables, static functions, types and 8034 enumerators) have to be visible. This recursive function calls 8035 pushclass for all enclosing class contexts until global or a local 8036 scope is reached. TYPE is the enclosed class. */ 8037 8038 void 8039 push_nested_class (tree type) 8040 { 8041 /* A namespace might be passed in error cases, like A::B:C. */ 8042 if (type == NULL_TREE 8043 || !CLASS_TYPE_P (type)) 8044 return; 8045 8046 push_nested_class (DECL_CONTEXT (TYPE_MAIN_DECL (type))); 8047 8048 pushclass (type); 8049 } 8050 8051 /* Undoes a push_nested_class call. */ 8052 8053 void 8054 pop_nested_class (void) 8055 { 8056 tree context = DECL_CONTEXT (TYPE_MAIN_DECL (current_class_type)); 8057 8058 popclass (); 8059 if (context && CLASS_TYPE_P (context)) 8060 pop_nested_class (); 8061 } 8062 8063 /* Returns the number of extern "LANG" blocks we are nested within. */ 8064 8065 int 8066 current_lang_depth (void) 8067 { 8068 return vec_safe_length (current_lang_base); 8069 } 8070 8071 /* Set global variables CURRENT_LANG_NAME to appropriate value 8072 so that behavior of name-mangling machinery is correct. */ 8073 8074 void 8075 push_lang_context (tree name) 8076 { 8077 vec_safe_push (current_lang_base, current_lang_name); 8078 8079 if (name == lang_name_cplusplus) 8080 current_lang_name = name; 8081 else if (name == lang_name_c) 8082 current_lang_name = name; 8083 else 8084 error ("language string %<\"%E\"%> not recognized", name); 8085 } 8086 8087 /* Get out of the current language scope. */ 8088 8089 void 8090 pop_lang_context (void) 8091 { 8092 current_lang_name = current_lang_base->pop (); 8093 } 8094 8095 /* Type instantiation routines. */ 8096 8097 /* Given an OVERLOAD and a TARGET_TYPE, return the function that 8098 matches the TARGET_TYPE. If there is no satisfactory match, return 8099 error_mark_node, and issue an error & warning messages under 8100 control of FLAGS. Permit pointers to member function if FLAGS 8101 permits. If TEMPLATE_ONLY, the name of the overloaded function was 8102 a template-id, and EXPLICIT_TARGS are the explicitly provided 8103 template arguments. 8104 8105 If OVERLOAD is for one or more member functions, then ACCESS_PATH 8106 is the base path used to reference those member functions. If 8107 the address is resolved to a member function, access checks will be 8108 performed and errors issued if appropriate. */ 8109 8110 static tree 8111 resolve_address_of_overloaded_function (tree target_type, 8112 tree overload, 8113 tsubst_flags_t complain, 8114 bool template_only, 8115 tree explicit_targs, 8116 tree access_path) 8117 { 8118 /* Here's what the standard says: 8119 8120 [over.over] 8121 8122 If the name is a function template, template argument deduction 8123 is done, and if the argument deduction succeeds, the deduced 8124 arguments are used to generate a single template function, which 8125 is added to the set of overloaded functions considered. 8126 8127 Non-member functions and static member functions match targets of 8128 type "pointer-to-function" or "reference-to-function." Nonstatic 8129 member functions match targets of type "pointer-to-member 8130 function;" the function type of the pointer to member is used to 8131 select the member function from the set of overloaded member 8132 functions. If a nonstatic member function is selected, the 8133 reference to the overloaded function name is required to have the 8134 form of a pointer to member as described in 5.3.1. 8135 8136 If more than one function is selected, any template functions in 8137 the set are eliminated if the set also contains a non-template 8138 function, and any given template function is eliminated if the 8139 set contains a second template function that is more specialized 8140 than the first according to the partial ordering rules 14.5.5.2. 8141 After such eliminations, if any, there shall remain exactly one 8142 selected function. */ 8143 8144 int is_ptrmem = 0; 8145 /* We store the matches in a TREE_LIST rooted here. The functions 8146 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy 8147 interoperability with most_specialized_instantiation. */ 8148 tree matches = NULL_TREE; 8149 tree fn; 8150 tree target_fn_type; 8151 8152 /* By the time we get here, we should be seeing only real 8153 pointer-to-member types, not the internal POINTER_TYPE to 8154 METHOD_TYPE representation. */ 8155 gcc_assert (!TYPE_PTR_P (target_type) 8156 || TREE_CODE (TREE_TYPE (target_type)) != METHOD_TYPE); 8157 8158 gcc_assert (is_overloaded_fn (overload)); 8159 8160 /* Check that the TARGET_TYPE is reasonable. */ 8161 if (TYPE_PTRFN_P (target_type) 8162 || TYPE_REFFN_P (target_type)) 8163 /* This is OK. */; 8164 else if (TYPE_PTRMEMFUNC_P (target_type)) 8165 /* This is OK, too. */ 8166 is_ptrmem = 1; 8167 else if (TREE_CODE (target_type) == FUNCTION_TYPE) 8168 /* This is OK, too. This comes from a conversion to reference 8169 type. */ 8170 target_type = build_reference_type (target_type); 8171 else 8172 { 8173 if (complain & tf_error) 8174 error ("cannot resolve overloaded function %qD based on" 8175 " conversion to type %qT", 8176 DECL_NAME (OVL_FUNCTION (overload)), target_type); 8177 return error_mark_node; 8178 } 8179 8180 /* Non-member functions and static member functions match targets of type 8181 "pointer-to-function" or "reference-to-function." Nonstatic member 8182 functions match targets of type "pointer-to-member-function;" the 8183 function type of the pointer to member is used to select the member 8184 function from the set of overloaded member functions. 8185 8186 So figure out the FUNCTION_TYPE that we want to match against. */ 8187 target_fn_type = static_fn_type (target_type); 8188 8189 /* If we can find a non-template function that matches, we can just 8190 use it. There's no point in generating template instantiations 8191 if we're just going to throw them out anyhow. But, of course, we 8192 can only do this when we don't *need* a template function. */ 8193 if (!template_only) 8194 { 8195 tree fns; 8196 8197 for (fns = overload; fns; fns = OVL_NEXT (fns)) 8198 { 8199 tree fn = OVL_CURRENT (fns); 8200 8201 if (TREE_CODE (fn) == TEMPLATE_DECL) 8202 /* We're not looking for templates just yet. */ 8203 continue; 8204 8205 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) 8206 != is_ptrmem) 8207 /* We're looking for a non-static member, and this isn't 8208 one, or vice versa. */ 8209 continue; 8210 8211 /* Ignore functions which haven't been explicitly 8212 declared. */ 8213 if (DECL_ANTICIPATED (fn)) 8214 continue; 8215 8216 /* In C++17 we need the noexcept-qualifier to compare types. */ 8217 if (flag_noexcept_type) 8218 maybe_instantiate_noexcept (fn); 8219 8220 /* See if there's a match. */ 8221 tree fntype = static_fn_type (fn); 8222 if (same_type_p (target_fn_type, fntype) 8223 || fnptr_conv_p (target_fn_type, fntype)) 8224 matches = tree_cons (fn, NULL_TREE, matches); 8225 } 8226 } 8227 8228 /* Now, if we've already got a match (or matches), there's no need 8229 to proceed to the template functions. But, if we don't have a 8230 match we need to look at them, too. */ 8231 if (!matches) 8232 { 8233 tree target_arg_types; 8234 tree target_ret_type; 8235 tree fns; 8236 tree *args; 8237 unsigned int nargs, ia; 8238 tree arg; 8239 8240 target_arg_types = TYPE_ARG_TYPES (target_fn_type); 8241 target_ret_type = TREE_TYPE (target_fn_type); 8242 8243 nargs = list_length (target_arg_types); 8244 args = XALLOCAVEC (tree, nargs); 8245 for (arg = target_arg_types, ia = 0; 8246 arg != NULL_TREE && arg != void_list_node; 8247 arg = TREE_CHAIN (arg), ++ia) 8248 args[ia] = TREE_VALUE (arg); 8249 nargs = ia; 8250 8251 for (fns = overload; fns; fns = OVL_NEXT (fns)) 8252 { 8253 tree fn = OVL_CURRENT (fns); 8254 tree instantiation; 8255 tree targs; 8256 8257 if (TREE_CODE (fn) != TEMPLATE_DECL) 8258 /* We're only looking for templates. */ 8259 continue; 8260 8261 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) 8262 != is_ptrmem) 8263 /* We're not looking for a non-static member, and this is 8264 one, or vice versa. */ 8265 continue; 8266 8267 tree ret = target_ret_type; 8268 8269 /* If the template has a deduced return type, don't expose it to 8270 template argument deduction. */ 8271 if (undeduced_auto_decl (fn)) 8272 ret = NULL_TREE; 8273 8274 /* Try to do argument deduction. */ 8275 targs = make_tree_vec (DECL_NTPARMS (fn)); 8276 instantiation = fn_type_unification (fn, explicit_targs, targs, args, 8277 nargs, ret, 8278 DEDUCE_EXACT, LOOKUP_NORMAL, 8279 false, false); 8280 if (instantiation == error_mark_node) 8281 /* Instantiation failed. */ 8282 continue; 8283 8284 /* Constraints must be satisfied. This is done before 8285 return type deduction since that instantiates the 8286 function. */ 8287 if (flag_concepts && !constraints_satisfied_p (instantiation)) 8288 continue; 8289 8290 /* And now force instantiation to do return type deduction. */ 8291 if (undeduced_auto_decl (instantiation)) 8292 { 8293 ++function_depth; 8294 instantiate_decl (instantiation, /*defer*/false, /*class*/false); 8295 --function_depth; 8296 8297 require_deduced_type (instantiation); 8298 } 8299 8300 /* In C++17 we need the noexcept-qualifier to compare types. */ 8301 if (flag_noexcept_type) 8302 maybe_instantiate_noexcept (instantiation); 8303 8304 /* See if there's a match. */ 8305 tree fntype = static_fn_type (instantiation); 8306 if (same_type_p (target_fn_type, fntype) 8307 || fnptr_conv_p (target_fn_type, fntype)) 8308 matches = tree_cons (instantiation, fn, matches); 8309 } 8310 8311 /* Now, remove all but the most specialized of the matches. */ 8312 if (matches) 8313 { 8314 tree match = most_specialized_instantiation (matches); 8315 8316 if (match != error_mark_node) 8317 matches = tree_cons (TREE_PURPOSE (match), 8318 NULL_TREE, 8319 NULL_TREE); 8320 } 8321 } 8322 8323 /* Now we should have exactly one function in MATCHES. */ 8324 if (matches == NULL_TREE) 8325 { 8326 /* There were *no* matches. */ 8327 if (complain & tf_error) 8328 { 8329 error ("no matches converting function %qD to type %q#T", 8330 DECL_NAME (OVL_CURRENT (overload)), 8331 target_type); 8332 8333 print_candidates (overload); 8334 } 8335 return error_mark_node; 8336 } 8337 else if (TREE_CHAIN (matches)) 8338 { 8339 /* There were too many matches. First check if they're all 8340 the same function. */ 8341 tree match = NULL_TREE; 8342 8343 fn = TREE_PURPOSE (matches); 8344 8345 /* For multi-versioned functions, more than one match is just fine and 8346 decls_match will return false as they are different. */ 8347 for (match = TREE_CHAIN (matches); match; match = TREE_CHAIN (match)) 8348 if (!decls_match (fn, TREE_PURPOSE (match)) 8349 && !targetm.target_option.function_versions 8350 (fn, TREE_PURPOSE (match))) 8351 break; 8352 8353 if (match) 8354 { 8355 if (complain & tf_error) 8356 { 8357 error ("converting overloaded function %qD to type %q#T is ambiguous", 8358 DECL_NAME (OVL_FUNCTION (overload)), 8359 target_type); 8360 8361 /* Since print_candidates expects the functions in the 8362 TREE_VALUE slot, we flip them here. */ 8363 for (match = matches; match; match = TREE_CHAIN (match)) 8364 TREE_VALUE (match) = TREE_PURPOSE (match); 8365 8366 print_candidates (matches); 8367 } 8368 8369 return error_mark_node; 8370 } 8371 } 8372 8373 /* Good, exactly one match. Now, convert it to the correct type. */ 8374 fn = TREE_PURPOSE (matches); 8375 8376 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) 8377 && !(complain & tf_ptrmem_ok) && !flag_ms_extensions) 8378 { 8379 static int explained; 8380 8381 if (!(complain & tf_error)) 8382 return error_mark_node; 8383 8384 permerror (input_location, "assuming pointer to member %qD", fn); 8385 if (!explained) 8386 { 8387 inform (input_location, "(a pointer to member can only be formed with %<&%E%>)", fn); 8388 explained = 1; 8389 } 8390 } 8391 8392 /* If a pointer to a function that is multi-versioned is requested, the 8393 pointer to the dispatcher function is returned instead. This works 8394 well because indirectly calling the function will dispatch the right 8395 function version at run-time. */ 8396 if (DECL_FUNCTION_VERSIONED (fn)) 8397 { 8398 fn = get_function_version_dispatcher (fn); 8399 if (fn == NULL) 8400 return error_mark_node; 8401 /* Mark all the versions corresponding to the dispatcher as used. */ 8402 if (!(complain & tf_conv)) 8403 mark_versions_used (fn); 8404 } 8405 8406 /* If we're doing overload resolution purely for the purpose of 8407 determining conversion sequences, we should not consider the 8408 function used. If this conversion sequence is selected, the 8409 function will be marked as used at this point. */ 8410 if (!(complain & tf_conv)) 8411 { 8412 /* Make =delete work with SFINAE. */ 8413 if (DECL_DELETED_FN (fn) && !(complain & tf_error)) 8414 return error_mark_node; 8415 if (!mark_used (fn, complain) && !(complain & tf_error)) 8416 return error_mark_node; 8417 } 8418 8419 /* We could not check access to member functions when this 8420 expression was originally created since we did not know at that 8421 time to which function the expression referred. */ 8422 if (DECL_FUNCTION_MEMBER_P (fn)) 8423 { 8424 gcc_assert (access_path); 8425 perform_or_defer_access_check (access_path, fn, fn, complain); 8426 } 8427 8428 if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type)) 8429 return cp_build_addr_expr (fn, complain); 8430 else 8431 { 8432 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op 8433 will mark the function as addressed, but here we must do it 8434 explicitly. */ 8435 cxx_mark_addressable (fn); 8436 8437 return fn; 8438 } 8439 } 8440 8441 /* This function will instantiate the type of the expression given in 8442 RHS to match the type of LHSTYPE. If errors exist, then return 8443 error_mark_node. COMPLAIN is a bit mask. If TF_ERROR is set, then 8444 we complain on errors. If we are not complaining, never modify rhs, 8445 as overload resolution wants to try many possible instantiations, in 8446 the hope that at least one will work. 8447 8448 For non-recursive calls, LHSTYPE should be a function, pointer to 8449 function, or a pointer to member function. */ 8450 8451 tree 8452 instantiate_type (tree lhstype, tree rhs, tsubst_flags_t complain) 8453 { 8454 tsubst_flags_t complain_in = complain; 8455 tree access_path = NULL_TREE; 8456 8457 complain &= ~tf_ptrmem_ok; 8458 8459 if (lhstype == unknown_type_node) 8460 { 8461 if (complain & tf_error) 8462 error ("not enough type information"); 8463 return error_mark_node; 8464 } 8465 8466 if (TREE_TYPE (rhs) != NULL_TREE && ! (type_unknown_p (rhs))) 8467 { 8468 tree fntype = non_reference (lhstype); 8469 if (same_type_p (fntype, TREE_TYPE (rhs))) 8470 return rhs; 8471 if (fnptr_conv_p (fntype, TREE_TYPE (rhs))) 8472 return rhs; 8473 if (flag_ms_extensions 8474 && TYPE_PTRMEMFUNC_P (fntype) 8475 && !TYPE_PTRMEMFUNC_P (TREE_TYPE (rhs))) 8476 /* Microsoft allows `A::f' to be resolved to a 8477 pointer-to-member. */ 8478 ; 8479 else 8480 { 8481 if (complain & tf_error) 8482 error ("cannot convert %qE from type %qT to type %qT", 8483 rhs, TREE_TYPE (rhs), fntype); 8484 return error_mark_node; 8485 } 8486 } 8487 8488 if (BASELINK_P (rhs)) 8489 { 8490 access_path = BASELINK_ACCESS_BINFO (rhs); 8491 rhs = BASELINK_FUNCTIONS (rhs); 8492 } 8493 8494 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot 8495 deduce any type information. */ 8496 if (TREE_CODE (rhs) == NON_DEPENDENT_EXPR) 8497 { 8498 if (complain & tf_error) 8499 error ("not enough type information"); 8500 return error_mark_node; 8501 } 8502 8503 /* If we instantiate a template, and it is a A ?: C expression 8504 with omitted B, look through the SAVE_EXPR. */ 8505 if (TREE_CODE (rhs) == SAVE_EXPR) 8506 rhs = TREE_OPERAND (rhs, 0); 8507 8508 /* There are only a few kinds of expressions that may have a type 8509 dependent on overload resolution. */ 8510 gcc_assert (TREE_CODE (rhs) == ADDR_EXPR 8511 || TREE_CODE (rhs) == COMPONENT_REF 8512 || is_overloaded_fn (rhs) 8513 || (flag_ms_extensions && TREE_CODE (rhs) == FUNCTION_DECL)); 8514 8515 /* This should really only be used when attempting to distinguish 8516 what sort of a pointer to function we have. For now, any 8517 arithmetic operation which is not supported on pointers 8518 is rejected as an error. */ 8519 8520 switch (TREE_CODE (rhs)) 8521 { 8522 case COMPONENT_REF: 8523 { 8524 tree member = TREE_OPERAND (rhs, 1); 8525 8526 member = instantiate_type (lhstype, member, complain); 8527 if (member != error_mark_node 8528 && TREE_SIDE_EFFECTS (TREE_OPERAND (rhs, 0))) 8529 /* Do not lose object's side effects. */ 8530 return build2 (COMPOUND_EXPR, TREE_TYPE (member), 8531 TREE_OPERAND (rhs, 0), member); 8532 return member; 8533 } 8534 8535 case OFFSET_REF: 8536 rhs = TREE_OPERAND (rhs, 1); 8537 if (BASELINK_P (rhs)) 8538 return instantiate_type (lhstype, rhs, complain_in); 8539 8540 /* This can happen if we are forming a pointer-to-member for a 8541 member template. */ 8542 gcc_assert (TREE_CODE (rhs) == TEMPLATE_ID_EXPR); 8543 8544 /* Fall through. */ 8545 8546 case TEMPLATE_ID_EXPR: 8547 { 8548 tree fns = TREE_OPERAND (rhs, 0); 8549 tree args = TREE_OPERAND (rhs, 1); 8550 8551 return 8552 resolve_address_of_overloaded_function (lhstype, fns, complain_in, 8553 /*template_only=*/true, 8554 args, access_path); 8555 } 8556 8557 case OVERLOAD: 8558 case FUNCTION_DECL: 8559 return 8560 resolve_address_of_overloaded_function (lhstype, rhs, complain_in, 8561 /*template_only=*/false, 8562 /*explicit_targs=*/NULL_TREE, 8563 access_path); 8564 8565 case ADDR_EXPR: 8566 { 8567 if (PTRMEM_OK_P (rhs)) 8568 complain |= tf_ptrmem_ok; 8569 8570 return instantiate_type (lhstype, TREE_OPERAND (rhs, 0), complain); 8571 } 8572 8573 case ERROR_MARK: 8574 return error_mark_node; 8575 8576 default: 8577 gcc_unreachable (); 8578 } 8579 return error_mark_node; 8580 } 8581 8582 /* Return the name of the virtual function pointer field 8583 (as an IDENTIFIER_NODE) for the given TYPE. Note that 8584 this may have to look back through base types to find the 8585 ultimate field name. (For single inheritance, these could 8586 all be the same name. Who knows for multiple inheritance). */ 8587 8588 static tree 8589 get_vfield_name (tree type) 8590 { 8591 tree binfo, base_binfo; 8592 char *buf; 8593 8594 for (binfo = TYPE_BINFO (type); 8595 BINFO_N_BASE_BINFOS (binfo); 8596 binfo = base_binfo) 8597 { 8598 base_binfo = BINFO_BASE_BINFO (binfo, 0); 8599 8600 if (BINFO_VIRTUAL_P (base_binfo) 8601 || !TYPE_CONTAINS_VPTR_P (BINFO_TYPE (base_binfo))) 8602 break; 8603 } 8604 8605 type = BINFO_TYPE (binfo); 8606 buf = (char *) alloca (sizeof (VFIELD_NAME_FORMAT) 8607 + TYPE_NAME_LENGTH (type) + 2); 8608 sprintf (buf, VFIELD_NAME_FORMAT, 8609 IDENTIFIER_POINTER (constructor_name (type))); 8610 return get_identifier (buf); 8611 } 8612 8613 void 8614 print_class_statistics (void) 8615 { 8616 if (! GATHER_STATISTICS) 8617 return; 8618 8619 fprintf (stderr, "convert_harshness = %d\n", n_convert_harshness); 8620 fprintf (stderr, "compute_conversion_costs = %d\n", n_compute_conversion_costs); 8621 if (n_vtables) 8622 { 8623 fprintf (stderr, "vtables = %d; vtable searches = %d\n", 8624 n_vtables, n_vtable_searches); 8625 fprintf (stderr, "vtable entries = %d; vtable elems = %d\n", 8626 n_vtable_entries, n_vtable_elems); 8627 } 8628 } 8629 8630 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works, 8631 according to [class]: 8632 The class-name is also inserted 8633 into the scope of the class itself. For purposes of access checking, 8634 the inserted class name is treated as if it were a public member name. */ 8635 8636 void 8637 build_self_reference (void) 8638 { 8639 tree name = constructor_name (current_class_type); 8640 tree value = build_lang_decl (TYPE_DECL, name, current_class_type); 8641 tree saved_cas; 8642 8643 DECL_NONLOCAL (value) = 1; 8644 DECL_CONTEXT (value) = current_class_type; 8645 DECL_ARTIFICIAL (value) = 1; 8646 SET_DECL_SELF_REFERENCE_P (value); 8647 set_underlying_type (value); 8648 8649 if (processing_template_decl) 8650 value = push_template_decl (value); 8651 8652 saved_cas = current_access_specifier; 8653 current_access_specifier = access_public_node; 8654 finish_member_declaration (value); 8655 current_access_specifier = saved_cas; 8656 } 8657 8658 /* Returns 1 if TYPE contains only padding bytes. */ 8659 8660 int 8661 is_empty_class (tree type) 8662 { 8663 if (type == error_mark_node) 8664 return 0; 8665 8666 if (! CLASS_TYPE_P (type)) 8667 return 0; 8668 8669 return CLASSTYPE_EMPTY_P (type); 8670 } 8671 8672 /* Returns true if TYPE contains no actual data, just various 8673 possible combinations of empty classes and possibly a vptr. */ 8674 8675 bool 8676 is_really_empty_class (tree type) 8677 { 8678 if (CLASS_TYPE_P (type)) 8679 { 8680 tree field; 8681 tree binfo; 8682 tree base_binfo; 8683 int i; 8684 8685 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid 8686 out, but we'd like to be able to check this before then. */ 8687 if (COMPLETE_TYPE_P (type) && is_empty_class (type)) 8688 return true; 8689 8690 for (binfo = TYPE_BINFO (type), i = 0; 8691 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 8692 if (!is_really_empty_class (BINFO_TYPE (base_binfo))) 8693 return false; 8694 for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) 8695 if (TREE_CODE (field) == FIELD_DECL 8696 && !DECL_ARTIFICIAL (field) 8697 /* An unnamed bit-field is not a data member. */ 8698 && (DECL_NAME (field) || !DECL_C_BIT_FIELD (field)) 8699 && !is_really_empty_class (TREE_TYPE (field))) 8700 return false; 8701 return true; 8702 } 8703 else if (TREE_CODE (type) == ARRAY_TYPE) 8704 return (integer_zerop (array_type_nelts_top (type)) 8705 || is_really_empty_class (TREE_TYPE (type))); 8706 return false; 8707 } 8708 8709 /* Note that NAME was looked up while the current class was being 8710 defined and that the result of that lookup was DECL. */ 8711 8712 void 8713 maybe_note_name_used_in_class (tree name, tree decl) 8714 { 8715 splay_tree names_used; 8716 8717 /* If we're not defining a class, there's nothing to do. */ 8718 if (!(innermost_scope_kind() == sk_class 8719 && TYPE_BEING_DEFINED (current_class_type) 8720 && !LAMBDA_TYPE_P (current_class_type))) 8721 return; 8722 8723 /* If there's already a binding for this NAME, then we don't have 8724 anything to worry about. */ 8725 if (lookup_member (current_class_type, name, 8726 /*protect=*/0, /*want_type=*/false, tf_warning_or_error)) 8727 return; 8728 8729 if (!current_class_stack[current_class_depth - 1].names_used) 8730 current_class_stack[current_class_depth - 1].names_used 8731 = splay_tree_new (splay_tree_compare_pointers, 0, 0); 8732 names_used = current_class_stack[current_class_depth - 1].names_used; 8733 8734 splay_tree_insert (names_used, 8735 (splay_tree_key) name, 8736 (splay_tree_value) decl); 8737 } 8738 8739 /* Note that NAME was declared (as DECL) in the current class. Check 8740 to see that the declaration is valid. */ 8741 8742 void 8743 note_name_declared_in_class (tree name, tree decl) 8744 { 8745 splay_tree names_used; 8746 splay_tree_node n; 8747 8748 /* Look to see if we ever used this name. */ 8749 names_used 8750 = current_class_stack[current_class_depth - 1].names_used; 8751 if (!names_used) 8752 return; 8753 /* The C language allows members to be declared with a type of the same 8754 name, and the C++ standard says this diagnostic is not required. So 8755 allow it in extern "C" blocks unless predantic is specified. 8756 Allow it in all cases if -ms-extensions is specified. */ 8757 if ((!pedantic && current_lang_name == lang_name_c) 8758 || flag_ms_extensions) 8759 return; 8760 n = splay_tree_lookup (names_used, (splay_tree_key) name); 8761 if (n) 8762 { 8763 /* [basic.scope.class] 8764 8765 A name N used in a class S shall refer to the same declaration 8766 in its context and when re-evaluated in the completed scope of 8767 S. */ 8768 permerror (input_location, "declaration of %q#D", decl); 8769 permerror (location_of ((tree) n->value), 8770 "changes meaning of %qD from %q#D", 8771 DECL_NAME (OVL_CURRENT (decl)), (tree) n->value); 8772 } 8773 } 8774 8775 /* Returns the VAR_DECL for the complete vtable associated with BINFO. 8776 Secondary vtables are merged with primary vtables; this function 8777 will return the VAR_DECL for the primary vtable. */ 8778 8779 tree 8780 get_vtbl_decl_for_binfo (tree binfo) 8781 { 8782 tree decl; 8783 8784 decl = BINFO_VTABLE (binfo); 8785 if (decl && TREE_CODE (decl) == POINTER_PLUS_EXPR) 8786 { 8787 gcc_assert (TREE_CODE (TREE_OPERAND (decl, 0)) == ADDR_EXPR); 8788 decl = TREE_OPERAND (TREE_OPERAND (decl, 0), 0); 8789 } 8790 if (decl) 8791 gcc_assert (VAR_P (decl)); 8792 return decl; 8793 } 8794 8795 8796 /* Returns the binfo for the primary base of BINFO. If the resulting 8797 BINFO is a virtual base, and it is inherited elsewhere in the 8798 hierarchy, then the returned binfo might not be the primary base of 8799 BINFO in the complete object. Check BINFO_PRIMARY_P or 8800 BINFO_LOST_PRIMARY_P to be sure. */ 8801 8802 static tree 8803 get_primary_binfo (tree binfo) 8804 { 8805 tree primary_base; 8806 8807 primary_base = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (binfo)); 8808 if (!primary_base) 8809 return NULL_TREE; 8810 8811 return copied_binfo (primary_base, binfo); 8812 } 8813 8814 /* As above, but iterate until we reach the binfo that actually provides the 8815 vptr for BINFO. */ 8816 8817 static tree 8818 most_primary_binfo (tree binfo) 8819 { 8820 tree b = binfo; 8821 while (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (b)) 8822 && !BINFO_LOST_PRIMARY_P (b)) 8823 { 8824 tree primary_base = get_primary_binfo (b); 8825 gcc_assert (BINFO_PRIMARY_P (primary_base) 8826 && BINFO_INHERITANCE_CHAIN (primary_base) == b); 8827 b = primary_base; 8828 } 8829 return b; 8830 } 8831 8832 /* Returns true if BINFO gets its vptr from a virtual base of the most derived 8833 type. Note that the virtual inheritance might be above or below BINFO in 8834 the hierarchy. */ 8835 8836 bool 8837 vptr_via_virtual_p (tree binfo) 8838 { 8839 if (TYPE_P (binfo)) 8840 binfo = TYPE_BINFO (binfo); 8841 tree primary = most_primary_binfo (binfo); 8842 /* Don't limit binfo_via_virtual, we want to return true when BINFO itself is 8843 a morally virtual base. */ 8844 tree virt = binfo_via_virtual (primary, NULL_TREE); 8845 return virt != NULL_TREE; 8846 } 8847 8848 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */ 8849 8850 static int 8851 maybe_indent_hierarchy (FILE * stream, int indent, int indented_p) 8852 { 8853 if (!indented_p) 8854 fprintf (stream, "%*s", indent, ""); 8855 return 1; 8856 } 8857 8858 /* Dump the offsets of all the bases rooted at BINFO to STREAM. 8859 INDENT should be zero when called from the top level; it is 8860 incremented recursively. IGO indicates the next expected BINFO in 8861 inheritance graph ordering. */ 8862 8863 static tree 8864 dump_class_hierarchy_r (FILE *stream, 8865 int flags, 8866 tree binfo, 8867 tree igo, 8868 int indent) 8869 { 8870 int indented = 0; 8871 tree base_binfo; 8872 int i; 8873 8874 indented = maybe_indent_hierarchy (stream, indent, 0); 8875 fprintf (stream, "%s (0x" HOST_WIDE_INT_PRINT_HEX ") ", 8876 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER), 8877 (HOST_WIDE_INT) (uintptr_t) binfo); 8878 if (binfo != igo) 8879 { 8880 fprintf (stream, "alternative-path\n"); 8881 return igo; 8882 } 8883 igo = TREE_CHAIN (binfo); 8884 8885 fprintf (stream, HOST_WIDE_INT_PRINT_DEC, 8886 tree_to_shwi (BINFO_OFFSET (binfo))); 8887 if (is_empty_class (BINFO_TYPE (binfo))) 8888 fprintf (stream, " empty"); 8889 else if (CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (binfo))) 8890 fprintf (stream, " nearly-empty"); 8891 if (BINFO_VIRTUAL_P (binfo)) 8892 fprintf (stream, " virtual"); 8893 fprintf (stream, "\n"); 8894 8895 indented = 0; 8896 if (BINFO_PRIMARY_P (binfo)) 8897 { 8898 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8899 fprintf (stream, " primary-for %s (0x" HOST_WIDE_INT_PRINT_HEX ")", 8900 type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)), 8901 TFF_PLAIN_IDENTIFIER), 8902 (HOST_WIDE_INT) (uintptr_t) BINFO_INHERITANCE_CHAIN (binfo)); 8903 } 8904 if (BINFO_LOST_PRIMARY_P (binfo)) 8905 { 8906 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8907 fprintf (stream, " lost-primary"); 8908 } 8909 if (indented) 8910 fprintf (stream, "\n"); 8911 8912 if (!(flags & TDF_SLIM)) 8913 { 8914 int indented = 0; 8915 8916 if (BINFO_SUBVTT_INDEX (binfo)) 8917 { 8918 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8919 fprintf (stream, " subvttidx=%s", 8920 expr_as_string (BINFO_SUBVTT_INDEX (binfo), 8921 TFF_PLAIN_IDENTIFIER)); 8922 } 8923 if (BINFO_VPTR_INDEX (binfo)) 8924 { 8925 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8926 fprintf (stream, " vptridx=%s", 8927 expr_as_string (BINFO_VPTR_INDEX (binfo), 8928 TFF_PLAIN_IDENTIFIER)); 8929 } 8930 if (BINFO_VPTR_FIELD (binfo)) 8931 { 8932 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8933 fprintf (stream, " vbaseoffset=%s", 8934 expr_as_string (BINFO_VPTR_FIELD (binfo), 8935 TFF_PLAIN_IDENTIFIER)); 8936 } 8937 if (BINFO_VTABLE (binfo)) 8938 { 8939 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 8940 fprintf (stream, " vptr=%s", 8941 expr_as_string (BINFO_VTABLE (binfo), 8942 TFF_PLAIN_IDENTIFIER)); 8943 } 8944 8945 if (indented) 8946 fprintf (stream, "\n"); 8947 } 8948 8949 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 8950 igo = dump_class_hierarchy_r (stream, flags, base_binfo, igo, indent + 2); 8951 8952 return igo; 8953 } 8954 8955 /* Dump the BINFO hierarchy for T. */ 8956 8957 static void 8958 dump_class_hierarchy_1 (FILE *stream, int flags, tree t) 8959 { 8960 fprintf (stream, "Class %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER)); 8961 fprintf (stream, " size=%lu align=%lu\n", 8962 (unsigned long)(tree_to_shwi (TYPE_SIZE (t)) / BITS_PER_UNIT), 8963 (unsigned long)(TYPE_ALIGN (t) / BITS_PER_UNIT)); 8964 fprintf (stream, " base size=%lu base align=%lu\n", 8965 (unsigned long)(tree_to_shwi (TYPE_SIZE (CLASSTYPE_AS_BASE (t))) 8966 / BITS_PER_UNIT), 8967 (unsigned long)(TYPE_ALIGN (CLASSTYPE_AS_BASE (t)) 8968 / BITS_PER_UNIT)); 8969 dump_class_hierarchy_r (stream, flags, TYPE_BINFO (t), TYPE_BINFO (t), 0); 8970 fprintf (stream, "\n"); 8971 } 8972 8973 /* Debug interface to hierarchy dumping. */ 8974 8975 void 8976 debug_class (tree t) 8977 { 8978 dump_class_hierarchy_1 (stderr, TDF_SLIM, t); 8979 } 8980 8981 static void 8982 dump_class_hierarchy (tree t) 8983 { 8984 int flags; 8985 FILE *stream = get_dump_info (TDI_class, &flags); 8986 8987 if (stream) 8988 { 8989 dump_class_hierarchy_1 (stream, flags, t); 8990 } 8991 } 8992 8993 static void 8994 dump_array (FILE * stream, tree decl) 8995 { 8996 tree value; 8997 unsigned HOST_WIDE_INT ix; 8998 HOST_WIDE_INT elt; 8999 tree size = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (decl))); 9000 9001 elt = (tree_to_shwi (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl)))) 9002 / BITS_PER_UNIT); 9003 fprintf (stream, "%s:", decl_as_string (decl, TFF_PLAIN_IDENTIFIER)); 9004 fprintf (stream, " %s entries", 9005 expr_as_string (size_binop (PLUS_EXPR, size, size_one_node), 9006 TFF_PLAIN_IDENTIFIER)); 9007 fprintf (stream, "\n"); 9008 9009 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (DECL_INITIAL (decl)), 9010 ix, value) 9011 fprintf (stream, "%-4ld %s\n", (long)(ix * elt), 9012 expr_as_string (value, TFF_PLAIN_IDENTIFIER)); 9013 } 9014 9015 static void 9016 dump_vtable (tree t, tree binfo, tree vtable) 9017 { 9018 int flags; 9019 FILE *stream = get_dump_info (TDI_class, &flags); 9020 9021 if (!stream) 9022 return; 9023 9024 if (!(flags & TDF_SLIM)) 9025 { 9026 int ctor_vtbl_p = TYPE_BINFO (t) != binfo; 9027 9028 fprintf (stream, "%s for %s", 9029 ctor_vtbl_p ? "Construction vtable" : "Vtable", 9030 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER)); 9031 if (ctor_vtbl_p) 9032 { 9033 if (!BINFO_VIRTUAL_P (binfo)) 9034 fprintf (stream, " (0x" HOST_WIDE_INT_PRINT_HEX " instance)", 9035 (HOST_WIDE_INT) (uintptr_t) binfo); 9036 fprintf (stream, " in %s", type_as_string (t, TFF_PLAIN_IDENTIFIER)); 9037 } 9038 fprintf (stream, "\n"); 9039 dump_array (stream, vtable); 9040 fprintf (stream, "\n"); 9041 } 9042 } 9043 9044 static void 9045 dump_vtt (tree t, tree vtt) 9046 { 9047 int flags; 9048 FILE *stream = get_dump_info (TDI_class, &flags); 9049 9050 if (!stream) 9051 return; 9052 9053 if (!(flags & TDF_SLIM)) 9054 { 9055 fprintf (stream, "VTT for %s\n", 9056 type_as_string (t, TFF_PLAIN_IDENTIFIER)); 9057 dump_array (stream, vtt); 9058 fprintf (stream, "\n"); 9059 } 9060 } 9061 9062 /* Dump a function or thunk and its thunkees. */ 9063 9064 static void 9065 dump_thunk (FILE *stream, int indent, tree thunk) 9066 { 9067 static const char spaces[] = " "; 9068 tree name = DECL_NAME (thunk); 9069 tree thunks; 9070 9071 fprintf (stream, "%.*s%p %s %s", indent, spaces, 9072 (void *)thunk, 9073 !DECL_THUNK_P (thunk) ? "function" 9074 : DECL_THIS_THUNK_P (thunk) ? "this-thunk" : "covariant-thunk", 9075 name ? IDENTIFIER_POINTER (name) : "<unset>"); 9076 if (DECL_THUNK_P (thunk)) 9077 { 9078 HOST_WIDE_INT fixed_adjust = THUNK_FIXED_OFFSET (thunk); 9079 tree virtual_adjust = THUNK_VIRTUAL_OFFSET (thunk); 9080 9081 fprintf (stream, " fixed=" HOST_WIDE_INT_PRINT_DEC, fixed_adjust); 9082 if (!virtual_adjust) 9083 /*NOP*/; 9084 else if (DECL_THIS_THUNK_P (thunk)) 9085 fprintf (stream, " vcall=" HOST_WIDE_INT_PRINT_DEC, 9086 tree_to_shwi (virtual_adjust)); 9087 else 9088 fprintf (stream, " vbase=" HOST_WIDE_INT_PRINT_DEC "(%s)", 9089 tree_to_shwi (BINFO_VPTR_FIELD (virtual_adjust)), 9090 type_as_string (BINFO_TYPE (virtual_adjust), TFF_SCOPE)); 9091 if (THUNK_ALIAS (thunk)) 9092 fprintf (stream, " alias to %p", (void *)THUNK_ALIAS (thunk)); 9093 } 9094 fprintf (stream, "\n"); 9095 for (thunks = DECL_THUNKS (thunk); thunks; thunks = TREE_CHAIN (thunks)) 9096 dump_thunk (stream, indent + 2, thunks); 9097 } 9098 9099 /* Dump the thunks for FN. */ 9100 9101 void 9102 debug_thunks (tree fn) 9103 { 9104 dump_thunk (stderr, 0, fn); 9105 } 9106 9107 /* Virtual function table initialization. */ 9108 9109 /* Create all the necessary vtables for T and its base classes. */ 9110 9111 static void 9112 finish_vtbls (tree t) 9113 { 9114 tree vbase; 9115 vec<constructor_elt, va_gc> *v = NULL; 9116 tree vtable = BINFO_VTABLE (TYPE_BINFO (t)); 9117 9118 /* We lay out the primary and secondary vtables in one contiguous 9119 vtable. The primary vtable is first, followed by the non-virtual 9120 secondary vtables in inheritance graph order. */ 9121 accumulate_vtbl_inits (TYPE_BINFO (t), TYPE_BINFO (t), TYPE_BINFO (t), 9122 vtable, t, &v); 9123 9124 /* Then come the virtual bases, also in inheritance graph order. */ 9125 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase)) 9126 { 9127 if (!BINFO_VIRTUAL_P (vbase)) 9128 continue; 9129 accumulate_vtbl_inits (vbase, vbase, TYPE_BINFO (t), vtable, t, &v); 9130 } 9131 9132 if (BINFO_VTABLE (TYPE_BINFO (t))) 9133 initialize_vtable (TYPE_BINFO (t), v); 9134 } 9135 9136 /* Initialize the vtable for BINFO with the INITS. */ 9137 9138 static void 9139 initialize_vtable (tree binfo, vec<constructor_elt, va_gc> *inits) 9140 { 9141 tree decl; 9142 9143 layout_vtable_decl (binfo, vec_safe_length (inits)); 9144 decl = get_vtbl_decl_for_binfo (binfo); 9145 initialize_artificial_var (decl, inits); 9146 dump_vtable (BINFO_TYPE (binfo), binfo, decl); 9147 } 9148 9149 /* Build the VTT (virtual table table) for T. 9150 A class requires a VTT if it has virtual bases. 9151 9152 This holds 9153 1 - primary virtual pointer for complete object T 9154 2 - secondary VTTs for each direct non-virtual base of T which requires a 9155 VTT 9156 3 - secondary virtual pointers for each direct or indirect base of T which 9157 has virtual bases or is reachable via a virtual path from T. 9158 4 - secondary VTTs for each direct or indirect virtual base of T. 9159 9160 Secondary VTTs look like complete object VTTs without part 4. */ 9161 9162 static void 9163 build_vtt (tree t) 9164 { 9165 tree type; 9166 tree vtt; 9167 tree index; 9168 vec<constructor_elt, va_gc> *inits; 9169 9170 /* Build up the initializers for the VTT. */ 9171 inits = NULL; 9172 index = size_zero_node; 9173 build_vtt_inits (TYPE_BINFO (t), t, &inits, &index); 9174 9175 /* If we didn't need a VTT, we're done. */ 9176 if (!inits) 9177 return; 9178 9179 /* Figure out the type of the VTT. */ 9180 type = build_array_of_n_type (const_ptr_type_node, 9181 inits->length ()); 9182 9183 /* Now, build the VTT object itself. */ 9184 vtt = build_vtable (t, mangle_vtt_for_type (t), type); 9185 initialize_artificial_var (vtt, inits); 9186 /* Add the VTT to the vtables list. */ 9187 DECL_CHAIN (vtt) = DECL_CHAIN (CLASSTYPE_VTABLES (t)); 9188 DECL_CHAIN (CLASSTYPE_VTABLES (t)) = vtt; 9189 9190 dump_vtt (t, vtt); 9191 } 9192 9193 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with 9194 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo, 9195 and CHAIN the vtable pointer for this binfo after construction is 9196 complete. VALUE can also be another BINFO, in which case we recurse. */ 9197 9198 static tree 9199 binfo_ctor_vtable (tree binfo) 9200 { 9201 tree vt; 9202 9203 while (1) 9204 { 9205 vt = BINFO_VTABLE (binfo); 9206 if (TREE_CODE (vt) == TREE_LIST) 9207 vt = TREE_VALUE (vt); 9208 if (TREE_CODE (vt) == TREE_BINFO) 9209 binfo = vt; 9210 else 9211 break; 9212 } 9213 9214 return vt; 9215 } 9216 9217 /* Data for secondary VTT initialization. */ 9218 struct secondary_vptr_vtt_init_data 9219 { 9220 /* Is this the primary VTT? */ 9221 bool top_level_p; 9222 9223 /* Current index into the VTT. */ 9224 tree index; 9225 9226 /* Vector of initializers built up. */ 9227 vec<constructor_elt, va_gc> *inits; 9228 9229 /* The type being constructed by this secondary VTT. */ 9230 tree type_being_constructed; 9231 }; 9232 9233 /* Recursively build the VTT-initializer for BINFO (which is in the 9234 hierarchy dominated by T). INITS points to the end of the initializer 9235 list to date. INDEX is the VTT index where the next element will be 9236 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e. 9237 not a subvtt for some base of T). When that is so, we emit the sub-VTTs 9238 for virtual bases of T. When it is not so, we build the constructor 9239 vtables for the BINFO-in-T variant. */ 9240 9241 static void 9242 build_vtt_inits (tree binfo, tree t, vec<constructor_elt, va_gc> **inits, 9243 tree *index) 9244 { 9245 int i; 9246 tree b; 9247 tree init; 9248 secondary_vptr_vtt_init_data data; 9249 int top_level_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t); 9250 9251 /* We only need VTTs for subobjects with virtual bases. */ 9252 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))) 9253 return; 9254 9255 /* We need to use a construction vtable if this is not the primary 9256 VTT. */ 9257 if (!top_level_p) 9258 { 9259 build_ctor_vtbl_group (binfo, t); 9260 9261 /* Record the offset in the VTT where this sub-VTT can be found. */ 9262 BINFO_SUBVTT_INDEX (binfo) = *index; 9263 } 9264 9265 /* Add the address of the primary vtable for the complete object. */ 9266 init = binfo_ctor_vtable (binfo); 9267 CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, init); 9268 if (top_level_p) 9269 { 9270 gcc_assert (!BINFO_VPTR_INDEX (binfo)); 9271 BINFO_VPTR_INDEX (binfo) = *index; 9272 } 9273 *index = size_binop (PLUS_EXPR, *index, TYPE_SIZE_UNIT (ptr_type_node)); 9274 9275 /* Recursively add the secondary VTTs for non-virtual bases. */ 9276 for (i = 0; BINFO_BASE_ITERATE (binfo, i, b); ++i) 9277 if (!BINFO_VIRTUAL_P (b)) 9278 build_vtt_inits (b, t, inits, index); 9279 9280 /* Add secondary virtual pointers for all subobjects of BINFO with 9281 either virtual bases or reachable along a virtual path, except 9282 subobjects that are non-virtual primary bases. */ 9283 data.top_level_p = top_level_p; 9284 data.index = *index; 9285 data.inits = *inits; 9286 data.type_being_constructed = BINFO_TYPE (binfo); 9287 9288 dfs_walk_once (binfo, dfs_build_secondary_vptr_vtt_inits, NULL, &data); 9289 9290 *index = data.index; 9291 9292 /* data.inits might have grown as we added secondary virtual pointers. 9293 Make sure our caller knows about the new vector. */ 9294 *inits = data.inits; 9295 9296 if (top_level_p) 9297 /* Add the secondary VTTs for virtual bases in inheritance graph 9298 order. */ 9299 for (b = TYPE_BINFO (BINFO_TYPE (binfo)); b; b = TREE_CHAIN (b)) 9300 { 9301 if (!BINFO_VIRTUAL_P (b)) 9302 continue; 9303 9304 build_vtt_inits (b, t, inits, index); 9305 } 9306 else 9307 /* Remove the ctor vtables we created. */ 9308 dfs_walk_all (binfo, dfs_fixup_binfo_vtbls, NULL, binfo); 9309 } 9310 9311 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base 9312 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */ 9313 9314 static tree 9315 dfs_build_secondary_vptr_vtt_inits (tree binfo, void *data_) 9316 { 9317 secondary_vptr_vtt_init_data *data = (secondary_vptr_vtt_init_data *)data_; 9318 9319 /* We don't care about bases that don't have vtables. */ 9320 if (!TYPE_VFIELD (BINFO_TYPE (binfo))) 9321 return dfs_skip_bases; 9322 9323 /* We're only interested in proper subobjects of the type being 9324 constructed. */ 9325 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->type_being_constructed)) 9326 return NULL_TREE; 9327 9328 /* We're only interested in bases with virtual bases or reachable 9329 via a virtual path from the type being constructed. */ 9330 if (!(CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)) 9331 || binfo_via_virtual (binfo, data->type_being_constructed))) 9332 return dfs_skip_bases; 9333 9334 /* We're not interested in non-virtual primary bases. */ 9335 if (!BINFO_VIRTUAL_P (binfo) && BINFO_PRIMARY_P (binfo)) 9336 return NULL_TREE; 9337 9338 /* Record the index where this secondary vptr can be found. */ 9339 if (data->top_level_p) 9340 { 9341 gcc_assert (!BINFO_VPTR_INDEX (binfo)); 9342 BINFO_VPTR_INDEX (binfo) = data->index; 9343 9344 if (BINFO_VIRTUAL_P (binfo)) 9345 { 9346 /* It's a primary virtual base, and this is not a 9347 construction vtable. Find the base this is primary of in 9348 the inheritance graph, and use that base's vtable 9349 now. */ 9350 while (BINFO_PRIMARY_P (binfo)) 9351 binfo = BINFO_INHERITANCE_CHAIN (binfo); 9352 } 9353 } 9354 9355 /* Add the initializer for the secondary vptr itself. */ 9356 CONSTRUCTOR_APPEND_ELT (data->inits, NULL_TREE, binfo_ctor_vtable (binfo)); 9357 9358 /* Advance the vtt index. */ 9359 data->index = size_binop (PLUS_EXPR, data->index, 9360 TYPE_SIZE_UNIT (ptr_type_node)); 9361 9362 return NULL_TREE; 9363 } 9364 9365 /* Called from build_vtt_inits via dfs_walk. After building 9366 constructor vtables and generating the sub-vtt from them, we need 9367 to restore the BINFO_VTABLES that were scribbled on. DATA is the 9368 binfo of the base whose sub vtt was generated. */ 9369 9370 static tree 9371 dfs_fixup_binfo_vtbls (tree binfo, void* data) 9372 { 9373 tree vtable = BINFO_VTABLE (binfo); 9374 9375 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) 9376 /* If this class has no vtable, none of its bases do. */ 9377 return dfs_skip_bases; 9378 9379 if (!vtable) 9380 /* This might be a primary base, so have no vtable in this 9381 hierarchy. */ 9382 return NULL_TREE; 9383 9384 /* If we scribbled the construction vtable vptr into BINFO, clear it 9385 out now. */ 9386 if (TREE_CODE (vtable) == TREE_LIST 9387 && (TREE_PURPOSE (vtable) == (tree) data)) 9388 BINFO_VTABLE (binfo) = TREE_CHAIN (vtable); 9389 9390 return NULL_TREE; 9391 } 9392 9393 /* Build the construction vtable group for BINFO which is in the 9394 hierarchy dominated by T. */ 9395 9396 static void 9397 build_ctor_vtbl_group (tree binfo, tree t) 9398 { 9399 tree type; 9400 tree vtbl; 9401 tree id; 9402 tree vbase; 9403 vec<constructor_elt, va_gc> *v; 9404 9405 /* See if we've already created this construction vtable group. */ 9406 id = mangle_ctor_vtbl_for_type (t, binfo); 9407 if (IDENTIFIER_GLOBAL_VALUE (id)) 9408 return; 9409 9410 gcc_assert (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t)); 9411 /* Build a version of VTBL (with the wrong type) for use in 9412 constructing the addresses of secondary vtables in the 9413 construction vtable group. */ 9414 vtbl = build_vtable (t, id, ptr_type_node); 9415 DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1; 9416 /* Don't export construction vtables from shared libraries. Even on 9417 targets that don't support hidden visibility, this tells 9418 can_refer_decl_in_current_unit_p not to assume that it's safe to 9419 access from a different compilation unit (bz 54314). */ 9420 DECL_VISIBILITY (vtbl) = VISIBILITY_HIDDEN; 9421 DECL_VISIBILITY_SPECIFIED (vtbl) = true; 9422 9423 v = NULL; 9424 accumulate_vtbl_inits (binfo, TYPE_BINFO (TREE_TYPE (binfo)), 9425 binfo, vtbl, t, &v); 9426 9427 /* Add the vtables for each of our virtual bases using the vbase in T 9428 binfo. */ 9429 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo)); 9430 vbase; 9431 vbase = TREE_CHAIN (vbase)) 9432 { 9433 tree b; 9434 9435 if (!BINFO_VIRTUAL_P (vbase)) 9436 continue; 9437 b = copied_binfo (vbase, binfo); 9438 9439 accumulate_vtbl_inits (b, vbase, binfo, vtbl, t, &v); 9440 } 9441 9442 /* Figure out the type of the construction vtable. */ 9443 type = build_array_of_n_type (vtable_entry_type, v->length ()); 9444 layout_type (type); 9445 TREE_TYPE (vtbl) = type; 9446 DECL_SIZE (vtbl) = DECL_SIZE_UNIT (vtbl) = NULL_TREE; 9447 layout_decl (vtbl, 0); 9448 9449 /* Initialize the construction vtable. */ 9450 CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl); 9451 initialize_artificial_var (vtbl, v); 9452 dump_vtable (t, binfo, vtbl); 9453 } 9454 9455 /* Add the vtbl initializers for BINFO (and its bases other than 9456 non-virtual primaries) to the list of INITS. BINFO is in the 9457 hierarchy dominated by T. RTTI_BINFO is the binfo within T of 9458 the constructor the vtbl inits should be accumulated for. (If this 9459 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).) 9460 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO). 9461 BINFO is the active base equivalent of ORIG_BINFO in the inheritance 9462 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE, 9463 but are not necessarily the same in terms of layout. */ 9464 9465 static void 9466 accumulate_vtbl_inits (tree binfo, 9467 tree orig_binfo, 9468 tree rtti_binfo, 9469 tree vtbl, 9470 tree t, 9471 vec<constructor_elt, va_gc> **inits) 9472 { 9473 int i; 9474 tree base_binfo; 9475 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); 9476 9477 gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (orig_binfo))); 9478 9479 /* If it doesn't have a vptr, we don't do anything. */ 9480 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) 9481 return; 9482 9483 /* If we're building a construction vtable, we're not interested in 9484 subobjects that don't require construction vtables. */ 9485 if (ctor_vtbl_p 9486 && !CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)) 9487 && !binfo_via_virtual (orig_binfo, BINFO_TYPE (rtti_binfo))) 9488 return; 9489 9490 /* Build the initializers for the BINFO-in-T vtable. */ 9491 dfs_accumulate_vtbl_inits (binfo, orig_binfo, rtti_binfo, vtbl, t, inits); 9492 9493 /* Walk the BINFO and its bases. We walk in preorder so that as we 9494 initialize each vtable we can figure out at what offset the 9495 secondary vtable lies from the primary vtable. We can't use 9496 dfs_walk here because we need to iterate through bases of BINFO 9497 and RTTI_BINFO simultaneously. */ 9498 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 9499 { 9500 /* Skip virtual bases. */ 9501 if (BINFO_VIRTUAL_P (base_binfo)) 9502 continue; 9503 accumulate_vtbl_inits (base_binfo, 9504 BINFO_BASE_BINFO (orig_binfo, i), 9505 rtti_binfo, vtbl, t, 9506 inits); 9507 } 9508 } 9509 9510 /* Called from accumulate_vtbl_inits. Adds the initializers for the 9511 BINFO vtable to L. */ 9512 9513 static void 9514 dfs_accumulate_vtbl_inits (tree binfo, 9515 tree orig_binfo, 9516 tree rtti_binfo, 9517 tree orig_vtbl, 9518 tree t, 9519 vec<constructor_elt, va_gc> **l) 9520 { 9521 tree vtbl = NULL_TREE; 9522 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); 9523 int n_inits; 9524 9525 if (ctor_vtbl_p 9526 && BINFO_VIRTUAL_P (orig_binfo) && BINFO_PRIMARY_P (orig_binfo)) 9527 { 9528 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a 9529 primary virtual base. If it is not the same primary in 9530 the hierarchy of T, we'll need to generate a ctor vtable 9531 for it, to place at its location in T. If it is the same 9532 primary, we still need a VTT entry for the vtable, but it 9533 should point to the ctor vtable for the base it is a 9534 primary for within the sub-hierarchy of RTTI_BINFO. 9535 9536 There are three possible cases: 9537 9538 1) We are in the same place. 9539 2) We are a primary base within a lost primary virtual base of 9540 RTTI_BINFO. 9541 3) We are primary to something not a base of RTTI_BINFO. */ 9542 9543 tree b; 9544 tree last = NULL_TREE; 9545 9546 /* First, look through the bases we are primary to for RTTI_BINFO 9547 or a virtual base. */ 9548 b = binfo; 9549 while (BINFO_PRIMARY_P (b)) 9550 { 9551 b = BINFO_INHERITANCE_CHAIN (b); 9552 last = b; 9553 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo) 9554 goto found; 9555 } 9556 /* If we run out of primary links, keep looking down our 9557 inheritance chain; we might be an indirect primary. */ 9558 for (b = last; b; b = BINFO_INHERITANCE_CHAIN (b)) 9559 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo) 9560 break; 9561 found: 9562 9563 /* If we found RTTI_BINFO, this is case 1. If we found a virtual 9564 base B and it is a base of RTTI_BINFO, this is case 2. In 9565 either case, we share our vtable with LAST, i.e. the 9566 derived-most base within B of which we are a primary. */ 9567 if (b == rtti_binfo 9568 || (b && binfo_for_vbase (BINFO_TYPE (b), BINFO_TYPE (rtti_binfo)))) 9569 /* Just set our BINFO_VTABLE to point to LAST, as we may not have 9570 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in 9571 binfo_ctor_vtable after everything's been set up. */ 9572 vtbl = last; 9573 9574 /* Otherwise, this is case 3 and we get our own. */ 9575 } 9576 else if (!BINFO_NEW_VTABLE_MARKED (orig_binfo)) 9577 return; 9578 9579 n_inits = vec_safe_length (*l); 9580 9581 if (!vtbl) 9582 { 9583 tree index; 9584 int non_fn_entries; 9585 9586 /* Add the initializer for this vtable. */ 9587 build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo, 9588 &non_fn_entries, l); 9589 9590 /* Figure out the position to which the VPTR should point. */ 9591 vtbl = build1 (ADDR_EXPR, vtbl_ptr_type_node, orig_vtbl); 9592 index = size_binop (MULT_EXPR, 9593 TYPE_SIZE_UNIT (vtable_entry_type), 9594 size_int (non_fn_entries + n_inits)); 9595 vtbl = fold_build_pointer_plus (vtbl, index); 9596 } 9597 9598 if (ctor_vtbl_p) 9599 /* For a construction vtable, we can't overwrite BINFO_VTABLE. 9600 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will 9601 straighten this out. */ 9602 BINFO_VTABLE (binfo) = tree_cons (rtti_binfo, vtbl, BINFO_VTABLE (binfo)); 9603 else if (BINFO_PRIMARY_P (binfo) && BINFO_VIRTUAL_P (binfo)) 9604 /* Throw away any unneeded intializers. */ 9605 (*l)->truncate (n_inits); 9606 else 9607 /* For an ordinary vtable, set BINFO_VTABLE. */ 9608 BINFO_VTABLE (binfo) = vtbl; 9609 } 9610 9611 static GTY(()) tree abort_fndecl_addr; 9612 9613 /* Construct the initializer for BINFO's virtual function table. BINFO 9614 is part of the hierarchy dominated by T. If we're building a 9615 construction vtable, the ORIG_BINFO is the binfo we should use to 9616 find the actual function pointers to put in the vtable - but they 9617 can be overridden on the path to most-derived in the graph that 9618 ORIG_BINFO belongs. Otherwise, 9619 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the 9620 BINFO that should be indicated by the RTTI information in the 9621 vtable; it will be a base class of T, rather than T itself, if we 9622 are building a construction vtable. 9623 9624 The value returned is a TREE_LIST suitable for wrapping in a 9625 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If 9626 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the 9627 number of non-function entries in the vtable. 9628 9629 It might seem that this function should never be called with a 9630 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a 9631 base is always subsumed by a derived class vtable. However, when 9632 we are building construction vtables, we do build vtables for 9633 primary bases; we need these while the primary base is being 9634 constructed. */ 9635 9636 static void 9637 build_vtbl_initializer (tree binfo, 9638 tree orig_binfo, 9639 tree t, 9640 tree rtti_binfo, 9641 int* non_fn_entries_p, 9642 vec<constructor_elt, va_gc> **inits) 9643 { 9644 tree v; 9645 vtbl_init_data vid; 9646 unsigned ix, jx; 9647 tree vbinfo; 9648 vec<tree, va_gc> *vbases; 9649 constructor_elt *e; 9650 9651 /* Initialize VID. */ 9652 memset (&vid, 0, sizeof (vid)); 9653 vid.binfo = binfo; 9654 vid.derived = t; 9655 vid.rtti_binfo = rtti_binfo; 9656 vid.primary_vtbl_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t); 9657 vid.ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); 9658 vid.generate_vcall_entries = true; 9659 /* The first vbase or vcall offset is at index -3 in the vtable. */ 9660 vid.index = ssize_int(-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE); 9661 9662 /* Add entries to the vtable for RTTI. */ 9663 build_rtti_vtbl_entries (binfo, &vid); 9664 9665 /* Create an array for keeping track of the functions we've 9666 processed. When we see multiple functions with the same 9667 signature, we share the vcall offsets. */ 9668 vec_alloc (vid.fns, 32); 9669 /* Add the vcall and vbase offset entries. */ 9670 build_vcall_and_vbase_vtbl_entries (binfo, &vid); 9671 9672 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by 9673 build_vbase_offset_vtbl_entries. */ 9674 for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0; 9675 vec_safe_iterate (vbases, ix, &vbinfo); ix++) 9676 BINFO_VTABLE_PATH_MARKED (vbinfo) = 0; 9677 9678 /* If the target requires padding between data entries, add that now. */ 9679 if (TARGET_VTABLE_DATA_ENTRY_DISTANCE > 1) 9680 { 9681 int n_entries = vec_safe_length (vid.inits); 9682 9683 vec_safe_grow (vid.inits, TARGET_VTABLE_DATA_ENTRY_DISTANCE * n_entries); 9684 9685 /* Move data entries into their new positions and add padding 9686 after the new positions. Iterate backwards so we don't 9687 overwrite entries that we would need to process later. */ 9688 for (ix = n_entries - 1; 9689 vid.inits->iterate (ix, &e); 9690 ix--) 9691 { 9692 int j; 9693 int new_position = (TARGET_VTABLE_DATA_ENTRY_DISTANCE * ix 9694 + (TARGET_VTABLE_DATA_ENTRY_DISTANCE - 1)); 9695 9696 (*vid.inits)[new_position] = *e; 9697 9698 for (j = 1; j < TARGET_VTABLE_DATA_ENTRY_DISTANCE; ++j) 9699 { 9700 constructor_elt *f = &(*vid.inits)[new_position - j]; 9701 f->index = NULL_TREE; 9702 f->value = build1 (NOP_EXPR, vtable_entry_type, 9703 null_pointer_node); 9704 } 9705 } 9706 } 9707 9708 if (non_fn_entries_p) 9709 *non_fn_entries_p = vec_safe_length (vid.inits); 9710 9711 /* The initializers for virtual functions were built up in reverse 9712 order. Straighten them out and add them to the running list in one 9713 step. */ 9714 jx = vec_safe_length (*inits); 9715 vec_safe_grow (*inits, jx + vid.inits->length ()); 9716 9717 for (ix = vid.inits->length () - 1; 9718 vid.inits->iterate (ix, &e); 9719 ix--, jx++) 9720 (**inits)[jx] = *e; 9721 9722 /* Go through all the ordinary virtual functions, building up 9723 initializers. */ 9724 for (v = BINFO_VIRTUALS (orig_binfo); v; v = TREE_CHAIN (v)) 9725 { 9726 tree delta; 9727 tree vcall_index; 9728 tree fn, fn_original; 9729 tree init = NULL_TREE; 9730 9731 fn = BV_FN (v); 9732 fn_original = fn; 9733 if (DECL_THUNK_P (fn)) 9734 { 9735 if (!DECL_NAME (fn)) 9736 finish_thunk (fn); 9737 if (THUNK_ALIAS (fn)) 9738 { 9739 fn = THUNK_ALIAS (fn); 9740 BV_FN (v) = fn; 9741 } 9742 fn_original = THUNK_TARGET (fn); 9743 } 9744 9745 /* If the only definition of this function signature along our 9746 primary base chain is from a lost primary, this vtable slot will 9747 never be used, so just zero it out. This is important to avoid 9748 requiring extra thunks which cannot be generated with the function. 9749 9750 We first check this in update_vtable_entry_for_fn, so we handle 9751 restored primary bases properly; we also need to do it here so we 9752 zero out unused slots in ctor vtables, rather than filling them 9753 with erroneous values (though harmless, apart from relocation 9754 costs). */ 9755 if (BV_LOST_PRIMARY (v)) 9756 init = size_zero_node; 9757 9758 if (! init) 9759 { 9760 /* Pull the offset for `this', and the function to call, out of 9761 the list. */ 9762 delta = BV_DELTA (v); 9763 vcall_index = BV_VCALL_INDEX (v); 9764 9765 gcc_assert (TREE_CODE (delta) == INTEGER_CST); 9766 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); 9767 9768 /* You can't call an abstract virtual function; it's abstract. 9769 So, we replace these functions with __pure_virtual. */ 9770 if (DECL_PURE_VIRTUAL_P (fn_original)) 9771 { 9772 fn = abort_fndecl; 9773 if (!TARGET_VTABLE_USES_DESCRIPTORS) 9774 { 9775 if (abort_fndecl_addr == NULL) 9776 abort_fndecl_addr 9777 = fold_convert (vfunc_ptr_type_node, 9778 build_fold_addr_expr (fn)); 9779 init = abort_fndecl_addr; 9780 } 9781 } 9782 /* Likewise for deleted virtuals. */ 9783 else if (DECL_DELETED_FN (fn_original)) 9784 { 9785 fn = get_identifier ("__cxa_deleted_virtual"); 9786 if (!get_global_value_if_present (fn, &fn)) 9787 fn = push_library_fn (fn, (build_function_type_list 9788 (void_type_node, NULL_TREE)), 9789 NULL_TREE, ECF_NORETURN); 9790 if (!TARGET_VTABLE_USES_DESCRIPTORS) 9791 init = fold_convert (vfunc_ptr_type_node, 9792 build_fold_addr_expr (fn)); 9793 } 9794 else 9795 { 9796 if (!integer_zerop (delta) || vcall_index) 9797 { 9798 fn = make_thunk (fn, /*this_adjusting=*/1, delta, vcall_index); 9799 if (!DECL_NAME (fn)) 9800 finish_thunk (fn); 9801 } 9802 /* Take the address of the function, considering it to be of an 9803 appropriate generic type. */ 9804 if (!TARGET_VTABLE_USES_DESCRIPTORS) 9805 init = fold_convert (vfunc_ptr_type_node, 9806 build_fold_addr_expr (fn)); 9807 /* Don't refer to a virtual destructor from a constructor 9808 vtable or a vtable for an abstract class, since destroying 9809 an object under construction is undefined behavior and we 9810 don't want it to be considered a candidate for speculative 9811 devirtualization. But do create the thunk for ABI 9812 compliance. */ 9813 if (DECL_DESTRUCTOR_P (fn_original) 9814 && (CLASSTYPE_PURE_VIRTUALS (DECL_CONTEXT (fn_original)) 9815 || orig_binfo != binfo)) 9816 init = size_zero_node; 9817 } 9818 } 9819 9820 /* And add it to the chain of initializers. */ 9821 if (TARGET_VTABLE_USES_DESCRIPTORS) 9822 { 9823 int i; 9824 if (init == size_zero_node) 9825 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i) 9826 CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, init); 9827 else 9828 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i) 9829 { 9830 tree fdesc = build2 (FDESC_EXPR, vfunc_ptr_type_node, 9831 fn, build_int_cst (NULL_TREE, i)); 9832 TREE_CONSTANT (fdesc) = 1; 9833 9834 CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, fdesc); 9835 } 9836 } 9837 else 9838 CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, init); 9839 } 9840 } 9841 9842 /* Adds to vid->inits the initializers for the vbase and vcall 9843 offsets in BINFO, which is in the hierarchy dominated by T. */ 9844 9845 static void 9846 build_vcall_and_vbase_vtbl_entries (tree binfo, vtbl_init_data* vid) 9847 { 9848 tree b; 9849 9850 /* If this is a derived class, we must first create entries 9851 corresponding to the primary base class. */ 9852 b = get_primary_binfo (binfo); 9853 if (b) 9854 build_vcall_and_vbase_vtbl_entries (b, vid); 9855 9856 /* Add the vbase entries for this base. */ 9857 build_vbase_offset_vtbl_entries (binfo, vid); 9858 /* Add the vcall entries for this base. */ 9859 build_vcall_offset_vtbl_entries (binfo, vid); 9860 } 9861 9862 /* Returns the initializers for the vbase offset entries in the vtable 9863 for BINFO (which is part of the class hierarchy dominated by T), in 9864 reverse order. VBASE_OFFSET_INDEX gives the vtable index 9865 where the next vbase offset will go. */ 9866 9867 static void 9868 build_vbase_offset_vtbl_entries (tree binfo, vtbl_init_data* vid) 9869 { 9870 tree vbase; 9871 tree t; 9872 tree non_primary_binfo; 9873 9874 /* If there are no virtual baseclasses, then there is nothing to 9875 do. */ 9876 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))) 9877 return; 9878 9879 t = vid->derived; 9880 9881 /* We might be a primary base class. Go up the inheritance hierarchy 9882 until we find the most derived class of which we are a primary base: 9883 it is the offset of that which we need to use. */ 9884 non_primary_binfo = binfo; 9885 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo)) 9886 { 9887 tree b; 9888 9889 /* If we have reached a virtual base, then it must be a primary 9890 base (possibly multi-level) of vid->binfo, or we wouldn't 9891 have called build_vcall_and_vbase_vtbl_entries for it. But it 9892 might be a lost primary, so just skip down to vid->binfo. */ 9893 if (BINFO_VIRTUAL_P (non_primary_binfo)) 9894 { 9895 non_primary_binfo = vid->binfo; 9896 break; 9897 } 9898 9899 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo); 9900 if (get_primary_binfo (b) != non_primary_binfo) 9901 break; 9902 non_primary_binfo = b; 9903 } 9904 9905 /* Go through the virtual bases, adding the offsets. */ 9906 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo)); 9907 vbase; 9908 vbase = TREE_CHAIN (vbase)) 9909 { 9910 tree b; 9911 tree delta; 9912 9913 if (!BINFO_VIRTUAL_P (vbase)) 9914 continue; 9915 9916 /* Find the instance of this virtual base in the complete 9917 object. */ 9918 b = copied_binfo (vbase, binfo); 9919 9920 /* If we've already got an offset for this virtual base, we 9921 don't need another one. */ 9922 if (BINFO_VTABLE_PATH_MARKED (b)) 9923 continue; 9924 BINFO_VTABLE_PATH_MARKED (b) = 1; 9925 9926 /* Figure out where we can find this vbase offset. */ 9927 delta = size_binop (MULT_EXPR, 9928 vid->index, 9929 fold_convert (ssizetype, 9930 TYPE_SIZE_UNIT (vtable_entry_type))); 9931 if (vid->primary_vtbl_p) 9932 BINFO_VPTR_FIELD (b) = delta; 9933 9934 if (binfo != TYPE_BINFO (t)) 9935 /* The vbase offset had better be the same. */ 9936 gcc_assert (tree_int_cst_equal (delta, BINFO_VPTR_FIELD (vbase))); 9937 9938 /* The next vbase will come at a more negative offset. */ 9939 vid->index = size_binop (MINUS_EXPR, vid->index, 9940 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE)); 9941 9942 /* The initializer is the delta from BINFO to this virtual base. 9943 The vbase offsets go in reverse inheritance-graph order, and 9944 we are walking in inheritance graph order so these end up in 9945 the right order. */ 9946 delta = size_diffop_loc (input_location, 9947 BINFO_OFFSET (b), BINFO_OFFSET (non_primary_binfo)); 9948 9949 CONSTRUCTOR_APPEND_ELT (vid->inits, NULL_TREE, 9950 fold_build1_loc (input_location, NOP_EXPR, 9951 vtable_entry_type, delta)); 9952 } 9953 } 9954 9955 /* Adds the initializers for the vcall offset entries in the vtable 9956 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED) 9957 to VID->INITS. */ 9958 9959 static void 9960 build_vcall_offset_vtbl_entries (tree binfo, vtbl_init_data* vid) 9961 { 9962 /* We only need these entries if this base is a virtual base. We 9963 compute the indices -- but do not add to the vtable -- when 9964 building the main vtable for a class. */ 9965 if (binfo == TYPE_BINFO (vid->derived) 9966 || (BINFO_VIRTUAL_P (binfo) 9967 /* If BINFO is RTTI_BINFO, then (since BINFO does not 9968 correspond to VID->DERIVED), we are building a primary 9969 construction virtual table. Since this is a primary 9970 virtual table, we do not need the vcall offsets for 9971 BINFO. */ 9972 && binfo != vid->rtti_binfo)) 9973 { 9974 /* We need a vcall offset for each of the virtual functions in this 9975 vtable. For example: 9976 9977 class A { virtual void f (); }; 9978 class B1 : virtual public A { virtual void f (); }; 9979 class B2 : virtual public A { virtual void f (); }; 9980 class C: public B1, public B2 { virtual void f (); }; 9981 9982 A C object has a primary base of B1, which has a primary base of A. A 9983 C also has a secondary base of B2, which no longer has a primary base 9984 of A. So the B2-in-C construction vtable needs a secondary vtable for 9985 A, which will adjust the A* to a B2* to call f. We have no way of 9986 knowing what (or even whether) this offset will be when we define B2, 9987 so we store this "vcall offset" in the A sub-vtable and look it up in 9988 a "virtual thunk" for B2::f. 9989 9990 We need entries for all the functions in our primary vtable and 9991 in our non-virtual bases' secondary vtables. */ 9992 vid->vbase = binfo; 9993 /* If we are just computing the vcall indices -- but do not need 9994 the actual entries -- not that. */ 9995 if (!BINFO_VIRTUAL_P (binfo)) 9996 vid->generate_vcall_entries = false; 9997 /* Now, walk through the non-virtual bases, adding vcall offsets. */ 9998 add_vcall_offset_vtbl_entries_r (binfo, vid); 9999 } 10000 } 10001 10002 /* Build vcall offsets, starting with those for BINFO. */ 10003 10004 static void 10005 add_vcall_offset_vtbl_entries_r (tree binfo, vtbl_init_data* vid) 10006 { 10007 int i; 10008 tree primary_binfo; 10009 tree base_binfo; 10010 10011 /* Don't walk into virtual bases -- except, of course, for the 10012 virtual base for which we are building vcall offsets. Any 10013 primary virtual base will have already had its offsets generated 10014 through the recursion in build_vcall_and_vbase_vtbl_entries. */ 10015 if (BINFO_VIRTUAL_P (binfo) && vid->vbase != binfo) 10016 return; 10017 10018 /* If BINFO has a primary base, process it first. */ 10019 primary_binfo = get_primary_binfo (binfo); 10020 if (primary_binfo) 10021 add_vcall_offset_vtbl_entries_r (primary_binfo, vid); 10022 10023 /* Add BINFO itself to the list. */ 10024 add_vcall_offset_vtbl_entries_1 (binfo, vid); 10025 10026 /* Scan the non-primary bases of BINFO. */ 10027 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 10028 if (base_binfo != primary_binfo) 10029 add_vcall_offset_vtbl_entries_r (base_binfo, vid); 10030 } 10031 10032 /* Called from build_vcall_offset_vtbl_entries_r. */ 10033 10034 static void 10035 add_vcall_offset_vtbl_entries_1 (tree binfo, vtbl_init_data* vid) 10036 { 10037 /* Make entries for the rest of the virtuals. */ 10038 tree orig_fn; 10039 10040 /* The ABI requires that the methods be processed in declaration 10041 order. */ 10042 for (orig_fn = TYPE_METHODS (BINFO_TYPE (binfo)); 10043 orig_fn; 10044 orig_fn = DECL_CHAIN (orig_fn)) 10045 if (TREE_CODE (orig_fn) == FUNCTION_DECL && DECL_VINDEX (orig_fn)) 10046 add_vcall_offset (orig_fn, binfo, vid); 10047 } 10048 10049 /* Add a vcall offset entry for ORIG_FN to the vtable. */ 10050 10051 static void 10052 add_vcall_offset (tree orig_fn, tree binfo, vtbl_init_data *vid) 10053 { 10054 size_t i; 10055 tree vcall_offset; 10056 tree derived_entry; 10057 10058 /* If there is already an entry for a function with the same 10059 signature as FN, then we do not need a second vcall offset. 10060 Check the list of functions already present in the derived 10061 class vtable. */ 10062 FOR_EACH_VEC_SAFE_ELT (vid->fns, i, derived_entry) 10063 { 10064 if (same_signature_p (derived_entry, orig_fn) 10065 /* We only use one vcall offset for virtual destructors, 10066 even though there are two virtual table entries. */ 10067 || (DECL_DESTRUCTOR_P (derived_entry) 10068 && DECL_DESTRUCTOR_P (orig_fn))) 10069 return; 10070 } 10071 10072 /* If we are building these vcall offsets as part of building 10073 the vtable for the most derived class, remember the vcall 10074 offset. */ 10075 if (vid->binfo == TYPE_BINFO (vid->derived)) 10076 { 10077 tree_pair_s elt = {orig_fn, vid->index}; 10078 vec_safe_push (CLASSTYPE_VCALL_INDICES (vid->derived), elt); 10079 } 10080 10081 /* The next vcall offset will be found at a more negative 10082 offset. */ 10083 vid->index = size_binop (MINUS_EXPR, vid->index, 10084 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE)); 10085 10086 /* Keep track of this function. */ 10087 vec_safe_push (vid->fns, orig_fn); 10088 10089 if (vid->generate_vcall_entries) 10090 { 10091 tree base; 10092 tree fn; 10093 10094 /* Find the overriding function. */ 10095 fn = find_final_overrider (vid->rtti_binfo, binfo, orig_fn); 10096 if (fn == error_mark_node) 10097 vcall_offset = build_zero_cst (vtable_entry_type); 10098 else 10099 { 10100 base = TREE_VALUE (fn); 10101 10102 /* The vbase we're working on is a primary base of 10103 vid->binfo. But it might be a lost primary, so its 10104 BINFO_OFFSET might be wrong, so we just use the 10105 BINFO_OFFSET from vid->binfo. */ 10106 vcall_offset = size_diffop_loc (input_location, 10107 BINFO_OFFSET (base), 10108 BINFO_OFFSET (vid->binfo)); 10109 vcall_offset = fold_build1_loc (input_location, 10110 NOP_EXPR, vtable_entry_type, 10111 vcall_offset); 10112 } 10113 /* Add the initializer to the vtable. */ 10114 CONSTRUCTOR_APPEND_ELT (vid->inits, NULL_TREE, vcall_offset); 10115 } 10116 } 10117 10118 /* Return vtbl initializers for the RTTI entries corresponding to the 10119 BINFO's vtable. The RTTI entries should indicate the object given 10120 by VID->rtti_binfo. */ 10121 10122 static void 10123 build_rtti_vtbl_entries (tree binfo, vtbl_init_data* vid) 10124 { 10125 tree b; 10126 tree t; 10127 tree offset; 10128 tree decl; 10129 tree init; 10130 10131 t = BINFO_TYPE (vid->rtti_binfo); 10132 10133 /* To find the complete object, we will first convert to our most 10134 primary base, and then add the offset in the vtbl to that value. */ 10135 b = most_primary_binfo (binfo); 10136 offset = size_diffop_loc (input_location, 10137 BINFO_OFFSET (vid->rtti_binfo), BINFO_OFFSET (b)); 10138 10139 /* The second entry is the address of the typeinfo object. */ 10140 if (flag_rtti) 10141 decl = build_address (get_tinfo_decl (t)); 10142 else 10143 decl = integer_zero_node; 10144 10145 /* Convert the declaration to a type that can be stored in the 10146 vtable. */ 10147 init = build_nop (vfunc_ptr_type_node, decl); 10148 CONSTRUCTOR_APPEND_ELT (vid->inits, NULL_TREE, init); 10149 10150 /* Add the offset-to-top entry. It comes earlier in the vtable than 10151 the typeinfo entry. Convert the offset to look like a 10152 function pointer, so that we can put it in the vtable. */ 10153 init = build_nop (vfunc_ptr_type_node, offset); 10154 CONSTRUCTOR_APPEND_ELT (vid->inits, NULL_TREE, init); 10155 } 10156 10157 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores 10158 accessibility. */ 10159 10160 bool 10161 uniquely_derived_from_p (tree parent, tree type) 10162 { 10163 tree base = lookup_base (type, parent, ba_unique, NULL, tf_none); 10164 return base && base != error_mark_node; 10165 } 10166 10167 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */ 10168 10169 bool 10170 publicly_uniquely_derived_p (tree parent, tree type) 10171 { 10172 tree base = lookup_base (type, parent, ba_ignore_scope | ba_check, 10173 NULL, tf_none); 10174 return base && base != error_mark_node; 10175 } 10176 10177 /* CTX1 and CTX2 are declaration contexts. Return the innermost common 10178 class between them, if any. */ 10179 10180 tree 10181 common_enclosing_class (tree ctx1, tree ctx2) 10182 { 10183 if (!TYPE_P (ctx1) || !TYPE_P (ctx2)) 10184 return NULL_TREE; 10185 gcc_assert (ctx1 == TYPE_MAIN_VARIANT (ctx1) 10186 && ctx2 == TYPE_MAIN_VARIANT (ctx2)); 10187 if (ctx1 == ctx2) 10188 return ctx1; 10189 for (tree t = ctx1; TYPE_P (t); t = TYPE_CONTEXT (t)) 10190 TYPE_MARKED_P (t) = true; 10191 tree found = NULL_TREE; 10192 for (tree t = ctx2; TYPE_P (t); t = TYPE_CONTEXT (t)) 10193 if (TYPE_MARKED_P (t)) 10194 { 10195 found = t; 10196 break; 10197 } 10198 for (tree t = ctx1; TYPE_P (t); t = TYPE_CONTEXT (t)) 10199 TYPE_MARKED_P (t) = false; 10200 return found; 10201 } 10202 10203 #include "gt-cp-class.h" 10204