1/* Functions related to building classes and their related objects. 2 Copyright (C) 1987, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 3 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. 4 Contributed by Michael Tiemann (tiemann@cygnus.com) 5 6This file is part of GCC. 7 8GCC is free software; you can redistribute it and/or modify 9it under the terms of the GNU General Public License as published by 10the Free Software Foundation; either version 2, or (at your option) 11any later version. 12 13GCC is distributed in the hope that it will be useful, 14but WITHOUT ANY WARRANTY; without even the implied warranty of 15MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16GNU General Public License for more details. 17 18You should have received a copy of the GNU General Public License 19along with GCC; see the file COPYING. If not, write to 20the Free Software Foundation, 51 Franklin Street, Fifth Floor, 21Boston, MA 02110-1301, USA. */ 22 23 24/* High-level class interface. */ 25 26#include "config.h" 27#include "system.h" 28#include "coretypes.h" 29#include "tm.h" 30#include "tree.h" 31#include "cp-tree.h" 32#include "flags.h" 33#include "rtl.h" 34#include "output.h" 35#include "toplev.h" 36#include "target.h" 37#include "convert.h" 38#include "cgraph.h" 39#include "tree-dump.h" 40 41/* The number of nested classes being processed. If we are not in the 42 scope of any class, this is zero. */ 43 44int current_class_depth; 45 46/* In order to deal with nested classes, we keep a stack of classes. 47 The topmost entry is the innermost class, and is the entry at index 48 CURRENT_CLASS_DEPTH */ 49 50typedef struct class_stack_node { 51 /* The name of the class. */ 52 tree name; 53 54 /* The _TYPE node for the class. */ 55 tree type; 56 57 /* The access specifier pending for new declarations in the scope of 58 this class. */ 59 tree access; 60 61 /* If were defining TYPE, the names used in this class. */ 62 splay_tree names_used; 63 64 /* Nonzero if this class is no longer open, because of a call to 65 push_to_top_level. */ 66 size_t hidden; 67}* class_stack_node_t; 68 69typedef struct vtbl_init_data_s 70{ 71 /* The base for which we're building initializers. */ 72 tree binfo; 73 /* The type of the most-derived type. */ 74 tree derived; 75 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived), 76 unless ctor_vtbl_p is true. */ 77 tree rtti_binfo; 78 /* The negative-index vtable initializers built up so far. These 79 are in order from least negative index to most negative index. */ 80 tree inits; 81 /* The last (i.e., most negative) entry in INITS. */ 82 tree* last_init; 83 /* The binfo for the virtual base for which we're building 84 vcall offset initializers. */ 85 tree vbase; 86 /* The functions in vbase for which we have already provided vcall 87 offsets. */ 88 VEC(tree,gc) *fns; 89 /* The vtable index of the next vcall or vbase offset. */ 90 tree index; 91 /* Nonzero if we are building the initializer for the primary 92 vtable. */ 93 int primary_vtbl_p; 94 /* Nonzero if we are building the initializer for a construction 95 vtable. */ 96 int ctor_vtbl_p; 97 /* True when adding vcall offset entries to the vtable. False when 98 merely computing the indices. */ 99 bool generate_vcall_entries; 100} vtbl_init_data; 101 102/* The type of a function passed to walk_subobject_offsets. */ 103typedef int (*subobject_offset_fn) (tree, tree, splay_tree); 104 105/* The stack itself. This is a dynamically resized array. The 106 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */ 107static int current_class_stack_size; 108static class_stack_node_t current_class_stack; 109 110/* The size of the largest empty class seen in this translation unit. */ 111static GTY (()) tree sizeof_biggest_empty_class; 112 113/* An array of all local classes present in this translation unit, in 114 declaration order. */ 115VEC(tree,gc) *local_classes; 116 117static tree get_vfield_name (tree); 118static void finish_struct_anon (tree); 119static tree get_vtable_name (tree); 120static tree get_basefndecls (tree, tree); 121static int build_primary_vtable (tree, tree); 122static int build_secondary_vtable (tree); 123static void finish_vtbls (tree); 124static void modify_vtable_entry (tree, tree, tree, tree, tree *); 125static void finish_struct_bits (tree); 126static int alter_access (tree, tree, tree); 127static void handle_using_decl (tree, tree); 128static tree dfs_modify_vtables (tree, void *); 129static tree modify_all_vtables (tree, tree); 130static void determine_primary_bases (tree); 131static void finish_struct_methods (tree); 132static void maybe_warn_about_overly_private_class (tree); 133static int method_name_cmp (const void *, const void *); 134static int resort_method_name_cmp (const void *, const void *); 135static void add_implicitly_declared_members (tree, int, int); 136static tree fixed_type_or_null (tree, int *, int *); 137static tree build_simple_base_path (tree expr, tree binfo); 138static tree build_vtbl_ref_1 (tree, tree); 139static tree build_vtbl_initializer (tree, tree, tree, tree, int *); 140static int count_fields (tree); 141static int add_fields_to_record_type (tree, struct sorted_fields_type*, int); 142static void check_bitfield_decl (tree); 143static void check_field_decl (tree, tree, int *, int *, int *); 144static void check_field_decls (tree, tree *, int *, int *); 145static tree *build_base_field (record_layout_info, tree, splay_tree, tree *); 146static void build_base_fields (record_layout_info, splay_tree, tree *); 147static void check_methods (tree); 148static void remove_zero_width_bit_fields (tree); 149static void check_bases (tree, int *, int *); 150static void check_bases_and_members (tree); 151static tree create_vtable_ptr (tree, tree *); 152static void include_empty_classes (record_layout_info); 153static void layout_class_type (tree, tree *); 154static void fixup_pending_inline (tree); 155static void fixup_inline_methods (tree); 156static void propagate_binfo_offsets (tree, tree); 157static void layout_virtual_bases (record_layout_info, splay_tree); 158static void build_vbase_offset_vtbl_entries (tree, vtbl_init_data *); 159static void add_vcall_offset_vtbl_entries_r (tree, vtbl_init_data *); 160static void add_vcall_offset_vtbl_entries_1 (tree, vtbl_init_data *); 161static void build_vcall_offset_vtbl_entries (tree, vtbl_init_data *); 162static void add_vcall_offset (tree, tree, vtbl_init_data *); 163static void layout_vtable_decl (tree, int); 164static tree dfs_find_final_overrider_pre (tree, void *); 165static tree dfs_find_final_overrider_post (tree, void *); 166static tree find_final_overrider (tree, tree, tree); 167static int make_new_vtable (tree, tree); 168static tree get_primary_binfo (tree); 169static int maybe_indent_hierarchy (FILE *, int, int); 170static tree dump_class_hierarchy_r (FILE *, int, tree, tree, int); 171static void dump_class_hierarchy (tree); 172static void dump_class_hierarchy_1 (FILE *, int, tree); 173static void dump_array (FILE *, tree); 174static void dump_vtable (tree, tree, tree); 175static void dump_vtt (tree, tree); 176static void dump_thunk (FILE *, int, tree); 177static tree build_vtable (tree, tree, tree); 178static void initialize_vtable (tree, tree); 179static void layout_nonempty_base_or_field (record_layout_info, 180 tree, tree, splay_tree); 181static tree end_of_class (tree, int); 182static bool layout_empty_base (tree, tree, splay_tree); 183static void accumulate_vtbl_inits (tree, tree, tree, tree, tree); 184static tree dfs_accumulate_vtbl_inits (tree, tree, tree, tree, 185 tree); 186static void build_rtti_vtbl_entries (tree, vtbl_init_data *); 187static void build_vcall_and_vbase_vtbl_entries (tree, vtbl_init_data *); 188static void clone_constructors_and_destructors (tree); 189static tree build_clone (tree, tree); 190static void update_vtable_entry_for_fn (tree, tree, tree, tree *, unsigned); 191static void build_ctor_vtbl_group (tree, tree); 192static void build_vtt (tree); 193static tree binfo_ctor_vtable (tree); 194static tree *build_vtt_inits (tree, tree, tree *, tree *); 195static tree dfs_build_secondary_vptr_vtt_inits (tree, void *); 196static tree dfs_fixup_binfo_vtbls (tree, void *); 197static int record_subobject_offset (tree, tree, splay_tree); 198static int check_subobject_offset (tree, tree, splay_tree); 199static int walk_subobject_offsets (tree, subobject_offset_fn, 200 tree, splay_tree, tree, int); 201static void record_subobject_offsets (tree, tree, splay_tree, bool); 202static int layout_conflict_p (tree, tree, splay_tree, int); 203static int splay_tree_compare_integer_csts (splay_tree_key k1, 204 splay_tree_key k2); 205static void warn_about_ambiguous_bases (tree); 206static bool type_requires_array_cookie (tree); 207static bool contains_empty_class_p (tree); 208static bool base_derived_from (tree, tree); 209static int empty_base_at_nonzero_offset_p (tree, tree, splay_tree); 210static tree end_of_base (tree); 211static tree get_vcall_index (tree, tree); 212 213/* Variables shared between class.c and call.c. */ 214 215#ifdef GATHER_STATISTICS 216int n_vtables = 0; 217int n_vtable_entries = 0; 218int n_vtable_searches = 0; 219int n_vtable_elems = 0; 220int n_convert_harshness = 0; 221int n_compute_conversion_costs = 0; 222int n_inner_fields_searched = 0; 223#endif 224 225/* Convert to or from a base subobject. EXPR is an expression of type 226 `A' or `A*', an expression of type `B' or `B*' is returned. To 227 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for 228 the B base instance within A. To convert base A to derived B, CODE 229 is MINUS_EXPR and BINFO is the binfo for the A instance within B. 230 In this latter case, A must not be a morally virtual base of B. 231 NONNULL is true if EXPR is known to be non-NULL (this is only 232 needed when EXPR is of pointer type). CV qualifiers are preserved 233 from EXPR. */ 234 235tree 236build_base_path (enum tree_code code, 237 tree expr, 238 tree binfo, 239 int nonnull) 240{ 241 tree v_binfo = NULL_TREE; 242 tree d_binfo = NULL_TREE; 243 tree probe; 244 tree offset; 245 tree target_type; 246 tree null_test = NULL; 247 tree ptr_target_type; 248 int fixed_type_p; 249 int want_pointer = TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE; 250 bool has_empty = false; 251 bool virtual_access; 252 253 if (expr == error_mark_node || binfo == error_mark_node || !binfo) 254 return error_mark_node; 255 256 for (probe = binfo; probe; probe = BINFO_INHERITANCE_CHAIN (probe)) 257 { 258 d_binfo = probe; 259 if (is_empty_class (BINFO_TYPE (probe))) 260 has_empty = true; 261 if (!v_binfo && BINFO_VIRTUAL_P (probe)) 262 v_binfo = probe; 263 } 264 265 probe = TYPE_MAIN_VARIANT (TREE_TYPE (expr)); 266 if (want_pointer) 267 probe = TYPE_MAIN_VARIANT (TREE_TYPE (probe)); 268 269 gcc_assert ((code == MINUS_EXPR 270 && SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), probe)) 271 || (code == PLUS_EXPR 272 && SAME_BINFO_TYPE_P (BINFO_TYPE (d_binfo), probe))); 273 274 if (binfo == d_binfo) 275 /* Nothing to do. */ 276 return expr; 277 278 if (code == MINUS_EXPR && v_binfo) 279 { 280 error ("cannot convert from base %qT to derived type %qT via virtual base %qT", 281 BINFO_TYPE (binfo), BINFO_TYPE (d_binfo), BINFO_TYPE (v_binfo)); 282 return error_mark_node; 283 } 284 285 if (!want_pointer) 286 /* This must happen before the call to save_expr. */ 287 expr = build_unary_op (ADDR_EXPR, expr, 0); 288 289 offset = BINFO_OFFSET (binfo); 290 fixed_type_p = resolves_to_fixed_type_p (expr, &nonnull); 291 target_type = code == PLUS_EXPR ? BINFO_TYPE (binfo) : BINFO_TYPE (d_binfo); 292 293 /* Do we need to look in the vtable for the real offset? */ 294 virtual_access = (v_binfo && fixed_type_p <= 0); 295 296 /* Do we need to check for a null pointer? */ 297 if (want_pointer && !nonnull) 298 { 299 /* If we know the conversion will not actually change the value 300 of EXPR, then we can avoid testing the expression for NULL. 301 We have to avoid generating a COMPONENT_REF for a base class 302 field, because other parts of the compiler know that such 303 expressions are always non-NULL. */ 304 if (!virtual_access && integer_zerop (offset)) 305 { 306 tree class_type; 307 /* TARGET_TYPE has been extracted from BINFO, and, is 308 therefore always cv-unqualified. Extract the 309 cv-qualifiers from EXPR so that the expression returned 310 matches the input. */ 311 class_type = TREE_TYPE (TREE_TYPE (expr)); 312 target_type 313 = cp_build_qualified_type (target_type, 314 cp_type_quals (class_type)); 315 return build_nop (build_pointer_type (target_type), expr); 316 } 317 null_test = error_mark_node; 318 } 319 320 /* Protect against multiple evaluation if necessary. */ 321 if (TREE_SIDE_EFFECTS (expr) && (null_test || virtual_access)) 322 expr = save_expr (expr); 323 324 /* Now that we've saved expr, build the real null test. */ 325 if (null_test) 326 { 327 tree zero = cp_convert (TREE_TYPE (expr), integer_zero_node); 328 null_test = fold_build2 (NE_EXPR, boolean_type_node, 329 expr, zero); 330 } 331 332 /* If this is a simple base reference, express it as a COMPONENT_REF. */ 333 if (code == PLUS_EXPR && !virtual_access 334 /* We don't build base fields for empty bases, and they aren't very 335 interesting to the optimizers anyway. */ 336 && !has_empty) 337 { 338 expr = build_indirect_ref (expr, NULL); 339 expr = build_simple_base_path (expr, binfo); 340 if (want_pointer) 341 expr = build_address (expr); 342 target_type = TREE_TYPE (expr); 343 goto out; 344 } 345 346 if (virtual_access) 347 { 348 /* Going via virtual base V_BINFO. We need the static offset 349 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to 350 V_BINFO. That offset is an entry in D_BINFO's vtable. */ 351 tree v_offset; 352 353 if (fixed_type_p < 0 && in_base_initializer) 354 { 355 /* In a base member initializer, we cannot rely on the 356 vtable being set up. We have to indirect via the 357 vtt_parm. */ 358 tree t; 359 360 t = TREE_TYPE (TYPE_VFIELD (current_class_type)); 361 t = build_pointer_type (t); 362 v_offset = convert (t, current_vtt_parm); 363 v_offset = build_indirect_ref (v_offset, NULL); 364 } 365 else 366 v_offset = build_vfield_ref (build_indirect_ref (expr, NULL), 367 TREE_TYPE (TREE_TYPE (expr))); 368 369 v_offset = build2 (PLUS_EXPR, TREE_TYPE (v_offset), 370 v_offset, BINFO_VPTR_FIELD (v_binfo)); 371 v_offset = build1 (NOP_EXPR, 372 build_pointer_type (ptrdiff_type_node), 373 v_offset); 374 v_offset = build_indirect_ref (v_offset, NULL); 375 TREE_CONSTANT (v_offset) = 1; 376 TREE_INVARIANT (v_offset) = 1; 377 378 offset = convert_to_integer (ptrdiff_type_node, 379 size_diffop (offset, 380 BINFO_OFFSET (v_binfo))); 381 382 if (!integer_zerop (offset)) 383 v_offset = build2 (code, ptrdiff_type_node, v_offset, offset); 384 385 if (fixed_type_p < 0) 386 /* Negative fixed_type_p means this is a constructor or destructor; 387 virtual base layout is fixed in in-charge [cd]tors, but not in 388 base [cd]tors. */ 389 offset = build3 (COND_EXPR, ptrdiff_type_node, 390 build2 (EQ_EXPR, boolean_type_node, 391 current_in_charge_parm, integer_zero_node), 392 v_offset, 393 convert_to_integer (ptrdiff_type_node, 394 BINFO_OFFSET (binfo))); 395 else 396 offset = v_offset; 397 } 398 399 target_type = cp_build_qualified_type 400 (target_type, cp_type_quals (TREE_TYPE (TREE_TYPE (expr)))); 401 ptr_target_type = build_pointer_type (target_type); 402 if (want_pointer) 403 target_type = ptr_target_type; 404 405 expr = build1 (NOP_EXPR, ptr_target_type, expr); 406 407 if (!integer_zerop (offset)) 408 expr = build2 (code, ptr_target_type, expr, offset); 409 else 410 null_test = NULL; 411 412 if (!want_pointer) 413 expr = build_indirect_ref (expr, NULL); 414 415 out: 416 if (null_test) 417 expr = fold_build3 (COND_EXPR, target_type, null_test, expr, 418 fold_build1 (NOP_EXPR, target_type, 419 integer_zero_node)); 420 421 return expr; 422} 423 424/* Subroutine of build_base_path; EXPR and BINFO are as in that function. 425 Perform a derived-to-base conversion by recursively building up a 426 sequence of COMPONENT_REFs to the appropriate base fields. */ 427 428static tree 429build_simple_base_path (tree expr, tree binfo) 430{ 431 tree type = BINFO_TYPE (binfo); 432 tree d_binfo = BINFO_INHERITANCE_CHAIN (binfo); 433 tree field; 434 435 if (d_binfo == NULL_TREE) 436 { 437 tree temp; 438 439 gcc_assert (TYPE_MAIN_VARIANT (TREE_TYPE (expr)) == type); 440 441 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' 442 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only 443 an lvalue in the frontend; only _DECLs and _REFs are lvalues 444 in the backend. */ 445 temp = unary_complex_lvalue (ADDR_EXPR, expr); 446 if (temp) 447 expr = build_indirect_ref (temp, NULL); 448 449 return expr; 450 } 451 452 /* Recurse. */ 453 expr = build_simple_base_path (expr, d_binfo); 454 455 for (field = TYPE_FIELDS (BINFO_TYPE (d_binfo)); 456 field; field = TREE_CHAIN (field)) 457 /* Is this the base field created by build_base_field? */ 458 if (TREE_CODE (field) == FIELD_DECL 459 && DECL_FIELD_IS_BASE (field) 460 && TREE_TYPE (field) == type) 461 { 462 /* We don't use build_class_member_access_expr here, as that 463 has unnecessary checks, and more importantly results in 464 recursive calls to dfs_walk_once. */ 465 int type_quals = cp_type_quals (TREE_TYPE (expr)); 466 467 expr = build3 (COMPONENT_REF, 468 cp_build_qualified_type (type, type_quals), 469 expr, field, NULL_TREE); 470 expr = fold_if_not_in_template (expr); 471 472 /* Mark the expression const or volatile, as appropriate. 473 Even though we've dealt with the type above, we still have 474 to mark the expression itself. */ 475 if (type_quals & TYPE_QUAL_CONST) 476 TREE_READONLY (expr) = 1; 477 if (type_quals & TYPE_QUAL_VOLATILE) 478 TREE_THIS_VOLATILE (expr) = 1; 479 480 return expr; 481 } 482 483 /* Didn't find the base field?!? */ 484 gcc_unreachable (); 485} 486 487/* Convert OBJECT to the base TYPE. OBJECT is an expression whose 488 type is a class type or a pointer to a class type. In the former 489 case, TYPE is also a class type; in the latter it is another 490 pointer type. If CHECK_ACCESS is true, an error message is emitted 491 if TYPE is inaccessible. If OBJECT has pointer type, the value is 492 assumed to be non-NULL. */ 493 494tree 495convert_to_base (tree object, tree type, bool check_access, bool nonnull) 496{ 497 tree binfo; 498 tree object_type; 499 500 if (TYPE_PTR_P (TREE_TYPE (object))) 501 { 502 object_type = TREE_TYPE (TREE_TYPE (object)); 503 type = TREE_TYPE (type); 504 } 505 else 506 object_type = TREE_TYPE (object); 507 508 binfo = lookup_base (object_type, type, 509 check_access ? ba_check : ba_unique, 510 NULL); 511 if (!binfo || binfo == error_mark_node) 512 return error_mark_node; 513 514 return build_base_path (PLUS_EXPR, object, binfo, nonnull); 515} 516 517/* EXPR is an expression with unqualified class type. BASE is a base 518 binfo of that class type. Returns EXPR, converted to the BASE 519 type. This function assumes that EXPR is the most derived class; 520 therefore virtual bases can be found at their static offsets. */ 521 522tree 523convert_to_base_statically (tree expr, tree base) 524{ 525 tree expr_type; 526 527 expr_type = TREE_TYPE (expr); 528 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (base), expr_type)) 529 { 530 tree pointer_type; 531 532 pointer_type = build_pointer_type (expr_type); 533 expr = build_unary_op (ADDR_EXPR, expr, /*noconvert=*/1); 534 if (!integer_zerop (BINFO_OFFSET (base))) 535 expr = build2 (PLUS_EXPR, pointer_type, expr, 536 build_nop (pointer_type, BINFO_OFFSET (base))); 537 expr = build_nop (build_pointer_type (BINFO_TYPE (base)), expr); 538 expr = build1 (INDIRECT_REF, BINFO_TYPE (base), expr); 539 } 540 541 return expr; 542} 543 544 545tree 546build_vfield_ref (tree datum, tree type) 547{ 548 tree vfield, vcontext; 549 550 if (datum == error_mark_node) 551 return error_mark_node; 552 553 /* First, convert to the requested type. */ 554 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (datum), type)) 555 datum = convert_to_base (datum, type, /*check_access=*/false, 556 /*nonnull=*/true); 557 558 /* Second, the requested type may not be the owner of its own vptr. 559 If not, convert to the base class that owns it. We cannot use 560 convert_to_base here, because VCONTEXT may appear more than once 561 in the inheritance hierarchy of TYPE, and thus direct conversion 562 between the types may be ambiguous. Following the path back up 563 one step at a time via primary bases avoids the problem. */ 564 vfield = TYPE_VFIELD (type); 565 vcontext = DECL_CONTEXT (vfield); 566 while (!same_type_ignoring_top_level_qualifiers_p (vcontext, type)) 567 { 568 datum = build_simple_base_path (datum, CLASSTYPE_PRIMARY_BINFO (type)); 569 type = TREE_TYPE (datum); 570 } 571 572 return build3 (COMPONENT_REF, TREE_TYPE (vfield), datum, vfield, NULL_TREE); 573} 574 575/* Given an object INSTANCE, return an expression which yields the 576 vtable element corresponding to INDEX. There are many special 577 cases for INSTANCE which we take care of here, mainly to avoid 578 creating extra tree nodes when we don't have to. */ 579 580static tree 581build_vtbl_ref_1 (tree instance, tree idx) 582{ 583 tree aref; 584 tree vtbl = NULL_TREE; 585 586 /* Try to figure out what a reference refers to, and 587 access its virtual function table directly. */ 588 589 int cdtorp = 0; 590 tree fixed_type = fixed_type_or_null (instance, NULL, &cdtorp); 591 592 tree basetype = non_reference (TREE_TYPE (instance)); 593 594 if (fixed_type && !cdtorp) 595 { 596 tree binfo = lookup_base (fixed_type, basetype, 597 ba_unique | ba_quiet, NULL); 598 if (binfo) 599 vtbl = unshare_expr (BINFO_VTABLE (binfo)); 600 } 601 602 if (!vtbl) 603 vtbl = build_vfield_ref (instance, basetype); 604 605 assemble_external (vtbl); 606 607 aref = build_array_ref (vtbl, idx); 608 TREE_CONSTANT (aref) |= TREE_CONSTANT (vtbl) && TREE_CONSTANT (idx); 609 TREE_INVARIANT (aref) = TREE_CONSTANT (aref); 610 611 return aref; 612} 613 614tree 615build_vtbl_ref (tree instance, tree idx) 616{ 617 tree aref = build_vtbl_ref_1 (instance, idx); 618 619 return aref; 620} 621 622/* Given a stable object pointer INSTANCE_PTR, return an expression which 623 yields a function pointer corresponding to vtable element INDEX. */ 624 625tree 626build_vfn_ref (tree instance_ptr, tree idx) 627{ 628 tree aref; 629 630 aref = build_vtbl_ref_1 (build_indirect_ref (instance_ptr, 0), idx); 631 632 /* When using function descriptors, the address of the 633 vtable entry is treated as a function pointer. */ 634 if (TARGET_VTABLE_USES_DESCRIPTORS) 635 aref = build1 (NOP_EXPR, TREE_TYPE (aref), 636 build_unary_op (ADDR_EXPR, aref, /*noconvert=*/1)); 637 638 /* Remember this as a method reference, for later devirtualization. */ 639 aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr, idx); 640 641 return aref; 642} 643 644/* Return the name of the virtual function table (as an IDENTIFIER_NODE) 645 for the given TYPE. */ 646 647static tree 648get_vtable_name (tree type) 649{ 650 return mangle_vtbl_for_type (type); 651} 652 653/* DECL is an entity associated with TYPE, like a virtual table or an 654 implicitly generated constructor. Determine whether or not DECL 655 should have external or internal linkage at the object file 656 level. This routine does not deal with COMDAT linkage and other 657 similar complexities; it simply sets TREE_PUBLIC if it possible for 658 entities in other translation units to contain copies of DECL, in 659 the abstract. */ 660 661void 662set_linkage_according_to_type (tree type, tree decl) 663{ 664 /* If TYPE involves a local class in a function with internal 665 linkage, then DECL should have internal linkage too. Other local 666 classes have no linkage -- but if their containing functions 667 have external linkage, it makes sense for DECL to have external 668 linkage too. That will allow template definitions to be merged, 669 for example. */ 670 if (no_linkage_check (type, /*relaxed_p=*/true)) 671 { 672 TREE_PUBLIC (decl) = 0; 673 DECL_INTERFACE_KNOWN (decl) = 1; 674 } 675 else 676 TREE_PUBLIC (decl) = 1; 677} 678 679/* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE. 680 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.) 681 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */ 682 683static tree 684build_vtable (tree class_type, tree name, tree vtable_type) 685{ 686 tree decl; 687 688 decl = build_lang_decl (VAR_DECL, name, vtable_type); 689 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME 690 now to avoid confusion in mangle_decl. */ 691 SET_DECL_ASSEMBLER_NAME (decl, name); 692 DECL_CONTEXT (decl) = class_type; 693 DECL_ARTIFICIAL (decl) = 1; 694 TREE_STATIC (decl) = 1; 695 TREE_READONLY (decl) = 1; 696 DECL_VIRTUAL_P (decl) = 1; 697 DECL_ALIGN (decl) = TARGET_VTABLE_ENTRY_ALIGN; 698 DECL_VTABLE_OR_VTT_P (decl) = 1; 699 /* At one time the vtable info was grabbed 2 words at a time. This 700 fails on sparc unless you have 8-byte alignment. (tiemann) */ 701 DECL_ALIGN (decl) = MAX (TYPE_ALIGN (double_type_node), 702 DECL_ALIGN (decl)); 703 set_linkage_according_to_type (class_type, decl); 704 /* The vtable has not been defined -- yet. */ 705 DECL_EXTERNAL (decl) = 1; 706 DECL_NOT_REALLY_EXTERN (decl) = 1; 707 708 /* Mark the VAR_DECL node representing the vtable itself as a 709 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It 710 is rather important that such things be ignored because any 711 effort to actually generate DWARF for them will run into 712 trouble when/if we encounter code like: 713 714 #pragma interface 715 struct S { virtual void member (); }; 716 717 because the artificial declaration of the vtable itself (as 718 manufactured by the g++ front end) will say that the vtable is 719 a static member of `S' but only *after* the debug output for 720 the definition of `S' has already been output. This causes 721 grief because the DWARF entry for the definition of the vtable 722 will try to refer back to an earlier *declaration* of the 723 vtable as a static member of `S' and there won't be one. We 724 might be able to arrange to have the "vtable static member" 725 attached to the member list for `S' before the debug info for 726 `S' get written (which would solve the problem) but that would 727 require more intrusive changes to the g++ front end. */ 728 DECL_IGNORED_P (decl) = 1; 729 730 return decl; 731} 732 733/* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic, 734 or even complete. If this does not exist, create it. If COMPLETE is 735 nonzero, then complete the definition of it -- that will render it 736 impossible to actually build the vtable, but is useful to get at those 737 which are known to exist in the runtime. */ 738 739tree 740get_vtable_decl (tree type, int complete) 741{ 742 tree decl; 743 744 if (CLASSTYPE_VTABLES (type)) 745 return CLASSTYPE_VTABLES (type); 746 747 decl = build_vtable (type, get_vtable_name (type), vtbl_type_node); 748 CLASSTYPE_VTABLES (type) = decl; 749 750 if (complete) 751 { 752 DECL_EXTERNAL (decl) = 1; 753 finish_decl (decl, NULL_TREE, NULL_TREE); 754 } 755 756 return decl; 757} 758 759/* Build the primary virtual function table for TYPE. If BINFO is 760 non-NULL, build the vtable starting with the initial approximation 761 that it is the same as the one which is the head of the association 762 list. Returns a nonzero value if a new vtable is actually 763 created. */ 764 765static int 766build_primary_vtable (tree binfo, tree type) 767{ 768 tree decl; 769 tree virtuals; 770 771 decl = get_vtable_decl (type, /*complete=*/0); 772 773 if (binfo) 774 { 775 if (BINFO_NEW_VTABLE_MARKED (binfo)) 776 /* We have already created a vtable for this base, so there's 777 no need to do it again. */ 778 return 0; 779 780 virtuals = copy_list (BINFO_VIRTUALS (binfo)); 781 TREE_TYPE (decl) = TREE_TYPE (get_vtbl_decl_for_binfo (binfo)); 782 DECL_SIZE (decl) = TYPE_SIZE (TREE_TYPE (decl)); 783 DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (TREE_TYPE (decl)); 784 } 785 else 786 { 787 gcc_assert (TREE_TYPE (decl) == vtbl_type_node); 788 virtuals = NULL_TREE; 789 } 790 791#ifdef GATHER_STATISTICS 792 n_vtables += 1; 793 n_vtable_elems += list_length (virtuals); 794#endif 795 796 /* Initialize the association list for this type, based 797 on our first approximation. */ 798 BINFO_VTABLE (TYPE_BINFO (type)) = decl; 799 BINFO_VIRTUALS (TYPE_BINFO (type)) = virtuals; 800 SET_BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (type)); 801 return 1; 802} 803 804/* Give BINFO a new virtual function table which is initialized 805 with a skeleton-copy of its original initialization. The only 806 entry that changes is the `delta' entry, so we can really 807 share a lot of structure. 808 809 FOR_TYPE is the most derived type which caused this table to 810 be needed. 811 812 Returns nonzero if we haven't met BINFO before. 813 814 The order in which vtables are built (by calling this function) for 815 an object must remain the same, otherwise a binary incompatibility 816 can result. */ 817 818static int 819build_secondary_vtable (tree binfo) 820{ 821 if (BINFO_NEW_VTABLE_MARKED (binfo)) 822 /* We already created a vtable for this base. There's no need to 823 do it again. */ 824 return 0; 825 826 /* Remember that we've created a vtable for this BINFO, so that we 827 don't try to do so again. */ 828 SET_BINFO_NEW_VTABLE_MARKED (binfo); 829 830 /* Make fresh virtual list, so we can smash it later. */ 831 BINFO_VIRTUALS (binfo) = copy_list (BINFO_VIRTUALS (binfo)); 832 833 /* Secondary vtables are laid out as part of the same structure as 834 the primary vtable. */ 835 BINFO_VTABLE (binfo) = NULL_TREE; 836 return 1; 837} 838 839/* Create a new vtable for BINFO which is the hierarchy dominated by 840 T. Return nonzero if we actually created a new vtable. */ 841 842static int 843make_new_vtable (tree t, tree binfo) 844{ 845 if (binfo == TYPE_BINFO (t)) 846 /* In this case, it is *type*'s vtable we are modifying. We start 847 with the approximation that its vtable is that of the 848 immediate base class. */ 849 return build_primary_vtable (binfo, t); 850 else 851 /* This is our very own copy of `basetype' to play with. Later, 852 we will fill in all the virtual functions that override the 853 virtual functions in these base classes which are not defined 854 by the current type. */ 855 return build_secondary_vtable (binfo); 856} 857 858/* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO 859 (which is in the hierarchy dominated by T) list FNDECL as its 860 BV_FN. DELTA is the required constant adjustment from the `this' 861 pointer where the vtable entry appears to the `this' required when 862 the function is actually called. */ 863 864static void 865modify_vtable_entry (tree t, 866 tree binfo, 867 tree fndecl, 868 tree delta, 869 tree *virtuals) 870{ 871 tree v; 872 873 v = *virtuals; 874 875 if (fndecl != BV_FN (v) 876 || !tree_int_cst_equal (delta, BV_DELTA (v))) 877 { 878 /* We need a new vtable for BINFO. */ 879 if (make_new_vtable (t, binfo)) 880 { 881 /* If we really did make a new vtable, we also made a copy 882 of the BINFO_VIRTUALS list. Now, we have to find the 883 corresponding entry in that list. */ 884 *virtuals = BINFO_VIRTUALS (binfo); 885 while (BV_FN (*virtuals) != BV_FN (v)) 886 *virtuals = TREE_CHAIN (*virtuals); 887 v = *virtuals; 888 } 889 890 BV_DELTA (v) = delta; 891 BV_VCALL_INDEX (v) = NULL_TREE; 892 BV_FN (v) = fndecl; 893 } 894} 895 896 897/* Add method METHOD to class TYPE. If USING_DECL is non-null, it is 898 the USING_DECL naming METHOD. Returns true if the method could be 899 added to the method vec. */ 900 901bool 902add_method (tree type, tree method, tree using_decl) 903{ 904 unsigned slot; 905 tree overload; 906 bool template_conv_p = false; 907 bool conv_p; 908 VEC(tree,gc) *method_vec; 909 bool complete_p; 910 bool insert_p = false; 911 tree current_fns; 912 913 if (method == error_mark_node) 914 return false; 915 916 complete_p = COMPLETE_TYPE_P (type); 917 conv_p = DECL_CONV_FN_P (method); 918 if (conv_p) 919 template_conv_p = (TREE_CODE (method) == TEMPLATE_DECL 920 && DECL_TEMPLATE_CONV_FN_P (method)); 921 922 method_vec = CLASSTYPE_METHOD_VEC (type); 923 if (!method_vec) 924 { 925 /* Make a new method vector. We start with 8 entries. We must 926 allocate at least two (for constructors and destructors), and 927 we're going to end up with an assignment operator at some 928 point as well. */ 929 method_vec = VEC_alloc (tree, gc, 8); 930 /* Create slots for constructors and destructors. */ 931 VEC_quick_push (tree, method_vec, NULL_TREE); 932 VEC_quick_push (tree, method_vec, NULL_TREE); 933 CLASSTYPE_METHOD_VEC (type) = method_vec; 934 } 935 936 /* Maintain TYPE_HAS_CONSTRUCTOR, etc. */ 937 grok_special_member_properties (method); 938 939 /* Constructors and destructors go in special slots. */ 940 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (method)) 941 slot = CLASSTYPE_CONSTRUCTOR_SLOT; 942 else if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method)) 943 { 944 slot = CLASSTYPE_DESTRUCTOR_SLOT; 945 946 if (TYPE_FOR_JAVA (type)) 947 { 948 if (!DECL_ARTIFICIAL (method)) 949 error ("Java class %qT cannot have a destructor", type); 950 else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 951 error ("Java class %qT cannot have an implicit non-trivial " 952 "destructor", 953 type); 954 } 955 } 956 else 957 { 958 tree m; 959 960 insert_p = true; 961 /* See if we already have an entry with this name. */ 962 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT; 963 VEC_iterate (tree, method_vec, slot, m); 964 ++slot) 965 { 966 m = OVL_CURRENT (m); 967 if (template_conv_p) 968 { 969 if (TREE_CODE (m) == TEMPLATE_DECL 970 && DECL_TEMPLATE_CONV_FN_P (m)) 971 insert_p = false; 972 break; 973 } 974 if (conv_p && !DECL_CONV_FN_P (m)) 975 break; 976 if (DECL_NAME (m) == DECL_NAME (method)) 977 { 978 insert_p = false; 979 break; 980 } 981 if (complete_p 982 && !DECL_CONV_FN_P (m) 983 && DECL_NAME (m) > DECL_NAME (method)) 984 break; 985 } 986 } 987 current_fns = insert_p ? NULL_TREE : VEC_index (tree, method_vec, slot); 988 989 if (processing_template_decl) 990 /* TYPE is a template class. Don't issue any errors now; wait 991 until instantiation time to complain. */ 992 ; 993 else 994 { 995 tree fns; 996 997 /* Check to see if we've already got this method. */ 998 for (fns = current_fns; fns; fns = OVL_NEXT (fns)) 999 { 1000 tree fn = OVL_CURRENT (fns); 1001 tree fn_type; 1002 tree method_type; 1003 tree parms1; 1004 tree parms2; 1005 1006 if (TREE_CODE (fn) != TREE_CODE (method)) 1007 continue; 1008 1009 /* [over.load] Member function declarations with the 1010 same name and the same parameter types cannot be 1011 overloaded if any of them is a static member 1012 function declaration. 1013 1014 [namespace.udecl] When a using-declaration brings names 1015 from a base class into a derived class scope, member 1016 functions in the derived class override and/or hide member 1017 functions with the same name and parameter types in a base 1018 class (rather than conflicting). */ 1019 fn_type = TREE_TYPE (fn); 1020 method_type = TREE_TYPE (method); 1021 parms1 = TYPE_ARG_TYPES (fn_type); 1022 parms2 = TYPE_ARG_TYPES (method_type); 1023 1024 /* Compare the quals on the 'this' parm. Don't compare 1025 the whole types, as used functions are treated as 1026 coming from the using class in overload resolution. */ 1027 if (! DECL_STATIC_FUNCTION_P (fn) 1028 && ! DECL_STATIC_FUNCTION_P (method) 1029 && (TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms1))) 1030 != TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms2))))) 1031 continue; 1032 1033 /* For templates, the return type and template parameters 1034 must be identical. */ 1035 if (TREE_CODE (fn) == TEMPLATE_DECL 1036 && (!same_type_p (TREE_TYPE (fn_type), 1037 TREE_TYPE (method_type)) 1038 || !comp_template_parms (DECL_TEMPLATE_PARMS (fn), 1039 DECL_TEMPLATE_PARMS (method)))) 1040 continue; 1041 1042 if (! DECL_STATIC_FUNCTION_P (fn)) 1043 parms1 = TREE_CHAIN (parms1); 1044 if (! DECL_STATIC_FUNCTION_P (method)) 1045 parms2 = TREE_CHAIN (parms2); 1046 1047 if (compparms (parms1, parms2) 1048 && (!DECL_CONV_FN_P (fn) 1049 || same_type_p (TREE_TYPE (fn_type), 1050 TREE_TYPE (method_type)))) 1051 { 1052 if (using_decl) 1053 { 1054 if (DECL_CONTEXT (fn) == type) 1055 /* Defer to the local function. */ 1056 return false; 1057 if (DECL_CONTEXT (fn) == DECL_CONTEXT (method)) 1058 error ("repeated using declaration %q+D", using_decl); 1059 else 1060 error ("using declaration %q+D conflicts with a previous using declaration", 1061 using_decl); 1062 } 1063 else 1064 { 1065 error ("%q+#D cannot be overloaded", method); 1066 error ("with %q+#D", fn); 1067 } 1068 1069 /* We don't call duplicate_decls here to merge the 1070 declarations because that will confuse things if the 1071 methods have inline definitions. In particular, we 1072 will crash while processing the definitions. */ 1073 return false; 1074 } 1075 } 1076 } 1077 1078 /* A class should never have more than one destructor. */ 1079 if (current_fns && DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method)) 1080 return false; 1081 1082 /* Add the new binding. */ 1083 overload = build_overload (method, current_fns); 1084 1085 if (conv_p) 1086 TYPE_HAS_CONVERSION (type) = 1; 1087 else if (slot >= CLASSTYPE_FIRST_CONVERSION_SLOT && !complete_p) 1088 push_class_level_binding (DECL_NAME (method), overload); 1089 1090 if (insert_p) 1091 { 1092 bool reallocated; 1093 1094 /* We only expect to add few methods in the COMPLETE_P case, so 1095 just make room for one more method in that case. */ 1096 if (complete_p) 1097 reallocated = VEC_reserve_exact (tree, gc, method_vec, 1); 1098 else 1099 reallocated = VEC_reserve (tree, gc, method_vec, 1); 1100 if (reallocated) 1101 CLASSTYPE_METHOD_VEC (type) = method_vec; 1102 if (slot == VEC_length (tree, method_vec)) 1103 VEC_quick_push (tree, method_vec, overload); 1104 else 1105 VEC_quick_insert (tree, method_vec, slot, overload); 1106 } 1107 else 1108 /* Replace the current slot. */ 1109 VEC_replace (tree, method_vec, slot, overload); 1110 return true; 1111} 1112 1113/* Subroutines of finish_struct. */ 1114 1115/* Change the access of FDECL to ACCESS in T. Return 1 if change was 1116 legit, otherwise return 0. */ 1117 1118static int 1119alter_access (tree t, tree fdecl, tree access) 1120{ 1121 tree elem; 1122 1123 if (!DECL_LANG_SPECIFIC (fdecl)) 1124 retrofit_lang_decl (fdecl); 1125 1126 gcc_assert (!DECL_DISCRIMINATOR_P (fdecl)); 1127 1128 elem = purpose_member (t, DECL_ACCESS (fdecl)); 1129 if (elem) 1130 { 1131 if (TREE_VALUE (elem) != access) 1132 { 1133 if (TREE_CODE (TREE_TYPE (fdecl)) == FUNCTION_DECL) 1134 error ("conflicting access specifications for method" 1135 " %q+D, ignored", TREE_TYPE (fdecl)); 1136 else 1137 error ("conflicting access specifications for field %qE, ignored", 1138 DECL_NAME (fdecl)); 1139 } 1140 else 1141 { 1142 /* They're changing the access to the same thing they changed 1143 it to before. That's OK. */ 1144 ; 1145 } 1146 } 1147 else 1148 { 1149 perform_or_defer_access_check (TYPE_BINFO (t), fdecl, fdecl); 1150 DECL_ACCESS (fdecl) = tree_cons (t, access, DECL_ACCESS (fdecl)); 1151 return 1; 1152 } 1153 return 0; 1154} 1155 1156/* Process the USING_DECL, which is a member of T. */ 1157 1158static void 1159handle_using_decl (tree using_decl, tree t) 1160{ 1161 tree decl = USING_DECL_DECLS (using_decl); 1162 tree name = DECL_NAME (using_decl); 1163 tree access 1164 = TREE_PRIVATE (using_decl) ? access_private_node 1165 : TREE_PROTECTED (using_decl) ? access_protected_node 1166 : access_public_node; 1167 tree flist = NULL_TREE; 1168 tree old_value; 1169 1170 gcc_assert (!processing_template_decl && decl); 1171 1172 old_value = lookup_member (t, name, /*protect=*/0, /*want_type=*/false); 1173 if (old_value) 1174 { 1175 if (is_overloaded_fn (old_value)) 1176 old_value = OVL_CURRENT (old_value); 1177 1178 if (DECL_P (old_value) && DECL_CONTEXT (old_value) == t) 1179 /* OK */; 1180 else 1181 old_value = NULL_TREE; 1182 } 1183 1184 cp_emit_debug_info_for_using (decl, USING_DECL_SCOPE (using_decl)); 1185 1186 if (is_overloaded_fn (decl)) 1187 flist = decl; 1188 1189 if (! old_value) 1190 ; 1191 else if (is_overloaded_fn (old_value)) 1192 { 1193 if (flist) 1194 /* It's OK to use functions from a base when there are functions with 1195 the same name already present in the current class. */; 1196 else 1197 { 1198 error ("%q+D invalid in %q#T", using_decl, t); 1199 error (" because of local method %q+#D with same name", 1200 OVL_CURRENT (old_value)); 1201 return; 1202 } 1203 } 1204 else if (!DECL_ARTIFICIAL (old_value)) 1205 { 1206 error ("%q+D invalid in %q#T", using_decl, t); 1207 error (" because of local member %q+#D with same name", old_value); 1208 return; 1209 } 1210 1211 /* Make type T see field decl FDECL with access ACCESS. */ 1212 if (flist) 1213 for (; flist; flist = OVL_NEXT (flist)) 1214 { 1215 add_method (t, OVL_CURRENT (flist), using_decl); 1216 alter_access (t, OVL_CURRENT (flist), access); 1217 } 1218 else 1219 alter_access (t, decl, access); 1220} 1221 1222/* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P, 1223 and NO_CONST_ASN_REF_P. Also set flag bits in T based on 1224 properties of the bases. */ 1225 1226static void 1227check_bases (tree t, 1228 int* cant_have_const_ctor_p, 1229 int* no_const_asn_ref_p) 1230{ 1231 int i; 1232 int seen_non_virtual_nearly_empty_base_p; 1233 tree base_binfo; 1234 tree binfo; 1235 1236 seen_non_virtual_nearly_empty_base_p = 0; 1237 1238 for (binfo = TYPE_BINFO (t), i = 0; 1239 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 1240 { 1241 tree basetype = TREE_TYPE (base_binfo); 1242 1243 gcc_assert (COMPLETE_TYPE_P (basetype)); 1244 1245 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P 1246 here because the case of virtual functions but non-virtual 1247 dtor is handled in finish_struct_1. */ 1248 if (!TYPE_POLYMORPHIC_P (basetype)) 1249 warning (OPT_Weffc__, 1250 "base class %q#T has a non-virtual destructor", basetype); 1251 1252 /* If the base class doesn't have copy constructors or 1253 assignment operators that take const references, then the 1254 derived class cannot have such a member automatically 1255 generated. */ 1256 if (! TYPE_HAS_CONST_INIT_REF (basetype)) 1257 *cant_have_const_ctor_p = 1; 1258 if (TYPE_HAS_ASSIGN_REF (basetype) 1259 && !TYPE_HAS_CONST_ASSIGN_REF (basetype)) 1260 *no_const_asn_ref_p = 1; 1261 1262 if (BINFO_VIRTUAL_P (base_binfo)) 1263 /* A virtual base does not effect nearly emptiness. */ 1264 ; 1265 else if (CLASSTYPE_NEARLY_EMPTY_P (basetype)) 1266 { 1267 if (seen_non_virtual_nearly_empty_base_p) 1268 /* And if there is more than one nearly empty base, then the 1269 derived class is not nearly empty either. */ 1270 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 1271 else 1272 /* Remember we've seen one. */ 1273 seen_non_virtual_nearly_empty_base_p = 1; 1274 } 1275 else if (!is_empty_class (basetype)) 1276 /* If the base class is not empty or nearly empty, then this 1277 class cannot be nearly empty. */ 1278 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 1279 1280 /* A lot of properties from the bases also apply to the derived 1281 class. */ 1282 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (basetype); 1283 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) 1284 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype); 1285 /* APPLE LOCAL begin omit calls to empty destructors 5559195 */ 1286 if (CLASSTYPE_HAS_NONTRIVIAL_DESTRUCTOR_BODY (basetype) 1287 || CLASSTYPE_DESTRUCTOR_NONTRIVIAL_BECAUSE_OF_BASE (basetype)) 1288 CLASSTYPE_DESTRUCTOR_NONTRIVIAL_BECAUSE_OF_BASE (t) = 1; 1289 /* APPLE LOCAL end omit calls to empty destructors 5559195 */ 1290 1291 TYPE_HAS_COMPLEX_ASSIGN_REF (t) 1292 |= TYPE_HAS_COMPLEX_ASSIGN_REF (basetype); 1293 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (basetype); 1294 TYPE_POLYMORPHIC_P (t) |= TYPE_POLYMORPHIC_P (basetype); 1295 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) 1296 |= CLASSTYPE_CONTAINS_EMPTY_CLASS_P (basetype); 1297 } 1298} 1299 1300/* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for 1301 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those 1302 that have had a nearly-empty virtual primary base stolen by some 1303 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for 1304 T. */ 1305 1306static void 1307determine_primary_bases (tree t) 1308{ 1309 unsigned i; 1310 tree primary = NULL_TREE; 1311 tree type_binfo = TYPE_BINFO (t); 1312 tree base_binfo; 1313 1314 /* Determine the primary bases of our bases. */ 1315 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo; 1316 base_binfo = TREE_CHAIN (base_binfo)) 1317 { 1318 tree primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (base_binfo)); 1319 1320 /* See if we're the non-virtual primary of our inheritance 1321 chain. */ 1322 if (!BINFO_VIRTUAL_P (base_binfo)) 1323 { 1324 tree parent = BINFO_INHERITANCE_CHAIN (base_binfo); 1325 tree parent_primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (parent)); 1326 1327 if (parent_primary 1328 && SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo), 1329 BINFO_TYPE (parent_primary))) 1330 /* We are the primary binfo. */ 1331 BINFO_PRIMARY_P (base_binfo) = 1; 1332 } 1333 /* Determine if we have a virtual primary base, and mark it so. 1334 */ 1335 if (primary && BINFO_VIRTUAL_P (primary)) 1336 { 1337 tree this_primary = copied_binfo (primary, base_binfo); 1338 1339 if (BINFO_PRIMARY_P (this_primary)) 1340 /* Someone already claimed this base. */ 1341 BINFO_LOST_PRIMARY_P (base_binfo) = 1; 1342 else 1343 { 1344 tree delta; 1345 1346 BINFO_PRIMARY_P (this_primary) = 1; 1347 BINFO_INHERITANCE_CHAIN (this_primary) = base_binfo; 1348 1349 /* A virtual binfo might have been copied from within 1350 another hierarchy. As we're about to use it as a 1351 primary base, make sure the offsets match. */ 1352 delta = size_diffop (convert (ssizetype, 1353 BINFO_OFFSET (base_binfo)), 1354 convert (ssizetype, 1355 BINFO_OFFSET (this_primary))); 1356 1357 propagate_binfo_offsets (this_primary, delta); 1358 } 1359 } 1360 } 1361 1362 /* First look for a dynamic direct non-virtual base. */ 1363 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, base_binfo); i++) 1364 { 1365 tree basetype = BINFO_TYPE (base_binfo); 1366 1367 if (TYPE_CONTAINS_VPTR_P (basetype) && !BINFO_VIRTUAL_P (base_binfo)) 1368 { 1369 primary = base_binfo; 1370 goto found; 1371 } 1372 } 1373 1374 /* A "nearly-empty" virtual base class can be the primary base 1375 class, if no non-virtual polymorphic base can be found. Look for 1376 a nearly-empty virtual dynamic base that is not already a primary 1377 base of something in the hierarchy. If there is no such base, 1378 just pick the first nearly-empty virtual base. */ 1379 1380 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo; 1381 base_binfo = TREE_CHAIN (base_binfo)) 1382 if (BINFO_VIRTUAL_P (base_binfo) 1383 && CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (base_binfo))) 1384 { 1385 if (!BINFO_PRIMARY_P (base_binfo)) 1386 { 1387 /* Found one that is not primary. */ 1388 primary = base_binfo; 1389 goto found; 1390 } 1391 else if (!primary) 1392 /* Remember the first candidate. */ 1393 primary = base_binfo; 1394 } 1395 1396 found: 1397 /* If we've got a primary base, use it. */ 1398 if (primary) 1399 { 1400 tree basetype = BINFO_TYPE (primary); 1401 1402 CLASSTYPE_PRIMARY_BINFO (t) = primary; 1403 if (BINFO_PRIMARY_P (primary)) 1404 /* We are stealing a primary base. */ 1405 BINFO_LOST_PRIMARY_P (BINFO_INHERITANCE_CHAIN (primary)) = 1; 1406 BINFO_PRIMARY_P (primary) = 1; 1407 if (BINFO_VIRTUAL_P (primary)) 1408 { 1409 tree delta; 1410 1411 BINFO_INHERITANCE_CHAIN (primary) = type_binfo; 1412 /* A virtual binfo might have been copied from within 1413 another hierarchy. As we're about to use it as a primary 1414 base, make sure the offsets match. */ 1415 delta = size_diffop (ssize_int (0), 1416 convert (ssizetype, BINFO_OFFSET (primary))); 1417 1418 propagate_binfo_offsets (primary, delta); 1419 } 1420 1421 primary = TYPE_BINFO (basetype); 1422 1423 TYPE_VFIELD (t) = TYPE_VFIELD (basetype); 1424 BINFO_VTABLE (type_binfo) = BINFO_VTABLE (primary); 1425 BINFO_VIRTUALS (type_binfo) = BINFO_VIRTUALS (primary); 1426 } 1427} 1428 1429/* Set memoizing fields and bits of T (and its variants) for later 1430 use. */ 1431 1432static void 1433finish_struct_bits (tree t) 1434{ 1435 tree variants; 1436 1437 /* Fix up variants (if any). */ 1438 for (variants = TYPE_NEXT_VARIANT (t); 1439 variants; 1440 variants = TYPE_NEXT_VARIANT (variants)) 1441 { 1442 /* These fields are in the _TYPE part of the node, not in 1443 the TYPE_LANG_SPECIFIC component, so they are not shared. */ 1444 TYPE_HAS_CONSTRUCTOR (variants) = TYPE_HAS_CONSTRUCTOR (t); 1445 TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t); 1446 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variants) 1447 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t); 1448 1449 /* APPLE LOCAL begin omit calls to empty destructors 5559195 */ 1450 CLASSTYPE_HAS_NONTRIVIAL_DESTRUCTOR_BODY (variants) = 1451 CLASSTYPE_HAS_NONTRIVIAL_DESTRUCTOR_BODY (t); 1452 CLASSTYPE_DESTRUCTOR_NONTRIVIAL_BECAUSE_OF_BASE (variants) = 1453 CLASSTYPE_DESTRUCTOR_NONTRIVIAL_BECAUSE_OF_BASE (t); 1454 /* APPLE LOCAL end omit calls to empty destructors 5559195 */ 1455 1456 TYPE_POLYMORPHIC_P (variants) = TYPE_POLYMORPHIC_P (t); 1457 1458 TYPE_BINFO (variants) = TYPE_BINFO (t); 1459 1460 /* Copy whatever these are holding today. */ 1461 TYPE_VFIELD (variants) = TYPE_VFIELD (t); 1462 TYPE_METHODS (variants) = TYPE_METHODS (t); 1463 TYPE_FIELDS (variants) = TYPE_FIELDS (t); 1464 } 1465 1466 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) && TYPE_POLYMORPHIC_P (t)) 1467 /* For a class w/o baseclasses, 'finish_struct' has set 1468 CLASSTYPE_PURE_VIRTUALS correctly (by definition). 1469 Similarly for a class whose base classes do not have vtables. 1470 When neither of these is true, we might have removed abstract 1471 virtuals (by providing a definition), added some (by declaring 1472 new ones), or redeclared ones from a base class. We need to 1473 recalculate what's really an abstract virtual at this point (by 1474 looking in the vtables). */ 1475 get_pure_virtuals (t); 1476 1477 /* If this type has a copy constructor or a destructor, force its 1478 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be 1479 nonzero. This will cause it to be passed by invisible reference 1480 and prevent it from being returned in a register. */ 1481 if (! TYPE_HAS_TRIVIAL_INIT_REF (t) || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)) 1482 { 1483 tree variants; 1484 DECL_MODE (TYPE_MAIN_DECL (t)) = BLKmode; 1485 for (variants = t; variants; variants = TYPE_NEXT_VARIANT (variants)) 1486 { 1487 TYPE_MODE (variants) = BLKmode; 1488 TREE_ADDRESSABLE (variants) = 1; 1489 } 1490 } 1491} 1492 1493/* Issue warnings about T having private constructors, but no friends, 1494 and so forth. 1495 1496 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or 1497 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any 1498 non-private static member functions. */ 1499 1500static void 1501maybe_warn_about_overly_private_class (tree t) 1502{ 1503 int has_member_fn = 0; 1504 int has_nonprivate_method = 0; 1505 tree fn; 1506 1507 if (!warn_ctor_dtor_privacy 1508 /* If the class has friends, those entities might create and 1509 access instances, so we should not warn. */ 1510 || (CLASSTYPE_FRIEND_CLASSES (t) 1511 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t))) 1512 /* We will have warned when the template was declared; there's 1513 no need to warn on every instantiation. */ 1514 || CLASSTYPE_TEMPLATE_INSTANTIATION (t)) 1515 /* There's no reason to even consider warning about this 1516 class. */ 1517 return; 1518 1519 /* We only issue one warning, if more than one applies, because 1520 otherwise, on code like: 1521 1522 class A { 1523 // Oops - forgot `public:' 1524 A(); 1525 A(const A&); 1526 ~A(); 1527 }; 1528 1529 we warn several times about essentially the same problem. */ 1530 1531 /* Check to see if all (non-constructor, non-destructor) member 1532 functions are private. (Since there are no friends or 1533 non-private statics, we can't ever call any of the private member 1534 functions.) */ 1535 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn)) 1536 /* We're not interested in compiler-generated methods; they don't 1537 provide any way to call private members. */ 1538 if (!DECL_ARTIFICIAL (fn)) 1539 { 1540 if (!TREE_PRIVATE (fn)) 1541 { 1542 if (DECL_STATIC_FUNCTION_P (fn)) 1543 /* A non-private static member function is just like a 1544 friend; it can create and invoke private member 1545 functions, and be accessed without a class 1546 instance. */ 1547 return; 1548 1549 has_nonprivate_method = 1; 1550 /* Keep searching for a static member function. */ 1551 } 1552 else if (!DECL_CONSTRUCTOR_P (fn) && !DECL_DESTRUCTOR_P (fn)) 1553 has_member_fn = 1; 1554 } 1555 1556 if (!has_nonprivate_method && has_member_fn) 1557 { 1558 /* There are no non-private methods, and there's at least one 1559 private member function that isn't a constructor or 1560 destructor. (If all the private members are 1561 constructors/destructors we want to use the code below that 1562 issues error messages specifically referring to 1563 constructors/destructors.) */ 1564 unsigned i; 1565 tree binfo = TYPE_BINFO (t); 1566 1567 for (i = 0; i != BINFO_N_BASE_BINFOS (binfo); i++) 1568 if (BINFO_BASE_ACCESS (binfo, i) != access_private_node) 1569 { 1570 has_nonprivate_method = 1; 1571 break; 1572 } 1573 if (!has_nonprivate_method) 1574 { 1575 warning (OPT_Wctor_dtor_privacy, 1576 "all member functions in class %qT are private", t); 1577 return; 1578 } 1579 } 1580 1581 /* Even if some of the member functions are non-private, the class 1582 won't be useful for much if all the constructors or destructors 1583 are private: such an object can never be created or destroyed. */ 1584 fn = CLASSTYPE_DESTRUCTORS (t); 1585 if (fn && TREE_PRIVATE (fn)) 1586 { 1587 warning (OPT_Wctor_dtor_privacy, 1588 "%q#T only defines a private destructor and has no friends", 1589 t); 1590 return; 1591 } 1592 1593 if (TYPE_HAS_CONSTRUCTOR (t) 1594 /* Implicitly generated constructors are always public. */ 1595 && (!CLASSTYPE_LAZY_DEFAULT_CTOR (t) 1596 || !CLASSTYPE_LAZY_COPY_CTOR (t))) 1597 { 1598 int nonprivate_ctor = 0; 1599 1600 /* If a non-template class does not define a copy 1601 constructor, one is defined for it, enabling it to avoid 1602 this warning. For a template class, this does not 1603 happen, and so we would normally get a warning on: 1604 1605 template <class T> class C { private: C(); }; 1606 1607 To avoid this asymmetry, we check TYPE_HAS_INIT_REF. All 1608 complete non-template or fully instantiated classes have this 1609 flag set. */ 1610 if (!TYPE_HAS_INIT_REF (t)) 1611 nonprivate_ctor = 1; 1612 else 1613 for (fn = CLASSTYPE_CONSTRUCTORS (t); fn; fn = OVL_NEXT (fn)) 1614 { 1615 tree ctor = OVL_CURRENT (fn); 1616 /* Ideally, we wouldn't count copy constructors (or, in 1617 fact, any constructor that takes an argument of the 1618 class type as a parameter) because such things cannot 1619 be used to construct an instance of the class unless 1620 you already have one. But, for now at least, we're 1621 more generous. */ 1622 if (! TREE_PRIVATE (ctor)) 1623 { 1624 nonprivate_ctor = 1; 1625 break; 1626 } 1627 } 1628 1629 if (nonprivate_ctor == 0) 1630 { 1631 warning (OPT_Wctor_dtor_privacy, 1632 "%q#T only defines private constructors and has no friends", 1633 t); 1634 return; 1635 } 1636 } 1637} 1638 1639static struct { 1640 gt_pointer_operator new_value; 1641 void *cookie; 1642} resort_data; 1643 1644/* Comparison function to compare two TYPE_METHOD_VEC entries by name. */ 1645 1646static int 1647method_name_cmp (const void* m1_p, const void* m2_p) 1648{ 1649 const tree *const m1 = (const tree *) m1_p; 1650 const tree *const m2 = (const tree *) m2_p; 1651 1652 if (*m1 == NULL_TREE && *m2 == NULL_TREE) 1653 return 0; 1654 if (*m1 == NULL_TREE) 1655 return -1; 1656 if (*m2 == NULL_TREE) 1657 return 1; 1658 if (DECL_NAME (OVL_CURRENT (*m1)) < DECL_NAME (OVL_CURRENT (*m2))) 1659 return -1; 1660 return 1; 1661} 1662 1663/* This routine compares two fields like method_name_cmp but using the 1664 pointer operator in resort_field_decl_data. */ 1665 1666static int 1667resort_method_name_cmp (const void* m1_p, const void* m2_p) 1668{ 1669 const tree *const m1 = (const tree *) m1_p; 1670 const tree *const m2 = (const tree *) m2_p; 1671 if (*m1 == NULL_TREE && *m2 == NULL_TREE) 1672 return 0; 1673 if (*m1 == NULL_TREE) 1674 return -1; 1675 if (*m2 == NULL_TREE) 1676 return 1; 1677 { 1678 tree d1 = DECL_NAME (OVL_CURRENT (*m1)); 1679 tree d2 = DECL_NAME (OVL_CURRENT (*m2)); 1680 resort_data.new_value (&d1, resort_data.cookie); 1681 resort_data.new_value (&d2, resort_data.cookie); 1682 if (d1 < d2) 1683 return -1; 1684 } 1685 return 1; 1686} 1687 1688/* Resort TYPE_METHOD_VEC because pointers have been reordered. */ 1689 1690void 1691resort_type_method_vec (void* obj, 1692 void* orig_obj ATTRIBUTE_UNUSED , 1693 gt_pointer_operator new_value, 1694 void* cookie) 1695{ 1696 VEC(tree,gc) *method_vec = (VEC(tree,gc) *) obj; 1697 int len = VEC_length (tree, method_vec); 1698 size_t slot; 1699 tree fn; 1700 1701 /* The type conversion ops have to live at the front of the vec, so we 1702 can't sort them. */ 1703 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT; 1704 VEC_iterate (tree, method_vec, slot, fn); 1705 ++slot) 1706 if (!DECL_CONV_FN_P (OVL_CURRENT (fn))) 1707 break; 1708 1709 if (len - slot > 1) 1710 { 1711 resort_data.new_value = new_value; 1712 resort_data.cookie = cookie; 1713 qsort (VEC_address (tree, method_vec) + slot, len - slot, sizeof (tree), 1714 resort_method_name_cmp); 1715 } 1716} 1717 1718/* Warn about duplicate methods in fn_fields. 1719 1720 Sort methods that are not special (i.e., constructors, destructors, 1721 and type conversion operators) so that we can find them faster in 1722 search. */ 1723 1724static void 1725finish_struct_methods (tree t) 1726{ 1727 tree fn_fields; 1728 VEC(tree,gc) *method_vec; 1729 int slot, len; 1730 1731 method_vec = CLASSTYPE_METHOD_VEC (t); 1732 if (!method_vec) 1733 return; 1734 1735 len = VEC_length (tree, method_vec); 1736 1737 /* Clear DECL_IN_AGGR_P for all functions. */ 1738 for (fn_fields = TYPE_METHODS (t); fn_fields; 1739 fn_fields = TREE_CHAIN (fn_fields)) 1740 DECL_IN_AGGR_P (fn_fields) = 0; 1741 1742 /* Issue warnings about private constructors and such. If there are 1743 no methods, then some public defaults are generated. */ 1744 maybe_warn_about_overly_private_class (t); 1745 1746 /* The type conversion ops have to live at the front of the vec, so we 1747 can't sort them. */ 1748 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT; 1749 VEC_iterate (tree, method_vec, slot, fn_fields); 1750 ++slot) 1751 if (!DECL_CONV_FN_P (OVL_CURRENT (fn_fields))) 1752 break; 1753 if (len - slot > 1) 1754 qsort (VEC_address (tree, method_vec) + slot, 1755 len-slot, sizeof (tree), method_name_cmp); 1756} 1757 1758/* Make BINFO's vtable have N entries, including RTTI entries, 1759 vbase and vcall offsets, etc. Set its type and call the backend 1760 to lay it out. */ 1761 1762static void 1763layout_vtable_decl (tree binfo, int n) 1764{ 1765 tree atype; 1766 tree vtable; 1767 1768 atype = build_cplus_array_type (vtable_entry_type, 1769 build_index_type (size_int (n - 1))); 1770 layout_type (atype); 1771 1772 /* We may have to grow the vtable. */ 1773 vtable = get_vtbl_decl_for_binfo (binfo); 1774 if (!same_type_p (TREE_TYPE (vtable), atype)) 1775 { 1776 TREE_TYPE (vtable) = atype; 1777 DECL_SIZE (vtable) = DECL_SIZE_UNIT (vtable) = NULL_TREE; 1778 layout_decl (vtable, 0); 1779 } 1780} 1781 1782/* True iff FNDECL and BASE_FNDECL (both non-static member functions) 1783 have the same signature. */ 1784 1785int 1786same_signature_p (tree fndecl, tree base_fndecl) 1787{ 1788 /* One destructor overrides another if they are the same kind of 1789 destructor. */ 1790 if (DECL_DESTRUCTOR_P (base_fndecl) && DECL_DESTRUCTOR_P (fndecl) 1791 && special_function_p (base_fndecl) == special_function_p (fndecl)) 1792 return 1; 1793 /* But a non-destructor never overrides a destructor, nor vice 1794 versa, nor do different kinds of destructors override 1795 one-another. For example, a complete object destructor does not 1796 override a deleting destructor. */ 1797 if (DECL_DESTRUCTOR_P (base_fndecl) || DECL_DESTRUCTOR_P (fndecl)) 1798 return 0; 1799 1800 if (DECL_NAME (fndecl) == DECL_NAME (base_fndecl) 1801 || (DECL_CONV_FN_P (fndecl) 1802 && DECL_CONV_FN_P (base_fndecl) 1803 && same_type_p (DECL_CONV_FN_TYPE (fndecl), 1804 DECL_CONV_FN_TYPE (base_fndecl)))) 1805 { 1806 tree types, base_types; 1807 types = TYPE_ARG_TYPES (TREE_TYPE (fndecl)); 1808 base_types = TYPE_ARG_TYPES (TREE_TYPE (base_fndecl)); 1809 if ((TYPE_QUALS (TREE_TYPE (TREE_VALUE (base_types))) 1810 == TYPE_QUALS (TREE_TYPE (TREE_VALUE (types)))) 1811 && compparms (TREE_CHAIN (base_types), TREE_CHAIN (types))) 1812 return 1; 1813 } 1814 return 0; 1815} 1816 1817/* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a 1818 subobject. */ 1819 1820static bool 1821base_derived_from (tree derived, tree base) 1822{ 1823 tree probe; 1824 1825 for (probe = base; probe; probe = BINFO_INHERITANCE_CHAIN (probe)) 1826 { 1827 if (probe == derived) 1828 return true; 1829 else if (BINFO_VIRTUAL_P (probe)) 1830 /* If we meet a virtual base, we can't follow the inheritance 1831 any more. See if the complete type of DERIVED contains 1832 such a virtual base. */ 1833 return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (derived)) 1834 != NULL_TREE); 1835 } 1836 return false; 1837} 1838 1839typedef struct find_final_overrider_data_s { 1840 /* The function for which we are trying to find a final overrider. */ 1841 tree fn; 1842 /* The base class in which the function was declared. */ 1843 tree declaring_base; 1844 /* The candidate overriders. */ 1845 tree candidates; 1846 /* Path to most derived. */ 1847 VEC(tree,heap) *path; 1848} find_final_overrider_data; 1849 1850/* Add the overrider along the current path to FFOD->CANDIDATES. 1851 Returns true if an overrider was found; false otherwise. */ 1852 1853static bool 1854dfs_find_final_overrider_1 (tree binfo, 1855 find_final_overrider_data *ffod, 1856 unsigned depth) 1857{ 1858 tree method; 1859 1860 /* If BINFO is not the most derived type, try a more derived class. 1861 A definition there will overrider a definition here. */ 1862 if (depth) 1863 { 1864 depth--; 1865 if (dfs_find_final_overrider_1 1866 (VEC_index (tree, ffod->path, depth), ffod, depth)) 1867 return true; 1868 } 1869 1870 method = look_for_overrides_here (BINFO_TYPE (binfo), ffod->fn); 1871 if (method) 1872 { 1873 tree *candidate = &ffod->candidates; 1874 1875 /* Remove any candidates overridden by this new function. */ 1876 while (*candidate) 1877 { 1878 /* If *CANDIDATE overrides METHOD, then METHOD 1879 cannot override anything else on the list. */ 1880 if (base_derived_from (TREE_VALUE (*candidate), binfo)) 1881 return true; 1882 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */ 1883 if (base_derived_from (binfo, TREE_VALUE (*candidate))) 1884 *candidate = TREE_CHAIN (*candidate); 1885 else 1886 candidate = &TREE_CHAIN (*candidate); 1887 } 1888 1889 /* Add the new function. */ 1890 ffod->candidates = tree_cons (method, binfo, ffod->candidates); 1891 return true; 1892 } 1893 1894 return false; 1895} 1896 1897/* Called from find_final_overrider via dfs_walk. */ 1898 1899static tree 1900dfs_find_final_overrider_pre (tree binfo, void *data) 1901{ 1902 find_final_overrider_data *ffod = (find_final_overrider_data *) data; 1903 1904 if (binfo == ffod->declaring_base) 1905 dfs_find_final_overrider_1 (binfo, ffod, VEC_length (tree, ffod->path)); 1906 VEC_safe_push (tree, heap, ffod->path, binfo); 1907 1908 return NULL_TREE; 1909} 1910 1911static tree 1912dfs_find_final_overrider_post (tree binfo ATTRIBUTE_UNUSED, void *data) 1913{ 1914 find_final_overrider_data *ffod = (find_final_overrider_data *) data; 1915 VEC_pop (tree, ffod->path); 1916 1917 return NULL_TREE; 1918} 1919 1920/* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for 1921 FN and whose TREE_VALUE is the binfo for the base where the 1922 overriding occurs. BINFO (in the hierarchy dominated by the binfo 1923 DERIVED) is the base object in which FN is declared. */ 1924 1925static tree 1926find_final_overrider (tree derived, tree binfo, tree fn) 1927{ 1928 find_final_overrider_data ffod; 1929 1930 /* Getting this right is a little tricky. This is valid: 1931 1932 struct S { virtual void f (); }; 1933 struct T { virtual void f (); }; 1934 struct U : public S, public T { }; 1935 1936 even though calling `f' in `U' is ambiguous. But, 1937 1938 struct R { virtual void f(); }; 1939 struct S : virtual public R { virtual void f (); }; 1940 struct T : virtual public R { virtual void f (); }; 1941 struct U : public S, public T { }; 1942 1943 is not -- there's no way to decide whether to put `S::f' or 1944 `T::f' in the vtable for `R'. 1945 1946 The solution is to look at all paths to BINFO. If we find 1947 different overriders along any two, then there is a problem. */ 1948 if (DECL_THUNK_P (fn)) 1949 fn = THUNK_TARGET (fn); 1950 1951 /* Determine the depth of the hierarchy. */ 1952 ffod.fn = fn; 1953 ffod.declaring_base = binfo; 1954 ffod.candidates = NULL_TREE; 1955 ffod.path = VEC_alloc (tree, heap, 30); 1956 1957 dfs_walk_all (derived, dfs_find_final_overrider_pre, 1958 dfs_find_final_overrider_post, &ffod); 1959 1960 VEC_free (tree, heap, ffod.path); 1961 1962 /* If there was no winner, issue an error message. */ 1963 if (!ffod.candidates || TREE_CHAIN (ffod.candidates)) 1964 return error_mark_node; 1965 1966 return ffod.candidates; 1967} 1968 1969/* Return the index of the vcall offset for FN when TYPE is used as a 1970 virtual base. */ 1971 1972static tree 1973get_vcall_index (tree fn, tree type) 1974{ 1975 VEC(tree_pair_s,gc) *indices = CLASSTYPE_VCALL_INDICES (type); 1976 tree_pair_p p; 1977 unsigned ix; 1978 1979 for (ix = 0; VEC_iterate (tree_pair_s, indices, ix, p); ix++) 1980 if ((DECL_DESTRUCTOR_P (fn) && DECL_DESTRUCTOR_P (p->purpose)) 1981 || same_signature_p (fn, p->purpose)) 1982 return p->value; 1983 1984 /* There should always be an appropriate index. */ 1985 gcc_unreachable (); 1986} 1987 1988/* Update an entry in the vtable for BINFO, which is in the hierarchy 1989 dominated by T. FN has been overridden in BINFO; VIRTUALS points to the 1990 corresponding position in the BINFO_VIRTUALS list. */ 1991 1992static void 1993update_vtable_entry_for_fn (tree t, tree binfo, tree fn, tree* virtuals, 1994 unsigned ix) 1995{ 1996 tree b; 1997 tree overrider; 1998 tree delta; 1999 tree virtual_base; 2000 tree first_defn; 2001 tree overrider_fn, overrider_target; 2002 tree target_fn = DECL_THUNK_P (fn) ? THUNK_TARGET (fn) : fn; 2003 tree over_return, base_return; 2004 bool lost = false; 2005 2006 /* Find the nearest primary base (possibly binfo itself) which defines 2007 this function; this is the class the caller will convert to when 2008 calling FN through BINFO. */ 2009 for (b = binfo; ; b = get_primary_binfo (b)) 2010 { 2011 gcc_assert (b); 2012 if (look_for_overrides_here (BINFO_TYPE (b), target_fn)) 2013 break; 2014 2015 /* The nearest definition is from a lost primary. */ 2016 if (BINFO_LOST_PRIMARY_P (b)) 2017 lost = true; 2018 } 2019 first_defn = b; 2020 2021 /* Find the final overrider. */ 2022 overrider = find_final_overrider (TYPE_BINFO (t), b, target_fn); 2023 if (overrider == error_mark_node) 2024 { 2025 error ("no unique final overrider for %qD in %qT", target_fn, t); 2026 return; 2027 } 2028 overrider_target = overrider_fn = TREE_PURPOSE (overrider); 2029 2030 /* Check for adjusting covariant return types. */ 2031 over_return = TREE_TYPE (TREE_TYPE (overrider_target)); 2032 base_return = TREE_TYPE (TREE_TYPE (target_fn)); 2033 2034 if (POINTER_TYPE_P (over_return) 2035 && TREE_CODE (over_return) == TREE_CODE (base_return) 2036 && CLASS_TYPE_P (TREE_TYPE (over_return)) 2037 && CLASS_TYPE_P (TREE_TYPE (base_return)) 2038 /* If the overrider is invalid, don't even try. */ 2039 && !DECL_INVALID_OVERRIDER_P (overrider_target)) 2040 { 2041 /* If FN is a covariant thunk, we must figure out the adjustment 2042 to the final base FN was converting to. As OVERRIDER_TARGET might 2043 also be converting to the return type of FN, we have to 2044 combine the two conversions here. */ 2045 tree fixed_offset, virtual_offset; 2046 2047 over_return = TREE_TYPE (over_return); 2048 base_return = TREE_TYPE (base_return); 2049 2050 if (DECL_THUNK_P (fn)) 2051 { 2052 gcc_assert (DECL_RESULT_THUNK_P (fn)); 2053 fixed_offset = ssize_int (THUNK_FIXED_OFFSET (fn)); 2054 virtual_offset = THUNK_VIRTUAL_OFFSET (fn); 2055 } 2056 else 2057 fixed_offset = virtual_offset = NULL_TREE; 2058 2059 if (virtual_offset) 2060 /* Find the equivalent binfo within the return type of the 2061 overriding function. We will want the vbase offset from 2062 there. */ 2063 virtual_offset = binfo_for_vbase (BINFO_TYPE (virtual_offset), 2064 over_return); 2065 else if (!same_type_ignoring_top_level_qualifiers_p 2066 (over_return, base_return)) 2067 { 2068 /* There was no existing virtual thunk (which takes 2069 precedence). So find the binfo of the base function's 2070 return type within the overriding function's return type. 2071 We cannot call lookup base here, because we're inside a 2072 dfs_walk, and will therefore clobber the BINFO_MARKED 2073 flags. Fortunately we know the covariancy is valid (it 2074 has already been checked), so we can just iterate along 2075 the binfos, which have been chained in inheritance graph 2076 order. Of course it is lame that we have to repeat the 2077 search here anyway -- we should really be caching pieces 2078 of the vtable and avoiding this repeated work. */ 2079 tree thunk_binfo, base_binfo; 2080 2081 /* Find the base binfo within the overriding function's 2082 return type. We will always find a thunk_binfo, except 2083 when the covariancy is invalid (which we will have 2084 already diagnosed). */ 2085 for (base_binfo = TYPE_BINFO (base_return), 2086 thunk_binfo = TYPE_BINFO (over_return); 2087 thunk_binfo; 2088 thunk_binfo = TREE_CHAIN (thunk_binfo)) 2089 if (SAME_BINFO_TYPE_P (BINFO_TYPE (thunk_binfo), 2090 BINFO_TYPE (base_binfo))) 2091 break; 2092 2093 /* See if virtual inheritance is involved. */ 2094 for (virtual_offset = thunk_binfo; 2095 virtual_offset; 2096 virtual_offset = BINFO_INHERITANCE_CHAIN (virtual_offset)) 2097 if (BINFO_VIRTUAL_P (virtual_offset)) 2098 break; 2099 2100 if (virtual_offset 2101 || (thunk_binfo && !BINFO_OFFSET_ZEROP (thunk_binfo))) 2102 { 2103 tree offset = convert (ssizetype, BINFO_OFFSET (thunk_binfo)); 2104 2105 if (virtual_offset) 2106 { 2107 /* We convert via virtual base. Adjust the fixed 2108 offset to be from there. */ 2109 offset = size_diffop 2110 (offset, convert 2111 (ssizetype, BINFO_OFFSET (virtual_offset))); 2112 } 2113 if (fixed_offset) 2114 /* There was an existing fixed offset, this must be 2115 from the base just converted to, and the base the 2116 FN was thunking to. */ 2117 fixed_offset = size_binop (PLUS_EXPR, fixed_offset, offset); 2118 else 2119 fixed_offset = offset; 2120 } 2121 } 2122 2123 if (fixed_offset || virtual_offset) 2124 /* Replace the overriding function with a covariant thunk. We 2125 will emit the overriding function in its own slot as 2126 well. */ 2127 overrider_fn = make_thunk (overrider_target, /*this_adjusting=*/0, 2128 fixed_offset, virtual_offset); 2129 } 2130 else 2131 gcc_assert (!DECL_THUNK_P (fn)); 2132 2133 /* Assume that we will produce a thunk that convert all the way to 2134 the final overrider, and not to an intermediate virtual base. */ 2135 virtual_base = NULL_TREE; 2136 2137 /* See if we can convert to an intermediate virtual base first, and then 2138 use the vcall offset located there to finish the conversion. */ 2139 for (; b; b = BINFO_INHERITANCE_CHAIN (b)) 2140 { 2141 /* If we find the final overrider, then we can stop 2142 walking. */ 2143 if (SAME_BINFO_TYPE_P (BINFO_TYPE (b), 2144 BINFO_TYPE (TREE_VALUE (overrider)))) 2145 break; 2146 2147 /* If we find a virtual base, and we haven't yet found the 2148 overrider, then there is a virtual base between the 2149 declaring base (first_defn) and the final overrider. */ 2150 if (BINFO_VIRTUAL_P (b)) 2151 { 2152 virtual_base = b; 2153 break; 2154 } 2155 } 2156 2157 if (overrider_fn != overrider_target && !virtual_base) 2158 { 2159 /* The ABI specifies that a covariant thunk includes a mangling 2160 for a this pointer adjustment. This-adjusting thunks that 2161 override a function from a virtual base have a vcall 2162 adjustment. When the virtual base in question is a primary 2163 virtual base, we know the adjustments are zero, (and in the 2164 non-covariant case, we would not use the thunk). 2165 Unfortunately we didn't notice this could happen, when 2166 designing the ABI and so never mandated that such a covariant 2167 thunk should be emitted. Because we must use the ABI mandated 2168 name, we must continue searching from the binfo where we 2169 found the most recent definition of the function, towards the 2170 primary binfo which first introduced the function into the 2171 vtable. If that enters a virtual base, we must use a vcall 2172 this-adjusting thunk. Bleah! */ 2173 tree probe = first_defn; 2174 2175 while ((probe = get_primary_binfo (probe)) 2176 && (unsigned) list_length (BINFO_VIRTUALS (probe)) > ix) 2177 if (BINFO_VIRTUAL_P (probe)) 2178 virtual_base = probe; 2179 2180 if (virtual_base) 2181 /* Even if we find a virtual base, the correct delta is 2182 between the overrider and the binfo we're building a vtable 2183 for. */ 2184 goto virtual_covariant; 2185 } 2186 2187 /* Compute the constant adjustment to the `this' pointer. The 2188 `this' pointer, when this function is called, will point at BINFO 2189 (or one of its primary bases, which are at the same offset). */ 2190 if (virtual_base) 2191 /* The `this' pointer needs to be adjusted from the declaration to 2192 the nearest virtual base. */ 2193 delta = size_diffop (convert (ssizetype, BINFO_OFFSET (virtual_base)), 2194 convert (ssizetype, BINFO_OFFSET (first_defn))); 2195 else if (lost) 2196 /* If the nearest definition is in a lost primary, we don't need an 2197 entry in our vtable. Except possibly in a constructor vtable, 2198 if we happen to get our primary back. In that case, the offset 2199 will be zero, as it will be a primary base. */ 2200 delta = size_zero_node; 2201 else 2202 /* The `this' pointer needs to be adjusted from pointing to 2203 BINFO to pointing at the base where the final overrider 2204 appears. */ 2205 virtual_covariant: 2206 delta = size_diffop (convert (ssizetype, 2207 BINFO_OFFSET (TREE_VALUE (overrider))), 2208 convert (ssizetype, BINFO_OFFSET (binfo))); 2209 2210 modify_vtable_entry (t, binfo, overrider_fn, delta, virtuals); 2211 2212 if (virtual_base) 2213 BV_VCALL_INDEX (*virtuals) 2214 = get_vcall_index (overrider_target, BINFO_TYPE (virtual_base)); 2215 else 2216 BV_VCALL_INDEX (*virtuals) = NULL_TREE; 2217} 2218 2219/* Called from modify_all_vtables via dfs_walk. */ 2220 2221static tree 2222dfs_modify_vtables (tree binfo, void* data) 2223{ 2224 tree t = (tree) data; 2225 tree virtuals; 2226 tree old_virtuals; 2227 unsigned ix; 2228 2229 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) 2230 /* A base without a vtable needs no modification, and its bases 2231 are uninteresting. */ 2232 return dfs_skip_bases; 2233 2234 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t) 2235 && !CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 2236 /* Don't do the primary vtable, if it's new. */ 2237 return NULL_TREE; 2238 2239 if (BINFO_PRIMARY_P (binfo) && !BINFO_VIRTUAL_P (binfo)) 2240 /* There's no need to modify the vtable for a non-virtual primary 2241 base; we're not going to use that vtable anyhow. We do still 2242 need to do this for virtual primary bases, as they could become 2243 non-primary in a construction vtable. */ 2244 return NULL_TREE; 2245 2246 make_new_vtable (t, binfo); 2247 2248 /* Now, go through each of the virtual functions in the virtual 2249 function table for BINFO. Find the final overrider, and update 2250 the BINFO_VIRTUALS list appropriately. */ 2251 for (ix = 0, virtuals = BINFO_VIRTUALS (binfo), 2252 old_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo))); 2253 virtuals; 2254 ix++, virtuals = TREE_CHAIN (virtuals), 2255 old_virtuals = TREE_CHAIN (old_virtuals)) 2256 update_vtable_entry_for_fn (t, 2257 binfo, 2258 BV_FN (old_virtuals), 2259 &virtuals, ix); 2260 2261 return NULL_TREE; 2262} 2263 2264/* Update all of the primary and secondary vtables for T. Create new 2265 vtables as required, and initialize their RTTI information. Each 2266 of the functions in VIRTUALS is declared in T and may override a 2267 virtual function from a base class; find and modify the appropriate 2268 entries to point to the overriding functions. Returns a list, in 2269 declaration order, of the virtual functions that are declared in T, 2270 but do not appear in the primary base class vtable, and which 2271 should therefore be appended to the end of the vtable for T. */ 2272 2273static tree 2274modify_all_vtables (tree t, tree virtuals) 2275{ 2276 tree binfo = TYPE_BINFO (t); 2277 tree *fnsp; 2278 2279 /* Update all of the vtables. */ 2280 dfs_walk_once (binfo, dfs_modify_vtables, NULL, t); 2281 2282 /* Add virtual functions not already in our primary vtable. These 2283 will be both those introduced by this class, and those overridden 2284 from secondary bases. It does not include virtuals merely 2285 inherited from secondary bases. */ 2286 for (fnsp = &virtuals; *fnsp; ) 2287 { 2288 tree fn = TREE_VALUE (*fnsp); 2289 2290 if (!value_member (fn, BINFO_VIRTUALS (binfo)) 2291 || DECL_VINDEX (fn) == error_mark_node) 2292 { 2293 /* We don't need to adjust the `this' pointer when 2294 calling this function. */ 2295 BV_DELTA (*fnsp) = integer_zero_node; 2296 BV_VCALL_INDEX (*fnsp) = NULL_TREE; 2297 2298 /* This is a function not already in our vtable. Keep it. */ 2299 fnsp = &TREE_CHAIN (*fnsp); 2300 } 2301 else 2302 /* We've already got an entry for this function. Skip it. */ 2303 *fnsp = TREE_CHAIN (*fnsp); 2304 } 2305 2306 return virtuals; 2307} 2308 2309/* Get the base virtual function declarations in T that have the 2310 indicated NAME. */ 2311 2312static tree 2313get_basefndecls (tree name, tree t) 2314{ 2315 tree methods; 2316 tree base_fndecls = NULL_TREE; 2317 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t)); 2318 int i; 2319 2320 /* Find virtual functions in T with the indicated NAME. */ 2321 i = lookup_fnfields_1 (t, name); 2322 if (i != -1) 2323 for (methods = VEC_index (tree, CLASSTYPE_METHOD_VEC (t), i); 2324 methods; 2325 methods = OVL_NEXT (methods)) 2326 { 2327 tree method = OVL_CURRENT (methods); 2328 2329 if (TREE_CODE (method) == FUNCTION_DECL 2330 && DECL_VINDEX (method)) 2331 base_fndecls = tree_cons (NULL_TREE, method, base_fndecls); 2332 } 2333 2334 if (base_fndecls) 2335 return base_fndecls; 2336 2337 for (i = 0; i < n_baseclasses; i++) 2338 { 2339 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (t), i)); 2340 base_fndecls = chainon (get_basefndecls (name, basetype), 2341 base_fndecls); 2342 } 2343 2344 return base_fndecls; 2345} 2346 2347/* If this declaration supersedes the declaration of 2348 a method declared virtual in the base class, then 2349 mark this field as being virtual as well. */ 2350 2351void 2352check_for_override (tree decl, tree ctype) 2353{ 2354 if (TREE_CODE (decl) == TEMPLATE_DECL) 2355 /* In [temp.mem] we have: 2356 2357 A specialization of a member function template does not 2358 override a virtual function from a base class. */ 2359 return; 2360 if ((DECL_DESTRUCTOR_P (decl) 2361 || IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) 2362 || DECL_CONV_FN_P (decl)) 2363 && look_for_overrides (ctype, decl) 2364 && !DECL_STATIC_FUNCTION_P (decl)) 2365 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor 2366 the error_mark_node so that we know it is an overriding 2367 function. */ 2368 DECL_VINDEX (decl) = decl; 2369 2370 if (DECL_VIRTUAL_P (decl)) 2371 { 2372 if (!DECL_VINDEX (decl)) 2373 DECL_VINDEX (decl) = error_mark_node; 2374 IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) = 1; 2375 if (DECL_DLLIMPORT_P (decl)) 2376 { 2377 /* When we handled the dllimport attribute we may not have known 2378 that this function is virtual We can't use dllimport 2379 semantics for a virtual method because we need to initialize 2380 the vtable entry with a constant address. */ 2381 DECL_DLLIMPORT_P (decl) = 0; 2382 DECL_ATTRIBUTES (decl) 2383 = remove_attribute ("dllimport", DECL_ATTRIBUTES (decl)); 2384 } 2385 } 2386} 2387 2388/* Warn about hidden virtual functions that are not overridden in t. 2389 We know that constructors and destructors don't apply. */ 2390 2391static void 2392warn_hidden (tree t) 2393{ 2394 VEC(tree,gc) *method_vec = CLASSTYPE_METHOD_VEC (t); 2395 tree fns; 2396 size_t i; 2397 2398 /* We go through each separately named virtual function. */ 2399 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT; 2400 VEC_iterate (tree, method_vec, i, fns); 2401 ++i) 2402 { 2403 tree fn; 2404 tree name; 2405 tree fndecl; 2406 tree base_fndecls; 2407 tree base_binfo; 2408 tree binfo; 2409 int j; 2410 2411 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will 2412 have the same name. Figure out what name that is. */ 2413 name = DECL_NAME (OVL_CURRENT (fns)); 2414 /* There are no possibly hidden functions yet. */ 2415 base_fndecls = NULL_TREE; 2416 /* Iterate through all of the base classes looking for possibly 2417 hidden functions. */ 2418 for (binfo = TYPE_BINFO (t), j = 0; 2419 BINFO_BASE_ITERATE (binfo, j, base_binfo); j++) 2420 { 2421 tree basetype = BINFO_TYPE (base_binfo); 2422 base_fndecls = chainon (get_basefndecls (name, basetype), 2423 base_fndecls); 2424 } 2425 2426 /* If there are no functions to hide, continue. */ 2427 if (!base_fndecls) 2428 continue; 2429 2430 /* Remove any overridden functions. */ 2431 for (fn = fns; fn; fn = OVL_NEXT (fn)) 2432 { 2433 fndecl = OVL_CURRENT (fn); 2434 if (DECL_VINDEX (fndecl)) 2435 { 2436 tree *prev = &base_fndecls; 2437 2438 while (*prev) 2439 /* If the method from the base class has the same 2440 signature as the method from the derived class, it 2441 has been overridden. */ 2442 if (same_signature_p (fndecl, TREE_VALUE (*prev))) 2443 *prev = TREE_CHAIN (*prev); 2444 else 2445 prev = &TREE_CHAIN (*prev); 2446 } 2447 } 2448 2449 /* Now give a warning for all base functions without overriders, 2450 as they are hidden. */ 2451 while (base_fndecls) 2452 { 2453 /* Here we know it is a hider, and no overrider exists. */ 2454 warning (0, "%q+D was hidden", TREE_VALUE (base_fndecls)); 2455 warning (0, " by %q+D", fns); 2456 base_fndecls = TREE_CHAIN (base_fndecls); 2457 } 2458 } 2459} 2460 2461/* Check for things that are invalid. There are probably plenty of other 2462 things we should check for also. */ 2463 2464static void 2465finish_struct_anon (tree t) 2466{ 2467 tree field; 2468 2469 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field)) 2470 { 2471 if (TREE_STATIC (field)) 2472 continue; 2473 if (TREE_CODE (field) != FIELD_DECL) 2474 continue; 2475 2476 if (DECL_NAME (field) == NULL_TREE 2477 && ANON_AGGR_TYPE_P (TREE_TYPE (field))) 2478 { 2479 tree elt = TYPE_FIELDS (TREE_TYPE (field)); 2480 for (; elt; elt = TREE_CHAIN (elt)) 2481 { 2482 /* We're generally only interested in entities the user 2483 declared, but we also find nested classes by noticing 2484 the TYPE_DECL that we create implicitly. You're 2485 allowed to put one anonymous union inside another, 2486 though, so we explicitly tolerate that. We use 2487 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that 2488 we also allow unnamed types used for defining fields. */ 2489 if (DECL_ARTIFICIAL (elt) 2490 && (!DECL_IMPLICIT_TYPEDEF_P (elt) 2491 || TYPE_ANONYMOUS_P (TREE_TYPE (elt)))) 2492 continue; 2493 2494 if (TREE_CODE (elt) != FIELD_DECL) 2495 { 2496 pedwarn ("%q+#D invalid; an anonymous union can " 2497 "only have non-static data members", elt); 2498 continue; 2499 } 2500 2501 if (TREE_PRIVATE (elt)) 2502 pedwarn ("private member %q+#D in anonymous union", elt); 2503 else if (TREE_PROTECTED (elt)) 2504 pedwarn ("protected member %q+#D in anonymous union", elt); 2505 2506 TREE_PRIVATE (elt) = TREE_PRIVATE (field); 2507 TREE_PROTECTED (elt) = TREE_PROTECTED (field); 2508 } 2509 } 2510 } 2511} 2512 2513/* Add T to CLASSTYPE_DECL_LIST of current_class_type which 2514 will be used later during class template instantiation. 2515 When FRIEND_P is zero, T can be a static member data (VAR_DECL), 2516 a non-static member data (FIELD_DECL), a member function 2517 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE), 2518 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL) 2519 When FRIEND_P is nonzero, T is either a friend class 2520 (RECORD_TYPE, TEMPLATE_DECL) or a friend function 2521 (FUNCTION_DECL, TEMPLATE_DECL). */ 2522 2523void 2524maybe_add_class_template_decl_list (tree type, tree t, int friend_p) 2525{ 2526 /* Save some memory by not creating TREE_LIST if TYPE is not template. */ 2527 if (CLASSTYPE_TEMPLATE_INFO (type)) 2528 CLASSTYPE_DECL_LIST (type) 2529 = tree_cons (friend_p ? NULL_TREE : type, 2530 t, CLASSTYPE_DECL_LIST (type)); 2531} 2532 2533/* Create default constructors, assignment operators, and so forth for 2534 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR, 2535 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason, 2536 the class cannot have a default constructor, copy constructor 2537 taking a const reference argument, or an assignment operator taking 2538 a const reference, respectively. */ 2539 2540static void 2541add_implicitly_declared_members (tree t, 2542 int cant_have_const_cctor, 2543 int cant_have_const_assignment) 2544{ 2545 /* Destructor. */ 2546 if (!CLASSTYPE_DESTRUCTORS (t)) 2547 { 2548 /* In general, we create destructors lazily. */ 2549 CLASSTYPE_LAZY_DESTRUCTOR (t) = 1; 2550 /* However, if the implicit destructor is non-trivial 2551 destructor, we sometimes have to create it at this point. */ 2552 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)) 2553 { 2554 bool lazy_p = true; 2555 2556 /* APPLE LOCAL begin omit calls to empty destructors 5559195 */ 2557 /* Since this is an empty destructor, it can only be nontrivial 2558 because one of its base classes has a destructor that must be 2559 called. */ 2560 CLASSTYPE_DESTRUCTOR_NONTRIVIAL_BECAUSE_OF_BASE (t) = 1; 2561 /* APPLE LOCAL end omit calls to empty destructors 5559195 */ 2562 2563 if (TYPE_FOR_JAVA (t)) 2564 /* If this a Java class, any non-trivial destructor is 2565 invalid, even if compiler-generated. Therefore, if the 2566 destructor is non-trivial we create it now. */ 2567 lazy_p = false; 2568 else 2569 { 2570 tree binfo; 2571 tree base_binfo; 2572 int ix; 2573 2574 /* If the implicit destructor will be virtual, then we must 2575 generate it now because (unfortunately) we do not 2576 generate virtual tables lazily. */ 2577 binfo = TYPE_BINFO (t); 2578 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++) 2579 { 2580 tree base_type; 2581 tree dtor; 2582 2583 base_type = BINFO_TYPE (base_binfo); 2584 dtor = CLASSTYPE_DESTRUCTORS (base_type); 2585 if (dtor && DECL_VIRTUAL_P (dtor)) 2586 { 2587 lazy_p = false; 2588 break; 2589 } 2590 } 2591 } 2592 2593 /* If we can't get away with being lazy, generate the destructor 2594 now. */ 2595 if (!lazy_p) 2596 lazily_declare_fn (sfk_destructor, t); 2597 } 2598 } 2599 2600 /* Default constructor. */ 2601 if (! TYPE_HAS_CONSTRUCTOR (t)) 2602 { 2603 TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 1; 2604 CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 1; 2605 } 2606 2607 /* Copy constructor. */ 2608 if (! TYPE_HAS_INIT_REF (t) && ! TYPE_FOR_JAVA (t)) 2609 { 2610 TYPE_HAS_INIT_REF (t) = 1; 2611 TYPE_HAS_CONST_INIT_REF (t) = !cant_have_const_cctor; 2612 CLASSTYPE_LAZY_COPY_CTOR (t) = 1; 2613 TYPE_HAS_CONSTRUCTOR (t) = 1; 2614 } 2615 2616 /* If there is no assignment operator, one will be created if and 2617 when it is needed. For now, just record whether or not the type 2618 of the parameter to the assignment operator will be a const or 2619 non-const reference. */ 2620 if (!TYPE_HAS_ASSIGN_REF (t) && !TYPE_FOR_JAVA (t)) 2621 { 2622 TYPE_HAS_ASSIGN_REF (t) = 1; 2623 TYPE_HAS_CONST_ASSIGN_REF (t) = !cant_have_const_assignment; 2624 CLASSTYPE_LAZY_ASSIGNMENT_OP (t) = 1; 2625 } 2626} 2627 2628/* Subroutine of finish_struct_1. Recursively count the number of fields 2629 in TYPE, including anonymous union members. */ 2630 2631static int 2632count_fields (tree fields) 2633{ 2634 tree x; 2635 int n_fields = 0; 2636 for (x = fields; x; x = TREE_CHAIN (x)) 2637 { 2638 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x))) 2639 n_fields += count_fields (TYPE_FIELDS (TREE_TYPE (x))); 2640 else 2641 n_fields += 1; 2642 } 2643 return n_fields; 2644} 2645 2646/* Subroutine of finish_struct_1. Recursively add all the fields in the 2647 TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX. */ 2648 2649static int 2650add_fields_to_record_type (tree fields, struct sorted_fields_type *field_vec, int idx) 2651{ 2652 tree x; 2653 for (x = fields; x; x = TREE_CHAIN (x)) 2654 { 2655 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x))) 2656 idx = add_fields_to_record_type (TYPE_FIELDS (TREE_TYPE (x)), field_vec, idx); 2657 else 2658 field_vec->elts[idx++] = x; 2659 } 2660 return idx; 2661} 2662 2663/* FIELD is a bit-field. We are finishing the processing for its 2664 enclosing type. Issue any appropriate messages and set appropriate 2665 flags. */ 2666 2667static void 2668check_bitfield_decl (tree field) 2669{ 2670 tree type = TREE_TYPE (field); 2671 tree w; 2672 2673 /* Extract the declared width of the bitfield, which has been 2674 temporarily stashed in DECL_INITIAL. */ 2675 w = DECL_INITIAL (field); 2676 gcc_assert (w != NULL_TREE); 2677 /* Remove the bit-field width indicator so that the rest of the 2678 compiler does not treat that value as an initializer. */ 2679 DECL_INITIAL (field) = NULL_TREE; 2680 2681 /* Detect invalid bit-field type. */ 2682 if (!INTEGRAL_TYPE_P (type)) 2683 { 2684 error ("bit-field %q+#D with non-integral type", field); 2685 TREE_TYPE (field) = error_mark_node; 2686 w = error_mark_node; 2687 } 2688 else 2689 { 2690 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */ 2691 STRIP_NOPS (w); 2692 2693 /* detect invalid field size. */ 2694 w = integral_constant_value (w); 2695 2696 if (TREE_CODE (w) != INTEGER_CST) 2697 { 2698 error ("bit-field %q+D width not an integer constant", field); 2699 w = error_mark_node; 2700 } 2701 else if (tree_int_cst_sgn (w) < 0) 2702 { 2703 error ("negative width in bit-field %q+D", field); 2704 w = error_mark_node; 2705 } 2706 else if (integer_zerop (w) && DECL_NAME (field) != 0) 2707 { 2708 error ("zero width for bit-field %q+D", field); 2709 w = error_mark_node; 2710 } 2711 else if (compare_tree_int (w, TYPE_PRECISION (type)) > 0 2712 && TREE_CODE (type) != ENUMERAL_TYPE 2713 && TREE_CODE (type) != BOOLEAN_TYPE) 2714 warning (0, "width of %q+D exceeds its type", field); 2715 else if (TREE_CODE (type) == ENUMERAL_TYPE 2716 && (0 > compare_tree_int (w, 2717 min_precision (TYPE_MIN_VALUE (type), 2718 TYPE_UNSIGNED (type))) 2719 || 0 > compare_tree_int (w, 2720 min_precision 2721 (TYPE_MAX_VALUE (type), 2722 TYPE_UNSIGNED (type))))) 2723 warning (0, "%q+D is too small to hold all values of %q#T", field, type); 2724 } 2725 2726 if (w != error_mark_node) 2727 { 2728 DECL_SIZE (field) = convert (bitsizetype, w); 2729 DECL_BIT_FIELD (field) = 1; 2730 } 2731 else 2732 { 2733 /* Non-bit-fields are aligned for their type. */ 2734 DECL_BIT_FIELD (field) = 0; 2735 CLEAR_DECL_C_BIT_FIELD (field); 2736 } 2737} 2738 2739/* FIELD is a non bit-field. We are finishing the processing for its 2740 enclosing type T. Issue any appropriate messages and set appropriate 2741 flags. */ 2742 2743static void 2744check_field_decl (tree field, 2745 tree t, 2746 int* cant_have_const_ctor, 2747 int* no_const_asn_ref, 2748 int* any_default_members) 2749{ 2750 tree type = strip_array_types (TREE_TYPE (field)); 2751 2752 /* An anonymous union cannot contain any fields which would change 2753 the settings of CANT_HAVE_CONST_CTOR and friends. */ 2754 if (ANON_UNION_TYPE_P (type)) 2755 ; 2756 /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous 2757 structs. So, we recurse through their fields here. */ 2758 else if (ANON_AGGR_TYPE_P (type)) 2759 { 2760 tree fields; 2761 2762 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields)) 2763 if (TREE_CODE (fields) == FIELD_DECL && !DECL_C_BIT_FIELD (field)) 2764 check_field_decl (fields, t, cant_have_const_ctor, 2765 no_const_asn_ref, any_default_members); 2766 } 2767 /* Check members with class type for constructors, destructors, 2768 etc. */ 2769 else if (CLASS_TYPE_P (type)) 2770 { 2771 /* Never let anything with uninheritable virtuals 2772 make it through without complaint. */ 2773 abstract_virtuals_error (field, type); 2774 2775 if (TREE_CODE (t) == UNION_TYPE) 2776 { 2777 if (TYPE_NEEDS_CONSTRUCTING (type)) 2778 error ("member %q+#D with constructor not allowed in union", 2779 field); 2780 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 2781 error ("member %q+#D with destructor not allowed in union", field); 2782 if (TYPE_HAS_COMPLEX_ASSIGN_REF (type)) 2783 error ("member %q+#D with copy assignment operator not allowed in union", 2784 field); 2785 } 2786 else 2787 { 2788 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (type); 2789 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) 2790 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type); 2791 TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_HAS_COMPLEX_ASSIGN_REF (type); 2792 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (type); 2793 } 2794 2795 if (!TYPE_HAS_CONST_INIT_REF (type)) 2796 *cant_have_const_ctor = 1; 2797 2798 if (!TYPE_HAS_CONST_ASSIGN_REF (type)) 2799 *no_const_asn_ref = 1; 2800 } 2801 if (DECL_INITIAL (field) != NULL_TREE) 2802 { 2803 /* `build_class_init_list' does not recognize 2804 non-FIELD_DECLs. */ 2805 if (TREE_CODE (t) == UNION_TYPE && any_default_members != 0) 2806 error ("multiple fields in union %qT initialized", t); 2807 *any_default_members = 1; 2808 } 2809} 2810 2811/* Check the data members (both static and non-static), class-scoped 2812 typedefs, etc., appearing in the declaration of T. Issue 2813 appropriate diagnostics. Sets ACCESS_DECLS to a list (in 2814 declaration order) of access declarations; each TREE_VALUE in this 2815 list is a USING_DECL. 2816 2817 In addition, set the following flags: 2818 2819 EMPTY_P 2820 The class is empty, i.e., contains no non-static data members. 2821 2822 CANT_HAVE_CONST_CTOR_P 2823 This class cannot have an implicitly generated copy constructor 2824 taking a const reference. 2825 2826 CANT_HAVE_CONST_ASN_REF 2827 This class cannot have an implicitly generated assignment 2828 operator taking a const reference. 2829 2830 All of these flags should be initialized before calling this 2831 function. 2832 2833 Returns a pointer to the end of the TYPE_FIELDs chain; additional 2834 fields can be added by adding to this chain. */ 2835 2836static void 2837check_field_decls (tree t, tree *access_decls, 2838 int *cant_have_const_ctor_p, 2839 int *no_const_asn_ref_p) 2840{ 2841 tree *field; 2842 tree *next; 2843 bool has_pointers; 2844 int any_default_members; 2845 int cant_pack = 0; 2846 2847 /* Assume there are no access declarations. */ 2848 *access_decls = NULL_TREE; 2849 /* Assume this class has no pointer members. */ 2850 has_pointers = false; 2851 /* Assume none of the members of this class have default 2852 initializations. */ 2853 any_default_members = 0; 2854 2855 for (field = &TYPE_FIELDS (t); *field; field = next) 2856 { 2857 tree x = *field; 2858 tree type = TREE_TYPE (x); 2859 2860 next = &TREE_CHAIN (x); 2861 2862 if (TREE_CODE (x) == USING_DECL) 2863 { 2864 /* Prune the access declaration from the list of fields. */ 2865 *field = TREE_CHAIN (x); 2866 2867 /* Save the access declarations for our caller. */ 2868 *access_decls = tree_cons (NULL_TREE, x, *access_decls); 2869 2870 /* Since we've reset *FIELD there's no reason to skip to the 2871 next field. */ 2872 next = field; 2873 continue; 2874 } 2875 2876 if (TREE_CODE (x) == TYPE_DECL 2877 || TREE_CODE (x) == TEMPLATE_DECL) 2878 continue; 2879 2880 /* If we've gotten this far, it's a data member, possibly static, 2881 or an enumerator. */ 2882 DECL_CONTEXT (x) = t; 2883 2884 /* When this goes into scope, it will be a non-local reference. */ 2885 DECL_NONLOCAL (x) = 1; 2886 2887 if (TREE_CODE (t) == UNION_TYPE) 2888 { 2889 /* [class.union] 2890 2891 If a union contains a static data member, or a member of 2892 reference type, the program is ill-formed. */ 2893 if (TREE_CODE (x) == VAR_DECL) 2894 { 2895 error ("%q+D may not be static because it is a member of a union", x); 2896 continue; 2897 } 2898 if (TREE_CODE (type) == REFERENCE_TYPE) 2899 { 2900 error ("%q+D may not have reference type %qT because" 2901 " it is a member of a union", 2902 x, type); 2903 continue; 2904 } 2905 } 2906 2907 /* Perform error checking that did not get done in 2908 grokdeclarator. */ 2909 if (TREE_CODE (type) == FUNCTION_TYPE) 2910 { 2911 error ("field %q+D invalidly declared function type", x); 2912 type = build_pointer_type (type); 2913 TREE_TYPE (x) = type; 2914 } 2915 else if (TREE_CODE (type) == METHOD_TYPE) 2916 { 2917 error ("field %q+D invalidly declared method type", x); 2918 type = build_pointer_type (type); 2919 TREE_TYPE (x) = type; 2920 } 2921 2922 if (type == error_mark_node) 2923 continue; 2924 2925 if (TREE_CODE (x) == CONST_DECL || TREE_CODE (x) == VAR_DECL) 2926 continue; 2927 2928 /* Now it can only be a FIELD_DECL. */ 2929 2930 if (TREE_PRIVATE (x) || TREE_PROTECTED (x)) 2931 CLASSTYPE_NON_AGGREGATE (t) = 1; 2932 2933 /* If this is of reference type, check if it needs an init. 2934 Also do a little ANSI jig if necessary. */ 2935 if (TREE_CODE (type) == REFERENCE_TYPE) 2936 { 2937 CLASSTYPE_NON_POD_P (t) = 1; 2938 if (DECL_INITIAL (x) == NULL_TREE) 2939 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1); 2940 2941 /* ARM $12.6.2: [A member initializer list] (or, for an 2942 aggregate, initialization by a brace-enclosed list) is the 2943 only way to initialize nonstatic const and reference 2944 members. */ 2945 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1; 2946 2947 if (! TYPE_HAS_CONSTRUCTOR (t) && CLASSTYPE_NON_AGGREGATE (t) 2948 && extra_warnings) 2949 warning (OPT_Wextra, "non-static reference %q+#D in class without a constructor", x); 2950 } 2951 2952 type = strip_array_types (type); 2953 2954 if (TYPE_PACKED (t)) 2955 { 2956 if (!pod_type_p (type) && !TYPE_PACKED (type)) 2957 { 2958 warning 2959 (0, 2960 "ignoring packed attribute because of unpacked non-POD field %q+#D", 2961 x); 2962 cant_pack = 1; 2963 } 2964 else if (TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT) 2965 DECL_PACKED (x) = 1; 2966 } 2967 2968 if (DECL_C_BIT_FIELD (x) && integer_zerop (DECL_INITIAL (x))) 2969 /* We don't treat zero-width bitfields as making a class 2970 non-empty. */ 2971 ; 2972 else 2973 { 2974 /* The class is non-empty. */ 2975 CLASSTYPE_EMPTY_P (t) = 0; 2976 /* The class is not even nearly empty. */ 2977 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 2978 /* If one of the data members contains an empty class, 2979 so does T. */ 2980 if (CLASS_TYPE_P (type) 2981 && CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type)) 2982 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1; 2983 } 2984 2985 /* This is used by -Weffc++ (see below). Warn only for pointers 2986 to members which might hold dynamic memory. So do not warn 2987 for pointers to functions or pointers to members. */ 2988 if (TYPE_PTR_P (type) 2989 && !TYPE_PTRFN_P (type) 2990 && !TYPE_PTR_TO_MEMBER_P (type)) 2991 has_pointers = true; 2992 2993 if (CLASS_TYPE_P (type)) 2994 { 2995 if (CLASSTYPE_REF_FIELDS_NEED_INIT (type)) 2996 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1); 2997 if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (type)) 2998 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1); 2999 } 3000 3001 if (DECL_MUTABLE_P (x) || TYPE_HAS_MUTABLE_P (type)) 3002 CLASSTYPE_HAS_MUTABLE (t) = 1; 3003 3004 if (! pod_type_p (type)) 3005 /* DR 148 now allows pointers to members (which are POD themselves), 3006 to be allowed in POD structs. */ 3007 CLASSTYPE_NON_POD_P (t) = 1; 3008 3009 if (! zero_init_p (type)) 3010 CLASSTYPE_NON_ZERO_INIT_P (t) = 1; 3011 3012 /* If any field is const, the structure type is pseudo-const. */ 3013 if (CP_TYPE_CONST_P (type)) 3014 { 3015 C_TYPE_FIELDS_READONLY (t) = 1; 3016 if (DECL_INITIAL (x) == NULL_TREE) 3017 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1); 3018 3019 /* ARM $12.6.2: [A member initializer list] (or, for an 3020 aggregate, initialization by a brace-enclosed list) is the 3021 only way to initialize nonstatic const and reference 3022 members. */ 3023 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1; 3024 3025 if (! TYPE_HAS_CONSTRUCTOR (t) && CLASSTYPE_NON_AGGREGATE (t) 3026 && extra_warnings) 3027 warning (OPT_Wextra, "non-static const member %q+#D in class without a constructor", x); 3028 } 3029 /* A field that is pseudo-const makes the structure likewise. */ 3030 else if (CLASS_TYPE_P (type)) 3031 { 3032 C_TYPE_FIELDS_READONLY (t) |= C_TYPE_FIELDS_READONLY (type); 3033 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 3034 CLASSTYPE_READONLY_FIELDS_NEED_INIT (t) 3035 | CLASSTYPE_READONLY_FIELDS_NEED_INIT (type)); 3036 } 3037 3038 /* Core issue 80: A nonstatic data member is required to have a 3039 different name from the class iff the class has a 3040 user-defined constructor. */ 3041 if (constructor_name_p (DECL_NAME (x), t) && TYPE_HAS_CONSTRUCTOR (t)) 3042 pedwarn ("field %q+#D with same name as class", x); 3043 3044 /* We set DECL_C_BIT_FIELD in grokbitfield. 3045 If the type and width are valid, we'll also set DECL_BIT_FIELD. */ 3046 if (DECL_C_BIT_FIELD (x)) 3047 check_bitfield_decl (x); 3048 else 3049 check_field_decl (x, t, 3050 cant_have_const_ctor_p, 3051 no_const_asn_ref_p, 3052 &any_default_members); 3053 } 3054 3055 /* Effective C++ rule 11: if a class has dynamic memory held by pointers, 3056 it should also define a copy constructor and an assignment operator to 3057 implement the correct copy semantic (deep vs shallow, etc.). As it is 3058 not feasible to check whether the constructors do allocate dynamic memory 3059 and store it within members, we approximate the warning like this: 3060 3061 -- Warn only if there are members which are pointers 3062 -- Warn only if there is a non-trivial constructor (otherwise, 3063 there cannot be memory allocated). 3064 -- Warn only if there is a non-trivial destructor. We assume that the 3065 user at least implemented the cleanup correctly, and a destructor 3066 is needed to free dynamic memory. 3067 3068 This seems enough for practical purposes. */ 3069 if (warn_ecpp 3070 && has_pointers 3071 && TYPE_HAS_CONSTRUCTOR (t) 3072 && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) 3073 && !(TYPE_HAS_INIT_REF (t) && TYPE_HAS_ASSIGN_REF (t))) 3074 { 3075 warning (OPT_Weffc__, "%q#T has pointer data members", t); 3076 3077 if (! TYPE_HAS_INIT_REF (t)) 3078 { 3079 warning (OPT_Weffc__, 3080 " but does not override %<%T(const %T&)%>", t, t); 3081 if (!TYPE_HAS_ASSIGN_REF (t)) 3082 warning (OPT_Weffc__, " or %<operator=(const %T&)%>", t); 3083 } 3084 else if (! TYPE_HAS_ASSIGN_REF (t)) 3085 warning (OPT_Weffc__, 3086 " but does not override %<operator=(const %T&)%>", t); 3087 } 3088 3089 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */ 3090 if (cant_pack) 3091 TYPE_PACKED (t) = 0; 3092 3093 /* Check anonymous struct/anonymous union fields. */ 3094 finish_struct_anon (t); 3095 3096 /* We've built up the list of access declarations in reverse order. 3097 Fix that now. */ 3098 *access_decls = nreverse (*access_decls); 3099} 3100 3101/* If TYPE is an empty class type, records its OFFSET in the table of 3102 OFFSETS. */ 3103 3104static int 3105record_subobject_offset (tree type, tree offset, splay_tree offsets) 3106{ 3107 splay_tree_node n; 3108 3109 if (!is_empty_class (type)) 3110 return 0; 3111 3112 /* Record the location of this empty object in OFFSETS. */ 3113 n = splay_tree_lookup (offsets, (splay_tree_key) offset); 3114 if (!n) 3115 n = splay_tree_insert (offsets, 3116 (splay_tree_key) offset, 3117 (splay_tree_value) NULL_TREE); 3118 n->value = ((splay_tree_value) 3119 tree_cons (NULL_TREE, 3120 type, 3121 (tree) n->value)); 3122 3123 return 0; 3124} 3125 3126/* Returns nonzero if TYPE is an empty class type and there is 3127 already an entry in OFFSETS for the same TYPE as the same OFFSET. */ 3128 3129static int 3130check_subobject_offset (tree type, tree offset, splay_tree offsets) 3131{ 3132 splay_tree_node n; 3133 tree t; 3134 3135 if (!is_empty_class (type)) 3136 return 0; 3137 3138 /* Record the location of this empty object in OFFSETS. */ 3139 n = splay_tree_lookup (offsets, (splay_tree_key) offset); 3140 if (!n) 3141 return 0; 3142 3143 for (t = (tree) n->value; t; t = TREE_CHAIN (t)) 3144 if (same_type_p (TREE_VALUE (t), type)) 3145 return 1; 3146 3147 return 0; 3148} 3149 3150/* Walk through all the subobjects of TYPE (located at OFFSET). Call 3151 F for every subobject, passing it the type, offset, and table of 3152 OFFSETS. If VBASES_P is one, then virtual non-primary bases should 3153 be traversed. 3154 3155 If MAX_OFFSET is non-NULL, then subobjects with an offset greater 3156 than MAX_OFFSET will not be walked. 3157 3158 If F returns a nonzero value, the traversal ceases, and that value 3159 is returned. Otherwise, returns zero. */ 3160 3161static int 3162walk_subobject_offsets (tree type, 3163 subobject_offset_fn f, 3164 tree offset, 3165 splay_tree offsets, 3166 tree max_offset, 3167 int vbases_p) 3168{ 3169 int r = 0; 3170 tree type_binfo = NULL_TREE; 3171 3172 /* If this OFFSET is bigger than the MAX_OFFSET, then we should 3173 stop. */ 3174 if (max_offset && INT_CST_LT (max_offset, offset)) 3175 return 0; 3176 3177 if (type == error_mark_node) 3178 return 0; 3179 3180 if (!TYPE_P (type)) 3181 { 3182 if (abi_version_at_least (2)) 3183 type_binfo = type; 3184 type = BINFO_TYPE (type); 3185 } 3186 3187 if (CLASS_TYPE_P (type)) 3188 { 3189 tree field; 3190 tree binfo; 3191 int i; 3192 3193 /* Avoid recursing into objects that are not interesting. */ 3194 if (!CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type)) 3195 return 0; 3196 3197 /* Record the location of TYPE. */ 3198 r = (*f) (type, offset, offsets); 3199 if (r) 3200 return r; 3201 3202 /* Iterate through the direct base classes of TYPE. */ 3203 if (!type_binfo) 3204 type_binfo = TYPE_BINFO (type); 3205 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, binfo); i++) 3206 { 3207 tree binfo_offset; 3208 3209 if (abi_version_at_least (2) 3210 && BINFO_VIRTUAL_P (binfo)) 3211 continue; 3212 3213 if (!vbases_p 3214 && BINFO_VIRTUAL_P (binfo) 3215 && !BINFO_PRIMARY_P (binfo)) 3216 continue; 3217 3218 if (!abi_version_at_least (2)) 3219 binfo_offset = size_binop (PLUS_EXPR, 3220 offset, 3221 BINFO_OFFSET (binfo)); 3222 else 3223 { 3224 tree orig_binfo; 3225 /* We cannot rely on BINFO_OFFSET being set for the base 3226 class yet, but the offsets for direct non-virtual 3227 bases can be calculated by going back to the TYPE. */ 3228 orig_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), i); 3229 binfo_offset = size_binop (PLUS_EXPR, 3230 offset, 3231 BINFO_OFFSET (orig_binfo)); 3232 } 3233 3234 r = walk_subobject_offsets (binfo, 3235 f, 3236 binfo_offset, 3237 offsets, 3238 max_offset, 3239 (abi_version_at_least (2) 3240 ? /*vbases_p=*/0 : vbases_p)); 3241 if (r) 3242 return r; 3243 } 3244 3245 if (abi_version_at_least (2) && CLASSTYPE_VBASECLASSES (type)) 3246 { 3247 unsigned ix; 3248 VEC(tree,gc) *vbases; 3249 3250 /* Iterate through the virtual base classes of TYPE. In G++ 3251 3.2, we included virtual bases in the direct base class 3252 loop above, which results in incorrect results; the 3253 correct offsets for virtual bases are only known when 3254 working with the most derived type. */ 3255 if (vbases_p) 3256 for (vbases = CLASSTYPE_VBASECLASSES (type), ix = 0; 3257 VEC_iterate (tree, vbases, ix, binfo); ix++) 3258 { 3259 r = walk_subobject_offsets (binfo, 3260 f, 3261 size_binop (PLUS_EXPR, 3262 offset, 3263 BINFO_OFFSET (binfo)), 3264 offsets, 3265 max_offset, 3266 /*vbases_p=*/0); 3267 if (r) 3268 return r; 3269 } 3270 else 3271 { 3272 /* We still have to walk the primary base, if it is 3273 virtual. (If it is non-virtual, then it was walked 3274 above.) */ 3275 tree vbase = get_primary_binfo (type_binfo); 3276 3277 if (vbase && BINFO_VIRTUAL_P (vbase) 3278 && BINFO_PRIMARY_P (vbase) 3279 && BINFO_INHERITANCE_CHAIN (vbase) == type_binfo) 3280 { 3281 r = (walk_subobject_offsets 3282 (vbase, f, offset, 3283 offsets, max_offset, /*vbases_p=*/0)); 3284 if (r) 3285 return r; 3286 } 3287 } 3288 } 3289 3290 /* Iterate through the fields of TYPE. */ 3291 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) 3292 if (TREE_CODE (field) == FIELD_DECL && !DECL_ARTIFICIAL (field)) 3293 { 3294 tree field_offset; 3295 3296 if (abi_version_at_least (2)) 3297 field_offset = byte_position (field); 3298 else 3299 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */ 3300 field_offset = DECL_FIELD_OFFSET (field); 3301 3302 r = walk_subobject_offsets (TREE_TYPE (field), 3303 f, 3304 size_binop (PLUS_EXPR, 3305 offset, 3306 field_offset), 3307 offsets, 3308 max_offset, 3309 /*vbases_p=*/1); 3310 if (r) 3311 return r; 3312 } 3313 } 3314 else if (TREE_CODE (type) == ARRAY_TYPE) 3315 { 3316 tree element_type = strip_array_types (type); 3317 tree domain = TYPE_DOMAIN (type); 3318 tree index; 3319 3320 /* Avoid recursing into objects that are not interesting. */ 3321 if (!CLASS_TYPE_P (element_type) 3322 || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type)) 3323 return 0; 3324 3325 /* Step through each of the elements in the array. */ 3326 for (index = size_zero_node; 3327 /* G++ 3.2 had an off-by-one error here. */ 3328 (abi_version_at_least (2) 3329 ? !INT_CST_LT (TYPE_MAX_VALUE (domain), index) 3330 : INT_CST_LT (index, TYPE_MAX_VALUE (domain))); 3331 index = size_binop (PLUS_EXPR, index, size_one_node)) 3332 { 3333 r = walk_subobject_offsets (TREE_TYPE (type), 3334 f, 3335 offset, 3336 offsets, 3337 max_offset, 3338 /*vbases_p=*/1); 3339 if (r) 3340 return r; 3341 offset = size_binop (PLUS_EXPR, offset, 3342 TYPE_SIZE_UNIT (TREE_TYPE (type))); 3343 /* If this new OFFSET is bigger than the MAX_OFFSET, then 3344 there's no point in iterating through the remaining 3345 elements of the array. */ 3346 if (max_offset && INT_CST_LT (max_offset, offset)) 3347 break; 3348 } 3349 } 3350 3351 return 0; 3352} 3353 3354/* Record all of the empty subobjects of TYPE (either a type or a 3355 binfo). If IS_DATA_MEMBER is true, then a non-static data member 3356 is being placed at OFFSET; otherwise, it is a base class that is 3357 being placed at OFFSET. */ 3358 3359static void 3360record_subobject_offsets (tree type, 3361 tree offset, 3362 splay_tree offsets, 3363 bool is_data_member) 3364{ 3365 tree max_offset; 3366 /* If recording subobjects for a non-static data member or a 3367 non-empty base class , we do not need to record offsets beyond 3368 the size of the biggest empty class. Additional data members 3369 will go at the end of the class. Additional base classes will go 3370 either at offset zero (if empty, in which case they cannot 3371 overlap with offsets past the size of the biggest empty class) or 3372 at the end of the class. 3373 3374 However, if we are placing an empty base class, then we must record 3375 all offsets, as either the empty class is at offset zero (where 3376 other empty classes might later be placed) or at the end of the 3377 class (where other objects might then be placed, so other empty 3378 subobjects might later overlap). */ 3379 if (is_data_member 3380 || !is_empty_class (BINFO_TYPE (type))) 3381 max_offset = sizeof_biggest_empty_class; 3382 else 3383 max_offset = NULL_TREE; 3384 walk_subobject_offsets (type, record_subobject_offset, offset, 3385 offsets, max_offset, is_data_member); 3386} 3387 3388/* Returns nonzero if any of the empty subobjects of TYPE (located at 3389 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero, 3390 virtual bases of TYPE are examined. */ 3391 3392static int 3393layout_conflict_p (tree type, 3394 tree offset, 3395 splay_tree offsets, 3396 int vbases_p) 3397{ 3398 splay_tree_node max_node; 3399 3400 /* Get the node in OFFSETS that indicates the maximum offset where 3401 an empty subobject is located. */ 3402 max_node = splay_tree_max (offsets); 3403 /* If there aren't any empty subobjects, then there's no point in 3404 performing this check. */ 3405 if (!max_node) 3406 return 0; 3407 3408 return walk_subobject_offsets (type, check_subobject_offset, offset, 3409 offsets, (tree) (max_node->key), 3410 vbases_p); 3411} 3412 3413/* DECL is a FIELD_DECL corresponding either to a base subobject of a 3414 non-static data member of the type indicated by RLI. BINFO is the 3415 binfo corresponding to the base subobject, OFFSETS maps offsets to 3416 types already located at those offsets. This function determines 3417 the position of the DECL. */ 3418 3419static void 3420layout_nonempty_base_or_field (record_layout_info rli, 3421 tree decl, 3422 tree binfo, 3423 splay_tree offsets) 3424{ 3425 tree offset = NULL_TREE; 3426 bool field_p; 3427 tree type; 3428 3429 if (binfo) 3430 { 3431 /* For the purposes of determining layout conflicts, we want to 3432 use the class type of BINFO; TREE_TYPE (DECL) will be the 3433 CLASSTYPE_AS_BASE version, which does not contain entries for 3434 zero-sized bases. */ 3435 type = TREE_TYPE (binfo); 3436 field_p = false; 3437 } 3438 else 3439 { 3440 type = TREE_TYPE (decl); 3441 field_p = true; 3442 } 3443 3444 /* Try to place the field. It may take more than one try if we have 3445 a hard time placing the field without putting two objects of the 3446 same type at the same address. */ 3447 while (1) 3448 { 3449 struct record_layout_info_s old_rli = *rli; 3450 3451 /* Place this field. */ 3452 place_field (rli, decl); 3453 offset = byte_position (decl); 3454 3455 /* We have to check to see whether or not there is already 3456 something of the same type at the offset we're about to use. 3457 For example, consider: 3458 3459 struct S {}; 3460 struct T : public S { int i; }; 3461 struct U : public S, public T {}; 3462 3463 Here, we put S at offset zero in U. Then, we can't put T at 3464 offset zero -- its S component would be at the same address 3465 as the S we already allocated. So, we have to skip ahead. 3466 Since all data members, including those whose type is an 3467 empty class, have nonzero size, any overlap can happen only 3468 with a direct or indirect base-class -- it can't happen with 3469 a data member. */ 3470 /* In a union, overlap is permitted; all members are placed at 3471 offset zero. */ 3472 if (TREE_CODE (rli->t) == UNION_TYPE) 3473 break; 3474 /* G++ 3.2 did not check for overlaps when placing a non-empty 3475 virtual base. */ 3476 if (!abi_version_at_least (2) && binfo && BINFO_VIRTUAL_P (binfo)) 3477 break; 3478 if (layout_conflict_p (field_p ? type : binfo, offset, 3479 offsets, field_p)) 3480 { 3481 /* Strip off the size allocated to this field. That puts us 3482 at the first place we could have put the field with 3483 proper alignment. */ 3484 *rli = old_rli; 3485 3486 /* Bump up by the alignment required for the type. */ 3487 rli->bitpos 3488 = size_binop (PLUS_EXPR, rli->bitpos, 3489 bitsize_int (binfo 3490 ? CLASSTYPE_ALIGN (type) 3491 : TYPE_ALIGN (type))); 3492 normalize_rli (rli); 3493 } 3494 else 3495 /* There was no conflict. We're done laying out this field. */ 3496 break; 3497 } 3498 3499 /* Now that we know where it will be placed, update its 3500 BINFO_OFFSET. */ 3501 if (binfo && CLASS_TYPE_P (BINFO_TYPE (binfo))) 3502 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at 3503 this point because their BINFO_OFFSET is copied from another 3504 hierarchy. Therefore, we may not need to add the entire 3505 OFFSET. */ 3506 propagate_binfo_offsets (binfo, 3507 size_diffop (convert (ssizetype, offset), 3508 convert (ssizetype, 3509 BINFO_OFFSET (binfo)))); 3510} 3511 3512/* Returns true if TYPE is empty and OFFSET is nonzero. */ 3513 3514static int 3515empty_base_at_nonzero_offset_p (tree type, 3516 tree offset, 3517 splay_tree offsets ATTRIBUTE_UNUSED) 3518{ 3519 return is_empty_class (type) && !integer_zerop (offset); 3520} 3521 3522/* Layout the empty base BINFO. EOC indicates the byte currently just 3523 past the end of the class, and should be correctly aligned for a 3524 class of the type indicated by BINFO; OFFSETS gives the offsets of 3525 the empty bases allocated so far. T is the most derived 3526 type. Return nonzero iff we added it at the end. */ 3527 3528static bool 3529layout_empty_base (tree binfo, tree eoc, splay_tree offsets) 3530{ 3531 tree alignment; 3532 tree basetype = BINFO_TYPE (binfo); 3533 bool atend = false; 3534 3535 /* This routine should only be used for empty classes. */ 3536 gcc_assert (is_empty_class (basetype)); 3537 alignment = ssize_int (CLASSTYPE_ALIGN_UNIT (basetype)); 3538 3539 if (!integer_zerop (BINFO_OFFSET (binfo))) 3540 { 3541 if (abi_version_at_least (2)) 3542 propagate_binfo_offsets 3543 (binfo, size_diffop (size_zero_node, BINFO_OFFSET (binfo))); 3544 else 3545 warning (OPT_Wabi, 3546 "offset of empty base %qT may not be ABI-compliant and may" 3547 "change in a future version of GCC", 3548 BINFO_TYPE (binfo)); 3549 } 3550 3551 /* This is an empty base class. We first try to put it at offset 3552 zero. */ 3553 if (layout_conflict_p (binfo, 3554 BINFO_OFFSET (binfo), 3555 offsets, 3556 /*vbases_p=*/0)) 3557 { 3558 /* That didn't work. Now, we move forward from the next 3559 available spot in the class. */ 3560 atend = true; 3561 propagate_binfo_offsets (binfo, convert (ssizetype, eoc)); 3562 while (1) 3563 { 3564 if (!layout_conflict_p (binfo, 3565 BINFO_OFFSET (binfo), 3566 offsets, 3567 /*vbases_p=*/0)) 3568 /* We finally found a spot where there's no overlap. */ 3569 break; 3570 3571 /* There's overlap here, too. Bump along to the next spot. */ 3572 propagate_binfo_offsets (binfo, alignment); 3573 } 3574 } 3575 return atend; 3576} 3577 3578/* Layout the base given by BINFO in the class indicated by RLI. 3579 *BASE_ALIGN is a running maximum of the alignments of 3580 any base class. OFFSETS gives the location of empty base 3581 subobjects. T is the most derived type. Return nonzero if the new 3582 object cannot be nearly-empty. A new FIELD_DECL is inserted at 3583 *NEXT_FIELD, unless BINFO is for an empty base class. 3584 3585 Returns the location at which the next field should be inserted. */ 3586 3587static tree * 3588build_base_field (record_layout_info rli, tree binfo, 3589 splay_tree offsets, tree *next_field) 3590{ 3591 tree t = rli->t; 3592 tree basetype = BINFO_TYPE (binfo); 3593 3594 if (!COMPLETE_TYPE_P (basetype)) 3595 /* This error is now reported in xref_tag, thus giving better 3596 location information. */ 3597 return next_field; 3598 3599 /* Place the base class. */ 3600 if (!is_empty_class (basetype)) 3601 { 3602 tree decl; 3603 3604 /* The containing class is non-empty because it has a non-empty 3605 base class. */ 3606 CLASSTYPE_EMPTY_P (t) = 0; 3607 3608 /* Create the FIELD_DECL. */ 3609 decl = build_decl (FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype)); 3610 DECL_ARTIFICIAL (decl) = 1; 3611 DECL_IGNORED_P (decl) = 1; 3612 DECL_FIELD_CONTEXT (decl) = t; 3613 DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype); 3614 DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype); 3615 DECL_ALIGN (decl) = CLASSTYPE_ALIGN (basetype); 3616 DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype); 3617 DECL_MODE (decl) = TYPE_MODE (basetype); 3618 DECL_FIELD_IS_BASE (decl) = 1; 3619 3620 /* Try to place the field. It may take more than one try if we 3621 have a hard time placing the field without putting two 3622 objects of the same type at the same address. */ 3623 layout_nonempty_base_or_field (rli, decl, binfo, offsets); 3624 /* Add the new FIELD_DECL to the list of fields for T. */ 3625 TREE_CHAIN (decl) = *next_field; 3626 *next_field = decl; 3627 next_field = &TREE_CHAIN (decl); 3628 } 3629 else 3630 { 3631 tree eoc; 3632 bool atend; 3633 3634 /* On some platforms (ARM), even empty classes will not be 3635 byte-aligned. */ 3636 eoc = round_up (rli_size_unit_so_far (rli), 3637 CLASSTYPE_ALIGN_UNIT (basetype)); 3638 atend = layout_empty_base (binfo, eoc, offsets); 3639 /* A nearly-empty class "has no proper base class that is empty, 3640 not morally virtual, and at an offset other than zero." */ 3641 if (!BINFO_VIRTUAL_P (binfo) && CLASSTYPE_NEARLY_EMPTY_P (t)) 3642 { 3643 if (atend) 3644 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 3645 /* The check above (used in G++ 3.2) is insufficient because 3646 an empty class placed at offset zero might itself have an 3647 empty base at a nonzero offset. */ 3648 else if (walk_subobject_offsets (basetype, 3649 empty_base_at_nonzero_offset_p, 3650 size_zero_node, 3651 /*offsets=*/NULL, 3652 /*max_offset=*/NULL_TREE, 3653 /*vbases_p=*/true)) 3654 { 3655 if (abi_version_at_least (2)) 3656 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 3657 else 3658 warning (OPT_Wabi, 3659 "class %qT will be considered nearly empty in a " 3660 "future version of GCC", t); 3661 } 3662 } 3663 3664 /* We do not create a FIELD_DECL for empty base classes because 3665 it might overlap some other field. We want to be able to 3666 create CONSTRUCTORs for the class by iterating over the 3667 FIELD_DECLs, and the back end does not handle overlapping 3668 FIELD_DECLs. */ 3669 3670 /* An empty virtual base causes a class to be non-empty 3671 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P 3672 here because that was already done when the virtual table 3673 pointer was created. */ 3674 } 3675 3676 /* Record the offsets of BINFO and its base subobjects. */ 3677 record_subobject_offsets (binfo, 3678 BINFO_OFFSET (binfo), 3679 offsets, 3680 /*is_data_member=*/false); 3681 3682 return next_field; 3683} 3684 3685/* Layout all of the non-virtual base classes. Record empty 3686 subobjects in OFFSETS. T is the most derived type. Return nonzero 3687 if the type cannot be nearly empty. The fields created 3688 corresponding to the base classes will be inserted at 3689 *NEXT_FIELD. */ 3690 3691static void 3692build_base_fields (record_layout_info rli, 3693 splay_tree offsets, tree *next_field) 3694{ 3695 /* Chain to hold all the new FIELD_DECLs which stand in for base class 3696 subobjects. */ 3697 tree t = rli->t; 3698 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t)); 3699 int i; 3700 3701 /* The primary base class is always allocated first. */ 3702 if (CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 3703 next_field = build_base_field (rli, CLASSTYPE_PRIMARY_BINFO (t), 3704 offsets, next_field); 3705 3706 /* Now allocate the rest of the bases. */ 3707 for (i = 0; i < n_baseclasses; ++i) 3708 { 3709 tree base_binfo; 3710 3711 base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i); 3712 3713 /* The primary base was already allocated above, so we don't 3714 need to allocate it again here. */ 3715 if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t)) 3716 continue; 3717 3718 /* Virtual bases are added at the end (a primary virtual base 3719 will have already been added). */ 3720 if (BINFO_VIRTUAL_P (base_binfo)) 3721 continue; 3722 3723 next_field = build_base_field (rli, base_binfo, 3724 offsets, next_field); 3725 } 3726} 3727 3728/* Go through the TYPE_METHODS of T issuing any appropriate 3729 diagnostics, figuring out which methods override which other 3730 methods, and so forth. */ 3731 3732static void 3733check_methods (tree t) 3734{ 3735 tree x; 3736 3737 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x)) 3738 { 3739 check_for_override (x, t); 3740 if (DECL_PURE_VIRTUAL_P (x) && ! DECL_VINDEX (x)) 3741 error ("initializer specified for non-virtual method %q+D", x); 3742 /* The name of the field is the original field name 3743 Save this in auxiliary field for later overloading. */ 3744 if (DECL_VINDEX (x)) 3745 { 3746 TYPE_POLYMORPHIC_P (t) = 1; 3747 if (DECL_PURE_VIRTUAL_P (x)) 3748 VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x); 3749 } 3750 /* All user-declared destructors are non-trivial. */ 3751 if (DECL_DESTRUCTOR_P (x)) 3752 /* APPLE LOCAL begin omit calls to empty destructors 5559195 */ 3753 { 3754 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = 1; 3755 3756 /* Conservatively assume that destructor body is nontrivial. Will 3757 be unmarked during parsing of function body if it happens to be 3758 trivial. */ 3759 CLASSTYPE_HAS_NONTRIVIAL_DESTRUCTOR_BODY (t) = 1; 3760 } 3761 /* APPLE LOCAL end omit calls to empty destructors 5559195 */ 3762 } 3763} 3764 3765/* FN is a constructor or destructor. Clone the declaration to create 3766 a specialized in-charge or not-in-charge version, as indicated by 3767 NAME. */ 3768 3769static tree 3770build_clone (tree fn, tree name) 3771{ 3772 tree parms; 3773 tree clone; 3774 3775 /* Copy the function. */ 3776 clone = copy_decl (fn); 3777 /* Remember where this function came from. */ 3778 DECL_CLONED_FUNCTION (clone) = fn; 3779 DECL_ABSTRACT_ORIGIN (clone) = fn; 3780 /* Reset the function name. */ 3781 DECL_NAME (clone) = name; 3782 SET_DECL_ASSEMBLER_NAME (clone, NULL_TREE); 3783 /* There's no pending inline data for this function. */ 3784 DECL_PENDING_INLINE_INFO (clone) = NULL; 3785 DECL_PENDING_INLINE_P (clone) = 0; 3786 /* And it hasn't yet been deferred. */ 3787 DECL_DEFERRED_FN (clone) = 0; 3788 3789 /* The base-class destructor is not virtual. */ 3790 if (name == base_dtor_identifier) 3791 { 3792 DECL_VIRTUAL_P (clone) = 0; 3793 if (TREE_CODE (clone) != TEMPLATE_DECL) 3794 DECL_VINDEX (clone) = NULL_TREE; 3795 } 3796 3797 /* If there was an in-charge parameter, drop it from the function 3798 type. */ 3799 if (DECL_HAS_IN_CHARGE_PARM_P (clone)) 3800 { 3801 tree basetype; 3802 tree parmtypes; 3803 tree exceptions; 3804 3805 exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone)); 3806 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone)); 3807 parmtypes = TYPE_ARG_TYPES (TREE_TYPE (clone)); 3808 /* Skip the `this' parameter. */ 3809 parmtypes = TREE_CHAIN (parmtypes); 3810 /* Skip the in-charge parameter. */ 3811 parmtypes = TREE_CHAIN (parmtypes); 3812 /* And the VTT parm, in a complete [cd]tor. */ 3813 if (DECL_HAS_VTT_PARM_P (fn) 3814 && ! DECL_NEEDS_VTT_PARM_P (clone)) 3815 parmtypes = TREE_CHAIN (parmtypes); 3816 /* If this is subobject constructor or destructor, add the vtt 3817 parameter. */ 3818 TREE_TYPE (clone) 3819 = build_method_type_directly (basetype, 3820 TREE_TYPE (TREE_TYPE (clone)), 3821 parmtypes); 3822 if (exceptions) 3823 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), 3824 exceptions); 3825 TREE_TYPE (clone) 3826 = cp_build_type_attribute_variant (TREE_TYPE (clone), 3827 TYPE_ATTRIBUTES (TREE_TYPE (fn))); 3828 } 3829 3830 /* Copy the function parameters. But, DECL_ARGUMENTS on a TEMPLATE_DECL 3831 aren't function parameters; those are the template parameters. */ 3832 if (TREE_CODE (clone) != TEMPLATE_DECL) 3833 { 3834 DECL_ARGUMENTS (clone) = copy_list (DECL_ARGUMENTS (clone)); 3835 /* Remove the in-charge parameter. */ 3836 if (DECL_HAS_IN_CHARGE_PARM_P (clone)) 3837 { 3838 TREE_CHAIN (DECL_ARGUMENTS (clone)) 3839 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone))); 3840 DECL_HAS_IN_CHARGE_PARM_P (clone) = 0; 3841 } 3842 /* And the VTT parm, in a complete [cd]tor. */ 3843 if (DECL_HAS_VTT_PARM_P (fn)) 3844 { 3845 if (DECL_NEEDS_VTT_PARM_P (clone)) 3846 DECL_HAS_VTT_PARM_P (clone) = 1; 3847 else 3848 { 3849 TREE_CHAIN (DECL_ARGUMENTS (clone)) 3850 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone))); 3851 DECL_HAS_VTT_PARM_P (clone) = 0; 3852 } 3853 } 3854 3855 for (parms = DECL_ARGUMENTS (clone); parms; parms = TREE_CHAIN (parms)) 3856 { 3857 DECL_CONTEXT (parms) = clone; 3858 cxx_dup_lang_specific_decl (parms); 3859 } 3860 } 3861 3862 /* Create the RTL for this function. */ 3863 SET_DECL_RTL (clone, NULL_RTX); 3864 rest_of_decl_compilation (clone, /*top_level=*/1, at_eof); 3865 3866 /* Make it easy to find the CLONE given the FN. */ 3867 TREE_CHAIN (clone) = TREE_CHAIN (fn); 3868 TREE_CHAIN (fn) = clone; 3869 3870 /* If this is a template, handle the DECL_TEMPLATE_RESULT as well. */ 3871 if (TREE_CODE (clone) == TEMPLATE_DECL) 3872 { 3873 tree result; 3874 3875 DECL_TEMPLATE_RESULT (clone) 3876 = build_clone (DECL_TEMPLATE_RESULT (clone), name); 3877 result = DECL_TEMPLATE_RESULT (clone); 3878 DECL_TEMPLATE_INFO (result) = copy_node (DECL_TEMPLATE_INFO (result)); 3879 DECL_TI_TEMPLATE (result) = clone; 3880 } 3881 else if (pch_file) 3882 note_decl_for_pch (clone); 3883 3884 return clone; 3885} 3886 3887/* Produce declarations for all appropriate clones of FN. If 3888 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the 3889 CLASTYPE_METHOD_VEC as well. */ 3890 3891void 3892clone_function_decl (tree fn, int update_method_vec_p) 3893{ 3894 tree clone; 3895 3896 /* Avoid inappropriate cloning. */ 3897 if (TREE_CHAIN (fn) 3898 && DECL_CLONED_FUNCTION (TREE_CHAIN (fn))) 3899 return; 3900 3901 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)) 3902 { 3903 /* For each constructor, we need two variants: an in-charge version 3904 and a not-in-charge version. */ 3905 clone = build_clone (fn, complete_ctor_identifier); 3906 if (update_method_vec_p) 3907 add_method (DECL_CONTEXT (clone), clone, NULL_TREE); 3908 clone = build_clone (fn, base_ctor_identifier); 3909 if (update_method_vec_p) 3910 add_method (DECL_CONTEXT (clone), clone, NULL_TREE); 3911 } 3912 else 3913 { 3914 gcc_assert (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)); 3915 3916 /* For each destructor, we need three variants: an in-charge 3917 version, a not-in-charge version, and an in-charge deleting 3918 version. We clone the deleting version first because that 3919 means it will go second on the TYPE_METHODS list -- and that 3920 corresponds to the correct layout order in the virtual 3921 function table. 3922 3923 For a non-virtual destructor, we do not build a deleting 3924 destructor. */ 3925 if (DECL_VIRTUAL_P (fn)) 3926 { 3927 clone = build_clone (fn, deleting_dtor_identifier); 3928 if (update_method_vec_p) 3929 add_method (DECL_CONTEXT (clone), clone, NULL_TREE); 3930 } 3931 clone = build_clone (fn, complete_dtor_identifier); 3932 if (update_method_vec_p) 3933 add_method (DECL_CONTEXT (clone), clone, NULL_TREE); 3934 clone = build_clone (fn, base_dtor_identifier); 3935 if (update_method_vec_p) 3936 add_method (DECL_CONTEXT (clone), clone, NULL_TREE); 3937 } 3938 3939 /* Note that this is an abstract function that is never emitted. */ 3940 DECL_ABSTRACT (fn) = 1; 3941} 3942 3943/* DECL is an in charge constructor, which is being defined. This will 3944 have had an in class declaration, from whence clones were 3945 declared. An out-of-class definition can specify additional default 3946 arguments. As it is the clones that are involved in overload 3947 resolution, we must propagate the information from the DECL to its 3948 clones. */ 3949 3950void 3951adjust_clone_args (tree decl) 3952{ 3953 tree clone; 3954 3955 for (clone = TREE_CHAIN (decl); clone && DECL_CLONED_FUNCTION (clone); 3956 clone = TREE_CHAIN (clone)) 3957 { 3958 tree orig_clone_parms = TYPE_ARG_TYPES (TREE_TYPE (clone)); 3959 tree orig_decl_parms = TYPE_ARG_TYPES (TREE_TYPE (decl)); 3960 tree decl_parms, clone_parms; 3961 3962 clone_parms = orig_clone_parms; 3963 3964 /* Skip the 'this' parameter. */ 3965 orig_clone_parms = TREE_CHAIN (orig_clone_parms); 3966 orig_decl_parms = TREE_CHAIN (orig_decl_parms); 3967 3968 if (DECL_HAS_IN_CHARGE_PARM_P (decl)) 3969 orig_decl_parms = TREE_CHAIN (orig_decl_parms); 3970 if (DECL_HAS_VTT_PARM_P (decl)) 3971 orig_decl_parms = TREE_CHAIN (orig_decl_parms); 3972 3973 clone_parms = orig_clone_parms; 3974 if (DECL_HAS_VTT_PARM_P (clone)) 3975 clone_parms = TREE_CHAIN (clone_parms); 3976 3977 for (decl_parms = orig_decl_parms; decl_parms; 3978 decl_parms = TREE_CHAIN (decl_parms), 3979 clone_parms = TREE_CHAIN (clone_parms)) 3980 { 3981 gcc_assert (same_type_p (TREE_TYPE (decl_parms), 3982 TREE_TYPE (clone_parms))); 3983 3984 if (TREE_PURPOSE (decl_parms) && !TREE_PURPOSE (clone_parms)) 3985 { 3986 /* A default parameter has been added. Adjust the 3987 clone's parameters. */ 3988 tree exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone)); 3989 tree basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone)); 3990 tree type; 3991 3992 clone_parms = orig_decl_parms; 3993 3994 if (DECL_HAS_VTT_PARM_P (clone)) 3995 { 3996 clone_parms = tree_cons (TREE_PURPOSE (orig_clone_parms), 3997 TREE_VALUE (orig_clone_parms), 3998 clone_parms); 3999 TREE_TYPE (clone_parms) = TREE_TYPE (orig_clone_parms); 4000 } 4001 type = build_method_type_directly (basetype, 4002 TREE_TYPE (TREE_TYPE (clone)), 4003 clone_parms); 4004 if (exceptions) 4005 type = build_exception_variant (type, exceptions); 4006 TREE_TYPE (clone) = type; 4007 4008 clone_parms = NULL_TREE; 4009 break; 4010 } 4011 } 4012 gcc_assert (!clone_parms); 4013 } 4014} 4015 4016/* For each of the constructors and destructors in T, create an 4017 in-charge and not-in-charge variant. */ 4018 4019static void 4020clone_constructors_and_destructors (tree t) 4021{ 4022 tree fns; 4023 4024 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail 4025 out now. */ 4026 if (!CLASSTYPE_METHOD_VEC (t)) 4027 return; 4028 4029 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns)) 4030 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1); 4031 for (fns = CLASSTYPE_DESTRUCTORS (t); fns; fns = OVL_NEXT (fns)) 4032 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1); 4033} 4034 4035/* Remove all zero-width bit-fields from T. */ 4036 4037static void 4038remove_zero_width_bit_fields (tree t) 4039{ 4040 tree *fieldsp; 4041 4042 fieldsp = &TYPE_FIELDS (t); 4043 while (*fieldsp) 4044 { 4045 if (TREE_CODE (*fieldsp) == FIELD_DECL 4046 && DECL_C_BIT_FIELD (*fieldsp) 4047 && DECL_INITIAL (*fieldsp)) 4048 *fieldsp = TREE_CHAIN (*fieldsp); 4049 else 4050 fieldsp = &TREE_CHAIN (*fieldsp); 4051 } 4052} 4053 4054/* Returns TRUE iff we need a cookie when dynamically allocating an 4055 array whose elements have the indicated class TYPE. */ 4056 4057static bool 4058type_requires_array_cookie (tree type) 4059{ 4060 tree fns; 4061 bool has_two_argument_delete_p = false; 4062 4063 gcc_assert (CLASS_TYPE_P (type)); 4064 4065 /* If there's a non-trivial destructor, we need a cookie. In order 4066 to iterate through the array calling the destructor for each 4067 element, we'll have to know how many elements there are. */ 4068 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 4069 return true; 4070 4071 /* If the usual deallocation function is a two-argument whose second 4072 argument is of type `size_t', then we have to pass the size of 4073 the array to the deallocation function, so we will need to store 4074 a cookie. */ 4075 fns = lookup_fnfields (TYPE_BINFO (type), 4076 ansi_opname (VEC_DELETE_EXPR), 4077 /*protect=*/0); 4078 /* If there are no `operator []' members, or the lookup is 4079 ambiguous, then we don't need a cookie. */ 4080 if (!fns || fns == error_mark_node) 4081 return false; 4082 /* Loop through all of the functions. */ 4083 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns)) 4084 { 4085 tree fn; 4086 tree second_parm; 4087 4088 /* Select the current function. */ 4089 fn = OVL_CURRENT (fns); 4090 /* See if this function is a one-argument delete function. If 4091 it is, then it will be the usual deallocation function. */ 4092 second_parm = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fn))); 4093 if (second_parm == void_list_node) 4094 return false; 4095 /* Otherwise, if we have a two-argument function and the second 4096 argument is `size_t', it will be the usual deallocation 4097 function -- unless there is one-argument function, too. */ 4098 if (TREE_CHAIN (second_parm) == void_list_node 4099 && same_type_p (TREE_VALUE (second_parm), sizetype)) 4100 has_two_argument_delete_p = true; 4101 } 4102 4103 return has_two_argument_delete_p; 4104} 4105 4106/* Check the validity of the bases and members declared in T. Add any 4107 implicitly-generated functions (like copy-constructors and 4108 assignment operators). Compute various flag bits (like 4109 CLASSTYPE_NON_POD_T) for T. This routine works purely at the C++ 4110 level: i.e., independently of the ABI in use. */ 4111 4112static void 4113check_bases_and_members (tree t) 4114{ 4115 /* Nonzero if the implicitly generated copy constructor should take 4116 a non-const reference argument. */ 4117 int cant_have_const_ctor; 4118 /* Nonzero if the implicitly generated assignment operator 4119 should take a non-const reference argument. */ 4120 int no_const_asn_ref; 4121 tree access_decls; 4122 4123 /* By default, we use const reference arguments and generate default 4124 constructors. */ 4125 cant_have_const_ctor = 0; 4126 no_const_asn_ref = 0; 4127 4128 /* Check all the base-classes. */ 4129 check_bases (t, &cant_have_const_ctor, 4130 &no_const_asn_ref); 4131 4132 /* Check all the method declarations. */ 4133 check_methods (t); 4134 4135 /* Check all the data member declarations. We cannot call 4136 check_field_decls until we have called check_bases check_methods, 4137 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR 4138 being set appropriately. */ 4139 check_field_decls (t, &access_decls, 4140 &cant_have_const_ctor, 4141 &no_const_asn_ref); 4142 4143 /* A nearly-empty class has to be vptr-containing; a nearly empty 4144 class contains just a vptr. */ 4145 if (!TYPE_CONTAINS_VPTR_P (t)) 4146 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 4147 4148 /* Do some bookkeeping that will guide the generation of implicitly 4149 declared member functions. */ 4150 TYPE_HAS_COMPLEX_INIT_REF (t) 4151 |= (TYPE_HAS_INIT_REF (t) || TYPE_CONTAINS_VPTR_P (t)); 4152 TYPE_NEEDS_CONSTRUCTING (t) 4153 |= (TYPE_HAS_CONSTRUCTOR (t) || TYPE_CONTAINS_VPTR_P (t)); 4154 CLASSTYPE_NON_AGGREGATE (t) 4155 |= (TYPE_HAS_CONSTRUCTOR (t) || TYPE_POLYMORPHIC_P (t)); 4156 CLASSTYPE_NON_POD_P (t) 4157 |= (CLASSTYPE_NON_AGGREGATE (t) 4158 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) 4159 || TYPE_HAS_ASSIGN_REF (t)); 4160 TYPE_HAS_COMPLEX_ASSIGN_REF (t) 4161 |= TYPE_HAS_ASSIGN_REF (t) || TYPE_CONTAINS_VPTR_P (t); 4162 4163 /* Synthesize any needed methods. */ 4164 add_implicitly_declared_members (t, 4165 cant_have_const_ctor, 4166 no_const_asn_ref); 4167 4168 /* Create the in-charge and not-in-charge variants of constructors 4169 and destructors. */ 4170 clone_constructors_and_destructors (t); 4171 4172 /* Process the using-declarations. */ 4173 for (; access_decls; access_decls = TREE_CHAIN (access_decls)) 4174 handle_using_decl (TREE_VALUE (access_decls), t); 4175 4176 /* Build and sort the CLASSTYPE_METHOD_VEC. */ 4177 finish_struct_methods (t); 4178 4179 /* Figure out whether or not we will need a cookie when dynamically 4180 allocating an array of this type. */ 4181 TYPE_LANG_SPECIFIC (t)->u.c.vec_new_uses_cookie 4182 = type_requires_array_cookie (t); 4183} 4184 4185/* If T needs a pointer to its virtual function table, set TYPE_VFIELD 4186 accordingly. If a new vfield was created (because T doesn't have a 4187 primary base class), then the newly created field is returned. It 4188 is not added to the TYPE_FIELDS list; it is the caller's 4189 responsibility to do that. Accumulate declared virtual functions 4190 on VIRTUALS_P. */ 4191 4192static tree 4193create_vtable_ptr (tree t, tree* virtuals_p) 4194{ 4195 tree fn; 4196 4197 /* Collect the virtual functions declared in T. */ 4198 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn)) 4199 if (DECL_VINDEX (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn) 4200 && TREE_CODE (DECL_VINDEX (fn)) != INTEGER_CST) 4201 { 4202 tree new_virtual = make_node (TREE_LIST); 4203 4204 BV_FN (new_virtual) = fn; 4205 BV_DELTA (new_virtual) = integer_zero_node; 4206 BV_VCALL_INDEX (new_virtual) = NULL_TREE; 4207 4208 TREE_CHAIN (new_virtual) = *virtuals_p; 4209 *virtuals_p = new_virtual; 4210 } 4211 4212 /* If we couldn't find an appropriate base class, create a new field 4213 here. Even if there weren't any new virtual functions, we might need a 4214 new virtual function table if we're supposed to include vptrs in 4215 all classes that need them. */ 4216 if (!TYPE_VFIELD (t) && (*virtuals_p || TYPE_CONTAINS_VPTR_P (t))) 4217 { 4218 /* We build this decl with vtbl_ptr_type_node, which is a 4219 `vtable_entry_type*'. It might seem more precise to use 4220 `vtable_entry_type (*)[N]' where N is the number of virtual 4221 functions. However, that would require the vtable pointer in 4222 base classes to have a different type than the vtable pointer 4223 in derived classes. We could make that happen, but that 4224 still wouldn't solve all the problems. In particular, the 4225 type-based alias analysis code would decide that assignments 4226 to the base class vtable pointer can't alias assignments to 4227 the derived class vtable pointer, since they have different 4228 types. Thus, in a derived class destructor, where the base 4229 class constructor was inlined, we could generate bad code for 4230 setting up the vtable pointer. 4231 4232 Therefore, we use one type for all vtable pointers. We still 4233 use a type-correct type; it's just doesn't indicate the array 4234 bounds. That's better than using `void*' or some such; it's 4235 cleaner, and it let's the alias analysis code know that these 4236 stores cannot alias stores to void*! */ 4237 tree field; 4238 4239 field = build_decl (FIELD_DECL, get_vfield_name (t), vtbl_ptr_type_node); 4240 DECL_VIRTUAL_P (field) = 1; 4241 DECL_ARTIFICIAL (field) = 1; 4242 DECL_FIELD_CONTEXT (field) = t; 4243 DECL_FCONTEXT (field) = t; 4244 4245 TYPE_VFIELD (t) = field; 4246 4247 /* This class is non-empty. */ 4248 CLASSTYPE_EMPTY_P (t) = 0; 4249 4250 return field; 4251 } 4252 4253 return NULL_TREE; 4254} 4255 4256/* Fixup the inline function given by INFO now that the class is 4257 complete. */ 4258 4259static void 4260fixup_pending_inline (tree fn) 4261{ 4262 if (DECL_PENDING_INLINE_INFO (fn)) 4263 { 4264 tree args = DECL_ARGUMENTS (fn); 4265 while (args) 4266 { 4267 DECL_CONTEXT (args) = fn; 4268 args = TREE_CHAIN (args); 4269 } 4270 } 4271} 4272 4273/* Fixup the inline methods and friends in TYPE now that TYPE is 4274 complete. */ 4275 4276static void 4277fixup_inline_methods (tree type) 4278{ 4279 tree method = TYPE_METHODS (type); 4280 VEC(tree,gc) *friends; 4281 unsigned ix; 4282 4283 if (method && TREE_CODE (method) == TREE_VEC) 4284 { 4285 if (TREE_VEC_ELT (method, 1)) 4286 method = TREE_VEC_ELT (method, 1); 4287 else if (TREE_VEC_ELT (method, 0)) 4288 method = TREE_VEC_ELT (method, 0); 4289 else 4290 method = TREE_VEC_ELT (method, 2); 4291 } 4292 4293 /* Do inline member functions. */ 4294 for (; method; method = TREE_CHAIN (method)) 4295 fixup_pending_inline (method); 4296 4297 /* Do friends. */ 4298 for (friends = CLASSTYPE_INLINE_FRIENDS (type), ix = 0; 4299 VEC_iterate (tree, friends, ix, method); ix++) 4300 fixup_pending_inline (method); 4301 CLASSTYPE_INLINE_FRIENDS (type) = NULL; 4302} 4303 4304/* Add OFFSET to all base types of BINFO which is a base in the 4305 hierarchy dominated by T. 4306 4307 OFFSET, which is a type offset, is number of bytes. */ 4308 4309static void 4310propagate_binfo_offsets (tree binfo, tree offset) 4311{ 4312 int i; 4313 tree primary_binfo; 4314 tree base_binfo; 4315 4316 /* Update BINFO's offset. */ 4317 BINFO_OFFSET (binfo) 4318 = convert (sizetype, 4319 size_binop (PLUS_EXPR, 4320 convert (ssizetype, BINFO_OFFSET (binfo)), 4321 offset)); 4322 4323 /* Find the primary base class. */ 4324 primary_binfo = get_primary_binfo (binfo); 4325 4326 if (primary_binfo && BINFO_INHERITANCE_CHAIN (primary_binfo) == binfo) 4327 propagate_binfo_offsets (primary_binfo, offset); 4328 4329 /* Scan all of the bases, pushing the BINFO_OFFSET adjust 4330 downwards. */ 4331 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 4332 { 4333 /* Don't do the primary base twice. */ 4334 if (base_binfo == primary_binfo) 4335 continue; 4336 4337 if (BINFO_VIRTUAL_P (base_binfo)) 4338 continue; 4339 4340 propagate_binfo_offsets (base_binfo, offset); 4341 } 4342} 4343 4344/* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update 4345 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of 4346 empty subobjects of T. */ 4347 4348static void 4349layout_virtual_bases (record_layout_info rli, splay_tree offsets) 4350{ 4351 tree vbase; 4352 tree t = rli->t; 4353 bool first_vbase = true; 4354 tree *next_field; 4355 4356 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) == 0) 4357 return; 4358 4359 if (!abi_version_at_least(2)) 4360 { 4361 /* In G++ 3.2, we incorrectly rounded the size before laying out 4362 the virtual bases. */ 4363 finish_record_layout (rli, /*free_p=*/false); 4364#ifdef STRUCTURE_SIZE_BOUNDARY 4365 /* Packed structures don't need to have minimum size. */ 4366 if (! TYPE_PACKED (t)) 4367 TYPE_ALIGN (t) = MAX (TYPE_ALIGN (t), (unsigned) STRUCTURE_SIZE_BOUNDARY); 4368#endif 4369 rli->offset = TYPE_SIZE_UNIT (t); 4370 rli->bitpos = bitsize_zero_node; 4371 rli->record_align = TYPE_ALIGN (t); 4372 } 4373 4374 /* Find the last field. The artificial fields created for virtual 4375 bases will go after the last extant field to date. */ 4376 next_field = &TYPE_FIELDS (t); 4377 while (*next_field) 4378 next_field = &TREE_CHAIN (*next_field); 4379 4380 /* Go through the virtual bases, allocating space for each virtual 4381 base that is not already a primary base class. These are 4382 allocated in inheritance graph order. */ 4383 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase)) 4384 { 4385 if (!BINFO_VIRTUAL_P (vbase)) 4386 continue; 4387 4388 if (!BINFO_PRIMARY_P (vbase)) 4389 { 4390 tree basetype = TREE_TYPE (vbase); 4391 4392 /* This virtual base is not a primary base of any class in the 4393 hierarchy, so we have to add space for it. */ 4394 next_field = build_base_field (rli, vbase, 4395 offsets, next_field); 4396 4397 /* If the first virtual base might have been placed at a 4398 lower address, had we started from CLASSTYPE_SIZE, rather 4399 than TYPE_SIZE, issue a warning. There can be both false 4400 positives and false negatives from this warning in rare 4401 cases; to deal with all the possibilities would probably 4402 require performing both layout algorithms and comparing 4403 the results which is not particularly tractable. */ 4404 if (warn_abi 4405 && first_vbase 4406 && (tree_int_cst_lt 4407 (size_binop (CEIL_DIV_EXPR, 4408 round_up (CLASSTYPE_SIZE (t), 4409 CLASSTYPE_ALIGN (basetype)), 4410 bitsize_unit_node), 4411 BINFO_OFFSET (vbase)))) 4412 warning (OPT_Wabi, 4413 "offset of virtual base %qT is not ABI-compliant and " 4414 "may change in a future version of GCC", 4415 basetype); 4416 4417 first_vbase = false; 4418 } 4419 } 4420} 4421 4422/* Returns the offset of the byte just past the end of the base class 4423 BINFO. */ 4424 4425static tree 4426end_of_base (tree binfo) 4427{ 4428 tree size; 4429 4430 if (is_empty_class (BINFO_TYPE (binfo))) 4431 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to 4432 allocate some space for it. It cannot have virtual bases, so 4433 TYPE_SIZE_UNIT is fine. */ 4434 size = TYPE_SIZE_UNIT (BINFO_TYPE (binfo)); 4435 else 4436 size = CLASSTYPE_SIZE_UNIT (BINFO_TYPE (binfo)); 4437 4438 return size_binop (PLUS_EXPR, BINFO_OFFSET (binfo), size); 4439} 4440 4441/* Returns the offset of the byte just past the end of the base class 4442 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then 4443 only non-virtual bases are included. */ 4444 4445static tree 4446end_of_class (tree t, int include_virtuals_p) 4447{ 4448 tree result = size_zero_node; 4449 VEC(tree,gc) *vbases; 4450 tree binfo; 4451 tree base_binfo; 4452 tree offset; 4453 int i; 4454 4455 for (binfo = TYPE_BINFO (t), i = 0; 4456 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 4457 { 4458 if (!include_virtuals_p 4459 && BINFO_VIRTUAL_P (base_binfo) 4460 && (!BINFO_PRIMARY_P (base_binfo) 4461 || BINFO_INHERITANCE_CHAIN (base_binfo) != TYPE_BINFO (t))) 4462 continue; 4463 4464 offset = end_of_base (base_binfo); 4465 if (INT_CST_LT_UNSIGNED (result, offset)) 4466 result = offset; 4467 } 4468 4469 /* G++ 3.2 did not check indirect virtual bases. */ 4470 if (abi_version_at_least (2) && include_virtuals_p) 4471 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0; 4472 VEC_iterate (tree, vbases, i, base_binfo); i++) 4473 { 4474 offset = end_of_base (base_binfo); 4475 if (INT_CST_LT_UNSIGNED (result, offset)) 4476 result = offset; 4477 } 4478 4479 return result; 4480} 4481 4482/* Warn about bases of T that are inaccessible because they are 4483 ambiguous. For example: 4484 4485 struct S {}; 4486 struct T : public S {}; 4487 struct U : public S, public T {}; 4488 4489 Here, `(S*) new U' is not allowed because there are two `S' 4490 subobjects of U. */ 4491 4492static void 4493warn_about_ambiguous_bases (tree t) 4494{ 4495 int i; 4496 VEC(tree,gc) *vbases; 4497 tree basetype; 4498 tree binfo; 4499 tree base_binfo; 4500 4501 /* If there are no repeated bases, nothing can be ambiguous. */ 4502 if (!CLASSTYPE_REPEATED_BASE_P (t)) 4503 return; 4504 4505 /* Check direct bases. */ 4506 for (binfo = TYPE_BINFO (t), i = 0; 4507 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 4508 { 4509 basetype = BINFO_TYPE (base_binfo); 4510 4511 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL)) 4512 warning (0, "direct base %qT inaccessible in %qT due to ambiguity", 4513 basetype, t); 4514 } 4515 4516 /* Check for ambiguous virtual bases. */ 4517 if (extra_warnings) 4518 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0; 4519 VEC_iterate (tree, vbases, i, binfo); i++) 4520 { 4521 basetype = BINFO_TYPE (binfo); 4522 4523 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL)) 4524 warning (OPT_Wextra, "virtual base %qT inaccessible in %qT due to ambiguity", 4525 basetype, t); 4526 } 4527} 4528 4529/* Compare two INTEGER_CSTs K1 and K2. */ 4530 4531static int 4532splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2) 4533{ 4534 return tree_int_cst_compare ((tree) k1, (tree) k2); 4535} 4536 4537/* Increase the size indicated in RLI to account for empty classes 4538 that are "off the end" of the class. */ 4539 4540static void 4541include_empty_classes (record_layout_info rli) 4542{ 4543 tree eoc; 4544 tree rli_size; 4545 4546 /* It might be the case that we grew the class to allocate a 4547 zero-sized base class. That won't be reflected in RLI, yet, 4548 because we are willing to overlay multiple bases at the same 4549 offset. However, now we need to make sure that RLI is big enough 4550 to reflect the entire class. */ 4551 eoc = end_of_class (rli->t, 4552 CLASSTYPE_AS_BASE (rli->t) != NULL_TREE); 4553 rli_size = rli_size_unit_so_far (rli); 4554 if (TREE_CODE (rli_size) == INTEGER_CST 4555 && INT_CST_LT_UNSIGNED (rli_size, eoc)) 4556 { 4557 if (!abi_version_at_least (2)) 4558 /* In version 1 of the ABI, the size of a class that ends with 4559 a bitfield was not rounded up to a whole multiple of a 4560 byte. Because rli_size_unit_so_far returns only the number 4561 of fully allocated bytes, any extra bits were not included 4562 in the size. */ 4563 rli->bitpos = round_down (rli->bitpos, BITS_PER_UNIT); 4564 else 4565 /* The size should have been rounded to a whole byte. */ 4566 gcc_assert (tree_int_cst_equal 4567 (rli->bitpos, round_down (rli->bitpos, BITS_PER_UNIT))); 4568 rli->bitpos 4569 = size_binop (PLUS_EXPR, 4570 rli->bitpos, 4571 size_binop (MULT_EXPR, 4572 convert (bitsizetype, 4573 size_binop (MINUS_EXPR, 4574 eoc, rli_size)), 4575 bitsize_int (BITS_PER_UNIT))); 4576 normalize_rli (rli); 4577 } 4578} 4579 4580/* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate 4581 BINFO_OFFSETs for all of the base-classes. Position the vtable 4582 pointer. Accumulate declared virtual functions on VIRTUALS_P. */ 4583 4584static void 4585layout_class_type (tree t, tree *virtuals_p) 4586{ 4587 tree non_static_data_members; 4588 tree field; 4589 tree vptr; 4590 record_layout_info rli; 4591 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of 4592 types that appear at that offset. */ 4593 splay_tree empty_base_offsets; 4594 /* True if the last field layed out was a bit-field. */ 4595 bool last_field_was_bitfield = false; 4596 /* The location at which the next field should be inserted. */ 4597 tree *next_field; 4598 /* T, as a base class. */ 4599 tree base_t; 4600 4601 /* Keep track of the first non-static data member. */ 4602 non_static_data_members = TYPE_FIELDS (t); 4603 4604 /* Start laying out the record. */ 4605 rli = start_record_layout (t); 4606 4607 /* Mark all the primary bases in the hierarchy. */ 4608 determine_primary_bases (t); 4609 4610 /* Create a pointer to our virtual function table. */ 4611 vptr = create_vtable_ptr (t, virtuals_p); 4612 4613 /* The vptr is always the first thing in the class. */ 4614 if (vptr) 4615 { 4616 TREE_CHAIN (vptr) = TYPE_FIELDS (t); 4617 TYPE_FIELDS (t) = vptr; 4618 next_field = &TREE_CHAIN (vptr); 4619 place_field (rli, vptr); 4620 } 4621 else 4622 next_field = &TYPE_FIELDS (t); 4623 4624 /* Build FIELD_DECLs for all of the non-virtual base-types. */ 4625 empty_base_offsets = splay_tree_new (splay_tree_compare_integer_csts, 4626 NULL, NULL); 4627 build_base_fields (rli, empty_base_offsets, next_field); 4628 4629 /* Layout the non-static data members. */ 4630 for (field = non_static_data_members; field; field = TREE_CHAIN (field)) 4631 { 4632 tree type; 4633 tree padding; 4634 4635 /* We still pass things that aren't non-static data members to 4636 the back-end, in case it wants to do something with them. */ 4637 if (TREE_CODE (field) != FIELD_DECL) 4638 { 4639 place_field (rli, field); 4640 /* If the static data member has incomplete type, keep track 4641 of it so that it can be completed later. (The handling 4642 of pending statics in finish_record_layout is 4643 insufficient; consider: 4644 4645 struct S1; 4646 struct S2 { static S1 s1; }; 4647 4648 At this point, finish_record_layout will be called, but 4649 S1 is still incomplete.) */ 4650 if (TREE_CODE (field) == VAR_DECL) 4651 { 4652 maybe_register_incomplete_var (field); 4653 /* The visibility of static data members is determined 4654 at their point of declaration, not their point of 4655 definition. */ 4656 determine_visibility (field); 4657 } 4658 continue; 4659 } 4660 4661 type = TREE_TYPE (field); 4662 if (type == error_mark_node) 4663 continue; 4664 4665 padding = NULL_TREE; 4666 4667 /* If this field is a bit-field whose width is greater than its 4668 type, then there are some special rules for allocating 4669 it. */ 4670 if (DECL_C_BIT_FIELD (field) 4671 && INT_CST_LT (TYPE_SIZE (type), DECL_SIZE (field))) 4672 { 4673 integer_type_kind itk; 4674 tree integer_type; 4675 bool was_unnamed_p = false; 4676 /* We must allocate the bits as if suitably aligned for the 4677 longest integer type that fits in this many bits. type 4678 of the field. Then, we are supposed to use the left over 4679 bits as additional padding. */ 4680 for (itk = itk_char; itk != itk_none; ++itk) 4681 if (INT_CST_LT (DECL_SIZE (field), 4682 TYPE_SIZE (integer_types[itk]))) 4683 break; 4684 4685 /* ITK now indicates a type that is too large for the 4686 field. We have to back up by one to find the largest 4687 type that fits. */ 4688 integer_type = integer_types[itk - 1]; 4689 4690 /* Figure out how much additional padding is required. GCC 4691 3.2 always created a padding field, even if it had zero 4692 width. */ 4693 if (!abi_version_at_least (2) 4694 || INT_CST_LT (TYPE_SIZE (integer_type), DECL_SIZE (field))) 4695 { 4696 if (abi_version_at_least (2) && TREE_CODE (t) == UNION_TYPE) 4697 /* In a union, the padding field must have the full width 4698 of the bit-field; all fields start at offset zero. */ 4699 padding = DECL_SIZE (field); 4700 else 4701 { 4702 if (TREE_CODE (t) == UNION_TYPE) 4703 warning (OPT_Wabi, "size assigned to %qT may not be " 4704 "ABI-compliant and may change in a future " 4705 "version of GCC", 4706 t); 4707 padding = size_binop (MINUS_EXPR, DECL_SIZE (field), 4708 TYPE_SIZE (integer_type)); 4709 } 4710 } 4711#ifdef PCC_BITFIELD_TYPE_MATTERS 4712 /* An unnamed bitfield does not normally affect the 4713 alignment of the containing class on a target where 4714 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not 4715 make any exceptions for unnamed bitfields when the 4716 bitfields are longer than their types. Therefore, we 4717 temporarily give the field a name. */ 4718 if (PCC_BITFIELD_TYPE_MATTERS && !DECL_NAME (field)) 4719 { 4720 was_unnamed_p = true; 4721 DECL_NAME (field) = make_anon_name (); 4722 } 4723#endif 4724 DECL_SIZE (field) = TYPE_SIZE (integer_type); 4725 DECL_ALIGN (field) = TYPE_ALIGN (integer_type); 4726 DECL_USER_ALIGN (field) = TYPE_USER_ALIGN (integer_type); 4727 layout_nonempty_base_or_field (rli, field, NULL_TREE, 4728 empty_base_offsets); 4729 if (was_unnamed_p) 4730 DECL_NAME (field) = NULL_TREE; 4731 /* Now that layout has been performed, set the size of the 4732 field to the size of its declared type; the rest of the 4733 field is effectively invisible. */ 4734 DECL_SIZE (field) = TYPE_SIZE (type); 4735 /* We must also reset the DECL_MODE of the field. */ 4736 if (abi_version_at_least (2)) 4737 DECL_MODE (field) = TYPE_MODE (type); 4738 else if (warn_abi 4739 && DECL_MODE (field) != TYPE_MODE (type)) 4740 /* Versions of G++ before G++ 3.4 did not reset the 4741 DECL_MODE. */ 4742 warning (OPT_Wabi, 4743 "the offset of %qD may not be ABI-compliant and may " 4744 "change in a future version of GCC", field); 4745 } 4746 else 4747 layout_nonempty_base_or_field (rli, field, NULL_TREE, 4748 empty_base_offsets); 4749 4750 /* Remember the location of any empty classes in FIELD. */ 4751 if (abi_version_at_least (2)) 4752 record_subobject_offsets (TREE_TYPE (field), 4753 byte_position(field), 4754 empty_base_offsets, 4755 /*is_data_member=*/true); 4756 4757 /* If a bit-field does not immediately follow another bit-field, 4758 and yet it starts in the middle of a byte, we have failed to 4759 comply with the ABI. */ 4760 if (warn_abi 4761 && DECL_C_BIT_FIELD (field) 4762 /* The TREE_NO_WARNING flag gets set by Objective-C when 4763 laying out an Objective-C class. The ObjC ABI differs 4764 from the C++ ABI, and so we do not want a warning 4765 here. */ 4766 && !TREE_NO_WARNING (field) 4767 && !last_field_was_bitfield 4768 && !integer_zerop (size_binop (TRUNC_MOD_EXPR, 4769 DECL_FIELD_BIT_OFFSET (field), 4770 bitsize_unit_node))) 4771 warning (OPT_Wabi, "offset of %q+D is not ABI-compliant and may " 4772 "change in a future version of GCC", field); 4773 4774 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte 4775 offset of the field. */ 4776 if (warn_abi 4777 && !tree_int_cst_equal (DECL_FIELD_OFFSET (field), 4778 byte_position (field)) 4779 && contains_empty_class_p (TREE_TYPE (field))) 4780 warning (OPT_Wabi, "%q+D contains empty classes which may cause base " 4781 "classes to be placed at different locations in a " 4782 "future version of GCC", field); 4783 4784 /* The middle end uses the type of expressions to determine the 4785 possible range of expression values. In order to optimize 4786 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end 4787 must be made aware of the width of "i", via its type. 4788 4789 Because C++ does not have integer types of arbitrary width, 4790 we must (for the purposes of the front end) convert from the 4791 type assigned here to the declared type of the bitfield 4792 whenever a bitfield expression is used as an rvalue. 4793 Similarly, when assigning a value to a bitfield, the value 4794 must be converted to the type given the bitfield here. */ 4795 if (DECL_C_BIT_FIELD (field)) 4796 { 4797 tree ftype; 4798 unsigned HOST_WIDE_INT width; 4799 ftype = TREE_TYPE (field); 4800 width = tree_low_cst (DECL_SIZE (field), /*unsignedp=*/1); 4801 if (width != TYPE_PRECISION (ftype)) 4802 TREE_TYPE (field) 4803 = c_build_bitfield_integer_type (width, 4804 TYPE_UNSIGNED (ftype)); 4805 } 4806 4807 /* If we needed additional padding after this field, add it 4808 now. */ 4809 if (padding) 4810 { 4811 tree padding_field; 4812 4813 padding_field = build_decl (FIELD_DECL, 4814 NULL_TREE, 4815 char_type_node); 4816 DECL_BIT_FIELD (padding_field) = 1; 4817 DECL_SIZE (padding_field) = padding; 4818 DECL_CONTEXT (padding_field) = t; 4819 DECL_ARTIFICIAL (padding_field) = 1; 4820 DECL_IGNORED_P (padding_field) = 1; 4821 layout_nonempty_base_or_field (rli, padding_field, 4822 NULL_TREE, 4823 empty_base_offsets); 4824 } 4825 4826 last_field_was_bitfield = DECL_C_BIT_FIELD (field); 4827 } 4828 4829 if (abi_version_at_least (2) && !integer_zerop (rli->bitpos)) 4830 { 4831 /* Make sure that we are on a byte boundary so that the size of 4832 the class without virtual bases will always be a round number 4833 of bytes. */ 4834 rli->bitpos = round_up (rli->bitpos, BITS_PER_UNIT); 4835 normalize_rli (rli); 4836 } 4837 4838 /* G++ 3.2 does not allow virtual bases to be overlaid with tail 4839 padding. */ 4840 if (!abi_version_at_least (2)) 4841 include_empty_classes(rli); 4842 4843 /* Delete all zero-width bit-fields from the list of fields. Now 4844 that the type is laid out they are no longer important. */ 4845 remove_zero_width_bit_fields (t); 4846 4847 /* Create the version of T used for virtual bases. We do not use 4848 make_aggr_type for this version; this is an artificial type. For 4849 a POD type, we just reuse T. */ 4850 if (CLASSTYPE_NON_POD_P (t) || CLASSTYPE_EMPTY_P (t)) 4851 { 4852 base_t = make_node (TREE_CODE (t)); 4853 4854 /* Set the size and alignment for the new type. In G++ 3.2, all 4855 empty classes were considered to have size zero when used as 4856 base classes. */ 4857 if (!abi_version_at_least (2) && CLASSTYPE_EMPTY_P (t)) 4858 { 4859 TYPE_SIZE (base_t) = bitsize_zero_node; 4860 TYPE_SIZE_UNIT (base_t) = size_zero_node; 4861 if (warn_abi && !integer_zerop (rli_size_unit_so_far (rli))) 4862 warning (OPT_Wabi, 4863 "layout of classes derived from empty class %qT " 4864 "may change in a future version of GCC", 4865 t); 4866 } 4867 else 4868 { 4869 tree eoc; 4870 4871 /* If the ABI version is not at least two, and the last 4872 field was a bit-field, RLI may not be on a byte 4873 boundary. In particular, rli_size_unit_so_far might 4874 indicate the last complete byte, while rli_size_so_far 4875 indicates the total number of bits used. Therefore, 4876 rli_size_so_far, rather than rli_size_unit_so_far, is 4877 used to compute TYPE_SIZE_UNIT. */ 4878 eoc = end_of_class (t, /*include_virtuals_p=*/0); 4879 TYPE_SIZE_UNIT (base_t) 4880 = size_binop (MAX_EXPR, 4881 convert (sizetype, 4882 size_binop (CEIL_DIV_EXPR, 4883 rli_size_so_far (rli), 4884 bitsize_int (BITS_PER_UNIT))), 4885 eoc); 4886 TYPE_SIZE (base_t) 4887 = size_binop (MAX_EXPR, 4888 rli_size_so_far (rli), 4889 size_binop (MULT_EXPR, 4890 convert (bitsizetype, eoc), 4891 bitsize_int (BITS_PER_UNIT))); 4892 } 4893 TYPE_ALIGN (base_t) = rli->record_align; 4894 TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t); 4895 4896 /* Copy the fields from T. */ 4897 next_field = &TYPE_FIELDS (base_t); 4898 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field)) 4899 if (TREE_CODE (field) == FIELD_DECL) 4900 { 4901 *next_field = build_decl (FIELD_DECL, 4902 DECL_NAME (field), 4903 TREE_TYPE (field)); 4904 DECL_CONTEXT (*next_field) = base_t; 4905 DECL_FIELD_OFFSET (*next_field) = DECL_FIELD_OFFSET (field); 4906 DECL_FIELD_BIT_OFFSET (*next_field) 4907 = DECL_FIELD_BIT_OFFSET (field); 4908 DECL_SIZE (*next_field) = DECL_SIZE (field); 4909 DECL_MODE (*next_field) = DECL_MODE (field); 4910 next_field = &TREE_CHAIN (*next_field); 4911 } 4912 4913 /* Record the base version of the type. */ 4914 CLASSTYPE_AS_BASE (t) = base_t; 4915 TYPE_CONTEXT (base_t) = t; 4916 } 4917 else 4918 CLASSTYPE_AS_BASE (t) = t; 4919 4920 /* Every empty class contains an empty class. */ 4921 if (CLASSTYPE_EMPTY_P (t)) 4922 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1; 4923 4924 /* Set the TYPE_DECL for this type to contain the right 4925 value for DECL_OFFSET, so that we can use it as part 4926 of a COMPONENT_REF for multiple inheritance. */ 4927 layout_decl (TYPE_MAIN_DECL (t), 0); 4928 4929 /* Now fix up any virtual base class types that we left lying 4930 around. We must get these done before we try to lay out the 4931 virtual function table. As a side-effect, this will remove the 4932 base subobject fields. */ 4933 layout_virtual_bases (rli, empty_base_offsets); 4934 4935 /* Make sure that empty classes are reflected in RLI at this 4936 point. */ 4937 include_empty_classes(rli); 4938 4939 /* Make sure not to create any structures with zero size. */ 4940 if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t)) 4941 place_field (rli, 4942 build_decl (FIELD_DECL, NULL_TREE, char_type_node)); 4943 4944 /* Let the back-end lay out the type. */ 4945 finish_record_layout (rli, /*free_p=*/true); 4946 4947 /* Warn about bases that can't be talked about due to ambiguity. */ 4948 warn_about_ambiguous_bases (t); 4949 4950 /* Now that we're done with layout, give the base fields the real types. */ 4951 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field)) 4952 if (DECL_ARTIFICIAL (field) && IS_FAKE_BASE_TYPE (TREE_TYPE (field))) 4953 TREE_TYPE (field) = TYPE_CONTEXT (TREE_TYPE (field)); 4954 4955 /* Clean up. */ 4956 splay_tree_delete (empty_base_offsets); 4957 4958 if (CLASSTYPE_EMPTY_P (t) 4959 && tree_int_cst_lt (sizeof_biggest_empty_class, 4960 TYPE_SIZE_UNIT (t))) 4961 sizeof_biggest_empty_class = TYPE_SIZE_UNIT (t); 4962} 4963 4964/* Determine the "key method" for the class type indicated by TYPE, 4965 and set CLASSTYPE_KEY_METHOD accordingly. */ 4966 4967void 4968determine_key_method (tree type) 4969{ 4970 tree method; 4971 4972 if (TYPE_FOR_JAVA (type) 4973 || processing_template_decl 4974 || CLASSTYPE_TEMPLATE_INSTANTIATION (type) 4975 || CLASSTYPE_INTERFACE_KNOWN (type)) 4976 return; 4977 4978 /* The key method is the first non-pure virtual function that is not 4979 inline at the point of class definition. On some targets the 4980 key function may not be inline; those targets should not call 4981 this function until the end of the translation unit. */ 4982 for (method = TYPE_METHODS (type); method != NULL_TREE; 4983 method = TREE_CHAIN (method)) 4984 if (DECL_VINDEX (method) != NULL_TREE 4985 && ! DECL_DECLARED_INLINE_P (method) 4986 && ! DECL_PURE_VIRTUAL_P (method)) 4987 { 4988 CLASSTYPE_KEY_METHOD (type) = method; 4989 break; 4990 } 4991 4992 return; 4993} 4994 4995/* Perform processing required when the definition of T (a class type) 4996 is complete. */ 4997 4998void 4999finish_struct_1 (tree t) 5000{ 5001 tree x; 5002 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */ 5003 tree virtuals = NULL_TREE; 5004 int n_fields = 0; 5005 5006 if (COMPLETE_TYPE_P (t)) 5007 { 5008 gcc_assert (IS_AGGR_TYPE (t)); 5009 error ("redefinition of %q#T", t); 5010 popclass (); 5011 return; 5012 } 5013 5014 /* If this type was previously laid out as a forward reference, 5015 make sure we lay it out again. */ 5016 TYPE_SIZE (t) = NULL_TREE; 5017 CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE; 5018 5019 fixup_inline_methods (t); 5020 5021 /* Make assumptions about the class; we'll reset the flags if 5022 necessary. */ 5023 CLASSTYPE_EMPTY_P (t) = 1; 5024 CLASSTYPE_NEARLY_EMPTY_P (t) = 1; 5025 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 0; 5026 5027 /* Do end-of-class semantic processing: checking the validity of the 5028 bases and members and add implicitly generated methods. */ 5029 check_bases_and_members (t); 5030 5031 /* Find the key method. */ 5032 if (TYPE_CONTAINS_VPTR_P (t)) 5033 { 5034 /* The Itanium C++ ABI permits the key method to be chosen when 5035 the class is defined -- even though the key method so 5036 selected may later turn out to be an inline function. On 5037 some systems (such as ARM Symbian OS) the key method cannot 5038 be determined until the end of the translation unit. On such 5039 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which 5040 will cause the class to be added to KEYED_CLASSES. Then, in 5041 finish_file we will determine the key method. */ 5042 if (targetm.cxx.key_method_may_be_inline ()) 5043 determine_key_method (t); 5044 5045 /* If a polymorphic class has no key method, we may emit the vtable 5046 in every translation unit where the class definition appears. */ 5047 if (CLASSTYPE_KEY_METHOD (t) == NULL_TREE) 5048 keyed_classes = tree_cons (NULL_TREE, t, keyed_classes); 5049 } 5050 5051 /* Layout the class itself. */ 5052 layout_class_type (t, &virtuals); 5053 if (CLASSTYPE_AS_BASE (t) != t) 5054 /* We use the base type for trivial assignments, and hence it 5055 needs a mode. */ 5056 compute_record_mode (CLASSTYPE_AS_BASE (t)); 5057 5058 virtuals = modify_all_vtables (t, nreverse (virtuals)); 5059 5060 /* If necessary, create the primary vtable for this class. */ 5061 if (virtuals || TYPE_CONTAINS_VPTR_P (t)) 5062 { 5063 /* We must enter these virtuals into the table. */ 5064 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 5065 build_primary_vtable (NULL_TREE, t); 5066 else if (! BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (t))) 5067 /* Here we know enough to change the type of our virtual 5068 function table, but we will wait until later this function. */ 5069 build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t); 5070 } 5071 5072 if (TYPE_CONTAINS_VPTR_P (t)) 5073 { 5074 int vindex; 5075 tree fn; 5076 5077 if (BINFO_VTABLE (TYPE_BINFO (t))) 5078 gcc_assert (DECL_VIRTUAL_P (BINFO_VTABLE (TYPE_BINFO (t)))); 5079 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 5080 gcc_assert (BINFO_VIRTUALS (TYPE_BINFO (t)) == NULL_TREE); 5081 5082 /* Add entries for virtual functions introduced by this class. */ 5083 BINFO_VIRTUALS (TYPE_BINFO (t)) 5084 = chainon (BINFO_VIRTUALS (TYPE_BINFO (t)), virtuals); 5085 5086 /* Set DECL_VINDEX for all functions declared in this class. */ 5087 for (vindex = 0, fn = BINFO_VIRTUALS (TYPE_BINFO (t)); 5088 fn; 5089 fn = TREE_CHAIN (fn), 5090 vindex += (TARGET_VTABLE_USES_DESCRIPTORS 5091 ? TARGET_VTABLE_USES_DESCRIPTORS : 1)) 5092 { 5093 tree fndecl = BV_FN (fn); 5094 5095 if (DECL_THUNK_P (fndecl)) 5096 /* A thunk. We should never be calling this entry directly 5097 from this vtable -- we'd use the entry for the non 5098 thunk base function. */ 5099 DECL_VINDEX (fndecl) = NULL_TREE; 5100 else if (TREE_CODE (DECL_VINDEX (fndecl)) != INTEGER_CST) 5101 DECL_VINDEX (fndecl) = build_int_cst (NULL_TREE, vindex); 5102 } 5103 } 5104 5105 finish_struct_bits (t); 5106 5107 /* Complete the rtl for any static member objects of the type we're 5108 working on. */ 5109 for (x = TYPE_FIELDS (t); x; x = TREE_CHAIN (x)) 5110 if (TREE_CODE (x) == VAR_DECL && TREE_STATIC (x) 5111 && TREE_TYPE (x) != error_mark_node 5112 && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t)) 5113 DECL_MODE (x) = TYPE_MODE (t); 5114 5115 /* Done with FIELDS...now decide whether to sort these for 5116 faster lookups later. 5117 5118 We use a small number because most searches fail (succeeding 5119 ultimately as the search bores through the inheritance 5120 hierarchy), and we want this failure to occur quickly. */ 5121 5122 n_fields = count_fields (TYPE_FIELDS (t)); 5123 if (n_fields > 7) 5124 { 5125 struct sorted_fields_type *field_vec = GGC_NEWVAR 5126 (struct sorted_fields_type, 5127 sizeof (struct sorted_fields_type) + n_fields * sizeof (tree)); 5128 field_vec->len = n_fields; 5129 add_fields_to_record_type (TYPE_FIELDS (t), field_vec, 0); 5130 qsort (field_vec->elts, n_fields, sizeof (tree), 5131 field_decl_cmp); 5132 if (! DECL_LANG_SPECIFIC (TYPE_MAIN_DECL (t))) 5133 retrofit_lang_decl (TYPE_MAIN_DECL (t)); 5134 DECL_SORTED_FIELDS (TYPE_MAIN_DECL (t)) = field_vec; 5135 } 5136 5137 /* Complain if one of the field types requires lower visibility. */ 5138 constrain_class_visibility (t); 5139 5140 /* Make the rtl for any new vtables we have created, and unmark 5141 the base types we marked. */ 5142 finish_vtbls (t); 5143 5144 /* Build the VTT for T. */ 5145 build_vtt (t); 5146 5147 /* This warning does not make sense for Java classes, since they 5148 cannot have destructors. */ 5149 if (!TYPE_FOR_JAVA (t) && warn_nonvdtor && TYPE_POLYMORPHIC_P (t)) 5150 { 5151 tree dtor; 5152 5153 dtor = CLASSTYPE_DESTRUCTORS (t); 5154 /* Warn only if the dtor is non-private or the class has 5155 friends. */ 5156 if (/* An implicitly declared destructor is always public. And, 5157 if it were virtual, we would have created it by now. */ 5158 !dtor 5159 || (!DECL_VINDEX (dtor) 5160 && (!TREE_PRIVATE (dtor) 5161 || CLASSTYPE_FRIEND_CLASSES (t) 5162 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t))))) 5163 warning (0, "%q#T has virtual functions but non-virtual destructor", 5164 t); 5165 } 5166 5167 complete_vars (t); 5168 5169 if (warn_overloaded_virtual) 5170 warn_hidden (t); 5171 5172 /* Class layout, assignment of virtual table slots, etc., is now 5173 complete. Give the back end a chance to tweak the visibility of 5174 the class or perform any other required target modifications. */ 5175 targetm.cxx.adjust_class_at_definition (t); 5176 5177 maybe_suppress_debug_info (t); 5178 5179 dump_class_hierarchy (t); 5180 5181 /* Finish debugging output for this type. */ 5182 rest_of_type_compilation (t, ! LOCAL_CLASS_P (t)); 5183} 5184 5185/* When T was built up, the member declarations were added in reverse 5186 order. Rearrange them to declaration order. */ 5187 5188void 5189unreverse_member_declarations (tree t) 5190{ 5191 tree next; 5192 tree prev; 5193 tree x; 5194 5195 /* The following lists are all in reverse order. Put them in 5196 declaration order now. */ 5197 TYPE_METHODS (t) = nreverse (TYPE_METHODS (t)); 5198 CLASSTYPE_DECL_LIST (t) = nreverse (CLASSTYPE_DECL_LIST (t)); 5199 5200 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in 5201 reverse order, so we can't just use nreverse. */ 5202 prev = NULL_TREE; 5203 for (x = TYPE_FIELDS (t); 5204 x && TREE_CODE (x) != TYPE_DECL; 5205 x = next) 5206 { 5207 next = TREE_CHAIN (x); 5208 TREE_CHAIN (x) = prev; 5209 prev = x; 5210 } 5211 if (prev) 5212 { 5213 TREE_CHAIN (TYPE_FIELDS (t)) = x; 5214 if (prev) 5215 TYPE_FIELDS (t) = prev; 5216 } 5217} 5218 5219tree 5220finish_struct (tree t, tree attributes) 5221{ 5222 location_t saved_loc = input_location; 5223 5224 /* Now that we've got all the field declarations, reverse everything 5225 as necessary. */ 5226 unreverse_member_declarations (t); 5227 5228 cplus_decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 5229 5230 /* Nadger the current location so that diagnostics point to the start of 5231 the struct, not the end. */ 5232 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (t)); 5233 5234 if (processing_template_decl) 5235 { 5236 tree x; 5237 5238 finish_struct_methods (t); 5239 TYPE_SIZE (t) = bitsize_zero_node; 5240 TYPE_SIZE_UNIT (t) = size_zero_node; 5241 5242 /* We need to emit an error message if this type was used as a parameter 5243 and it is an abstract type, even if it is a template. We construct 5244 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into 5245 account and we call complete_vars with this type, which will check 5246 the PARM_DECLS. Note that while the type is being defined, 5247 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends 5248 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */ 5249 CLASSTYPE_PURE_VIRTUALS (t) = NULL; 5250 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x)) 5251 if (DECL_PURE_VIRTUAL_P (x)) 5252 VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x); 5253 complete_vars (t); 5254 } 5255 else 5256 finish_struct_1 (t); 5257 5258 input_location = saved_loc; 5259 5260 TYPE_BEING_DEFINED (t) = 0; 5261 5262 if (current_class_type) 5263 popclass (); 5264 else 5265 error ("trying to finish struct, but kicked out due to previous parse errors"); 5266 5267 if (processing_template_decl && at_function_scope_p ()) 5268 add_stmt (build_min (TAG_DEFN, t)); 5269 5270 return t; 5271} 5272 5273/* Return the dynamic type of INSTANCE, if known. 5274 Used to determine whether the virtual function table is needed 5275 or not. 5276 5277 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless 5278 of our knowledge of its type. *NONNULL should be initialized 5279 before this function is called. */ 5280 5281static tree 5282fixed_type_or_null (tree instance, int* nonnull, int* cdtorp) 5283{ 5284 switch (TREE_CODE (instance)) 5285 { 5286 case INDIRECT_REF: 5287 if (POINTER_TYPE_P (TREE_TYPE (instance))) 5288 return NULL_TREE; 5289 else 5290 return fixed_type_or_null (TREE_OPERAND (instance, 0), 5291 nonnull, cdtorp); 5292 5293 case CALL_EXPR: 5294 /* This is a call to a constructor, hence it's never zero. */ 5295 if (TREE_HAS_CONSTRUCTOR (instance)) 5296 { 5297 if (nonnull) 5298 *nonnull = 1; 5299 return TREE_TYPE (instance); 5300 } 5301 return NULL_TREE; 5302 5303 case SAVE_EXPR: 5304 /* This is a call to a constructor, hence it's never zero. */ 5305 if (TREE_HAS_CONSTRUCTOR (instance)) 5306 { 5307 if (nonnull) 5308 *nonnull = 1; 5309 return TREE_TYPE (instance); 5310 } 5311 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp); 5312 5313 case PLUS_EXPR: 5314 case MINUS_EXPR: 5315 if (TREE_CODE (TREE_OPERAND (instance, 0)) == ADDR_EXPR) 5316 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp); 5317 if (TREE_CODE (TREE_OPERAND (instance, 1)) == INTEGER_CST) 5318 /* Propagate nonnull. */ 5319 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp); 5320 return NULL_TREE; 5321 5322 case NOP_EXPR: 5323 case CONVERT_EXPR: 5324 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp); 5325 5326 case ADDR_EXPR: 5327 instance = TREE_OPERAND (instance, 0); 5328 if (nonnull) 5329 { 5330 /* Just because we see an ADDR_EXPR doesn't mean we're dealing 5331 with a real object -- given &p->f, p can still be null. */ 5332 tree t = get_base_address (instance); 5333 /* ??? Probably should check DECL_WEAK here. */ 5334 if (t && DECL_P (t)) 5335 *nonnull = 1; 5336 } 5337 return fixed_type_or_null (instance, nonnull, cdtorp); 5338 5339 case COMPONENT_REF: 5340 /* If this component is really a base class reference, then the field 5341 itself isn't definitive. */ 5342 if (DECL_FIELD_IS_BASE (TREE_OPERAND (instance, 1))) 5343 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp); 5344 return fixed_type_or_null (TREE_OPERAND (instance, 1), nonnull, cdtorp); 5345 5346 case VAR_DECL: 5347 case FIELD_DECL: 5348 if (TREE_CODE (TREE_TYPE (instance)) == ARRAY_TYPE 5349 && IS_AGGR_TYPE (TREE_TYPE (TREE_TYPE (instance)))) 5350 { 5351 if (nonnull) 5352 *nonnull = 1; 5353 return TREE_TYPE (TREE_TYPE (instance)); 5354 } 5355 /* fall through... */ 5356 case TARGET_EXPR: 5357 case PARM_DECL: 5358 case RESULT_DECL: 5359 if (IS_AGGR_TYPE (TREE_TYPE (instance))) 5360 { 5361 if (nonnull) 5362 *nonnull = 1; 5363 return TREE_TYPE (instance); 5364 } 5365 else if (instance == current_class_ptr) 5366 { 5367 if (nonnull) 5368 *nonnull = 1; 5369 5370 /* if we're in a ctor or dtor, we know our type. */ 5371 if (DECL_LANG_SPECIFIC (current_function_decl) 5372 && (DECL_CONSTRUCTOR_P (current_function_decl) 5373 || DECL_DESTRUCTOR_P (current_function_decl))) 5374 { 5375 if (cdtorp) 5376 *cdtorp = 1; 5377 return TREE_TYPE (TREE_TYPE (instance)); 5378 } 5379 } 5380 else if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE) 5381 { 5382 /* We only need one hash table because it is always left empty. */ 5383 static htab_t ht; 5384 if (!ht) 5385 ht = htab_create (37, 5386 htab_hash_pointer, 5387 htab_eq_pointer, 5388 /*htab_del=*/NULL); 5389 5390 /* Reference variables should be references to objects. */ 5391 if (nonnull) 5392 *nonnull = 1; 5393 5394 /* Enter the INSTANCE in a table to prevent recursion; a 5395 variable's initializer may refer to the variable 5396 itself. */ 5397 if (TREE_CODE (instance) == VAR_DECL 5398 && DECL_INITIAL (instance) 5399 && !htab_find (ht, instance)) 5400 { 5401 tree type; 5402 void **slot; 5403 5404 slot = htab_find_slot (ht, instance, INSERT); 5405 *slot = instance; 5406 type = fixed_type_or_null (DECL_INITIAL (instance), 5407 nonnull, cdtorp); 5408 htab_remove_elt (ht, instance); 5409 5410 return type; 5411 } 5412 } 5413 return NULL_TREE; 5414 5415 default: 5416 return NULL_TREE; 5417 } 5418} 5419 5420/* Return nonzero if the dynamic type of INSTANCE is known, and 5421 equivalent to the static type. We also handle the case where 5422 INSTANCE is really a pointer. Return negative if this is a 5423 ctor/dtor. There the dynamic type is known, but this might not be 5424 the most derived base of the original object, and hence virtual 5425 bases may not be layed out according to this type. 5426 5427 Used to determine whether the virtual function table is needed 5428 or not. 5429 5430 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless 5431 of our knowledge of its type. *NONNULL should be initialized 5432 before this function is called. */ 5433 5434int 5435resolves_to_fixed_type_p (tree instance, int* nonnull) 5436{ 5437 tree t = TREE_TYPE (instance); 5438 int cdtorp = 0; 5439 5440 tree fixed = fixed_type_or_null (instance, nonnull, &cdtorp); 5441 if (fixed == NULL_TREE) 5442 return 0; 5443 if (POINTER_TYPE_P (t)) 5444 t = TREE_TYPE (t); 5445 if (!same_type_ignoring_top_level_qualifiers_p (t, fixed)) 5446 return 0; 5447 return cdtorp ? -1 : 1; 5448} 5449 5450 5451void 5452init_class_processing (void) 5453{ 5454 current_class_depth = 0; 5455 current_class_stack_size = 10; 5456 current_class_stack 5457 = XNEWVEC (struct class_stack_node, current_class_stack_size); 5458 local_classes = VEC_alloc (tree, gc, 8); 5459 sizeof_biggest_empty_class = size_zero_node; 5460 5461 ridpointers[(int) RID_PUBLIC] = access_public_node; 5462 ridpointers[(int) RID_PRIVATE] = access_private_node; 5463 ridpointers[(int) RID_PROTECTED] = access_protected_node; 5464} 5465 5466/* Restore the cached PREVIOUS_CLASS_LEVEL. */ 5467 5468static void 5469restore_class_cache (void) 5470{ 5471 tree type; 5472 5473 /* We are re-entering the same class we just left, so we don't 5474 have to search the whole inheritance matrix to find all the 5475 decls to bind again. Instead, we install the cached 5476 class_shadowed list and walk through it binding names. */ 5477 push_binding_level (previous_class_level); 5478 class_binding_level = previous_class_level; 5479 /* Restore IDENTIFIER_TYPE_VALUE. */ 5480 for (type = class_binding_level->type_shadowed; 5481 type; 5482 type = TREE_CHAIN (type)) 5483 SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (type), TREE_TYPE (type)); 5484} 5485 5486/* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as 5487 appropriate for TYPE. 5488 5489 So that we may avoid calls to lookup_name, we cache the _TYPE 5490 nodes of local TYPE_DECLs in the TREE_TYPE field of the name. 5491 5492 For multiple inheritance, we perform a two-pass depth-first search 5493 of the type lattice. */ 5494 5495void 5496pushclass (tree type) 5497{ 5498 class_stack_node_t csn; 5499 5500 type = TYPE_MAIN_VARIANT (type); 5501 5502 /* Make sure there is enough room for the new entry on the stack. */ 5503 if (current_class_depth + 1 >= current_class_stack_size) 5504 { 5505 current_class_stack_size *= 2; 5506 current_class_stack 5507 = XRESIZEVEC (struct class_stack_node, current_class_stack, 5508 current_class_stack_size); 5509 } 5510 5511 /* Insert a new entry on the class stack. */ 5512 csn = current_class_stack + current_class_depth; 5513 csn->name = current_class_name; 5514 csn->type = current_class_type; 5515 csn->access = current_access_specifier; 5516 csn->names_used = 0; 5517 csn->hidden = 0; 5518 current_class_depth++; 5519 5520 /* Now set up the new type. */ 5521 current_class_name = TYPE_NAME (type); 5522 if (TREE_CODE (current_class_name) == TYPE_DECL) 5523 current_class_name = DECL_NAME (current_class_name); 5524 current_class_type = type; 5525 5526 /* By default, things in classes are private, while things in 5527 structures or unions are public. */ 5528 current_access_specifier = (CLASSTYPE_DECLARED_CLASS (type) 5529 ? access_private_node 5530 : access_public_node); 5531 5532 if (previous_class_level 5533 && type != previous_class_level->this_entity 5534 && current_class_depth == 1) 5535 { 5536 /* Forcibly remove any old class remnants. */ 5537 invalidate_class_lookup_cache (); 5538 } 5539 5540 if (!previous_class_level 5541 || type != previous_class_level->this_entity 5542 || current_class_depth > 1) 5543 pushlevel_class (); 5544 else 5545 restore_class_cache (); 5546} 5547 5548/* When we exit a toplevel class scope, we save its binding level so 5549 that we can restore it quickly. Here, we've entered some other 5550 class, so we must invalidate our cache. */ 5551 5552void 5553invalidate_class_lookup_cache (void) 5554{ 5555 previous_class_level = NULL; 5556} 5557 5558/* Get out of the current class scope. If we were in a class scope 5559 previously, that is the one popped to. */ 5560 5561void 5562popclass (void) 5563{ 5564 poplevel_class (); 5565 5566 current_class_depth--; 5567 current_class_name = current_class_stack[current_class_depth].name; 5568 current_class_type = current_class_stack[current_class_depth].type; 5569 current_access_specifier = current_class_stack[current_class_depth].access; 5570 if (current_class_stack[current_class_depth].names_used) 5571 splay_tree_delete (current_class_stack[current_class_depth].names_used); 5572} 5573 5574/* Mark the top of the class stack as hidden. */ 5575 5576void 5577push_class_stack (void) 5578{ 5579 if (current_class_depth) 5580 ++current_class_stack[current_class_depth - 1].hidden; 5581} 5582 5583/* Mark the top of the class stack as un-hidden. */ 5584 5585void 5586pop_class_stack (void) 5587{ 5588 if (current_class_depth) 5589 --current_class_stack[current_class_depth - 1].hidden; 5590} 5591 5592/* Returns 1 if the class type currently being defined is either T or 5593 a nested type of T. */ 5594 5595bool 5596currently_open_class (tree t) 5597{ 5598 int i; 5599 5600 /* We start looking from 1 because entry 0 is from global scope, 5601 and has no type. */ 5602 for (i = current_class_depth; i > 0; --i) 5603 { 5604 tree c; 5605 if (i == current_class_depth) 5606 c = current_class_type; 5607 else 5608 { 5609 if (current_class_stack[i].hidden) 5610 break; 5611 c = current_class_stack[i].type; 5612 } 5613 if (!c) 5614 continue; 5615 if (same_type_p (c, t)) 5616 return true; 5617 } 5618 return false; 5619} 5620 5621/* If either current_class_type or one of its enclosing classes are derived 5622 from T, return the appropriate type. Used to determine how we found 5623 something via unqualified lookup. */ 5624 5625tree 5626currently_open_derived_class (tree t) 5627{ 5628 int i; 5629 5630 /* The bases of a dependent type are unknown. */ 5631 if (dependent_type_p (t)) 5632 return NULL_TREE; 5633 5634 if (!current_class_type) 5635 return NULL_TREE; 5636 5637 if (DERIVED_FROM_P (t, current_class_type)) 5638 return current_class_type; 5639 5640 for (i = current_class_depth - 1; i > 0; --i) 5641 { 5642 if (current_class_stack[i].hidden) 5643 break; 5644 if (DERIVED_FROM_P (t, current_class_stack[i].type)) 5645 return current_class_stack[i].type; 5646 } 5647 5648 return NULL_TREE; 5649} 5650 5651/* When entering a class scope, all enclosing class scopes' names with 5652 static meaning (static variables, static functions, types and 5653 enumerators) have to be visible. This recursive function calls 5654 pushclass for all enclosing class contexts until global or a local 5655 scope is reached. TYPE is the enclosed class. */ 5656 5657void 5658push_nested_class (tree type) 5659{ 5660 tree context; 5661 5662 /* A namespace might be passed in error cases, like A::B:C. */ 5663 if (type == NULL_TREE 5664 || type == error_mark_node 5665 || TREE_CODE (type) == NAMESPACE_DECL 5666 || ! IS_AGGR_TYPE (type) 5667 || TREE_CODE (type) == TEMPLATE_TYPE_PARM 5668 || TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM) 5669 return; 5670 5671 context = DECL_CONTEXT (TYPE_MAIN_DECL (type)); 5672 5673 if (context && CLASS_TYPE_P (context)) 5674 push_nested_class (context); 5675 pushclass (type); 5676} 5677 5678/* Undoes a push_nested_class call. */ 5679 5680void 5681pop_nested_class (void) 5682{ 5683 tree context = DECL_CONTEXT (TYPE_MAIN_DECL (current_class_type)); 5684 5685 popclass (); 5686 if (context && CLASS_TYPE_P (context)) 5687 pop_nested_class (); 5688} 5689 5690/* Returns the number of extern "LANG" blocks we are nested within. */ 5691 5692int 5693current_lang_depth (void) 5694{ 5695 return VEC_length (tree, current_lang_base); 5696} 5697 5698/* Set global variables CURRENT_LANG_NAME to appropriate value 5699 so that behavior of name-mangling machinery is correct. */ 5700 5701void 5702push_lang_context (tree name) 5703{ 5704 VEC_safe_push (tree, gc, current_lang_base, current_lang_name); 5705 5706 if (name == lang_name_cplusplus) 5707 { 5708 current_lang_name = name; 5709 } 5710 else if (name == lang_name_java) 5711 { 5712 current_lang_name = name; 5713 /* DECL_IGNORED_P is initially set for these types, to avoid clutter. 5714 (See record_builtin_java_type in decl.c.) However, that causes 5715 incorrect debug entries if these types are actually used. 5716 So we re-enable debug output after extern "Java". */ 5717 DECL_IGNORED_P (TYPE_NAME (java_byte_type_node)) = 0; 5718 DECL_IGNORED_P (TYPE_NAME (java_short_type_node)) = 0; 5719 DECL_IGNORED_P (TYPE_NAME (java_int_type_node)) = 0; 5720 DECL_IGNORED_P (TYPE_NAME (java_long_type_node)) = 0; 5721 DECL_IGNORED_P (TYPE_NAME (java_float_type_node)) = 0; 5722 DECL_IGNORED_P (TYPE_NAME (java_double_type_node)) = 0; 5723 DECL_IGNORED_P (TYPE_NAME (java_char_type_node)) = 0; 5724 DECL_IGNORED_P (TYPE_NAME (java_boolean_type_node)) = 0; 5725 } 5726 else if (name == lang_name_c) 5727 { 5728 current_lang_name = name; 5729 } 5730 else 5731 error ("language string %<\"%E\"%> not recognized", name); 5732} 5733 5734/* Get out of the current language scope. */ 5735 5736void 5737pop_lang_context (void) 5738{ 5739 current_lang_name = VEC_pop (tree, current_lang_base); 5740} 5741 5742/* Type instantiation routines. */ 5743 5744/* Given an OVERLOAD and a TARGET_TYPE, return the function that 5745 matches the TARGET_TYPE. If there is no satisfactory match, return 5746 error_mark_node, and issue an error & warning messages under 5747 control of FLAGS. Permit pointers to member function if FLAGS 5748 permits. If TEMPLATE_ONLY, the name of the overloaded function was 5749 a template-id, and EXPLICIT_TARGS are the explicitly provided 5750 template arguments. If OVERLOAD is for one or more member 5751 functions, then ACCESS_PATH is the base path used to reference 5752 those member functions. */ 5753 5754static tree 5755resolve_address_of_overloaded_function (tree target_type, 5756 tree overload, 5757 tsubst_flags_t flags, 5758 bool template_only, 5759 tree explicit_targs, 5760 tree access_path) 5761{ 5762 /* Here's what the standard says: 5763 5764 [over.over] 5765 5766 If the name is a function template, template argument deduction 5767 is done, and if the argument deduction succeeds, the deduced 5768 arguments are used to generate a single template function, which 5769 is added to the set of overloaded functions considered. 5770 5771 Non-member functions and static member functions match targets of 5772 type "pointer-to-function" or "reference-to-function." Nonstatic 5773 member functions match targets of type "pointer-to-member 5774 function;" the function type of the pointer to member is used to 5775 select the member function from the set of overloaded member 5776 functions. If a nonstatic member function is selected, the 5777 reference to the overloaded function name is required to have the 5778 form of a pointer to member as described in 5.3.1. 5779 5780 If more than one function is selected, any template functions in 5781 the set are eliminated if the set also contains a non-template 5782 function, and any given template function is eliminated if the 5783 set contains a second template function that is more specialized 5784 than the first according to the partial ordering rules 14.5.5.2. 5785 After such eliminations, if any, there shall remain exactly one 5786 selected function. */ 5787 5788 int is_ptrmem = 0; 5789 int is_reference = 0; 5790 /* We store the matches in a TREE_LIST rooted here. The functions 5791 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy 5792 interoperability with most_specialized_instantiation. */ 5793 tree matches = NULL_TREE; 5794 tree fn; 5795 5796 /* By the time we get here, we should be seeing only real 5797 pointer-to-member types, not the internal POINTER_TYPE to 5798 METHOD_TYPE representation. */ 5799 gcc_assert (TREE_CODE (target_type) != POINTER_TYPE 5800 || TREE_CODE (TREE_TYPE (target_type)) != METHOD_TYPE); 5801 5802 gcc_assert (is_overloaded_fn (overload)); 5803 5804 /* Check that the TARGET_TYPE is reasonable. */ 5805 if (TYPE_PTRFN_P (target_type)) 5806 /* This is OK. */; 5807 else if (TYPE_PTRMEMFUNC_P (target_type)) 5808 /* This is OK, too. */ 5809 is_ptrmem = 1; 5810 else if (TREE_CODE (target_type) == FUNCTION_TYPE) 5811 { 5812 /* This is OK, too. This comes from a conversion to reference 5813 type. */ 5814 target_type = build_reference_type (target_type); 5815 is_reference = 1; 5816 } 5817 else 5818 { 5819 if (flags & tf_error) 5820 error ("cannot resolve overloaded function %qD based on" 5821 " conversion to type %qT", 5822 DECL_NAME (OVL_FUNCTION (overload)), target_type); 5823 return error_mark_node; 5824 } 5825 5826 /* If we can find a non-template function that matches, we can just 5827 use it. There's no point in generating template instantiations 5828 if we're just going to throw them out anyhow. But, of course, we 5829 can only do this when we don't *need* a template function. */ 5830 if (!template_only) 5831 { 5832 tree fns; 5833 5834 for (fns = overload; fns; fns = OVL_NEXT (fns)) 5835 { 5836 tree fn = OVL_CURRENT (fns); 5837 tree fntype; 5838 5839 if (TREE_CODE (fn) == TEMPLATE_DECL) 5840 /* We're not looking for templates just yet. */ 5841 continue; 5842 5843 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) 5844 != is_ptrmem) 5845 /* We're looking for a non-static member, and this isn't 5846 one, or vice versa. */ 5847 continue; 5848 5849 /* Ignore functions which haven't been explicitly 5850 declared. */ 5851 if (DECL_ANTICIPATED (fn)) 5852 continue; 5853 5854 /* See if there's a match. */ 5855 fntype = TREE_TYPE (fn); 5856 if (is_ptrmem) 5857 fntype = build_ptrmemfunc_type (build_pointer_type (fntype)); 5858 else if (!is_reference) 5859 fntype = build_pointer_type (fntype); 5860 5861 if (can_convert_arg (target_type, fntype, fn, LOOKUP_NORMAL)) 5862 matches = tree_cons (fn, NULL_TREE, matches); 5863 } 5864 } 5865 5866 /* Now, if we've already got a match (or matches), there's no need 5867 to proceed to the template functions. But, if we don't have a 5868 match we need to look at them, too. */ 5869 if (!matches) 5870 { 5871 tree target_fn_type; 5872 tree target_arg_types; 5873 tree target_ret_type; 5874 tree fns; 5875 5876 if (is_ptrmem) 5877 target_fn_type 5878 = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (target_type)); 5879 else 5880 target_fn_type = TREE_TYPE (target_type); 5881 target_arg_types = TYPE_ARG_TYPES (target_fn_type); 5882 target_ret_type = TREE_TYPE (target_fn_type); 5883 5884 /* Never do unification on the 'this' parameter. */ 5885 if (TREE_CODE (target_fn_type) == METHOD_TYPE) 5886 target_arg_types = TREE_CHAIN (target_arg_types); 5887 5888 for (fns = overload; fns; fns = OVL_NEXT (fns)) 5889 { 5890 tree fn = OVL_CURRENT (fns); 5891 tree instantiation; 5892 tree instantiation_type; 5893 tree targs; 5894 5895 if (TREE_CODE (fn) != TEMPLATE_DECL) 5896 /* We're only looking for templates. */ 5897 continue; 5898 5899 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) 5900 != is_ptrmem) 5901 /* We're not looking for a non-static member, and this is 5902 one, or vice versa. */ 5903 continue; 5904 5905 /* Try to do argument deduction. */ 5906 targs = make_tree_vec (DECL_NTPARMS (fn)); 5907 if (fn_type_unification (fn, explicit_targs, targs, 5908 target_arg_types, target_ret_type, 5909 DEDUCE_EXACT, LOOKUP_NORMAL)) 5910 /* Argument deduction failed. */ 5911 continue; 5912 5913 /* Instantiate the template. */ 5914 instantiation = instantiate_template (fn, targs, flags); 5915 if (instantiation == error_mark_node) 5916 /* Instantiation failed. */ 5917 continue; 5918 5919 /* See if there's a match. */ 5920 instantiation_type = TREE_TYPE (instantiation); 5921 if (is_ptrmem) 5922 instantiation_type = 5923 build_ptrmemfunc_type (build_pointer_type (instantiation_type)); 5924 else if (!is_reference) 5925 instantiation_type = build_pointer_type (instantiation_type); 5926 if (can_convert_arg (target_type, instantiation_type, instantiation, 5927 LOOKUP_NORMAL)) 5928 matches = tree_cons (instantiation, fn, matches); 5929 } 5930 5931 /* Now, remove all but the most specialized of the matches. */ 5932 if (matches) 5933 { 5934 tree match = most_specialized_instantiation (matches); 5935 5936 if (match != error_mark_node) 5937 matches = tree_cons (TREE_PURPOSE (match), 5938 NULL_TREE, 5939 NULL_TREE); 5940 } 5941 } 5942 5943 /* Now we should have exactly one function in MATCHES. */ 5944 if (matches == NULL_TREE) 5945 { 5946 /* There were *no* matches. */ 5947 if (flags & tf_error) 5948 { 5949 error ("no matches converting function %qD to type %q#T", 5950 DECL_NAME (OVL_FUNCTION (overload)), 5951 target_type); 5952 5953 /* print_candidates expects a chain with the functions in 5954 TREE_VALUE slots, so we cons one up here (we're losing anyway, 5955 so why be clever?). */ 5956 for (; overload; overload = OVL_NEXT (overload)) 5957 matches = tree_cons (NULL_TREE, OVL_CURRENT (overload), 5958 matches); 5959 5960 print_candidates (matches); 5961 } 5962 return error_mark_node; 5963 } 5964 else if (TREE_CHAIN (matches)) 5965 { 5966 /* There were too many matches. */ 5967 5968 if (flags & tf_error) 5969 { 5970 tree match; 5971 5972 error ("converting overloaded function %qD to type %q#T is ambiguous", 5973 DECL_NAME (OVL_FUNCTION (overload)), 5974 target_type); 5975 5976 /* Since print_candidates expects the functions in the 5977 TREE_VALUE slot, we flip them here. */ 5978 for (match = matches; match; match = TREE_CHAIN (match)) 5979 TREE_VALUE (match) = TREE_PURPOSE (match); 5980 5981 print_candidates (matches); 5982 } 5983 5984 return error_mark_node; 5985 } 5986 5987 /* Good, exactly one match. Now, convert it to the correct type. */ 5988 fn = TREE_PURPOSE (matches); 5989 5990 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) 5991 && !(flags & tf_ptrmem_ok) && !flag_ms_extensions) 5992 { 5993 static int explained; 5994 5995 if (!(flags & tf_error)) 5996 return error_mark_node; 5997 5998 pedwarn ("assuming pointer to member %qD", fn); 5999 if (!explained) 6000 { 6001 pedwarn ("(a pointer to member can only be formed with %<&%E%>)", fn); 6002 explained = 1; 6003 } 6004 } 6005 6006 /* If we're doing overload resolution purely for the purpose of 6007 determining conversion sequences, we should not consider the 6008 function used. If this conversion sequence is selected, the 6009 function will be marked as used at this point. */ 6010 if (!(flags & tf_conv)) 6011 { 6012 mark_used (fn); 6013 /* We could not check access when this expression was originally 6014 created since we did not know at that time to which function 6015 the expression referred. */ 6016 if (DECL_FUNCTION_MEMBER_P (fn)) 6017 { 6018 gcc_assert (access_path); 6019 perform_or_defer_access_check (access_path, fn, fn); 6020 } 6021 } 6022 6023 if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type)) 6024 return build_unary_op (ADDR_EXPR, fn, 0); 6025 else 6026 { 6027 /* The target must be a REFERENCE_TYPE. Above, build_unary_op 6028 will mark the function as addressed, but here we must do it 6029 explicitly. */ 6030 cxx_mark_addressable (fn); 6031 6032 return fn; 6033 } 6034} 6035 6036/* This function will instantiate the type of the expression given in 6037 RHS to match the type of LHSTYPE. If errors exist, then return 6038 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then 6039 we complain on errors. If we are not complaining, never modify rhs, 6040 as overload resolution wants to try many possible instantiations, in 6041 the hope that at least one will work. 6042 6043 For non-recursive calls, LHSTYPE should be a function, pointer to 6044 function, or a pointer to member function. */ 6045 6046tree 6047instantiate_type (tree lhstype, tree rhs, tsubst_flags_t flags) 6048{ 6049 tsubst_flags_t flags_in = flags; 6050 tree access_path = NULL_TREE; 6051 6052 flags &= ~tf_ptrmem_ok; 6053 6054 if (TREE_CODE (lhstype) == UNKNOWN_TYPE) 6055 { 6056 if (flags & tf_error) 6057 error ("not enough type information"); 6058 return error_mark_node; 6059 } 6060 6061 if (TREE_TYPE (rhs) != NULL_TREE && ! (type_unknown_p (rhs))) 6062 { 6063 if (same_type_p (lhstype, TREE_TYPE (rhs))) 6064 return rhs; 6065 if (flag_ms_extensions 6066 && TYPE_PTRMEMFUNC_P (lhstype) 6067 && !TYPE_PTRMEMFUNC_P (TREE_TYPE (rhs))) 6068 /* Microsoft allows `A::f' to be resolved to a 6069 pointer-to-member. */ 6070 ; 6071 else 6072 { 6073 if (flags & tf_error) 6074 error ("argument of type %qT does not match %qT", 6075 TREE_TYPE (rhs), lhstype); 6076 return error_mark_node; 6077 } 6078 } 6079 6080 if (TREE_CODE (rhs) == BASELINK) 6081 { 6082 access_path = BASELINK_ACCESS_BINFO (rhs); 6083 rhs = BASELINK_FUNCTIONS (rhs); 6084 } 6085 6086 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot 6087 deduce any type information. */ 6088 if (TREE_CODE (rhs) == NON_DEPENDENT_EXPR) 6089 { 6090 if (flags & tf_error) 6091 error ("not enough type information"); 6092 return error_mark_node; 6093 } 6094 6095 /* There only a few kinds of expressions that may have a type 6096 dependent on overload resolution. */ 6097 gcc_assert (TREE_CODE (rhs) == ADDR_EXPR 6098 || TREE_CODE (rhs) == COMPONENT_REF 6099 || TREE_CODE (rhs) == COMPOUND_EXPR 6100 || really_overloaded_fn (rhs)); 6101 6102 /* We don't overwrite rhs if it is an overloaded function. 6103 Copying it would destroy the tree link. */ 6104 if (TREE_CODE (rhs) != OVERLOAD) 6105 rhs = copy_node (rhs); 6106 6107 /* This should really only be used when attempting to distinguish 6108 what sort of a pointer to function we have. For now, any 6109 arithmetic operation which is not supported on pointers 6110 is rejected as an error. */ 6111 6112 switch (TREE_CODE (rhs)) 6113 { 6114 case COMPONENT_REF: 6115 { 6116 tree member = TREE_OPERAND (rhs, 1); 6117 6118 member = instantiate_type (lhstype, member, flags); 6119 if (member != error_mark_node 6120 && TREE_SIDE_EFFECTS (TREE_OPERAND (rhs, 0))) 6121 /* Do not lose object's side effects. */ 6122 return build2 (COMPOUND_EXPR, TREE_TYPE (member), 6123 TREE_OPERAND (rhs, 0), member); 6124 return member; 6125 } 6126 6127 case OFFSET_REF: 6128 rhs = TREE_OPERAND (rhs, 1); 6129 if (BASELINK_P (rhs)) 6130 return instantiate_type (lhstype, rhs, flags_in); 6131 6132 /* This can happen if we are forming a pointer-to-member for a 6133 member template. */ 6134 gcc_assert (TREE_CODE (rhs) == TEMPLATE_ID_EXPR); 6135 6136 /* Fall through. */ 6137 6138 case TEMPLATE_ID_EXPR: 6139 { 6140 tree fns = TREE_OPERAND (rhs, 0); 6141 tree args = TREE_OPERAND (rhs, 1); 6142 6143 return 6144 resolve_address_of_overloaded_function (lhstype, fns, flags_in, 6145 /*template_only=*/true, 6146 args, access_path); 6147 } 6148 6149 case OVERLOAD: 6150 case FUNCTION_DECL: 6151 return 6152 resolve_address_of_overloaded_function (lhstype, rhs, flags_in, 6153 /*template_only=*/false, 6154 /*explicit_targs=*/NULL_TREE, 6155 access_path); 6156 6157 case COMPOUND_EXPR: 6158 TREE_OPERAND (rhs, 0) 6159 = instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags); 6160 if (TREE_OPERAND (rhs, 0) == error_mark_node) 6161 return error_mark_node; 6162 TREE_OPERAND (rhs, 1) 6163 = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags); 6164 if (TREE_OPERAND (rhs, 1) == error_mark_node) 6165 return error_mark_node; 6166 6167 TREE_TYPE (rhs) = lhstype; 6168 return rhs; 6169 6170 case ADDR_EXPR: 6171 { 6172 if (PTRMEM_OK_P (rhs)) 6173 flags |= tf_ptrmem_ok; 6174 6175 return instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags); 6176 } 6177 6178 case ERROR_MARK: 6179 return error_mark_node; 6180 6181 default: 6182 gcc_unreachable (); 6183 } 6184 return error_mark_node; 6185} 6186 6187/* Return the name of the virtual function pointer field 6188 (as an IDENTIFIER_NODE) for the given TYPE. Note that 6189 this may have to look back through base types to find the 6190 ultimate field name. (For single inheritance, these could 6191 all be the same name. Who knows for multiple inheritance). */ 6192 6193static tree 6194get_vfield_name (tree type) 6195{ 6196 tree binfo, base_binfo; 6197 char *buf; 6198 6199 for (binfo = TYPE_BINFO (type); 6200 BINFO_N_BASE_BINFOS (binfo); 6201 binfo = base_binfo) 6202 { 6203 base_binfo = BINFO_BASE_BINFO (binfo, 0); 6204 6205 if (BINFO_VIRTUAL_P (base_binfo) 6206 || !TYPE_CONTAINS_VPTR_P (BINFO_TYPE (base_binfo))) 6207 break; 6208 } 6209 6210 type = BINFO_TYPE (binfo); 6211 buf = (char *) alloca (sizeof (VFIELD_NAME_FORMAT) 6212 + TYPE_NAME_LENGTH (type) + 2); 6213 sprintf (buf, VFIELD_NAME_FORMAT, 6214 IDENTIFIER_POINTER (constructor_name (type))); 6215 return get_identifier (buf); 6216} 6217 6218void 6219print_class_statistics (void) 6220{ 6221#ifdef GATHER_STATISTICS 6222 fprintf (stderr, "convert_harshness = %d\n", n_convert_harshness); 6223 fprintf (stderr, "compute_conversion_costs = %d\n", n_compute_conversion_costs); 6224 if (n_vtables) 6225 { 6226 fprintf (stderr, "vtables = %d; vtable searches = %d\n", 6227 n_vtables, n_vtable_searches); 6228 fprintf (stderr, "vtable entries = %d; vtable elems = %d\n", 6229 n_vtable_entries, n_vtable_elems); 6230 } 6231#endif 6232} 6233 6234/* Build a dummy reference to ourselves so Derived::Base (and A::A) works, 6235 according to [class]: 6236 The class-name is also inserted 6237 into the scope of the class itself. For purposes of access checking, 6238 the inserted class name is treated as if it were a public member name. */ 6239 6240void 6241build_self_reference (void) 6242{ 6243 tree name = constructor_name (current_class_type); 6244 tree value = build_lang_decl (TYPE_DECL, name, current_class_type); 6245 tree saved_cas; 6246 6247 DECL_NONLOCAL (value) = 1; 6248 DECL_CONTEXT (value) = current_class_type; 6249 DECL_ARTIFICIAL (value) = 1; 6250 SET_DECL_SELF_REFERENCE_P (value); 6251 6252 if (processing_template_decl) 6253 value = push_template_decl (value); 6254 6255 saved_cas = current_access_specifier; 6256 current_access_specifier = access_public_node; 6257 finish_member_declaration (value); 6258 current_access_specifier = saved_cas; 6259} 6260 6261/* Returns 1 if TYPE contains only padding bytes. */ 6262 6263int 6264is_empty_class (tree type) 6265{ 6266 if (type == error_mark_node) 6267 return 0; 6268 6269 if (! IS_AGGR_TYPE (type)) 6270 return 0; 6271 6272 /* In G++ 3.2, whether or not a class was empty was determined by 6273 looking at its size. */ 6274 if (abi_version_at_least (2)) 6275 return CLASSTYPE_EMPTY_P (type); 6276 else 6277 return integer_zerop (CLASSTYPE_SIZE (type)); 6278} 6279 6280/* Returns true if TYPE contains an empty class. */ 6281 6282static bool 6283contains_empty_class_p (tree type) 6284{ 6285 if (is_empty_class (type)) 6286 return true; 6287 if (CLASS_TYPE_P (type)) 6288 { 6289 tree field; 6290 tree binfo; 6291 tree base_binfo; 6292 int i; 6293 6294 for (binfo = TYPE_BINFO (type), i = 0; 6295 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 6296 if (contains_empty_class_p (BINFO_TYPE (base_binfo))) 6297 return true; 6298 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) 6299 if (TREE_CODE (field) == FIELD_DECL 6300 && !DECL_ARTIFICIAL (field) 6301 && is_empty_class (TREE_TYPE (field))) 6302 return true; 6303 } 6304 else if (TREE_CODE (type) == ARRAY_TYPE) 6305 return contains_empty_class_p (TREE_TYPE (type)); 6306 return false; 6307} 6308 6309/* Note that NAME was looked up while the current class was being 6310 defined and that the result of that lookup was DECL. */ 6311 6312void 6313maybe_note_name_used_in_class (tree name, tree decl) 6314{ 6315 splay_tree names_used; 6316 6317 /* If we're not defining a class, there's nothing to do. */ 6318 if (!(innermost_scope_kind() == sk_class 6319 && TYPE_BEING_DEFINED (current_class_type))) 6320 return; 6321 6322 /* If there's already a binding for this NAME, then we don't have 6323 anything to worry about. */ 6324 if (lookup_member (current_class_type, name, 6325 /*protect=*/0, /*want_type=*/false)) 6326 return; 6327 6328 if (!current_class_stack[current_class_depth - 1].names_used) 6329 current_class_stack[current_class_depth - 1].names_used 6330 = splay_tree_new (splay_tree_compare_pointers, 0, 0); 6331 names_used = current_class_stack[current_class_depth - 1].names_used; 6332 6333 splay_tree_insert (names_used, 6334 (splay_tree_key) name, 6335 (splay_tree_value) decl); 6336} 6337 6338/* Note that NAME was declared (as DECL) in the current class. Check 6339 to see that the declaration is valid. */ 6340 6341void 6342note_name_declared_in_class (tree name, tree decl) 6343{ 6344 splay_tree names_used; 6345 splay_tree_node n; 6346 6347 /* Look to see if we ever used this name. */ 6348 names_used 6349 = current_class_stack[current_class_depth - 1].names_used; 6350 if (!names_used) 6351 return; 6352 6353 n = splay_tree_lookup (names_used, (splay_tree_key) name); 6354 if (n) 6355 { 6356 /* [basic.scope.class] 6357 6358 A name N used in a class S shall refer to the same declaration 6359 in its context and when re-evaluated in the completed scope of 6360 S. */ 6361 error ("declaration of %q#D", decl); 6362 error ("changes meaning of %qD from %q+#D", 6363 DECL_NAME (OVL_CURRENT (decl)), (tree) n->value); 6364 } 6365} 6366 6367/* Returns the VAR_DECL for the complete vtable associated with BINFO. 6368 Secondary vtables are merged with primary vtables; this function 6369 will return the VAR_DECL for the primary vtable. */ 6370 6371tree 6372get_vtbl_decl_for_binfo (tree binfo) 6373{ 6374 tree decl; 6375 6376 decl = BINFO_VTABLE (binfo); 6377 if (decl && TREE_CODE (decl) == PLUS_EXPR) 6378 { 6379 gcc_assert (TREE_CODE (TREE_OPERAND (decl, 0)) == ADDR_EXPR); 6380 decl = TREE_OPERAND (TREE_OPERAND (decl, 0), 0); 6381 } 6382 if (decl) 6383 gcc_assert (TREE_CODE (decl) == VAR_DECL); 6384 return decl; 6385} 6386 6387 6388/* Returns the binfo for the primary base of BINFO. If the resulting 6389 BINFO is a virtual base, and it is inherited elsewhere in the 6390 hierarchy, then the returned binfo might not be the primary base of 6391 BINFO in the complete object. Check BINFO_PRIMARY_P or 6392 BINFO_LOST_PRIMARY_P to be sure. */ 6393 6394static tree 6395get_primary_binfo (tree binfo) 6396{ 6397 tree primary_base; 6398 6399 primary_base = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (binfo)); 6400 if (!primary_base) 6401 return NULL_TREE; 6402 6403 return copied_binfo (primary_base, binfo); 6404} 6405 6406/* If INDENTED_P is zero, indent to INDENT. Return nonzero. */ 6407 6408static int 6409maybe_indent_hierarchy (FILE * stream, int indent, int indented_p) 6410{ 6411 if (!indented_p) 6412 fprintf (stream, "%*s", indent, ""); 6413 return 1; 6414} 6415 6416/* Dump the offsets of all the bases rooted at BINFO to STREAM. 6417 INDENT should be zero when called from the top level; it is 6418 incremented recursively. IGO indicates the next expected BINFO in 6419 inheritance graph ordering. */ 6420 6421static tree 6422dump_class_hierarchy_r (FILE *stream, 6423 int flags, 6424 tree binfo, 6425 tree igo, 6426 int indent) 6427{ 6428 int indented = 0; 6429 tree base_binfo; 6430 int i; 6431 6432 indented = maybe_indent_hierarchy (stream, indent, 0); 6433 fprintf (stream, "%s (0x%lx) ", 6434 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER), 6435 (unsigned long) binfo); 6436 if (binfo != igo) 6437 { 6438 fprintf (stream, "alternative-path\n"); 6439 return igo; 6440 } 6441 igo = TREE_CHAIN (binfo); 6442 6443 fprintf (stream, HOST_WIDE_INT_PRINT_DEC, 6444 tree_low_cst (BINFO_OFFSET (binfo), 0)); 6445 if (is_empty_class (BINFO_TYPE (binfo))) 6446 fprintf (stream, " empty"); 6447 else if (CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (binfo))) 6448 fprintf (stream, " nearly-empty"); 6449 if (BINFO_VIRTUAL_P (binfo)) 6450 fprintf (stream, " virtual"); 6451 fprintf (stream, "\n"); 6452 6453 indented = 0; 6454 if (BINFO_PRIMARY_P (binfo)) 6455 { 6456 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 6457 fprintf (stream, " primary-for %s (0x%lx)", 6458 type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)), 6459 TFF_PLAIN_IDENTIFIER), 6460 (unsigned long)BINFO_INHERITANCE_CHAIN (binfo)); 6461 } 6462 if (BINFO_LOST_PRIMARY_P (binfo)) 6463 { 6464 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 6465 fprintf (stream, " lost-primary"); 6466 } 6467 if (indented) 6468 fprintf (stream, "\n"); 6469 6470 if (!(flags & TDF_SLIM)) 6471 { 6472 int indented = 0; 6473 6474 if (BINFO_SUBVTT_INDEX (binfo)) 6475 { 6476 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 6477 fprintf (stream, " subvttidx=%s", 6478 expr_as_string (BINFO_SUBVTT_INDEX (binfo), 6479 TFF_PLAIN_IDENTIFIER)); 6480 } 6481 if (BINFO_VPTR_INDEX (binfo)) 6482 { 6483 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 6484 fprintf (stream, " vptridx=%s", 6485 expr_as_string (BINFO_VPTR_INDEX (binfo), 6486 TFF_PLAIN_IDENTIFIER)); 6487 } 6488 if (BINFO_VPTR_FIELD (binfo)) 6489 { 6490 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 6491 fprintf (stream, " vbaseoffset=%s", 6492 expr_as_string (BINFO_VPTR_FIELD (binfo), 6493 TFF_PLAIN_IDENTIFIER)); 6494 } 6495 if (BINFO_VTABLE (binfo)) 6496 { 6497 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 6498 fprintf (stream, " vptr=%s", 6499 expr_as_string (BINFO_VTABLE (binfo), 6500 TFF_PLAIN_IDENTIFIER)); 6501 } 6502 6503 if (indented) 6504 fprintf (stream, "\n"); 6505 } 6506 6507 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 6508 igo = dump_class_hierarchy_r (stream, flags, base_binfo, igo, indent + 2); 6509 6510 return igo; 6511} 6512 6513/* Dump the BINFO hierarchy for T. */ 6514 6515static void 6516dump_class_hierarchy_1 (FILE *stream, int flags, tree t) 6517{ 6518 fprintf (stream, "Class %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER)); 6519 fprintf (stream, " size=%lu align=%lu\n", 6520 (unsigned long)(tree_low_cst (TYPE_SIZE (t), 0) / BITS_PER_UNIT), 6521 (unsigned long)(TYPE_ALIGN (t) / BITS_PER_UNIT)); 6522 fprintf (stream, " base size=%lu base align=%lu\n", 6523 (unsigned long)(tree_low_cst (TYPE_SIZE (CLASSTYPE_AS_BASE (t)), 0) 6524 / BITS_PER_UNIT), 6525 (unsigned long)(TYPE_ALIGN (CLASSTYPE_AS_BASE (t)) 6526 / BITS_PER_UNIT)); 6527 dump_class_hierarchy_r (stream, flags, TYPE_BINFO (t), TYPE_BINFO (t), 0); 6528 fprintf (stream, "\n"); 6529} 6530 6531/* Debug interface to hierarchy dumping. */ 6532 6533void 6534debug_class (tree t) 6535{ 6536 dump_class_hierarchy_1 (stderr, TDF_SLIM, t); 6537} 6538 6539static void 6540dump_class_hierarchy (tree t) 6541{ 6542 int flags; 6543 FILE *stream = dump_begin (TDI_class, &flags); 6544 6545 if (stream) 6546 { 6547 dump_class_hierarchy_1 (stream, flags, t); 6548 dump_end (TDI_class, stream); 6549 } 6550} 6551 6552static void 6553dump_array (FILE * stream, tree decl) 6554{ 6555 tree value; 6556 unsigned HOST_WIDE_INT ix; 6557 HOST_WIDE_INT elt; 6558 tree size = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (decl))); 6559 6560 elt = (tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl))), 0) 6561 / BITS_PER_UNIT); 6562 fprintf (stream, "%s:", decl_as_string (decl, TFF_PLAIN_IDENTIFIER)); 6563 fprintf (stream, " %s entries", 6564 expr_as_string (size_binop (PLUS_EXPR, size, size_one_node), 6565 TFF_PLAIN_IDENTIFIER)); 6566 fprintf (stream, "\n"); 6567 6568 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (DECL_INITIAL (decl)), 6569 ix, value) 6570 fprintf (stream, "%-4ld %s\n", (long)(ix * elt), 6571 expr_as_string (value, TFF_PLAIN_IDENTIFIER)); 6572} 6573 6574static void 6575dump_vtable (tree t, tree binfo, tree vtable) 6576{ 6577 int flags; 6578 FILE *stream = dump_begin (TDI_class, &flags); 6579 6580 if (!stream) 6581 return; 6582 6583 if (!(flags & TDF_SLIM)) 6584 { 6585 int ctor_vtbl_p = TYPE_BINFO (t) != binfo; 6586 6587 fprintf (stream, "%s for %s", 6588 ctor_vtbl_p ? "Construction vtable" : "Vtable", 6589 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER)); 6590 if (ctor_vtbl_p) 6591 { 6592 if (!BINFO_VIRTUAL_P (binfo)) 6593 fprintf (stream, " (0x%lx instance)", (unsigned long)binfo); 6594 fprintf (stream, " in %s", type_as_string (t, TFF_PLAIN_IDENTIFIER)); 6595 } 6596 fprintf (stream, "\n"); 6597 dump_array (stream, vtable); 6598 fprintf (stream, "\n"); 6599 } 6600 6601 dump_end (TDI_class, stream); 6602} 6603 6604static void 6605dump_vtt (tree t, tree vtt) 6606{ 6607 int flags; 6608 FILE *stream = dump_begin (TDI_class, &flags); 6609 6610 if (!stream) 6611 return; 6612 6613 if (!(flags & TDF_SLIM)) 6614 { 6615 fprintf (stream, "VTT for %s\n", 6616 type_as_string (t, TFF_PLAIN_IDENTIFIER)); 6617 dump_array (stream, vtt); 6618 fprintf (stream, "\n"); 6619 } 6620 6621 dump_end (TDI_class, stream); 6622} 6623 6624/* Dump a function or thunk and its thunkees. */ 6625 6626static void 6627dump_thunk (FILE *stream, int indent, tree thunk) 6628{ 6629 static const char spaces[] = " "; 6630 tree name = DECL_NAME (thunk); 6631 tree thunks; 6632 6633 fprintf (stream, "%.*s%p %s %s", indent, spaces, 6634 (void *)thunk, 6635 !DECL_THUNK_P (thunk) ? "function" 6636 : DECL_THIS_THUNK_P (thunk) ? "this-thunk" : "covariant-thunk", 6637 name ? IDENTIFIER_POINTER (name) : "<unset>"); 6638 if (DECL_THUNK_P (thunk)) 6639 { 6640 HOST_WIDE_INT fixed_adjust = THUNK_FIXED_OFFSET (thunk); 6641 tree virtual_adjust = THUNK_VIRTUAL_OFFSET (thunk); 6642 6643 fprintf (stream, " fixed=" HOST_WIDE_INT_PRINT_DEC, fixed_adjust); 6644 if (!virtual_adjust) 6645 /*NOP*/; 6646 else if (DECL_THIS_THUNK_P (thunk)) 6647 fprintf (stream, " vcall=" HOST_WIDE_INT_PRINT_DEC, 6648 tree_low_cst (virtual_adjust, 0)); 6649 else 6650 fprintf (stream, " vbase=" HOST_WIDE_INT_PRINT_DEC "(%s)", 6651 tree_low_cst (BINFO_VPTR_FIELD (virtual_adjust), 0), 6652 type_as_string (BINFO_TYPE (virtual_adjust), TFF_SCOPE)); 6653 if (THUNK_ALIAS (thunk)) 6654 fprintf (stream, " alias to %p", (void *)THUNK_ALIAS (thunk)); 6655 } 6656 fprintf (stream, "\n"); 6657 for (thunks = DECL_THUNKS (thunk); thunks; thunks = TREE_CHAIN (thunks)) 6658 dump_thunk (stream, indent + 2, thunks); 6659} 6660 6661/* Dump the thunks for FN. */ 6662 6663void 6664debug_thunks (tree fn) 6665{ 6666 dump_thunk (stderr, 0, fn); 6667} 6668 6669/* Virtual function table initialization. */ 6670 6671/* Create all the necessary vtables for T and its base classes. */ 6672 6673static void 6674finish_vtbls (tree t) 6675{ 6676 tree list; 6677 tree vbase; 6678 6679 /* We lay out the primary and secondary vtables in one contiguous 6680 vtable. The primary vtable is first, followed by the non-virtual 6681 secondary vtables in inheritance graph order. */ 6682 list = build_tree_list (BINFO_VTABLE (TYPE_BINFO (t)), NULL_TREE); 6683 accumulate_vtbl_inits (TYPE_BINFO (t), TYPE_BINFO (t), 6684 TYPE_BINFO (t), t, list); 6685 6686 /* Then come the virtual bases, also in inheritance graph order. */ 6687 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase)) 6688 { 6689 if (!BINFO_VIRTUAL_P (vbase)) 6690 continue; 6691 accumulate_vtbl_inits (vbase, vbase, TYPE_BINFO (t), t, list); 6692 } 6693 6694 if (BINFO_VTABLE (TYPE_BINFO (t))) 6695 initialize_vtable (TYPE_BINFO (t), TREE_VALUE (list)); 6696} 6697 6698/* Initialize the vtable for BINFO with the INITS. */ 6699 6700static void 6701initialize_vtable (tree binfo, tree inits) 6702{ 6703 tree decl; 6704 6705 layout_vtable_decl (binfo, list_length (inits)); 6706 decl = get_vtbl_decl_for_binfo (binfo); 6707 initialize_artificial_var (decl, inits); 6708 dump_vtable (BINFO_TYPE (binfo), binfo, decl); 6709} 6710 6711/* Build the VTT (virtual table table) for T. 6712 A class requires a VTT if it has virtual bases. 6713 6714 This holds 6715 1 - primary virtual pointer for complete object T 6716 2 - secondary VTTs for each direct non-virtual base of T which requires a 6717 VTT 6718 3 - secondary virtual pointers for each direct or indirect base of T which 6719 has virtual bases or is reachable via a virtual path from T. 6720 4 - secondary VTTs for each direct or indirect virtual base of T. 6721 6722 Secondary VTTs look like complete object VTTs without part 4. */ 6723 6724static void 6725build_vtt (tree t) 6726{ 6727 tree inits; 6728 tree type; 6729 tree vtt; 6730 tree index; 6731 6732 /* Build up the initializers for the VTT. */ 6733 inits = NULL_TREE; 6734 index = size_zero_node; 6735 build_vtt_inits (TYPE_BINFO (t), t, &inits, &index); 6736 6737 /* If we didn't need a VTT, we're done. */ 6738 if (!inits) 6739 return; 6740 6741 /* Figure out the type of the VTT. */ 6742 type = build_index_type (size_int (list_length (inits) - 1)); 6743 type = build_cplus_array_type (const_ptr_type_node, type); 6744 6745 /* Now, build the VTT object itself. */ 6746 vtt = build_vtable (t, mangle_vtt_for_type (t), type); 6747 initialize_artificial_var (vtt, inits); 6748 /* Add the VTT to the vtables list. */ 6749 TREE_CHAIN (vtt) = TREE_CHAIN (CLASSTYPE_VTABLES (t)); 6750 TREE_CHAIN (CLASSTYPE_VTABLES (t)) = vtt; 6751 6752 dump_vtt (t, vtt); 6753} 6754 6755/* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with 6756 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo, 6757 and CHAIN the vtable pointer for this binfo after construction is 6758 complete. VALUE can also be another BINFO, in which case we recurse. */ 6759 6760static tree 6761binfo_ctor_vtable (tree binfo) 6762{ 6763 tree vt; 6764 6765 while (1) 6766 { 6767 vt = BINFO_VTABLE (binfo); 6768 if (TREE_CODE (vt) == TREE_LIST) 6769 vt = TREE_VALUE (vt); 6770 if (TREE_CODE (vt) == TREE_BINFO) 6771 binfo = vt; 6772 else 6773 break; 6774 } 6775 6776 return vt; 6777} 6778 6779/* Data for secondary VTT initialization. */ 6780typedef struct secondary_vptr_vtt_init_data_s 6781{ 6782 /* Is this the primary VTT? */ 6783 bool top_level_p; 6784 6785 /* Current index into the VTT. */ 6786 tree index; 6787 6788 /* TREE_LIST of initializers built up. */ 6789 tree inits; 6790 6791 /* The type being constructed by this secondary VTT. */ 6792 tree type_being_constructed; 6793} secondary_vptr_vtt_init_data; 6794 6795/* Recursively build the VTT-initializer for BINFO (which is in the 6796 hierarchy dominated by T). INITS points to the end of the initializer 6797 list to date. INDEX is the VTT index where the next element will be 6798 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e. 6799 not a subvtt for some base of T). When that is so, we emit the sub-VTTs 6800 for virtual bases of T. When it is not so, we build the constructor 6801 vtables for the BINFO-in-T variant. */ 6802 6803static tree * 6804build_vtt_inits (tree binfo, tree t, tree *inits, tree *index) 6805{ 6806 int i; 6807 tree b; 6808 tree init; 6809 tree secondary_vptrs; 6810 secondary_vptr_vtt_init_data data; 6811 int top_level_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t); 6812 6813 /* We only need VTTs for subobjects with virtual bases. */ 6814 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))) 6815 return inits; 6816 6817 /* We need to use a construction vtable if this is not the primary 6818 VTT. */ 6819 if (!top_level_p) 6820 { 6821 build_ctor_vtbl_group (binfo, t); 6822 6823 /* Record the offset in the VTT where this sub-VTT can be found. */ 6824 BINFO_SUBVTT_INDEX (binfo) = *index; 6825 } 6826 6827 /* Add the address of the primary vtable for the complete object. */ 6828 init = binfo_ctor_vtable (binfo); 6829 *inits = build_tree_list (NULL_TREE, init); 6830 inits = &TREE_CHAIN (*inits); 6831 if (top_level_p) 6832 { 6833 gcc_assert (!BINFO_VPTR_INDEX (binfo)); 6834 BINFO_VPTR_INDEX (binfo) = *index; 6835 } 6836 *index = size_binop (PLUS_EXPR, *index, TYPE_SIZE_UNIT (ptr_type_node)); 6837 6838 /* Recursively add the secondary VTTs for non-virtual bases. */ 6839 for (i = 0; BINFO_BASE_ITERATE (binfo, i, b); ++i) 6840 if (!BINFO_VIRTUAL_P (b)) 6841 inits = build_vtt_inits (b, t, inits, index); 6842 6843 /* Add secondary virtual pointers for all subobjects of BINFO with 6844 either virtual bases or reachable along a virtual path, except 6845 subobjects that are non-virtual primary bases. */ 6846 data.top_level_p = top_level_p; 6847 data.index = *index; 6848 data.inits = NULL; 6849 data.type_being_constructed = BINFO_TYPE (binfo); 6850 6851 dfs_walk_once (binfo, dfs_build_secondary_vptr_vtt_inits, NULL, &data); 6852 6853 *index = data.index; 6854 6855 /* The secondary vptrs come back in reverse order. After we reverse 6856 them, and add the INITS, the last init will be the first element 6857 of the chain. */ 6858 secondary_vptrs = data.inits; 6859 if (secondary_vptrs) 6860 { 6861 *inits = nreverse (secondary_vptrs); 6862 inits = &TREE_CHAIN (secondary_vptrs); 6863 gcc_assert (*inits == NULL_TREE); 6864 } 6865 6866 if (top_level_p) 6867 /* Add the secondary VTTs for virtual bases in inheritance graph 6868 order. */ 6869 for (b = TYPE_BINFO (BINFO_TYPE (binfo)); b; b = TREE_CHAIN (b)) 6870 { 6871 if (!BINFO_VIRTUAL_P (b)) 6872 continue; 6873 6874 inits = build_vtt_inits (b, t, inits, index); 6875 } 6876 else 6877 /* Remove the ctor vtables we created. */ 6878 dfs_walk_all (binfo, dfs_fixup_binfo_vtbls, NULL, binfo); 6879 6880 return inits; 6881} 6882 6883/* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base 6884 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */ 6885 6886static tree 6887dfs_build_secondary_vptr_vtt_inits (tree binfo, void *data_) 6888{ 6889 secondary_vptr_vtt_init_data *data = (secondary_vptr_vtt_init_data *)data_; 6890 6891 /* We don't care about bases that don't have vtables. */ 6892 if (!TYPE_VFIELD (BINFO_TYPE (binfo))) 6893 return dfs_skip_bases; 6894 6895 /* We're only interested in proper subobjects of the type being 6896 constructed. */ 6897 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->type_being_constructed)) 6898 return NULL_TREE; 6899 6900 /* We're only interested in bases with virtual bases or reachable 6901 via a virtual path from the type being constructed. */ 6902 if (!(CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)) 6903 || binfo_via_virtual (binfo, data->type_being_constructed))) 6904 return dfs_skip_bases; 6905 6906 /* We're not interested in non-virtual primary bases. */ 6907 if (!BINFO_VIRTUAL_P (binfo) && BINFO_PRIMARY_P (binfo)) 6908 return NULL_TREE; 6909 6910 /* Record the index where this secondary vptr can be found. */ 6911 if (data->top_level_p) 6912 { 6913 gcc_assert (!BINFO_VPTR_INDEX (binfo)); 6914 BINFO_VPTR_INDEX (binfo) = data->index; 6915 6916 if (BINFO_VIRTUAL_P (binfo)) 6917 { 6918 /* It's a primary virtual base, and this is not a 6919 construction vtable. Find the base this is primary of in 6920 the inheritance graph, and use that base's vtable 6921 now. */ 6922 while (BINFO_PRIMARY_P (binfo)) 6923 binfo = BINFO_INHERITANCE_CHAIN (binfo); 6924 } 6925 } 6926 6927 /* Add the initializer for the secondary vptr itself. */ 6928 data->inits = tree_cons (NULL_TREE, binfo_ctor_vtable (binfo), data->inits); 6929 6930 /* Advance the vtt index. */ 6931 data->index = size_binop (PLUS_EXPR, data->index, 6932 TYPE_SIZE_UNIT (ptr_type_node)); 6933 6934 return NULL_TREE; 6935} 6936 6937/* Called from build_vtt_inits via dfs_walk. After building 6938 constructor vtables and generating the sub-vtt from them, we need 6939 to restore the BINFO_VTABLES that were scribbled on. DATA is the 6940 binfo of the base whose sub vtt was generated. */ 6941 6942static tree 6943dfs_fixup_binfo_vtbls (tree binfo, void* data) 6944{ 6945 tree vtable = BINFO_VTABLE (binfo); 6946 6947 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) 6948 /* If this class has no vtable, none of its bases do. */ 6949 return dfs_skip_bases; 6950 6951 if (!vtable) 6952 /* This might be a primary base, so have no vtable in this 6953 hierarchy. */ 6954 return NULL_TREE; 6955 6956 /* If we scribbled the construction vtable vptr into BINFO, clear it 6957 out now. */ 6958 if (TREE_CODE (vtable) == TREE_LIST 6959 && (TREE_PURPOSE (vtable) == (tree) data)) 6960 BINFO_VTABLE (binfo) = TREE_CHAIN (vtable); 6961 6962 return NULL_TREE; 6963} 6964 6965/* Build the construction vtable group for BINFO which is in the 6966 hierarchy dominated by T. */ 6967 6968static void 6969build_ctor_vtbl_group (tree binfo, tree t) 6970{ 6971 tree list; 6972 tree type; 6973 tree vtbl; 6974 tree inits; 6975 tree id; 6976 tree vbase; 6977 6978 /* See if we've already created this construction vtable group. */ 6979 id = mangle_ctor_vtbl_for_type (t, binfo); 6980 if (IDENTIFIER_GLOBAL_VALUE (id)) 6981 return; 6982 6983 gcc_assert (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t)); 6984 /* Build a version of VTBL (with the wrong type) for use in 6985 constructing the addresses of secondary vtables in the 6986 construction vtable group. */ 6987 vtbl = build_vtable (t, id, ptr_type_node); 6988 DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1; 6989 list = build_tree_list (vtbl, NULL_TREE); 6990 accumulate_vtbl_inits (binfo, TYPE_BINFO (TREE_TYPE (binfo)), 6991 binfo, t, list); 6992 6993 /* Add the vtables for each of our virtual bases using the vbase in T 6994 binfo. */ 6995 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo)); 6996 vbase; 6997 vbase = TREE_CHAIN (vbase)) 6998 { 6999 tree b; 7000 7001 if (!BINFO_VIRTUAL_P (vbase)) 7002 continue; 7003 b = copied_binfo (vbase, binfo); 7004 7005 accumulate_vtbl_inits (b, vbase, binfo, t, list); 7006 } 7007 inits = TREE_VALUE (list); 7008 7009 /* Figure out the type of the construction vtable. */ 7010 type = build_index_type (size_int (list_length (inits) - 1)); 7011 type = build_cplus_array_type (vtable_entry_type, type); 7012 TREE_TYPE (vtbl) = type; 7013 7014 /* Initialize the construction vtable. */ 7015 CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl); 7016 initialize_artificial_var (vtbl, inits); 7017 dump_vtable (t, binfo, vtbl); 7018} 7019 7020/* Add the vtbl initializers for BINFO (and its bases other than 7021 non-virtual primaries) to the list of INITS. BINFO is in the 7022 hierarchy dominated by T. RTTI_BINFO is the binfo within T of 7023 the constructor the vtbl inits should be accumulated for. (If this 7024 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).) 7025 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO). 7026 BINFO is the active base equivalent of ORIG_BINFO in the inheritance 7027 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE, 7028 but are not necessarily the same in terms of layout. */ 7029 7030static void 7031accumulate_vtbl_inits (tree binfo, 7032 tree orig_binfo, 7033 tree rtti_binfo, 7034 tree t, 7035 tree inits) 7036{ 7037 int i; 7038 tree base_binfo; 7039 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); 7040 7041 gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (orig_binfo))); 7042 7043 /* If it doesn't have a vptr, we don't do anything. */ 7044 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) 7045 return; 7046 7047 /* If we're building a construction vtable, we're not interested in 7048 subobjects that don't require construction vtables. */ 7049 if (ctor_vtbl_p 7050 && !CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)) 7051 && !binfo_via_virtual (orig_binfo, BINFO_TYPE (rtti_binfo))) 7052 return; 7053 7054 /* Build the initializers for the BINFO-in-T vtable. */ 7055 TREE_VALUE (inits) 7056 = chainon (TREE_VALUE (inits), 7057 dfs_accumulate_vtbl_inits (binfo, orig_binfo, 7058 rtti_binfo, t, inits)); 7059 7060 /* Walk the BINFO and its bases. We walk in preorder so that as we 7061 initialize each vtable we can figure out at what offset the 7062 secondary vtable lies from the primary vtable. We can't use 7063 dfs_walk here because we need to iterate through bases of BINFO 7064 and RTTI_BINFO simultaneously. */ 7065 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 7066 { 7067 /* Skip virtual bases. */ 7068 if (BINFO_VIRTUAL_P (base_binfo)) 7069 continue; 7070 accumulate_vtbl_inits (base_binfo, 7071 BINFO_BASE_BINFO (orig_binfo, i), 7072 rtti_binfo, t, 7073 inits); 7074 } 7075} 7076 7077/* Called from accumulate_vtbl_inits. Returns the initializers for 7078 the BINFO vtable. */ 7079 7080static tree 7081dfs_accumulate_vtbl_inits (tree binfo, 7082 tree orig_binfo, 7083 tree rtti_binfo, 7084 tree t, 7085 tree l) 7086{ 7087 tree inits = NULL_TREE; 7088 tree vtbl = NULL_TREE; 7089 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); 7090 7091 if (ctor_vtbl_p 7092 && BINFO_VIRTUAL_P (orig_binfo) && BINFO_PRIMARY_P (orig_binfo)) 7093 { 7094 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a 7095 primary virtual base. If it is not the same primary in 7096 the hierarchy of T, we'll need to generate a ctor vtable 7097 for it, to place at its location in T. If it is the same 7098 primary, we still need a VTT entry for the vtable, but it 7099 should point to the ctor vtable for the base it is a 7100 primary for within the sub-hierarchy of RTTI_BINFO. 7101 7102 There are three possible cases: 7103 7104 1) We are in the same place. 7105 2) We are a primary base within a lost primary virtual base of 7106 RTTI_BINFO. 7107 3) We are primary to something not a base of RTTI_BINFO. */ 7108 7109 tree b; 7110 tree last = NULL_TREE; 7111 7112 /* First, look through the bases we are primary to for RTTI_BINFO 7113 or a virtual base. */ 7114 b = binfo; 7115 while (BINFO_PRIMARY_P (b)) 7116 { 7117 b = BINFO_INHERITANCE_CHAIN (b); 7118 last = b; 7119 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo) 7120 goto found; 7121 } 7122 /* If we run out of primary links, keep looking down our 7123 inheritance chain; we might be an indirect primary. */ 7124 for (b = last; b; b = BINFO_INHERITANCE_CHAIN (b)) 7125 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo) 7126 break; 7127 found: 7128 7129 /* If we found RTTI_BINFO, this is case 1. If we found a virtual 7130 base B and it is a base of RTTI_BINFO, this is case 2. In 7131 either case, we share our vtable with LAST, i.e. the 7132 derived-most base within B of which we are a primary. */ 7133 if (b == rtti_binfo 7134 || (b && binfo_for_vbase (BINFO_TYPE (b), BINFO_TYPE (rtti_binfo)))) 7135 /* Just set our BINFO_VTABLE to point to LAST, as we may not have 7136 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in 7137 binfo_ctor_vtable after everything's been set up. */ 7138 vtbl = last; 7139 7140 /* Otherwise, this is case 3 and we get our own. */ 7141 } 7142 else if (!BINFO_NEW_VTABLE_MARKED (orig_binfo)) 7143 return inits; 7144 7145 if (!vtbl) 7146 { 7147 tree index; 7148 int non_fn_entries; 7149 7150 /* Compute the initializer for this vtable. */ 7151 inits = build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo, 7152 &non_fn_entries); 7153 7154 /* Figure out the position to which the VPTR should point. */ 7155 vtbl = TREE_PURPOSE (l); 7156 vtbl = build_address (vtbl); 7157 /* ??? We should call fold_convert to convert the address to 7158 vtbl_ptr_type_node, which is the type of elements in the 7159 vtable. However, the resulting NOP_EXPRs confuse other parts 7160 of the C++ front end. */ 7161 gcc_assert (TREE_CODE (vtbl) == ADDR_EXPR); 7162 TREE_TYPE (vtbl) = vtbl_ptr_type_node; 7163 index = size_binop (PLUS_EXPR, 7164 size_int (non_fn_entries), 7165 size_int (list_length (TREE_VALUE (l)))); 7166 index = size_binop (MULT_EXPR, 7167 TYPE_SIZE_UNIT (vtable_entry_type), 7168 index); 7169 vtbl = build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, index); 7170 } 7171 7172 if (ctor_vtbl_p) 7173 /* For a construction vtable, we can't overwrite BINFO_VTABLE. 7174 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will 7175 straighten this out. */ 7176 BINFO_VTABLE (binfo) = tree_cons (rtti_binfo, vtbl, BINFO_VTABLE (binfo)); 7177 else if (BINFO_PRIMARY_P (binfo) && BINFO_VIRTUAL_P (binfo)) 7178 inits = NULL_TREE; 7179 else 7180 /* For an ordinary vtable, set BINFO_VTABLE. */ 7181 BINFO_VTABLE (binfo) = vtbl; 7182 7183 return inits; 7184} 7185 7186static GTY(()) tree abort_fndecl_addr; 7187 7188/* Construct the initializer for BINFO's virtual function table. BINFO 7189 is part of the hierarchy dominated by T. If we're building a 7190 construction vtable, the ORIG_BINFO is the binfo we should use to 7191 find the actual function pointers to put in the vtable - but they 7192 can be overridden on the path to most-derived in the graph that 7193 ORIG_BINFO belongs. Otherwise, 7194 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the 7195 BINFO that should be indicated by the RTTI information in the 7196 vtable; it will be a base class of T, rather than T itself, if we 7197 are building a construction vtable. 7198 7199 The value returned is a TREE_LIST suitable for wrapping in a 7200 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If 7201 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the 7202 number of non-function entries in the vtable. 7203 7204 It might seem that this function should never be called with a 7205 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a 7206 base is always subsumed by a derived class vtable. However, when 7207 we are building construction vtables, we do build vtables for 7208 primary bases; we need these while the primary base is being 7209 constructed. */ 7210 7211static tree 7212build_vtbl_initializer (tree binfo, 7213 tree orig_binfo, 7214 tree t, 7215 tree rtti_binfo, 7216 int* non_fn_entries_p) 7217{ 7218 tree v, b; 7219 tree vfun_inits; 7220 vtbl_init_data vid; 7221 unsigned ix; 7222 tree vbinfo; 7223 VEC(tree,gc) *vbases; 7224 7225 /* Initialize VID. */ 7226 memset (&vid, 0, sizeof (vid)); 7227 vid.binfo = binfo; 7228 vid.derived = t; 7229 vid.rtti_binfo = rtti_binfo; 7230 vid.last_init = &vid.inits; 7231 vid.primary_vtbl_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t); 7232 vid.ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); 7233 vid.generate_vcall_entries = true; 7234 /* The first vbase or vcall offset is at index -3 in the vtable. */ 7235 vid.index = ssize_int(-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE); 7236 7237 /* Add entries to the vtable for RTTI. */ 7238 build_rtti_vtbl_entries (binfo, &vid); 7239 7240 /* Create an array for keeping track of the functions we've 7241 processed. When we see multiple functions with the same 7242 signature, we share the vcall offsets. */ 7243 vid.fns = VEC_alloc (tree, gc, 32); 7244 /* Add the vcall and vbase offset entries. */ 7245 build_vcall_and_vbase_vtbl_entries (binfo, &vid); 7246 7247 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by 7248 build_vbase_offset_vtbl_entries. */ 7249 for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0; 7250 VEC_iterate (tree, vbases, ix, vbinfo); ix++) 7251 BINFO_VTABLE_PATH_MARKED (vbinfo) = 0; 7252 7253 /* If the target requires padding between data entries, add that now. */ 7254 if (TARGET_VTABLE_DATA_ENTRY_DISTANCE > 1) 7255 { 7256 tree cur, *prev; 7257 7258 for (prev = &vid.inits; (cur = *prev); prev = &TREE_CHAIN (cur)) 7259 { 7260 tree add = cur; 7261 int i; 7262 7263 for (i = 1; i < TARGET_VTABLE_DATA_ENTRY_DISTANCE; ++i) 7264 add = tree_cons (NULL_TREE, 7265 build1 (NOP_EXPR, vtable_entry_type, 7266 null_pointer_node), 7267 add); 7268 *prev = add; 7269 } 7270 } 7271 7272 if (non_fn_entries_p) 7273 *non_fn_entries_p = list_length (vid.inits); 7274 7275 /* Go through all the ordinary virtual functions, building up 7276 initializers. */ 7277 vfun_inits = NULL_TREE; 7278 for (v = BINFO_VIRTUALS (orig_binfo); v; v = TREE_CHAIN (v)) 7279 { 7280 tree delta; 7281 tree vcall_index; 7282 tree fn, fn_original; 7283 tree init = NULL_TREE; 7284 7285 fn = BV_FN (v); 7286 fn_original = fn; 7287 if (DECL_THUNK_P (fn)) 7288 { 7289 if (!DECL_NAME (fn)) 7290 finish_thunk (fn); 7291 if (THUNK_ALIAS (fn)) 7292 { 7293 fn = THUNK_ALIAS (fn); 7294 BV_FN (v) = fn; 7295 } 7296 fn_original = THUNK_TARGET (fn); 7297 } 7298 7299 /* If the only definition of this function signature along our 7300 primary base chain is from a lost primary, this vtable slot will 7301 never be used, so just zero it out. This is important to avoid 7302 requiring extra thunks which cannot be generated with the function. 7303 7304 We first check this in update_vtable_entry_for_fn, so we handle 7305 restored primary bases properly; we also need to do it here so we 7306 zero out unused slots in ctor vtables, rather than filling themff 7307 with erroneous values (though harmless, apart from relocation 7308 costs). */ 7309 for (b = binfo; ; b = get_primary_binfo (b)) 7310 { 7311 /* We found a defn before a lost primary; go ahead as normal. */ 7312 if (look_for_overrides_here (BINFO_TYPE (b), fn_original)) 7313 break; 7314 7315 /* The nearest definition is from a lost primary; clear the 7316 slot. */ 7317 if (BINFO_LOST_PRIMARY_P (b)) 7318 { 7319 init = size_zero_node; 7320 break; 7321 } 7322 } 7323 7324 if (! init) 7325 { 7326 /* Pull the offset for `this', and the function to call, out of 7327 the list. */ 7328 delta = BV_DELTA (v); 7329 vcall_index = BV_VCALL_INDEX (v); 7330 7331 gcc_assert (TREE_CODE (delta) == INTEGER_CST); 7332 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); 7333 7334 /* You can't call an abstract virtual function; it's abstract. 7335 So, we replace these functions with __pure_virtual. */ 7336 if (DECL_PURE_VIRTUAL_P (fn_original)) 7337 { 7338 fn = abort_fndecl; 7339 if (abort_fndecl_addr == NULL) 7340 abort_fndecl_addr = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn); 7341 init = abort_fndecl_addr; 7342 } 7343 else 7344 { 7345 if (!integer_zerop (delta) || vcall_index) 7346 { 7347 fn = make_thunk (fn, /*this_adjusting=*/1, delta, vcall_index); 7348 if (!DECL_NAME (fn)) 7349 finish_thunk (fn); 7350 } 7351 /* Take the address of the function, considering it to be of an 7352 appropriate generic type. */ 7353 init = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn); 7354 } 7355 } 7356 7357 /* And add it to the chain of initializers. */ 7358 if (TARGET_VTABLE_USES_DESCRIPTORS) 7359 { 7360 int i; 7361 if (init == size_zero_node) 7362 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i) 7363 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits); 7364 else 7365 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i) 7366 { 7367 tree fdesc = build2 (FDESC_EXPR, vfunc_ptr_type_node, 7368 TREE_OPERAND (init, 0), 7369 build_int_cst (NULL_TREE, i)); 7370 TREE_CONSTANT (fdesc) = 1; 7371 TREE_INVARIANT (fdesc) = 1; 7372 7373 vfun_inits = tree_cons (NULL_TREE, fdesc, vfun_inits); 7374 } 7375 } 7376 else 7377 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits); 7378 } 7379 7380 /* The initializers for virtual functions were built up in reverse 7381 order; straighten them out now. */ 7382 vfun_inits = nreverse (vfun_inits); 7383 7384 /* The negative offset initializers are also in reverse order. */ 7385 vid.inits = nreverse (vid.inits); 7386 7387 /* Chain the two together. */ 7388 return chainon (vid.inits, vfun_inits); 7389} 7390 7391/* Adds to vid->inits the initializers for the vbase and vcall 7392 offsets in BINFO, which is in the hierarchy dominated by T. */ 7393 7394static void 7395build_vcall_and_vbase_vtbl_entries (tree binfo, vtbl_init_data* vid) 7396{ 7397 tree b; 7398 7399 /* If this is a derived class, we must first create entries 7400 corresponding to the primary base class. */ 7401 b = get_primary_binfo (binfo); 7402 if (b) 7403 build_vcall_and_vbase_vtbl_entries (b, vid); 7404 7405 /* Add the vbase entries for this base. */ 7406 build_vbase_offset_vtbl_entries (binfo, vid); 7407 /* Add the vcall entries for this base. */ 7408 build_vcall_offset_vtbl_entries (binfo, vid); 7409} 7410 7411/* Returns the initializers for the vbase offset entries in the vtable 7412 for BINFO (which is part of the class hierarchy dominated by T), in 7413 reverse order. VBASE_OFFSET_INDEX gives the vtable index 7414 where the next vbase offset will go. */ 7415 7416static void 7417build_vbase_offset_vtbl_entries (tree binfo, vtbl_init_data* vid) 7418{ 7419 tree vbase; 7420 tree t; 7421 tree non_primary_binfo; 7422 7423 /* If there are no virtual baseclasses, then there is nothing to 7424 do. */ 7425 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))) 7426 return; 7427 7428 t = vid->derived; 7429 7430 /* We might be a primary base class. Go up the inheritance hierarchy 7431 until we find the most derived class of which we are a primary base: 7432 it is the offset of that which we need to use. */ 7433 non_primary_binfo = binfo; 7434 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo)) 7435 { 7436 tree b; 7437 7438 /* If we have reached a virtual base, then it must be a primary 7439 base (possibly multi-level) of vid->binfo, or we wouldn't 7440 have called build_vcall_and_vbase_vtbl_entries for it. But it 7441 might be a lost primary, so just skip down to vid->binfo. */ 7442 if (BINFO_VIRTUAL_P (non_primary_binfo)) 7443 { 7444 non_primary_binfo = vid->binfo; 7445 break; 7446 } 7447 7448 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo); 7449 if (get_primary_binfo (b) != non_primary_binfo) 7450 break; 7451 non_primary_binfo = b; 7452 } 7453 7454 /* Go through the virtual bases, adding the offsets. */ 7455 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo)); 7456 vbase; 7457 vbase = TREE_CHAIN (vbase)) 7458 { 7459 tree b; 7460 tree delta; 7461 7462 if (!BINFO_VIRTUAL_P (vbase)) 7463 continue; 7464 7465 /* Find the instance of this virtual base in the complete 7466 object. */ 7467 b = copied_binfo (vbase, binfo); 7468 7469 /* If we've already got an offset for this virtual base, we 7470 don't need another one. */ 7471 if (BINFO_VTABLE_PATH_MARKED (b)) 7472 continue; 7473 BINFO_VTABLE_PATH_MARKED (b) = 1; 7474 7475 /* Figure out where we can find this vbase offset. */ 7476 delta = size_binop (MULT_EXPR, 7477 vid->index, 7478 convert (ssizetype, 7479 TYPE_SIZE_UNIT (vtable_entry_type))); 7480 if (vid->primary_vtbl_p) 7481 BINFO_VPTR_FIELD (b) = delta; 7482 7483 if (binfo != TYPE_BINFO (t)) 7484 /* The vbase offset had better be the same. */ 7485 gcc_assert (tree_int_cst_equal (delta, BINFO_VPTR_FIELD (vbase))); 7486 7487 /* The next vbase will come at a more negative offset. */ 7488 vid->index = size_binop (MINUS_EXPR, vid->index, 7489 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE)); 7490 7491 /* The initializer is the delta from BINFO to this virtual base. 7492 The vbase offsets go in reverse inheritance-graph order, and 7493 we are walking in inheritance graph order so these end up in 7494 the right order. */ 7495 delta = size_diffop (BINFO_OFFSET (b), BINFO_OFFSET (non_primary_binfo)); 7496 7497 *vid->last_init 7498 = build_tree_list (NULL_TREE, 7499 fold_build1 (NOP_EXPR, 7500 vtable_entry_type, 7501 delta)); 7502 vid->last_init = &TREE_CHAIN (*vid->last_init); 7503 } 7504} 7505 7506/* Adds the initializers for the vcall offset entries in the vtable 7507 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED) 7508 to VID->INITS. */ 7509 7510static void 7511build_vcall_offset_vtbl_entries (tree binfo, vtbl_init_data* vid) 7512{ 7513 /* We only need these entries if this base is a virtual base. We 7514 compute the indices -- but do not add to the vtable -- when 7515 building the main vtable for a class. */ 7516 if (BINFO_VIRTUAL_P (binfo) || binfo == TYPE_BINFO (vid->derived)) 7517 { 7518 /* We need a vcall offset for each of the virtual functions in this 7519 vtable. For example: 7520 7521 class A { virtual void f (); }; 7522 class B1 : virtual public A { virtual void f (); }; 7523 class B2 : virtual public A { virtual void f (); }; 7524 class C: public B1, public B2 { virtual void f (); }; 7525 7526 A C object has a primary base of B1, which has a primary base of A. A 7527 C also has a secondary base of B2, which no longer has a primary base 7528 of A. So the B2-in-C construction vtable needs a secondary vtable for 7529 A, which will adjust the A* to a B2* to call f. We have no way of 7530 knowing what (or even whether) this offset will be when we define B2, 7531 so we store this "vcall offset" in the A sub-vtable and look it up in 7532 a "virtual thunk" for B2::f. 7533 7534 We need entries for all the functions in our primary vtable and 7535 in our non-virtual bases' secondary vtables. */ 7536 vid->vbase = binfo; 7537 /* If we are just computing the vcall indices -- but do not need 7538 the actual entries -- not that. */ 7539 if (!BINFO_VIRTUAL_P (binfo)) 7540 vid->generate_vcall_entries = false; 7541 /* Now, walk through the non-virtual bases, adding vcall offsets. */ 7542 add_vcall_offset_vtbl_entries_r (binfo, vid); 7543 } 7544} 7545 7546/* Build vcall offsets, starting with those for BINFO. */ 7547 7548static void 7549add_vcall_offset_vtbl_entries_r (tree binfo, vtbl_init_data* vid) 7550{ 7551 int i; 7552 tree primary_binfo; 7553 tree base_binfo; 7554 7555 /* Don't walk into virtual bases -- except, of course, for the 7556 virtual base for which we are building vcall offsets. Any 7557 primary virtual base will have already had its offsets generated 7558 through the recursion in build_vcall_and_vbase_vtbl_entries. */ 7559 if (BINFO_VIRTUAL_P (binfo) && vid->vbase != binfo) 7560 return; 7561 7562 /* If BINFO has a primary base, process it first. */ 7563 primary_binfo = get_primary_binfo (binfo); 7564 if (primary_binfo) 7565 add_vcall_offset_vtbl_entries_r (primary_binfo, vid); 7566 7567 /* Add BINFO itself to the list. */ 7568 add_vcall_offset_vtbl_entries_1 (binfo, vid); 7569 7570 /* Scan the non-primary bases of BINFO. */ 7571 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 7572 if (base_binfo != primary_binfo) 7573 add_vcall_offset_vtbl_entries_r (base_binfo, vid); 7574} 7575 7576/* Called from build_vcall_offset_vtbl_entries_r. */ 7577 7578static void 7579add_vcall_offset_vtbl_entries_1 (tree binfo, vtbl_init_data* vid) 7580{ 7581 /* Make entries for the rest of the virtuals. */ 7582 if (abi_version_at_least (2)) 7583 { 7584 tree orig_fn; 7585 7586 /* The ABI requires that the methods be processed in declaration 7587 order. G++ 3.2 used the order in the vtable. */ 7588 for (orig_fn = TYPE_METHODS (BINFO_TYPE (binfo)); 7589 orig_fn; 7590 orig_fn = TREE_CHAIN (orig_fn)) 7591 if (DECL_VINDEX (orig_fn)) 7592 add_vcall_offset (orig_fn, binfo, vid); 7593 } 7594 else 7595 { 7596 tree derived_virtuals; 7597 tree base_virtuals; 7598 tree orig_virtuals; 7599 /* If BINFO is a primary base, the most derived class which has 7600 BINFO as a primary base; otherwise, just BINFO. */ 7601 tree non_primary_binfo; 7602 7603 /* We might be a primary base class. Go up the inheritance hierarchy 7604 until we find the most derived class of which we are a primary base: 7605 it is the BINFO_VIRTUALS there that we need to consider. */ 7606 non_primary_binfo = binfo; 7607 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo)) 7608 { 7609 tree b; 7610 7611 /* If we have reached a virtual base, then it must be vid->vbase, 7612 because we ignore other virtual bases in 7613 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary 7614 base (possibly multi-level) of vid->binfo, or we wouldn't 7615 have called build_vcall_and_vbase_vtbl_entries for it. But it 7616 might be a lost primary, so just skip down to vid->binfo. */ 7617 if (BINFO_VIRTUAL_P (non_primary_binfo)) 7618 { 7619 gcc_assert (non_primary_binfo == vid->vbase); 7620 non_primary_binfo = vid->binfo; 7621 break; 7622 } 7623 7624 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo); 7625 if (get_primary_binfo (b) != non_primary_binfo) 7626 break; 7627 non_primary_binfo = b; 7628 } 7629 7630 if (vid->ctor_vtbl_p) 7631 /* For a ctor vtable we need the equivalent binfo within the hierarchy 7632 where rtti_binfo is the most derived type. */ 7633 non_primary_binfo 7634 = original_binfo (non_primary_binfo, vid->rtti_binfo); 7635 7636 for (base_virtuals = BINFO_VIRTUALS (binfo), 7637 derived_virtuals = BINFO_VIRTUALS (non_primary_binfo), 7638 orig_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo))); 7639 base_virtuals; 7640 base_virtuals = TREE_CHAIN (base_virtuals), 7641 derived_virtuals = TREE_CHAIN (derived_virtuals), 7642 orig_virtuals = TREE_CHAIN (orig_virtuals)) 7643 { 7644 tree orig_fn; 7645 7646 /* Find the declaration that originally caused this function to 7647 be present in BINFO_TYPE (binfo). */ 7648 orig_fn = BV_FN (orig_virtuals); 7649 7650 /* When processing BINFO, we only want to generate vcall slots for 7651 function slots introduced in BINFO. So don't try to generate 7652 one if the function isn't even defined in BINFO. */ 7653 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), DECL_CONTEXT (orig_fn))) 7654 continue; 7655 7656 add_vcall_offset (orig_fn, binfo, vid); 7657 } 7658 } 7659} 7660 7661/* Add a vcall offset entry for ORIG_FN to the vtable. */ 7662 7663static void 7664add_vcall_offset (tree orig_fn, tree binfo, vtbl_init_data *vid) 7665{ 7666 size_t i; 7667 tree vcall_offset; 7668 tree derived_entry; 7669 7670 /* If there is already an entry for a function with the same 7671 signature as FN, then we do not need a second vcall offset. 7672 Check the list of functions already present in the derived 7673 class vtable. */ 7674 for (i = 0; VEC_iterate (tree, vid->fns, i, derived_entry); ++i) 7675 { 7676 if (same_signature_p (derived_entry, orig_fn) 7677 /* We only use one vcall offset for virtual destructors, 7678 even though there are two virtual table entries. */ 7679 || (DECL_DESTRUCTOR_P (derived_entry) 7680 && DECL_DESTRUCTOR_P (orig_fn))) 7681 return; 7682 } 7683 7684 /* If we are building these vcall offsets as part of building 7685 the vtable for the most derived class, remember the vcall 7686 offset. */ 7687 if (vid->binfo == TYPE_BINFO (vid->derived)) 7688 { 7689 tree_pair_p elt = VEC_safe_push (tree_pair_s, gc, 7690 CLASSTYPE_VCALL_INDICES (vid->derived), 7691 NULL); 7692 elt->purpose = orig_fn; 7693 elt->value = vid->index; 7694 } 7695 7696 /* The next vcall offset will be found at a more negative 7697 offset. */ 7698 vid->index = size_binop (MINUS_EXPR, vid->index, 7699 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE)); 7700 7701 /* Keep track of this function. */ 7702 VEC_safe_push (tree, gc, vid->fns, orig_fn); 7703 7704 if (vid->generate_vcall_entries) 7705 { 7706 tree base; 7707 tree fn; 7708 7709 /* Find the overriding function. */ 7710 fn = find_final_overrider (vid->rtti_binfo, binfo, orig_fn); 7711 if (fn == error_mark_node) 7712 vcall_offset = build1 (NOP_EXPR, vtable_entry_type, 7713 integer_zero_node); 7714 else 7715 { 7716 base = TREE_VALUE (fn); 7717 7718 /* The vbase we're working on is a primary base of 7719 vid->binfo. But it might be a lost primary, so its 7720 BINFO_OFFSET might be wrong, so we just use the 7721 BINFO_OFFSET from vid->binfo. */ 7722 vcall_offset = size_diffop (BINFO_OFFSET (base), 7723 BINFO_OFFSET (vid->binfo)); 7724 vcall_offset = fold_build1 (NOP_EXPR, vtable_entry_type, 7725 vcall_offset); 7726 } 7727 /* Add the initializer to the vtable. */ 7728 *vid->last_init = build_tree_list (NULL_TREE, vcall_offset); 7729 vid->last_init = &TREE_CHAIN (*vid->last_init); 7730 } 7731} 7732 7733/* Return vtbl initializers for the RTTI entries corresponding to the 7734 BINFO's vtable. The RTTI entries should indicate the object given 7735 by VID->rtti_binfo. */ 7736 7737static void 7738build_rtti_vtbl_entries (tree binfo, vtbl_init_data* vid) 7739{ 7740 tree b; 7741 tree t; 7742 tree basetype; 7743 tree offset; 7744 tree decl; 7745 tree init; 7746 7747 basetype = BINFO_TYPE (binfo); 7748 t = BINFO_TYPE (vid->rtti_binfo); 7749 7750 /* To find the complete object, we will first convert to our most 7751 primary base, and then add the offset in the vtbl to that value. */ 7752 b = binfo; 7753 while (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (b)) 7754 && !BINFO_LOST_PRIMARY_P (b)) 7755 { 7756 tree primary_base; 7757 7758 primary_base = get_primary_binfo (b); 7759 gcc_assert (BINFO_PRIMARY_P (primary_base) 7760 && BINFO_INHERITANCE_CHAIN (primary_base) == b); 7761 b = primary_base; 7762 } 7763 offset = size_diffop (BINFO_OFFSET (vid->rtti_binfo), BINFO_OFFSET (b)); 7764 7765 /* The second entry is the address of the typeinfo object. */ 7766 if (flag_rtti) 7767 decl = build_address (get_tinfo_decl (t)); 7768 else 7769 decl = integer_zero_node; 7770 7771 /* Convert the declaration to a type that can be stored in the 7772 vtable. */ 7773 init = build_nop (vfunc_ptr_type_node, decl); 7774 *vid->last_init = build_tree_list (NULL_TREE, init); 7775 vid->last_init = &TREE_CHAIN (*vid->last_init); 7776 7777 /* Add the offset-to-top entry. It comes earlier in the vtable than 7778 the typeinfo entry. Convert the offset to look like a 7779 function pointer, so that we can put it in the vtable. */ 7780 init = build_nop (vfunc_ptr_type_node, offset); 7781 *vid->last_init = build_tree_list (NULL_TREE, init); 7782 vid->last_init = &TREE_CHAIN (*vid->last_init); 7783} 7784 7785/* Fold a OBJ_TYPE_REF expression to the address of a function. 7786 KNOWN_TYPE carries the true type of OBJ_TYPE_REF_OBJECT(REF). */ 7787 7788tree 7789cp_fold_obj_type_ref (tree ref, tree known_type) 7790{ 7791 HOST_WIDE_INT index = tree_low_cst (OBJ_TYPE_REF_TOKEN (ref), 1); 7792 HOST_WIDE_INT i = 0; 7793 tree v = BINFO_VIRTUALS (TYPE_BINFO (known_type)); 7794 tree fndecl; 7795 7796 while (i != index) 7797 { 7798 i += (TARGET_VTABLE_USES_DESCRIPTORS 7799 ? TARGET_VTABLE_USES_DESCRIPTORS : 1); 7800 v = TREE_CHAIN (v); 7801 } 7802 7803 fndecl = BV_FN (v); 7804 7805#ifdef ENABLE_CHECKING 7806 gcc_assert (tree_int_cst_equal (OBJ_TYPE_REF_TOKEN (ref), 7807 DECL_VINDEX (fndecl))); 7808#endif 7809 7810 cgraph_node (fndecl)->local.vtable_method = true; 7811 7812 return build_address (fndecl); 7813} 7814 7815#include "gt-cp-class.h" 7816