gcc/cp/class.c

   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  Free Software Foundation, Inc.
   4    Contributed by Michael Tiemann (tiemann@cygnus.com)
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 2, or (at your option)
  11 any later version.
  12
  13 GCC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING.  If not, write to
  20 the Free Software Foundation, 59 Temple Place - Suite 330,
  21 Boston, MA 02111-1307, 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
  39 /* The number of nested classes being processed.  If we are not in the
  40    scope of any class, this is zero.  */
  41
  42 int current_class_depth;
  43
  44 /* In order to deal with nested classes, we keep a stack of classes.
  45    The topmost entry is the innermost class, and is the entry at index
  46    CURRENT_CLASS_DEPTH  */
  47
  48 typedef struct class_stack_node {
  49   /* The name of the class.  */
  50   tree name;
  51
  52   /* The _TYPE node for the class.  */
  53   tree type;
  54
  55   /* The access specifier pending for new declarations in the scope of
  56      this class.  */
  57   tree access;
  58
  59   /* If were defining TYPE, the names used in this class.  */
  60   splay_tree names_used;
  61 }* class_stack_node_t;
  62
  63 typedef struct vtbl_init_data_s
  64 {
  65   /* The base for which we're building initializers.  */
  66   tree binfo;
  67   /* The type of the most-derived type.  */
  68   tree derived;
  69   /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
  70      unless ctor_vtbl_p is true.  */
  71   tree rtti_binfo;
  72   /* The negative-index vtable initializers built up so far.  These
  73      are in order from least negative index to most negative index.  */
  74   tree inits;
  75   /* The last (i.e., most negative) entry in INITS.  */
  76   tree* last_init;
  77   /* The binfo for the virtual base for which we're building
  78      vcall offset initializers.  */
  79   tree vbase;
  80   /* The functions in vbase for which we have already provided vcall
  81      offsets.  */
  82   varray_type fns;
  83   /* The vtable index of the next vcall or vbase offset.  */
  84   tree index;
  85   /* Nonzero if we are building the initializer for the primary
  86      vtable.  */
  87   int primary_vtbl_p;
  88   /* Nonzero if we are building the initializer for a construction
  89      vtable.  */
  90   int ctor_vtbl_p;
  91   /* True when adding vcall offset entries to the vtable.  False when
  92      merely computing the indices.  */
  93   bool generate_vcall_entries;
  94 } vtbl_init_data;
  95
  96 /* The type of a function passed to walk_subobject_offsets.  */
  97 typedef int (*subobject_offset_fn) (tree, tree, splay_tree);
  98
  99 /* The stack itself.  This is a dynamically resized array.  The
 100    number of elements allocated is CURRENT_CLASS_STACK_SIZE.  */
 101 static int current_class_stack_size;
 102 static class_stack_node_t current_class_stack;
 103
 104 /* An array of all local classes present in this translation unit, in
 105    declaration order.  */
 106 varray_type local_classes;
 107
 108 static tree get_vfield_name (tree);
 109 static void finish_struct_anon (tree);
 110 static tree get_vtable_name (tree);
 111 static tree get_basefndecls (tree, tree);
 112 static int build_primary_vtable (tree, tree);
 113 static int build_secondary_vtable (tree);
 114 static void finish_vtbls (tree);
 115 static void modify_vtable_entry (tree, tree, tree, tree, tree *);
 116 static void finish_struct_bits (tree);
 117 static int alter_access (tree, tree, tree);
 118 static void handle_using_decl (tree, tree);
 119 static void check_for_override (tree, tree);
 120 static tree dfs_modify_vtables (tree, void *);
 121 static tree modify_all_vtables (tree, tree);
 122 static void determine_primary_bases (tree);
 123 static void finish_struct_methods (tree);
 124 static void maybe_warn_about_overly_private_class (tree);
 125 static int method_name_cmp (const void *, const void *);
 126 static int resort_method_name_cmp (const void *, const void *);
 127 static void add_implicitly_declared_members (tree, int, int, int);
 128 static tree fixed_type_or_null (tree, int *, int *);
 129 static tree resolve_address_of_overloaded_function (tree, tree, tsubst_flags_t,
 130                                                     bool, tree);
 131 static tree build_simple_base_path (tree expr, tree binfo);
 132 static tree build_vtbl_ref_1 (tree, tree);
 133 static tree build_vtbl_initializer (tree, tree, tree, tree, int *);
 134 static int count_fields (tree);
 135 static int add_fields_to_record_type (tree, struct sorted_fields_type*, int);
 136 static void check_bitfield_decl (tree);
 137 static void check_field_decl (tree, tree, int *, int *, int *, int *);
 138 static void check_field_decls (tree, tree *, int *, int *, int *);
 139 static tree *build_base_field (record_layout_info, tree, splay_tree, tree *);
 140 static void build_base_fields (record_layout_info, splay_tree, tree *);
 141 static void check_methods (tree);
 142 static void remove_zero_width_bit_fields (tree);
 143 static void check_bases (tree, int *, int *, int *);
 144 static void check_bases_and_members (tree);
 145 static tree create_vtable_ptr (tree, tree *);
 146 static void include_empty_classes (record_layout_info);
 147 static void layout_class_type (tree, tree *);
 148 static void fixup_pending_inline (tree);
 149 static void fixup_inline_methods (tree);
 150 static void propagate_binfo_offsets (tree, tree);
 151 static void layout_virtual_bases (record_layout_info, splay_tree);
 152 static void build_vbase_offset_vtbl_entries (tree, vtbl_init_data *);
 153 static void add_vcall_offset_vtbl_entries_r (tree, vtbl_init_data *);
 154 static void add_vcall_offset_vtbl_entries_1 (tree, vtbl_init_data *);
 155 static void build_vcall_offset_vtbl_entries (tree, vtbl_init_data *);
 156 static void add_vcall_offset (tree, tree, vtbl_init_data *);
 157 static void layout_vtable_decl (tree, int);
 158 static tree dfs_find_final_overrider (tree, void *);
 159 static tree dfs_find_final_overrider_post (tree, void *);
 160 static tree dfs_find_final_overrider_q (tree, int, void *);
 161 static tree find_final_overrider (tree, tree, tree);
 162 static int make_new_vtable (tree, tree);
 163 static int maybe_indent_hierarchy (FILE *, int, int);
 164 static tree dump_class_hierarchy_r (FILE *, int, tree, tree, int);
 165 static void dump_class_hierarchy (tree);
 166 static void dump_class_hierarchy_1 (FILE *, int, tree);
 167 static void dump_array (FILE *, tree);
 168 static void dump_vtable (tree, tree, tree);
 169 static void dump_vtt (tree, tree);
 170 static void dump_thunk (FILE *, int, tree);
 171 static tree build_vtable (tree, tree, tree);
 172 static void initialize_vtable (tree, tree);
 173 static void layout_nonempty_base_or_field (record_layout_info,
 174                                                    tree, tree, splay_tree);
 175 static tree end_of_class (tree, int);
 176 static bool layout_empty_base (tree, tree, splay_tree);
 177 static void accumulate_vtbl_inits (tree, tree, tree, tree, tree);
 178 static tree dfs_accumulate_vtbl_inits (tree, tree, tree, tree,
 179                                                tree);
 180 static void build_rtti_vtbl_entries (tree, vtbl_init_data *);
 181 static void build_vcall_and_vbase_vtbl_entries (tree,
 182                                                         vtbl_init_data *);
 183 static void clone_constructors_and_destructors (tree);
 184 static tree build_clone (tree, tree);
 185 static void update_vtable_entry_for_fn (tree, tree, tree, tree *, unsigned);
 186 static void build_ctor_vtbl_group (tree, tree);
 187 static void build_vtt (tree);
 188 static tree binfo_ctor_vtable (tree);
 189 static tree *build_vtt_inits (tree, tree, tree *, tree *);
 190 static tree dfs_build_secondary_vptr_vtt_inits (tree, void *);
 191 static tree dfs_ctor_vtable_bases_queue_p (tree, int, void *data);
 192 static tree dfs_fixup_binfo_vtbls (tree, void *);
 193 static int record_subobject_offset (tree, tree, splay_tree);
 194 static int check_subobject_offset (tree, tree, splay_tree);
 195 static int walk_subobject_offsets (tree, subobject_offset_fn,
 196                                            tree, splay_tree, tree, int);
 197 static void record_subobject_offsets (tree, tree, splay_tree, int);
 198 static int layout_conflict_p (tree, tree, splay_tree, int);
 199 static int splay_tree_compare_integer_csts (splay_tree_key k1,
 200                                                     splay_tree_key k2);
 201 static void warn_about_ambiguous_bases (tree);
 202 static bool type_requires_array_cookie (tree);
 203 static bool contains_empty_class_p (tree);
 204 static bool base_derived_from (tree, tree);
 205 static int empty_base_at_nonzero_offset_p (tree, tree, splay_tree);
 206 static tree end_of_base (tree);
 207 static tree get_vcall_index (tree, tree);
 208
 209 /* Macros for dfs walking during vtt construction. See
 210    dfs_ctor_vtable_bases_queue_p, dfs_build_secondary_vptr_vtt_inits
 211    and dfs_fixup_binfo_vtbls.  */
 212 #define VTT_TOP_LEVEL_P(NODE) (TREE_LIST_CHECK (NODE)->common.unsigned_flag)
 213 #define VTT_MARKED_BINFO_P(NODE) TREE_USED (NODE)
 214
 215 /* Variables shared between class.c and call.c.  */
 216
 217 #ifdef GATHER_STATISTICS
 218 int n_vtables = 0;
 219 int n_vtable_entries = 0;
 220 int n_vtable_searches = 0;
 221 int n_vtable_elems = 0;
 222 int n_convert_harshness = 0;
 223 int n_compute_conversion_costs = 0;
 224 int n_inner_fields_searched = 0;
 225 #endif
 226
 227 /* Convert to or from a base subobject.  EXPR is an expression of type
 228    `A' or `A*', an expression of type `B' or `B*' is returned.  To
 229    convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
 230    the B base instance within A.  To convert base A to derived B, CODE
 231    is MINUS_EXPR and BINFO is the binfo for the A instance within B.
 232    In this latter case, A must not be a morally virtual base of B.
 233    NONNULL is true if EXPR is known to be non-NULL (this is only
 234    needed when EXPR is of pointer type).  CV qualifiers are preserved
 235    from EXPR.  */
 236
 237 tree
 238 build_base_path (enum tree_code code,
 239                  tree expr,
 240                  tree binfo,
 241                  int nonnull)
 242 {
 243   tree v_binfo = NULL_TREE;
 244   tree d_binfo = NULL_TREE;
 245   tree probe;
 246   tree offset;
 247   tree target_type;
 248   tree null_test = NULL;
 249   tree ptr_target_type;
 250   int fixed_type_p;
 251   int want_pointer = TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE;
 252   bool has_empty = false;
 253   bool virtual_access;
 254
 255   if (expr == error_mark_node || binfo == error_mark_node || !binfo)
 256     return error_mark_node;
 257
 258   for (probe = binfo; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
 259     {
 260       d_binfo = probe;
 261       if (is_empty_class (BINFO_TYPE (probe)))
 262         has_empty = true;
 263       if (!v_binfo && BINFO_VIRTUAL_P (probe))
 264         v_binfo = probe;
 265     }
 266
 267   probe = TYPE_MAIN_VARIANT (TREE_TYPE (expr));
 268   if (want_pointer)
 269     probe = TYPE_MAIN_VARIANT (TREE_TYPE (probe));
 270
 271   gcc_assert (code == MINUS_EXPR
 272               ? same_type_p (BINFO_TYPE (binfo), probe)
 273               : code == PLUS_EXPR
 274               ? same_type_p (BINFO_TYPE (d_binfo), probe)
 275               : false);
 276
 277   if (binfo == d_binfo)
 278     /* Nothing to do.  */
 279     return expr;
 280
 281   if (code == MINUS_EXPR && v_binfo)
 282     {
 283       error ("cannot convert from base `%T' to derived type `%T' via virtual base `%T'",
 284              BINFO_TYPE (binfo), BINFO_TYPE (d_binfo), BINFO_TYPE (v_binfo));
 285       return error_mark_node;
 286     }
 287
 288   if (!want_pointer)
 289     /* This must happen before the call to save_expr.  */
 290     expr = build_unary_op (ADDR_EXPR, expr, 0);
 291
 292   offset = BINFO_OFFSET (binfo);
 293   fixed_type_p = resolves_to_fixed_type_p (expr, &nonnull);
 294
 295   /* Do we need to look in the vtable for the real offset?  */
 296   virtual_access = (v_binfo && fixed_type_p <= 0);
 297
 298   /* Do we need to check for a null pointer?  */
 299   if (want_pointer && !nonnull && (virtual_access || !integer_zerop (offset)))
 300     null_test = error_mark_node;
 301
 302   /* Protect against multiple evaluation if necessary.  */
 303   if (TREE_SIDE_EFFECTS (expr) && (null_test || virtual_access))
 304     expr = save_expr (expr);
 305
 306   /* Now that we've saved expr, build the real null test.  */
 307   if (null_test)
 308     null_test = fold (build2 (NE_EXPR, boolean_type_node,
 309                               expr, integer_zero_node));
 310
 311   /* If this is a simple base reference, express it as a COMPONENT_REF.  */
 312   if (code == PLUS_EXPR && !virtual_access
 313       /* We don't build base fields for empty bases, and they aren't very
 314          interesting to the optimizers anyway.  */
 315       && !has_empty)
 316     {
 317       expr = build_indirect_ref (expr, NULL);
 318       expr = build_simple_base_path (expr, binfo);
 319       if (want_pointer)
 320         expr = build_address (expr);
 321       target_type = TREE_TYPE (expr);
 322       goto out;
 323     }
 324
 325   if (virtual_access)
 326     {
 327       /* Going via virtual base V_BINFO.  We need the static offset
 328          from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
 329          V_BINFO.  That offset is an entry in D_BINFO's vtable.  */
 330       tree v_offset;
 331
 332       if (fixed_type_p < 0 && in_base_initializer)
 333         {
 334           /* In a base member initializer, we cannot rely on
 335              the vtable being set up. We have to use the vtt_parm.  */
 336           tree derived = BINFO_INHERITANCE_CHAIN (v_binfo);
 337           tree t;
 338
 339           t = TREE_TYPE (TYPE_VFIELD (BINFO_TYPE (derived)));
 340           t = build_pointer_type (t);
 341           v_offset = convert (t, current_vtt_parm);
 342           v_offset = build2 (PLUS_EXPR, t, v_offset,
 343                              BINFO_VPTR_INDEX (derived));
 344           v_offset = build_indirect_ref (v_offset, NULL);
 345         }
 346       else
 347         v_offset = build_vfield_ref (build_indirect_ref (expr, NULL),
 348                                      TREE_TYPE (TREE_TYPE (expr)));
 349
 350       v_offset = build2 (PLUS_EXPR, TREE_TYPE (v_offset),
 351                          v_offset,  BINFO_VPTR_FIELD (v_binfo));
 352       v_offset = build1 (NOP_EXPR,
 353                          build_pointer_type (ptrdiff_type_node),
 354                          v_offset);
 355       v_offset = build_indirect_ref (v_offset, NULL);
 356       TREE_CONSTANT (v_offset) = 1;
 357       TREE_INVARIANT (v_offset) = 1;
 358
 359       offset = convert_to_integer (ptrdiff_type_node,
 360                                    size_diffop (offset,
 361                                                 BINFO_OFFSET (v_binfo)));
 362
 363       if (!integer_zerop (offset))
 364         v_offset = build2 (code, ptrdiff_type_node, v_offset, offset);
 365
 366       if (fixed_type_p < 0)
 367         /* Negative fixed_type_p means this is a constructor or destructor;
 368            virtual base layout is fixed in in-charge [cd]tors, but not in
 369            base [cd]tors.  */
 370         offset = build3 (COND_EXPR, ptrdiff_type_node,
 371                          build2 (EQ_EXPR, boolean_type_node,
 372                                  current_in_charge_parm, integer_zero_node),
 373                          v_offset,
 374                          BINFO_OFFSET (binfo));
 375       else
 376         offset = v_offset;
 377     }
 378
 379   target_type = code == PLUS_EXPR ? BINFO_TYPE (binfo) : BINFO_TYPE (d_binfo);
 380
 381   target_type = cp_build_qualified_type
 382     (target_type, cp_type_quals (TREE_TYPE (TREE_TYPE (expr))));
 383   ptr_target_type = build_pointer_type (target_type);
 384   if (want_pointer)
 385     target_type = ptr_target_type;
 386
 387   expr = build1 (NOP_EXPR, ptr_target_type, expr);
 388
 389   if (!integer_zerop (offset))
 390     expr = build2 (code, ptr_target_type, expr, offset);
 391   else
 392     null_test = NULL;
 393
 394   if (!want_pointer)
 395     expr = build_indirect_ref (expr, NULL);
 396
 397  out:
 398   if (null_test)
 399     expr = fold (build3 (COND_EXPR, target_type, null_test, expr,
 400                          fold (build1 (NOP_EXPR, target_type,
 401                                        integer_zero_node))));
 402
 403   return expr;
 404 }
 405
 406 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
 407    Perform a derived-to-base conversion by recursively building up a
 408    sequence of COMPONENT_REFs to the appropriate base fields.  */
 409
 410 static tree
 411 build_simple_base_path (tree expr, tree binfo)
 412 {
 413   tree type = BINFO_TYPE (binfo);
 414   tree d_binfo = BINFO_INHERITANCE_CHAIN (binfo);
 415   tree field;
 416
 417   if (d_binfo == NULL_TREE)
 418     {
 419       gcc_assert (TYPE_MAIN_VARIANT (TREE_TYPE (expr)) == type);
 420       return expr;
 421     }
 422
 423   /* Recurse.  */
 424   expr = build_simple_base_path (expr, d_binfo);
 425
 426   for (field = TYPE_FIELDS (BINFO_TYPE (d_binfo));
 427        field; field = TREE_CHAIN (field))
 428     /* Is this the base field created by build_base_field?  */
 429     if (TREE_CODE (field) == FIELD_DECL
 430         && DECL_FIELD_IS_BASE (field)
 431         && TREE_TYPE (field) == type)
 432       return build_class_member_access_expr (expr, field,
 433                                              NULL_TREE, false);
 434
 435   /* Didn't find the base field?!?  */
 436   gcc_unreachable ();
 437 }
 438
 439 /* Convert OBJECT to the base TYPE.  If CHECK_ACCESS is true, an error
 440    message is emitted if TYPE is inaccessible.  OBJECT is assumed to
 441    be non-NULL.  */
 442
 443 tree
 444 convert_to_base (tree object, tree type, bool check_access)
 445 {
 446   tree binfo;
 447
 448   binfo = lookup_base (TREE_TYPE (object), type,
 449                        check_access ? ba_check : ba_ignore,
 450                        NULL);
 451   if (!binfo || binfo == error_mark_node)
 452     return error_mark_node;
 453
 454   return build_base_path (PLUS_EXPR, object, binfo, /*nonnull=*/1);
 455 }
 456
 457 /* EXPR is an expression with class type.  BASE is a base class (a
 458    BINFO) of that class type.  Returns EXPR, converted to the BASE
 459    type.  This function assumes that EXPR is the most derived class;
 460    therefore virtual bases can be found at their static offsets.  */
 461
 462 tree
 463 convert_to_base_statically (tree expr, tree base)
 464 {
 465   tree expr_type;
 466
 467   expr_type = TREE_TYPE (expr);
 468   if (!same_type_p (expr_type, BINFO_TYPE (base)))
 469     {
 470       tree pointer_type;
 471
 472       pointer_type = build_pointer_type (expr_type);
 473       expr = build_unary_op (ADDR_EXPR, expr, /*noconvert=*/1);
 474       if (!integer_zerop (BINFO_OFFSET (base)))
 475           expr = build2 (PLUS_EXPR, pointer_type, expr,
 476                          build_nop (pointer_type, BINFO_OFFSET (base)));
 477       expr = build_nop (build_pointer_type (BINFO_TYPE (base)), expr);
 478       expr = build1 (INDIRECT_REF, BINFO_TYPE (base), expr);
 479     }
 480
 481   return expr;
 482 }
 483
 484 \f
 485 tree
 486 build_vfield_ref (tree datum, tree type)
 487 {
 488   tree vfield, vcontext;
 489
 490   if (datum == error_mark_node)
 491     return error_mark_node;
 492
 493   if (TREE_CODE (TREE_TYPE (datum)) == REFERENCE_TYPE)
 494     datum = convert_from_reference (datum);
 495
 496   /* First, convert to the requested type.  */
 497   if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (datum), type))
 498     datum = convert_to_base (datum, type, /*check_access=*/false);
 499
 500   /* Second, the requested type may not be the owner of its own vptr.
 501      If not, convert to the base class that owns it.  We cannot use
 502      convert_to_base here, because VCONTEXT may appear more than once
 503      in the inheritance hierarchy of TYPE, and thus direct conversion
 504      between the types may be ambiguous.  Following the path back up
 505      one step at a time via primary bases avoids the problem.  */
 506   vfield = TYPE_VFIELD (type);
 507   vcontext = DECL_CONTEXT (vfield);
 508   while (!same_type_ignoring_top_level_qualifiers_p (vcontext, type))
 509     {
 510       datum = build_simple_base_path (datum, CLASSTYPE_PRIMARY_BINFO (type));
 511       type = TREE_TYPE (datum);
 512     }
 513
 514   return build3 (COMPONENT_REF, TREE_TYPE (vfield), datum, vfield, NULL_TREE);
 515 }
 516
 517 /* Given an object INSTANCE, return an expression which yields the
 518    vtable element corresponding to INDEX.  There are many special
 519    cases for INSTANCE which we take care of here, mainly to avoid
 520    creating extra tree nodes when we don't have to.  */
 521
 522 static tree
 523 build_vtbl_ref_1 (tree instance, tree idx)
 524 {
 525   tree aref;
 526   tree vtbl = NULL_TREE;
 527
 528   /* Try to figure out what a reference refers to, and
 529      access its virtual function table directly.  */
 530
 531   int cdtorp = 0;
 532   tree fixed_type = fixed_type_or_null (instance, NULL, &cdtorp);
 533
 534   tree basetype = non_reference (TREE_TYPE (instance));
 535
 536   if (fixed_type && !cdtorp)
 537     {
 538       tree binfo = lookup_base (fixed_type, basetype,
 539                                 ba_ignore|ba_quiet, NULL);
 540       if (binfo)
 541         vtbl = unshare_expr (BINFO_VTABLE (binfo));
 542     }
 543
 544   if (!vtbl)
 545     vtbl = build_vfield_ref (instance, basetype);
 546
 547   assemble_external (vtbl);
 548
 549   aref = build_array_ref (vtbl, idx);
 550   TREE_CONSTANT (aref) |= TREE_CONSTANT (vtbl) && TREE_CONSTANT (idx);
 551   TREE_INVARIANT (aref) = TREE_CONSTANT (aref);
 552
 553   return aref;
 554 }
 555
 556 tree
 557 build_vtbl_ref (tree instance, tree idx)
 558 {
 559   tree aref = build_vtbl_ref_1 (instance, idx);
 560
 561   return aref;
 562 }
 563
 564 /* Given a stable object pointer INSTANCE_PTR, return an expression which
 565    yields a function pointer corresponding to vtable element INDEX.  */
 566
 567 tree
 568 build_vfn_ref (tree instance_ptr, tree idx)
 569 {
 570   tree aref;
 571
 572   aref = build_vtbl_ref_1 (build_indirect_ref (instance_ptr, 0), idx);
 573
 574   /* When using function descriptors, the address of the
 575      vtable entry is treated as a function pointer.  */
 576   if (TARGET_VTABLE_USES_DESCRIPTORS)
 577     aref = build1 (NOP_EXPR, TREE_TYPE (aref),
 578                    build_unary_op (ADDR_EXPR, aref, /*noconvert=*/1));
 579
 580   /* Remember this as a method reference, for later devirtualization.  */
 581   aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr, idx);
 582
 583   return aref;
 584 }
 585
 586 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
 587    for the given TYPE.  */
 588
 589 static tree
 590 get_vtable_name (tree type)
 591 {
 592   return mangle_vtbl_for_type (type);
 593 }
 594
 595 /* Return an IDENTIFIER_NODE for the name of the virtual table table
 596    for TYPE.  */
 597
 598 tree
 599 get_vtt_name (tree type)
 600 {
 601   return mangle_vtt_for_type (type);
 602 }
 603
 604 /* DECL is an entity associated with TYPE, like a virtual table or an
 605    implicitly generated constructor.  Determine whether or not DECL
 606    should have external or internal linkage at the object file
 607    level.  This routine does not deal with COMDAT linkage and other
 608    similar complexities; it simply sets TREE_PUBLIC if it possible for
 609    entities in other translation units to contain copies of DECL, in
 610    the abstract.  */
 611
 612 void
 613 set_linkage_according_to_type (tree type, tree decl)
 614 {
 615   /* If TYPE involves a local class in a function with internal
 616      linkage, then DECL should have internal linkage too.  Other local
 617      classes have no linkage -- but if their containing functions
 618      have external linkage, it makes sense for DECL to have external
 619      linkage too.  That will allow template definitions to be merged,
 620      for example.  */
 621   if (no_linkage_check (type, /*relaxed_p=*/true))
 622     {
 623       TREE_PUBLIC (decl) = 0;
 624       DECL_INTERFACE_KNOWN (decl) = 1;
 625     }
 626   else
 627     TREE_PUBLIC (decl) = 1;
 628 }
 629
 630 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
 631    (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
 632    Use NAME for the name of the vtable, and VTABLE_TYPE for its type.  */
 633
 634 static tree
 635 build_vtable (tree class_type, tree name, tree vtable_type)
 636 {
 637   tree decl;
 638
 639   decl = build_lang_decl (VAR_DECL, name, vtable_type);
 640   /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
 641      now to avoid confusion in mangle_decl.  */
 642   SET_DECL_ASSEMBLER_NAME (decl, name);
 643   DECL_CONTEXT (decl) = class_type;
 644   DECL_ARTIFICIAL (decl) = 1;
 645   TREE_STATIC (decl) = 1;
 646   TREE_READONLY (decl) = 1;
 647   DECL_VIRTUAL_P (decl) = 1;
 648   DECL_ALIGN (decl) = TARGET_VTABLE_ENTRY_ALIGN;
 649   DECL_VTABLE_OR_VTT_P (decl) = 1;
 650   /* At one time the vtable info was grabbed 2 words at a time.  This
 651      fails on sparc unless you have 8-byte alignment.  (tiemann) */
 652   DECL_ALIGN (decl) = MAX (TYPE_ALIGN (double_type_node),
 653                            DECL_ALIGN (decl));
 654   set_linkage_according_to_type (class_type, decl);
 655   /* The vtable has not been defined -- yet.  */
 656   DECL_EXTERNAL (decl) = 1;
 657   DECL_NOT_REALLY_EXTERN (decl) = 1;
 658
 659   if (write_symbols == DWARF2_DEBUG)
 660     /* Mark the VAR_DECL node representing the vtable itself as a
 661        "gratuitous" one, thereby forcing dwarfout.c to ignore it.  It
 662        is rather important that such things be ignored because any
 663        effort to actually generate DWARF for them will run into
 664        trouble when/if we encounter code like:
 665
 666          #pragma interface
 667          struct S { virtual void member (); };
 668
 669        because the artificial declaration of the vtable itself (as
 670        manufactured by the g++ front end) will say that the vtable is
 671        a static member of `S' but only *after* the debug output for
 672        the definition of `S' has already been output.  This causes
 673        grief because the DWARF entry for the definition of the vtable
 674        will try to refer back to an earlier *declaration* of the
 675        vtable as a static member of `S' and there won't be one.  We
 676        might be able to arrange to have the "vtable static member"
 677        attached to the member list for `S' before the debug info for
 678        `S' get written (which would solve the problem) but that would
 679        require more intrusive changes to the g++ front end.  */
 680     DECL_IGNORED_P (decl) = 1;
 681
 682   return decl;
 683 }
 684
 685 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
 686    or even complete.  If this does not exist, create it.  If COMPLETE is
 687    nonzero, then complete the definition of it -- that will render it
 688    impossible to actually build the vtable, but is useful to get at those
 689    which are known to exist in the runtime.  */
 690
 691 tree
 692 get_vtable_decl (tree type, int complete)
 693 {
 694   tree decl;
 695
 696   if (CLASSTYPE_VTABLES (type))
 697     return CLASSTYPE_VTABLES (type);
 698
 699   decl = build_vtable (type, get_vtable_name (type), vtbl_type_node);
 700   CLASSTYPE_VTABLES (type) = decl;
 701
 702   if (complete)
 703     {
 704       DECL_EXTERNAL (decl) = 1;
 705       cp_finish_decl (decl, NULL_TREE, NULL_TREE, 0);
 706     }
 707
 708   return decl;
 709 }
 710
 711 /* Build the primary virtual function table for TYPE.  If BINFO is
 712    non-NULL, build the vtable starting with the initial approximation
 713    that it is the same as the one which is the head of the association
 714    list.  Returns a nonzero value if a new vtable is actually
 715    created.  */
 716
 717 static int
 718 build_primary_vtable (tree binfo, tree type)
 719 {
 720   tree decl;
 721   tree virtuals;
 722
 723   decl = get_vtable_decl (type, /*complete=*/0);
 724
 725   if (binfo)
 726     {
 727       if (BINFO_NEW_VTABLE_MARKED (binfo))
 728         /* We have already created a vtable for this base, so there's
 729            no need to do it again.  */
 730         return 0;
 731
 732       virtuals = copy_list (BINFO_VIRTUALS (binfo));
 733       TREE_TYPE (decl) = TREE_TYPE (get_vtbl_decl_for_binfo (binfo));
 734       DECL_SIZE (decl) = TYPE_SIZE (TREE_TYPE (decl));
 735       DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (TREE_TYPE (decl));
 736     }
 737   else
 738     {
 739       gcc_assert (TREE_TYPE (decl) == vtbl_type_node);
 740       virtuals = NULL_TREE;
 741     }
 742
 743 #ifdef GATHER_STATISTICS
 744   n_vtables += 1;
 745   n_vtable_elems += list_length (virtuals);
 746 #endif
 747
 748   /* Initialize the association list for this type, based
 749      on our first approximation.  */
 750   BINFO_VTABLE (TYPE_BINFO (type)) = decl;
 751   BINFO_VIRTUALS (TYPE_BINFO (type)) = virtuals;
 752   SET_BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (type));
 753   return 1;
 754 }
 755
 756 /* Give BINFO a new virtual function table which is initialized
 757    with a skeleton-copy of its original initialization.  The only
 758    entry that changes is the `delta' entry, so we can really
 759    share a lot of structure.
 760
 761    FOR_TYPE is the most derived type which caused this table to
 762    be needed.
 763
 764    Returns nonzero if we haven't met BINFO before.
 765
 766    The order in which vtables are built (by calling this function) for
 767    an object must remain the same, otherwise a binary incompatibility
 768    can result.  */
 769
 770 static int
 771 build_secondary_vtable (tree binfo)
 772 {
 773   if (BINFO_NEW_VTABLE_MARKED (binfo))
 774     /* We already created a vtable for this base.  There's no need to
 775        do it again.  */
 776     return 0;
 777
 778   /* Remember that we've created a vtable for this BINFO, so that we
 779      don't try to do so again.  */
 780   SET_BINFO_NEW_VTABLE_MARKED (binfo);
 781
 782   /* Make fresh virtual list, so we can smash it later.  */
 783   BINFO_VIRTUALS (binfo) = copy_list (BINFO_VIRTUALS (binfo));
 784
 785   /* Secondary vtables are laid out as part of the same structure as
 786      the primary vtable.  */
 787   BINFO_VTABLE (binfo) = NULL_TREE;
 788   return 1;
 789 }
 790
 791 /* Create a new vtable for BINFO which is the hierarchy dominated by
 792    T. Return nonzero if we actually created a new vtable.  */
 793
 794 static int
 795 make_new_vtable (tree t, tree binfo)
 796 {
 797   if (binfo == TYPE_BINFO (t))
 798     /* In this case, it is *type*'s vtable we are modifying.  We start
 799        with the approximation that its vtable is that of the
 800        immediate base class.  */
 801     return build_primary_vtable (binfo, t);
 802   else
 803     /* This is our very own copy of `basetype' to play with.  Later,
 804        we will fill in all the virtual functions that override the
 805        virtual functions in these base classes which are not defined
 806        by the current type.  */
 807     return build_secondary_vtable (binfo);
 808 }
 809
 810 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
 811    (which is in the hierarchy dominated by T) list FNDECL as its
 812    BV_FN.  DELTA is the required constant adjustment from the `this'
 813    pointer where the vtable entry appears to the `this' required when
 814    the function is actually called.  */
 815
 816 static void
 817 modify_vtable_entry (tree t,
 818                      tree binfo,
 819                      tree fndecl,
 820                      tree delta,
 821                      tree *virtuals)
 822 {
 823   tree v;
 824
 825   v = *virtuals;
 826
 827   if (fndecl != BV_FN (v)
 828       || !tree_int_cst_equal (delta, BV_DELTA (v)))
 829     {
 830       /* We need a new vtable for BINFO.  */
 831       if (make_new_vtable (t, binfo))
 832         {
 833           /* If we really did make a new vtable, we also made a copy
 834              of the BINFO_VIRTUALS list.  Now, we have to find the
 835              corresponding entry in that list.  */
 836           *virtuals = BINFO_VIRTUALS (binfo);
 837           while (BV_FN (*virtuals) != BV_FN (v))
 838             *virtuals = TREE_CHAIN (*virtuals);
 839           v = *virtuals;
 840         }
 841
 842       BV_DELTA (v) = delta;
 843       BV_VCALL_INDEX (v) = NULL_TREE;
 844       BV_FN (v) = fndecl;
 845     }
 846 }
 847
 848 \f
 849 /* Add method METHOD to class TYPE.  */
 850
 851 void
 852 add_method (tree type, tree method)
 853 {
 854   int using;
 855   unsigned slot;
 856   tree overload;
 857   int template_conv_p;
 858   VEC(tree) *method_vec;
 859   bool complete_p;
 860   bool insert_p = false;
 861   tree current_fns;
 862
 863   if (method == error_mark_node)
 864     return;
 865
 866   complete_p = COMPLETE_TYPE_P (type);
 867   using = (DECL_CONTEXT (method) != type);
 868   template_conv_p = (TREE_CODE (method) == TEMPLATE_DECL
 869                      && DECL_TEMPLATE_CONV_FN_P (method));
 870
 871   method_vec = CLASSTYPE_METHOD_VEC (type);
 872   if (!method_vec)
 873     {
 874       /* Make a new method vector.  We start with 8 entries.  We must
 875          allocate at least two (for constructors and destructors), and
 876          we're going to end up with an assignment operator at some
 877          point as well.  */
 878       method_vec = VEC_alloc (tree, 8);
 879       /* Create slots for constructors and destructors.  */
 880       VEC_quick_push (tree, method_vec, NULL_TREE);
 881       VEC_quick_push (tree, method_vec, NULL_TREE);
 882       CLASSTYPE_METHOD_VEC (type) = method_vec;
 883     }
 884
 885   /* Constructors and destructors go in special slots.  */
 886   if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (method))
 887     slot = CLASSTYPE_CONSTRUCTOR_SLOT;
 888   else if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method))
 889     {
 890       slot = CLASSTYPE_DESTRUCTOR_SLOT;
 891       TYPE_HAS_DESTRUCTOR (type) = 1;
 892
 893       if (TYPE_FOR_JAVA (type))
 894         error (DECL_ARTIFICIAL (method)
 895                ? "Java class '%T' cannot have an implicit non-trivial destructor"
 896                : "Java class '%T' cannot have a destructor",
 897                DECL_CONTEXT (method));
 898     }
 899   else
 900     {
 901       bool conv_p = DECL_CONV_FN_P (method);
 902       tree m;
 903
 904       insert_p = true;
 905       /* See if we already have an entry with this name.  */
 906       for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
 907            VEC_iterate (tree, method_vec, slot, m);
 908            ++slot)
 909         {
 910           m = OVL_CURRENT (m);
 911           if (template_conv_p)
 912             {
 913               if (TREE_CODE (m) == TEMPLATE_DECL
 914                   && DECL_TEMPLATE_CONV_FN_P (m))
 915                 insert_p = false;
 916               break;
 917             }
 918           if (conv_p && !DECL_CONV_FN_P (m))
 919             break;
 920           if (DECL_NAME (m) == DECL_NAME (method))
 921             {
 922               insert_p = false;
 923               break;
 924             }
 925           if (complete_p
 926               && !DECL_CONV_FN_P (m)
 927               && DECL_NAME (m) > DECL_NAME (method))
 928             break;
 929         }
 930     }
 931   current_fns = insert_p ? NULL_TREE : VEC_index (tree, method_vec, slot);
 932
 933   if (processing_template_decl)
 934     /* TYPE is a template class.  Don't issue any errors now; wait
 935        until instantiation time to complain.  */
 936     ;
 937   else
 938     {
 939       tree fns;
 940
 941       /* Check to see if we've already got this method.  */
 942       for (fns = current_fns; fns; fns = OVL_NEXT (fns))
 943         {
 944           tree fn = OVL_CURRENT (fns);
 945           tree parms1;
 946           tree parms2;
 947           bool same = 1;
 948
 949           if (TREE_CODE (fn) != TREE_CODE (method))
 950             continue;
 951
 952           /* [over.load] Member function declarations with the
 953              same name and the same parameter types cannot be
 954              overloaded if any of them is a static member
 955              function declaration.
 956
 957              [namespace.udecl] When a using-declaration brings names
 958              from a base class into a derived class scope, member
 959              functions in the derived class override and/or hide member
 960              functions with the same name and parameter types in a base
 961              class (rather than conflicting).  */
 962           parms1 = TYPE_ARG_TYPES (TREE_TYPE (fn));
 963           parms2 = TYPE_ARG_TYPES (TREE_TYPE (method));
 964
 965           /* Compare the quals on the 'this' parm.  Don't compare
 966              the whole types, as used functions are treated as
 967              coming from the using class in overload resolution.  */
 968           if (! DECL_STATIC_FUNCTION_P (fn)
 969               && ! DECL_STATIC_FUNCTION_P (method)
 970               && (TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms1)))
 971                   != TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms2)))))
 972             same = 0;
 973
 974           /* For templates, the template parms must be identical.  */
 975           if (TREE_CODE (fn) == TEMPLATE_DECL
 976               && !comp_template_parms (DECL_TEMPLATE_PARMS (fn),
 977                                        DECL_TEMPLATE_PARMS (method)))
 978             same = 0;
 979
 980           if (! DECL_STATIC_FUNCTION_P (fn))
 981             parms1 = TREE_CHAIN (parms1);
 982           if (! DECL_STATIC_FUNCTION_P (method))
 983             parms2 = TREE_CHAIN (parms2);
 984
 985           if (same && compparms (parms1, parms2)
 986               && (!DECL_CONV_FN_P (fn)
 987                   || same_type_p (TREE_TYPE (TREE_TYPE (fn)),
 988                                   TREE_TYPE (TREE_TYPE (method)))))
 989             {
 990               if (using && DECL_CONTEXT (fn) == type)
 991                 /* Defer to the local function.  */
 992                 return;
 993               else
 994                 {
 995                   cp_error_at ("`%#D' and `%#D' cannot be overloaded",
 996                                method, fn);
 997
 998                   /* We don't call duplicate_decls here to merge
 999                      the declarations because that will confuse
1000                      things if the methods have inline
1001                      definitions.  In particular, we will crash
1002                      while processing the definitions.  */
1003                   return;
1004                 }
1005             }
1006         }
1007     }
1008
1009   /* Add the new binding.  */
1010   overload = build_overload (method, current_fns);
1011
1012   if (slot >= CLASSTYPE_FIRST_CONVERSION_SLOT && !complete_p)
1013     push_class_level_binding (DECL_NAME (method), overload);
1014
1015   if (insert_p)
1016     {
1017       /* We only expect to add few methods in the COMPLETE_P case, so
1018          just make room for one more method in that case.  */
1019       if (VEC_reserve (tree, method_vec, complete_p ? 1 : -1))
1020         CLASSTYPE_METHOD_VEC (type) = method_vec;
1021       if (slot == VEC_length (tree, method_vec))
1022         VEC_quick_push (tree, method_vec, overload);
1023       else
1024         VEC_quick_insert (tree, method_vec, slot, overload);
1025     }
1026   else
1027     /* Replace the current slot. */
1028     VEC_replace (tree, method_vec, slot, overload);
1029 }
1030
1031 /* Subroutines of finish_struct.  */
1032
1033 /* Change the access of FDECL to ACCESS in T.  Return 1 if change was
1034    legit, otherwise return 0.  */
1035
1036 static int
1037 alter_access (tree t, tree fdecl, tree access)
1038 {
1039   tree elem;
1040
1041   if (!DECL_LANG_SPECIFIC (fdecl))
1042     retrofit_lang_decl (fdecl);
1043
1044   gcc_assert (!DECL_DISCRIMINATOR_P (fdecl));
1045
1046   elem = purpose_member (t, DECL_ACCESS (fdecl));
1047   if (elem)
1048     {
1049       if (TREE_VALUE (elem) != access)
1050         {
1051           if (TREE_CODE (TREE_TYPE (fdecl)) == FUNCTION_DECL)
1052             cp_error_at ("conflicting access specifications for method `%D', ignored", TREE_TYPE (fdecl));
1053           else
1054             error ("conflicting access specifications for field `%E', ignored",
1055                    DECL_NAME (fdecl));
1056         }
1057       else
1058         {
1059           /* They're changing the access to the same thing they changed
1060              it to before.  That's OK.  */
1061           ;
1062         }
1063     }
1064   else
1065     {
1066       perform_or_defer_access_check (TYPE_BINFO (t), fdecl);
1067       DECL_ACCESS (fdecl) = tree_cons (t, access, DECL_ACCESS (fdecl));
1068       return 1;
1069     }
1070   return 0;
1071 }
1072
1073 /* Process the USING_DECL, which is a member of T.  */
1074
1075 static void
1076 handle_using_decl (tree using_decl, tree t)
1077 {
1078   tree ctype = DECL_INITIAL (using_decl);
1079   tree name = DECL_NAME (using_decl);
1080   tree access
1081     = TREE_PRIVATE (using_decl) ? access_private_node
1082     : TREE_PROTECTED (using_decl) ? access_protected_node
1083     : access_public_node;
1084   tree fdecl, binfo;
1085   tree flist = NULL_TREE;
1086   tree old_value;
1087
1088   if (ctype == error_mark_node)
1089     return;
1090
1091   binfo = lookup_base (t, ctype, ba_any, NULL);
1092   if (! binfo)
1093     {
1094       location_t saved_loc = input_location;
1095
1096       input_location = DECL_SOURCE_LOCATION (using_decl);
1097       error_not_base_type (ctype, t);
1098       input_location = saved_loc;
1099       return;
1100     }
1101
1102   if (constructor_name_p (name, ctype))
1103     {
1104       cp_error_at ("`%D' names constructor", using_decl);
1105       return;
1106     }
1107   if (constructor_name_p (name, t))
1108     {
1109       cp_error_at ("`%D' invalid in `%T'", using_decl, t);
1110       return;
1111     }
1112
1113   fdecl = lookup_member (binfo, name, 0, false);
1114
1115   if (!fdecl)
1116     {
1117       cp_error_at ("no members matching `%D' in `%#T'", using_decl, ctype);
1118       return;
1119     }
1120
1121   if (BASELINK_P (fdecl))
1122     /* Ignore base type this came from.  */
1123     fdecl = BASELINK_FUNCTIONS (fdecl);
1124
1125   old_value = lookup_member (t, name, /*protect=*/0, /*want_type=*/false);
1126   if (old_value)
1127     {
1128       if (is_overloaded_fn (old_value))
1129         old_value = OVL_CURRENT (old_value);
1130
1131       if (DECL_P (old_value) && DECL_CONTEXT (old_value) == t)
1132         /* OK */;
1133       else
1134         old_value = NULL_TREE;
1135     }
1136
1137   if (is_overloaded_fn (fdecl))
1138     flist = fdecl;
1139
1140   if (! old_value)
1141     ;
1142   else if (is_overloaded_fn (old_value))
1143     {
1144       if (flist)
1145         /* It's OK to use functions from a base when there are functions with
1146            the same name already present in the current class.  */;
1147       else
1148         {
1149           cp_error_at ("`%D' invalid in `%#T'", using_decl, t);
1150           cp_error_at ("  because of local method `%#D' with same name",
1151                        OVL_CURRENT (old_value));
1152           return;
1153         }
1154     }
1155   else if (!DECL_ARTIFICIAL (old_value))
1156     {
1157       cp_error_at ("`%D' invalid in `%#T'", using_decl, t);
1158       cp_error_at ("  because of local member `%#D' with same name", old_value);
1159       return;
1160     }
1161
1162   /* Make type T see field decl FDECL with access ACCESS.  */
1163   if (flist)
1164     for (; flist; flist = OVL_NEXT (flist))
1165       {
1166         add_method (t, OVL_CURRENT (flist));
1167         alter_access (t, OVL_CURRENT (flist), access);
1168       }
1169   else
1170     alter_access (t, fdecl, access);
1171 }
1172 \f
1173 /* Run through the base classes of T, updating
1174    CANT_HAVE_DEFAULT_CTOR_P, CANT_HAVE_CONST_CTOR_P, and
1175    NO_CONST_ASN_REF_P.  Also set flag bits in T based on properties of
1176    the bases.  */
1177
1178 static void
1179 check_bases (tree t,
1180              int* cant_have_default_ctor_p,
1181              int* cant_have_const_ctor_p,
1182              int* no_const_asn_ref_p)
1183 {
1184   int i;
1185   int seen_non_virtual_nearly_empty_base_p;
1186   tree base_binfo;
1187   tree binfo;
1188
1189   seen_non_virtual_nearly_empty_base_p = 0;
1190
1191   for (binfo = TYPE_BINFO (t), i = 0;
1192        BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
1193     {
1194       tree basetype = TREE_TYPE (base_binfo);
1195
1196       gcc_assert (COMPLETE_TYPE_P (basetype));
1197
1198       /* Effective C++ rule 14.  We only need to check TYPE_POLYMORPHIC_P
1199          here because the case of virtual functions but non-virtual
1200          dtor is handled in finish_struct_1.  */
1201       if (warn_ecpp && ! TYPE_POLYMORPHIC_P (basetype)
1202           && TYPE_HAS_DESTRUCTOR (basetype))
1203         warning ("base class `%#T' has a non-virtual destructor",
1204                     basetype);
1205
1206       /* If the base class doesn't have copy constructors or
1207          assignment operators that take const references, then the
1208          derived class cannot have such a member automatically
1209          generated.  */
1210       if (! TYPE_HAS_CONST_INIT_REF (basetype))
1211         *cant_have_const_ctor_p = 1;
1212       if (TYPE_HAS_ASSIGN_REF (basetype)
1213           && !TYPE_HAS_CONST_ASSIGN_REF (basetype))
1214         *no_const_asn_ref_p = 1;
1215       /* Similarly, if the base class doesn't have a default
1216          constructor, then the derived class won't have an
1217          automatically generated default constructor.  */
1218       if (TYPE_HAS_CONSTRUCTOR (basetype)
1219           && ! TYPE_HAS_DEFAULT_CONSTRUCTOR (basetype))
1220         {
1221           *cant_have_default_ctor_p = 1;
1222           if (! TYPE_HAS_CONSTRUCTOR (t))
1223             pedwarn ("base `%T' with only non-default constructor in class without a constructor",
1224                         basetype);
1225         }
1226
1227       if (BINFO_VIRTUAL_P (base_binfo))
1228         /* A virtual base does not effect nearly emptiness.  */
1229         ;
1230       else if (CLASSTYPE_NEARLY_EMPTY_P (basetype))
1231         {
1232           if (seen_non_virtual_nearly_empty_base_p)
1233             /* And if there is more than one nearly empty base, then the
1234                derived class is not nearly empty either.  */
1235             CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1236           else
1237             /* Remember we've seen one.  */
1238             seen_non_virtual_nearly_empty_base_p = 1;
1239         }
1240       else if (!is_empty_class (basetype))
1241         /* If the base class is not empty or nearly empty, then this
1242            class cannot be nearly empty.  */
1243         CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1244
1245       /* A lot of properties from the bases also apply to the derived
1246          class.  */
1247       TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (basetype);
1248       TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
1249         |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype);
1250       TYPE_HAS_COMPLEX_ASSIGN_REF (t)
1251         |= TYPE_HAS_COMPLEX_ASSIGN_REF (basetype);
1252       TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (basetype);
1253       TYPE_POLYMORPHIC_P (t) |= TYPE_POLYMORPHIC_P (basetype);
1254       CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t)
1255         |= CLASSTYPE_CONTAINS_EMPTY_CLASS_P (basetype);
1256     }
1257 }
1258
1259 /* Determine all the primary bases within T.  Sets BINFO_PRIMARY_BASE_P for
1260    those that are primaries.  Sets BINFO_LOST_PRIMARY_P for those
1261    that have had a nearly-empty virtual primary base stolen by some
1262    other base in the hierarchy.  Determines CLASSTYPE_PRIMARY_BASE for
1263    T.  */
1264
1265 static void
1266 determine_primary_bases (tree t)
1267 {
1268   unsigned i;
1269   tree primary = NULL_TREE;
1270   tree type_binfo = TYPE_BINFO (t);
1271   tree base_binfo;
1272
1273   /* Determine the primary bases of our bases.  */
1274   for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1275        base_binfo = TREE_CHAIN (base_binfo))
1276     {
1277       tree primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (base_binfo));
1278
1279       /* See if we're the non-virtual primary of our inheritance
1280          chain.  */
1281       if (!BINFO_VIRTUAL_P (base_binfo))
1282         {
1283           tree parent = BINFO_INHERITANCE_CHAIN (base_binfo);
1284           tree parent_primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (parent));
1285
1286           if (parent_primary
1287               && BINFO_TYPE (base_binfo) == BINFO_TYPE (parent_primary))
1288             /* We are the primary binfo.  */
1289             BINFO_PRIMARY_P (base_binfo) = 1;
1290         }
1291       /* Determine if we have a virtual primary base, and mark it so.
1292        */
1293       if (primary && BINFO_VIRTUAL_P (primary))
1294         {
1295           tree this_primary = copied_binfo (primary, base_binfo);
1296
1297           if (BINFO_PRIMARY_P (this_primary))
1298             /* Someone already claimed this base.  */
1299             BINFO_LOST_PRIMARY_P (base_binfo) = 1;
1300           else
1301             {
1302               tree delta;
1303
1304               BINFO_PRIMARY_P (this_primary) = 1;
1305               BINFO_INHERITANCE_CHAIN (this_primary) = base_binfo;
1306
1307               /* A virtual binfo might have been copied from within
1308                  another hierarchy. As we're about to use it as a
1309                  primary base, make sure the offsets match.  */
1310               delta = size_diffop (convert (ssizetype,
1311                                             BINFO_OFFSET (base_binfo)),
1312                                    convert (ssizetype,
1313                                             BINFO_OFFSET (this_primary)));
1314
1315               propagate_binfo_offsets (this_primary, delta);
1316             }
1317         }
1318     }
1319
1320   /* First look for a dynamic direct non-virtual base.  */
1321   for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, base_binfo); i++)
1322     {
1323       tree basetype = BINFO_TYPE (base_binfo);
1324
1325       if (TYPE_CONTAINS_VPTR_P (basetype) && !BINFO_VIRTUAL_P (base_binfo))
1326         {
1327           primary = base_binfo;
1328           goto found;
1329         }
1330     }
1331
1332   /* A "nearly-empty" virtual base class can be the primary base
1333      class, if no non-virtual polymorphic base can be found.  Look for
1334      a nearly-empty virtual dynamic base that is not already a primary
1335      base of something in the hierarchy.  If there is no such base,
1336      just pick the first nearly-empty virtual base.  */
1337
1338   for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1339        base_binfo = TREE_CHAIN (base_binfo))
1340     if (BINFO_VIRTUAL_P (base_binfo)
1341         && CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (base_binfo)))
1342       {
1343         if (!BINFO_PRIMARY_P (base_binfo))
1344           {
1345             /* Found one that is not primary.  */
1346             primary = base_binfo;
1347             goto found;
1348           }
1349         else if (!primary)
1350           /* Remember the first candidate.  */
1351           primary = base_binfo;
1352       }
1353
1354  found:
1355   /* If we've got a primary base, use it.  */
1356   if (primary)
1357     {
1358       tree basetype = BINFO_TYPE (primary);
1359
1360       CLASSTYPE_PRIMARY_BINFO (t) = primary;
1361       if (BINFO_PRIMARY_P (primary))
1362         /* We are stealing a primary base.  */
1363         BINFO_LOST_PRIMARY_P (BINFO_INHERITANCE_CHAIN (primary)) = 1;
1364       BINFO_PRIMARY_P (primary) = 1;
1365       if (BINFO_VIRTUAL_P (primary))
1366         {
1367           tree delta;
1368
1369           BINFO_INHERITANCE_CHAIN (primary) = type_binfo;
1370           /* A virtual binfo might have been copied from within
1371              another hierarchy. As we're about to use it as a primary
1372              base, make sure the offsets match.  */
1373           delta = size_diffop (ssize_int (0),
1374                                convert (ssizetype, BINFO_OFFSET (primary)));
1375
1376           propagate_binfo_offsets (primary, delta);
1377         }
1378
1379       primary = TYPE_BINFO (basetype);
1380
1381       TYPE_VFIELD (t) = TYPE_VFIELD (basetype);
1382       BINFO_VTABLE (type_binfo) = BINFO_VTABLE (primary);
1383       BINFO_VIRTUALS (type_binfo) = BINFO_VIRTUALS (primary);
1384     }
1385 }
1386 \f
1387 /* Set memoizing fields and bits of T (and its variants) for later
1388    use.  */
1389
1390 static void
1391 finish_struct_bits (tree t)
1392 {
1393   tree variants;
1394
1395   /* Fix up variants (if any).  */
1396   for (variants = TYPE_NEXT_VARIANT (t);
1397        variants;
1398        variants = TYPE_NEXT_VARIANT (variants))
1399     {
1400       /* These fields are in the _TYPE part of the node, not in
1401          the TYPE_LANG_SPECIFIC component, so they are not shared.  */
1402       TYPE_HAS_CONSTRUCTOR (variants) = TYPE_HAS_CONSTRUCTOR (t);
1403       TYPE_HAS_DESTRUCTOR (variants) = TYPE_HAS_DESTRUCTOR (t);
1404       TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t);
1405       TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variants)
1406         = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
1407
1408       TYPE_POLYMORPHIC_P (variants) = TYPE_POLYMORPHIC_P (t);
1409
1410       TYPE_BINFO (variants) = TYPE_BINFO (t);
1411
1412       /* Copy whatever these are holding today.  */
1413       TYPE_VFIELD (variants) = TYPE_VFIELD (t);
1414       TYPE_METHODS (variants) = TYPE_METHODS (t);
1415       TYPE_FIELDS (variants) = TYPE_FIELDS (t);
1416       TYPE_SIZE (variants) = TYPE_SIZE (t);
1417       TYPE_SIZE_UNIT (variants) = TYPE_SIZE_UNIT (t);
1418     }
1419
1420   if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) && TYPE_POLYMORPHIC_P (t))
1421     /* For a class w/o baseclasses, 'finish_struct' has set
1422        CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1423        Similarly for a class whose base classes do not have vtables.
1424        When neither of these is true, we might have removed abstract
1425        virtuals (by providing a definition), added some (by declaring
1426        new ones), or redeclared ones from a base class.  We need to
1427        recalculate what's really an abstract virtual at this point (by
1428        looking in the vtables).  */
1429     get_pure_virtuals (t);
1430
1431   /* If this type has a copy constructor or a destructor, force its
1432      mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1433      nonzero.  This will cause it to be passed by invisible reference
1434      and prevent it from being returned in a register.  */
1435   if (! TYPE_HAS_TRIVIAL_INIT_REF (t) || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
1436     {
1437       tree variants;
1438       DECL_MODE (TYPE_MAIN_DECL (t)) = BLKmode;
1439       for (variants = t; variants; variants = TYPE_NEXT_VARIANT (variants))
1440         {
1441           TYPE_MODE (variants) = BLKmode;
1442           TREE_ADDRESSABLE (variants) = 1;
1443         }
1444     }
1445 }
1446
1447 /* Issue warnings about T having private constructors, but no friends,
1448    and so forth.
1449
1450    HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1451    static members.  HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1452    non-private static member functions.  */
1453
1454 static void
1455 maybe_warn_about_overly_private_class (tree t)
1456 {
1457   int has_member_fn = 0;
1458   int has_nonprivate_method = 0;
1459   tree fn;
1460
1461   if (!warn_ctor_dtor_privacy
1462       /* If the class has friends, those entities might create and
1463          access instances, so we should not warn.  */
1464       || (CLASSTYPE_FRIEND_CLASSES (t)
1465           || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))
1466       /* We will have warned when the template was declared; there's
1467          no need to warn on every instantiation.  */
1468       || CLASSTYPE_TEMPLATE_INSTANTIATION (t))
1469     /* There's no reason to even consider warning about this
1470        class.  */
1471     return;
1472
1473   /* We only issue one warning, if more than one applies, because
1474      otherwise, on code like:
1475
1476      class A {
1477        // Oops - forgot `public:'
1478        A();
1479        A(const A&);
1480        ~A();
1481      };
1482
1483      we warn several times about essentially the same problem.  */
1484
1485   /* Check to see if all (non-constructor, non-destructor) member
1486      functions are private.  (Since there are no friends or
1487      non-private statics, we can't ever call any of the private member
1488      functions.)  */
1489   for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
1490     /* We're not interested in compiler-generated methods; they don't
1491        provide any way to call private members.  */
1492     if (!DECL_ARTIFICIAL (fn))
1493       {
1494         if (!TREE_PRIVATE (fn))
1495           {
1496             if (DECL_STATIC_FUNCTION_P (fn))
1497               /* A non-private static member function is just like a
1498                  friend; it can create and invoke private member
1499                  functions, and be accessed without a class
1500                  instance.  */
1501               return;
1502
1503             has_nonprivate_method = 1;
1504             /* Keep searching for a static member function.  */
1505           }
1506         else if (!DECL_CONSTRUCTOR_P (fn) && !DECL_DESTRUCTOR_P (fn))
1507           has_member_fn = 1;
1508       }
1509
1510   if (!has_nonprivate_method && has_member_fn)
1511     {
1512       /* There are no non-private methods, and there's at least one
1513          private member function that isn't a constructor or
1514          destructor.  (If all the private members are
1515          constructors/destructors we want to use the code below that
1516          issues error messages specifically referring to
1517          constructors/destructors.)  */
1518       unsigned i;
1519       tree binfo = TYPE_BINFO (t);
1520
1521       for (i = 0; i != BINFO_N_BASE_BINFOS (binfo); i++)
1522         if (BINFO_BASE_ACCESS (binfo, i) != access_private_node)
1523           {
1524             has_nonprivate_method = 1;
1525             break;
1526           }
1527       if (!has_nonprivate_method)
1528         {
1529           warning ("all member functions in class `%T' are private", t);
1530           return;
1531         }
1532     }
1533
1534   /* Even if some of the member functions are non-private, the class
1535      won't be useful for much if all the constructors or destructors
1536      are private: such an object can never be created or destroyed.  */
1537   if (TYPE_HAS_DESTRUCTOR (t)
1538       && TREE_PRIVATE (CLASSTYPE_DESTRUCTORS (t)))
1539     {
1540       warning ("`%#T' only defines a private destructor and has no friends",
1541                t);
1542       return;
1543     }
1544
1545   if (TYPE_HAS_CONSTRUCTOR (t))
1546     {
1547       int nonprivate_ctor = 0;
1548
1549       /* If a non-template class does not define a copy
1550          constructor, one is defined for it, enabling it to avoid
1551          this warning.  For a template class, this does not
1552          happen, and so we would normally get a warning on:
1553
1554            template <class T> class C { private: C(); };
1555
1556          To avoid this asymmetry, we check TYPE_HAS_INIT_REF.  All
1557          complete non-template or fully instantiated classes have this
1558          flag set.  */
1559       if (!TYPE_HAS_INIT_REF (t))
1560         nonprivate_ctor = 1;
1561       else
1562         for (fn = CLASSTYPE_CONSTRUCTORS (t); fn; fn = OVL_NEXT (fn))
1563           {
1564             tree ctor = OVL_CURRENT (fn);
1565             /* Ideally, we wouldn't count copy constructors (or, in
1566                fact, any constructor that takes an argument of the
1567                class type as a parameter) because such things cannot
1568                be used to construct an instance of the class unless
1569                you already have one.  But, for now at least, we're
1570                more generous.  */
1571             if (! TREE_PRIVATE (ctor))
1572               {
1573                 nonprivate_ctor = 1;
1574                 break;
1575               }
1576           }
1577
1578       if (nonprivate_ctor == 0)
1579         {
1580           warning ("`%#T' only defines private constructors and has no friends",
1581                       t);
1582           return;
1583         }
1584     }
1585 }
1586
1587 static struct {
1588   gt_pointer_operator new_value;
1589   void *cookie;
1590 } resort_data;
1591
1592 /* Comparison function to compare two TYPE_METHOD_VEC entries by name.  */
1593
1594 static int
1595 method_name_cmp (const void* m1_p, const void* m2_p)
1596 {
1597   const tree *const m1 = m1_p;
1598   const tree *const m2 = m2_p;
1599
1600   if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1601     return 0;
1602   if (*m1 == NULL_TREE)
1603     return -1;
1604   if (*m2 == NULL_TREE)
1605     return 1;
1606   if (DECL_NAME (OVL_CURRENT (*m1)) < DECL_NAME (OVL_CURRENT (*m2)))
1607     return -1;
1608   return 1;
1609 }
1610
1611 /* This routine compares two fields like method_name_cmp but using the
1612    pointer operator in resort_field_decl_data.  */
1613
1614 static int
1615 resort_method_name_cmp (const void* m1_p, const void* m2_p)
1616 {
1617   const tree *const m1 = m1_p;
1618   const tree *const m2 = m2_p;
1619   if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1620     return 0;
1621   if (*m1 == NULL_TREE)
1622     return -1;
1623   if (*m2 == NULL_TREE)
1624     return 1;
1625   {
1626     tree d1 = DECL_NAME (OVL_CURRENT (*m1));
1627     tree d2 = DECL_NAME (OVL_CURRENT (*m2));
1628     resort_data.new_value (&d1, resort_data.cookie);
1629     resort_data.new_value (&d2, resort_data.cookie);
1630     if (d1 < d2)
1631       return -1;
1632   }
1633   return 1;
1634 }
1635
1636 /* Resort TYPE_METHOD_VEC because pointers have been reordered.  */
1637
1638 void
1639 resort_type_method_vec (void* obj,
1640                         void* orig_obj ATTRIBUTE_UNUSED ,
1641                         gt_pointer_operator new_value,
1642                         void* cookie)
1643 {
1644   VEC(tree) *method_vec = (VEC(tree) *) obj;
1645   int len = VEC_length (tree, method_vec);
1646   size_t slot;
1647   tree fn;
1648
1649   /* The type conversion ops have to live at the front of the vec, so we
1650      can't sort them.  */
1651   for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1652        VEC_iterate (tree, method_vec, slot, fn);
1653        ++slot)
1654     if (!DECL_CONV_FN_P (OVL_CURRENT (fn)))
1655       break;
1656
1657   if (len - slot > 1)
1658     {
1659       resort_data.new_value = new_value;
1660       resort_data.cookie = cookie;
1661       qsort (VEC_address (tree, method_vec) + slot, len - slot, sizeof (tree),
1662              resort_method_name_cmp);
1663     }
1664 }
1665
1666 /* Warn about duplicate methods in fn_fields.  Also compact method
1667    lists so that lookup can be made faster.
1668
1669    Data Structure: List of method lists.  The outer list is a
1670    TREE_LIST, whose TREE_PURPOSE field is the field name and the
1671    TREE_VALUE is the DECL_CHAIN of the FUNCTION_DECLs.  TREE_CHAIN
1672    links the entire list of methods for TYPE_METHODS.  Friends are
1673    chained in the same way as member functions (? TREE_CHAIN or
1674    DECL_CHAIN), but they live in the TREE_TYPE field of the outer
1675    list.  That allows them to be quickly deleted, and requires no
1676    extra storage.
1677
1678    Sort methods that are not special (i.e., constructors, destructors,
1679    and type conversion operators) so that we can find them faster in
1680    search.  */
1681
1682 static void
1683 finish_struct_methods (tree t)
1684 {
1685   tree fn_fields;
1686   VEC(tree) *method_vec;
1687   int slot, len;
1688
1689   method_vec = CLASSTYPE_METHOD_VEC (t);
1690   if (!method_vec)
1691     return;
1692
1693   len = VEC_length (tree, method_vec);
1694
1695   /* First fill in entry 0 with the constructors, entry 1 with destructors,
1696      and the next few with type conversion operators (if any).  */
1697   for (fn_fields = TYPE_METHODS (t); fn_fields;
1698        fn_fields = TREE_CHAIN (fn_fields))
1699     /* Clear out this flag.  */
1700     DECL_IN_AGGR_P (fn_fields) = 0;
1701
1702   if (TYPE_HAS_DESTRUCTOR (t) && !CLASSTYPE_DESTRUCTORS (t))
1703     /* We thought there was a destructor, but there wasn't.  Some
1704        parse errors cause this anomalous situation.  */
1705     TYPE_HAS_DESTRUCTOR (t) = 0;
1706
1707   /* Issue warnings about private constructors and such.  If there are
1708      no methods, then some public defaults are generated.  */
1709   maybe_warn_about_overly_private_class (t);
1710
1711   /* The type conversion ops have to live at the front of the vec, so we
1712      can't sort them.  */
1713   for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1714        VEC_iterate (tree, method_vec, slot, fn_fields);
1715        ++slot)
1716     if (!DECL_CONV_FN_P (OVL_CURRENT (fn_fields)))
1717       break;
1718   if (len - slot > 1)
1719     qsort (VEC_address (tree, method_vec) + slot,
1720            len-slot, sizeof (tree), method_name_cmp);
1721 }
1722
1723 /* Make BINFO's vtable have N entries, including RTTI entries,
1724    vbase and vcall offsets, etc.  Set its type and call the backend
1725    to lay it out.  */
1726
1727 static void
1728 layout_vtable_decl (tree binfo, int n)
1729 {
1730   tree atype;
1731   tree vtable;
1732
1733   atype = build_cplus_array_type (vtable_entry_type,
1734                                   build_index_type (size_int (n - 1)));
1735   layout_type (atype);
1736
1737   /* We may have to grow the vtable.  */
1738   vtable = get_vtbl_decl_for_binfo (binfo);
1739   if (!same_type_p (TREE_TYPE (vtable), atype))
1740     {
1741       TREE_TYPE (vtable) = atype;
1742       DECL_SIZE (vtable) = DECL_SIZE_UNIT (vtable) = NULL_TREE;
1743       layout_decl (vtable, 0);
1744     }
1745 }
1746
1747 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1748    have the same signature.  */
1749
1750 int
1751 same_signature_p (tree fndecl, tree base_fndecl)
1752 {
1753   /* One destructor overrides another if they are the same kind of
1754      destructor.  */
1755   if (DECL_DESTRUCTOR_P (base_fndecl) && DECL_DESTRUCTOR_P (fndecl)
1756       && special_function_p (base_fndecl) == special_function_p (fndecl))
1757     return 1;
1758   /* But a non-destructor never overrides a destructor, nor vice
1759      versa, nor do different kinds of destructors override
1760      one-another.  For example, a complete object destructor does not
1761      override a deleting destructor.  */
1762   if (DECL_DESTRUCTOR_P (base_fndecl) || DECL_DESTRUCTOR_P (fndecl))
1763     return 0;
1764
1765   if (DECL_NAME (fndecl) == DECL_NAME (base_fndecl)
1766       || (DECL_CONV_FN_P (fndecl)
1767           && DECL_CONV_FN_P (base_fndecl)
1768           && same_type_p (DECL_CONV_FN_TYPE (fndecl),
1769                           DECL_CONV_FN_TYPE (base_fndecl))))
1770     {
1771       tree types, base_types;
1772       types = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
1773       base_types = TYPE_ARG_TYPES (TREE_TYPE (base_fndecl));
1774       if ((TYPE_QUALS (TREE_TYPE (TREE_VALUE (base_types)))
1775            == TYPE_QUALS (TREE_TYPE (TREE_VALUE (types))))
1776           && compparms (TREE_CHAIN (base_types), TREE_CHAIN (types)))
1777         return 1;
1778     }
1779   return 0;
1780 }
1781
1782 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1783    subobject.  */
1784
1785 static bool
1786 base_derived_from (tree derived, tree base)
1787 {
1788   tree probe;
1789
1790   for (probe = base; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
1791     {
1792       if (probe == derived)
1793         return true;
1794       else if (BINFO_VIRTUAL_P (probe))
1795         /* If we meet a virtual base, we can't follow the inheritance
1796            any more.  See if the complete type of DERIVED contains
1797            such a virtual base.  */
1798         return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (derived))
1799                 != NULL_TREE);
1800     }
1801   return false;
1802 }
1803
1804 typedef struct count_depth_data {
1805   /* The depth of the current subobject, with "1" as the depth of the
1806      most derived object in the hierarchy.  */
1807   size_t depth;
1808   /* The maximum depth found so far.  */
1809   size_t max_depth;
1810 } count_depth_data;
1811
1812 /* Called from find_final_overrider via dfs_walk.  */
1813
1814 static tree
1815 dfs_depth_post (tree binfo ATTRIBUTE_UNUSED, void *data)
1816 {
1817   count_depth_data *cd = (count_depth_data *) data;
1818   if (cd->depth > cd->max_depth)
1819     cd->max_depth = cd->depth;
1820   cd->depth--;
1821   return NULL_TREE;
1822 }
1823
1824 /* Called from find_final_overrider via dfs_walk.  */
1825
1826 static tree
1827 dfs_depth_q (tree derived, int i, void *data)
1828 {
1829   count_depth_data *cd = (count_depth_data *) data;
1830   cd->depth++;
1831   return BINFO_BASE_BINFO (derived, i);
1832 }
1833
1834 typedef struct find_final_overrider_data_s {
1835   /* The function for which we are trying to find a final overrider.  */
1836   tree fn;
1837   /* The base class in which the function was declared.  */
1838   tree declaring_base;
1839   /* The most derived class in the hierarchy.  */
1840   tree most_derived_type;
1841   /* The candidate overriders.  */
1842   tree candidates;
1843   /* Each entry in this array is the next-most-derived class for a
1844      virtual base class along the current path.  */
1845   tree *vpath_list;
1846   /* A pointer one past the top of the VPATH_LIST.  */
1847   tree *vpath;
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
1853 static bool
1854 dfs_find_final_overrider_1 (tree binfo,
1855                             tree *vpath,
1856                             find_final_overrider_data *ffod)
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 (!same_type_p (BINFO_TYPE (binfo), ffod->most_derived_type))
1863     {
1864       tree derived;
1865
1866       if (BINFO_VIRTUAL_P (binfo))
1867         derived = *--vpath;
1868       else
1869         derived = BINFO_INHERITANCE_CHAIN (binfo);
1870       if (dfs_find_final_overrider_1 (derived, vpath, ffod))
1871         return true;
1872     }
1873
1874   method = look_for_overrides_here (BINFO_TYPE (binfo), ffod->fn);
1875   if (method)
1876     {
1877       tree *candidate = &ffod->candidates;
1878
1879       /* Remove any candidates overridden by this new function.  */
1880       while (*candidate)
1881         {
1882           /* If *CANDIDATE overrides METHOD, then METHOD
1883              cannot override anything else on the list.  */
1884           if (base_derived_from (TREE_VALUE (*candidate), binfo))
1885             return true;
1886           /* If METHOD overrides *CANDIDATE, remove *CANDIDATE.  */
1887           if (base_derived_from (binfo, TREE_VALUE (*candidate)))
1888             *candidate = TREE_CHAIN (*candidate);
1889           else
1890             candidate = &TREE_CHAIN (*candidate);
1891         }
1892
1893       /* Add the new function.  */
1894       ffod->candidates = tree_cons (method, binfo, ffod->candidates);
1895       return true;
1896     }
1897
1898   return false;
1899 }
1900
1901 /* Called from find_final_overrider via dfs_walk.  */
1902
1903 static tree
1904 dfs_find_final_overrider (tree binfo, void* data)
1905 {
1906   find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1907
1908   if (binfo == ffod->declaring_base)
1909     dfs_find_final_overrider_1 (binfo, ffod->vpath, ffod);
1910
1911   return NULL_TREE;
1912 }
1913
1914 static tree
1915 dfs_find_final_overrider_q (tree derived, int ix, void *data)
1916 {
1917   tree binfo = BINFO_BASE_BINFO (derived, ix);
1918   find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1919
1920   if (BINFO_VIRTUAL_P (binfo))
1921     *ffod->vpath++ = derived;
1922
1923   return binfo;
1924 }
1925
1926 static tree
1927 dfs_find_final_overrider_post (tree binfo, void *data)
1928 {
1929   find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1930
1931   if (BINFO_VIRTUAL_P (binfo))
1932     ffod->vpath--;
1933
1934   return NULL_TREE;
1935 }
1936
1937 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
1938    FN and whose TREE_VALUE is the binfo for the base where the
1939    overriding occurs.  BINFO (in the hierarchy dominated by the binfo
1940    DERIVED) is the base object in which FN is declared.  */
1941
1942 static tree
1943 find_final_overrider (tree derived, tree binfo, tree fn)
1944 {
1945   find_final_overrider_data ffod;
1946   count_depth_data cd;
1947
1948   /* Getting this right is a little tricky.  This is valid:
1949
1950        struct S { virtual void f (); };
1951        struct T { virtual void f (); };
1952        struct U : public S, public T { };
1953
1954      even though calling `f' in `U' is ambiguous.  But,
1955
1956        struct R { virtual void f(); };
1957        struct S : virtual public R { virtual void f (); };
1958        struct T : virtual public R { virtual void f (); };
1959        struct U : public S, public T { };
1960
1961      is not -- there's no way to decide whether to put `S::f' or
1962      `T::f' in the vtable for `R'.
1963
1964      The solution is to look at all paths to BINFO.  If we find
1965      different overriders along any two, then there is a problem.  */
1966   if (DECL_THUNK_P (fn))
1967     fn = THUNK_TARGET (fn);
1968
1969   /* Determine the depth of the hierarchy.  */
1970   cd.depth = 0;
1971   cd.max_depth = 0;
1972   dfs_walk (derived, dfs_depth_post, dfs_depth_q, &cd);
1973
1974   ffod.fn = fn;
1975   ffod.declaring_base = binfo;
1976   ffod.most_derived_type = BINFO_TYPE (derived);
1977   ffod.candidates = NULL_TREE;
1978   ffod.vpath_list = (tree *) xcalloc (cd.max_depth, sizeof (tree));
1979   ffod.vpath = ffod.vpath_list;
1980
1981   dfs_walk_real (derived,
1982                  dfs_find_final_overrider,
1983                  dfs_find_final_overrider_post,
1984                  dfs_find_final_overrider_q,
1985                  &ffod);
1986
1987   free (ffod.vpath_list);
1988
1989   /* If there was no winner, issue an error message.  */
1990   if (!ffod.candidates || TREE_CHAIN (ffod.candidates))
1991     {
1992       error ("no unique final overrider for `%D' in `%T'", fn,
1993              BINFO_TYPE (derived));
1994       return error_mark_node;
1995     }
1996
1997   return ffod.candidates;
1998 }
1999
2000 /* Return the index of the vcall offset for FN when TYPE is used as a
2001    virtual base.  */
2002
2003 static tree
2004 get_vcall_index (tree fn, tree type)
2005 {
2006   VEC (tree_pair_s) *indices = CLASSTYPE_VCALL_INDICES (type);
2007   tree_pair_p p;
2008   unsigned ix;
2009
2010   for (ix = 0; VEC_iterate (tree_pair_s, indices, ix, p); ix++)
2011     if ((DECL_DESTRUCTOR_P (fn) && DECL_DESTRUCTOR_P (p->purpose))
2012         || same_signature_p (fn, p->purpose))
2013       return p->value;
2014
2015   /* There should always be an appropriate index.  */
2016   gcc_unreachable ();
2017 }
2018
2019 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2020    dominated by T.  FN has been overridden in BINFO; VIRTUALS points to the
2021    corresponding position in the BINFO_VIRTUALS list.  */
2022
2023 static void
2024 update_vtable_entry_for_fn (tree t, tree binfo, tree fn, tree* virtuals,
2025                             unsigned ix)
2026 {
2027   tree b;
2028   tree overrider;
2029   tree delta;
2030   tree virtual_base;
2031   tree first_defn;
2032   tree overrider_fn, overrider_target;
2033   tree target_fn = DECL_THUNK_P (fn) ? THUNK_TARGET (fn) : fn;
2034   tree over_return, base_return;
2035   bool lost = false;
2036
2037   /* Find the nearest primary base (possibly binfo itself) which defines
2038      this function; this is the class the caller will convert to when
2039      calling FN through BINFO.  */
2040   for (b = binfo; ; b = get_primary_binfo (b))
2041     {
2042       gcc_assert (b);
2043       if (look_for_overrides_here (BINFO_TYPE (b), target_fn))
2044         break;
2045
2046       /* The nearest definition is from a lost primary.  */
2047       if (BINFO_LOST_PRIMARY_P (b))
2048         lost = true;
2049     }
2050   first_defn = b;
2051
2052   /* Find the final overrider.  */
2053   overrider = find_final_overrider (TYPE_BINFO (t), b, target_fn);
2054   if (overrider == error_mark_node)
2055     return;
2056   overrider_target = overrider_fn = TREE_PURPOSE (overrider);
2057
2058   /* Check for adjusting covariant return types.  */
2059   over_return = TREE_TYPE (TREE_TYPE (overrider_target));
2060   base_return = TREE_TYPE (TREE_TYPE (target_fn));
2061
2062   if (POINTER_TYPE_P (over_return)
2063       && TREE_CODE (over_return) == TREE_CODE (base_return)
2064       && CLASS_TYPE_P (TREE_TYPE (over_return))
2065       && CLASS_TYPE_P (TREE_TYPE (base_return)))
2066     {
2067       /* If FN is a covariant thunk, we must figure out the adjustment
2068          to the final base FN was converting to. As OVERRIDER_TARGET might
2069          also be converting to the return type of FN, we have to
2070          combine the two conversions here.  */
2071       tree fixed_offset, virtual_offset;
2072
2073       if (DECL_THUNK_P (fn))
2074         {
2075           gcc_assert (DECL_RESULT_THUNK_P (fn));
2076           fixed_offset = ssize_int (THUNK_FIXED_OFFSET (fn));
2077           virtual_offset = THUNK_VIRTUAL_OFFSET (fn);
2078         }
2079       else
2080         fixed_offset = virtual_offset = NULL_TREE;
2081
2082       if (virtual_offset)
2083         /* Find the equivalent binfo within the return type of the
2084            overriding function. We will want the vbase offset from
2085            there.  */
2086         virtual_offset = binfo_for_vbase (BINFO_TYPE (virtual_offset),
2087                                           TREE_TYPE (over_return));
2088       else if (!same_type_p (TREE_TYPE (over_return),
2089                              TREE_TYPE (base_return)))
2090         {
2091           /* There was no existing virtual thunk (which takes
2092              precedence).  */
2093           tree thunk_binfo;
2094           base_kind kind;
2095
2096           thunk_binfo = lookup_base (TREE_TYPE (over_return),
2097                                      TREE_TYPE (base_return),
2098                                      ba_check | ba_quiet, &kind);
2099
2100           if (thunk_binfo && (kind == bk_via_virtual
2101                               || !BINFO_OFFSET_ZEROP (thunk_binfo)))
2102             {
2103               tree offset = convert (ssizetype, BINFO_OFFSET (thunk_binfo));
2104
2105               if (kind == bk_via_virtual)
2106                 {
2107                   /* We convert via virtual base. Find the virtual
2108                      base and adjust the fixed offset to be from there.  */
2109                   while (!BINFO_VIRTUAL_P (thunk_binfo))
2110                     thunk_binfo = BINFO_INHERITANCE_CHAIN (thunk_binfo);
2111
2112                   virtual_offset = thunk_binfo;
2113                   offset = size_diffop
2114                     (offset, convert
2115                      (ssizetype, BINFO_OFFSET (virtual_offset)));
2116                 }
2117               if (fixed_offset)
2118                 /* There was an existing fixed offset, this must be
2119                    from the base just converted to, and the base the
2120                    FN was thunking to.  */
2121                 fixed_offset = size_binop (PLUS_EXPR, fixed_offset, offset);
2122               else
2123                 fixed_offset = offset;
2124             }
2125         }
2126
2127       if (fixed_offset || virtual_offset)
2128         /* Replace the overriding function with a covariant thunk.  We
2129            will emit the overriding function in its own slot as
2130            well.  */
2131         overrider_fn = make_thunk (overrider_target, /*this_adjusting=*/0,
2132                                    fixed_offset, virtual_offset);
2133     }
2134   else
2135     gcc_assert (!DECL_THUNK_P (fn));
2136
2137   /* Assume that we will produce a thunk that convert all the way to
2138      the final overrider, and not to an intermediate virtual base.  */
2139   virtual_base = NULL_TREE;
2140
2141   /* See if we can convert to an intermediate virtual base first, and then
2142      use the vcall offset located there to finish the conversion.  */
2143   for (; b; b = BINFO_INHERITANCE_CHAIN (b))
2144     {
2145       /* If we find the final overrider, then we can stop
2146          walking.  */
2147       if (same_type_p (BINFO_TYPE (b),
2148                        BINFO_TYPE (TREE_VALUE (overrider))))
2149         break;
2150
2151       /* If we find a virtual base, and we haven't yet found the
2152          overrider, then there is a virtual base between the
2153          declaring base (first_defn) and the final overrider.  */
2154       if (BINFO_VIRTUAL_P (b))
2155         {
2156           virtual_base = b;
2157           break;
2158         }
2159     }
2160
2161   if (overrider_fn != overrider_target && !virtual_base)
2162     {
2163       /* The ABI specifies that a covariant thunk includes a mangling
2164          for a this pointer adjustment.  This-adjusting thunks that
2165          override a function from a virtual base have a vcall
2166          adjustment.  When the virtual base in question is a primary
2167          virtual base, we know the adjustments are zero, (and in the
2168          non-covariant case, we would not use the thunk).
2169          Unfortunately we didn't notice this could happen, when
2170          designing the ABI and so never mandated that such a covariant
2171          thunk should be emitted.  Because we must use the ABI mandated
2172          name, we must continue searching from the binfo where we
2173          found the most recent definition of the function, towards the
2174          primary binfo which first introduced the function into the
2175          vtable.  If that enters a virtual base, we must use a vcall
2176          this-adjusting thunk.  Bleah! */
2177       tree probe = first_defn;
2178
2179       while ((probe = get_primary_binfo (probe))
2180              && (unsigned) list_length (BINFO_VIRTUALS (probe)) > ix)
2181         if (BINFO_VIRTUAL_P (probe))
2182           virtual_base = probe;
2183
2184       if (virtual_base)
2185         /* Even if we find a virtual base, the correct delta is
2186            between the overrider and the binfo we're building a vtable
2187            for.  */
2188         goto virtual_covariant;
2189     }
2190
2191   /* Compute the constant adjustment to the `this' pointer.  The
2192      `this' pointer, when this function is called, will point at BINFO
2193      (or one of its primary bases, which are at the same offset).  */
2194   if (virtual_base)
2195     /* The `this' pointer needs to be adjusted from the declaration to
2196        the nearest virtual base.  */
2197     delta = size_diffop (convert (ssizetype, BINFO_OFFSET (virtual_base)),
2198                          convert (ssizetype, BINFO_OFFSET (first_defn)));
2199   else if (lost)
2200     /* If the nearest definition is in a lost primary, we don't need an
2201        entry in our vtable.  Except possibly in a constructor vtable,
2202        if we happen to get our primary back.  In that case, the offset
2203        will be zero, as it will be a primary base.  */
2204     delta = size_zero_node;
2205   else
2206     /* The `this' pointer needs to be adjusted from pointing to
2207        BINFO to pointing at the base where the final overrider
2208        appears.  */
2209     virtual_covariant:
2210     delta = size_diffop (convert (ssizetype,
2211                                   BINFO_OFFSET (TREE_VALUE (overrider))),
2212                          convert (ssizetype, BINFO_OFFSET (binfo)));
2213
2214   modify_vtable_entry (t, binfo, overrider_fn, delta, virtuals);
2215
2216   if (virtual_base)
2217     BV_VCALL_INDEX (*virtuals)
2218       = get_vcall_index (overrider_target, BINFO_TYPE (virtual_base));
2219   else
2220     BV_VCALL_INDEX (*virtuals) = NULL_TREE;
2221 }
2222
2223 /* Called from modify_all_vtables via dfs_walk.  */
2224
2225 static tree
2226 dfs_modify_vtables (tree binfo, void* data)
2227 {
2228   tree t = (tree) data;
2229
2230   if (/* There's no need to modify the vtable for a non-virtual
2231          primary base; we're not going to use that vtable anyhow.
2232          We do still need to do this for virtual primary bases, as they
2233          could become non-primary in a construction vtable.  */
2234       (!BINFO_PRIMARY_P (binfo) || BINFO_VIRTUAL_P (binfo))
2235       /* Similarly, a base without a vtable needs no modification.  */
2236       && TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))
2237       /* Don't do the primary vtable, if it's new.  */
2238       && (BINFO_TYPE (binfo) != t || CLASSTYPE_HAS_PRIMARY_BASE_P (t)))
2239     {
2240       tree virtuals;
2241       tree old_virtuals;
2242       unsigned ix;
2243
2244       make_new_vtable (t, binfo);
2245
2246       /* Now, go through each of the virtual functions in the virtual
2247          function table for BINFO.  Find the final overrider, and
2248          update the BINFO_VIRTUALS list appropriately.  */
2249       for (ix = 0, virtuals = BINFO_VIRTUALS (binfo),
2250              old_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
2251            virtuals;
2252            ix++, virtuals = TREE_CHAIN (virtuals),
2253              old_virtuals = TREE_CHAIN (old_virtuals))
2254         update_vtable_entry_for_fn (t,
2255                                     binfo,
2256                                     BV_FN (old_virtuals),
2257                                     &virtuals, ix);
2258     }
2259
2260   BINFO_MARKED (binfo) = 1;
2261
2262   return NULL_TREE;
2263 }
2264
2265 /* Update all of the primary and secondary vtables for T.  Create new
2266    vtables as required, and initialize their RTTI information.  Each
2267    of the functions in VIRTUALS is declared in T and may override a
2268    virtual function from a base class; find and modify the appropriate
2269    entries to point to the overriding functions.  Returns a list, in
2270    declaration order, of the virtual functions that are declared in T,
2271    but do not appear in the primary base class vtable, and which
2272    should therefore be appended to the end of the vtable for T.  */
2273
2274 static tree
2275 modify_all_vtables (tree t, tree virtuals)
2276 {
2277   tree binfo = TYPE_BINFO (t);
2278   tree *fnsp;
2279
2280   /* Update all of the vtables.  */
2281   dfs_walk (binfo, dfs_modify_vtables, unmarkedp, t);
2282   dfs_walk (binfo, dfs_unmark, markedp, t);
2283
2284   /* Add virtual functions not already in our primary vtable. These
2285      will be both those introduced by this class, and those overridden
2286      from secondary bases.  It does not include virtuals merely
2287      inherited from secondary bases.  */
2288   for (fnsp = &virtuals; *fnsp; )
2289     {
2290       tree fn = TREE_VALUE (*fnsp);
2291
2292       if (!value_member (fn, BINFO_VIRTUALS (binfo))
2293           || DECL_VINDEX (fn) == error_mark_node)
2294         {
2295           /* We don't need to adjust the `this' pointer when
2296              calling this function.  */
2297           BV_DELTA (*fnsp) = integer_zero_node;
2298           BV_VCALL_INDEX (*fnsp) = NULL_TREE;
2299
2300           /* This is a function not already in our vtable.  Keep it.  */
2301           fnsp = &TREE_CHAIN (*fnsp);
2302         }
2303       else
2304         /* We've already got an entry for this function.  Skip it.  */
2305         *fnsp = TREE_CHAIN (*fnsp);
2306     }
2307
2308   return virtuals;
2309 }
2310
2311 /* Get the base virtual function declarations in T that have the
2312    indicated NAME.  */
2313
2314 static tree
2315 get_basefndecls (tree name, tree t)
2316 {
2317   tree methods;
2318   tree base_fndecls = NULL_TREE;
2319   int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
2320   int i;
2321
2322   /* Find virtual functions in T with the indicated NAME.  */
2323   i = lookup_fnfields_1 (t, name);
2324   if (i != -1)
2325     for (methods = VEC_index (tree, CLASSTYPE_METHOD_VEC (t), i);
2326          methods;
2327          methods = OVL_NEXT (methods))
2328       {
2329         tree method = OVL_CURRENT (methods);
2330
2331         if (TREE_CODE (method) == FUNCTION_DECL
2332             && DECL_VINDEX (method))
2333           base_fndecls = tree_cons (NULL_TREE, method, base_fndecls);
2334       }
2335
2336   if (base_fndecls)
2337     return base_fndecls;
2338
2339   for (i = 0; i < n_baseclasses; i++)
2340     {
2341       tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (t), i));
2342       base_fndecls = chainon (get_basefndecls (name, basetype),
2343                               base_fndecls);
2344     }
2345
2346   return base_fndecls;
2347 }
2348
2349 /* If this declaration supersedes the declaration of
2350    a method declared virtual in the base class, then
2351    mark this field as being virtual as well.  */
2352
2353 static void
2354 check_for_override (tree decl, tree ctype)
2355 {
2356   if (TREE_CODE (decl) == TEMPLATE_DECL)
2357     /* In [temp.mem] we have:
2358
2359          A specialization of a member function template does not
2360          override a virtual function from a base class.  */
2361     return;
2362   if ((DECL_DESTRUCTOR_P (decl)
2363        || IDENTIFIER_VIRTUAL_P (DECL_NAME (decl))
2364        || DECL_CONV_FN_P (decl))
2365       && look_for_overrides (ctype, decl)
2366       && !DECL_STATIC_FUNCTION_P (decl))
2367     /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2368        the error_mark_node so that we know it is an overriding
2369        function.  */
2370     DECL_VINDEX (decl) = decl;
2371
2372   if (DECL_VIRTUAL_P (decl))
2373     {
2374       if (!DECL_VINDEX (decl))
2375         DECL_VINDEX (decl) = error_mark_node;
2376       IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) = 1;
2377     }
2378 }
2379
2380 /* Warn about hidden virtual functions that are not overridden in t.
2381    We know that constructors and destructors don't apply.  */
2382
2383 void
2384 warn_hidden (tree t)
2385 {
2386   VEC(tree) *method_vec = CLASSTYPE_METHOD_VEC (t);
2387   tree fns;
2388   size_t i;
2389
2390   /* We go through each separately named virtual function.  */
2391   for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
2392        VEC_iterate (tree, method_vec, i, fns);
2393        ++i)
2394     {
2395       tree fn;
2396       tree name;
2397       tree fndecl;
2398       tree base_fndecls;
2399       tree base_binfo;
2400       tree binfo;
2401       int j;
2402
2403       /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2404          have the same name.  Figure out what name that is.  */
2405       name = DECL_NAME (OVL_CURRENT (fns));
2406       /* There are no possibly hidden functions yet.  */
2407       base_fndecls = NULL_TREE;
2408       /* Iterate through all of the base classes looking for possibly
2409          hidden functions.  */
2410       for (binfo = TYPE_BINFO (t), j = 0;
2411            BINFO_BASE_ITERATE (binfo, j, base_binfo); j++)
2412         {
2413           tree basetype = BINFO_TYPE (base_binfo);
2414           base_fndecls = chainon (get_basefndecls (name, basetype),
2415                                   base_fndecls);
2416         }
2417
2418       /* If there are no functions to hide, continue.  */
2419       if (!base_fndecls)
2420         continue;
2421
2422       /* Remove any overridden functions.  */
2423       for (fn = fns; fn; fn = OVL_NEXT (fn))
2424         {
2425           fndecl = OVL_CURRENT (fn);
2426           if (DECL_VINDEX (fndecl))
2427             {
2428               tree *prev = &base_fndecls;
2429
2430               while (*prev)
2431                 /* If the method from the base class has the same
2432                    signature as the method from the derived class, it
2433                    has been overridden.  */
2434                 if (same_signature_p (fndecl, TREE_VALUE (*prev)))
2435                   *prev = TREE_CHAIN (*prev);
2436                 else
2437                   prev = &TREE_CHAIN (*prev);
2438             }
2439         }
2440
2441       /* Now give a warning for all base functions without overriders,
2442          as they are hidden.  */
2443       while (base_fndecls)
2444         {
2445           /* Here we know it is a hider, and no overrider exists.  */
2446           cp_warning_at ("`%D' was hidden", TREE_VALUE (base_fndecls));
2447           cp_warning_at ("  by `%D'", fns);
2448           base_fndecls = TREE_CHAIN (base_fndecls);
2449         }
2450     }
2451 }
2452
2453 /* Check for things that are invalid.  There are probably plenty of other
2454    things we should check for also.  */
2455
2456 static void
2457 finish_struct_anon (tree t)
2458 {
2459   tree field;
2460
2461   for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
2462     {
2463       if (TREE_STATIC (field))
2464         continue;
2465       if (TREE_CODE (field) != FIELD_DECL)
2466         continue;
2467
2468       if (DECL_NAME (field) == NULL_TREE
2469           && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
2470         {
2471           tree elt = TYPE_FIELDS (TREE_TYPE (field));
2472           for (; elt; elt = TREE_CHAIN (elt))
2473             {
2474               /* We're generally only interested in entities the user
2475                  declared, but we also find nested classes by noticing
2476                  the TYPE_DECL that we create implicitly.  You're
2477                  allowed to put one anonymous union inside another,
2478                  though, so we explicitly tolerate that.  We use
2479                  TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2480                  we also allow unnamed types used for defining fields.  */
2481               if (DECL_ARTIFICIAL (elt)
2482                   && (!DECL_IMPLICIT_TYPEDEF_P (elt)
2483                       || TYPE_ANONYMOUS_P (TREE_TYPE (elt))))
2484                 continue;
2485
2486               if (TREE_CODE (elt) != FIELD_DECL)
2487                 {
2488                   cp_pedwarn_at ("`%#D' invalid; an anonymous union can only have non-static data members",
2489                                  elt);
2490                   continue;
2491                 }
2492
2493               if (TREE_PRIVATE (elt))
2494                 cp_pedwarn_at ("private member `%#D' in anonymous union",
2495                                elt);
2496               else if (TREE_PROTECTED (elt))
2497                 cp_pedwarn_at ("protected member `%#D' in anonymous union",
2498                                elt);
2499
2500               TREE_PRIVATE (elt) = TREE_PRIVATE (field);
2501               TREE_PROTECTED (elt) = TREE_PROTECTED (field);
2502             }
2503         }
2504     }
2505 }
2506
2507 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2508    will be used later during class template instantiation.
2509    When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2510    a non-static member data (FIELD_DECL), a member function
2511    (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2512    a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2513    When FRIEND_P is nonzero, T is either a friend class
2514    (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2515    (FUNCTION_DECL, TEMPLATE_DECL).  */
2516
2517 void
2518 maybe_add_class_template_decl_list (tree type, tree t, int friend_p)
2519 {
2520   /* Save some memory by not creating TREE_LIST if TYPE is not template.  */
2521   if (CLASSTYPE_TEMPLATE_INFO (type))
2522     CLASSTYPE_DECL_LIST (type)
2523       = tree_cons (friend_p ? NULL_TREE : type,
2524                    t, CLASSTYPE_DECL_LIST (type));
2525 }
2526
2527 /* Create default constructors, assignment operators, and so forth for
2528    the type indicated by T, if they are needed.
2529    CANT_HAVE_DEFAULT_CTOR, CANT_HAVE_CONST_CTOR, and
2530    CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason, the
2531    class cannot have a default constructor, copy constructor taking a
2532    const reference argument, or an assignment operator taking a const
2533    reference, respectively.  If a virtual destructor is created, its
2534    DECL is returned; otherwise the return value is NULL_TREE.  */
2535
2536 static void
2537 add_implicitly_declared_members (tree t,
2538                                  int cant_have_default_ctor,
2539                                  int cant_have_const_cctor,
2540                                  int cant_have_const_assignment)
2541 {
2542   tree default_fn;
2543   tree implicit_fns = NULL_TREE;
2544   tree virtual_dtor = NULL_TREE;
2545   tree *f;
2546
2547   /* Destructor.  */
2548   if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) && !TYPE_HAS_DESTRUCTOR (t))
2549     {
2550       default_fn = implicitly_declare_fn (sfk_destructor, t, /*const_p=*/0);
2551       check_for_override (default_fn, t);
2552
2553       /* If we couldn't make it work, then pretend we didn't need it.  */
2554       if (default_fn == void_type_node)
2555         TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = 0;
2556       else
2557         {
2558           TREE_CHAIN (default_fn) = implicit_fns;
2559           implicit_fns = default_fn;
2560
2561           if (DECL_VINDEX (default_fn))
2562             virtual_dtor = default_fn;
2563         }
2564     }
2565   else
2566     /* Any non-implicit destructor is non-trivial.  */
2567     TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) |= TYPE_HAS_DESTRUCTOR (t);
2568
2569   /* Default constructor.  */
2570   if (! TYPE_HAS_CONSTRUCTOR (t) && ! cant_have_default_ctor)
2571     {
2572       TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 1;
2573       CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 1;
2574     }
2575
2576   /* Copy constructor.  */
2577   if (! TYPE_HAS_INIT_REF (t) && ! TYPE_FOR_JAVA (t))
2578     {
2579       TYPE_HAS_INIT_REF (t) = 1;
2580       TYPE_HAS_CONST_INIT_REF (t) = !cant_have_const_cctor;
2581       CLASSTYPE_LAZY_COPY_CTOR (t) = 1;
2582       TYPE_HAS_CONSTRUCTOR (t) = 1;
2583     }
2584
2585   /* If there is no assignment operator, one will be created if and
2586      when it is needed.  For now, just record whether or not the type
2587      of the parameter to the assignment operator will be a const or
2588      non-const reference.  */
2589   if (!TYPE_HAS_ASSIGN_REF (t) && !TYPE_FOR_JAVA (t))
2590     {
2591       TYPE_HAS_ASSIGN_REF (t) = 1;
2592       TYPE_HAS_CONST_ASSIGN_REF (t) = !cant_have_const_assignment;
2593       CLASSTYPE_LAZY_ASSIGNMENT_OP (t) = 1;
2594     }
2595
2596   /* Now, hook all of the new functions on to TYPE_METHODS,
2597      and add them to the CLASSTYPE_METHOD_VEC.  */
2598   for (f = &implicit_fns; *f; f = &TREE_CHAIN (*f))
2599     {
2600       add_method (t, *f);
2601       maybe_add_class_template_decl_list (current_class_type, *f, /*friend_p=*/0);
2602     }
2603   if (abi_version_at_least (2))
2604     /* G++ 3.2 put the implicit destructor at the *beginning* of the
2605        list, which cause the destructor to be emitted in an incorrect
2606        location in the vtable.  */
2607     TYPE_METHODS (t) = chainon (TYPE_METHODS (t), implicit_fns);
2608   else
2609     {
2610       if (warn_abi && virtual_dtor)
2611         warning ("vtable layout for class `%T' may not be ABI-compliant "
2612                  "and may change in a future version of GCC due to implicit "
2613                  "virtual destructor",
2614                  t);
2615       *f = TYPE_METHODS (t);
2616       TYPE_METHODS (t) = implicit_fns;
2617     }
2618 }
2619
2620 /* Subroutine of finish_struct_1.  Recursively count the number of fields
2621    in TYPE, including anonymous union members.  */
2622
2623 static int
2624 count_fields (tree fields)
2625 {
2626   tree x;
2627   int n_fields = 0;
2628   for (x = fields; x; x = TREE_CHAIN (x))
2629     {
2630       if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2631         n_fields += count_fields (TYPE_FIELDS (TREE_TYPE (x)));
2632       else
2633         n_fields += 1;
2634     }
2635   return n_fields;
2636 }
2637
2638 /* Subroutine of finish_struct_1.  Recursively add all the fields in the
2639    TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX.  */
2640
2641 static int
2642 add_fields_to_record_type (tree fields, struct sorted_fields_type *field_vec, int idx)
2643 {
2644   tree x;
2645   for (x = fields; x; x = TREE_CHAIN (x))
2646     {
2647       if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2648         idx = add_fields_to_record_type (TYPE_FIELDS (TREE_TYPE (x)), field_vec, idx);
2649       else
2650         field_vec->elts[idx++] = x;
2651     }
2652   return idx;
2653 }
2654
2655 /* FIELD is a bit-field.  We are finishing the processing for its
2656    enclosing type.  Issue any appropriate messages and set appropriate
2657    flags.  */
2658
2659 static void
2660 check_bitfield_decl (tree field)
2661 {
2662   tree type = TREE_TYPE (field);
2663   tree w = NULL_TREE;
2664
2665   /* Detect invalid bit-field type.  */
2666   if (DECL_INITIAL (field)
2667       && ! INTEGRAL_TYPE_P (TREE_TYPE (field)))
2668     {
2669       cp_error_at ("bit-field `%#D' with non-integral type", field);
2670       w = error_mark_node;
2671     }
2672
2673   /* Detect and ignore out of range field width.  */
2674   if (DECL_INITIAL (field))
2675     {
2676       w = DECL_INITIAL (field);
2677
2678       /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs.  */
2679       STRIP_NOPS (w);
2680
2681       /* detect invalid field size.  */
2682       if (TREE_CODE (w) == CONST_DECL)
2683         w = DECL_INITIAL (w);
2684       else
2685         w = decl_constant_value (w);
2686
2687       if (TREE_CODE (w) != INTEGER_CST)
2688         {
2689           cp_error_at ("bit-field `%D' width not an integer constant",
2690                        field);
2691           w = error_mark_node;
2692         }
2693       else if (tree_int_cst_sgn (w) < 0)
2694         {
2695           cp_error_at ("negative width in bit-field `%D'", field);
2696           w = error_mark_node;
2697         }
2698       else if (integer_zerop (w) && DECL_NAME (field) != 0)
2699         {
2700           cp_error_at ("zero width for bit-field `%D'", field);
2701           w = error_mark_node;
2702         }
2703       else if (compare_tree_int (w, TYPE_PRECISION (type)) > 0
2704                && TREE_CODE (type) != ENUMERAL_TYPE
2705                && TREE_CODE (type) != BOOLEAN_TYPE)
2706         cp_warning_at ("width of `%D' exceeds its type", field);
2707       else if (TREE_CODE (type) == ENUMERAL_TYPE
2708                && (0 > compare_tree_int (w,
2709                                          min_precision (TYPE_MIN_VALUE (type),
2710                                                         TYPE_UNSIGNED (type)))
2711                    ||  0 > compare_tree_int (w,
2712                                              min_precision
2713                                              (TYPE_MAX_VALUE (type),
2714                                               TYPE_UNSIGNED (type)))))
2715         cp_warning_at ("`%D' is too small to hold all values of `%#T'",
2716                        field, type);
2717     }
2718
2719   /* Remove the bit-field width indicator so that the rest of the
2720      compiler does not treat that value as an initializer.  */
2721   DECL_INITIAL (field) = NULL_TREE;
2722
2723   if (w != error_mark_node)
2724     {
2725       DECL_SIZE (field) = convert (bitsizetype, w);
2726       DECL_BIT_FIELD (field) = 1;
2727     }
2728   else
2729     {
2730       /* Non-bit-fields are aligned for their type.  */
2731       DECL_BIT_FIELD (field) = 0;
2732       CLEAR_DECL_C_BIT_FIELD (field);
2733     }
2734 }
2735
2736 /* FIELD is a non bit-field.  We are finishing the processing for its
2737    enclosing type T.  Issue any appropriate messages and set appropriate
2738    flags.  */
2739
2740 static void
2741 check_field_decl (tree field,
2742                   tree t,
2743                   int* cant_have_const_ctor,
2744                   int* cant_have_default_ctor,
2745                   int* no_const_asn_ref,
2746                   int* any_default_members)
2747 {
2748   tree type = strip_array_types (TREE_TYPE (field));
2749
2750   /* An anonymous union cannot contain any fields which would change
2751      the settings of CANT_HAVE_CONST_CTOR and friends.  */
2752   if (ANON_UNION_TYPE_P (type))
2753     ;
2754   /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
2755      structs.  So, we recurse through their fields here.  */
2756   else if (ANON_AGGR_TYPE_P (type))
2757     {
2758       tree fields;
2759
2760       for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2761         if (TREE_CODE (fields) == FIELD_DECL && !DECL_C_BIT_FIELD (field))
2762           check_field_decl (fields, t, cant_have_const_ctor,
2763                             cant_have_default_ctor, no_const_asn_ref,
2764                             any_default_members);
2765     }
2766   /* Check members with class type for constructors, destructors,
2767      etc.  */
2768   else if (CLASS_TYPE_P (type))
2769     {
2770       /* Never let anything with uninheritable virtuals
2771          make it through without complaint.  */
2772       abstract_virtuals_error (field, type);
2773
2774       if (TREE_CODE (t) == UNION_TYPE)
2775         {
2776           if (TYPE_NEEDS_CONSTRUCTING (type))
2777             cp_error_at ("member `%#D' with constructor not allowed in union",
2778                          field);
2779           if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
2780             cp_error_at ("member `%#D' with destructor not allowed in union",
2781                          field);
2782           if (TYPE_HAS_COMPLEX_ASSIGN_REF (type))
2783             cp_error_at ("member `%#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 (TYPE_HAS_CONSTRUCTOR (type)
2802           && ! TYPE_HAS_DEFAULT_CONSTRUCTOR (type))
2803         *cant_have_default_ctor = 1;
2804     }
2805   if (DECL_INITIAL (field) != NULL_TREE)
2806     {
2807       /* `build_class_init_list' does not recognize
2808          non-FIELD_DECLs.  */
2809       if (TREE_CODE (t) == UNION_TYPE && any_default_members != 0)
2810         error ("multiple fields in union `%T' initialized", t);
2811       *any_default_members = 1;
2812     }
2813 }
2814
2815 /* Check the data members (both static and non-static), class-scoped
2816    typedefs, etc., appearing in the declaration of T.  Issue
2817    appropriate diagnostics.  Sets ACCESS_DECLS to a list (in
2818    declaration order) of access declarations; each TREE_VALUE in this
2819    list is a USING_DECL.
2820
2821    In addition, set the following flags:
2822
2823      EMPTY_P
2824        The class is empty, i.e., contains no non-static data members.
2825
2826      CANT_HAVE_DEFAULT_CTOR_P
2827        This class cannot have an implicitly generated default
2828        constructor.
2829
2830      CANT_HAVE_CONST_CTOR_P
2831        This class cannot have an implicitly generated copy constructor
2832        taking a const reference.
2833
2834      CANT_HAVE_CONST_ASN_REF
2835        This class cannot have an implicitly generated assignment
2836        operator taking a const reference.
2837
2838    All of these flags should be initialized before calling this
2839    function.
2840
2841    Returns a pointer to the end of the TYPE_FIELDs chain; additional
2842    fields can be added by adding to this chain.  */
2843
2844 static void
2845 check_field_decls (tree t, tree *access_decls,
2846                    int *cant_have_default_ctor_p,
2847                    int *cant_have_const_ctor_p,
2848                    int *no_const_asn_ref_p)
2849 {
2850   tree *field;
2851   tree *next;
2852   bool has_pointers;
2853   int any_default_members;
2854
2855   /* Assume there are no access declarations.  */
2856   *access_decls = NULL_TREE;
2857   /* Assume this class has no pointer members.  */
2858   has_pointers = false;
2859   /* Assume none of the members of this class have default
2860      initializations.  */
2861   any_default_members = 0;
2862
2863   for (field = &TYPE_FIELDS (t); *field; field = next)
2864     {
2865       tree x = *field;
2866       tree type = TREE_TYPE (x);
2867
2868       next = &TREE_CHAIN (x);
2869
2870       if (TREE_CODE (x) == FIELD_DECL)
2871         {
2872           if (TYPE_PACKED (t))
2873             {
2874               if (!pod_type_p (TREE_TYPE (x)) && !TYPE_PACKED (TREE_TYPE (x)))
2875                 cp_warning_at
2876                   ("ignoring packed attribute on unpacked non-POD field `%#D'",
2877                    x);
2878               else
2879                 DECL_PACKED (x) = 1;
2880             }
2881
2882           if (DECL_C_BIT_FIELD (x) && integer_zerop (DECL_INITIAL (x)))
2883             /* We don't treat zero-width bitfields as making a class
2884                non-empty.  */
2885             ;
2886           else
2887             {
2888               tree element_type;
2889
2890               /* The class is non-empty.  */
2891               CLASSTYPE_EMPTY_P (t) = 0;
2892               /* The class is not even nearly empty.  */
2893               CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
2894               /* If one of the data members contains an empty class,
2895                  so does T.  */
2896               element_type = strip_array_types (type);
2897               if (CLASS_TYPE_P (element_type)
2898                   && CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type))
2899                 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
2900             }
2901         }
2902
2903       if (TREE_CODE (x) == USING_DECL)
2904         {
2905           /* Prune the access declaration from the list of fields.  */
2906           *field = TREE_CHAIN (x);
2907
2908           /* Save the access declarations for our caller.  */
2909           *access_decls = tree_cons (NULL_TREE, x, *access_decls);
2910
2911           /* Since we've reset *FIELD there's no reason to skip to the
2912              next field.  */
2913           next = field;
2914           continue;
2915         }
2916
2917       if (TREE_CODE (x) == TYPE_DECL
2918           || TREE_CODE (x) == TEMPLATE_DECL)
2919         continue;
2920
2921       /* If we've gotten this far, it's a data member, possibly static,
2922          or an enumerator.  */
2923       DECL_CONTEXT (x) = t;
2924
2925       /* When this goes into scope, it will be a non-local reference.  */
2926       DECL_NONLOCAL (x) = 1;
2927
2928       if (TREE_CODE (t) == UNION_TYPE)
2929         {
2930           /* [class.union]
2931
2932              If a union contains a static data member, or a member of
2933              reference type, the program is ill-formed.  */
2934           if (TREE_CODE (x) == VAR_DECL)
2935             {
2936               cp_error_at ("`%D' may not be static because it is a member of a union", x);
2937               continue;
2938             }
2939           if (TREE_CODE (type) == REFERENCE_TYPE)
2940             {
2941               cp_error_at ("`%D' may not have reference type `%T' because it is a member of a union",
2942                            x, type);
2943               continue;
2944             }
2945         }
2946
2947       /* ``A local class cannot have static data members.'' ARM 9.4 */
2948       if (current_function_decl && TREE_STATIC (x))
2949         cp_error_at ("field `%D' in local class cannot be static", x);
2950
2951       /* Perform error checking that did not get done in
2952          grokdeclarator.  */
2953       if (TREE_CODE (type) == FUNCTION_TYPE)
2954         {
2955           cp_error_at ("field `%D' invalidly declared function type",
2956                        x);
2957           type = build_pointer_type (type);
2958           TREE_TYPE (x) = type;
2959         }
2960       else if (TREE_CODE (type) == METHOD_TYPE)
2961         {
2962           cp_error_at ("field `%D' invalidly declared method type", x);
2963           type = build_pointer_type (type);
2964           TREE_TYPE (x) = type;
2965         }
2966
2967       if (type == error_mark_node)
2968         continue;
2969
2970       if (TREE_CODE (x) == CONST_DECL || TREE_CODE (x) == VAR_DECL)
2971         continue;
2972
2973       /* Now it can only be a FIELD_DECL.  */
2974
2975       if (TREE_PRIVATE (x) || TREE_PROTECTED (x))
2976         CLASSTYPE_NON_AGGREGATE (t) = 1;
2977
2978       /* If this is of reference type, check if it needs an init.
2979          Also do a little ANSI jig if necessary.  */
2980       if (TREE_CODE (type) == REFERENCE_TYPE)
2981         {
2982           CLASSTYPE_NON_POD_P (t) = 1;
2983           if (DECL_INITIAL (x) == NULL_TREE)
2984             SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
2985
2986           /* ARM $12.6.2: [A member initializer list] (or, for an
2987              aggregate, initialization by a brace-enclosed list) is the
2988              only way to initialize nonstatic const and reference
2989              members.  */
2990           *cant_have_default_ctor_p = 1;
2991           TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
2992
2993           if (! TYPE_HAS_CONSTRUCTOR (t) && CLASSTYPE_NON_AGGREGATE (t)
2994               && extra_warnings)
2995             cp_warning_at ("non-static reference `%#D' in class without a constructor", x);
2996         }
2997
2998       type = strip_array_types (type);
2999
3000       /* This is used by -Weffc++ (see below). Warn only for pointers
3001          to members which might hold dynamic memory. So do not warn
3002          for pointers to functions or pointers to members.  */
3003       if (TYPE_PTR_P (type)
3004           && !TYPE_PTRFN_P (type)
3005           && !TYPE_PTR_TO_MEMBER_P (type))
3006         has_pointers = true;
3007
3008       if (CLASS_TYPE_P (type))
3009         {
3010           if (CLASSTYPE_REF_FIELDS_NEED_INIT (type))
3011             SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
3012           if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (type))
3013             SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
3014         }
3015
3016       if (DECL_MUTABLE_P (x) || TYPE_HAS_MUTABLE_P (type))
3017         CLASSTYPE_HAS_MUTABLE (t) = 1;
3018
3019       if (! pod_type_p (type))
3020         /* DR 148 now allows pointers to members (which are POD themselves),
3021            to be allowed in POD structs.  */
3022         CLASSTYPE_NON_POD_P (t) = 1;
3023
3024       if (! zero_init_p (type))
3025         CLASSTYPE_NON_ZERO_INIT_P (t) = 1;
3026
3027       /* If any field is const, the structure type is pseudo-const.  */
3028       if (CP_TYPE_CONST_P (type))
3029         {
3030           C_TYPE_FIELDS_READONLY (t) = 1;
3031           if (DECL_INITIAL (x) == NULL_TREE)
3032             SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
3033
3034           /* ARM $12.6.2: [A member initializer list] (or, for an
3035              aggregate, initialization by a brace-enclosed list) is the
3036              only way to initialize nonstatic const and reference
3037              members.  */
3038           *cant_have_default_ctor_p = 1;
3039           TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
3040
3041           if (! TYPE_HAS_CONSTRUCTOR (t) && CLASSTYPE_NON_AGGREGATE (t)
3042               && extra_warnings)
3043             cp_warning_at ("non-static const member `%#D' in class without a constructor", x);
3044         }
3045       /* A field that is pseudo-const makes the structure likewise.  */
3046       else if (CLASS_TYPE_P (type))
3047         {
3048           C_TYPE_FIELDS_READONLY (t) |= C_TYPE_FIELDS_READONLY (type);
3049           SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t,
3050             CLASSTYPE_READONLY_FIELDS_NEED_INIT (t)
3051             | CLASSTYPE_READONLY_FIELDS_NEED_INIT (type));
3052         }
3053
3054       /* Core issue 80: A nonstatic data member is required to have a
3055          different name from the class iff the class has a
3056          user-defined constructor.  */
3057       if (constructor_name_p (DECL_NAME (x), t) && TYPE_HAS_CONSTRUCTOR (t))
3058         cp_pedwarn_at ("field `%#D' with same name as class", x);
3059
3060       /* We set DECL_C_BIT_FIELD in grokbitfield.
3061          If the type and width are valid, we'll also set DECL_BIT_FIELD.  */
3062       if (DECL_C_BIT_FIELD (x))
3063         check_bitfield_decl (x);
3064       else
3065         check_field_decl (x, t,
3066                           cant_have_const_ctor_p,
3067                           cant_have_default_ctor_p,
3068                           no_const_asn_ref_p,
3069                           &any_default_members);
3070     }
3071
3072   /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3073      it should also define a copy constructor and an assignment operator to
3074      implement the correct copy semantic (deep vs shallow, etc.). As it is
3075      not feasible to check whether the constructors do allocate dynamic memory
3076      and store it within members, we approximate the warning like this:
3077
3078      -- Warn only if there are members which are pointers
3079      -- Warn only if there is a non-trivial constructor (otherwise,
3080         there cannot be memory allocated).
3081      -- Warn only if there is a non-trivial destructor. We assume that the
3082         user at least implemented the cleanup correctly, and a destructor
3083         is needed to free dynamic memory.
3084
3085      This seems enough for practical purposes.  */
3086     if (warn_ecpp
3087         && has_pointers
3088         && TYPE_HAS_CONSTRUCTOR (t)
3089         && TYPE_HAS_DESTRUCTOR (t)
3090         && !(TYPE_HAS_INIT_REF (t) && TYPE_HAS_ASSIGN_REF (t)))
3091     {
3092       warning ("`%#T' has pointer data members", t);
3093
3094       if (! TYPE_HAS_INIT_REF (t))
3095         {
3096           warning ("  but does not override `%T(const %T&)'", t, t);
3097           if (! TYPE_HAS_ASSIGN_REF (t))
3098             warning ("  or `operator=(const %T&)'", t);
3099         }
3100       else if (! TYPE_HAS_ASSIGN_REF (t))
3101         warning ("  but does not override `operator=(const %T&)'", t);
3102     }
3103
3104
3105   /* Check anonymous struct/anonymous union fields.  */
3106   finish_struct_anon (t);
3107
3108   /* We've built up the list of access declarations in reverse order.
3109      Fix that now.  */
3110   *access_decls = nreverse (*access_decls);
3111 }
3112
3113 /* If TYPE is an empty class type, records its OFFSET in the table of
3114    OFFSETS.  */
3115
3116 static int
3117 record_subobject_offset (tree type, tree offset, splay_tree offsets)
3118 {
3119   splay_tree_node n;
3120
3121   if (!is_empty_class (type))
3122     return 0;
3123
3124   /* Record the location of this empty object in OFFSETS.  */
3125   n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3126   if (!n)
3127     n = splay_tree_insert (offsets,
3128                            (splay_tree_key) offset,
3129                            (splay_tree_value) NULL_TREE);
3130   n->value = ((splay_tree_value)
3131               tree_cons (NULL_TREE,
3132                          type,
3133                          (tree) n->value));
3134
3135   return 0;
3136 }
3137
3138 /* Returns nonzero if TYPE is an empty class type and there is
3139    already an entry in OFFSETS for the same TYPE as the same OFFSET.  */
3140
3141 static int
3142 check_subobject_offset (tree type, tree offset, splay_tree offsets)
3143 {
3144   splay_tree_node n;
3145   tree t;
3146
3147   if (!is_empty_class (type))
3148     return 0;
3149
3150   /* Record the location of this empty object in OFFSETS.  */
3151   n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3152   if (!n)
3153     return 0;
3154
3155   for (t = (tree) n->value; t; t = TREE_CHAIN (t))
3156     if (same_type_p (TREE_VALUE (t), type))
3157       return 1;
3158
3159   return 0;
3160 }
3161
3162 /* Walk through all the subobjects of TYPE (located at OFFSET).  Call
3163    F for every subobject, passing it the type, offset, and table of
3164    OFFSETS.  If VBASES_P is one, then virtual non-primary bases should
3165    be traversed.
3166
3167    If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3168    than MAX_OFFSET will not be walked.
3169
3170    If F returns a nonzero value, the traversal ceases, and that value
3171    is returned.  Otherwise, returns zero.  */
3172
3173 static int
3174 walk_subobject_offsets (tree type,
3175                         subobject_offset_fn f,
3176                         tree offset,
3177                         splay_tree offsets,
3178                         tree max_offset,
3179                         int vbases_p)
3180 {
3181   int r = 0;
3182   tree type_binfo = NULL_TREE;
3183
3184   /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3185      stop.  */
3186   if (max_offset && INT_CST_LT (max_offset, offset))
3187     return 0;
3188
3189   if (!TYPE_P (type))
3190     {
3191       if (abi_version_at_least (2))
3192         type_binfo = type;
3193       type = BINFO_TYPE (type);
3194     }
3195
3196   if (CLASS_TYPE_P (type))
3197     {
3198       tree field;
3199       tree binfo;
3200       int i;
3201
3202       /* Avoid recursing into objects that are not interesting.  */
3203       if (!CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type))
3204         return 0;
3205
3206       /* Record the location of TYPE.  */
3207       r = (*f) (type, offset, offsets);
3208       if (r)
3209         return r;
3210
3211       /* Iterate through the direct base classes of TYPE.  */
3212       if (!type_binfo)
3213         type_binfo = TYPE_BINFO (type);
3214       for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, binfo); i++)
3215         {
3216           tree binfo_offset;
3217
3218           if (abi_version_at_least (2)
3219               && BINFO_VIRTUAL_P (binfo))
3220             continue;
3221
3222           if (!vbases_p
3223               && BINFO_VIRTUAL_P (binfo)
3224               && !BINFO_PRIMARY_P (binfo))
3225             continue;
3226
3227           if (!abi_version_at_least (2))
3228             binfo_offset = size_binop (PLUS_EXPR,
3229                                        offset,
3230                                        BINFO_OFFSET (binfo));
3231           else
3232             {
3233               tree orig_binfo;
3234               /* We cannot rely on BINFO_OFFSET being set for the base
3235                  class yet, but the offsets for direct non-virtual
3236                  bases can be calculated by going back to the TYPE.  */
3237               orig_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), i);
3238               binfo_offset = size_binop (PLUS_EXPR,
3239                                          offset,
3240                                          BINFO_OFFSET (orig_binfo));
3241             }
3242
3243           r = walk_subobject_offsets (binfo,
3244                                       f,
3245                                       binfo_offset,
3246                                       offsets,
3247                                       max_offset,
3248                                       (abi_version_at_least (2)
3249                                        ? /*vbases_p=*/0 : vbases_p));
3250           if (r)
3251             return r;
3252         }
3253
3254       if (abi_version_at_least (2) && CLASSTYPE_VBASECLASSES (type))
3255         {
3256           unsigned ix;
3257           VEC (tree) *vbases;
3258
3259           /* Iterate through the virtual base classes of TYPE.  In G++
3260              3.2, we included virtual bases in the direct base class
3261              loop above, which results in incorrect results; the
3262              correct offsets for virtual bases are only known when
3263              working with the most derived type.  */
3264           if (vbases_p)
3265             for (vbases = CLASSTYPE_VBASECLASSES (type), ix = 0;
3266                  VEC_iterate (tree, vbases, ix, binfo); ix++)
3267               {
3268                 r = walk_subobject_offsets (binfo,
3269                                             f,
3270                                             size_binop (PLUS_EXPR,
3271                                                         offset,
3272                                                         BINFO_OFFSET (binfo)),
3273                                             offsets,
3274                                             max_offset,
3275                                             /*vbases_p=*/0);
3276                 if (r)
3277                   return r;
3278               }
3279           else
3280             {
3281               /* We still have to walk the primary base, if it is
3282                  virtual.  (If it is non-virtual, then it was walked
3283                  above.)  */
3284               tree vbase = get_primary_binfo (type_binfo);
3285
3286               if (vbase && BINFO_VIRTUAL_P (vbase)
3287                   && BINFO_PRIMARY_P (vbase)
3288                   && BINFO_INHERITANCE_CHAIN (vbase) == type_binfo)
3289                 {
3290                   r = (walk_subobject_offsets
3291                        (vbase, f, offset,
3292                         offsets, max_offset, /*vbases_p=*/0));
3293                   if (r)
3294                     return r;
3295                 }
3296             }
3297         }
3298
3299       /* Iterate through the fields of TYPE.  */
3300       for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3301         if (TREE_CODE (field) == FIELD_DECL && !DECL_ARTIFICIAL (field))
3302           {
3303             tree field_offset;
3304
3305             if (abi_version_at_least (2))
3306               field_offset = byte_position (field);
3307             else
3308               /* In G++ 3.2, DECL_FIELD_OFFSET was used.  */
3309               field_offset = DECL_FIELD_OFFSET (field);
3310
3311             r = walk_subobject_offsets (TREE_TYPE (field),
3312                                         f,
3313                                         size_binop (PLUS_EXPR,
3314                                                     offset,
3315                                                     field_offset),
3316                                         offsets,
3317                                         max_offset,
3318                                         /*vbases_p=*/1);
3319             if (r)
3320               return r;
3321           }
3322     }
3323   else if (TREE_CODE (type) == ARRAY_TYPE)
3324     {
3325       tree element_type = strip_array_types (type);
3326       tree domain = TYPE_DOMAIN (type);
3327       tree index;
3328
3329       /* Avoid recursing into objects that are not interesting.  */
3330       if (!CLASS_TYPE_P (element_type)
3331           || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type))
3332         return 0;
3333
3334       /* Step through each of the elements in the array.  */
3335       for (index = size_zero_node;
3336            /* G++ 3.2 had an off-by-one error here.  */
3337            (abi_version_at_least (2)
3338             ? !INT_CST_LT (TYPE_MAX_VALUE (domain), index)
3339             : INT_CST_LT (index, TYPE_MAX_VALUE (domain)));
3340            index = size_binop (PLUS_EXPR, index, size_one_node))
3341         {
3342           r = walk_subobject_offsets (TREE_TYPE (type),
3343                                       f,
3344                                       offset,
3345                                       offsets,
3346                                       max_offset,
3347                                       /*vbases_p=*/1);
3348           if (r)
3349             return r;
3350           offset = size_binop (PLUS_EXPR, offset,
3351                                TYPE_SIZE_UNIT (TREE_TYPE (type)));
3352           /* If this new OFFSET is bigger than the MAX_OFFSET, then
3353              there's no point in iterating through the remaining
3354              elements of the array.  */
3355           if (max_offset && INT_CST_LT (max_offset, offset))
3356             break;
3357         }
3358     }
3359
3360   return 0;
3361 }
3362
3363 /* Record all of the empty subobjects of TYPE (located at OFFSET) in
3364    OFFSETS.  If VBASES_P is nonzero, virtual bases of TYPE are
3365    examined.  */
3366
3367 static void
3368 record_subobject_offsets (tree type,
3369                           tree offset,
3370                           splay_tree offsets,
3371                           int vbases_p)
3372 {
3373   walk_subobject_offsets (type, record_subobject_offset, offset,
3374                           offsets, /*max_offset=*/NULL_TREE, vbases_p);
3375 }
3376
3377 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3378    OFFSET) conflict with entries in OFFSETS.  If VBASES_P is nonzero,
3379    virtual bases of TYPE are examined.  */
3380
3381 static int
3382 layout_conflict_p (tree type,
3383                    tree offset,
3384                    splay_tree offsets,
3385                    int vbases_p)
3386 {
3387   splay_tree_node max_node;
3388
3389   /* Get the node in OFFSETS that indicates the maximum offset where
3390      an empty subobject is located.  */
3391   max_node = splay_tree_max (offsets);
3392   /* If there aren't any empty subobjects, then there's no point in
3393      performing this check.  */
3394   if (!max_node)
3395     return 0;
3396
3397   return walk_subobject_offsets (type, check_subobject_offset, offset,
3398                                  offsets, (tree) (max_node->key),
3399                                  vbases_p);
3400 }
3401
3402 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3403    non-static data member of the type indicated by RLI.  BINFO is the
3404    binfo corresponding to the base subobject, OFFSETS maps offsets to
3405    types already located at those offsets.  This function determines
3406    the position of the DECL.  */
3407
3408 static void
3409 layout_nonempty_base_or_field (record_layout_info rli,
3410                                tree decl,
3411                                tree binfo,
3412                                splay_tree offsets)
3413 {
3414   tree offset = NULL_TREE;
3415   bool field_p;
3416   tree type;
3417
3418   if (binfo)
3419     {
3420       /* For the purposes of determining layout conflicts, we want to
3421          use the class type of BINFO; TREE_TYPE (DECL) will be the
3422          CLASSTYPE_AS_BASE version, which does not contain entries for
3423          zero-sized bases.  */
3424       type = TREE_TYPE (binfo);
3425       field_p = false;
3426     }
3427   else
3428     {
3429       type = TREE_TYPE (decl);
3430       field_p = true;
3431     }
3432
3433   /* Try to place the field.  It may take more than one try if we have
3434      a hard time placing the field without putting two objects of the
3435      same type at the same address.  */
3436   while (1)
3437     {
3438       struct record_layout_info_s old_rli = *rli;
3439
3440       /* Place this field.  */
3441       place_field (rli, decl);
3442       offset = byte_position (decl);
3443
3444       /* We have to check to see whether or not there is already
3445          something of the same type at the offset we're about to use.
3446          For example, consider:
3447
3448            struct S {};
3449            struct T : public S { int i; };
3450            struct U : public S, public T {};
3451
3452          Here, we put S at offset zero in U.  Then, we can't put T at
3453          offset zero -- its S component would be at the same address
3454          as the S we already allocated.  So, we have to skip ahead.
3455          Since all data members, including those whose type is an
3456          empty class, have nonzero size, any overlap can happen only
3457          with a direct or indirect base-class -- it can't happen with
3458          a data member.  */
3459       /* In a union, overlap is permitted; all members are placed at
3460          offset zero.  */
3461       if (TREE_CODE (rli->t) == UNION_TYPE)
3462         break;
3463       /* G++ 3.2 did not check for overlaps when placing a non-empty
3464          virtual base.  */
3465       if (!abi_version_at_least (2) && binfo && BINFO_VIRTUAL_P (binfo))
3466         break;
3467       if (layout_conflict_p (field_p ? type : binfo, offset,
3468                              offsets, field_p))
3469         {
3470           /* Strip off the size allocated to this field.  That puts us
3471              at the first place we could have put the field with
3472              proper alignment.  */
3473           *rli = old_rli;
3474
3475           /* Bump up by the alignment required for the type.  */
3476           rli->bitpos
3477             = size_binop (PLUS_EXPR, rli->bitpos,
3478                           bitsize_int (binfo
3479                                        ? CLASSTYPE_ALIGN (type)
3480                                        : TYPE_ALIGN (type)));
3481           normalize_rli (rli);
3482         }
3483       else
3484         /* There was no conflict.  We're done laying out this field.  */
3485         break;
3486     }
3487
3488   /* Now that we know where it will be placed, update its
3489      BINFO_OFFSET.  */
3490   if (binfo && CLASS_TYPE_P (BINFO_TYPE (binfo)))
3491     /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3492        this point because their BINFO_OFFSET is copied from another
3493        hierarchy.  Therefore, we may not need to add the entire
3494        OFFSET.  */
3495     propagate_binfo_offsets (binfo,
3496                              size_diffop (convert (ssizetype, offset),
3497                                           convert (ssizetype,
3498                                                    BINFO_OFFSET (binfo))));
3499 }
3500
3501 /* Returns true if TYPE is empty and OFFSET is nonzero.  */
3502
3503 static int
3504 empty_base_at_nonzero_offset_p (tree type,
3505                                 tree offset,
3506                                 splay_tree offsets ATTRIBUTE_UNUSED)
3507 {
3508   return is_empty_class (type) && !integer_zerop (offset);
3509 }
3510
3511 /* Layout the empty base BINFO.  EOC indicates the byte currently just
3512    past the end of the class, and should be correctly aligned for a
3513    class of the type indicated by BINFO; OFFSETS gives the offsets of
3514    the empty bases allocated so far. T is the most derived
3515    type.  Return nonzero iff we added it at the end.  */
3516
3517 static bool
3518 layout_empty_base (tree binfo, tree eoc, splay_tree offsets)
3519 {
3520   tree alignment;
3521   tree basetype = BINFO_TYPE (binfo);
3522   bool atend = false;
3523
3524   /* This routine should only be used for empty classes.  */
3525   gcc_assert (is_empty_class (basetype));
3526   alignment = ssize_int (CLASSTYPE_ALIGN_UNIT (basetype));
3527
3528   if (!integer_zerop (BINFO_OFFSET (binfo)))
3529     {
3530       if (abi_version_at_least (2))
3531         propagate_binfo_offsets
3532           (binfo, size_diffop (size_zero_node, BINFO_OFFSET (binfo)));
3533       else if (warn_abi)
3534         warning ("offset of empty base `%T' may not be ABI-compliant and may"
3535                  "change in a future version of GCC",
3536                  BINFO_TYPE (binfo));
3537     }
3538
3539   /* This is an empty base class.  We first try to put it at offset
3540      zero.  */
3541   if (layout_conflict_p (binfo,
3542                          BINFO_OFFSET (binfo),
3543                          offsets,
3544                          /*vbases_p=*/0))
3545     {
3546       /* That didn't work.  Now, we move forward from the next
3547          available spot in the class.  */
3548       atend = true;
3549       propagate_binfo_offsets (binfo, convert (ssizetype, eoc));
3550       while (1)
3551         {
3552           if (!layout_conflict_p (binfo,
3553                                   BINFO_OFFSET (binfo),
3554                                   offsets,
3555                                   /*vbases_p=*/0))
3556             /* We finally found a spot where there's no overlap.  */
3557             break;
3558
3559           /* There's overlap here, too.  Bump along to the next spot.  */
3560           propagate_binfo_offsets (binfo, alignment);
3561         }
3562     }
3563   return atend;
3564 }
3565
3566 /* Layout the the base given by BINFO in the class indicated by RLI.
3567    *BASE_ALIGN is a running maximum of the alignments of
3568    any base class.  OFFSETS gives the location of empty base
3569    subobjects.  T is the most derived type.  Return nonzero if the new
3570    object cannot be nearly-empty.  A new FIELD_DECL is inserted at
3571    *NEXT_FIELD, unless BINFO is for an empty base class.
3572
3573    Returns the location at which the next field should be inserted.  */
3574
3575 static tree *
3576 build_base_field (record_layout_info rli, tree binfo,
3577                   splay_tree offsets, tree *next_field)
3578 {
3579   tree t = rli->t;
3580   tree basetype = BINFO_TYPE (binfo);
3581
3582   if (!COMPLETE_TYPE_P (basetype))
3583     /* This error is now reported in xref_tag, thus giving better
3584        location information.  */
3585     return next_field;
3586
3587   /* Place the base class.  */
3588   if (!is_empty_class (basetype))
3589     {
3590       tree decl;
3591
3592       /* The containing class is non-empty because it has a non-empty
3593          base class.  */
3594       CLASSTYPE_EMPTY_P (t) = 0;
3595
3596       /* Create the FIELD_DECL.  */
3597       decl = build_decl (FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype));
3598       DECL_ARTIFICIAL (decl) = 1;
3599       DECL_FIELD_CONTEXT (decl) = t;
3600       DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype);
3601       DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype);
3602       DECL_ALIGN (decl) = CLASSTYPE_ALIGN (basetype);
3603       DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype);
3604       DECL_IGNORED_P (decl) = 1;
3605       DECL_FIELD_IS_BASE (decl) = 1;
3606
3607       /* Try to place the field.  It may take more than one try if we
3608          have a hard time placing the field without putting two
3609          objects of the same type at the same address.  */
3610       layout_nonempty_base_or_field (rli, decl, binfo, offsets);
3611       /* Add the new FIELD_DECL to the list of fields for T.  */
3612       TREE_CHAIN (decl) = *next_field;
3613       *next_field = decl;
3614       next_field = &TREE_CHAIN (decl);
3615     }
3616   else
3617     {
3618       tree eoc;
3619       bool atend;
3620
3621       /* On some platforms (ARM), even empty classes will not be
3622          byte-aligned.  */
3623       eoc = round_up (rli_size_unit_so_far (rli),
3624                       CLASSTYPE_ALIGN_UNIT (basetype));
3625       atend = layout_empty_base (binfo, eoc, offsets);
3626       /* A nearly-empty class "has no proper base class that is empty,
3627          not morally virtual, and at an offset other than zero."  */
3628       if (!BINFO_VIRTUAL_P (binfo) && CLASSTYPE_NEARLY_EMPTY_P (t))
3629         {
3630           if (atend)
3631             CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3632           /* The check above (used in G++ 3.2) is insufficient  because
3633              an empty class placed at offset zero might itself have an
3634              empty base at a nonzero offset.  */
3635           else if (walk_subobject_offsets (basetype,
3636                                            empty_base_at_nonzero_offset_p,
3637                                            size_zero_node,
3638                                            /*offsets=*/NULL,
3639                                            /*max_offset=*/NULL_TREE,
3640                                            /*vbases_p=*/true))
3641             {
3642               if (abi_version_at_least (2))
3643                 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3644               else if (warn_abi)
3645                 warning ("class `%T' will be considered nearly empty in a "
3646                          "future version of GCC", t);
3647             }
3648         }
3649
3650       /* We do not create a FIELD_DECL for empty base classes because
3651          it might overlap some other field.  We want to be able to
3652          create CONSTRUCTORs for the class by iterating over the
3653          FIELD_DECLs, and the back end does not handle overlapping
3654          FIELD_DECLs.  */
3655
3656       /* An empty virtual base causes a class to be non-empty
3657          -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3658          here because that was already done when the virtual table
3659          pointer was created.  */
3660     }
3661
3662   /* Record the offsets of BINFO and its base subobjects.  */
3663   record_subobject_offsets (binfo,
3664                             BINFO_OFFSET (binfo),
3665                             offsets,
3666                             /*vbases_p=*/0);
3667
3668   return next_field;
3669 }
3670
3671 /* Layout all of the non-virtual base classes.  Record empty
3672    subobjects in OFFSETS.  T is the most derived type.  Return nonzero
3673    if the type cannot be nearly empty.  The fields created
3674    corresponding to the base classes will be inserted at
3675    *NEXT_FIELD.  */
3676
3677 static void
3678 build_base_fields (record_layout_info rli,
3679                    splay_tree offsets, tree *next_field)
3680 {
3681   /* Chain to hold all the new FIELD_DECLs which stand in for base class
3682      subobjects.  */
3683   tree t = rli->t;
3684   int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
3685   int i;
3686
3687   /* The primary base class is always allocated first.  */
3688   if (CLASSTYPE_HAS_PRIMARY_BASE_P (t))
3689     next_field = build_base_field (rli, CLASSTYPE_PRIMARY_BINFO (t),
3690                                    offsets, next_field);
3691
3692   /* Now allocate the rest of the bases.  */
3693   for (i = 0; i < n_baseclasses; ++i)
3694     {
3695       tree base_binfo;
3696
3697       base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i);
3698
3699       /* The primary base was already allocated above, so we don't
3700          need to allocate it again here.  */
3701       if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t))
3702         continue;
3703
3704       /* Virtual bases are added at the end (a primary virtual base
3705          will have already been added).  */
3706       if (BINFO_VIRTUAL_P (base_binfo))
3707         continue;
3708
3709       next_field = build_base_field (rli, base_binfo,
3710                                      offsets, next_field);
3711     }
3712 }
3713
3714 /* Go through the TYPE_METHODS of T issuing any appropriate
3715    diagnostics, figuring out which methods override which other
3716    methods, and so forth.  */
3717
3718 static void
3719 check_methods (tree t)
3720 {
3721   tree x;
3722
3723   for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
3724     {
3725       check_for_override (x, t);
3726       if (DECL_PURE_VIRTUAL_P (x) && ! DECL_VINDEX (x))
3727         cp_error_at ("initializer specified for non-virtual method `%D'", x);
3728       /* The name of the field is the original field name
3729          Save this in auxiliary field for later overloading.  */
3730       if (DECL_VINDEX (x))
3731         {
3732           TYPE_POLYMORPHIC_P (t) = 1;
3733           if (DECL_PURE_VIRTUAL_P (x))
3734             VEC_safe_push (tree, CLASSTYPE_PURE_VIRTUALS (t), x);
3735         }
3736     }
3737 }
3738
3739 /* FN is a constructor or destructor.  Clone the declaration to create
3740    a specialized in-charge or not-in-charge version, as indicated by
3741    NAME.  */
3742
3743 static tree
3744 build_clone (tree fn, tree name)
3745 {
3746   tree parms;
3747   tree clone;
3748
3749   /* Copy the function.  */
3750   clone = copy_decl (fn);
3751   /* Remember where this function came from.  */
3752   DECL_CLONED_FUNCTION (clone) = fn;
3753   DECL_ABSTRACT_ORIGIN (clone) = fn;
3754   /* Reset the function name.  */
3755   DECL_NAME (clone) = name;
3756   SET_DECL_ASSEMBLER_NAME (clone, NULL_TREE);
3757   /* There's no pending inline data for this function.  */
3758   DECL_PENDING_INLINE_INFO (clone) = NULL;
3759   DECL_PENDING_INLINE_P (clone) = 0;
3760   /* And it hasn't yet been deferred.  */
3761   DECL_DEFERRED_FN (clone) = 0;
3762
3763   /* The base-class destructor is not virtual.  */
3764   if (name == base_dtor_identifier)
3765     {
3766       DECL_VIRTUAL_P (clone) = 0;
3767       if (TREE_CODE (clone) != TEMPLATE_DECL)
3768         DECL_VINDEX (clone) = NULL_TREE;
3769     }
3770
3771   /* If there was an in-charge parameter, drop it from the function
3772      type.  */
3773   if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3774     {
3775       tree basetype;
3776       tree parmtypes;
3777       tree exceptions;
3778
3779       exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
3780       basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
3781       parmtypes = TYPE_ARG_TYPES (TREE_TYPE (clone));
3782       /* Skip the `this' parameter.  */
3783       parmtypes = TREE_CHAIN (parmtypes);
3784       /* Skip the in-charge parameter.  */
3785       parmtypes = TREE_CHAIN (parmtypes);
3786       /* And the VTT parm, in a complete [cd]tor.  */
3787       if (DECL_HAS_VTT_PARM_P (fn)
3788           && ! DECL_NEEDS_VTT_PARM_P (clone))
3789         parmtypes = TREE_CHAIN (parmtypes);
3790        /* If this is subobject constructor or destructor, add the vtt
3791          parameter.  */
3792       TREE_TYPE (clone)
3793         = build_method_type_directly (basetype,
3794                                       TREE_TYPE (TREE_TYPE (clone)),
3795                                       parmtypes);
3796       if (exceptions)
3797         TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone),
3798                                                      exceptions);
3799       TREE_TYPE (clone)
3800         = cp_build_type_attribute_variant (TREE_TYPE (clone),
3801                                            TYPE_ATTRIBUTES (TREE_TYPE (fn)));
3802     }
3803
3804   /* Copy the function parameters.  But, DECL_ARGUMENTS on a TEMPLATE_DECL
3805      aren't function parameters; those are the template parameters.  */
3806   if (TREE_CODE (clone) != TEMPLATE_DECL)
3807     {
3808       DECL_ARGUMENTS (clone) = copy_list (DECL_ARGUMENTS (clone));
3809       /* Remove the in-charge parameter.  */
3810       if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3811         {
3812           TREE_CHAIN (DECL_ARGUMENTS (clone))
3813             = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3814           DECL_HAS_IN_CHARGE_PARM_P (clone) = 0;
3815         }
3816       /* And the VTT parm, in a complete [cd]tor.  */
3817       if (DECL_HAS_VTT_PARM_P (fn))
3818         {
3819           if (DECL_NEEDS_VTT_PARM_P (clone))
3820             DECL_HAS_VTT_PARM_P (clone) = 1;
3821           else
3822             {
3823               TREE_CHAIN (DECL_ARGUMENTS (clone))
3824                 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3825               DECL_HAS_VTT_PARM_P (clone) = 0;
3826             }
3827         }
3828
3829       for (parms = DECL_ARGUMENTS (clone); parms; parms = TREE_CHAIN (parms))
3830         {
3831           DECL_CONTEXT (parms) = clone;
3832           cxx_dup_lang_specific_decl (parms);
3833         }
3834     }
3835
3836   /* Create the RTL for this function.  */
3837   SET_DECL_RTL (clone, NULL_RTX);
3838   rest_of_decl_compilation (clone, /*top_level=*/1, at_eof);
3839
3840   /* Make it easy to find the CLONE given the FN.  */
3841   TREE_CHAIN (clone) = TREE_CHAIN (fn);
3842   TREE_CHAIN (fn) = clone;
3843
3844   /* If this is a template, handle the DECL_TEMPLATE_RESULT as well.  */
3845   if (TREE_CODE (clone) == TEMPLATE_DECL)
3846     {
3847       tree result;
3848
3849       DECL_TEMPLATE_RESULT (clone)
3850         = build_clone (DECL_TEMPLATE_RESULT (clone), name);
3851       result = DECL_TEMPLATE_RESULT (clone);
3852       DECL_TEMPLATE_INFO (result) = copy_node (DECL_TEMPLATE_INFO (result));
3853       DECL_TI_TEMPLATE (result) = clone;
3854     }
3855
3856   return clone;
3857 }
3858
3859 /* Produce declarations for all appropriate clones of FN.  If
3860    UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
3861    CLASTYPE_METHOD_VEC as well.  */
3862
3863 void
3864 clone_function_decl (tree fn, int update_method_vec_p)
3865 {
3866   tree clone;
3867
3868   /* Avoid inappropriate cloning.  */
3869   if (TREE_CHAIN (fn)
3870       && DECL_CLONED_FUNCTION (TREE_CHAIN (fn)))
3871     return;
3872
3873   if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
3874     {
3875       /* For each constructor, we need two variants: an in-charge version
3876          and a not-in-charge version.  */
3877       clone = build_clone (fn, complete_ctor_identifier);
3878       if (update_method_vec_p)
3879         add_method (DECL_CONTEXT (clone), clone);
3880       clone = build_clone (fn, base_ctor_identifier);
3881       if (update_method_vec_p)
3882         add_method (DECL_CONTEXT (clone), clone);
3883     }
3884   else
3885     {
3886       gcc_assert (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn));
3887
3888       /* For each destructor, we need three variants: an in-charge
3889          version, a not-in-charge version, and an in-charge deleting
3890          version.  We clone the deleting version first because that
3891          means it will go second on the TYPE_METHODS list -- and that
3892          corresponds to the correct layout order in the virtual
3893          function table.
3894
3895          For a non-virtual destructor, we do not build a deleting
3896          destructor.  */
3897       if (DECL_VIRTUAL_P (fn))
3898         {
3899           clone = build_clone (fn, deleting_dtor_identifier);
3900           if (update_method_vec_p)
3901             add_method (DECL_CONTEXT (clone), clone);
3902         }
3903       clone = build_clone (fn, complete_dtor_identifier);
3904       if (update_method_vec_p)
3905         add_method (DECL_CONTEXT (clone), clone);
3906       clone = build_clone (fn, base_dtor_identifier);
3907       if (update_method_vec_p)
3908         add_method (DECL_CONTEXT (clone), clone);
3909     }
3910
3911   /* Note that this is an abstract function that is never emitted.  */
3912   DECL_ABSTRACT (fn) = 1;
3913 }
3914
3915 /* DECL is an in charge constructor, which is being defined. This will
3916    have had an in class declaration, from whence clones were
3917    declared. An out-of-class definition can specify additional default
3918    arguments. As it is the clones that are involved in overload
3919    resolution, we must propagate the information from the DECL to its
3920    clones.  */
3921
3922 void
3923 adjust_clone_args (tree decl)
3924 {
3925   tree clone;
3926
3927   for (clone = TREE_CHAIN (decl); clone && DECL_CLONED_FUNCTION (clone);
3928        clone = TREE_CHAIN (clone))
3929     {
3930       tree orig_clone_parms = TYPE_ARG_TYPES (TREE_TYPE (clone));
3931       tree orig_decl_parms = TYPE_ARG_TYPES (TREE_TYPE (decl));
3932       tree decl_parms, clone_parms;
3933
3934       clone_parms = orig_clone_parms;
3935
3936       /* Skip the 'this' parameter.  */
3937       orig_clone_parms = TREE_CHAIN (orig_clone_parms);
3938       orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3939
3940       if (DECL_HAS_IN_CHARGE_PARM_P (decl))
3941         orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3942       if (DECL_HAS_VTT_PARM_P (decl))
3943         orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3944
3945       clone_parms = orig_clone_parms;
3946       if (DECL_HAS_VTT_PARM_P (clone))
3947         clone_parms = TREE_CHAIN (clone_parms);
3948
3949       for (decl_parms = orig_decl_parms; decl_parms;
3950            decl_parms = TREE_CHAIN (decl_parms),
3951              clone_parms = TREE_CHAIN (clone_parms))
3952         {
3953           gcc_assert (same_type_p (TREE_TYPE (decl_parms),
3954                                    TREE_TYPE (clone_parms)));
3955
3956           if (TREE_PURPOSE (decl_parms) && !TREE_PURPOSE (clone_parms))
3957             {
3958               /* A default parameter has been added. Adjust the
3959                  clone's parameters.  */
3960               tree exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
3961               tree basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
3962               tree type;
3963
3964               clone_parms = orig_decl_parms;
3965
3966               if (DECL_HAS_VTT_PARM_P (clone))
3967                 {
3968                   clone_parms = tree_cons (TREE_PURPOSE (orig_clone_parms),
3969                                            TREE_VALUE (orig_clone_parms),
3970                                            clone_parms);
3971                   TREE_TYPE (clone_parms) = TREE_TYPE (orig_clone_parms);
3972                 }
3973               type = build_method_type_directly (basetype,
3974                                                  TREE_TYPE (TREE_TYPE (clone)),
3975                                                  clone_parms);
3976               if (exceptions)
3977                 type = build_exception_variant (type, exceptions);
3978               TREE_TYPE (clone) = type;
3979
3980               clone_parms = NULL_TREE;
3981               break;
3982             }
3983         }
3984       gcc_assert (!clone_parms);
3985     }
3986 }
3987
3988 /* For each of the constructors and destructors in T, create an
3989    in-charge and not-in-charge variant.  */
3990
3991 static void
3992 clone_constructors_and_destructors (tree t)
3993 {
3994   tree fns;
3995
3996   /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
3997      out now.  */
3998   if (!CLASSTYPE_METHOD_VEC (t))
3999     return;
4000
4001   for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4002     clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
4003   for (fns = CLASSTYPE_DESTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4004     clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
4005 }
4006
4007 /* Remove all zero-width bit-fields from T.  */
4008
4009 static void
4010 remove_zero_width_bit_fields (tree t)
4011 {
4012   tree *fieldsp;
4013
4014   fieldsp = &TYPE_FIELDS (t);
4015   while (*fieldsp)
4016     {
4017       if (TREE_CODE (*fieldsp) == FIELD_DECL
4018           && DECL_C_BIT_FIELD (*fieldsp)
4019           && DECL_INITIAL (*fieldsp))
4020         *fieldsp = TREE_CHAIN (*fieldsp);
4021       else
4022         fieldsp = &TREE_CHAIN (*fieldsp);
4023     }
4024 }
4025
4026 /* Returns TRUE iff we need a cookie when dynamically allocating an
4027    array whose elements have the indicated class TYPE.  */
4028
4029 static bool
4030 type_requires_array_cookie (tree type)
4031 {
4032   tree fns;
4033   bool has_two_argument_delete_p = false;
4034
4035   gcc_assert (CLASS_TYPE_P (type));
4036
4037   /* If there's a non-trivial destructor, we need a cookie.  In order
4038      to iterate through the array calling the destructor for each
4039      element, we'll have to know how many elements there are.  */
4040   if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
4041     return true;
4042
4043   /* If the usual deallocation function is a two-argument whose second
4044      argument is of type `size_t', then we have to pass the size of
4045      the array to the deallocation function, so we will need to store
4046      a cookie.  */
4047   fns = lookup_fnfields (TYPE_BINFO (type),
4048                          ansi_opname (VEC_DELETE_EXPR),
4049                          /*protect=*/0);
4050   /* If there are no `operator []' members, or the lookup is
4051      ambiguous, then we don't need a cookie.  */
4052   if (!fns || fns == error_mark_node)
4053     return false;
4054   /* Loop through all of the functions.  */
4055   for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
4056     {
4057       tree fn;
4058       tree second_parm;
4059
4060       /* Select the current function.  */
4061       fn = OVL_CURRENT (fns);
4062       /* See if this function is a one-argument delete function.  If
4063          it is, then it will be the usual deallocation function.  */
4064       second_parm = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fn)));
4065       if (second_parm == void_list_node)
4066         return false;
4067       /* Otherwise, if we have a two-argument function and the second
4068          argument is `size_t', it will be the usual deallocation
4069          function -- unless there is one-argument function, too.  */
4070       if (TREE_CHAIN (second_parm) == void_list_node
4071           && same_type_p (TREE_VALUE (second_parm), sizetype))
4072         has_two_argument_delete_p = true;
4073     }
4074
4075   return has_two_argument_delete_p;
4076 }
4077
4078 /* Check the validity of the bases and members declared in T.  Add any
4079    implicitly-generated functions (like copy-constructors and
4080    assignment operators).  Compute various flag bits (like
4081    CLASSTYPE_NON_POD_T) for T.  This routine works purely at the C++
4082    level: i.e., independently of the ABI in use.  */
4083
4084 static void
4085 check_bases_and_members (tree t)
4086 {
4087   /* Nonzero if we are not allowed to generate a default constructor
4088      for this case.  */
4089   int cant_have_default_ctor;
4090   /* Nonzero if the implicitly generated copy constructor should take
4091      a non-const reference argument.  */
4092   int cant_have_const_ctor;
4093   /* Nonzero if the the implicitly generated assignment operator
4094      should take a non-const reference argument.  */
4095   int no_const_asn_ref;
4096   tree access_decls;
4097
4098   /* By default, we use const reference arguments and generate default
4099      constructors.  */
4100   cant_have_default_ctor = 0;
4101   cant_have_const_ctor = 0;
4102   no_const_asn_ref = 0;
4103
4104   /* Check all the base-classes.  */
4105   check_bases (t, &cant_have_default_ctor, &cant_have_const_ctor,
4106                &no_const_asn_ref);
4107
4108   /* Check all the data member declarations.  */
4109   check_field_decls (t, &access_decls,
4110                      &cant_have_default_ctor,
4111                      &cant_have_const_ctor,
4112                      &no_const_asn_ref);
4113
4114   /* Check all the method declarations.  */
4115   check_methods (t);
4116
4117   /* A nearly-empty class has to be vptr-containing; a nearly empty
4118      class contains just a vptr.  */
4119   if (!TYPE_CONTAINS_VPTR_P (t))
4120     CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
4121
4122   /* Do some bookkeeping that will guide the generation of implicitly
4123      declared member functions.  */
4124   TYPE_HAS_COMPLEX_INIT_REF (t)
4125     |= (TYPE_HAS_INIT_REF (t) || TYPE_CONTAINS_VPTR_P (t));
4126   TYPE_NEEDS_CONSTRUCTING (t)
4127     |= (TYPE_HAS_CONSTRUCTOR (t) || TYPE_CONTAINS_VPTR_P (t));
4128   CLASSTYPE_NON_AGGREGATE (t)
4129     |= (TYPE_HAS_CONSTRUCTOR (t) || TYPE_POLYMORPHIC_P (t));
4130   CLASSTYPE_NON_POD_P (t)
4131     |= (CLASSTYPE_NON_AGGREGATE (t) || TYPE_HAS_DESTRUCTOR (t)
4132         || TYPE_HAS_ASSIGN_REF (t));
4133   TYPE_HAS_COMPLEX_ASSIGN_REF (t)
4134     |= TYPE_HAS_ASSIGN_REF (t) || TYPE_CONTAINS_VPTR_P (t);
4135
4136   /* Synthesize any needed methods.   */
4137   add_implicitly_declared_members (t, cant_have_default_ctor,
4138                                    cant_have_const_ctor,
4139                                    no_const_asn_ref);
4140
4141   /* Create the in-charge and not-in-charge variants of constructors
4142      and destructors.  */
4143   clone_constructors_and_destructors (t);
4144
4145   /* Process the using-declarations.  */
4146   for (; access_decls; access_decls = TREE_CHAIN (access_decls))
4147     handle_using_decl (TREE_VALUE (access_decls), t);
4148
4149   /* Build and sort the CLASSTYPE_METHOD_VEC.  */
4150   finish_struct_methods (t);
4151
4152   /* Figure out whether or not we will need a cookie when dynamically
4153      allocating an array of this type.  */
4154   TYPE_LANG_SPECIFIC (t)->u.c.vec_new_uses_cookie
4155     = type_requires_array_cookie (t);
4156 }
4157
4158 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4159    accordingly.  If a new vfield was created (because T doesn't have a
4160    primary base class), then the newly created field is returned.  It
4161    is not added to the TYPE_FIELDS list; it is the caller's
4162    responsibility to do that.  Accumulate declared virtual functions
4163    on VIRTUALS_P.  */
4164
4165 static tree
4166 create_vtable_ptr (tree t, tree* virtuals_p)
4167 {
4168   tree fn;
4169
4170   /* Collect the virtual functions declared in T.  */
4171   for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
4172     if (DECL_VINDEX (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)
4173         && TREE_CODE (DECL_VINDEX (fn)) != INTEGER_CST)
4174       {
4175         tree new_virtual = make_node (TREE_LIST);
4176
4177         BV_FN (new_virtual) = fn;
4178         BV_DELTA (new_virtual) = integer_zero_node;
4179         BV_VCALL_INDEX (new_virtual) = NULL_TREE;
4180
4181         TREE_CHAIN (new_virtual) = *virtuals_p;
4182         *virtuals_p = new_virtual;
4183       }
4184
4185   /* If we couldn't find an appropriate base class, create a new field
4186      here.  Even if there weren't any new virtual functions, we might need a
4187      new virtual function table if we're supposed to include vptrs in
4188      all classes that need them.  */
4189   if (!TYPE_VFIELD (t) && (*virtuals_p || TYPE_CONTAINS_VPTR_P (t)))
4190     {
4191       /* We build this decl with vtbl_ptr_type_node, which is a
4192          `vtable_entry_type*'.  It might seem more precise to use
4193          `vtable_entry_type (*)[N]' where N is the number of virtual
4194          functions.  However, that would require the vtable pointer in
4195          base classes to have a different type than the vtable pointer
4196          in derived classes.  We could make that happen, but that
4197          still wouldn't solve all the problems.  In particular, the
4198          type-based alias analysis code would decide that assignments
4199          to the base class vtable pointer can't alias assignments to
4200          the derived class vtable pointer, since they have different
4201          types.  Thus, in a derived class destructor, where the base
4202          class constructor was inlined, we could generate bad code for
4203          setting up the vtable pointer.
4204
4205          Therefore, we use one type for all vtable pointers.  We still
4206          use a type-correct type; it's just doesn't indicate the array
4207          bounds.  That's better than using `void*' or some such; it's
4208          cleaner, and it let's the alias analysis code know that these
4209          stores cannot alias stores to void*!  */
4210       tree field;
4211
4212       field = build_decl (FIELD_DECL, get_vfield_name (t), vtbl_ptr_type_node);
4213       SET_DECL_ASSEMBLER_NAME (field, get_identifier (VFIELD_BASE));
4214       DECL_VIRTUAL_P (field) = 1;
4215       DECL_ARTIFICIAL (field) = 1;
4216       DECL_FIELD_CONTEXT (field) = t;
4217       DECL_FCONTEXT (field) = t;
4218
4219       TYPE_VFIELD (t) = field;
4220
4221       /* This class is non-empty.  */
4222       CLASSTYPE_EMPTY_P (t) = 0;
4223
4224       return field;
4225     }
4226
4227   return NULL_TREE;
4228 }
4229
4230 /* Fixup the inline function given by INFO now that the class is
4231    complete.  */
4232
4233 static void
4234 fixup_pending_inline (tree fn)
4235 {
4236   if (DECL_PENDING_INLINE_INFO (fn))
4237     {
4238       tree args = DECL_ARGUMENTS (fn);
4239       while (args)
4240         {
4241           DECL_CONTEXT (args) = fn;
4242           args = TREE_CHAIN (args);
4243         }
4244     }
4245 }
4246
4247 /* Fixup the inline methods and friends in TYPE now that TYPE is
4248    complete.  */
4249
4250 static void
4251 fixup_inline_methods (tree type)
4252 {
4253   tree method = TYPE_METHODS (type);
4254   VEC (tree) *friends;
4255   unsigned ix;
4256
4257   if (method && TREE_CODE (method) == TREE_VEC)
4258     {
4259       if (TREE_VEC_ELT (method, 1))
4260         method = TREE_VEC_ELT (method, 1);
4261       else if (TREE_VEC_ELT (method, 0))
4262         method = TREE_VEC_ELT (method, 0);
4263       else
4264         method = TREE_VEC_ELT (method, 2);
4265     }
4266
4267   /* Do inline member functions.  */
4268   for (; method; method = TREE_CHAIN (method))
4269     fixup_pending_inline (method);
4270
4271   /* Do friends.  */
4272   for (friends = CLASSTYPE_INLINE_FRIENDS (type), ix = 0;
4273        VEC_iterate (tree, friends, ix, method); ix++)
4274     fixup_pending_inline (method);
4275   CLASSTYPE_INLINE_FRIENDS (type) = NULL;
4276 }
4277
4278 /* Add OFFSET to all base types of BINFO which is a base in the
4279    hierarchy dominated by T.
4280
4281    OFFSET, which is a type offset, is number of bytes.  */
4282
4283 static void
4284 propagate_binfo_offsets (tree binfo, tree offset)
4285 {
4286   int i;
4287   tree primary_binfo;
4288   tree base_binfo;
4289
4290   /* Update BINFO's offset.  */
4291   BINFO_OFFSET (binfo)
4292     = convert (sizetype,
4293                size_binop (PLUS_EXPR,
4294                            convert (ssizetype, BINFO_OFFSET (binfo)),
4295                            offset));
4296
4297   /* Find the primary base class.  */
4298   primary_binfo = get_primary_binfo (binfo);
4299
4300   if (primary_binfo && BINFO_INHERITANCE_CHAIN (primary_binfo) == binfo)
4301     propagate_binfo_offsets (primary_binfo, offset);
4302
4303   /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4304      downwards.  */
4305   for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4306     {
4307       /* Don't do the primary base twice.  */
4308       if (base_binfo == primary_binfo)
4309         continue;
4310
4311       if (BINFO_VIRTUAL_P (base_binfo))
4312         continue;
4313
4314       propagate_binfo_offsets (base_binfo, offset);
4315     }
4316 }
4317
4318 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T.  Update
4319    TYPE_ALIGN and TYPE_SIZE for T.  OFFSETS gives the location of
4320    empty subobjects of T.  */
4321
4322 static void
4323 layout_virtual_bases (record_layout_info rli, splay_tree offsets)
4324 {
4325   tree vbase;
4326   tree t = rli->t;
4327   bool first_vbase = true;
4328   tree *next_field;
4329
4330   if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) == 0)
4331     return;
4332
4333   if (!abi_version_at_least(2))
4334     {
4335       /* In G++ 3.2, we incorrectly rounded the size before laying out
4336          the virtual bases.  */
4337       finish_record_layout (rli, /*free_p=*/false);
4338 #ifdef STRUCTURE_SIZE_BOUNDARY
4339       /* Packed structures don't need to have minimum size.  */
4340       if (! TYPE_PACKED (t))
4341         TYPE_ALIGN (t) = MAX (TYPE_ALIGN (t), (unsigned) STRUCTURE_SIZE_BOUNDARY);
4342 #endif
4343       rli->offset = TYPE_SIZE_UNIT (t);
4344       rli->bitpos = bitsize_zero_node;
4345       rli->record_align = TYPE_ALIGN (t);
4346     }
4347
4348   /* Find the last field.  The artificial fields created for virtual
4349      bases will go after the last extant field to date.  */
4350   next_field = &TYPE_FIELDS (t);
4351   while (*next_field)
4352     next_field = &TREE_CHAIN (*next_field);
4353
4354   /* Go through the virtual bases, allocating space for each virtual
4355      base that is not already a primary base class.  These are
4356      allocated in inheritance graph order.  */
4357   for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
4358     {
4359       if (!BINFO_VIRTUAL_P (vbase))
4360         continue;
4361
4362       if (!BINFO_PRIMARY_P (vbase))
4363         {
4364           tree basetype = TREE_TYPE (vbase);
4365
4366           /* This virtual base is not a primary base of any class in the
4367              hierarchy, so we have to add space for it.  */
4368           next_field = build_base_field (rli, vbase,
4369                                          offsets, next_field);
4370
4371           /* If the first virtual base might have been placed at a
4372              lower address, had we started from CLASSTYPE_SIZE, rather
4373              than TYPE_SIZE, issue a warning.  There can be both false
4374              positives and false negatives from this warning in rare
4375              cases; to deal with all the possibilities would probably
4376              require performing both layout algorithms and comparing
4377              the results which is not particularly tractable.  */
4378           if (warn_abi
4379               && first_vbase
4380               && (tree_int_cst_lt
4381                   (size_binop (CEIL_DIV_EXPR,
4382                                round_up (CLASSTYPE_SIZE (t),
4383                                          CLASSTYPE_ALIGN (basetype)),
4384                                bitsize_unit_node),
4385                    BINFO_OFFSET (vbase))))
4386             warning ("offset of virtual base `%T' is not ABI-compliant and may change in a future version of GCC",
4387                      basetype);
4388
4389           first_vbase = false;
4390         }
4391     }
4392 }
4393
4394 /* Returns the offset of the byte just past the end of the base class
4395    BINFO.  */
4396
4397 static tree
4398 end_of_base (tree binfo)
4399 {
4400   tree size;
4401
4402   if (is_empty_class (BINFO_TYPE (binfo)))
4403     /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4404        allocate some space for it. It cannot have virtual bases, so
4405        TYPE_SIZE_UNIT is fine.  */
4406     size = TYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4407   else
4408     size = CLASSTYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4409
4410   return size_binop (PLUS_EXPR, BINFO_OFFSET (binfo), size);
4411 }
4412
4413 /* Returns the offset of the byte just past the end of the base class
4414    with the highest offset in T.  If INCLUDE_VIRTUALS_P is zero, then
4415    only non-virtual bases are included.  */
4416
4417 static tree
4418 end_of_class (tree t, int include_virtuals_p)
4419 {
4420   tree result = size_zero_node;
4421   VEC (tree) *vbases;
4422   tree binfo;
4423   tree base_binfo;
4424   tree offset;
4425   int i;
4426
4427   for (binfo = TYPE_BINFO (t), i = 0;
4428        BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4429     {
4430       if (!include_virtuals_p
4431           && BINFO_VIRTUAL_P (base_binfo)
4432           && (!BINFO_PRIMARY_P (base_binfo)
4433               || BINFO_INHERITANCE_CHAIN (base_binfo) != TYPE_BINFO (t)))
4434         continue;
4435
4436       offset = end_of_base (base_binfo);
4437       if (INT_CST_LT_UNSIGNED (result, offset))
4438         result = offset;
4439     }
4440
4441   /* G++ 3.2 did not check indirect virtual bases.  */
4442   if (abi_version_at_least (2) && include_virtuals_p)
4443     for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4444          VEC_iterate (tree, vbases, i, base_binfo); i++)
4445       {
4446         offset = end_of_base (base_binfo);
4447         if (INT_CST_LT_UNSIGNED (result, offset))
4448           result = offset;
4449       }
4450
4451   return result;
4452 }
4453
4454 /* Warn about bases of T that are inaccessible because they are
4455    ambiguous.  For example:
4456
4457      struct S {};
4458      struct T : public S {};
4459      struct U : public S, public T {};
4460
4461    Here, `(S*) new U' is not allowed because there are two `S'
4462    subobjects of U.  */
4463
4464 static void
4465 warn_about_ambiguous_bases (tree t)
4466 {
4467   int i;
4468   VEC (tree) *vbases;
4469   tree basetype;
4470   tree binfo;
4471   tree base_binfo;
4472
4473   /* Check direct bases.  */
4474   for (binfo = TYPE_BINFO (t), i = 0;
4475        BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4476     {
4477       basetype = BINFO_TYPE (base_binfo);
4478
4479       if (!lookup_base (t, basetype, ba_ignore | ba_quiet, NULL))
4480         warning ("direct base `%T' inaccessible in `%T' due to ambiguity",
4481                  basetype, t);
4482     }
4483
4484   /* Check for ambiguous virtual bases.  */
4485   if (extra_warnings)
4486     for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4487          VEC_iterate (tree, vbases, i, binfo); i++)
4488       {
4489         basetype = BINFO_TYPE (binfo);
4490
4491         if (!lookup_base (t, basetype, ba_ignore | ba_quiet, NULL))
4492           warning ("virtual base `%T' inaccessible in `%T' due to ambiguity",
4493                    basetype, t);
4494       }
4495 }
4496
4497 /* Compare two INTEGER_CSTs K1 and K2.  */
4498
4499 static int
4500 splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2)
4501 {
4502   return tree_int_cst_compare ((tree) k1, (tree) k2);
4503 }
4504
4505 /* Increase the size indicated in RLI to account for empty classes
4506    that are "off the end" of the class.  */
4507
4508 static void
4509 include_empty_classes (record_layout_info rli)
4510 {
4511   tree eoc;
4512   tree rli_size;
4513
4514   /* It might be the case that we grew the class to allocate a
4515      zero-sized base class.  That won't be reflected in RLI, yet,
4516      because we are willing to overlay multiple bases at the same
4517      offset.  However, now we need to make sure that RLI is big enough
4518      to reflect the entire class.  */
4519   eoc = end_of_class (rli->t,
4520                       CLASSTYPE_AS_BASE (rli->t) != NULL_TREE);
4521   rli_size = rli_size_unit_so_far (rli);
4522   if (TREE_CODE (rli_size) == INTEGER_CST
4523       && INT_CST_LT_UNSIGNED (rli_size, eoc))
4524     {
4525       if (!abi_version_at_least (2))
4526         /* In version 1 of the ABI, the size of a class that ends with
4527            a bitfield was not rounded up to a whole multiple of a
4528            byte.  Because rli_size_unit_so_far returns only the number
4529            of fully allocated bytes, any extra bits were not included
4530            in the size.  */
4531         rli->bitpos = round_down (rli->bitpos, BITS_PER_UNIT);
4532       else
4533         /* The size should have been rounded to a whole byte.  */
4534         gcc_assert (tree_int_cst_equal
4535                     (rli->bitpos, round_down (rli->bitpos, BITS_PER_UNIT)));
4536       rli->bitpos
4537         = size_binop (PLUS_EXPR,
4538                       rli->bitpos,
4539                       size_binop (MULT_EXPR,
4540                                   convert (bitsizetype,
4541                                            size_binop (MINUS_EXPR,
4542                                                        eoc, rli_size)),
4543                                   bitsize_int (BITS_PER_UNIT)));
4544       normalize_rli (rli);
4545     }
4546 }
4547
4548 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T.  Calculate
4549    BINFO_OFFSETs for all of the base-classes.  Position the vtable
4550    pointer.  Accumulate declared virtual functions on VIRTUALS_P.  */
4551
4552 static void
4553 layout_class_type (tree t, tree *virtuals_p)
4554 {
4555   tree non_static_data_members;
4556   tree field;
4557   tree vptr;
4558   record_layout_info rli;
4559   /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4560      types that appear at that offset.  */
4561   splay_tree empty_base_offsets;
4562   /* True if the last field layed out was a bit-field.  */
4563   bool last_field_was_bitfield = false;
4564   /* The location at which the next field should be inserted.  */
4565   tree *next_field;
4566   /* T, as a base class.  */
4567   tree base_t;
4568
4569   /* Keep track of the first non-static data member.  */
4570   non_static_data_members = TYPE_FIELDS (t);
4571
4572   /* Start laying out the record.  */
4573   rli = start_record_layout (t);
4574
4575   /* Mark all the primary bases in the hierarchy.  */
4576   determine_primary_bases (t);
4577
4578   /* Create a pointer to our virtual function table.  */
4579   vptr = create_vtable_ptr (t, virtuals_p);
4580
4581   /* The vptr is always the first thing in the class.  */
4582   if (vptr)
4583     {
4584       TREE_CHAIN (vptr) = TYPE_FIELDS (t);
4585       TYPE_FIELDS (t) = vptr;
4586       next_field = &TREE_CHAIN (vptr);
4587       place_field (rli, vptr);
4588     }
4589   else
4590     next_field = &TYPE_FIELDS (t);
4591
4592   /* Build FIELD_DECLs for all of the non-virtual base-types.  */
4593   empty_base_offsets = splay_tree_new (splay_tree_compare_integer_csts,
4594                                        NULL, NULL);
4595   build_base_fields (rli, empty_base_offsets, next_field);
4596
4597   /* Layout the non-static data members.  */
4598   for (field = non_static_data_members; field; field = TREE_CHAIN (field))
4599     {
4600       tree type;
4601       tree padding;
4602
4603       /* We still pass things that aren't non-static data members to
4604          the back-end, in case it wants to do something with them.  */
4605       if (TREE_CODE (field) != FIELD_DECL)
4606         {
4607           place_field (rli, field);
4608           /* If the static data member has incomplete type, keep track
4609              of it so that it can be completed later.  (The handling
4610              of pending statics in finish_record_layout is
4611              insufficient; consider:
4612
4613                struct S1;
4614                struct S2 { static S1 s1; };
4615
4616              At this point, finish_record_layout will be called, but
4617              S1 is still incomplete.)  */
4618           if (TREE_CODE (field) == VAR_DECL)
4619             maybe_register_incomplete_var (field);
4620           continue;
4621         }
4622
4623       type = TREE_TYPE (field);
4624
4625       padding = NULL_TREE;
4626
4627       /* If this field is a bit-field whose width is greater than its
4628          type, then there are some special rules for allocating
4629          it.  */
4630       if (DECL_C_BIT_FIELD (field)
4631           && INT_CST_LT (TYPE_SIZE (type), DECL_SIZE (field)))
4632         {
4633           integer_type_kind itk;
4634           tree integer_type;
4635           bool was_unnamed_p = false;
4636           /* We must allocate the bits as if suitably aligned for the
4637              longest integer type that fits in this many bits.  type
4638              of the field.  Then, we are supposed to use the left over
4639              bits as additional padding.  */
4640           for (itk = itk_char; itk != itk_none; ++itk)
4641             if (INT_CST_LT (DECL_SIZE (field),
4642                             TYPE_SIZE (integer_types[itk])))
4643               break;
4644
4645           /* ITK now indicates a type that is too large for the
4646              field.  We have to back up by one to find the largest
4647              type that fits.  */
4648           integer_type = integer_types[itk - 1];
4649
4650           /* Figure out how much additional padding is required.  GCC
4651              3.2 always created a padding field, even if it had zero
4652              width.  */
4653           if (!abi_version_at_least (2)
4654               || INT_CST_LT (TYPE_SIZE (integer_type), DECL_SIZE (field)))
4655             {
4656               if (abi_version_at_least (2) && TREE_CODE (t) == UNION_TYPE)
4657                 /* In a union, the padding field must have the full width
4658                    of the bit-field; all fields start at offset zero.  */
4659                 padding = DECL_SIZE (field);
4660               else
4661                 {
4662                   if (warn_abi && TREE_CODE (t) == UNION_TYPE)
4663                     warning ("size assigned to `%T' may not be "
4664                              "ABI-compliant and may change in a future "
4665                              "version of GCC",
4666                              t);
4667                   padding = size_binop (MINUS_EXPR, DECL_SIZE (field),
4668                                         TYPE_SIZE (integer_type));
4669                 }
4670             }
4671 #ifdef PCC_BITFIELD_TYPE_MATTERS
4672           /* An unnamed bitfield does not normally affect the
4673              alignment of the containing class on a target where
4674              PCC_BITFIELD_TYPE_MATTERS.  But, the C++ ABI does not
4675              make any exceptions for unnamed bitfields when the
4676              bitfields are longer than their types.  Therefore, we
4677              temporarily give the field a name.  */
4678           if (PCC_BITFIELD_TYPE_MATTERS && !DECL_NAME (field))
4679             {
4680               was_unnamed_p = true;
4681               DECL_NAME (field) = make_anon_name ();
4682             }
4683 #endif
4684           DECL_SIZE (field) = TYPE_SIZE (integer_type);
4685           DECL_ALIGN (field) = TYPE_ALIGN (integer_type);
4686           DECL_USER_ALIGN (field) = TYPE_USER_ALIGN (integer_type);
4687           layout_nonempty_base_or_field (rli, field, NULL_TREE,
4688                                          empty_base_offsets);
4689           if (was_unnamed_p)
4690             DECL_NAME (field) = NULL_TREE;
4691           /* Now that layout has been performed, set the size of the
4692              field to the size of its declared type; the rest of the
4693              field is effectively invisible.  */
4694           DECL_SIZE (field) = TYPE_SIZE (type);
4695           /* We must also reset the DECL_MODE of the field.  */
4696           if (abi_version_at_least (2))
4697             DECL_MODE (field) = TYPE_MODE (type);
4698           else if (warn_abi
4699                    && DECL_MODE (field) != TYPE_MODE (type))
4700             /* Versions of G++ before G++ 3.4 did not reset the
4701                DECL_MODE.  */
4702             warning ("the offset of `%D' may not be ABI-compliant and may "
4703                      "change in a future version of GCC", field);
4704         }
4705       else
4706         layout_nonempty_base_or_field (rli, field, NULL_TREE,
4707                                        empty_base_offsets);
4708
4709       /* Remember the location of any empty classes in FIELD.  */
4710       if (abi_version_at_least (2))
4711         record_subobject_offsets (TREE_TYPE (field),
4712                                   byte_position(field),
4713                                   empty_base_offsets,
4714                                   /*vbases_p=*/1);
4715
4716       /* If a bit-field does not immediately follow another bit-field,
4717          and yet it starts in the middle of a byte, we have failed to
4718          comply with the ABI.  */
4719       if (warn_abi
4720           && DECL_C_BIT_FIELD (field)
4721           && !last_field_was_bitfield
4722           && !integer_zerop (size_binop (TRUNC_MOD_EXPR,
4723                                          DECL_FIELD_BIT_OFFSET (field),
4724                                          bitsize_unit_node)))
4725         cp_warning_at ("offset of `%D' is not ABI-compliant and may change in a future version of GCC",
4726                        field);
4727
4728       /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
4729          offset of the field.  */
4730       if (warn_abi
4731           && !tree_int_cst_equal (DECL_FIELD_OFFSET (field),
4732                                   byte_position (field))
4733           && contains_empty_class_p (TREE_TYPE (field)))
4734         cp_warning_at ("`%D' contains empty classes which may cause base "
4735                        "classes to be placed at different locations in a "
4736                        "future version of GCC",
4737                        field);
4738
4739       /* If we needed additional padding after this field, add it
4740          now.  */
4741       if (padding)
4742         {
4743           tree padding_field;
4744
4745           padding_field = build_decl (FIELD_DECL,
4746                                       NULL_TREE,
4747                                       char_type_node);
4748           DECL_BIT_FIELD (padding_field) = 1;
4749           DECL_SIZE (padding_field) = padding;
4750           DECL_CONTEXT (padding_field) = t;
4751           DECL_ARTIFICIAL (padding_field) = 1;
4752           layout_nonempty_base_or_field (rli, padding_field,
4753                                          NULL_TREE,
4754                                          empty_base_offsets);
4755         }
4756
4757       last_field_was_bitfield = DECL_C_BIT_FIELD (field);
4758     }
4759
4760   if (abi_version_at_least (2) && !integer_zerop (rli->bitpos))
4761     {
4762       /* Make sure that we are on a byte boundary so that the size of
4763          the class without virtual bases will always be a round number
4764          of bytes.  */
4765       rli->bitpos = round_up (rli->bitpos, BITS_PER_UNIT);
4766       normalize_rli (rli);
4767     }
4768
4769   /* G++ 3.2 does not allow virtual bases to be overlaid with tail
4770      padding.  */
4771   if (!abi_version_at_least (2))
4772     include_empty_classes(rli);
4773
4774   /* Delete all zero-width bit-fields from the list of fields.  Now
4775      that the type is laid out they are no longer important.  */
4776   remove_zero_width_bit_fields (t);
4777
4778   /* Create the version of T used for virtual bases.  We do not use
4779      make_aggr_type for this version; this is an artificial type.  For
4780      a POD type, we just reuse T.  */
4781   if (CLASSTYPE_NON_POD_P (t) || CLASSTYPE_EMPTY_P (t))
4782     {
4783       base_t = make_node (TREE_CODE (t));
4784
4785       /* Set the size and alignment for the new type.  In G++ 3.2, all
4786          empty classes were considered to have size zero when used as
4787          base classes.  */
4788       if (!abi_version_at_least (2) && CLASSTYPE_EMPTY_P (t))
4789         {
4790           TYPE_SIZE (base_t) = bitsize_zero_node;
4791           TYPE_SIZE_UNIT (base_t) = size_zero_node;
4792           if (warn_abi && !integer_zerop (rli_size_unit_so_far (rli)))
4793             warning ("layout of classes derived from empty class `%T' "
4794                      "may change in a future version of GCC",
4795                      t);
4796         }
4797       else
4798         {
4799           tree eoc;
4800
4801           /* If the ABI version is not at least two, and the last
4802              field was a bit-field, RLI may not be on a byte
4803              boundary.  In particular, rli_size_unit_so_far might
4804              indicate the last complete byte, while rli_size_so_far
4805              indicates the total number of bits used.  Therefore,
4806              rli_size_so_far, rather than rli_size_unit_so_far, is
4807              used to compute TYPE_SIZE_UNIT.  */
4808           eoc = end_of_class (t, /*include_virtuals_p=*/0);
4809           TYPE_SIZE_UNIT (base_t)
4810             = size_binop (MAX_EXPR,
4811                           convert (sizetype,
4812                                    size_binop (CEIL_DIV_EXPR,
4813                                                rli_size_so_far (rli),
4814                                                bitsize_int (BITS_PER_UNIT))),
4815                           eoc);
4816           TYPE_SIZE (base_t)
4817             = size_binop (MAX_EXPR,
4818                           rli_size_so_far (rli),
4819                           size_binop (MULT_EXPR,
4820                                       convert (bitsizetype, eoc),
4821                                       bitsize_int (BITS_PER_UNIT)));
4822         }
4823       TYPE_ALIGN (base_t) = rli->record_align;
4824       TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t);
4825
4826       /* Copy the fields from T.  */
4827       next_field = &TYPE_FIELDS (base_t);
4828       for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
4829         if (TREE_CODE (field) == FIELD_DECL)
4830           {
4831             *next_field = build_decl (FIELD_DECL,
4832                                       DECL_NAME (field),
4833                                       TREE_TYPE (field));
4834             DECL_CONTEXT (*next_field) = base_t;
4835             DECL_FIELD_OFFSET (*next_field) = DECL_FIELD_OFFSET (field);
4836             DECL_FIELD_BIT_OFFSET (*next_field)
4837               = DECL_FIELD_BIT_OFFSET (field);
4838             DECL_SIZE (*next_field) = DECL_SIZE (field);
4839             DECL_MODE (*next_field) = DECL_MODE (field);
4840             next_field = &TREE_CHAIN (*next_field);
4841           }
4842
4843       /* Record the base version of the type.  */
4844       CLASSTYPE_AS_BASE (t) = base_t;
4845       TYPE_CONTEXT (base_t) = t;
4846     }
4847   else
4848     CLASSTYPE_AS_BASE (t) = t;
4849
4850   /* Every empty class contains an empty class.  */
4851   if (CLASSTYPE_EMPTY_P (t))
4852     CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
4853
4854   /* Set the TYPE_DECL for this type to contain the right
4855      value for DECL_OFFSET, so that we can use it as part
4856      of a COMPONENT_REF for multiple inheritance.  */
4857   layout_decl (TYPE_MAIN_DECL (t), 0);
4858
4859   /* Now fix up any virtual base class types that we left lying
4860      around.  We must get these done before we try to lay out the
4861      virtual function table.  As a side-effect, this will remove the
4862      base subobject fields.  */
4863   layout_virtual_bases (rli, empty_base_offsets);
4864
4865   /* Make sure that empty classes are reflected in RLI at this
4866      point.  */
4867   include_empty_classes(rli);
4868
4869   /* Make sure not to create any structures with zero size.  */
4870   if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t))
4871     place_field (rli,
4872                  build_decl (FIELD_DECL, NULL_TREE, char_type_node));
4873
4874   /* Let the back-end lay out the type.  */
4875   finish_record_layout (rli, /*free_p=*/true);
4876
4877   /* Warn about bases that can't be talked about due to ambiguity.  */
4878   warn_about_ambiguous_bases (t);
4879
4880   /* Now that we're done with layout, give the base fields the real types.  */
4881   for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
4882     if (DECL_ARTIFICIAL (field) && IS_FAKE_BASE_TYPE (TREE_TYPE (field)))
4883       TREE_TYPE (field) = TYPE_CONTEXT (TREE_TYPE (field));
4884
4885   /* Clean up.  */
4886   splay_tree_delete (empty_base_offsets);
4887 }
4888
4889 /* Determine the "key method" for the class type indicated by TYPE,
4890    and set CLASSTYPE_KEY_METHOD accordingly.  */
4891
4892 void
4893 determine_key_method (tree type)
4894 {
4895   tree method;
4896
4897   if (TYPE_FOR_JAVA (type)
4898       || processing_template_decl
4899       || CLASSTYPE_TEMPLATE_INSTANTIATION (type)
4900       || CLASSTYPE_INTERFACE_KNOWN (type))
4901     return;
4902
4903   /* The key method is the first non-pure virtual function that is not
4904      inline at the point of class definition.  On some targets the
4905      key function may not be inline; those targets should not call
4906      this function until the end of the translation unit.  */
4907   for (method = TYPE_METHODS (type); method != NULL_TREE;
4908        method = TREE_CHAIN (method))
4909     if (DECL_VINDEX (method) != NULL_TREE
4910         && ! DECL_DECLARED_INLINE_P (method)
4911         && ! DECL_PURE_VIRTUAL_P (method))
4912       {
4913         CLASSTYPE_KEY_METHOD (type) = method;
4914         break;
4915       }
4916
4917   return;
4918 }
4919
4920 /* Perform processing required when the definition of T (a class type)
4921    is complete.  */
4922
4923 void
4924 finish_struct_1 (tree t)
4925 {
4926   tree x;
4927   /* A TREE_LIST.  The TREE_VALUE of each node is a FUNCTION_DECL.  */
4928   tree virtuals = NULL_TREE;
4929   int n_fields = 0;
4930
4931   if (COMPLETE_TYPE_P (t))
4932     {
4933       gcc_assert (IS_AGGR_TYPE (t));
4934       error ("redefinition of `%#T'", t);
4935       popclass ();
4936       return;
4937     }
4938
4939   /* If this type was previously laid out as a forward reference,
4940      make sure we lay it out again.  */
4941   TYPE_SIZE (t) = NULL_TREE;
4942   CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE;
4943
4944   fixup_inline_methods (t);
4945
4946   /* Make assumptions about the class; we'll reset the flags if
4947      necessary.  */
4948   CLASSTYPE_EMPTY_P (t) = 1;
4949   CLASSTYPE_NEARLY_EMPTY_P (t) = 1;
4950   CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 0;
4951
4952   /* Do end-of-class semantic processing: checking the validity of the
4953      bases and members and add implicitly generated methods.  */
4954   check_bases_and_members (t);
4955
4956   /* Find the key method.  */
4957   if (TYPE_CONTAINS_VPTR_P (t))
4958     {
4959       /* The Itanium C++ ABI permits the key method to be chosen when
4960          the class is defined -- even though the key method so
4961          selected may later turn out to be an inline function.  On
4962          some systems (such as ARM Symbian OS) the key method cannot
4963          be determined until the end of the translation unit.  On such
4964          systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
4965          will cause the class to be added to KEYED_CLASSES.  Then, in
4966          finish_file we will determine the key method.  */
4967       if (targetm.cxx.key_method_may_be_inline ())
4968         determine_key_method (t);
4969
4970       /* If a polymorphic class has no key method, we may emit the vtable
4971          in every translation unit where the class definition appears.  */
4972       if (CLASSTYPE_KEY_METHOD (t) == NULL_TREE)
4973         keyed_classes = tree_cons (NULL_TREE, t, keyed_classes);
4974     }
4975
4976   /* Layout the class itself.  */
4977   layout_class_type (t, &virtuals);
4978   if (CLASSTYPE_AS_BASE (t) != t)
4979     /* We use the base type for trivial assignments, and hence it
4980        needs a mode.  */
4981     compute_record_mode (CLASSTYPE_AS_BASE (t));
4982
4983   virtuals = modify_all_vtables (t, nreverse (virtuals));
4984
4985   /* If necessary, create the primary vtable for this class.  */
4986   if (virtuals || TYPE_CONTAINS_VPTR_P (t))
4987     {
4988       /* We must enter these virtuals into the table.  */
4989       if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
4990         build_primary_vtable (NULL_TREE, t);
4991       else if (! BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (t)))
4992         /* Here we know enough to change the type of our virtual
4993            function table, but we will wait until later this function.  */
4994         build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t);
4995     }
4996
4997   if (TYPE_CONTAINS_VPTR_P (t))
4998     {
4999       int vindex;
5000       tree fn;
5001
5002       if (BINFO_VTABLE (TYPE_BINFO (t)))
5003         gcc_assert (DECL_VIRTUAL_P (BINFO_VTABLE (TYPE_BINFO (t))));
5004       if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
5005         gcc_assert (BINFO_VIRTUALS (TYPE_BINFO (t)) == NULL_TREE);
5006
5007       /* Add entries for virtual functions introduced by this class.  */
5008       BINFO_VIRTUALS (TYPE_BINFO (t))
5009         = chainon (BINFO_VIRTUALS (TYPE_BINFO (t)), virtuals);
5010
5011       /* Set DECL_VINDEX for all functions declared in this class.  */
5012       for (vindex = 0, fn = BINFO_VIRTUALS (TYPE_BINFO (t));
5013            fn;
5014            fn = TREE_CHAIN (fn),
5015              vindex += (TARGET_VTABLE_USES_DESCRIPTORS
5016                         ? TARGET_VTABLE_USES_DESCRIPTORS : 1))
5017         {
5018           tree fndecl = BV_FN (fn);
5019
5020           if (DECL_THUNK_P (fndecl))
5021             /* A thunk. We should never be calling this entry directly
5022                from this vtable -- we'd use the entry for the non
5023                thunk base function.  */
5024             DECL_VINDEX (fndecl) = NULL_TREE;
5025           else if (TREE_CODE (DECL_VINDEX (fndecl)) != INTEGER_CST)
5026             DECL_VINDEX (fndecl) = build_int_cst (NULL_TREE, vindex);
5027         }
5028     }
5029
5030   finish_struct_bits (t);
5031
5032   /* Complete the rtl for any static member objects of the type we're
5033      working on.  */
5034   for (x = TYPE_FIELDS (t); x; x = TREE_CHAIN (x))
5035     if (TREE_CODE (x) == VAR_DECL && TREE_STATIC (x)
5036         && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t))
5037       DECL_MODE (x) = TYPE_MODE (t);
5038
5039   /* Done with FIELDS...now decide whether to sort these for
5040      faster lookups later.
5041
5042      We use a small number because most searches fail (succeeding
5043      ultimately as the search bores through the inheritance
5044      hierarchy), and we want this failure to occur quickly.  */
5045
5046   n_fields = count_fields (TYPE_FIELDS (t));
5047   if (n_fields > 7)
5048     {
5049       struct sorted_fields_type *field_vec = GGC_NEWVAR
5050          (struct sorted_fields_type,
5051           sizeof (struct sorted_fields_type) + n_fields * sizeof (tree));
5052       field_vec->len = n_fields;
5053       add_fields_to_record_type (TYPE_FIELDS (t), field_vec, 0);
5054       qsort (field_vec->elts, n_fields, sizeof (tree),
5055              field_decl_cmp);
5056       if (! DECL_LANG_SPECIFIC (TYPE_MAIN_DECL (t)))
5057         retrofit_lang_decl (TYPE_MAIN_DECL (t));
5058       DECL_SORTED_FIELDS (TYPE_MAIN_DECL (t)) = field_vec;
5059     }
5060
5061   /* Make the rtl for any new vtables we have created, and unmark
5062      the base types we marked.  */
5063   finish_vtbls (t);
5064
5065   /* Build the VTT for T.  */
5066   build_vtt (t);
5067
5068   if (warn_nonvdtor && TYPE_POLYMORPHIC_P (t) && TYPE_HAS_DESTRUCTOR (t)
5069       && !DECL_VINDEX (CLASSTYPE_DESTRUCTORS (t)))
5070
5071     {
5072       tree dtor = CLASSTYPE_DESTRUCTORS (t);
5073
5074       /* Warn only if the dtor is non-private or the class has friends */
5075       if (!TREE_PRIVATE (dtor) ||
5076           (CLASSTYPE_FRIEND_CLASSES (t) ||
5077            DECL_FRIENDLIST (TYPE_MAIN_DECL (t))))
5078         warning ("%#T' has virtual functions but non-virtual destructor", t);
5079     }
5080
5081   complete_vars (t);
5082
5083   if (warn_overloaded_virtual)
5084     warn_hidden (t);
5085
5086   maybe_suppress_debug_info (t);
5087
5088   dump_class_hierarchy (t);
5089
5090   /* Finish debugging output for this type.  */
5091   rest_of_type_compilation (t, ! LOCAL_CLASS_P (t));
5092 }
5093
5094 /* When T was built up, the member declarations were added in reverse
5095    order.  Rearrange them to declaration order.  */
5096
5097 void
5098 unreverse_member_declarations (tree t)
5099 {
5100   tree next;
5101   tree prev;
5102   tree x;
5103
5104   /* The following lists are all in reverse order.  Put them in
5105      declaration order now.  */
5106   TYPE_METHODS (t) = nreverse (TYPE_METHODS (t));
5107   CLASSTYPE_DECL_LIST (t) = nreverse (CLASSTYPE_DECL_LIST (t));
5108
5109   /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5110      reverse order, so we can't just use nreverse.  */
5111   prev = NULL_TREE;
5112   for (x = TYPE_FIELDS (t);
5113        x && TREE_CODE (x) != TYPE_DECL;
5114        x = next)
5115     {
5116       next = TREE_CHAIN (x);
5117       TREE_CHAIN (x) = prev;
5118       prev = x;
5119     }
5120   if (prev)
5121     {
5122       TREE_CHAIN (TYPE_FIELDS (t)) = x;
5123       if (prev)
5124         TYPE_FIELDS (t) = prev;
5125     }
5126 }
5127
5128 tree
5129 finish_struct (tree t, tree attributes)
5130 {
5131   location_t saved_loc = input_location;
5132
5133   /* Now that we've got all the field declarations, reverse everything
5134      as necessary.  */
5135   unreverse_member_declarations (t);
5136
5137   cplus_decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
5138
5139   /* Nadger the current location so that diagnostics point to the start of
5140      the struct, not the end.  */
5141   input_location = DECL_SOURCE_LOCATION (TYPE_NAME (t));
5142
5143   if (processing_template_decl)
5144     {
5145       tree x;
5146
5147       finish_struct_methods (t);
5148       TYPE_SIZE (t) = bitsize_zero_node;
5149
5150       /* We need to emit an error message if this type was used as a parameter
5151          and it is an abstract type, even if it is a template. We construct
5152          a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
5153          account and we call complete_vars with this type, which will check
5154          the PARM_DECLS. Note that while the type is being defined,
5155          CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
5156          (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it.  */
5157       CLASSTYPE_PURE_VIRTUALS (t) = NULL;
5158       for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
5159         if (DECL_PURE_VIRTUAL_P (x))
5160           VEC_safe_push (tree, CLASSTYPE_PURE_VIRTUALS (t), x);
5161       complete_vars (t);
5162     }
5163   else
5164     finish_struct_1 (t);
5165
5166   input_location = saved_loc;
5167
5168   TYPE_BEING_DEFINED (t) = 0;
5169
5170   if (current_class_type)
5171     popclass ();
5172   else
5173     error ("trying to finish struct, but kicked out due to previous parse errors");
5174
5175   if (processing_template_decl && at_function_scope_p ())
5176     add_stmt (build_min (TAG_DEFN, t));
5177
5178   return t;
5179 }
5180 \f
5181 /* Return the dynamic type of INSTANCE, if known.
5182    Used to determine whether the virtual function table is needed
5183    or not.
5184
5185    *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5186    of our knowledge of its type.  *NONNULL should be initialized
5187    before this function is called.  */
5188
5189 static tree
5190 fixed_type_or_null (tree instance, int* nonnull, int* cdtorp)
5191 {
5192   switch (TREE_CODE (instance))
5193     {
5194     case INDIRECT_REF:
5195       if (POINTER_TYPE_P (TREE_TYPE (instance)))
5196         return NULL_TREE;
5197       else
5198         return fixed_type_or_null (TREE_OPERAND (instance, 0),
5199                                    nonnull, cdtorp);
5200
5201     case CALL_EXPR:
5202       /* This is a call to a constructor, hence it's never zero.  */
5203       if (TREE_HAS_CONSTRUCTOR (instance))
5204         {
5205           if (nonnull)
5206             *nonnull = 1;
5207           return TREE_TYPE (instance);
5208         }
5209       return NULL_TREE;
5210
5211     case SAVE_EXPR:
5212       /* This is a call to a constructor, hence it's never zero.  */
5213       if (TREE_HAS_CONSTRUCTOR (instance))
5214         {
5215           if (nonnull)
5216             *nonnull = 1;
5217           return TREE_TYPE (instance);
5218         }
5219       return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5220
5221     case PLUS_EXPR:
5222     case MINUS_EXPR:
5223       if (TREE_CODE (TREE_OPERAND (instance, 0)) == ADDR_EXPR)
5224         return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5225       if (TREE_CODE (TREE_OPERAND (instance, 1)) == INTEGER_CST)
5226         /* Propagate nonnull.  */
5227         return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5228       return NULL_TREE;
5229
5230     case NOP_EXPR:
5231     case CONVERT_EXPR:
5232       return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5233
5234     case ADDR_EXPR:
5235       instance = TREE_OPERAND (instance, 0);
5236       if (nonnull)
5237         {
5238           /* Just because we see an ADDR_EXPR doesn't mean we're dealing
5239              with a real object -- given &p->f, p can still be null.  */
5240           tree t = get_base_address (instance);
5241           /* ??? Probably should check DECL_WEAK here.  */
5242           if (t && DECL_P (t))
5243             *nonnull = 1;
5244         }
5245       return fixed_type_or_null (instance, nonnull, cdtorp);
5246
5247     case COMPONENT_REF:
5248       /* If this component is really a base class reference, then the field
5249          itself isn't definitive.  */
5250       if (DECL_FIELD_IS_BASE (TREE_OPERAND (instance, 1)))
5251         return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5252       return fixed_type_or_null (TREE_OPERAND (instance, 1), nonnull, cdtorp);
5253
5254     case VAR_DECL:
5255     case FIELD_DECL:
5256       if (TREE_CODE (TREE_TYPE (instance)) == ARRAY_TYPE
5257           && IS_AGGR_TYPE (TREE_TYPE (TREE_TYPE (instance))))
5258         {
5259           if (nonnull)
5260             *nonnull = 1;
5261           return TREE_TYPE (TREE_TYPE (instance));
5262         }
5263       /* fall through...  */
5264     case TARGET_EXPR:
5265     case PARM_DECL:
5266     case RESULT_DECL:
5267       if (IS_AGGR_TYPE (TREE_TYPE (instance)))
5268         {
5269           if (nonnull)
5270             *nonnull = 1;
5271           return TREE_TYPE (instance);
5272         }
5273       else if (instance == current_class_ptr)
5274         {
5275           if (nonnull)
5276             *nonnull = 1;
5277
5278           /* if we're in a ctor or dtor, we know our type.  */
5279           if (DECL_LANG_SPECIFIC (current_function_decl)
5280               && (DECL_CONSTRUCTOR_P (current_function_decl)
5281                   || DECL_DESTRUCTOR_P (current_function_decl)))
5282             {
5283               if (cdtorp)
5284                 *cdtorp = 1;
5285               return TREE_TYPE (TREE_TYPE (instance));
5286             }
5287         }
5288       else if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE)
5289         {
5290           /* Reference variables should be references to objects.  */
5291           if (nonnull)
5292             *nonnull = 1;
5293
5294           /* DECL_VAR_MARKED_P is used to prevent recursion; a
5295              variable's initializer may refer to the variable
5296              itself.  */
5297           if (TREE_CODE (instance) == VAR_DECL
5298               && DECL_INITIAL (instance)
5299               && !DECL_VAR_MARKED_P (instance))
5300             {
5301               tree type;
5302               DECL_VAR_MARKED_P (instance) = 1;
5303               type = fixed_type_or_null (DECL_INITIAL (instance),
5304                                          nonnull, cdtorp);
5305               DECL_VAR_MARKED_P (instance) = 0;
5306               return type;
5307             }
5308         }
5309       return NULL_TREE;
5310
5311     default:
5312       return NULL_TREE;
5313     }
5314 }
5315
5316 /* Return nonzero if the dynamic type of INSTANCE is known, and
5317    equivalent to the static type.  We also handle the case where
5318    INSTANCE is really a pointer. Return negative if this is a
5319    ctor/dtor. There the dynamic type is known, but this might not be
5320    the most derived base of the original object, and hence virtual
5321    bases may not be layed out according to this type.
5322
5323    Used to determine whether the virtual function table is needed
5324    or not.
5325
5326    *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5327    of our knowledge of its type.  *NONNULL should be initialized
5328    before this function is called.  */
5329
5330 int
5331 resolves_to_fixed_type_p (tree instance, int* nonnull)
5332 {
5333   tree t = TREE_TYPE (instance);
5334   int cdtorp = 0;
5335
5336   tree fixed = fixed_type_or_null (instance, nonnull, &cdtorp);
5337   if (fixed == NULL_TREE)
5338     return 0;
5339   if (POINTER_TYPE_P (t))
5340     t = TREE_TYPE (t);
5341   if (!same_type_ignoring_top_level_qualifiers_p (t, fixed))
5342     return 0;
5343   return cdtorp ? -1 : 1;
5344 }
5345
5346 \f
5347 void
5348 init_class_processing (void)
5349 {
5350   current_class_depth = 0;
5351   current_class_stack_size = 10;
5352   current_class_stack
5353     = xmalloc (current_class_stack_size * sizeof (struct class_stack_node));
5354   VARRAY_TREE_INIT (local_classes, 8, "local_classes");
5355
5356   ridpointers[(int) RID_PUBLIC] = access_public_node;
5357   ridpointers[(int) RID_PRIVATE] = access_private_node;
5358   ridpointers[(int) RID_PROTECTED] = access_protected_node;
5359 }
5360
5361 /* Restore the cached PREVIOUS_CLASS_LEVEL.  */
5362
5363 static void
5364 restore_class_cache (void)
5365 {
5366   tree type;
5367
5368   /* We are re-entering the same class we just left, so we don't
5369      have to search the whole inheritance matrix to find all the
5370      decls to bind again.  Instead, we install the cached
5371      class_shadowed list and walk through it binding names.  */
5372   push_binding_level (previous_class_level);
5373   class_binding_level = previous_class_level;
5374   /* Restore IDENTIFIER_TYPE_VALUE.  */
5375   for (type = class_binding_level->type_shadowed;
5376        type;
5377        type = TREE_CHAIN (type))
5378     SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (type), TREE_TYPE (type));
5379 }
5380
5381 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
5382    appropriate for TYPE.
5383
5384    So that we may avoid calls to lookup_name, we cache the _TYPE
5385    nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5386
5387    For multiple inheritance, we perform a two-pass depth-first search
5388    of the type lattice.  */
5389
5390 void
5391 pushclass (tree type)
5392 {
5393   type = TYPE_MAIN_VARIANT (type);
5394
5395   /* Make sure there is enough room for the new entry on the stack.  */
5396   if (current_class_depth + 1 >= current_class_stack_size)
5397     {
5398       current_class_stack_size *= 2;
5399       current_class_stack
5400         = xrealloc (current_class_stack,
5401                     current_class_stack_size
5402                     * sizeof (struct class_stack_node));
5403     }
5404
5405   /* Insert a new entry on the class stack.  */
5406   current_class_stack[current_class_depth].name = current_class_name;
5407   current_class_stack[current_class_depth].type = current_class_type;
5408   current_class_stack[current_class_depth].access = current_access_specifier;
5409   current_class_stack[current_class_depth].names_used = 0;
5410   current_class_depth++;
5411
5412   /* Now set up the new type.  */
5413   current_class_name = TYPE_NAME (type);
5414   if (TREE_CODE (current_class_name) == TYPE_DECL)
5415     current_class_name = DECL_NAME (current_class_name);
5416   current_class_type = type;
5417
5418   /* By default, things in classes are private, while things in
5419      structures or unions are public.  */
5420   current_access_specifier = (CLASSTYPE_DECLARED_CLASS (type)
5421                               ? access_private_node
5422                               : access_public_node);
5423
5424   if (previous_class_level
5425       && type != previous_class_level->this_entity
5426       && current_class_depth == 1)
5427     {
5428       /* Forcibly remove any old class remnants.  */
5429       invalidate_class_lookup_cache ();
5430     }
5431
5432   if (!previous_class_level
5433       || type != previous_class_level->this_entity
5434       || current_class_depth > 1)
5435     pushlevel_class ();
5436   else
5437     restore_class_cache ();
5438
5439   cxx_remember_type_decls (CLASSTYPE_NESTED_UTDS (type));
5440 }
5441
5442 /* When we exit a toplevel class scope, we save its binding level so
5443    that we can restore it quickly.  Here, we've entered some other
5444    class, so we must invalidate our cache.  */
5445
5446 void
5447 invalidate_class_lookup_cache (void)
5448 {
5449   previous_class_level = NULL;
5450 }
5451
5452 /* Get out of the current class scope. If we were in a class scope
5453    previously, that is the one popped to.  */
5454
5455 void
5456 popclass (void)
5457 {
5458   poplevel_class ();
5459
5460   current_class_depth--;
5461   current_class_name = current_class_stack[current_class_depth].name;
5462   current_class_type = current_class_stack[current_class_depth].type;
5463   current_access_specifier = current_class_stack[current_class_depth].access;
5464   if (current_class_stack[current_class_depth].names_used)
5465     splay_tree_delete (current_class_stack[current_class_depth].names_used);
5466 }
5467
5468 /* Returns 1 if current_class_type is either T or a nested type of T.
5469    We start looking from 1 because entry 0 is from global scope, and has
5470    no type.  */
5471
5472 int
5473 currently_open_class (tree t)
5474 {
5475   int i;
5476   if (current_class_type && same_type_p (t, current_class_type))
5477     return 1;
5478   for (i = 1; i < current_class_depth; ++i)
5479     if (current_class_stack[i].type
5480         && same_type_p (current_class_stack [i].type, t))
5481       return 1;
5482   return 0;
5483 }
5484
5485 /* If either current_class_type or one of its enclosing classes are derived
5486    from T, return the appropriate type.  Used to determine how we found
5487    something via unqualified lookup.  */
5488
5489 tree
5490 currently_open_derived_class (tree t)
5491 {
5492   int i;
5493
5494   /* The bases of a dependent type are unknown.  */
5495   if (dependent_type_p (t))
5496     return NULL_TREE;
5497
5498   if (!current_class_type)
5499     return NULL_TREE;
5500
5501   if (DERIVED_FROM_P (t, current_class_type))
5502     return current_class_type;
5503
5504   for (i = current_class_depth - 1; i > 0; --i)
5505     if (DERIVED_FROM_P (t, current_class_stack[i].type))
5506       return current_class_stack[i].type;
5507
5508   return NULL_TREE;
5509 }
5510
5511 /* When entering a class scope, all enclosing class scopes' names with
5512    static meaning (static variables, static functions, types and
5513    enumerators) have to be visible.  This recursive function calls
5514    pushclass for all enclosing class contexts until global or a local
5515    scope is reached.  TYPE is the enclosed class.  */
5516
5517 void
5518 push_nested_class (tree type)
5519 {
5520   tree context;
5521
5522   /* A namespace might be passed in error cases, like A::B:C.  */
5523   if (type == NULL_TREE
5524       || type == error_mark_node
5525       || TREE_CODE (type) == NAMESPACE_DECL
5526       || ! IS_AGGR_TYPE (type)
5527       || TREE_CODE (type) == TEMPLATE_TYPE_PARM
5528       || TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
5529     return;
5530
5531   context = DECL_CONTEXT (TYPE_MAIN_DECL (type));
5532
5533   if (context && CLASS_TYPE_P (context))
5534     push_nested_class (context);
5535   pushclass (type);
5536 }
5537
5538 /* Undoes a push_nested_class call.  */
5539
5540 void
5541 pop_nested_class (void)
5542 {
5543   tree context = DECL_CONTEXT (TYPE_MAIN_DECL (current_class_type));
5544
5545   popclass ();
5546   if (context && CLASS_TYPE_P (context))
5547     pop_nested_class ();
5548 }
5549
5550 /* Returns the number of extern "LANG" blocks we are nested within.  */
5551
5552 int
5553 current_lang_depth (void)
5554 {
5555   return VARRAY_ACTIVE_SIZE (current_lang_base);
5556 }
5557
5558 /* Set global variables CURRENT_LANG_NAME to appropriate value
5559    so that behavior of name-mangling machinery is correct.  */
5560
5561 void
5562 push_lang_context (tree name)
5563 {
5564   VARRAY_PUSH_TREE (current_lang_base, current_lang_name);
5565
5566   if (name == lang_name_cplusplus)
5567     {
5568       current_lang_name = name;
5569     }
5570   else if (name == lang_name_java)
5571     {
5572       current_lang_name = name;
5573       /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5574          (See record_builtin_java_type in decl.c.)  However, that causes
5575          incorrect debug entries if these types are actually used.
5576          So we re-enable debug output after extern "Java".  */
5577       DECL_IGNORED_P (TYPE_NAME (java_byte_type_node)) = 0;
5578       DECL_IGNORED_P (TYPE_NAME (java_short_type_node)) = 0;
5579       DECL_IGNORED_P (TYPE_NAME (java_int_type_node)) = 0;
5580       DECL_IGNORED_P (TYPE_NAME (java_long_type_node)) = 0;
5581       DECL_IGNORED_P (TYPE_NAME (java_float_type_node)) = 0;
5582       DECL_IGNORED_P (TYPE_NAME (java_double_type_node)) = 0;
5583       DECL_IGNORED_P (TYPE_NAME (java_char_type_node)) = 0;
5584       DECL_IGNORED_P (TYPE_NAME (java_boolean_type_node)) = 0;
5585     }
5586   else if (name == lang_name_c)
5587     {
5588       current_lang_name = name;
5589     }
5590   else
5591     error ("language string `\"%E\"' not recognized", name);
5592 }
5593
5594 /* Get out of the current language scope.  */
5595
5596 void
5597 pop_lang_context (void)
5598 {
5599   current_lang_name = VARRAY_TOP_TREE (current_lang_base);
5600   VARRAY_POP (current_lang_base);
5601 }
5602 \f
5603 /* Type instantiation routines.  */
5604
5605 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
5606    matches the TARGET_TYPE.  If there is no satisfactory match, return
5607    error_mark_node, and issue a error & warning messages under control
5608    of FLAGS.  Permit pointers to member function if FLAGS permits.  If
5609    TEMPLATE_ONLY, the name of the overloaded function was a
5610    template-id, and EXPLICIT_TARGS are the explicitly provided
5611    template arguments.  */
5612
5613 static tree
5614 resolve_address_of_overloaded_function (tree target_type,
5615                                         tree overload,
5616                                         tsubst_flags_t flags,
5617                                         bool template_only,
5618                                         tree explicit_targs)
5619 {
5620   /* Here's what the standard says:
5621
5622        [over.over]
5623
5624        If the name is a function template, template argument deduction
5625        is done, and if the argument deduction succeeds, the deduced
5626        arguments are used to generate a single template function, which
5627        is added to the set of overloaded functions considered.
5628
5629        Non-member functions and static member functions match targets of
5630        type "pointer-to-function" or "reference-to-function."  Nonstatic
5631        member functions match targets of type "pointer-to-member
5632        function;" the function type of the pointer to member is used to
5633        select the member function from the set of overloaded member
5634        functions.  If a nonstatic member function is selected, the
5635        reference to the overloaded function name is required to have the
5636        form of a pointer to member as described in 5.3.1.
5637
5638        If more than one function is selected, any template functions in
5639        the set are eliminated if the set also contains a non-template
5640        function, and any given template function is eliminated if the
5641        set contains a second template function that is more specialized
5642        than the first according to the partial ordering rules 14.5.5.2.
5643        After such eliminations, if any, there shall remain exactly one
5644        selected function.  */
5645
5646   int is_ptrmem = 0;
5647   int is_reference = 0;
5648   /* We store the matches in a TREE_LIST rooted here.  The functions
5649      are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
5650      interoperability with most_specialized_instantiation.  */
5651   tree matches = NULL_TREE;
5652   tree fn;
5653
5654   /* By the time we get here, we should be seeing only real
5655      pointer-to-member types, not the internal POINTER_TYPE to
5656      METHOD_TYPE representation.  */
5657   gcc_assert (TREE_CODE (target_type) != POINTER_TYPE
5658               || TREE_CODE (TREE_TYPE (target_type)) != METHOD_TYPE);
5659
5660   gcc_assert (is_overloaded_fn (overload));
5661
5662   /* Check that the TARGET_TYPE is reasonable.  */
5663   if (TYPE_PTRFN_P (target_type))
5664     /* This is OK.  */;
5665   else if (TYPE_PTRMEMFUNC_P (target_type))
5666     /* This is OK, too.  */
5667     is_ptrmem = 1;
5668   else if (TREE_CODE (target_type) == FUNCTION_TYPE)
5669     {
5670       /* This is OK, too.  This comes from a conversion to reference
5671          type.  */
5672       target_type = build_reference_type (target_type);
5673       is_reference = 1;
5674     }
5675   else
5676     {
5677       if (flags & tf_error)
5678         error ("\
5679 cannot resolve overloaded function `%D' based on conversion to type `%T'",
5680                   DECL_NAME (OVL_FUNCTION (overload)), target_type);
5681       return error_mark_node;
5682     }
5683
5684   /* If we can find a non-template function that matches, we can just
5685      use it.  There's no point in generating template instantiations
5686      if we're just going to throw them out anyhow.  But, of course, we
5687      can only do this when we don't *need* a template function.  */
5688   if (!template_only)
5689     {
5690       tree fns;
5691
5692       for (fns = overload; fns; fns = OVL_NEXT (fns))
5693         {
5694           tree fn = OVL_CURRENT (fns);
5695           tree fntype;
5696
5697           if (TREE_CODE (fn) == TEMPLATE_DECL)
5698             /* We're not looking for templates just yet.  */
5699             continue;
5700
5701           if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
5702               != is_ptrmem)
5703             /* We're looking for a non-static member, and this isn't
5704                one, or vice versa.  */
5705             continue;
5706
5707           /* Ignore anticipated decls of undeclared builtins.  */
5708           if (DECL_ANTICIPATED (fn))
5709             continue;
5710
5711           /* See if there's a match.  */
5712           fntype = TREE_TYPE (fn);
5713           if (is_ptrmem)
5714             fntype = build_ptrmemfunc_type (build_pointer_type (fntype));
5715           else if (!is_reference)
5716             fntype = build_pointer_type (fntype);
5717
5718           if (can_convert_arg (target_type, fntype, fn))
5719             matches = tree_cons (fn, NULL_TREE, matches);
5720         }
5721     }
5722
5723   /* Now, if we've already got a match (or matches), there's no need
5724      to proceed to the template functions.  But, if we don't have a
5725      match we need to look at them, too.  */
5726   if (!matches)
5727     {
5728       tree target_fn_type;
5729       tree target_arg_types;
5730       tree target_ret_type;
5731       tree fns;
5732
5733       if (is_ptrmem)
5734         target_fn_type
5735           = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (target_type));
5736       else
5737         target_fn_type = TREE_TYPE (target_type);
5738       target_arg_types = TYPE_ARG_TYPES (target_fn_type);
5739       target_ret_type = TREE_TYPE (target_fn_type);
5740
5741       /* Never do unification on the 'this' parameter.  */
5742       if (TREE_CODE (target_fn_type) == METHOD_TYPE)
5743         target_arg_types = TREE_CHAIN (target_arg_types);
5744
5745       for (fns = overload; fns; fns = OVL_NEXT (fns))
5746         {
5747           tree fn = OVL_CURRENT (fns);
5748           tree instantiation;
5749           tree instantiation_type;
5750           tree targs;
5751
5752           if (TREE_CODE (fn) != TEMPLATE_DECL)
5753             /* We're only looking for templates.  */
5754             continue;
5755
5756           if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
5757               != is_ptrmem)
5758             /* We're not looking for a non-static member, and this is
5759                one, or vice versa.  */
5760             continue;
5761
5762           /* Try to do argument deduction.  */
5763           targs = make_tree_vec (DECL_NTPARMS (fn));
5764           if (fn_type_unification (fn, explicit_targs, targs,
5765                                    target_arg_types, target_ret_type,
5766                                    DEDUCE_EXACT, -1) != 0)
5767             /* Argument deduction failed.  */
5768             continue;
5769
5770           /* Instantiate the template.  */
5771           instantiation = instantiate_template (fn, targs, flags);
5772           if (instantiation == error_mark_node)
5773             /* Instantiation failed.  */
5774             continue;
5775
5776           /* See if there's a match.  */
5777           instantiation_type = TREE_TYPE (instantiation);
5778           if (is_ptrmem)
5779             instantiation_type =
5780               build_ptrmemfunc_type (build_pointer_type (instantiation_type));
5781           else if (!is_reference)
5782             instantiation_type = build_pointer_type (instantiation_type);
5783           if (can_convert_arg (target_type, instantiation_type, instantiation))
5784             matches = tree_cons (instantiation, fn, matches);
5785         }
5786
5787       /* Now, remove all but the most specialized of the matches.  */
5788       if (matches)
5789         {
5790           tree match = most_specialized_instantiation (matches);
5791
5792           if (match != error_mark_node)
5793             matches = tree_cons (match, NULL_TREE, NULL_TREE);
5794         }
5795     }
5796
5797   /* Now we should have exactly one function in MATCHES.  */
5798   if (matches == NULL_TREE)
5799     {
5800       /* There were *no* matches.  */
5801       if (flags & tf_error)
5802         {
5803           error ("no matches converting function `%D' to type `%#T'",
5804                     DECL_NAME (OVL_FUNCTION (overload)),
5805                     target_type);
5806
5807           /* print_candidates expects a chain with the functions in
5808              TREE_VALUE slots, so we cons one up here (we're losing anyway,
5809              so why be clever?).  */
5810           for (; overload; overload = OVL_NEXT (overload))
5811             matches = tree_cons (NULL_TREE, OVL_CURRENT (overload),
5812                                  matches);
5813
5814           print_candidates (matches);
5815         }
5816       return error_mark_node;
5817     }
5818   else if (TREE_CHAIN (matches))
5819     {
5820       /* There were too many matches.  */
5821
5822       if (flags & tf_error)
5823         {
5824           tree match;
5825
5826           error ("converting overloaded function `%D' to type `%#T' is ambiguous",
5827                     DECL_NAME (OVL_FUNCTION (overload)),
5828                     target_type);
5829
5830           /* Since print_candidates expects the functions in the
5831              TREE_VALUE slot, we flip them here.  */
5832           for (match = matches; match; match = TREE_CHAIN (match))
5833             TREE_VALUE (match) = TREE_PURPOSE (match);
5834
5835           print_candidates (matches);
5836         }
5837
5838       return error_mark_node;
5839     }
5840
5841   /* Good, exactly one match.  Now, convert it to the correct type.  */
5842   fn = TREE_PURPOSE (matches);
5843
5844   if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
5845       && !(flags & tf_ptrmem_ok) && !flag_ms_extensions)
5846     {
5847       static int explained;
5848
5849       if (!(flags & tf_error))
5850         return error_mark_node;
5851
5852       pedwarn ("assuming pointer to member `%D'", fn);
5853       if (!explained)
5854         {
5855           pedwarn ("(a pointer to member can only be formed with `&%E')", fn);
5856           explained = 1;
5857         }
5858     }
5859
5860   /* If we're doing overload resolution purely for the purpose of
5861      determining conversion sequences, we should not consider the
5862      function used.  If this conversion sequence is selected, the
5863      function will be marked as used at this point.  */
5864   if (!(flags & tf_conv))
5865     mark_used (fn);
5866
5867   if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type))
5868     return build_unary_op (ADDR_EXPR, fn, 0);
5869   else
5870     {
5871       /* The target must be a REFERENCE_TYPE.  Above, build_unary_op
5872          will mark the function as addressed, but here we must do it
5873          explicitly.  */
5874       cxx_mark_addressable (fn);
5875
5876       return fn;
5877     }
5878 }
5879
5880 /* This function will instantiate the type of the expression given in
5881    RHS to match the type of LHSTYPE.  If errors exist, then return
5882    error_mark_node. FLAGS is a bit mask.  If TF_ERROR is set, then
5883    we complain on errors.  If we are not complaining, never modify rhs,
5884    as overload resolution wants to try many possible instantiations, in
5885    the hope that at least one will work.
5886
5887    For non-recursive calls, LHSTYPE should be a function, pointer to
5888    function, or a pointer to member function.  */
5889
5890 tree
5891 instantiate_type (tree lhstype, tree rhs, tsubst_flags_t flags)
5892 {
5893   tsubst_flags_t flags_in = flags;
5894
5895   flags &= ~tf_ptrmem_ok;
5896
5897   if (TREE_CODE (lhstype) == UNKNOWN_TYPE)
5898     {
5899       if (flags & tf_error)
5900         error ("not enough type information");
5901       return error_mark_node;
5902     }
5903
5904   if (TREE_TYPE (rhs) != NULL_TREE && ! (type_unknown_p (rhs)))
5905     {
5906       if (same_type_p (lhstype, TREE_TYPE (rhs)))
5907         return rhs;
5908       if (flag_ms_extensions
5909           && TYPE_PTRMEMFUNC_P (lhstype)
5910           && !TYPE_PTRMEMFUNC_P (TREE_TYPE (rhs)))
5911         /* Microsoft allows `A::f' to be resolved to a
5912            pointer-to-member.  */
5913         ;
5914       else
5915         {
5916           if (flags & tf_error)
5917             error ("argument of type `%T' does not match `%T'",
5918                    TREE_TYPE (rhs), lhstype);
5919           return error_mark_node;
5920         }
5921     }
5922
5923   if (TREE_CODE (rhs) == BASELINK)
5924     rhs = BASELINK_FUNCTIONS (rhs);
5925
5926   /* We don't overwrite rhs if it is an overloaded function.
5927      Copying it would destroy the tree link.  */
5928   if (TREE_CODE (rhs) != OVERLOAD)
5929     rhs = copy_node (rhs);
5930
5931   /* This should really only be used when attempting to distinguish
5932      what sort of a pointer to function we have.  For now, any
5933      arithmetic operation which is not supported on pointers
5934      is rejected as an error.  */
5935
5936   switch (TREE_CODE (rhs))
5937     {
5938     case TYPE_EXPR:
5939     case CONVERT_EXPR:
5940     case SAVE_EXPR:
5941     case CONSTRUCTOR:
5942       gcc_unreachable ();
5943
5944     case INDIRECT_REF:
5945     case ARRAY_REF:
5946       {
5947         tree new_rhs;
5948
5949         new_rhs = instantiate_type (build_pointer_type (lhstype),
5950                                     TREE_OPERAND (rhs, 0), flags);
5951         if (new_rhs == error_mark_node)
5952           return error_mark_node;
5953
5954         TREE_TYPE (rhs) = lhstype;
5955         TREE_OPERAND (rhs, 0) = new_rhs;
5956         return rhs;
5957       }
5958
5959     case NOP_EXPR:
5960       rhs = copy_node (TREE_OPERAND (rhs, 0));
5961       TREE_TYPE (rhs) = unknown_type_node;
5962       return instantiate_type (lhstype, rhs, flags);
5963
5964     case COMPONENT_REF:
5965       {
5966         tree addr = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
5967
5968         if (addr != error_mark_node
5969             && TREE_SIDE_EFFECTS (TREE_OPERAND (rhs, 0)))
5970           /* Do not lose object's side effects.  */
5971           addr = build2 (COMPOUND_EXPR, TREE_TYPE (addr),
5972                          TREE_OPERAND (rhs, 0), addr);
5973         return addr;
5974       }
5975
5976     case OFFSET_REF:
5977       rhs = TREE_OPERAND (rhs, 1);
5978       if (BASELINK_P (rhs))
5979         return instantiate_type (lhstype, BASELINK_FUNCTIONS (rhs), flags_in);
5980
5981       /* This can happen if we are forming a pointer-to-member for a
5982          member template.  */
5983       gcc_assert (TREE_CODE (rhs) == TEMPLATE_ID_EXPR);
5984
5985       /* Fall through.  */
5986
5987     case TEMPLATE_ID_EXPR:
5988       {
5989         tree fns = TREE_OPERAND (rhs, 0);
5990         tree args = TREE_OPERAND (rhs, 1);
5991
5992         return
5993           resolve_address_of_overloaded_function (lhstype, fns, flags_in,
5994                                                   /*template_only=*/true,
5995                                                   args);
5996       }
5997
5998     case OVERLOAD:
5999     case FUNCTION_DECL:
6000       return
6001         resolve_address_of_overloaded_function (lhstype, rhs, flags_in,
6002                                                 /*template_only=*/false,
6003                                                 /*explicit_targs=*/NULL_TREE);
6004
6005     case TREE_LIST:
6006       /* Now we should have a baselink.  */
6007       gcc_assert (BASELINK_P (rhs));
6008
6009       return instantiate_type (lhstype, BASELINK_FUNCTIONS (rhs), flags);
6010
6011     case CALL_EXPR:
6012       /* This is too hard for now.  */
6013       gcc_unreachable ();
6014
6015     case PLUS_EXPR:
6016     case MINUS_EXPR:
6017     case COMPOUND_EXPR:
6018       TREE_OPERAND (rhs, 0)
6019         = instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
6020       if (TREE_OPERAND (rhs, 0) == error_mark_node)
6021         return error_mark_node;
6022       TREE_OPERAND (rhs, 1)
6023         = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
6024       if (TREE_OPERAND (rhs, 1) == error_mark_node)
6025         return error_mark_node;
6026
6027       TREE_TYPE (rhs) = lhstype;
6028       return rhs;
6029
6030     case MULT_EXPR:
6031     case TRUNC_DIV_EXPR:
6032     case FLOOR_DIV_EXPR:
6033     case CEIL_DIV_EXPR:
6034     case ROUND_DIV_EXPR:
6035     case RDIV_EXPR:
6036     case TRUNC_MOD_EXPR:
6037     case FLOOR_MOD_EXPR:
6038     case CEIL_MOD_EXPR:
6039     case ROUND_MOD_EXPR:
6040     case FIX_ROUND_EXPR:
6041     case FIX_FLOOR_EXPR:
6042     case FIX_CEIL_EXPR:
6043     case FIX_TRUNC_EXPR:
6044     case FLOAT_EXPR:
6045     case NEGATE_EXPR:
6046     case ABS_EXPR:
6047     case MAX_EXPR:
6048     case MIN_EXPR:
6049
6050     case BIT_AND_EXPR:
6051     case BIT_IOR_EXPR:
6052     case BIT_XOR_EXPR:
6053     case LSHIFT_EXPR:
6054     case RSHIFT_EXPR:
6055     case LROTATE_EXPR:
6056     case RROTATE_EXPR:
6057
6058     case PREINCREMENT_EXPR:
6059     case PREDECREMENT_EXPR:
6060     case POSTINCREMENT_EXPR:
6061     case POSTDECREMENT_EXPR:
6062       if (flags & tf_error)
6063         error ("invalid operation on uninstantiated type");
6064       return error_mark_node;
6065
6066     case TRUTH_AND_EXPR:
6067     case TRUTH_OR_EXPR:
6068     case TRUTH_XOR_EXPR:
6069     case LT_EXPR:
6070     case LE_EXPR:
6071     case GT_EXPR:
6072     case GE_EXPR:
6073     case EQ_EXPR:
6074     case NE_EXPR:
6075     case TRUTH_ANDIF_EXPR:
6076     case TRUTH_ORIF_EXPR:
6077     case TRUTH_NOT_EXPR:
6078       if (flags & tf_error)
6079         error ("not enough type information");
6080       return error_mark_node;
6081
6082     case COND_EXPR:
6083       if (type_unknown_p (TREE_OPERAND (rhs, 0)))
6084         {
6085           if (flags & tf_error)
6086             error ("not enough type information");
6087           return error_mark_node;
6088         }
6089       TREE_OPERAND (rhs, 1)
6090         = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
6091       if (TREE_OPERAND (rhs, 1) == error_mark_node)
6092         return error_mark_node;
6093       TREE_OPERAND (rhs, 2)
6094         = instantiate_type (lhstype, TREE_OPERAND (rhs, 2), flags);
6095       if (TREE_OPERAND (rhs, 2) == error_mark_node)
6096         return error_mark_node;
6097
6098       TREE_TYPE (rhs) = lhstype;
6099       return rhs;
6100
6101     case MODIFY_EXPR:
6102       TREE_OPERAND (rhs, 1)
6103         = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
6104       if (TREE_OPERAND (rhs, 1) == error_mark_node)
6105         return error_mark_node;
6106
6107       TREE_TYPE (rhs) = lhstype;
6108       return rhs;
6109
6110     case ADDR_EXPR:
6111     {
6112       if (PTRMEM_OK_P (rhs))
6113         flags |= tf_ptrmem_ok;
6114
6115       return instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
6116     }
6117
6118     case ERROR_MARK:
6119       return error_mark_node;
6120
6121     default:
6122       gcc_unreachable ();
6123     }
6124   return error_mark_node;
6125 }
6126 \f
6127 /* Return the name of the virtual function pointer field
6128    (as an IDENTIFIER_NODE) for the given TYPE.  Note that
6129    this may have to look back through base types to find the
6130    ultimate field name.  (For single inheritance, these could
6131    all be the same name.  Who knows for multiple inheritance).  */
6132
6133 static tree
6134 get_vfield_name (tree type)
6135 {
6136   tree binfo, base_binfo;
6137   char *buf;
6138
6139   for (binfo = TYPE_BINFO (type);
6140        BINFO_N_BASE_BINFOS (binfo);
6141        binfo = base_binfo)
6142     {
6143       base_binfo = BINFO_BASE_BINFO (binfo, 0);
6144
6145       if (BINFO_VIRTUAL_P (base_binfo)
6146           || !TYPE_CONTAINS_VPTR_P (BINFO_TYPE (base_binfo)))
6147         break;
6148     }
6149
6150   type = BINFO_TYPE (binfo);
6151   buf = alloca (sizeof (VFIELD_NAME_FORMAT) + TYPE_NAME_LENGTH (type) + 2);
6152   sprintf (buf, VFIELD_NAME_FORMAT,
6153            IDENTIFIER_POINTER (constructor_name (type)));
6154   return get_identifier (buf);
6155 }
6156
6157 void
6158 print_class_statistics (void)
6159 {
6160 #ifdef GATHER_STATISTICS
6161   fprintf (stderr, "convert_harshness = %d\n", n_convert_harshness);
6162   fprintf (stderr, "compute_conversion_costs = %d\n", n_compute_conversion_costs);
6163   if (n_vtables)
6164     {
6165       fprintf (stderr, "vtables = %d; vtable searches = %d\n",
6166                n_vtables, n_vtable_searches);
6167       fprintf (stderr, "vtable entries = %d; vtable elems = %d\n",
6168                n_vtable_entries, n_vtable_elems);
6169     }
6170 #endif
6171 }
6172
6173 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6174    according to [class]:
6175                                           The class-name is also inserted
6176    into  the scope of the class itself.  For purposes of access checking,
6177    the inserted class name is treated as if it were a public member name.  */
6178
6179 void
6180 build_self_reference (void)
6181 {
6182   tree name = constructor_name (current_class_type);
6183   tree value = build_lang_decl (TYPE_DECL, name, current_class_type);
6184   tree saved_cas;
6185
6186   DECL_NONLOCAL (value) = 1;
6187   DECL_CONTEXT (value) = current_class_type;
6188   DECL_ARTIFICIAL (value) = 1;
6189   SET_DECL_SELF_REFERENCE_P (value);
6190
6191   if (processing_template_decl)
6192     value = push_template_decl (value);
6193
6194   saved_cas = current_access_specifier;
6195   current_access_specifier = access_public_node;
6196   finish_member_declaration (value);
6197   current_access_specifier = saved_cas;
6198 }
6199
6200 /* Returns 1 if TYPE contains only padding bytes.  */
6201
6202 int
6203 is_empty_class (tree type)
6204 {
6205   if (type == error_mark_node)
6206     return 0;
6207
6208   if (! IS_AGGR_TYPE (type))
6209     return 0;
6210
6211   /* In G++ 3.2, whether or not a class was empty was determined by
6212      looking at its size.  */
6213   if (abi_version_at_least (2))
6214     return CLASSTYPE_EMPTY_P (type);
6215   else
6216     return integer_zerop (CLASSTYPE_SIZE (type));
6217 }
6218
6219 /* Returns true if TYPE contains an empty class.  */
6220
6221 static bool
6222 contains_empty_class_p (tree type)
6223 {
6224   if (is_empty_class (type))
6225     return true;
6226   if (CLASS_TYPE_P (type))
6227     {
6228       tree field;
6229       tree binfo;
6230       tree base_binfo;
6231       int i;
6232
6233       for (binfo = TYPE_BINFO (type), i = 0;
6234            BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
6235         if (contains_empty_class_p (BINFO_TYPE (base_binfo)))
6236           return true;
6237       for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
6238         if (TREE_CODE (field) == FIELD_DECL
6239             && !DECL_ARTIFICIAL (field)
6240             && is_empty_class (TREE_TYPE (field)))
6241           return true;
6242     }
6243   else if (TREE_CODE (type) == ARRAY_TYPE)
6244     return contains_empty_class_p (TREE_TYPE (type));
6245   return false;
6246 }
6247
6248 /* Find the enclosing class of the given NODE.  NODE can be a *_DECL or
6249    a *_TYPE node.  NODE can also be a local class.  */
6250
6251 tree
6252 get_enclosing_class (tree type)
6253 {
6254   tree node = type;
6255
6256   while (node && TREE_CODE (node) != NAMESPACE_DECL)
6257     {
6258       switch (TREE_CODE_CLASS (TREE_CODE (node)))
6259         {
6260         case tcc_declaration:
6261           node = DECL_CONTEXT (node);
6262           break;
6263
6264         case tcc_type:
6265           if (node != type)
6266             return node;
6267           node = TYPE_CONTEXT (node);
6268           break;
6269
6270         default:
6271           gcc_unreachable ();
6272         }
6273     }
6274   return NULL_TREE;
6275 }
6276
6277 /* Note that NAME was looked up while the current class was being
6278    defined and that the result of that lookup was DECL.  */
6279
6280 void
6281 maybe_note_name_used_in_class (tree name, tree decl)
6282 {
6283   splay_tree names_used;
6284
6285   /* If we're not defining a class, there's nothing to do.  */
6286   if (!(innermost_scope_kind() == sk_class
6287         && TYPE_BEING_DEFINED (current_class_type)))
6288     return;
6289
6290   /* If there's already a binding for this NAME, then we don't have
6291      anything to worry about.  */
6292   if (lookup_member (current_class_type, name,
6293                      /*protect=*/0, /*want_type=*/false))
6294     return;
6295
6296   if (!current_class_stack[current_class_depth - 1].names_used)
6297     current_class_stack[current_class_depth - 1].names_used
6298       = splay_tree_new (splay_tree_compare_pointers, 0, 0);
6299   names_used = current_class_stack[current_class_depth - 1].names_used;
6300
6301   splay_tree_insert (names_used,
6302                      (splay_tree_key) name,
6303                      (splay_tree_value) decl);
6304 }
6305
6306 /* Note that NAME was declared (as DECL) in the current class.  Check
6307    to see that the declaration is valid.  */
6308
6309 void
6310 note_name_declared_in_class (tree name, tree decl)
6311 {
6312   splay_tree names_used;
6313   splay_tree_node n;
6314
6315   /* Look to see if we ever used this name.  */
6316   names_used
6317     = current_class_stack[current_class_depth - 1].names_used;
6318   if (!names_used)
6319     return;
6320
6321   n = splay_tree_lookup (names_used, (splay_tree_key) name);
6322   if (n)
6323     {
6324       /* [basic.scope.class]
6325
6326          A name N used in a class S shall refer to the same declaration
6327          in its context and when re-evaluated in the completed scope of
6328          S.  */
6329       error ("declaration of `%#D'", decl);
6330       cp_error_at ("changes meaning of `%D' from `%+#D'",
6331                    DECL_NAME (OVL_CURRENT (decl)),
6332                    (tree) n->value);
6333     }
6334 }
6335
6336 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6337    Secondary vtables are merged with primary vtables; this function
6338    will return the VAR_DECL for the primary vtable.  */
6339
6340 tree
6341 get_vtbl_decl_for_binfo (tree binfo)
6342 {
6343   tree decl;
6344
6345   decl = BINFO_VTABLE (binfo);
6346   if (decl && TREE_CODE (decl) == PLUS_EXPR)
6347     {
6348       gcc_assert (TREE_CODE (TREE_OPERAND (decl, 0)) == ADDR_EXPR);
6349       decl = TREE_OPERAND (TREE_OPERAND (decl, 0), 0);
6350     }
6351   if (decl)
6352     gcc_assert (TREE_CODE (decl) == VAR_DECL);
6353   return decl;
6354 }
6355
6356
6357 /* Returns the binfo for the primary base of BINFO.  If the resulting
6358    BINFO is a virtual base, and it is inherited elsewhere in the
6359    hierarchy, then the returned binfo might not be the primary base of
6360    BINFO in the complete object.  Check BINFO_PRIMARY_P or
6361    BINFO_LOST_PRIMARY_P to be sure.  */
6362
6363 tree
6364 get_primary_binfo (tree binfo)
6365 {
6366   tree primary_base;
6367   tree result;
6368
6369   primary_base = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (binfo));
6370   if (!primary_base)
6371     return NULL_TREE;
6372
6373   result = copied_binfo (primary_base, binfo);
6374   return result;
6375 }
6376
6377 /* If INDENTED_P is zero, indent to INDENT. Return nonzero.  */
6378
6379 static int
6380 maybe_indent_hierarchy (FILE * stream, int indent, int indented_p)
6381 {
6382   if (!indented_p)
6383     fprintf (stream, "%*s", indent, "");
6384   return 1;
6385 }
6386
6387 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
6388    INDENT should be zero when called from the top level; it is
6389    incremented recursively.  IGO indicates the next expected BINFO in
6390    inheritance graph ordering.  */
6391
6392 static tree
6393 dump_class_hierarchy_r (FILE *stream,
6394                         int flags,
6395                         tree binfo,
6396                         tree igo,
6397                         int indent)
6398 {
6399   int indented = 0;
6400   tree base_binfo;
6401   int i;
6402
6403   indented = maybe_indent_hierarchy (stream, indent, 0);
6404   fprintf (stream, "%s (0x%lx) ",
6405            type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER),
6406            (unsigned long) binfo);
6407   if (binfo != igo)
6408     {
6409       fprintf (stream, "alternative-path\n");
6410       return igo;
6411     }
6412   igo = TREE_CHAIN (binfo);
6413
6414   fprintf (stream, HOST_WIDE_INT_PRINT_DEC,
6415            tree_low_cst (BINFO_OFFSET (binfo), 0));
6416   if (is_empty_class (BINFO_TYPE (binfo)))
6417     fprintf (stream, " empty");
6418   else if (CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (binfo)))
6419     fprintf (stream, " nearly-empty");
6420   if (BINFO_VIRTUAL_P (binfo))
6421     fprintf (stream, " virtual");
6422   fprintf (stream, "\n");
6423
6424   indented = 0;
6425   if (BINFO_PRIMARY_P (binfo))
6426     {
6427       indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6428       fprintf (stream, " primary-for %s (0x%lx)",
6429                type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)),
6430                                TFF_PLAIN_IDENTIFIER),
6431                (unsigned long)BINFO_INHERITANCE_CHAIN (binfo));
6432     }
6433   if (BINFO_LOST_PRIMARY_P (binfo))
6434     {
6435       indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6436       fprintf (stream, " lost-primary");
6437     }
6438   if (indented)
6439     fprintf (stream, "\n");
6440
6441   if (!(flags & TDF_SLIM))
6442     {
6443       int indented = 0;
6444
6445       if (BINFO_SUBVTT_INDEX (binfo))
6446         {
6447           indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6448           fprintf (stream, " subvttidx=%s",
6449                    expr_as_string (BINFO_SUBVTT_INDEX (binfo),
6450                                    TFF_PLAIN_IDENTIFIER));
6451         }
6452       if (BINFO_VPTR_INDEX (binfo))
6453         {
6454           indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6455           fprintf (stream, " vptridx=%s",
6456                    expr_as_string (BINFO_VPTR_INDEX (binfo),
6457                                    TFF_PLAIN_IDENTIFIER));
6458         }
6459       if (BINFO_VPTR_FIELD (binfo))
6460         {
6461           indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6462           fprintf (stream, " vbaseoffset=%s",
6463                    expr_as_string (BINFO_VPTR_FIELD (binfo),
6464                                    TFF_PLAIN_IDENTIFIER));
6465         }
6466       if (BINFO_VTABLE (binfo))
6467         {
6468           indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6469           fprintf (stream, " vptr=%s",
6470                    expr_as_string (BINFO_VTABLE (binfo),
6471                                    TFF_PLAIN_IDENTIFIER));
6472         }
6473
6474       if (indented)
6475         fprintf (stream, "\n");
6476     }
6477
6478   for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
6479     igo = dump_class_hierarchy_r (stream, flags, base_binfo, igo, indent + 2);
6480
6481   return igo;
6482 }
6483
6484 /* Dump the BINFO hierarchy for T.  */
6485
6486 static void
6487 dump_class_hierarchy_1 (FILE *stream, int flags, tree t)
6488 {
6489   fprintf (stream, "Class %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6490   fprintf (stream, "   size=%lu align=%lu\n",
6491            (unsigned long)(tree_low_cst (TYPE_SIZE (t), 0) / BITS_PER_UNIT),
6492            (unsigned long)(TYPE_ALIGN (t) / BITS_PER_UNIT));
6493   fprintf (stream, "   base size=%lu base align=%lu\n",
6494            (unsigned long)(tree_low_cst (TYPE_SIZE (CLASSTYPE_AS_BASE (t)), 0)
6495                            / BITS_PER_UNIT),
6496            (unsigned long)(TYPE_ALIGN (CLASSTYPE_AS_BASE (t))
6497                            / BITS_PER_UNIT));
6498   dump_class_hierarchy_r (stream, flags, TYPE_BINFO (t), TYPE_BINFO (t), 0);
6499   fprintf (stream, "\n");
6500 }
6501
6502 /* Debug interface to hierarchy dumping.  */
6503
6504 extern void
6505 debug_class (tree t)
6506 {
6507   dump_class_hierarchy_1 (stderr, TDF_SLIM, t);
6508 }
6509
6510 static void
6511 dump_class_hierarchy (tree t)
6512 {
6513   int flags;
6514   FILE *stream = dump_begin (TDI_class, &flags);
6515
6516   if (stream)
6517     {
6518       dump_class_hierarchy_1 (stream, flags, t);
6519       dump_end (TDI_class, stream);
6520     }
6521 }
6522
6523 static void
6524 dump_array (FILE * stream, tree decl)
6525 {
6526   tree inits;
6527   int ix;
6528   HOST_WIDE_INT elt;
6529   tree size = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (decl)));
6530
6531   elt = (tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl))), 0)
6532          / BITS_PER_UNIT);
6533   fprintf (stream, "%s:", decl_as_string (decl, TFF_PLAIN_IDENTIFIER));
6534   fprintf (stream, " %s entries",
6535            expr_as_string (size_binop (PLUS_EXPR, size, size_one_node),
6536                            TFF_PLAIN_IDENTIFIER));
6537   fprintf (stream, "\n");
6538
6539   for (ix = 0, inits = CONSTRUCTOR_ELTS (DECL_INITIAL (decl));
6540        inits; ix++, inits = TREE_CHAIN (inits))
6541     fprintf (stream, "%-4ld  %s\n", (long)(ix * elt),
6542              expr_as_string (TREE_VALUE (inits), TFF_PLAIN_IDENTIFIER));
6543 }
6544
6545 static void
6546 dump_vtable (tree t, tree binfo, tree vtable)
6547 {
6548   int flags;
6549   FILE *stream = dump_begin (TDI_class, &flags);
6550
6551   if (!stream)
6552     return;
6553
6554   if (!(flags & TDF_SLIM))
6555     {
6556       int ctor_vtbl_p = TYPE_BINFO (t) != binfo;
6557
6558       fprintf (stream, "%s for %s",
6559                ctor_vtbl_p ? "Construction vtable" : "Vtable",
6560                type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER));
6561       if (ctor_vtbl_p)
6562         {
6563           if (!BINFO_VIRTUAL_P (binfo))
6564             fprintf (stream, " (0x%lx instance)", (unsigned long)binfo);
6565           fprintf (stream, " in %s", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6566         }
6567       fprintf (stream, "\n");
6568       dump_array (stream, vtable);
6569       fprintf (stream, "\n");
6570     }
6571
6572   dump_end (TDI_class, stream);
6573 }
6574
6575 static void
6576 dump_vtt (tree t, tree vtt)
6577 {
6578   int flags;
6579   FILE *stream = dump_begin (TDI_class, &flags);
6580
6581   if (!stream)
6582     return;
6583
6584   if (!(flags & TDF_SLIM))
6585     {
6586       fprintf (stream, "VTT for %s\n",
6587                type_as_string (t, TFF_PLAIN_IDENTIFIER));
6588       dump_array (stream, vtt);
6589       fprintf (stream, "\n");
6590     }
6591
6592   dump_end (TDI_class, stream);
6593 }
6594
6595 /* Dump a function or thunk and its thunkees.  */
6596
6597 static void
6598 dump_thunk (FILE *stream, int indent, tree thunk)
6599 {
6600   static const char spaces[] = "        ";
6601   tree name = DECL_NAME (thunk);
6602   tree thunks;
6603
6604   fprintf (stream, "%.*s%p %s %s", indent, spaces,
6605            (void *)thunk,
6606            !DECL_THUNK_P (thunk) ? "function"
6607            : DECL_THIS_THUNK_P (thunk) ? "this-thunk" : "covariant-thunk",
6608            name ? IDENTIFIER_POINTER (name) : "<unset>");
6609   if (DECL_THUNK_P (thunk))
6610     {
6611       HOST_WIDE_INT fixed_adjust = THUNK_FIXED_OFFSET (thunk);
6612       tree virtual_adjust = THUNK_VIRTUAL_OFFSET (thunk);
6613
6614       fprintf (stream, " fixed=" HOST_WIDE_INT_PRINT_DEC, fixed_adjust);
6615       if (!virtual_adjust)
6616         /*NOP*/;
6617       else if (DECL_THIS_THUNK_P (thunk))
6618         fprintf (stream, " vcall="  HOST_WIDE_INT_PRINT_DEC,
6619                  tree_low_cst (virtual_adjust, 0));
6620       else
6621         fprintf (stream, " vbase=" HOST_WIDE_INT_PRINT_DEC "(%s)",
6622                  tree_low_cst (BINFO_VPTR_FIELD (virtual_adjust), 0),
6623                  type_as_string (BINFO_TYPE (virtual_adjust), TFF_SCOPE));
6624       if (THUNK_ALIAS (thunk))
6625         fprintf (stream, " alias to %p", (void *)THUNK_ALIAS (thunk));
6626     }
6627   fprintf (stream, "\n");
6628   for (thunks = DECL_THUNKS (thunk); thunks; thunks = TREE_CHAIN (thunks))
6629     dump_thunk (stream, indent + 2, thunks);
6630 }
6631
6632 /* Dump the thunks for FN.  */
6633
6634 extern void
6635 debug_thunks (tree fn)
6636 {
6637   dump_thunk (stderr, 0, fn);
6638 }
6639
6640 /* Virtual function table initialization.  */
6641
6642 /* Create all the necessary vtables for T and its base classes.  */
6643
6644 static void
6645 finish_vtbls (tree t)
6646 {
6647   tree list;
6648   tree vbase;
6649
6650   /* We lay out the primary and secondary vtables in one contiguous
6651      vtable.  The primary vtable is first, followed by the non-virtual
6652      secondary vtables in inheritance graph order.  */
6653   list = build_tree_list (BINFO_VTABLE (TYPE_BINFO (t)), NULL_TREE);
6654   accumulate_vtbl_inits (TYPE_BINFO (t), TYPE_BINFO (t),
6655                          TYPE_BINFO (t), t, list);
6656
6657   /* Then come the virtual bases, also in inheritance graph order.  */
6658   for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
6659     {
6660       if (!BINFO_VIRTUAL_P (vbase))
6661         continue;
6662       accumulate_vtbl_inits (vbase, vbase, TYPE_BINFO (t), t, list);
6663     }
6664
6665   if (BINFO_VTABLE (TYPE_BINFO (t)))
6666     initialize_vtable (TYPE_BINFO (t), TREE_VALUE (list));
6667 }
6668
6669 /* Initialize the vtable for BINFO with the INITS.  */
6670
6671 static void
6672 initialize_vtable (tree binfo, tree inits)
6673 {
6674   tree decl;
6675
6676   layout_vtable_decl (binfo, list_length (inits));
6677   decl = get_vtbl_decl_for_binfo (binfo);
6678   initialize_artificial_var (decl, inits);
6679   dump_vtable (BINFO_TYPE (binfo), binfo, decl);
6680 }
6681
6682 /* Build the VTT (virtual table table) for T.
6683    A class requires a VTT if it has virtual bases.
6684
6685    This holds
6686    1 - primary virtual pointer for complete object T
6687    2 - secondary VTTs for each direct non-virtual base of T which requires a
6688        VTT
6689    3 - secondary virtual pointers for each direct or indirect base of T which
6690        has virtual bases or is reachable via a virtual path from T.
6691    4 - secondary VTTs for each direct or indirect virtual base of T.
6692
6693    Secondary VTTs look like complete object VTTs without part 4.  */
6694
6695 static void
6696 build_vtt (tree t)
6697 {
6698   tree inits;
6699   tree type;
6700   tree vtt;
6701   tree index;
6702
6703   /* Build up the initializers for the VTT.  */
6704   inits = NULL_TREE;
6705   index = size_zero_node;
6706   build_vtt_inits (TYPE_BINFO (t), t, &inits, &index);
6707
6708   /* If we didn't need a VTT, we're done.  */
6709   if (!inits)
6710     return;
6711
6712   /* Figure out the type of the VTT.  */
6713   type = build_index_type (size_int (list_length (inits) - 1));
6714   type = build_cplus_array_type (const_ptr_type_node, type);
6715
6716   /* Now, build the VTT object itself.  */
6717   vtt = build_vtable (t, get_vtt_name (t), type);
6718   initialize_artificial_var (vtt, inits);
6719   /* Add the VTT to the vtables list.  */
6720   TREE_CHAIN (vtt) = TREE_CHAIN (CLASSTYPE_VTABLES (t));
6721   TREE_CHAIN (CLASSTYPE_VTABLES (t)) = vtt;
6722
6723   dump_vtt (t, vtt);
6724 }
6725
6726 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
6727    PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
6728    and CHAIN the vtable pointer for this binfo after construction is
6729    complete.  VALUE can also be another BINFO, in which case we recurse.  */
6730
6731 static tree
6732 binfo_ctor_vtable (tree binfo)
6733 {
6734   tree vt;
6735
6736   while (1)
6737     {
6738       vt = BINFO_VTABLE (binfo);
6739       if (TREE_CODE (vt) == TREE_LIST)
6740         vt = TREE_VALUE (vt);
6741       if (TREE_CODE (vt) == TREE_BINFO)
6742         binfo = vt;
6743       else
6744         break;
6745     }
6746
6747   return vt;
6748 }
6749
6750 /* Recursively build the VTT-initializer for BINFO (which is in the
6751    hierarchy dominated by T).  INITS points to the end of the initializer
6752    list to date.  INDEX is the VTT index where the next element will be
6753    replaced.  Iff BINFO is the binfo for T, this is the top level VTT (i.e.
6754    not a subvtt for some base of T).  When that is so, we emit the sub-VTTs
6755    for virtual bases of T. When it is not so, we build the constructor
6756    vtables for the BINFO-in-T variant.  */
6757
6758 static tree *
6759 build_vtt_inits (tree binfo, tree t, tree* inits, tree* index)
6760 {
6761   int i;
6762   tree b;
6763   tree init;
6764   tree secondary_vptrs;
6765   int top_level_p = same_type_p (TREE_TYPE (binfo), t);
6766
6767   /* We only need VTTs for subobjects with virtual bases.  */
6768   if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
6769     return inits;
6770
6771   /* We need to use a construction vtable if this is not the primary
6772      VTT.  */
6773   if (!top_level_p)
6774     {
6775       build_ctor_vtbl_group (binfo, t);
6776
6777       /* Record the offset in the VTT where this sub-VTT can be found.  */
6778       BINFO_SUBVTT_INDEX (binfo) = *index;
6779     }
6780
6781   /* Add the address of the primary vtable for the complete object.  */
6782   init = binfo_ctor_vtable (binfo);
6783   *inits = build_tree_list (NULL_TREE, init);
6784   inits = &TREE_CHAIN (*inits);
6785   if (top_level_p)
6786     {
6787       gcc_assert (!BINFO_VPTR_INDEX (binfo));
6788       BINFO_VPTR_INDEX (binfo) = *index;
6789     }
6790   *index = size_binop (PLUS_EXPR, *index, TYPE_SIZE_UNIT (ptr_type_node));
6791
6792   /* Recursively add the secondary VTTs for non-virtual bases.  */
6793   for (i = 0; BINFO_BASE_ITERATE (binfo, i, b); ++i)
6794     if (!BINFO_VIRTUAL_P (b))
6795       inits = build_vtt_inits (BINFO_BASE_BINFO (binfo, i), t, inits, index);
6796
6797   /* Add secondary virtual pointers for all subobjects of BINFO with
6798      either virtual bases or reachable along a virtual path, except
6799      subobjects that are non-virtual primary bases.  */
6800   secondary_vptrs = tree_cons (t, NULL_TREE, BINFO_TYPE (binfo));
6801   TREE_TYPE (secondary_vptrs) = *index;
6802   VTT_TOP_LEVEL_P (secondary_vptrs) = top_level_p;
6803   VTT_MARKED_BINFO_P (secondary_vptrs) = 0;
6804
6805   dfs_walk_real (binfo,
6806                  dfs_build_secondary_vptr_vtt_inits,
6807                  NULL,
6808                  dfs_ctor_vtable_bases_queue_p,
6809                  secondary_vptrs);
6810   VTT_MARKED_BINFO_P (secondary_vptrs) = 1;
6811   dfs_walk (binfo, dfs_unmark, dfs_ctor_vtable_bases_queue_p,
6812             secondary_vptrs);
6813
6814   *index = TREE_TYPE (secondary_vptrs);
6815
6816   /* The secondary vptrs come back in reverse order.  After we reverse
6817      them, and add the INITS, the last init will be the first element
6818      of the chain.  */
6819   secondary_vptrs = TREE_VALUE (secondary_vptrs);
6820   if (secondary_vptrs)
6821     {
6822       *inits = nreverse (secondary_vptrs);
6823       inits = &TREE_CHAIN (secondary_vptrs);
6824       gcc_assert (*inits == NULL_TREE);
6825     }
6826
6827   /* Add the secondary VTTs for virtual bases.  */
6828   if (top_level_p)
6829     for (b = TYPE_BINFO (BINFO_TYPE (binfo)); b; b = TREE_CHAIN (b))
6830       {
6831         if (!BINFO_VIRTUAL_P (b))
6832           continue;
6833
6834         inits = build_vtt_inits (b, t, inits, index);
6835       }
6836
6837   if (!top_level_p)
6838     {
6839       tree data = tree_cons (t, binfo, NULL_TREE);
6840       VTT_TOP_LEVEL_P (data) = 0;
6841       VTT_MARKED_BINFO_P (data) = 0;
6842
6843       dfs_walk (binfo, dfs_fixup_binfo_vtbls,
6844                 dfs_ctor_vtable_bases_queue_p,
6845                 data);
6846     }
6847
6848   return inits;
6849 }
6850
6851 /* Called from build_vtt_inits via dfs_walk.  BINFO is the binfo for the base
6852    in most derived. DATA is a TREE_LIST who's TREE_CHAIN is the type of the
6853    base being constructed whilst this secondary vptr is live.  The
6854    TREE_TOP_LEVEL flag indicates that this is the primary VTT.  */
6855
6856 static tree
6857 dfs_build_secondary_vptr_vtt_inits (tree binfo, void *data)
6858 {
6859   tree l;
6860   tree t;
6861   tree init;
6862   tree index;
6863   int top_level_p;
6864
6865   l = (tree) data;
6866   t = TREE_CHAIN (l);
6867   top_level_p = VTT_TOP_LEVEL_P (l);
6868
6869   BINFO_MARKED (binfo) = 1;
6870
6871   /* We don't care about bases that don't have vtables.  */
6872   if (!TYPE_VFIELD (BINFO_TYPE (binfo)))
6873     return NULL_TREE;
6874
6875   /* We're only interested in proper subobjects of T.  */
6876   if (same_type_p (BINFO_TYPE (binfo), t))
6877     return NULL_TREE;
6878
6879   /* We're not interested in non-virtual primary bases.  */
6880   if (!BINFO_VIRTUAL_P (binfo) && BINFO_PRIMARY_P (binfo))
6881     return NULL_TREE;
6882
6883   /* If BINFO has virtual bases or is reachable via a virtual path
6884      from T, it'll have a secondary vptr.  */
6885   if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
6886       && !binfo_via_virtual (binfo, t))
6887     return NULL_TREE;
6888
6889   /* Record the index where this secondary vptr can be found.  */
6890   index = TREE_TYPE (l);
6891   if (top_level_p)
6892     {
6893       gcc_assert (!BINFO_VPTR_INDEX (binfo));
6894       BINFO_VPTR_INDEX (binfo) = index;
6895     }
6896   TREE_TYPE (l) = size_binop (PLUS_EXPR, index,
6897                               TYPE_SIZE_UNIT (ptr_type_node));
6898
6899   /* Add the initializer for the secondary vptr itself.  */
6900   if (top_level_p && BINFO_VIRTUAL_P (binfo))
6901     {
6902       /* It's a primary virtual base, and this is not the construction
6903          vtable. Find the base this is primary of in the inheritance graph,
6904          and use that base's vtable now.  */
6905       while (BINFO_PRIMARY_P (binfo))
6906         binfo = BINFO_INHERITANCE_CHAIN (binfo);
6907     }
6908   init = binfo_ctor_vtable (binfo);
6909   TREE_VALUE (l) = tree_cons (NULL_TREE, init, TREE_VALUE (l));
6910
6911   return NULL_TREE;
6912 }
6913
6914 /* dfs_walk_real predicate for building vtables. DATA is a TREE_LIST,
6915    VTT_MARKED_BINFO_P indicates whether marked or unmarked bases
6916    should be walked.  TREE_PURPOSE is the TREE_TYPE that dominates the
6917    hierarchy.  */
6918
6919 static tree
6920 dfs_ctor_vtable_bases_queue_p (tree derived, int ix,
6921                                void* data)
6922 {
6923   tree binfo = BINFO_BASE_BINFO (derived, ix);
6924
6925   if (!BINFO_MARKED (binfo) == VTT_MARKED_BINFO_P ((tree) data))
6926     return NULL_TREE;
6927   return binfo;
6928 }
6929
6930 /* Called from build_vtt_inits via dfs_walk. After building constructor
6931    vtables and generating the sub-vtt from them, we need to restore the
6932    BINFO_VTABLES that were scribbled on.  DATA is a TREE_LIST whose
6933    TREE_VALUE is the TREE_TYPE of the base whose sub vtt was generated.  */
6934
6935 static tree
6936 dfs_fixup_binfo_vtbls (tree binfo, void* data)
6937 {
6938   BINFO_MARKED (binfo) = 0;
6939
6940   /* We don't care about bases that don't have vtables.  */
6941   if (!TYPE_VFIELD (BINFO_TYPE (binfo)))
6942     return NULL_TREE;
6943
6944   /* If we scribbled the construction vtable vptr into BINFO, clear it
6945      out now.  */
6946   if (BINFO_VTABLE (binfo)
6947       && TREE_CODE (BINFO_VTABLE (binfo)) == TREE_LIST
6948       && (TREE_PURPOSE (BINFO_VTABLE (binfo))
6949           == TREE_VALUE ((tree) data)))
6950     BINFO_VTABLE (binfo) = TREE_CHAIN (BINFO_VTABLE (binfo));
6951
6952   return NULL_TREE;
6953 }
6954
6955 /* Build the construction vtable group for BINFO which is in the
6956    hierarchy dominated by T.  */
6957
6958 static void
6959 build_ctor_vtbl_group (tree binfo, tree t)
6960 {
6961   tree list;
6962   tree type;
6963   tree vtbl;
6964   tree inits;
6965   tree id;
6966   tree vbase;
6967
6968   /* See if we've already created this construction vtable group.  */
6969   id = mangle_ctor_vtbl_for_type (t, binfo);
6970   if (IDENTIFIER_GLOBAL_VALUE (id))
6971     return;
6972
6973   gcc_assert (!same_type_p (BINFO_TYPE (binfo), t));
6974   /* Build a version of VTBL (with the wrong type) for use in
6975      constructing the addresses of secondary vtables in the
6976      construction vtable group.  */
6977   vtbl = build_vtable (t, id, ptr_type_node);
6978   DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1;
6979   list = build_tree_list (vtbl, NULL_TREE);
6980   accumulate_vtbl_inits (binfo, TYPE_BINFO (TREE_TYPE (binfo)),
6981                          binfo, t, list);
6982
6983   /* Add the vtables for each of our virtual bases using the vbase in T
6984      binfo.  */
6985   for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
6986        vbase;
6987        vbase = TREE_CHAIN (vbase))
6988     {
6989       tree b;
6990
6991       if (!BINFO_VIRTUAL_P (vbase))
6992         continue;
6993       b = copied_binfo (vbase, binfo);
6994
6995       accumulate_vtbl_inits (b, vbase, binfo, t, list);
6996     }
6997   inits = TREE_VALUE (list);
6998
6999   /* Figure out the type of the construction vtable.  */
7000   type = build_index_type (size_int (list_length (inits) - 1));
7001   type = build_cplus_array_type (vtable_entry_type, type);
7002   TREE_TYPE (vtbl) = type;
7003
7004   /* Initialize the construction vtable.  */
7005   CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl);
7006   initialize_artificial_var (vtbl, inits);
7007   dump_vtable (t, binfo, vtbl);
7008 }
7009
7010 /* Add the vtbl initializers for BINFO (and its bases other than
7011    non-virtual primaries) to the list of INITS.  BINFO is in the
7012    hierarchy dominated by T.  RTTI_BINFO is the binfo within T of
7013    the constructor the vtbl inits should be accumulated for. (If this
7014    is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
7015    ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
7016    BINFO is the active base equivalent of ORIG_BINFO in the inheritance
7017    graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
7018    but are not necessarily the same in terms of layout.  */
7019
7020 static void
7021 accumulate_vtbl_inits (tree binfo,
7022                        tree orig_binfo,
7023                        tree rtti_binfo,
7024                        tree t,
7025                        tree inits)
7026 {
7027   int i;
7028   tree base_binfo;
7029   int ctor_vtbl_p = !same_type_p (BINFO_TYPE (rtti_binfo), t);
7030
7031   gcc_assert (same_type_p (BINFO_TYPE (binfo), BINFO_TYPE (orig_binfo)));
7032
7033   /* If it doesn't have a vptr, we don't do anything.  */
7034   if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
7035     return;
7036
7037   /* If we're building a construction vtable, we're not interested in
7038      subobjects that don't require construction vtables.  */
7039   if (ctor_vtbl_p
7040       && !CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
7041       && !binfo_via_virtual (orig_binfo, BINFO_TYPE (rtti_binfo)))
7042     return;
7043
7044   /* Build the initializers for the BINFO-in-T vtable.  */
7045   TREE_VALUE (inits)
7046     = chainon (TREE_VALUE (inits),
7047                dfs_accumulate_vtbl_inits (binfo, orig_binfo,
7048                                           rtti_binfo, t, inits));
7049
7050   /* Walk the BINFO and its bases.  We walk in preorder so that as we
7051      initialize each vtable we can figure out at what offset the
7052      secondary vtable lies from the primary vtable.  We can't use
7053      dfs_walk here because we need to iterate through bases of BINFO
7054      and RTTI_BINFO simultaneously.  */
7055   for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7056     {
7057       /* Skip virtual bases.  */
7058       if (BINFO_VIRTUAL_P (base_binfo))
7059         continue;
7060       accumulate_vtbl_inits (base_binfo,
7061                              BINFO_BASE_BINFO (orig_binfo, i),
7062                              rtti_binfo, t,
7063                              inits);
7064     }
7065 }
7066
7067 /* Called from accumulate_vtbl_inits.  Returns the initializers for
7068    the BINFO vtable.  */
7069
7070 static tree
7071 dfs_accumulate_vtbl_inits (tree binfo,
7072                            tree orig_binfo,
7073                            tree rtti_binfo,
7074                            tree t,
7075                            tree l)
7076 {
7077   tree inits = NULL_TREE;
7078   tree vtbl = NULL_TREE;
7079   int ctor_vtbl_p = !same_type_p (BINFO_TYPE (rtti_binfo), t);
7080
7081   if (ctor_vtbl_p
7082       && BINFO_VIRTUAL_P (orig_binfo) && BINFO_PRIMARY_P (orig_binfo))
7083     {
7084       /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7085          primary virtual base.  If it is not the same primary in
7086          the hierarchy of T, we'll need to generate a ctor vtable
7087          for it, to place at its location in T.  If it is the same
7088          primary, we still need a VTT entry for the vtable, but it
7089          should point to the ctor vtable for the base it is a
7090          primary for within the sub-hierarchy of RTTI_BINFO.
7091
7092          There are three possible cases:
7093
7094          1) We are in the same place.
7095          2) We are a primary base within a lost primary virtual base of
7096          RTTI_BINFO.
7097          3) We are primary to something not a base of RTTI_BINFO.  */
7098
7099       tree b;
7100       tree last = NULL_TREE;
7101
7102       /* First, look through the bases we are primary to for RTTI_BINFO
7103          or a virtual base.  */
7104       b = binfo;
7105       while (BINFO_PRIMARY_P (b))
7106         {
7107           b = BINFO_INHERITANCE_CHAIN (b);
7108           last = b;
7109           if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7110             goto found;
7111         }
7112       /* If we run out of primary links, keep looking down our
7113          inheritance chain; we might be an indirect primary.  */
7114       for (b = last; b; b = BINFO_INHERITANCE_CHAIN (b))
7115         if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7116           break;
7117     found:
7118
7119       /* If we found RTTI_BINFO, this is case 1.  If we found a virtual
7120          base B and it is a base of RTTI_BINFO, this is case 2.  In
7121          either case, we share our vtable with LAST, i.e. the
7122          derived-most base within B of which we are a primary.  */
7123       if (b == rtti_binfo
7124           || (b && binfo_for_vbase (BINFO_TYPE (b), BINFO_TYPE (rtti_binfo))))
7125         /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7126            set LAST's BINFO_VTABLE yet.  We'll extract the actual vptr in
7127            binfo_ctor_vtable after everything's been set up.  */
7128         vtbl = last;
7129
7130       /* Otherwise, this is case 3 and we get our own.  */
7131     }
7132   else if (!BINFO_NEW_VTABLE_MARKED (orig_binfo))
7133     return inits;
7134
7135   if (!vtbl)
7136     {
7137       tree index;
7138       int non_fn_entries;
7139
7140       /* Compute the initializer for this vtable.  */
7141       inits = build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo,
7142                                       &non_fn_entries);
7143
7144       /* Figure out the position to which the VPTR should point.  */
7145       vtbl = TREE_PURPOSE (l);
7146       vtbl = build1 (ADDR_EXPR, vtbl_ptr_type_node, vtbl);
7147       index = size_binop (PLUS_EXPR,
7148                           size_int (non_fn_entries),
7149                           size_int (list_length (TREE_VALUE (l))));
7150       index = size_binop (MULT_EXPR,
7151                           TYPE_SIZE_UNIT (vtable_entry_type),
7152                           index);
7153       vtbl = build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, index);
7154     }
7155
7156   if (ctor_vtbl_p)
7157     /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7158        So, we make a TREE_LIST.  Later, dfs_fixup_binfo_vtbls will
7159        straighten this out.  */
7160     BINFO_VTABLE (binfo) = tree_cons (rtti_binfo, vtbl, BINFO_VTABLE (binfo));
7161   else if (BINFO_PRIMARY_P (binfo) && BINFO_VIRTUAL_P (binfo))
7162     inits = NULL_TREE;
7163   else
7164      /* For an ordinary vtable, set BINFO_VTABLE.  */
7165     BINFO_VTABLE (binfo) = vtbl;
7166
7167   return inits;
7168 }
7169
7170 /* Construct the initializer for BINFO's virtual function table.  BINFO
7171    is part of the hierarchy dominated by T.  If we're building a
7172    construction vtable, the ORIG_BINFO is the binfo we should use to
7173    find the actual function pointers to put in the vtable - but they
7174    can be overridden on the path to most-derived in the graph that
7175    ORIG_BINFO belongs.  Otherwise,
7176    ORIG_BINFO should be the same as BINFO.  The RTTI_BINFO is the
7177    BINFO that should be indicated by the RTTI information in the
7178    vtable; it will be a base class of T, rather than T itself, if we
7179    are building a construction vtable.
7180
7181    The value returned is a TREE_LIST suitable for wrapping in a
7182    CONSTRUCTOR to use as the DECL_INITIAL for a vtable.  If
7183    NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7184    number of non-function entries in the vtable.
7185
7186    It might seem that this function should never be called with a
7187    BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7188    base is always subsumed by a derived class vtable.  However, when
7189    we are building construction vtables, we do build vtables for
7190    primary bases; we need these while the primary base is being
7191    constructed.  */
7192
7193 static tree
7194 build_vtbl_initializer (tree binfo,
7195                         tree orig_binfo,
7196                         tree t,
7197                         tree rtti_binfo,
7198                         int* non_fn_entries_p)
7199 {
7200   tree v, b;
7201   tree vfun_inits;
7202   vtbl_init_data vid;
7203   unsigned ix;
7204   tree vbinfo;
7205   VEC (tree) *vbases;
7206
7207   /* Initialize VID.  */
7208   memset (&vid, 0, sizeof (vid));
7209   vid.binfo = binfo;
7210   vid.derived = t;
7211   vid.rtti_binfo = rtti_binfo;
7212   vid.last_init = &vid.inits;
7213   vid.primary_vtbl_p = (binfo == TYPE_BINFO (t));
7214   vid.ctor_vtbl_p = !same_type_p (BINFO_TYPE (rtti_binfo), t);
7215   vid.generate_vcall_entries = true;
7216   /* The first vbase or vcall offset is at index -3 in the vtable.  */
7217   vid.index = ssize_int(-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE);
7218
7219   /* Add entries to the vtable for RTTI.  */
7220   build_rtti_vtbl_entries (binfo, &vid);
7221
7222   /* Create an array for keeping track of the functions we've
7223      processed.  When we see multiple functions with the same
7224      signature, we share the vcall offsets.  */
7225   VARRAY_TREE_INIT (vid.fns, 32, "fns");
7226   /* Add the vcall and vbase offset entries.  */
7227   build_vcall_and_vbase_vtbl_entries (binfo, &vid);
7228
7229   /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7230      build_vbase_offset_vtbl_entries.  */
7231   for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0;
7232        VEC_iterate (tree, vbases, ix, vbinfo); ix++)
7233     BINFO_VTABLE_PATH_MARKED (vbinfo) = 0;
7234
7235   /* If the target requires padding between data entries, add that now.  */
7236   if (TARGET_VTABLE_DATA_ENTRY_DISTANCE > 1)
7237     {
7238       tree cur, *prev;
7239
7240       for (prev = &vid.inits; (cur = *prev); prev = &TREE_CHAIN (cur))
7241         {
7242           tree add = cur;
7243           int i;
7244
7245           for (i = 1; i < TARGET_VTABLE_DATA_ENTRY_DISTANCE; ++i)
7246             add = tree_cons (NULL_TREE,
7247                              build1 (NOP_EXPR, vtable_entry_type,
7248                                      null_pointer_node),
7249                              add);
7250           *prev = add;
7251         }
7252     }
7253
7254   if (non_fn_entries_p)
7255     *non_fn_entries_p = list_length (vid.inits);
7256
7257   /* Go through all the ordinary virtual functions, building up
7258      initializers.  */
7259   vfun_inits = NULL_TREE;
7260   for (v = BINFO_VIRTUALS (orig_binfo); v; v = TREE_CHAIN (v))
7261     {
7262       tree delta;
7263       tree vcall_index;
7264       tree fn, fn_original;
7265       tree init = NULL_TREE;
7266
7267       fn = BV_FN (v);
7268       fn_original = fn;
7269       if (DECL_THUNK_P (fn))
7270         {
7271           if (!DECL_NAME (fn))
7272             finish_thunk (fn);
7273           if (THUNK_ALIAS (fn))
7274             {
7275               fn = THUNK_ALIAS (fn);
7276               BV_FN (v) = fn;
7277             }
7278           fn_original = THUNK_TARGET (fn);
7279         }
7280
7281       /* If the only definition of this function signature along our
7282          primary base chain is from a lost primary, this vtable slot will
7283          never be used, so just zero it out.  This is important to avoid
7284          requiring extra thunks which cannot be generated with the function.
7285
7286          We first check this in update_vtable_entry_for_fn, so we handle
7287          restored primary bases properly; we also need to do it here so we
7288          zero out unused slots in ctor vtables, rather than filling themff
7289          with erroneous values (though harmless, apart from relocation
7290          costs).  */
7291       for (b = binfo; ; b = get_primary_binfo (b))
7292         {
7293           /* We found a defn before a lost primary; go ahead as normal.  */
7294           if (look_for_overrides_here (BINFO_TYPE (b), fn_original))
7295             break;
7296
7297           /* The nearest definition is from a lost primary; clear the
7298              slot.  */
7299           if (BINFO_LOST_PRIMARY_P (b))
7300             {
7301               init = size_zero_node;
7302               break;
7303             }
7304         }
7305
7306       if (! init)
7307         {
7308           /* Pull the offset for `this', and the function to call, out of
7309              the list.  */
7310           delta = BV_DELTA (v);
7311           vcall_index = BV_VCALL_INDEX (v);
7312
7313           gcc_assert (TREE_CODE (delta) == INTEGER_CST);
7314           gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
7315
7316           /* You can't call an abstract virtual function; it's abstract.
7317              So, we replace these functions with __pure_virtual.  */
7318           if (DECL_PURE_VIRTUAL_P (fn_original))
7319             fn = abort_fndecl;
7320           else if (!integer_zerop (delta) || vcall_index)
7321             {
7322               fn = make_thunk (fn, /*this_adjusting=*/1, delta, vcall_index);
7323               if (!DECL_NAME (fn))
7324                 finish_thunk (fn);
7325             }
7326           /* Take the address of the function, considering it to be of an
7327              appropriate generic type.  */
7328           init = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7329         }
7330
7331       /* And add it to the chain of initializers.  */
7332       if (TARGET_VTABLE_USES_DESCRIPTORS)
7333         {
7334           int i;
7335           if (init == size_zero_node)
7336             for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7337               vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7338           else
7339             for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7340               {
7341                 tree fdesc = build2 (FDESC_EXPR, vfunc_ptr_type_node,
7342                                      TREE_OPERAND (init, 0),
7343                                      build_int_cst (NULL_TREE, i));
7344                 TREE_CONSTANT (fdesc) = 1;
7345                 TREE_INVARIANT (fdesc) = 1;
7346
7347                 vfun_inits = tree_cons (NULL_TREE, fdesc, vfun_inits);
7348               }
7349         }
7350       else
7351         vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7352     }
7353
7354   /* The initializers for virtual functions were built up in reverse
7355      order; straighten them out now.  */
7356   vfun_inits = nreverse (vfun_inits);
7357
7358   /* The negative offset initializers are also in reverse order.  */
7359   vid.inits = nreverse (vid.inits);
7360
7361   /* Chain the two together.  */
7362   return chainon (vid.inits, vfun_inits);
7363 }
7364
7365 /* Adds to vid->inits the initializers for the vbase and vcall
7366    offsets in BINFO, which is in the hierarchy dominated by T.  */
7367
7368 static void
7369 build_vcall_and_vbase_vtbl_entries (tree binfo, vtbl_init_data* vid)
7370 {
7371   tree b;
7372
7373   /* If this is a derived class, we must first create entries
7374      corresponding to the primary base class.  */
7375   b = get_primary_binfo (binfo);
7376   if (b)
7377     build_vcall_and_vbase_vtbl_entries (b, vid);
7378
7379   /* Add the vbase entries for this base.  */
7380   build_vbase_offset_vtbl_entries (binfo, vid);
7381   /* Add the vcall entries for this base.  */
7382   build_vcall_offset_vtbl_entries (binfo, vid);
7383 }
7384
7385 /* Returns the initializers for the vbase offset entries in the vtable
7386    for BINFO (which is part of the class hierarchy dominated by T), in
7387    reverse order.  VBASE_OFFSET_INDEX gives the vtable index
7388    where the next vbase offset will go.  */
7389
7390 static void
7391 build_vbase_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7392 {
7393   tree vbase;
7394   tree t;
7395   tree non_primary_binfo;
7396
7397   /* If there are no virtual baseclasses, then there is nothing to
7398      do.  */
7399   if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
7400     return;
7401
7402   t = vid->derived;
7403
7404   /* We might be a primary base class.  Go up the inheritance hierarchy
7405      until we find the most derived class of which we are a primary base:
7406      it is the offset of that which we need to use.  */
7407   non_primary_binfo = binfo;
7408   while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7409     {
7410       tree b;
7411
7412       /* If we have reached a virtual base, then it must be a primary
7413          base (possibly multi-level) of vid->binfo, or we wouldn't
7414          have called build_vcall_and_vbase_vtbl_entries for it.  But it
7415          might be a lost primary, so just skip down to vid->binfo.  */
7416       if (BINFO_VIRTUAL_P (non_primary_binfo))
7417         {
7418           non_primary_binfo = vid->binfo;
7419           break;
7420         }
7421
7422       b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7423       if (get_primary_binfo (b) != non_primary_binfo)
7424         break;
7425       non_primary_binfo = b;
7426     }
7427
7428   /* Go through the virtual bases, adding the offsets.  */
7429   for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
7430        vbase;
7431        vbase = TREE_CHAIN (vbase))
7432     {
7433       tree b;
7434       tree delta;
7435
7436       if (!BINFO_VIRTUAL_P (vbase))
7437         continue;
7438
7439       /* Find the instance of this virtual base in the complete
7440          object.  */
7441       b = copied_binfo (vbase, binfo);
7442
7443       /* If we've already got an offset for this virtual base, we
7444          don't need another one.  */
7445       if (BINFO_VTABLE_PATH_MARKED (b))
7446         continue;
7447       BINFO_VTABLE_PATH_MARKED (b) = 1;
7448
7449       /* Figure out where we can find this vbase offset.  */
7450       delta = size_binop (MULT_EXPR,
7451                           vid->index,
7452                           convert (ssizetype,
7453                                    TYPE_SIZE_UNIT (vtable_entry_type)));
7454       if (vid->primary_vtbl_p)
7455         BINFO_VPTR_FIELD (b) = delta;
7456
7457       if (binfo != TYPE_BINFO (t))
7458         /* The vbase offset had better be the same.  */
7459         gcc_assert (tree_int_cst_equal (delta, BINFO_VPTR_FIELD (vbase)));
7460
7461       /* The next vbase will come at a more negative offset.  */
7462       vid->index = size_binop (MINUS_EXPR, vid->index,
7463                                ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7464
7465       /* The initializer is the delta from BINFO to this virtual base.
7466          The vbase offsets go in reverse inheritance-graph order, and
7467          we are walking in inheritance graph order so these end up in
7468          the right order.  */
7469       delta = size_diffop (BINFO_OFFSET (b), BINFO_OFFSET (non_primary_binfo));
7470
7471       *vid->last_init
7472         = build_tree_list (NULL_TREE,
7473                            fold (build1 (NOP_EXPR,
7474                                          vtable_entry_type,
7475                                          delta)));
7476       vid->last_init = &TREE_CHAIN (*vid->last_init);
7477     }
7478 }
7479
7480 /* Adds the initializers for the vcall offset entries in the vtable
7481    for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7482    to VID->INITS.  */
7483
7484 static void
7485 build_vcall_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7486 {
7487   /* We only need these entries if this base is a virtual base.  We
7488      compute the indices -- but do not add to the vtable -- when
7489      building the main vtable for a class.  */
7490   if (BINFO_VIRTUAL_P (binfo) || binfo == TYPE_BINFO (vid->derived))
7491     {
7492       /* We need a vcall offset for each of the virtual functions in this
7493          vtable.  For example:
7494
7495            class A { virtual void f (); };
7496            class B1 : virtual public A { virtual void f (); };
7497            class B2 : virtual public A { virtual void f (); };
7498            class C: public B1, public B2 { virtual void f (); };
7499
7500          A C object has a primary base of B1, which has a primary base of A.  A
7501          C also has a secondary base of B2, which no longer has a primary base
7502          of A.  So the B2-in-C construction vtable needs a secondary vtable for
7503          A, which will adjust the A* to a B2* to call f.  We have no way of
7504          knowing what (or even whether) this offset will be when we define B2,
7505          so we store this "vcall offset" in the A sub-vtable and look it up in
7506          a "virtual thunk" for B2::f.
7507
7508          We need entries for all the functions in our primary vtable and
7509          in our non-virtual bases' secondary vtables.  */
7510       vid->vbase = binfo;
7511       /* If we are just computing the vcall indices -- but do not need
7512          the actual entries -- not that.  */
7513       if (!BINFO_VIRTUAL_P (binfo))
7514         vid->generate_vcall_entries = false;
7515       /* Now, walk through the non-virtual bases, adding vcall offsets.  */
7516       add_vcall_offset_vtbl_entries_r (binfo, vid);
7517     }
7518 }
7519
7520 /* Build vcall offsets, starting with those for BINFO.  */
7521
7522 static void
7523 add_vcall_offset_vtbl_entries_r (tree binfo, vtbl_init_data* vid)
7524 {
7525   int i;
7526   tree primary_binfo;
7527   tree base_binfo;
7528
7529   /* Don't walk into virtual bases -- except, of course, for the
7530      virtual base for which we are building vcall offsets.  Any
7531      primary virtual base will have already had its offsets generated
7532      through the recursion in build_vcall_and_vbase_vtbl_entries.  */
7533   if (BINFO_VIRTUAL_P (binfo) && vid->vbase != binfo)
7534     return;
7535
7536   /* If BINFO has a primary base, process it first.  */
7537   primary_binfo = get_primary_binfo (binfo);
7538   if (primary_binfo)
7539     add_vcall_offset_vtbl_entries_r (primary_binfo, vid);
7540
7541   /* Add BINFO itself to the list.  */
7542   add_vcall_offset_vtbl_entries_1 (binfo, vid);
7543
7544   /* Scan the non-primary bases of BINFO.  */
7545   for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7546     if (base_binfo != primary_binfo)
7547       add_vcall_offset_vtbl_entries_r (base_binfo, vid);
7548 }
7549
7550 /* Called from build_vcall_offset_vtbl_entries_r.  */
7551
7552 static void
7553 add_vcall_offset_vtbl_entries_1 (tree binfo, vtbl_init_data* vid)
7554 {
7555   /* Make entries for the rest of the virtuals.  */
7556   if (abi_version_at_least (2))
7557     {
7558       tree orig_fn;
7559
7560       /* The ABI requires that the methods be processed in declaration
7561          order.  G++ 3.2 used the order in the vtable.  */
7562       for (orig_fn = TYPE_METHODS (BINFO_TYPE (binfo));
7563            orig_fn;
7564            orig_fn = TREE_CHAIN (orig_fn))
7565         if (DECL_VINDEX (orig_fn))
7566           add_vcall_offset (orig_fn, binfo, vid);
7567     }
7568   else
7569     {
7570       tree derived_virtuals;
7571       tree base_virtuals;
7572       tree orig_virtuals;
7573       /* If BINFO is a primary base, the most derived class which has
7574          BINFO as a primary base; otherwise, just BINFO.  */
7575       tree non_primary_binfo;
7576
7577       /* We might be a primary base class.  Go up the inheritance hierarchy
7578          until we find the most derived class of which we are a primary base:
7579          it is the BINFO_VIRTUALS there that we need to consider.  */
7580       non_primary_binfo = binfo;
7581       while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7582         {
7583           tree b;
7584
7585           /* If we have reached a virtual base, then it must be vid->vbase,
7586              because we ignore other virtual bases in
7587              add_vcall_offset_vtbl_entries_r.  In turn, it must be a primary
7588              base (possibly multi-level) of vid->binfo, or we wouldn't
7589              have called build_vcall_and_vbase_vtbl_entries for it.  But it
7590              might be a lost primary, so just skip down to vid->binfo.  */
7591           if (BINFO_VIRTUAL_P (non_primary_binfo))
7592             {
7593               gcc_assert (non_primary_binfo == vid->vbase);
7594               non_primary_binfo = vid->binfo;
7595               break;
7596             }
7597
7598           b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7599           if (get_primary_binfo (b) != non_primary_binfo)
7600             break;
7601           non_primary_binfo = b;
7602         }
7603
7604       if (vid->ctor_vtbl_p)
7605         /* For a ctor vtable we need the equivalent binfo within the hierarchy
7606            where rtti_binfo is the most derived type.  */
7607         non_primary_binfo
7608           = original_binfo (non_primary_binfo, vid->rtti_binfo);
7609
7610       for (base_virtuals = BINFO_VIRTUALS (binfo),
7611              derived_virtuals = BINFO_VIRTUALS (non_primary_binfo),
7612              orig_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
7613            base_virtuals;
7614            base_virtuals = TREE_CHAIN (base_virtuals),
7615              derived_virtuals = TREE_CHAIN (derived_virtuals),
7616              orig_virtuals = TREE_CHAIN (orig_virtuals))
7617         {
7618           tree orig_fn;
7619
7620           /* Find the declaration that originally caused this function to
7621              be present in BINFO_TYPE (binfo).  */
7622           orig_fn = BV_FN (orig_virtuals);
7623
7624           /* When processing BINFO, we only want to generate vcall slots for
7625              function slots introduced in BINFO.  So don't try to generate
7626              one if the function isn't even defined in BINFO.  */
7627           if (!same_type_p (DECL_CONTEXT (orig_fn), BINFO_TYPE (binfo)))
7628             continue;
7629
7630           add_vcall_offset (orig_fn, binfo, vid);
7631         }
7632     }
7633 }
7634
7635 /* Add a vcall offset entry for ORIG_FN to the vtable.  */
7636
7637 static void
7638 add_vcall_offset (tree orig_fn, tree binfo, vtbl_init_data *vid)
7639 {
7640   size_t i;
7641   tree vcall_offset;
7642
7643   /* If there is already an entry for a function with the same
7644      signature as FN, then we do not need a second vcall offset.
7645      Check the list of functions already present in the derived
7646      class vtable.  */
7647   for (i = 0; i < VARRAY_ACTIVE_SIZE (vid->fns); ++i)
7648     {
7649       tree derived_entry;
7650
7651       derived_entry = VARRAY_TREE (vid->fns, i);
7652       if (same_signature_p (derived_entry, orig_fn)
7653           /* We only use one vcall offset for virtual destructors,
7654              even though there are two virtual table entries.  */
7655           || (DECL_DESTRUCTOR_P (derived_entry)
7656               && DECL_DESTRUCTOR_P (orig_fn)))
7657         return;
7658     }
7659
7660   /* If we are building these vcall offsets as part of building
7661      the vtable for the most derived class, remember the vcall
7662      offset.  */
7663   if (vid->binfo == TYPE_BINFO (vid->derived))
7664     {
7665       tree_pair_p elt = VEC_safe_push (tree_pair_s,
7666                                        CLASSTYPE_VCALL_INDICES (vid->derived),
7667                                        NULL);
7668       elt->purpose = orig_fn;
7669       elt->value = vid->index;
7670     }
7671
7672   /* The next vcall offset will be found at a more negative
7673      offset.  */
7674   vid->index = size_binop (MINUS_EXPR, vid->index,
7675                            ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7676
7677   /* Keep track of this function.  */
7678   VARRAY_PUSH_TREE (vid->fns, orig_fn);
7679
7680   if (vid->generate_vcall_entries)
7681     {
7682       tree base;
7683       tree fn;
7684
7685       /* Find the overriding function.  */
7686       fn = find_final_overrider (vid->rtti_binfo, binfo, orig_fn);
7687       if (fn == error_mark_node)
7688         vcall_offset = build1 (NOP_EXPR, vtable_entry_type,
7689                                integer_zero_node);
7690       else
7691         {
7692           base = TREE_VALUE (fn);
7693
7694           /* The vbase we're working on is a primary base of
7695              vid->binfo.  But it might be a lost primary, so its
7696              BINFO_OFFSET might be wrong, so we just use the
7697              BINFO_OFFSET from vid->binfo.  */
7698           vcall_offset = size_diffop (BINFO_OFFSET (base),
7699                                       BINFO_OFFSET (vid->binfo));
7700           vcall_offset = fold (build1 (NOP_EXPR, vtable_entry_type,
7701                                        vcall_offset));
7702         }
7703       /* Add the initializer to the vtable.  */
7704       *vid->last_init = build_tree_list (NULL_TREE, vcall_offset);
7705       vid->last_init = &TREE_CHAIN (*vid->last_init);
7706     }
7707 }
7708
7709 /* Return vtbl initializers for the RTTI entries corresponding to the
7710    BINFO's vtable.  The RTTI entries should indicate the object given
7711    by VID->rtti_binfo.  */
7712
7713 static void
7714 build_rtti_vtbl_entries (tree binfo, vtbl_init_data* vid)
7715 {
7716   tree b;
7717   tree t;
7718   tree basetype;
7719   tree offset;
7720   tree decl;
7721   tree init;
7722
7723   basetype = BINFO_TYPE (binfo);
7724   t = BINFO_TYPE (vid->rtti_binfo);
7725
7726   /* To find the complete object, we will first convert to our most
7727      primary base, and then add the offset in the vtbl to that value.  */
7728   b = binfo;
7729   while (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (b))
7730          && !BINFO_LOST_PRIMARY_P (b))
7731     {
7732       tree primary_base;
7733
7734       primary_base = get_primary_binfo (b);
7735       gcc_assert (BINFO_PRIMARY_P (primary_base)
7736                   && BINFO_INHERITANCE_CHAIN (primary_base) == b);
7737       b = primary_base;
7738     }
7739   offset = size_diffop (BINFO_OFFSET (vid->rtti_binfo), BINFO_OFFSET (b));
7740
7741   /* The second entry is the address of the typeinfo object.  */
7742   if (flag_rtti)
7743     decl = build_address (get_tinfo_decl (t));
7744   else
7745     decl = integer_zero_node;
7746
7747   /* Convert the declaration to a type that can be stored in the
7748      vtable.  */
7749   init = build_nop (vfunc_ptr_type_node, decl);
7750   *vid->last_init = build_tree_list (NULL_TREE, init);
7751   vid->last_init = &TREE_CHAIN (*vid->last_init);
7752
7753   /* Add the offset-to-top entry.  It comes earlier in the vtable that
7754      the the typeinfo entry.  Convert the offset to look like a
7755      function pointer, so that we can put it in the vtable.  */
7756   init = build_nop (vfunc_ptr_type_node, offset);
7757   *vid->last_init = build_tree_list (NULL_TREE, init);
7758   vid->last_init = &TREE_CHAIN (*vid->last_init);
7759 }
7760
7761 /* Fold a OBJ_TYPE_REF expression to the address of a function.
7762    KNOWN_TYPE carries the true type of OBJ_TYPE_REF_OBJECT(REF).  */
7763
7764 tree
7765 cp_fold_obj_type_ref (tree ref, tree known_type)
7766 {
7767   HOST_WIDE_INT index = tree_low_cst (OBJ_TYPE_REF_TOKEN (ref), 1);
7768   HOST_WIDE_INT i = 0;
7769   tree v = BINFO_VIRTUALS (TYPE_BINFO (known_type));
7770   tree fndecl;
7771
7772   while (i != index)
7773     {
7774       i += (TARGET_VTABLE_USES_DESCRIPTORS
7775             ? TARGET_VTABLE_USES_DESCRIPTORS : 1);
7776       v = TREE_CHAIN (v);
7777     }
7778
7779   fndecl = BV_FN (v);
7780
7781 #ifdef ENABLE_CHECKING
7782   gcc_assert (tree_int_cst_equal (OBJ_TYPE_REF_TOKEN (ref),
7783                                   DECL_VINDEX (fndecl)));
7784 #endif
7785
7786   return build_address (fndecl);
7787 }
7788