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, 2005  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 tree dfs_modify_vtables (tree, void *);
 120 static tree modify_all_vtables (tree, tree);
 121 static void determine_primary_bases (tree);
 122 static void finish_struct_methods (tree);
 123 static void maybe_warn_about_overly_private_class (tree);
 124 static int method_name_cmp (const void *, const void *);
 125 static int resort_method_name_cmp (const void *, const void *);
 126 static void add_implicitly_declared_members (tree, int, int);
 127 static tree fixed_type_or_null (tree, int *, int *);
 128 static tree resolve_address_of_overloaded_function (tree, tree, tsubst_flags_t,
 129                                                     bool, tree);
 130 static tree build_simple_base_path (tree expr, tree binfo);
 131 static tree build_vtbl_ref_1 (tree, tree);
 132 static tree build_vtbl_initializer (tree, tree, tree, tree, int *);
 133 static int count_fields (tree);
 134 static int add_fields_to_record_type (tree, struct sorted_fields_type*, int);
 135 static void check_bitfield_decl (tree);
 136 static void check_field_decl (tree, tree, int *, int *, int *);
 137 static void check_field_decls (tree, tree *, int *, int *);
 138 static tree *build_base_field (record_layout_info, tree, splay_tree, tree *);
 139 static void build_base_fields (record_layout_info, splay_tree, tree *);
 140 static void check_methods (tree);
 141 static void remove_zero_width_bit_fields (tree);
 142 static void check_bases (tree, int *, int *);
 143 static void check_bases_and_members (tree);
 144 static tree create_vtable_ptr (tree, tree *);
 145 static void include_empty_classes (record_layout_info);
 146 static void layout_class_type (tree, tree *);
 147 static void fixup_pending_inline (tree);
 148 static void fixup_inline_methods (tree);
 149 static void propagate_binfo_offsets (tree, tree);
 150 static void layout_virtual_bases (record_layout_info, splay_tree);
 151 static void build_vbase_offset_vtbl_entries (tree, vtbl_init_data *);
 152 static void add_vcall_offset_vtbl_entries_r (tree, vtbl_init_data *);
 153 static void add_vcall_offset_vtbl_entries_1 (tree, vtbl_init_data *);
 154 static void build_vcall_offset_vtbl_entries (tree, vtbl_init_data *);
 155 static void add_vcall_offset (tree, tree, vtbl_init_data *);
 156 static void layout_vtable_decl (tree, int);
 157 static tree dfs_find_final_overrider_pre (tree, void *);
 158 static tree dfs_find_final_overrider_post (tree, void *);
 159 static tree find_final_overrider (tree, tree, tree);
 160 static int make_new_vtable (tree, tree);
 161 static int maybe_indent_hierarchy (FILE *, int, int);
 162 static tree dump_class_hierarchy_r (FILE *, int, tree, tree, int);
 163 static void dump_class_hierarchy (tree);
 164 static void dump_class_hierarchy_1 (FILE *, int, tree);
 165 static void dump_array (FILE *, tree);
 166 static void dump_vtable (tree, tree, tree);
 167 static void dump_vtt (tree, tree);
 168 static void dump_thunk (FILE *, int, tree);
 169 static tree build_vtable (tree, tree, tree);
 170 static void initialize_vtable (tree, tree);
 171 static void layout_nonempty_base_or_field (record_layout_info,
 172                                            tree, tree, splay_tree);
 173 static tree end_of_class (tree, int);
 174 static bool layout_empty_base (tree, tree, splay_tree);
 175 static void accumulate_vtbl_inits (tree, tree, tree, tree, tree);
 176 static tree dfs_accumulate_vtbl_inits (tree, tree, tree, tree,
 177                                                tree);
 178 static void build_rtti_vtbl_entries (tree, vtbl_init_data *);
 179 static void build_vcall_and_vbase_vtbl_entries (tree, vtbl_init_data *);
 180 static void clone_constructors_and_destructors (tree);
 181 static tree build_clone (tree, tree);
 182 static void update_vtable_entry_for_fn (tree, tree, tree, tree *, unsigned);
 183 static void build_ctor_vtbl_group (tree, tree);
 184 static void build_vtt (tree);
 185 static tree binfo_ctor_vtable (tree);
 186 static tree *build_vtt_inits (tree, tree, tree *, tree *);
 187 static tree dfs_build_secondary_vptr_vtt_inits (tree, void *);
 188 static tree dfs_fixup_binfo_vtbls (tree, void *);
 189 static int record_subobject_offset (tree, tree, splay_tree);
 190 static int check_subobject_offset (tree, tree, splay_tree);
 191 static int walk_subobject_offsets (tree, subobject_offset_fn,
 192                                    tree, splay_tree, tree, int);
 193 static void record_subobject_offsets (tree, tree, splay_tree, int);
 194 static int layout_conflict_p (tree, tree, splay_tree, int);
 195 static int splay_tree_compare_integer_csts (splay_tree_key k1,
 196                                             splay_tree_key k2);
 197 static void warn_about_ambiguous_bases (tree);
 198 static bool type_requires_array_cookie (tree);
 199 static bool contains_empty_class_p (tree);
 200 static bool base_derived_from (tree, tree);
 201 static int empty_base_at_nonzero_offset_p (tree, tree, splay_tree);
 202 static tree end_of_base (tree);
 203 static tree get_vcall_index (tree, tree);
 204
 205 /* Variables shared between class.c and call.c.  */
 206
 207 #ifdef GATHER_STATISTICS
 208 int n_vtables = 0;
 209 int n_vtable_entries = 0;
 210 int n_vtable_searches = 0;
 211 int n_vtable_elems = 0;
 212 int n_convert_harshness = 0;
 213 int n_compute_conversion_costs = 0;
 214 int n_inner_fields_searched = 0;
 215 #endif
 216
 217 /* Convert to or from a base subobject.  EXPR is an expression of type
 218    `A' or `A*', an expression of type `B' or `B*' is returned.  To
 219    convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
 220    the B base instance within A.  To convert base A to derived B, CODE
 221    is MINUS_EXPR and BINFO is the binfo for the A instance within B.
 222    In this latter case, A must not be a morally virtual base of B.
 223    NONNULL is true if EXPR is known to be non-NULL (this is only
 224    needed when EXPR is of pointer type).  CV qualifiers are preserved
 225    from EXPR.  */
 226
 227 tree
 228 build_base_path (enum tree_code code,
 229                  tree expr,
 230                  tree binfo,
 231                  int nonnull)
 232 {
 233   tree v_binfo = NULL_TREE;
 234   tree d_binfo = NULL_TREE;
 235   tree probe;
 236   tree offset;
 237   tree target_type;
 238   tree null_test = NULL;
 239   tree ptr_target_type;
 240   int fixed_type_p;
 241   int want_pointer = TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE;
 242   bool has_empty = false;
 243   bool virtual_access;
 244
 245   if (expr == error_mark_node || binfo == error_mark_node || !binfo)
 246     return error_mark_node;
 247
 248   for (probe = binfo; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
 249     {
 250       d_binfo = probe;
 251       if (is_empty_class (BINFO_TYPE (probe)))
 252         has_empty = true;
 253       if (!v_binfo && BINFO_VIRTUAL_P (probe))
 254         v_binfo = probe;
 255     }
 256
 257   probe = TYPE_MAIN_VARIANT (TREE_TYPE (expr));
 258   if (want_pointer)
 259     probe = TYPE_MAIN_VARIANT (TREE_TYPE (probe));
 260
 261   gcc_assert ((code == MINUS_EXPR
 262                && SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), probe))
 263               || (code == PLUS_EXPR
 264                   && SAME_BINFO_TYPE_P (BINFO_TYPE (d_binfo), probe)));
 265
 266   if (binfo == d_binfo)
 267     /* Nothing to do.  */
 268     return expr;
 269
 270   if (code == MINUS_EXPR && v_binfo)
 271     {
 272       error ("cannot convert from base %qT to derived type %qT via virtual base %qT",
 273              BINFO_TYPE (binfo), BINFO_TYPE (d_binfo), BINFO_TYPE (v_binfo));
 274       return error_mark_node;
 275     }
 276
 277   if (!want_pointer)
 278     /* This must happen before the call to save_expr.  */
 279     expr = build_unary_op (ADDR_EXPR, expr, 0);
 280
 281   offset = BINFO_OFFSET (binfo);
 282   fixed_type_p = resolves_to_fixed_type_p (expr, &nonnull);
 283
 284   /* Do we need to look in the vtable for the real offset?  */
 285   virtual_access = (v_binfo && fixed_type_p <= 0);
 286
 287   /* Do we need to check for a null pointer?  */
 288   if (want_pointer && !nonnull && (virtual_access || !integer_zerop (offset)))
 289     null_test = error_mark_node;
 290
 291   /* Protect against multiple evaluation if necessary.  */
 292   if (TREE_SIDE_EFFECTS (expr) && (null_test || virtual_access))
 293     expr = save_expr (expr);
 294
 295   /* Now that we've saved expr, build the real null test.  */
 296   if (null_test)
 297     {
 298       tree zero = cp_convert (TREE_TYPE (expr), integer_zero_node);
 299       null_test = fold_build2 (NE_EXPR, boolean_type_node,
 300                                expr, zero);
 301     }
 302
 303   /* If this is a simple base reference, express it as a COMPONENT_REF.  */
 304   if (code == PLUS_EXPR && !virtual_access
 305       /* We don't build base fields for empty bases, and they aren't very
 306          interesting to the optimizers anyway.  */
 307       && !has_empty)
 308     {
 309       expr = build_indirect_ref (expr, NULL);
 310       expr = build_simple_base_path (expr, binfo);
 311       if (want_pointer)
 312         expr = build_address (expr);
 313       target_type = TREE_TYPE (expr);
 314       goto out;
 315     }
 316
 317   if (virtual_access)
 318     {
 319       /* Going via virtual base V_BINFO.  We need the static offset
 320          from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
 321          V_BINFO.  That offset is an entry in D_BINFO's vtable.  */
 322       tree v_offset;
 323
 324       if (fixed_type_p < 0 && in_base_initializer)
 325         {
 326           /* In a base member initializer, we cannot rely on
 327              the vtable being set up. We have to use the vtt_parm.  */
 328           tree derived = BINFO_INHERITANCE_CHAIN (v_binfo);
 329           tree t;
 330
 331           t = TREE_TYPE (TYPE_VFIELD (BINFO_TYPE (derived)));
 332           t = build_pointer_type (t);
 333           v_offset = convert (t, current_vtt_parm);
 334           v_offset = build2 (PLUS_EXPR, t, v_offset,
 335                              BINFO_VPTR_INDEX (derived));
 336           v_offset = build_indirect_ref (v_offset, NULL);
 337         }
 338       else
 339         v_offset = build_vfield_ref (build_indirect_ref (expr, NULL),
 340                                      TREE_TYPE (TREE_TYPE (expr)));
 341
 342       v_offset = build2 (PLUS_EXPR, TREE_TYPE (v_offset),
 343                          v_offset,  BINFO_VPTR_FIELD (v_binfo));
 344       v_offset = build1 (NOP_EXPR,
 345                          build_pointer_type (ptrdiff_type_node),
 346                          v_offset);
 347       v_offset = build_indirect_ref (v_offset, NULL);
 348       TREE_CONSTANT (v_offset) = 1;
 349       TREE_INVARIANT (v_offset) = 1;
 350
 351       offset = convert_to_integer (ptrdiff_type_node,
 352                                    size_diffop (offset,
 353                                                 BINFO_OFFSET (v_binfo)));
 354
 355       if (!integer_zerop (offset))
 356         v_offset = build2 (code, ptrdiff_type_node, v_offset, offset);
 357
 358       if (fixed_type_p < 0)
 359         /* Negative fixed_type_p means this is a constructor or destructor;
 360            virtual base layout is fixed in in-charge [cd]tors, but not in
 361            base [cd]tors.  */
 362         offset = build3 (COND_EXPR, ptrdiff_type_node,
 363                          build2 (EQ_EXPR, boolean_type_node,
 364                                  current_in_charge_parm, integer_zero_node),
 365                          v_offset,
 366                          BINFO_OFFSET (binfo));
 367       else
 368         offset = v_offset;
 369     }
 370
 371   target_type = code == PLUS_EXPR ? BINFO_TYPE (binfo) : BINFO_TYPE (d_binfo);
 372
 373   target_type = cp_build_qualified_type
 374     (target_type, cp_type_quals (TREE_TYPE (TREE_TYPE (expr))));
 375   ptr_target_type = build_pointer_type (target_type);
 376   if (want_pointer)
 377     target_type = ptr_target_type;
 378
 379   expr = build1 (NOP_EXPR, ptr_target_type, expr);
 380
 381   if (!integer_zerop (offset))
 382     expr = build2 (code, ptr_target_type, expr, offset);
 383   else
 384     null_test = NULL;
 385
 386   if (!want_pointer)
 387     expr = build_indirect_ref (expr, NULL);
 388
 389  out:
 390   if (null_test)
 391     expr = fold_build3 (COND_EXPR, target_type, null_test, expr,
 392                         fold_build1 (NOP_EXPR, target_type,
 393                                      integer_zero_node));
 394
 395   return expr;
 396 }
 397
 398 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
 399    Perform a derived-to-base conversion by recursively building up a
 400    sequence of COMPONENT_REFs to the appropriate base fields.  */
 401
 402 static tree
 403 build_simple_base_path (tree expr, tree binfo)
 404 {
 405   tree type = BINFO_TYPE (binfo);
 406   tree d_binfo = BINFO_INHERITANCE_CHAIN (binfo);
 407   tree field;
 408
 409   if (d_binfo == NULL_TREE)
 410     {
 411       tree temp;
 412
 413       gcc_assert (TYPE_MAIN_VARIANT (TREE_TYPE (expr)) == type);
 414
 415       /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
 416          into `(*(a ?  &b : &c)).x', and so on.  A COND_EXPR is only
 417          an lvalue in the frontend; only _DECLs and _REFs are lvalues
 418          in the backend.  */
 419       temp = unary_complex_lvalue (ADDR_EXPR, expr);
 420       if (temp)
 421         expr = build_indirect_ref (temp, NULL);
 422
 423       return expr;
 424     }
 425
 426   /* Recurse.  */
 427   expr = build_simple_base_path (expr, d_binfo);
 428
 429   for (field = TYPE_FIELDS (BINFO_TYPE (d_binfo));
 430        field; field = TREE_CHAIN (field))
 431     /* Is this the base field created by build_base_field?  */
 432     if (TREE_CODE (field) == FIELD_DECL
 433         && DECL_FIELD_IS_BASE (field)
 434         && TREE_TYPE (field) == type)
 435       {
 436         /* We don't use build_class_member_access_expr here, as that
 437            has unnecessary checks, and more importantly results in
 438            recursive calls to dfs_walk_once.  */
 439         int type_quals = cp_type_quals (TREE_TYPE (expr));
 440
 441         expr = build3 (COMPONENT_REF,
 442                        cp_build_qualified_type (type, type_quals),
 443                        expr, field, NULL_TREE);
 444         expr = fold_if_not_in_template (expr);
 445
 446         /* Mark the expression const or volatile, as appropriate.
 447            Even though we've dealt with the type above, we still have
 448            to mark the expression itself.  */
 449         if (type_quals & TYPE_QUAL_CONST)
 450           TREE_READONLY (expr) = 1;
 451         if (type_quals & TYPE_QUAL_VOLATILE)
 452           TREE_THIS_VOLATILE (expr) = 1;
 453
 454         return expr;
 455       }
 456
 457   /* Didn't find the base field?!?  */
 458   gcc_unreachable ();
 459 }
 460
 461 /* Convert OBJECT to the base TYPE.  OBJECT is an expression whose
 462    type is a class type or a pointer to a class type.  In the former
 463    case, TYPE is also a class type; in the latter it is another
 464    pointer type.  If CHECK_ACCESS is true, an error message is emitted
 465    if TYPE is inaccessible.  If OBJECT has pointer type, the value is
 466    assumed to be non-NULL.  */
 467
 468 tree
 469 convert_to_base (tree object, tree type, bool check_access, bool nonnull)
 470 {
 471   tree binfo;
 472   tree object_type;
 473
 474   if (TYPE_PTR_P (TREE_TYPE (object)))
 475     {
 476       object_type = TREE_TYPE (TREE_TYPE (object));
 477       type = TREE_TYPE (type);
 478     }
 479   else
 480     object_type = TREE_TYPE (object);
 481
 482   binfo = lookup_base (object_type, type,
 483                        check_access ? ba_check : ba_unique,
 484                        NULL);
 485   if (!binfo || binfo == error_mark_node)
 486     return error_mark_node;
 487
 488   return build_base_path (PLUS_EXPR, object, binfo, nonnull);
 489 }
 490
 491 /* EXPR is an expression with unqualified class type.  BASE is a base
 492    binfo of that class type.  Returns EXPR, converted to the BASE
 493    type.  This function assumes that EXPR is the most derived class;
 494    therefore virtual bases can be found at their static offsets.  */
 495
 496 tree
 497 convert_to_base_statically (tree expr, tree base)
 498 {
 499   tree expr_type;
 500
 501   expr_type = TREE_TYPE (expr);
 502   if (!SAME_BINFO_TYPE_P (BINFO_TYPE (base), expr_type))
 503     {
 504       tree pointer_type;
 505
 506       pointer_type = build_pointer_type (expr_type);
 507       expr = build_unary_op (ADDR_EXPR, expr, /*noconvert=*/1);
 508       if (!integer_zerop (BINFO_OFFSET (base)))
 509           expr = build2 (PLUS_EXPR, pointer_type, expr,
 510                          build_nop (pointer_type, BINFO_OFFSET (base)));
 511       expr = build_nop (build_pointer_type (BINFO_TYPE (base)), expr);
 512       expr = build1 (INDIRECT_REF, BINFO_TYPE (base), expr);
 513     }
 514
 515   return expr;
 516 }
 517
 518 \f
 519 tree
 520 build_vfield_ref (tree datum, tree type)
 521 {
 522   tree vfield, vcontext;
 523
 524   if (datum == error_mark_node)
 525     return error_mark_node;
 526
 527   /* First, convert to the requested type.  */
 528   if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (datum), type))
 529     datum = convert_to_base (datum, type, /*check_access=*/false,
 530                              /*nonnull=*/true);
 531
 532   /* Second, the requested type may not be the owner of its own vptr.
 533      If not, convert to the base class that owns it.  We cannot use
 534      convert_to_base here, because VCONTEXT may appear more than once
 535      in the inheritance hierarchy of TYPE, and thus direct conversion
 536      between the types may be ambiguous.  Following the path back up
 537      one step at a time via primary bases avoids the problem.  */
 538   vfield = TYPE_VFIELD (type);
 539   vcontext = DECL_CONTEXT (vfield);
 540   while (!same_type_ignoring_top_level_qualifiers_p (vcontext, type))
 541     {
 542       datum = build_simple_base_path (datum, CLASSTYPE_PRIMARY_BINFO (type));
 543       type = TREE_TYPE (datum);
 544     }
 545
 546   return build3 (COMPONENT_REF, TREE_TYPE (vfield), datum, vfield, NULL_TREE);
 547 }
 548
 549 /* Given an object INSTANCE, return an expression which yields the
 550    vtable element corresponding to INDEX.  There are many special
 551    cases for INSTANCE which we take care of here, mainly to avoid
 552    creating extra tree nodes when we don't have to.  */
 553
 554 static tree
 555 build_vtbl_ref_1 (tree instance, tree idx)
 556 {
 557   tree aref;
 558   tree vtbl = NULL_TREE;
 559
 560   /* Try to figure out what a reference refers to, and
 561      access its virtual function table directly.  */
 562
 563   int cdtorp = 0;
 564   tree fixed_type = fixed_type_or_null (instance, NULL, &cdtorp);
 565
 566   tree basetype = non_reference (TREE_TYPE (instance));
 567
 568   if (fixed_type && !cdtorp)
 569     {
 570       tree binfo = lookup_base (fixed_type, basetype,
 571                                 ba_unique | ba_quiet, NULL);
 572       if (binfo)
 573         vtbl = unshare_expr (BINFO_VTABLE (binfo));
 574     }
 575
 576   if (!vtbl)
 577     vtbl = build_vfield_ref (instance, basetype);
 578
 579   assemble_external (vtbl);
 580
 581   aref = build_array_ref (vtbl, idx);
 582   TREE_CONSTANT (aref) |= TREE_CONSTANT (vtbl) && TREE_CONSTANT (idx);
 583   TREE_INVARIANT (aref) = TREE_CONSTANT (aref);
 584
 585   return aref;
 586 }
 587
 588 tree
 589 build_vtbl_ref (tree instance, tree idx)
 590 {
 591   tree aref = build_vtbl_ref_1 (instance, idx);
 592
 593   return aref;
 594 }
 595
 596 /* Given a stable object pointer INSTANCE_PTR, return an expression which
 597    yields a function pointer corresponding to vtable element INDEX.  */
 598
 599 tree
 600 build_vfn_ref (tree instance_ptr, tree idx)
 601 {
 602   tree aref;
 603
 604   aref = build_vtbl_ref_1 (build_indirect_ref (instance_ptr, 0), idx);
 605
 606   /* When using function descriptors, the address of the
 607      vtable entry is treated as a function pointer.  */
 608   if (TARGET_VTABLE_USES_DESCRIPTORS)
 609     aref = build1 (NOP_EXPR, TREE_TYPE (aref),
 610                    build_unary_op (ADDR_EXPR, aref, /*noconvert=*/1));
 611
 612   /* Remember this as a method reference, for later devirtualization.  */
 613   aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr, idx);
 614
 615   return aref;
 616 }
 617
 618 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
 619    for the given TYPE.  */
 620
 621 static tree
 622 get_vtable_name (tree type)
 623 {
 624   return mangle_vtbl_for_type (type);
 625 }
 626
 627 /* Return an IDENTIFIER_NODE for the name of the virtual table table
 628    for TYPE.  */
 629
 630 tree
 631 get_vtt_name (tree type)
 632 {
 633   return mangle_vtt_for_type (type);
 634 }
 635
 636 /* DECL is an entity associated with TYPE, like a virtual table or an
 637    implicitly generated constructor.  Determine whether or not DECL
 638    should have external or internal linkage at the object file
 639    level.  This routine does not deal with COMDAT linkage and other
 640    similar complexities; it simply sets TREE_PUBLIC if it possible for
 641    entities in other translation units to contain copies of DECL, in
 642    the abstract.  */
 643
 644 void
 645 set_linkage_according_to_type (tree type, tree decl)
 646 {
 647   /* If TYPE involves a local class in a function with internal
 648      linkage, then DECL should have internal linkage too.  Other local
 649      classes have no linkage -- but if their containing functions
 650      have external linkage, it makes sense for DECL to have external
 651      linkage too.  That will allow template definitions to be merged,
 652      for example.  */
 653   if (no_linkage_check (type, /*relaxed_p=*/true))
 654     {
 655       TREE_PUBLIC (decl) = 0;
 656       DECL_INTERFACE_KNOWN (decl) = 1;
 657     }
 658   else
 659     TREE_PUBLIC (decl) = 1;
 660 }
 661
 662 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
 663    (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
 664    Use NAME for the name of the vtable, and VTABLE_TYPE for its type.  */
 665
 666 static tree
 667 build_vtable (tree class_type, tree name, tree vtable_type)
 668 {
 669   tree decl;
 670
 671   decl = build_lang_decl (VAR_DECL, name, vtable_type);
 672   /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
 673      now to avoid confusion in mangle_decl.  */
 674   SET_DECL_ASSEMBLER_NAME (decl, name);
 675   DECL_CONTEXT (decl) = class_type;
 676   DECL_ARTIFICIAL (decl) = 1;
 677   TREE_STATIC (decl) = 1;
 678   TREE_READONLY (decl) = 1;
 679   DECL_VIRTUAL_P (decl) = 1;
 680   DECL_ALIGN (decl) = TARGET_VTABLE_ENTRY_ALIGN;
 681   DECL_VTABLE_OR_VTT_P (decl) = 1;
 682   /* At one time the vtable info was grabbed 2 words at a time.  This
 683      fails on sparc unless you have 8-byte alignment.  (tiemann) */
 684   DECL_ALIGN (decl) = MAX (TYPE_ALIGN (double_type_node),
 685                            DECL_ALIGN (decl));
 686   set_linkage_according_to_type (class_type, decl);
 687   /* The vtable has not been defined -- yet.  */
 688   DECL_EXTERNAL (decl) = 1;
 689   DECL_NOT_REALLY_EXTERN (decl) = 1;
 690
 691   /* Mark the VAR_DECL node representing the vtable itself as a
 692      "gratuitous" one, thereby forcing dwarfout.c to ignore it.  It
 693      is rather important that such things be ignored because any
 694      effort to actually generate DWARF for them will run into
 695      trouble when/if we encounter code like:
 696
 697      #pragma interface
 698      struct S { virtual void member (); };
 699
 700      because the artificial declaration of the vtable itself (as
 701      manufactured by the g++ front end) will say that the vtable is
 702      a static member of `S' but only *after* the debug output for
 703      the definition of `S' has already been output.  This causes
 704      grief because the DWARF entry for the definition of the vtable
 705      will try to refer back to an earlier *declaration* of the
 706      vtable as a static member of `S' and there won't be one.  We
 707      might be able to arrange to have the "vtable static member"
 708      attached to the member list for `S' before the debug info for
 709      `S' get written (which would solve the problem) but that would
 710      require more intrusive changes to the g++ front end.  */
 711   DECL_IGNORED_P (decl) = 1;
 712
 713   return decl;
 714 }
 715
 716 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
 717    or even complete.  If this does not exist, create it.  If COMPLETE is
 718    nonzero, then complete the definition of it -- that will render it
 719    impossible to actually build the vtable, but is useful to get at those
 720    which are known to exist in the runtime.  */
 721
 722 tree
 723 get_vtable_decl (tree type, int complete)
 724 {
 725   tree decl;
 726
 727   if (CLASSTYPE_VTABLES (type))
 728     return CLASSTYPE_VTABLES (type);
 729
 730   decl = build_vtable (type, get_vtable_name (type), vtbl_type_node);
 731   CLASSTYPE_VTABLES (type) = decl;
 732
 733   if (complete)
 734     {
 735       DECL_EXTERNAL (decl) = 1;
 736       cp_finish_decl (decl, NULL_TREE, NULL_TREE, 0);
 737     }
 738
 739   return decl;
 740 }
 741
 742 /* Build the primary virtual function table for TYPE.  If BINFO is
 743    non-NULL, build the vtable starting with the initial approximation
 744    that it is the same as the one which is the head of the association
 745    list.  Returns a nonzero value if a new vtable is actually
 746    created.  */
 747
 748 static int
 749 build_primary_vtable (tree binfo, tree type)
 750 {
 751   tree decl;
 752   tree virtuals;
 753
 754   decl = get_vtable_decl (type, /*complete=*/0);
 755
 756   if (binfo)
 757     {
 758       if (BINFO_NEW_VTABLE_MARKED (binfo))
 759         /* We have already created a vtable for this base, so there's
 760            no need to do it again.  */
 761         return 0;
 762
 763       virtuals = copy_list (BINFO_VIRTUALS (binfo));
 764       TREE_TYPE (decl) = TREE_TYPE (get_vtbl_decl_for_binfo (binfo));
 765       DECL_SIZE (decl) = TYPE_SIZE (TREE_TYPE (decl));
 766       DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (TREE_TYPE (decl));
 767     }
 768   else
 769     {
 770       gcc_assert (TREE_TYPE (decl) == vtbl_type_node);
 771       virtuals = NULL_TREE;
 772     }
 773
 774 #ifdef GATHER_STATISTICS
 775   n_vtables += 1;
 776   n_vtable_elems += list_length (virtuals);
 777 #endif
 778
 779   /* Initialize the association list for this type, based
 780      on our first approximation.  */
 781   BINFO_VTABLE (TYPE_BINFO (type)) = decl;
 782   BINFO_VIRTUALS (TYPE_BINFO (type)) = virtuals;
 783   SET_BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (type));
 784   return 1;
 785 }
 786
 787 /* Give BINFO a new virtual function table which is initialized
 788    with a skeleton-copy of its original initialization.  The only
 789    entry that changes is the `delta' entry, so we can really
 790    share a lot of structure.
 791
 792    FOR_TYPE is the most derived type which caused this table to
 793    be needed.
 794
 795    Returns nonzero if we haven't met BINFO before.
 796
 797    The order in which vtables are built (by calling this function) for
 798    an object must remain the same, otherwise a binary incompatibility
 799    can result.  */
 800
 801 static int
 802 build_secondary_vtable (tree binfo)
 803 {
 804   if (BINFO_NEW_VTABLE_MARKED (binfo))
 805     /* We already created a vtable for this base.  There's no need to
 806        do it again.  */
 807     return 0;
 808
 809   /* Remember that we've created a vtable for this BINFO, so that we
 810      don't try to do so again.  */
 811   SET_BINFO_NEW_VTABLE_MARKED (binfo);
 812
 813   /* Make fresh virtual list, so we can smash it later.  */
 814   BINFO_VIRTUALS (binfo) = copy_list (BINFO_VIRTUALS (binfo));
 815
 816   /* Secondary vtables are laid out as part of the same structure as
 817      the primary vtable.  */
 818   BINFO_VTABLE (binfo) = NULL_TREE;
 819   return 1;
 820 }
 821
 822 /* Create a new vtable for BINFO which is the hierarchy dominated by
 823    T. Return nonzero if we actually created a new vtable.  */
 824
 825 static int
 826 make_new_vtable (tree t, tree binfo)
 827 {
 828   if (binfo == TYPE_BINFO (t))
 829     /* In this case, it is *type*'s vtable we are modifying.  We start
 830        with the approximation that its vtable is that of the
 831        immediate base class.  */
 832     return build_primary_vtable (binfo, t);
 833   else
 834     /* This is our very own copy of `basetype' to play with.  Later,
 835        we will fill in all the virtual functions that override the
 836        virtual functions in these base classes which are not defined
 837        by the current type.  */
 838     return build_secondary_vtable (binfo);
 839 }
 840
 841 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
 842    (which is in the hierarchy dominated by T) list FNDECL as its
 843    BV_FN.  DELTA is the required constant adjustment from the `this'
 844    pointer where the vtable entry appears to the `this' required when
 845    the function is actually called.  */
 846
 847 static void
 848 modify_vtable_entry (tree t,
 849                      tree binfo,
 850                      tree fndecl,
 851                      tree delta,
 852                      tree *virtuals)
 853 {
 854   tree v;
 855
 856   v = *virtuals;
 857
 858   if (fndecl != BV_FN (v)
 859       || !tree_int_cst_equal (delta, BV_DELTA (v)))
 860     {
 861       /* We need a new vtable for BINFO.  */
 862       if (make_new_vtable (t, binfo))
 863         {
 864           /* If we really did make a new vtable, we also made a copy
 865              of the BINFO_VIRTUALS list.  Now, we have to find the
 866              corresponding entry in that list.  */
 867           *virtuals = BINFO_VIRTUALS (binfo);
 868           while (BV_FN (*virtuals) != BV_FN (v))
 869             *virtuals = TREE_CHAIN (*virtuals);
 870           v = *virtuals;
 871         }
 872
 873       BV_DELTA (v) = delta;
 874       BV_VCALL_INDEX (v) = NULL_TREE;
 875       BV_FN (v) = fndecl;
 876     }
 877 }
 878
 879 \f
 880 /* Add method METHOD to class TYPE.  */
 881
 882 void
 883 add_method (tree type, tree method)
 884 {
 885   int using;
 886   unsigned slot;
 887   tree overload;
 888   bool template_conv_p = false;
 889   bool conv_p;
 890   VEC(tree) *method_vec;
 891   bool complete_p;
 892   bool insert_p = false;
 893   tree current_fns;
 894
 895   if (method == error_mark_node)
 896     return;
 897
 898   complete_p = COMPLETE_TYPE_P (type);
 899   using = (DECL_CONTEXT (method) != type);
 900   conv_p = DECL_CONV_FN_P (method);
 901   if (conv_p)
 902     template_conv_p = (TREE_CODE (method) == TEMPLATE_DECL
 903                        && DECL_TEMPLATE_CONV_FN_P (method));
 904
 905   method_vec = CLASSTYPE_METHOD_VEC (type);
 906   if (!method_vec)
 907     {
 908       /* Make a new method vector.  We start with 8 entries.  We must
 909          allocate at least two (for constructors and destructors), and
 910          we're going to end up with an assignment operator at some
 911          point as well.  */
 912       method_vec = VEC_alloc (tree, 8);
 913       /* Create slots for constructors and destructors.  */
 914       VEC_quick_push (tree, method_vec, NULL_TREE);
 915       VEC_quick_push (tree, method_vec, NULL_TREE);
 916       CLASSTYPE_METHOD_VEC (type) = method_vec;
 917     }
 918
 919   /* Constructors and destructors go in special slots.  */
 920   if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (method))
 921     slot = CLASSTYPE_CONSTRUCTOR_SLOT;
 922   else if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method))
 923     {
 924       slot = CLASSTYPE_DESTRUCTOR_SLOT;
 925
 926       if (TYPE_FOR_JAVA (type))
 927         {
 928           if (!DECL_ARTIFICIAL (method))
 929             error ("Java class %qT cannot have a destructor", type);
 930           else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
 931             error ("Java class %qT cannot have an implicit non-trivial "
 932                    "destructor",
 933                    type);
 934         }
 935     }
 936   else
 937     {
 938       tree m;
 939
 940       insert_p = true;
 941       /* See if we already have an entry with this name.  */
 942       for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
 943            VEC_iterate (tree, method_vec, slot, m);
 944            ++slot)
 945         {
 946           m = OVL_CURRENT (m);
 947           if (template_conv_p)
 948             {
 949               if (TREE_CODE (m) == TEMPLATE_DECL
 950                   && DECL_TEMPLATE_CONV_FN_P (m))
 951                 insert_p = false;
 952               break;
 953             }
 954           if (conv_p && !DECL_CONV_FN_P (m))
 955             break;
 956           if (DECL_NAME (m) == DECL_NAME (method))
 957             {
 958               insert_p = false;
 959               break;
 960             }
 961           if (complete_p
 962               && !DECL_CONV_FN_P (m)
 963               && DECL_NAME (m) > DECL_NAME (method))
 964             break;
 965         }
 966     }
 967   current_fns = insert_p ? NULL_TREE : VEC_index (tree, method_vec, slot);
 968
 969   if (processing_template_decl)
 970     /* TYPE is a template class.  Don't issue any errors now; wait
 971        until instantiation time to complain.  */
 972     ;
 973   else
 974     {
 975       tree fns;
 976
 977       /* Check to see if we've already got this method.  */
 978       for (fns = current_fns; fns; fns = OVL_NEXT (fns))
 979         {
 980           tree fn = OVL_CURRENT (fns);
 981           tree parms1;
 982           tree parms2;
 983           bool same = 1;
 984
 985           if (TREE_CODE (fn) != TREE_CODE (method))
 986             continue;
 987
 988           /* [over.load] Member function declarations with the
 989              same name and the same parameter types cannot be
 990              overloaded if any of them is a static member
 991              function declaration.
 992
 993              [namespace.udecl] When a using-declaration brings names
 994              from a base class into a derived class scope, member
 995              functions in the derived class override and/or hide member
 996              functions with the same name and parameter types in a base
 997              class (rather than conflicting).  */
 998           parms1 = TYPE_ARG_TYPES (TREE_TYPE (fn));
 999           parms2 = TYPE_ARG_TYPES (TREE_TYPE (method));
1000
1001           /* Compare the quals on the 'this' parm.  Don't compare
1002              the whole types, as used functions are treated as
1003              coming from the using class in overload resolution.  */
1004           if (! DECL_STATIC_FUNCTION_P (fn)
1005               && ! DECL_STATIC_FUNCTION_P (method)
1006               && (TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms1)))
1007                   != TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms2)))))
1008             same = 0;
1009
1010           /* For templates, the template parms must be identical.  */
1011           if (TREE_CODE (fn) == TEMPLATE_DECL
1012               && !comp_template_parms (DECL_TEMPLATE_PARMS (fn),
1013                                        DECL_TEMPLATE_PARMS (method)))
1014             same = 0;
1015
1016           if (! DECL_STATIC_FUNCTION_P (fn))
1017             parms1 = TREE_CHAIN (parms1);
1018           if (! DECL_STATIC_FUNCTION_P (method))
1019             parms2 = TREE_CHAIN (parms2);
1020
1021           if (same && compparms (parms1, parms2)
1022               && (!DECL_CONV_FN_P (fn)
1023                   || same_type_p (TREE_TYPE (TREE_TYPE (fn)),
1024                                   TREE_TYPE (TREE_TYPE (method)))))
1025             {
1026               if (using && DECL_CONTEXT (fn) == type)
1027                 /* Defer to the local function.  */
1028                 return;
1029               else
1030                 {
1031                   cp_error_at ("%q#D and %q#D cannot be overloaded",
1032                                method, fn);
1033
1034                   /* We don't call duplicate_decls here to merge
1035                      the declarations because that will confuse
1036                      things if the methods have inline
1037                      definitions.  In particular, we will crash
1038                      while processing the definitions.  */
1039                   return;
1040                 }
1041             }
1042         }
1043     }
1044
1045   /* Add the new binding.  */
1046   overload = build_overload (method, current_fns);
1047
1048   if (!conv_p && slot >= CLASSTYPE_FIRST_CONVERSION_SLOT && !complete_p)
1049     push_class_level_binding (DECL_NAME (method), overload);
1050
1051   if (insert_p)
1052     {
1053       /* We only expect to add few methods in the COMPLETE_P case, so
1054          just make room for one more method in that case.  */
1055       if (VEC_reserve (tree, method_vec, complete_p ? 1 : -1))
1056         CLASSTYPE_METHOD_VEC (type) = method_vec;
1057       if (slot == VEC_length (tree, method_vec))
1058         VEC_quick_push (tree, method_vec, overload);
1059       else
1060         VEC_quick_insert (tree, method_vec, slot, overload);
1061     }
1062   else
1063     /* Replace the current slot.  */
1064     VEC_replace (tree, method_vec, slot, overload);
1065 }
1066
1067 /* Subroutines of finish_struct.  */
1068
1069 /* Change the access of FDECL to ACCESS in T.  Return 1 if change was
1070    legit, otherwise return 0.  */
1071
1072 static int
1073 alter_access (tree t, tree fdecl, tree access)
1074 {
1075   tree elem;
1076
1077   if (!DECL_LANG_SPECIFIC (fdecl))
1078     retrofit_lang_decl (fdecl);
1079
1080   gcc_assert (!DECL_DISCRIMINATOR_P (fdecl));
1081
1082   elem = purpose_member (t, DECL_ACCESS (fdecl));
1083   if (elem)
1084     {
1085       if (TREE_VALUE (elem) != access)
1086         {
1087           if (TREE_CODE (TREE_TYPE (fdecl)) == FUNCTION_DECL)
1088             cp_error_at ("conflicting access specifications for method"
1089                          " %qD, ignored", TREE_TYPE (fdecl));
1090           else
1091             error ("conflicting access specifications for field %qE, ignored",
1092                    DECL_NAME (fdecl));
1093         }
1094       else
1095         {
1096           /* They're changing the access to the same thing they changed
1097              it to before.  That's OK.  */
1098           ;
1099         }
1100     }
1101   else
1102     {
1103       perform_or_defer_access_check (TYPE_BINFO (t), fdecl);
1104       DECL_ACCESS (fdecl) = tree_cons (t, access, DECL_ACCESS (fdecl));
1105       return 1;
1106     }
1107   return 0;
1108 }
1109
1110 /* Process the USING_DECL, which is a member of T.  */
1111
1112 static void
1113 handle_using_decl (tree using_decl, tree t)
1114 {
1115   tree ctype = DECL_INITIAL (using_decl);
1116   tree name = DECL_NAME (using_decl);
1117   tree access
1118     = TREE_PRIVATE (using_decl) ? access_private_node
1119     : TREE_PROTECTED (using_decl) ? access_protected_node
1120     : access_public_node;
1121   tree fdecl, binfo;
1122   tree flist = NULL_TREE;
1123   tree old_value;
1124
1125   if (ctype == error_mark_node)
1126     return;
1127
1128   binfo = lookup_base (t, ctype, ba_any, NULL);
1129   if (! binfo)
1130     {
1131       location_t saved_loc = input_location;
1132
1133       input_location = DECL_SOURCE_LOCATION (using_decl);
1134       error_not_base_type (ctype, t);
1135       input_location = saved_loc;
1136       return;
1137     }
1138
1139   if (constructor_name_p (name, ctype))
1140     {
1141       cp_error_at ("%qD names constructor", using_decl);
1142       return;
1143     }
1144   if (constructor_name_p (name, t))
1145     {
1146       cp_error_at ("%qD invalid in %qT", using_decl, t);
1147       return;
1148     }
1149
1150   fdecl = lookup_member (binfo, name, 0, false);
1151
1152   if (!fdecl)
1153     {
1154       cp_error_at ("no members matching %qD in %q#T", using_decl, ctype);
1155       return;
1156     }
1157
1158   if (BASELINK_P (fdecl))
1159     /* Ignore base type this came from.  */
1160     fdecl = BASELINK_FUNCTIONS (fdecl);
1161
1162   old_value = lookup_member (t, name, /*protect=*/0, /*want_type=*/false);
1163   if (old_value)
1164     {
1165       if (is_overloaded_fn (old_value))
1166         old_value = OVL_CURRENT (old_value);
1167
1168       if (DECL_P (old_value) && DECL_CONTEXT (old_value) == t)
1169         /* OK */;
1170       else
1171         old_value = NULL_TREE;
1172     }
1173
1174   if (is_overloaded_fn (fdecl))
1175     flist = fdecl;
1176
1177   if (! old_value)
1178     ;
1179   else if (is_overloaded_fn (old_value))
1180     {
1181       if (flist)
1182         /* It's OK to use functions from a base when there are functions with
1183            the same name already present in the current class.  */;
1184       else
1185         {
1186           cp_error_at ("%qD invalid in %q#T", using_decl, t);
1187           cp_error_at ("  because of local method %q#D with same name",
1188                        OVL_CURRENT (old_value));
1189           return;
1190         }
1191     }
1192   else if (!DECL_ARTIFICIAL (old_value))
1193     {
1194       cp_error_at ("%qD invalid in %q#T", using_decl, t);
1195       cp_error_at ("  because of local member %q#D with same name", old_value);
1196       return;
1197     }
1198
1199   /* Make type T see field decl FDECL with access ACCESS.  */
1200   if (flist)
1201     for (; flist; flist = OVL_NEXT (flist))
1202       {
1203         add_method (t, OVL_CURRENT (flist));
1204         alter_access (t, OVL_CURRENT (flist), access);
1205       }
1206   else
1207     alter_access (t, fdecl, access);
1208 }
1209 \f
1210 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1211    and NO_CONST_ASN_REF_P.  Also set flag bits in T based on
1212    properties of the bases.  */
1213
1214 static void
1215 check_bases (tree t,
1216              int* cant_have_const_ctor_p,
1217              int* no_const_asn_ref_p)
1218 {
1219   int i;
1220   int seen_non_virtual_nearly_empty_base_p;
1221   tree base_binfo;
1222   tree binfo;
1223
1224   seen_non_virtual_nearly_empty_base_p = 0;
1225
1226   for (binfo = TYPE_BINFO (t), i = 0;
1227        BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
1228     {
1229       tree basetype = TREE_TYPE (base_binfo);
1230
1231       gcc_assert (COMPLETE_TYPE_P (basetype));
1232
1233       /* Effective C++ rule 14.  We only need to check TYPE_POLYMORPHIC_P
1234          here because the case of virtual functions but non-virtual
1235          dtor is handled in finish_struct_1.  */
1236       if (warn_ecpp && ! TYPE_POLYMORPHIC_P (basetype))
1237         warning ("base class %q#T has a non-virtual destructor", basetype);
1238
1239       /* If the base class doesn't have copy constructors or
1240          assignment operators that take const references, then the
1241          derived class cannot have such a member automatically
1242          generated.  */
1243       if (! TYPE_HAS_CONST_INIT_REF (basetype))
1244         *cant_have_const_ctor_p = 1;
1245       if (TYPE_HAS_ASSIGN_REF (basetype)
1246           && !TYPE_HAS_CONST_ASSIGN_REF (basetype))
1247         *no_const_asn_ref_p = 1;
1248
1249       if (BINFO_VIRTUAL_P (base_binfo))
1250         /* A virtual base does not effect nearly emptiness.  */
1251         ;
1252       else if (CLASSTYPE_NEARLY_EMPTY_P (basetype))
1253         {
1254           if (seen_non_virtual_nearly_empty_base_p)
1255             /* And if there is more than one nearly empty base, then the
1256                derived class is not nearly empty either.  */
1257             CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1258           else
1259             /* Remember we've seen one.  */
1260             seen_non_virtual_nearly_empty_base_p = 1;
1261         }
1262       else if (!is_empty_class (basetype))
1263         /* If the base class is not empty or nearly empty, then this
1264            class cannot be nearly empty.  */
1265         CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1266
1267       /* A lot of properties from the bases also apply to the derived
1268          class.  */
1269       TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (basetype);
1270       TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
1271         |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype);
1272       TYPE_HAS_COMPLEX_ASSIGN_REF (t)
1273         |= TYPE_HAS_COMPLEX_ASSIGN_REF (basetype);
1274       TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (basetype);
1275       TYPE_POLYMORPHIC_P (t) |= TYPE_POLYMORPHIC_P (basetype);
1276       CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t)
1277         |= CLASSTYPE_CONTAINS_EMPTY_CLASS_P (basetype);
1278     }
1279 }
1280
1281 /* Determine all the primary bases within T.  Sets BINFO_PRIMARY_BASE_P for
1282    those that are primaries.  Sets BINFO_LOST_PRIMARY_P for those
1283    that have had a nearly-empty virtual primary base stolen by some
1284    other base in the hierarchy.  Determines CLASSTYPE_PRIMARY_BASE for
1285    T.  */
1286
1287 static void
1288 determine_primary_bases (tree t)
1289 {
1290   unsigned i;
1291   tree primary = NULL_TREE;
1292   tree type_binfo = TYPE_BINFO (t);
1293   tree base_binfo;
1294
1295   /* Determine the primary bases of our bases.  */
1296   for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1297        base_binfo = TREE_CHAIN (base_binfo))
1298     {
1299       tree primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (base_binfo));
1300
1301       /* See if we're the non-virtual primary of our inheritance
1302          chain.  */
1303       if (!BINFO_VIRTUAL_P (base_binfo))
1304         {
1305           tree parent = BINFO_INHERITANCE_CHAIN (base_binfo);
1306           tree parent_primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (parent));
1307
1308           if (parent_primary
1309               && SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo),
1310                                     BINFO_TYPE (parent_primary)))
1311             /* We are the primary binfo.  */
1312             BINFO_PRIMARY_P (base_binfo) = 1;
1313         }
1314       /* Determine if we have a virtual primary base, and mark it so.
1315        */
1316       if (primary && BINFO_VIRTUAL_P (primary))
1317         {
1318           tree this_primary = copied_binfo (primary, base_binfo);
1319
1320           if (BINFO_PRIMARY_P (this_primary))
1321             /* Someone already claimed this base.  */
1322             BINFO_LOST_PRIMARY_P (base_binfo) = 1;
1323           else
1324             {
1325               tree delta;
1326
1327               BINFO_PRIMARY_P (this_primary) = 1;
1328               BINFO_INHERITANCE_CHAIN (this_primary) = base_binfo;
1329
1330               /* A virtual binfo might have been copied from within
1331                  another hierarchy. As we're about to use it as a
1332                  primary base, make sure the offsets match.  */
1333               delta = size_diffop (convert (ssizetype,
1334                                             BINFO_OFFSET (base_binfo)),
1335                                    convert (ssizetype,
1336                                             BINFO_OFFSET (this_primary)));
1337
1338               propagate_binfo_offsets (this_primary, delta);
1339             }
1340         }
1341     }
1342
1343   /* First look for a dynamic direct non-virtual base.  */
1344   for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, base_binfo); i++)
1345     {
1346       tree basetype = BINFO_TYPE (base_binfo);
1347
1348       if (TYPE_CONTAINS_VPTR_P (basetype) && !BINFO_VIRTUAL_P (base_binfo))
1349         {
1350           primary = base_binfo;
1351           goto found;
1352         }
1353     }
1354
1355   /* A "nearly-empty" virtual base class can be the primary base
1356      class, if no non-virtual polymorphic base can be found.  Look for
1357      a nearly-empty virtual dynamic base that is not already a primary
1358      base of something in the hierarchy.  If there is no such base,
1359      just pick the first nearly-empty virtual base.  */
1360
1361   for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1362        base_binfo = TREE_CHAIN (base_binfo))
1363     if (BINFO_VIRTUAL_P (base_binfo)
1364         && CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (base_binfo)))
1365       {
1366         if (!BINFO_PRIMARY_P (base_binfo))
1367           {
1368             /* Found one that is not primary.  */
1369             primary = base_binfo;
1370             goto found;
1371           }
1372         else if (!primary)
1373           /* Remember the first candidate.  */
1374           primary = base_binfo;
1375       }
1376
1377  found:
1378   /* If we've got a primary base, use it.  */
1379   if (primary)
1380     {
1381       tree basetype = BINFO_TYPE (primary);
1382
1383       CLASSTYPE_PRIMARY_BINFO (t) = primary;
1384       if (BINFO_PRIMARY_P (primary))
1385         /* We are stealing a primary base.  */
1386         BINFO_LOST_PRIMARY_P (BINFO_INHERITANCE_CHAIN (primary)) = 1;
1387       BINFO_PRIMARY_P (primary) = 1;
1388       if (BINFO_VIRTUAL_P (primary))
1389         {
1390           tree delta;
1391
1392           BINFO_INHERITANCE_CHAIN (primary) = type_binfo;
1393           /* A virtual binfo might have been copied from within
1394              another hierarchy. As we're about to use it as a primary
1395              base, make sure the offsets match.  */
1396           delta = size_diffop (ssize_int (0),
1397                                convert (ssizetype, BINFO_OFFSET (primary)));
1398
1399           propagate_binfo_offsets (primary, delta);
1400         }
1401
1402       primary = TYPE_BINFO (basetype);
1403
1404       TYPE_VFIELD (t) = TYPE_VFIELD (basetype);
1405       BINFO_VTABLE (type_binfo) = BINFO_VTABLE (primary);
1406       BINFO_VIRTUALS (type_binfo) = BINFO_VIRTUALS (primary);
1407     }
1408 }
1409 \f
1410 /* Set memoizing fields and bits of T (and its variants) for later
1411    use.  */
1412
1413 static void
1414 finish_struct_bits (tree t)
1415 {
1416   tree variants;
1417
1418   /* Fix up variants (if any).  */
1419   for (variants = TYPE_NEXT_VARIANT (t);
1420        variants;
1421        variants = TYPE_NEXT_VARIANT (variants))
1422     {
1423       /* These fields are in the _TYPE part of the node, not in
1424          the TYPE_LANG_SPECIFIC component, so they are not shared.  */
1425       TYPE_HAS_CONSTRUCTOR (variants) = TYPE_HAS_CONSTRUCTOR (t);
1426       TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t);
1427       TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variants)
1428         = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
1429
1430       TYPE_POLYMORPHIC_P (variants) = TYPE_POLYMORPHIC_P (t);
1431
1432       TYPE_BINFO (variants) = TYPE_BINFO (t);
1433
1434       /* Copy whatever these are holding today.  */
1435       TYPE_VFIELD (variants) = TYPE_VFIELD (t);
1436       TYPE_METHODS (variants) = TYPE_METHODS (t);
1437       TYPE_FIELDS (variants) = TYPE_FIELDS (t);
1438       TYPE_SIZE (variants) = TYPE_SIZE (t);
1439       TYPE_SIZE_UNIT (variants) = TYPE_SIZE_UNIT (t);
1440     }
1441
1442   if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) && TYPE_POLYMORPHIC_P (t))
1443     /* For a class w/o baseclasses, 'finish_struct' has set
1444        CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1445        Similarly for a class whose base classes do not have vtables.
1446        When neither of these is true, we might have removed abstract
1447        virtuals (by providing a definition), added some (by declaring
1448        new ones), or redeclared ones from a base class.  We need to
1449        recalculate what's really an abstract virtual at this point (by
1450        looking in the vtables).  */
1451     get_pure_virtuals (t);
1452
1453   /* If this type has a copy constructor or a destructor, force its
1454      mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1455      nonzero.  This will cause it to be passed by invisible reference
1456      and prevent it from being returned in a register.  */
1457   if (! TYPE_HAS_TRIVIAL_INIT_REF (t) || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
1458     {
1459       tree variants;
1460       DECL_MODE (TYPE_MAIN_DECL (t)) = BLKmode;
1461       for (variants = t; variants; variants = TYPE_NEXT_VARIANT (variants))
1462         {
1463           TYPE_MODE (variants) = BLKmode;
1464           TREE_ADDRESSABLE (variants) = 1;
1465         }
1466     }
1467 }
1468
1469 /* Issue warnings about T having private constructors, but no friends,
1470    and so forth.
1471
1472    HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1473    static members.  HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1474    non-private static member functions.  */
1475
1476 static void
1477 maybe_warn_about_overly_private_class (tree t)
1478 {
1479   int has_member_fn = 0;
1480   int has_nonprivate_method = 0;
1481   tree fn;
1482
1483   if (!warn_ctor_dtor_privacy
1484       /* If the class has friends, those entities might create and
1485          access instances, so we should not warn.  */
1486       || (CLASSTYPE_FRIEND_CLASSES (t)
1487           || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))
1488       /* We will have warned when the template was declared; there's
1489          no need to warn on every instantiation.  */
1490       || CLASSTYPE_TEMPLATE_INSTANTIATION (t))
1491     /* There's no reason to even consider warning about this
1492        class.  */
1493     return;
1494
1495   /* We only issue one warning, if more than one applies, because
1496      otherwise, on code like:
1497
1498      class A {
1499        // Oops - forgot `public:'
1500        A();
1501        A(const A&);
1502        ~A();
1503      };
1504
1505      we warn several times about essentially the same problem.  */
1506
1507   /* Check to see if all (non-constructor, non-destructor) member
1508      functions are private.  (Since there are no friends or
1509      non-private statics, we can't ever call any of the private member
1510      functions.)  */
1511   for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
1512     /* We're not interested in compiler-generated methods; they don't
1513        provide any way to call private members.  */
1514     if (!DECL_ARTIFICIAL (fn))
1515       {
1516         if (!TREE_PRIVATE (fn))
1517           {
1518             if (DECL_STATIC_FUNCTION_P (fn))
1519               /* A non-private static member function is just like a
1520                  friend; it can create and invoke private member
1521                  functions, and be accessed without a class
1522                  instance.  */
1523               return;
1524
1525             has_nonprivate_method = 1;
1526             /* Keep searching for a static member function.  */
1527           }
1528         else if (!DECL_CONSTRUCTOR_P (fn) && !DECL_DESTRUCTOR_P (fn))
1529           has_member_fn = 1;
1530       }
1531
1532   if (!has_nonprivate_method && has_member_fn)
1533     {
1534       /* There are no non-private methods, and there's at least one
1535          private member function that isn't a constructor or
1536          destructor.  (If all the private members are
1537          constructors/destructors we want to use the code below that
1538          issues error messages specifically referring to
1539          constructors/destructors.)  */
1540       unsigned i;
1541       tree binfo = TYPE_BINFO (t);
1542
1543       for (i = 0; i != BINFO_N_BASE_BINFOS (binfo); i++)
1544         if (BINFO_BASE_ACCESS (binfo, i) != access_private_node)
1545           {
1546             has_nonprivate_method = 1;
1547             break;
1548           }
1549       if (!has_nonprivate_method)
1550         {
1551           warning ("all member functions in class %qT are private", t);
1552           return;
1553         }
1554     }
1555
1556   /* Even if some of the member functions are non-private, the class
1557      won't be useful for much if all the constructors or destructors
1558      are private: such an object can never be created or destroyed.  */
1559   fn = CLASSTYPE_DESTRUCTORS (t);
1560   if (fn && TREE_PRIVATE (fn))
1561     {
1562       warning ("%q#T only defines a private destructor and has no friends",
1563                t);
1564       return;
1565     }
1566
1567   if (TYPE_HAS_CONSTRUCTOR (t))
1568     {
1569       int nonprivate_ctor = 0;
1570
1571       /* If a non-template class does not define a copy
1572          constructor, one is defined for it, enabling it to avoid
1573          this warning.  For a template class, this does not
1574          happen, and so we would normally get a warning on:
1575
1576            template <class T> class C { private: C(); };
1577
1578          To avoid this asymmetry, we check TYPE_HAS_INIT_REF.  All
1579          complete non-template or fully instantiated classes have this
1580          flag set.  */
1581       if (!TYPE_HAS_INIT_REF (t))
1582         nonprivate_ctor = 1;
1583       else
1584         for (fn = CLASSTYPE_CONSTRUCTORS (t); fn; fn = OVL_NEXT (fn))
1585           {
1586             tree ctor = OVL_CURRENT (fn);
1587             /* Ideally, we wouldn't count copy constructors (or, in
1588                fact, any constructor that takes an argument of the
1589                class type as a parameter) because such things cannot
1590                be used to construct an instance of the class unless
1591                you already have one.  But, for now at least, we're
1592                more generous.  */
1593             if (! TREE_PRIVATE (ctor))
1594               {
1595                 nonprivate_ctor = 1;
1596                 break;
1597               }
1598           }
1599
1600       if (nonprivate_ctor == 0)
1601         {
1602           warning ("%q#T only defines private constructors and has no friends",
1603                    t);
1604           return;
1605         }
1606     }
1607 }
1608
1609 static struct {
1610   gt_pointer_operator new_value;
1611   void *cookie;
1612 } resort_data;
1613
1614 /* Comparison function to compare two TYPE_METHOD_VEC entries by name.  */
1615
1616 static int
1617 method_name_cmp (const void* m1_p, const void* m2_p)
1618 {
1619   const tree *const m1 = m1_p;
1620   const tree *const m2 = m2_p;
1621
1622   if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1623     return 0;
1624   if (*m1 == NULL_TREE)
1625     return -1;
1626   if (*m2 == NULL_TREE)
1627     return 1;
1628   if (DECL_NAME (OVL_CURRENT (*m1)) < DECL_NAME (OVL_CURRENT (*m2)))
1629     return -1;
1630   return 1;
1631 }
1632
1633 /* This routine compares two fields like method_name_cmp but using the
1634    pointer operator in resort_field_decl_data.  */
1635
1636 static int
1637 resort_method_name_cmp (const void* m1_p, const void* m2_p)
1638 {
1639   const tree *const m1 = m1_p;
1640   const tree *const m2 = m2_p;
1641   if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1642     return 0;
1643   if (*m1 == NULL_TREE)
1644     return -1;
1645   if (*m2 == NULL_TREE)
1646     return 1;
1647   {
1648     tree d1 = DECL_NAME (OVL_CURRENT (*m1));
1649     tree d2 = DECL_NAME (OVL_CURRENT (*m2));
1650     resort_data.new_value (&d1, resort_data.cookie);
1651     resort_data.new_value (&d2, resort_data.cookie);
1652     if (d1 < d2)
1653       return -1;
1654   }
1655   return 1;
1656 }
1657
1658 /* Resort TYPE_METHOD_VEC because pointers have been reordered.  */
1659
1660 void
1661 resort_type_method_vec (void* obj,
1662                         void* orig_obj ATTRIBUTE_UNUSED ,
1663                         gt_pointer_operator new_value,
1664                         void* cookie)
1665 {
1666   VEC(tree) *method_vec = (VEC(tree) *) obj;
1667   int len = VEC_length (tree, method_vec);
1668   size_t slot;
1669   tree fn;
1670
1671   /* The type conversion ops have to live at the front of the vec, so we
1672      can't sort them.  */
1673   for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1674        VEC_iterate (tree, method_vec, slot, fn);
1675        ++slot)
1676     if (!DECL_CONV_FN_P (OVL_CURRENT (fn)))
1677       break;
1678
1679   if (len - slot > 1)
1680     {
1681       resort_data.new_value = new_value;
1682       resort_data.cookie = cookie;
1683       qsort (VEC_address (tree, method_vec) + slot, len - slot, sizeof (tree),
1684              resort_method_name_cmp);
1685     }
1686 }
1687
1688 /* Warn about duplicate methods in fn_fields.
1689
1690    Sort methods that are not special (i.e., constructors, destructors,
1691    and type conversion operators) so that we can find them faster in
1692    search.  */
1693
1694 static void
1695 finish_struct_methods (tree t)
1696 {
1697   tree fn_fields;
1698   VEC(tree) *method_vec;
1699   int slot, len;
1700
1701   method_vec = CLASSTYPE_METHOD_VEC (t);
1702   if (!method_vec)
1703     return;
1704
1705   len = VEC_length (tree, method_vec);
1706
1707   /* Clear DECL_IN_AGGR_P for all functions.  */
1708   for (fn_fields = TYPE_METHODS (t); fn_fields;
1709        fn_fields = TREE_CHAIN (fn_fields))
1710     DECL_IN_AGGR_P (fn_fields) = 0;
1711
1712   /* Issue warnings about private constructors and such.  If there are
1713      no methods, then some public defaults are generated.  */
1714   maybe_warn_about_overly_private_class (t);
1715
1716   /* The type conversion ops have to live at the front of the vec, so we
1717      can't sort them.  */
1718   for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1719        VEC_iterate (tree, method_vec, slot, fn_fields);
1720        ++slot)
1721     if (!DECL_CONV_FN_P (OVL_CURRENT (fn_fields)))
1722       break;
1723   if (len - slot > 1)
1724     qsort (VEC_address (tree, method_vec) + slot,
1725            len-slot, sizeof (tree), method_name_cmp);
1726 }
1727
1728 /* Make BINFO's vtable have N entries, including RTTI entries,
1729    vbase and vcall offsets, etc.  Set its type and call the backend
1730    to lay it out.  */
1731
1732 static void
1733 layout_vtable_decl (tree binfo, int n)
1734 {
1735   tree atype;
1736   tree vtable;
1737
1738   atype = build_cplus_array_type (vtable_entry_type,
1739                                   build_index_type (size_int (n - 1)));
1740   layout_type (atype);
1741
1742   /* We may have to grow the vtable.  */
1743   vtable = get_vtbl_decl_for_binfo (binfo);
1744   if (!same_type_p (TREE_TYPE (vtable), atype))
1745     {
1746       TREE_TYPE (vtable) = atype;
1747       DECL_SIZE (vtable) = DECL_SIZE_UNIT (vtable) = NULL_TREE;
1748       layout_decl (vtable, 0);
1749     }
1750 }
1751
1752 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1753    have the same signature.  */
1754
1755 int
1756 same_signature_p (tree fndecl, tree base_fndecl)
1757 {
1758   /* One destructor overrides another if they are the same kind of
1759      destructor.  */
1760   if (DECL_DESTRUCTOR_P (base_fndecl) && DECL_DESTRUCTOR_P (fndecl)
1761       && special_function_p (base_fndecl) == special_function_p (fndecl))
1762     return 1;
1763   /* But a non-destructor never overrides a destructor, nor vice
1764      versa, nor do different kinds of destructors override
1765      one-another.  For example, a complete object destructor does not
1766      override a deleting destructor.  */
1767   if (DECL_DESTRUCTOR_P (base_fndecl) || DECL_DESTRUCTOR_P (fndecl))
1768     return 0;
1769
1770   if (DECL_NAME (fndecl) == DECL_NAME (base_fndecl)
1771       || (DECL_CONV_FN_P (fndecl)
1772           && DECL_CONV_FN_P (base_fndecl)
1773           && same_type_p (DECL_CONV_FN_TYPE (fndecl),
1774                           DECL_CONV_FN_TYPE (base_fndecl))))
1775     {
1776       tree types, base_types;
1777       types = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
1778       base_types = TYPE_ARG_TYPES (TREE_TYPE (base_fndecl));
1779       if ((TYPE_QUALS (TREE_TYPE (TREE_VALUE (base_types)))
1780            == TYPE_QUALS (TREE_TYPE (TREE_VALUE (types))))
1781           && compparms (TREE_CHAIN (base_types), TREE_CHAIN (types)))
1782         return 1;
1783     }
1784   return 0;
1785 }
1786
1787 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1788    subobject.  */
1789
1790 static bool
1791 base_derived_from (tree derived, tree base)
1792 {
1793   tree probe;
1794
1795   for (probe = base; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
1796     {
1797       if (probe == derived)
1798         return true;
1799       else if (BINFO_VIRTUAL_P (probe))
1800         /* If we meet a virtual base, we can't follow the inheritance
1801            any more.  See if the complete type of DERIVED contains
1802            such a virtual base.  */
1803         return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (derived))
1804                 != NULL_TREE);
1805     }
1806   return false;
1807 }
1808
1809 typedef struct find_final_overrider_data_s {
1810   /* The function for which we are trying to find a final overrider.  */
1811   tree fn;
1812   /* The base class in which the function was declared.  */
1813   tree declaring_base;
1814   /* The candidate overriders.  */
1815   tree candidates;
1816   /* Path to most derived.  */
1817   VEC (tree) *path;
1818 } find_final_overrider_data;
1819
1820 /* Add the overrider along the current path to FFOD->CANDIDATES.
1821    Returns true if an overrider was found; false otherwise.  */
1822
1823 static bool
1824 dfs_find_final_overrider_1 (tree binfo,
1825                             find_final_overrider_data *ffod,
1826                             unsigned depth)
1827 {
1828   tree method;
1829
1830   /* If BINFO is not the most derived type, try a more derived class.
1831      A definition there will overrider a definition here.  */
1832   if (depth)
1833     {
1834       depth--;
1835       if (dfs_find_final_overrider_1
1836           (VEC_index (tree, ffod->path, depth), ffod, depth))
1837         return true;
1838     }
1839
1840   method = look_for_overrides_here (BINFO_TYPE (binfo), ffod->fn);
1841   if (method)
1842     {
1843       tree *candidate = &ffod->candidates;
1844
1845       /* Remove any candidates overridden by this new function.  */
1846       while (*candidate)
1847         {
1848           /* If *CANDIDATE overrides METHOD, then METHOD
1849              cannot override anything else on the list.  */
1850           if (base_derived_from (TREE_VALUE (*candidate), binfo))
1851             return true;
1852           /* If METHOD overrides *CANDIDATE, remove *CANDIDATE.  */
1853           if (base_derived_from (binfo, TREE_VALUE (*candidate)))
1854             *candidate = TREE_CHAIN (*candidate);
1855           else
1856             candidate = &TREE_CHAIN (*candidate);
1857         }
1858
1859       /* Add the new function.  */
1860       ffod->candidates = tree_cons (method, binfo, ffod->candidates);
1861       return true;
1862     }
1863
1864   return false;
1865 }
1866
1867 /* Called from find_final_overrider via dfs_walk.  */
1868
1869 static tree
1870 dfs_find_final_overrider_pre (tree binfo, void *data)
1871 {
1872   find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1873
1874   if (binfo == ffod->declaring_base)
1875     dfs_find_final_overrider_1 (binfo, ffod, VEC_length (tree, ffod->path));
1876   VEC_safe_push (tree, ffod->path, binfo);
1877
1878   return NULL_TREE;
1879 }
1880
1881 static tree
1882 dfs_find_final_overrider_post (tree binfo ATTRIBUTE_UNUSED, void *data)
1883 {
1884   find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1885   VEC_pop (tree, ffod->path);
1886
1887   return NULL_TREE;
1888 }
1889
1890 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
1891    FN and whose TREE_VALUE is the binfo for the base where the
1892    overriding occurs.  BINFO (in the hierarchy dominated by the binfo
1893    DERIVED) is the base object in which FN is declared.  */
1894
1895 static tree
1896 find_final_overrider (tree derived, tree binfo, tree fn)
1897 {
1898   find_final_overrider_data ffod;
1899
1900   /* Getting this right is a little tricky.  This is valid:
1901
1902        struct S { virtual void f (); };
1903        struct T { virtual void f (); };
1904        struct U : public S, public T { };
1905
1906      even though calling `f' in `U' is ambiguous.  But,
1907
1908        struct R { virtual void f(); };
1909        struct S : virtual public R { virtual void f (); };
1910        struct T : virtual public R { virtual void f (); };
1911        struct U : public S, public T { };
1912
1913      is not -- there's no way to decide whether to put `S::f' or
1914      `T::f' in the vtable for `R'.
1915
1916      The solution is to look at all paths to BINFO.  If we find
1917      different overriders along any two, then there is a problem.  */
1918   if (DECL_THUNK_P (fn))
1919     fn = THUNK_TARGET (fn);
1920
1921   /* Determine the depth of the hierarchy.  */
1922   ffod.fn = fn;
1923   ffod.declaring_base = binfo;
1924   ffod.candidates = NULL_TREE;
1925   ffod.path = VEC_alloc (tree, 30);
1926
1927   dfs_walk_all (derived, dfs_find_final_overrider_pre,
1928                 dfs_find_final_overrider_post, &ffod);
1929
1930   VEC_free (tree, ffod.path);
1931
1932   /* If there was no winner, issue an error message.  */
1933   if (!ffod.candidates || TREE_CHAIN (ffod.candidates))
1934     {
1935       error ("no unique final overrider for %qD in %qT", fn,
1936              BINFO_TYPE (derived));
1937       return error_mark_node;
1938     }
1939
1940   return ffod.candidates;
1941 }
1942
1943 /* Return the index of the vcall offset for FN when TYPE is used as a
1944    virtual base.  */
1945
1946 static tree
1947 get_vcall_index (tree fn, tree type)
1948 {
1949   VEC (tree_pair_s) *indices = CLASSTYPE_VCALL_INDICES (type);
1950   tree_pair_p p;
1951   unsigned ix;
1952
1953   for (ix = 0; VEC_iterate (tree_pair_s, indices, ix, p); ix++)
1954     if ((DECL_DESTRUCTOR_P (fn) && DECL_DESTRUCTOR_P (p->purpose))
1955         || same_signature_p (fn, p->purpose))
1956       return p->value;
1957
1958   /* There should always be an appropriate index.  */
1959   gcc_unreachable ();
1960 }
1961
1962 /* Update an entry in the vtable for BINFO, which is in the hierarchy
1963    dominated by T.  FN has been overridden in BINFO; VIRTUALS points to the
1964    corresponding position in the BINFO_VIRTUALS list.  */
1965
1966 static void
1967 update_vtable_entry_for_fn (tree t, tree binfo, tree fn, tree* virtuals,
1968                             unsigned ix)
1969 {
1970   tree b;
1971   tree overrider;
1972   tree delta;
1973   tree virtual_base;
1974   tree first_defn;
1975   tree overrider_fn, overrider_target;
1976   tree target_fn = DECL_THUNK_P (fn) ? THUNK_TARGET (fn) : fn;
1977   tree over_return, base_return;
1978   bool lost = false;
1979
1980   /* Find the nearest primary base (possibly binfo itself) which defines
1981      this function; this is the class the caller will convert to when
1982      calling FN through BINFO.  */
1983   for (b = binfo; ; b = get_primary_binfo (b))
1984     {
1985       gcc_assert (b);
1986       if (look_for_overrides_here (BINFO_TYPE (b), target_fn))
1987         break;
1988
1989       /* The nearest definition is from a lost primary.  */
1990       if (BINFO_LOST_PRIMARY_P (b))
1991         lost = true;
1992     }
1993   first_defn = b;
1994
1995   /* Find the final overrider.  */
1996   overrider = find_final_overrider (TYPE_BINFO (t), b, target_fn);
1997   if (overrider == error_mark_node)
1998     return;
1999   overrider_target = overrider_fn = TREE_PURPOSE (overrider);
2000
2001   /* Check for adjusting covariant return types.  */
2002   over_return = TREE_TYPE (TREE_TYPE (overrider_target));
2003   base_return = TREE_TYPE (TREE_TYPE (target_fn));
2004
2005   if (POINTER_TYPE_P (over_return)
2006       && TREE_CODE (over_return) == TREE_CODE (base_return)
2007       && CLASS_TYPE_P (TREE_TYPE (over_return))
2008       && CLASS_TYPE_P (TREE_TYPE (base_return)))
2009     {
2010       /* If FN is a covariant thunk, we must figure out the adjustment
2011          to the final base FN was converting to. As OVERRIDER_TARGET might
2012          also be converting to the return type of FN, we have to
2013          combine the two conversions here.  */
2014       tree fixed_offset, virtual_offset;
2015
2016       over_return = TREE_TYPE (over_return);
2017       base_return = TREE_TYPE (base_return);
2018
2019       if (DECL_THUNK_P (fn))
2020         {
2021           gcc_assert (DECL_RESULT_THUNK_P (fn));
2022           fixed_offset = ssize_int (THUNK_FIXED_OFFSET (fn));
2023           virtual_offset = THUNK_VIRTUAL_OFFSET (fn);
2024         }
2025       else
2026         fixed_offset = virtual_offset = NULL_TREE;
2027
2028       if (virtual_offset)
2029         /* Find the equivalent binfo within the return type of the
2030            overriding function. We will want the vbase offset from
2031            there.  */
2032         virtual_offset = binfo_for_vbase (BINFO_TYPE (virtual_offset),
2033                                           over_return);
2034       else if (!same_type_ignoring_top_level_qualifiers_p
2035                (over_return, base_return))
2036         {
2037           /* There was no existing virtual thunk (which takes
2038              precedence).  So find the binfo of the base function's
2039              return type within the overriding function's return type.
2040              We cannot call lookup base here, because we're inside a
2041              dfs_walk, and will therefore clobber the BINFO_MARKED
2042              flags.  Fortunately we know the covariancy is valid (it
2043              has already been checked), so we can just iterate along
2044              the binfos, which have been chained in inheritance graph
2045              order.  Of course it is lame that we have to repeat the
2046              search here anyway -- we should really be caching pieces
2047              of the vtable and avoiding this repeated work.  */
2048           tree thunk_binfo, base_binfo;
2049
2050           /* Find the base binfo within the overriding function's
2051              return type.  We will always find a thunk_binfo, except
2052              when the covariancy is invalid (which we will have
2053              already diagnosed).  */
2054           for (base_binfo = TYPE_BINFO (base_return),
2055                thunk_binfo = TYPE_BINFO (over_return);
2056                thunk_binfo;
2057                thunk_binfo = TREE_CHAIN (thunk_binfo))
2058             if (SAME_BINFO_TYPE_P (BINFO_TYPE (thunk_binfo),
2059                                    BINFO_TYPE (base_binfo)))
2060               break;
2061
2062           /* See if virtual inheritance is involved.  */
2063           for (virtual_offset = thunk_binfo;
2064                virtual_offset;
2065                virtual_offset = BINFO_INHERITANCE_CHAIN (virtual_offset))
2066             if (BINFO_VIRTUAL_P (virtual_offset))
2067               break;
2068
2069           if (virtual_offset
2070               || (thunk_binfo && !BINFO_OFFSET_ZEROP (thunk_binfo)))
2071             {
2072               tree offset = convert (ssizetype, BINFO_OFFSET (thunk_binfo));
2073
2074               if (virtual_offset)
2075                 {
2076                   /* We convert via virtual base.  Adjust the fixed
2077                      offset to be from there.  */
2078                   offset = size_diffop
2079                     (offset, convert
2080                      (ssizetype, BINFO_OFFSET (virtual_offset)));
2081                 }
2082               if (fixed_offset)
2083                 /* There was an existing fixed offset, this must be
2084                    from the base just converted to, and the base the
2085                    FN was thunking to.  */
2086                 fixed_offset = size_binop (PLUS_EXPR, fixed_offset, offset);
2087               else
2088                 fixed_offset = offset;
2089             }
2090         }
2091
2092       if (fixed_offset || virtual_offset)
2093         /* Replace the overriding function with a covariant thunk.  We
2094            will emit the overriding function in its own slot as
2095            well.  */
2096         overrider_fn = make_thunk (overrider_target, /*this_adjusting=*/0,
2097                                    fixed_offset, virtual_offset);
2098     }
2099   else
2100     gcc_assert (!DECL_THUNK_P (fn));
2101
2102   /* Assume that we will produce a thunk that convert all the way to
2103      the final overrider, and not to an intermediate virtual base.  */
2104   virtual_base = NULL_TREE;
2105
2106   /* See if we can convert to an intermediate virtual base first, and then
2107      use the vcall offset located there to finish the conversion.  */
2108   for (; b; b = BINFO_INHERITANCE_CHAIN (b))
2109     {
2110       /* If we find the final overrider, then we can stop
2111          walking.  */
2112       if (SAME_BINFO_TYPE_P (BINFO_TYPE (b),
2113                              BINFO_TYPE (TREE_VALUE (overrider))))
2114         break;
2115
2116       /* If we find a virtual base, and we haven't yet found the
2117          overrider, then there is a virtual base between the
2118          declaring base (first_defn) and the final overrider.  */
2119       if (BINFO_VIRTUAL_P (b))
2120         {
2121           virtual_base = b;
2122           break;
2123         }
2124     }
2125
2126   if (overrider_fn != overrider_target && !virtual_base)
2127     {
2128       /* The ABI specifies that a covariant thunk includes a mangling
2129          for a this pointer adjustment.  This-adjusting thunks that
2130          override a function from a virtual base have a vcall
2131          adjustment.  When the virtual base in question is a primary
2132          virtual base, we know the adjustments are zero, (and in the
2133          non-covariant case, we would not use the thunk).
2134          Unfortunately we didn't notice this could happen, when
2135          designing the ABI and so never mandated that such a covariant
2136          thunk should be emitted.  Because we must use the ABI mandated
2137          name, we must continue searching from the binfo where we
2138          found the most recent definition of the function, towards the
2139          primary binfo which first introduced the function into the
2140          vtable.  If that enters a virtual base, we must use a vcall
2141          this-adjusting thunk.  Bleah! */
2142       tree probe = first_defn;
2143
2144       while ((probe = get_primary_binfo (probe))
2145              && (unsigned) list_length (BINFO_VIRTUALS (probe)) > ix)
2146         if (BINFO_VIRTUAL_P (probe))
2147           virtual_base = probe;
2148
2149       if (virtual_base)
2150         /* Even if we find a virtual base, the correct delta is
2151            between the overrider and the binfo we're building a vtable
2152            for.  */
2153         goto virtual_covariant;
2154     }
2155
2156   /* Compute the constant adjustment to the `this' pointer.  The
2157      `this' pointer, when this function is called, will point at BINFO
2158      (or one of its primary bases, which are at the same offset).  */
2159   if (virtual_base)
2160     /* The `this' pointer needs to be adjusted from the declaration to
2161        the nearest virtual base.  */
2162     delta = size_diffop (convert (ssizetype, BINFO_OFFSET (virtual_base)),
2163                          convert (ssizetype, BINFO_OFFSET (first_defn)));
2164   else if (lost)
2165     /* If the nearest definition is in a lost primary, we don't need an
2166        entry in our vtable.  Except possibly in a constructor vtable,
2167        if we happen to get our primary back.  In that case, the offset
2168        will be zero, as it will be a primary base.  */
2169     delta = size_zero_node;
2170   else
2171     /* The `this' pointer needs to be adjusted from pointing to
2172        BINFO to pointing at the base where the final overrider
2173        appears.  */
2174     virtual_covariant:
2175     delta = size_diffop (convert (ssizetype,
2176                                   BINFO_OFFSET (TREE_VALUE (overrider))),
2177                          convert (ssizetype, BINFO_OFFSET (binfo)));
2178
2179   modify_vtable_entry (t, binfo, overrider_fn, delta, virtuals);
2180
2181   if (virtual_base)
2182     BV_VCALL_INDEX (*virtuals)
2183       = get_vcall_index (overrider_target, BINFO_TYPE (virtual_base));
2184   else
2185     BV_VCALL_INDEX (*virtuals) = NULL_TREE;
2186 }
2187
2188 /* Called from modify_all_vtables via dfs_walk.  */
2189
2190 static tree
2191 dfs_modify_vtables (tree binfo, void* data)
2192 {
2193   tree t = (tree) data;
2194   tree virtuals;
2195   tree old_virtuals;
2196   unsigned ix;
2197
2198   if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
2199     /* A base without a vtable needs no modification, and its bases
2200        are uninteresting.  */
2201     return dfs_skip_bases;
2202
2203   if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t)
2204       && !CLASSTYPE_HAS_PRIMARY_BASE_P (t))
2205     /* Don't do the primary vtable, if it's new.  */
2206     return NULL_TREE;
2207
2208   if (BINFO_PRIMARY_P (binfo) && !BINFO_VIRTUAL_P (binfo))
2209     /* There's no need to modify the vtable for a non-virtual primary
2210        base; we're not going to use that vtable anyhow.  We do still
2211        need to do this for virtual primary bases, as they could become
2212        non-primary in a construction vtable.  */
2213     return NULL_TREE;
2214
2215   make_new_vtable (t, binfo);
2216
2217   /* Now, go through each of the virtual functions in the virtual
2218      function table for BINFO.  Find the final overrider, and update
2219      the BINFO_VIRTUALS list appropriately.  */
2220   for (ix = 0, virtuals = BINFO_VIRTUALS (binfo),
2221          old_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
2222        virtuals;
2223        ix++, virtuals = TREE_CHAIN (virtuals),
2224          old_virtuals = TREE_CHAIN (old_virtuals))
2225     update_vtable_entry_for_fn (t,
2226                                 binfo,
2227                                 BV_FN (old_virtuals),
2228                                 &virtuals, ix);
2229
2230   return NULL_TREE;
2231 }
2232
2233 /* Update all of the primary and secondary vtables for T.  Create new
2234    vtables as required, and initialize their RTTI information.  Each
2235    of the functions in VIRTUALS is declared in T and may override a
2236    virtual function from a base class; find and modify the appropriate
2237    entries to point to the overriding functions.  Returns a list, in
2238    declaration order, of the virtual functions that are declared in T,
2239    but do not appear in the primary base class vtable, and which
2240    should therefore be appended to the end of the vtable for T.  */
2241
2242 static tree
2243 modify_all_vtables (tree t, tree virtuals)
2244 {
2245   tree binfo = TYPE_BINFO (t);
2246   tree *fnsp;
2247
2248   /* Update all of the vtables.  */
2249   dfs_walk_once (binfo, dfs_modify_vtables, NULL, t);
2250
2251   /* Add virtual functions not already in our primary vtable. These
2252      will be both those introduced by this class, and those overridden
2253      from secondary bases.  It does not include virtuals merely
2254      inherited from secondary bases.  */
2255   for (fnsp = &virtuals; *fnsp; )
2256     {
2257       tree fn = TREE_VALUE (*fnsp);
2258
2259       if (!value_member (fn, BINFO_VIRTUALS (binfo))
2260           || DECL_VINDEX (fn) == error_mark_node)
2261         {
2262           /* We don't need to adjust the `this' pointer when
2263              calling this function.  */
2264           BV_DELTA (*fnsp) = integer_zero_node;
2265           BV_VCALL_INDEX (*fnsp) = NULL_TREE;
2266
2267           /* This is a function not already in our vtable.  Keep it.  */
2268           fnsp = &TREE_CHAIN (*fnsp);
2269         }
2270       else
2271         /* We've already got an entry for this function.  Skip it.  */
2272         *fnsp = TREE_CHAIN (*fnsp);
2273     }
2274
2275   return virtuals;
2276 }
2277
2278 /* Get the base virtual function declarations in T that have the
2279    indicated NAME.  */
2280
2281 static tree
2282 get_basefndecls (tree name, tree t)
2283 {
2284   tree methods;
2285   tree base_fndecls = NULL_TREE;
2286   int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
2287   int i;
2288
2289   /* Find virtual functions in T with the indicated NAME.  */
2290   i = lookup_fnfields_1 (t, name);
2291   if (i != -1)
2292     for (methods = VEC_index (tree, CLASSTYPE_METHOD_VEC (t), i);
2293          methods;
2294          methods = OVL_NEXT (methods))
2295       {
2296         tree method = OVL_CURRENT (methods);
2297
2298         if (TREE_CODE (method) == FUNCTION_DECL
2299             && DECL_VINDEX (method))
2300           base_fndecls = tree_cons (NULL_TREE, method, base_fndecls);
2301       }
2302
2303   if (base_fndecls)
2304     return base_fndecls;
2305
2306   for (i = 0; i < n_baseclasses; i++)
2307     {
2308       tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (t), i));
2309       base_fndecls = chainon (get_basefndecls (name, basetype),
2310                               base_fndecls);
2311     }
2312
2313   return base_fndecls;
2314 }
2315
2316 /* If this declaration supersedes the declaration of
2317    a method declared virtual in the base class, then
2318    mark this field as being virtual as well.  */
2319
2320 void
2321 check_for_override (tree decl, tree ctype)
2322 {
2323   if (TREE_CODE (decl) == TEMPLATE_DECL)
2324     /* In [temp.mem] we have:
2325
2326          A specialization of a member function template does not
2327          override a virtual function from a base class.  */
2328     return;
2329   if ((DECL_DESTRUCTOR_P (decl)
2330        || IDENTIFIER_VIRTUAL_P (DECL_NAME (decl))
2331        || DECL_CONV_FN_P (decl))
2332       && look_for_overrides (ctype, decl)
2333       && !DECL_STATIC_FUNCTION_P (decl))
2334     /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2335        the error_mark_node so that we know it is an overriding
2336        function.  */
2337     DECL_VINDEX (decl) = decl;
2338
2339   if (DECL_VIRTUAL_P (decl))
2340     {
2341       if (!DECL_VINDEX (decl))
2342         DECL_VINDEX (decl) = error_mark_node;
2343       IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) = 1;
2344     }
2345 }
2346
2347 /* Warn about hidden virtual functions that are not overridden in t.
2348    We know that constructors and destructors don't apply.  */
2349
2350 void
2351 warn_hidden (tree t)
2352 {
2353   VEC(tree) *method_vec = CLASSTYPE_METHOD_VEC (t);
2354   tree fns;
2355   size_t i;
2356
2357   /* We go through each separately named virtual function.  */
2358   for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
2359        VEC_iterate (tree, method_vec, i, fns);
2360        ++i)
2361     {
2362       tree fn;
2363       tree name;
2364       tree fndecl;
2365       tree base_fndecls;
2366       tree base_binfo;
2367       tree binfo;
2368       int j;
2369
2370       /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2371          have the same name.  Figure out what name that is.  */
2372       name = DECL_NAME (OVL_CURRENT (fns));
2373       /* There are no possibly hidden functions yet.  */
2374       base_fndecls = NULL_TREE;
2375       /* Iterate through all of the base classes looking for possibly
2376          hidden functions.  */
2377       for (binfo = TYPE_BINFO (t), j = 0;
2378            BINFO_BASE_ITERATE (binfo, j, base_binfo); j++)
2379         {
2380           tree basetype = BINFO_TYPE (base_binfo);
2381           base_fndecls = chainon (get_basefndecls (name, basetype),
2382                                   base_fndecls);
2383         }
2384
2385       /* If there are no functions to hide, continue.  */
2386       if (!base_fndecls)
2387         continue;
2388
2389       /* Remove any overridden functions.  */
2390       for (fn = fns; fn; fn = OVL_NEXT (fn))
2391         {
2392           fndecl = OVL_CURRENT (fn);
2393           if (DECL_VINDEX (fndecl))
2394             {
2395               tree *prev = &base_fndecls;
2396
2397               while (*prev)
2398                 /* If the method from the base class has the same
2399                    signature as the method from the derived class, it
2400                    has been overridden.  */
2401                 if (same_signature_p (fndecl, TREE_VALUE (*prev)))
2402                   *prev = TREE_CHAIN (*prev);
2403                 else
2404                   prev = &TREE_CHAIN (*prev);
2405             }
2406         }
2407
2408       /* Now give a warning for all base functions without overriders,
2409          as they are hidden.  */
2410       while (base_fndecls)
2411         {
2412           /* Here we know it is a hider, and no overrider exists.  */
2413           cp_warning_at ("%qD was hidden", TREE_VALUE (base_fndecls));
2414           cp_warning_at ("  by %qD", fns);
2415           base_fndecls = TREE_CHAIN (base_fndecls);
2416         }
2417     }
2418 }
2419
2420 /* Check for things that are invalid.  There are probably plenty of other
2421    things we should check for also.  */
2422
2423 static void
2424 finish_struct_anon (tree t)
2425 {
2426   tree field;
2427
2428   for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
2429     {
2430       if (TREE_STATIC (field))
2431         continue;
2432       if (TREE_CODE (field) != FIELD_DECL)
2433         continue;
2434
2435       if (DECL_NAME (field) == NULL_TREE
2436           && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
2437         {
2438           tree elt = TYPE_FIELDS (TREE_TYPE (field));
2439           for (; elt; elt = TREE_CHAIN (elt))
2440             {
2441               /* We're generally only interested in entities the user
2442                  declared, but we also find nested classes by noticing
2443                  the TYPE_DECL that we create implicitly.  You're
2444                  allowed to put one anonymous union inside another,
2445                  though, so we explicitly tolerate that.  We use
2446                  TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2447                  we also allow unnamed types used for defining fields.  */
2448               if (DECL_ARTIFICIAL (elt)
2449                   && (!DECL_IMPLICIT_TYPEDEF_P (elt)
2450                       || TYPE_ANONYMOUS_P (TREE_TYPE (elt))))
2451                 continue;
2452
2453               if (TREE_CODE (elt) != FIELD_DECL)
2454                 {
2455                   cp_pedwarn_at ("%q#D invalid; an anonymous union can "
2456                                  "only have non-static data members",
2457                                  elt);
2458                   continue;
2459                 }
2460
2461               if (TREE_PRIVATE (elt))
2462                 cp_pedwarn_at ("private member %q#D in anonymous union",
2463                                elt);
2464               else if (TREE_PROTECTED (elt))
2465                 cp_pedwarn_at ("protected member %q#D in anonymous union",
2466                                elt);
2467
2468               TREE_PRIVATE (elt) = TREE_PRIVATE (field);
2469               TREE_PROTECTED (elt) = TREE_PROTECTED (field);
2470             }
2471         }
2472     }
2473 }
2474
2475 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2476    will be used later during class template instantiation.
2477    When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2478    a non-static member data (FIELD_DECL), a member function
2479    (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2480    a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2481    When FRIEND_P is nonzero, T is either a friend class
2482    (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2483    (FUNCTION_DECL, TEMPLATE_DECL).  */
2484
2485 void
2486 maybe_add_class_template_decl_list (tree type, tree t, int friend_p)
2487 {
2488   /* Save some memory by not creating TREE_LIST if TYPE is not template.  */
2489   if (CLASSTYPE_TEMPLATE_INFO (type))
2490     CLASSTYPE_DECL_LIST (type)
2491       = tree_cons (friend_p ? NULL_TREE : type,
2492                    t, CLASSTYPE_DECL_LIST (type));
2493 }
2494
2495 /* Create default constructors, assignment operators, and so forth for
2496    the type indicated by T, if they are needed.  CANT_HAVE_CONST_CTOR,
2497    and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2498    the class cannot have a default constructor, copy constructor
2499    taking a const reference argument, or an assignment operator taking
2500    a const reference, respectively.  */
2501
2502 static void
2503 add_implicitly_declared_members (tree t,
2504                                  int cant_have_const_cctor,
2505                                  int cant_have_const_assignment)
2506 {
2507   /* Destructor.  */
2508   if (!CLASSTYPE_DESTRUCTORS (t))
2509     {
2510       /* In general, we create destructors lazily.  */
2511       CLASSTYPE_LAZY_DESTRUCTOR (t) = 1;
2512       /* However, if the implicit destructor is non-trivial
2513          destructor, we sometimes have to create it at this point.  */
2514       if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
2515         {
2516           bool lazy_p = true;
2517
2518           if (TYPE_FOR_JAVA (t))
2519             /* If this a Java class, any non-trivial destructor is
2520                invalid, even if compiler-generated.  Therefore, if the
2521                destructor is non-trivial we create it now.  */
2522             lazy_p = false;
2523           else
2524             {
2525               tree binfo;
2526               tree base_binfo;
2527               int ix;
2528
2529               /* If the implicit destructor will be virtual, then we must
2530                  generate it now because (unfortunately) we do not
2531                  generate virtual tables lazily.  */
2532               binfo = TYPE_BINFO (t);
2533               for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
2534                 {
2535                   tree base_type;
2536                   tree dtor;
2537
2538                   base_type = BINFO_TYPE (base_binfo);
2539                   dtor = CLASSTYPE_DESTRUCTORS (base_type);
2540                   if (dtor && DECL_VIRTUAL_P (dtor))
2541                     {
2542                       lazy_p = false;
2543                       break;
2544                     }
2545                 }
2546             }
2547
2548           /* If we can't get away with being lazy, generate the destructor
2549              now.  */
2550           if (!lazy_p)
2551             lazily_declare_fn (sfk_destructor, t);
2552         }
2553     }
2554
2555   /* Default constructor.  */
2556   if (! TYPE_HAS_CONSTRUCTOR (t))
2557     {
2558       TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 1;
2559       CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 1;
2560     }
2561
2562   /* Copy constructor.  */
2563   if (! TYPE_HAS_INIT_REF (t) && ! TYPE_FOR_JAVA (t))
2564     {
2565       TYPE_HAS_INIT_REF (t) = 1;
2566       TYPE_HAS_CONST_INIT_REF (t) = !cant_have_const_cctor;
2567       CLASSTYPE_LAZY_COPY_CTOR (t) = 1;
2568       TYPE_HAS_CONSTRUCTOR (t) = 1;
2569     }
2570
2571   /* If there is no assignment operator, one will be created if and
2572      when it is needed.  For now, just record whether or not the type
2573      of the parameter to the assignment operator will be a const or
2574      non-const reference.  */
2575   if (!TYPE_HAS_ASSIGN_REF (t) && !TYPE_FOR_JAVA (t))
2576     {
2577       TYPE_HAS_ASSIGN_REF (t) = 1;
2578       TYPE_HAS_CONST_ASSIGN_REF (t) = !cant_have_const_assignment;
2579       CLASSTYPE_LAZY_ASSIGNMENT_OP (t) = 1;
2580     }
2581 }
2582
2583 /* Subroutine of finish_struct_1.  Recursively count the number of fields
2584    in TYPE, including anonymous union members.  */
2585
2586 static int
2587 count_fields (tree fields)
2588 {
2589   tree x;
2590   int n_fields = 0;
2591   for (x = fields; x; x = TREE_CHAIN (x))
2592     {
2593       if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2594         n_fields += count_fields (TYPE_FIELDS (TREE_TYPE (x)));
2595       else
2596         n_fields += 1;
2597     }
2598   return n_fields;
2599 }
2600
2601 /* Subroutine of finish_struct_1.  Recursively add all the fields in the
2602    TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX.  */
2603
2604 static int
2605 add_fields_to_record_type (tree fields, struct sorted_fields_type *field_vec, int idx)
2606 {
2607   tree x;
2608   for (x = fields; x; x = TREE_CHAIN (x))
2609     {
2610       if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2611         idx = add_fields_to_record_type (TYPE_FIELDS (TREE_TYPE (x)), field_vec, idx);
2612       else
2613         field_vec->elts[idx++] = x;
2614     }
2615   return idx;
2616 }
2617
2618 /* FIELD is a bit-field.  We are finishing the processing for its
2619    enclosing type.  Issue any appropriate messages and set appropriate
2620    flags.  */
2621
2622 static void
2623 check_bitfield_decl (tree field)
2624 {
2625   tree type = TREE_TYPE (field);
2626   tree w = NULL_TREE;
2627
2628   /* Detect invalid bit-field type.  */
2629   if (DECL_INITIAL (field)
2630       && ! INTEGRAL_TYPE_P (TREE_TYPE (field)))
2631     {
2632       cp_error_at ("bit-field %q#D with non-integral type", field);
2633       w = error_mark_node;
2634     }
2635
2636   /* Detect and ignore out of range field width.  */
2637   if (DECL_INITIAL (field))
2638     {
2639       w = DECL_INITIAL (field);
2640
2641       /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs.  */
2642       STRIP_NOPS (w);
2643
2644       /* detect invalid field size.  */
2645       w = integral_constant_value (w);
2646
2647       if (TREE_CODE (w) != INTEGER_CST)
2648         {
2649           cp_error_at ("bit-field %qD width not an integer constant",
2650                        field);
2651           w = error_mark_node;
2652         }
2653       else if (tree_int_cst_sgn (w) < 0)
2654         {
2655           cp_error_at ("negative width in bit-field %qD", field);
2656           w = error_mark_node;
2657         }
2658       else if (integer_zerop (w) && DECL_NAME (field) != 0)
2659         {
2660           cp_error_at ("zero width for bit-field %qD", field);
2661           w = error_mark_node;
2662         }
2663       else if (compare_tree_int (w, TYPE_PRECISION (type)) > 0
2664                && TREE_CODE (type) != ENUMERAL_TYPE
2665                && TREE_CODE (type) != BOOLEAN_TYPE)
2666         cp_warning_at ("width of %qD exceeds its type", field);
2667       else if (TREE_CODE (type) == ENUMERAL_TYPE
2668                && (0 > compare_tree_int (w,
2669                                          min_precision (TYPE_MIN_VALUE (type),
2670                                                         TYPE_UNSIGNED (type)))
2671                    ||  0 > compare_tree_int (w,
2672                                              min_precision
2673                                              (TYPE_MAX_VALUE (type),
2674                                               TYPE_UNSIGNED (type)))))
2675         cp_warning_at ("%qD is too small to hold all values of %q#T",
2676                        field, type);
2677     }
2678
2679   /* Remove the bit-field width indicator so that the rest of the
2680      compiler does not treat that value as an initializer.  */
2681   DECL_INITIAL (field) = NULL_TREE;
2682
2683   if (w != error_mark_node)
2684     {
2685       DECL_SIZE (field) = convert (bitsizetype, w);
2686       DECL_BIT_FIELD (field) = 1;
2687     }
2688   else
2689     {
2690       /* Non-bit-fields are aligned for their type.  */
2691       DECL_BIT_FIELD (field) = 0;
2692       CLEAR_DECL_C_BIT_FIELD (field);
2693     }
2694 }
2695
2696 /* FIELD is a non bit-field.  We are finishing the processing for its
2697    enclosing type T.  Issue any appropriate messages and set appropriate
2698    flags.  */
2699
2700 static void
2701 check_field_decl (tree field,
2702                   tree t,
2703                   int* cant_have_const_ctor,
2704                   int* no_const_asn_ref,
2705                   int* any_default_members)
2706 {
2707   tree type = strip_array_types (TREE_TYPE (field));
2708
2709   /* An anonymous union cannot contain any fields which would change
2710      the settings of CANT_HAVE_CONST_CTOR and friends.  */
2711   if (ANON_UNION_TYPE_P (type))
2712     ;
2713   /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
2714      structs.  So, we recurse through their fields here.  */
2715   else if (ANON_AGGR_TYPE_P (type))
2716     {
2717       tree fields;
2718
2719       for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2720         if (TREE_CODE (fields) == FIELD_DECL && !DECL_C_BIT_FIELD (field))
2721           check_field_decl (fields, t, cant_have_const_ctor,
2722                             no_const_asn_ref, any_default_members);
2723     }
2724   /* Check members with class type for constructors, destructors,
2725      etc.  */
2726   else if (CLASS_TYPE_P (type))
2727     {
2728       /* Never let anything with uninheritable virtuals
2729          make it through without complaint.  */
2730       abstract_virtuals_error (field, type);
2731
2732       if (TREE_CODE (t) == UNION_TYPE)
2733         {
2734           if (TYPE_NEEDS_CONSTRUCTING (type))
2735             cp_error_at ("member %q#D with constructor not allowed in union",
2736                          field);
2737           if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
2738             cp_error_at ("member %q#D with destructor not allowed in union",
2739                          field);
2740           if (TYPE_HAS_COMPLEX_ASSIGN_REF (type))
2741             cp_error_at ("member %q#D with copy assignment operator not allowed in union",
2742                          field);
2743         }
2744       else
2745         {
2746           TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (type);
2747           TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
2748             |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type);
2749           TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_HAS_COMPLEX_ASSIGN_REF (type);
2750           TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (type);
2751         }
2752
2753       if (!TYPE_HAS_CONST_INIT_REF (type))
2754         *cant_have_const_ctor = 1;
2755
2756       if (!TYPE_HAS_CONST_ASSIGN_REF (type))
2757         *no_const_asn_ref = 1;
2758     }
2759   if (DECL_INITIAL (field) != NULL_TREE)
2760     {
2761       /* `build_class_init_list' does not recognize
2762          non-FIELD_DECLs.  */
2763       if (TREE_CODE (t) == UNION_TYPE && any_default_members != 0)
2764         error ("multiple fields in union %qT initialized", t);
2765       *any_default_members = 1;
2766     }
2767 }
2768
2769 /* Check the data members (both static and non-static), class-scoped
2770    typedefs, etc., appearing in the declaration of T.  Issue
2771    appropriate diagnostics.  Sets ACCESS_DECLS to a list (in
2772    declaration order) of access declarations; each TREE_VALUE in this
2773    list is a USING_DECL.
2774
2775    In addition, set the following flags:
2776
2777      EMPTY_P
2778        The class is empty, i.e., contains no non-static data members.
2779
2780      CANT_HAVE_CONST_CTOR_P
2781        This class cannot have an implicitly generated copy constructor
2782        taking a const reference.
2783
2784      CANT_HAVE_CONST_ASN_REF
2785        This class cannot have an implicitly generated assignment
2786        operator taking a const reference.
2787
2788    All of these flags should be initialized before calling this
2789    function.
2790
2791    Returns a pointer to the end of the TYPE_FIELDs chain; additional
2792    fields can be added by adding to this chain.  */
2793
2794 static void
2795 check_field_decls (tree t, tree *access_decls,
2796                    int *cant_have_const_ctor_p,
2797                    int *no_const_asn_ref_p)
2798 {
2799   tree *field;
2800   tree *next;
2801   bool has_pointers;
2802   int any_default_members;
2803
2804   /* Assume there are no access declarations.  */
2805   *access_decls = NULL_TREE;
2806   /* Assume this class has no pointer members.  */
2807   has_pointers = false;
2808   /* Assume none of the members of this class have default
2809      initializations.  */
2810   any_default_members = 0;
2811
2812   for (field = &TYPE_FIELDS (t); *field; field = next)
2813     {
2814       tree x = *field;
2815       tree type = TREE_TYPE (x);
2816
2817       next = &TREE_CHAIN (x);
2818
2819       if (TREE_CODE (x) == FIELD_DECL)
2820         {
2821           if (TYPE_PACKED (t))
2822             {
2823               if (!pod_type_p (TREE_TYPE (x)) && !TYPE_PACKED (TREE_TYPE (x)))
2824                 cp_warning_at
2825                   ("ignoring packed attribute on unpacked non-POD field %q#D",
2826                    x);
2827               else
2828                 DECL_PACKED (x) = 1;
2829             }
2830
2831           if (DECL_C_BIT_FIELD (x) && integer_zerop (DECL_INITIAL (x)))
2832             /* We don't treat zero-width bitfields as making a class
2833                non-empty.  */
2834             ;
2835           else
2836             {
2837               tree element_type;
2838
2839               /* The class is non-empty.  */
2840               CLASSTYPE_EMPTY_P (t) = 0;
2841               /* The class is not even nearly empty.  */
2842               CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
2843               /* If one of the data members contains an empty class,
2844                  so does T.  */
2845               element_type = strip_array_types (type);
2846               if (CLASS_TYPE_P (element_type)
2847                   && CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type))
2848                 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
2849             }
2850         }
2851
2852       if (TREE_CODE (x) == USING_DECL)
2853         {
2854           /* Prune the access declaration from the list of fields.  */
2855           *field = TREE_CHAIN (x);
2856
2857           /* Save the access declarations for our caller.  */
2858           *access_decls = tree_cons (NULL_TREE, x, *access_decls);
2859
2860           /* Since we've reset *FIELD there's no reason to skip to the
2861              next field.  */
2862           next = field;
2863           continue;
2864         }
2865
2866       if (TREE_CODE (x) == TYPE_DECL
2867           || TREE_CODE (x) == TEMPLATE_DECL)
2868         continue;
2869
2870       /* If we've gotten this far, it's a data member, possibly static,
2871          or an enumerator.  */
2872       DECL_CONTEXT (x) = t;
2873
2874       /* When this goes into scope, it will be a non-local reference.  */
2875       DECL_NONLOCAL (x) = 1;
2876
2877       if (TREE_CODE (t) == UNION_TYPE)
2878         {
2879           /* [class.union]
2880
2881              If a union contains a static data member, or a member of
2882              reference type, the program is ill-formed.  */
2883           if (TREE_CODE (x) == VAR_DECL)
2884             {
2885               cp_error_at ("%qD may not be static because it is a member of a union", x);
2886               continue;
2887             }
2888           if (TREE_CODE (type) == REFERENCE_TYPE)
2889             {
2890               cp_error_at ("%qD may not have reference type %qT because"
2891                            " it is a member of a union",
2892                            x, type);
2893               continue;
2894             }
2895         }
2896
2897       /* ``A local class cannot have static data members.'' ARM 9.4 */
2898       if (current_function_decl && TREE_STATIC (x))
2899         cp_error_at ("field %qD in local class cannot be static", x);
2900
2901       /* Perform error checking that did not get done in
2902          grokdeclarator.  */
2903       if (TREE_CODE (type) == FUNCTION_TYPE)
2904         {
2905           cp_error_at ("field %qD invalidly declared function type", x);
2906           type = build_pointer_type (type);
2907           TREE_TYPE (x) = type;
2908         }
2909       else if (TREE_CODE (type) == METHOD_TYPE)
2910         {
2911           cp_error_at ("field %qD invalidly declared method type", x);
2912           type = build_pointer_type (type);
2913           TREE_TYPE (x) = type;
2914         }
2915
2916       if (type == error_mark_node)
2917         continue;
2918
2919       if (TREE_CODE (x) == CONST_DECL || TREE_CODE (x) == VAR_DECL)
2920         continue;
2921
2922       /* Now it can only be a FIELD_DECL.  */
2923
2924       if (TREE_PRIVATE (x) || TREE_PROTECTED (x))
2925         CLASSTYPE_NON_AGGREGATE (t) = 1;
2926
2927       /* If this is of reference type, check if it needs an init.
2928          Also do a little ANSI jig if necessary.  */
2929       if (TREE_CODE (type) == REFERENCE_TYPE)
2930         {
2931           CLASSTYPE_NON_POD_P (t) = 1;
2932           if (DECL_INITIAL (x) == NULL_TREE)
2933             SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
2934
2935           /* ARM $12.6.2: [A member initializer list] (or, for an
2936              aggregate, initialization by a brace-enclosed list) is the
2937              only way to initialize nonstatic const and reference
2938              members.  */
2939           TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
2940
2941           if (! TYPE_HAS_CONSTRUCTOR (t) && CLASSTYPE_NON_AGGREGATE (t)
2942               && extra_warnings)
2943             cp_warning_at ("non-static reference %q#D in class without a constructor", x);
2944         }
2945
2946       type = strip_array_types (type);
2947
2948       /* This is used by -Weffc++ (see below). Warn only for pointers
2949          to members which might hold dynamic memory. So do not warn
2950          for pointers to functions or pointers to members.  */
2951       if (TYPE_PTR_P (type)
2952           && !TYPE_PTRFN_P (type)
2953           && !TYPE_PTR_TO_MEMBER_P (type))
2954         has_pointers = true;
2955
2956       if (CLASS_TYPE_P (type))
2957         {
2958           if (CLASSTYPE_REF_FIELDS_NEED_INIT (type))
2959             SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
2960           if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (type))
2961             SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
2962         }
2963
2964       if (DECL_MUTABLE_P (x) || TYPE_HAS_MUTABLE_P (type))
2965         CLASSTYPE_HAS_MUTABLE (t) = 1;
2966
2967       if (! pod_type_p (type))
2968         /* DR 148 now allows pointers to members (which are POD themselves),
2969            to be allowed in POD structs.  */
2970         CLASSTYPE_NON_POD_P (t) = 1;
2971
2972       if (! zero_init_p (type))
2973         CLASSTYPE_NON_ZERO_INIT_P (t) = 1;
2974
2975       /* If any field is const, the structure type is pseudo-const.  */
2976       if (CP_TYPE_CONST_P (type))
2977         {
2978           C_TYPE_FIELDS_READONLY (t) = 1;
2979           if (DECL_INITIAL (x) == NULL_TREE)
2980             SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
2981
2982           /* ARM $12.6.2: [A member initializer list] (or, for an
2983              aggregate, initialization by a brace-enclosed list) is the
2984              only way to initialize nonstatic const and reference
2985              members.  */
2986           TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
2987
2988           if (! TYPE_HAS_CONSTRUCTOR (t) && CLASSTYPE_NON_AGGREGATE (t)
2989               && extra_warnings)
2990             cp_warning_at ("non-static const member %q#D in class without a constructor", x);
2991         }
2992       /* A field that is pseudo-const makes the structure likewise.  */
2993       else if (CLASS_TYPE_P (type))
2994         {
2995           C_TYPE_FIELDS_READONLY (t) |= C_TYPE_FIELDS_READONLY (type);
2996           SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t,
2997             CLASSTYPE_READONLY_FIELDS_NEED_INIT (t)
2998             | CLASSTYPE_READONLY_FIELDS_NEED_INIT (type));
2999         }
3000
3001       /* Core issue 80: A nonstatic data member is required to have a
3002          different name from the class iff the class has a
3003          user-defined constructor.  */
3004       if (constructor_name_p (DECL_NAME (x), t) && TYPE_HAS_CONSTRUCTOR (t))
3005         cp_pedwarn_at ("field %q#D with same name as class", x);
3006
3007       /* We set DECL_C_BIT_FIELD in grokbitfield.
3008          If the type and width are valid, we'll also set DECL_BIT_FIELD.  */
3009       if (DECL_C_BIT_FIELD (x))
3010         check_bitfield_decl (x);
3011       else
3012         check_field_decl (x, t,
3013                           cant_have_const_ctor_p,
3014                           no_const_asn_ref_p,
3015                           &any_default_members);
3016     }
3017
3018   /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3019      it should also define a copy constructor and an assignment operator to
3020      implement the correct copy semantic (deep vs shallow, etc.). As it is
3021      not feasible to check whether the constructors do allocate dynamic memory
3022      and store it within members, we approximate the warning like this:
3023
3024      -- Warn only if there are members which are pointers
3025      -- Warn only if there is a non-trivial constructor (otherwise,
3026         there cannot be memory allocated).
3027      -- Warn only if there is a non-trivial destructor. We assume that the
3028         user at least implemented the cleanup correctly, and a destructor
3029         is needed to free dynamic memory.
3030
3031      This seems enough for practical purposes.  */
3032     if (warn_ecpp
3033         && has_pointers
3034         && TYPE_HAS_CONSTRUCTOR (t)
3035         && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
3036         && !(TYPE_HAS_INIT_REF (t) && TYPE_HAS_ASSIGN_REF (t)))
3037     {
3038       warning ("%q#T has pointer data members", t);
3039
3040       if (! TYPE_HAS_INIT_REF (t))
3041         {
3042           warning ("  but does not override %<%T(const %T&)%>", t, t);
3043           if (! TYPE_HAS_ASSIGN_REF (t))
3044             warning ("  or %<operator=(const %T&)%>", t);
3045         }
3046       else if (! TYPE_HAS_ASSIGN_REF (t))
3047         warning ("  but does not override %<operator=(const %T&)%>", t);
3048     }
3049
3050
3051   /* Check anonymous struct/anonymous union fields.  */
3052   finish_struct_anon (t);
3053
3054   /* We've built up the list of access declarations in reverse order.
3055      Fix that now.  */
3056   *access_decls = nreverse (*access_decls);
3057 }
3058
3059 /* If TYPE is an empty class type, records its OFFSET in the table of
3060    OFFSETS.  */
3061
3062 static int
3063 record_subobject_offset (tree type, tree offset, splay_tree offsets)
3064 {
3065   splay_tree_node n;
3066
3067   if (!is_empty_class (type))
3068     return 0;
3069
3070   /* Record the location of this empty object in OFFSETS.  */
3071   n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3072   if (!n)
3073     n = splay_tree_insert (offsets,
3074                            (splay_tree_key) offset,
3075                            (splay_tree_value) NULL_TREE);
3076   n->value = ((splay_tree_value)
3077               tree_cons (NULL_TREE,
3078                          type,
3079                          (tree) n->value));
3080
3081   return 0;
3082 }
3083
3084 /* Returns nonzero if TYPE is an empty class type and there is
3085    already an entry in OFFSETS for the same TYPE as the same OFFSET.  */
3086
3087 static int
3088 check_subobject_offset (tree type, tree offset, splay_tree offsets)
3089 {
3090   splay_tree_node n;
3091   tree t;
3092
3093   if (!is_empty_class (type))
3094     return 0;
3095
3096   /* Record the location of this empty object in OFFSETS.  */
3097   n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3098   if (!n)
3099     return 0;
3100
3101   for (t = (tree) n->value; t; t = TREE_CHAIN (t))
3102     if (same_type_p (TREE_VALUE (t), type))
3103       return 1;
3104
3105   return 0;
3106 }
3107
3108 /* Walk through all the subobjects of TYPE (located at OFFSET).  Call
3109    F for every subobject, passing it the type, offset, and table of
3110    OFFSETS.  If VBASES_P is one, then virtual non-primary bases should
3111    be traversed.
3112
3113    If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3114    than MAX_OFFSET will not be walked.
3115
3116    If F returns a nonzero value, the traversal ceases, and that value
3117    is returned.  Otherwise, returns zero.  */
3118
3119 static int
3120 walk_subobject_offsets (tree type,
3121                         subobject_offset_fn f,
3122                         tree offset,
3123                         splay_tree offsets,
3124                         tree max_offset,
3125                         int vbases_p)
3126 {
3127   int r = 0;
3128   tree type_binfo = NULL_TREE;
3129
3130   /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3131      stop.  */
3132   if (max_offset && INT_CST_LT (max_offset, offset))
3133     return 0;
3134
3135   if (!TYPE_P (type))
3136     {
3137       if (abi_version_at_least (2))
3138         type_binfo = type;
3139       type = BINFO_TYPE (type);
3140     }
3141
3142   if (CLASS_TYPE_P (type))
3143     {
3144       tree field;
3145       tree binfo;
3146       int i;
3147
3148       /* Avoid recursing into objects that are not interesting.  */
3149       if (!CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type))
3150         return 0;
3151
3152       /* Record the location of TYPE.  */
3153       r = (*f) (type, offset, offsets);
3154       if (r)
3155         return r;
3156
3157       /* Iterate through the direct base classes of TYPE.  */
3158       if (!type_binfo)
3159         type_binfo = TYPE_BINFO (type);
3160       for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, binfo); i++)
3161         {
3162           tree binfo_offset;
3163
3164           if (abi_version_at_least (2)
3165               && BINFO_VIRTUAL_P (binfo))
3166             continue;
3167
3168           if (!vbases_p
3169               && BINFO_VIRTUAL_P (binfo)
3170               && !BINFO_PRIMARY_P (binfo))
3171             continue;
3172
3173           if (!abi_version_at_least (2))
3174             binfo_offset = size_binop (PLUS_EXPR,
3175                                        offset,
3176                                        BINFO_OFFSET (binfo));
3177           else
3178             {
3179               tree orig_binfo;
3180               /* We cannot rely on BINFO_OFFSET being set for the base
3181                  class yet, but the offsets for direct non-virtual
3182                  bases can be calculated by going back to the TYPE.  */
3183               orig_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), i);
3184               binfo_offset = size_binop (PLUS_EXPR,
3185                                          offset,
3186                                          BINFO_OFFSET (orig_binfo));
3187             }
3188
3189           r = walk_subobject_offsets (binfo,
3190                                       f,
3191                                       binfo_offset,
3192                                       offsets,
3193                                       max_offset,
3194                                       (abi_version_at_least (2)
3195                                        ? /*vbases_p=*/0 : vbases_p));
3196           if (r)
3197             return r;
3198         }
3199
3200       if (abi_version_at_least (2) && CLASSTYPE_VBASECLASSES (type))
3201         {
3202           unsigned ix;
3203           VEC (tree) *vbases;
3204
3205           /* Iterate through the virtual base classes of TYPE.  In G++
3206              3.2, we included virtual bases in the direct base class
3207              loop above, which results in incorrect results; the
3208              correct offsets for virtual bases are only known when
3209              working with the most derived type.  */
3210           if (vbases_p)
3211             for (vbases = CLASSTYPE_VBASECLASSES (type), ix = 0;
3212                  VEC_iterate (tree, vbases, ix, binfo); ix++)
3213               {
3214                 r = walk_subobject_offsets (binfo,
3215                                             f,
3216                                             size_binop (PLUS_EXPR,
3217                                                         offset,
3218                                                         BINFO_OFFSET (binfo)),
3219                                             offsets,
3220                                             max_offset,
3221                                             /*vbases_p=*/0);
3222                 if (r)
3223                   return r;
3224               }
3225           else
3226             {
3227               /* We still have to walk the primary base, if it is
3228                  virtual.  (If it is non-virtual, then it was walked
3229                  above.)  */
3230               tree vbase = get_primary_binfo (type_binfo);
3231
3232               if (vbase && BINFO_VIRTUAL_P (vbase)
3233                   && BINFO_PRIMARY_P (vbase)
3234                   && BINFO_INHERITANCE_CHAIN (vbase) == type_binfo)
3235                 {
3236                   r = (walk_subobject_offsets
3237                        (vbase, f, offset,
3238                         offsets, max_offset, /*vbases_p=*/0));
3239                   if (r)
3240                     return r;
3241                 }
3242             }
3243         }
3244
3245       /* Iterate through the fields of TYPE.  */
3246       for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3247         if (TREE_CODE (field) == FIELD_DECL && !DECL_ARTIFICIAL (field))
3248           {
3249             tree field_offset;
3250
3251             if (abi_version_at_least (2))
3252               field_offset = byte_position (field);
3253             else
3254               /* In G++ 3.2, DECL_FIELD_OFFSET was used.  */
3255               field_offset = DECL_FIELD_OFFSET (field);
3256
3257             r = walk_subobject_offsets (TREE_TYPE (field),
3258                                         f,
3259                                         size_binop (PLUS_EXPR,
3260                                                     offset,
3261                                                     field_offset),
3262                                         offsets,
3263                                         max_offset,
3264                                         /*vbases_p=*/1);
3265             if (r)
3266               return r;
3267           }
3268     }
3269   else if (TREE_CODE (type) == ARRAY_TYPE)
3270     {
3271       tree element_type = strip_array_types (type);
3272       tree domain = TYPE_DOMAIN (type);
3273       tree index;
3274
3275       /* Avoid recursing into objects that are not interesting.  */
3276       if (!CLASS_TYPE_P (element_type)
3277           || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type))
3278         return 0;
3279
3280       /* Step through each of the elements in the array.  */
3281       for (index = size_zero_node;
3282            /* G++ 3.2 had an off-by-one error here.  */
3283            (abi_version_at_least (2)
3284             ? !INT_CST_LT (TYPE_MAX_VALUE (domain), index)
3285             : INT_CST_LT (index, TYPE_MAX_VALUE (domain)));
3286            index = size_binop (PLUS_EXPR, index, size_one_node))
3287         {
3288           r = walk_subobject_offsets (TREE_TYPE (type),
3289                                       f,
3290                                       offset,
3291                                       offsets,
3292                                       max_offset,
3293                                       /*vbases_p=*/1);
3294           if (r)
3295             return r;
3296           offset = size_binop (PLUS_EXPR, offset,
3297                                TYPE_SIZE_UNIT (TREE_TYPE (type)));
3298           /* If this new OFFSET is bigger than the MAX_OFFSET, then
3299              there's no point in iterating through the remaining
3300              elements of the array.  */
3301           if (max_offset && INT_CST_LT (max_offset, offset))
3302             break;
3303         }
3304     }
3305
3306   return 0;
3307 }
3308
3309 /* Record all of the empty subobjects of TYPE (located at OFFSET) in
3310    OFFSETS.  If VBASES_P is nonzero, virtual bases of TYPE are
3311    examined.  */
3312
3313 static void
3314 record_subobject_offsets (tree type,
3315                           tree offset,
3316                           splay_tree offsets,
3317                           int vbases_p)
3318 {
3319   walk_subobject_offsets (type, record_subobject_offset, offset,
3320                           offsets, /*max_offset=*/NULL_TREE, vbases_p);
3321 }
3322
3323 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3324    OFFSET) conflict with entries in OFFSETS.  If VBASES_P is nonzero,
3325    virtual bases of TYPE are examined.  */
3326
3327 static int
3328 layout_conflict_p (tree type,
3329                    tree offset,
3330                    splay_tree offsets,
3331                    int vbases_p)
3332 {
3333   splay_tree_node max_node;
3334
3335   /* Get the node in OFFSETS that indicates the maximum offset where
3336      an empty subobject is located.  */
3337   max_node = splay_tree_max (offsets);
3338   /* If there aren't any empty subobjects, then there's no point in
3339      performing this check.  */
3340   if (!max_node)
3341     return 0;
3342
3343   return walk_subobject_offsets (type, check_subobject_offset, offset,
3344                                  offsets, (tree) (max_node->key),
3345                                  vbases_p);
3346 }
3347
3348 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3349    non-static data member of the type indicated by RLI.  BINFO is the
3350    binfo corresponding to the base subobject, OFFSETS maps offsets to
3351    types already located at those offsets.  This function determines
3352    the position of the DECL.  */
3353
3354 static void
3355 layout_nonempty_base_or_field (record_layout_info rli,
3356                                tree decl,
3357                                tree binfo,
3358                                splay_tree offsets)
3359 {
3360   tree offset = NULL_TREE;
3361   bool field_p;
3362   tree type;
3363
3364   if (binfo)
3365     {
3366       /* For the purposes of determining layout conflicts, we want to
3367          use the class type of BINFO; TREE_TYPE (DECL) will be the
3368          CLASSTYPE_AS_BASE version, which does not contain entries for
3369          zero-sized bases.  */
3370       type = TREE_TYPE (binfo);
3371       field_p = false;
3372     }
3373   else
3374     {
3375       type = TREE_TYPE (decl);
3376       field_p = true;
3377     }
3378
3379   /* Try to place the field.  It may take more than one try if we have
3380      a hard time placing the field without putting two objects of the
3381      same type at the same address.  */
3382   while (1)
3383     {
3384       struct record_layout_info_s old_rli = *rli;
3385
3386       /* Place this field.  */
3387       place_field (rli, decl);
3388       offset = byte_position (decl);
3389
3390       /* We have to check to see whether or not there is already
3391          something of the same type at the offset we're about to use.
3392          For example, consider:
3393
3394            struct S {};
3395            struct T : public S { int i; };
3396            struct U : public S, public T {};
3397
3398          Here, we put S at offset zero in U.  Then, we can't put T at
3399          offset zero -- its S component would be at the same address
3400          as the S we already allocated.  So, we have to skip ahead.
3401          Since all data members, including those whose type is an
3402          empty class, have nonzero size, any overlap can happen only
3403          with a direct or indirect base-class -- it can't happen with
3404          a data member.  */
3405       /* In a union, overlap is permitted; all members are placed at
3406          offset zero.  */
3407       if (TREE_CODE (rli->t) == UNION_TYPE)
3408         break;
3409       /* G++ 3.2 did not check for overlaps when placing a non-empty
3410          virtual base.  */
3411       if (!abi_version_at_least (2) && binfo && BINFO_VIRTUAL_P (binfo))
3412         break;
3413       if (layout_conflict_p (field_p ? type : binfo, offset,
3414                              offsets, field_p))
3415         {
3416           /* Strip off the size allocated to this field.  That puts us
3417              at the first place we could have put the field with
3418              proper alignment.  */
3419           *rli = old_rli;
3420
3421           /* Bump up by the alignment required for the type.  */
3422           rli->bitpos
3423             = size_binop (PLUS_EXPR, rli->bitpos,
3424                           bitsize_int (binfo
3425                                        ? CLASSTYPE_ALIGN (type)
3426                                        : TYPE_ALIGN (type)));
3427           normalize_rli (rli);
3428         }
3429       else
3430         /* There was no conflict.  We're done laying out this field.  */
3431         break;
3432     }
3433
3434   /* Now that we know where it will be placed, update its
3435      BINFO_OFFSET.  */
3436   if (binfo && CLASS_TYPE_P (BINFO_TYPE (binfo)))
3437     /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3438        this point because their BINFO_OFFSET is copied from another
3439        hierarchy.  Therefore, we may not need to add the entire
3440        OFFSET.  */
3441     propagate_binfo_offsets (binfo,
3442                              size_diffop (convert (ssizetype, offset),
3443                                           convert (ssizetype,
3444                                                    BINFO_OFFSET (binfo))));
3445 }
3446
3447 /* Returns true if TYPE is empty and OFFSET is nonzero.  */
3448
3449 static int
3450 empty_base_at_nonzero_offset_p (tree type,
3451                                 tree offset,
3452                                 splay_tree offsets ATTRIBUTE_UNUSED)
3453 {
3454   return is_empty_class (type) && !integer_zerop (offset);
3455 }
3456
3457 /* Layout the empty base BINFO.  EOC indicates the byte currently just
3458    past the end of the class, and should be correctly aligned for a
3459    class of the type indicated by BINFO; OFFSETS gives the offsets of
3460    the empty bases allocated so far. T is the most derived
3461    type.  Return nonzero iff we added it at the end.  */
3462
3463 static bool
3464 layout_empty_base (tree binfo, tree eoc, splay_tree offsets)
3465 {
3466   tree alignment;
3467   tree basetype = BINFO_TYPE (binfo);
3468   bool atend = false;
3469
3470   /* This routine should only be used for empty classes.  */
3471   gcc_assert (is_empty_class (basetype));
3472   alignment = ssize_int (CLASSTYPE_ALIGN_UNIT (basetype));
3473
3474   if (!integer_zerop (BINFO_OFFSET (binfo)))
3475     {
3476       if (abi_version_at_least (2))
3477         propagate_binfo_offsets
3478           (binfo, size_diffop (size_zero_node, BINFO_OFFSET (binfo)));
3479       else if (warn_abi)
3480         warning ("offset of empty base %qT may not be ABI-compliant and may"
3481                  "change in a future version of GCC",
3482                  BINFO_TYPE (binfo));
3483     }
3484
3485   /* This is an empty base class.  We first try to put it at offset
3486      zero.  */
3487   if (layout_conflict_p (binfo,
3488                          BINFO_OFFSET (binfo),
3489                          offsets,
3490                          /*vbases_p=*/0))
3491     {
3492       /* That didn't work.  Now, we move forward from the next
3493          available spot in the class.  */
3494       atend = true;
3495       propagate_binfo_offsets (binfo, convert (ssizetype, eoc));
3496       while (1)
3497         {
3498           if (!layout_conflict_p (binfo,
3499                                   BINFO_OFFSET (binfo),
3500                                   offsets,
3501                                   /*vbases_p=*/0))
3502             /* We finally found a spot where there's no overlap.  */
3503             break;
3504
3505           /* There's overlap here, too.  Bump along to the next spot.  */
3506           propagate_binfo_offsets (binfo, alignment);
3507         }
3508     }
3509   return atend;
3510 }
3511
3512 /* Layout the base given by BINFO in the class indicated by RLI.
3513    *BASE_ALIGN is a running maximum of the alignments of
3514    any base class.  OFFSETS gives the location of empty base
3515    subobjects.  T is the most derived type.  Return nonzero if the new
3516    object cannot be nearly-empty.  A new FIELD_DECL is inserted at
3517    *NEXT_FIELD, unless BINFO is for an empty base class.
3518
3519    Returns the location at which the next field should be inserted.  */
3520
3521 static tree *
3522 build_base_field (record_layout_info rli, tree binfo,
3523                   splay_tree offsets, tree *next_field)
3524 {
3525   tree t = rli->t;
3526   tree basetype = BINFO_TYPE (binfo);
3527
3528   if (!COMPLETE_TYPE_P (basetype))
3529     /* This error is now reported in xref_tag, thus giving better
3530        location information.  */
3531     return next_field;
3532
3533   /* Place the base class.  */
3534   if (!is_empty_class (basetype))
3535     {
3536       tree decl;
3537
3538       /* The containing class is non-empty because it has a non-empty
3539          base class.  */
3540       CLASSTYPE_EMPTY_P (t) = 0;
3541
3542       /* Create the FIELD_DECL.  */
3543       decl = build_decl (FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype));
3544       DECL_ARTIFICIAL (decl) = 1;
3545       DECL_IGNORED_P (decl) = 1;
3546       DECL_FIELD_CONTEXT (decl) = t;
3547       DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype);
3548       DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype);
3549       DECL_ALIGN (decl) = CLASSTYPE_ALIGN (basetype);
3550       DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype);
3551       DECL_MODE (decl) = TYPE_MODE (basetype);
3552       DECL_FIELD_IS_BASE (decl) = 1;
3553
3554       /* Try to place the field.  It may take more than one try if we
3555          have a hard time placing the field without putting two
3556          objects of the same type at the same address.  */
3557       layout_nonempty_base_or_field (rli, decl, binfo, offsets);
3558       /* Add the new FIELD_DECL to the list of fields for T.  */
3559       TREE_CHAIN (decl) = *next_field;
3560       *next_field = decl;
3561       next_field = &TREE_CHAIN (decl);
3562     }
3563   else
3564     {
3565       tree eoc;
3566       bool atend;
3567
3568       /* On some platforms (ARM), even empty classes will not be
3569          byte-aligned.  */
3570       eoc = round_up (rli_size_unit_so_far (rli),
3571                       CLASSTYPE_ALIGN_UNIT (basetype));
3572       atend = layout_empty_base (binfo, eoc, offsets);
3573       /* A nearly-empty class "has no proper base class that is empty,
3574          not morally virtual, and at an offset other than zero."  */
3575       if (!BINFO_VIRTUAL_P (binfo) && CLASSTYPE_NEARLY_EMPTY_P (t))
3576         {
3577           if (atend)
3578             CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3579           /* The check above (used in G++ 3.2) is insufficient  because
3580              an empty class placed at offset zero might itself have an
3581              empty base at a nonzero offset.  */
3582           else if (walk_subobject_offsets (basetype,
3583                                            empty_base_at_nonzero_offset_p,
3584                                            size_zero_node,
3585                                            /*offsets=*/NULL,
3586                                            /*max_offset=*/NULL_TREE,
3587                                            /*vbases_p=*/true))
3588             {
3589               if (abi_version_at_least (2))
3590                 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3591               else if (warn_abi)
3592                 warning ("class %qT will be considered nearly empty in a "
3593                          "future version of GCC", t);
3594             }
3595         }
3596
3597       /* We do not create a FIELD_DECL for empty base classes because
3598          it might overlap some other field.  We want to be able to
3599          create CONSTRUCTORs for the class by iterating over the
3600          FIELD_DECLs, and the back end does not handle overlapping
3601          FIELD_DECLs.  */
3602
3603       /* An empty virtual base causes a class to be non-empty
3604          -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3605          here because that was already done when the virtual table
3606          pointer was created.  */
3607     }
3608
3609   /* Record the offsets of BINFO and its base subobjects.  */
3610   record_subobject_offsets (binfo,
3611                             BINFO_OFFSET (binfo),
3612                             offsets,
3613                             /*vbases_p=*/0);
3614
3615   return next_field;
3616 }
3617
3618 /* Layout all of the non-virtual base classes.  Record empty
3619    subobjects in OFFSETS.  T is the most derived type.  Return nonzero
3620    if the type cannot be nearly empty.  The fields created
3621    corresponding to the base classes will be inserted at
3622    *NEXT_FIELD.  */
3623
3624 static void
3625 build_base_fields (record_layout_info rli,
3626                    splay_tree offsets, tree *next_field)
3627 {
3628   /* Chain to hold all the new FIELD_DECLs which stand in for base class
3629      subobjects.  */
3630   tree t = rli->t;
3631   int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
3632   int i;
3633
3634   /* The primary base class is always allocated first.  */
3635   if (CLASSTYPE_HAS_PRIMARY_BASE_P (t))
3636     next_field = build_base_field (rli, CLASSTYPE_PRIMARY_BINFO (t),
3637                                    offsets, next_field);
3638
3639   /* Now allocate the rest of the bases.  */
3640   for (i = 0; i < n_baseclasses; ++i)
3641     {
3642       tree base_binfo;
3643
3644       base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i);
3645
3646       /* The primary base was already allocated above, so we don't
3647          need to allocate it again here.  */
3648       if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t))
3649         continue;
3650
3651       /* Virtual bases are added at the end (a primary virtual base
3652          will have already been added).  */
3653       if (BINFO_VIRTUAL_P (base_binfo))
3654         continue;
3655
3656       next_field = build_base_field (rli, base_binfo,
3657                                      offsets, next_field);
3658     }
3659 }
3660
3661 /* Go through the TYPE_METHODS of T issuing any appropriate
3662    diagnostics, figuring out which methods override which other
3663    methods, and so forth.  */
3664
3665 static void
3666 check_methods (tree t)
3667 {
3668   tree x;
3669
3670   for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
3671     {
3672       check_for_override (x, t);
3673       if (DECL_PURE_VIRTUAL_P (x) && ! DECL_VINDEX (x))
3674         cp_error_at ("initializer specified for non-virtual method %qD", x);
3675       /* The name of the field is the original field name
3676          Save this in auxiliary field for later overloading.  */
3677       if (DECL_VINDEX (x))
3678         {
3679           TYPE_POLYMORPHIC_P (t) = 1;
3680           if (DECL_PURE_VIRTUAL_P (x))
3681             VEC_safe_push (tree, CLASSTYPE_PURE_VIRTUALS (t), x);
3682         }
3683       /* All user-declared destructors are non-trivial.  */
3684       if (DECL_DESTRUCTOR_P (x))
3685         TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = 1;
3686     }
3687 }
3688
3689 /* FN is a constructor or destructor.  Clone the declaration to create
3690    a specialized in-charge or not-in-charge version, as indicated by
3691    NAME.  */
3692
3693 static tree
3694 build_clone (tree fn, tree name)
3695 {
3696   tree parms;
3697   tree clone;
3698
3699   /* Copy the function.  */
3700   clone = copy_decl (fn);
3701   /* Remember where this function came from.  */
3702   DECL_CLONED_FUNCTION (clone) = fn;
3703   DECL_ABSTRACT_ORIGIN (clone) = fn;
3704   /* Reset the function name.  */
3705   DECL_NAME (clone) = name;
3706   SET_DECL_ASSEMBLER_NAME (clone, NULL_TREE);
3707   /* There's no pending inline data for this function.  */
3708   DECL_PENDING_INLINE_INFO (clone) = NULL;
3709   DECL_PENDING_INLINE_P (clone) = 0;
3710   /* And it hasn't yet been deferred.  */
3711   DECL_DEFERRED_FN (clone) = 0;
3712
3713   /* The base-class destructor is not virtual.  */
3714   if (name == base_dtor_identifier)
3715     {
3716       DECL_VIRTUAL_P (clone) = 0;
3717       if (TREE_CODE (clone) != TEMPLATE_DECL)
3718         DECL_VINDEX (clone) = NULL_TREE;
3719     }
3720
3721   /* If there was an in-charge parameter, drop it from the function
3722      type.  */
3723   if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3724     {
3725       tree basetype;
3726       tree parmtypes;
3727       tree exceptions;
3728
3729       exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
3730       basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
3731       parmtypes = TYPE_ARG_TYPES (TREE_TYPE (clone));
3732       /* Skip the `this' parameter.  */
3733       parmtypes = TREE_CHAIN (parmtypes);
3734       /* Skip the in-charge parameter.  */
3735       parmtypes = TREE_CHAIN (parmtypes);
3736       /* And the VTT parm, in a complete [cd]tor.  */
3737       if (DECL_HAS_VTT_PARM_P (fn)
3738           && ! DECL_NEEDS_VTT_PARM_P (clone))
3739         parmtypes = TREE_CHAIN (parmtypes);
3740        /* If this is subobject constructor or destructor, add the vtt
3741          parameter.  */
3742       TREE_TYPE (clone)
3743         = build_method_type_directly (basetype,
3744                                       TREE_TYPE (TREE_TYPE (clone)),
3745                                       parmtypes);
3746       if (exceptions)
3747         TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone),
3748                                                      exceptions);
3749       TREE_TYPE (clone)
3750         = cp_build_type_attribute_variant (TREE_TYPE (clone),
3751                                            TYPE_ATTRIBUTES (TREE_TYPE (fn)));
3752     }
3753
3754   /* Copy the function parameters.  But, DECL_ARGUMENTS on a TEMPLATE_DECL
3755      aren't function parameters; those are the template parameters.  */
3756   if (TREE_CODE (clone) != TEMPLATE_DECL)
3757     {
3758       DECL_ARGUMENTS (clone) = copy_list (DECL_ARGUMENTS (clone));
3759       /* Remove the in-charge parameter.  */
3760       if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3761         {
3762           TREE_CHAIN (DECL_ARGUMENTS (clone))
3763             = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3764           DECL_HAS_IN_CHARGE_PARM_P (clone) = 0;
3765         }
3766       /* And the VTT parm, in a complete [cd]tor.  */
3767       if (DECL_HAS_VTT_PARM_P (fn))
3768         {
3769           if (DECL_NEEDS_VTT_PARM_P (clone))
3770             DECL_HAS_VTT_PARM_P (clone) = 1;
3771           else
3772             {
3773               TREE_CHAIN (DECL_ARGUMENTS (clone))
3774                 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3775               DECL_HAS_VTT_PARM_P (clone) = 0;
3776             }
3777         }
3778
3779       for (parms = DECL_ARGUMENTS (clone); parms; parms = TREE_CHAIN (parms))
3780         {
3781           DECL_CONTEXT (parms) = clone;
3782           cxx_dup_lang_specific_decl (parms);
3783         }
3784     }
3785
3786   /* Create the RTL for this function.  */
3787   SET_DECL_RTL (clone, NULL_RTX);
3788   rest_of_decl_compilation (clone, /*top_level=*/1, at_eof);
3789
3790   /* Make it easy to find the CLONE given the FN.  */
3791   TREE_CHAIN (clone) = TREE_CHAIN (fn);
3792   TREE_CHAIN (fn) = clone;
3793
3794   /* If this is a template, handle the DECL_TEMPLATE_RESULT as well.  */
3795   if (TREE_CODE (clone) == TEMPLATE_DECL)
3796     {
3797       tree result;
3798
3799       DECL_TEMPLATE_RESULT (clone)
3800         = build_clone (DECL_TEMPLATE_RESULT (clone), name);
3801       result = DECL_TEMPLATE_RESULT (clone);
3802       DECL_TEMPLATE_INFO (result) = copy_node (DECL_TEMPLATE_INFO (result));
3803       DECL_TI_TEMPLATE (result) = clone;
3804     }
3805   else if (pch_file)
3806     note_decl_for_pch (clone);
3807
3808   return clone;
3809 }
3810
3811 /* Produce declarations for all appropriate clones of FN.  If
3812    UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
3813    CLASTYPE_METHOD_VEC as well.  */
3814
3815 void
3816 clone_function_decl (tree fn, int update_method_vec_p)
3817 {
3818   tree clone;
3819
3820   /* Avoid inappropriate cloning.  */
3821   if (TREE_CHAIN (fn)
3822       && DECL_CLONED_FUNCTION (TREE_CHAIN (fn)))
3823     return;
3824
3825   if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
3826     {
3827       /* For each constructor, we need two variants: an in-charge version
3828          and a not-in-charge version.  */
3829       clone = build_clone (fn, complete_ctor_identifier);
3830       if (update_method_vec_p)
3831         add_method (DECL_CONTEXT (clone), clone);
3832       clone = build_clone (fn, base_ctor_identifier);
3833       if (update_method_vec_p)
3834         add_method (DECL_CONTEXT (clone), clone);
3835     }
3836   else
3837     {
3838       gcc_assert (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn));
3839
3840       /* For each destructor, we need three variants: an in-charge
3841          version, a not-in-charge version, and an in-charge deleting
3842          version.  We clone the deleting version first because that
3843          means it will go second on the TYPE_METHODS list -- and that
3844          corresponds to the correct layout order in the virtual
3845          function table.
3846
3847          For a non-virtual destructor, we do not build a deleting
3848          destructor.  */
3849       if (DECL_VIRTUAL_P (fn))
3850         {
3851           clone = build_clone (fn, deleting_dtor_identifier);
3852           if (update_method_vec_p)
3853             add_method (DECL_CONTEXT (clone), clone);
3854         }
3855       clone = build_clone (fn, complete_dtor_identifier);
3856       if (update_method_vec_p)
3857         add_method (DECL_CONTEXT (clone), clone);
3858       clone = build_clone (fn, base_dtor_identifier);
3859       if (update_method_vec_p)
3860         add_method (DECL_CONTEXT (clone), clone);
3861     }
3862
3863   /* Note that this is an abstract function that is never emitted.  */
3864   DECL_ABSTRACT (fn) = 1;
3865 }
3866
3867 /* DECL is an in charge constructor, which is being defined. This will
3868    have had an in class declaration, from whence clones were
3869    declared. An out-of-class definition can specify additional default
3870    arguments. As it is the clones that are involved in overload
3871    resolution, we must propagate the information from the DECL to its
3872    clones.  */
3873
3874 void
3875 adjust_clone_args (tree decl)
3876 {
3877   tree clone;
3878
3879   for (clone = TREE_CHAIN (decl); clone && DECL_CLONED_FUNCTION (clone);
3880        clone = TREE_CHAIN (clone))
3881     {
3882       tree orig_clone_parms = TYPE_ARG_TYPES (TREE_TYPE (clone));
3883       tree orig_decl_parms = TYPE_ARG_TYPES (TREE_TYPE (decl));
3884       tree decl_parms, clone_parms;
3885
3886       clone_parms = orig_clone_parms;
3887
3888       /* Skip the 'this' parameter.  */
3889       orig_clone_parms = TREE_CHAIN (orig_clone_parms);
3890       orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3891
3892       if (DECL_HAS_IN_CHARGE_PARM_P (decl))
3893         orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3894       if (DECL_HAS_VTT_PARM_P (decl))
3895         orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3896
3897       clone_parms = orig_clone_parms;
3898       if (DECL_HAS_VTT_PARM_P (clone))
3899         clone_parms = TREE_CHAIN (clone_parms);
3900
3901       for (decl_parms = orig_decl_parms; decl_parms;
3902            decl_parms = TREE_CHAIN (decl_parms),
3903              clone_parms = TREE_CHAIN (clone_parms))
3904         {
3905           gcc_assert (same_type_p (TREE_TYPE (decl_parms),
3906                                    TREE_TYPE (clone_parms)));
3907
3908           if (TREE_PURPOSE (decl_parms) && !TREE_PURPOSE (clone_parms))
3909             {
3910               /* A default parameter has been added. Adjust the
3911                  clone's parameters.  */
3912               tree exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
3913               tree basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
3914               tree type;
3915
3916               clone_parms = orig_decl_parms;
3917
3918               if (DECL_HAS_VTT_PARM_P (clone))
3919                 {
3920                   clone_parms = tree_cons (TREE_PURPOSE (orig_clone_parms),
3921                                            TREE_VALUE (orig_clone_parms),
3922                                            clone_parms);
3923                   TREE_TYPE (clone_parms) = TREE_TYPE (orig_clone_parms);
3924                 }
3925               type = build_method_type_directly (basetype,
3926                                                  TREE_TYPE (TREE_TYPE (clone)),
3927                                                  clone_parms);
3928               if (exceptions)
3929                 type = build_exception_variant (type, exceptions);
3930               TREE_TYPE (clone) = type;
3931
3932               clone_parms = NULL_TREE;
3933               break;
3934             }
3935         }
3936       gcc_assert (!clone_parms);
3937     }
3938 }
3939
3940 /* For each of the constructors and destructors in T, create an
3941    in-charge and not-in-charge variant.  */
3942
3943 static void
3944 clone_constructors_and_destructors (tree t)
3945 {
3946   tree fns;
3947
3948   /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
3949      out now.  */
3950   if (!CLASSTYPE_METHOD_VEC (t))
3951     return;
3952
3953   for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
3954     clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
3955   for (fns = CLASSTYPE_DESTRUCTORS (t); fns; fns = OVL_NEXT (fns))
3956     clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
3957 }
3958
3959 /* Remove all zero-width bit-fields from T.  */
3960
3961 static void
3962 remove_zero_width_bit_fields (tree t)
3963 {
3964   tree *fieldsp;
3965
3966   fieldsp = &TYPE_FIELDS (t);
3967   while (*fieldsp)
3968     {
3969       if (TREE_CODE (*fieldsp) == FIELD_DECL
3970           && DECL_C_BIT_FIELD (*fieldsp)
3971           && DECL_INITIAL (*fieldsp))
3972         *fieldsp = TREE_CHAIN (*fieldsp);
3973       else
3974         fieldsp = &TREE_CHAIN (*fieldsp);
3975     }
3976 }
3977
3978 /* Returns TRUE iff we need a cookie when dynamically allocating an
3979    array whose elements have the indicated class TYPE.  */
3980
3981 static bool
3982 type_requires_array_cookie (tree type)
3983 {
3984   tree fns;
3985   bool has_two_argument_delete_p = false;
3986
3987   gcc_assert (CLASS_TYPE_P (type));
3988
3989   /* If there's a non-trivial destructor, we need a cookie.  In order
3990      to iterate through the array calling the destructor for each
3991      element, we'll have to know how many elements there are.  */
3992   if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
3993     return true;
3994
3995   /* If the usual deallocation function is a two-argument whose second
3996      argument is of type `size_t', then we have to pass the size of
3997      the array to the deallocation function, so we will need to store
3998      a cookie.  */
3999   fns = lookup_fnfields (TYPE_BINFO (type),
4000                          ansi_opname (VEC_DELETE_EXPR),
4001                          /*protect=*/0);
4002   /* If there are no `operator []' members, or the lookup is
4003      ambiguous, then we don't need a cookie.  */
4004   if (!fns || fns == error_mark_node)
4005     return false;
4006   /* Loop through all of the functions.  */
4007   for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
4008     {
4009       tree fn;
4010       tree second_parm;
4011
4012       /* Select the current function.  */
4013       fn = OVL_CURRENT (fns);
4014       /* See if this function is a one-argument delete function.  If
4015          it is, then it will be the usual deallocation function.  */
4016       second_parm = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fn)));
4017       if (second_parm == void_list_node)
4018         return false;
4019       /* Otherwise, if we have a two-argument function and the second
4020          argument is `size_t', it will be the usual deallocation
4021          function -- unless there is one-argument function, too.  */
4022       if (TREE_CHAIN (second_parm) == void_list_node
4023           && same_type_p (TREE_VALUE (second_parm), sizetype))
4024         has_two_argument_delete_p = true;
4025     }
4026
4027   return has_two_argument_delete_p;
4028 }
4029
4030 /* Check the validity of the bases and members declared in T.  Add any
4031    implicitly-generated functions (like copy-constructors and
4032    assignment operators).  Compute various flag bits (like
4033    CLASSTYPE_NON_POD_T) for T.  This routine works purely at the C++
4034    level: i.e., independently of the ABI in use.  */
4035
4036 static void
4037 check_bases_and_members (tree t)
4038 {
4039   /* Nonzero if the implicitly generated copy constructor should take
4040      a non-const reference argument.  */
4041   int cant_have_const_ctor;
4042   /* Nonzero if the implicitly generated assignment operator
4043      should take a non-const reference argument.  */
4044   int no_const_asn_ref;
4045   tree access_decls;
4046
4047   /* By default, we use const reference arguments and generate default
4048      constructors.  */
4049   cant_have_const_ctor = 0;
4050   no_const_asn_ref = 0;
4051
4052   /* Check all the base-classes.  */
4053   check_bases (t, &cant_have_const_ctor,
4054                &no_const_asn_ref);
4055
4056   /* Check all the method declarations.  */
4057   check_methods (t);
4058
4059   /* Check all the data member declarations.  We cannot call
4060      check_field_decls until we have called check_bases check_methods,
4061      as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
4062      being set appropriately.  */
4063   check_field_decls (t, &access_decls,
4064                      &cant_have_const_ctor,
4065                      &no_const_asn_ref);
4066
4067   /* A nearly-empty class has to be vptr-containing; a nearly empty
4068      class contains just a vptr.  */
4069   if (!TYPE_CONTAINS_VPTR_P (t))
4070     CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
4071
4072   /* Do some bookkeeping that will guide the generation of implicitly
4073      declared member functions.  */
4074   TYPE_HAS_COMPLEX_INIT_REF (t)
4075     |= (TYPE_HAS_INIT_REF (t) || TYPE_CONTAINS_VPTR_P (t));
4076   TYPE_NEEDS_CONSTRUCTING (t)
4077     |= (TYPE_HAS_CONSTRUCTOR (t) || TYPE_CONTAINS_VPTR_P (t));
4078   CLASSTYPE_NON_AGGREGATE (t)
4079     |= (TYPE_HAS_CONSTRUCTOR (t) || TYPE_POLYMORPHIC_P (t));
4080   CLASSTYPE_NON_POD_P (t)
4081     |= (CLASSTYPE_NON_AGGREGATE (t)
4082         || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
4083         || TYPE_HAS_ASSIGN_REF (t));
4084   TYPE_HAS_COMPLEX_ASSIGN_REF (t)
4085     |= TYPE_HAS_ASSIGN_REF (t) || TYPE_CONTAINS_VPTR_P (t);
4086
4087   /* Synthesize any needed methods.  */
4088   add_implicitly_declared_members (t,
4089                                    cant_have_const_ctor,
4090                                    no_const_asn_ref);
4091
4092   /* Create the in-charge and not-in-charge variants of constructors
4093      and destructors.  */
4094   clone_constructors_and_destructors (t);
4095
4096   /* Process the using-declarations.  */
4097   for (; access_decls; access_decls = TREE_CHAIN (access_decls))
4098     handle_using_decl (TREE_VALUE (access_decls), t);
4099
4100   /* Build and sort the CLASSTYPE_METHOD_VEC.  */
4101   finish_struct_methods (t);
4102
4103   /* Figure out whether or not we will need a cookie when dynamically
4104      allocating an array of this type.  */
4105   TYPE_LANG_SPECIFIC (t)->u.c.vec_new_uses_cookie
4106     = type_requires_array_cookie (t);
4107 }
4108
4109 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4110    accordingly.  If a new vfield was created (because T doesn't have a
4111    primary base class), then the newly created field is returned.  It
4112    is not added to the TYPE_FIELDS list; it is the caller's
4113    responsibility to do that.  Accumulate declared virtual functions
4114    on VIRTUALS_P.  */
4115
4116 static tree
4117 create_vtable_ptr (tree t, tree* virtuals_p)
4118 {
4119   tree fn;
4120
4121   /* Collect the virtual functions declared in T.  */
4122   for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
4123     if (DECL_VINDEX (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)
4124         && TREE_CODE (DECL_VINDEX (fn)) != INTEGER_CST)
4125       {
4126         tree new_virtual = make_node (TREE_LIST);
4127
4128         BV_FN (new_virtual) = fn;
4129         BV_DELTA (new_virtual) = integer_zero_node;
4130         BV_VCALL_INDEX (new_virtual) = NULL_TREE;
4131
4132         TREE_CHAIN (new_virtual) = *virtuals_p;
4133         *virtuals_p = new_virtual;
4134       }
4135
4136   /* If we couldn't find an appropriate base class, create a new field
4137      here.  Even if there weren't any new virtual functions, we might need a
4138      new virtual function table if we're supposed to include vptrs in
4139      all classes that need them.  */
4140   if (!TYPE_VFIELD (t) && (*virtuals_p || TYPE_CONTAINS_VPTR_P (t)))
4141     {
4142       /* We build this decl with vtbl_ptr_type_node, which is a
4143          `vtable_entry_type*'.  It might seem more precise to use
4144          `vtable_entry_type (*)[N]' where N is the number of virtual
4145          functions.  However, that would require the vtable pointer in
4146          base classes to have a different type than the vtable pointer
4147          in derived classes.  We could make that happen, but that
4148          still wouldn't solve all the problems.  In particular, the
4149          type-based alias analysis code would decide that assignments
4150          to the base class vtable pointer can't alias assignments to
4151          the derived class vtable pointer, since they have different
4152          types.  Thus, in a derived class destructor, where the base
4153          class constructor was inlined, we could generate bad code for
4154          setting up the vtable pointer.
4155
4156          Therefore, we use one type for all vtable pointers.  We still
4157          use a type-correct type; it's just doesn't indicate the array
4158          bounds.  That's better than using `void*' or some such; it's
4159          cleaner, and it let's the alias analysis code know that these
4160          stores cannot alias stores to void*!  */
4161       tree field;
4162
4163       field = build_decl (FIELD_DECL, get_vfield_name (t), vtbl_ptr_type_node);
4164       SET_DECL_ASSEMBLER_NAME (field, get_identifier (VFIELD_BASE));
4165       DECL_VIRTUAL_P (field) = 1;
4166       DECL_ARTIFICIAL (field) = 1;
4167       DECL_FIELD_CONTEXT (field) = t;
4168       DECL_FCONTEXT (field) = t;
4169
4170       TYPE_VFIELD (t) = field;
4171
4172       /* This class is non-empty.  */
4173       CLASSTYPE_EMPTY_P (t) = 0;
4174
4175       return field;
4176     }
4177
4178   return NULL_TREE;
4179 }
4180
4181 /* Fixup the inline function given by INFO now that the class is
4182    complete.  */
4183
4184 static void
4185 fixup_pending_inline (tree fn)
4186 {
4187   if (DECL_PENDING_INLINE_INFO (fn))
4188     {
4189       tree args = DECL_ARGUMENTS (fn);
4190       while (args)
4191         {
4192           DECL_CONTEXT (args) = fn;
4193           args = TREE_CHAIN (args);
4194         }
4195     }
4196 }
4197
4198 /* Fixup the inline methods and friends in TYPE now that TYPE is
4199    complete.  */
4200
4201 static void
4202 fixup_inline_methods (tree type)
4203 {
4204   tree method = TYPE_METHODS (type);
4205   VEC (tree) *friends;
4206   unsigned ix;
4207
4208   if (method && TREE_CODE (method) == TREE_VEC)
4209     {
4210       if (TREE_VEC_ELT (method, 1))
4211         method = TREE_VEC_ELT (method, 1);
4212       else if (TREE_VEC_ELT (method, 0))
4213         method = TREE_VEC_ELT (method, 0);
4214       else
4215         method = TREE_VEC_ELT (method, 2);
4216     }
4217
4218   /* Do inline member functions.  */
4219   for (; method; method = TREE_CHAIN (method))
4220     fixup_pending_inline (method);
4221
4222   /* Do friends.  */
4223   for (friends = CLASSTYPE_INLINE_FRIENDS (type), ix = 0;
4224        VEC_iterate (tree, friends, ix, method); ix++)
4225     fixup_pending_inline (method);
4226   CLASSTYPE_INLINE_FRIENDS (type) = NULL;
4227 }
4228
4229 /* Add OFFSET to all base types of BINFO which is a base in the
4230    hierarchy dominated by T.
4231
4232    OFFSET, which is a type offset, is number of bytes.  */
4233
4234 static void
4235 propagate_binfo_offsets (tree binfo, tree offset)
4236 {
4237   int i;
4238   tree primary_binfo;
4239   tree base_binfo;
4240
4241   /* Update BINFO's offset.  */
4242   BINFO_OFFSET (binfo)
4243     = convert (sizetype,
4244                size_binop (PLUS_EXPR,
4245                            convert (ssizetype, BINFO_OFFSET (binfo)),
4246                            offset));
4247
4248   /* Find the primary base class.  */
4249   primary_binfo = get_primary_binfo (binfo);
4250
4251   if (primary_binfo && BINFO_INHERITANCE_CHAIN (primary_binfo) == binfo)
4252     propagate_binfo_offsets (primary_binfo, offset);
4253
4254   /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4255      downwards.  */
4256   for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4257     {
4258       /* Don't do the primary base twice.  */
4259       if (base_binfo == primary_binfo)
4260         continue;
4261
4262       if (BINFO_VIRTUAL_P (base_binfo))
4263         continue;
4264
4265       propagate_binfo_offsets (base_binfo, offset);
4266     }
4267 }
4268
4269 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T.  Update
4270    TYPE_ALIGN and TYPE_SIZE for T.  OFFSETS gives the location of
4271    empty subobjects of T.  */
4272
4273 static void
4274 layout_virtual_bases (record_layout_info rli, splay_tree offsets)
4275 {
4276   tree vbase;
4277   tree t = rli->t;
4278   bool first_vbase = true;
4279   tree *next_field;
4280
4281   if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) == 0)
4282     return;
4283
4284   if (!abi_version_at_least(2))
4285     {
4286       /* In G++ 3.2, we incorrectly rounded the size before laying out
4287          the virtual bases.  */
4288       finish_record_layout (rli, /*free_p=*/false);
4289 #ifdef STRUCTURE_SIZE_BOUNDARY
4290       /* Packed structures don't need to have minimum size.  */
4291       if (! TYPE_PACKED (t))
4292         TYPE_ALIGN (t) = MAX (TYPE_ALIGN (t), (unsigned) STRUCTURE_SIZE_BOUNDARY);
4293 #endif
4294       rli->offset = TYPE_SIZE_UNIT (t);
4295       rli->bitpos = bitsize_zero_node;
4296       rli->record_align = TYPE_ALIGN (t);
4297     }
4298
4299   /* Find the last field.  The artificial fields created for virtual
4300      bases will go after the last extant field to date.  */
4301   next_field = &TYPE_FIELDS (t);
4302   while (*next_field)
4303     next_field = &TREE_CHAIN (*next_field);
4304
4305   /* Go through the virtual bases, allocating space for each virtual
4306      base that is not already a primary base class.  These are
4307      allocated in inheritance graph order.  */
4308   for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
4309     {
4310       if (!BINFO_VIRTUAL_P (vbase))
4311         continue;
4312
4313       if (!BINFO_PRIMARY_P (vbase))
4314         {
4315           tree basetype = TREE_TYPE (vbase);
4316
4317           /* This virtual base is not a primary base of any class in the
4318              hierarchy, so we have to add space for it.  */
4319           next_field = build_base_field (rli, vbase,
4320                                          offsets, next_field);
4321
4322           /* If the first virtual base might have been placed at a
4323              lower address, had we started from CLASSTYPE_SIZE, rather
4324              than TYPE_SIZE, issue a warning.  There can be both false
4325              positives and false negatives from this warning in rare
4326              cases; to deal with all the possibilities would probably
4327              require performing both layout algorithms and comparing
4328              the results which is not particularly tractable.  */
4329           if (warn_abi
4330               && first_vbase
4331               && (tree_int_cst_lt
4332                   (size_binop (CEIL_DIV_EXPR,
4333                                round_up (CLASSTYPE_SIZE (t),
4334                                          CLASSTYPE_ALIGN (basetype)),
4335                                bitsize_unit_node),
4336                    BINFO_OFFSET (vbase))))
4337             warning ("offset of virtual base %qT is not ABI-compliant and "
4338                      "may change in a future version of GCC",
4339                      basetype);
4340
4341           first_vbase = false;
4342         }
4343     }
4344 }
4345
4346 /* Returns the offset of the byte just past the end of the base class
4347    BINFO.  */
4348
4349 static tree
4350 end_of_base (tree binfo)
4351 {
4352   tree size;
4353
4354   if (is_empty_class (BINFO_TYPE (binfo)))
4355     /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4356        allocate some space for it. It cannot have virtual bases, so
4357        TYPE_SIZE_UNIT is fine.  */
4358     size = TYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4359   else
4360     size = CLASSTYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4361
4362   return size_binop (PLUS_EXPR, BINFO_OFFSET (binfo), size);
4363 }
4364
4365 /* Returns the offset of the byte just past the end of the base class
4366    with the highest offset in T.  If INCLUDE_VIRTUALS_P is zero, then
4367    only non-virtual bases are included.  */
4368
4369 static tree
4370 end_of_class (tree t, int include_virtuals_p)
4371 {
4372   tree result = size_zero_node;
4373   VEC (tree) *vbases;
4374   tree binfo;
4375   tree base_binfo;
4376   tree offset;
4377   int i;
4378
4379   for (binfo = TYPE_BINFO (t), i = 0;
4380        BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4381     {
4382       if (!include_virtuals_p
4383           && BINFO_VIRTUAL_P (base_binfo)
4384           && (!BINFO_PRIMARY_P (base_binfo)
4385               || BINFO_INHERITANCE_CHAIN (base_binfo) != TYPE_BINFO (t)))
4386         continue;
4387
4388       offset = end_of_base (base_binfo);
4389       if (INT_CST_LT_UNSIGNED (result, offset))
4390         result = offset;
4391     }
4392
4393   /* G++ 3.2 did not check indirect virtual bases.  */
4394   if (abi_version_at_least (2) && include_virtuals_p)
4395     for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4396          VEC_iterate (tree, vbases, i, base_binfo); i++)
4397       {
4398         offset = end_of_base (base_binfo);
4399         if (INT_CST_LT_UNSIGNED (result, offset))
4400           result = offset;
4401       }
4402
4403   return result;
4404 }
4405
4406 /* Warn about bases of T that are inaccessible because they are
4407    ambiguous.  For example:
4408
4409      struct S {};
4410      struct T : public S {};
4411      struct U : public S, public T {};
4412
4413    Here, `(S*) new U' is not allowed because there are two `S'
4414    subobjects of U.  */
4415
4416 static void
4417 warn_about_ambiguous_bases (tree t)
4418 {
4419   int i;
4420   VEC (tree) *vbases;
4421   tree basetype;
4422   tree binfo;
4423   tree base_binfo;
4424
4425   /* If there are no repeated bases, nothing can be ambiguous.  */
4426   if (!CLASSTYPE_REPEATED_BASE_P (t))
4427     return;
4428
4429   /* Check direct bases.  */
4430   for (binfo = TYPE_BINFO (t), i = 0;
4431        BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4432     {
4433       basetype = BINFO_TYPE (base_binfo);
4434
4435       if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4436         warning ("direct base %qT inaccessible in %qT due to ambiguity",
4437                  basetype, t);
4438     }
4439
4440   /* Check for ambiguous virtual bases.  */
4441   if (extra_warnings)
4442     for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4443          VEC_iterate (tree, vbases, i, binfo); i++)
4444       {
4445         basetype = BINFO_TYPE (binfo);
4446
4447         if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4448           warning ("virtual base %qT inaccessible in %qT due to ambiguity",
4449                    basetype, t);
4450       }
4451 }
4452
4453 /* Compare two INTEGER_CSTs K1 and K2.  */
4454
4455 static int
4456 splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2)
4457 {
4458   return tree_int_cst_compare ((tree) k1, (tree) k2);
4459 }
4460
4461 /* Increase the size indicated in RLI to account for empty classes
4462    that are "off the end" of the class.  */
4463
4464 static void
4465 include_empty_classes (record_layout_info rli)
4466 {
4467   tree eoc;
4468   tree rli_size;
4469
4470   /* It might be the case that we grew the class to allocate a
4471      zero-sized base class.  That won't be reflected in RLI, yet,
4472      because we are willing to overlay multiple bases at the same
4473      offset.  However, now we need to make sure that RLI is big enough
4474      to reflect the entire class.  */
4475   eoc = end_of_class (rli->t,
4476                       CLASSTYPE_AS_BASE (rli->t) != NULL_TREE);
4477   rli_size = rli_size_unit_so_far (rli);
4478   if (TREE_CODE (rli_size) == INTEGER_CST
4479       && INT_CST_LT_UNSIGNED (rli_size, eoc))
4480     {
4481       if (!abi_version_at_least (2))
4482         /* In version 1 of the ABI, the size of a class that ends with
4483            a bitfield was not rounded up to a whole multiple of a
4484            byte.  Because rli_size_unit_so_far returns only the number
4485            of fully allocated bytes, any extra bits were not included
4486            in the size.  */
4487         rli->bitpos = round_down (rli->bitpos, BITS_PER_UNIT);
4488       else
4489         /* The size should have been rounded to a whole byte.  */
4490         gcc_assert (tree_int_cst_equal
4491                     (rli->bitpos, round_down (rli->bitpos, BITS_PER_UNIT)));
4492       rli->bitpos
4493         = size_binop (PLUS_EXPR,
4494                       rli->bitpos,
4495                       size_binop (MULT_EXPR,
4496                                   convert (bitsizetype,
4497                                            size_binop (MINUS_EXPR,
4498                                                        eoc, rli_size)),
4499                                   bitsize_int (BITS_PER_UNIT)));
4500       normalize_rli (rli);
4501     }
4502 }
4503
4504 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T.  Calculate
4505    BINFO_OFFSETs for all of the base-classes.  Position the vtable
4506    pointer.  Accumulate declared virtual functions on VIRTUALS_P.  */
4507
4508 static void
4509 layout_class_type (tree t, tree *virtuals_p)
4510 {
4511   tree non_static_data_members;
4512   tree field;
4513   tree vptr;
4514   record_layout_info rli;
4515   /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4516      types that appear at that offset.  */
4517   splay_tree empty_base_offsets;
4518   /* True if the last field layed out was a bit-field.  */
4519   bool last_field_was_bitfield = false;
4520   /* The location at which the next field should be inserted.  */
4521   tree *next_field;
4522   /* T, as a base class.  */
4523   tree base_t;
4524
4525   /* Keep track of the first non-static data member.  */
4526   non_static_data_members = TYPE_FIELDS (t);
4527
4528   /* Start laying out the record.  */
4529   rli = start_record_layout (t);
4530
4531   /* Mark all the primary bases in the hierarchy.  */
4532   determine_primary_bases (t);
4533
4534   /* Create a pointer to our virtual function table.  */
4535   vptr = create_vtable_ptr (t, virtuals_p);
4536
4537   /* The vptr is always the first thing in the class.  */
4538   if (vptr)
4539     {
4540       TREE_CHAIN (vptr) = TYPE_FIELDS (t);
4541       TYPE_FIELDS (t) = vptr;
4542       next_field = &TREE_CHAIN (vptr);
4543       place_field (rli, vptr);
4544     }
4545   else
4546     next_field = &TYPE_FIELDS (t);
4547
4548   /* Build FIELD_DECLs for all of the non-virtual base-types.  */
4549   empty_base_offsets = splay_tree_new (splay_tree_compare_integer_csts,
4550                                        NULL, NULL);
4551   build_base_fields (rli, empty_base_offsets, next_field);
4552
4553   /* Layout the non-static data members.  */
4554   for (field = non_static_data_members; field; field = TREE_CHAIN (field))
4555     {
4556       tree type;
4557       tree padding;
4558
4559       /* We still pass things that aren't non-static data members to
4560          the back-end, in case it wants to do something with them.  */
4561       if (TREE_CODE (field) != FIELD_DECL)
4562         {
4563           place_field (rli, field);
4564           /* If the static data member has incomplete type, keep track
4565              of it so that it can be completed later.  (The handling
4566              of pending statics in finish_record_layout is
4567              insufficient; consider:
4568
4569                struct S1;
4570                struct S2 { static S1 s1; };
4571
4572              At this point, finish_record_layout will be called, but
4573              S1 is still incomplete.)  */
4574           if (TREE_CODE (field) == VAR_DECL)
4575             {
4576               maybe_register_incomplete_var (field);
4577               /* The visibility of static data members is determined
4578                  at their point of declaration, not their point of
4579                  definition.  */
4580               determine_visibility (field);
4581             }
4582           continue;
4583         }
4584
4585       type = TREE_TYPE (field);
4586
4587       padding = NULL_TREE;
4588
4589       /* If this field is a bit-field whose width is greater than its
4590          type, then there are some special rules for allocating
4591          it.  */
4592       if (DECL_C_BIT_FIELD (field)
4593           && INT_CST_LT (TYPE_SIZE (type), DECL_SIZE (field)))
4594         {
4595           integer_type_kind itk;
4596           tree integer_type;
4597           bool was_unnamed_p = false;
4598           /* We must allocate the bits as if suitably aligned for the
4599              longest integer type that fits in this many bits.  type
4600              of the field.  Then, we are supposed to use the left over
4601              bits as additional padding.  */
4602           for (itk = itk_char; itk != itk_none; ++itk)
4603             if (INT_CST_LT (DECL_SIZE (field),
4604                             TYPE_SIZE (integer_types[itk])))
4605               break;
4606
4607           /* ITK now indicates a type that is too large for the
4608              field.  We have to back up by one to find the largest
4609              type that fits.  */
4610           integer_type = integer_types[itk - 1];
4611
4612           /* Figure out how much additional padding is required.  GCC
4613              3.2 always created a padding field, even if it had zero
4614              width.  */
4615           if (!abi_version_at_least (2)
4616               || INT_CST_LT (TYPE_SIZE (integer_type), DECL_SIZE (field)))
4617             {
4618               if (abi_version_at_least (2) && TREE_CODE (t) == UNION_TYPE)
4619                 /* In a union, the padding field must have the full width
4620                    of the bit-field; all fields start at offset zero.  */
4621                 padding = DECL_SIZE (field);
4622               else
4623                 {
4624                   if (warn_abi && TREE_CODE (t) == UNION_TYPE)
4625                     warning ("size assigned to %qT may not be "
4626                              "ABI-compliant and may change in a future "
4627                              "version of GCC",
4628                              t);
4629                   padding = size_binop (MINUS_EXPR, DECL_SIZE (field),
4630                                         TYPE_SIZE (integer_type));
4631                 }
4632             }
4633 #ifdef PCC_BITFIELD_TYPE_MATTERS
4634           /* An unnamed bitfield does not normally affect the
4635              alignment of the containing class on a target where
4636              PCC_BITFIELD_TYPE_MATTERS.  But, the C++ ABI does not
4637              make any exceptions for unnamed bitfields when the
4638              bitfields are longer than their types.  Therefore, we
4639              temporarily give the field a name.  */
4640           if (PCC_BITFIELD_TYPE_MATTERS && !DECL_NAME (field))
4641             {
4642               was_unnamed_p = true;
4643               DECL_NAME (field) = make_anon_name ();
4644             }
4645 #endif
4646           DECL_SIZE (field) = TYPE_SIZE (integer_type);
4647           DECL_ALIGN (field) = TYPE_ALIGN (integer_type);
4648           DECL_USER_ALIGN (field) = TYPE_USER_ALIGN (integer_type);
4649           layout_nonempty_base_or_field (rli, field, NULL_TREE,
4650                                          empty_base_offsets);
4651           if (was_unnamed_p)
4652             DECL_NAME (field) = NULL_TREE;
4653           /* Now that layout has been performed, set the size of the
4654              field to the size of its declared type; the rest of the
4655              field is effectively invisible.  */
4656           DECL_SIZE (field) = TYPE_SIZE (type);
4657           /* We must also reset the DECL_MODE of the field.  */
4658           if (abi_version_at_least (2))
4659             DECL_MODE (field) = TYPE_MODE (type);
4660           else if (warn_abi
4661                    && DECL_MODE (field) != TYPE_MODE (type))
4662             /* Versions of G++ before G++ 3.4 did not reset the
4663                DECL_MODE.  */
4664             warning ("the offset of %qD may not be ABI-compliant and may "
4665                      "change in a future version of GCC", field);
4666         }
4667       else
4668         layout_nonempty_base_or_field (rli, field, NULL_TREE,
4669                                        empty_base_offsets);
4670
4671       /* Remember the location of any empty classes in FIELD.  */
4672       if (abi_version_at_least (2))
4673         record_subobject_offsets (TREE_TYPE (field),
4674                                   byte_position(field),
4675                                   empty_base_offsets,
4676                                   /*vbases_p=*/1);
4677
4678       /* If a bit-field does not immediately follow another bit-field,
4679          and yet it starts in the middle of a byte, we have failed to
4680          comply with the ABI.  */
4681       if (warn_abi
4682           && DECL_C_BIT_FIELD (field)
4683           && !last_field_was_bitfield
4684           && !integer_zerop (size_binop (TRUNC_MOD_EXPR,
4685                                          DECL_FIELD_BIT_OFFSET (field),
4686                                          bitsize_unit_node)))
4687         cp_warning_at ("offset of %qD is not ABI-compliant and may "
4688                        "change in a future version of GCC",
4689                        field);
4690
4691       /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
4692          offset of the field.  */
4693       if (warn_abi
4694           && !tree_int_cst_equal (DECL_FIELD_OFFSET (field),
4695                                   byte_position (field))
4696           && contains_empty_class_p (TREE_TYPE (field)))
4697         cp_warning_at ("%qD contains empty classes which may cause base "
4698                        "classes to be placed at different locations in a "
4699                        "future version of GCC",
4700                        field);
4701
4702       /* If we needed additional padding after this field, add it
4703          now.  */
4704       if (padding)
4705         {
4706           tree padding_field;
4707
4708           padding_field = build_decl (FIELD_DECL,
4709                                       NULL_TREE,
4710                                       char_type_node);
4711           DECL_BIT_FIELD (padding_field) = 1;
4712           DECL_SIZE (padding_field) = padding;
4713           DECL_CONTEXT (padding_field) = t;
4714           DECL_ARTIFICIAL (padding_field) = 1;
4715           DECL_IGNORED_P (padding_field) = 1;
4716           layout_nonempty_base_or_field (rli, padding_field,
4717                                          NULL_TREE,
4718                                          empty_base_offsets);
4719         }
4720
4721       last_field_was_bitfield = DECL_C_BIT_FIELD (field);
4722     }
4723
4724   if (abi_version_at_least (2) && !integer_zerop (rli->bitpos))
4725     {
4726       /* Make sure that we are on a byte boundary so that the size of
4727          the class without virtual bases will always be a round number
4728          of bytes.  */
4729       rli->bitpos = round_up (rli->bitpos, BITS_PER_UNIT);
4730       normalize_rli (rli);
4731     }
4732
4733   /* G++ 3.2 does not allow virtual bases to be overlaid with tail
4734      padding.  */
4735   if (!abi_version_at_least (2))
4736     include_empty_classes(rli);
4737
4738   /* Delete all zero-width bit-fields from the list of fields.  Now
4739      that the type is laid out they are no longer important.  */
4740   remove_zero_width_bit_fields (t);
4741
4742   /* Create the version of T used for virtual bases.  We do not use
4743      make_aggr_type for this version; this is an artificial type.  For
4744      a POD type, we just reuse T.  */
4745   if (CLASSTYPE_NON_POD_P (t) || CLASSTYPE_EMPTY_P (t))
4746     {
4747       base_t = make_node (TREE_CODE (t));
4748
4749       /* Set the size and alignment for the new type.  In G++ 3.2, all
4750          empty classes were considered to have size zero when used as
4751          base classes.  */
4752       if (!abi_version_at_least (2) && CLASSTYPE_EMPTY_P (t))
4753         {
4754           TYPE_SIZE (base_t) = bitsize_zero_node;
4755           TYPE_SIZE_UNIT (base_t) = size_zero_node;
4756           if (warn_abi && !integer_zerop (rli_size_unit_so_far (rli)))
4757             warning ("layout of classes derived from empty class %qT "
4758                      "may change in a future version of GCC",
4759                      t);
4760         }
4761       else
4762         {
4763           tree eoc;
4764
4765           /* If the ABI version is not at least two, and the last
4766              field was a bit-field, RLI may not be on a byte
4767              boundary.  In particular, rli_size_unit_so_far might
4768              indicate the last complete byte, while rli_size_so_far
4769              indicates the total number of bits used.  Therefore,
4770              rli_size_so_far, rather than rli_size_unit_so_far, is
4771              used to compute TYPE_SIZE_UNIT.  */
4772           eoc = end_of_class (t, /*include_virtuals_p=*/0);
4773           TYPE_SIZE_UNIT (base_t)
4774             = size_binop (MAX_EXPR,
4775                           convert (sizetype,
4776                                    size_binop (CEIL_DIV_EXPR,
4777                                                rli_size_so_far (rli),
4778                                                bitsize_int (BITS_PER_UNIT))),
4779                           eoc);
4780           TYPE_SIZE (base_t)
4781             = size_binop (MAX_EXPR,
4782                           rli_size_so_far (rli),
4783                           size_binop (MULT_EXPR,
4784                                       convert (bitsizetype, eoc),
4785                                       bitsize_int (BITS_PER_UNIT)));
4786         }
4787       TYPE_ALIGN (base_t) = rli->record_align;
4788       TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t);
4789
4790       /* Copy the fields from T.  */
4791       next_field = &TYPE_FIELDS (base_t);
4792       for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
4793         if (TREE_CODE (field) == FIELD_DECL)
4794           {
4795             *next_field = build_decl (FIELD_DECL,
4796                                       DECL_NAME (field),
4797                                       TREE_TYPE (field));
4798             DECL_CONTEXT (*next_field) = base_t;
4799             DECL_FIELD_OFFSET (*next_field) = DECL_FIELD_OFFSET (field);
4800             DECL_FIELD_BIT_OFFSET (*next_field)
4801               = DECL_FIELD_BIT_OFFSET (field);
4802             DECL_SIZE (*next_field) = DECL_SIZE (field);
4803             DECL_MODE (*next_field) = DECL_MODE (field);
4804             next_field = &TREE_CHAIN (*next_field);
4805           }
4806
4807       /* Record the base version of the type.  */
4808       CLASSTYPE_AS_BASE (t) = base_t;
4809       TYPE_CONTEXT (base_t) = t;
4810     }
4811   else
4812     CLASSTYPE_AS_BASE (t) = t;
4813
4814   /* Every empty class contains an empty class.  */
4815   if (CLASSTYPE_EMPTY_P (t))
4816     CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
4817
4818   /* Set the TYPE_DECL for this type to contain the right
4819      value for DECL_OFFSET, so that we can use it as part
4820      of a COMPONENT_REF for multiple inheritance.  */
4821   layout_decl (TYPE_MAIN_DECL (t), 0);
4822
4823   /* Now fix up any virtual base class types that we left lying
4824      around.  We must get these done before we try to lay out the
4825      virtual function table.  As a side-effect, this will remove the
4826      base subobject fields.  */
4827   layout_virtual_bases (rli, empty_base_offsets);
4828
4829   /* Make sure that empty classes are reflected in RLI at this
4830      point.  */
4831   include_empty_classes(rli);
4832
4833   /* Make sure not to create any structures with zero size.  */
4834   if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t))
4835     place_field (rli,
4836                  build_decl (FIELD_DECL, NULL_TREE, char_type_node));
4837
4838   /* Let the back-end lay out the type.  */
4839   finish_record_layout (rli, /*free_p=*/true);
4840
4841   /* Warn about bases that can't be talked about due to ambiguity.  */
4842   warn_about_ambiguous_bases (t);
4843
4844   /* Now that we're done with layout, give the base fields the real types.  */
4845   for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
4846     if (DECL_ARTIFICIAL (field) && IS_FAKE_BASE_TYPE (TREE_TYPE (field)))
4847       TREE_TYPE (field) = TYPE_CONTEXT (TREE_TYPE (field));
4848
4849   /* Clean up.  */
4850   splay_tree_delete (empty_base_offsets);
4851 }
4852
4853 /* Determine the "key method" for the class type indicated by TYPE,
4854    and set CLASSTYPE_KEY_METHOD accordingly.  */
4855
4856 void
4857 determine_key_method (tree type)
4858 {
4859   tree method;
4860
4861   if (TYPE_FOR_JAVA (type)
4862       || processing_template_decl
4863       || CLASSTYPE_TEMPLATE_INSTANTIATION (type)
4864       || CLASSTYPE_INTERFACE_KNOWN (type))
4865     return;
4866
4867   /* The key method is the first non-pure virtual function that is not
4868      inline at the point of class definition.  On some targets the
4869      key function may not be inline; those targets should not call
4870      this function until the end of the translation unit.  */
4871   for (method = TYPE_METHODS (type); method != NULL_TREE;
4872        method = TREE_CHAIN (method))
4873     if (DECL_VINDEX (method) != NULL_TREE
4874         && ! DECL_DECLARED_INLINE_P (method)
4875         && ! DECL_PURE_VIRTUAL_P (method))
4876       {
4877         CLASSTYPE_KEY_METHOD (type) = method;
4878         break;
4879       }
4880
4881   return;
4882 }
4883
4884 /* Perform processing required when the definition of T (a class type)
4885    is complete.  */
4886
4887 void
4888 finish_struct_1 (tree t)
4889 {
4890   tree x;
4891   /* A TREE_LIST.  The TREE_VALUE of each node is a FUNCTION_DECL.  */
4892   tree virtuals = NULL_TREE;
4893   int n_fields = 0;
4894
4895   if (COMPLETE_TYPE_P (t))
4896     {
4897       gcc_assert (IS_AGGR_TYPE (t));
4898       error ("redefinition of %q#T", t);
4899       popclass ();
4900       return;
4901     }
4902
4903   /* If this type was previously laid out as a forward reference,
4904      make sure we lay it out again.  */
4905   TYPE_SIZE (t) = NULL_TREE;
4906   CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE;
4907
4908   fixup_inline_methods (t);
4909
4910   /* Make assumptions about the class; we'll reset the flags if
4911      necessary.  */
4912   CLASSTYPE_EMPTY_P (t) = 1;
4913   CLASSTYPE_NEARLY_EMPTY_P (t) = 1;
4914   CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 0;
4915
4916   /* Do end-of-class semantic processing: checking the validity of the
4917      bases and members and add implicitly generated methods.  */
4918   check_bases_and_members (t);
4919
4920   /* Find the key method.  */
4921   if (TYPE_CONTAINS_VPTR_P (t))
4922     {
4923       /* The Itanium C++ ABI permits the key method to be chosen when
4924          the class is defined -- even though the key method so
4925          selected may later turn out to be an inline function.  On
4926          some systems (such as ARM Symbian OS) the key method cannot
4927          be determined until the end of the translation unit.  On such
4928          systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
4929          will cause the class to be added to KEYED_CLASSES.  Then, in
4930          finish_file we will determine the key method.  */
4931       if (targetm.cxx.key_method_may_be_inline ())
4932         determine_key_method (t);
4933
4934       /* If a polymorphic class has no key method, we may emit the vtable
4935          in every translation unit where the class definition appears.  */
4936       if (CLASSTYPE_KEY_METHOD (t) == NULL_TREE)
4937         keyed_classes = tree_cons (NULL_TREE, t, keyed_classes);
4938     }
4939
4940   /* Layout the class itself.  */
4941   layout_class_type (t, &virtuals);
4942   if (CLASSTYPE_AS_BASE (t) != t)
4943     /* We use the base type for trivial assignments, and hence it
4944        needs a mode.  */
4945     compute_record_mode (CLASSTYPE_AS_BASE (t));
4946
4947   virtuals = modify_all_vtables (t, nreverse (virtuals));
4948
4949   /* If necessary, create the primary vtable for this class.  */
4950   if (virtuals || TYPE_CONTAINS_VPTR_P (t))
4951     {
4952       /* We must enter these virtuals into the table.  */
4953       if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
4954         build_primary_vtable (NULL_TREE, t);
4955       else if (! BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (t)))
4956         /* Here we know enough to change the type of our virtual
4957            function table, but we will wait until later this function.  */
4958         build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t);
4959     }
4960
4961   if (TYPE_CONTAINS_VPTR_P (t))
4962     {
4963       int vindex;
4964       tree fn;
4965
4966       if (BINFO_VTABLE (TYPE_BINFO (t)))
4967         gcc_assert (DECL_VIRTUAL_P (BINFO_VTABLE (TYPE_BINFO (t))));
4968       if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
4969         gcc_assert (BINFO_VIRTUALS (TYPE_BINFO (t)) == NULL_TREE);
4970
4971       /* Add entries for virtual functions introduced by this class.  */
4972       BINFO_VIRTUALS (TYPE_BINFO (t))
4973         = chainon (BINFO_VIRTUALS (TYPE_BINFO (t)), virtuals);
4974
4975       /* Set DECL_VINDEX for all functions declared in this class.  */
4976       for (vindex = 0, fn = BINFO_VIRTUALS (TYPE_BINFO (t));
4977            fn;
4978            fn = TREE_CHAIN (fn),
4979              vindex += (TARGET_VTABLE_USES_DESCRIPTORS
4980                         ? TARGET_VTABLE_USES_DESCRIPTORS : 1))
4981         {
4982           tree fndecl = BV_FN (fn);
4983
4984           if (DECL_THUNK_P (fndecl))
4985             /* A thunk. We should never be calling this entry directly
4986                from this vtable -- we'd use the entry for the non
4987                thunk base function.  */
4988             DECL_VINDEX (fndecl) = NULL_TREE;
4989           else if (TREE_CODE (DECL_VINDEX (fndecl)) != INTEGER_CST)
4990             DECL_VINDEX (fndecl) = build_int_cst (NULL_TREE, vindex);
4991         }
4992     }
4993
4994   finish_struct_bits (t);
4995
4996   /* Complete the rtl for any static member objects of the type we're
4997      working on.  */
4998   for (x = TYPE_FIELDS (t); x; x = TREE_CHAIN (x))
4999     if (TREE_CODE (x) == VAR_DECL && TREE_STATIC (x)
5000         && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t))
5001       DECL_MODE (x) = TYPE_MODE (t);
5002
5003   /* Done with FIELDS...now decide whether to sort these for
5004      faster lookups later.
5005
5006      We use a small number because most searches fail (succeeding
5007      ultimately as the search bores through the inheritance
5008      hierarchy), and we want this failure to occur quickly.  */
5009
5010   n_fields = count_fields (TYPE_FIELDS (t));
5011   if (n_fields > 7)
5012     {
5013       struct sorted_fields_type *field_vec = GGC_NEWVAR
5014          (struct sorted_fields_type,
5015           sizeof (struct sorted_fields_type) + n_fields * sizeof (tree));
5016       field_vec->len = n_fields;
5017       add_fields_to_record_type (TYPE_FIELDS (t), field_vec, 0);
5018       qsort (field_vec->elts, n_fields, sizeof (tree),
5019              field_decl_cmp);
5020       if (! DECL_LANG_SPECIFIC (TYPE_MAIN_DECL (t)))
5021         retrofit_lang_decl (TYPE_MAIN_DECL (t));
5022       DECL_SORTED_FIELDS (TYPE_MAIN_DECL (t)) = field_vec;
5023     }
5024
5025   /* Make the rtl for any new vtables we have created, and unmark
5026      the base types we marked.  */
5027   finish_vtbls (t);
5028
5029   /* Build the VTT for T.  */
5030   build_vtt (t);
5031
5032   /* This warning does not make sense for Java classes, since they
5033      cannot have destructors.  */
5034   if (!TYPE_FOR_JAVA (t) && warn_nonvdtor && TYPE_POLYMORPHIC_P (t))
5035     {
5036       tree dtor;
5037
5038       dtor = CLASSTYPE_DESTRUCTORS (t);
5039       /* Warn only if the dtor is non-private or the class has
5040          friends.  */
5041       if (/* An implicitly declared destructor is always public.  And,
5042              if it were virtual, we would have created it by now.  */
5043           !dtor
5044           || (!DECL_VINDEX (dtor)
5045               && (!TREE_PRIVATE (dtor)
5046                   || CLASSTYPE_FRIEND_CLASSES (t)
5047                   || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))))
5048         warning ("%q#T has virtual functions but non-virtual destructor",
5049                  t);
5050     }
5051
5052   complete_vars (t);
5053
5054   if (warn_overloaded_virtual)
5055     warn_hidden (t);
5056
5057   maybe_suppress_debug_info (t);
5058
5059   dump_class_hierarchy (t);
5060
5061   /* Finish debugging output for this type.  */
5062   rest_of_type_compilation (t, ! LOCAL_CLASS_P (t));
5063 }
5064
5065 /* When T was built up, the member declarations were added in reverse
5066    order.  Rearrange them to declaration order.  */
5067
5068 void
5069 unreverse_member_declarations (tree t)
5070 {
5071   tree next;
5072   tree prev;
5073   tree x;
5074
5075   /* The following lists are all in reverse order.  Put them in
5076      declaration order now.  */
5077   TYPE_METHODS (t) = nreverse (TYPE_METHODS (t));
5078   CLASSTYPE_DECL_LIST (t) = nreverse (CLASSTYPE_DECL_LIST (t));
5079
5080   /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5081      reverse order, so we can't just use nreverse.  */
5082   prev = NULL_TREE;
5083   for (x = TYPE_FIELDS (t);
5084        x && TREE_CODE (x) != TYPE_DECL;
5085        x = next)
5086     {
5087       next = TREE_CHAIN (x);
5088       TREE_CHAIN (x) = prev;
5089       prev = x;
5090     }
5091   if (prev)
5092     {
5093       TREE_CHAIN (TYPE_FIELDS (t)) = x;
5094       if (prev)
5095         TYPE_FIELDS (t) = prev;
5096     }
5097 }
5098
5099 tree
5100 finish_struct (tree t, tree attributes)
5101 {
5102   location_t saved_loc = input_location;
5103
5104   /* Now that we've got all the field declarations, reverse everything
5105      as necessary.  */
5106   unreverse_member_declarations (t);
5107
5108   cplus_decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
5109
5110   /* Nadger the current location so that diagnostics point to the start of
5111      the struct, not the end.  */
5112   input_location = DECL_SOURCE_LOCATION (TYPE_NAME (t));
5113
5114   if (processing_template_decl)
5115     {
5116       tree x;
5117
5118       finish_struct_methods (t);
5119       TYPE_SIZE (t) = bitsize_zero_node;
5120       TYPE_SIZE_UNIT (t) = size_zero_node;
5121
5122       /* We need to emit an error message if this type was used as a parameter
5123          and it is an abstract type, even if it is a template. We construct
5124          a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
5125          account and we call complete_vars with this type, which will check
5126          the PARM_DECLS. Note that while the type is being defined,
5127          CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
5128          (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it.  */
5129       CLASSTYPE_PURE_VIRTUALS (t) = NULL;
5130       for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
5131         if (DECL_PURE_VIRTUAL_P (x))
5132           VEC_safe_push (tree, CLASSTYPE_PURE_VIRTUALS (t), x);
5133       complete_vars (t);
5134     }
5135   else
5136     finish_struct_1 (t);
5137
5138   input_location = saved_loc;
5139
5140   TYPE_BEING_DEFINED (t) = 0;
5141
5142   if (current_class_type)
5143     popclass ();
5144   else
5145     error ("trying to finish struct, but kicked out due to previous parse errors");
5146
5147   if (processing_template_decl && at_function_scope_p ())
5148     add_stmt (build_min (TAG_DEFN, t));
5149
5150   return t;
5151 }
5152 \f
5153 /* Return the dynamic type of INSTANCE, if known.
5154    Used to determine whether the virtual function table is needed
5155    or not.
5156
5157    *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5158    of our knowledge of its type.  *NONNULL should be initialized
5159    before this function is called.  */
5160
5161 static tree
5162 fixed_type_or_null (tree instance, int* nonnull, int* cdtorp)
5163 {
5164   switch (TREE_CODE (instance))
5165     {
5166     case INDIRECT_REF:
5167       if (POINTER_TYPE_P (TREE_TYPE (instance)))
5168         return NULL_TREE;
5169       else
5170         return fixed_type_or_null (TREE_OPERAND (instance, 0),
5171                                    nonnull, cdtorp);
5172
5173     case CALL_EXPR:
5174       /* This is a call to a constructor, hence it's never zero.  */
5175       if (TREE_HAS_CONSTRUCTOR (instance))
5176         {
5177           if (nonnull)
5178             *nonnull = 1;
5179           return TREE_TYPE (instance);
5180         }
5181       return NULL_TREE;
5182
5183     case SAVE_EXPR:
5184       /* This is a call to a constructor, hence it's never zero.  */
5185       if (TREE_HAS_CONSTRUCTOR (instance))
5186         {
5187           if (nonnull)
5188             *nonnull = 1;
5189           return TREE_TYPE (instance);
5190         }
5191       return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5192
5193     case PLUS_EXPR:
5194     case MINUS_EXPR:
5195       if (TREE_CODE (TREE_OPERAND (instance, 0)) == ADDR_EXPR)
5196         return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5197       if (TREE_CODE (TREE_OPERAND (instance, 1)) == INTEGER_CST)
5198         /* Propagate nonnull.  */
5199         return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5200       return NULL_TREE;
5201
5202     case NOP_EXPR:
5203     case CONVERT_EXPR:
5204       return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5205
5206     case ADDR_EXPR:
5207       instance = TREE_OPERAND (instance, 0);
5208       if (nonnull)
5209         {
5210           /* Just because we see an ADDR_EXPR doesn't mean we're dealing
5211              with a real object -- given &p->f, p can still be null.  */
5212           tree t = get_base_address (instance);
5213           /* ??? Probably should check DECL_WEAK here.  */
5214           if (t && DECL_P (t))
5215             *nonnull = 1;
5216         }
5217       return fixed_type_or_null (instance, nonnull, cdtorp);
5218
5219     case COMPONENT_REF:
5220       /* If this component is really a base class reference, then the field
5221          itself isn't definitive.  */
5222       if (DECL_FIELD_IS_BASE (TREE_OPERAND (instance, 1)))
5223         return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5224       return fixed_type_or_null (TREE_OPERAND (instance, 1), nonnull, cdtorp);
5225
5226     case VAR_DECL:
5227     case FIELD_DECL:
5228       if (TREE_CODE (TREE_TYPE (instance)) == ARRAY_TYPE
5229           && IS_AGGR_TYPE (TREE_TYPE (TREE_TYPE (instance))))
5230         {
5231           if (nonnull)
5232             *nonnull = 1;
5233           return TREE_TYPE (TREE_TYPE (instance));
5234         }
5235       /* fall through...  */
5236     case TARGET_EXPR:
5237     case PARM_DECL:
5238     case RESULT_DECL:
5239       if (IS_AGGR_TYPE (TREE_TYPE (instance)))
5240         {
5241           if (nonnull)
5242             *nonnull = 1;
5243           return TREE_TYPE (instance);
5244         }
5245       else if (instance == current_class_ptr)
5246         {
5247           if (nonnull)
5248             *nonnull = 1;
5249
5250           /* if we're in a ctor or dtor, we know our type.  */
5251           if (DECL_LANG_SPECIFIC (current_function_decl)
5252               && (DECL_CONSTRUCTOR_P (current_function_decl)
5253                   || DECL_DESTRUCTOR_P (current_function_decl)))
5254             {
5255               if (cdtorp)
5256                 *cdtorp = 1;
5257               return TREE_TYPE (TREE_TYPE (instance));
5258             }
5259         }
5260       else if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE)
5261         {
5262           /* Reference variables should be references to objects.  */
5263           if (nonnull)
5264             *nonnull = 1;
5265
5266           /* DECL_VAR_MARKED_P is used to prevent recursion; a
5267              variable's initializer may refer to the variable
5268              itself.  */
5269           if (TREE_CODE (instance) == VAR_DECL
5270               && DECL_INITIAL (instance)
5271               && !DECL_VAR_MARKED_P (instance))
5272             {
5273               tree type;
5274               DECL_VAR_MARKED_P (instance) = 1;
5275               type = fixed_type_or_null (DECL_INITIAL (instance),
5276                                          nonnull, cdtorp);
5277               DECL_VAR_MARKED_P (instance) = 0;
5278               return type;
5279             }
5280         }
5281       return NULL_TREE;
5282
5283     default:
5284       return NULL_TREE;
5285     }
5286 }
5287
5288 /* Return nonzero if the dynamic type of INSTANCE is known, and
5289    equivalent to the static type.  We also handle the case where
5290    INSTANCE is really a pointer. Return negative if this is a
5291    ctor/dtor. There the dynamic type is known, but this might not be
5292    the most derived base of the original object, and hence virtual
5293    bases may not be layed out according to this type.
5294
5295    Used to determine whether the virtual function table is needed
5296    or not.
5297
5298    *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5299    of our knowledge of its type.  *NONNULL should be initialized
5300    before this function is called.  */
5301
5302 int
5303 resolves_to_fixed_type_p (tree instance, int* nonnull)
5304 {
5305   tree t = TREE_TYPE (instance);
5306   int cdtorp = 0;
5307
5308   tree fixed = fixed_type_or_null (instance, nonnull, &cdtorp);
5309   if (fixed == NULL_TREE)
5310     return 0;
5311   if (POINTER_TYPE_P (t))
5312     t = TREE_TYPE (t);
5313   if (!same_type_ignoring_top_level_qualifiers_p (t, fixed))
5314     return 0;
5315   return cdtorp ? -1 : 1;
5316 }
5317
5318 \f
5319 void
5320 init_class_processing (void)
5321 {
5322   current_class_depth = 0;
5323   current_class_stack_size = 10;
5324   current_class_stack
5325     = xmalloc (current_class_stack_size * sizeof (struct class_stack_node));
5326   VARRAY_TREE_INIT (local_classes, 8, "local_classes");
5327
5328   ridpointers[(int) RID_PUBLIC] = access_public_node;
5329   ridpointers[(int) RID_PRIVATE] = access_private_node;
5330   ridpointers[(int) RID_PROTECTED] = access_protected_node;
5331 }
5332
5333 /* Restore the cached PREVIOUS_CLASS_LEVEL.  */
5334
5335 static void
5336 restore_class_cache (void)
5337 {
5338   tree type;
5339
5340   /* We are re-entering the same class we just left, so we don't
5341      have to search the whole inheritance matrix to find all the
5342      decls to bind again.  Instead, we install the cached
5343      class_shadowed list and walk through it binding names.  */
5344   push_binding_level (previous_class_level);
5345   class_binding_level = previous_class_level;
5346   /* Restore IDENTIFIER_TYPE_VALUE.  */
5347   for (type = class_binding_level->type_shadowed;
5348        type;
5349        type = TREE_CHAIN (type))
5350     SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (type), TREE_TYPE (type));
5351 }
5352
5353 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
5354    appropriate for TYPE.
5355
5356    So that we may avoid calls to lookup_name, we cache the _TYPE
5357    nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5358
5359    For multiple inheritance, we perform a two-pass depth-first search
5360    of the type lattice.  */
5361
5362 void
5363 pushclass (tree type)
5364 {
5365   type = TYPE_MAIN_VARIANT (type);
5366
5367   /* Make sure there is enough room for the new entry on the stack.  */
5368   if (current_class_depth + 1 >= current_class_stack_size)
5369     {
5370       current_class_stack_size *= 2;
5371       current_class_stack
5372         = xrealloc (current_class_stack,
5373                     current_class_stack_size
5374                     * sizeof (struct class_stack_node));
5375     }
5376
5377   /* Insert a new entry on the class stack.  */
5378   current_class_stack[current_class_depth].name = current_class_name;
5379   current_class_stack[current_class_depth].type = current_class_type;
5380   current_class_stack[current_class_depth].access = current_access_specifier;
5381   current_class_stack[current_class_depth].names_used = 0;
5382   current_class_depth++;
5383
5384   /* Now set up the new type.  */
5385   current_class_name = TYPE_NAME (type);
5386   if (TREE_CODE (current_class_name) == TYPE_DECL)
5387     current_class_name = DECL_NAME (current_class_name);
5388   current_class_type = type;
5389
5390   /* By default, things in classes are private, while things in
5391      structures or unions are public.  */
5392   current_access_specifier = (CLASSTYPE_DECLARED_CLASS (type)
5393                               ? access_private_node
5394                               : access_public_node);
5395
5396   if (previous_class_level
5397       && type != previous_class_level->this_entity
5398       && current_class_depth == 1)
5399     {
5400       /* Forcibly remove any old class remnants.  */
5401       invalidate_class_lookup_cache ();
5402     }
5403
5404   if (!previous_class_level
5405       || type != previous_class_level->this_entity
5406       || current_class_depth > 1)
5407     pushlevel_class ();
5408   else
5409     restore_class_cache ();
5410 }
5411
5412 /* When we exit a toplevel class scope, we save its binding level so
5413    that we can restore it quickly.  Here, we've entered some other
5414    class, so we must invalidate our cache.  */
5415
5416 void
5417 invalidate_class_lookup_cache (void)
5418 {
5419   previous_class_level = NULL;
5420 }
5421
5422 /* Get out of the current class scope. If we were in a class scope
5423    previously, that is the one popped to.  */
5424
5425 void
5426 popclass (void)
5427 {
5428   poplevel_class ();
5429
5430   current_class_depth--;
5431   current_class_name = current_class_stack[current_class_depth].name;
5432   current_class_type = current_class_stack[current_class_depth].type;
5433   current_access_specifier = current_class_stack[current_class_depth].access;
5434   if (current_class_stack[current_class_depth].names_used)
5435     splay_tree_delete (current_class_stack[current_class_depth].names_used);
5436 }
5437
5438 /* Returns 1 if current_class_type is either T or a nested type of T.
5439    We start looking from 1 because entry 0 is from global scope, and has
5440    no type.  */
5441
5442 int
5443 currently_open_class (tree t)
5444 {
5445   int i;
5446   if (current_class_type && same_type_p (t, current_class_type))
5447     return 1;
5448   for (i = 1; i < current_class_depth; ++i)
5449     if (current_class_stack[i].type
5450         && same_type_p (current_class_stack [i].type, t))
5451       return 1;
5452   return 0;
5453 }
5454
5455 /* If either current_class_type or one of its enclosing classes are derived
5456    from T, return the appropriate type.  Used to determine how we found
5457    something via unqualified lookup.  */
5458
5459 tree
5460 currently_open_derived_class (tree t)
5461 {
5462   int i;
5463
5464   /* The bases of a dependent type are unknown.  */
5465   if (dependent_type_p (t))
5466     return NULL_TREE;
5467
5468   if (!current_class_type)
5469     return NULL_TREE;
5470
5471   if (DERIVED_FROM_P (t, current_class_type))
5472     return current_class_type;
5473
5474   for (i = current_class_depth - 1; i > 0; --i)
5475     if (DERIVED_FROM_P (t, current_class_stack[i].type))
5476       return current_class_stack[i].type;
5477
5478   return NULL_TREE;
5479 }
5480
5481 /* When entering a class scope, all enclosing class scopes' names with
5482    static meaning (static variables, static functions, types and
5483    enumerators) have to be visible.  This recursive function calls
5484    pushclass for all enclosing class contexts until global or a local
5485    scope is reached.  TYPE is the enclosed class.  */
5486
5487 void
5488 push_nested_class (tree type)
5489 {
5490   tree context;
5491
5492   /* A namespace might be passed in error cases, like A::B:C.  */
5493   if (type == NULL_TREE
5494       || type == error_mark_node
5495       || TREE_CODE (type) == NAMESPACE_DECL
5496       || ! IS_AGGR_TYPE (type)
5497       || TREE_CODE (type) == TEMPLATE_TYPE_PARM
5498       || TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
5499     return;
5500
5501   context = DECL_CONTEXT (TYPE_MAIN_DECL (type));
5502
5503   if (context && CLASS_TYPE_P (context))
5504     push_nested_class (context);
5505   pushclass (type);
5506 }
5507
5508 /* Undoes a push_nested_class call.  */
5509
5510 void
5511 pop_nested_class (void)
5512 {
5513   tree context = DECL_CONTEXT (TYPE_MAIN_DECL (current_class_type));
5514
5515   popclass ();
5516   if (context && CLASS_TYPE_P (context))
5517     pop_nested_class ();
5518 }
5519
5520 /* Returns the number of extern "LANG" blocks we are nested within.  */
5521
5522 int
5523 current_lang_depth (void)
5524 {
5525   return VARRAY_ACTIVE_SIZE (current_lang_base);
5526 }
5527
5528 /* Set global variables CURRENT_LANG_NAME to appropriate value
5529    so that behavior of name-mangling machinery is correct.  */
5530
5531 void
5532 push_lang_context (tree name)
5533 {
5534   VARRAY_PUSH_TREE (current_lang_base, current_lang_name);
5535
5536   if (name == lang_name_cplusplus)
5537     {
5538       current_lang_name = name;
5539     }
5540   else if (name == lang_name_java)
5541     {
5542       current_lang_name = name;
5543       /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5544          (See record_builtin_java_type in decl.c.)  However, that causes
5545          incorrect debug entries if these types are actually used.
5546          So we re-enable debug output after extern "Java".  */
5547       DECL_IGNORED_P (TYPE_NAME (java_byte_type_node)) = 0;
5548       DECL_IGNORED_P (TYPE_NAME (java_short_type_node)) = 0;
5549       DECL_IGNORED_P (TYPE_NAME (java_int_type_node)) = 0;
5550       DECL_IGNORED_P (TYPE_NAME (java_long_type_node)) = 0;
5551       DECL_IGNORED_P (TYPE_NAME (java_float_type_node)) = 0;
5552       DECL_IGNORED_P (TYPE_NAME (java_double_type_node)) = 0;
5553       DECL_IGNORED_P (TYPE_NAME (java_char_type_node)) = 0;
5554       DECL_IGNORED_P (TYPE_NAME (java_boolean_type_node)) = 0;
5555     }
5556   else if (name == lang_name_c)
5557     {
5558       current_lang_name = name;
5559     }
5560   else
5561     error ("language string %<\"%E\"%> not recognized", name);
5562 }
5563
5564 /* Get out of the current language scope.  */
5565
5566 void
5567 pop_lang_context (void)
5568 {
5569   current_lang_name = VARRAY_TOP_TREE (current_lang_base);
5570   VARRAY_POP (current_lang_base);
5571 }
5572 \f
5573 /* Type instantiation routines.  */
5574
5575 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
5576    matches the TARGET_TYPE.  If there is no satisfactory match, return
5577    error_mark_node, and issue a error & warning messages under control
5578    of FLAGS.  Permit pointers to member function if FLAGS permits.  If
5579    TEMPLATE_ONLY, the name of the overloaded function was a
5580    template-id, and EXPLICIT_TARGS are the explicitly provided
5581    template arguments.  */
5582
5583 static tree
5584 resolve_address_of_overloaded_function (tree target_type,
5585                                         tree overload,
5586                                         tsubst_flags_t flags,
5587                                         bool template_only,
5588                                         tree explicit_targs)
5589 {
5590   /* Here's what the standard says:
5591
5592        [over.over]
5593
5594        If the name is a function template, template argument deduction
5595        is done, and if the argument deduction succeeds, the deduced
5596        arguments are used to generate a single template function, which
5597        is added to the set of overloaded functions considered.
5598
5599        Non-member functions and static member functions match targets of
5600        type "pointer-to-function" or "reference-to-function."  Nonstatic
5601        member functions match targets of type "pointer-to-member
5602        function;" the function type of the pointer to member is used to
5603        select the member function from the set of overloaded member
5604        functions.  If a nonstatic member function is selected, the
5605        reference to the overloaded function name is required to have the
5606        form of a pointer to member as described in 5.3.1.
5607
5608        If more than one function is selected, any template functions in
5609        the set are eliminated if the set also contains a non-template
5610        function, and any given template function is eliminated if the
5611        set contains a second template function that is more specialized
5612        than the first according to the partial ordering rules 14.5.5.2.
5613        After such eliminations, if any, there shall remain exactly one
5614        selected function.  */
5615
5616   int is_ptrmem = 0;
5617   int is_reference = 0;
5618   /* We store the matches in a TREE_LIST rooted here.  The functions
5619      are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
5620      interoperability with most_specialized_instantiation.  */
5621   tree matches = NULL_TREE;
5622   tree fn;
5623
5624   /* By the time we get here, we should be seeing only real
5625      pointer-to-member types, not the internal POINTER_TYPE to
5626      METHOD_TYPE representation.  */
5627   gcc_assert (TREE_CODE (target_type) != POINTER_TYPE
5628               || TREE_CODE (TREE_TYPE (target_type)) != METHOD_TYPE);
5629
5630   gcc_assert (is_overloaded_fn (overload));
5631
5632   /* Check that the TARGET_TYPE is reasonable.  */
5633   if (TYPE_PTRFN_P (target_type))
5634     /* This is OK.  */;
5635   else if (TYPE_PTRMEMFUNC_P (target_type))
5636     /* This is OK, too.  */
5637     is_ptrmem = 1;
5638   else if (TREE_CODE (target_type) == FUNCTION_TYPE)
5639     {
5640       /* This is OK, too.  This comes from a conversion to reference
5641          type.  */
5642       target_type = build_reference_type (target_type);
5643       is_reference = 1;
5644     }
5645   else
5646     {
5647       if (flags & tf_error)
5648         error ("cannot resolve overloaded function %qD based on"
5649                " conversion to type %qT",
5650                DECL_NAME (OVL_FUNCTION (overload)), target_type);
5651       return error_mark_node;
5652     }
5653
5654   /* If we can find a non-template function that matches, we can just
5655      use it.  There's no point in generating template instantiations
5656      if we're just going to throw them out anyhow.  But, of course, we
5657      can only do this when we don't *need* a template function.  */
5658   if (!template_only)
5659     {
5660       tree fns;
5661
5662       for (fns = overload; fns; fns = OVL_NEXT (fns))
5663         {
5664           tree fn = OVL_CURRENT (fns);
5665           tree fntype;
5666
5667           if (TREE_CODE (fn) == TEMPLATE_DECL)
5668             /* We're not looking for templates just yet.  */
5669             continue;
5670
5671           if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
5672               != is_ptrmem)
5673             /* We're looking for a non-static member, and this isn't
5674                one, or vice versa.  */
5675             continue;
5676
5677           /* Ignore anticipated decls of undeclared builtins.  */
5678           if (DECL_ANTICIPATED (fn))
5679             continue;
5680
5681           /* See if there's a match.  */
5682           fntype = TREE_TYPE (fn);
5683           if (is_ptrmem)
5684             fntype = build_ptrmemfunc_type (build_pointer_type (fntype));
5685           else if (!is_reference)
5686             fntype = build_pointer_type (fntype);
5687
5688           if (can_convert_arg (target_type, fntype, fn))
5689             matches = tree_cons (fn, NULL_TREE, matches);
5690         }
5691     }
5692
5693   /* Now, if we've already got a match (or matches), there's no need
5694      to proceed to the template functions.  But, if we don't have a
5695      match we need to look at them, too.  */
5696   if (!matches)
5697     {
5698       tree target_fn_type;
5699       tree target_arg_types;
5700       tree target_ret_type;
5701       tree fns;
5702
5703       if (is_ptrmem)
5704         target_fn_type
5705           = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (target_type));
5706       else
5707         target_fn_type = TREE_TYPE (target_type);
5708       target_arg_types = TYPE_ARG_TYPES (target_fn_type);
5709       target_ret_type = TREE_TYPE (target_fn_type);
5710
5711       /* Never do unification on the 'this' parameter.  */
5712       if (TREE_CODE (target_fn_type) == METHOD_TYPE)
5713         target_arg_types = TREE_CHAIN (target_arg_types);
5714
5715       for (fns = overload; fns; fns = OVL_NEXT (fns))
5716         {
5717           tree fn = OVL_CURRENT (fns);
5718           tree instantiation;
5719           tree instantiation_type;
5720           tree targs;
5721
5722           if (TREE_CODE (fn) != TEMPLATE_DECL)
5723             /* We're only looking for templates.  */
5724             continue;
5725
5726           if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
5727               != is_ptrmem)
5728             /* We're not looking for a non-static member, and this is
5729                one, or vice versa.  */
5730             continue;
5731
5732           /* Try to do argument deduction.  */
5733           targs = make_tree_vec (DECL_NTPARMS (fn));
5734           if (fn_type_unification (fn, explicit_targs, targs,
5735                                    target_arg_types, target_ret_type,
5736                                    DEDUCE_EXACT, -1) != 0)
5737             /* Argument deduction failed.  */
5738             continue;
5739
5740           /* Instantiate the template.  */
5741           instantiation = instantiate_template (fn, targs, flags);
5742           if (instantiation == error_mark_node)
5743             /* Instantiation failed.  */
5744             continue;
5745
5746           /* See if there's a match.  */
5747           instantiation_type = TREE_TYPE (instantiation);
5748           if (is_ptrmem)
5749             instantiation_type =
5750               build_ptrmemfunc_type (build_pointer_type (instantiation_type));
5751           else if (!is_reference)
5752             instantiation_type = build_pointer_type (instantiation_type);
5753           if (can_convert_arg (target_type, instantiation_type, instantiation))
5754             matches = tree_cons (instantiation, fn, matches);
5755         }
5756
5757       /* Now, remove all but the most specialized of the matches.  */
5758       if (matches)
5759         {
5760           tree match = most_specialized_instantiation (matches);
5761
5762           if (match != error_mark_node)
5763             matches = tree_cons (match, NULL_TREE, NULL_TREE);
5764         }
5765     }
5766
5767   /* Now we should have exactly one function in MATCHES.  */
5768   if (matches == NULL_TREE)
5769     {
5770       /* There were *no* matches.  */
5771       if (flags & tf_error)
5772         {
5773           error ("no matches converting function %qD to type %q#T",
5774                  DECL_NAME (OVL_FUNCTION (overload)),
5775                  target_type);
5776
5777           /* print_candidates expects a chain with the functions in
5778              TREE_VALUE slots, so we cons one up here (we're losing anyway,
5779              so why be clever?).  */
5780           for (; overload; overload = OVL_NEXT (overload))
5781             matches = tree_cons (NULL_TREE, OVL_CURRENT (overload),
5782                                  matches);
5783
5784           print_candidates (matches);
5785         }
5786       return error_mark_node;
5787     }
5788   else if (TREE_CHAIN (matches))
5789     {
5790       /* There were too many matches.  */
5791
5792       if (flags & tf_error)
5793         {
5794           tree match;
5795
5796           error ("converting overloaded function %qD to type %q#T is ambiguous",
5797                     DECL_NAME (OVL_FUNCTION (overload)),
5798                     target_type);
5799
5800           /* Since print_candidates expects the functions in the
5801              TREE_VALUE slot, we flip them here.  */
5802           for (match = matches; match; match = TREE_CHAIN (match))
5803             TREE_VALUE (match) = TREE_PURPOSE (match);
5804
5805           print_candidates (matches);
5806         }
5807
5808       return error_mark_node;
5809     }
5810
5811   /* Good, exactly one match.  Now, convert it to the correct type.  */
5812   fn = TREE_PURPOSE (matches);
5813
5814   if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
5815       && !(flags & tf_ptrmem_ok) && !flag_ms_extensions)
5816     {
5817       static int explained;
5818
5819       if (!(flags & tf_error))
5820         return error_mark_node;
5821
5822       pedwarn ("assuming pointer to member %qD", fn);
5823       if (!explained)
5824         {
5825           pedwarn ("(a pointer to member can only be formed with %<&%E%>)", fn);
5826           explained = 1;
5827         }
5828     }
5829
5830   /* If we're doing overload resolution purely for the purpose of
5831      determining conversion sequences, we should not consider the
5832      function used.  If this conversion sequence is selected, the
5833      function will be marked as used at this point.  */
5834   if (!(flags & tf_conv))
5835     mark_used (fn);
5836
5837   if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type))
5838     return build_unary_op (ADDR_EXPR, fn, 0);
5839   else
5840     {
5841       /* The target must be a REFERENCE_TYPE.  Above, build_unary_op
5842          will mark the function as addressed, but here we must do it
5843          explicitly.  */
5844       cxx_mark_addressable (fn);
5845
5846       return fn;
5847     }
5848 }
5849
5850 /* This function will instantiate the type of the expression given in
5851    RHS to match the type of LHSTYPE.  If errors exist, then return
5852    error_mark_node. FLAGS is a bit mask.  If TF_ERROR is set, then
5853    we complain on errors.  If we are not complaining, never modify rhs,
5854    as overload resolution wants to try many possible instantiations, in
5855    the hope that at least one will work.
5856
5857    For non-recursive calls, LHSTYPE should be a function, pointer to
5858    function, or a pointer to member function.  */
5859
5860 tree
5861 instantiate_type (tree lhstype, tree rhs, tsubst_flags_t flags)
5862 {
5863   tsubst_flags_t flags_in = flags;
5864
5865   flags &= ~tf_ptrmem_ok;
5866
5867   if (TREE_CODE (lhstype) == UNKNOWN_TYPE)
5868     {
5869       if (flags & tf_error)
5870         error ("not enough type information");
5871       return error_mark_node;
5872     }
5873
5874   if (TREE_TYPE (rhs) != NULL_TREE && ! (type_unknown_p (rhs)))
5875     {
5876       if (same_type_p (lhstype, TREE_TYPE (rhs)))
5877         return rhs;
5878       if (flag_ms_extensions
5879           && TYPE_PTRMEMFUNC_P (lhstype)
5880           && !TYPE_PTRMEMFUNC_P (TREE_TYPE (rhs)))
5881         /* Microsoft allows `A::f' to be resolved to a
5882            pointer-to-member.  */
5883         ;
5884       else
5885         {
5886           if (flags & tf_error)
5887             error ("argument of type %qT does not match %qT",
5888                    TREE_TYPE (rhs), lhstype);
5889           return error_mark_node;
5890         }
5891     }
5892
5893   if (TREE_CODE (rhs) == BASELINK)
5894     rhs = BASELINK_FUNCTIONS (rhs);
5895
5896   /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
5897      deduce any type information.  */
5898   if (TREE_CODE (rhs) == NON_DEPENDENT_EXPR)
5899     {
5900       if (flags & tf_error)
5901         error ("not enough type information");
5902       return error_mark_node;
5903     }
5904
5905   /* We don't overwrite rhs if it is an overloaded function.
5906      Copying it would destroy the tree link.  */
5907   if (TREE_CODE (rhs) != OVERLOAD)
5908     rhs = copy_node (rhs);
5909
5910   /* This should really only be used when attempting to distinguish
5911      what sort of a pointer to function we have.  For now, any
5912      arithmetic operation which is not supported on pointers
5913      is rejected as an error.  */
5914
5915   switch (TREE_CODE (rhs))
5916     {
5917     case TYPE_EXPR:
5918     case CONVERT_EXPR:
5919     case SAVE_EXPR:
5920     case CONSTRUCTOR:
5921       gcc_unreachable ();
5922
5923     case INDIRECT_REF:
5924     case ARRAY_REF:
5925       {
5926         tree new_rhs;
5927
5928         new_rhs = instantiate_type (build_pointer_type (lhstype),
5929                                     TREE_OPERAND (rhs, 0), flags);
5930         if (new_rhs == error_mark_node)
5931           return error_mark_node;
5932
5933         TREE_TYPE (rhs) = lhstype;
5934         TREE_OPERAND (rhs, 0) = new_rhs;
5935         return rhs;
5936       }
5937
5938     case NOP_EXPR:
5939       rhs = copy_node (TREE_OPERAND (rhs, 0));
5940       TREE_TYPE (rhs) = unknown_type_node;
5941       return instantiate_type (lhstype, rhs, flags);
5942
5943     case COMPONENT_REF:
5944       {
5945         tree member = TREE_OPERAND (rhs, 1);
5946
5947         member = instantiate_type (lhstype, member, flags);
5948         if (member != error_mark_node
5949             && TREE_SIDE_EFFECTS (TREE_OPERAND (rhs, 0)))
5950           /* Do not lose object's side effects.  */
5951           return build2 (COMPOUND_EXPR, TREE_TYPE (member),
5952                          TREE_OPERAND (rhs, 0), member);
5953         return member;
5954       }
5955
5956     case OFFSET_REF:
5957       rhs = TREE_OPERAND (rhs, 1);
5958       if (BASELINK_P (rhs))
5959         return instantiate_type (lhstype, BASELINK_FUNCTIONS (rhs), flags_in);
5960
5961       /* This can happen if we are forming a pointer-to-member for a
5962          member template.  */
5963       gcc_assert (TREE_CODE (rhs) == TEMPLATE_ID_EXPR);
5964
5965       /* Fall through.  */
5966
5967     case TEMPLATE_ID_EXPR:
5968       {
5969         tree fns = TREE_OPERAND (rhs, 0);
5970         tree args = TREE_OPERAND (rhs, 1);
5971
5972         return
5973           resolve_address_of_overloaded_function (lhstype, fns, flags_in,
5974                                                   /*template_only=*/true,
5975                                                   args);
5976       }
5977
5978     case OVERLOAD:
5979     case FUNCTION_DECL:
5980       return
5981         resolve_address_of_overloaded_function (lhstype, rhs, flags_in,
5982                                                 /*template_only=*/false,
5983                                                 /*explicit_targs=*/NULL_TREE);
5984
5985     case CALL_EXPR:
5986       /* This is too hard for now.  */
5987       gcc_unreachable ();
5988
5989     case PLUS_EXPR:
5990     case MINUS_EXPR:
5991     case COMPOUND_EXPR:
5992       TREE_OPERAND (rhs, 0)
5993         = instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
5994       if (TREE_OPERAND (rhs, 0) == error_mark_node)
5995         return error_mark_node;
5996       TREE_OPERAND (rhs, 1)
5997         = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
5998       if (TREE_OPERAND (rhs, 1) == error_mark_node)
5999         return error_mark_node;
6000
6001       TREE_TYPE (rhs) = lhstype;
6002       return rhs;
6003
6004     case MULT_EXPR:
6005     case TRUNC_DIV_EXPR:
6006     case FLOOR_DIV_EXPR:
6007     case CEIL_DIV_EXPR:
6008     case ROUND_DIV_EXPR:
6009     case RDIV_EXPR:
6010     case TRUNC_MOD_EXPR:
6011     case FLOOR_MOD_EXPR:
6012     case CEIL_MOD_EXPR:
6013     case ROUND_MOD_EXPR:
6014     case FIX_ROUND_EXPR:
6015     case FIX_FLOOR_EXPR:
6016     case FIX_CEIL_EXPR:
6017     case FIX_TRUNC_EXPR:
6018     case FLOAT_EXPR:
6019     case NEGATE_EXPR:
6020     case ABS_EXPR:
6021     case MAX_EXPR:
6022     case MIN_EXPR:
6023
6024     case BIT_AND_EXPR:
6025     case BIT_IOR_EXPR:
6026     case BIT_XOR_EXPR:
6027     case LSHIFT_EXPR:
6028     case RSHIFT_EXPR:
6029     case LROTATE_EXPR:
6030     case RROTATE_EXPR:
6031
6032     case PREINCREMENT_EXPR:
6033     case PREDECREMENT_EXPR:
6034     case POSTINCREMENT_EXPR:
6035     case POSTDECREMENT_EXPR:
6036       if (flags & tf_error)
6037         error ("invalid operation on uninstantiated type");
6038       return error_mark_node;
6039
6040     case TRUTH_AND_EXPR:
6041     case TRUTH_OR_EXPR:
6042     case TRUTH_XOR_EXPR:
6043     case LT_EXPR:
6044     case LE_EXPR:
6045     case GT_EXPR:
6046     case GE_EXPR:
6047     case EQ_EXPR:
6048     case NE_EXPR:
6049     case TRUTH_ANDIF_EXPR:
6050     case TRUTH_ORIF_EXPR:
6051     case TRUTH_NOT_EXPR:
6052       if (flags & tf_error)
6053         error ("not enough type information");
6054       return error_mark_node;
6055
6056     case COND_EXPR:
6057       if (type_unknown_p (TREE_OPERAND (rhs, 0)))
6058         {
6059           if (flags & tf_error)
6060             error ("not enough type information");
6061           return error_mark_node;
6062         }
6063       TREE_OPERAND (rhs, 1)
6064         = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
6065       if (TREE_OPERAND (rhs, 1) == error_mark_node)
6066         return error_mark_node;
6067       TREE_OPERAND (rhs, 2)
6068         = instantiate_type (lhstype, TREE_OPERAND (rhs, 2), flags);
6069       if (TREE_OPERAND (rhs, 2) == error_mark_node)
6070         return error_mark_node;
6071
6072       TREE_TYPE (rhs) = lhstype;
6073       return rhs;
6074
6075     case MODIFY_EXPR:
6076       TREE_OPERAND (rhs, 1)
6077         = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
6078       if (TREE_OPERAND (rhs, 1) == error_mark_node)
6079         return error_mark_node;
6080
6081       TREE_TYPE (rhs) = lhstype;
6082       return rhs;
6083
6084     case ADDR_EXPR:
6085     {
6086       if (PTRMEM_OK_P (rhs))
6087         flags |= tf_ptrmem_ok;
6088
6089       return instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
6090     }
6091
6092     case ERROR_MARK:
6093       return error_mark_node;
6094
6095     default:
6096       gcc_unreachable ();
6097     }
6098   return error_mark_node;
6099 }
6100 \f
6101 /* Return the name of the virtual function pointer field
6102    (as an IDENTIFIER_NODE) for the given TYPE.  Note that
6103    this may have to look back through base types to find the
6104    ultimate field name.  (For single inheritance, these could
6105    all be the same name.  Who knows for multiple inheritance).  */
6106
6107 static tree
6108 get_vfield_name (tree type)
6109 {
6110   tree binfo, base_binfo;
6111   char *buf;
6112
6113   for (binfo = TYPE_BINFO (type);
6114        BINFO_N_BASE_BINFOS (binfo);
6115        binfo = base_binfo)
6116     {
6117       base_binfo = BINFO_BASE_BINFO (binfo, 0);
6118
6119       if (BINFO_VIRTUAL_P (base_binfo)
6120           || !TYPE_CONTAINS_VPTR_P (BINFO_TYPE (base_binfo)))
6121         break;
6122     }
6123
6124   type = BINFO_TYPE (binfo);
6125   buf = alloca (sizeof (VFIELD_NAME_FORMAT) + TYPE_NAME_LENGTH (type) + 2);
6126   sprintf (buf, VFIELD_NAME_FORMAT,
6127            IDENTIFIER_POINTER (constructor_name (type)));
6128   return get_identifier (buf);
6129 }
6130
6131 void
6132 print_class_statistics (void)
6133 {
6134 #ifdef GATHER_STATISTICS
6135   fprintf (stderr, "convert_harshness = %d\n", n_convert_harshness);
6136   fprintf (stderr, "compute_conversion_costs = %d\n", n_compute_conversion_costs);
6137   if (n_vtables)
6138     {
6139       fprintf (stderr, "vtables = %d; vtable searches = %d\n",
6140                n_vtables, n_vtable_searches);
6141       fprintf (stderr, "vtable entries = %d; vtable elems = %d\n",
6142                n_vtable_entries, n_vtable_elems);
6143     }
6144 #endif
6145 }
6146
6147 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6148    according to [class]:
6149                                           The class-name is also inserted
6150    into  the scope of the class itself.  For purposes of access checking,
6151    the inserted class name is treated as if it were a public member name.  */
6152
6153 void
6154 build_self_reference (void)
6155 {
6156   tree name = constructor_name (current_class_type);
6157   tree value = build_lang_decl (TYPE_DECL, name, current_class_type);
6158   tree saved_cas;
6159
6160   DECL_NONLOCAL (value) = 1;
6161   DECL_CONTEXT (value) = current_class_type;
6162   DECL_ARTIFICIAL (value) = 1;
6163   SET_DECL_SELF_REFERENCE_P (value);
6164
6165   if (processing_template_decl)
6166     value = push_template_decl (value);
6167
6168   saved_cas = current_access_specifier;
6169   current_access_specifier = access_public_node;
6170   finish_member_declaration (value);
6171   current_access_specifier = saved_cas;
6172 }
6173
6174 /* Returns 1 if TYPE contains only padding bytes.  */
6175
6176 int
6177 is_empty_class (tree type)
6178 {
6179   if (type == error_mark_node)
6180     return 0;
6181
6182   if (! IS_AGGR_TYPE (type))
6183     return 0;
6184
6185   /* In G++ 3.2, whether or not a class was empty was determined by
6186      looking at its size.  */
6187   if (abi_version_at_least (2))
6188     return CLASSTYPE_EMPTY_P (type);
6189   else
6190     return integer_zerop (CLASSTYPE_SIZE (type));
6191 }
6192
6193 /* Returns true if TYPE contains an empty class.  */
6194
6195 static bool
6196 contains_empty_class_p (tree type)
6197 {
6198   if (is_empty_class (type))
6199     return true;
6200   if (CLASS_TYPE_P (type))
6201     {
6202       tree field;
6203       tree binfo;
6204       tree base_binfo;
6205       int i;
6206
6207       for (binfo = TYPE_BINFO (type), i = 0;
6208            BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
6209         if (contains_empty_class_p (BINFO_TYPE (base_binfo)))
6210           return true;
6211       for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
6212         if (TREE_CODE (field) == FIELD_DECL
6213             && !DECL_ARTIFICIAL (field)
6214             && is_empty_class (TREE_TYPE (field)))
6215           return true;
6216     }
6217   else if (TREE_CODE (type) == ARRAY_TYPE)
6218     return contains_empty_class_p (TREE_TYPE (type));
6219   return false;
6220 }
6221
6222 /* Note that NAME was looked up while the current class was being
6223    defined and that the result of that lookup was DECL.  */
6224
6225 void
6226 maybe_note_name_used_in_class (tree name, tree decl)
6227 {
6228   splay_tree names_used;
6229
6230   /* If we're not defining a class, there's nothing to do.  */
6231   if (!(innermost_scope_kind() == sk_class
6232         && TYPE_BEING_DEFINED (current_class_type)))
6233     return;
6234
6235   /* If there's already a binding for this NAME, then we don't have
6236      anything to worry about.  */
6237   if (lookup_member (current_class_type, name,
6238                      /*protect=*/0, /*want_type=*/false))
6239     return;
6240
6241   if (!current_class_stack[current_class_depth - 1].names_used)
6242     current_class_stack[current_class_depth - 1].names_used
6243       = splay_tree_new (splay_tree_compare_pointers, 0, 0);
6244   names_used = current_class_stack[current_class_depth - 1].names_used;
6245
6246   splay_tree_insert (names_used,
6247                      (splay_tree_key) name,
6248                      (splay_tree_value) decl);
6249 }
6250
6251 /* Note that NAME was declared (as DECL) in the current class.  Check
6252    to see that the declaration is valid.  */
6253
6254 void
6255 note_name_declared_in_class (tree name, tree decl)
6256 {
6257   splay_tree names_used;
6258   splay_tree_node n;
6259
6260   /* Look to see if we ever used this name.  */
6261   names_used
6262     = current_class_stack[current_class_depth - 1].names_used;
6263   if (!names_used)
6264     return;
6265
6266   n = splay_tree_lookup (names_used, (splay_tree_key) name);
6267   if (n)
6268     {
6269       /* [basic.scope.class]
6270
6271          A name N used in a class S shall refer to the same declaration
6272          in its context and when re-evaluated in the completed scope of
6273          S.  */
6274       error ("declaration of %q#D", decl);
6275       cp_error_at ("changes meaning of %qD from %q+#D",
6276                    DECL_NAME (OVL_CURRENT (decl)),
6277                    (tree) n->value);
6278     }
6279 }
6280
6281 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6282    Secondary vtables are merged with primary vtables; this function
6283    will return the VAR_DECL for the primary vtable.  */
6284
6285 tree
6286 get_vtbl_decl_for_binfo (tree binfo)
6287 {
6288   tree decl;
6289
6290   decl = BINFO_VTABLE (binfo);
6291   if (decl && TREE_CODE (decl) == PLUS_EXPR)
6292     {
6293       gcc_assert (TREE_CODE (TREE_OPERAND (decl, 0)) == ADDR_EXPR);
6294       decl = TREE_OPERAND (TREE_OPERAND (decl, 0), 0);
6295     }
6296   if (decl)
6297     gcc_assert (TREE_CODE (decl) == VAR_DECL);
6298   return decl;
6299 }
6300
6301
6302 /* Returns the binfo for the primary base of BINFO.  If the resulting
6303    BINFO is a virtual base, and it is inherited elsewhere in the
6304    hierarchy, then the returned binfo might not be the primary base of
6305    BINFO in the complete object.  Check BINFO_PRIMARY_P or
6306    BINFO_LOST_PRIMARY_P to be sure.  */
6307
6308 tree
6309 get_primary_binfo (tree binfo)
6310 {
6311   tree primary_base;
6312   tree result;
6313
6314   primary_base = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (binfo));
6315   if (!primary_base)
6316     return NULL_TREE;
6317
6318   result = copied_binfo (primary_base, binfo);
6319   return result;
6320 }
6321
6322 /* If INDENTED_P is zero, indent to INDENT. Return nonzero.  */
6323
6324 static int
6325 maybe_indent_hierarchy (FILE * stream, int indent, int indented_p)
6326 {
6327   if (!indented_p)
6328     fprintf (stream, "%*s", indent, "");
6329   return 1;
6330 }
6331
6332 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
6333    INDENT should be zero when called from the top level; it is
6334    incremented recursively.  IGO indicates the next expected BINFO in
6335    inheritance graph ordering.  */
6336
6337 static tree
6338 dump_class_hierarchy_r (FILE *stream,
6339                         int flags,
6340                         tree binfo,
6341                         tree igo,
6342                         int indent)
6343 {
6344   int indented = 0;
6345   tree base_binfo;
6346   int i;
6347
6348   indented = maybe_indent_hierarchy (stream, indent, 0);
6349   fprintf (stream, "%s (0x%lx) ",
6350            type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER),
6351            (unsigned long) binfo);
6352   if (binfo != igo)
6353     {
6354       fprintf (stream, "alternative-path\n");
6355       return igo;
6356     }
6357   igo = TREE_CHAIN (binfo);
6358
6359   fprintf (stream, HOST_WIDE_INT_PRINT_DEC,
6360            tree_low_cst (BINFO_OFFSET (binfo), 0));
6361   if (is_empty_class (BINFO_TYPE (binfo)))
6362     fprintf (stream, " empty");
6363   else if (CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (binfo)))
6364     fprintf (stream, " nearly-empty");
6365   if (BINFO_VIRTUAL_P (binfo))
6366     fprintf (stream, " virtual");
6367   fprintf (stream, "\n");
6368
6369   indented = 0;
6370   if (BINFO_PRIMARY_P (binfo))
6371     {
6372       indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6373       fprintf (stream, " primary-for %s (0x%lx)",
6374                type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)),
6375                                TFF_PLAIN_IDENTIFIER),
6376                (unsigned long)BINFO_INHERITANCE_CHAIN (binfo));
6377     }
6378   if (BINFO_LOST_PRIMARY_P (binfo))
6379     {
6380       indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6381       fprintf (stream, " lost-primary");
6382     }
6383   if (indented)
6384     fprintf (stream, "\n");
6385
6386   if (!(flags & TDF_SLIM))
6387     {
6388       int indented = 0;
6389
6390       if (BINFO_SUBVTT_INDEX (binfo))
6391         {
6392           indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6393           fprintf (stream, " subvttidx=%s",
6394                    expr_as_string (BINFO_SUBVTT_INDEX (binfo),
6395                                    TFF_PLAIN_IDENTIFIER));
6396         }
6397       if (BINFO_VPTR_INDEX (binfo))
6398         {
6399           indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6400           fprintf (stream, " vptridx=%s",
6401                    expr_as_string (BINFO_VPTR_INDEX (binfo),
6402                                    TFF_PLAIN_IDENTIFIER));
6403         }
6404       if (BINFO_VPTR_FIELD (binfo))
6405         {
6406           indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6407           fprintf (stream, " vbaseoffset=%s",
6408                    expr_as_string (BINFO_VPTR_FIELD (binfo),
6409                                    TFF_PLAIN_IDENTIFIER));
6410         }
6411       if (BINFO_VTABLE (binfo))
6412         {
6413           indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6414           fprintf (stream, " vptr=%s",
6415                    expr_as_string (BINFO_VTABLE (binfo),
6416                                    TFF_PLAIN_IDENTIFIER));
6417         }
6418
6419       if (indented)
6420         fprintf (stream, "\n");
6421     }
6422
6423   for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
6424     igo = dump_class_hierarchy_r (stream, flags, base_binfo, igo, indent + 2);
6425
6426   return igo;
6427 }
6428
6429 /* Dump the BINFO hierarchy for T.  */
6430
6431 static void
6432 dump_class_hierarchy_1 (FILE *stream, int flags, tree t)
6433 {
6434   fprintf (stream, "Class %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6435   fprintf (stream, "   size=%lu align=%lu\n",
6436            (unsigned long)(tree_low_cst (TYPE_SIZE (t), 0) / BITS_PER_UNIT),
6437            (unsigned long)(TYPE_ALIGN (t) / BITS_PER_UNIT));
6438   fprintf (stream, "   base size=%lu base align=%lu\n",
6439            (unsigned long)(tree_low_cst (TYPE_SIZE (CLASSTYPE_AS_BASE (t)), 0)
6440                            / BITS_PER_UNIT),
6441            (unsigned long)(TYPE_ALIGN (CLASSTYPE_AS_BASE (t))
6442                            / BITS_PER_UNIT));
6443   dump_class_hierarchy_r (stream, flags, TYPE_BINFO (t), TYPE_BINFO (t), 0);
6444   fprintf (stream, "\n");
6445 }
6446
6447 /* Debug interface to hierarchy dumping.  */
6448
6449 extern void
6450 debug_class (tree t)
6451 {
6452   dump_class_hierarchy_1 (stderr, TDF_SLIM, t);
6453 }
6454
6455 static void
6456 dump_class_hierarchy (tree t)
6457 {
6458   int flags;
6459   FILE *stream = dump_begin (TDI_class, &flags);
6460
6461   if (stream)
6462     {
6463       dump_class_hierarchy_1 (stream, flags, t);
6464       dump_end (TDI_class, stream);
6465     }
6466 }
6467
6468 static void
6469 dump_array (FILE * stream, tree decl)
6470 {
6471   tree inits;
6472   int ix;
6473   HOST_WIDE_INT elt;
6474   tree size = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (decl)));
6475
6476   elt = (tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl))), 0)
6477          / BITS_PER_UNIT);
6478   fprintf (stream, "%s:", decl_as_string (decl, TFF_PLAIN_IDENTIFIER));
6479   fprintf (stream, " %s entries",
6480            expr_as_string (size_binop (PLUS_EXPR, size, size_one_node),
6481                            TFF_PLAIN_IDENTIFIER));
6482   fprintf (stream, "\n");
6483
6484   for (ix = 0, inits = CONSTRUCTOR_ELTS (DECL_INITIAL (decl));
6485        inits; ix++, inits = TREE_CHAIN (inits))
6486     fprintf (stream, "%-4ld  %s\n", (long)(ix * elt),
6487              expr_as_string (TREE_VALUE (inits), TFF_PLAIN_IDENTIFIER));
6488 }
6489
6490 static void
6491 dump_vtable (tree t, tree binfo, tree vtable)
6492 {
6493   int flags;
6494   FILE *stream = dump_begin (TDI_class, &flags);
6495
6496   if (!stream)
6497     return;
6498
6499   if (!(flags & TDF_SLIM))
6500     {
6501       int ctor_vtbl_p = TYPE_BINFO (t) != binfo;
6502
6503       fprintf (stream, "%s for %s",
6504                ctor_vtbl_p ? "Construction vtable" : "Vtable",
6505                type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER));
6506       if (ctor_vtbl_p)
6507         {
6508           if (!BINFO_VIRTUAL_P (binfo))
6509             fprintf (stream, " (0x%lx instance)", (unsigned long)binfo);
6510           fprintf (stream, " in %s", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6511         }
6512       fprintf (stream, "\n");
6513       dump_array (stream, vtable);
6514       fprintf (stream, "\n");
6515     }
6516
6517   dump_end (TDI_class, stream);
6518 }
6519
6520 static void
6521 dump_vtt (tree t, tree vtt)
6522 {
6523   int flags;
6524   FILE *stream = dump_begin (TDI_class, &flags);
6525
6526   if (!stream)
6527     return;
6528
6529   if (!(flags & TDF_SLIM))
6530     {
6531       fprintf (stream, "VTT for %s\n",
6532                type_as_string (t, TFF_PLAIN_IDENTIFIER));
6533       dump_array (stream, vtt);
6534       fprintf (stream, "\n");
6535     }
6536
6537   dump_end (TDI_class, stream);
6538 }
6539
6540 /* Dump a function or thunk and its thunkees.  */
6541
6542 static void
6543 dump_thunk (FILE *stream, int indent, tree thunk)
6544 {
6545   static const char spaces[] = "        ";
6546   tree name = DECL_NAME (thunk);
6547   tree thunks;
6548
6549   fprintf (stream, "%.*s%p %s %s", indent, spaces,
6550            (void *)thunk,
6551            !DECL_THUNK_P (thunk) ? "function"
6552            : DECL_THIS_THUNK_P (thunk) ? "this-thunk" : "covariant-thunk",
6553            name ? IDENTIFIER_POINTER (name) : "<unset>");
6554   if (DECL_THUNK_P (thunk))
6555     {
6556       HOST_WIDE_INT fixed_adjust = THUNK_FIXED_OFFSET (thunk);
6557       tree virtual_adjust = THUNK_VIRTUAL_OFFSET (thunk);
6558
6559       fprintf (stream, " fixed=" HOST_WIDE_INT_PRINT_DEC, fixed_adjust);
6560       if (!virtual_adjust)
6561         /*NOP*/;
6562       else if (DECL_THIS_THUNK_P (thunk))
6563         fprintf (stream, " vcall="  HOST_WIDE_INT_PRINT_DEC,
6564                  tree_low_cst (virtual_adjust, 0));
6565       else
6566         fprintf (stream, " vbase=" HOST_WIDE_INT_PRINT_DEC "(%s)",
6567                  tree_low_cst (BINFO_VPTR_FIELD (virtual_adjust), 0),
6568                  type_as_string (BINFO_TYPE (virtual_adjust), TFF_SCOPE));
6569       if (THUNK_ALIAS (thunk))
6570         fprintf (stream, " alias to %p", (void *)THUNK_ALIAS (thunk));
6571     }
6572   fprintf (stream, "\n");
6573   for (thunks = DECL_THUNKS (thunk); thunks; thunks = TREE_CHAIN (thunks))
6574     dump_thunk (stream, indent + 2, thunks);
6575 }
6576
6577 /* Dump the thunks for FN.  */
6578
6579 extern void
6580 debug_thunks (tree fn)
6581 {
6582   dump_thunk (stderr, 0, fn);
6583 }
6584
6585 /* Virtual function table initialization.  */
6586
6587 /* Create all the necessary vtables for T and its base classes.  */
6588
6589 static void
6590 finish_vtbls (tree t)
6591 {
6592   tree list;
6593   tree vbase;
6594
6595   /* We lay out the primary and secondary vtables in one contiguous
6596      vtable.  The primary vtable is first, followed by the non-virtual
6597      secondary vtables in inheritance graph order.  */
6598   list = build_tree_list (BINFO_VTABLE (TYPE_BINFO (t)), NULL_TREE);
6599   accumulate_vtbl_inits (TYPE_BINFO (t), TYPE_BINFO (t),
6600                          TYPE_BINFO (t), t, list);
6601
6602   /* Then come the virtual bases, also in inheritance graph order.  */
6603   for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
6604     {
6605       if (!BINFO_VIRTUAL_P (vbase))
6606         continue;
6607       accumulate_vtbl_inits (vbase, vbase, TYPE_BINFO (t), t, list);
6608     }
6609
6610   if (BINFO_VTABLE (TYPE_BINFO (t)))
6611     initialize_vtable (TYPE_BINFO (t), TREE_VALUE (list));
6612 }
6613
6614 /* Initialize the vtable for BINFO with the INITS.  */
6615
6616 static void
6617 initialize_vtable (tree binfo, tree inits)
6618 {
6619   tree decl;
6620
6621   layout_vtable_decl (binfo, list_length (inits));
6622   decl = get_vtbl_decl_for_binfo (binfo);
6623   initialize_artificial_var (decl, inits);
6624   dump_vtable (BINFO_TYPE (binfo), binfo, decl);
6625 }
6626
6627 /* Build the VTT (virtual table table) for T.
6628    A class requires a VTT if it has virtual bases.
6629
6630    This holds
6631    1 - primary virtual pointer for complete object T
6632    2 - secondary VTTs for each direct non-virtual base of T which requires a
6633        VTT
6634    3 - secondary virtual pointers for each direct or indirect base of T which
6635        has virtual bases or is reachable via a virtual path from T.
6636    4 - secondary VTTs for each direct or indirect virtual base of T.
6637
6638    Secondary VTTs look like complete object VTTs without part 4.  */
6639
6640 static void
6641 build_vtt (tree t)
6642 {
6643   tree inits;
6644   tree type;
6645   tree vtt;
6646   tree index;
6647
6648   /* Build up the initializers for the VTT.  */
6649   inits = NULL_TREE;
6650   index = size_zero_node;
6651   build_vtt_inits (TYPE_BINFO (t), t, &inits, &index);
6652
6653   /* If we didn't need a VTT, we're done.  */
6654   if (!inits)
6655     return;
6656
6657   /* Figure out the type of the VTT.  */
6658   type = build_index_type (size_int (list_length (inits) - 1));
6659   type = build_cplus_array_type (const_ptr_type_node, type);
6660
6661   /* Now, build the VTT object itself.  */
6662   vtt = build_vtable (t, get_vtt_name (t), type);
6663   initialize_artificial_var (vtt, inits);
6664   /* Add the VTT to the vtables list.  */
6665   TREE_CHAIN (vtt) = TREE_CHAIN (CLASSTYPE_VTABLES (t));
6666   TREE_CHAIN (CLASSTYPE_VTABLES (t)) = vtt;
6667
6668   dump_vtt (t, vtt);
6669 }
6670
6671 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
6672    PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
6673    and CHAIN the vtable pointer for this binfo after construction is
6674    complete.  VALUE can also be another BINFO, in which case we recurse.  */
6675
6676 static tree
6677 binfo_ctor_vtable (tree binfo)
6678 {
6679   tree vt;
6680
6681   while (1)
6682     {
6683       vt = BINFO_VTABLE (binfo);
6684       if (TREE_CODE (vt) == TREE_LIST)
6685         vt = TREE_VALUE (vt);
6686       if (TREE_CODE (vt) == TREE_BINFO)
6687         binfo = vt;
6688       else
6689         break;
6690     }
6691
6692   return vt;
6693 }
6694
6695 /* Data for secondary VTT initialization.  */
6696 typedef struct secondary_vptr_vtt_init_data_s
6697 {
6698   /* Is this the primary VTT? */
6699   bool top_level_p;
6700
6701   /* Current index into the VTT.  */
6702   tree index;
6703
6704   /* TREE_LIST of initializers built up.  */
6705   tree inits;
6706
6707   /* The type being constructed by this secondary VTT.  */
6708   tree type_being_constructed;
6709 } secondary_vptr_vtt_init_data;
6710
6711 /* Recursively build the VTT-initializer for BINFO (which is in the
6712    hierarchy dominated by T).  INITS points to the end of the initializer
6713    list to date.  INDEX is the VTT index where the next element will be
6714    replaced.  Iff BINFO is the binfo for T, this is the top level VTT (i.e.
6715    not a subvtt for some base of T).  When that is so, we emit the sub-VTTs
6716    for virtual bases of T. When it is not so, we build the constructor
6717    vtables for the BINFO-in-T variant.  */
6718
6719 static tree *
6720 build_vtt_inits (tree binfo, tree t, tree *inits, tree *index)
6721 {
6722   int i;
6723   tree b;
6724   tree init;
6725   tree secondary_vptrs;
6726   secondary_vptr_vtt_init_data data;
6727   int top_level_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
6728
6729   /* We only need VTTs for subobjects with virtual bases.  */
6730   if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
6731     return inits;
6732
6733   /* We need to use a construction vtable if this is not the primary
6734      VTT.  */
6735   if (!top_level_p)
6736     {
6737       build_ctor_vtbl_group (binfo, t);
6738
6739       /* Record the offset in the VTT where this sub-VTT can be found.  */
6740       BINFO_SUBVTT_INDEX (binfo) = *index;
6741     }
6742
6743   /* Add the address of the primary vtable for the complete object.  */
6744   init = binfo_ctor_vtable (binfo);
6745   *inits = build_tree_list (NULL_TREE, init);
6746   inits = &TREE_CHAIN (*inits);
6747   if (top_level_p)
6748     {
6749       gcc_assert (!BINFO_VPTR_INDEX (binfo));
6750       BINFO_VPTR_INDEX (binfo) = *index;
6751     }
6752   *index = size_binop (PLUS_EXPR, *index, TYPE_SIZE_UNIT (ptr_type_node));
6753
6754   /* Recursively add the secondary VTTs for non-virtual bases.  */
6755   for (i = 0; BINFO_BASE_ITERATE (binfo, i, b); ++i)
6756     if (!BINFO_VIRTUAL_P (b))
6757       inits = build_vtt_inits (b, t, inits, index);
6758
6759   /* Add secondary virtual pointers for all subobjects of BINFO with
6760      either virtual bases or reachable along a virtual path, except
6761      subobjects that are non-virtual primary bases.  */
6762   data.top_level_p = top_level_p;
6763   data.index = *index;
6764   data.inits = NULL;
6765   data.type_being_constructed = BINFO_TYPE (binfo);
6766
6767   dfs_walk_once (binfo, dfs_build_secondary_vptr_vtt_inits, NULL, &data);
6768
6769   *index = data.index;
6770
6771   /* The secondary vptrs come back in reverse order.  After we reverse
6772      them, and add the INITS, the last init will be the first element
6773      of the chain.  */
6774   secondary_vptrs = data.inits;
6775   if (secondary_vptrs)
6776     {
6777       *inits = nreverse (secondary_vptrs);
6778       inits = &TREE_CHAIN (secondary_vptrs);
6779       gcc_assert (*inits == NULL_TREE);
6780     }
6781
6782   if (top_level_p)
6783     /* Add the secondary VTTs for virtual bases in inheritance graph
6784        order.  */
6785     for (b = TYPE_BINFO (BINFO_TYPE (binfo)); b; b = TREE_CHAIN (b))
6786       {
6787         if (!BINFO_VIRTUAL_P (b))
6788           continue;
6789
6790         inits = build_vtt_inits (b, t, inits, index);
6791       }
6792   else
6793     /* Remove the ctor vtables we created.  */
6794     dfs_walk_all (binfo, dfs_fixup_binfo_vtbls, NULL, binfo);
6795
6796   return inits;
6797 }
6798
6799 /* Called from build_vtt_inits via dfs_walk.  BINFO is the binfo for the base
6800    in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure.  */
6801
6802 static tree
6803 dfs_build_secondary_vptr_vtt_inits (tree binfo, void *data_)
6804 {
6805   secondary_vptr_vtt_init_data *data = (secondary_vptr_vtt_init_data *)data_;
6806
6807   /* We don't care about bases that don't have vtables.  */
6808   if (!TYPE_VFIELD (BINFO_TYPE (binfo)))
6809     return dfs_skip_bases;
6810
6811   /* We're only interested in proper subobjects of the type being
6812      constructed.  */
6813   if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->type_being_constructed))
6814     return NULL_TREE;
6815
6816   /* We're only interested in bases with virtual bases or reachable
6817      via a virtual path from the type being constructed.  */
6818   if (!(CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
6819         || binfo_via_virtual (binfo, data->type_being_constructed)))
6820     return dfs_skip_bases;
6821
6822   /* We're not interested in non-virtual primary bases.  */
6823   if (!BINFO_VIRTUAL_P (binfo) && BINFO_PRIMARY_P (binfo))
6824     return NULL_TREE;
6825
6826   /* Record the index where this secondary vptr can be found.  */
6827   if (data->top_level_p)
6828     {
6829       gcc_assert (!BINFO_VPTR_INDEX (binfo));
6830       BINFO_VPTR_INDEX (binfo) = data->index;
6831
6832       if (BINFO_VIRTUAL_P (binfo))
6833         {
6834           /* It's a primary virtual base, and this is not a
6835              construction vtable.  Find the base this is primary of in
6836              the inheritance graph, and use that base's vtable
6837              now.  */
6838           while (BINFO_PRIMARY_P (binfo))
6839             binfo = BINFO_INHERITANCE_CHAIN (binfo);
6840         }
6841     }
6842
6843   /* Add the initializer for the secondary vptr itself.  */
6844   data->inits = tree_cons (NULL_TREE, binfo_ctor_vtable (binfo), data->inits);
6845
6846   /* Advance the vtt index.  */
6847   data->index = size_binop (PLUS_EXPR, data->index,
6848                             TYPE_SIZE_UNIT (ptr_type_node));
6849
6850   return NULL_TREE;
6851 }
6852
6853 /* Called from build_vtt_inits via dfs_walk. After building
6854    constructor vtables and generating the sub-vtt from them, we need
6855    to restore the BINFO_VTABLES that were scribbled on.  DATA is the
6856    binfo of the base whose sub vtt was generated.  */
6857
6858 static tree
6859 dfs_fixup_binfo_vtbls (tree binfo, void* data)
6860 {
6861   tree vtable = BINFO_VTABLE (binfo);
6862
6863   if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
6864     /* If this class has no vtable, none of its bases do.  */
6865     return dfs_skip_bases;
6866
6867   if (!vtable)
6868     /* This might be a primary base, so have no vtable in this
6869        hierarchy.  */
6870     return NULL_TREE;
6871
6872   /* If we scribbled the construction vtable vptr into BINFO, clear it
6873      out now.  */
6874   if (TREE_CODE (vtable) == TREE_LIST
6875       && (TREE_PURPOSE (vtable) == (tree) data))
6876     BINFO_VTABLE (binfo) = TREE_CHAIN (vtable);
6877
6878   return NULL_TREE;
6879 }
6880
6881 /* Build the construction vtable group for BINFO which is in the
6882    hierarchy dominated by T.  */
6883
6884 static void
6885 build_ctor_vtbl_group (tree binfo, tree t)
6886 {
6887   tree list;
6888   tree type;
6889   tree vtbl;
6890   tree inits;
6891   tree id;
6892   tree vbase;
6893
6894   /* See if we've already created this construction vtable group.  */
6895   id = mangle_ctor_vtbl_for_type (t, binfo);
6896   if (IDENTIFIER_GLOBAL_VALUE (id))
6897     return;
6898
6899   gcc_assert (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t));
6900   /* Build a version of VTBL (with the wrong type) for use in
6901      constructing the addresses of secondary vtables in the
6902      construction vtable group.  */
6903   vtbl = build_vtable (t, id, ptr_type_node);
6904   DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1;
6905   list = build_tree_list (vtbl, NULL_TREE);
6906   accumulate_vtbl_inits (binfo, TYPE_BINFO (TREE_TYPE (binfo)),
6907                          binfo, t, list);
6908
6909   /* Add the vtables for each of our virtual bases using the vbase in T
6910      binfo.  */
6911   for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
6912        vbase;
6913        vbase = TREE_CHAIN (vbase))
6914     {
6915       tree b;
6916
6917       if (!BINFO_VIRTUAL_P (vbase))
6918         continue;
6919       b = copied_binfo (vbase, binfo);
6920
6921       accumulate_vtbl_inits (b, vbase, binfo, t, list);
6922     }
6923   inits = TREE_VALUE (list);
6924
6925   /* Figure out the type of the construction vtable.  */
6926   type = build_index_type (size_int (list_length (inits) - 1));
6927   type = build_cplus_array_type (vtable_entry_type, type);
6928   TREE_TYPE (vtbl) = type;
6929
6930   /* Initialize the construction vtable.  */
6931   CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl);
6932   initialize_artificial_var (vtbl, inits);
6933   dump_vtable (t, binfo, vtbl);
6934 }
6935
6936 /* Add the vtbl initializers for BINFO (and its bases other than
6937    non-virtual primaries) to the list of INITS.  BINFO is in the
6938    hierarchy dominated by T.  RTTI_BINFO is the binfo within T of
6939    the constructor the vtbl inits should be accumulated for. (If this
6940    is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
6941    ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
6942    BINFO is the active base equivalent of ORIG_BINFO in the inheritance
6943    graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
6944    but are not necessarily the same in terms of layout.  */
6945
6946 static void
6947 accumulate_vtbl_inits (tree binfo,
6948                        tree orig_binfo,
6949                        tree rtti_binfo,
6950                        tree t,
6951                        tree inits)
6952 {
6953   int i;
6954   tree base_binfo;
6955   int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
6956
6957   gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (orig_binfo)));
6958
6959   /* If it doesn't have a vptr, we don't do anything.  */
6960   if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
6961     return;
6962
6963   /* If we're building a construction vtable, we're not interested in
6964      subobjects that don't require construction vtables.  */
6965   if (ctor_vtbl_p
6966       && !CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
6967       && !binfo_via_virtual (orig_binfo, BINFO_TYPE (rtti_binfo)))
6968     return;
6969
6970   /* Build the initializers for the BINFO-in-T vtable.  */
6971   TREE_VALUE (inits)
6972     = chainon (TREE_VALUE (inits),
6973                dfs_accumulate_vtbl_inits (binfo, orig_binfo,
6974                                           rtti_binfo, t, inits));
6975
6976   /* Walk the BINFO and its bases.  We walk in preorder so that as we
6977      initialize each vtable we can figure out at what offset the
6978      secondary vtable lies from the primary vtable.  We can't use
6979      dfs_walk here because we need to iterate through bases of BINFO
6980      and RTTI_BINFO simultaneously.  */
6981   for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
6982     {
6983       /* Skip virtual bases.  */
6984       if (BINFO_VIRTUAL_P (base_binfo))
6985         continue;
6986       accumulate_vtbl_inits (base_binfo,
6987                              BINFO_BASE_BINFO (orig_binfo, i),
6988                              rtti_binfo, t,
6989                              inits);
6990     }
6991 }
6992
6993 /* Called from accumulate_vtbl_inits.  Returns the initializers for
6994    the BINFO vtable.  */
6995
6996 static tree
6997 dfs_accumulate_vtbl_inits (tree binfo,
6998                            tree orig_binfo,
6999                            tree rtti_binfo,
7000                            tree t,
7001                            tree l)
7002 {
7003   tree inits = NULL_TREE;
7004   tree vtbl = NULL_TREE;
7005   int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7006
7007   if (ctor_vtbl_p
7008       && BINFO_VIRTUAL_P (orig_binfo) && BINFO_PRIMARY_P (orig_binfo))
7009     {
7010       /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7011          primary virtual base.  If it is not the same primary in
7012          the hierarchy of T, we'll need to generate a ctor vtable
7013          for it, to place at its location in T.  If it is the same
7014          primary, we still need a VTT entry for the vtable, but it
7015          should point to the ctor vtable for the base it is a
7016          primary for within the sub-hierarchy of RTTI_BINFO.
7017
7018          There are three possible cases:
7019
7020          1) We are in the same place.
7021          2) We are a primary base within a lost primary virtual base of
7022          RTTI_BINFO.
7023          3) We are primary to something not a base of RTTI_BINFO.  */
7024
7025       tree b;
7026       tree last = NULL_TREE;
7027
7028       /* First, look through the bases we are primary to for RTTI_BINFO
7029          or a virtual base.  */
7030       b = binfo;
7031       while (BINFO_PRIMARY_P (b))
7032         {
7033           b = BINFO_INHERITANCE_CHAIN (b);
7034           last = b;
7035           if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7036             goto found;
7037         }
7038       /* If we run out of primary links, keep looking down our
7039          inheritance chain; we might be an indirect primary.  */
7040       for (b = last; b; b = BINFO_INHERITANCE_CHAIN (b))
7041         if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7042           break;
7043     found:
7044
7045       /* If we found RTTI_BINFO, this is case 1.  If we found a virtual
7046          base B and it is a base of RTTI_BINFO, this is case 2.  In
7047          either case, we share our vtable with LAST, i.e. the
7048          derived-most base within B of which we are a primary.  */
7049       if (b == rtti_binfo
7050           || (b && binfo_for_vbase (BINFO_TYPE (b), BINFO_TYPE (rtti_binfo))))
7051         /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7052            set LAST's BINFO_VTABLE yet.  We'll extract the actual vptr in
7053            binfo_ctor_vtable after everything's been set up.  */
7054         vtbl = last;
7055
7056       /* Otherwise, this is case 3 and we get our own.  */
7057     }
7058   else if (!BINFO_NEW_VTABLE_MARKED (orig_binfo))
7059     return inits;
7060
7061   if (!vtbl)
7062     {
7063       tree index;
7064       int non_fn_entries;
7065
7066       /* Compute the initializer for this vtable.  */
7067       inits = build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo,
7068                                       &non_fn_entries);
7069
7070       /* Figure out the position to which the VPTR should point.  */
7071       vtbl = TREE_PURPOSE (l);
7072       vtbl = build1 (ADDR_EXPR, vtbl_ptr_type_node, vtbl);
7073       index = size_binop (PLUS_EXPR,
7074                           size_int (non_fn_entries),
7075                           size_int (list_length (TREE_VALUE (l))));
7076       index = size_binop (MULT_EXPR,
7077                           TYPE_SIZE_UNIT (vtable_entry_type),
7078                           index);
7079       vtbl = build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, index);
7080     }
7081
7082   if (ctor_vtbl_p)
7083     /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7084        So, we make a TREE_LIST.  Later, dfs_fixup_binfo_vtbls will
7085        straighten this out.  */
7086     BINFO_VTABLE (binfo) = tree_cons (rtti_binfo, vtbl, BINFO_VTABLE (binfo));
7087   else if (BINFO_PRIMARY_P (binfo) && BINFO_VIRTUAL_P (binfo))
7088     inits = NULL_TREE;
7089   else
7090      /* For an ordinary vtable, set BINFO_VTABLE.  */
7091     BINFO_VTABLE (binfo) = vtbl;
7092
7093   return inits;
7094 }
7095
7096 static GTY(()) tree abort_fndecl_addr;
7097
7098 /* Construct the initializer for BINFO's virtual function table.  BINFO
7099    is part of the hierarchy dominated by T.  If we're building a
7100    construction vtable, the ORIG_BINFO is the binfo we should use to
7101    find the actual function pointers to put in the vtable - but they
7102    can be overridden on the path to most-derived in the graph that
7103    ORIG_BINFO belongs.  Otherwise,
7104    ORIG_BINFO should be the same as BINFO.  The RTTI_BINFO is the
7105    BINFO that should be indicated by the RTTI information in the
7106    vtable; it will be a base class of T, rather than T itself, if we
7107    are building a construction vtable.
7108
7109    The value returned is a TREE_LIST suitable for wrapping in a
7110    CONSTRUCTOR to use as the DECL_INITIAL for a vtable.  If
7111    NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7112    number of non-function entries in the vtable.
7113
7114    It might seem that this function should never be called with a
7115    BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7116    base is always subsumed by a derived class vtable.  However, when
7117    we are building construction vtables, we do build vtables for
7118    primary bases; we need these while the primary base is being
7119    constructed.  */
7120
7121 static tree
7122 build_vtbl_initializer (tree binfo,
7123                         tree orig_binfo,
7124                         tree t,
7125                         tree rtti_binfo,
7126                         int* non_fn_entries_p)
7127 {
7128   tree v, b;
7129   tree vfun_inits;
7130   vtbl_init_data vid;
7131   unsigned ix;
7132   tree vbinfo;
7133   VEC (tree) *vbases;
7134
7135   /* Initialize VID.  */
7136   memset (&vid, 0, sizeof (vid));
7137   vid.binfo = binfo;
7138   vid.derived = t;
7139   vid.rtti_binfo = rtti_binfo;
7140   vid.last_init = &vid.inits;
7141   vid.primary_vtbl_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
7142   vid.ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7143   vid.generate_vcall_entries = true;
7144   /* The first vbase or vcall offset is at index -3 in the vtable.  */
7145   vid.index = ssize_int(-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE);
7146
7147   /* Add entries to the vtable for RTTI.  */
7148   build_rtti_vtbl_entries (binfo, &vid);
7149
7150   /* Create an array for keeping track of the functions we've
7151      processed.  When we see multiple functions with the same
7152      signature, we share the vcall offsets.  */
7153   VARRAY_TREE_INIT (vid.fns, 32, "fns");
7154   /* Add the vcall and vbase offset entries.  */
7155   build_vcall_and_vbase_vtbl_entries (binfo, &vid);
7156
7157   /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7158      build_vbase_offset_vtbl_entries.  */
7159   for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0;
7160        VEC_iterate (tree, vbases, ix, vbinfo); ix++)
7161     BINFO_VTABLE_PATH_MARKED (vbinfo) = 0;
7162
7163   /* If the target requires padding between data entries, add that now.  */
7164   if (TARGET_VTABLE_DATA_ENTRY_DISTANCE > 1)
7165     {
7166       tree cur, *prev;
7167
7168       for (prev = &vid.inits; (cur = *prev); prev = &TREE_CHAIN (cur))
7169         {
7170           tree add = cur;
7171           int i;
7172
7173           for (i = 1; i < TARGET_VTABLE_DATA_ENTRY_DISTANCE; ++i)
7174             add = tree_cons (NULL_TREE,
7175                              build1 (NOP_EXPR, vtable_entry_type,
7176                                      null_pointer_node),
7177                              add);
7178           *prev = add;
7179         }
7180     }
7181
7182   if (non_fn_entries_p)
7183     *non_fn_entries_p = list_length (vid.inits);
7184
7185   /* Go through all the ordinary virtual functions, building up
7186      initializers.  */
7187   vfun_inits = NULL_TREE;
7188   for (v = BINFO_VIRTUALS (orig_binfo); v; v = TREE_CHAIN (v))
7189     {
7190       tree delta;
7191       tree vcall_index;
7192       tree fn, fn_original;
7193       tree init = NULL_TREE;
7194
7195       fn = BV_FN (v);
7196       fn_original = fn;
7197       if (DECL_THUNK_P (fn))
7198         {
7199           if (!DECL_NAME (fn))
7200             finish_thunk (fn);
7201           if (THUNK_ALIAS (fn))
7202             {
7203               fn = THUNK_ALIAS (fn);
7204               BV_FN (v) = fn;
7205             }
7206           fn_original = THUNK_TARGET (fn);
7207         }
7208
7209       /* If the only definition of this function signature along our
7210          primary base chain is from a lost primary, this vtable slot will
7211          never be used, so just zero it out.  This is important to avoid
7212          requiring extra thunks which cannot be generated with the function.
7213
7214          We first check this in update_vtable_entry_for_fn, so we handle
7215          restored primary bases properly; we also need to do it here so we
7216          zero out unused slots in ctor vtables, rather than filling themff
7217          with erroneous values (though harmless, apart from relocation
7218          costs).  */
7219       for (b = binfo; ; b = get_primary_binfo (b))
7220         {
7221           /* We found a defn before a lost primary; go ahead as normal.  */
7222           if (look_for_overrides_here (BINFO_TYPE (b), fn_original))
7223             break;
7224
7225           /* The nearest definition is from a lost primary; clear the
7226              slot.  */
7227           if (BINFO_LOST_PRIMARY_P (b))
7228             {
7229               init = size_zero_node;
7230               break;
7231             }
7232         }
7233
7234       if (! init)
7235         {
7236           /* Pull the offset for `this', and the function to call, out of
7237              the list.  */
7238           delta = BV_DELTA (v);
7239           vcall_index = BV_VCALL_INDEX (v);
7240
7241           gcc_assert (TREE_CODE (delta) == INTEGER_CST);
7242           gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
7243
7244           /* You can't call an abstract virtual function; it's abstract.
7245              So, we replace these functions with __pure_virtual.  */
7246           if (DECL_PURE_VIRTUAL_P (fn_original))
7247             {
7248               fn = abort_fndecl;
7249               if (abort_fndecl_addr == NULL)
7250                 abort_fndecl_addr = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7251               init = abort_fndecl_addr;
7252             }
7253           else
7254             {
7255               if (!integer_zerop (delta) || vcall_index)
7256                 {
7257                   fn = make_thunk (fn, /*this_adjusting=*/1, delta, vcall_index);
7258                   if (!DECL_NAME (fn))
7259                     finish_thunk (fn);
7260                 }
7261               /* Take the address of the function, considering it to be of an
7262                  appropriate generic type.  */
7263               init = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7264             }
7265         }
7266
7267       /* And add it to the chain of initializers.  */
7268       if (TARGET_VTABLE_USES_DESCRIPTORS)
7269         {
7270           int i;
7271           if (init == size_zero_node)
7272             for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7273               vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7274           else
7275             for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7276               {
7277                 tree fdesc = build2 (FDESC_EXPR, vfunc_ptr_type_node,
7278                                      TREE_OPERAND (init, 0),
7279                                      build_int_cst (NULL_TREE, i));
7280                 TREE_CONSTANT (fdesc) = 1;
7281                 TREE_INVARIANT (fdesc) = 1;
7282
7283                 vfun_inits = tree_cons (NULL_TREE, fdesc, vfun_inits);
7284               }
7285         }
7286       else
7287         vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7288     }
7289
7290   /* The initializers for virtual functions were built up in reverse
7291      order; straighten them out now.  */
7292   vfun_inits = nreverse (vfun_inits);
7293
7294   /* The negative offset initializers are also in reverse order.  */
7295   vid.inits = nreverse (vid.inits);
7296
7297   /* Chain the two together.  */
7298   return chainon (vid.inits, vfun_inits);
7299 }
7300
7301 /* Adds to vid->inits the initializers for the vbase and vcall
7302    offsets in BINFO, which is in the hierarchy dominated by T.  */
7303
7304 static void
7305 build_vcall_and_vbase_vtbl_entries (tree binfo, vtbl_init_data* vid)
7306 {
7307   tree b;
7308
7309   /* If this is a derived class, we must first create entries
7310      corresponding to the primary base class.  */
7311   b = get_primary_binfo (binfo);
7312   if (b)
7313     build_vcall_and_vbase_vtbl_entries (b, vid);
7314
7315   /* Add the vbase entries for this base.  */
7316   build_vbase_offset_vtbl_entries (binfo, vid);
7317   /* Add the vcall entries for this base.  */
7318   build_vcall_offset_vtbl_entries (binfo, vid);
7319 }
7320
7321 /* Returns the initializers for the vbase offset entries in the vtable
7322    for BINFO (which is part of the class hierarchy dominated by T), in
7323    reverse order.  VBASE_OFFSET_INDEX gives the vtable index
7324    where the next vbase offset will go.  */
7325
7326 static void
7327 build_vbase_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7328 {
7329   tree vbase;
7330   tree t;
7331   tree non_primary_binfo;
7332
7333   /* If there are no virtual baseclasses, then there is nothing to
7334      do.  */
7335   if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
7336     return;
7337
7338   t = vid->derived;
7339
7340   /* We might be a primary base class.  Go up the inheritance hierarchy
7341      until we find the most derived class of which we are a primary base:
7342      it is the offset of that which we need to use.  */
7343   non_primary_binfo = binfo;
7344   while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7345     {
7346       tree b;
7347
7348       /* If we have reached a virtual base, then it must be a primary
7349          base (possibly multi-level) of vid->binfo, or we wouldn't
7350          have called build_vcall_and_vbase_vtbl_entries for it.  But it
7351          might be a lost primary, so just skip down to vid->binfo.  */
7352       if (BINFO_VIRTUAL_P (non_primary_binfo))
7353         {
7354           non_primary_binfo = vid->binfo;
7355           break;
7356         }
7357
7358       b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7359       if (get_primary_binfo (b) != non_primary_binfo)
7360         break;
7361       non_primary_binfo = b;
7362     }
7363
7364   /* Go through the virtual bases, adding the offsets.  */
7365   for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
7366        vbase;
7367        vbase = TREE_CHAIN (vbase))
7368     {
7369       tree b;
7370       tree delta;
7371
7372       if (!BINFO_VIRTUAL_P (vbase))
7373         continue;
7374
7375       /* Find the instance of this virtual base in the complete
7376          object.  */
7377       b = copied_binfo (vbase, binfo);
7378
7379       /* If we've already got an offset for this virtual base, we
7380          don't need another one.  */
7381       if (BINFO_VTABLE_PATH_MARKED (b))
7382         continue;
7383       BINFO_VTABLE_PATH_MARKED (b) = 1;
7384
7385       /* Figure out where we can find this vbase offset.  */
7386       delta = size_binop (MULT_EXPR,
7387                           vid->index,
7388                           convert (ssizetype,
7389                                    TYPE_SIZE_UNIT (vtable_entry_type)));
7390       if (vid->primary_vtbl_p)
7391         BINFO_VPTR_FIELD (b) = delta;
7392
7393       if (binfo != TYPE_BINFO (t))
7394         /* The vbase offset had better be the same.  */
7395         gcc_assert (tree_int_cst_equal (delta, BINFO_VPTR_FIELD (vbase)));
7396
7397       /* The next vbase will come at a more negative offset.  */
7398       vid->index = size_binop (MINUS_EXPR, vid->index,
7399                                ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7400
7401       /* The initializer is the delta from BINFO to this virtual base.
7402          The vbase offsets go in reverse inheritance-graph order, and
7403          we are walking in inheritance graph order so these end up in
7404          the right order.  */
7405       delta = size_diffop (BINFO_OFFSET (b), BINFO_OFFSET (non_primary_binfo));
7406
7407       *vid->last_init
7408         = build_tree_list (NULL_TREE,
7409                            fold_build1 (NOP_EXPR,
7410                                         vtable_entry_type,
7411                                         delta));
7412       vid->last_init = &TREE_CHAIN (*vid->last_init);
7413     }
7414 }
7415
7416 /* Adds the initializers for the vcall offset entries in the vtable
7417    for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7418    to VID->INITS.  */
7419
7420 static void
7421 build_vcall_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7422 {
7423   /* We only need these entries if this base is a virtual base.  We
7424      compute the indices -- but do not add to the vtable -- when
7425      building the main vtable for a class.  */
7426   if (BINFO_VIRTUAL_P (binfo) || binfo == TYPE_BINFO (vid->derived))
7427     {
7428       /* We need a vcall offset for each of the virtual functions in this
7429          vtable.  For example:
7430
7431            class A { virtual void f (); };
7432            class B1 : virtual public A { virtual void f (); };
7433            class B2 : virtual public A { virtual void f (); };
7434            class C: public B1, public B2 { virtual void f (); };
7435
7436          A C object has a primary base of B1, which has a primary base of A.  A
7437          C also has a secondary base of B2, which no longer has a primary base
7438          of A.  So the B2-in-C construction vtable needs a secondary vtable for
7439          A, which will adjust the A* to a B2* to call f.  We have no way of
7440          knowing what (or even whether) this offset will be when we define B2,
7441          so we store this "vcall offset" in the A sub-vtable and look it up in
7442          a "virtual thunk" for B2::f.
7443
7444          We need entries for all the functions in our primary vtable and
7445          in our non-virtual bases' secondary vtables.  */
7446       vid->vbase = binfo;
7447       /* If we are just computing the vcall indices -- but do not need
7448          the actual entries -- not that.  */
7449       if (!BINFO_VIRTUAL_P (binfo))
7450         vid->generate_vcall_entries = false;
7451       /* Now, walk through the non-virtual bases, adding vcall offsets.  */
7452       add_vcall_offset_vtbl_entries_r (binfo, vid);
7453     }
7454 }
7455
7456 /* Build vcall offsets, starting with those for BINFO.  */
7457
7458 static void
7459 add_vcall_offset_vtbl_entries_r (tree binfo, vtbl_init_data* vid)
7460 {
7461   int i;
7462   tree primary_binfo;
7463   tree base_binfo;
7464
7465   /* Don't walk into virtual bases -- except, of course, for the
7466      virtual base for which we are building vcall offsets.  Any
7467      primary virtual base will have already had its offsets generated
7468      through the recursion in build_vcall_and_vbase_vtbl_entries.  */
7469   if (BINFO_VIRTUAL_P (binfo) && vid->vbase != binfo)
7470     return;
7471
7472   /* If BINFO has a primary base, process it first.  */
7473   primary_binfo = get_primary_binfo (binfo);
7474   if (primary_binfo)
7475     add_vcall_offset_vtbl_entries_r (primary_binfo, vid);
7476
7477   /* Add BINFO itself to the list.  */
7478   add_vcall_offset_vtbl_entries_1 (binfo, vid);
7479
7480   /* Scan the non-primary bases of BINFO.  */
7481   for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7482     if (base_binfo != primary_binfo)
7483       add_vcall_offset_vtbl_entries_r (base_binfo, vid);
7484 }
7485
7486 /* Called from build_vcall_offset_vtbl_entries_r.  */
7487
7488 static void
7489 add_vcall_offset_vtbl_entries_1 (tree binfo, vtbl_init_data* vid)
7490 {
7491   /* Make entries for the rest of the virtuals.  */
7492   if (abi_version_at_least (2))
7493     {
7494       tree orig_fn;
7495
7496       /* The ABI requires that the methods be processed in declaration
7497          order.  G++ 3.2 used the order in the vtable.  */
7498       for (orig_fn = TYPE_METHODS (BINFO_TYPE (binfo));
7499            orig_fn;
7500            orig_fn = TREE_CHAIN (orig_fn))
7501         if (DECL_VINDEX (orig_fn))
7502           add_vcall_offset (orig_fn, binfo, vid);
7503     }
7504   else
7505     {
7506       tree derived_virtuals;
7507       tree base_virtuals;
7508       tree orig_virtuals;
7509       /* If BINFO is a primary base, the most derived class which has
7510          BINFO as a primary base; otherwise, just BINFO.  */
7511       tree non_primary_binfo;
7512
7513       /* We might be a primary base class.  Go up the inheritance hierarchy
7514          until we find the most derived class of which we are a primary base:
7515          it is the BINFO_VIRTUALS there that we need to consider.  */
7516       non_primary_binfo = binfo;
7517       while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7518         {
7519           tree b;
7520
7521           /* If we have reached a virtual base, then it must be vid->vbase,
7522              because we ignore other virtual bases in
7523              add_vcall_offset_vtbl_entries_r.  In turn, it must be a primary
7524              base (possibly multi-level) of vid->binfo, or we wouldn't
7525              have called build_vcall_and_vbase_vtbl_entries for it.  But it
7526              might be a lost primary, so just skip down to vid->binfo.  */
7527           if (BINFO_VIRTUAL_P (non_primary_binfo))
7528             {
7529               gcc_assert (non_primary_binfo == vid->vbase);
7530               non_primary_binfo = vid->binfo;
7531               break;
7532             }
7533
7534           b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7535           if (get_primary_binfo (b) != non_primary_binfo)
7536             break;
7537           non_primary_binfo = b;
7538         }
7539
7540       if (vid->ctor_vtbl_p)
7541         /* For a ctor vtable we need the equivalent binfo within the hierarchy
7542            where rtti_binfo is the most derived type.  */
7543         non_primary_binfo
7544           = original_binfo (non_primary_binfo, vid->rtti_binfo);
7545
7546       for (base_virtuals = BINFO_VIRTUALS (binfo),
7547              derived_virtuals = BINFO_VIRTUALS (non_primary_binfo),
7548              orig_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
7549            base_virtuals;
7550            base_virtuals = TREE_CHAIN (base_virtuals),
7551              derived_virtuals = TREE_CHAIN (derived_virtuals),
7552              orig_virtuals = TREE_CHAIN (orig_virtuals))
7553         {
7554           tree orig_fn;
7555
7556           /* Find the declaration that originally caused this function to
7557              be present in BINFO_TYPE (binfo).  */
7558           orig_fn = BV_FN (orig_virtuals);
7559
7560           /* When processing BINFO, we only want to generate vcall slots for
7561              function slots introduced in BINFO.  So don't try to generate
7562              one if the function isn't even defined in BINFO.  */
7563           if (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), DECL_CONTEXT (orig_fn)))
7564             continue;
7565
7566           add_vcall_offset (orig_fn, binfo, vid);
7567         }
7568     }
7569 }
7570
7571 /* Add a vcall offset entry for ORIG_FN to the vtable.  */
7572
7573 static void
7574 add_vcall_offset (tree orig_fn, tree binfo, vtbl_init_data *vid)
7575 {
7576   size_t i;
7577   tree vcall_offset;
7578
7579   /* If there is already an entry for a function with the same
7580      signature as FN, then we do not need a second vcall offset.
7581      Check the list of functions already present in the derived
7582      class vtable.  */
7583   for (i = 0; i < VARRAY_ACTIVE_SIZE (vid->fns); ++i)
7584     {
7585       tree derived_entry;
7586
7587       derived_entry = VARRAY_TREE (vid->fns, i);
7588       if (same_signature_p (derived_entry, orig_fn)
7589           /* We only use one vcall offset for virtual destructors,
7590              even though there are two virtual table entries.  */
7591           || (DECL_DESTRUCTOR_P (derived_entry)
7592               && DECL_DESTRUCTOR_P (orig_fn)))
7593         return;
7594     }
7595
7596   /* If we are building these vcall offsets as part of building
7597      the vtable for the most derived class, remember the vcall
7598      offset.  */
7599   if (vid->binfo == TYPE_BINFO (vid->derived))
7600     {
7601       tree_pair_p elt = VEC_safe_push (tree_pair_s,
7602                                        CLASSTYPE_VCALL_INDICES (vid->derived),
7603                                        NULL);
7604       elt->purpose = orig_fn;
7605       elt->value = vid->index;
7606     }
7607
7608   /* The next vcall offset will be found at a more negative
7609      offset.  */
7610   vid->index = size_binop (MINUS_EXPR, vid->index,
7611                            ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7612
7613   /* Keep track of this function.  */
7614   VARRAY_PUSH_TREE (vid->fns, orig_fn);
7615
7616   if (vid->generate_vcall_entries)
7617     {
7618       tree base;
7619       tree fn;
7620
7621       /* Find the overriding function.  */
7622       fn = find_final_overrider (vid->rtti_binfo, binfo, orig_fn);
7623       if (fn == error_mark_node)
7624         vcall_offset = build1 (NOP_EXPR, vtable_entry_type,
7625                                integer_zero_node);
7626       else
7627         {
7628           base = TREE_VALUE (fn);
7629
7630           /* The vbase we're working on is a primary base of
7631              vid->binfo.  But it might be a lost primary, so its
7632              BINFO_OFFSET might be wrong, so we just use the
7633              BINFO_OFFSET from vid->binfo.  */
7634           vcall_offset = size_diffop (BINFO_OFFSET (base),
7635                                       BINFO_OFFSET (vid->binfo));
7636           vcall_offset = fold_build1 (NOP_EXPR, vtable_entry_type,
7637                                       vcall_offset);
7638         }
7639       /* Add the initializer to the vtable.  */
7640       *vid->last_init = build_tree_list (NULL_TREE, vcall_offset);
7641       vid->last_init = &TREE_CHAIN (*vid->last_init);
7642     }
7643 }
7644
7645 /* Return vtbl initializers for the RTTI entries corresponding to the
7646    BINFO's vtable.  The RTTI entries should indicate the object given
7647    by VID->rtti_binfo.  */
7648
7649 static void
7650 build_rtti_vtbl_entries (tree binfo, vtbl_init_data* vid)
7651 {
7652   tree b;
7653   tree t;
7654   tree basetype;
7655   tree offset;
7656   tree decl;
7657   tree init;
7658
7659   basetype = BINFO_TYPE (binfo);
7660   t = BINFO_TYPE (vid->rtti_binfo);
7661
7662   /* To find the complete object, we will first convert to our most
7663      primary base, and then add the offset in the vtbl to that value.  */
7664   b = binfo;
7665   while (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (b))
7666          && !BINFO_LOST_PRIMARY_P (b))
7667     {
7668       tree primary_base;
7669
7670       primary_base = get_primary_binfo (b);
7671       gcc_assert (BINFO_PRIMARY_P (primary_base)
7672                   && BINFO_INHERITANCE_CHAIN (primary_base) == b);
7673       b = primary_base;
7674     }
7675   offset = size_diffop (BINFO_OFFSET (vid->rtti_binfo), BINFO_OFFSET (b));
7676
7677   /* The second entry is the address of the typeinfo object.  */
7678   if (flag_rtti)
7679     decl = build_address (get_tinfo_decl (t));
7680   else
7681     decl = integer_zero_node;
7682
7683   /* Convert the declaration to a type that can be stored in the
7684      vtable.  */
7685   init = build_nop (vfunc_ptr_type_node, decl);
7686   *vid->last_init = build_tree_list (NULL_TREE, init);
7687   vid->last_init = &TREE_CHAIN (*vid->last_init);
7688
7689   /* Add the offset-to-top entry.  It comes earlier in the vtable than
7690      the typeinfo entry.  Convert the offset to look like a
7691      function pointer, so that we can put it in the vtable.  */
7692   init = build_nop (vfunc_ptr_type_node, offset);
7693   *vid->last_init = build_tree_list (NULL_TREE, init);
7694   vid->last_init = &TREE_CHAIN (*vid->last_init);
7695 }
7696
7697 /* Fold a OBJ_TYPE_REF expression to the address of a function.
7698    KNOWN_TYPE carries the true type of OBJ_TYPE_REF_OBJECT(REF).  */
7699
7700 tree
7701 cp_fold_obj_type_ref (tree ref, tree known_type)
7702 {
7703   HOST_WIDE_INT index = tree_low_cst (OBJ_TYPE_REF_TOKEN (ref), 1);
7704   HOST_WIDE_INT i = 0;
7705   tree v = BINFO_VIRTUALS (TYPE_BINFO (known_type));
7706   tree fndecl;
7707
7708   while (i != index)
7709     {
7710       i += (TARGET_VTABLE_USES_DESCRIPTORS
7711             ? TARGET_VTABLE_USES_DESCRIPTORS : 1);
7712       v = TREE_CHAIN (v);
7713     }
7714
7715   fndecl = BV_FN (v);
7716
7717 #ifdef ENABLE_CHECKING
7718   gcc_assert (tree_int_cst_equal (OBJ_TYPE_REF_TOKEN (ref),
7719                                   DECL_VINDEX (fndecl)));
7720 #endif
7721
7722   return build_address (fndecl);
7723 }
7724
7725 #include "gt-cp-class.h"