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, 51 Franklin Street, Fifth Floor,
  21 Boston, MA 02110-1301, USA.  */
  22
  23
  24 /* High-level class interface.  */
  25
  26 #include "config.h"
  27 #include "system.h"
  28 #include "coretypes.h"
  29 #include "tm.h"
  30 #include "tree.h"
  31 #include "cp-tree.h"
  32 #include "flags.h"
  33 #include "rtl.h"
  34 #include "output.h"
  35 #include "toplev.h"
  36 #include "target.h"
  37 #include "convert.h"
  38 #include "cgraph.h"
  39
  40 /* The number of nested classes being processed.  If we are not in the
  41    scope of any class, this is zero.  */
  42
  43 int current_class_depth;
  44
  45 /* In order to deal with nested classes, we keep a stack of classes.
  46    The topmost entry is the innermost class, and is the entry at index
  47    CURRENT_CLASS_DEPTH  */
  48
  49 typedef struct class_stack_node {
  50   /* The name of the class.  */
  51   tree name;
  52
  53   /* The _TYPE node for the class.  */
  54   tree type;
  55
  56   /* The access specifier pending for new declarations in the scope of
  57      this class.  */
  58   tree access;
  59
  60   /* If were defining TYPE, the names used in this class.  */
  61   splay_tree names_used;
  62 }* class_stack_node_t;
  63
  64 typedef struct vtbl_init_data_s
  65 {
  66   /* The base for which we're building initializers.  */
  67   tree binfo;
  68   /* The type of the most-derived type.  */
  69   tree derived;
  70   /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
  71      unless ctor_vtbl_p is true.  */
  72   tree rtti_binfo;
  73   /* The negative-index vtable initializers built up so far.  These
  74      are in order from least negative index to most negative index.  */
  75   tree inits;
  76   /* The last (i.e., most negative) entry in INITS.  */
  77   tree* last_init;
  78   /* The binfo for the virtual base for which we're building
  79      vcall offset initializers.  */
  80   tree vbase;
  81   /* The functions in vbase for which we have already provided vcall
  82      offsets.  */
  83   VEC(tree,gc) *fns;
  84   /* The vtable index of the next vcall or vbase offset.  */
  85   tree index;
  86   /* Nonzero if we are building the initializer for the primary
  87      vtable.  */
  88   int primary_vtbl_p;
  89   /* Nonzero if we are building the initializer for a construction
  90      vtable.  */
  91   int ctor_vtbl_p;
  92   /* True when adding vcall offset entries to the vtable.  False when
  93      merely computing the indices.  */
  94   bool generate_vcall_entries;
  95 } vtbl_init_data;
  96
  97 /* The type of a function passed to walk_subobject_offsets.  */
  98 typedef int (*subobject_offset_fn) (tree, tree, splay_tree);
  99
 100 /* The stack itself.  This is a dynamically resized array.  The
 101    number of elements allocated is CURRENT_CLASS_STACK_SIZE.  */
 102 static int current_class_stack_size;
 103 static class_stack_node_t current_class_stack;
 104
 105 /* An array of all local classes present in this translation unit, in
 106    declaration order.  */
 107 VEC(tree,gc) *local_classes;
 108
 109 static tree get_vfield_name (tree);
 110 static void finish_struct_anon (tree);
 111 static tree get_vtable_name (tree);
 112 static tree get_basefndecls (tree, tree);
 113 static int build_primary_vtable (tree, tree);
 114 static int build_secondary_vtable (tree);
 115 static void finish_vtbls (tree);
 116 static void modify_vtable_entry (tree, tree, tree, tree, tree *);
 117 static void finish_struct_bits (tree);
 118 static int alter_access (tree, tree, tree);
 119 static void handle_using_decl (tree, tree);
 120 static tree dfs_modify_vtables (tree, void *);
 121 static tree modify_all_vtables (tree, tree);
 122 static void determine_primary_bases (tree);
 123 static void finish_struct_methods (tree);
 124 static void maybe_warn_about_overly_private_class (tree);
 125 static int method_name_cmp (const void *, const void *);
 126 static int resort_method_name_cmp (const void *, const void *);
 127 static void add_implicitly_declared_members (tree, int, int);
 128 static tree fixed_type_or_null (tree, int *, int *);
 129 static tree resolve_address_of_overloaded_function (tree, tree, tsubst_flags_t,
 130                                                     bool, tree);
 131 static tree build_simple_base_path (tree expr, tree binfo);
 132 static tree build_vtbl_ref_1 (tree, tree);
 133 static tree build_vtbl_initializer (tree, tree, tree, tree, int *);
 134 static int count_fields (tree);
 135 static int add_fields_to_record_type (tree, struct sorted_fields_type*, int);
 136 static void check_bitfield_decl (tree);
 137 static void check_field_decl (tree, tree, int *, int *, int *);
 138 static void check_field_decls (tree, tree *, int *, int *);
 139 static tree *build_base_field (record_layout_info, tree, splay_tree, tree *);
 140 static void build_base_fields (record_layout_info, splay_tree, tree *);
 141 static void check_methods (tree);
 142 static void remove_zero_width_bit_fields (tree);
 143 static void check_bases (tree, int *, int *);
 144 static void check_bases_and_members (tree);
 145 static tree create_vtable_ptr (tree, tree *);
 146 static void include_empty_classes (record_layout_info);
 147 static void layout_class_type (tree, tree *);
 148 static void fixup_pending_inline (tree);
 149 static void fixup_inline_methods (tree);
 150 static void propagate_binfo_offsets (tree, tree);
 151 static void layout_virtual_bases (record_layout_info, splay_tree);
 152 static void build_vbase_offset_vtbl_entries (tree, vtbl_init_data *);
 153 static void add_vcall_offset_vtbl_entries_r (tree, vtbl_init_data *);
 154 static void add_vcall_offset_vtbl_entries_1 (tree, vtbl_init_data *);
 155 static void build_vcall_offset_vtbl_entries (tree, vtbl_init_data *);
 156 static void add_vcall_offset (tree, tree, vtbl_init_data *);
 157 static void layout_vtable_decl (tree, int);
 158 static tree dfs_find_final_overrider_pre (tree, void *);
 159 static tree dfs_find_final_overrider_post (tree, void *);
 160 static tree find_final_overrider (tree, tree, tree);
 161 static int make_new_vtable (tree, tree);
 162 static int maybe_indent_hierarchy (FILE *, int, int);
 163 static tree dump_class_hierarchy_r (FILE *, int, tree, tree, int);
 164 static void dump_class_hierarchy (tree);
 165 static void dump_class_hierarchy_1 (FILE *, int, tree);
 166 static void dump_array (FILE *, tree);
 167 static void dump_vtable (tree, tree, tree);
 168 static void dump_vtt (tree, tree);
 169 static void dump_thunk (FILE *, int, tree);
 170 static tree build_vtable (tree, tree, tree);
 171 static void initialize_vtable (tree, tree);
 172 static void layout_nonempty_base_or_field (record_layout_info,
 173                                            tree, tree, splay_tree);
 174 static tree end_of_class (tree, int);
 175 static bool layout_empty_base (tree, tree, splay_tree);
 176 static void accumulate_vtbl_inits (tree, tree, tree, tree, tree);
 177 static tree dfs_accumulate_vtbl_inits (tree, tree, tree, tree,
 178                                                tree);
 179 static void build_rtti_vtbl_entries (tree, vtbl_init_data *);
 180 static void build_vcall_and_vbase_vtbl_entries (tree, vtbl_init_data *);
 181 static void clone_constructors_and_destructors (tree);
 182 static tree build_clone (tree, tree);
 183 static void update_vtable_entry_for_fn (tree, tree, tree, tree *, unsigned);
 184 static void build_ctor_vtbl_group (tree, tree);
 185 static void build_vtt (tree);
 186 static tree binfo_ctor_vtable (tree);
 187 static tree *build_vtt_inits (tree, tree, tree *, tree *);
 188 static tree dfs_build_secondary_vptr_vtt_inits (tree, void *);
 189 static tree dfs_fixup_binfo_vtbls (tree, void *);
 190 static int record_subobject_offset (tree, tree, splay_tree);
 191 static int check_subobject_offset (tree, tree, splay_tree);
 192 static int walk_subobject_offsets (tree, subobject_offset_fn,
 193                                    tree, splay_tree, tree, int);
 194 static void record_subobject_offsets (tree, tree, splay_tree, int);
 195 static int layout_conflict_p (tree, tree, splay_tree, int);
 196 static int splay_tree_compare_integer_csts (splay_tree_key k1,
 197                                             splay_tree_key k2);
 198 static void warn_about_ambiguous_bases (tree);
 199 static bool type_requires_array_cookie (tree);
 200 static bool contains_empty_class_p (tree);
 201 static bool base_derived_from (tree, tree);
 202 static int empty_base_at_nonzero_offset_p (tree, tree, splay_tree);
 203 static tree end_of_base (tree);
 204 static tree get_vcall_index (tree, tree);
 205
 206 /* Variables shared between class.c and call.c.  */
 207
 208 #ifdef GATHER_STATISTICS
 209 int n_vtables = 0;
 210 int n_vtable_entries = 0;
 211 int n_vtable_searches = 0;
 212 int n_vtable_elems = 0;
 213 int n_convert_harshness = 0;
 214 int n_compute_conversion_costs = 0;
 215 int n_inner_fields_searched = 0;
 216 #endif
 217
 218 /* Convert to or from a base subobject.  EXPR is an expression of type
 219    `A' or `A*', an expression of type `B' or `B*' is returned.  To
 220    convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
 221    the B base instance within A.  To convert base A to derived B, CODE
 222    is MINUS_EXPR and BINFO is the binfo for the A instance within B.
 223    In this latter case, A must not be a morally virtual base of B.
 224    NONNULL is true if EXPR is known to be non-NULL (this is only
 225    needed when EXPR is of pointer type).  CV qualifiers are preserved
 226    from EXPR.  */
 227
 228 tree
 229 build_base_path (enum tree_code code,
 230                  tree expr,
 231                  tree binfo,
 232                  int nonnull)
 233 {
 234   tree v_binfo = NULL_TREE;
 235   tree d_binfo = NULL_TREE;
 236   tree probe;
 237   tree offset;
 238   tree target_type;
 239   tree null_test = NULL;
 240   tree ptr_target_type;
 241   int fixed_type_p;
 242   int want_pointer = TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE;
 243   bool has_empty = false;
 244   bool virtual_access;
 245
 246   if (expr == error_mark_node || binfo == error_mark_node || !binfo)
 247     return error_mark_node;
 248
 249   for (probe = binfo; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
 250     {
 251       d_binfo = probe;
 252       if (is_empty_class (BINFO_TYPE (probe)))
 253         has_empty = true;
 254       if (!v_binfo && BINFO_VIRTUAL_P (probe))
 255         v_binfo = probe;
 256     }
 257
 258   probe = TYPE_MAIN_VARIANT (TREE_TYPE (expr));
 259   if (want_pointer)
 260     probe = TYPE_MAIN_VARIANT (TREE_TYPE (probe));
 261
 262   gcc_assert ((code == MINUS_EXPR
 263                && SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), probe))
 264               || (code == PLUS_EXPR
 265                   && SAME_BINFO_TYPE_P (BINFO_TYPE (d_binfo), probe)));
 266
 267   if (binfo == d_binfo)
 268     /* Nothing to do.  */
 269     return expr;
 270
 271   if (code == MINUS_EXPR && v_binfo)
 272     {
 273       error ("cannot convert from base %qT to derived type %qT via virtual base %qT",
 274              BINFO_TYPE (binfo), BINFO_TYPE (d_binfo), BINFO_TYPE (v_binfo));
 275       return error_mark_node;
 276     }
 277
 278   if (!want_pointer)
 279     /* This must happen before the call to save_expr.  */
 280     expr = build_unary_op (ADDR_EXPR, expr, 0);
 281
 282   offset = BINFO_OFFSET (binfo);
 283   fixed_type_p = resolves_to_fixed_type_p (expr, &nonnull);
 284
 285   /* Do we need to look in the vtable for the real offset?  */
 286   virtual_access = (v_binfo && fixed_type_p <= 0);
 287
 288   /* Do we need to check for a null pointer?  */
 289   if (want_pointer && !nonnull && (virtual_access || !integer_zerop (offset)))
 290     null_test = error_mark_node;
 291
 292   /* Protect against multiple evaluation if necessary.  */
 293   if (TREE_SIDE_EFFECTS (expr) && (null_test || virtual_access))
 294     expr = save_expr (expr);
 295
 296   /* Now that we've saved expr, build the real null test.  */
 297   if (null_test)
 298     {
 299       tree zero = cp_convert (TREE_TYPE (expr), integer_zero_node);
 300       null_test = fold_build2 (NE_EXPR, boolean_type_node,
 301                                expr, zero);
 302     }
 303
 304   /* If this is a simple base reference, express it as a COMPONENT_REF.  */
 305   if (code == PLUS_EXPR && !virtual_access
 306       /* We don't build base fields for empty bases, and they aren't very
 307          interesting to the optimizers anyway.  */
 308       && !has_empty)
 309     {
 310       expr = build_indirect_ref (expr, NULL);
 311       expr = build_simple_base_path (expr, binfo);
 312       if (want_pointer)
 313         expr = build_address (expr);
 314       target_type = TREE_TYPE (expr);
 315       goto out;
 316     }
 317
 318   if (virtual_access)
 319     {
 320       /* Going via virtual base V_BINFO.  We need the static offset
 321          from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
 322          V_BINFO.  That offset is an entry in D_BINFO's vtable.  */
 323       tree v_offset;
 324
 325       if (fixed_type_p < 0 && in_base_initializer)
 326         {
 327           /* In a base member initializer, we cannot rely on
 328              the vtable being set up. We have to use the vtt_parm.  */
 329           tree derived = BINFO_INHERITANCE_CHAIN (v_binfo);
 330           tree t;
 331
 332           t = TREE_TYPE (TYPE_VFIELD (BINFO_TYPE (derived)));
 333           t = build_pointer_type (t);
 334           v_offset = convert (t, current_vtt_parm);
 335           v_offset = build2 (PLUS_EXPR, t, v_offset,
 336                              BINFO_VPTR_INDEX (derived));
 337           v_offset = build_indirect_ref (v_offset, NULL);
 338         }
 339       else
 340         v_offset = build_vfield_ref (build_indirect_ref (expr, NULL),
 341                                      TREE_TYPE (TREE_TYPE (expr)));
 342
 343       v_offset = build2 (PLUS_EXPR, TREE_TYPE (v_offset),
 344                          v_offset,  BINFO_VPTR_FIELD (v_binfo));
 345       v_offset = build1 (NOP_EXPR,
 346                          build_pointer_type (ptrdiff_type_node),
 347                          v_offset);
 348       v_offset = build_indirect_ref (v_offset, NULL);
 349       TREE_CONSTANT (v_offset) = 1;
 350       TREE_INVARIANT (v_offset) = 1;
 351
 352       offset = convert_to_integer (ptrdiff_type_node,
 353                                    size_diffop (offset,
 354                                                 BINFO_OFFSET (v_binfo)));
 355
 356       if (!integer_zerop (offset))
 357         v_offset = build2 (code, ptrdiff_type_node, v_offset, offset);
 358
 359       if (fixed_type_p < 0)
 360         /* Negative fixed_type_p means this is a constructor or destructor;
 361            virtual base layout is fixed in in-charge [cd]tors, but not in
 362            base [cd]tors.  */
 363         offset = build3 (COND_EXPR, ptrdiff_type_node,
 364                          build2 (EQ_EXPR, boolean_type_node,
 365                                  current_in_charge_parm, integer_zero_node),
 366                          v_offset,
 367                          BINFO_OFFSET (binfo));
 368       else
 369         offset = v_offset;
 370     }
 371
 372   target_type = code == PLUS_EXPR ? BINFO_TYPE (binfo) : BINFO_TYPE (d_binfo);
 373
 374   target_type = cp_build_qualified_type
 375     (target_type, cp_type_quals (TREE_TYPE (TREE_TYPE (expr))));
 376   ptr_target_type = build_pointer_type (target_type);
 377   if (want_pointer)
 378     target_type = ptr_target_type;
 379
 380   expr = build1 (NOP_EXPR, ptr_target_type, expr);
 381
 382   if (!integer_zerop (offset))
 383     expr = build2 (code, ptr_target_type, expr, offset);
 384   else
 385     null_test = NULL;
 386
 387   if (!want_pointer)
 388     expr = build_indirect_ref (expr, NULL);
 389
 390  out:
 391   if (null_test)
 392     expr = fold_build3 (COND_EXPR, target_type, null_test, expr,
 393                         fold_build1 (NOP_EXPR, target_type,
 394                                      integer_zero_node));
 395
 396   return expr;
 397 }
 398
 399 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
 400    Perform a derived-to-base conversion by recursively building up a
 401    sequence of COMPONENT_REFs to the appropriate base fields.  */
 402
 403 static tree
 404 build_simple_base_path (tree expr, tree binfo)
 405 {
 406   tree type = BINFO_TYPE (binfo);
 407   tree d_binfo = BINFO_INHERITANCE_CHAIN (binfo);
 408   tree field;
 409
 410   if (d_binfo == NULL_TREE)
 411     {
 412       tree temp;
 413
 414       gcc_assert (TYPE_MAIN_VARIANT (TREE_TYPE (expr)) == type);
 415
 416       /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
 417          into `(*(a ?  &b : &c)).x', and so on.  A COND_EXPR is only
 418          an lvalue in the frontend; only _DECLs and _REFs are lvalues
 419          in the backend.  */
 420       temp = unary_complex_lvalue (ADDR_EXPR, expr);
 421       if (temp)
 422         expr = build_indirect_ref (temp, NULL);
 423
 424       return expr;
 425     }
 426
 427   /* Recurse.  */
 428   expr = build_simple_base_path (expr, d_binfo);
 429
 430   for (field = TYPE_FIELDS (BINFO_TYPE (d_binfo));
 431        field; field = TREE_CHAIN (field))
 432     /* Is this the base field created by build_base_field?  */
 433     if (TREE_CODE (field) == FIELD_DECL
 434         && DECL_FIELD_IS_BASE (field)
 435         && TREE_TYPE (field) == type)
 436       {
 437         /* We don't use build_class_member_access_expr here, as that
 438            has unnecessary checks, and more importantly results in
 439            recursive calls to dfs_walk_once.  */
 440         int type_quals = cp_type_quals (TREE_TYPE (expr));
 441
 442         expr = build3 (COMPONENT_REF,
 443                        cp_build_qualified_type (type, type_quals),
 444                        expr, field, NULL_TREE);
 445         expr = fold_if_not_in_template (expr);
 446
 447         /* Mark the expression const or volatile, as appropriate.
 448            Even though we've dealt with the type above, we still have
 449            to mark the expression itself.  */
 450         if (type_quals & TYPE_QUAL_CONST)
 451           TREE_READONLY (expr) = 1;
 452         if (type_quals & TYPE_QUAL_VOLATILE)
 453           TREE_THIS_VOLATILE (expr) = 1;
 454
 455         return expr;
 456       }
 457
 458   /* Didn't find the base field?!?  */
 459   gcc_unreachable ();
 460 }
 461
 462 /* Convert OBJECT to the base TYPE.  OBJECT is an expression whose
 463    type is a class type or a pointer to a class type.  In the former
 464    case, TYPE is also a class type; in the latter it is another
 465    pointer type.  If CHECK_ACCESS is true, an error message is emitted
 466    if TYPE is inaccessible.  If OBJECT has pointer type, the value is
 467    assumed to be non-NULL.  */
 468
 469 tree
 470 convert_to_base (tree object, tree type, bool check_access, bool nonnull)
 471 {
 472   tree binfo;
 473   tree object_type;
 474
 475   if (TYPE_PTR_P (TREE_TYPE (object)))
 476     {
 477       object_type = TREE_TYPE (TREE_TYPE (object));
 478       type = TREE_TYPE (type);
 479     }
 480   else
 481     object_type = TREE_TYPE (object);
 482
 483   binfo = lookup_base (object_type, type,
 484                        check_access ? ba_check : ba_unique,
 485                        NULL);
 486   if (!binfo || binfo == error_mark_node)
 487     return error_mark_node;
 488
 489   return build_base_path (PLUS_EXPR, object, binfo, nonnull);
 490 }
 491
 492 /* EXPR is an expression with unqualified class type.  BASE is a base
 493    binfo of that class type.  Returns EXPR, converted to the BASE
 494    type.  This function assumes that EXPR is the most derived class;
 495    therefore virtual bases can be found at their static offsets.  */
 496
 497 tree
 498 convert_to_base_statically (tree expr, tree base)
 499 {
 500   tree expr_type;
 501
 502   expr_type = TREE_TYPE (expr);
 503   if (!SAME_BINFO_TYPE_P (BINFO_TYPE (base), expr_type))
 504     {
 505       tree pointer_type;
 506
 507       pointer_type = build_pointer_type (expr_type);
 508       expr = build_unary_op (ADDR_EXPR, expr, /*noconvert=*/1);
 509       if (!integer_zerop (BINFO_OFFSET (base)))
 510           expr = build2 (PLUS_EXPR, pointer_type, expr,
 511                          build_nop (pointer_type, BINFO_OFFSET (base)));
 512       expr = build_nop (build_pointer_type (BINFO_TYPE (base)), expr);
 513       expr = build1 (INDIRECT_REF, BINFO_TYPE (base), expr);
 514     }
 515
 516   return expr;
 517 }
 518
 519 \f
 520 tree
 521 build_vfield_ref (tree datum, tree type)
 522 {
 523   tree vfield, vcontext;
 524
 525   if (datum == error_mark_node)
 526     return error_mark_node;
 527
 528   /* First, convert to the requested type.  */
 529   if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (datum), type))
 530     datum = convert_to_base (datum, type, /*check_access=*/false,
 531                              /*nonnull=*/true);
 532
 533   /* Second, the requested type may not be the owner of its own vptr.
 534      If not, convert to the base class that owns it.  We cannot use
 535      convert_to_base here, because VCONTEXT may appear more than once
 536      in the inheritance hierarchy of TYPE, and thus direct conversion
 537      between the types may be ambiguous.  Following the path back up
 538      one step at a time via primary bases avoids the problem.  */
 539   vfield = TYPE_VFIELD (type);
 540   vcontext = DECL_CONTEXT (vfield);
 541   while (!same_type_ignoring_top_level_qualifiers_p (vcontext, type))
 542     {
 543       datum = build_simple_base_path (datum, CLASSTYPE_PRIMARY_BINFO (type));
 544       type = TREE_TYPE (datum);
 545     }
 546
 547   return build3 (COMPONENT_REF, TREE_TYPE (vfield), datum, vfield, NULL_TREE);
 548 }
 549
 550 /* Given an object INSTANCE, return an expression which yields the
 551    vtable element corresponding to INDEX.  There are many special
 552    cases for INSTANCE which we take care of here, mainly to avoid
 553    creating extra tree nodes when we don't have to.  */
 554
 555 static tree
 556 build_vtbl_ref_1 (tree instance, tree idx)
 557 {
 558   tree aref;
 559   tree vtbl = NULL_TREE;
 560
 561   /* Try to figure out what a reference refers to, and
 562      access its virtual function table directly.  */
 563
 564   int cdtorp = 0;
 565   tree fixed_type = fixed_type_or_null (instance, NULL, &cdtorp);
 566
 567   tree basetype = non_reference (TREE_TYPE (instance));
 568
 569   if (fixed_type && !cdtorp)
 570     {
 571       tree binfo = lookup_base (fixed_type, basetype,
 572                                 ba_unique | ba_quiet, NULL);
 573       if (binfo)
 574         vtbl = unshare_expr (BINFO_VTABLE (binfo));
 575     }
 576
 577   if (!vtbl)
 578     vtbl = build_vfield_ref (instance, basetype);
 579
 580   assemble_external (vtbl);
 581
 582   aref = build_array_ref (vtbl, idx);
 583   TREE_CONSTANT (aref) |= TREE_CONSTANT (vtbl) && TREE_CONSTANT (idx);
 584   TREE_INVARIANT (aref) = TREE_CONSTANT (aref);
 585
 586   return aref;
 587 }
 588
 589 tree
 590 build_vtbl_ref (tree instance, tree idx)
 591 {
 592   tree aref = build_vtbl_ref_1 (instance, idx);
 593
 594   return aref;
 595 }
 596
 597 /* Given a stable object pointer INSTANCE_PTR, return an expression which
 598    yields a function pointer corresponding to vtable element INDEX.  */
 599
 600 tree
 601 build_vfn_ref (tree instance_ptr, tree idx)
 602 {
 603   tree aref;
 604
 605   aref = build_vtbl_ref_1 (build_indirect_ref (instance_ptr, 0), idx);
 606
 607   /* When using function descriptors, the address of the
 608      vtable entry is treated as a function pointer.  */
 609   if (TARGET_VTABLE_USES_DESCRIPTORS)
 610     aref = build1 (NOP_EXPR, TREE_TYPE (aref),
 611                    build_unary_op (ADDR_EXPR, aref, /*noconvert=*/1));
 612
 613   /* Remember this as a method reference, for later devirtualization.  */
 614   aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr, idx);
 615
 616   return aref;
 617 }
 618
 619 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
 620    for the given TYPE.  */
 621
 622 static tree
 623 get_vtable_name (tree type)
 624 {
 625   return mangle_vtbl_for_type (type);
 626 }
 627
 628 /* Return an IDENTIFIER_NODE for the name of the virtual table table
 629    for TYPE.  */
 630
 631 tree
 632 get_vtt_name (tree type)
 633 {
 634   return mangle_vtt_for_type (type);
 635 }
 636
 637 /* DECL is an entity associated with TYPE, like a virtual table or an
 638    implicitly generated constructor.  Determine whether or not DECL
 639    should have external or internal linkage at the object file
 640    level.  This routine does not deal with COMDAT linkage and other
 641    similar complexities; it simply sets TREE_PUBLIC if it possible for
 642    entities in other translation units to contain copies of DECL, in
 643    the abstract.  */
 644
 645 void
 646 set_linkage_according_to_type (tree type, tree decl)
 647 {
 648   /* If TYPE involves a local class in a function with internal
 649      linkage, then DECL should have internal linkage too.  Other local
 650      classes have no linkage -- but if their containing functions
 651      have external linkage, it makes sense for DECL to have external
 652      linkage too.  That will allow template definitions to be merged,
 653      for example.  */
 654   if (no_linkage_check (type, /*relaxed_p=*/true))
 655     {
 656       TREE_PUBLIC (decl) = 0;
 657       DECL_INTERFACE_KNOWN (decl) = 1;
 658     }
 659   else
 660     TREE_PUBLIC (decl) = 1;
 661 }
 662
 663 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
 664    (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
 665    Use NAME for the name of the vtable, and VTABLE_TYPE for its type.  */
 666
 667 static tree
 668 build_vtable (tree class_type, tree name, tree vtable_type)
 669 {
 670   tree decl;
 671
 672   decl = build_lang_decl (VAR_DECL, name, vtable_type);
 673   /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
 674      now to avoid confusion in mangle_decl.  */
 675   SET_DECL_ASSEMBLER_NAME (decl, name);
 676   DECL_CONTEXT (decl) = class_type;
 677   DECL_ARTIFICIAL (decl) = 1;
 678   TREE_STATIC (decl) = 1;
 679   TREE_READONLY (decl) = 1;
 680   DECL_VIRTUAL_P (decl) = 1;
 681   DECL_ALIGN (decl) = TARGET_VTABLE_ENTRY_ALIGN;
 682   DECL_VTABLE_OR_VTT_P (decl) = 1;
 683   /* At one time the vtable info was grabbed 2 words at a time.  This
 684      fails on sparc unless you have 8-byte alignment.  (tiemann) */
 685   DECL_ALIGN (decl) = MAX (TYPE_ALIGN (double_type_node),
 686                            DECL_ALIGN (decl));
 687   set_linkage_according_to_type (class_type, decl);
 688   /* The vtable has not been defined -- yet.  */
 689   DECL_EXTERNAL (decl) = 1;
 690   DECL_NOT_REALLY_EXTERN (decl) = 1;
 691
 692   /* Mark the VAR_DECL node representing the vtable itself as a
 693      "gratuitous" one, thereby forcing dwarfout.c to ignore it.  It
 694      is rather important that such things be ignored because any
 695      effort to actually generate DWARF for them will run into
 696      trouble when/if we encounter code like:
 697
 698      #pragma interface
 699      struct S { virtual void member (); };
 700
 701      because the artificial declaration of the vtable itself (as
 702      manufactured by the g++ front end) will say that the vtable is
 703      a static member of `S' but only *after* the debug output for
 704      the definition of `S' has already been output.  This causes
 705      grief because the DWARF entry for the definition of the vtable
 706      will try to refer back to an earlier *declaration* of the
 707      vtable as a static member of `S' and there won't be one.  We
 708      might be able to arrange to have the "vtable static member"
 709      attached to the member list for `S' before the debug info for
 710      `S' get written (which would solve the problem) but that would
 711      require more intrusive changes to the g++ front end.  */
 712   DECL_IGNORED_P (decl) = 1;
 713
 714   return decl;
 715 }
 716
 717 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
 718    or even complete.  If this does not exist, create it.  If COMPLETE is
 719    nonzero, then complete the definition of it -- that will render it
 720    impossible to actually build the vtable, but is useful to get at those
 721    which are known to exist in the runtime.  */
 722
 723 tree
 724 get_vtable_decl (tree type, int complete)
 725 {
 726   tree decl;
 727
 728   if (CLASSTYPE_VTABLES (type))
 729     return CLASSTYPE_VTABLES (type);
 730
 731   decl = build_vtable (type, get_vtable_name (type), vtbl_type_node);
 732   CLASSTYPE_VTABLES (type) = decl;
 733
 734   if (complete)
 735     {
 736       DECL_EXTERNAL (decl) = 1;
 737       cp_finish_decl (decl, NULL_TREE, NULL_TREE, 0);
 738     }
 739
 740   return decl;
 741 }
 742
 743 /* Build the primary virtual function table for TYPE.  If BINFO is
 744    non-NULL, build the vtable starting with the initial approximation
 745    that it is the same as the one which is the head of the association
 746    list.  Returns a nonzero value if a new vtable is actually
 747    created.  */
 748
 749 static int
 750 build_primary_vtable (tree binfo, tree type)
 751 {
 752   tree decl;
 753   tree virtuals;
 754
 755   decl = get_vtable_decl (type, /*complete=*/0);
 756
 757   if (binfo)
 758     {
 759       if (BINFO_NEW_VTABLE_MARKED (binfo))
 760         /* We have already created a vtable for this base, so there's
 761            no need to do it again.  */
 762         return 0;
 763
 764       virtuals = copy_list (BINFO_VIRTUALS (binfo));
 765       TREE_TYPE (decl) = TREE_TYPE (get_vtbl_decl_for_binfo (binfo));
 766       DECL_SIZE (decl) = TYPE_SIZE (TREE_TYPE (decl));
 767       DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (TREE_TYPE (decl));
 768     }
 769   else
 770     {
 771       gcc_assert (TREE_TYPE (decl) == vtbl_type_node);
 772       virtuals = NULL_TREE;
 773     }
 774
 775 #ifdef GATHER_STATISTICS
 776   n_vtables += 1;
 777   n_vtable_elems += list_length (virtuals);
 778 #endif
 779
 780   /* Initialize the association list for this type, based
 781      on our first approximation.  */
 782   BINFO_VTABLE (TYPE_BINFO (type)) = decl;
 783   BINFO_VIRTUALS (TYPE_BINFO (type)) = virtuals;
 784   SET_BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (type));
 785   return 1;
 786 }
 787
 788 /* Give BINFO a new virtual function table which is initialized
 789    with a skeleton-copy of its original initialization.  The only
 790    entry that changes is the `delta' entry, so we can really
 791    share a lot of structure.
 792
 793    FOR_TYPE is the most derived type which caused this table to
 794    be needed.
 795
 796    Returns nonzero if we haven't met BINFO before.
 797
 798    The order in which vtables are built (by calling this function) for
 799    an object must remain the same, otherwise a binary incompatibility
 800    can result.  */
 801
 802 static int
 803 build_secondary_vtable (tree binfo)
 804 {
 805   if (BINFO_NEW_VTABLE_MARKED (binfo))
 806     /* We already created a vtable for this base.  There's no need to
 807        do it again.  */
 808     return 0;
 809
 810   /* Remember that we've created a vtable for this BINFO, so that we
 811      don't try to do so again.  */
 812   SET_BINFO_NEW_VTABLE_MARKED (binfo);
 813
 814   /* Make fresh virtual list, so we can smash it later.  */
 815   BINFO_VIRTUALS (binfo) = copy_list (BINFO_VIRTUALS (binfo));
 816
 817   /* Secondary vtables are laid out as part of the same structure as
 818      the primary vtable.  */
 819   BINFO_VTABLE (binfo) = NULL_TREE;
 820   return 1;
 821 }
 822
 823 /* Create a new vtable for BINFO which is the hierarchy dominated by
 824    T. Return nonzero if we actually created a new vtable.  */
 825
 826 static int
 827 make_new_vtable (tree t, tree binfo)
 828 {
 829   if (binfo == TYPE_BINFO (t))
 830     /* In this case, it is *type*'s vtable we are modifying.  We start
 831        with the approximation that its vtable is that of the
 832        immediate base class.  */
 833     return build_primary_vtable (binfo, t);
 834   else
 835     /* This is our very own copy of `basetype' to play with.  Later,
 836        we will fill in all the virtual functions that override the
 837        virtual functions in these base classes which are not defined
 838        by the current type.  */
 839     return build_secondary_vtable (binfo);
 840 }
 841
 842 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
 843    (which is in the hierarchy dominated by T) list FNDECL as its
 844    BV_FN.  DELTA is the required constant adjustment from the `this'
 845    pointer where the vtable entry appears to the `this' required when
 846    the function is actually called.  */
 847
 848 static void
 849 modify_vtable_entry (tree t,
 850                      tree binfo,
 851                      tree fndecl,
 852                      tree delta,
 853                      tree *virtuals)
 854 {
 855   tree v;
 856
 857   v = *virtuals;
 858
 859   if (fndecl != BV_FN (v)
 860       || !tree_int_cst_equal (delta, BV_DELTA (v)))
 861     {
 862       /* We need a new vtable for BINFO.  */
 863       if (make_new_vtable (t, binfo))
 864         {
 865           /* If we really did make a new vtable, we also made a copy
 866              of the BINFO_VIRTUALS list.  Now, we have to find the
 867              corresponding entry in that list.  */
 868           *virtuals = BINFO_VIRTUALS (binfo);
 869           while (BV_FN (*virtuals) != BV_FN (v))
 870             *virtuals = TREE_CHAIN (*virtuals);
 871           v = *virtuals;
 872         }
 873
 874       BV_DELTA (v) = delta;
 875       BV_VCALL_INDEX (v) = NULL_TREE;
 876       BV_FN (v) = fndecl;
 877     }
 878 }
 879
 880 \f
 881 /* Add method METHOD to class TYPE.  If USING_DECL is non-null, it is
 882    the USING_DECL naming METHOD.  */
 883
 884 void
 885 add_method (tree type, tree method, tree using_decl)
 886 {
 887   unsigned slot;
 888   tree overload;
 889   bool template_conv_p = false;
 890   bool conv_p;
 891   VEC(tree,gc) *method_vec;
 892   bool complete_p;
 893   bool insert_p = false;
 894   tree current_fns;
 895
 896   if (method == error_mark_node)
 897     return;
 898
 899   complete_p = COMPLETE_TYPE_P (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, gc, 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)
1027                 {
1028                   if (DECL_CONTEXT (fn) == type)
1029                     /* Defer to the local function.  */
1030                     return;
1031                   if (DECL_CONTEXT (fn) == DECL_CONTEXT (method))
1032                     error ("repeated using declaration %q+D", using_decl);
1033                   else
1034                     error ("using declaration %q+D conflicts with a previous using declaration",
1035                            using_decl);
1036                 }
1037               else
1038                 {
1039                   error ("%q+#D cannot be overloaded", method);
1040                   error ("with %q+#D", fn);
1041                 }
1042
1043               /* We don't call duplicate_decls here to merge the
1044                  declarations because that will confuse things if the
1045                  methods have inline definitions.  In particular, we
1046                  will crash while processing the definitions.  */
1047               return;
1048             }
1049         }
1050     }
1051
1052   /* Add the new binding.  */
1053   overload = build_overload (method, current_fns);
1054
1055   if (!conv_p && slot >= CLASSTYPE_FIRST_CONVERSION_SLOT && !complete_p)
1056     push_class_level_binding (DECL_NAME (method), overload);
1057
1058   if (insert_p)
1059     {
1060       /* We only expect to add few methods in the COMPLETE_P case, so
1061          just make room for one more method in that case.  */
1062       if (VEC_reserve (tree, gc, method_vec, complete_p ? -1 : 1))
1063         CLASSTYPE_METHOD_VEC (type) = method_vec;
1064       if (slot == VEC_length (tree, method_vec))
1065         VEC_quick_push (tree, method_vec, overload);
1066       else
1067         VEC_quick_insert (tree, method_vec, slot, overload);
1068     }
1069   else
1070     /* Replace the current slot.  */
1071     VEC_replace (tree, method_vec, slot, overload);
1072 }
1073
1074 /* Subroutines of finish_struct.  */
1075
1076 /* Change the access of FDECL to ACCESS in T.  Return 1 if change was
1077    legit, otherwise return 0.  */
1078
1079 static int
1080 alter_access (tree t, tree fdecl, tree access)
1081 {
1082   tree elem;
1083
1084   if (!DECL_LANG_SPECIFIC (fdecl))
1085     retrofit_lang_decl (fdecl);
1086
1087   gcc_assert (!DECL_DISCRIMINATOR_P (fdecl));
1088
1089   elem = purpose_member (t, DECL_ACCESS (fdecl));
1090   if (elem)
1091     {
1092       if (TREE_VALUE (elem) != access)
1093         {
1094           if (TREE_CODE (TREE_TYPE (fdecl)) == FUNCTION_DECL)
1095             error ("conflicting access specifications for method"
1096                    " %q+D, ignored", TREE_TYPE (fdecl));
1097           else
1098             error ("conflicting access specifications for field %qE, ignored",
1099                    DECL_NAME (fdecl));
1100         }
1101       else
1102         {
1103           /* They're changing the access to the same thing they changed
1104              it to before.  That's OK.  */
1105           ;
1106         }
1107     }
1108   else
1109     {
1110       perform_or_defer_access_check (TYPE_BINFO (t), fdecl);
1111       DECL_ACCESS (fdecl) = tree_cons (t, access, DECL_ACCESS (fdecl));
1112       return 1;
1113     }
1114   return 0;
1115 }
1116
1117 /* Process the USING_DECL, which is a member of T.  */
1118
1119 static void
1120 handle_using_decl (tree using_decl, tree t)
1121 {
1122   tree decl = USING_DECL_DECLS (using_decl);
1123   tree name = DECL_NAME (using_decl);
1124   tree access
1125     = TREE_PRIVATE (using_decl) ? access_private_node
1126     : TREE_PROTECTED (using_decl) ? access_protected_node
1127     : access_public_node;
1128   tree flist = NULL_TREE;
1129   tree old_value;
1130
1131   gcc_assert (!processing_template_decl && decl);
1132
1133   old_value = lookup_member (t, name, /*protect=*/0, /*want_type=*/false);
1134   if (old_value)
1135     {
1136       if (is_overloaded_fn (old_value))
1137         old_value = OVL_CURRENT (old_value);
1138
1139       if (DECL_P (old_value) && DECL_CONTEXT (old_value) == t)
1140         /* OK */;
1141       else
1142         old_value = NULL_TREE;
1143     }
1144
1145   cp_emit_debug_info_for_using (decl, current_class_type);
1146
1147   if (is_overloaded_fn (decl))
1148     flist = decl;
1149
1150   if (! old_value)
1151     ;
1152   else if (is_overloaded_fn (old_value))
1153     {
1154       if (flist)
1155         /* It's OK to use functions from a base when there are functions with
1156            the same name already present in the current class.  */;
1157       else
1158         {
1159           error ("%q+D invalid in %q#T", using_decl, t);
1160           error ("  because of local method %q+#D with same name",
1161                  OVL_CURRENT (old_value));
1162           return;
1163         }
1164     }
1165   else if (!DECL_ARTIFICIAL (old_value))
1166     {
1167       error ("%q+D invalid in %q#T", using_decl, t);
1168       error ("  because of local member %q+#D with same name", old_value);
1169       return;
1170     }
1171
1172   /* Make type T see field decl FDECL with access ACCESS.  */
1173   if (flist)
1174     for (; flist; flist = OVL_NEXT (flist))
1175       {
1176         add_method (t, OVL_CURRENT (flist), using_decl);
1177         alter_access (t, OVL_CURRENT (flist), access);
1178       }
1179   else
1180     alter_access (t, decl, access);
1181 }
1182 \f
1183 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1184    and NO_CONST_ASN_REF_P.  Also set flag bits in T based on
1185    properties of the bases.  */
1186
1187 static void
1188 check_bases (tree t,
1189              int* cant_have_const_ctor_p,
1190              int* no_const_asn_ref_p)
1191 {
1192   int i;
1193   int seen_non_virtual_nearly_empty_base_p;
1194   tree base_binfo;
1195   tree binfo;
1196
1197   seen_non_virtual_nearly_empty_base_p = 0;
1198
1199   for (binfo = TYPE_BINFO (t), i = 0;
1200        BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
1201     {
1202       tree basetype = TREE_TYPE (base_binfo);
1203
1204       gcc_assert (COMPLETE_TYPE_P (basetype));
1205
1206       /* Effective C++ rule 14.  We only need to check TYPE_POLYMORPHIC_P
1207          here because the case of virtual functions but non-virtual
1208          dtor is handled in finish_struct_1.  */
1209       if (warn_ecpp && ! TYPE_POLYMORPHIC_P (basetype))
1210         warning (0, "base class %q#T has a non-virtual destructor", basetype);
1211
1212       /* If the base class doesn't have copy constructors or
1213          assignment operators that take const references, then the
1214          derived class cannot have such a member automatically
1215          generated.  */
1216       if (! TYPE_HAS_CONST_INIT_REF (basetype))
1217         *cant_have_const_ctor_p = 1;
1218       if (TYPE_HAS_ASSIGN_REF (basetype)
1219           && !TYPE_HAS_CONST_ASSIGN_REF (basetype))
1220         *no_const_asn_ref_p = 1;
1221
1222       if (BINFO_VIRTUAL_P (base_binfo))
1223         /* A virtual base does not effect nearly emptiness.  */
1224         ;
1225       else if (CLASSTYPE_NEARLY_EMPTY_P (basetype))
1226         {
1227           if (seen_non_virtual_nearly_empty_base_p)
1228             /* And if there is more than one nearly empty base, then the
1229                derived class is not nearly empty either.  */
1230             CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1231           else
1232             /* Remember we've seen one.  */
1233             seen_non_virtual_nearly_empty_base_p = 1;
1234         }
1235       else if (!is_empty_class (basetype))
1236         /* If the base class is not empty or nearly empty, then this
1237            class cannot be nearly empty.  */
1238         CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1239
1240       /* A lot of properties from the bases also apply to the derived
1241          class.  */
1242       TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (basetype);
1243       TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
1244         |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype);
1245       TYPE_HAS_COMPLEX_ASSIGN_REF (t)
1246         |= TYPE_HAS_COMPLEX_ASSIGN_REF (basetype);
1247       TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (basetype);
1248       TYPE_POLYMORPHIC_P (t) |= TYPE_POLYMORPHIC_P (basetype);
1249       CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t)
1250         |= CLASSTYPE_CONTAINS_EMPTY_CLASS_P (basetype);
1251     }
1252 }
1253
1254 /* Determine all the primary bases within T.  Sets BINFO_PRIMARY_BASE_P for
1255    those that are primaries.  Sets BINFO_LOST_PRIMARY_P for those
1256    that have had a nearly-empty virtual primary base stolen by some
1257    other base in the hierarchy.  Determines CLASSTYPE_PRIMARY_BASE for
1258    T.  */
1259
1260 static void
1261 determine_primary_bases (tree t)
1262 {
1263   unsigned i;
1264   tree primary = NULL_TREE;
1265   tree type_binfo = TYPE_BINFO (t);
1266   tree base_binfo;
1267
1268   /* Determine the primary bases of our bases.  */
1269   for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1270        base_binfo = TREE_CHAIN (base_binfo))
1271     {
1272       tree primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (base_binfo));
1273
1274       /* See if we're the non-virtual primary of our inheritance
1275          chain.  */
1276       if (!BINFO_VIRTUAL_P (base_binfo))
1277         {
1278           tree parent = BINFO_INHERITANCE_CHAIN (base_binfo);
1279           tree parent_primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (parent));
1280
1281           if (parent_primary
1282               && SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo),
1283                                     BINFO_TYPE (parent_primary)))
1284             /* We are the primary binfo.  */
1285             BINFO_PRIMARY_P (base_binfo) = 1;
1286         }
1287       /* Determine if we have a virtual primary base, and mark it so.
1288        */
1289       if (primary && BINFO_VIRTUAL_P (primary))
1290         {
1291           tree this_primary = copied_binfo (primary, base_binfo);
1292
1293           if (BINFO_PRIMARY_P (this_primary))
1294             /* Someone already claimed this base.  */
1295             BINFO_LOST_PRIMARY_P (base_binfo) = 1;
1296           else
1297             {
1298               tree delta;
1299
1300               BINFO_PRIMARY_P (this_primary) = 1;
1301               BINFO_INHERITANCE_CHAIN (this_primary) = base_binfo;
1302
1303               /* A virtual binfo might have been copied from within
1304                  another hierarchy. As we're about to use it as a
1305                  primary base, make sure the offsets match.  */
1306               delta = size_diffop (convert (ssizetype,
1307                                             BINFO_OFFSET (base_binfo)),
1308                                    convert (ssizetype,
1309                                             BINFO_OFFSET (this_primary)));
1310
1311               propagate_binfo_offsets (this_primary, delta);
1312             }
1313         }
1314     }
1315
1316   /* First look for a dynamic direct non-virtual base.  */
1317   for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, base_binfo); i++)
1318     {
1319       tree basetype = BINFO_TYPE (base_binfo);
1320
1321       if (TYPE_CONTAINS_VPTR_P (basetype) && !BINFO_VIRTUAL_P (base_binfo))
1322         {
1323           primary = base_binfo;
1324           goto found;
1325         }
1326     }
1327
1328   /* A "nearly-empty" virtual base class can be the primary base
1329      class, if no non-virtual polymorphic base can be found.  Look for
1330      a nearly-empty virtual dynamic base that is not already a primary
1331      base of something in the hierarchy.  If there is no such base,
1332      just pick the first nearly-empty virtual base.  */
1333
1334   for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1335        base_binfo = TREE_CHAIN (base_binfo))
1336     if (BINFO_VIRTUAL_P (base_binfo)
1337         && CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (base_binfo)))
1338       {
1339         if (!BINFO_PRIMARY_P (base_binfo))
1340           {
1341             /* Found one that is not primary.  */
1342             primary = base_binfo;
1343             goto found;
1344           }
1345         else if (!primary)
1346           /* Remember the first candidate.  */
1347           primary = base_binfo;
1348       }
1349
1350  found:
1351   /* If we've got a primary base, use it.  */
1352   if (primary)
1353     {
1354       tree basetype = BINFO_TYPE (primary);
1355
1356       CLASSTYPE_PRIMARY_BINFO (t) = primary;
1357       if (BINFO_PRIMARY_P (primary))
1358         /* We are stealing a primary base.  */
1359         BINFO_LOST_PRIMARY_P (BINFO_INHERITANCE_CHAIN (primary)) = 1;
1360       BINFO_PRIMARY_P (primary) = 1;
1361       if (BINFO_VIRTUAL_P (primary))
1362         {
1363           tree delta;
1364
1365           BINFO_INHERITANCE_CHAIN (primary) = type_binfo;
1366           /* A virtual binfo might have been copied from within
1367              another hierarchy. As we're about to use it as a primary
1368              base, make sure the offsets match.  */
1369           delta = size_diffop (ssize_int (0),
1370                                convert (ssizetype, BINFO_OFFSET (primary)));
1371
1372           propagate_binfo_offsets (primary, delta);
1373         }
1374
1375       primary = TYPE_BINFO (basetype);
1376
1377       TYPE_VFIELD (t) = TYPE_VFIELD (basetype);
1378       BINFO_VTABLE (type_binfo) = BINFO_VTABLE (primary);
1379       BINFO_VIRTUALS (type_binfo) = BINFO_VIRTUALS (primary);
1380     }
1381 }
1382 \f
1383 /* Set memoizing fields and bits of T (and its variants) for later
1384    use.  */
1385
1386 static void
1387 finish_struct_bits (tree t)
1388 {
1389   tree variants;
1390
1391   /* Fix up variants (if any).  */
1392   for (variants = TYPE_NEXT_VARIANT (t);
1393        variants;
1394        variants = TYPE_NEXT_VARIANT (variants))
1395     {
1396       /* These fields are in the _TYPE part of the node, not in
1397          the TYPE_LANG_SPECIFIC component, so they are not shared.  */
1398       TYPE_HAS_CONSTRUCTOR (variants) = TYPE_HAS_CONSTRUCTOR (t);
1399       TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t);
1400       TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variants)
1401         = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
1402
1403       TYPE_POLYMORPHIC_P (variants) = TYPE_POLYMORPHIC_P (t);
1404
1405       TYPE_BINFO (variants) = TYPE_BINFO (t);
1406
1407       /* Copy whatever these are holding today.  */
1408       TYPE_VFIELD (variants) = TYPE_VFIELD (t);
1409       TYPE_METHODS (variants) = TYPE_METHODS (t);
1410       TYPE_FIELDS (variants) = TYPE_FIELDS (t);
1411       TYPE_SIZE (variants) = TYPE_SIZE (t);
1412       TYPE_SIZE_UNIT (variants) = TYPE_SIZE_UNIT (t);
1413     }
1414
1415   if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) && TYPE_POLYMORPHIC_P (t))
1416     /* For a class w/o baseclasses, 'finish_struct' has set
1417        CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1418        Similarly for a class whose base classes do not have vtables.
1419        When neither of these is true, we might have removed abstract
1420        virtuals (by providing a definition), added some (by declaring
1421        new ones), or redeclared ones from a base class.  We need to
1422        recalculate what's really an abstract virtual at this point (by
1423        looking in the vtables).  */
1424     get_pure_virtuals (t);
1425
1426   /* If this type has a copy constructor or a destructor, force its
1427      mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1428      nonzero.  This will cause it to be passed by invisible reference
1429      and prevent it from being returned in a register.  */
1430   if (! TYPE_HAS_TRIVIAL_INIT_REF (t) || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
1431     {
1432       tree variants;
1433       DECL_MODE (TYPE_MAIN_DECL (t)) = BLKmode;
1434       for (variants = t; variants; variants = TYPE_NEXT_VARIANT (variants))
1435         {
1436           TYPE_MODE (variants) = BLKmode;
1437           TREE_ADDRESSABLE (variants) = 1;
1438         }
1439     }
1440 }
1441
1442 /* Issue warnings about T having private constructors, but no friends,
1443    and so forth.
1444
1445    HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1446    static members.  HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1447    non-private static member functions.  */
1448
1449 static void
1450 maybe_warn_about_overly_private_class (tree t)
1451 {
1452   int has_member_fn = 0;
1453   int has_nonprivate_method = 0;
1454   tree fn;
1455
1456   if (!warn_ctor_dtor_privacy
1457       /* If the class has friends, those entities might create and
1458          access instances, so we should not warn.  */
1459       || (CLASSTYPE_FRIEND_CLASSES (t)
1460           || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))
1461       /* We will have warned when the template was declared; there's
1462          no need to warn on every instantiation.  */
1463       || CLASSTYPE_TEMPLATE_INSTANTIATION (t))
1464     /* There's no reason to even consider warning about this
1465        class.  */
1466     return;
1467
1468   /* We only issue one warning, if more than one applies, because
1469      otherwise, on code like:
1470
1471      class A {
1472        // Oops - forgot `public:'
1473        A();
1474        A(const A&);
1475        ~A();
1476      };
1477
1478      we warn several times about essentially the same problem.  */
1479
1480   /* Check to see if all (non-constructor, non-destructor) member
1481      functions are private.  (Since there are no friends or
1482      non-private statics, we can't ever call any of the private member
1483      functions.)  */
1484   for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
1485     /* We're not interested in compiler-generated methods; they don't
1486        provide any way to call private members.  */
1487     if (!DECL_ARTIFICIAL (fn))
1488       {
1489         if (!TREE_PRIVATE (fn))
1490           {
1491             if (DECL_STATIC_FUNCTION_P (fn))
1492               /* A non-private static member function is just like a
1493                  friend; it can create and invoke private member
1494                  functions, and be accessed without a class
1495                  instance.  */
1496               return;
1497
1498             has_nonprivate_method = 1;
1499             /* Keep searching for a static member function.  */
1500           }
1501         else if (!DECL_CONSTRUCTOR_P (fn) && !DECL_DESTRUCTOR_P (fn))
1502           has_member_fn = 1;
1503       }
1504
1505   if (!has_nonprivate_method && has_member_fn)
1506     {
1507       /* There are no non-private methods, and there's at least one
1508          private member function that isn't a constructor or
1509          destructor.  (If all the private members are
1510          constructors/destructors we want to use the code below that
1511          issues error messages specifically referring to
1512          constructors/destructors.)  */
1513       unsigned i;
1514       tree binfo = TYPE_BINFO (t);
1515
1516       for (i = 0; i != BINFO_N_BASE_BINFOS (binfo); i++)
1517         if (BINFO_BASE_ACCESS (binfo, i) != access_private_node)
1518           {
1519             has_nonprivate_method = 1;
1520             break;
1521           }
1522       if (!has_nonprivate_method)
1523         {
1524           warning (0, "all member functions in class %qT are private", t);
1525           return;
1526         }
1527     }
1528
1529   /* Even if some of the member functions are non-private, the class
1530      won't be useful for much if all the constructors or destructors
1531      are private: such an object can never be created or destroyed.  */
1532   fn = CLASSTYPE_DESTRUCTORS (t);
1533   if (fn && TREE_PRIVATE (fn))
1534     {
1535       warning (0, "%q#T only defines a private destructor and has no friends",
1536                t);
1537       return;
1538     }
1539
1540   if (TYPE_HAS_CONSTRUCTOR (t))
1541     {
1542       int nonprivate_ctor = 0;
1543
1544       /* If a non-template class does not define a copy
1545          constructor, one is defined for it, enabling it to avoid
1546          this warning.  For a template class, this does not
1547          happen, and so we would normally get a warning on:
1548
1549            template <class T> class C { private: C(); };
1550
1551          To avoid this asymmetry, we check TYPE_HAS_INIT_REF.  All
1552          complete non-template or fully instantiated classes have this
1553          flag set.  */
1554       if (!TYPE_HAS_INIT_REF (t))
1555         nonprivate_ctor = 1;
1556       else
1557         for (fn = CLASSTYPE_CONSTRUCTORS (t); fn; fn = OVL_NEXT (fn))
1558           {
1559             tree ctor = OVL_CURRENT (fn);
1560             /* Ideally, we wouldn't count copy constructors (or, in
1561                fact, any constructor that takes an argument of the
1562                class type as a parameter) because such things cannot
1563                be used to construct an instance of the class unless
1564                you already have one.  But, for now at least, we're
1565                more generous.  */
1566             if (! TREE_PRIVATE (ctor))
1567               {
1568                 nonprivate_ctor = 1;
1569                 break;
1570               }
1571           }
1572
1573       if (nonprivate_ctor == 0)
1574         {
1575           warning (0, "%q#T only defines private constructors and has no friends",
1576                    t);
1577           return;
1578         }
1579     }
1580 }
1581
1582 static struct {
1583   gt_pointer_operator new_value;
1584   void *cookie;
1585 } resort_data;
1586
1587 /* Comparison function to compare two TYPE_METHOD_VEC entries by name.  */
1588
1589 static int
1590 method_name_cmp (const void* m1_p, const void* m2_p)
1591 {
1592   const tree *const m1 = m1_p;
1593   const tree *const m2 = m2_p;
1594
1595   if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1596     return 0;
1597   if (*m1 == NULL_TREE)
1598     return -1;
1599   if (*m2 == NULL_TREE)
1600     return 1;
1601   if (DECL_NAME (OVL_CURRENT (*m1)) < DECL_NAME (OVL_CURRENT (*m2)))
1602     return -1;
1603   return 1;
1604 }
1605
1606 /* This routine compares two fields like method_name_cmp but using the
1607    pointer operator in resort_field_decl_data.  */
1608
1609 static int
1610 resort_method_name_cmp (const void* m1_p, const void* m2_p)
1611 {
1612   const tree *const m1 = m1_p;
1613   const tree *const m2 = m2_p;
1614   if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1615     return 0;
1616   if (*m1 == NULL_TREE)
1617     return -1;
1618   if (*m2 == NULL_TREE)
1619     return 1;
1620   {
1621     tree d1 = DECL_NAME (OVL_CURRENT (*m1));
1622     tree d2 = DECL_NAME (OVL_CURRENT (*m2));
1623     resort_data.new_value (&d1, resort_data.cookie);
1624     resort_data.new_value (&d2, resort_data.cookie);
1625     if (d1 < d2)
1626       return -1;
1627   }
1628   return 1;
1629 }
1630
1631 /* Resort TYPE_METHOD_VEC because pointers have been reordered.  */
1632
1633 void
1634 resort_type_method_vec (void* obj,
1635                         void* orig_obj ATTRIBUTE_UNUSED ,
1636                         gt_pointer_operator new_value,
1637                         void* cookie)
1638 {
1639   VEC(tree,gc) *method_vec = (VEC(tree,gc) *) obj;
1640   int len = VEC_length (tree, method_vec);
1641   size_t slot;
1642   tree fn;
1643
1644   /* The type conversion ops have to live at the front of the vec, so we
1645      can't sort them.  */
1646   for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1647        VEC_iterate (tree, method_vec, slot, fn);
1648        ++slot)
1649     if (!DECL_CONV_FN_P (OVL_CURRENT (fn)))
1650       break;
1651
1652   if (len - slot > 1)
1653     {
1654       resort_data.new_value = new_value;
1655       resort_data.cookie = cookie;
1656       qsort (VEC_address (tree, method_vec) + slot, len - slot, sizeof (tree),
1657              resort_method_name_cmp);
1658     }
1659 }
1660
1661 /* Warn about duplicate methods in fn_fields.
1662
1663    Sort methods that are not special (i.e., constructors, destructors,
1664    and type conversion operators) so that we can find them faster in
1665    search.  */
1666
1667 static void
1668 finish_struct_methods (tree t)
1669 {
1670   tree fn_fields;
1671   VEC(tree,gc) *method_vec;
1672   int slot, len;
1673
1674   method_vec = CLASSTYPE_METHOD_VEC (t);
1675   if (!method_vec)
1676     return;
1677
1678   len = VEC_length (tree, method_vec);
1679
1680   /* Clear DECL_IN_AGGR_P for all functions.  */
1681   for (fn_fields = TYPE_METHODS (t); fn_fields;
1682        fn_fields = TREE_CHAIN (fn_fields))
1683     DECL_IN_AGGR_P (fn_fields) = 0;
1684
1685   /* Issue warnings about private constructors and such.  If there are
1686      no methods, then some public defaults are generated.  */
1687   maybe_warn_about_overly_private_class (t);
1688
1689   /* The type conversion ops have to live at the front of the vec, so we
1690      can't sort them.  */
1691   for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1692        VEC_iterate (tree, method_vec, slot, fn_fields);
1693        ++slot)
1694     if (!DECL_CONV_FN_P (OVL_CURRENT (fn_fields)))
1695       break;
1696   if (len - slot > 1)
1697     qsort (VEC_address (tree, method_vec) + slot,
1698            len-slot, sizeof (tree), method_name_cmp);
1699 }
1700
1701 /* Make BINFO's vtable have N entries, including RTTI entries,
1702    vbase and vcall offsets, etc.  Set its type and call the backend
1703    to lay it out.  */
1704
1705 static void
1706 layout_vtable_decl (tree binfo, int n)
1707 {
1708   tree atype;
1709   tree vtable;
1710
1711   atype = build_cplus_array_type (vtable_entry_type,
1712                                   build_index_type (size_int (n - 1)));
1713   layout_type (atype);
1714
1715   /* We may have to grow the vtable.  */
1716   vtable = get_vtbl_decl_for_binfo (binfo);
1717   if (!same_type_p (TREE_TYPE (vtable), atype))
1718     {
1719       TREE_TYPE (vtable) = atype;
1720       DECL_SIZE (vtable) = DECL_SIZE_UNIT (vtable) = NULL_TREE;
1721       layout_decl (vtable, 0);
1722     }
1723 }
1724
1725 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1726    have the same signature.  */
1727
1728 int
1729 same_signature_p (tree fndecl, tree base_fndecl)
1730 {
1731   /* One destructor overrides another if they are the same kind of
1732      destructor.  */
1733   if (DECL_DESTRUCTOR_P (base_fndecl) && DECL_DESTRUCTOR_P (fndecl)
1734       && special_function_p (base_fndecl) == special_function_p (fndecl))
1735     return 1;
1736   /* But a non-destructor never overrides a destructor, nor vice
1737      versa, nor do different kinds of destructors override
1738      one-another.  For example, a complete object destructor does not
1739      override a deleting destructor.  */
1740   if (DECL_DESTRUCTOR_P (base_fndecl) || DECL_DESTRUCTOR_P (fndecl))
1741     return 0;
1742
1743   if (DECL_NAME (fndecl) == DECL_NAME (base_fndecl)
1744       || (DECL_CONV_FN_P (fndecl)
1745           && DECL_CONV_FN_P (base_fndecl)
1746           && same_type_p (DECL_CONV_FN_TYPE (fndecl),
1747                           DECL_CONV_FN_TYPE (base_fndecl))))
1748     {
1749       tree types, base_types;
1750       types = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
1751       base_types = TYPE_ARG_TYPES (TREE_TYPE (base_fndecl));
1752       if ((TYPE_QUALS (TREE_TYPE (TREE_VALUE (base_types)))
1753            == TYPE_QUALS (TREE_TYPE (TREE_VALUE (types))))
1754           && compparms (TREE_CHAIN (base_types), TREE_CHAIN (types)))
1755         return 1;
1756     }
1757   return 0;
1758 }
1759
1760 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1761    subobject.  */
1762
1763 static bool
1764 base_derived_from (tree derived, tree base)
1765 {
1766   tree probe;
1767
1768   for (probe = base; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
1769     {
1770       if (probe == derived)
1771         return true;
1772       else if (BINFO_VIRTUAL_P (probe))
1773         /* If we meet a virtual base, we can't follow the inheritance
1774            any more.  See if the complete type of DERIVED contains
1775            such a virtual base.  */
1776         return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (derived))
1777                 != NULL_TREE);
1778     }
1779   return false;
1780 }
1781
1782 typedef struct find_final_overrider_data_s {
1783   /* The function for which we are trying to find a final overrider.  */
1784   tree fn;
1785   /* The base class in which the function was declared.  */
1786   tree declaring_base;
1787   /* The candidate overriders.  */
1788   tree candidates;
1789   /* Path to most derived.  */
1790   VEC(tree,heap) *path;
1791 } find_final_overrider_data;
1792
1793 /* Add the overrider along the current path to FFOD->CANDIDATES.
1794    Returns true if an overrider was found; false otherwise.  */
1795
1796 static bool
1797 dfs_find_final_overrider_1 (tree binfo,
1798                             find_final_overrider_data *ffod,
1799                             unsigned depth)
1800 {
1801   tree method;
1802
1803   /* If BINFO is not the most derived type, try a more derived class.
1804      A definition there will overrider a definition here.  */
1805   if (depth)
1806     {
1807       depth--;
1808       if (dfs_find_final_overrider_1
1809           (VEC_index (tree, ffod->path, depth), ffod, depth))
1810         return true;
1811     }
1812
1813   method = look_for_overrides_here (BINFO_TYPE (binfo), ffod->fn);
1814   if (method)
1815     {
1816       tree *candidate = &ffod->candidates;
1817
1818       /* Remove any candidates overridden by this new function.  */
1819       while (*candidate)
1820         {
1821           /* If *CANDIDATE overrides METHOD, then METHOD
1822              cannot override anything else on the list.  */
1823           if (base_derived_from (TREE_VALUE (*candidate), binfo))
1824             return true;
1825           /* If METHOD overrides *CANDIDATE, remove *CANDIDATE.  */
1826           if (base_derived_from (binfo, TREE_VALUE (*candidate)))
1827             *candidate = TREE_CHAIN (*candidate);
1828           else
1829             candidate = &TREE_CHAIN (*candidate);
1830         }
1831
1832       /* Add the new function.  */
1833       ffod->candidates = tree_cons (method, binfo, ffod->candidates);
1834       return true;
1835     }
1836
1837   return false;
1838 }
1839
1840 /* Called from find_final_overrider via dfs_walk.  */
1841
1842 static tree
1843 dfs_find_final_overrider_pre (tree binfo, void *data)
1844 {
1845   find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1846
1847   if (binfo == ffod->declaring_base)
1848     dfs_find_final_overrider_1 (binfo, ffod, VEC_length (tree, ffod->path));
1849   VEC_safe_push (tree, heap, ffod->path, binfo);
1850
1851   return NULL_TREE;
1852 }
1853
1854 static tree
1855 dfs_find_final_overrider_post (tree binfo ATTRIBUTE_UNUSED, void *data)
1856 {
1857   find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1858   VEC_pop (tree, ffod->path);
1859
1860   return NULL_TREE;
1861 }
1862
1863 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
1864    FN and whose TREE_VALUE is the binfo for the base where the
1865    overriding occurs.  BINFO (in the hierarchy dominated by the binfo
1866    DERIVED) is the base object in which FN is declared.  */
1867
1868 static tree
1869 find_final_overrider (tree derived, tree binfo, tree fn)
1870 {
1871   find_final_overrider_data ffod;
1872
1873   /* Getting this right is a little tricky.  This is valid:
1874
1875        struct S { virtual void f (); };
1876        struct T { virtual void f (); };
1877        struct U : public S, public T { };
1878
1879      even though calling `f' in `U' is ambiguous.  But,
1880
1881        struct R { virtual void f(); };
1882        struct S : virtual public R { virtual void f (); };
1883        struct T : virtual public R { virtual void f (); };
1884        struct U : public S, public T { };
1885
1886      is not -- there's no way to decide whether to put `S::f' or
1887      `T::f' in the vtable for `R'.
1888
1889      The solution is to look at all paths to BINFO.  If we find
1890      different overriders along any two, then there is a problem.  */
1891   if (DECL_THUNK_P (fn))
1892     fn = THUNK_TARGET (fn);
1893
1894   /* Determine the depth of the hierarchy.  */
1895   ffod.fn = fn;
1896   ffod.declaring_base = binfo;
1897   ffod.candidates = NULL_TREE;
1898   ffod.path = VEC_alloc (tree, heap, 30);
1899
1900   dfs_walk_all (derived, dfs_find_final_overrider_pre,
1901                 dfs_find_final_overrider_post, &ffod);
1902
1903   VEC_free (tree, heap, ffod.path);
1904
1905   /* If there was no winner, issue an error message.  */
1906   if (!ffod.candidates || TREE_CHAIN (ffod.candidates))
1907     {
1908       error ("no unique final overrider for %qD in %qT", fn,
1909              BINFO_TYPE (derived));
1910       return error_mark_node;
1911     }
1912
1913   return ffod.candidates;
1914 }
1915
1916 /* Return the index of the vcall offset for FN when TYPE is used as a
1917    virtual base.  */
1918
1919 static tree
1920 get_vcall_index (tree fn, tree type)
1921 {
1922   VEC(tree_pair_s,gc) *indices = CLASSTYPE_VCALL_INDICES (type);
1923   tree_pair_p p;
1924   unsigned ix;
1925
1926   for (ix = 0; VEC_iterate (tree_pair_s, indices, ix, p); ix++)
1927     if ((DECL_DESTRUCTOR_P (fn) && DECL_DESTRUCTOR_P (p->purpose))
1928         || same_signature_p (fn, p->purpose))
1929       return p->value;
1930
1931   /* There should always be an appropriate index.  */
1932   gcc_unreachable ();
1933 }
1934
1935 /* Update an entry in the vtable for BINFO, which is in the hierarchy
1936    dominated by T.  FN has been overridden in BINFO; VIRTUALS points to the
1937    corresponding position in the BINFO_VIRTUALS list.  */
1938
1939 static void
1940 update_vtable_entry_for_fn (tree t, tree binfo, tree fn, tree* virtuals,
1941                             unsigned ix)
1942 {
1943   tree b;
1944   tree overrider;
1945   tree delta;
1946   tree virtual_base;
1947   tree first_defn;
1948   tree overrider_fn, overrider_target;
1949   tree target_fn = DECL_THUNK_P (fn) ? THUNK_TARGET (fn) : fn;
1950   tree over_return, base_return;
1951   bool lost = false;
1952
1953   /* Find the nearest primary base (possibly binfo itself) which defines
1954      this function; this is the class the caller will convert to when
1955      calling FN through BINFO.  */
1956   for (b = binfo; ; b = get_primary_binfo (b))
1957     {
1958       gcc_assert (b);
1959       if (look_for_overrides_here (BINFO_TYPE (b), target_fn))
1960         break;
1961
1962       /* The nearest definition is from a lost primary.  */
1963       if (BINFO_LOST_PRIMARY_P (b))
1964         lost = true;
1965     }
1966   first_defn = b;
1967
1968   /* Find the final overrider.  */
1969   overrider = find_final_overrider (TYPE_BINFO (t), b, target_fn);
1970   if (overrider == error_mark_node)
1971     return;
1972   overrider_target = overrider_fn = TREE_PURPOSE (overrider);
1973
1974   /* Check for adjusting covariant return types.  */
1975   over_return = TREE_TYPE (TREE_TYPE (overrider_target));
1976   base_return = TREE_TYPE (TREE_TYPE (target_fn));
1977
1978   if (POINTER_TYPE_P (over_return)
1979       && TREE_CODE (over_return) == TREE_CODE (base_return)
1980       && CLASS_TYPE_P (TREE_TYPE (over_return))
1981       && CLASS_TYPE_P (TREE_TYPE (base_return)))
1982     {
1983       /* If FN is a covariant thunk, we must figure out the adjustment
1984          to the final base FN was converting to. As OVERRIDER_TARGET might
1985          also be converting to the return type of FN, we have to
1986          combine the two conversions here.  */
1987       tree fixed_offset, virtual_offset;
1988
1989       over_return = TREE_TYPE (over_return);
1990       base_return = TREE_TYPE (base_return);
1991
1992       if (DECL_THUNK_P (fn))
1993         {
1994           gcc_assert (DECL_RESULT_THUNK_P (fn));
1995           fixed_offset = ssize_int (THUNK_FIXED_OFFSET (fn));
1996           virtual_offset = THUNK_VIRTUAL_OFFSET (fn);
1997         }
1998       else
1999         fixed_offset = virtual_offset = NULL_TREE;
2000
2001       if (virtual_offset)
2002         /* Find the equivalent binfo within the return type of the
2003            overriding function. We will want the vbase offset from
2004            there.  */
2005         virtual_offset = binfo_for_vbase (BINFO_TYPE (virtual_offset),
2006                                           over_return);
2007       else if (!same_type_ignoring_top_level_qualifiers_p
2008                (over_return, base_return))
2009         {
2010           /* There was no existing virtual thunk (which takes
2011              precedence).  So find the binfo of the base function's
2012              return type within the overriding function's return type.
2013              We cannot call lookup base here, because we're inside a
2014              dfs_walk, and will therefore clobber the BINFO_MARKED
2015              flags.  Fortunately we know the covariancy is valid (it
2016              has already been checked), so we can just iterate along
2017              the binfos, which have been chained in inheritance graph
2018              order.  Of course it is lame that we have to repeat the
2019              search here anyway -- we should really be caching pieces
2020              of the vtable and avoiding this repeated work.  */
2021           tree thunk_binfo, base_binfo;
2022
2023           /* Find the base binfo within the overriding function's
2024              return type.  We will always find a thunk_binfo, except
2025              when the covariancy is invalid (which we will have
2026              already diagnosed).  */
2027           for (base_binfo = TYPE_BINFO (base_return),
2028                thunk_binfo = TYPE_BINFO (over_return);
2029                thunk_binfo;
2030                thunk_binfo = TREE_CHAIN (thunk_binfo))
2031             if (SAME_BINFO_TYPE_P (BINFO_TYPE (thunk_binfo),
2032                                    BINFO_TYPE (base_binfo)))
2033               break;
2034
2035           /* See if virtual inheritance is involved.  */
2036           for (virtual_offset = thunk_binfo;
2037                virtual_offset;
2038                virtual_offset = BINFO_INHERITANCE_CHAIN (virtual_offset))
2039             if (BINFO_VIRTUAL_P (virtual_offset))
2040               break;
2041
2042           if (virtual_offset
2043               || (thunk_binfo && !BINFO_OFFSET_ZEROP (thunk_binfo)))
2044             {
2045               tree offset = convert (ssizetype, BINFO_OFFSET (thunk_binfo));
2046
2047               if (virtual_offset)
2048                 {
2049                   /* We convert via virtual base.  Adjust the fixed
2050                      offset to be from there.  */
2051                   offset = size_diffop
2052                     (offset, convert
2053                      (ssizetype, BINFO_OFFSET (virtual_offset)));
2054                 }
2055               if (fixed_offset)
2056                 /* There was an existing fixed offset, this must be
2057                    from the base just converted to, and the base the
2058                    FN was thunking to.  */
2059                 fixed_offset = size_binop (PLUS_EXPR, fixed_offset, offset);
2060               else
2061                 fixed_offset = offset;
2062             }
2063         }
2064
2065       if (fixed_offset || virtual_offset)
2066         /* Replace the overriding function with a covariant thunk.  We
2067            will emit the overriding function in its own slot as
2068            well.  */
2069         overrider_fn = make_thunk (overrider_target, /*this_adjusting=*/0,
2070                                    fixed_offset, virtual_offset);
2071     }
2072   else
2073     gcc_assert (!DECL_THUNK_P (fn));
2074
2075   /* Assume that we will produce a thunk that convert all the way to
2076      the final overrider, and not to an intermediate virtual base.  */
2077   virtual_base = NULL_TREE;
2078
2079   /* See if we can convert to an intermediate virtual base first, and then
2080      use the vcall offset located there to finish the conversion.  */
2081   for (; b; b = BINFO_INHERITANCE_CHAIN (b))
2082     {
2083       /* If we find the final overrider, then we can stop
2084          walking.  */
2085       if (SAME_BINFO_TYPE_P (BINFO_TYPE (b),
2086                              BINFO_TYPE (TREE_VALUE (overrider))))
2087         break;
2088
2089       /* If we find a virtual base, and we haven't yet found the
2090          overrider, then there is a virtual base between the
2091          declaring base (first_defn) and the final overrider.  */
2092       if (BINFO_VIRTUAL_P (b))
2093         {
2094           virtual_base = b;
2095           break;
2096         }
2097     }
2098
2099   if (overrider_fn != overrider_target && !virtual_base)
2100     {
2101       /* The ABI specifies that a covariant thunk includes a mangling
2102          for a this pointer adjustment.  This-adjusting thunks that
2103          override a function from a virtual base have a vcall
2104          adjustment.  When the virtual base in question is a primary
2105          virtual base, we know the adjustments are zero, (and in the
2106          non-covariant case, we would not use the thunk).
2107          Unfortunately we didn't notice this could happen, when
2108          designing the ABI and so never mandated that such a covariant
2109          thunk should be emitted.  Because we must use the ABI mandated
2110          name, we must continue searching from the binfo where we
2111          found the most recent definition of the function, towards the
2112          primary binfo which first introduced the function into the
2113          vtable.  If that enters a virtual base, we must use a vcall
2114          this-adjusting thunk.  Bleah! */
2115       tree probe = first_defn;
2116
2117       while ((probe = get_primary_binfo (probe))
2118              && (unsigned) list_length (BINFO_VIRTUALS (probe)) > ix)
2119         if (BINFO_VIRTUAL_P (probe))
2120           virtual_base = probe;
2121
2122       if (virtual_base)
2123         /* Even if we find a virtual base, the correct delta is
2124            between the overrider and the binfo we're building a vtable
2125            for.  */
2126         goto virtual_covariant;
2127     }
2128
2129   /* Compute the constant adjustment to the `this' pointer.  The
2130      `this' pointer, when this function is called, will point at BINFO
2131      (or one of its primary bases, which are at the same offset).  */
2132   if (virtual_base)
2133     /* The `this' pointer needs to be adjusted from the declaration to
2134        the nearest virtual base.  */
2135     delta = size_diffop (convert (ssizetype, BINFO_OFFSET (virtual_base)),
2136                          convert (ssizetype, BINFO_OFFSET (first_defn)));
2137   else if (lost)
2138     /* If the nearest definition is in a lost primary, we don't need an
2139        entry in our vtable.  Except possibly in a constructor vtable,
2140        if we happen to get our primary back.  In that case, the offset
2141        will be zero, as it will be a primary base.  */
2142     delta = size_zero_node;
2143   else
2144     /* The `this' pointer needs to be adjusted from pointing to
2145        BINFO to pointing at the base where the final overrider
2146        appears.  */
2147     virtual_covariant:
2148     delta = size_diffop (convert (ssizetype,
2149                                   BINFO_OFFSET (TREE_VALUE (overrider))),
2150                          convert (ssizetype, BINFO_OFFSET (binfo)));
2151
2152   modify_vtable_entry (t, binfo, overrider_fn, delta, virtuals);
2153
2154   if (virtual_base)
2155     BV_VCALL_INDEX (*virtuals)
2156       = get_vcall_index (overrider_target, BINFO_TYPE (virtual_base));
2157   else
2158     BV_VCALL_INDEX (*virtuals) = NULL_TREE;
2159 }
2160
2161 /* Called from modify_all_vtables via dfs_walk.  */
2162
2163 static tree
2164 dfs_modify_vtables (tree binfo, void* data)
2165 {
2166   tree t = (tree) data;
2167   tree virtuals;
2168   tree old_virtuals;
2169   unsigned ix;
2170
2171   if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
2172     /* A base without a vtable needs no modification, and its bases
2173        are uninteresting.  */
2174     return dfs_skip_bases;
2175
2176   if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t)
2177       && !CLASSTYPE_HAS_PRIMARY_BASE_P (t))
2178     /* Don't do the primary vtable, if it's new.  */
2179     return NULL_TREE;
2180
2181   if (BINFO_PRIMARY_P (binfo) && !BINFO_VIRTUAL_P (binfo))
2182     /* There's no need to modify the vtable for a non-virtual primary
2183        base; we're not going to use that vtable anyhow.  We do still
2184        need to do this for virtual primary bases, as they could become
2185        non-primary in a construction vtable.  */
2186     return NULL_TREE;
2187
2188   make_new_vtable (t, binfo);
2189
2190   /* Now, go through each of the virtual functions in the virtual
2191      function table for BINFO.  Find the final overrider, and update
2192      the BINFO_VIRTUALS list appropriately.  */
2193   for (ix = 0, virtuals = BINFO_VIRTUALS (binfo),
2194          old_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
2195        virtuals;
2196        ix++, virtuals = TREE_CHAIN (virtuals),
2197          old_virtuals = TREE_CHAIN (old_virtuals))
2198     update_vtable_entry_for_fn (t,
2199                                 binfo,
2200                                 BV_FN (old_virtuals),
2201                                 &virtuals, ix);
2202
2203   return NULL_TREE;
2204 }
2205
2206 /* Update all of the primary and secondary vtables for T.  Create new
2207    vtables as required, and initialize their RTTI information.  Each
2208    of the functions in VIRTUALS is declared in T and may override a
2209    virtual function from a base class; find and modify the appropriate
2210    entries to point to the overriding functions.  Returns a list, in
2211    declaration order, of the virtual functions that are declared in T,
2212    but do not appear in the primary base class vtable, and which
2213    should therefore be appended to the end of the vtable for T.  */
2214
2215 static tree
2216 modify_all_vtables (tree t, tree virtuals)
2217 {
2218   tree binfo = TYPE_BINFO (t);
2219   tree *fnsp;
2220
2221   /* Update all of the vtables.  */
2222   dfs_walk_once (binfo, dfs_modify_vtables, NULL, t);
2223
2224   /* Add virtual functions not already in our primary vtable. These
2225      will be both those introduced by this class, and those overridden
2226      from secondary bases.  It does not include virtuals merely
2227      inherited from secondary bases.  */
2228   for (fnsp = &virtuals; *fnsp; )
2229     {
2230       tree fn = TREE_VALUE (*fnsp);
2231
2232       if (!value_member (fn, BINFO_VIRTUALS (binfo))
2233           || DECL_VINDEX (fn) == error_mark_node)
2234         {
2235           /* We don't need to adjust the `this' pointer when
2236              calling this function.  */
2237           BV_DELTA (*fnsp) = integer_zero_node;
2238           BV_VCALL_INDEX (*fnsp) = NULL_TREE;
2239
2240           /* This is a function not already in our vtable.  Keep it.  */
2241           fnsp = &TREE_CHAIN (*fnsp);
2242         }
2243       else
2244         /* We've already got an entry for this function.  Skip it.  */
2245         *fnsp = TREE_CHAIN (*fnsp);
2246     }
2247
2248   return virtuals;
2249 }
2250
2251 /* Get the base virtual function declarations in T that have the
2252    indicated NAME.  */
2253
2254 static tree
2255 get_basefndecls (tree name, tree t)
2256 {
2257   tree methods;
2258   tree base_fndecls = NULL_TREE;
2259   int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
2260   int i;
2261
2262   /* Find virtual functions in T with the indicated NAME.  */
2263   i = lookup_fnfields_1 (t, name);
2264   if (i != -1)
2265     for (methods = VEC_index (tree, CLASSTYPE_METHOD_VEC (t), i);
2266          methods;
2267          methods = OVL_NEXT (methods))
2268       {
2269         tree method = OVL_CURRENT (methods);
2270
2271         if (TREE_CODE (method) == FUNCTION_DECL
2272             && DECL_VINDEX (method))
2273           base_fndecls = tree_cons (NULL_TREE, method, base_fndecls);
2274       }
2275
2276   if (base_fndecls)
2277     return base_fndecls;
2278
2279   for (i = 0; i < n_baseclasses; i++)
2280     {
2281       tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (t), i));
2282       base_fndecls = chainon (get_basefndecls (name, basetype),
2283                               base_fndecls);
2284     }
2285
2286   return base_fndecls;
2287 }
2288
2289 /* If this declaration supersedes the declaration of
2290    a method declared virtual in the base class, then
2291    mark this field as being virtual as well.  */
2292
2293 void
2294 check_for_override (tree decl, tree ctype)
2295 {
2296   if (TREE_CODE (decl) == TEMPLATE_DECL)
2297     /* In [temp.mem] we have:
2298
2299          A specialization of a member function template does not
2300          override a virtual function from a base class.  */
2301     return;
2302   if ((DECL_DESTRUCTOR_P (decl)
2303        || IDENTIFIER_VIRTUAL_P (DECL_NAME (decl))
2304        || DECL_CONV_FN_P (decl))
2305       && look_for_overrides (ctype, decl)
2306       && !DECL_STATIC_FUNCTION_P (decl))
2307     /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2308        the error_mark_node so that we know it is an overriding
2309        function.  */
2310     DECL_VINDEX (decl) = decl;
2311
2312   if (DECL_VIRTUAL_P (decl))
2313     {
2314       if (!DECL_VINDEX (decl))
2315         DECL_VINDEX (decl) = error_mark_node;
2316       IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) = 1;
2317     }
2318 }
2319
2320 /* Warn about hidden virtual functions that are not overridden in t.
2321    We know that constructors and destructors don't apply.  */
2322
2323 void
2324 warn_hidden (tree t)
2325 {
2326   VEC(tree,gc) *method_vec = CLASSTYPE_METHOD_VEC (t);
2327   tree fns;
2328   size_t i;
2329
2330   /* We go through each separately named virtual function.  */
2331   for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
2332        VEC_iterate (tree, method_vec, i, fns);
2333        ++i)
2334     {
2335       tree fn;
2336       tree name;
2337       tree fndecl;
2338       tree base_fndecls;
2339       tree base_binfo;
2340       tree binfo;
2341       int j;
2342
2343       /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2344          have the same name.  Figure out what name that is.  */
2345       name = DECL_NAME (OVL_CURRENT (fns));
2346       /* There are no possibly hidden functions yet.  */
2347       base_fndecls = NULL_TREE;
2348       /* Iterate through all of the base classes looking for possibly
2349          hidden functions.  */
2350       for (binfo = TYPE_BINFO (t), j = 0;
2351            BINFO_BASE_ITERATE (binfo, j, base_binfo); j++)
2352         {
2353           tree basetype = BINFO_TYPE (base_binfo);
2354           base_fndecls = chainon (get_basefndecls (name, basetype),
2355                                   base_fndecls);
2356         }
2357
2358       /* If there are no functions to hide, continue.  */
2359       if (!base_fndecls)
2360         continue;
2361
2362       /* Remove any overridden functions.  */
2363       for (fn = fns; fn; fn = OVL_NEXT (fn))
2364         {
2365           fndecl = OVL_CURRENT (fn);
2366           if (DECL_VINDEX (fndecl))
2367             {
2368               tree *prev = &base_fndecls;
2369
2370               while (*prev)
2371                 /* If the method from the base class has the same
2372                    signature as the method from the derived class, it
2373                    has been overridden.  */
2374                 if (same_signature_p (fndecl, TREE_VALUE (*prev)))
2375                   *prev = TREE_CHAIN (*prev);
2376                 else
2377                   prev = &TREE_CHAIN (*prev);
2378             }
2379         }
2380
2381       /* Now give a warning for all base functions without overriders,
2382          as they are hidden.  */
2383       while (base_fndecls)
2384         {
2385           /* Here we know it is a hider, and no overrider exists.  */
2386           warning (0, "%q+D was hidden", TREE_VALUE (base_fndecls));
2387           warning (0, "  by %q+D", fns);
2388           base_fndecls = TREE_CHAIN (base_fndecls);
2389         }
2390     }
2391 }
2392
2393 /* Check for things that are invalid.  There are probably plenty of other
2394    things we should check for also.  */
2395
2396 static void
2397 finish_struct_anon (tree t)
2398 {
2399   tree field;
2400
2401   for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
2402     {
2403       if (TREE_STATIC (field))
2404         continue;
2405       if (TREE_CODE (field) != FIELD_DECL)
2406         continue;
2407
2408       if (DECL_NAME (field) == NULL_TREE
2409           && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
2410         {
2411           tree elt = TYPE_FIELDS (TREE_TYPE (field));
2412           for (; elt; elt = TREE_CHAIN (elt))
2413             {
2414               /* We're generally only interested in entities the user
2415                  declared, but we also find nested classes by noticing
2416                  the TYPE_DECL that we create implicitly.  You're
2417                  allowed to put one anonymous union inside another,
2418                  though, so we explicitly tolerate that.  We use
2419                  TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2420                  we also allow unnamed types used for defining fields.  */
2421               if (DECL_ARTIFICIAL (elt)
2422                   && (!DECL_IMPLICIT_TYPEDEF_P (elt)
2423                       || TYPE_ANONYMOUS_P (TREE_TYPE (elt))))
2424                 continue;
2425
2426               if (TREE_CODE (elt) != FIELD_DECL)
2427                 {
2428                   pedwarn ("%q+#D invalid; an anonymous union can "
2429                            "only have non-static data members", elt);
2430                   continue;
2431                 }
2432
2433               if (TREE_PRIVATE (elt))
2434                 pedwarn ("private member %q+#D in anonymous union", elt);
2435               else if (TREE_PROTECTED (elt))
2436                 pedwarn ("protected member %q+#D in anonymous union", elt);
2437
2438               TREE_PRIVATE (elt) = TREE_PRIVATE (field);
2439               TREE_PROTECTED (elt) = TREE_PROTECTED (field);
2440             }
2441         }
2442     }
2443 }
2444
2445 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2446    will be used later during class template instantiation.
2447    When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2448    a non-static member data (FIELD_DECL), a member function
2449    (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2450    a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2451    When FRIEND_P is nonzero, T is either a friend class
2452    (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2453    (FUNCTION_DECL, TEMPLATE_DECL).  */
2454
2455 void
2456 maybe_add_class_template_decl_list (tree type, tree t, int friend_p)
2457 {
2458   /* Save some memory by not creating TREE_LIST if TYPE is not template.  */
2459   if (CLASSTYPE_TEMPLATE_INFO (type))
2460     CLASSTYPE_DECL_LIST (type)
2461       = tree_cons (friend_p ? NULL_TREE : type,
2462                    t, CLASSTYPE_DECL_LIST (type));
2463 }
2464
2465 /* Create default constructors, assignment operators, and so forth for
2466    the type indicated by T, if they are needed.  CANT_HAVE_CONST_CTOR,
2467    and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2468    the class cannot have a default constructor, copy constructor
2469    taking a const reference argument, or an assignment operator taking
2470    a const reference, respectively.  */
2471
2472 static void
2473 add_implicitly_declared_members (tree t,
2474                                  int cant_have_const_cctor,
2475                                  int cant_have_const_assignment)
2476 {
2477   /* Destructor.  */
2478   if (!CLASSTYPE_DESTRUCTORS (t))
2479     {
2480       /* In general, we create destructors lazily.  */
2481       CLASSTYPE_LAZY_DESTRUCTOR (t) = 1;
2482       /* However, if the implicit destructor is non-trivial
2483          destructor, we sometimes have to create it at this point.  */
2484       if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
2485         {
2486           bool lazy_p = true;
2487
2488           if (TYPE_FOR_JAVA (t))
2489             /* If this a Java class, any non-trivial destructor is
2490                invalid, even if compiler-generated.  Therefore, if the
2491                destructor is non-trivial we create it now.  */
2492             lazy_p = false;
2493           else
2494             {
2495               tree binfo;
2496               tree base_binfo;
2497               int ix;
2498
2499               /* If the implicit destructor will be virtual, then we must
2500                  generate it now because (unfortunately) we do not
2501                  generate virtual tables lazily.  */
2502               binfo = TYPE_BINFO (t);
2503               for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
2504                 {
2505                   tree base_type;
2506                   tree dtor;
2507
2508                   base_type = BINFO_TYPE (base_binfo);
2509                   dtor = CLASSTYPE_DESTRUCTORS (base_type);
2510                   if (dtor && DECL_VIRTUAL_P (dtor))
2511                     {
2512                       lazy_p = false;
2513                       break;
2514                     }
2515                 }
2516             }
2517
2518           /* If we can't get away with being lazy, generate the destructor
2519              now.  */
2520           if (!lazy_p)
2521             lazily_declare_fn (sfk_destructor, t);
2522         }
2523     }
2524
2525   /* Default constructor.  */
2526   if (! TYPE_HAS_CONSTRUCTOR (t))
2527     {
2528       TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 1;
2529       CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 1;
2530     }
2531
2532   /* Copy constructor.  */
2533   if (! TYPE_HAS_INIT_REF (t) && ! TYPE_FOR_JAVA (t))
2534     {
2535       TYPE_HAS_INIT_REF (t) = 1;
2536       TYPE_HAS_CONST_INIT_REF (t) = !cant_have_const_cctor;
2537       CLASSTYPE_LAZY_COPY_CTOR (t) = 1;
2538       TYPE_HAS_CONSTRUCTOR (t) = 1;
2539     }
2540
2541   /* If there is no assignment operator, one will be created if and
2542      when it is needed.  For now, just record whether or not the type
2543      of the parameter to the assignment operator will be a const or
2544      non-const reference.  */
2545   if (!TYPE_HAS_ASSIGN_REF (t) && !TYPE_FOR_JAVA (t))
2546     {
2547       TYPE_HAS_ASSIGN_REF (t) = 1;
2548       TYPE_HAS_CONST_ASSIGN_REF (t) = !cant_have_const_assignment;
2549       CLASSTYPE_LAZY_ASSIGNMENT_OP (t) = 1;
2550     }
2551 }
2552
2553 /* Subroutine of finish_struct_1.  Recursively count the number of fields
2554    in TYPE, including anonymous union members.  */
2555
2556 static int
2557 count_fields (tree fields)
2558 {
2559   tree x;
2560   int n_fields = 0;
2561   for (x = fields; x; x = TREE_CHAIN (x))
2562     {
2563       if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2564         n_fields += count_fields (TYPE_FIELDS (TREE_TYPE (x)));
2565       else
2566         n_fields += 1;
2567     }
2568   return n_fields;
2569 }
2570
2571 /* Subroutine of finish_struct_1.  Recursively add all the fields in the
2572    TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX.  */
2573
2574 static int
2575 add_fields_to_record_type (tree fields, struct sorted_fields_type *field_vec, int idx)
2576 {
2577   tree x;
2578   for (x = fields; x; x = TREE_CHAIN (x))
2579     {
2580       if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2581         idx = add_fields_to_record_type (TYPE_FIELDS (TREE_TYPE (x)), field_vec, idx);
2582       else
2583         field_vec->elts[idx++] = x;
2584     }
2585   return idx;
2586 }
2587
2588 /* FIELD is a bit-field.  We are finishing the processing for its
2589    enclosing type.  Issue any appropriate messages and set appropriate
2590    flags.  */
2591
2592 static void
2593 check_bitfield_decl (tree field)
2594 {
2595   tree type = TREE_TYPE (field);
2596   tree w = NULL_TREE;
2597
2598   /* Detect invalid bit-field type.  */
2599   if (DECL_INITIAL (field)
2600       && ! INTEGRAL_TYPE_P (TREE_TYPE (field)))
2601     {
2602       error ("bit-field %q+#D with non-integral type", field);
2603       w = error_mark_node;
2604     }
2605
2606   /* Detect and ignore out of range field width.  */
2607   if (DECL_INITIAL (field))
2608     {
2609       w = DECL_INITIAL (field);
2610
2611       /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs.  */
2612       STRIP_NOPS (w);
2613
2614       /* detect invalid field size.  */
2615       w = integral_constant_value (w);
2616
2617       if (TREE_CODE (w) != INTEGER_CST)
2618         {
2619           error ("bit-field %q+D width not an integer constant", field);
2620           w = error_mark_node;
2621         }
2622       else if (tree_int_cst_sgn (w) < 0)
2623         {
2624           error ("negative width in bit-field %q+D", field);
2625           w = error_mark_node;
2626         }
2627       else if (integer_zerop (w) && DECL_NAME (field) != 0)
2628         {
2629           error ("zero width for bit-field %q+D", field);
2630           w = error_mark_node;
2631         }
2632       else if (compare_tree_int (w, TYPE_PRECISION (type)) > 0
2633                && TREE_CODE (type) != ENUMERAL_TYPE
2634                && TREE_CODE (type) != BOOLEAN_TYPE)
2635         warning (0, "width of %q+D exceeds its type", field);
2636       else if (TREE_CODE (type) == ENUMERAL_TYPE
2637                && (0 > compare_tree_int (w,
2638                                          min_precision (TYPE_MIN_VALUE (type),
2639                                                         TYPE_UNSIGNED (type)))
2640                    ||  0 > compare_tree_int (w,
2641                                              min_precision
2642                                              (TYPE_MAX_VALUE (type),
2643                                               TYPE_UNSIGNED (type)))))
2644         warning (0, "%q+D is too small to hold all values of %q#T", field, type);
2645     }
2646
2647   /* Remove the bit-field width indicator so that the rest of the
2648      compiler does not treat that value as an initializer.  */
2649   DECL_INITIAL (field) = NULL_TREE;
2650
2651   if (w != error_mark_node)
2652     {
2653       DECL_SIZE (field) = convert (bitsizetype, w);
2654       DECL_BIT_FIELD (field) = 1;
2655     }
2656   else
2657     {
2658       /* Non-bit-fields are aligned for their type.  */
2659       DECL_BIT_FIELD (field) = 0;
2660       CLEAR_DECL_C_BIT_FIELD (field);
2661     }
2662 }
2663
2664 /* FIELD is a non bit-field.  We are finishing the processing for its
2665    enclosing type T.  Issue any appropriate messages and set appropriate
2666    flags.  */
2667
2668 static void
2669 check_field_decl (tree field,
2670                   tree t,
2671                   int* cant_have_const_ctor,
2672                   int* no_const_asn_ref,
2673                   int* any_default_members)
2674 {
2675   tree type = strip_array_types (TREE_TYPE (field));
2676
2677   /* An anonymous union cannot contain any fields which would change
2678      the settings of CANT_HAVE_CONST_CTOR and friends.  */
2679   if (ANON_UNION_TYPE_P (type))
2680     ;
2681   /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
2682      structs.  So, we recurse through their fields here.  */
2683   else if (ANON_AGGR_TYPE_P (type))
2684     {
2685       tree fields;
2686
2687       for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2688         if (TREE_CODE (fields) == FIELD_DECL && !DECL_C_BIT_FIELD (field))
2689           check_field_decl (fields, t, cant_have_const_ctor,
2690                             no_const_asn_ref, any_default_members);
2691     }
2692   /* Check members with class type for constructors, destructors,
2693      etc.  */
2694   else if (CLASS_TYPE_P (type))
2695     {
2696       /* Never let anything with uninheritable virtuals
2697          make it through without complaint.  */
2698       abstract_virtuals_error (field, type);
2699
2700       if (TREE_CODE (t) == UNION_TYPE)
2701         {
2702           if (TYPE_NEEDS_CONSTRUCTING (type))
2703             error ("member %q+#D with constructor not allowed in union",
2704                    field);
2705           if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
2706             error ("member %q+#D with destructor not allowed in union", field);
2707           if (TYPE_HAS_COMPLEX_ASSIGN_REF (type))
2708             error ("member %q+#D with copy assignment operator not allowed in union",
2709                    field);
2710         }
2711       else
2712         {
2713           TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (type);
2714           TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
2715             |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type);
2716           TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_HAS_COMPLEX_ASSIGN_REF (type);
2717           TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (type);
2718         }
2719
2720       if (!TYPE_HAS_CONST_INIT_REF (type))
2721         *cant_have_const_ctor = 1;
2722
2723       if (!TYPE_HAS_CONST_ASSIGN_REF (type))
2724         *no_const_asn_ref = 1;
2725     }
2726   if (DECL_INITIAL (field) != NULL_TREE)
2727     {
2728       /* `build_class_init_list' does not recognize
2729          non-FIELD_DECLs.  */
2730       if (TREE_CODE (t) == UNION_TYPE && any_default_members != 0)
2731         error ("multiple fields in union %qT initialized", t);
2732       *any_default_members = 1;
2733     }
2734 }
2735
2736 /* Check the data members (both static and non-static), class-scoped
2737    typedefs, etc., appearing in the declaration of T.  Issue
2738    appropriate diagnostics.  Sets ACCESS_DECLS to a list (in
2739    declaration order) of access declarations; each TREE_VALUE in this
2740    list is a USING_DECL.
2741
2742    In addition, set the following flags:
2743
2744      EMPTY_P
2745        The class is empty, i.e., contains no non-static data members.
2746
2747      CANT_HAVE_CONST_CTOR_P
2748        This class cannot have an implicitly generated copy constructor
2749        taking a const reference.
2750
2751      CANT_HAVE_CONST_ASN_REF
2752        This class cannot have an implicitly generated assignment
2753        operator taking a const reference.
2754
2755    All of these flags should be initialized before calling this
2756    function.
2757
2758    Returns a pointer to the end of the TYPE_FIELDs chain; additional
2759    fields can be added by adding to this chain.  */
2760
2761 static void
2762 check_field_decls (tree t, tree *access_decls,
2763                    int *cant_have_const_ctor_p,
2764                    int *no_const_asn_ref_p)
2765 {
2766   tree *field;
2767   tree *next;
2768   bool has_pointers;
2769   int any_default_members;
2770
2771   /* Assume there are no access declarations.  */
2772   *access_decls = NULL_TREE;
2773   /* Assume this class has no pointer members.  */
2774   has_pointers = false;
2775   /* Assume none of the members of this class have default
2776      initializations.  */
2777   any_default_members = 0;
2778
2779   for (field = &TYPE_FIELDS (t); *field; field = next)
2780     {
2781       tree x = *field;
2782       tree type = TREE_TYPE (x);
2783
2784       next = &TREE_CHAIN (x);
2785
2786       if (TREE_CODE (x) == FIELD_DECL)
2787         {
2788           if (TYPE_PACKED (t))
2789             {
2790               if (!pod_type_p (TREE_TYPE (x)) && !TYPE_PACKED (TREE_TYPE (x)))
2791                 warning
2792                   (0,
2793                    "ignoring packed attribute on unpacked non-POD field %q+#D",
2794                    x);
2795               else
2796                 DECL_PACKED (x) = 1;
2797             }
2798
2799           if (DECL_C_BIT_FIELD (x) && integer_zerop (DECL_INITIAL (x)))
2800             /* We don't treat zero-width bitfields as making a class
2801                non-empty.  */
2802             ;
2803           else
2804             {
2805               tree element_type;
2806
2807               /* The class is non-empty.  */
2808               CLASSTYPE_EMPTY_P (t) = 0;
2809               /* The class is not even nearly empty.  */
2810               CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
2811               /* If one of the data members contains an empty class,
2812                  so does T.  */
2813               element_type = strip_array_types (type);
2814               if (CLASS_TYPE_P (element_type)
2815                   && CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type))
2816                 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
2817             }
2818         }
2819
2820       if (TREE_CODE (x) == USING_DECL)
2821         {
2822           /* Prune the access declaration from the list of fields.  */
2823           *field = TREE_CHAIN (x);
2824
2825           /* Save the access declarations for our caller.  */
2826           *access_decls = tree_cons (NULL_TREE, x, *access_decls);
2827
2828           /* Since we've reset *FIELD there's no reason to skip to the
2829              next field.  */
2830           next = field;
2831           continue;
2832         }
2833
2834       if (TREE_CODE (x) == TYPE_DECL
2835           || TREE_CODE (x) == TEMPLATE_DECL)
2836         continue;
2837
2838       /* If we've gotten this far, it's a data member, possibly static,
2839          or an enumerator.  */
2840       DECL_CONTEXT (x) = t;
2841
2842       /* When this goes into scope, it will be a non-local reference.  */
2843       DECL_NONLOCAL (x) = 1;
2844
2845       if (TREE_CODE (t) == UNION_TYPE)
2846         {
2847           /* [class.union]
2848
2849              If a union contains a static data member, or a member of
2850              reference type, the program is ill-formed.  */
2851           if (TREE_CODE (x) == VAR_DECL)
2852             {
2853               error ("%q+D may not be static because it is a member of a union", x);
2854               continue;
2855             }
2856           if (TREE_CODE (type) == REFERENCE_TYPE)
2857             {
2858               error ("%q+D may not have reference type %qT because"
2859                      " it is a member of a union",
2860                      x, type);
2861               continue;
2862             }
2863         }
2864
2865       /* ``A local class cannot have static data members.'' ARM 9.4 */
2866       if (current_function_decl && TREE_STATIC (x))
2867         error ("field %q+D in local class cannot be static", x);
2868
2869       /* Perform error checking that did not get done in
2870          grokdeclarator.  */
2871       if (TREE_CODE (type) == FUNCTION_TYPE)
2872         {
2873           error ("field %q+D invalidly declared function type", x);
2874           type = build_pointer_type (type);
2875           TREE_TYPE (x) = type;
2876         }
2877       else if (TREE_CODE (type) == METHOD_TYPE)
2878         {
2879           error ("field %q+D invalidly declared method type", x);
2880           type = build_pointer_type (type);
2881           TREE_TYPE (x) = type;
2882         }
2883
2884       if (type == error_mark_node)
2885         continue;
2886
2887       if (TREE_CODE (x) == CONST_DECL || TREE_CODE (x) == VAR_DECL)
2888         continue;
2889
2890       /* Now it can only be a FIELD_DECL.  */
2891
2892       if (TREE_PRIVATE (x) || TREE_PROTECTED (x))
2893         CLASSTYPE_NON_AGGREGATE (t) = 1;
2894
2895       /* If this is of reference type, check if it needs an init.
2896          Also do a little ANSI jig if necessary.  */
2897       if (TREE_CODE (type) == REFERENCE_TYPE)
2898         {
2899           CLASSTYPE_NON_POD_P (t) = 1;
2900           if (DECL_INITIAL (x) == NULL_TREE)
2901             SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
2902
2903           /* ARM $12.6.2: [A member initializer list] (or, for an
2904              aggregate, initialization by a brace-enclosed list) is the
2905              only way to initialize nonstatic const and reference
2906              members.  */
2907           TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
2908
2909           if (! TYPE_HAS_CONSTRUCTOR (t) && CLASSTYPE_NON_AGGREGATE (t)
2910               && extra_warnings)
2911             warning (0, "non-static reference %q+#D in class without a constructor", x);
2912         }
2913
2914       type = strip_array_types (type);
2915
2916       /* This is used by -Weffc++ (see below). Warn only for pointers
2917          to members which might hold dynamic memory. So do not warn
2918          for pointers to functions or pointers to members.  */
2919       if (TYPE_PTR_P (type)
2920           && !TYPE_PTRFN_P (type)
2921           && !TYPE_PTR_TO_MEMBER_P (type))
2922         has_pointers = true;
2923
2924       if (CLASS_TYPE_P (type))
2925         {
2926           if (CLASSTYPE_REF_FIELDS_NEED_INIT (type))
2927             SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
2928           if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (type))
2929             SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
2930         }
2931
2932       if (DECL_MUTABLE_P (x) || TYPE_HAS_MUTABLE_P (type))
2933         CLASSTYPE_HAS_MUTABLE (t) = 1;
2934
2935       if (! pod_type_p (type))
2936         /* DR 148 now allows pointers to members (which are POD themselves),
2937            to be allowed in POD structs.  */
2938         CLASSTYPE_NON_POD_P (t) = 1;
2939
2940       if (! zero_init_p (type))
2941         CLASSTYPE_NON_ZERO_INIT_P (t) = 1;
2942
2943       /* If any field is const, the structure type is pseudo-const.  */
2944       if (CP_TYPE_CONST_P (type))
2945         {
2946           C_TYPE_FIELDS_READONLY (t) = 1;
2947           if (DECL_INITIAL (x) == NULL_TREE)
2948             SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
2949
2950           /* ARM $12.6.2: [A member initializer list] (or, for an
2951              aggregate, initialization by a brace-enclosed list) is the
2952              only way to initialize nonstatic const and reference
2953              members.  */
2954           TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
2955
2956           if (! TYPE_HAS_CONSTRUCTOR (t) && CLASSTYPE_NON_AGGREGATE (t)
2957               && extra_warnings)
2958             warning (0, "non-static const member %q+#D in class without a constructor", x);
2959         }
2960       /* A field that is pseudo-const makes the structure likewise.  */
2961       else if (CLASS_TYPE_P (type))
2962         {
2963           C_TYPE_FIELDS_READONLY (t) |= C_TYPE_FIELDS_READONLY (type);
2964           SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t,
2965             CLASSTYPE_READONLY_FIELDS_NEED_INIT (t)
2966             | CLASSTYPE_READONLY_FIELDS_NEED_INIT (type));
2967         }
2968
2969       /* Core issue 80: A nonstatic data member is required to have a
2970          different name from the class iff the class has a
2971          user-defined constructor.  */
2972       if (constructor_name_p (DECL_NAME (x), t) && TYPE_HAS_CONSTRUCTOR (t))
2973         pedwarn ("field %q+#D with same name as class", x);
2974
2975       /* We set DECL_C_BIT_FIELD in grokbitfield.
2976          If the type and width are valid, we'll also set DECL_BIT_FIELD.  */
2977       if (DECL_C_BIT_FIELD (x))
2978         check_bitfield_decl (x);
2979       else
2980         check_field_decl (x, t,
2981                           cant_have_const_ctor_p,
2982                           no_const_asn_ref_p,
2983                           &any_default_members);
2984     }
2985
2986   /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
2987      it should also define a copy constructor and an assignment operator to
2988      implement the correct copy semantic (deep vs shallow, etc.). As it is
2989      not feasible to check whether the constructors do allocate dynamic memory
2990      and store it within members, we approximate the warning like this:
2991
2992      -- Warn only if there are members which are pointers
2993      -- Warn only if there is a non-trivial constructor (otherwise,
2994         there cannot be memory allocated).
2995      -- Warn only if there is a non-trivial destructor. We assume that the
2996         user at least implemented the cleanup correctly, and a destructor
2997         is needed to free dynamic memory.
2998
2999      This seems enough for practical purposes.  */
3000     if (warn_ecpp
3001         && has_pointers
3002         && TYPE_HAS_CONSTRUCTOR (t)
3003         && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
3004         && !(TYPE_HAS_INIT_REF (t) && TYPE_HAS_ASSIGN_REF (t)))
3005     {
3006       warning (0, "%q#T has pointer data members", t);
3007
3008       if (! TYPE_HAS_INIT_REF (t))
3009         {
3010           warning (0, "  but does not override %<%T(const %T&)%>", t, t);
3011           if (! TYPE_HAS_ASSIGN_REF (t))
3012             warning (0, "  or %<operator=(const %T&)%>", t);
3013         }
3014       else if (! TYPE_HAS_ASSIGN_REF (t))
3015         warning (0, "  but does not override %<operator=(const %T&)%>", t);
3016     }
3017
3018
3019   /* Check anonymous struct/anonymous union fields.  */
3020   finish_struct_anon (t);
3021
3022   /* We've built up the list of access declarations in reverse order.
3023      Fix that now.  */
3024   *access_decls = nreverse (*access_decls);
3025 }
3026
3027 /* If TYPE is an empty class type, records its OFFSET in the table of
3028    OFFSETS.  */
3029
3030 static int
3031 record_subobject_offset (tree type, tree offset, splay_tree offsets)
3032 {
3033   splay_tree_node n;
3034
3035   if (!is_empty_class (type))
3036     return 0;
3037
3038   /* Record the location of this empty object in OFFSETS.  */
3039   n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3040   if (!n)
3041     n = splay_tree_insert (offsets,
3042                            (splay_tree_key) offset,
3043                            (splay_tree_value) NULL_TREE);
3044   n->value = ((splay_tree_value)
3045               tree_cons (NULL_TREE,
3046                          type,
3047                          (tree) n->value));
3048
3049   return 0;
3050 }
3051
3052 /* Returns nonzero if TYPE is an empty class type and there is
3053    already an entry in OFFSETS for the same TYPE as the same OFFSET.  */
3054
3055 static int
3056 check_subobject_offset (tree type, tree offset, splay_tree offsets)
3057 {
3058   splay_tree_node n;
3059   tree t;
3060
3061   if (!is_empty_class (type))
3062     return 0;
3063
3064   /* Record the location of this empty object in OFFSETS.  */
3065   n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3066   if (!n)
3067     return 0;
3068
3069   for (t = (tree) n->value; t; t = TREE_CHAIN (t))
3070     if (same_type_p (TREE_VALUE (t), type))
3071       return 1;
3072
3073   return 0;
3074 }
3075
3076 /* Walk through all the subobjects of TYPE (located at OFFSET).  Call
3077    F for every subobject, passing it the type, offset, and table of
3078    OFFSETS.  If VBASES_P is one, then virtual non-primary bases should
3079    be traversed.
3080
3081    If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3082    than MAX_OFFSET will not be walked.
3083
3084    If F returns a nonzero value, the traversal ceases, and that value
3085    is returned.  Otherwise, returns zero.  */
3086
3087 static int
3088 walk_subobject_offsets (tree type,
3089                         subobject_offset_fn f,
3090                         tree offset,
3091                         splay_tree offsets,
3092                         tree max_offset,
3093                         int vbases_p)
3094 {
3095   int r = 0;
3096   tree type_binfo = NULL_TREE;
3097
3098   /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3099      stop.  */
3100   if (max_offset && INT_CST_LT (max_offset, offset))
3101     return 0;
3102
3103   if (!TYPE_P (type))
3104     {
3105       if (abi_version_at_least (2))
3106         type_binfo = type;
3107       type = BINFO_TYPE (type);
3108     }
3109
3110   if (CLASS_TYPE_P (type))
3111     {
3112       tree field;
3113       tree binfo;
3114       int i;
3115
3116       /* Avoid recursing into objects that are not interesting.  */
3117       if (!CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type))
3118         return 0;
3119
3120       /* Record the location of TYPE.  */
3121       r = (*f) (type, offset, offsets);
3122       if (r)
3123         return r;
3124
3125       /* Iterate through the direct base classes of TYPE.  */
3126       if (!type_binfo)
3127         type_binfo = TYPE_BINFO (type);
3128       for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, binfo); i++)
3129         {
3130           tree binfo_offset;
3131
3132           if (abi_version_at_least (2)
3133               && BINFO_VIRTUAL_P (binfo))
3134             continue;
3135
3136           if (!vbases_p
3137               && BINFO_VIRTUAL_P (binfo)
3138               && !BINFO_PRIMARY_P (binfo))
3139             continue;
3140
3141           if (!abi_version_at_least (2))
3142             binfo_offset = size_binop (PLUS_EXPR,
3143                                        offset,
3144                                        BINFO_OFFSET (binfo));
3145           else
3146             {
3147               tree orig_binfo;
3148               /* We cannot rely on BINFO_OFFSET being set for the base
3149                  class yet, but the offsets for direct non-virtual
3150                  bases can be calculated by going back to the TYPE.  */
3151               orig_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), i);
3152               binfo_offset = size_binop (PLUS_EXPR,
3153                                          offset,
3154                                          BINFO_OFFSET (orig_binfo));
3155             }
3156
3157           r = walk_subobject_offsets (binfo,
3158                                       f,
3159                                       binfo_offset,
3160                                       offsets,
3161                                       max_offset,
3162                                       (abi_version_at_least (2)
3163                                        ? /*vbases_p=*/0 : vbases_p));
3164           if (r)
3165             return r;
3166         }
3167
3168       if (abi_version_at_least (2) && CLASSTYPE_VBASECLASSES (type))
3169         {
3170           unsigned ix;
3171           VEC(tree,gc) *vbases;
3172
3173           /* Iterate through the virtual base classes of TYPE.  In G++
3174              3.2, we included virtual bases in the direct base class
3175              loop above, which results in incorrect results; the
3176              correct offsets for virtual bases are only known when
3177              working with the most derived type.  */
3178           if (vbases_p)
3179             for (vbases = CLASSTYPE_VBASECLASSES (type), ix = 0;
3180                  VEC_iterate (tree, vbases, ix, binfo); ix++)
3181               {
3182                 r = walk_subobject_offsets (binfo,
3183                                             f,
3184                                             size_binop (PLUS_EXPR,
3185                                                         offset,
3186                                                         BINFO_OFFSET (binfo)),
3187                                             offsets,
3188                                             max_offset,
3189                                             /*vbases_p=*/0);
3190                 if (r)
3191                   return r;
3192               }
3193           else
3194             {
3195               /* We still have to walk the primary base, if it is
3196                  virtual.  (If it is non-virtual, then it was walked
3197                  above.)  */
3198               tree vbase = get_primary_binfo (type_binfo);
3199
3200               if (vbase && BINFO_VIRTUAL_P (vbase)
3201                   && BINFO_PRIMARY_P (vbase)
3202                   && BINFO_INHERITANCE_CHAIN (vbase) == type_binfo)
3203                 {
3204                   r = (walk_subobject_offsets
3205                        (vbase, f, offset,
3206                         offsets, max_offset, /*vbases_p=*/0));
3207                   if (r)
3208                     return r;
3209                 }
3210             }
3211         }
3212
3213       /* Iterate through the fields of TYPE.  */
3214       for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3215         if (TREE_CODE (field) == FIELD_DECL && !DECL_ARTIFICIAL (field))
3216           {
3217             tree field_offset;
3218
3219             if (abi_version_at_least (2))
3220               field_offset = byte_position (field);
3221             else
3222               /* In G++ 3.2, DECL_FIELD_OFFSET was used.  */
3223               field_offset = DECL_FIELD_OFFSET (field);
3224
3225             r = walk_subobject_offsets (TREE_TYPE (field),
3226                                         f,
3227                                         size_binop (PLUS_EXPR,
3228                                                     offset,
3229                                                     field_offset),
3230                                         offsets,
3231                                         max_offset,
3232                                         /*vbases_p=*/1);
3233             if (r)
3234               return r;
3235           }
3236     }
3237   else if (TREE_CODE (type) == ARRAY_TYPE)
3238     {
3239       tree element_type = strip_array_types (type);
3240       tree domain = TYPE_DOMAIN (type);
3241       tree index;
3242
3243       /* Avoid recursing into objects that are not interesting.  */
3244       if (!CLASS_TYPE_P (element_type)
3245           || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type))
3246         return 0;
3247
3248       /* Step through each of the elements in the array.  */
3249       for (index = size_zero_node;
3250            /* G++ 3.2 had an off-by-one error here.  */
3251            (abi_version_at_least (2)
3252             ? !INT_CST_LT (TYPE_MAX_VALUE (domain), index)
3253             : INT_CST_LT (index, TYPE_MAX_VALUE (domain)));
3254            index = size_binop (PLUS_EXPR, index, size_one_node))
3255         {
3256           r = walk_subobject_offsets (TREE_TYPE (type),
3257                                       f,
3258                                       offset,
3259                                       offsets,
3260                                       max_offset,
3261                                       /*vbases_p=*/1);
3262           if (r)
3263             return r;
3264           offset = size_binop (PLUS_EXPR, offset,
3265                                TYPE_SIZE_UNIT (TREE_TYPE (type)));
3266           /* If this new OFFSET is bigger than the MAX_OFFSET, then
3267              there's no point in iterating through the remaining
3268              elements of the array.  */
3269           if (max_offset && INT_CST_LT (max_offset, offset))
3270             break;
3271         }
3272     }
3273
3274   return 0;
3275 }
3276
3277 /* Record all of the empty subobjects of TYPE (located at OFFSET) in
3278    OFFSETS.  If VBASES_P is nonzero, virtual bases of TYPE are
3279    examined.  */
3280
3281 static void
3282 record_subobject_offsets (tree type,
3283                           tree offset,
3284                           splay_tree offsets,
3285                           int vbases_p)
3286 {
3287   walk_subobject_offsets (type, record_subobject_offset, offset,
3288                           offsets, /*max_offset=*/NULL_TREE, vbases_p);
3289 }
3290
3291 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3292    OFFSET) conflict with entries in OFFSETS.  If VBASES_P is nonzero,
3293    virtual bases of TYPE are examined.  */
3294
3295 static int
3296 layout_conflict_p (tree type,
3297                    tree offset,
3298                    splay_tree offsets,
3299                    int vbases_p)
3300 {
3301   splay_tree_node max_node;
3302
3303   /* Get the node in OFFSETS that indicates the maximum offset where
3304      an empty subobject is located.  */
3305   max_node = splay_tree_max (offsets);
3306   /* If there aren't any empty subobjects, then there's no point in
3307      performing this check.  */
3308   if (!max_node)
3309     return 0;
3310
3311   return walk_subobject_offsets (type, check_subobject_offset, offset,
3312                                  offsets, (tree) (max_node->key),
3313                                  vbases_p);
3314 }
3315
3316 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3317    non-static data member of the type indicated by RLI.  BINFO is the
3318    binfo corresponding to the base subobject, OFFSETS maps offsets to
3319    types already located at those offsets.  This function determines
3320    the position of the DECL.  */
3321
3322 static void
3323 layout_nonempty_base_or_field (record_layout_info rli,
3324                                tree decl,
3325                                tree binfo,
3326                                splay_tree offsets)
3327 {
3328   tree offset = NULL_TREE;
3329   bool field_p;
3330   tree type;
3331
3332   if (binfo)
3333     {
3334       /* For the purposes of determining layout conflicts, we want to
3335          use the class type of BINFO; TREE_TYPE (DECL) will be the
3336          CLASSTYPE_AS_BASE version, which does not contain entries for
3337          zero-sized bases.  */
3338       type = TREE_TYPE (binfo);
3339       field_p = false;
3340     }
3341   else
3342     {
3343       type = TREE_TYPE (decl);
3344       field_p = true;
3345     }
3346
3347   /* Try to place the field.  It may take more than one try if we have
3348      a hard time placing the field without putting two objects of the
3349      same type at the same address.  */
3350   while (1)
3351     {
3352       struct record_layout_info_s old_rli = *rli;
3353
3354       /* Place this field.  */
3355       place_field (rli, decl);
3356       offset = byte_position (decl);
3357
3358       /* We have to check to see whether or not there is already
3359          something of the same type at the offset we're about to use.
3360          For example, consider:
3361
3362            struct S {};
3363            struct T : public S { int i; };
3364            struct U : public S, public T {};
3365
3366          Here, we put S at offset zero in U.  Then, we can't put T at
3367          offset zero -- its S component would be at the same address
3368          as the S we already allocated.  So, we have to skip ahead.
3369          Since all data members, including those whose type is an
3370          empty class, have nonzero size, any overlap can happen only
3371          with a direct or indirect base-class -- it can't happen with
3372          a data member.  */
3373       /* In a union, overlap is permitted; all members are placed at
3374          offset zero.  */
3375       if (TREE_CODE (rli->t) == UNION_TYPE)
3376         break;
3377       /* G++ 3.2 did not check for overlaps when placing a non-empty
3378          virtual base.  */
3379       if (!abi_version_at_least (2) && binfo && BINFO_VIRTUAL_P (binfo))
3380         break;
3381       if (layout_conflict_p (field_p ? type : binfo, offset,
3382                              offsets, field_p))
3383         {
3384           /* Strip off the size allocated to this field.  That puts us
3385              at the first place we could have put the field with
3386              proper alignment.  */
3387           *rli = old_rli;
3388
3389           /* Bump up by the alignment required for the type.  */
3390           rli->bitpos
3391             = size_binop (PLUS_EXPR, rli->bitpos,
3392                           bitsize_int (binfo
3393                                        ? CLASSTYPE_ALIGN (type)
3394                                        : TYPE_ALIGN (type)));
3395           normalize_rli (rli);
3396         }
3397       else
3398         /* There was no conflict.  We're done laying out this field.  */
3399         break;
3400     }
3401
3402   /* Now that we know where it will be placed, update its
3403      BINFO_OFFSET.  */
3404   if (binfo && CLASS_TYPE_P (BINFO_TYPE (binfo)))
3405     /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3406        this point because their BINFO_OFFSET is copied from another
3407        hierarchy.  Therefore, we may not need to add the entire
3408        OFFSET.  */
3409     propagate_binfo_offsets (binfo,
3410                              size_diffop (convert (ssizetype, offset),
3411                                           convert (ssizetype,
3412                                                    BINFO_OFFSET (binfo))));
3413 }
3414
3415 /* Returns true if TYPE is empty and OFFSET is nonzero.  */
3416
3417 static int
3418 empty_base_at_nonzero_offset_p (tree type,
3419                                 tree offset,
3420                                 splay_tree offsets ATTRIBUTE_UNUSED)
3421 {
3422   return is_empty_class (type) && !integer_zerop (offset);
3423 }
3424
3425 /* Layout the empty base BINFO.  EOC indicates the byte currently just
3426    past the end of the class, and should be correctly aligned for a
3427    class of the type indicated by BINFO; OFFSETS gives the offsets of
3428    the empty bases allocated so far. T is the most derived
3429    type.  Return nonzero iff we added it at the end.  */
3430
3431 static bool
3432 layout_empty_base (tree binfo, tree eoc, splay_tree offsets)
3433 {
3434   tree alignment;
3435   tree basetype = BINFO_TYPE (binfo);
3436   bool atend = false;
3437
3438   /* This routine should only be used for empty classes.  */
3439   gcc_assert (is_empty_class (basetype));
3440   alignment = ssize_int (CLASSTYPE_ALIGN_UNIT (basetype));
3441
3442   if (!integer_zerop (BINFO_OFFSET (binfo)))
3443     {
3444       if (abi_version_at_least (2))
3445         propagate_binfo_offsets
3446           (binfo, size_diffop (size_zero_node, BINFO_OFFSET (binfo)));
3447       else if (warn_abi)
3448         warning (0, "offset of empty base %qT may not be ABI-compliant and may"
3449                  "change in a future version of GCC",
3450                  BINFO_TYPE (binfo));
3451     }
3452
3453   /* This is an empty base class.  We first try to put it at offset
3454      zero.  */
3455   if (layout_conflict_p (binfo,
3456                          BINFO_OFFSET (binfo),
3457                          offsets,
3458                          /*vbases_p=*/0))
3459     {
3460       /* That didn't work.  Now, we move forward from the next
3461          available spot in the class.  */
3462       atend = true;
3463       propagate_binfo_offsets (binfo, convert (ssizetype, eoc));
3464       while (1)
3465         {
3466           if (!layout_conflict_p (binfo,
3467                                   BINFO_OFFSET (binfo),
3468                                   offsets,
3469                                   /*vbases_p=*/0))
3470             /* We finally found a spot where there's no overlap.  */
3471             break;
3472
3473           /* There's overlap here, too.  Bump along to the next spot.  */
3474           propagate_binfo_offsets (binfo, alignment);
3475         }
3476     }
3477   return atend;
3478 }
3479
3480 /* Layout the base given by BINFO in the class indicated by RLI.
3481    *BASE_ALIGN is a running maximum of the alignments of
3482    any base class.  OFFSETS gives the location of empty base
3483    subobjects.  T is the most derived type.  Return nonzero if the new
3484    object cannot be nearly-empty.  A new FIELD_DECL is inserted at
3485    *NEXT_FIELD, unless BINFO is for an empty base class.
3486
3487    Returns the location at which the next field should be inserted.  */
3488
3489 static tree *
3490 build_base_field (record_layout_info rli, tree binfo,
3491                   splay_tree offsets, tree *next_field)
3492 {
3493   tree t = rli->t;
3494   tree basetype = BINFO_TYPE (binfo);
3495
3496   if (!COMPLETE_TYPE_P (basetype))
3497     /* This error is now reported in xref_tag, thus giving better
3498        location information.  */
3499     return next_field;
3500
3501   /* Place the base class.  */
3502   if (!is_empty_class (basetype))
3503     {
3504       tree decl;
3505
3506       /* The containing class is non-empty because it has a non-empty
3507          base class.  */
3508       CLASSTYPE_EMPTY_P (t) = 0;
3509
3510       /* Create the FIELD_DECL.  */
3511       decl = build_decl (FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype));
3512       DECL_ARTIFICIAL (decl) = 1;
3513       DECL_IGNORED_P (decl) = 1;
3514       DECL_FIELD_CONTEXT (decl) = t;
3515       DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype);
3516       DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype);
3517       DECL_ALIGN (decl) = CLASSTYPE_ALIGN (basetype);
3518       DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype);
3519       DECL_MODE (decl) = TYPE_MODE (basetype);
3520       DECL_FIELD_IS_BASE (decl) = 1;
3521
3522       /* Try to place the field.  It may take more than one try if we
3523          have a hard time placing the field without putting two
3524          objects of the same type at the same address.  */
3525       layout_nonempty_base_or_field (rli, decl, binfo, offsets);
3526       /* Add the new FIELD_DECL to the list of fields for T.  */
3527       TREE_CHAIN (decl) = *next_field;
3528       *next_field = decl;
3529       next_field = &TREE_CHAIN (decl);
3530     }
3531   else
3532     {
3533       tree eoc;
3534       bool atend;
3535
3536       /* On some platforms (ARM), even empty classes will not be
3537          byte-aligned.  */
3538       eoc = round_up (rli_size_unit_so_far (rli),
3539                       CLASSTYPE_ALIGN_UNIT (basetype));
3540       atend = layout_empty_base (binfo, eoc, offsets);
3541       /* A nearly-empty class "has no proper base class that is empty,
3542          not morally virtual, and at an offset other than zero."  */
3543       if (!BINFO_VIRTUAL_P (binfo) && CLASSTYPE_NEARLY_EMPTY_P (t))
3544         {
3545           if (atend)
3546             CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3547           /* The check above (used in G++ 3.2) is insufficient  because
3548              an empty class placed at offset zero might itself have an
3549              empty base at a nonzero offset.  */
3550           else if (walk_subobject_offsets (basetype,
3551                                            empty_base_at_nonzero_offset_p,
3552                                            size_zero_node,
3553                                            /*offsets=*/NULL,
3554                                            /*max_offset=*/NULL_TREE,
3555                                            /*vbases_p=*/true))
3556             {
3557               if (abi_version_at_least (2))
3558                 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3559               else if (warn_abi)
3560                 warning (0, "class %qT will be considered nearly empty in a "
3561                          "future version of GCC", t);
3562             }
3563         }
3564
3565       /* We do not create a FIELD_DECL for empty base classes because
3566          it might overlap some other field.  We want to be able to
3567          create CONSTRUCTORs for the class by iterating over the
3568          FIELD_DECLs, and the back end does not handle overlapping
3569          FIELD_DECLs.  */
3570
3571       /* An empty virtual base causes a class to be non-empty
3572          -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3573          here because that was already done when the virtual table
3574          pointer was created.  */
3575     }
3576
3577   /* Record the offsets of BINFO and its base subobjects.  */
3578   record_subobject_offsets (binfo,
3579                             BINFO_OFFSET (binfo),
3580                             offsets,
3581                             /*vbases_p=*/0);
3582
3583   return next_field;
3584 }
3585
3586 /* Layout all of the non-virtual base classes.  Record empty
3587    subobjects in OFFSETS.  T is the most derived type.  Return nonzero
3588    if the type cannot be nearly empty.  The fields created
3589    corresponding to the base classes will be inserted at
3590    *NEXT_FIELD.  */
3591
3592 static void
3593 build_base_fields (record_layout_info rli,
3594                    splay_tree offsets, tree *next_field)
3595 {
3596   /* Chain to hold all the new FIELD_DECLs which stand in for base class
3597      subobjects.  */
3598   tree t = rli->t;
3599   int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
3600   int i;
3601
3602   /* The primary base class is always allocated first.  */
3603   if (CLASSTYPE_HAS_PRIMARY_BASE_P (t))
3604     next_field = build_base_field (rli, CLASSTYPE_PRIMARY_BINFO (t),
3605                                    offsets, next_field);
3606
3607   /* Now allocate the rest of the bases.  */
3608   for (i = 0; i < n_baseclasses; ++i)
3609     {
3610       tree base_binfo;
3611
3612       base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i);
3613
3614       /* The primary base was already allocated above, so we don't
3615          need to allocate it again here.  */
3616       if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t))
3617         continue;
3618
3619       /* Virtual bases are added at the end (a primary virtual base
3620          will have already been added).  */
3621       if (BINFO_VIRTUAL_P (base_binfo))
3622         continue;
3623
3624       next_field = build_base_field (rli, base_binfo,
3625                                      offsets, next_field);
3626     }
3627 }
3628
3629 /* Go through the TYPE_METHODS of T issuing any appropriate
3630    diagnostics, figuring out which methods override which other
3631    methods, and so forth.  */
3632
3633 static void
3634 check_methods (tree t)
3635 {
3636   tree x;
3637
3638   for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
3639     {
3640       check_for_override (x, t);
3641       if (DECL_PURE_VIRTUAL_P (x) && ! DECL_VINDEX (x))
3642         error ("initializer specified for non-virtual method %q+D", x);
3643       /* The name of the field is the original field name
3644          Save this in auxiliary field for later overloading.  */
3645       if (DECL_VINDEX (x))
3646         {
3647           TYPE_POLYMORPHIC_P (t) = 1;
3648           if (DECL_PURE_VIRTUAL_P (x))
3649             VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x);
3650         }
3651       /* All user-declared destructors are non-trivial.  */
3652       if (DECL_DESTRUCTOR_P (x))
3653         TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = 1;
3654     }
3655 }
3656
3657 /* FN is a constructor or destructor.  Clone the declaration to create
3658    a specialized in-charge or not-in-charge version, as indicated by
3659    NAME.  */
3660
3661 static tree
3662 build_clone (tree fn, tree name)
3663 {
3664   tree parms;
3665   tree clone;
3666
3667   /* Copy the function.  */
3668   clone = copy_decl (fn);
3669   /* Remember where this function came from.  */
3670   DECL_CLONED_FUNCTION (clone) = fn;
3671   DECL_ABSTRACT_ORIGIN (clone) = fn;
3672   /* Reset the function name.  */
3673   DECL_NAME (clone) = name;
3674   SET_DECL_ASSEMBLER_NAME (clone, NULL_TREE);
3675   /* There's no pending inline data for this function.  */
3676   DECL_PENDING_INLINE_INFO (clone) = NULL;
3677   DECL_PENDING_INLINE_P (clone) = 0;
3678   /* And it hasn't yet been deferred.  */
3679   DECL_DEFERRED_FN (clone) = 0;
3680
3681   /* The base-class destructor is not virtual.  */
3682   if (name == base_dtor_identifier)
3683     {
3684       DECL_VIRTUAL_P (clone) = 0;
3685       if (TREE_CODE (clone) != TEMPLATE_DECL)
3686         DECL_VINDEX (clone) = NULL_TREE;
3687     }
3688
3689   /* If there was an in-charge parameter, drop it from the function
3690      type.  */
3691   if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3692     {
3693       tree basetype;
3694       tree parmtypes;
3695       tree exceptions;
3696
3697       exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
3698       basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
3699       parmtypes = TYPE_ARG_TYPES (TREE_TYPE (clone));
3700       /* Skip the `this' parameter.  */
3701       parmtypes = TREE_CHAIN (parmtypes);
3702       /* Skip the in-charge parameter.  */
3703       parmtypes = TREE_CHAIN (parmtypes);
3704       /* And the VTT parm, in a complete [cd]tor.  */
3705       if (DECL_HAS_VTT_PARM_P (fn)
3706           && ! DECL_NEEDS_VTT_PARM_P (clone))
3707         parmtypes = TREE_CHAIN (parmtypes);
3708        /* If this is subobject constructor or destructor, add the vtt
3709          parameter.  */
3710       TREE_TYPE (clone)
3711         = build_method_type_directly (basetype,
3712                                       TREE_TYPE (TREE_TYPE (clone)),
3713                                       parmtypes);
3714       if (exceptions)
3715         TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone),
3716                                                      exceptions);
3717       TREE_TYPE (clone)
3718         = cp_build_type_attribute_variant (TREE_TYPE (clone),
3719                                            TYPE_ATTRIBUTES (TREE_TYPE (fn)));
3720     }
3721
3722   /* Copy the function parameters.  But, DECL_ARGUMENTS on a TEMPLATE_DECL
3723      aren't function parameters; those are the template parameters.  */
3724   if (TREE_CODE (clone) != TEMPLATE_DECL)
3725     {
3726       DECL_ARGUMENTS (clone) = copy_list (DECL_ARGUMENTS (clone));
3727       /* Remove the in-charge parameter.  */
3728       if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3729         {
3730           TREE_CHAIN (DECL_ARGUMENTS (clone))
3731             = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3732           DECL_HAS_IN_CHARGE_PARM_P (clone) = 0;
3733         }
3734       /* And the VTT parm, in a complete [cd]tor.  */
3735       if (DECL_HAS_VTT_PARM_P (fn))
3736         {
3737           if (DECL_NEEDS_VTT_PARM_P (clone))
3738             DECL_HAS_VTT_PARM_P (clone) = 1;
3739           else
3740             {
3741               TREE_CHAIN (DECL_ARGUMENTS (clone))
3742                 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3743               DECL_HAS_VTT_PARM_P (clone) = 0;
3744             }
3745         }
3746
3747       for (parms = DECL_ARGUMENTS (clone); parms; parms = TREE_CHAIN (parms))
3748         {
3749           DECL_CONTEXT (parms) = clone;
3750           cxx_dup_lang_specific_decl (parms);
3751         }
3752     }
3753
3754   /* Create the RTL for this function.  */
3755   SET_DECL_RTL (clone, NULL_RTX);
3756   rest_of_decl_compilation (clone, /*top_level=*/1, at_eof);
3757
3758   /* Make it easy to find the CLONE given the FN.  */
3759   TREE_CHAIN (clone) = TREE_CHAIN (fn);
3760   TREE_CHAIN (fn) = clone;
3761
3762   /* If this is a template, handle the DECL_TEMPLATE_RESULT as well.  */
3763   if (TREE_CODE (clone) == TEMPLATE_DECL)
3764     {
3765       tree result;
3766
3767       DECL_TEMPLATE_RESULT (clone)
3768         = build_clone (DECL_TEMPLATE_RESULT (clone), name);
3769       result = DECL_TEMPLATE_RESULT (clone);
3770       DECL_TEMPLATE_INFO (result) = copy_node (DECL_TEMPLATE_INFO (result));
3771       DECL_TI_TEMPLATE (result) = clone;
3772     }
3773   else if (pch_file)
3774     note_decl_for_pch (clone);
3775
3776   return clone;
3777 }
3778
3779 /* Produce declarations for all appropriate clones of FN.  If
3780    UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
3781    CLASTYPE_METHOD_VEC as well.  */
3782
3783 void
3784 clone_function_decl (tree fn, int update_method_vec_p)
3785 {
3786   tree clone;
3787
3788   /* Avoid inappropriate cloning.  */
3789   if (TREE_CHAIN (fn)
3790       && DECL_CLONED_FUNCTION (TREE_CHAIN (fn)))
3791     return;
3792
3793   if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
3794     {
3795       /* For each constructor, we need two variants: an in-charge version
3796          and a not-in-charge version.  */
3797       clone = build_clone (fn, complete_ctor_identifier);
3798       if (update_method_vec_p)
3799         add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3800       clone = build_clone (fn, base_ctor_identifier);
3801       if (update_method_vec_p)
3802         add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3803     }
3804   else
3805     {
3806       gcc_assert (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn));
3807
3808       /* For each destructor, we need three variants: an in-charge
3809          version, a not-in-charge version, and an in-charge deleting
3810          version.  We clone the deleting version first because that
3811          means it will go second on the TYPE_METHODS list -- and that
3812          corresponds to the correct layout order in the virtual
3813          function table.
3814
3815          For a non-virtual destructor, we do not build a deleting
3816          destructor.  */
3817       if (DECL_VIRTUAL_P (fn))
3818         {
3819           clone = build_clone (fn, deleting_dtor_identifier);
3820           if (update_method_vec_p)
3821             add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3822         }
3823       clone = build_clone (fn, complete_dtor_identifier);
3824       if (update_method_vec_p)
3825         add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3826       clone = build_clone (fn, base_dtor_identifier);
3827       if (update_method_vec_p)
3828         add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3829     }
3830
3831   /* Note that this is an abstract function that is never emitted.  */
3832   DECL_ABSTRACT (fn) = 1;
3833 }
3834
3835 /* DECL is an in charge constructor, which is being defined. This will
3836    have had an in class declaration, from whence clones were
3837    declared. An out-of-class definition can specify additional default
3838    arguments. As it is the clones that are involved in overload
3839    resolution, we must propagate the information from the DECL to its
3840    clones.  */
3841
3842 void
3843 adjust_clone_args (tree decl)
3844 {
3845   tree clone;
3846
3847   for (clone = TREE_CHAIN (decl); clone && DECL_CLONED_FUNCTION (clone);
3848        clone = TREE_CHAIN (clone))
3849     {
3850       tree orig_clone_parms = TYPE_ARG_TYPES (TREE_TYPE (clone));
3851       tree orig_decl_parms = TYPE_ARG_TYPES (TREE_TYPE (decl));
3852       tree decl_parms, clone_parms;
3853
3854       clone_parms = orig_clone_parms;
3855
3856       /* Skip the 'this' parameter.  */
3857       orig_clone_parms = TREE_CHAIN (orig_clone_parms);
3858       orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3859
3860       if (DECL_HAS_IN_CHARGE_PARM_P (decl))
3861         orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3862       if (DECL_HAS_VTT_PARM_P (decl))
3863         orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3864
3865       clone_parms = orig_clone_parms;
3866       if (DECL_HAS_VTT_PARM_P (clone))
3867         clone_parms = TREE_CHAIN (clone_parms);
3868
3869       for (decl_parms = orig_decl_parms; decl_parms;
3870            decl_parms = TREE_CHAIN (decl_parms),
3871              clone_parms = TREE_CHAIN (clone_parms))
3872         {
3873           gcc_assert (same_type_p (TREE_TYPE (decl_parms),
3874                                    TREE_TYPE (clone_parms)));
3875
3876           if (TREE_PURPOSE (decl_parms) && !TREE_PURPOSE (clone_parms))
3877             {
3878               /* A default parameter has been added. Adjust the
3879                  clone's parameters.  */
3880               tree exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
3881               tree basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
3882               tree type;
3883
3884               clone_parms = orig_decl_parms;
3885
3886               if (DECL_HAS_VTT_PARM_P (clone))
3887                 {
3888                   clone_parms = tree_cons (TREE_PURPOSE (orig_clone_parms),
3889                                            TREE_VALUE (orig_clone_parms),
3890                                            clone_parms);
3891                   TREE_TYPE (clone_parms) = TREE_TYPE (orig_clone_parms);
3892                 }
3893               type = build_method_type_directly (basetype,
3894                                                  TREE_TYPE (TREE_TYPE (clone)),
3895                                                  clone_parms);
3896               if (exceptions)
3897                 type = build_exception_variant (type, exceptions);
3898               TREE_TYPE (clone) = type;
3899
3900               clone_parms = NULL_TREE;
3901               break;
3902             }
3903         }
3904       gcc_assert (!clone_parms);
3905     }
3906 }
3907
3908 /* For each of the constructors and destructors in T, create an
3909    in-charge and not-in-charge variant.  */
3910
3911 static void
3912 clone_constructors_and_destructors (tree t)
3913 {
3914   tree fns;
3915
3916   /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
3917      out now.  */
3918   if (!CLASSTYPE_METHOD_VEC (t))
3919     return;
3920
3921   for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
3922     clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
3923   for (fns = CLASSTYPE_DESTRUCTORS (t); fns; fns = OVL_NEXT (fns))
3924     clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
3925 }
3926
3927 /* Remove all zero-width bit-fields from T.  */
3928
3929 static void
3930 remove_zero_width_bit_fields (tree t)
3931 {
3932   tree *fieldsp;
3933
3934   fieldsp = &TYPE_FIELDS (t);
3935   while (*fieldsp)
3936     {
3937       if (TREE_CODE (*fieldsp) == FIELD_DECL
3938           && DECL_C_BIT_FIELD (*fieldsp)
3939           && DECL_INITIAL (*fieldsp))
3940         *fieldsp = TREE_CHAIN (*fieldsp);
3941       else
3942         fieldsp = &TREE_CHAIN (*fieldsp);
3943     }
3944 }
3945
3946 /* Returns TRUE iff we need a cookie when dynamically allocating an
3947    array whose elements have the indicated class TYPE.  */
3948
3949 static bool
3950 type_requires_array_cookie (tree type)
3951 {
3952   tree fns;
3953   bool has_two_argument_delete_p = false;
3954
3955   gcc_assert (CLASS_TYPE_P (type));
3956
3957   /* If there's a non-trivial destructor, we need a cookie.  In order
3958      to iterate through the array calling the destructor for each
3959      element, we'll have to know how many elements there are.  */
3960   if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
3961     return true;
3962
3963   /* If the usual deallocation function is a two-argument whose second
3964      argument is of type `size_t', then we have to pass the size of
3965      the array to the deallocation function, so we will need to store
3966      a cookie.  */
3967   fns = lookup_fnfields (TYPE_BINFO (type),
3968                          ansi_opname (VEC_DELETE_EXPR),
3969                          /*protect=*/0);
3970   /* If there are no `operator []' members, or the lookup is
3971      ambiguous, then we don't need a cookie.  */
3972   if (!fns || fns == error_mark_node)
3973     return false;
3974   /* Loop through all of the functions.  */
3975   for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
3976     {
3977       tree fn;
3978       tree second_parm;
3979
3980       /* Select the current function.  */
3981       fn = OVL_CURRENT (fns);
3982       /* See if this function is a one-argument delete function.  If
3983          it is, then it will be the usual deallocation function.  */
3984       second_parm = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fn)));
3985       if (second_parm == void_list_node)
3986         return false;
3987       /* Otherwise, if we have a two-argument function and the second
3988          argument is `size_t', it will be the usual deallocation
3989          function -- unless there is one-argument function, too.  */
3990       if (TREE_CHAIN (second_parm) == void_list_node
3991           && same_type_p (TREE_VALUE (second_parm), sizetype))
3992         has_two_argument_delete_p = true;
3993     }
3994
3995   return has_two_argument_delete_p;
3996 }
3997
3998 /* Check the validity of the bases and members declared in T.  Add any
3999    implicitly-generated functions (like copy-constructors and
4000    assignment operators).  Compute various flag bits (like
4001    CLASSTYPE_NON_POD_T) for T.  This routine works purely at the C++
4002    level: i.e., independently of the ABI in use.  */
4003
4004 static void
4005 check_bases_and_members (tree t)
4006 {
4007   /* Nonzero if the implicitly generated copy constructor should take
4008      a non-const reference argument.  */
4009   int cant_have_const_ctor;
4010   /* Nonzero if the implicitly generated assignment operator
4011      should take a non-const reference argument.  */
4012   int no_const_asn_ref;
4013   tree access_decls;
4014
4015   /* By default, we use const reference arguments and generate default
4016      constructors.  */
4017   cant_have_const_ctor = 0;
4018   no_const_asn_ref = 0;
4019
4020   /* Check all the base-classes.  */
4021   check_bases (t, &cant_have_const_ctor,
4022                &no_const_asn_ref);
4023
4024   /* Check all the method declarations.  */
4025   check_methods (t);
4026
4027   /* Check all the data member declarations.  We cannot call
4028      check_field_decls until we have called check_bases check_methods,
4029      as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
4030      being set appropriately.  */
4031   check_field_decls (t, &access_decls,
4032                      &cant_have_const_ctor,
4033                      &no_const_asn_ref);
4034
4035   /* A nearly-empty class has to be vptr-containing; a nearly empty
4036      class contains just a vptr.  */
4037   if (!TYPE_CONTAINS_VPTR_P (t))
4038     CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
4039
4040   /* Do some bookkeeping that will guide the generation of implicitly
4041      declared member functions.  */
4042   TYPE_HAS_COMPLEX_INIT_REF (t)
4043     |= (TYPE_HAS_INIT_REF (t) || TYPE_CONTAINS_VPTR_P (t));
4044   TYPE_NEEDS_CONSTRUCTING (t)
4045     |= (TYPE_HAS_CONSTRUCTOR (t) || TYPE_CONTAINS_VPTR_P (t));
4046   CLASSTYPE_NON_AGGREGATE (t)
4047     |= (TYPE_HAS_CONSTRUCTOR (t) || TYPE_POLYMORPHIC_P (t));
4048   CLASSTYPE_NON_POD_P (t)
4049     |= (CLASSTYPE_NON_AGGREGATE (t)
4050         || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
4051         || TYPE_HAS_ASSIGN_REF (t));
4052   TYPE_HAS_COMPLEX_ASSIGN_REF (t)
4053     |= TYPE_HAS_ASSIGN_REF (t) || TYPE_CONTAINS_VPTR_P (t);
4054
4055   /* Synthesize any needed methods.  */
4056   add_implicitly_declared_members (t,
4057                                    cant_have_const_ctor,
4058                                    no_const_asn_ref);
4059
4060   /* Create the in-charge and not-in-charge variants of constructors
4061      and destructors.  */
4062   clone_constructors_and_destructors (t);
4063
4064   /* Process the using-declarations.  */
4065   for (; access_decls; access_decls = TREE_CHAIN (access_decls))
4066     handle_using_decl (TREE_VALUE (access_decls), t);
4067
4068   /* Build and sort the CLASSTYPE_METHOD_VEC.  */
4069   finish_struct_methods (t);
4070
4071   /* Figure out whether or not we will need a cookie when dynamically
4072      allocating an array of this type.  */
4073   TYPE_LANG_SPECIFIC (t)->u.c.vec_new_uses_cookie
4074     = type_requires_array_cookie (t);
4075 }
4076
4077 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4078    accordingly.  If a new vfield was created (because T doesn't have a
4079    primary base class), then the newly created field is returned.  It
4080    is not added to the TYPE_FIELDS list; it is the caller's
4081    responsibility to do that.  Accumulate declared virtual functions
4082    on VIRTUALS_P.  */
4083
4084 static tree
4085 create_vtable_ptr (tree t, tree* virtuals_p)
4086 {
4087   tree fn;
4088
4089   /* Collect the virtual functions declared in T.  */
4090   for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
4091     if (DECL_VINDEX (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)
4092         && TREE_CODE (DECL_VINDEX (fn)) != INTEGER_CST)
4093       {
4094         tree new_virtual = make_node (TREE_LIST);
4095
4096         BV_FN (new_virtual) = fn;
4097         BV_DELTA (new_virtual) = integer_zero_node;
4098         BV_VCALL_INDEX (new_virtual) = NULL_TREE;
4099
4100         TREE_CHAIN (new_virtual) = *virtuals_p;
4101         *virtuals_p = new_virtual;
4102       }
4103
4104   /* If we couldn't find an appropriate base class, create a new field
4105      here.  Even if there weren't any new virtual functions, we might need a
4106      new virtual function table if we're supposed to include vptrs in
4107      all classes that need them.  */
4108   if (!TYPE_VFIELD (t) && (*virtuals_p || TYPE_CONTAINS_VPTR_P (t)))
4109     {
4110       /* We build this decl with vtbl_ptr_type_node, which is a
4111          `vtable_entry_type*'.  It might seem more precise to use
4112          `vtable_entry_type (*)[N]' where N is the number of virtual
4113          functions.  However, that would require the vtable pointer in
4114          base classes to have a different type than the vtable pointer
4115          in derived classes.  We could make that happen, but that
4116          still wouldn't solve all the problems.  In particular, the
4117          type-based alias analysis code would decide that assignments
4118          to the base class vtable pointer can't alias assignments to
4119          the derived class vtable pointer, since they have different
4120          types.  Thus, in a derived class destructor, where the base
4121          class constructor was inlined, we could generate bad code for
4122          setting up the vtable pointer.
4123
4124          Therefore, we use one type for all vtable pointers.  We still
4125          use a type-correct type; it's just doesn't indicate the array
4126          bounds.  That's better than using `void*' or some such; it's
4127          cleaner, and it let's the alias analysis code know that these
4128          stores cannot alias stores to void*!  */
4129       tree field;
4130
4131       field = build_decl (FIELD_DECL, get_vfield_name (t), vtbl_ptr_type_node);
4132       SET_DECL_ASSEMBLER_NAME (field, get_identifier (VFIELD_BASE));
4133       DECL_VIRTUAL_P (field) = 1;
4134       DECL_ARTIFICIAL (field) = 1;
4135       DECL_FIELD_CONTEXT (field) = t;
4136       DECL_FCONTEXT (field) = t;
4137
4138       TYPE_VFIELD (t) = field;
4139
4140       /* This class is non-empty.  */
4141       CLASSTYPE_EMPTY_P (t) = 0;
4142
4143       return field;
4144     }
4145
4146   return NULL_TREE;
4147 }
4148
4149 /* Fixup the inline function given by INFO now that the class is
4150    complete.  */
4151
4152 static void
4153 fixup_pending_inline (tree fn)
4154 {
4155   if (DECL_PENDING_INLINE_INFO (fn))
4156     {
4157       tree args = DECL_ARGUMENTS (fn);
4158       while (args)
4159         {
4160           DECL_CONTEXT (args) = fn;
4161           args = TREE_CHAIN (args);
4162         }
4163     }
4164 }
4165
4166 /* Fixup the inline methods and friends in TYPE now that TYPE is
4167    complete.  */
4168
4169 static void
4170 fixup_inline_methods (tree type)
4171 {
4172   tree method = TYPE_METHODS (type);
4173   VEC(tree,gc) *friends;
4174   unsigned ix;
4175
4176   if (method && TREE_CODE (method) == TREE_VEC)
4177     {
4178       if (TREE_VEC_ELT (method, 1))
4179         method = TREE_VEC_ELT (method, 1);
4180       else if (TREE_VEC_ELT (method, 0))
4181         method = TREE_VEC_ELT (method, 0);
4182       else
4183         method = TREE_VEC_ELT (method, 2);
4184     }
4185
4186   /* Do inline member functions.  */
4187   for (; method; method = TREE_CHAIN (method))
4188     fixup_pending_inline (method);
4189
4190   /* Do friends.  */
4191   for (friends = CLASSTYPE_INLINE_FRIENDS (type), ix = 0;
4192        VEC_iterate (tree, friends, ix, method); ix++)
4193     fixup_pending_inline (method);
4194   CLASSTYPE_INLINE_FRIENDS (type) = NULL;
4195 }
4196
4197 /* Add OFFSET to all base types of BINFO which is a base in the
4198    hierarchy dominated by T.
4199
4200    OFFSET, which is a type offset, is number of bytes.  */
4201
4202 static void
4203 propagate_binfo_offsets (tree binfo, tree offset)
4204 {
4205   int i;
4206   tree primary_binfo;
4207   tree base_binfo;
4208
4209   /* Update BINFO's offset.  */
4210   BINFO_OFFSET (binfo)
4211     = convert (sizetype,
4212                size_binop (PLUS_EXPR,
4213                            convert (ssizetype, BINFO_OFFSET (binfo)),
4214                            offset));
4215
4216   /* Find the primary base class.  */
4217   primary_binfo = get_primary_binfo (binfo);
4218
4219   if (primary_binfo && BINFO_INHERITANCE_CHAIN (primary_binfo) == binfo)
4220     propagate_binfo_offsets (primary_binfo, offset);
4221
4222   /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4223      downwards.  */
4224   for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4225     {
4226       /* Don't do the primary base twice.  */
4227       if (base_binfo == primary_binfo)
4228         continue;
4229
4230       if (BINFO_VIRTUAL_P (base_binfo))
4231         continue;
4232
4233       propagate_binfo_offsets (base_binfo, offset);
4234     }
4235 }
4236
4237 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T.  Update
4238    TYPE_ALIGN and TYPE_SIZE for T.  OFFSETS gives the location of
4239    empty subobjects of T.  */
4240
4241 static void
4242 layout_virtual_bases (record_layout_info rli, splay_tree offsets)
4243 {
4244   tree vbase;
4245   tree t = rli->t;
4246   bool first_vbase = true;
4247   tree *next_field;
4248
4249   if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) == 0)
4250     return;
4251
4252   if (!abi_version_at_least(2))
4253     {
4254       /* In G++ 3.2, we incorrectly rounded the size before laying out
4255          the virtual bases.  */
4256       finish_record_layout (rli, /*free_p=*/false);
4257 #ifdef STRUCTURE_SIZE_BOUNDARY
4258       /* Packed structures don't need to have minimum size.  */
4259       if (! TYPE_PACKED (t))
4260         TYPE_ALIGN (t) = MAX (TYPE_ALIGN (t), (unsigned) STRUCTURE_SIZE_BOUNDARY);
4261 #endif
4262       rli->offset = TYPE_SIZE_UNIT (t);
4263       rli->bitpos = bitsize_zero_node;
4264       rli->record_align = TYPE_ALIGN (t);
4265     }
4266
4267   /* Find the last field.  The artificial fields created for virtual
4268      bases will go after the last extant field to date.  */
4269   next_field = &TYPE_FIELDS (t);
4270   while (*next_field)
4271     next_field = &TREE_CHAIN (*next_field);
4272
4273   /* Go through the virtual bases, allocating space for each virtual
4274      base that is not already a primary base class.  These are
4275      allocated in inheritance graph order.  */
4276   for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
4277     {
4278       if (!BINFO_VIRTUAL_P (vbase))
4279         continue;
4280
4281       if (!BINFO_PRIMARY_P (vbase))
4282         {
4283           tree basetype = TREE_TYPE (vbase);
4284
4285           /* This virtual base is not a primary base of any class in the
4286              hierarchy, so we have to add space for it.  */
4287           next_field = build_base_field (rli, vbase,
4288                                          offsets, next_field);
4289
4290           /* If the first virtual base might have been placed at a
4291              lower address, had we started from CLASSTYPE_SIZE, rather
4292              than TYPE_SIZE, issue a warning.  There can be both false
4293              positives and false negatives from this warning in rare
4294              cases; to deal with all the possibilities would probably
4295              require performing both layout algorithms and comparing
4296              the results which is not particularly tractable.  */
4297           if (warn_abi
4298               && first_vbase
4299               && (tree_int_cst_lt
4300                   (size_binop (CEIL_DIV_EXPR,
4301                                round_up (CLASSTYPE_SIZE (t),
4302                                          CLASSTYPE_ALIGN (basetype)),
4303                                bitsize_unit_node),
4304                    BINFO_OFFSET (vbase))))
4305             warning (0, "offset of virtual base %qT is not ABI-compliant and "
4306                      "may change in a future version of GCC",
4307                      basetype);
4308
4309           first_vbase = false;
4310         }
4311     }
4312 }
4313
4314 /* Returns the offset of the byte just past the end of the base class
4315    BINFO.  */
4316
4317 static tree
4318 end_of_base (tree binfo)
4319 {
4320   tree size;
4321
4322   if (is_empty_class (BINFO_TYPE (binfo)))
4323     /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4324        allocate some space for it. It cannot have virtual bases, so
4325        TYPE_SIZE_UNIT is fine.  */
4326     size = TYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4327   else
4328     size = CLASSTYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4329
4330   return size_binop (PLUS_EXPR, BINFO_OFFSET (binfo), size);
4331 }
4332
4333 /* Returns the offset of the byte just past the end of the base class
4334    with the highest offset in T.  If INCLUDE_VIRTUALS_P is zero, then
4335    only non-virtual bases are included.  */
4336
4337 static tree
4338 end_of_class (tree t, int include_virtuals_p)
4339 {
4340   tree result = size_zero_node;
4341   VEC(tree,gc) *vbases;
4342   tree binfo;
4343   tree base_binfo;
4344   tree offset;
4345   int i;
4346
4347   for (binfo = TYPE_BINFO (t), i = 0;
4348        BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4349     {
4350       if (!include_virtuals_p
4351           && BINFO_VIRTUAL_P (base_binfo)
4352           && (!BINFO_PRIMARY_P (base_binfo)
4353               || BINFO_INHERITANCE_CHAIN (base_binfo) != TYPE_BINFO (t)))
4354         continue;
4355
4356       offset = end_of_base (base_binfo);
4357       if (INT_CST_LT_UNSIGNED (result, offset))
4358         result = offset;
4359     }
4360
4361   /* G++ 3.2 did not check indirect virtual bases.  */
4362   if (abi_version_at_least (2) && include_virtuals_p)
4363     for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4364          VEC_iterate (tree, vbases, i, base_binfo); i++)
4365       {
4366         offset = end_of_base (base_binfo);
4367         if (INT_CST_LT_UNSIGNED (result, offset))
4368           result = offset;
4369       }
4370
4371   return result;
4372 }
4373
4374 /* Warn about bases of T that are inaccessible because they are
4375    ambiguous.  For example:
4376
4377      struct S {};
4378      struct T : public S {};
4379      struct U : public S, public T {};
4380
4381    Here, `(S*) new U' is not allowed because there are two `S'
4382    subobjects of U.  */
4383
4384 static void
4385 warn_about_ambiguous_bases (tree t)
4386 {
4387   int i;
4388   VEC(tree,gc) *vbases;
4389   tree basetype;
4390   tree binfo;
4391   tree base_binfo;
4392
4393   /* If there are no repeated bases, nothing can be ambiguous.  */
4394   if (!CLASSTYPE_REPEATED_BASE_P (t))
4395     return;
4396
4397   /* Check direct bases.  */
4398   for (binfo = TYPE_BINFO (t), i = 0;
4399        BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4400     {
4401       basetype = BINFO_TYPE (base_binfo);
4402
4403       if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4404         warning (0, "direct base %qT inaccessible in %qT due to ambiguity",
4405                  basetype, t);
4406     }
4407
4408   /* Check for ambiguous virtual bases.  */
4409   if (extra_warnings)
4410     for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4411          VEC_iterate (tree, vbases, i, binfo); i++)
4412       {
4413         basetype = BINFO_TYPE (binfo);
4414
4415         if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4416           warning (0, "virtual base %qT inaccessible in %qT due to ambiguity",
4417                    basetype, t);
4418       }
4419 }
4420
4421 /* Compare two INTEGER_CSTs K1 and K2.  */
4422
4423 static int
4424 splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2)
4425 {
4426   return tree_int_cst_compare ((tree) k1, (tree) k2);
4427 }
4428
4429 /* Increase the size indicated in RLI to account for empty classes
4430    that are "off the end" of the class.  */
4431
4432 static void
4433 include_empty_classes (record_layout_info rli)
4434 {
4435   tree eoc;
4436   tree rli_size;
4437
4438   /* It might be the case that we grew the class to allocate a
4439      zero-sized base class.  That won't be reflected in RLI, yet,
4440      because we are willing to overlay multiple bases at the same
4441      offset.  However, now we need to make sure that RLI is big enough
4442      to reflect the entire class.  */
4443   eoc = end_of_class (rli->t,
4444                       CLASSTYPE_AS_BASE (rli->t) != NULL_TREE);
4445   rli_size = rli_size_unit_so_far (rli);
4446   if (TREE_CODE (rli_size) == INTEGER_CST
4447       && INT_CST_LT_UNSIGNED (rli_size, eoc))
4448     {
4449       if (!abi_version_at_least (2))
4450         /* In version 1 of the ABI, the size of a class that ends with
4451            a bitfield was not rounded up to a whole multiple of a
4452            byte.  Because rli_size_unit_so_far returns only the number
4453            of fully allocated bytes, any extra bits were not included
4454            in the size.  */
4455         rli->bitpos = round_down (rli->bitpos, BITS_PER_UNIT);
4456       else
4457         /* The size should have been rounded to a whole byte.  */
4458         gcc_assert (tree_int_cst_equal
4459                     (rli->bitpos, round_down (rli->bitpos, BITS_PER_UNIT)));
4460       rli->bitpos
4461         = size_binop (PLUS_EXPR,
4462                       rli->bitpos,
4463                       size_binop (MULT_EXPR,
4464                                   convert (bitsizetype,
4465                                            size_binop (MINUS_EXPR,
4466                                                        eoc, rli_size)),
4467                                   bitsize_int (BITS_PER_UNIT)));
4468       normalize_rli (rli);
4469     }
4470 }
4471
4472 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T.  Calculate
4473    BINFO_OFFSETs for all of the base-classes.  Position the vtable
4474    pointer.  Accumulate declared virtual functions on VIRTUALS_P.  */
4475
4476 static void
4477 layout_class_type (tree t, tree *virtuals_p)
4478 {
4479   tree non_static_data_members;
4480   tree field;
4481   tree vptr;
4482   record_layout_info rli;
4483   /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4484      types that appear at that offset.  */
4485   splay_tree empty_base_offsets;
4486   /* True if the last field layed out was a bit-field.  */
4487   bool last_field_was_bitfield = false;
4488   /* The location at which the next field should be inserted.  */
4489   tree *next_field;
4490   /* T, as a base class.  */
4491   tree base_t;
4492
4493   /* Keep track of the first non-static data member.  */
4494   non_static_data_members = TYPE_FIELDS (t);
4495
4496   /* Start laying out the record.  */
4497   rli = start_record_layout (t);
4498
4499   /* Mark all the primary bases in the hierarchy.  */
4500   determine_primary_bases (t);
4501
4502   /* Create a pointer to our virtual function table.  */
4503   vptr = create_vtable_ptr (t, virtuals_p);
4504
4505   /* The vptr is always the first thing in the class.  */
4506   if (vptr)
4507     {
4508       TREE_CHAIN (vptr) = TYPE_FIELDS (t);
4509       TYPE_FIELDS (t) = vptr;
4510       next_field = &TREE_CHAIN (vptr);
4511       place_field (rli, vptr);
4512     }
4513   else
4514     next_field = &TYPE_FIELDS (t);
4515
4516   /* Build FIELD_DECLs for all of the non-virtual base-types.  */
4517   empty_base_offsets = splay_tree_new (splay_tree_compare_integer_csts,
4518                                        NULL, NULL);
4519   build_base_fields (rli, empty_base_offsets, next_field);
4520
4521   /* Layout the non-static data members.  */
4522   for (field = non_static_data_members; field; field = TREE_CHAIN (field))
4523     {
4524       tree type;
4525       tree padding;
4526
4527       /* We still pass things that aren't non-static data members to
4528          the back-end, in case it wants to do something with them.  */
4529       if (TREE_CODE (field) != FIELD_DECL)
4530         {
4531           place_field (rli, field);
4532           /* If the static data member has incomplete type, keep track
4533              of it so that it can be completed later.  (The handling
4534              of pending statics in finish_record_layout is
4535              insufficient; consider:
4536
4537                struct S1;
4538                struct S2 { static S1 s1; };
4539
4540              At this point, finish_record_layout will be called, but
4541              S1 is still incomplete.)  */
4542           if (TREE_CODE (field) == VAR_DECL)
4543             {
4544               maybe_register_incomplete_var (field);
4545               /* The visibility of static data members is determined
4546                  at their point of declaration, not their point of
4547                  definition.  */
4548               determine_visibility (field);
4549             }
4550           continue;
4551         }
4552
4553       type = TREE_TYPE (field);
4554
4555       padding = NULL_TREE;
4556
4557       /* If this field is a bit-field whose width is greater than its
4558          type, then there are some special rules for allocating
4559          it.  */
4560       if (DECL_C_BIT_FIELD (field)
4561           && INT_CST_LT (TYPE_SIZE (type), DECL_SIZE (field)))
4562         {
4563           integer_type_kind itk;
4564           tree integer_type;
4565           bool was_unnamed_p = false;
4566           /* We must allocate the bits as if suitably aligned for the
4567              longest integer type that fits in this many bits.  type
4568              of the field.  Then, we are supposed to use the left over
4569              bits as additional padding.  */
4570           for (itk = itk_char; itk != itk_none; ++itk)
4571             if (INT_CST_LT (DECL_SIZE (field),
4572                             TYPE_SIZE (integer_types[itk])))
4573               break;
4574
4575           /* ITK now indicates a type that is too large for the
4576              field.  We have to back up by one to find the largest
4577              type that fits.  */
4578           integer_type = integer_types[itk - 1];
4579
4580           /* Figure out how much additional padding is required.  GCC
4581              3.2 always created a padding field, even if it had zero
4582              width.  */
4583           if (!abi_version_at_least (2)
4584               || INT_CST_LT (TYPE_SIZE (integer_type), DECL_SIZE (field)))
4585             {
4586               if (abi_version_at_least (2) && TREE_CODE (t) == UNION_TYPE)
4587                 /* In a union, the padding field must have the full width
4588                    of the bit-field; all fields start at offset zero.  */
4589                 padding = DECL_SIZE (field);
4590               else
4591                 {
4592                   if (warn_abi && TREE_CODE (t) == UNION_TYPE)
4593                     warning (0, "size assigned to %qT may not be "
4594                              "ABI-compliant and may change in a future "
4595                              "version of GCC",
4596                              t);
4597                   padding = size_binop (MINUS_EXPR, DECL_SIZE (field),
4598                                         TYPE_SIZE (integer_type));
4599                 }
4600             }
4601 #ifdef PCC_BITFIELD_TYPE_MATTERS
4602           /* An unnamed bitfield does not normally affect the
4603              alignment of the containing class on a target where
4604              PCC_BITFIELD_TYPE_MATTERS.  But, the C++ ABI does not
4605              make any exceptions for unnamed bitfields when the
4606              bitfields are longer than their types.  Therefore, we
4607              temporarily give the field a name.  */
4608           if (PCC_BITFIELD_TYPE_MATTERS && !DECL_NAME (field))
4609             {
4610               was_unnamed_p = true;
4611               DECL_NAME (field) = make_anon_name ();
4612             }
4613 #endif
4614           DECL_SIZE (field) = TYPE_SIZE (integer_type);
4615           DECL_ALIGN (field) = TYPE_ALIGN (integer_type);
4616           DECL_USER_ALIGN (field) = TYPE_USER_ALIGN (integer_type);
4617           layout_nonempty_base_or_field (rli, field, NULL_TREE,
4618                                          empty_base_offsets);
4619           if (was_unnamed_p)
4620             DECL_NAME (field) = NULL_TREE;
4621           /* Now that layout has been performed, set the size of the
4622              field to the size of its declared type; the rest of the
4623              field is effectively invisible.  */
4624           DECL_SIZE (field) = TYPE_SIZE (type);
4625           /* We must also reset the DECL_MODE of the field.  */
4626           if (abi_version_at_least (2))
4627             DECL_MODE (field) = TYPE_MODE (type);
4628           else if (warn_abi
4629                    && DECL_MODE (field) != TYPE_MODE (type))
4630             /* Versions of G++ before G++ 3.4 did not reset the
4631                DECL_MODE.  */
4632             warning (0, "the offset of %qD may not be ABI-compliant and may "
4633                      "change in a future version of GCC", field);
4634         }
4635       else
4636         layout_nonempty_base_or_field (rli, field, NULL_TREE,
4637                                        empty_base_offsets);
4638
4639       /* Remember the location of any empty classes in FIELD.  */
4640       if (abi_version_at_least (2))
4641         record_subobject_offsets (TREE_TYPE (field),
4642                                   byte_position(field),
4643                                   empty_base_offsets,
4644                                   /*vbases_p=*/1);
4645
4646       /* If a bit-field does not immediately follow another bit-field,
4647          and yet it starts in the middle of a byte, we have failed to
4648          comply with the ABI.  */
4649       if (warn_abi
4650           && DECL_C_BIT_FIELD (field)
4651           /* The TREE_NO_WARNING flag gets set by Objective-C when
4652              laying out an Objective-C class.  The ObjC ABI differs
4653              from the C++ ABI, and so we do not want a warning
4654              here.  */
4655           && !TREE_NO_WARNING (field)
4656           && !last_field_was_bitfield
4657           && !integer_zerop (size_binop (TRUNC_MOD_EXPR,
4658                                          DECL_FIELD_BIT_OFFSET (field),
4659                                          bitsize_unit_node)))
4660         warning (0, "offset of %q+D is not ABI-compliant and may "
4661                  "change in a future version of GCC", field);
4662
4663       /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
4664          offset of the field.  */
4665       if (warn_abi
4666           && !tree_int_cst_equal (DECL_FIELD_OFFSET (field),
4667                                   byte_position (field))
4668           && contains_empty_class_p (TREE_TYPE (field)))
4669         warning (0, "%q+D contains empty classes which may cause base "
4670                  "classes to be placed at different locations in a "
4671                  "future version of GCC", field);
4672
4673       /* If we needed additional padding after this field, add it
4674          now.  */
4675       if (padding)
4676         {
4677           tree padding_field;
4678
4679           padding_field = build_decl (FIELD_DECL,
4680                                       NULL_TREE,
4681                                       char_type_node);
4682           DECL_BIT_FIELD (padding_field) = 1;
4683           DECL_SIZE (padding_field) = padding;
4684           DECL_CONTEXT (padding_field) = t;
4685           DECL_ARTIFICIAL (padding_field) = 1;
4686           DECL_IGNORED_P (padding_field) = 1;
4687           layout_nonempty_base_or_field (rli, padding_field,
4688                                          NULL_TREE,
4689                                          empty_base_offsets);
4690         }
4691
4692       last_field_was_bitfield = DECL_C_BIT_FIELD (field);
4693     }
4694
4695   if (abi_version_at_least (2) && !integer_zerop (rli->bitpos))
4696     {
4697       /* Make sure that we are on a byte boundary so that the size of
4698          the class without virtual bases will always be a round number
4699          of bytes.  */
4700       rli->bitpos = round_up (rli->bitpos, BITS_PER_UNIT);
4701       normalize_rli (rli);
4702     }
4703
4704   /* G++ 3.2 does not allow virtual bases to be overlaid with tail
4705      padding.  */
4706   if (!abi_version_at_least (2))
4707     include_empty_classes(rli);
4708
4709   /* Delete all zero-width bit-fields from the list of fields.  Now
4710      that the type is laid out they are no longer important.  */
4711   remove_zero_width_bit_fields (t);
4712
4713   /* Create the version of T used for virtual bases.  We do not use
4714      make_aggr_type for this version; this is an artificial type.  For
4715      a POD type, we just reuse T.  */
4716   if (CLASSTYPE_NON_POD_P (t) || CLASSTYPE_EMPTY_P (t))
4717     {
4718       base_t = make_node (TREE_CODE (t));
4719
4720       /* Set the size and alignment for the new type.  In G++ 3.2, all
4721          empty classes were considered to have size zero when used as
4722          base classes.  */
4723       if (!abi_version_at_least (2) && CLASSTYPE_EMPTY_P (t))
4724         {
4725           TYPE_SIZE (base_t) = bitsize_zero_node;
4726           TYPE_SIZE_UNIT (base_t) = size_zero_node;
4727           if (warn_abi && !integer_zerop (rli_size_unit_so_far (rli)))
4728             warning (0, "layout of classes derived from empty class %qT "
4729                      "may change in a future version of GCC",
4730                      t);
4731         }
4732       else
4733         {
4734           tree eoc;
4735
4736           /* If the ABI version is not at least two, and the last
4737              field was a bit-field, RLI may not be on a byte
4738              boundary.  In particular, rli_size_unit_so_far might
4739              indicate the last complete byte, while rli_size_so_far
4740              indicates the total number of bits used.  Therefore,
4741              rli_size_so_far, rather than rli_size_unit_so_far, is
4742              used to compute TYPE_SIZE_UNIT.  */
4743           eoc = end_of_class (t, /*include_virtuals_p=*/0);
4744           TYPE_SIZE_UNIT (base_t)
4745             = size_binop (MAX_EXPR,
4746                           convert (sizetype,
4747                                    size_binop (CEIL_DIV_EXPR,
4748                                                rli_size_so_far (rli),
4749                                                bitsize_int (BITS_PER_UNIT))),
4750                           eoc);
4751           TYPE_SIZE (base_t)
4752             = size_binop (MAX_EXPR,
4753                           rli_size_so_far (rli),
4754                           size_binop (MULT_EXPR,
4755                                       convert (bitsizetype, eoc),
4756                                       bitsize_int (BITS_PER_UNIT)));
4757         }
4758       TYPE_ALIGN (base_t) = rli->record_align;
4759       TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t);
4760
4761       /* Copy the fields from T.  */
4762       next_field = &TYPE_FIELDS (base_t);
4763       for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
4764         if (TREE_CODE (field) == FIELD_DECL)
4765           {
4766             *next_field = build_decl (FIELD_DECL,
4767                                       DECL_NAME (field),
4768                                       TREE_TYPE (field));
4769             DECL_CONTEXT (*next_field) = base_t;
4770             DECL_FIELD_OFFSET (*next_field) = DECL_FIELD_OFFSET (field);
4771             DECL_FIELD_BIT_OFFSET (*next_field)
4772               = DECL_FIELD_BIT_OFFSET (field);
4773             DECL_SIZE (*next_field) = DECL_SIZE (field);
4774             DECL_MODE (*next_field) = DECL_MODE (field);
4775             next_field = &TREE_CHAIN (*next_field);
4776           }
4777
4778       /* Record the base version of the type.  */
4779       CLASSTYPE_AS_BASE (t) = base_t;
4780       TYPE_CONTEXT (base_t) = t;
4781     }
4782   else
4783     CLASSTYPE_AS_BASE (t) = t;
4784
4785   /* Every empty class contains an empty class.  */
4786   if (CLASSTYPE_EMPTY_P (t))
4787     CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
4788
4789   /* Set the TYPE_DECL for this type to contain the right
4790      value for DECL_OFFSET, so that we can use it as part
4791      of a COMPONENT_REF for multiple inheritance.  */
4792   layout_decl (TYPE_MAIN_DECL (t), 0);
4793
4794   /* Now fix up any virtual base class types that we left lying
4795      around.  We must get these done before we try to lay out the
4796      virtual function table.  As a side-effect, this will remove the
4797      base subobject fields.  */
4798   layout_virtual_bases (rli, empty_base_offsets);
4799
4800   /* Make sure that empty classes are reflected in RLI at this
4801      point.  */
4802   include_empty_classes(rli);
4803
4804   /* Make sure not to create any structures with zero size.  */
4805   if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t))
4806     place_field (rli,
4807                  build_decl (FIELD_DECL, NULL_TREE, char_type_node));
4808
4809   /* Let the back-end lay out the type.  */
4810   finish_record_layout (rli, /*free_p=*/true);
4811
4812   /* Warn about bases that can't be talked about due to ambiguity.  */
4813   warn_about_ambiguous_bases (t);
4814
4815   /* Now that we're done with layout, give the base fields the real types.  */
4816   for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
4817     if (DECL_ARTIFICIAL (field) && IS_FAKE_BASE_TYPE (TREE_TYPE (field)))
4818       TREE_TYPE (field) = TYPE_CONTEXT (TREE_TYPE (field));
4819
4820   /* Clean up.  */
4821   splay_tree_delete (empty_base_offsets);
4822 }
4823
4824 /* Determine the "key method" for the class type indicated by TYPE,
4825    and set CLASSTYPE_KEY_METHOD accordingly.  */
4826
4827 void
4828 determine_key_method (tree type)
4829 {
4830   tree method;
4831
4832   if (TYPE_FOR_JAVA (type)
4833       || processing_template_decl
4834       || CLASSTYPE_TEMPLATE_INSTANTIATION (type)
4835       || CLASSTYPE_INTERFACE_KNOWN (type))
4836     return;
4837
4838   /* The key method is the first non-pure virtual function that is not
4839      inline at the point of class definition.  On some targets the
4840      key function may not be inline; those targets should not call
4841      this function until the end of the translation unit.  */
4842   for (method = TYPE_METHODS (type); method != NULL_TREE;
4843        method = TREE_CHAIN (method))
4844     if (DECL_VINDEX (method) != NULL_TREE
4845         && ! DECL_DECLARED_INLINE_P (method)
4846         && ! DECL_PURE_VIRTUAL_P (method))
4847       {
4848         CLASSTYPE_KEY_METHOD (type) = method;
4849         break;
4850       }
4851
4852   return;
4853 }
4854
4855 /* Perform processing required when the definition of T (a class type)
4856    is complete.  */
4857
4858 void
4859 finish_struct_1 (tree t)
4860 {
4861   tree x;
4862   /* A TREE_LIST.  The TREE_VALUE of each node is a FUNCTION_DECL.  */
4863   tree virtuals = NULL_TREE;
4864   int n_fields = 0;
4865
4866   if (COMPLETE_TYPE_P (t))
4867     {
4868       gcc_assert (IS_AGGR_TYPE (t));
4869       error ("redefinition of %q#T", t);
4870       popclass ();
4871       return;
4872     }
4873
4874   /* If this type was previously laid out as a forward reference,
4875      make sure we lay it out again.  */
4876   TYPE_SIZE (t) = NULL_TREE;
4877   CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE;
4878
4879   fixup_inline_methods (t);
4880
4881   /* Make assumptions about the class; we'll reset the flags if
4882      necessary.  */
4883   CLASSTYPE_EMPTY_P (t) = 1;
4884   CLASSTYPE_NEARLY_EMPTY_P (t) = 1;
4885   CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 0;
4886
4887   /* Do end-of-class semantic processing: checking the validity of the
4888      bases and members and add implicitly generated methods.  */
4889   check_bases_and_members (t);
4890
4891   /* Find the key method.  */
4892   if (TYPE_CONTAINS_VPTR_P (t))
4893     {
4894       /* The Itanium C++ ABI permits the key method to be chosen when
4895          the class is defined -- even though the key method so
4896          selected may later turn out to be an inline function.  On
4897          some systems (such as ARM Symbian OS) the key method cannot
4898          be determined until the end of the translation unit.  On such
4899          systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
4900          will cause the class to be added to KEYED_CLASSES.  Then, in
4901          finish_file we will determine the key method.  */
4902       if (targetm.cxx.key_method_may_be_inline ())
4903         determine_key_method (t);
4904
4905       /* If a polymorphic class has no key method, we may emit the vtable
4906          in every translation unit where the class definition appears.  */
4907       if (CLASSTYPE_KEY_METHOD (t) == NULL_TREE)
4908         keyed_classes = tree_cons (NULL_TREE, t, keyed_classes);
4909     }
4910
4911   /* Layout the class itself.  */
4912   layout_class_type (t, &virtuals);
4913   if (CLASSTYPE_AS_BASE (t) != t)
4914     /* We use the base type for trivial assignments, and hence it
4915        needs a mode.  */
4916     compute_record_mode (CLASSTYPE_AS_BASE (t));
4917
4918   virtuals = modify_all_vtables (t, nreverse (virtuals));
4919
4920   /* If necessary, create the primary vtable for this class.  */
4921   if (virtuals || TYPE_CONTAINS_VPTR_P (t))
4922     {
4923       /* We must enter these virtuals into the table.  */
4924       if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
4925         build_primary_vtable (NULL_TREE, t);
4926       else if (! BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (t)))
4927         /* Here we know enough to change the type of our virtual
4928            function table, but we will wait until later this function.  */
4929         build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t);
4930     }
4931
4932   if (TYPE_CONTAINS_VPTR_P (t))
4933     {
4934       int vindex;
4935       tree fn;
4936
4937       if (BINFO_VTABLE (TYPE_BINFO (t)))
4938         gcc_assert (DECL_VIRTUAL_P (BINFO_VTABLE (TYPE_BINFO (t))));
4939       if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
4940         gcc_assert (BINFO_VIRTUALS (TYPE_BINFO (t)) == NULL_TREE);
4941
4942       /* Add entries for virtual functions introduced by this class.  */
4943       BINFO_VIRTUALS (TYPE_BINFO (t))
4944         = chainon (BINFO_VIRTUALS (TYPE_BINFO (t)), virtuals);
4945
4946       /* Set DECL_VINDEX for all functions declared in this class.  */
4947       for (vindex = 0, fn = BINFO_VIRTUALS (TYPE_BINFO (t));
4948            fn;
4949            fn = TREE_CHAIN (fn),
4950              vindex += (TARGET_VTABLE_USES_DESCRIPTORS
4951                         ? TARGET_VTABLE_USES_DESCRIPTORS : 1))
4952         {
4953           tree fndecl = BV_FN (fn);
4954
4955           if (DECL_THUNK_P (fndecl))
4956             /* A thunk. We should never be calling this entry directly
4957                from this vtable -- we'd use the entry for the non
4958                thunk base function.  */
4959             DECL_VINDEX (fndecl) = NULL_TREE;
4960           else if (TREE_CODE (DECL_VINDEX (fndecl)) != INTEGER_CST)
4961             DECL_VINDEX (fndecl) = build_int_cst (NULL_TREE, vindex);
4962         }
4963     }
4964
4965   finish_struct_bits (t);
4966
4967   /* Complete the rtl for any static member objects of the type we're
4968      working on.  */
4969   for (x = TYPE_FIELDS (t); x; x = TREE_CHAIN (x))
4970     if (TREE_CODE (x) == VAR_DECL && TREE_STATIC (x)
4971         && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t))
4972       DECL_MODE (x) = TYPE_MODE (t);
4973
4974   /* Done with FIELDS...now decide whether to sort these for
4975      faster lookups later.
4976
4977      We use a small number because most searches fail (succeeding
4978      ultimately as the search bores through the inheritance
4979      hierarchy), and we want this failure to occur quickly.  */
4980
4981   n_fields = count_fields (TYPE_FIELDS (t));
4982   if (n_fields > 7)
4983     {
4984       struct sorted_fields_type *field_vec = GGC_NEWVAR
4985          (struct sorted_fields_type,
4986           sizeof (struct sorted_fields_type) + n_fields * sizeof (tree));
4987       field_vec->len = n_fields;
4988       add_fields_to_record_type (TYPE_FIELDS (t), field_vec, 0);
4989       qsort (field_vec->elts, n_fields, sizeof (tree),
4990              field_decl_cmp);
4991       if (! DECL_LANG_SPECIFIC (TYPE_MAIN_DECL (t)))
4992         retrofit_lang_decl (TYPE_MAIN_DECL (t));
4993       DECL_SORTED_FIELDS (TYPE_MAIN_DECL (t)) = field_vec;
4994     }
4995
4996   /* Make the rtl for any new vtables we have created, and unmark
4997      the base types we marked.  */
4998   finish_vtbls (t);
4999
5000   /* Build the VTT for T.  */
5001   build_vtt (t);
5002
5003   /* This warning does not make sense for Java classes, since they
5004      cannot have destructors.  */
5005   if (!TYPE_FOR_JAVA (t) && warn_nonvdtor && TYPE_POLYMORPHIC_P (t))
5006     {
5007       tree dtor;
5008
5009       dtor = CLASSTYPE_DESTRUCTORS (t);
5010       /* Warn only if the dtor is non-private or the class has
5011          friends.  */
5012       if (/* An implicitly declared destructor is always public.  And,
5013              if it were virtual, we would have created it by now.  */
5014           !dtor
5015           || (!DECL_VINDEX (dtor)
5016               && (!TREE_PRIVATE (dtor)
5017                   || CLASSTYPE_FRIEND_CLASSES (t)
5018                   || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))))
5019         warning (0, "%q#T has virtual functions but non-virtual destructor",
5020                  t);
5021     }
5022
5023   complete_vars (t);
5024
5025   if (warn_overloaded_virtual)
5026     warn_hidden (t);
5027
5028   maybe_suppress_debug_info (t);
5029
5030   dump_class_hierarchy (t);
5031
5032   /* Finish debugging output for this type.  */
5033   rest_of_type_compilation (t, ! LOCAL_CLASS_P (t));
5034 }
5035
5036 /* When T was built up, the member declarations were added in reverse
5037    order.  Rearrange them to declaration order.  */
5038
5039 void
5040 unreverse_member_declarations (tree t)
5041 {
5042   tree next;
5043   tree prev;
5044   tree x;
5045
5046   /* The following lists are all in reverse order.  Put them in
5047      declaration order now.  */
5048   TYPE_METHODS (t) = nreverse (TYPE_METHODS (t));
5049   CLASSTYPE_DECL_LIST (t) = nreverse (CLASSTYPE_DECL_LIST (t));
5050
5051   /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5052      reverse order, so we can't just use nreverse.  */
5053   prev = NULL_TREE;
5054   for (x = TYPE_FIELDS (t);
5055        x && TREE_CODE (x) != TYPE_DECL;
5056        x = next)
5057     {
5058       next = TREE_CHAIN (x);
5059       TREE_CHAIN (x) = prev;
5060       prev = x;
5061     }
5062   if (prev)
5063     {
5064       TREE_CHAIN (TYPE_FIELDS (t)) = x;
5065       if (prev)
5066         TYPE_FIELDS (t) = prev;
5067     }
5068 }
5069
5070 tree
5071 finish_struct (tree t, tree attributes)
5072 {
5073   location_t saved_loc = input_location;
5074
5075   /* Now that we've got all the field declarations, reverse everything
5076      as necessary.  */
5077   unreverse_member_declarations (t);
5078
5079   cplus_decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
5080
5081   /* Nadger the current location so that diagnostics point to the start of
5082      the struct, not the end.  */
5083   input_location = DECL_SOURCE_LOCATION (TYPE_NAME (t));
5084
5085   if (processing_template_decl)
5086     {
5087       tree x;
5088
5089       finish_struct_methods (t);
5090       TYPE_SIZE (t) = bitsize_zero_node;
5091       TYPE_SIZE_UNIT (t) = size_zero_node;
5092
5093       /* We need to emit an error message if this type was used as a parameter
5094          and it is an abstract type, even if it is a template. We construct
5095          a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
5096          account and we call complete_vars with this type, which will check
5097          the PARM_DECLS. Note that while the type is being defined,
5098          CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
5099          (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it.  */
5100       CLASSTYPE_PURE_VIRTUALS (t) = NULL;
5101       for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
5102         if (DECL_PURE_VIRTUAL_P (x))
5103           VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x);
5104       complete_vars (t);
5105     }
5106   else
5107     finish_struct_1 (t);
5108
5109   input_location = saved_loc;
5110
5111   TYPE_BEING_DEFINED (t) = 0;
5112
5113   if (current_class_type)
5114     popclass ();
5115   else
5116     error ("trying to finish struct, but kicked out due to previous parse errors");
5117
5118   if (processing_template_decl && at_function_scope_p ())
5119     add_stmt (build_min (TAG_DEFN, t));
5120
5121   return t;
5122 }
5123 \f
5124 /* Return the dynamic type of INSTANCE, if known.
5125    Used to determine whether the virtual function table is needed
5126    or not.
5127
5128    *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5129    of our knowledge of its type.  *NONNULL should be initialized
5130    before this function is called.  */
5131
5132 static tree
5133 fixed_type_or_null (tree instance, int* nonnull, int* cdtorp)
5134 {
5135   switch (TREE_CODE (instance))
5136     {
5137     case INDIRECT_REF:
5138       if (POINTER_TYPE_P (TREE_TYPE (instance)))
5139         return NULL_TREE;
5140       else
5141         return fixed_type_or_null (TREE_OPERAND (instance, 0),
5142                                    nonnull, cdtorp);
5143
5144     case CALL_EXPR:
5145       /* This is a call to a constructor, hence it's never zero.  */
5146       if (TREE_HAS_CONSTRUCTOR (instance))
5147         {
5148           if (nonnull)
5149             *nonnull = 1;
5150           return TREE_TYPE (instance);
5151         }
5152       return NULL_TREE;
5153
5154     case SAVE_EXPR:
5155       /* This is a call to a constructor, hence it's never zero.  */
5156       if (TREE_HAS_CONSTRUCTOR (instance))
5157         {
5158           if (nonnull)
5159             *nonnull = 1;
5160           return TREE_TYPE (instance);
5161         }
5162       return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5163
5164     case PLUS_EXPR:
5165     case MINUS_EXPR:
5166       if (TREE_CODE (TREE_OPERAND (instance, 0)) == ADDR_EXPR)
5167         return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5168       if (TREE_CODE (TREE_OPERAND (instance, 1)) == INTEGER_CST)
5169         /* Propagate nonnull.  */
5170         return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5171       return NULL_TREE;
5172
5173     case NOP_EXPR:
5174     case CONVERT_EXPR:
5175       return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5176
5177     case ADDR_EXPR:
5178       instance = TREE_OPERAND (instance, 0);
5179       if (nonnull)
5180         {
5181           /* Just because we see an ADDR_EXPR doesn't mean we're dealing
5182              with a real object -- given &p->f, p can still be null.  */
5183           tree t = get_base_address (instance);
5184           /* ??? Probably should check DECL_WEAK here.  */
5185           if (t && DECL_P (t))
5186             *nonnull = 1;
5187         }
5188       return fixed_type_or_null (instance, nonnull, cdtorp);
5189
5190     case COMPONENT_REF:
5191       /* If this component is really a base class reference, then the field
5192          itself isn't definitive.  */
5193       if (DECL_FIELD_IS_BASE (TREE_OPERAND (instance, 1)))
5194         return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5195       return fixed_type_or_null (TREE_OPERAND (instance, 1), nonnull, cdtorp);
5196
5197     case VAR_DECL:
5198     case FIELD_DECL:
5199       if (TREE_CODE (TREE_TYPE (instance)) == ARRAY_TYPE
5200           && IS_AGGR_TYPE (TREE_TYPE (TREE_TYPE (instance))))
5201         {
5202           if (nonnull)
5203             *nonnull = 1;
5204           return TREE_TYPE (TREE_TYPE (instance));
5205         }
5206       /* fall through...  */
5207     case TARGET_EXPR:
5208     case PARM_DECL:
5209     case RESULT_DECL:
5210       if (IS_AGGR_TYPE (TREE_TYPE (instance)))
5211         {
5212           if (nonnull)
5213             *nonnull = 1;
5214           return TREE_TYPE (instance);
5215         }
5216       else if (instance == current_class_ptr)
5217         {
5218           if (nonnull)
5219             *nonnull = 1;
5220
5221           /* if we're in a ctor or dtor, we know our type.  */
5222           if (DECL_LANG_SPECIFIC (current_function_decl)
5223               && (DECL_CONSTRUCTOR_P (current_function_decl)
5224                   || DECL_DESTRUCTOR_P (current_function_decl)))
5225             {
5226               if (cdtorp)
5227                 *cdtorp = 1;
5228               return TREE_TYPE (TREE_TYPE (instance));
5229             }
5230         }
5231       else if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE)
5232         {
5233           /* Reference variables should be references to objects.  */
5234           if (nonnull)
5235             *nonnull = 1;
5236
5237           /* DECL_VAR_MARKED_P is used to prevent recursion; a
5238              variable's initializer may refer to the variable
5239              itself.  */
5240           if (TREE_CODE (instance) == VAR_DECL
5241               && DECL_INITIAL (instance)
5242               && !DECL_VAR_MARKED_P (instance))
5243             {
5244               tree type;
5245               DECL_VAR_MARKED_P (instance) = 1;
5246               type = fixed_type_or_null (DECL_INITIAL (instance),
5247                                          nonnull, cdtorp);
5248               DECL_VAR_MARKED_P (instance) = 0;
5249               return type;
5250             }
5251         }
5252       return NULL_TREE;
5253
5254     default:
5255       return NULL_TREE;
5256     }
5257 }
5258
5259 /* Return nonzero if the dynamic type of INSTANCE is known, and
5260    equivalent to the static type.  We also handle the case where
5261    INSTANCE is really a pointer. Return negative if this is a
5262    ctor/dtor. There the dynamic type is known, but this might not be
5263    the most derived base of the original object, and hence virtual
5264    bases may not be layed out according to this type.
5265
5266    Used to determine whether the virtual function table is needed
5267    or not.
5268
5269    *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5270    of our knowledge of its type.  *NONNULL should be initialized
5271    before this function is called.  */
5272
5273 int
5274 resolves_to_fixed_type_p (tree instance, int* nonnull)
5275 {
5276   tree t = TREE_TYPE (instance);
5277   int cdtorp = 0;
5278
5279   tree fixed = fixed_type_or_null (instance, nonnull, &cdtorp);
5280   if (fixed == NULL_TREE)
5281     return 0;
5282   if (POINTER_TYPE_P (t))
5283     t = TREE_TYPE (t);
5284   if (!same_type_ignoring_top_level_qualifiers_p (t, fixed))
5285     return 0;
5286   return cdtorp ? -1 : 1;
5287 }
5288
5289 \f
5290 void
5291 init_class_processing (void)
5292 {
5293   current_class_depth = 0;
5294   current_class_stack_size = 10;
5295   current_class_stack
5296     = xmalloc (current_class_stack_size * sizeof (struct class_stack_node));
5297   local_classes = VEC_alloc (tree, gc, 8);
5298
5299   ridpointers[(int) RID_PUBLIC] = access_public_node;
5300   ridpointers[(int) RID_PRIVATE] = access_private_node;
5301   ridpointers[(int) RID_PROTECTED] = access_protected_node;
5302 }
5303
5304 /* Restore the cached PREVIOUS_CLASS_LEVEL.  */
5305
5306 static void
5307 restore_class_cache (void)
5308 {
5309   tree type;
5310
5311   /* We are re-entering the same class we just left, so we don't
5312      have to search the whole inheritance matrix to find all the
5313      decls to bind again.  Instead, we install the cached
5314      class_shadowed list and walk through it binding names.  */
5315   push_binding_level (previous_class_level);
5316   class_binding_level = previous_class_level;
5317   /* Restore IDENTIFIER_TYPE_VALUE.  */
5318   for (type = class_binding_level->type_shadowed;
5319        type;
5320        type = TREE_CHAIN (type))
5321     SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (type), TREE_TYPE (type));
5322 }
5323
5324 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
5325    appropriate for TYPE.
5326
5327    So that we may avoid calls to lookup_name, we cache the _TYPE
5328    nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5329
5330    For multiple inheritance, we perform a two-pass depth-first search
5331    of the type lattice.  */
5332
5333 void
5334 pushclass (tree type)
5335 {
5336   type = TYPE_MAIN_VARIANT (type);
5337
5338   /* Make sure there is enough room for the new entry on the stack.  */
5339   if (current_class_depth + 1 >= current_class_stack_size)
5340     {
5341       current_class_stack_size *= 2;
5342       current_class_stack
5343         = xrealloc (current_class_stack,
5344                     current_class_stack_size
5345                     * sizeof (struct class_stack_node));
5346     }
5347
5348   /* Insert a new entry on the class stack.  */
5349   current_class_stack[current_class_depth].name = current_class_name;
5350   current_class_stack[current_class_depth].type = current_class_type;
5351   current_class_stack[current_class_depth].access = current_access_specifier;
5352   current_class_stack[current_class_depth].names_used = 0;
5353   current_class_depth++;
5354
5355   /* Now set up the new type.  */
5356   current_class_name = TYPE_NAME (type);
5357   if (TREE_CODE (current_class_name) == TYPE_DECL)
5358     current_class_name = DECL_NAME (current_class_name);
5359   current_class_type = type;
5360
5361   /* By default, things in classes are private, while things in
5362      structures or unions are public.  */
5363   current_access_specifier = (CLASSTYPE_DECLARED_CLASS (type)
5364                               ? access_private_node
5365                               : access_public_node);
5366
5367   if (previous_class_level
5368       && type != previous_class_level->this_entity
5369       && current_class_depth == 1)
5370     {
5371       /* Forcibly remove any old class remnants.  */
5372       invalidate_class_lookup_cache ();
5373     }
5374
5375   if (!previous_class_level
5376       || type != previous_class_level->this_entity
5377       || current_class_depth > 1)
5378     pushlevel_class ();
5379   else
5380     restore_class_cache ();
5381 }
5382
5383 /* When we exit a toplevel class scope, we save its binding level so
5384    that we can restore it quickly.  Here, we've entered some other
5385    class, so we must invalidate our cache.  */
5386
5387 void
5388 invalidate_class_lookup_cache (void)
5389 {
5390   previous_class_level = NULL;
5391 }
5392
5393 /* Get out of the current class scope. If we were in a class scope
5394    previously, that is the one popped to.  */
5395
5396 void
5397 popclass (void)
5398 {
5399   poplevel_class ();
5400
5401   current_class_depth--;
5402   current_class_name = current_class_stack[current_class_depth].name;
5403   current_class_type = current_class_stack[current_class_depth].type;
5404   current_access_specifier = current_class_stack[current_class_depth].access;
5405   if (current_class_stack[current_class_depth].names_used)
5406     splay_tree_delete (current_class_stack[current_class_depth].names_used);
5407 }
5408
5409 /* Returns 1 if current_class_type is either T or a nested type of T.
5410    We start looking from 1 because entry 0 is from global scope, and has
5411    no type.  */
5412
5413 int
5414 currently_open_class (tree t)
5415 {
5416   int i;
5417   if (current_class_type && same_type_p (t, current_class_type))
5418     return 1;
5419   for (i = 1; i < current_class_depth; ++i)
5420     if (current_class_stack[i].type
5421         && same_type_p (current_class_stack [i].type, t))
5422       return 1;
5423   return 0;
5424 }
5425
5426 /* If either current_class_type or one of its enclosing classes are derived
5427    from T, return the appropriate type.  Used to determine how we found
5428    something via unqualified lookup.  */
5429
5430 tree
5431 currently_open_derived_class (tree t)
5432 {
5433   int i;
5434
5435   /* The bases of a dependent type are unknown.  */
5436   if (dependent_type_p (t))
5437     return NULL_TREE;
5438
5439   if (!current_class_type)
5440     return NULL_TREE;
5441
5442   if (DERIVED_FROM_P (t, current_class_type))
5443     return current_class_type;
5444
5445   for (i = current_class_depth - 1; i > 0; --i)
5446     if (DERIVED_FROM_P (t, current_class_stack[i].type))
5447       return current_class_stack[i].type;
5448
5449   return NULL_TREE;
5450 }
5451
5452 /* When entering a class scope, all enclosing class scopes' names with
5453    static meaning (static variables, static functions, types and
5454    enumerators) have to be visible.  This recursive function calls
5455    pushclass for all enclosing class contexts until global or a local
5456    scope is reached.  TYPE is the enclosed class.  */
5457
5458 void
5459 push_nested_class (tree type)
5460 {
5461   tree context;
5462
5463   /* A namespace might be passed in error cases, like A::B:C.  */
5464   if (type == NULL_TREE
5465       || type == error_mark_node
5466       || TREE_CODE (type) == NAMESPACE_DECL
5467       || ! IS_AGGR_TYPE (type)
5468       || TREE_CODE (type) == TEMPLATE_TYPE_PARM
5469       || TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
5470     return;
5471
5472   context = DECL_CONTEXT (TYPE_MAIN_DECL (type));
5473
5474   if (context && CLASS_TYPE_P (context))
5475     push_nested_class (context);
5476   pushclass (type);
5477 }
5478
5479 /* Undoes a push_nested_class call.  */
5480
5481 void
5482 pop_nested_class (void)
5483 {
5484   tree context = DECL_CONTEXT (TYPE_MAIN_DECL (current_class_type));
5485
5486   popclass ();
5487   if (context && CLASS_TYPE_P (context))
5488     pop_nested_class ();
5489 }
5490
5491 /* Returns the number of extern "LANG" blocks we are nested within.  */
5492
5493 int
5494 current_lang_depth (void)
5495 {
5496   return VEC_length (tree, current_lang_base);
5497 }
5498
5499 /* Set global variables CURRENT_LANG_NAME to appropriate value
5500    so that behavior of name-mangling machinery is correct.  */
5501
5502 void
5503 push_lang_context (tree name)
5504 {
5505   VEC_safe_push (tree, gc, current_lang_base, current_lang_name);
5506
5507   if (name == lang_name_cplusplus)
5508     {
5509       current_lang_name = name;
5510     }
5511   else if (name == lang_name_java)
5512     {
5513       current_lang_name = name;
5514       /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5515          (See record_builtin_java_type in decl.c.)  However, that causes
5516          incorrect debug entries if these types are actually used.
5517          So we re-enable debug output after extern "Java".  */
5518       DECL_IGNORED_P (TYPE_NAME (java_byte_type_node)) = 0;
5519       DECL_IGNORED_P (TYPE_NAME (java_short_type_node)) = 0;
5520       DECL_IGNORED_P (TYPE_NAME (java_int_type_node)) = 0;
5521       DECL_IGNORED_P (TYPE_NAME (java_long_type_node)) = 0;
5522       DECL_IGNORED_P (TYPE_NAME (java_float_type_node)) = 0;
5523       DECL_IGNORED_P (TYPE_NAME (java_double_type_node)) = 0;
5524       DECL_IGNORED_P (TYPE_NAME (java_char_type_node)) = 0;
5525       DECL_IGNORED_P (TYPE_NAME (java_boolean_type_node)) = 0;
5526     }
5527   else if (name == lang_name_c)
5528     {
5529       current_lang_name = name;
5530     }
5531   else
5532     error ("language string %<\"%E\"%> not recognized", name);
5533 }
5534
5535 /* Get out of the current language scope.  */
5536
5537 void
5538 pop_lang_context (void)
5539 {
5540   current_lang_name = VEC_pop (tree, current_lang_base);
5541 }
5542 \f
5543 /* Type instantiation routines.  */
5544
5545 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
5546    matches the TARGET_TYPE.  If there is no satisfactory match, return
5547    error_mark_node, and issue a error & warning messages under control
5548    of FLAGS.  Permit pointers to member function if FLAGS permits.  If
5549    TEMPLATE_ONLY, the name of the overloaded function was a
5550    template-id, and EXPLICIT_TARGS are the explicitly provided
5551    template arguments.  */
5552
5553 static tree
5554 resolve_address_of_overloaded_function (tree target_type,
5555                                         tree overload,
5556                                         tsubst_flags_t flags,
5557                                         bool template_only,
5558                                         tree explicit_targs)
5559 {
5560   /* Here's what the standard says:
5561
5562        [over.over]
5563
5564        If the name is a function template, template argument deduction
5565        is done, and if the argument deduction succeeds, the deduced
5566        arguments are used to generate a single template function, which
5567        is added to the set of overloaded functions considered.
5568
5569        Non-member functions and static member functions match targets of
5570        type "pointer-to-function" or "reference-to-function."  Nonstatic
5571        member functions match targets of type "pointer-to-member
5572        function;" the function type of the pointer to member is used to
5573        select the member function from the set of overloaded member
5574        functions.  If a nonstatic member function is selected, the
5575        reference to the overloaded function name is required to have the
5576        form of a pointer to member as described in 5.3.1.
5577
5578        If more than one function is selected, any template functions in
5579        the set are eliminated if the set also contains a non-template
5580        function, and any given template function is eliminated if the
5581        set contains a second template function that is more specialized
5582        than the first according to the partial ordering rules 14.5.5.2.
5583        After such eliminations, if any, there shall remain exactly one
5584        selected function.  */
5585
5586   int is_ptrmem = 0;
5587   int is_reference = 0;
5588   /* We store the matches in a TREE_LIST rooted here.  The functions
5589      are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
5590      interoperability with most_specialized_instantiation.  */
5591   tree matches = NULL_TREE;
5592   tree fn;
5593
5594   /* By the time we get here, we should be seeing only real
5595      pointer-to-member types, not the internal POINTER_TYPE to
5596      METHOD_TYPE representation.  */
5597   gcc_assert (TREE_CODE (target_type) != POINTER_TYPE
5598               || TREE_CODE (TREE_TYPE (target_type)) != METHOD_TYPE);
5599
5600   gcc_assert (is_overloaded_fn (overload));
5601
5602   /* Check that the TARGET_TYPE is reasonable.  */
5603   if (TYPE_PTRFN_P (target_type))
5604     /* This is OK.  */;
5605   else if (TYPE_PTRMEMFUNC_P (target_type))
5606     /* This is OK, too.  */
5607     is_ptrmem = 1;
5608   else if (TREE_CODE (target_type) == FUNCTION_TYPE)
5609     {
5610       /* This is OK, too.  This comes from a conversion to reference
5611          type.  */
5612       target_type = build_reference_type (target_type);
5613       is_reference = 1;
5614     }
5615   else
5616     {
5617       if (flags & tf_error)
5618         error ("cannot resolve overloaded function %qD based on"
5619                " conversion to type %qT",
5620                DECL_NAME (OVL_FUNCTION (overload)), target_type);
5621       return error_mark_node;
5622     }
5623
5624   /* If we can find a non-template function that matches, we can just
5625      use it.  There's no point in generating template instantiations
5626      if we're just going to throw them out anyhow.  But, of course, we
5627      can only do this when we don't *need* a template function.  */
5628   if (!template_only)
5629     {
5630       tree fns;
5631
5632       for (fns = overload; fns; fns = OVL_NEXT (fns))
5633         {
5634           tree fn = OVL_CURRENT (fns);
5635           tree fntype;
5636
5637           if (TREE_CODE (fn) == TEMPLATE_DECL)
5638             /* We're not looking for templates just yet.  */
5639             continue;
5640
5641           if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
5642               != is_ptrmem)
5643             /* We're looking for a non-static member, and this isn't
5644                one, or vice versa.  */
5645             continue;
5646
5647           /* Ignore anticipated decls of undeclared builtins.  */
5648           if (DECL_ANTICIPATED (fn))
5649             continue;
5650
5651           /* See if there's a match.  */
5652           fntype = TREE_TYPE (fn);
5653           if (is_ptrmem)
5654             fntype = build_ptrmemfunc_type (build_pointer_type (fntype));
5655           else if (!is_reference)
5656             fntype = build_pointer_type (fntype);
5657
5658           if (can_convert_arg (target_type, fntype, fn))
5659             matches = tree_cons (fn, NULL_TREE, matches);
5660         }
5661     }
5662
5663   /* Now, if we've already got a match (or matches), there's no need
5664      to proceed to the template functions.  But, if we don't have a
5665      match we need to look at them, too.  */
5666   if (!matches)
5667     {
5668       tree target_fn_type;
5669       tree target_arg_types;
5670       tree target_ret_type;
5671       tree fns;
5672
5673       if (is_ptrmem)
5674         target_fn_type
5675           = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (target_type));
5676       else
5677         target_fn_type = TREE_TYPE (target_type);
5678       target_arg_types = TYPE_ARG_TYPES (target_fn_type);
5679       target_ret_type = TREE_TYPE (target_fn_type);
5680
5681       /* Never do unification on the 'this' parameter.  */
5682       if (TREE_CODE (target_fn_type) == METHOD_TYPE)
5683         target_arg_types = TREE_CHAIN (target_arg_types);
5684
5685       for (fns = overload; fns; fns = OVL_NEXT (fns))
5686         {
5687           tree fn = OVL_CURRENT (fns);
5688           tree instantiation;
5689           tree instantiation_type;
5690           tree targs;
5691
5692           if (TREE_CODE (fn) != TEMPLATE_DECL)
5693             /* We're only looking for templates.  */
5694             continue;
5695
5696           if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
5697               != is_ptrmem)
5698             /* We're not looking for a non-static member, and this is
5699                one, or vice versa.  */
5700             continue;
5701
5702           /* Try to do argument deduction.  */
5703           targs = make_tree_vec (DECL_NTPARMS (fn));
5704           if (fn_type_unification (fn, explicit_targs, targs,
5705                                    target_arg_types, target_ret_type,
5706                                    DEDUCE_EXACT))
5707             /* Argument deduction failed.  */
5708             continue;
5709
5710           /* Instantiate the template.  */
5711           instantiation = instantiate_template (fn, targs, flags);
5712           if (instantiation == error_mark_node)
5713             /* Instantiation failed.  */
5714             continue;
5715
5716           /* See if there's a match.  */
5717           instantiation_type = TREE_TYPE (instantiation);
5718           if (is_ptrmem)
5719             instantiation_type =
5720               build_ptrmemfunc_type (build_pointer_type (instantiation_type));
5721           else if (!is_reference)
5722             instantiation_type = build_pointer_type (instantiation_type);
5723           if (can_convert_arg (target_type, instantiation_type, instantiation))
5724             matches = tree_cons (instantiation, fn, matches);
5725         }
5726
5727       /* Now, remove all but the most specialized of the matches.  */
5728       if (matches)
5729         {
5730           tree match = most_specialized_instantiation (matches);
5731
5732           if (match != error_mark_node)
5733             matches = tree_cons (match, NULL_TREE, NULL_TREE);
5734         }
5735     }
5736
5737   /* Now we should have exactly one function in MATCHES.  */
5738   if (matches == NULL_TREE)
5739     {
5740       /* There were *no* matches.  */
5741       if (flags & tf_error)
5742         {
5743           error ("no matches converting function %qD to type %q#T",
5744                  DECL_NAME (OVL_FUNCTION (overload)),
5745                  target_type);
5746
5747           /* print_candidates expects a chain with the functions in
5748              TREE_VALUE slots, so we cons one up here (we're losing anyway,
5749              so why be clever?).  */
5750           for (; overload; overload = OVL_NEXT (overload))
5751             matches = tree_cons (NULL_TREE, OVL_CURRENT (overload),
5752                                  matches);
5753
5754           print_candidates (matches);
5755         }
5756       return error_mark_node;
5757     }
5758   else if (TREE_CHAIN (matches))
5759     {
5760       /* There were too many matches.  */
5761
5762       if (flags & tf_error)
5763         {
5764           tree match;
5765
5766           error ("converting overloaded function %qD to type %q#T is ambiguous",
5767                     DECL_NAME (OVL_FUNCTION (overload)),
5768                     target_type);
5769
5770           /* Since print_candidates expects the functions in the
5771              TREE_VALUE slot, we flip them here.  */
5772           for (match = matches; match; match = TREE_CHAIN (match))
5773             TREE_VALUE (match) = TREE_PURPOSE (match);
5774
5775           print_candidates (matches);
5776         }
5777
5778       return error_mark_node;
5779     }
5780
5781   /* Good, exactly one match.  Now, convert it to the correct type.  */
5782   fn = TREE_PURPOSE (matches);
5783
5784   if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
5785       && !(flags & tf_ptrmem_ok) && !flag_ms_extensions)
5786     {
5787       static int explained;
5788
5789       if (!(flags & tf_error))
5790         return error_mark_node;
5791
5792       pedwarn ("assuming pointer to member %qD", fn);
5793       if (!explained)
5794         {
5795           pedwarn ("(a pointer to member can only be formed with %<&%E%>)", fn);
5796           explained = 1;
5797         }
5798     }
5799
5800   /* If we're doing overload resolution purely for the purpose of
5801      determining conversion sequences, we should not consider the
5802      function used.  If this conversion sequence is selected, the
5803      function will be marked as used at this point.  */
5804   if (!(flags & tf_conv))
5805     mark_used (fn);
5806
5807   if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type))
5808     return build_unary_op (ADDR_EXPR, fn, 0);
5809   else
5810     {
5811       /* The target must be a REFERENCE_TYPE.  Above, build_unary_op
5812          will mark the function as addressed, but here we must do it
5813          explicitly.  */
5814       cxx_mark_addressable (fn);
5815
5816       return fn;
5817     }
5818 }
5819
5820 /* This function will instantiate the type of the expression given in
5821    RHS to match the type of LHSTYPE.  If errors exist, then return
5822    error_mark_node. FLAGS is a bit mask.  If TF_ERROR is set, then
5823    we complain on errors.  If we are not complaining, never modify rhs,
5824    as overload resolution wants to try many possible instantiations, in
5825    the hope that at least one will work.
5826
5827    For non-recursive calls, LHSTYPE should be a function, pointer to
5828    function, or a pointer to member function.  */
5829
5830 tree
5831 instantiate_type (tree lhstype, tree rhs, tsubst_flags_t flags)
5832 {
5833   tsubst_flags_t flags_in = flags;
5834
5835   flags &= ~tf_ptrmem_ok;
5836
5837   if (TREE_CODE (lhstype) == UNKNOWN_TYPE)
5838     {
5839       if (flags & tf_error)
5840         error ("not enough type information");
5841       return error_mark_node;
5842     }
5843
5844   if (TREE_TYPE (rhs) != NULL_TREE && ! (type_unknown_p (rhs)))
5845     {
5846       if (same_type_p (lhstype, TREE_TYPE (rhs)))
5847         return rhs;
5848       if (flag_ms_extensions
5849           && TYPE_PTRMEMFUNC_P (lhstype)
5850           && !TYPE_PTRMEMFUNC_P (TREE_TYPE (rhs)))
5851         /* Microsoft allows `A::f' to be resolved to a
5852            pointer-to-member.  */
5853         ;
5854       else
5855         {
5856           if (flags & tf_error)
5857             error ("argument of type %qT does not match %qT",
5858                    TREE_TYPE (rhs), lhstype);
5859           return error_mark_node;
5860         }
5861     }
5862
5863   if (TREE_CODE (rhs) == BASELINK)
5864     rhs = BASELINK_FUNCTIONS (rhs);
5865
5866   /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
5867      deduce any type information.  */
5868   if (TREE_CODE (rhs) == NON_DEPENDENT_EXPR)
5869     {
5870       if (flags & tf_error)
5871         error ("not enough type information");
5872       return error_mark_node;
5873     }
5874
5875   /* We don't overwrite rhs if it is an overloaded function.
5876      Copying it would destroy the tree link.  */
5877   if (TREE_CODE (rhs) != OVERLOAD)
5878     rhs = copy_node (rhs);
5879
5880   /* This should really only be used when attempting to distinguish
5881      what sort of a pointer to function we have.  For now, any
5882      arithmetic operation which is not supported on pointers
5883      is rejected as an error.  */
5884
5885   switch (TREE_CODE (rhs))
5886     {
5887     case TYPE_EXPR:
5888     case CONVERT_EXPR:
5889     case SAVE_EXPR:
5890     case CONSTRUCTOR:
5891       gcc_unreachable ();
5892
5893     case INDIRECT_REF:
5894     case ARRAY_REF:
5895       {
5896         tree new_rhs;
5897
5898         new_rhs = instantiate_type (build_pointer_type (lhstype),
5899                                     TREE_OPERAND (rhs, 0), flags);
5900         if (new_rhs == error_mark_node)
5901           return error_mark_node;
5902
5903         TREE_TYPE (rhs) = lhstype;
5904         TREE_OPERAND (rhs, 0) = new_rhs;
5905         return rhs;
5906       }
5907
5908     case NOP_EXPR:
5909       rhs = copy_node (TREE_OPERAND (rhs, 0));
5910       TREE_TYPE (rhs) = unknown_type_node;
5911       return instantiate_type (lhstype, rhs, flags);
5912
5913     case COMPONENT_REF:
5914       {
5915         tree member = TREE_OPERAND (rhs, 1);
5916
5917         member = instantiate_type (lhstype, member, flags);
5918         if (member != error_mark_node
5919             && TREE_SIDE_EFFECTS (TREE_OPERAND (rhs, 0)))
5920           /* Do not lose object's side effects.  */
5921           return build2 (COMPOUND_EXPR, TREE_TYPE (member),
5922                          TREE_OPERAND (rhs, 0), member);
5923         return member;
5924       }
5925
5926     case OFFSET_REF:
5927       rhs = TREE_OPERAND (rhs, 1);
5928       if (BASELINK_P (rhs))
5929         return instantiate_type (lhstype, BASELINK_FUNCTIONS (rhs), flags_in);
5930
5931       /* This can happen if we are forming a pointer-to-member for a
5932          member template.  */
5933       gcc_assert (TREE_CODE (rhs) == TEMPLATE_ID_EXPR);
5934
5935       /* Fall through.  */
5936
5937     case TEMPLATE_ID_EXPR:
5938       {
5939         tree fns = TREE_OPERAND (rhs, 0);
5940         tree args = TREE_OPERAND (rhs, 1);
5941
5942         return
5943           resolve_address_of_overloaded_function (lhstype, fns, flags_in,
5944                                                   /*template_only=*/true,
5945                                                   args);
5946       }
5947
5948     case OVERLOAD:
5949     case FUNCTION_DECL:
5950       return
5951         resolve_address_of_overloaded_function (lhstype, rhs, flags_in,
5952                                                 /*template_only=*/false,
5953                                                 /*explicit_targs=*/NULL_TREE);
5954
5955     case CALL_EXPR:
5956       /* This is too hard for now.  */
5957       gcc_unreachable ();
5958
5959     case PLUS_EXPR:
5960     case MINUS_EXPR:
5961     case COMPOUND_EXPR:
5962       TREE_OPERAND (rhs, 0)
5963         = instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
5964       if (TREE_OPERAND (rhs, 0) == error_mark_node)
5965         return error_mark_node;
5966       TREE_OPERAND (rhs, 1)
5967         = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
5968       if (TREE_OPERAND (rhs, 1) == error_mark_node)
5969         return error_mark_node;
5970
5971       TREE_TYPE (rhs) = lhstype;
5972       return rhs;
5973
5974     case MULT_EXPR:
5975     case TRUNC_DIV_EXPR:
5976     case FLOOR_DIV_EXPR:
5977     case CEIL_DIV_EXPR:
5978     case ROUND_DIV_EXPR:
5979     case RDIV_EXPR:
5980     case TRUNC_MOD_EXPR:
5981     case FLOOR_MOD_EXPR:
5982     case CEIL_MOD_EXPR:
5983     case ROUND_MOD_EXPR:
5984     case FIX_ROUND_EXPR:
5985     case FIX_FLOOR_EXPR:
5986     case FIX_CEIL_EXPR:
5987     case FIX_TRUNC_EXPR:
5988     case FLOAT_EXPR:
5989     case NEGATE_EXPR:
5990     case ABS_EXPR:
5991     case MAX_EXPR:
5992     case MIN_EXPR:
5993
5994     case BIT_AND_EXPR:
5995     case BIT_IOR_EXPR:
5996     case BIT_XOR_EXPR:
5997     case LSHIFT_EXPR:
5998     case RSHIFT_EXPR:
5999     case LROTATE_EXPR:
6000     case RROTATE_EXPR:
6001
6002     case PREINCREMENT_EXPR:
6003     case PREDECREMENT_EXPR:
6004     case POSTINCREMENT_EXPR:
6005     case POSTDECREMENT_EXPR:
6006       if (flags & tf_error)
6007         error ("invalid operation on uninstantiated type");
6008       return error_mark_node;
6009
6010     case TRUTH_AND_EXPR:
6011     case TRUTH_OR_EXPR:
6012     case TRUTH_XOR_EXPR:
6013     case LT_EXPR:
6014     case LE_EXPR:
6015     case GT_EXPR:
6016     case GE_EXPR:
6017     case EQ_EXPR:
6018     case NE_EXPR:
6019     case TRUTH_ANDIF_EXPR:
6020     case TRUTH_ORIF_EXPR:
6021     case TRUTH_NOT_EXPR:
6022       if (flags & tf_error)
6023         error ("not enough type information");
6024       return error_mark_node;
6025
6026     case COND_EXPR:
6027       if (type_unknown_p (TREE_OPERAND (rhs, 0)))
6028         {
6029           if (flags & tf_error)
6030             error ("not enough type information");
6031           return error_mark_node;
6032         }
6033       TREE_OPERAND (rhs, 1)
6034         = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
6035       if (TREE_OPERAND (rhs, 1) == error_mark_node)
6036         return error_mark_node;
6037       TREE_OPERAND (rhs, 2)
6038         = instantiate_type (lhstype, TREE_OPERAND (rhs, 2), flags);
6039       if (TREE_OPERAND (rhs, 2) == error_mark_node)
6040         return error_mark_node;
6041
6042       TREE_TYPE (rhs) = lhstype;
6043       return rhs;
6044
6045     case MODIFY_EXPR:
6046       TREE_OPERAND (rhs, 1)
6047         = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
6048       if (TREE_OPERAND (rhs, 1) == error_mark_node)
6049         return error_mark_node;
6050
6051       TREE_TYPE (rhs) = lhstype;
6052       return rhs;
6053
6054     case ADDR_EXPR:
6055     {
6056       if (PTRMEM_OK_P (rhs))
6057         flags |= tf_ptrmem_ok;
6058
6059       return instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
6060     }
6061
6062     case ERROR_MARK:
6063       return error_mark_node;
6064
6065     default:
6066       gcc_unreachable ();
6067     }
6068   return error_mark_node;
6069 }
6070 \f
6071 /* Return the name of the virtual function pointer field
6072    (as an IDENTIFIER_NODE) for the given TYPE.  Note that
6073    this may have to look back through base types to find the
6074    ultimate field name.  (For single inheritance, these could
6075    all be the same name.  Who knows for multiple inheritance).  */
6076
6077 static tree
6078 get_vfield_name (tree type)
6079 {
6080   tree binfo, base_binfo;
6081   char *buf;
6082
6083   for (binfo = TYPE_BINFO (type);
6084        BINFO_N_BASE_BINFOS (binfo);
6085        binfo = base_binfo)
6086     {
6087       base_binfo = BINFO_BASE_BINFO (binfo, 0);
6088
6089       if (BINFO_VIRTUAL_P (base_binfo)
6090           || !TYPE_CONTAINS_VPTR_P (BINFO_TYPE (base_binfo)))
6091         break;
6092     }
6093
6094   type = BINFO_TYPE (binfo);
6095   buf = alloca (sizeof (VFIELD_NAME_FORMAT) + TYPE_NAME_LENGTH (type) + 2);
6096   sprintf (buf, VFIELD_NAME_FORMAT,
6097            IDENTIFIER_POINTER (constructor_name (type)));
6098   return get_identifier (buf);
6099 }
6100
6101 void
6102 print_class_statistics (void)
6103 {
6104 #ifdef GATHER_STATISTICS
6105   fprintf (stderr, "convert_harshness = %d\n", n_convert_harshness);
6106   fprintf (stderr, "compute_conversion_costs = %d\n", n_compute_conversion_costs);
6107   if (n_vtables)
6108     {
6109       fprintf (stderr, "vtables = %d; vtable searches = %d\n",
6110                n_vtables, n_vtable_searches);
6111       fprintf (stderr, "vtable entries = %d; vtable elems = %d\n",
6112                n_vtable_entries, n_vtable_elems);
6113     }
6114 #endif
6115 }
6116
6117 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6118    according to [class]:
6119                                           The class-name is also inserted
6120    into  the scope of the class itself.  For purposes of access checking,
6121    the inserted class name is treated as if it were a public member name.  */
6122
6123 void
6124 build_self_reference (void)
6125 {
6126   tree name = constructor_name (current_class_type);
6127   tree value = build_lang_decl (TYPE_DECL, name, current_class_type);
6128   tree saved_cas;
6129
6130   DECL_NONLOCAL (value) = 1;
6131   DECL_CONTEXT (value) = current_class_type;
6132   DECL_ARTIFICIAL (value) = 1;
6133   SET_DECL_SELF_REFERENCE_P (value);
6134
6135   if (processing_template_decl)
6136     value = push_template_decl (value);
6137
6138   saved_cas = current_access_specifier;
6139   current_access_specifier = access_public_node;
6140   finish_member_declaration (value);
6141   current_access_specifier = saved_cas;
6142 }
6143
6144 /* Returns 1 if TYPE contains only padding bytes.  */
6145
6146 int
6147 is_empty_class (tree type)
6148 {
6149   if (type == error_mark_node)
6150     return 0;
6151
6152   if (! IS_AGGR_TYPE (type))
6153     return 0;
6154
6155   /* In G++ 3.2, whether or not a class was empty was determined by
6156      looking at its size.  */
6157   if (abi_version_at_least (2))
6158     return CLASSTYPE_EMPTY_P (type);
6159   else
6160     return integer_zerop (CLASSTYPE_SIZE (type));
6161 }
6162
6163 /* Returns true if TYPE contains an empty class.  */
6164
6165 static bool
6166 contains_empty_class_p (tree type)
6167 {
6168   if (is_empty_class (type))
6169     return true;
6170   if (CLASS_TYPE_P (type))
6171     {
6172       tree field;
6173       tree binfo;
6174       tree base_binfo;
6175       int i;
6176
6177       for (binfo = TYPE_BINFO (type), i = 0;
6178            BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
6179         if (contains_empty_class_p (BINFO_TYPE (base_binfo)))
6180           return true;
6181       for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
6182         if (TREE_CODE (field) == FIELD_DECL
6183             && !DECL_ARTIFICIAL (field)
6184             && is_empty_class (TREE_TYPE (field)))
6185           return true;
6186     }
6187   else if (TREE_CODE (type) == ARRAY_TYPE)
6188     return contains_empty_class_p (TREE_TYPE (type));
6189   return false;
6190 }
6191
6192 /* Note that NAME was looked up while the current class was being
6193    defined and that the result of that lookup was DECL.  */
6194
6195 void
6196 maybe_note_name_used_in_class (tree name, tree decl)
6197 {
6198   splay_tree names_used;
6199
6200   /* If we're not defining a class, there's nothing to do.  */
6201   if (!(innermost_scope_kind() == sk_class
6202         && TYPE_BEING_DEFINED (current_class_type)))
6203     return;
6204
6205   /* If there's already a binding for this NAME, then we don't have
6206      anything to worry about.  */
6207   if (lookup_member (current_class_type, name,
6208                      /*protect=*/0, /*want_type=*/false))
6209     return;
6210
6211   if (!current_class_stack[current_class_depth - 1].names_used)
6212     current_class_stack[current_class_depth - 1].names_used
6213       = splay_tree_new (splay_tree_compare_pointers, 0, 0);
6214   names_used = current_class_stack[current_class_depth - 1].names_used;
6215
6216   splay_tree_insert (names_used,
6217                      (splay_tree_key) name,
6218                      (splay_tree_value) decl);
6219 }
6220
6221 /* Note that NAME was declared (as DECL) in the current class.  Check
6222    to see that the declaration is valid.  */
6223
6224 void
6225 note_name_declared_in_class (tree name, tree decl)
6226 {
6227   splay_tree names_used;
6228   splay_tree_node n;
6229
6230   /* Look to see if we ever used this name.  */
6231   names_used
6232     = current_class_stack[current_class_depth - 1].names_used;
6233   if (!names_used)
6234     return;
6235
6236   n = splay_tree_lookup (names_used, (splay_tree_key) name);
6237   if (n)
6238     {
6239       /* [basic.scope.class]
6240
6241          A name N used in a class S shall refer to the same declaration
6242          in its context and when re-evaluated in the completed scope of
6243          S.  */
6244       error ("declaration of %q#D", decl);
6245       error ("changes meaning of %qD from %q+#D",
6246              DECL_NAME (OVL_CURRENT (decl)), (tree) n->value);
6247     }
6248 }
6249
6250 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6251    Secondary vtables are merged with primary vtables; this function
6252    will return the VAR_DECL for the primary vtable.  */
6253
6254 tree
6255 get_vtbl_decl_for_binfo (tree binfo)
6256 {
6257   tree decl;
6258
6259   decl = BINFO_VTABLE (binfo);
6260   if (decl && TREE_CODE (decl) == PLUS_EXPR)
6261     {
6262       gcc_assert (TREE_CODE (TREE_OPERAND (decl, 0)) == ADDR_EXPR);
6263       decl = TREE_OPERAND (TREE_OPERAND (decl, 0), 0);
6264     }
6265   if (decl)
6266     gcc_assert (TREE_CODE (decl) == VAR_DECL);
6267   return decl;
6268 }
6269
6270
6271 /* Returns the binfo for the primary base of BINFO.  If the resulting
6272    BINFO is a virtual base, and it is inherited elsewhere in the
6273    hierarchy, then the returned binfo might not be the primary base of
6274    BINFO in the complete object.  Check BINFO_PRIMARY_P or
6275    BINFO_LOST_PRIMARY_P to be sure.  */
6276
6277 tree
6278 get_primary_binfo (tree binfo)
6279 {
6280   tree primary_base;
6281   tree result;
6282
6283   primary_base = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (binfo));
6284   if (!primary_base)
6285     return NULL_TREE;
6286
6287   result = copied_binfo (primary_base, binfo);
6288   return result;
6289 }
6290
6291 /* If INDENTED_P is zero, indent to INDENT. Return nonzero.  */
6292
6293 static int
6294 maybe_indent_hierarchy (FILE * stream, int indent, int indented_p)
6295 {
6296   if (!indented_p)
6297     fprintf (stream, "%*s", indent, "");
6298   return 1;
6299 }
6300
6301 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
6302    INDENT should be zero when called from the top level; it is
6303    incremented recursively.  IGO indicates the next expected BINFO in
6304    inheritance graph ordering.  */
6305
6306 static tree
6307 dump_class_hierarchy_r (FILE *stream,
6308                         int flags,
6309                         tree binfo,
6310                         tree igo,
6311                         int indent)
6312 {
6313   int indented = 0;
6314   tree base_binfo;
6315   int i;
6316
6317   indented = maybe_indent_hierarchy (stream, indent, 0);
6318   fprintf (stream, "%s (0x%lx) ",
6319            type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER),
6320            (unsigned long) binfo);
6321   if (binfo != igo)
6322     {
6323       fprintf (stream, "alternative-path\n");
6324       return igo;
6325     }
6326   igo = TREE_CHAIN (binfo);
6327
6328   fprintf (stream, HOST_WIDE_INT_PRINT_DEC,
6329            tree_low_cst (BINFO_OFFSET (binfo), 0));
6330   if (is_empty_class (BINFO_TYPE (binfo)))
6331     fprintf (stream, " empty");
6332   else if (CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (binfo)))
6333     fprintf (stream, " nearly-empty");
6334   if (BINFO_VIRTUAL_P (binfo))
6335     fprintf (stream, " virtual");
6336   fprintf (stream, "\n");
6337
6338   indented = 0;
6339   if (BINFO_PRIMARY_P (binfo))
6340     {
6341       indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6342       fprintf (stream, " primary-for %s (0x%lx)",
6343                type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)),
6344                                TFF_PLAIN_IDENTIFIER),
6345                (unsigned long)BINFO_INHERITANCE_CHAIN (binfo));
6346     }
6347   if (BINFO_LOST_PRIMARY_P (binfo))
6348     {
6349       indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6350       fprintf (stream, " lost-primary");
6351     }
6352   if (indented)
6353     fprintf (stream, "\n");
6354
6355   if (!(flags & TDF_SLIM))
6356     {
6357       int indented = 0;
6358
6359       if (BINFO_SUBVTT_INDEX (binfo))
6360         {
6361           indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6362           fprintf (stream, " subvttidx=%s",
6363                    expr_as_string (BINFO_SUBVTT_INDEX (binfo),
6364                                    TFF_PLAIN_IDENTIFIER));
6365         }
6366       if (BINFO_VPTR_INDEX (binfo))
6367         {
6368           indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6369           fprintf (stream, " vptridx=%s",
6370                    expr_as_string (BINFO_VPTR_INDEX (binfo),
6371                                    TFF_PLAIN_IDENTIFIER));
6372         }
6373       if (BINFO_VPTR_FIELD (binfo))
6374         {
6375           indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6376           fprintf (stream, " vbaseoffset=%s",
6377                    expr_as_string (BINFO_VPTR_FIELD (binfo),
6378                                    TFF_PLAIN_IDENTIFIER));
6379         }
6380       if (BINFO_VTABLE (binfo))
6381         {
6382           indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6383           fprintf (stream, " vptr=%s",
6384                    expr_as_string (BINFO_VTABLE (binfo),
6385                                    TFF_PLAIN_IDENTIFIER));
6386         }
6387
6388       if (indented)
6389         fprintf (stream, "\n");
6390     }
6391
6392   for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
6393     igo = dump_class_hierarchy_r (stream, flags, base_binfo, igo, indent + 2);
6394
6395   return igo;
6396 }
6397
6398 /* Dump the BINFO hierarchy for T.  */
6399
6400 static void
6401 dump_class_hierarchy_1 (FILE *stream, int flags, tree t)
6402 {
6403   fprintf (stream, "Class %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6404   fprintf (stream, "   size=%lu align=%lu\n",
6405            (unsigned long)(tree_low_cst (TYPE_SIZE (t), 0) / BITS_PER_UNIT),
6406            (unsigned long)(TYPE_ALIGN (t) / BITS_PER_UNIT));
6407   fprintf (stream, "   base size=%lu base align=%lu\n",
6408            (unsigned long)(tree_low_cst (TYPE_SIZE (CLASSTYPE_AS_BASE (t)), 0)
6409                            / BITS_PER_UNIT),
6410            (unsigned long)(TYPE_ALIGN (CLASSTYPE_AS_BASE (t))
6411                            / BITS_PER_UNIT));
6412   dump_class_hierarchy_r (stream, flags, TYPE_BINFO (t), TYPE_BINFO (t), 0);
6413   fprintf (stream, "\n");
6414 }
6415
6416 /* Debug interface to hierarchy dumping.  */
6417
6418 extern void
6419 debug_class (tree t)
6420 {
6421   dump_class_hierarchy_1 (stderr, TDF_SLIM, t);
6422 }
6423
6424 static void
6425 dump_class_hierarchy (tree t)
6426 {
6427   int flags;
6428   FILE *stream = dump_begin (TDI_class, &flags);
6429
6430   if (stream)
6431     {
6432       dump_class_hierarchy_1 (stream, flags, t);
6433       dump_end (TDI_class, stream);
6434     }
6435 }
6436
6437 static void
6438 dump_array (FILE * stream, tree decl)
6439 {
6440   tree inits;
6441   int ix;
6442   HOST_WIDE_INT elt;
6443   tree size = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (decl)));
6444
6445   elt = (tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl))), 0)
6446          / BITS_PER_UNIT);
6447   fprintf (stream, "%s:", decl_as_string (decl, TFF_PLAIN_IDENTIFIER));
6448   fprintf (stream, " %s entries",
6449            expr_as_string (size_binop (PLUS_EXPR, size, size_one_node),
6450                            TFF_PLAIN_IDENTIFIER));
6451   fprintf (stream, "\n");
6452
6453   for (ix = 0, inits = CONSTRUCTOR_ELTS (DECL_INITIAL (decl));
6454        inits; ix++, inits = TREE_CHAIN (inits))
6455     fprintf (stream, "%-4ld  %s\n", (long)(ix * elt),
6456              expr_as_string (TREE_VALUE (inits), TFF_PLAIN_IDENTIFIER));
6457 }
6458
6459 static void
6460 dump_vtable (tree t, tree binfo, tree vtable)
6461 {
6462   int flags;
6463   FILE *stream = dump_begin (TDI_class, &flags);
6464
6465   if (!stream)
6466     return;
6467
6468   if (!(flags & TDF_SLIM))
6469     {
6470       int ctor_vtbl_p = TYPE_BINFO (t) != binfo;
6471
6472       fprintf (stream, "%s for %s",
6473                ctor_vtbl_p ? "Construction vtable" : "Vtable",
6474                type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER));
6475       if (ctor_vtbl_p)
6476         {
6477           if (!BINFO_VIRTUAL_P (binfo))
6478             fprintf (stream, " (0x%lx instance)", (unsigned long)binfo);
6479           fprintf (stream, " in %s", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6480         }
6481       fprintf (stream, "\n");
6482       dump_array (stream, vtable);
6483       fprintf (stream, "\n");
6484     }
6485
6486   dump_end (TDI_class, stream);
6487 }
6488
6489 static void
6490 dump_vtt (tree t, tree vtt)
6491 {
6492   int flags;
6493   FILE *stream = dump_begin (TDI_class, &flags);
6494
6495   if (!stream)
6496     return;
6497
6498   if (!(flags & TDF_SLIM))
6499     {
6500       fprintf (stream, "VTT for %s\n",
6501                type_as_string (t, TFF_PLAIN_IDENTIFIER));
6502       dump_array (stream, vtt);
6503       fprintf (stream, "\n");
6504     }
6505
6506   dump_end (TDI_class, stream);
6507 }
6508
6509 /* Dump a function or thunk and its thunkees.  */
6510
6511 static void
6512 dump_thunk (FILE *stream, int indent, tree thunk)
6513 {
6514   static const char spaces[] = "        ";
6515   tree name = DECL_NAME (thunk);
6516   tree thunks;
6517
6518   fprintf (stream, "%.*s%p %s %s", indent, spaces,
6519            (void *)thunk,
6520            !DECL_THUNK_P (thunk) ? "function"
6521            : DECL_THIS_THUNK_P (thunk) ? "this-thunk" : "covariant-thunk",
6522            name ? IDENTIFIER_POINTER (name) : "<unset>");
6523   if (DECL_THUNK_P (thunk))
6524     {
6525       HOST_WIDE_INT fixed_adjust = THUNK_FIXED_OFFSET (thunk);
6526       tree virtual_adjust = THUNK_VIRTUAL_OFFSET (thunk);
6527
6528       fprintf (stream, " fixed=" HOST_WIDE_INT_PRINT_DEC, fixed_adjust);
6529       if (!virtual_adjust)
6530         /*NOP*/;
6531       else if (DECL_THIS_THUNK_P (thunk))
6532         fprintf (stream, " vcall="  HOST_WIDE_INT_PRINT_DEC,
6533                  tree_low_cst (virtual_adjust, 0));
6534       else
6535         fprintf (stream, " vbase=" HOST_WIDE_INT_PRINT_DEC "(%s)",
6536                  tree_low_cst (BINFO_VPTR_FIELD (virtual_adjust), 0),
6537                  type_as_string (BINFO_TYPE (virtual_adjust), TFF_SCOPE));
6538       if (THUNK_ALIAS (thunk))
6539         fprintf (stream, " alias to %p", (void *)THUNK_ALIAS (thunk));
6540     }
6541   fprintf (stream, "\n");
6542   for (thunks = DECL_THUNKS (thunk); thunks; thunks = TREE_CHAIN (thunks))
6543     dump_thunk (stream, indent + 2, thunks);
6544 }
6545
6546 /* Dump the thunks for FN.  */
6547
6548 extern void
6549 debug_thunks (tree fn)
6550 {
6551   dump_thunk (stderr, 0, fn);
6552 }
6553
6554 /* Virtual function table initialization.  */
6555
6556 /* Create all the necessary vtables for T and its base classes.  */
6557
6558 static void
6559 finish_vtbls (tree t)
6560 {
6561   tree list;
6562   tree vbase;
6563
6564   /* We lay out the primary and secondary vtables in one contiguous
6565      vtable.  The primary vtable is first, followed by the non-virtual
6566      secondary vtables in inheritance graph order.  */
6567   list = build_tree_list (BINFO_VTABLE (TYPE_BINFO (t)), NULL_TREE);
6568   accumulate_vtbl_inits (TYPE_BINFO (t), TYPE_BINFO (t),
6569                          TYPE_BINFO (t), t, list);
6570
6571   /* Then come the virtual bases, also in inheritance graph order.  */
6572   for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
6573     {
6574       if (!BINFO_VIRTUAL_P (vbase))
6575         continue;
6576       accumulate_vtbl_inits (vbase, vbase, TYPE_BINFO (t), t, list);
6577     }
6578
6579   if (BINFO_VTABLE (TYPE_BINFO (t)))
6580     initialize_vtable (TYPE_BINFO (t), TREE_VALUE (list));
6581 }
6582
6583 /* Initialize the vtable for BINFO with the INITS.  */
6584
6585 static void
6586 initialize_vtable (tree binfo, tree inits)
6587 {
6588   tree decl;
6589
6590   layout_vtable_decl (binfo, list_length (inits));
6591   decl = get_vtbl_decl_for_binfo (binfo);
6592   initialize_artificial_var (decl, inits);
6593   dump_vtable (BINFO_TYPE (binfo), binfo, decl);
6594 }
6595
6596 /* Build the VTT (virtual table table) for T.
6597    A class requires a VTT if it has virtual bases.
6598
6599    This holds
6600    1 - primary virtual pointer for complete object T
6601    2 - secondary VTTs for each direct non-virtual base of T which requires a
6602        VTT
6603    3 - secondary virtual pointers for each direct or indirect base of T which
6604        has virtual bases or is reachable via a virtual path from T.
6605    4 - secondary VTTs for each direct or indirect virtual base of T.
6606
6607    Secondary VTTs look like complete object VTTs without part 4.  */
6608
6609 static void
6610 build_vtt (tree t)
6611 {
6612   tree inits;
6613   tree type;
6614   tree vtt;
6615   tree index;
6616
6617   /* Build up the initializers for the VTT.  */
6618   inits = NULL_TREE;
6619   index = size_zero_node;
6620   build_vtt_inits (TYPE_BINFO (t), t, &inits, &index);
6621
6622   /* If we didn't need a VTT, we're done.  */
6623   if (!inits)
6624     return;
6625
6626   /* Figure out the type of the VTT.  */
6627   type = build_index_type (size_int (list_length (inits) - 1));
6628   type = build_cplus_array_type (const_ptr_type_node, type);
6629
6630   /* Now, build the VTT object itself.  */
6631   vtt = build_vtable (t, get_vtt_name (t), type);
6632   initialize_artificial_var (vtt, inits);
6633   /* Add the VTT to the vtables list.  */
6634   TREE_CHAIN (vtt) = TREE_CHAIN (CLASSTYPE_VTABLES (t));
6635   TREE_CHAIN (CLASSTYPE_VTABLES (t)) = vtt;
6636
6637   dump_vtt (t, vtt);
6638 }
6639
6640 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
6641    PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
6642    and CHAIN the vtable pointer for this binfo after construction is
6643    complete.  VALUE can also be another BINFO, in which case we recurse.  */
6644
6645 static tree
6646 binfo_ctor_vtable (tree binfo)
6647 {
6648   tree vt;
6649
6650   while (1)
6651     {
6652       vt = BINFO_VTABLE (binfo);
6653       if (TREE_CODE (vt) == TREE_LIST)
6654         vt = TREE_VALUE (vt);
6655       if (TREE_CODE (vt) == TREE_BINFO)
6656         binfo = vt;
6657       else
6658         break;
6659     }
6660
6661   return vt;
6662 }
6663
6664 /* Data for secondary VTT initialization.  */
6665 typedef struct secondary_vptr_vtt_init_data_s
6666 {
6667   /* Is this the primary VTT? */
6668   bool top_level_p;
6669
6670   /* Current index into the VTT.  */
6671   tree index;
6672
6673   /* TREE_LIST of initializers built up.  */
6674   tree inits;
6675
6676   /* The type being constructed by this secondary VTT.  */
6677   tree type_being_constructed;
6678 } secondary_vptr_vtt_init_data;
6679
6680 /* Recursively build the VTT-initializer for BINFO (which is in the
6681    hierarchy dominated by T).  INITS points to the end of the initializer
6682    list to date.  INDEX is the VTT index where the next element will be
6683    replaced.  Iff BINFO is the binfo for T, this is the top level VTT (i.e.
6684    not a subvtt for some base of T).  When that is so, we emit the sub-VTTs
6685    for virtual bases of T. When it is not so, we build the constructor
6686    vtables for the BINFO-in-T variant.  */
6687
6688 static tree *
6689 build_vtt_inits (tree binfo, tree t, tree *inits, tree *index)
6690 {
6691   int i;
6692   tree b;
6693   tree init;
6694   tree secondary_vptrs;
6695   secondary_vptr_vtt_init_data data;
6696   int top_level_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
6697
6698   /* We only need VTTs for subobjects with virtual bases.  */
6699   if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
6700     return inits;
6701
6702   /* We need to use a construction vtable if this is not the primary
6703      VTT.  */
6704   if (!top_level_p)
6705     {
6706       build_ctor_vtbl_group (binfo, t);
6707
6708       /* Record the offset in the VTT where this sub-VTT can be found.  */
6709       BINFO_SUBVTT_INDEX (binfo) = *index;
6710     }
6711
6712   /* Add the address of the primary vtable for the complete object.  */
6713   init = binfo_ctor_vtable (binfo);
6714   *inits = build_tree_list (NULL_TREE, init);
6715   inits = &TREE_CHAIN (*inits);
6716   if (top_level_p)
6717     {
6718       gcc_assert (!BINFO_VPTR_INDEX (binfo));
6719       BINFO_VPTR_INDEX (binfo) = *index;
6720     }
6721   *index = size_binop (PLUS_EXPR, *index, TYPE_SIZE_UNIT (ptr_type_node));
6722
6723   /* Recursively add the secondary VTTs for non-virtual bases.  */
6724   for (i = 0; BINFO_BASE_ITERATE (binfo, i, b); ++i)
6725     if (!BINFO_VIRTUAL_P (b))
6726       inits = build_vtt_inits (b, t, inits, index);
6727
6728   /* Add secondary virtual pointers for all subobjects of BINFO with
6729      either virtual bases or reachable along a virtual path, except
6730      subobjects that are non-virtual primary bases.  */
6731   data.top_level_p = top_level_p;
6732   data.index = *index;
6733   data.inits = NULL;
6734   data.type_being_constructed = BINFO_TYPE (binfo);
6735
6736   dfs_walk_once (binfo, dfs_build_secondary_vptr_vtt_inits, NULL, &data);
6737
6738   *index = data.index;
6739
6740   /* The secondary vptrs come back in reverse order.  After we reverse
6741      them, and add the INITS, the last init will be the first element
6742      of the chain.  */
6743   secondary_vptrs = data.inits;
6744   if (secondary_vptrs)
6745     {
6746       *inits = nreverse (secondary_vptrs);
6747       inits = &TREE_CHAIN (secondary_vptrs);
6748       gcc_assert (*inits == NULL_TREE);
6749     }
6750
6751   if (top_level_p)
6752     /* Add the secondary VTTs for virtual bases in inheritance graph
6753        order.  */
6754     for (b = TYPE_BINFO (BINFO_TYPE (binfo)); b; b = TREE_CHAIN (b))
6755       {
6756         if (!BINFO_VIRTUAL_P (b))
6757           continue;
6758
6759         inits = build_vtt_inits (b, t, inits, index);
6760       }
6761   else
6762     /* Remove the ctor vtables we created.  */
6763     dfs_walk_all (binfo, dfs_fixup_binfo_vtbls, NULL, binfo);
6764
6765   return inits;
6766 }
6767
6768 /* Called from build_vtt_inits via dfs_walk.  BINFO is the binfo for the base
6769    in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure.  */
6770
6771 static tree
6772 dfs_build_secondary_vptr_vtt_inits (tree binfo, void *data_)
6773 {
6774   secondary_vptr_vtt_init_data *data = (secondary_vptr_vtt_init_data *)data_;
6775
6776   /* We don't care about bases that don't have vtables.  */
6777   if (!TYPE_VFIELD (BINFO_TYPE (binfo)))
6778     return dfs_skip_bases;
6779
6780   /* We're only interested in proper subobjects of the type being
6781      constructed.  */
6782   if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->type_being_constructed))
6783     return NULL_TREE;
6784
6785   /* We're only interested in bases with virtual bases or reachable
6786      via a virtual path from the type being constructed.  */
6787   if (!(CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
6788         || binfo_via_virtual (binfo, data->type_being_constructed)))
6789     return dfs_skip_bases;
6790
6791   /* We're not interested in non-virtual primary bases.  */
6792   if (!BINFO_VIRTUAL_P (binfo) && BINFO_PRIMARY_P (binfo))
6793     return NULL_TREE;
6794
6795   /* Record the index where this secondary vptr can be found.  */
6796   if (data->top_level_p)
6797     {
6798       gcc_assert (!BINFO_VPTR_INDEX (binfo));
6799       BINFO_VPTR_INDEX (binfo) = data->index;
6800
6801       if (BINFO_VIRTUAL_P (binfo))
6802         {
6803           /* It's a primary virtual base, and this is not a
6804              construction vtable.  Find the base this is primary of in
6805              the inheritance graph, and use that base's vtable
6806              now.  */
6807           while (BINFO_PRIMARY_P (binfo))
6808             binfo = BINFO_INHERITANCE_CHAIN (binfo);
6809         }
6810     }
6811
6812   /* Add the initializer for the secondary vptr itself.  */
6813   data->inits = tree_cons (NULL_TREE, binfo_ctor_vtable (binfo), data->inits);
6814
6815   /* Advance the vtt index.  */
6816   data->index = size_binop (PLUS_EXPR, data->index,
6817                             TYPE_SIZE_UNIT (ptr_type_node));
6818
6819   return NULL_TREE;
6820 }
6821
6822 /* Called from build_vtt_inits via dfs_walk. After building
6823    constructor vtables and generating the sub-vtt from them, we need
6824    to restore the BINFO_VTABLES that were scribbled on.  DATA is the
6825    binfo of the base whose sub vtt was generated.  */
6826
6827 static tree
6828 dfs_fixup_binfo_vtbls (tree binfo, void* data)
6829 {
6830   tree vtable = BINFO_VTABLE (binfo);
6831
6832   if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
6833     /* If this class has no vtable, none of its bases do.  */
6834     return dfs_skip_bases;
6835
6836   if (!vtable)
6837     /* This might be a primary base, so have no vtable in this
6838        hierarchy.  */
6839     return NULL_TREE;
6840
6841   /* If we scribbled the construction vtable vptr into BINFO, clear it
6842      out now.  */
6843   if (TREE_CODE (vtable) == TREE_LIST
6844       && (TREE_PURPOSE (vtable) == (tree) data))
6845     BINFO_VTABLE (binfo) = TREE_CHAIN (vtable);
6846
6847   return NULL_TREE;
6848 }
6849
6850 /* Build the construction vtable group for BINFO which is in the
6851    hierarchy dominated by T.  */
6852
6853 static void
6854 build_ctor_vtbl_group (tree binfo, tree t)
6855 {
6856   tree list;
6857   tree type;
6858   tree vtbl;
6859   tree inits;
6860   tree id;
6861   tree vbase;
6862
6863   /* See if we've already created this construction vtable group.  */
6864   id = mangle_ctor_vtbl_for_type (t, binfo);
6865   if (IDENTIFIER_GLOBAL_VALUE (id))
6866     return;
6867
6868   gcc_assert (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t));
6869   /* Build a version of VTBL (with the wrong type) for use in
6870      constructing the addresses of secondary vtables in the
6871      construction vtable group.  */
6872   vtbl = build_vtable (t, id, ptr_type_node);
6873   DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1;
6874   list = build_tree_list (vtbl, NULL_TREE);
6875   accumulate_vtbl_inits (binfo, TYPE_BINFO (TREE_TYPE (binfo)),
6876                          binfo, t, list);
6877
6878   /* Add the vtables for each of our virtual bases using the vbase in T
6879      binfo.  */
6880   for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
6881        vbase;
6882        vbase = TREE_CHAIN (vbase))
6883     {
6884       tree b;
6885
6886       if (!BINFO_VIRTUAL_P (vbase))
6887         continue;
6888       b = copied_binfo (vbase, binfo);
6889
6890       accumulate_vtbl_inits (b, vbase, binfo, t, list);
6891     }
6892   inits = TREE_VALUE (list);
6893
6894   /* Figure out the type of the construction vtable.  */
6895   type = build_index_type (size_int (list_length (inits) - 1));
6896   type = build_cplus_array_type (vtable_entry_type, type);
6897   TREE_TYPE (vtbl) = type;
6898
6899   /* Initialize the construction vtable.  */
6900   CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl);
6901   initialize_artificial_var (vtbl, inits);
6902   dump_vtable (t, binfo, vtbl);
6903 }
6904
6905 /* Add the vtbl initializers for BINFO (and its bases other than
6906    non-virtual primaries) to the list of INITS.  BINFO is in the
6907    hierarchy dominated by T.  RTTI_BINFO is the binfo within T of
6908    the constructor the vtbl inits should be accumulated for. (If this
6909    is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
6910    ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
6911    BINFO is the active base equivalent of ORIG_BINFO in the inheritance
6912    graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
6913    but are not necessarily the same in terms of layout.  */
6914
6915 static void
6916 accumulate_vtbl_inits (tree binfo,
6917                        tree orig_binfo,
6918                        tree rtti_binfo,
6919                        tree t,
6920                        tree inits)
6921 {
6922   int i;
6923   tree base_binfo;
6924   int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
6925
6926   gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (orig_binfo)));
6927
6928   /* If it doesn't have a vptr, we don't do anything.  */
6929   if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
6930     return;
6931
6932   /* If we're building a construction vtable, we're not interested in
6933      subobjects that don't require construction vtables.  */
6934   if (ctor_vtbl_p
6935       && !CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
6936       && !binfo_via_virtual (orig_binfo, BINFO_TYPE (rtti_binfo)))
6937     return;
6938
6939   /* Build the initializers for the BINFO-in-T vtable.  */
6940   TREE_VALUE (inits)
6941     = chainon (TREE_VALUE (inits),
6942                dfs_accumulate_vtbl_inits (binfo, orig_binfo,
6943                                           rtti_binfo, t, inits));
6944
6945   /* Walk the BINFO and its bases.  We walk in preorder so that as we
6946      initialize each vtable we can figure out at what offset the
6947      secondary vtable lies from the primary vtable.  We can't use
6948      dfs_walk here because we need to iterate through bases of BINFO
6949      and RTTI_BINFO simultaneously.  */
6950   for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
6951     {
6952       /* Skip virtual bases.  */
6953       if (BINFO_VIRTUAL_P (base_binfo))
6954         continue;
6955       accumulate_vtbl_inits (base_binfo,
6956                              BINFO_BASE_BINFO (orig_binfo, i),
6957                              rtti_binfo, t,
6958                              inits);
6959     }
6960 }
6961
6962 /* Called from accumulate_vtbl_inits.  Returns the initializers for
6963    the BINFO vtable.  */
6964
6965 static tree
6966 dfs_accumulate_vtbl_inits (tree binfo,
6967                            tree orig_binfo,
6968                            tree rtti_binfo,
6969                            tree t,
6970                            tree l)
6971 {
6972   tree inits = NULL_TREE;
6973   tree vtbl = NULL_TREE;
6974   int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
6975
6976   if (ctor_vtbl_p
6977       && BINFO_VIRTUAL_P (orig_binfo) && BINFO_PRIMARY_P (orig_binfo))
6978     {
6979       /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
6980          primary virtual base.  If it is not the same primary in
6981          the hierarchy of T, we'll need to generate a ctor vtable
6982          for it, to place at its location in T.  If it is the same
6983          primary, we still need a VTT entry for the vtable, but it
6984          should point to the ctor vtable for the base it is a
6985          primary for within the sub-hierarchy of RTTI_BINFO.
6986
6987          There are three possible cases:
6988
6989          1) We are in the same place.
6990          2) We are a primary base within a lost primary virtual base of
6991          RTTI_BINFO.
6992          3) We are primary to something not a base of RTTI_BINFO.  */
6993
6994       tree b;
6995       tree last = NULL_TREE;
6996
6997       /* First, look through the bases we are primary to for RTTI_BINFO
6998          or a virtual base.  */
6999       b = binfo;
7000       while (BINFO_PRIMARY_P (b))
7001         {
7002           b = BINFO_INHERITANCE_CHAIN (b);
7003           last = b;
7004           if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7005             goto found;
7006         }
7007       /* If we run out of primary links, keep looking down our
7008          inheritance chain; we might be an indirect primary.  */
7009       for (b = last; b; b = BINFO_INHERITANCE_CHAIN (b))
7010         if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7011           break;
7012     found:
7013
7014       /* If we found RTTI_BINFO, this is case 1.  If we found a virtual
7015          base B and it is a base of RTTI_BINFO, this is case 2.  In
7016          either case, we share our vtable with LAST, i.e. the
7017          derived-most base within B of which we are a primary.  */
7018       if (b == rtti_binfo
7019           || (b && binfo_for_vbase (BINFO_TYPE (b), BINFO_TYPE (rtti_binfo))))
7020         /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7021            set LAST's BINFO_VTABLE yet.  We'll extract the actual vptr in
7022            binfo_ctor_vtable after everything's been set up.  */
7023         vtbl = last;
7024
7025       /* Otherwise, this is case 3 and we get our own.  */
7026     }
7027   else if (!BINFO_NEW_VTABLE_MARKED (orig_binfo))
7028     return inits;
7029
7030   if (!vtbl)
7031     {
7032       tree index;
7033       int non_fn_entries;
7034
7035       /* Compute the initializer for this vtable.  */
7036       inits = build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo,
7037                                       &non_fn_entries);
7038
7039       /* Figure out the position to which the VPTR should point.  */
7040       vtbl = TREE_PURPOSE (l);
7041       vtbl = build1 (ADDR_EXPR, vtbl_ptr_type_node, vtbl);
7042       index = size_binop (PLUS_EXPR,
7043                           size_int (non_fn_entries),
7044                           size_int (list_length (TREE_VALUE (l))));
7045       index = size_binop (MULT_EXPR,
7046                           TYPE_SIZE_UNIT (vtable_entry_type),
7047                           index);
7048       vtbl = build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, index);
7049     }
7050
7051   if (ctor_vtbl_p)
7052     /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7053        So, we make a TREE_LIST.  Later, dfs_fixup_binfo_vtbls will
7054        straighten this out.  */
7055     BINFO_VTABLE (binfo) = tree_cons (rtti_binfo, vtbl, BINFO_VTABLE (binfo));
7056   else if (BINFO_PRIMARY_P (binfo) && BINFO_VIRTUAL_P (binfo))
7057     inits = NULL_TREE;
7058   else
7059      /* For an ordinary vtable, set BINFO_VTABLE.  */
7060     BINFO_VTABLE (binfo) = vtbl;
7061
7062   return inits;
7063 }
7064
7065 static GTY(()) tree abort_fndecl_addr;
7066
7067 /* Construct the initializer for BINFO's virtual function table.  BINFO
7068    is part of the hierarchy dominated by T.  If we're building a
7069    construction vtable, the ORIG_BINFO is the binfo we should use to
7070    find the actual function pointers to put in the vtable - but they
7071    can be overridden on the path to most-derived in the graph that
7072    ORIG_BINFO belongs.  Otherwise,
7073    ORIG_BINFO should be the same as BINFO.  The RTTI_BINFO is the
7074    BINFO that should be indicated by the RTTI information in the
7075    vtable; it will be a base class of T, rather than T itself, if we
7076    are building a construction vtable.
7077
7078    The value returned is a TREE_LIST suitable for wrapping in a
7079    CONSTRUCTOR to use as the DECL_INITIAL for a vtable.  If
7080    NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7081    number of non-function entries in the vtable.
7082
7083    It might seem that this function should never be called with a
7084    BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7085    base is always subsumed by a derived class vtable.  However, when
7086    we are building construction vtables, we do build vtables for
7087    primary bases; we need these while the primary base is being
7088    constructed.  */
7089
7090 static tree
7091 build_vtbl_initializer (tree binfo,
7092                         tree orig_binfo,
7093                         tree t,
7094                         tree rtti_binfo,
7095                         int* non_fn_entries_p)
7096 {
7097   tree v, b;
7098   tree vfun_inits;
7099   vtbl_init_data vid;
7100   unsigned ix;
7101   tree vbinfo;
7102   VEC(tree,gc) *vbases;
7103
7104   /* Initialize VID.  */
7105   memset (&vid, 0, sizeof (vid));
7106   vid.binfo = binfo;
7107   vid.derived = t;
7108   vid.rtti_binfo = rtti_binfo;
7109   vid.last_init = &vid.inits;
7110   vid.primary_vtbl_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
7111   vid.ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7112   vid.generate_vcall_entries = true;
7113   /* The first vbase or vcall offset is at index -3 in the vtable.  */
7114   vid.index = ssize_int(-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE);
7115
7116   /* Add entries to the vtable for RTTI.  */
7117   build_rtti_vtbl_entries (binfo, &vid);
7118
7119   /* Create an array for keeping track of the functions we've
7120      processed.  When we see multiple functions with the same
7121      signature, we share the vcall offsets.  */
7122   vid.fns = VEC_alloc (tree, gc, 32);
7123   /* Add the vcall and vbase offset entries.  */
7124   build_vcall_and_vbase_vtbl_entries (binfo, &vid);
7125
7126   /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7127      build_vbase_offset_vtbl_entries.  */
7128   for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0;
7129        VEC_iterate (tree, vbases, ix, vbinfo); ix++)
7130     BINFO_VTABLE_PATH_MARKED (vbinfo) = 0;
7131
7132   /* If the target requires padding between data entries, add that now.  */
7133   if (TARGET_VTABLE_DATA_ENTRY_DISTANCE > 1)
7134     {
7135       tree cur, *prev;
7136
7137       for (prev = &vid.inits; (cur = *prev); prev = &TREE_CHAIN (cur))
7138         {
7139           tree add = cur;
7140           int i;
7141
7142           for (i = 1; i < TARGET_VTABLE_DATA_ENTRY_DISTANCE; ++i)
7143             add = tree_cons (NULL_TREE,
7144                              build1 (NOP_EXPR, vtable_entry_type,
7145                                      null_pointer_node),
7146                              add);
7147           *prev = add;
7148         }
7149     }
7150
7151   if (non_fn_entries_p)
7152     *non_fn_entries_p = list_length (vid.inits);
7153
7154   /* Go through all the ordinary virtual functions, building up
7155      initializers.  */
7156   vfun_inits = NULL_TREE;
7157   for (v = BINFO_VIRTUALS (orig_binfo); v; v = TREE_CHAIN (v))
7158     {
7159       tree delta;
7160       tree vcall_index;
7161       tree fn, fn_original;
7162       tree init = NULL_TREE;
7163
7164       fn = BV_FN (v);
7165       fn_original = fn;
7166       if (DECL_THUNK_P (fn))
7167         {
7168           if (!DECL_NAME (fn))
7169             finish_thunk (fn);
7170           if (THUNK_ALIAS (fn))
7171             {
7172               fn = THUNK_ALIAS (fn);
7173               BV_FN (v) = fn;
7174             }
7175           fn_original = THUNK_TARGET (fn);
7176         }
7177
7178       /* If the only definition of this function signature along our
7179          primary base chain is from a lost primary, this vtable slot will
7180          never be used, so just zero it out.  This is important to avoid
7181          requiring extra thunks which cannot be generated with the function.
7182
7183          We first check this in update_vtable_entry_for_fn, so we handle
7184          restored primary bases properly; we also need to do it here so we
7185          zero out unused slots in ctor vtables, rather than filling themff
7186          with erroneous values (though harmless, apart from relocation
7187          costs).  */
7188       for (b = binfo; ; b = get_primary_binfo (b))
7189         {
7190           /* We found a defn before a lost primary; go ahead as normal.  */
7191           if (look_for_overrides_here (BINFO_TYPE (b), fn_original))
7192             break;
7193
7194           /* The nearest definition is from a lost primary; clear the
7195              slot.  */
7196           if (BINFO_LOST_PRIMARY_P (b))
7197             {
7198               init = size_zero_node;
7199               break;
7200             }
7201         }
7202
7203       if (! init)
7204         {
7205           /* Pull the offset for `this', and the function to call, out of
7206              the list.  */
7207           delta = BV_DELTA (v);
7208           vcall_index = BV_VCALL_INDEX (v);
7209
7210           gcc_assert (TREE_CODE (delta) == INTEGER_CST);
7211           gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
7212
7213           /* You can't call an abstract virtual function; it's abstract.
7214              So, we replace these functions with __pure_virtual.  */
7215           if (DECL_PURE_VIRTUAL_P (fn_original))
7216             {
7217               fn = abort_fndecl;
7218               if (abort_fndecl_addr == NULL)
7219                 abort_fndecl_addr = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7220               init = abort_fndecl_addr;
7221             }
7222           else
7223             {
7224               if (!integer_zerop (delta) || vcall_index)
7225                 {
7226                   fn = make_thunk (fn, /*this_adjusting=*/1, delta, vcall_index);
7227                   if (!DECL_NAME (fn))
7228                     finish_thunk (fn);
7229                 }
7230               /* Take the address of the function, considering it to be of an
7231                  appropriate generic type.  */
7232               init = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7233             }
7234         }
7235
7236       /* And add it to the chain of initializers.  */
7237       if (TARGET_VTABLE_USES_DESCRIPTORS)
7238         {
7239           int i;
7240           if (init == size_zero_node)
7241             for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7242               vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7243           else
7244             for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7245               {
7246                 tree fdesc = build2 (FDESC_EXPR, vfunc_ptr_type_node,
7247                                      TREE_OPERAND (init, 0),
7248                                      build_int_cst (NULL_TREE, i));
7249                 TREE_CONSTANT (fdesc) = 1;
7250                 TREE_INVARIANT (fdesc) = 1;
7251
7252                 vfun_inits = tree_cons (NULL_TREE, fdesc, vfun_inits);
7253               }
7254         }
7255       else
7256         vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7257     }
7258
7259   /* The initializers for virtual functions were built up in reverse
7260      order; straighten them out now.  */
7261   vfun_inits = nreverse (vfun_inits);
7262
7263   /* The negative offset initializers are also in reverse order.  */
7264   vid.inits = nreverse (vid.inits);
7265
7266   /* Chain the two together.  */
7267   return chainon (vid.inits, vfun_inits);
7268 }
7269
7270 /* Adds to vid->inits the initializers for the vbase and vcall
7271    offsets in BINFO, which is in the hierarchy dominated by T.  */
7272
7273 static void
7274 build_vcall_and_vbase_vtbl_entries (tree binfo, vtbl_init_data* vid)
7275 {
7276   tree b;
7277
7278   /* If this is a derived class, we must first create entries
7279      corresponding to the primary base class.  */
7280   b = get_primary_binfo (binfo);
7281   if (b)
7282     build_vcall_and_vbase_vtbl_entries (b, vid);
7283
7284   /* Add the vbase entries for this base.  */
7285   build_vbase_offset_vtbl_entries (binfo, vid);
7286   /* Add the vcall entries for this base.  */
7287   build_vcall_offset_vtbl_entries (binfo, vid);
7288 }
7289
7290 /* Returns the initializers for the vbase offset entries in the vtable
7291    for BINFO (which is part of the class hierarchy dominated by T), in
7292    reverse order.  VBASE_OFFSET_INDEX gives the vtable index
7293    where the next vbase offset will go.  */
7294
7295 static void
7296 build_vbase_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7297 {
7298   tree vbase;
7299   tree t;
7300   tree non_primary_binfo;
7301
7302   /* If there are no virtual baseclasses, then there is nothing to
7303      do.  */
7304   if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
7305     return;
7306
7307   t = vid->derived;
7308
7309   /* We might be a primary base class.  Go up the inheritance hierarchy
7310      until we find the most derived class of which we are a primary base:
7311      it is the offset of that which we need to use.  */
7312   non_primary_binfo = binfo;
7313   while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7314     {
7315       tree b;
7316
7317       /* If we have reached a virtual base, then it must be a primary
7318          base (possibly multi-level) of vid->binfo, or we wouldn't
7319          have called build_vcall_and_vbase_vtbl_entries for it.  But it
7320          might be a lost primary, so just skip down to vid->binfo.  */
7321       if (BINFO_VIRTUAL_P (non_primary_binfo))
7322         {
7323           non_primary_binfo = vid->binfo;
7324           break;
7325         }
7326
7327       b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7328       if (get_primary_binfo (b) != non_primary_binfo)
7329         break;
7330       non_primary_binfo = b;
7331     }
7332
7333   /* Go through the virtual bases, adding the offsets.  */
7334   for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
7335        vbase;
7336        vbase = TREE_CHAIN (vbase))
7337     {
7338       tree b;
7339       tree delta;
7340
7341       if (!BINFO_VIRTUAL_P (vbase))
7342         continue;
7343
7344       /* Find the instance of this virtual base in the complete
7345          object.  */
7346       b = copied_binfo (vbase, binfo);
7347
7348       /* If we've already got an offset for this virtual base, we
7349          don't need another one.  */
7350       if (BINFO_VTABLE_PATH_MARKED (b))
7351         continue;
7352       BINFO_VTABLE_PATH_MARKED (b) = 1;
7353
7354       /* Figure out where we can find this vbase offset.  */
7355       delta = size_binop (MULT_EXPR,
7356                           vid->index,
7357                           convert (ssizetype,
7358                                    TYPE_SIZE_UNIT (vtable_entry_type)));
7359       if (vid->primary_vtbl_p)
7360         BINFO_VPTR_FIELD (b) = delta;
7361
7362       if (binfo != TYPE_BINFO (t))
7363         /* The vbase offset had better be the same.  */
7364         gcc_assert (tree_int_cst_equal (delta, BINFO_VPTR_FIELD (vbase)));
7365
7366       /* The next vbase will come at a more negative offset.  */
7367       vid->index = size_binop (MINUS_EXPR, vid->index,
7368                                ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7369
7370       /* The initializer is the delta from BINFO to this virtual base.
7371          The vbase offsets go in reverse inheritance-graph order, and
7372          we are walking in inheritance graph order so these end up in
7373          the right order.  */
7374       delta = size_diffop (BINFO_OFFSET (b), BINFO_OFFSET (non_primary_binfo));
7375
7376       *vid->last_init
7377         = build_tree_list (NULL_TREE,
7378                            fold_build1 (NOP_EXPR,
7379                                         vtable_entry_type,
7380                                         delta));
7381       vid->last_init = &TREE_CHAIN (*vid->last_init);
7382     }
7383 }
7384
7385 /* Adds the initializers for the vcall offset entries in the vtable
7386    for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7387    to VID->INITS.  */
7388
7389 static void
7390 build_vcall_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7391 {
7392   /* We only need these entries if this base is a virtual base.  We
7393      compute the indices -- but do not add to the vtable -- when
7394      building the main vtable for a class.  */
7395   if (BINFO_VIRTUAL_P (binfo) || binfo == TYPE_BINFO (vid->derived))
7396     {
7397       /* We need a vcall offset for each of the virtual functions in this
7398          vtable.  For example:
7399
7400            class A { virtual void f (); };
7401            class B1 : virtual public A { virtual void f (); };
7402            class B2 : virtual public A { virtual void f (); };
7403            class C: public B1, public B2 { virtual void f (); };
7404
7405          A C object has a primary base of B1, which has a primary base of A.  A
7406          C also has a secondary base of B2, which no longer has a primary base
7407          of A.  So the B2-in-C construction vtable needs a secondary vtable for
7408          A, which will adjust the A* to a B2* to call f.  We have no way of
7409          knowing what (or even whether) this offset will be when we define B2,
7410          so we store this "vcall offset" in the A sub-vtable and look it up in
7411          a "virtual thunk" for B2::f.
7412
7413          We need entries for all the functions in our primary vtable and
7414          in our non-virtual bases' secondary vtables.  */
7415       vid->vbase = binfo;
7416       /* If we are just computing the vcall indices -- but do not need
7417          the actual entries -- not that.  */
7418       if (!BINFO_VIRTUAL_P (binfo))
7419         vid->generate_vcall_entries = false;
7420       /* Now, walk through the non-virtual bases, adding vcall offsets.  */
7421       add_vcall_offset_vtbl_entries_r (binfo, vid);
7422     }
7423 }
7424
7425 /* Build vcall offsets, starting with those for BINFO.  */
7426
7427 static void
7428 add_vcall_offset_vtbl_entries_r (tree binfo, vtbl_init_data* vid)
7429 {
7430   int i;
7431   tree primary_binfo;
7432   tree base_binfo;
7433
7434   /* Don't walk into virtual bases -- except, of course, for the
7435      virtual base for which we are building vcall offsets.  Any
7436      primary virtual base will have already had its offsets generated
7437      through the recursion in build_vcall_and_vbase_vtbl_entries.  */
7438   if (BINFO_VIRTUAL_P (binfo) && vid->vbase != binfo)
7439     return;
7440
7441   /* If BINFO has a primary base, process it first.  */
7442   primary_binfo = get_primary_binfo (binfo);
7443   if (primary_binfo)
7444     add_vcall_offset_vtbl_entries_r (primary_binfo, vid);
7445
7446   /* Add BINFO itself to the list.  */
7447   add_vcall_offset_vtbl_entries_1 (binfo, vid);
7448
7449   /* Scan the non-primary bases of BINFO.  */
7450   for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7451     if (base_binfo != primary_binfo)
7452       add_vcall_offset_vtbl_entries_r (base_binfo, vid);
7453 }
7454
7455 /* Called from build_vcall_offset_vtbl_entries_r.  */
7456
7457 static void
7458 add_vcall_offset_vtbl_entries_1 (tree binfo, vtbl_init_data* vid)
7459 {
7460   /* Make entries for the rest of the virtuals.  */
7461   if (abi_version_at_least (2))
7462     {
7463       tree orig_fn;
7464
7465       /* The ABI requires that the methods be processed in declaration
7466          order.  G++ 3.2 used the order in the vtable.  */
7467       for (orig_fn = TYPE_METHODS (BINFO_TYPE (binfo));
7468            orig_fn;
7469            orig_fn = TREE_CHAIN (orig_fn))
7470         if (DECL_VINDEX (orig_fn))
7471           add_vcall_offset (orig_fn, binfo, vid);
7472     }
7473   else
7474     {
7475       tree derived_virtuals;
7476       tree base_virtuals;
7477       tree orig_virtuals;
7478       /* If BINFO is a primary base, the most derived class which has
7479          BINFO as a primary base; otherwise, just BINFO.  */
7480       tree non_primary_binfo;
7481
7482       /* We might be a primary base class.  Go up the inheritance hierarchy
7483          until we find the most derived class of which we are a primary base:
7484          it is the BINFO_VIRTUALS there that we need to consider.  */
7485       non_primary_binfo = binfo;
7486       while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7487         {
7488           tree b;
7489
7490           /* If we have reached a virtual base, then it must be vid->vbase,
7491              because we ignore other virtual bases in
7492              add_vcall_offset_vtbl_entries_r.  In turn, it must be a primary
7493              base (possibly multi-level) of vid->binfo, or we wouldn't
7494              have called build_vcall_and_vbase_vtbl_entries for it.  But it
7495              might be a lost primary, so just skip down to vid->binfo.  */
7496           if (BINFO_VIRTUAL_P (non_primary_binfo))
7497             {
7498               gcc_assert (non_primary_binfo == vid->vbase);
7499               non_primary_binfo = vid->binfo;
7500               break;
7501             }
7502
7503           b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7504           if (get_primary_binfo (b) != non_primary_binfo)
7505             break;
7506           non_primary_binfo = b;
7507         }
7508
7509       if (vid->ctor_vtbl_p)
7510         /* For a ctor vtable we need the equivalent binfo within the hierarchy
7511            where rtti_binfo is the most derived type.  */
7512         non_primary_binfo
7513           = original_binfo (non_primary_binfo, vid->rtti_binfo);
7514
7515       for (base_virtuals = BINFO_VIRTUALS (binfo),
7516              derived_virtuals = BINFO_VIRTUALS (non_primary_binfo),
7517              orig_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
7518            base_virtuals;
7519            base_virtuals = TREE_CHAIN (base_virtuals),
7520              derived_virtuals = TREE_CHAIN (derived_virtuals),
7521              orig_virtuals = TREE_CHAIN (orig_virtuals))
7522         {
7523           tree orig_fn;
7524
7525           /* Find the declaration that originally caused this function to
7526              be present in BINFO_TYPE (binfo).  */
7527           orig_fn = BV_FN (orig_virtuals);
7528
7529           /* When processing BINFO, we only want to generate vcall slots for
7530              function slots introduced in BINFO.  So don't try to generate
7531              one if the function isn't even defined in BINFO.  */
7532           if (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), DECL_CONTEXT (orig_fn)))
7533             continue;
7534
7535           add_vcall_offset (orig_fn, binfo, vid);
7536         }
7537     }
7538 }
7539
7540 /* Add a vcall offset entry for ORIG_FN to the vtable.  */
7541
7542 static void
7543 add_vcall_offset (tree orig_fn, tree binfo, vtbl_init_data *vid)
7544 {
7545   size_t i;
7546   tree vcall_offset;
7547   tree derived_entry;
7548
7549   /* If there is already an entry for a function with the same
7550      signature as FN, then we do not need a second vcall offset.
7551      Check the list of functions already present in the derived
7552      class vtable.  */
7553   for (i = 0; VEC_iterate (tree, vid->fns, i, derived_entry); ++i)
7554     {
7555       if (same_signature_p (derived_entry, orig_fn)
7556           /* We only use one vcall offset for virtual destructors,
7557              even though there are two virtual table entries.  */
7558           || (DECL_DESTRUCTOR_P (derived_entry)
7559               && DECL_DESTRUCTOR_P (orig_fn)))
7560         return;
7561     }
7562
7563   /* If we are building these vcall offsets as part of building
7564      the vtable for the most derived class, remember the vcall
7565      offset.  */
7566   if (vid->binfo == TYPE_BINFO (vid->derived))
7567     {
7568       tree_pair_p elt = VEC_safe_push (tree_pair_s, gc,
7569                                        CLASSTYPE_VCALL_INDICES (vid->derived),
7570                                        NULL);
7571       elt->purpose = orig_fn;
7572       elt->value = vid->index;
7573     }
7574
7575   /* The next vcall offset will be found at a more negative
7576      offset.  */
7577   vid->index = size_binop (MINUS_EXPR, vid->index,
7578                            ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7579
7580   /* Keep track of this function.  */
7581   VEC_safe_push (tree, gc, vid->fns, orig_fn);
7582
7583   if (vid->generate_vcall_entries)
7584     {
7585       tree base;
7586       tree fn;
7587
7588       /* Find the overriding function.  */
7589       fn = find_final_overrider (vid->rtti_binfo, binfo, orig_fn);
7590       if (fn == error_mark_node)
7591         vcall_offset = build1 (NOP_EXPR, vtable_entry_type,
7592                                integer_zero_node);
7593       else
7594         {
7595           base = TREE_VALUE (fn);
7596
7597           /* The vbase we're working on is a primary base of
7598              vid->binfo.  But it might be a lost primary, so its
7599              BINFO_OFFSET might be wrong, so we just use the
7600              BINFO_OFFSET from vid->binfo.  */
7601           vcall_offset = size_diffop (BINFO_OFFSET (base),
7602                                       BINFO_OFFSET (vid->binfo));
7603           vcall_offset = fold_build1 (NOP_EXPR, vtable_entry_type,
7604                                       vcall_offset);
7605         }
7606       /* Add the initializer to the vtable.  */
7607       *vid->last_init = build_tree_list (NULL_TREE, vcall_offset);
7608       vid->last_init = &TREE_CHAIN (*vid->last_init);
7609     }
7610 }
7611
7612 /* Return vtbl initializers for the RTTI entries corresponding to the
7613    BINFO's vtable.  The RTTI entries should indicate the object given
7614    by VID->rtti_binfo.  */
7615
7616 static void
7617 build_rtti_vtbl_entries (tree binfo, vtbl_init_data* vid)
7618 {
7619   tree b;
7620   tree t;
7621   tree basetype;
7622   tree offset;
7623   tree decl;
7624   tree init;
7625
7626   basetype = BINFO_TYPE (binfo);
7627   t = BINFO_TYPE (vid->rtti_binfo);
7628
7629   /* To find the complete object, we will first convert to our most
7630      primary base, and then add the offset in the vtbl to that value.  */
7631   b = binfo;
7632   while (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (b))
7633          && !BINFO_LOST_PRIMARY_P (b))
7634     {
7635       tree primary_base;
7636
7637       primary_base = get_primary_binfo (b);
7638       gcc_assert (BINFO_PRIMARY_P (primary_base)
7639                   && BINFO_INHERITANCE_CHAIN (primary_base) == b);
7640       b = primary_base;
7641     }
7642   offset = size_diffop (BINFO_OFFSET (vid->rtti_binfo), BINFO_OFFSET (b));
7643
7644   /* The second entry is the address of the typeinfo object.  */
7645   if (flag_rtti)
7646     decl = build_address (get_tinfo_decl (t));
7647   else
7648     decl = integer_zero_node;
7649
7650   /* Convert the declaration to a type that can be stored in the
7651      vtable.  */
7652   init = build_nop (vfunc_ptr_type_node, decl);
7653   *vid->last_init = build_tree_list (NULL_TREE, init);
7654   vid->last_init = &TREE_CHAIN (*vid->last_init);
7655
7656   /* Add the offset-to-top entry.  It comes earlier in the vtable than
7657      the typeinfo entry.  Convert the offset to look like a
7658      function pointer, so that we can put it in the vtable.  */
7659   init = build_nop (vfunc_ptr_type_node, offset);
7660   *vid->last_init = build_tree_list (NULL_TREE, init);
7661   vid->last_init = &TREE_CHAIN (*vid->last_init);
7662 }
7663
7664 /* Fold a OBJ_TYPE_REF expression to the address of a function.
7665    KNOWN_TYPE carries the true type of OBJ_TYPE_REF_OBJECT(REF).  */
7666
7667 tree
7668 cp_fold_obj_type_ref (tree ref, tree known_type)
7669 {
7670   HOST_WIDE_INT index = tree_low_cst (OBJ_TYPE_REF_TOKEN (ref), 1);
7671   HOST_WIDE_INT i = 0;
7672   tree v = BINFO_VIRTUALS (TYPE_BINFO (known_type));
7673   tree fndecl;
7674
7675   while (i != index)
7676     {
7677       i += (TARGET_VTABLE_USES_DESCRIPTORS
7678             ? TARGET_VTABLE_USES_DESCRIPTORS : 1);
7679       v = TREE_CHAIN (v);
7680     }
7681
7682   fndecl = BV_FN (v);
7683
7684 #ifdef ENABLE_CHECKING
7685   gcc_assert (tree_int_cst_equal (OBJ_TYPE_REF_TOKEN (ref),
7686                                   DECL_VINDEX (fndecl)));
7687 #endif
7688
7689   cgraph_node (fndecl)->local.vtable_method = true;
7690
7691   return build_address (fndecl);
7692 }
7693
7694 #include "gt-cp-class.h"