cp-tree.h (get_primary_binfo): Remove prototype.
[gcc.git] / 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 #include "tree-dump.h"
40
41 /* The number of nested classes being processed. If we are not in the
42 scope of any class, this is zero. */
43
44 int current_class_depth;
45
46 /* In order to deal with nested classes, we keep a stack of classes.
47 The topmost entry is the innermost class, and is the entry at index
48 CURRENT_CLASS_DEPTH */
49
50 typedef struct class_stack_node {
51 /* The name of the class. */
52 tree name;
53
54 /* The _TYPE node for the class. */
55 tree type;
56
57 /* The access specifier pending for new declarations in the scope of
58 this class. */
59 tree access;
60
61 /* If were defining TYPE, the names used in this class. */
62 splay_tree names_used;
63
64 /* Nonzero if this class is no longer open, because of a call to
65 push_to_top_level. */
66 size_t hidden;
67 }* class_stack_node_t;
68
69 typedef struct vtbl_init_data_s
70 {
71 /* The base for which we're building initializers. */
72 tree binfo;
73 /* The type of the most-derived type. */
74 tree derived;
75 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
76 unless ctor_vtbl_p is true. */
77 tree rtti_binfo;
78 /* The negative-index vtable initializers built up so far. These
79 are in order from least negative index to most negative index. */
80 tree inits;
81 /* The last (i.e., most negative) entry in INITS. */
82 tree* last_init;
83 /* The binfo for the virtual base for which we're building
84 vcall offset initializers. */
85 tree vbase;
86 /* The functions in vbase for which we have already provided vcall
87 offsets. */
88 VEC(tree,gc) *fns;
89 /* The vtable index of the next vcall or vbase offset. */
90 tree index;
91 /* Nonzero if we are building the initializer for the primary
92 vtable. */
93 int primary_vtbl_p;
94 /* Nonzero if we are building the initializer for a construction
95 vtable. */
96 int ctor_vtbl_p;
97 /* True when adding vcall offset entries to the vtable. False when
98 merely computing the indices. */
99 bool generate_vcall_entries;
100 } vtbl_init_data;
101
102 /* The type of a function passed to walk_subobject_offsets. */
103 typedef int (*subobject_offset_fn) (tree, tree, splay_tree);
104
105 /* The stack itself. This is a dynamically resized array. The
106 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
107 static int current_class_stack_size;
108 static class_stack_node_t current_class_stack;
109
110 /* The size of the largest empty class seen in this translation unit. */
111 static GTY (()) tree sizeof_biggest_empty_class;
112
113 /* An array of all local classes present in this translation unit, in
114 declaration order. */
115 VEC(tree,gc) *local_classes;
116
117 static tree get_vfield_name (tree);
118 static void finish_struct_anon (tree);
119 static tree get_vtable_name (tree);
120 static tree get_basefndecls (tree, tree);
121 static int build_primary_vtable (tree, tree);
122 static int build_secondary_vtable (tree);
123 static void finish_vtbls (tree);
124 static void modify_vtable_entry (tree, tree, tree, tree, tree *);
125 static void finish_struct_bits (tree);
126 static int alter_access (tree, tree, tree);
127 static void handle_using_decl (tree, tree);
128 static tree dfs_modify_vtables (tree, void *);
129 static tree modify_all_vtables (tree, tree);
130 static void determine_primary_bases (tree);
131 static void finish_struct_methods (tree);
132 static void maybe_warn_about_overly_private_class (tree);
133 static int method_name_cmp (const void *, const void *);
134 static int resort_method_name_cmp (const void *, const void *);
135 static void add_implicitly_declared_members (tree, int, int);
136 static tree fixed_type_or_null (tree, int *, int *);
137 static tree resolve_address_of_overloaded_function (tree, tree, tsubst_flags_t,
138 bool, tree);
139 static tree build_simple_base_path (tree expr, tree binfo);
140 static tree build_vtbl_ref_1 (tree, tree);
141 static tree build_vtbl_initializer (tree, tree, tree, tree, int *);
142 static int count_fields (tree);
143 static int add_fields_to_record_type (tree, struct sorted_fields_type*, int);
144 static void check_bitfield_decl (tree);
145 static void check_field_decl (tree, tree, int *, int *, int *);
146 static void check_field_decls (tree, tree *, int *, int *);
147 static tree *build_base_field (record_layout_info, tree, splay_tree, tree *);
148 static void build_base_fields (record_layout_info, splay_tree, tree *);
149 static void check_methods (tree);
150 static void remove_zero_width_bit_fields (tree);
151 static void check_bases (tree, int *, int *);
152 static void check_bases_and_members (tree);
153 static tree create_vtable_ptr (tree, tree *);
154 static void include_empty_classes (record_layout_info);
155 static void layout_class_type (tree, tree *);
156 static void fixup_pending_inline (tree);
157 static void fixup_inline_methods (tree);
158 static void propagate_binfo_offsets (tree, tree);
159 static void layout_virtual_bases (record_layout_info, splay_tree);
160 static void build_vbase_offset_vtbl_entries (tree, vtbl_init_data *);
161 static void add_vcall_offset_vtbl_entries_r (tree, vtbl_init_data *);
162 static void add_vcall_offset_vtbl_entries_1 (tree, vtbl_init_data *);
163 static void build_vcall_offset_vtbl_entries (tree, vtbl_init_data *);
164 static void add_vcall_offset (tree, tree, vtbl_init_data *);
165 static void layout_vtable_decl (tree, int);
166 static tree dfs_find_final_overrider_pre (tree, void *);
167 static tree dfs_find_final_overrider_post (tree, void *);
168 static tree find_final_overrider (tree, tree, tree);
169 static int make_new_vtable (tree, tree);
170 static tree get_primary_binfo (tree);
171 static int maybe_indent_hierarchy (FILE *, int, int);
172 static tree dump_class_hierarchy_r (FILE *, int, tree, tree, int);
173 static void dump_class_hierarchy (tree);
174 static void dump_class_hierarchy_1 (FILE *, int, tree);
175 static void dump_array (FILE *, tree);
176 static void dump_vtable (tree, tree, tree);
177 static void dump_vtt (tree, tree);
178 static void dump_thunk (FILE *, int, tree);
179 static tree build_vtable (tree, tree, tree);
180 static void initialize_vtable (tree, tree);
181 static void layout_nonempty_base_or_field (record_layout_info,
182 tree, tree, splay_tree);
183 static tree end_of_class (tree, int);
184 static bool layout_empty_base (tree, tree, splay_tree);
185 static void accumulate_vtbl_inits (tree, tree, tree, tree, tree);
186 static tree dfs_accumulate_vtbl_inits (tree, tree, tree, tree,
187 tree);
188 static void build_rtti_vtbl_entries (tree, vtbl_init_data *);
189 static void build_vcall_and_vbase_vtbl_entries (tree, vtbl_init_data *);
190 static void clone_constructors_and_destructors (tree);
191 static tree build_clone (tree, tree);
192 static void update_vtable_entry_for_fn (tree, tree, tree, tree *, unsigned);
193 static void build_ctor_vtbl_group (tree, tree);
194 static void build_vtt (tree);
195 static tree binfo_ctor_vtable (tree);
196 static tree *build_vtt_inits (tree, tree, tree *, tree *);
197 static tree dfs_build_secondary_vptr_vtt_inits (tree, void *);
198 static tree dfs_fixup_binfo_vtbls (tree, void *);
199 static int record_subobject_offset (tree, tree, splay_tree);
200 static int check_subobject_offset (tree, tree, splay_tree);
201 static int walk_subobject_offsets (tree, subobject_offset_fn,
202 tree, splay_tree, tree, int);
203 static void record_subobject_offsets (tree, tree, splay_tree, bool);
204 static int layout_conflict_p (tree, tree, splay_tree, int);
205 static int splay_tree_compare_integer_csts (splay_tree_key k1,
206 splay_tree_key k2);
207 static void warn_about_ambiguous_bases (tree);
208 static bool type_requires_array_cookie (tree);
209 static bool contains_empty_class_p (tree);
210 static bool base_derived_from (tree, tree);
211 static int empty_base_at_nonzero_offset_p (tree, tree, splay_tree);
212 static tree end_of_base (tree);
213 static tree get_vcall_index (tree, tree);
214
215 /* Variables shared between class.c and call.c. */
216
217 #ifdef GATHER_STATISTICS
218 int n_vtables = 0;
219 int n_vtable_entries = 0;
220 int n_vtable_searches = 0;
221 int n_vtable_elems = 0;
222 int n_convert_harshness = 0;
223 int n_compute_conversion_costs = 0;
224 int n_inner_fields_searched = 0;
225 #endif
226
227 /* Convert to or from a base subobject. EXPR is an expression of type
228 `A' or `A*', an expression of type `B' or `B*' is returned. To
229 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
230 the B base instance within A. To convert base A to derived B, CODE
231 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
232 In this latter case, A must not be a morally virtual base of B.
233 NONNULL is true if EXPR is known to be non-NULL (this is only
234 needed when EXPR is of pointer type). CV qualifiers are preserved
235 from EXPR. */
236
237 tree
238 build_base_path (enum tree_code code,
239 tree expr,
240 tree binfo,
241 int nonnull)
242 {
243 tree v_binfo = NULL_TREE;
244 tree d_binfo = NULL_TREE;
245 tree probe;
246 tree offset;
247 tree target_type;
248 tree null_test = NULL;
249 tree ptr_target_type;
250 int fixed_type_p;
251 int want_pointer = TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE;
252 bool has_empty = false;
253 bool virtual_access;
254
255 if (expr == error_mark_node || binfo == error_mark_node || !binfo)
256 return error_mark_node;
257
258 for (probe = binfo; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
259 {
260 d_binfo = probe;
261 if (is_empty_class (BINFO_TYPE (probe)))
262 has_empty = true;
263 if (!v_binfo && BINFO_VIRTUAL_P (probe))
264 v_binfo = probe;
265 }
266
267 probe = TYPE_MAIN_VARIANT (TREE_TYPE (expr));
268 if (want_pointer)
269 probe = TYPE_MAIN_VARIANT (TREE_TYPE (probe));
270
271 gcc_assert ((code == MINUS_EXPR
272 && SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), probe))
273 || (code == PLUS_EXPR
274 && SAME_BINFO_TYPE_P (BINFO_TYPE (d_binfo), probe)));
275
276 if (binfo == d_binfo)
277 /* Nothing to do. */
278 return expr;
279
280 if (code == MINUS_EXPR && v_binfo)
281 {
282 error ("cannot convert from base %qT to derived type %qT via virtual base %qT",
283 BINFO_TYPE (binfo), BINFO_TYPE (d_binfo), BINFO_TYPE (v_binfo));
284 return error_mark_node;
285 }
286
287 if (!want_pointer)
288 /* This must happen before the call to save_expr. */
289 expr = build_unary_op (ADDR_EXPR, expr, 0);
290
291 offset = BINFO_OFFSET (binfo);
292 fixed_type_p = resolves_to_fixed_type_p (expr, &nonnull);
293 target_type = code == PLUS_EXPR ? BINFO_TYPE (binfo) : BINFO_TYPE (d_binfo);
294
295 /* Do we need to look in the vtable for the real offset? */
296 virtual_access = (v_binfo && fixed_type_p <= 0);
297
298 /* Do we need to check for a null pointer? */
299 if (want_pointer && !nonnull)
300 {
301 /* If we know the conversion will not actually change the value
302 of EXPR, then we can avoid testing the expression for NULL.
303 We have to avoid generating a COMPONENT_REF for a base class
304 field, because other parts of the compiler know that such
305 expressions are always non-NULL. */
306 if (!virtual_access && integer_zerop (offset))
307 return build_nop (build_pointer_type (target_type), expr);
308 null_test = error_mark_node;
309 }
310
311 /* Protect against multiple evaluation if necessary. */
312 if (TREE_SIDE_EFFECTS (expr) && (null_test || virtual_access))
313 expr = save_expr (expr);
314
315 /* Now that we've saved expr, build the real null test. */
316 if (null_test)
317 {
318 tree zero = cp_convert (TREE_TYPE (expr), integer_zero_node);
319 null_test = fold_build2 (NE_EXPR, boolean_type_node,
320 expr, zero);
321 }
322
323 /* If this is a simple base reference, express it as a COMPONENT_REF. */
324 if (code == PLUS_EXPR && !virtual_access
325 /* We don't build base fields for empty bases, and they aren't very
326 interesting to the optimizers anyway. */
327 && !has_empty)
328 {
329 expr = build_indirect_ref (expr, NULL);
330 expr = build_simple_base_path (expr, binfo);
331 if (want_pointer)
332 expr = build_address (expr);
333 target_type = TREE_TYPE (expr);
334 goto out;
335 }
336
337 if (virtual_access)
338 {
339 /* Going via virtual base V_BINFO. We need the static offset
340 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
341 V_BINFO. That offset is an entry in D_BINFO's vtable. */
342 tree v_offset;
343
344 if (fixed_type_p < 0 && in_base_initializer)
345 {
346 /* In a base member initializer, we cannot rely on the
347 vtable being set up. We have to indirect via the
348 vtt_parm. */
349 tree t;
350
351 t = TREE_TYPE (TYPE_VFIELD (current_class_type));
352 t = build_pointer_type (t);
353 v_offset = convert (t, current_vtt_parm);
354 v_offset = build_indirect_ref (v_offset, NULL);
355 }
356 else
357 v_offset = build_vfield_ref (build_indirect_ref (expr, NULL),
358 TREE_TYPE (TREE_TYPE (expr)));
359
360 v_offset = build2 (PLUS_EXPR, TREE_TYPE (v_offset),
361 v_offset, BINFO_VPTR_FIELD (v_binfo));
362 v_offset = build1 (NOP_EXPR,
363 build_pointer_type (ptrdiff_type_node),
364 v_offset);
365 v_offset = build_indirect_ref (v_offset, NULL);
366 TREE_CONSTANT (v_offset) = 1;
367 TREE_INVARIANT (v_offset) = 1;
368
369 offset = convert_to_integer (ptrdiff_type_node,
370 size_diffop (offset,
371 BINFO_OFFSET (v_binfo)));
372
373 if (!integer_zerop (offset))
374 v_offset = build2 (code, ptrdiff_type_node, v_offset, offset);
375
376 if (fixed_type_p < 0)
377 /* Negative fixed_type_p means this is a constructor or destructor;
378 virtual base layout is fixed in in-charge [cd]tors, but not in
379 base [cd]tors. */
380 offset = build3 (COND_EXPR, ptrdiff_type_node,
381 build2 (EQ_EXPR, boolean_type_node,
382 current_in_charge_parm, integer_zero_node),
383 v_offset,
384 convert_to_integer (ptrdiff_type_node,
385 BINFO_OFFSET (binfo)));
386 else
387 offset = v_offset;
388 }
389
390 target_type = cp_build_qualified_type
391 (target_type, cp_type_quals (TREE_TYPE (TREE_TYPE (expr))));
392 ptr_target_type = build_pointer_type (target_type);
393 if (want_pointer)
394 target_type = ptr_target_type;
395
396 expr = build1 (NOP_EXPR, ptr_target_type, expr);
397
398 if (!integer_zerop (offset))
399 expr = build2 (code, ptr_target_type, expr, offset);
400 else
401 null_test = NULL;
402
403 if (!want_pointer)
404 expr = build_indirect_ref (expr, NULL);
405
406 out:
407 if (null_test)
408 expr = fold_build3 (COND_EXPR, target_type, null_test, expr,
409 fold_build1 (NOP_EXPR, target_type,
410 integer_zero_node));
411
412 return expr;
413 }
414
415 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
416 Perform a derived-to-base conversion by recursively building up a
417 sequence of COMPONENT_REFs to the appropriate base fields. */
418
419 static tree
420 build_simple_base_path (tree expr, tree binfo)
421 {
422 tree type = BINFO_TYPE (binfo);
423 tree d_binfo = BINFO_INHERITANCE_CHAIN (binfo);
424 tree field;
425
426 if (d_binfo == NULL_TREE)
427 {
428 tree temp;
429
430 gcc_assert (TYPE_MAIN_VARIANT (TREE_TYPE (expr)) == type);
431
432 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
433 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
434 an lvalue in the frontend; only _DECLs and _REFs are lvalues
435 in the backend. */
436 temp = unary_complex_lvalue (ADDR_EXPR, expr);
437 if (temp)
438 expr = build_indirect_ref (temp, NULL);
439
440 return expr;
441 }
442
443 /* Recurse. */
444 expr = build_simple_base_path (expr, d_binfo);
445
446 for (field = TYPE_FIELDS (BINFO_TYPE (d_binfo));
447 field; field = TREE_CHAIN (field))
448 /* Is this the base field created by build_base_field? */
449 if (TREE_CODE (field) == FIELD_DECL
450 && DECL_FIELD_IS_BASE (field)
451 && TREE_TYPE (field) == type)
452 {
453 /* We don't use build_class_member_access_expr here, as that
454 has unnecessary checks, and more importantly results in
455 recursive calls to dfs_walk_once. */
456 int type_quals = cp_type_quals (TREE_TYPE (expr));
457
458 expr = build3 (COMPONENT_REF,
459 cp_build_qualified_type (type, type_quals),
460 expr, field, NULL_TREE);
461 expr = fold_if_not_in_template (expr);
462
463 /* Mark the expression const or volatile, as appropriate.
464 Even though we've dealt with the type above, we still have
465 to mark the expression itself. */
466 if (type_quals & TYPE_QUAL_CONST)
467 TREE_READONLY (expr) = 1;
468 if (type_quals & TYPE_QUAL_VOLATILE)
469 TREE_THIS_VOLATILE (expr) = 1;
470
471 return expr;
472 }
473
474 /* Didn't find the base field?!? */
475 gcc_unreachable ();
476 }
477
478 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
479 type is a class type or a pointer to a class type. In the former
480 case, TYPE is also a class type; in the latter it is another
481 pointer type. If CHECK_ACCESS is true, an error message is emitted
482 if TYPE is inaccessible. If OBJECT has pointer type, the value is
483 assumed to be non-NULL. */
484
485 tree
486 convert_to_base (tree object, tree type, bool check_access, bool nonnull)
487 {
488 tree binfo;
489 tree object_type;
490
491 if (TYPE_PTR_P (TREE_TYPE (object)))
492 {
493 object_type = TREE_TYPE (TREE_TYPE (object));
494 type = TREE_TYPE (type);
495 }
496 else
497 object_type = TREE_TYPE (object);
498
499 binfo = lookup_base (object_type, type,
500 check_access ? ba_check : ba_unique,
501 NULL);
502 if (!binfo || binfo == error_mark_node)
503 return error_mark_node;
504
505 return build_base_path (PLUS_EXPR, object, binfo, nonnull);
506 }
507
508 /* EXPR is an expression with unqualified class type. BASE is a base
509 binfo of that class type. Returns EXPR, converted to the BASE
510 type. This function assumes that EXPR is the most derived class;
511 therefore virtual bases can be found at their static offsets. */
512
513 tree
514 convert_to_base_statically (tree expr, tree base)
515 {
516 tree expr_type;
517
518 expr_type = TREE_TYPE (expr);
519 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (base), expr_type))
520 {
521 tree pointer_type;
522
523 pointer_type = build_pointer_type (expr_type);
524 expr = build_unary_op (ADDR_EXPR, expr, /*noconvert=*/1);
525 if (!integer_zerop (BINFO_OFFSET (base)))
526 expr = build2 (PLUS_EXPR, pointer_type, expr,
527 build_nop (pointer_type, BINFO_OFFSET (base)));
528 expr = build_nop (build_pointer_type (BINFO_TYPE (base)), expr);
529 expr = build1 (INDIRECT_REF, BINFO_TYPE (base), expr);
530 }
531
532 return expr;
533 }
534
535 \f
536 tree
537 build_vfield_ref (tree datum, tree type)
538 {
539 tree vfield, vcontext;
540
541 if (datum == error_mark_node)
542 return error_mark_node;
543
544 /* First, convert to the requested type. */
545 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (datum), type))
546 datum = convert_to_base (datum, type, /*check_access=*/false,
547 /*nonnull=*/true);
548
549 /* Second, the requested type may not be the owner of its own vptr.
550 If not, convert to the base class that owns it. We cannot use
551 convert_to_base here, because VCONTEXT may appear more than once
552 in the inheritance hierarchy of TYPE, and thus direct conversion
553 between the types may be ambiguous. Following the path back up
554 one step at a time via primary bases avoids the problem. */
555 vfield = TYPE_VFIELD (type);
556 vcontext = DECL_CONTEXT (vfield);
557 while (!same_type_ignoring_top_level_qualifiers_p (vcontext, type))
558 {
559 datum = build_simple_base_path (datum, CLASSTYPE_PRIMARY_BINFO (type));
560 type = TREE_TYPE (datum);
561 }
562
563 return build3 (COMPONENT_REF, TREE_TYPE (vfield), datum, vfield, NULL_TREE);
564 }
565
566 /* Given an object INSTANCE, return an expression which yields the
567 vtable element corresponding to INDEX. There are many special
568 cases for INSTANCE which we take care of here, mainly to avoid
569 creating extra tree nodes when we don't have to. */
570
571 static tree
572 build_vtbl_ref_1 (tree instance, tree idx)
573 {
574 tree aref;
575 tree vtbl = NULL_TREE;
576
577 /* Try to figure out what a reference refers to, and
578 access its virtual function table directly. */
579
580 int cdtorp = 0;
581 tree fixed_type = fixed_type_or_null (instance, NULL, &cdtorp);
582
583 tree basetype = non_reference (TREE_TYPE (instance));
584
585 if (fixed_type && !cdtorp)
586 {
587 tree binfo = lookup_base (fixed_type, basetype,
588 ba_unique | ba_quiet, NULL);
589 if (binfo)
590 vtbl = unshare_expr (BINFO_VTABLE (binfo));
591 }
592
593 if (!vtbl)
594 vtbl = build_vfield_ref (instance, basetype);
595
596 assemble_external (vtbl);
597
598 aref = build_array_ref (vtbl, idx);
599 TREE_CONSTANT (aref) |= TREE_CONSTANT (vtbl) && TREE_CONSTANT (idx);
600 TREE_INVARIANT (aref) = TREE_CONSTANT (aref);
601
602 return aref;
603 }
604
605 tree
606 build_vtbl_ref (tree instance, tree idx)
607 {
608 tree aref = build_vtbl_ref_1 (instance, idx);
609
610 return aref;
611 }
612
613 /* Given a stable object pointer INSTANCE_PTR, return an expression which
614 yields a function pointer corresponding to vtable element INDEX. */
615
616 tree
617 build_vfn_ref (tree instance_ptr, tree idx)
618 {
619 tree aref;
620
621 aref = build_vtbl_ref_1 (build_indirect_ref (instance_ptr, 0), idx);
622
623 /* When using function descriptors, the address of the
624 vtable entry is treated as a function pointer. */
625 if (TARGET_VTABLE_USES_DESCRIPTORS)
626 aref = build1 (NOP_EXPR, TREE_TYPE (aref),
627 build_unary_op (ADDR_EXPR, aref, /*noconvert=*/1));
628
629 /* Remember this as a method reference, for later devirtualization. */
630 aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr, idx);
631
632 return aref;
633 }
634
635 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
636 for the given TYPE. */
637
638 static tree
639 get_vtable_name (tree type)
640 {
641 return mangle_vtbl_for_type (type);
642 }
643
644 /* DECL is an entity associated with TYPE, like a virtual table or an
645 implicitly generated constructor. Determine whether or not DECL
646 should have external or internal linkage at the object file
647 level. This routine does not deal with COMDAT linkage and other
648 similar complexities; it simply sets TREE_PUBLIC if it possible for
649 entities in other translation units to contain copies of DECL, in
650 the abstract. */
651
652 void
653 set_linkage_according_to_type (tree type, tree decl)
654 {
655 /* If TYPE involves a local class in a function with internal
656 linkage, then DECL should have internal linkage too. Other local
657 classes have no linkage -- but if their containing functions
658 have external linkage, it makes sense for DECL to have external
659 linkage too. That will allow template definitions to be merged,
660 for example. */
661 if (no_linkage_check (type, /*relaxed_p=*/true))
662 {
663 TREE_PUBLIC (decl) = 0;
664 DECL_INTERFACE_KNOWN (decl) = 1;
665 }
666 else
667 TREE_PUBLIC (decl) = 1;
668 }
669
670 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
671 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
672 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
673
674 static tree
675 build_vtable (tree class_type, tree name, tree vtable_type)
676 {
677 tree decl;
678
679 decl = build_lang_decl (VAR_DECL, name, vtable_type);
680 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
681 now to avoid confusion in mangle_decl. */
682 SET_DECL_ASSEMBLER_NAME (decl, name);
683 DECL_CONTEXT (decl) = class_type;
684 DECL_ARTIFICIAL (decl) = 1;
685 TREE_STATIC (decl) = 1;
686 TREE_READONLY (decl) = 1;
687 DECL_VIRTUAL_P (decl) = 1;
688 DECL_ALIGN (decl) = TARGET_VTABLE_ENTRY_ALIGN;
689 DECL_VTABLE_OR_VTT_P (decl) = 1;
690 /* At one time the vtable info was grabbed 2 words at a time. This
691 fails on sparc unless you have 8-byte alignment. (tiemann) */
692 DECL_ALIGN (decl) = MAX (TYPE_ALIGN (double_type_node),
693 DECL_ALIGN (decl));
694 set_linkage_according_to_type (class_type, decl);
695 /* The vtable has not been defined -- yet. */
696 DECL_EXTERNAL (decl) = 1;
697 DECL_NOT_REALLY_EXTERN (decl) = 1;
698
699 /* Mark the VAR_DECL node representing the vtable itself as a
700 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
701 is rather important that such things be ignored because any
702 effort to actually generate DWARF for them will run into
703 trouble when/if we encounter code like:
704
705 #pragma interface
706 struct S { virtual void member (); };
707
708 because the artificial declaration of the vtable itself (as
709 manufactured by the g++ front end) will say that the vtable is
710 a static member of `S' but only *after* the debug output for
711 the definition of `S' has already been output. This causes
712 grief because the DWARF entry for the definition of the vtable
713 will try to refer back to an earlier *declaration* of the
714 vtable as a static member of `S' and there won't be one. We
715 might be able to arrange to have the "vtable static member"
716 attached to the member list for `S' before the debug info for
717 `S' get written (which would solve the problem) but that would
718 require more intrusive changes to the g++ front end. */
719 DECL_IGNORED_P (decl) = 1;
720
721 return decl;
722 }
723
724 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
725 or even complete. If this does not exist, create it. If COMPLETE is
726 nonzero, then complete the definition of it -- that will render it
727 impossible to actually build the vtable, but is useful to get at those
728 which are known to exist in the runtime. */
729
730 tree
731 get_vtable_decl (tree type, int complete)
732 {
733 tree decl;
734
735 if (CLASSTYPE_VTABLES (type))
736 return CLASSTYPE_VTABLES (type);
737
738 decl = build_vtable (type, get_vtable_name (type), vtbl_type_node);
739 CLASSTYPE_VTABLES (type) = decl;
740
741 if (complete)
742 {
743 DECL_EXTERNAL (decl) = 1;
744 cp_finish_decl (decl, NULL_TREE, NULL_TREE, 0);
745 }
746
747 return decl;
748 }
749
750 /* Build the primary virtual function table for TYPE. If BINFO is
751 non-NULL, build the vtable starting with the initial approximation
752 that it is the same as the one which is the head of the association
753 list. Returns a nonzero value if a new vtable is actually
754 created. */
755
756 static int
757 build_primary_vtable (tree binfo, tree type)
758 {
759 tree decl;
760 tree virtuals;
761
762 decl = get_vtable_decl (type, /*complete=*/0);
763
764 if (binfo)
765 {
766 if (BINFO_NEW_VTABLE_MARKED (binfo))
767 /* We have already created a vtable for this base, so there's
768 no need to do it again. */
769 return 0;
770
771 virtuals = copy_list (BINFO_VIRTUALS (binfo));
772 TREE_TYPE (decl) = TREE_TYPE (get_vtbl_decl_for_binfo (binfo));
773 DECL_SIZE (decl) = TYPE_SIZE (TREE_TYPE (decl));
774 DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (TREE_TYPE (decl));
775 }
776 else
777 {
778 gcc_assert (TREE_TYPE (decl) == vtbl_type_node);
779 virtuals = NULL_TREE;
780 }
781
782 #ifdef GATHER_STATISTICS
783 n_vtables += 1;
784 n_vtable_elems += list_length (virtuals);
785 #endif
786
787 /* Initialize the association list for this type, based
788 on our first approximation. */
789 BINFO_VTABLE (TYPE_BINFO (type)) = decl;
790 BINFO_VIRTUALS (TYPE_BINFO (type)) = virtuals;
791 SET_BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (type));
792 return 1;
793 }
794
795 /* Give BINFO a new virtual function table which is initialized
796 with a skeleton-copy of its original initialization. The only
797 entry that changes is the `delta' entry, so we can really
798 share a lot of structure.
799
800 FOR_TYPE is the most derived type which caused this table to
801 be needed.
802
803 Returns nonzero if we haven't met BINFO before.
804
805 The order in which vtables are built (by calling this function) for
806 an object must remain the same, otherwise a binary incompatibility
807 can result. */
808
809 static int
810 build_secondary_vtable (tree binfo)
811 {
812 if (BINFO_NEW_VTABLE_MARKED (binfo))
813 /* We already created a vtable for this base. There's no need to
814 do it again. */
815 return 0;
816
817 /* Remember that we've created a vtable for this BINFO, so that we
818 don't try to do so again. */
819 SET_BINFO_NEW_VTABLE_MARKED (binfo);
820
821 /* Make fresh virtual list, so we can smash it later. */
822 BINFO_VIRTUALS (binfo) = copy_list (BINFO_VIRTUALS (binfo));
823
824 /* Secondary vtables are laid out as part of the same structure as
825 the primary vtable. */
826 BINFO_VTABLE (binfo) = NULL_TREE;
827 return 1;
828 }
829
830 /* Create a new vtable for BINFO which is the hierarchy dominated by
831 T. Return nonzero if we actually created a new vtable. */
832
833 static int
834 make_new_vtable (tree t, tree binfo)
835 {
836 if (binfo == TYPE_BINFO (t))
837 /* In this case, it is *type*'s vtable we are modifying. We start
838 with the approximation that its vtable is that of the
839 immediate base class. */
840 return build_primary_vtable (binfo, t);
841 else
842 /* This is our very own copy of `basetype' to play with. Later,
843 we will fill in all the virtual functions that override the
844 virtual functions in these base classes which are not defined
845 by the current type. */
846 return build_secondary_vtable (binfo);
847 }
848
849 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
850 (which is in the hierarchy dominated by T) list FNDECL as its
851 BV_FN. DELTA is the required constant adjustment from the `this'
852 pointer where the vtable entry appears to the `this' required when
853 the function is actually called. */
854
855 static void
856 modify_vtable_entry (tree t,
857 tree binfo,
858 tree fndecl,
859 tree delta,
860 tree *virtuals)
861 {
862 tree v;
863
864 v = *virtuals;
865
866 if (fndecl != BV_FN (v)
867 || !tree_int_cst_equal (delta, BV_DELTA (v)))
868 {
869 /* We need a new vtable for BINFO. */
870 if (make_new_vtable (t, binfo))
871 {
872 /* If we really did make a new vtable, we also made a copy
873 of the BINFO_VIRTUALS list. Now, we have to find the
874 corresponding entry in that list. */
875 *virtuals = BINFO_VIRTUALS (binfo);
876 while (BV_FN (*virtuals) != BV_FN (v))
877 *virtuals = TREE_CHAIN (*virtuals);
878 v = *virtuals;
879 }
880
881 BV_DELTA (v) = delta;
882 BV_VCALL_INDEX (v) = NULL_TREE;
883 BV_FN (v) = fndecl;
884 }
885 }
886
887 \f
888 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
889 the USING_DECL naming METHOD. Returns true if the method could be
890 added to the method vec. */
891
892 bool
893 add_method (tree type, tree method, tree using_decl)
894 {
895 unsigned slot;
896 tree overload;
897 bool template_conv_p = false;
898 bool conv_p;
899 VEC(tree,gc) *method_vec;
900 bool complete_p;
901 bool insert_p = false;
902 tree current_fns;
903
904 if (method == error_mark_node)
905 return false;
906
907 complete_p = COMPLETE_TYPE_P (type);
908 conv_p = DECL_CONV_FN_P (method);
909 if (conv_p)
910 template_conv_p = (TREE_CODE (method) == TEMPLATE_DECL
911 && DECL_TEMPLATE_CONV_FN_P (method));
912
913 method_vec = CLASSTYPE_METHOD_VEC (type);
914 if (!method_vec)
915 {
916 /* Make a new method vector. We start with 8 entries. We must
917 allocate at least two (for constructors and destructors), and
918 we're going to end up with an assignment operator at some
919 point as well. */
920 method_vec = VEC_alloc (tree, gc, 8);
921 /* Create slots for constructors and destructors. */
922 VEC_quick_push (tree, method_vec, NULL_TREE);
923 VEC_quick_push (tree, method_vec, NULL_TREE);
924 CLASSTYPE_METHOD_VEC (type) = method_vec;
925 }
926
927 /* Constructors and destructors go in special slots. */
928 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (method))
929 slot = CLASSTYPE_CONSTRUCTOR_SLOT;
930 else if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method))
931 {
932 slot = CLASSTYPE_DESTRUCTOR_SLOT;
933
934 if (TYPE_FOR_JAVA (type))
935 {
936 if (!DECL_ARTIFICIAL (method))
937 error ("Java class %qT cannot have a destructor", type);
938 else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
939 error ("Java class %qT cannot have an implicit non-trivial "
940 "destructor",
941 type);
942 }
943 }
944 else
945 {
946 tree m;
947
948 insert_p = true;
949 /* See if we already have an entry with this name. */
950 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
951 VEC_iterate (tree, method_vec, slot, m);
952 ++slot)
953 {
954 m = OVL_CURRENT (m);
955 if (template_conv_p)
956 {
957 if (TREE_CODE (m) == TEMPLATE_DECL
958 && DECL_TEMPLATE_CONV_FN_P (m))
959 insert_p = false;
960 break;
961 }
962 if (conv_p && !DECL_CONV_FN_P (m))
963 break;
964 if (DECL_NAME (m) == DECL_NAME (method))
965 {
966 insert_p = false;
967 break;
968 }
969 if (complete_p
970 && !DECL_CONV_FN_P (m)
971 && DECL_NAME (m) > DECL_NAME (method))
972 break;
973 }
974 }
975 current_fns = insert_p ? NULL_TREE : VEC_index (tree, method_vec, slot);
976
977 if (processing_template_decl)
978 /* TYPE is a template class. Don't issue any errors now; wait
979 until instantiation time to complain. */
980 ;
981 else
982 {
983 tree fns;
984
985 /* Check to see if we've already got this method. */
986 for (fns = current_fns; fns; fns = OVL_NEXT (fns))
987 {
988 tree fn = OVL_CURRENT (fns);
989 tree fn_type;
990 tree method_type;
991 tree parms1;
992 tree parms2;
993
994 if (TREE_CODE (fn) != TREE_CODE (method))
995 continue;
996
997 /* [over.load] Member function declarations with the
998 same name and the same parameter types cannot be
999 overloaded if any of them is a static member
1000 function declaration.
1001
1002 [namespace.udecl] When a using-declaration brings names
1003 from a base class into a derived class scope, member
1004 functions in the derived class override and/or hide member
1005 functions with the same name and parameter types in a base
1006 class (rather than conflicting). */
1007 fn_type = TREE_TYPE (fn);
1008 method_type = TREE_TYPE (method);
1009 parms1 = TYPE_ARG_TYPES (fn_type);
1010 parms2 = TYPE_ARG_TYPES (method_type);
1011
1012 /* Compare the quals on the 'this' parm. Don't compare
1013 the whole types, as used functions are treated as
1014 coming from the using class in overload resolution. */
1015 if (! DECL_STATIC_FUNCTION_P (fn)
1016 && ! DECL_STATIC_FUNCTION_P (method)
1017 && (TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms1)))
1018 != TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms2)))))
1019 continue;
1020
1021 /* For templates, the return type and template parameters
1022 must be identical. */
1023 if (TREE_CODE (fn) == TEMPLATE_DECL
1024 && (!same_type_p (TREE_TYPE (fn_type),
1025 TREE_TYPE (method_type))
1026 || !comp_template_parms (DECL_TEMPLATE_PARMS (fn),
1027 DECL_TEMPLATE_PARMS (method))))
1028 continue;
1029
1030 if (! DECL_STATIC_FUNCTION_P (fn))
1031 parms1 = TREE_CHAIN (parms1);
1032 if (! DECL_STATIC_FUNCTION_P (method))
1033 parms2 = TREE_CHAIN (parms2);
1034
1035 if (compparms (parms1, parms2)
1036 && (!DECL_CONV_FN_P (fn)
1037 || same_type_p (TREE_TYPE (fn_type),
1038 TREE_TYPE (method_type))))
1039 {
1040 if (using_decl)
1041 {
1042 if (DECL_CONTEXT (fn) == type)
1043 /* Defer to the local function. */
1044 return false;
1045 if (DECL_CONTEXT (fn) == DECL_CONTEXT (method))
1046 error ("repeated using declaration %q+D", using_decl);
1047 else
1048 error ("using declaration %q+D conflicts with a previous using declaration",
1049 using_decl);
1050 }
1051 else
1052 {
1053 error ("%q+#D cannot be overloaded", method);
1054 error ("with %q+#D", fn);
1055 }
1056
1057 /* We don't call duplicate_decls here to merge the
1058 declarations because that will confuse things if the
1059 methods have inline definitions. In particular, we
1060 will crash while processing the definitions. */
1061 return false;
1062 }
1063 }
1064 }
1065
1066 /* A class should never have more than one destructor. */
1067 if (current_fns && DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method))
1068 return false;
1069
1070 /* Add the new binding. */
1071 overload = build_overload (method, current_fns);
1072
1073 if (conv_p)
1074 TYPE_HAS_CONVERSION (type) = 1;
1075 else if (slot >= CLASSTYPE_FIRST_CONVERSION_SLOT && !complete_p)
1076 push_class_level_binding (DECL_NAME (method), overload);
1077
1078 if (insert_p)
1079 {
1080 /* We only expect to add few methods in the COMPLETE_P case, so
1081 just make room for one more method in that case. */
1082 if (VEC_reserve (tree, gc, method_vec, complete_p ? -1 : 1))
1083 CLASSTYPE_METHOD_VEC (type) = method_vec;
1084 if (slot == VEC_length (tree, method_vec))
1085 VEC_quick_push (tree, method_vec, overload);
1086 else
1087 VEC_quick_insert (tree, method_vec, slot, overload);
1088 }
1089 else
1090 /* Replace the current slot. */
1091 VEC_replace (tree, method_vec, slot, overload);
1092 return true;
1093 }
1094
1095 /* Subroutines of finish_struct. */
1096
1097 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1098 legit, otherwise return 0. */
1099
1100 static int
1101 alter_access (tree t, tree fdecl, tree access)
1102 {
1103 tree elem;
1104
1105 if (!DECL_LANG_SPECIFIC (fdecl))
1106 retrofit_lang_decl (fdecl);
1107
1108 gcc_assert (!DECL_DISCRIMINATOR_P (fdecl));
1109
1110 elem = purpose_member (t, DECL_ACCESS (fdecl));
1111 if (elem)
1112 {
1113 if (TREE_VALUE (elem) != access)
1114 {
1115 if (TREE_CODE (TREE_TYPE (fdecl)) == FUNCTION_DECL)
1116 error ("conflicting access specifications for method"
1117 " %q+D, ignored", TREE_TYPE (fdecl));
1118 else
1119 error ("conflicting access specifications for field %qE, ignored",
1120 DECL_NAME (fdecl));
1121 }
1122 else
1123 {
1124 /* They're changing the access to the same thing they changed
1125 it to before. That's OK. */
1126 ;
1127 }
1128 }
1129 else
1130 {
1131 perform_or_defer_access_check (TYPE_BINFO (t), fdecl);
1132 DECL_ACCESS (fdecl) = tree_cons (t, access, DECL_ACCESS (fdecl));
1133 return 1;
1134 }
1135 return 0;
1136 }
1137
1138 /* Process the USING_DECL, which is a member of T. */
1139
1140 static void
1141 handle_using_decl (tree using_decl, tree t)
1142 {
1143 tree decl = USING_DECL_DECLS (using_decl);
1144 tree name = DECL_NAME (using_decl);
1145 tree access
1146 = TREE_PRIVATE (using_decl) ? access_private_node
1147 : TREE_PROTECTED (using_decl) ? access_protected_node
1148 : access_public_node;
1149 tree flist = NULL_TREE;
1150 tree old_value;
1151
1152 gcc_assert (!processing_template_decl && decl);
1153
1154 old_value = lookup_member (t, name, /*protect=*/0, /*want_type=*/false);
1155 if (old_value)
1156 {
1157 if (is_overloaded_fn (old_value))
1158 old_value = OVL_CURRENT (old_value);
1159
1160 if (DECL_P (old_value) && DECL_CONTEXT (old_value) == t)
1161 /* OK */;
1162 else
1163 old_value = NULL_TREE;
1164 }
1165
1166 cp_emit_debug_info_for_using (decl, USING_DECL_SCOPE (using_decl));
1167
1168 if (is_overloaded_fn (decl))
1169 flist = decl;
1170
1171 if (! old_value)
1172 ;
1173 else if (is_overloaded_fn (old_value))
1174 {
1175 if (flist)
1176 /* It's OK to use functions from a base when there are functions with
1177 the same name already present in the current class. */;
1178 else
1179 {
1180 error ("%q+D invalid in %q#T", using_decl, t);
1181 error (" because of local method %q+#D with same name",
1182 OVL_CURRENT (old_value));
1183 return;
1184 }
1185 }
1186 else if (!DECL_ARTIFICIAL (old_value))
1187 {
1188 error ("%q+D invalid in %q#T", using_decl, t);
1189 error (" because of local member %q+#D with same name", old_value);
1190 return;
1191 }
1192
1193 /* Make type T see field decl FDECL with access ACCESS. */
1194 if (flist)
1195 for (; flist; flist = OVL_NEXT (flist))
1196 {
1197 add_method (t, OVL_CURRENT (flist), using_decl);
1198 alter_access (t, OVL_CURRENT (flist), access);
1199 }
1200 else
1201 alter_access (t, decl, access);
1202 }
1203 \f
1204 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1205 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1206 properties of the bases. */
1207
1208 static void
1209 check_bases (tree t,
1210 int* cant_have_const_ctor_p,
1211 int* no_const_asn_ref_p)
1212 {
1213 int i;
1214 int seen_non_virtual_nearly_empty_base_p;
1215 tree base_binfo;
1216 tree binfo;
1217
1218 seen_non_virtual_nearly_empty_base_p = 0;
1219
1220 for (binfo = TYPE_BINFO (t), i = 0;
1221 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
1222 {
1223 tree basetype = TREE_TYPE (base_binfo);
1224
1225 gcc_assert (COMPLETE_TYPE_P (basetype));
1226
1227 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1228 here because the case of virtual functions but non-virtual
1229 dtor is handled in finish_struct_1. */
1230 if (warn_ecpp && ! TYPE_POLYMORPHIC_P (basetype))
1231 warning (0, "base class %q#T has a non-virtual destructor", basetype);
1232
1233 /* If the base class doesn't have copy constructors or
1234 assignment operators that take const references, then the
1235 derived class cannot have such a member automatically
1236 generated. */
1237 if (! TYPE_HAS_CONST_INIT_REF (basetype))
1238 *cant_have_const_ctor_p = 1;
1239 if (TYPE_HAS_ASSIGN_REF (basetype)
1240 && !TYPE_HAS_CONST_ASSIGN_REF (basetype))
1241 *no_const_asn_ref_p = 1;
1242
1243 if (BINFO_VIRTUAL_P (base_binfo))
1244 /* A virtual base does not effect nearly emptiness. */
1245 ;
1246 else if (CLASSTYPE_NEARLY_EMPTY_P (basetype))
1247 {
1248 if (seen_non_virtual_nearly_empty_base_p)
1249 /* And if there is more than one nearly empty base, then the
1250 derived class is not nearly empty either. */
1251 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1252 else
1253 /* Remember we've seen one. */
1254 seen_non_virtual_nearly_empty_base_p = 1;
1255 }
1256 else if (!is_empty_class (basetype))
1257 /* If the base class is not empty or nearly empty, then this
1258 class cannot be nearly empty. */
1259 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1260
1261 /* A lot of properties from the bases also apply to the derived
1262 class. */
1263 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (basetype);
1264 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
1265 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype);
1266 TYPE_HAS_COMPLEX_ASSIGN_REF (t)
1267 |= TYPE_HAS_COMPLEX_ASSIGN_REF (basetype);
1268 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (basetype);
1269 TYPE_POLYMORPHIC_P (t) |= TYPE_POLYMORPHIC_P (basetype);
1270 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t)
1271 |= CLASSTYPE_CONTAINS_EMPTY_CLASS_P (basetype);
1272 }
1273 }
1274
1275 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1276 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1277 that have had a nearly-empty virtual primary base stolen by some
1278 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1279 T. */
1280
1281 static void
1282 determine_primary_bases (tree t)
1283 {
1284 unsigned i;
1285 tree primary = NULL_TREE;
1286 tree type_binfo = TYPE_BINFO (t);
1287 tree base_binfo;
1288
1289 /* Determine the primary bases of our bases. */
1290 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1291 base_binfo = TREE_CHAIN (base_binfo))
1292 {
1293 tree primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (base_binfo));
1294
1295 /* See if we're the non-virtual primary of our inheritance
1296 chain. */
1297 if (!BINFO_VIRTUAL_P (base_binfo))
1298 {
1299 tree parent = BINFO_INHERITANCE_CHAIN (base_binfo);
1300 tree parent_primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (parent));
1301
1302 if (parent_primary
1303 && SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo),
1304 BINFO_TYPE (parent_primary)))
1305 /* We are the primary binfo. */
1306 BINFO_PRIMARY_P (base_binfo) = 1;
1307 }
1308 /* Determine if we have a virtual primary base, and mark it so.
1309 */
1310 if (primary && BINFO_VIRTUAL_P (primary))
1311 {
1312 tree this_primary = copied_binfo (primary, base_binfo);
1313
1314 if (BINFO_PRIMARY_P (this_primary))
1315 /* Someone already claimed this base. */
1316 BINFO_LOST_PRIMARY_P (base_binfo) = 1;
1317 else
1318 {
1319 tree delta;
1320
1321 BINFO_PRIMARY_P (this_primary) = 1;
1322 BINFO_INHERITANCE_CHAIN (this_primary) = base_binfo;
1323
1324 /* A virtual binfo might have been copied from within
1325 another hierarchy. As we're about to use it as a
1326 primary base, make sure the offsets match. */
1327 delta = size_diffop (convert (ssizetype,
1328 BINFO_OFFSET (base_binfo)),
1329 convert (ssizetype,
1330 BINFO_OFFSET (this_primary)));
1331
1332 propagate_binfo_offsets (this_primary, delta);
1333 }
1334 }
1335 }
1336
1337 /* First look for a dynamic direct non-virtual base. */
1338 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, base_binfo); i++)
1339 {
1340 tree basetype = BINFO_TYPE (base_binfo);
1341
1342 if (TYPE_CONTAINS_VPTR_P (basetype) && !BINFO_VIRTUAL_P (base_binfo))
1343 {
1344 primary = base_binfo;
1345 goto found;
1346 }
1347 }
1348
1349 /* A "nearly-empty" virtual base class can be the primary base
1350 class, if no non-virtual polymorphic base can be found. Look for
1351 a nearly-empty virtual dynamic base that is not already a primary
1352 base of something in the hierarchy. If there is no such base,
1353 just pick the first nearly-empty virtual base. */
1354
1355 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1356 base_binfo = TREE_CHAIN (base_binfo))
1357 if (BINFO_VIRTUAL_P (base_binfo)
1358 && CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (base_binfo)))
1359 {
1360 if (!BINFO_PRIMARY_P (base_binfo))
1361 {
1362 /* Found one that is not primary. */
1363 primary = base_binfo;
1364 goto found;
1365 }
1366 else if (!primary)
1367 /* Remember the first candidate. */
1368 primary = base_binfo;
1369 }
1370
1371 found:
1372 /* If we've got a primary base, use it. */
1373 if (primary)
1374 {
1375 tree basetype = BINFO_TYPE (primary);
1376
1377 CLASSTYPE_PRIMARY_BINFO (t) = primary;
1378 if (BINFO_PRIMARY_P (primary))
1379 /* We are stealing a primary base. */
1380 BINFO_LOST_PRIMARY_P (BINFO_INHERITANCE_CHAIN (primary)) = 1;
1381 BINFO_PRIMARY_P (primary) = 1;
1382 if (BINFO_VIRTUAL_P (primary))
1383 {
1384 tree delta;
1385
1386 BINFO_INHERITANCE_CHAIN (primary) = type_binfo;
1387 /* A virtual binfo might have been copied from within
1388 another hierarchy. As we're about to use it as a primary
1389 base, make sure the offsets match. */
1390 delta = size_diffop (ssize_int (0),
1391 convert (ssizetype, BINFO_OFFSET (primary)));
1392
1393 propagate_binfo_offsets (primary, delta);
1394 }
1395
1396 primary = TYPE_BINFO (basetype);
1397
1398 TYPE_VFIELD (t) = TYPE_VFIELD (basetype);
1399 BINFO_VTABLE (type_binfo) = BINFO_VTABLE (primary);
1400 BINFO_VIRTUALS (type_binfo) = BINFO_VIRTUALS (primary);
1401 }
1402 }
1403 \f
1404 /* Set memoizing fields and bits of T (and its variants) for later
1405 use. */
1406
1407 static void
1408 finish_struct_bits (tree t)
1409 {
1410 tree variants;
1411
1412 /* Fix up variants (if any). */
1413 for (variants = TYPE_NEXT_VARIANT (t);
1414 variants;
1415 variants = TYPE_NEXT_VARIANT (variants))
1416 {
1417 /* These fields are in the _TYPE part of the node, not in
1418 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1419 TYPE_HAS_CONSTRUCTOR (variants) = TYPE_HAS_CONSTRUCTOR (t);
1420 TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t);
1421 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variants)
1422 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
1423
1424 TYPE_POLYMORPHIC_P (variants) = TYPE_POLYMORPHIC_P (t);
1425
1426 TYPE_BINFO (variants) = TYPE_BINFO (t);
1427
1428 /* Copy whatever these are holding today. */
1429 TYPE_VFIELD (variants) = TYPE_VFIELD (t);
1430 TYPE_METHODS (variants) = TYPE_METHODS (t);
1431 TYPE_FIELDS (variants) = TYPE_FIELDS (t);
1432 TYPE_SIZE (variants) = TYPE_SIZE (t);
1433 TYPE_SIZE_UNIT (variants) = TYPE_SIZE_UNIT (t);
1434 }
1435
1436 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) && TYPE_POLYMORPHIC_P (t))
1437 /* For a class w/o baseclasses, 'finish_struct' has set
1438 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1439 Similarly for a class whose base classes do not have vtables.
1440 When neither of these is true, we might have removed abstract
1441 virtuals (by providing a definition), added some (by declaring
1442 new ones), or redeclared ones from a base class. We need to
1443 recalculate what's really an abstract virtual at this point (by
1444 looking in the vtables). */
1445 get_pure_virtuals (t);
1446
1447 /* If this type has a copy constructor or a destructor, force its
1448 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1449 nonzero. This will cause it to be passed by invisible reference
1450 and prevent it from being returned in a register. */
1451 if (! TYPE_HAS_TRIVIAL_INIT_REF (t) || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
1452 {
1453 tree variants;
1454 DECL_MODE (TYPE_MAIN_DECL (t)) = BLKmode;
1455 for (variants = t; variants; variants = TYPE_NEXT_VARIANT (variants))
1456 {
1457 TYPE_MODE (variants) = BLKmode;
1458 TREE_ADDRESSABLE (variants) = 1;
1459 }
1460 }
1461 }
1462
1463 /* Issue warnings about T having private constructors, but no friends,
1464 and so forth.
1465
1466 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1467 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1468 non-private static member functions. */
1469
1470 static void
1471 maybe_warn_about_overly_private_class (tree t)
1472 {
1473 int has_member_fn = 0;
1474 int has_nonprivate_method = 0;
1475 tree fn;
1476
1477 if (!warn_ctor_dtor_privacy
1478 /* If the class has friends, those entities might create and
1479 access instances, so we should not warn. */
1480 || (CLASSTYPE_FRIEND_CLASSES (t)
1481 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))
1482 /* We will have warned when the template was declared; there's
1483 no need to warn on every instantiation. */
1484 || CLASSTYPE_TEMPLATE_INSTANTIATION (t))
1485 /* There's no reason to even consider warning about this
1486 class. */
1487 return;
1488
1489 /* We only issue one warning, if more than one applies, because
1490 otherwise, on code like:
1491
1492 class A {
1493 // Oops - forgot `public:'
1494 A();
1495 A(const A&);
1496 ~A();
1497 };
1498
1499 we warn several times about essentially the same problem. */
1500
1501 /* Check to see if all (non-constructor, non-destructor) member
1502 functions are private. (Since there are no friends or
1503 non-private statics, we can't ever call any of the private member
1504 functions.) */
1505 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
1506 /* We're not interested in compiler-generated methods; they don't
1507 provide any way to call private members. */
1508 if (!DECL_ARTIFICIAL (fn))
1509 {
1510 if (!TREE_PRIVATE (fn))
1511 {
1512 if (DECL_STATIC_FUNCTION_P (fn))
1513 /* A non-private static member function is just like a
1514 friend; it can create and invoke private member
1515 functions, and be accessed without a class
1516 instance. */
1517 return;
1518
1519 has_nonprivate_method = 1;
1520 /* Keep searching for a static member function. */
1521 }
1522 else if (!DECL_CONSTRUCTOR_P (fn) && !DECL_DESTRUCTOR_P (fn))
1523 has_member_fn = 1;
1524 }
1525
1526 if (!has_nonprivate_method && has_member_fn)
1527 {
1528 /* There are no non-private methods, and there's at least one
1529 private member function that isn't a constructor or
1530 destructor. (If all the private members are
1531 constructors/destructors we want to use the code below that
1532 issues error messages specifically referring to
1533 constructors/destructors.) */
1534 unsigned i;
1535 tree binfo = TYPE_BINFO (t);
1536
1537 for (i = 0; i != BINFO_N_BASE_BINFOS (binfo); i++)
1538 if (BINFO_BASE_ACCESS (binfo, i) != access_private_node)
1539 {
1540 has_nonprivate_method = 1;
1541 break;
1542 }
1543 if (!has_nonprivate_method)
1544 {
1545 warning (0, "all member functions in class %qT are private", t);
1546 return;
1547 }
1548 }
1549
1550 /* Even if some of the member functions are non-private, the class
1551 won't be useful for much if all the constructors or destructors
1552 are private: such an object can never be created or destroyed. */
1553 fn = CLASSTYPE_DESTRUCTORS (t);
1554 if (fn && TREE_PRIVATE (fn))
1555 {
1556 warning (0, "%q#T only defines a private destructor and has no friends",
1557 t);
1558 return;
1559 }
1560
1561 if (TYPE_HAS_CONSTRUCTOR (t)
1562 /* Implicitly generated constructors are always public. */
1563 && (!CLASSTYPE_LAZY_DEFAULT_CTOR (t)
1564 || !CLASSTYPE_LAZY_COPY_CTOR (t)))
1565 {
1566 int nonprivate_ctor = 0;
1567
1568 /* If a non-template class does not define a copy
1569 constructor, one is defined for it, enabling it to avoid
1570 this warning. For a template class, this does not
1571 happen, and so we would normally get a warning on:
1572
1573 template <class T> class C { private: C(); };
1574
1575 To avoid this asymmetry, we check TYPE_HAS_INIT_REF. All
1576 complete non-template or fully instantiated classes have this
1577 flag set. */
1578 if (!TYPE_HAS_INIT_REF (t))
1579 nonprivate_ctor = 1;
1580 else
1581 for (fn = CLASSTYPE_CONSTRUCTORS (t); fn; fn = OVL_NEXT (fn))
1582 {
1583 tree ctor = OVL_CURRENT (fn);
1584 /* Ideally, we wouldn't count copy constructors (or, in
1585 fact, any constructor that takes an argument of the
1586 class type as a parameter) because such things cannot
1587 be used to construct an instance of the class unless
1588 you already have one. But, for now at least, we're
1589 more generous. */
1590 if (! TREE_PRIVATE (ctor))
1591 {
1592 nonprivate_ctor = 1;
1593 break;
1594 }
1595 }
1596
1597 if (nonprivate_ctor == 0)
1598 {
1599 warning (0, "%q#T only defines private constructors and has no friends",
1600 t);
1601 return;
1602 }
1603 }
1604 }
1605
1606 static struct {
1607 gt_pointer_operator new_value;
1608 void *cookie;
1609 } resort_data;
1610
1611 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1612
1613 static int
1614 method_name_cmp (const void* m1_p, const void* m2_p)
1615 {
1616 const tree *const m1 = m1_p;
1617 const tree *const m2 = m2_p;
1618
1619 if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1620 return 0;
1621 if (*m1 == NULL_TREE)
1622 return -1;
1623 if (*m2 == NULL_TREE)
1624 return 1;
1625 if (DECL_NAME (OVL_CURRENT (*m1)) < DECL_NAME (OVL_CURRENT (*m2)))
1626 return -1;
1627 return 1;
1628 }
1629
1630 /* This routine compares two fields like method_name_cmp but using the
1631 pointer operator in resort_field_decl_data. */
1632
1633 static int
1634 resort_method_name_cmp (const void* m1_p, const void* m2_p)
1635 {
1636 const tree *const m1 = m1_p;
1637 const tree *const m2 = m2_p;
1638 if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1639 return 0;
1640 if (*m1 == NULL_TREE)
1641 return -1;
1642 if (*m2 == NULL_TREE)
1643 return 1;
1644 {
1645 tree d1 = DECL_NAME (OVL_CURRENT (*m1));
1646 tree d2 = DECL_NAME (OVL_CURRENT (*m2));
1647 resort_data.new_value (&d1, resort_data.cookie);
1648 resort_data.new_value (&d2, resort_data.cookie);
1649 if (d1 < d2)
1650 return -1;
1651 }
1652 return 1;
1653 }
1654
1655 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1656
1657 void
1658 resort_type_method_vec (void* obj,
1659 void* orig_obj ATTRIBUTE_UNUSED ,
1660 gt_pointer_operator new_value,
1661 void* cookie)
1662 {
1663 VEC(tree,gc) *method_vec = (VEC(tree,gc) *) obj;
1664 int len = VEC_length (tree, method_vec);
1665 size_t slot;
1666 tree fn;
1667
1668 /* The type conversion ops have to live at the front of the vec, so we
1669 can't sort them. */
1670 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1671 VEC_iterate (tree, method_vec, slot, fn);
1672 ++slot)
1673 if (!DECL_CONV_FN_P (OVL_CURRENT (fn)))
1674 break;
1675
1676 if (len - slot > 1)
1677 {
1678 resort_data.new_value = new_value;
1679 resort_data.cookie = cookie;
1680 qsort (VEC_address (tree, method_vec) + slot, len - slot, sizeof (tree),
1681 resort_method_name_cmp);
1682 }
1683 }
1684
1685 /* Warn about duplicate methods in fn_fields.
1686
1687 Sort methods that are not special (i.e., constructors, destructors,
1688 and type conversion operators) so that we can find them faster in
1689 search. */
1690
1691 static void
1692 finish_struct_methods (tree t)
1693 {
1694 tree fn_fields;
1695 VEC(tree,gc) *method_vec;
1696 int slot, len;
1697
1698 method_vec = CLASSTYPE_METHOD_VEC (t);
1699 if (!method_vec)
1700 return;
1701
1702 len = VEC_length (tree, method_vec);
1703
1704 /* Clear DECL_IN_AGGR_P for all functions. */
1705 for (fn_fields = TYPE_METHODS (t); fn_fields;
1706 fn_fields = TREE_CHAIN (fn_fields))
1707 DECL_IN_AGGR_P (fn_fields) = 0;
1708
1709 /* Issue warnings about private constructors and such. If there are
1710 no methods, then some public defaults are generated. */
1711 maybe_warn_about_overly_private_class (t);
1712
1713 /* The type conversion ops have to live at the front of the vec, so we
1714 can't sort them. */
1715 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1716 VEC_iterate (tree, method_vec, slot, fn_fields);
1717 ++slot)
1718 if (!DECL_CONV_FN_P (OVL_CURRENT (fn_fields)))
1719 break;
1720 if (len - slot > 1)
1721 qsort (VEC_address (tree, method_vec) + slot,
1722 len-slot, sizeof (tree), method_name_cmp);
1723 }
1724
1725 /* Make BINFO's vtable have N entries, including RTTI entries,
1726 vbase and vcall offsets, etc. Set its type and call the backend
1727 to lay it out. */
1728
1729 static void
1730 layout_vtable_decl (tree binfo, int n)
1731 {
1732 tree atype;
1733 tree vtable;
1734
1735 atype = build_cplus_array_type (vtable_entry_type,
1736 build_index_type (size_int (n - 1)));
1737 layout_type (atype);
1738
1739 /* We may have to grow the vtable. */
1740 vtable = get_vtbl_decl_for_binfo (binfo);
1741 if (!same_type_p (TREE_TYPE (vtable), atype))
1742 {
1743 TREE_TYPE (vtable) = atype;
1744 DECL_SIZE (vtable) = DECL_SIZE_UNIT (vtable) = NULL_TREE;
1745 layout_decl (vtable, 0);
1746 }
1747 }
1748
1749 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1750 have the same signature. */
1751
1752 int
1753 same_signature_p (tree fndecl, tree base_fndecl)
1754 {
1755 /* One destructor overrides another if they are the same kind of
1756 destructor. */
1757 if (DECL_DESTRUCTOR_P (base_fndecl) && DECL_DESTRUCTOR_P (fndecl)
1758 && special_function_p (base_fndecl) == special_function_p (fndecl))
1759 return 1;
1760 /* But a non-destructor never overrides a destructor, nor vice
1761 versa, nor do different kinds of destructors override
1762 one-another. For example, a complete object destructor does not
1763 override a deleting destructor. */
1764 if (DECL_DESTRUCTOR_P (base_fndecl) || DECL_DESTRUCTOR_P (fndecl))
1765 return 0;
1766
1767 if (DECL_NAME (fndecl) == DECL_NAME (base_fndecl)
1768 || (DECL_CONV_FN_P (fndecl)
1769 && DECL_CONV_FN_P (base_fndecl)
1770 && same_type_p (DECL_CONV_FN_TYPE (fndecl),
1771 DECL_CONV_FN_TYPE (base_fndecl))))
1772 {
1773 tree types, base_types;
1774 types = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
1775 base_types = TYPE_ARG_TYPES (TREE_TYPE (base_fndecl));
1776 if ((TYPE_QUALS (TREE_TYPE (TREE_VALUE (base_types)))
1777 == TYPE_QUALS (TREE_TYPE (TREE_VALUE (types))))
1778 && compparms (TREE_CHAIN (base_types), TREE_CHAIN (types)))
1779 return 1;
1780 }
1781 return 0;
1782 }
1783
1784 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1785 subobject. */
1786
1787 static bool
1788 base_derived_from (tree derived, tree base)
1789 {
1790 tree probe;
1791
1792 for (probe = base; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
1793 {
1794 if (probe == derived)
1795 return true;
1796 else if (BINFO_VIRTUAL_P (probe))
1797 /* If we meet a virtual base, we can't follow the inheritance
1798 any more. See if the complete type of DERIVED contains
1799 such a virtual base. */
1800 return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (derived))
1801 != NULL_TREE);
1802 }
1803 return false;
1804 }
1805
1806 typedef struct find_final_overrider_data_s {
1807 /* The function for which we are trying to find a final overrider. */
1808 tree fn;
1809 /* The base class in which the function was declared. */
1810 tree declaring_base;
1811 /* The candidate overriders. */
1812 tree candidates;
1813 /* Path to most derived. */
1814 VEC(tree,heap) *path;
1815 } find_final_overrider_data;
1816
1817 /* Add the overrider along the current path to FFOD->CANDIDATES.
1818 Returns true if an overrider was found; false otherwise. */
1819
1820 static bool
1821 dfs_find_final_overrider_1 (tree binfo,
1822 find_final_overrider_data *ffod,
1823 unsigned depth)
1824 {
1825 tree method;
1826
1827 /* If BINFO is not the most derived type, try a more derived class.
1828 A definition there will overrider a definition here. */
1829 if (depth)
1830 {
1831 depth--;
1832 if (dfs_find_final_overrider_1
1833 (VEC_index (tree, ffod->path, depth), ffod, depth))
1834 return true;
1835 }
1836
1837 method = look_for_overrides_here (BINFO_TYPE (binfo), ffod->fn);
1838 if (method)
1839 {
1840 tree *candidate = &ffod->candidates;
1841
1842 /* Remove any candidates overridden by this new function. */
1843 while (*candidate)
1844 {
1845 /* If *CANDIDATE overrides METHOD, then METHOD
1846 cannot override anything else on the list. */
1847 if (base_derived_from (TREE_VALUE (*candidate), binfo))
1848 return true;
1849 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
1850 if (base_derived_from (binfo, TREE_VALUE (*candidate)))
1851 *candidate = TREE_CHAIN (*candidate);
1852 else
1853 candidate = &TREE_CHAIN (*candidate);
1854 }
1855
1856 /* Add the new function. */
1857 ffod->candidates = tree_cons (method, binfo, ffod->candidates);
1858 return true;
1859 }
1860
1861 return false;
1862 }
1863
1864 /* Called from find_final_overrider via dfs_walk. */
1865
1866 static tree
1867 dfs_find_final_overrider_pre (tree binfo, void *data)
1868 {
1869 find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1870
1871 if (binfo == ffod->declaring_base)
1872 dfs_find_final_overrider_1 (binfo, ffod, VEC_length (tree, ffod->path));
1873 VEC_safe_push (tree, heap, ffod->path, binfo);
1874
1875 return NULL_TREE;
1876 }
1877
1878 static tree
1879 dfs_find_final_overrider_post (tree binfo ATTRIBUTE_UNUSED, void *data)
1880 {
1881 find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1882 VEC_pop (tree, ffod->path);
1883
1884 return NULL_TREE;
1885 }
1886
1887 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
1888 FN and whose TREE_VALUE is the binfo for the base where the
1889 overriding occurs. BINFO (in the hierarchy dominated by the binfo
1890 DERIVED) is the base object in which FN is declared. */
1891
1892 static tree
1893 find_final_overrider (tree derived, tree binfo, tree fn)
1894 {
1895 find_final_overrider_data ffod;
1896
1897 /* Getting this right is a little tricky. This is valid:
1898
1899 struct S { virtual void f (); };
1900 struct T { virtual void f (); };
1901 struct U : public S, public T { };
1902
1903 even though calling `f' in `U' is ambiguous. But,
1904
1905 struct R { virtual void f(); };
1906 struct S : virtual public R { virtual void f (); };
1907 struct T : virtual public R { virtual void f (); };
1908 struct U : public S, public T { };
1909
1910 is not -- there's no way to decide whether to put `S::f' or
1911 `T::f' in the vtable for `R'.
1912
1913 The solution is to look at all paths to BINFO. If we find
1914 different overriders along any two, then there is a problem. */
1915 if (DECL_THUNK_P (fn))
1916 fn = THUNK_TARGET (fn);
1917
1918 /* Determine the depth of the hierarchy. */
1919 ffod.fn = fn;
1920 ffod.declaring_base = binfo;
1921 ffod.candidates = NULL_TREE;
1922 ffod.path = VEC_alloc (tree, heap, 30);
1923
1924 dfs_walk_all (derived, dfs_find_final_overrider_pre,
1925 dfs_find_final_overrider_post, &ffod);
1926
1927 VEC_free (tree, heap, ffod.path);
1928
1929 /* If there was no winner, issue an error message. */
1930 if (!ffod.candidates || TREE_CHAIN (ffod.candidates))
1931 return error_mark_node;
1932
1933 return ffod.candidates;
1934 }
1935
1936 /* Return the index of the vcall offset for FN when TYPE is used as a
1937 virtual base. */
1938
1939 static tree
1940 get_vcall_index (tree fn, tree type)
1941 {
1942 VEC(tree_pair_s,gc) *indices = CLASSTYPE_VCALL_INDICES (type);
1943 tree_pair_p p;
1944 unsigned ix;
1945
1946 for (ix = 0; VEC_iterate (tree_pair_s, indices, ix, p); ix++)
1947 if ((DECL_DESTRUCTOR_P (fn) && DECL_DESTRUCTOR_P (p->purpose))
1948 || same_signature_p (fn, p->purpose))
1949 return p->value;
1950
1951 /* There should always be an appropriate index. */
1952 gcc_unreachable ();
1953 }
1954
1955 /* Update an entry in the vtable for BINFO, which is in the hierarchy
1956 dominated by T. FN has been overridden in BINFO; VIRTUALS points to the
1957 corresponding position in the BINFO_VIRTUALS list. */
1958
1959 static void
1960 update_vtable_entry_for_fn (tree t, tree binfo, tree fn, tree* virtuals,
1961 unsigned ix)
1962 {
1963 tree b;
1964 tree overrider;
1965 tree delta;
1966 tree virtual_base;
1967 tree first_defn;
1968 tree overrider_fn, overrider_target;
1969 tree target_fn = DECL_THUNK_P (fn) ? THUNK_TARGET (fn) : fn;
1970 tree over_return, base_return;
1971 bool lost = false;
1972
1973 /* Find the nearest primary base (possibly binfo itself) which defines
1974 this function; this is the class the caller will convert to when
1975 calling FN through BINFO. */
1976 for (b = binfo; ; b = get_primary_binfo (b))
1977 {
1978 gcc_assert (b);
1979 if (look_for_overrides_here (BINFO_TYPE (b), target_fn))
1980 break;
1981
1982 /* The nearest definition is from a lost primary. */
1983 if (BINFO_LOST_PRIMARY_P (b))
1984 lost = true;
1985 }
1986 first_defn = b;
1987
1988 /* Find the final overrider. */
1989 overrider = find_final_overrider (TYPE_BINFO (t), b, target_fn);
1990 if (overrider == error_mark_node)
1991 {
1992 error ("no unique final overrider for %qD in %qT", target_fn, t);
1993 return;
1994 }
1995 overrider_target = overrider_fn = TREE_PURPOSE (overrider);
1996
1997 /* Check for adjusting covariant return types. */
1998 over_return = TREE_TYPE (TREE_TYPE (overrider_target));
1999 base_return = TREE_TYPE (TREE_TYPE (target_fn));
2000
2001 if (POINTER_TYPE_P (over_return)
2002 && TREE_CODE (over_return) == TREE_CODE (base_return)
2003 && CLASS_TYPE_P (TREE_TYPE (over_return))
2004 && CLASS_TYPE_P (TREE_TYPE (base_return))
2005 /* If the overrider is invalid, don't even try. */
2006 && !DECL_INVALID_OVERRIDER_P (overrider_target))
2007 {
2008 /* If FN is a covariant thunk, we must figure out the adjustment
2009 to the final base FN was converting to. As OVERRIDER_TARGET might
2010 also be converting to the return type of FN, we have to
2011 combine the two conversions here. */
2012 tree fixed_offset, virtual_offset;
2013
2014 over_return = TREE_TYPE (over_return);
2015 base_return = TREE_TYPE (base_return);
2016
2017 if (DECL_THUNK_P (fn))
2018 {
2019 gcc_assert (DECL_RESULT_THUNK_P (fn));
2020 fixed_offset = ssize_int (THUNK_FIXED_OFFSET (fn));
2021 virtual_offset = THUNK_VIRTUAL_OFFSET (fn);
2022 }
2023 else
2024 fixed_offset = virtual_offset = NULL_TREE;
2025
2026 if (virtual_offset)
2027 /* Find the equivalent binfo within the return type of the
2028 overriding function. We will want the vbase offset from
2029 there. */
2030 virtual_offset = binfo_for_vbase (BINFO_TYPE (virtual_offset),
2031 over_return);
2032 else if (!same_type_ignoring_top_level_qualifiers_p
2033 (over_return, base_return))
2034 {
2035 /* There was no existing virtual thunk (which takes
2036 precedence). So find the binfo of the base function's
2037 return type within the overriding function's return type.
2038 We cannot call lookup base here, because we're inside a
2039 dfs_walk, and will therefore clobber the BINFO_MARKED
2040 flags. Fortunately we know the covariancy is valid (it
2041 has already been checked), so we can just iterate along
2042 the binfos, which have been chained in inheritance graph
2043 order. Of course it is lame that we have to repeat the
2044 search here anyway -- we should really be caching pieces
2045 of the vtable and avoiding this repeated work. */
2046 tree thunk_binfo, base_binfo;
2047
2048 /* Find the base binfo within the overriding function's
2049 return type. We will always find a thunk_binfo, except
2050 when the covariancy is invalid (which we will have
2051 already diagnosed). */
2052 for (base_binfo = TYPE_BINFO (base_return),
2053 thunk_binfo = TYPE_BINFO (over_return);
2054 thunk_binfo;
2055 thunk_binfo = TREE_CHAIN (thunk_binfo))
2056 if (SAME_BINFO_TYPE_P (BINFO_TYPE (thunk_binfo),
2057 BINFO_TYPE (base_binfo)))
2058 break;
2059
2060 /* See if virtual inheritance is involved. */
2061 for (virtual_offset = thunk_binfo;
2062 virtual_offset;
2063 virtual_offset = BINFO_INHERITANCE_CHAIN (virtual_offset))
2064 if (BINFO_VIRTUAL_P (virtual_offset))
2065 break;
2066
2067 if (virtual_offset
2068 || (thunk_binfo && !BINFO_OFFSET_ZEROP (thunk_binfo)))
2069 {
2070 tree offset = convert (ssizetype, BINFO_OFFSET (thunk_binfo));
2071
2072 if (virtual_offset)
2073 {
2074 /* We convert via virtual base. Adjust the fixed
2075 offset to be from there. */
2076 offset = size_diffop
2077 (offset, convert
2078 (ssizetype, BINFO_OFFSET (virtual_offset)));
2079 }
2080 if (fixed_offset)
2081 /* There was an existing fixed offset, this must be
2082 from the base just converted to, and the base the
2083 FN was thunking to. */
2084 fixed_offset = size_binop (PLUS_EXPR, fixed_offset, offset);
2085 else
2086 fixed_offset = offset;
2087 }
2088 }
2089
2090 if (fixed_offset || virtual_offset)
2091 /* Replace the overriding function with a covariant thunk. We
2092 will emit the overriding function in its own slot as
2093 well. */
2094 overrider_fn = make_thunk (overrider_target, /*this_adjusting=*/0,
2095 fixed_offset, virtual_offset);
2096 }
2097 else
2098 gcc_assert (!DECL_THUNK_P (fn));
2099
2100 /* Assume that we will produce a thunk that convert all the way to
2101 the final overrider, and not to an intermediate virtual base. */
2102 virtual_base = NULL_TREE;
2103
2104 /* See if we can convert to an intermediate virtual base first, and then
2105 use the vcall offset located there to finish the conversion. */
2106 for (; b; b = BINFO_INHERITANCE_CHAIN (b))
2107 {
2108 /* If we find the final overrider, then we can stop
2109 walking. */
2110 if (SAME_BINFO_TYPE_P (BINFO_TYPE (b),
2111 BINFO_TYPE (TREE_VALUE (overrider))))
2112 break;
2113
2114 /* If we find a virtual base, and we haven't yet found the
2115 overrider, then there is a virtual base between the
2116 declaring base (first_defn) and the final overrider. */
2117 if (BINFO_VIRTUAL_P (b))
2118 {
2119 virtual_base = b;
2120 break;
2121 }
2122 }
2123
2124 if (overrider_fn != overrider_target && !virtual_base)
2125 {
2126 /* The ABI specifies that a covariant thunk includes a mangling
2127 for a this pointer adjustment. This-adjusting thunks that
2128 override a function from a virtual base have a vcall
2129 adjustment. When the virtual base in question is a primary
2130 virtual base, we know the adjustments are zero, (and in the
2131 non-covariant case, we would not use the thunk).
2132 Unfortunately we didn't notice this could happen, when
2133 designing the ABI and so never mandated that such a covariant
2134 thunk should be emitted. Because we must use the ABI mandated
2135 name, we must continue searching from the binfo where we
2136 found the most recent definition of the function, towards the
2137 primary binfo which first introduced the function into the
2138 vtable. If that enters a virtual base, we must use a vcall
2139 this-adjusting thunk. Bleah! */
2140 tree probe = first_defn;
2141
2142 while ((probe = get_primary_binfo (probe))
2143 && (unsigned) list_length (BINFO_VIRTUALS (probe)) > ix)
2144 if (BINFO_VIRTUAL_P (probe))
2145 virtual_base = probe;
2146
2147 if (virtual_base)
2148 /* Even if we find a virtual base, the correct delta is
2149 between the overrider and the binfo we're building a vtable
2150 for. */
2151 goto virtual_covariant;
2152 }
2153
2154 /* Compute the constant adjustment to the `this' pointer. The
2155 `this' pointer, when this function is called, will point at BINFO
2156 (or one of its primary bases, which are at the same offset). */
2157 if (virtual_base)
2158 /* The `this' pointer needs to be adjusted from the declaration to
2159 the nearest virtual base. */
2160 delta = size_diffop (convert (ssizetype, BINFO_OFFSET (virtual_base)),
2161 convert (ssizetype, BINFO_OFFSET (first_defn)));
2162 else if (lost)
2163 /* If the nearest definition is in a lost primary, we don't need an
2164 entry in our vtable. Except possibly in a constructor vtable,
2165 if we happen to get our primary back. In that case, the offset
2166 will be zero, as it will be a primary base. */
2167 delta = size_zero_node;
2168 else
2169 /* The `this' pointer needs to be adjusted from pointing to
2170 BINFO to pointing at the base where the final overrider
2171 appears. */
2172 virtual_covariant:
2173 delta = size_diffop (convert (ssizetype,
2174 BINFO_OFFSET (TREE_VALUE (overrider))),
2175 convert (ssizetype, BINFO_OFFSET (binfo)));
2176
2177 modify_vtable_entry (t, binfo, overrider_fn, delta, virtuals);
2178
2179 if (virtual_base)
2180 BV_VCALL_INDEX (*virtuals)
2181 = get_vcall_index (overrider_target, BINFO_TYPE (virtual_base));
2182 else
2183 BV_VCALL_INDEX (*virtuals) = NULL_TREE;
2184 }
2185
2186 /* Called from modify_all_vtables via dfs_walk. */
2187
2188 static tree
2189 dfs_modify_vtables (tree binfo, void* data)
2190 {
2191 tree t = (tree) data;
2192 tree virtuals;
2193 tree old_virtuals;
2194 unsigned ix;
2195
2196 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
2197 /* A base without a vtable needs no modification, and its bases
2198 are uninteresting. */
2199 return dfs_skip_bases;
2200
2201 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t)
2202 && !CLASSTYPE_HAS_PRIMARY_BASE_P (t))
2203 /* Don't do the primary vtable, if it's new. */
2204 return NULL_TREE;
2205
2206 if (BINFO_PRIMARY_P (binfo) && !BINFO_VIRTUAL_P (binfo))
2207 /* There's no need to modify the vtable for a non-virtual primary
2208 base; we're not going to use that vtable anyhow. We do still
2209 need to do this for virtual primary bases, as they could become
2210 non-primary in a construction vtable. */
2211 return NULL_TREE;
2212
2213 make_new_vtable (t, binfo);
2214
2215 /* Now, go through each of the virtual functions in the virtual
2216 function table for BINFO. Find the final overrider, and update
2217 the BINFO_VIRTUALS list appropriately. */
2218 for (ix = 0, virtuals = BINFO_VIRTUALS (binfo),
2219 old_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
2220 virtuals;
2221 ix++, virtuals = TREE_CHAIN (virtuals),
2222 old_virtuals = TREE_CHAIN (old_virtuals))
2223 update_vtable_entry_for_fn (t,
2224 binfo,
2225 BV_FN (old_virtuals),
2226 &virtuals, ix);
2227
2228 return NULL_TREE;
2229 }
2230
2231 /* Update all of the primary and secondary vtables for T. Create new
2232 vtables as required, and initialize their RTTI information. Each
2233 of the functions in VIRTUALS is declared in T and may override a
2234 virtual function from a base class; find and modify the appropriate
2235 entries to point to the overriding functions. Returns a list, in
2236 declaration order, of the virtual functions that are declared in T,
2237 but do not appear in the primary base class vtable, and which
2238 should therefore be appended to the end of the vtable for T. */
2239
2240 static tree
2241 modify_all_vtables (tree t, tree virtuals)
2242 {
2243 tree binfo = TYPE_BINFO (t);
2244 tree *fnsp;
2245
2246 /* Update all of the vtables. */
2247 dfs_walk_once (binfo, dfs_modify_vtables, NULL, t);
2248
2249 /* Add virtual functions not already in our primary vtable. These
2250 will be both those introduced by this class, and those overridden
2251 from secondary bases. It does not include virtuals merely
2252 inherited from secondary bases. */
2253 for (fnsp = &virtuals; *fnsp; )
2254 {
2255 tree fn = TREE_VALUE (*fnsp);
2256
2257 if (!value_member (fn, BINFO_VIRTUALS (binfo))
2258 || DECL_VINDEX (fn) == error_mark_node)
2259 {
2260 /* We don't need to adjust the `this' pointer when
2261 calling this function. */
2262 BV_DELTA (*fnsp) = integer_zero_node;
2263 BV_VCALL_INDEX (*fnsp) = NULL_TREE;
2264
2265 /* This is a function not already in our vtable. Keep it. */
2266 fnsp = &TREE_CHAIN (*fnsp);
2267 }
2268 else
2269 /* We've already got an entry for this function. Skip it. */
2270 *fnsp = TREE_CHAIN (*fnsp);
2271 }
2272
2273 return virtuals;
2274 }
2275
2276 /* Get the base virtual function declarations in T that have the
2277 indicated NAME. */
2278
2279 static tree
2280 get_basefndecls (tree name, tree t)
2281 {
2282 tree methods;
2283 tree base_fndecls = NULL_TREE;
2284 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
2285 int i;
2286
2287 /* Find virtual functions in T with the indicated NAME. */
2288 i = lookup_fnfields_1 (t, name);
2289 if (i != -1)
2290 for (methods = VEC_index (tree, CLASSTYPE_METHOD_VEC (t), i);
2291 methods;
2292 methods = OVL_NEXT (methods))
2293 {
2294 tree method = OVL_CURRENT (methods);
2295
2296 if (TREE_CODE (method) == FUNCTION_DECL
2297 && DECL_VINDEX (method))
2298 base_fndecls = tree_cons (NULL_TREE, method, base_fndecls);
2299 }
2300
2301 if (base_fndecls)
2302 return base_fndecls;
2303
2304 for (i = 0; i < n_baseclasses; i++)
2305 {
2306 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (t), i));
2307 base_fndecls = chainon (get_basefndecls (name, basetype),
2308 base_fndecls);
2309 }
2310
2311 return base_fndecls;
2312 }
2313
2314 /* If this declaration supersedes the declaration of
2315 a method declared virtual in the base class, then
2316 mark this field as being virtual as well. */
2317
2318 void
2319 check_for_override (tree decl, tree ctype)
2320 {
2321 if (TREE_CODE (decl) == TEMPLATE_DECL)
2322 /* In [temp.mem] we have:
2323
2324 A specialization of a member function template does not
2325 override a virtual function from a base class. */
2326 return;
2327 if ((DECL_DESTRUCTOR_P (decl)
2328 || IDENTIFIER_VIRTUAL_P (DECL_NAME (decl))
2329 || DECL_CONV_FN_P (decl))
2330 && look_for_overrides (ctype, decl)
2331 && !DECL_STATIC_FUNCTION_P (decl))
2332 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2333 the error_mark_node so that we know it is an overriding
2334 function. */
2335 DECL_VINDEX (decl) = decl;
2336
2337 if (DECL_VIRTUAL_P (decl))
2338 {
2339 if (!DECL_VINDEX (decl))
2340 DECL_VINDEX (decl) = error_mark_node;
2341 IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) = 1;
2342 }
2343 }
2344
2345 /* Warn about hidden virtual functions that are not overridden in t.
2346 We know that constructors and destructors don't apply. */
2347
2348 void
2349 warn_hidden (tree t)
2350 {
2351 VEC(tree,gc) *method_vec = CLASSTYPE_METHOD_VEC (t);
2352 tree fns;
2353 size_t i;
2354
2355 /* We go through each separately named virtual function. */
2356 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
2357 VEC_iterate (tree, method_vec, i, fns);
2358 ++i)
2359 {
2360 tree fn;
2361 tree name;
2362 tree fndecl;
2363 tree base_fndecls;
2364 tree base_binfo;
2365 tree binfo;
2366 int j;
2367
2368 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2369 have the same name. Figure out what name that is. */
2370 name = DECL_NAME (OVL_CURRENT (fns));
2371 /* There are no possibly hidden functions yet. */
2372 base_fndecls = NULL_TREE;
2373 /* Iterate through all of the base classes looking for possibly
2374 hidden functions. */
2375 for (binfo = TYPE_BINFO (t), j = 0;
2376 BINFO_BASE_ITERATE (binfo, j, base_binfo); j++)
2377 {
2378 tree basetype = BINFO_TYPE (base_binfo);
2379 base_fndecls = chainon (get_basefndecls (name, basetype),
2380 base_fndecls);
2381 }
2382
2383 /* If there are no functions to hide, continue. */
2384 if (!base_fndecls)
2385 continue;
2386
2387 /* Remove any overridden functions. */
2388 for (fn = fns; fn; fn = OVL_NEXT (fn))
2389 {
2390 fndecl = OVL_CURRENT (fn);
2391 if (DECL_VINDEX (fndecl))
2392 {
2393 tree *prev = &base_fndecls;
2394
2395 while (*prev)
2396 /* If the method from the base class has the same
2397 signature as the method from the derived class, it
2398 has been overridden. */
2399 if (same_signature_p (fndecl, TREE_VALUE (*prev)))
2400 *prev = TREE_CHAIN (*prev);
2401 else
2402 prev = &TREE_CHAIN (*prev);
2403 }
2404 }
2405
2406 /* Now give a warning for all base functions without overriders,
2407 as they are hidden. */
2408 while (base_fndecls)
2409 {
2410 /* Here we know it is a hider, and no overrider exists. */
2411 warning (0, "%q+D was hidden", TREE_VALUE (base_fndecls));
2412 warning (0, " by %q+D", fns);
2413 base_fndecls = TREE_CHAIN (base_fndecls);
2414 }
2415 }
2416 }
2417
2418 /* Check for things that are invalid. There are probably plenty of other
2419 things we should check for also. */
2420
2421 static void
2422 finish_struct_anon (tree t)
2423 {
2424 tree field;
2425
2426 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
2427 {
2428 if (TREE_STATIC (field))
2429 continue;
2430 if (TREE_CODE (field) != FIELD_DECL)
2431 continue;
2432
2433 if (DECL_NAME (field) == NULL_TREE
2434 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
2435 {
2436 tree elt = TYPE_FIELDS (TREE_TYPE (field));
2437 for (; elt; elt = TREE_CHAIN (elt))
2438 {
2439 /* We're generally only interested in entities the user
2440 declared, but we also find nested classes by noticing
2441 the TYPE_DECL that we create implicitly. You're
2442 allowed to put one anonymous union inside another,
2443 though, so we explicitly tolerate that. We use
2444 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2445 we also allow unnamed types used for defining fields. */
2446 if (DECL_ARTIFICIAL (elt)
2447 && (!DECL_IMPLICIT_TYPEDEF_P (elt)
2448 || TYPE_ANONYMOUS_P (TREE_TYPE (elt))))
2449 continue;
2450
2451 if (TREE_CODE (elt) != FIELD_DECL)
2452 {
2453 pedwarn ("%q+#D invalid; an anonymous union can "
2454 "only have non-static data members", elt);
2455 continue;
2456 }
2457
2458 if (TREE_PRIVATE (elt))
2459 pedwarn ("private member %q+#D in anonymous union", elt);
2460 else if (TREE_PROTECTED (elt))
2461 pedwarn ("protected member %q+#D in anonymous union", elt);
2462
2463 TREE_PRIVATE (elt) = TREE_PRIVATE (field);
2464 TREE_PROTECTED (elt) = TREE_PROTECTED (field);
2465 }
2466 }
2467 }
2468 }
2469
2470 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2471 will be used later during class template instantiation.
2472 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2473 a non-static member data (FIELD_DECL), a member function
2474 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2475 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2476 When FRIEND_P is nonzero, T is either a friend class
2477 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2478 (FUNCTION_DECL, TEMPLATE_DECL). */
2479
2480 void
2481 maybe_add_class_template_decl_list (tree type, tree t, int friend_p)
2482 {
2483 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2484 if (CLASSTYPE_TEMPLATE_INFO (type))
2485 CLASSTYPE_DECL_LIST (type)
2486 = tree_cons (friend_p ? NULL_TREE : type,
2487 t, CLASSTYPE_DECL_LIST (type));
2488 }
2489
2490 /* Create default constructors, assignment operators, and so forth for
2491 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2492 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2493 the class cannot have a default constructor, copy constructor
2494 taking a const reference argument, or an assignment operator taking
2495 a const reference, respectively. */
2496
2497 static void
2498 add_implicitly_declared_members (tree t,
2499 int cant_have_const_cctor,
2500 int cant_have_const_assignment)
2501 {
2502 /* Destructor. */
2503 if (!CLASSTYPE_DESTRUCTORS (t))
2504 {
2505 /* In general, we create destructors lazily. */
2506 CLASSTYPE_LAZY_DESTRUCTOR (t) = 1;
2507 /* However, if the implicit destructor is non-trivial
2508 destructor, we sometimes have to create it at this point. */
2509 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
2510 {
2511 bool lazy_p = true;
2512
2513 if (TYPE_FOR_JAVA (t))
2514 /* If this a Java class, any non-trivial destructor is
2515 invalid, even if compiler-generated. Therefore, if the
2516 destructor is non-trivial we create it now. */
2517 lazy_p = false;
2518 else
2519 {
2520 tree binfo;
2521 tree base_binfo;
2522 int ix;
2523
2524 /* If the implicit destructor will be virtual, then we must
2525 generate it now because (unfortunately) we do not
2526 generate virtual tables lazily. */
2527 binfo = TYPE_BINFO (t);
2528 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
2529 {
2530 tree base_type;
2531 tree dtor;
2532
2533 base_type = BINFO_TYPE (base_binfo);
2534 dtor = CLASSTYPE_DESTRUCTORS (base_type);
2535 if (dtor && DECL_VIRTUAL_P (dtor))
2536 {
2537 lazy_p = false;
2538 break;
2539 }
2540 }
2541 }
2542
2543 /* If we can't get away with being lazy, generate the destructor
2544 now. */
2545 if (!lazy_p)
2546 lazily_declare_fn (sfk_destructor, t);
2547 }
2548 }
2549
2550 /* Default constructor. */
2551 if (! TYPE_HAS_CONSTRUCTOR (t))
2552 {
2553 TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 1;
2554 CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 1;
2555 }
2556
2557 /* Copy constructor. */
2558 if (! TYPE_HAS_INIT_REF (t) && ! TYPE_FOR_JAVA (t))
2559 {
2560 TYPE_HAS_INIT_REF (t) = 1;
2561 TYPE_HAS_CONST_INIT_REF (t) = !cant_have_const_cctor;
2562 CLASSTYPE_LAZY_COPY_CTOR (t) = 1;
2563 TYPE_HAS_CONSTRUCTOR (t) = 1;
2564 }
2565
2566 /* If there is no assignment operator, one will be created if and
2567 when it is needed. For now, just record whether or not the type
2568 of the parameter to the assignment operator will be a const or
2569 non-const reference. */
2570 if (!TYPE_HAS_ASSIGN_REF (t) && !TYPE_FOR_JAVA (t))
2571 {
2572 TYPE_HAS_ASSIGN_REF (t) = 1;
2573 TYPE_HAS_CONST_ASSIGN_REF (t) = !cant_have_const_assignment;
2574 CLASSTYPE_LAZY_ASSIGNMENT_OP (t) = 1;
2575 }
2576 }
2577
2578 /* Subroutine of finish_struct_1. Recursively count the number of fields
2579 in TYPE, including anonymous union members. */
2580
2581 static int
2582 count_fields (tree fields)
2583 {
2584 tree x;
2585 int n_fields = 0;
2586 for (x = fields; x; x = TREE_CHAIN (x))
2587 {
2588 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2589 n_fields += count_fields (TYPE_FIELDS (TREE_TYPE (x)));
2590 else
2591 n_fields += 1;
2592 }
2593 return n_fields;
2594 }
2595
2596 /* Subroutine of finish_struct_1. Recursively add all the fields in the
2597 TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX. */
2598
2599 static int
2600 add_fields_to_record_type (tree fields, struct sorted_fields_type *field_vec, int idx)
2601 {
2602 tree x;
2603 for (x = fields; x; x = TREE_CHAIN (x))
2604 {
2605 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2606 idx = add_fields_to_record_type (TYPE_FIELDS (TREE_TYPE (x)), field_vec, idx);
2607 else
2608 field_vec->elts[idx++] = x;
2609 }
2610 return idx;
2611 }
2612
2613 /* FIELD is a bit-field. We are finishing the processing for its
2614 enclosing type. Issue any appropriate messages and set appropriate
2615 flags. */
2616
2617 static void
2618 check_bitfield_decl (tree field)
2619 {
2620 tree type = TREE_TYPE (field);
2621 tree w = NULL_TREE;
2622
2623 /* Detect invalid bit-field type. */
2624 if (DECL_INITIAL (field)
2625 && ! INTEGRAL_TYPE_P (TREE_TYPE (field)))
2626 {
2627 error ("bit-field %q+#D with non-integral type", field);
2628 w = error_mark_node;
2629 }
2630
2631 /* Detect and ignore out of range field width. */
2632 if (DECL_INITIAL (field))
2633 {
2634 w = DECL_INITIAL (field);
2635
2636 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2637 STRIP_NOPS (w);
2638
2639 /* detect invalid field size. */
2640 w = integral_constant_value (w);
2641
2642 if (TREE_CODE (w) != INTEGER_CST)
2643 {
2644 error ("bit-field %q+D width not an integer constant", field);
2645 w = error_mark_node;
2646 }
2647 else if (tree_int_cst_sgn (w) < 0)
2648 {
2649 error ("negative width in bit-field %q+D", field);
2650 w = error_mark_node;
2651 }
2652 else if (integer_zerop (w) && DECL_NAME (field) != 0)
2653 {
2654 error ("zero width for bit-field %q+D", field);
2655 w = error_mark_node;
2656 }
2657 else if (compare_tree_int (w, TYPE_PRECISION (type)) > 0
2658 && TREE_CODE (type) != ENUMERAL_TYPE
2659 && TREE_CODE (type) != BOOLEAN_TYPE)
2660 warning (0, "width of %q+D exceeds its type", field);
2661 else if (TREE_CODE (type) == ENUMERAL_TYPE
2662 && (0 > compare_tree_int (w,
2663 min_precision (TYPE_MIN_VALUE (type),
2664 TYPE_UNSIGNED (type)))
2665 || 0 > compare_tree_int (w,
2666 min_precision
2667 (TYPE_MAX_VALUE (type),
2668 TYPE_UNSIGNED (type)))))
2669 warning (0, "%q+D is too small to hold all values of %q#T", field, type);
2670 }
2671
2672 /* Remove the bit-field width indicator so that the rest of the
2673 compiler does not treat that value as an initializer. */
2674 DECL_INITIAL (field) = NULL_TREE;
2675
2676 if (w != error_mark_node)
2677 {
2678 DECL_SIZE (field) = convert (bitsizetype, w);
2679 DECL_BIT_FIELD (field) = 1;
2680 }
2681 else
2682 {
2683 /* Non-bit-fields are aligned for their type. */
2684 DECL_BIT_FIELD (field) = 0;
2685 CLEAR_DECL_C_BIT_FIELD (field);
2686 }
2687 }
2688
2689 /* FIELD is a non bit-field. We are finishing the processing for its
2690 enclosing type T. Issue any appropriate messages and set appropriate
2691 flags. */
2692
2693 static void
2694 check_field_decl (tree field,
2695 tree t,
2696 int* cant_have_const_ctor,
2697 int* no_const_asn_ref,
2698 int* any_default_members)
2699 {
2700 tree type = strip_array_types (TREE_TYPE (field));
2701
2702 /* An anonymous union cannot contain any fields which would change
2703 the settings of CANT_HAVE_CONST_CTOR and friends. */
2704 if (ANON_UNION_TYPE_P (type))
2705 ;
2706 /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
2707 structs. So, we recurse through their fields here. */
2708 else if (ANON_AGGR_TYPE_P (type))
2709 {
2710 tree fields;
2711
2712 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2713 if (TREE_CODE (fields) == FIELD_DECL && !DECL_C_BIT_FIELD (field))
2714 check_field_decl (fields, t, cant_have_const_ctor,
2715 no_const_asn_ref, any_default_members);
2716 }
2717 /* Check members with class type for constructors, destructors,
2718 etc. */
2719 else if (CLASS_TYPE_P (type))
2720 {
2721 /* Never let anything with uninheritable virtuals
2722 make it through without complaint. */
2723 abstract_virtuals_error (field, type);
2724
2725 if (TREE_CODE (t) == UNION_TYPE)
2726 {
2727 if (TYPE_NEEDS_CONSTRUCTING (type))
2728 error ("member %q+#D with constructor not allowed in union",
2729 field);
2730 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
2731 error ("member %q+#D with destructor not allowed in union", field);
2732 if (TYPE_HAS_COMPLEX_ASSIGN_REF (type))
2733 error ("member %q+#D with copy assignment operator not allowed in union",
2734 field);
2735 }
2736 else
2737 {
2738 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (type);
2739 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
2740 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type);
2741 TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_HAS_COMPLEX_ASSIGN_REF (type);
2742 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (type);
2743 }
2744
2745 if (!TYPE_HAS_CONST_INIT_REF (type))
2746 *cant_have_const_ctor = 1;
2747
2748 if (!TYPE_HAS_CONST_ASSIGN_REF (type))
2749 *no_const_asn_ref = 1;
2750 }
2751 if (DECL_INITIAL (field) != NULL_TREE)
2752 {
2753 /* `build_class_init_list' does not recognize
2754 non-FIELD_DECLs. */
2755 if (TREE_CODE (t) == UNION_TYPE && any_default_members != 0)
2756 error ("multiple fields in union %qT initialized", t);
2757 *any_default_members = 1;
2758 }
2759 }
2760
2761 /* Check the data members (both static and non-static), class-scoped
2762 typedefs, etc., appearing in the declaration of T. Issue
2763 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
2764 declaration order) of access declarations; each TREE_VALUE in this
2765 list is a USING_DECL.
2766
2767 In addition, set the following flags:
2768
2769 EMPTY_P
2770 The class is empty, i.e., contains no non-static data members.
2771
2772 CANT_HAVE_CONST_CTOR_P
2773 This class cannot have an implicitly generated copy constructor
2774 taking a const reference.
2775
2776 CANT_HAVE_CONST_ASN_REF
2777 This class cannot have an implicitly generated assignment
2778 operator taking a const reference.
2779
2780 All of these flags should be initialized before calling this
2781 function.
2782
2783 Returns a pointer to the end of the TYPE_FIELDs chain; additional
2784 fields can be added by adding to this chain. */
2785
2786 static void
2787 check_field_decls (tree t, tree *access_decls,
2788 int *cant_have_const_ctor_p,
2789 int *no_const_asn_ref_p)
2790 {
2791 tree *field;
2792 tree *next;
2793 bool has_pointers;
2794 int any_default_members;
2795
2796 /* Assume there are no access declarations. */
2797 *access_decls = NULL_TREE;
2798 /* Assume this class has no pointer members. */
2799 has_pointers = false;
2800 /* Assume none of the members of this class have default
2801 initializations. */
2802 any_default_members = 0;
2803
2804 for (field = &TYPE_FIELDS (t); *field; field = next)
2805 {
2806 tree x = *field;
2807 tree type = TREE_TYPE (x);
2808
2809 next = &TREE_CHAIN (x);
2810
2811 if (TREE_CODE (x) == FIELD_DECL)
2812 {
2813 if (TYPE_PACKED (t))
2814 {
2815 if (!pod_type_p (TREE_TYPE (x)) && !TYPE_PACKED (TREE_TYPE (x)))
2816 warning
2817 (0,
2818 "ignoring packed attribute on unpacked non-POD field %q+#D",
2819 x);
2820 else if (TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT)
2821 DECL_PACKED (x) = 1;
2822 }
2823
2824 if (DECL_C_BIT_FIELD (x) && integer_zerop (DECL_INITIAL (x)))
2825 /* We don't treat zero-width bitfields as making a class
2826 non-empty. */
2827 ;
2828 else
2829 {
2830 tree element_type;
2831
2832 /* The class is non-empty. */
2833 CLASSTYPE_EMPTY_P (t) = 0;
2834 /* The class is not even nearly empty. */
2835 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
2836 /* If one of the data members contains an empty class,
2837 so does T. */
2838 element_type = strip_array_types (type);
2839 if (CLASS_TYPE_P (element_type)
2840 && CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type))
2841 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
2842 }
2843 }
2844
2845 if (TREE_CODE (x) == USING_DECL)
2846 {
2847 /* Prune the access declaration from the list of fields. */
2848 *field = TREE_CHAIN (x);
2849
2850 /* Save the access declarations for our caller. */
2851 *access_decls = tree_cons (NULL_TREE, x, *access_decls);
2852
2853 /* Since we've reset *FIELD there's no reason to skip to the
2854 next field. */
2855 next = field;
2856 continue;
2857 }
2858
2859 if (TREE_CODE (x) == TYPE_DECL
2860 || TREE_CODE (x) == TEMPLATE_DECL)
2861 continue;
2862
2863 /* If we've gotten this far, it's a data member, possibly static,
2864 or an enumerator. */
2865 DECL_CONTEXT (x) = t;
2866
2867 /* When this goes into scope, it will be a non-local reference. */
2868 DECL_NONLOCAL (x) = 1;
2869
2870 if (TREE_CODE (t) == UNION_TYPE)
2871 {
2872 /* [class.union]
2873
2874 If a union contains a static data member, or a member of
2875 reference type, the program is ill-formed. */
2876 if (TREE_CODE (x) == VAR_DECL)
2877 {
2878 error ("%q+D may not be static because it is a member of a union", x);
2879 continue;
2880 }
2881 if (TREE_CODE (type) == REFERENCE_TYPE)
2882 {
2883 error ("%q+D may not have reference type %qT because"
2884 " it is a member of a union",
2885 x, type);
2886 continue;
2887 }
2888 }
2889
2890 /* ``A local class cannot have static data members.'' ARM 9.4 */
2891 if (current_function_decl && TREE_STATIC (x))
2892 error ("field %q+D in local class cannot be static", x);
2893
2894 /* Perform error checking that did not get done in
2895 grokdeclarator. */
2896 if (TREE_CODE (type) == FUNCTION_TYPE)
2897 {
2898 error ("field %q+D invalidly declared function type", x);
2899 type = build_pointer_type (type);
2900 TREE_TYPE (x) = type;
2901 }
2902 else if (TREE_CODE (type) == METHOD_TYPE)
2903 {
2904 error ("field %q+D invalidly declared method type", x);
2905 type = build_pointer_type (type);
2906 TREE_TYPE (x) = type;
2907 }
2908
2909 if (type == error_mark_node)
2910 continue;
2911
2912 if (TREE_CODE (x) == CONST_DECL || TREE_CODE (x) == VAR_DECL)
2913 continue;
2914
2915 /* Now it can only be a FIELD_DECL. */
2916
2917 if (TREE_PRIVATE (x) || TREE_PROTECTED (x))
2918 CLASSTYPE_NON_AGGREGATE (t) = 1;
2919
2920 /* If this is of reference type, check if it needs an init.
2921 Also do a little ANSI jig if necessary. */
2922 if (TREE_CODE (type) == REFERENCE_TYPE)
2923 {
2924 CLASSTYPE_NON_POD_P (t) = 1;
2925 if (DECL_INITIAL (x) == NULL_TREE)
2926 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
2927
2928 /* ARM $12.6.2: [A member initializer list] (or, for an
2929 aggregate, initialization by a brace-enclosed list) is the
2930 only way to initialize nonstatic const and reference
2931 members. */
2932 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
2933
2934 if (! TYPE_HAS_CONSTRUCTOR (t) && CLASSTYPE_NON_AGGREGATE (t)
2935 && extra_warnings)
2936 warning (0, "non-static reference %q+#D in class without a constructor", x);
2937 }
2938
2939 type = strip_array_types (type);
2940
2941 /* This is used by -Weffc++ (see below). Warn only for pointers
2942 to members which might hold dynamic memory. So do not warn
2943 for pointers to functions or pointers to members. */
2944 if (TYPE_PTR_P (type)
2945 && !TYPE_PTRFN_P (type)
2946 && !TYPE_PTR_TO_MEMBER_P (type))
2947 has_pointers = true;
2948
2949 if (CLASS_TYPE_P (type))
2950 {
2951 if (CLASSTYPE_REF_FIELDS_NEED_INIT (type))
2952 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
2953 if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (type))
2954 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
2955 }
2956
2957 if (DECL_MUTABLE_P (x) || TYPE_HAS_MUTABLE_P (type))
2958 CLASSTYPE_HAS_MUTABLE (t) = 1;
2959
2960 if (! pod_type_p (type))
2961 /* DR 148 now allows pointers to members (which are POD themselves),
2962 to be allowed in POD structs. */
2963 CLASSTYPE_NON_POD_P (t) = 1;
2964
2965 if (! zero_init_p (type))
2966 CLASSTYPE_NON_ZERO_INIT_P (t) = 1;
2967
2968 /* If any field is const, the structure type is pseudo-const. */
2969 if (CP_TYPE_CONST_P (type))
2970 {
2971 C_TYPE_FIELDS_READONLY (t) = 1;
2972 if (DECL_INITIAL (x) == NULL_TREE)
2973 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
2974
2975 /* ARM $12.6.2: [A member initializer list] (or, for an
2976 aggregate, initialization by a brace-enclosed list) is the
2977 only way to initialize nonstatic const and reference
2978 members. */
2979 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
2980
2981 if (! TYPE_HAS_CONSTRUCTOR (t) && CLASSTYPE_NON_AGGREGATE (t)
2982 && extra_warnings)
2983 warning (0, "non-static const member %q+#D in class without a constructor", x);
2984 }
2985 /* A field that is pseudo-const makes the structure likewise. */
2986 else if (CLASS_TYPE_P (type))
2987 {
2988 C_TYPE_FIELDS_READONLY (t) |= C_TYPE_FIELDS_READONLY (type);
2989 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t,
2990 CLASSTYPE_READONLY_FIELDS_NEED_INIT (t)
2991 | CLASSTYPE_READONLY_FIELDS_NEED_INIT (type));
2992 }
2993
2994 /* Core issue 80: A nonstatic data member is required to have a
2995 different name from the class iff the class has a
2996 user-defined constructor. */
2997 if (constructor_name_p (DECL_NAME (x), t) && TYPE_HAS_CONSTRUCTOR (t))
2998 pedwarn ("field %q+#D with same name as class", x);
2999
3000 /* We set DECL_C_BIT_FIELD in grokbitfield.
3001 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3002 if (DECL_C_BIT_FIELD (x))
3003 check_bitfield_decl (x);
3004 else
3005 check_field_decl (x, t,
3006 cant_have_const_ctor_p,
3007 no_const_asn_ref_p,
3008 &any_default_members);
3009 }
3010
3011 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3012 it should also define a copy constructor and an assignment operator to
3013 implement the correct copy semantic (deep vs shallow, etc.). As it is
3014 not feasible to check whether the constructors do allocate dynamic memory
3015 and store it within members, we approximate the warning like this:
3016
3017 -- Warn only if there are members which are pointers
3018 -- Warn only if there is a non-trivial constructor (otherwise,
3019 there cannot be memory allocated).
3020 -- Warn only if there is a non-trivial destructor. We assume that the
3021 user at least implemented the cleanup correctly, and a destructor
3022 is needed to free dynamic memory.
3023
3024 This seems enough for practical purposes. */
3025 if (warn_ecpp
3026 && has_pointers
3027 && TYPE_HAS_CONSTRUCTOR (t)
3028 && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
3029 && !(TYPE_HAS_INIT_REF (t) && TYPE_HAS_ASSIGN_REF (t)))
3030 {
3031 warning (0, "%q#T has pointer data members", t);
3032
3033 if (! TYPE_HAS_INIT_REF (t))
3034 {
3035 warning (0, " but does not override %<%T(const %T&)%>", t, t);
3036 if (! TYPE_HAS_ASSIGN_REF (t))
3037 warning (0, " or %<operator=(const %T&)%>", t);
3038 }
3039 else if (! TYPE_HAS_ASSIGN_REF (t))
3040 warning (0, " but does not override %<operator=(const %T&)%>", t);
3041 }
3042
3043
3044 /* Check anonymous struct/anonymous union fields. */
3045 finish_struct_anon (t);
3046
3047 /* We've built up the list of access declarations in reverse order.
3048 Fix that now. */
3049 *access_decls = nreverse (*access_decls);
3050 }
3051
3052 /* If TYPE is an empty class type, records its OFFSET in the table of
3053 OFFSETS. */
3054
3055 static int
3056 record_subobject_offset (tree type, tree offset, splay_tree offsets)
3057 {
3058 splay_tree_node n;
3059
3060 if (!is_empty_class (type))
3061 return 0;
3062
3063 /* Record the location of this empty object in OFFSETS. */
3064 n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3065 if (!n)
3066 n = splay_tree_insert (offsets,
3067 (splay_tree_key) offset,
3068 (splay_tree_value) NULL_TREE);
3069 n->value = ((splay_tree_value)
3070 tree_cons (NULL_TREE,
3071 type,
3072 (tree) n->value));
3073
3074 return 0;
3075 }
3076
3077 /* Returns nonzero if TYPE is an empty class type and there is
3078 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3079
3080 static int
3081 check_subobject_offset (tree type, tree offset, splay_tree offsets)
3082 {
3083 splay_tree_node n;
3084 tree t;
3085
3086 if (!is_empty_class (type))
3087 return 0;
3088
3089 /* Record the location of this empty object in OFFSETS. */
3090 n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3091 if (!n)
3092 return 0;
3093
3094 for (t = (tree) n->value; t; t = TREE_CHAIN (t))
3095 if (same_type_p (TREE_VALUE (t), type))
3096 return 1;
3097
3098 return 0;
3099 }
3100
3101 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3102 F for every subobject, passing it the type, offset, and table of
3103 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3104 be traversed.
3105
3106 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3107 than MAX_OFFSET will not be walked.
3108
3109 If F returns a nonzero value, the traversal ceases, and that value
3110 is returned. Otherwise, returns zero. */
3111
3112 static int
3113 walk_subobject_offsets (tree type,
3114 subobject_offset_fn f,
3115 tree offset,
3116 splay_tree offsets,
3117 tree max_offset,
3118 int vbases_p)
3119 {
3120 int r = 0;
3121 tree type_binfo = NULL_TREE;
3122
3123 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3124 stop. */
3125 if (max_offset && INT_CST_LT (max_offset, offset))
3126 return 0;
3127
3128 if (type == error_mark_node)
3129 return 0;
3130
3131 if (!TYPE_P (type))
3132 {
3133 if (abi_version_at_least (2))
3134 type_binfo = type;
3135 type = BINFO_TYPE (type);
3136 }
3137
3138 if (CLASS_TYPE_P (type))
3139 {
3140 tree field;
3141 tree binfo;
3142 int i;
3143
3144 /* Avoid recursing into objects that are not interesting. */
3145 if (!CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type))
3146 return 0;
3147
3148 /* Record the location of TYPE. */
3149 r = (*f) (type, offset, offsets);
3150 if (r)
3151 return r;
3152
3153 /* Iterate through the direct base classes of TYPE. */
3154 if (!type_binfo)
3155 type_binfo = TYPE_BINFO (type);
3156 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, binfo); i++)
3157 {
3158 tree binfo_offset;
3159
3160 if (abi_version_at_least (2)
3161 && BINFO_VIRTUAL_P (binfo))
3162 continue;
3163
3164 if (!vbases_p
3165 && BINFO_VIRTUAL_P (binfo)
3166 && !BINFO_PRIMARY_P (binfo))
3167 continue;
3168
3169 if (!abi_version_at_least (2))
3170 binfo_offset = size_binop (PLUS_EXPR,
3171 offset,
3172 BINFO_OFFSET (binfo));
3173 else
3174 {
3175 tree orig_binfo;
3176 /* We cannot rely on BINFO_OFFSET being set for the base
3177 class yet, but the offsets for direct non-virtual
3178 bases can be calculated by going back to the TYPE. */
3179 orig_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), i);
3180 binfo_offset = size_binop (PLUS_EXPR,
3181 offset,
3182 BINFO_OFFSET (orig_binfo));
3183 }
3184
3185 r = walk_subobject_offsets (binfo,
3186 f,
3187 binfo_offset,
3188 offsets,
3189 max_offset,
3190 (abi_version_at_least (2)
3191 ? /*vbases_p=*/0 : vbases_p));
3192 if (r)
3193 return r;
3194 }
3195
3196 if (abi_version_at_least (2) && CLASSTYPE_VBASECLASSES (type))
3197 {
3198 unsigned ix;
3199 VEC(tree,gc) *vbases;
3200
3201 /* Iterate through the virtual base classes of TYPE. In G++
3202 3.2, we included virtual bases in the direct base class
3203 loop above, which results in incorrect results; the
3204 correct offsets for virtual bases are only known when
3205 working with the most derived type. */
3206 if (vbases_p)
3207 for (vbases = CLASSTYPE_VBASECLASSES (type), ix = 0;
3208 VEC_iterate (tree, vbases, ix, binfo); ix++)
3209 {
3210 r = walk_subobject_offsets (binfo,
3211 f,
3212 size_binop (PLUS_EXPR,
3213 offset,
3214 BINFO_OFFSET (binfo)),
3215 offsets,
3216 max_offset,
3217 /*vbases_p=*/0);
3218 if (r)
3219 return r;
3220 }
3221 else
3222 {
3223 /* We still have to walk the primary base, if it is
3224 virtual. (If it is non-virtual, then it was walked
3225 above.) */
3226 tree vbase = get_primary_binfo (type_binfo);
3227
3228 if (vbase && BINFO_VIRTUAL_P (vbase)
3229 && BINFO_PRIMARY_P (vbase)
3230 && BINFO_INHERITANCE_CHAIN (vbase) == type_binfo)
3231 {
3232 r = (walk_subobject_offsets
3233 (vbase, f, offset,
3234 offsets, max_offset, /*vbases_p=*/0));
3235 if (r)
3236 return r;
3237 }
3238 }
3239 }
3240
3241 /* Iterate through the fields of TYPE. */
3242 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3243 if (TREE_CODE (field) == FIELD_DECL && !DECL_ARTIFICIAL (field))
3244 {
3245 tree field_offset;
3246
3247 if (abi_version_at_least (2))
3248 field_offset = byte_position (field);
3249 else
3250 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3251 field_offset = DECL_FIELD_OFFSET (field);
3252
3253 r = walk_subobject_offsets (TREE_TYPE (field),
3254 f,
3255 size_binop (PLUS_EXPR,
3256 offset,
3257 field_offset),
3258 offsets,
3259 max_offset,
3260 /*vbases_p=*/1);
3261 if (r)
3262 return r;
3263 }
3264 }
3265 else if (TREE_CODE (type) == ARRAY_TYPE)
3266 {
3267 tree element_type = strip_array_types (type);
3268 tree domain = TYPE_DOMAIN (type);
3269 tree index;
3270
3271 /* Avoid recursing into objects that are not interesting. */
3272 if (!CLASS_TYPE_P (element_type)
3273 || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type))
3274 return 0;
3275
3276 /* Step through each of the elements in the array. */
3277 for (index = size_zero_node;
3278 /* G++ 3.2 had an off-by-one error here. */
3279 (abi_version_at_least (2)
3280 ? !INT_CST_LT (TYPE_MAX_VALUE (domain), index)
3281 : INT_CST_LT (index, TYPE_MAX_VALUE (domain)));
3282 index = size_binop (PLUS_EXPR, index, size_one_node))
3283 {
3284 r = walk_subobject_offsets (TREE_TYPE (type),
3285 f,
3286 offset,
3287 offsets,
3288 max_offset,
3289 /*vbases_p=*/1);
3290 if (r)
3291 return r;
3292 offset = size_binop (PLUS_EXPR, offset,
3293 TYPE_SIZE_UNIT (TREE_TYPE (type)));
3294 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3295 there's no point in iterating through the remaining
3296 elements of the array. */
3297 if (max_offset && INT_CST_LT (max_offset, offset))
3298 break;
3299 }
3300 }
3301
3302 return 0;
3303 }
3304
3305 /* Record all of the empty subobjects of TYPE (either a type or a
3306 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3307 is being placed at OFFSET; otherwise, it is a base class that is
3308 being placed at OFFSET. */
3309
3310 static void
3311 record_subobject_offsets (tree type,
3312 tree offset,
3313 splay_tree offsets,
3314 bool is_data_member)
3315 {
3316 tree max_offset;
3317 /* If recording subobjects for a non-static data member or a
3318 non-empty base class , we do not need to record offsets beyond
3319 the size of the biggest empty class. Additional data members
3320 will go at the end of the class. Additional base classes will go
3321 either at offset zero (if empty, in which case they cannot
3322 overlap with offsets past the size of the biggest empty class) or
3323 at the end of the class.
3324
3325 However, if we are placing an empty base class, then we must record
3326 all offsets, as either the empty class is at offset zero (where
3327 other empty classes might later be placed) or at the end of the
3328 class (where other objects might then be placed, so other empty
3329 subobjects might later overlap). */
3330 if (is_data_member
3331 || !is_empty_class (BINFO_TYPE (type)))
3332 max_offset = sizeof_biggest_empty_class;
3333 else
3334 max_offset = NULL_TREE;
3335 walk_subobject_offsets (type, record_subobject_offset, offset,
3336 offsets, max_offset, is_data_member);
3337 }
3338
3339 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3340 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3341 virtual bases of TYPE are examined. */
3342
3343 static int
3344 layout_conflict_p (tree type,
3345 tree offset,
3346 splay_tree offsets,
3347 int vbases_p)
3348 {
3349 splay_tree_node max_node;
3350
3351 /* Get the node in OFFSETS that indicates the maximum offset where
3352 an empty subobject is located. */
3353 max_node = splay_tree_max (offsets);
3354 /* If there aren't any empty subobjects, then there's no point in
3355 performing this check. */
3356 if (!max_node)
3357 return 0;
3358
3359 return walk_subobject_offsets (type, check_subobject_offset, offset,
3360 offsets, (tree) (max_node->key),
3361 vbases_p);
3362 }
3363
3364 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3365 non-static data member of the type indicated by RLI. BINFO is the
3366 binfo corresponding to the base subobject, OFFSETS maps offsets to
3367 types already located at those offsets. This function determines
3368 the position of the DECL. */
3369
3370 static void
3371 layout_nonempty_base_or_field (record_layout_info rli,
3372 tree decl,
3373 tree binfo,
3374 splay_tree offsets)
3375 {
3376 tree offset = NULL_TREE;
3377 bool field_p;
3378 tree type;
3379
3380 if (binfo)
3381 {
3382 /* For the purposes of determining layout conflicts, we want to
3383 use the class type of BINFO; TREE_TYPE (DECL) will be the
3384 CLASSTYPE_AS_BASE version, which does not contain entries for
3385 zero-sized bases. */
3386 type = TREE_TYPE (binfo);
3387 field_p = false;
3388 }
3389 else
3390 {
3391 type = TREE_TYPE (decl);
3392 field_p = true;
3393 }
3394
3395 /* Try to place the field. It may take more than one try if we have
3396 a hard time placing the field without putting two objects of the
3397 same type at the same address. */
3398 while (1)
3399 {
3400 struct record_layout_info_s old_rli = *rli;
3401
3402 /* Place this field. */
3403 place_field (rli, decl);
3404 offset = byte_position (decl);
3405
3406 /* We have to check to see whether or not there is already
3407 something of the same type at the offset we're about to use.
3408 For example, consider:
3409
3410 struct S {};
3411 struct T : public S { int i; };
3412 struct U : public S, public T {};
3413
3414 Here, we put S at offset zero in U. Then, we can't put T at
3415 offset zero -- its S component would be at the same address
3416 as the S we already allocated. So, we have to skip ahead.
3417 Since all data members, including those whose type is an
3418 empty class, have nonzero size, any overlap can happen only
3419 with a direct or indirect base-class -- it can't happen with
3420 a data member. */
3421 /* In a union, overlap is permitted; all members are placed at
3422 offset zero. */
3423 if (TREE_CODE (rli->t) == UNION_TYPE)
3424 break;
3425 /* G++ 3.2 did not check for overlaps when placing a non-empty
3426 virtual base. */
3427 if (!abi_version_at_least (2) && binfo && BINFO_VIRTUAL_P (binfo))
3428 break;
3429 if (layout_conflict_p (field_p ? type : binfo, offset,
3430 offsets, field_p))
3431 {
3432 /* Strip off the size allocated to this field. That puts us
3433 at the first place we could have put the field with
3434 proper alignment. */
3435 *rli = old_rli;
3436
3437 /* Bump up by the alignment required for the type. */
3438 rli->bitpos
3439 = size_binop (PLUS_EXPR, rli->bitpos,
3440 bitsize_int (binfo
3441 ? CLASSTYPE_ALIGN (type)
3442 : TYPE_ALIGN (type)));
3443 normalize_rli (rli);
3444 }
3445 else
3446 /* There was no conflict. We're done laying out this field. */
3447 break;
3448 }
3449
3450 /* Now that we know where it will be placed, update its
3451 BINFO_OFFSET. */
3452 if (binfo && CLASS_TYPE_P (BINFO_TYPE (binfo)))
3453 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3454 this point because their BINFO_OFFSET is copied from another
3455 hierarchy. Therefore, we may not need to add the entire
3456 OFFSET. */
3457 propagate_binfo_offsets (binfo,
3458 size_diffop (convert (ssizetype, offset),
3459 convert (ssizetype,
3460 BINFO_OFFSET (binfo))));
3461 }
3462
3463 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3464
3465 static int
3466 empty_base_at_nonzero_offset_p (tree type,
3467 tree offset,
3468 splay_tree offsets ATTRIBUTE_UNUSED)
3469 {
3470 return is_empty_class (type) && !integer_zerop (offset);
3471 }
3472
3473 /* Layout the empty base BINFO. EOC indicates the byte currently just
3474 past the end of the class, and should be correctly aligned for a
3475 class of the type indicated by BINFO; OFFSETS gives the offsets of
3476 the empty bases allocated so far. T is the most derived
3477 type. Return nonzero iff we added it at the end. */
3478
3479 static bool
3480 layout_empty_base (tree binfo, tree eoc, splay_tree offsets)
3481 {
3482 tree alignment;
3483 tree basetype = BINFO_TYPE (binfo);
3484 bool atend = false;
3485
3486 /* This routine should only be used for empty classes. */
3487 gcc_assert (is_empty_class (basetype));
3488 alignment = ssize_int (CLASSTYPE_ALIGN_UNIT (basetype));
3489
3490 if (!integer_zerop (BINFO_OFFSET (binfo)))
3491 {
3492 if (abi_version_at_least (2))
3493 propagate_binfo_offsets
3494 (binfo, size_diffop (size_zero_node, BINFO_OFFSET (binfo)));
3495 else if (warn_abi)
3496 warning (0, "offset of empty base %qT may not be ABI-compliant and may"
3497 "change in a future version of GCC",
3498 BINFO_TYPE (binfo));
3499 }
3500
3501 /* This is an empty base class. We first try to put it at offset
3502 zero. */
3503 if (layout_conflict_p (binfo,
3504 BINFO_OFFSET (binfo),
3505 offsets,
3506 /*vbases_p=*/0))
3507 {
3508 /* That didn't work. Now, we move forward from the next
3509 available spot in the class. */
3510 atend = true;
3511 propagate_binfo_offsets (binfo, convert (ssizetype, eoc));
3512 while (1)
3513 {
3514 if (!layout_conflict_p (binfo,
3515 BINFO_OFFSET (binfo),
3516 offsets,
3517 /*vbases_p=*/0))
3518 /* We finally found a spot where there's no overlap. */
3519 break;
3520
3521 /* There's overlap here, too. Bump along to the next spot. */
3522 propagate_binfo_offsets (binfo, alignment);
3523 }
3524 }
3525 return atend;
3526 }
3527
3528 /* Layout the base given by BINFO in the class indicated by RLI.
3529 *BASE_ALIGN is a running maximum of the alignments of
3530 any base class. OFFSETS gives the location of empty base
3531 subobjects. T is the most derived type. Return nonzero if the new
3532 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3533 *NEXT_FIELD, unless BINFO is for an empty base class.
3534
3535 Returns the location at which the next field should be inserted. */
3536
3537 static tree *
3538 build_base_field (record_layout_info rli, tree binfo,
3539 splay_tree offsets, tree *next_field)
3540 {
3541 tree t = rli->t;
3542 tree basetype = BINFO_TYPE (binfo);
3543
3544 if (!COMPLETE_TYPE_P (basetype))
3545 /* This error is now reported in xref_tag, thus giving better
3546 location information. */
3547 return next_field;
3548
3549 /* Place the base class. */
3550 if (!is_empty_class (basetype))
3551 {
3552 tree decl;
3553
3554 /* The containing class is non-empty because it has a non-empty
3555 base class. */
3556 CLASSTYPE_EMPTY_P (t) = 0;
3557
3558 /* Create the FIELD_DECL. */
3559 decl = build_decl (FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype));
3560 DECL_ARTIFICIAL (decl) = 1;
3561 DECL_IGNORED_P (decl) = 1;
3562 DECL_FIELD_CONTEXT (decl) = t;
3563 DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype);
3564 DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype);
3565 DECL_ALIGN (decl) = CLASSTYPE_ALIGN (basetype);
3566 DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype);
3567 DECL_MODE (decl) = TYPE_MODE (basetype);
3568 DECL_FIELD_IS_BASE (decl) = 1;
3569
3570 /* Try to place the field. It may take more than one try if we
3571 have a hard time placing the field without putting two
3572 objects of the same type at the same address. */
3573 layout_nonempty_base_or_field (rli, decl, binfo, offsets);
3574 /* Add the new FIELD_DECL to the list of fields for T. */
3575 TREE_CHAIN (decl) = *next_field;
3576 *next_field = decl;
3577 next_field = &TREE_CHAIN (decl);
3578 }
3579 else
3580 {
3581 tree eoc;
3582 bool atend;
3583
3584 /* On some platforms (ARM), even empty classes will not be
3585 byte-aligned. */
3586 eoc = round_up (rli_size_unit_so_far (rli),
3587 CLASSTYPE_ALIGN_UNIT (basetype));
3588 atend = layout_empty_base (binfo, eoc, offsets);
3589 /* A nearly-empty class "has no proper base class that is empty,
3590 not morally virtual, and at an offset other than zero." */
3591 if (!BINFO_VIRTUAL_P (binfo) && CLASSTYPE_NEARLY_EMPTY_P (t))
3592 {
3593 if (atend)
3594 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3595 /* The check above (used in G++ 3.2) is insufficient because
3596 an empty class placed at offset zero might itself have an
3597 empty base at a nonzero offset. */
3598 else if (walk_subobject_offsets (basetype,
3599 empty_base_at_nonzero_offset_p,
3600 size_zero_node,
3601 /*offsets=*/NULL,
3602 /*max_offset=*/NULL_TREE,
3603 /*vbases_p=*/true))
3604 {
3605 if (abi_version_at_least (2))
3606 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3607 else if (warn_abi)
3608 warning (0, "class %qT will be considered nearly empty in a "
3609 "future version of GCC", t);
3610 }
3611 }
3612
3613 /* We do not create a FIELD_DECL for empty base classes because
3614 it might overlap some other field. We want to be able to
3615 create CONSTRUCTORs for the class by iterating over the
3616 FIELD_DECLs, and the back end does not handle overlapping
3617 FIELD_DECLs. */
3618
3619 /* An empty virtual base causes a class to be non-empty
3620 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3621 here because that was already done when the virtual table
3622 pointer was created. */
3623 }
3624
3625 /* Record the offsets of BINFO and its base subobjects. */
3626 record_subobject_offsets (binfo,
3627 BINFO_OFFSET (binfo),
3628 offsets,
3629 /*is_data_member=*/false);
3630
3631 return next_field;
3632 }
3633
3634 /* Layout all of the non-virtual base classes. Record empty
3635 subobjects in OFFSETS. T is the most derived type. Return nonzero
3636 if the type cannot be nearly empty. The fields created
3637 corresponding to the base classes will be inserted at
3638 *NEXT_FIELD. */
3639
3640 static void
3641 build_base_fields (record_layout_info rli,
3642 splay_tree offsets, tree *next_field)
3643 {
3644 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3645 subobjects. */
3646 tree t = rli->t;
3647 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
3648 int i;
3649
3650 /* The primary base class is always allocated first. */
3651 if (CLASSTYPE_HAS_PRIMARY_BASE_P (t))
3652 next_field = build_base_field (rli, CLASSTYPE_PRIMARY_BINFO (t),
3653 offsets, next_field);
3654
3655 /* Now allocate the rest of the bases. */
3656 for (i = 0; i < n_baseclasses; ++i)
3657 {
3658 tree base_binfo;
3659
3660 base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i);
3661
3662 /* The primary base was already allocated above, so we don't
3663 need to allocate it again here. */
3664 if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t))
3665 continue;
3666
3667 /* Virtual bases are added at the end (a primary virtual base
3668 will have already been added). */
3669 if (BINFO_VIRTUAL_P (base_binfo))
3670 continue;
3671
3672 next_field = build_base_field (rli, base_binfo,
3673 offsets, next_field);
3674 }
3675 }
3676
3677 /* Go through the TYPE_METHODS of T issuing any appropriate
3678 diagnostics, figuring out which methods override which other
3679 methods, and so forth. */
3680
3681 static void
3682 check_methods (tree t)
3683 {
3684 tree x;
3685
3686 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
3687 {
3688 check_for_override (x, t);
3689 if (DECL_PURE_VIRTUAL_P (x) && ! DECL_VINDEX (x))
3690 error ("initializer specified for non-virtual method %q+D", x);
3691 /* The name of the field is the original field name
3692 Save this in auxiliary field for later overloading. */
3693 if (DECL_VINDEX (x))
3694 {
3695 TYPE_POLYMORPHIC_P (t) = 1;
3696 if (DECL_PURE_VIRTUAL_P (x))
3697 VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x);
3698 }
3699 /* All user-declared destructors are non-trivial. */
3700 if (DECL_DESTRUCTOR_P (x))
3701 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = 1;
3702 }
3703 }
3704
3705 /* FN is a constructor or destructor. Clone the declaration to create
3706 a specialized in-charge or not-in-charge version, as indicated by
3707 NAME. */
3708
3709 static tree
3710 build_clone (tree fn, tree name)
3711 {
3712 tree parms;
3713 tree clone;
3714
3715 /* Copy the function. */
3716 clone = copy_decl (fn);
3717 /* Remember where this function came from. */
3718 DECL_CLONED_FUNCTION (clone) = fn;
3719 DECL_ABSTRACT_ORIGIN (clone) = fn;
3720 /* Reset the function name. */
3721 DECL_NAME (clone) = name;
3722 SET_DECL_ASSEMBLER_NAME (clone, NULL_TREE);
3723 /* There's no pending inline data for this function. */
3724 DECL_PENDING_INLINE_INFO (clone) = NULL;
3725 DECL_PENDING_INLINE_P (clone) = 0;
3726 /* And it hasn't yet been deferred. */
3727 DECL_DEFERRED_FN (clone) = 0;
3728
3729 /* The base-class destructor is not virtual. */
3730 if (name == base_dtor_identifier)
3731 {
3732 DECL_VIRTUAL_P (clone) = 0;
3733 if (TREE_CODE (clone) != TEMPLATE_DECL)
3734 DECL_VINDEX (clone) = NULL_TREE;
3735 }
3736
3737 /* If there was an in-charge parameter, drop it from the function
3738 type. */
3739 if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3740 {
3741 tree basetype;
3742 tree parmtypes;
3743 tree exceptions;
3744
3745 exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
3746 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
3747 parmtypes = TYPE_ARG_TYPES (TREE_TYPE (clone));
3748 /* Skip the `this' parameter. */
3749 parmtypes = TREE_CHAIN (parmtypes);
3750 /* Skip the in-charge parameter. */
3751 parmtypes = TREE_CHAIN (parmtypes);
3752 /* And the VTT parm, in a complete [cd]tor. */
3753 if (DECL_HAS_VTT_PARM_P (fn)
3754 && ! DECL_NEEDS_VTT_PARM_P (clone))
3755 parmtypes = TREE_CHAIN (parmtypes);
3756 /* If this is subobject constructor or destructor, add the vtt
3757 parameter. */
3758 TREE_TYPE (clone)
3759 = build_method_type_directly (basetype,
3760 TREE_TYPE (TREE_TYPE (clone)),
3761 parmtypes);
3762 if (exceptions)
3763 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone),
3764 exceptions);
3765 TREE_TYPE (clone)
3766 = cp_build_type_attribute_variant (TREE_TYPE (clone),
3767 TYPE_ATTRIBUTES (TREE_TYPE (fn)));
3768 }
3769
3770 /* Copy the function parameters. But, DECL_ARGUMENTS on a TEMPLATE_DECL
3771 aren't function parameters; those are the template parameters. */
3772 if (TREE_CODE (clone) != TEMPLATE_DECL)
3773 {
3774 DECL_ARGUMENTS (clone) = copy_list (DECL_ARGUMENTS (clone));
3775 /* Remove the in-charge parameter. */
3776 if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3777 {
3778 TREE_CHAIN (DECL_ARGUMENTS (clone))
3779 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3780 DECL_HAS_IN_CHARGE_PARM_P (clone) = 0;
3781 }
3782 /* And the VTT parm, in a complete [cd]tor. */
3783 if (DECL_HAS_VTT_PARM_P (fn))
3784 {
3785 if (DECL_NEEDS_VTT_PARM_P (clone))
3786 DECL_HAS_VTT_PARM_P (clone) = 1;
3787 else
3788 {
3789 TREE_CHAIN (DECL_ARGUMENTS (clone))
3790 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3791 DECL_HAS_VTT_PARM_P (clone) = 0;
3792 }
3793 }
3794
3795 for (parms = DECL_ARGUMENTS (clone); parms; parms = TREE_CHAIN (parms))
3796 {
3797 DECL_CONTEXT (parms) = clone;
3798 cxx_dup_lang_specific_decl (parms);
3799 }
3800 }
3801
3802 /* Create the RTL for this function. */
3803 SET_DECL_RTL (clone, NULL_RTX);
3804 rest_of_decl_compilation (clone, /*top_level=*/1, at_eof);
3805
3806 /* Make it easy to find the CLONE given the FN. */
3807 TREE_CHAIN (clone) = TREE_CHAIN (fn);
3808 TREE_CHAIN (fn) = clone;
3809
3810 /* If this is a template, handle the DECL_TEMPLATE_RESULT as well. */
3811 if (TREE_CODE (clone) == TEMPLATE_DECL)
3812 {
3813 tree result;
3814
3815 DECL_TEMPLATE_RESULT (clone)
3816 = build_clone (DECL_TEMPLATE_RESULT (clone), name);
3817 result = DECL_TEMPLATE_RESULT (clone);
3818 DECL_TEMPLATE_INFO (result) = copy_node (DECL_TEMPLATE_INFO (result));
3819 DECL_TI_TEMPLATE (result) = clone;
3820 }
3821 else if (pch_file)
3822 note_decl_for_pch (clone);
3823
3824 return clone;
3825 }
3826
3827 /* Produce declarations for all appropriate clones of FN. If
3828 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
3829 CLASTYPE_METHOD_VEC as well. */
3830
3831 void
3832 clone_function_decl (tree fn, int update_method_vec_p)
3833 {
3834 tree clone;
3835
3836 /* Avoid inappropriate cloning. */
3837 if (TREE_CHAIN (fn)
3838 && DECL_CLONED_FUNCTION (TREE_CHAIN (fn)))
3839 return;
3840
3841 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
3842 {
3843 /* For each constructor, we need two variants: an in-charge version
3844 and a not-in-charge version. */
3845 clone = build_clone (fn, complete_ctor_identifier);
3846 if (update_method_vec_p)
3847 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3848 clone = build_clone (fn, base_ctor_identifier);
3849 if (update_method_vec_p)
3850 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3851 }
3852 else
3853 {
3854 gcc_assert (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn));
3855
3856 /* For each destructor, we need three variants: an in-charge
3857 version, a not-in-charge version, and an in-charge deleting
3858 version. We clone the deleting version first because that
3859 means it will go second on the TYPE_METHODS list -- and that
3860 corresponds to the correct layout order in the virtual
3861 function table.
3862
3863 For a non-virtual destructor, we do not build a deleting
3864 destructor. */
3865 if (DECL_VIRTUAL_P (fn))
3866 {
3867 clone = build_clone (fn, deleting_dtor_identifier);
3868 if (update_method_vec_p)
3869 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3870 }
3871 clone = build_clone (fn, complete_dtor_identifier);
3872 if (update_method_vec_p)
3873 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3874 clone = build_clone (fn, base_dtor_identifier);
3875 if (update_method_vec_p)
3876 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3877 }
3878
3879 /* Note that this is an abstract function that is never emitted. */
3880 DECL_ABSTRACT (fn) = 1;
3881 }
3882
3883 /* DECL is an in charge constructor, which is being defined. This will
3884 have had an in class declaration, from whence clones were
3885 declared. An out-of-class definition can specify additional default
3886 arguments. As it is the clones that are involved in overload
3887 resolution, we must propagate the information from the DECL to its
3888 clones. */
3889
3890 void
3891 adjust_clone_args (tree decl)
3892 {
3893 tree clone;
3894
3895 for (clone = TREE_CHAIN (decl); clone && DECL_CLONED_FUNCTION (clone);
3896 clone = TREE_CHAIN (clone))
3897 {
3898 tree orig_clone_parms = TYPE_ARG_TYPES (TREE_TYPE (clone));
3899 tree orig_decl_parms = TYPE_ARG_TYPES (TREE_TYPE (decl));
3900 tree decl_parms, clone_parms;
3901
3902 clone_parms = orig_clone_parms;
3903
3904 /* Skip the 'this' parameter. */
3905 orig_clone_parms = TREE_CHAIN (orig_clone_parms);
3906 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3907
3908 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
3909 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3910 if (DECL_HAS_VTT_PARM_P (decl))
3911 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3912
3913 clone_parms = orig_clone_parms;
3914 if (DECL_HAS_VTT_PARM_P (clone))
3915 clone_parms = TREE_CHAIN (clone_parms);
3916
3917 for (decl_parms = orig_decl_parms; decl_parms;
3918 decl_parms = TREE_CHAIN (decl_parms),
3919 clone_parms = TREE_CHAIN (clone_parms))
3920 {
3921 gcc_assert (same_type_p (TREE_TYPE (decl_parms),
3922 TREE_TYPE (clone_parms)));
3923
3924 if (TREE_PURPOSE (decl_parms) && !TREE_PURPOSE (clone_parms))
3925 {
3926 /* A default parameter has been added. Adjust the
3927 clone's parameters. */
3928 tree exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
3929 tree basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
3930 tree type;
3931
3932 clone_parms = orig_decl_parms;
3933
3934 if (DECL_HAS_VTT_PARM_P (clone))
3935 {
3936 clone_parms = tree_cons (TREE_PURPOSE (orig_clone_parms),
3937 TREE_VALUE (orig_clone_parms),
3938 clone_parms);
3939 TREE_TYPE (clone_parms) = TREE_TYPE (orig_clone_parms);
3940 }
3941 type = build_method_type_directly (basetype,
3942 TREE_TYPE (TREE_TYPE (clone)),
3943 clone_parms);
3944 if (exceptions)
3945 type = build_exception_variant (type, exceptions);
3946 TREE_TYPE (clone) = type;
3947
3948 clone_parms = NULL_TREE;
3949 break;
3950 }
3951 }
3952 gcc_assert (!clone_parms);
3953 }
3954 }
3955
3956 /* For each of the constructors and destructors in T, create an
3957 in-charge and not-in-charge variant. */
3958
3959 static void
3960 clone_constructors_and_destructors (tree t)
3961 {
3962 tree fns;
3963
3964 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
3965 out now. */
3966 if (!CLASSTYPE_METHOD_VEC (t))
3967 return;
3968
3969 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
3970 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
3971 for (fns = CLASSTYPE_DESTRUCTORS (t); fns; fns = OVL_NEXT (fns))
3972 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
3973 }
3974
3975 /* Remove all zero-width bit-fields from T. */
3976
3977 static void
3978 remove_zero_width_bit_fields (tree t)
3979 {
3980 tree *fieldsp;
3981
3982 fieldsp = &TYPE_FIELDS (t);
3983 while (*fieldsp)
3984 {
3985 if (TREE_CODE (*fieldsp) == FIELD_DECL
3986 && DECL_C_BIT_FIELD (*fieldsp)
3987 && DECL_INITIAL (*fieldsp))
3988 *fieldsp = TREE_CHAIN (*fieldsp);
3989 else
3990 fieldsp = &TREE_CHAIN (*fieldsp);
3991 }
3992 }
3993
3994 /* Returns TRUE iff we need a cookie when dynamically allocating an
3995 array whose elements have the indicated class TYPE. */
3996
3997 static bool
3998 type_requires_array_cookie (tree type)
3999 {
4000 tree fns;
4001 bool has_two_argument_delete_p = false;
4002
4003 gcc_assert (CLASS_TYPE_P (type));
4004
4005 /* If there's a non-trivial destructor, we need a cookie. In order
4006 to iterate through the array calling the destructor for each
4007 element, we'll have to know how many elements there are. */
4008 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
4009 return true;
4010
4011 /* If the usual deallocation function is a two-argument whose second
4012 argument is of type `size_t', then we have to pass the size of
4013 the array to the deallocation function, so we will need to store
4014 a cookie. */
4015 fns = lookup_fnfields (TYPE_BINFO (type),
4016 ansi_opname (VEC_DELETE_EXPR),
4017 /*protect=*/0);
4018 /* If there are no `operator []' members, or the lookup is
4019 ambiguous, then we don't need a cookie. */
4020 if (!fns || fns == error_mark_node)
4021 return false;
4022 /* Loop through all of the functions. */
4023 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
4024 {
4025 tree fn;
4026 tree second_parm;
4027
4028 /* Select the current function. */
4029 fn = OVL_CURRENT (fns);
4030 /* See if this function is a one-argument delete function. If
4031 it is, then it will be the usual deallocation function. */
4032 second_parm = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fn)));
4033 if (second_parm == void_list_node)
4034 return false;
4035 /* Otherwise, if we have a two-argument function and the second
4036 argument is `size_t', it will be the usual deallocation
4037 function -- unless there is one-argument function, too. */
4038 if (TREE_CHAIN (second_parm) == void_list_node
4039 && same_type_p (TREE_VALUE (second_parm), sizetype))
4040 has_two_argument_delete_p = true;
4041 }
4042
4043 return has_two_argument_delete_p;
4044 }
4045
4046 /* Check the validity of the bases and members declared in T. Add any
4047 implicitly-generated functions (like copy-constructors and
4048 assignment operators). Compute various flag bits (like
4049 CLASSTYPE_NON_POD_T) for T. This routine works purely at the C++
4050 level: i.e., independently of the ABI in use. */
4051
4052 static void
4053 check_bases_and_members (tree t)
4054 {
4055 /* Nonzero if the implicitly generated copy constructor should take
4056 a non-const reference argument. */
4057 int cant_have_const_ctor;
4058 /* Nonzero if the implicitly generated assignment operator
4059 should take a non-const reference argument. */
4060 int no_const_asn_ref;
4061 tree access_decls;
4062
4063 /* By default, we use const reference arguments and generate default
4064 constructors. */
4065 cant_have_const_ctor = 0;
4066 no_const_asn_ref = 0;
4067
4068 /* Check all the base-classes. */
4069 check_bases (t, &cant_have_const_ctor,
4070 &no_const_asn_ref);
4071
4072 /* Check all the method declarations. */
4073 check_methods (t);
4074
4075 /* Check all the data member declarations. We cannot call
4076 check_field_decls until we have called check_bases check_methods,
4077 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
4078 being set appropriately. */
4079 check_field_decls (t, &access_decls,
4080 &cant_have_const_ctor,
4081 &no_const_asn_ref);
4082
4083 /* A nearly-empty class has to be vptr-containing; a nearly empty
4084 class contains just a vptr. */
4085 if (!TYPE_CONTAINS_VPTR_P (t))
4086 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
4087
4088 /* Do some bookkeeping that will guide the generation of implicitly
4089 declared member functions. */
4090 TYPE_HAS_COMPLEX_INIT_REF (t)
4091 |= (TYPE_HAS_INIT_REF (t) || TYPE_CONTAINS_VPTR_P (t));
4092 TYPE_NEEDS_CONSTRUCTING (t)
4093 |= (TYPE_HAS_CONSTRUCTOR (t) || TYPE_CONTAINS_VPTR_P (t));
4094 CLASSTYPE_NON_AGGREGATE (t)
4095 |= (TYPE_HAS_CONSTRUCTOR (t) || TYPE_POLYMORPHIC_P (t));
4096 CLASSTYPE_NON_POD_P (t)
4097 |= (CLASSTYPE_NON_AGGREGATE (t)
4098 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
4099 || TYPE_HAS_ASSIGN_REF (t));
4100 TYPE_HAS_COMPLEX_ASSIGN_REF (t)
4101 |= TYPE_HAS_ASSIGN_REF (t) || TYPE_CONTAINS_VPTR_P (t);
4102
4103 /* Synthesize any needed methods. */
4104 add_implicitly_declared_members (t,
4105 cant_have_const_ctor,
4106 no_const_asn_ref);
4107
4108 /* Create the in-charge and not-in-charge variants of constructors
4109 and destructors. */
4110 clone_constructors_and_destructors (t);
4111
4112 /* Process the using-declarations. */
4113 for (; access_decls; access_decls = TREE_CHAIN (access_decls))
4114 handle_using_decl (TREE_VALUE (access_decls), t);
4115
4116 /* Build and sort the CLASSTYPE_METHOD_VEC. */
4117 finish_struct_methods (t);
4118
4119 /* Figure out whether or not we will need a cookie when dynamically
4120 allocating an array of this type. */
4121 TYPE_LANG_SPECIFIC (t)->u.c.vec_new_uses_cookie
4122 = type_requires_array_cookie (t);
4123 }
4124
4125 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4126 accordingly. If a new vfield was created (because T doesn't have a
4127 primary base class), then the newly created field is returned. It
4128 is not added to the TYPE_FIELDS list; it is the caller's
4129 responsibility to do that. Accumulate declared virtual functions
4130 on VIRTUALS_P. */
4131
4132 static tree
4133 create_vtable_ptr (tree t, tree* virtuals_p)
4134 {
4135 tree fn;
4136
4137 /* Collect the virtual functions declared in T. */
4138 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
4139 if (DECL_VINDEX (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)
4140 && TREE_CODE (DECL_VINDEX (fn)) != INTEGER_CST)
4141 {
4142 tree new_virtual = make_node (TREE_LIST);
4143
4144 BV_FN (new_virtual) = fn;
4145 BV_DELTA (new_virtual) = integer_zero_node;
4146 BV_VCALL_INDEX (new_virtual) = NULL_TREE;
4147
4148 TREE_CHAIN (new_virtual) = *virtuals_p;
4149 *virtuals_p = new_virtual;
4150 }
4151
4152 /* If we couldn't find an appropriate base class, create a new field
4153 here. Even if there weren't any new virtual functions, we might need a
4154 new virtual function table if we're supposed to include vptrs in
4155 all classes that need them. */
4156 if (!TYPE_VFIELD (t) && (*virtuals_p || TYPE_CONTAINS_VPTR_P (t)))
4157 {
4158 /* We build this decl with vtbl_ptr_type_node, which is a
4159 `vtable_entry_type*'. It might seem more precise to use
4160 `vtable_entry_type (*)[N]' where N is the number of virtual
4161 functions. However, that would require the vtable pointer in
4162 base classes to have a different type than the vtable pointer
4163 in derived classes. We could make that happen, but that
4164 still wouldn't solve all the problems. In particular, the
4165 type-based alias analysis code would decide that assignments
4166 to the base class vtable pointer can't alias assignments to
4167 the derived class vtable pointer, since they have different
4168 types. Thus, in a derived class destructor, where the base
4169 class constructor was inlined, we could generate bad code for
4170 setting up the vtable pointer.
4171
4172 Therefore, we use one type for all vtable pointers. We still
4173 use a type-correct type; it's just doesn't indicate the array
4174 bounds. That's better than using `void*' or some such; it's
4175 cleaner, and it let's the alias analysis code know that these
4176 stores cannot alias stores to void*! */
4177 tree field;
4178
4179 field = build_decl (FIELD_DECL, get_vfield_name (t), vtbl_ptr_type_node);
4180 DECL_VIRTUAL_P (field) = 1;
4181 DECL_ARTIFICIAL (field) = 1;
4182 DECL_FIELD_CONTEXT (field) = t;
4183 DECL_FCONTEXT (field) = t;
4184
4185 TYPE_VFIELD (t) = field;
4186
4187 /* This class is non-empty. */
4188 CLASSTYPE_EMPTY_P (t) = 0;
4189
4190 return field;
4191 }
4192
4193 return NULL_TREE;
4194 }
4195
4196 /* Fixup the inline function given by INFO now that the class is
4197 complete. */
4198
4199 static void
4200 fixup_pending_inline (tree fn)
4201 {
4202 if (DECL_PENDING_INLINE_INFO (fn))
4203 {
4204 tree args = DECL_ARGUMENTS (fn);
4205 while (args)
4206 {
4207 DECL_CONTEXT (args) = fn;
4208 args = TREE_CHAIN (args);
4209 }
4210 }
4211 }
4212
4213 /* Fixup the inline methods and friends in TYPE now that TYPE is
4214 complete. */
4215
4216 static void
4217 fixup_inline_methods (tree type)
4218 {
4219 tree method = TYPE_METHODS (type);
4220 VEC(tree,gc) *friends;
4221 unsigned ix;
4222
4223 if (method && TREE_CODE (method) == TREE_VEC)
4224 {
4225 if (TREE_VEC_ELT (method, 1))
4226 method = TREE_VEC_ELT (method, 1);
4227 else if (TREE_VEC_ELT (method, 0))
4228 method = TREE_VEC_ELT (method, 0);
4229 else
4230 method = TREE_VEC_ELT (method, 2);
4231 }
4232
4233 /* Do inline member functions. */
4234 for (; method; method = TREE_CHAIN (method))
4235 fixup_pending_inline (method);
4236
4237 /* Do friends. */
4238 for (friends = CLASSTYPE_INLINE_FRIENDS (type), ix = 0;
4239 VEC_iterate (tree, friends, ix, method); ix++)
4240 fixup_pending_inline (method);
4241 CLASSTYPE_INLINE_FRIENDS (type) = NULL;
4242 }
4243
4244 /* Add OFFSET to all base types of BINFO which is a base in the
4245 hierarchy dominated by T.
4246
4247 OFFSET, which is a type offset, is number of bytes. */
4248
4249 static void
4250 propagate_binfo_offsets (tree binfo, tree offset)
4251 {
4252 int i;
4253 tree primary_binfo;
4254 tree base_binfo;
4255
4256 /* Update BINFO's offset. */
4257 BINFO_OFFSET (binfo)
4258 = convert (sizetype,
4259 size_binop (PLUS_EXPR,
4260 convert (ssizetype, BINFO_OFFSET (binfo)),
4261 offset));
4262
4263 /* Find the primary base class. */
4264 primary_binfo = get_primary_binfo (binfo);
4265
4266 if (primary_binfo && BINFO_INHERITANCE_CHAIN (primary_binfo) == binfo)
4267 propagate_binfo_offsets (primary_binfo, offset);
4268
4269 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4270 downwards. */
4271 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4272 {
4273 /* Don't do the primary base twice. */
4274 if (base_binfo == primary_binfo)
4275 continue;
4276
4277 if (BINFO_VIRTUAL_P (base_binfo))
4278 continue;
4279
4280 propagate_binfo_offsets (base_binfo, offset);
4281 }
4282 }
4283
4284 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
4285 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
4286 empty subobjects of T. */
4287
4288 static void
4289 layout_virtual_bases (record_layout_info rli, splay_tree offsets)
4290 {
4291 tree vbase;
4292 tree t = rli->t;
4293 bool first_vbase = true;
4294 tree *next_field;
4295
4296 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) == 0)
4297 return;
4298
4299 if (!abi_version_at_least(2))
4300 {
4301 /* In G++ 3.2, we incorrectly rounded the size before laying out
4302 the virtual bases. */
4303 finish_record_layout (rli, /*free_p=*/false);
4304 #ifdef STRUCTURE_SIZE_BOUNDARY
4305 /* Packed structures don't need to have minimum size. */
4306 if (! TYPE_PACKED (t))
4307 TYPE_ALIGN (t) = MAX (TYPE_ALIGN (t), (unsigned) STRUCTURE_SIZE_BOUNDARY);
4308 #endif
4309 rli->offset = TYPE_SIZE_UNIT (t);
4310 rli->bitpos = bitsize_zero_node;
4311 rli->record_align = TYPE_ALIGN (t);
4312 }
4313
4314 /* Find the last field. The artificial fields created for virtual
4315 bases will go after the last extant field to date. */
4316 next_field = &TYPE_FIELDS (t);
4317 while (*next_field)
4318 next_field = &TREE_CHAIN (*next_field);
4319
4320 /* Go through the virtual bases, allocating space for each virtual
4321 base that is not already a primary base class. These are
4322 allocated in inheritance graph order. */
4323 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
4324 {
4325 if (!BINFO_VIRTUAL_P (vbase))
4326 continue;
4327
4328 if (!BINFO_PRIMARY_P (vbase))
4329 {
4330 tree basetype = TREE_TYPE (vbase);
4331
4332 /* This virtual base is not a primary base of any class in the
4333 hierarchy, so we have to add space for it. */
4334 next_field = build_base_field (rli, vbase,
4335 offsets, next_field);
4336
4337 /* If the first virtual base might have been placed at a
4338 lower address, had we started from CLASSTYPE_SIZE, rather
4339 than TYPE_SIZE, issue a warning. There can be both false
4340 positives and false negatives from this warning in rare
4341 cases; to deal with all the possibilities would probably
4342 require performing both layout algorithms and comparing
4343 the results which is not particularly tractable. */
4344 if (warn_abi
4345 && first_vbase
4346 && (tree_int_cst_lt
4347 (size_binop (CEIL_DIV_EXPR,
4348 round_up (CLASSTYPE_SIZE (t),
4349 CLASSTYPE_ALIGN (basetype)),
4350 bitsize_unit_node),
4351 BINFO_OFFSET (vbase))))
4352 warning (0, "offset of virtual base %qT is not ABI-compliant and "
4353 "may change in a future version of GCC",
4354 basetype);
4355
4356 first_vbase = false;
4357 }
4358 }
4359 }
4360
4361 /* Returns the offset of the byte just past the end of the base class
4362 BINFO. */
4363
4364 static tree
4365 end_of_base (tree binfo)
4366 {
4367 tree size;
4368
4369 if (is_empty_class (BINFO_TYPE (binfo)))
4370 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4371 allocate some space for it. It cannot have virtual bases, so
4372 TYPE_SIZE_UNIT is fine. */
4373 size = TYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4374 else
4375 size = CLASSTYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4376
4377 return size_binop (PLUS_EXPR, BINFO_OFFSET (binfo), size);
4378 }
4379
4380 /* Returns the offset of the byte just past the end of the base class
4381 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
4382 only non-virtual bases are included. */
4383
4384 static tree
4385 end_of_class (tree t, int include_virtuals_p)
4386 {
4387 tree result = size_zero_node;
4388 VEC(tree,gc) *vbases;
4389 tree binfo;
4390 tree base_binfo;
4391 tree offset;
4392 int i;
4393
4394 for (binfo = TYPE_BINFO (t), i = 0;
4395 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4396 {
4397 if (!include_virtuals_p
4398 && BINFO_VIRTUAL_P (base_binfo)
4399 && (!BINFO_PRIMARY_P (base_binfo)
4400 || BINFO_INHERITANCE_CHAIN (base_binfo) != TYPE_BINFO (t)))
4401 continue;
4402
4403 offset = end_of_base (base_binfo);
4404 if (INT_CST_LT_UNSIGNED (result, offset))
4405 result = offset;
4406 }
4407
4408 /* G++ 3.2 did not check indirect virtual bases. */
4409 if (abi_version_at_least (2) && include_virtuals_p)
4410 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4411 VEC_iterate (tree, vbases, i, base_binfo); i++)
4412 {
4413 offset = end_of_base (base_binfo);
4414 if (INT_CST_LT_UNSIGNED (result, offset))
4415 result = offset;
4416 }
4417
4418 return result;
4419 }
4420
4421 /* Warn about bases of T that are inaccessible because they are
4422 ambiguous. For example:
4423
4424 struct S {};
4425 struct T : public S {};
4426 struct U : public S, public T {};
4427
4428 Here, `(S*) new U' is not allowed because there are two `S'
4429 subobjects of U. */
4430
4431 static void
4432 warn_about_ambiguous_bases (tree t)
4433 {
4434 int i;
4435 VEC(tree,gc) *vbases;
4436 tree basetype;
4437 tree binfo;
4438 tree base_binfo;
4439
4440 /* If there are no repeated bases, nothing can be ambiguous. */
4441 if (!CLASSTYPE_REPEATED_BASE_P (t))
4442 return;
4443
4444 /* Check direct bases. */
4445 for (binfo = TYPE_BINFO (t), i = 0;
4446 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4447 {
4448 basetype = BINFO_TYPE (base_binfo);
4449
4450 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4451 warning (0, "direct base %qT inaccessible in %qT due to ambiguity",
4452 basetype, t);
4453 }
4454
4455 /* Check for ambiguous virtual bases. */
4456 if (extra_warnings)
4457 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4458 VEC_iterate (tree, vbases, i, binfo); i++)
4459 {
4460 basetype = BINFO_TYPE (binfo);
4461
4462 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4463 warning (0, "virtual base %qT inaccessible in %qT due to ambiguity",
4464 basetype, t);
4465 }
4466 }
4467
4468 /* Compare two INTEGER_CSTs K1 and K2. */
4469
4470 static int
4471 splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2)
4472 {
4473 return tree_int_cst_compare ((tree) k1, (tree) k2);
4474 }
4475
4476 /* Increase the size indicated in RLI to account for empty classes
4477 that are "off the end" of the class. */
4478
4479 static void
4480 include_empty_classes (record_layout_info rli)
4481 {
4482 tree eoc;
4483 tree rli_size;
4484
4485 /* It might be the case that we grew the class to allocate a
4486 zero-sized base class. That won't be reflected in RLI, yet,
4487 because we are willing to overlay multiple bases at the same
4488 offset. However, now we need to make sure that RLI is big enough
4489 to reflect the entire class. */
4490 eoc = end_of_class (rli->t,
4491 CLASSTYPE_AS_BASE (rli->t) != NULL_TREE);
4492 rli_size = rli_size_unit_so_far (rli);
4493 if (TREE_CODE (rli_size) == INTEGER_CST
4494 && INT_CST_LT_UNSIGNED (rli_size, eoc))
4495 {
4496 if (!abi_version_at_least (2))
4497 /* In version 1 of the ABI, the size of a class that ends with
4498 a bitfield was not rounded up to a whole multiple of a
4499 byte. Because rli_size_unit_so_far returns only the number
4500 of fully allocated bytes, any extra bits were not included
4501 in the size. */
4502 rli->bitpos = round_down (rli->bitpos, BITS_PER_UNIT);
4503 else
4504 /* The size should have been rounded to a whole byte. */
4505 gcc_assert (tree_int_cst_equal
4506 (rli->bitpos, round_down (rli->bitpos, BITS_PER_UNIT)));
4507 rli->bitpos
4508 = size_binop (PLUS_EXPR,
4509 rli->bitpos,
4510 size_binop (MULT_EXPR,
4511 convert (bitsizetype,
4512 size_binop (MINUS_EXPR,
4513 eoc, rli_size)),
4514 bitsize_int (BITS_PER_UNIT)));
4515 normalize_rli (rli);
4516 }
4517 }
4518
4519 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
4520 BINFO_OFFSETs for all of the base-classes. Position the vtable
4521 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
4522
4523 static void
4524 layout_class_type (tree t, tree *virtuals_p)
4525 {
4526 tree non_static_data_members;
4527 tree field;
4528 tree vptr;
4529 record_layout_info rli;
4530 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4531 types that appear at that offset. */
4532 splay_tree empty_base_offsets;
4533 /* True if the last field layed out was a bit-field. */
4534 bool last_field_was_bitfield = false;
4535 /* The location at which the next field should be inserted. */
4536 tree *next_field;
4537 /* T, as a base class. */
4538 tree base_t;
4539
4540 /* Keep track of the first non-static data member. */
4541 non_static_data_members = TYPE_FIELDS (t);
4542
4543 /* Start laying out the record. */
4544 rli = start_record_layout (t);
4545
4546 /* Mark all the primary bases in the hierarchy. */
4547 determine_primary_bases (t);
4548
4549 /* Create a pointer to our virtual function table. */
4550 vptr = create_vtable_ptr (t, virtuals_p);
4551
4552 /* The vptr is always the first thing in the class. */
4553 if (vptr)
4554 {
4555 TREE_CHAIN (vptr) = TYPE_FIELDS (t);
4556 TYPE_FIELDS (t) = vptr;
4557 next_field = &TREE_CHAIN (vptr);
4558 place_field (rli, vptr);
4559 }
4560 else
4561 next_field = &TYPE_FIELDS (t);
4562
4563 /* Build FIELD_DECLs for all of the non-virtual base-types. */
4564 empty_base_offsets = splay_tree_new (splay_tree_compare_integer_csts,
4565 NULL, NULL);
4566 build_base_fields (rli, empty_base_offsets, next_field);
4567
4568 /* Layout the non-static data members. */
4569 for (field = non_static_data_members; field; field = TREE_CHAIN (field))
4570 {
4571 tree type;
4572 tree padding;
4573
4574 /* We still pass things that aren't non-static data members to
4575 the back-end, in case it wants to do something with them. */
4576 if (TREE_CODE (field) != FIELD_DECL)
4577 {
4578 place_field (rli, field);
4579 /* If the static data member has incomplete type, keep track
4580 of it so that it can be completed later. (The handling
4581 of pending statics in finish_record_layout is
4582 insufficient; consider:
4583
4584 struct S1;
4585 struct S2 { static S1 s1; };
4586
4587 At this point, finish_record_layout will be called, but
4588 S1 is still incomplete.) */
4589 if (TREE_CODE (field) == VAR_DECL)
4590 {
4591 maybe_register_incomplete_var (field);
4592 /* The visibility of static data members is determined
4593 at their point of declaration, not their point of
4594 definition. */
4595 determine_visibility (field);
4596 }
4597 continue;
4598 }
4599
4600 type = TREE_TYPE (field);
4601
4602 padding = NULL_TREE;
4603
4604 /* If this field is a bit-field whose width is greater than its
4605 type, then there are some special rules for allocating
4606 it. */
4607 if (DECL_C_BIT_FIELD (field)
4608 && INT_CST_LT (TYPE_SIZE (type), DECL_SIZE (field)))
4609 {
4610 integer_type_kind itk;
4611 tree integer_type;
4612 bool was_unnamed_p = false;
4613 /* We must allocate the bits as if suitably aligned for the
4614 longest integer type that fits in this many bits. type
4615 of the field. Then, we are supposed to use the left over
4616 bits as additional padding. */
4617 for (itk = itk_char; itk != itk_none; ++itk)
4618 if (INT_CST_LT (DECL_SIZE (field),
4619 TYPE_SIZE (integer_types[itk])))
4620 break;
4621
4622 /* ITK now indicates a type that is too large for the
4623 field. We have to back up by one to find the largest
4624 type that fits. */
4625 integer_type = integer_types[itk - 1];
4626
4627 /* Figure out how much additional padding is required. GCC
4628 3.2 always created a padding field, even if it had zero
4629 width. */
4630 if (!abi_version_at_least (2)
4631 || INT_CST_LT (TYPE_SIZE (integer_type), DECL_SIZE (field)))
4632 {
4633 if (abi_version_at_least (2) && TREE_CODE (t) == UNION_TYPE)
4634 /* In a union, the padding field must have the full width
4635 of the bit-field; all fields start at offset zero. */
4636 padding = DECL_SIZE (field);
4637 else
4638 {
4639 if (warn_abi && TREE_CODE (t) == UNION_TYPE)
4640 warning (0, "size assigned to %qT may not be "
4641 "ABI-compliant and may change in a future "
4642 "version of GCC",
4643 t);
4644 padding = size_binop (MINUS_EXPR, DECL_SIZE (field),
4645 TYPE_SIZE (integer_type));
4646 }
4647 }
4648 #ifdef PCC_BITFIELD_TYPE_MATTERS
4649 /* An unnamed bitfield does not normally affect the
4650 alignment of the containing class on a target where
4651 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
4652 make any exceptions for unnamed bitfields when the
4653 bitfields are longer than their types. Therefore, we
4654 temporarily give the field a name. */
4655 if (PCC_BITFIELD_TYPE_MATTERS && !DECL_NAME (field))
4656 {
4657 was_unnamed_p = true;
4658 DECL_NAME (field) = make_anon_name ();
4659 }
4660 #endif
4661 DECL_SIZE (field) = TYPE_SIZE (integer_type);
4662 DECL_ALIGN (field) = TYPE_ALIGN (integer_type);
4663 DECL_USER_ALIGN (field) = TYPE_USER_ALIGN (integer_type);
4664 layout_nonempty_base_or_field (rli, field, NULL_TREE,
4665 empty_base_offsets);
4666 if (was_unnamed_p)
4667 DECL_NAME (field) = NULL_TREE;
4668 /* Now that layout has been performed, set the size of the
4669 field to the size of its declared type; the rest of the
4670 field is effectively invisible. */
4671 DECL_SIZE (field) = TYPE_SIZE (type);
4672 /* We must also reset the DECL_MODE of the field. */
4673 if (abi_version_at_least (2))
4674 DECL_MODE (field) = TYPE_MODE (type);
4675 else if (warn_abi
4676 && DECL_MODE (field) != TYPE_MODE (type))
4677 /* Versions of G++ before G++ 3.4 did not reset the
4678 DECL_MODE. */
4679 warning (0, "the offset of %qD may not be ABI-compliant and may "
4680 "change in a future version of GCC", field);
4681 }
4682 else
4683 layout_nonempty_base_or_field (rli, field, NULL_TREE,
4684 empty_base_offsets);
4685
4686 /* Remember the location of any empty classes in FIELD. */
4687 if (abi_version_at_least (2))
4688 record_subobject_offsets (TREE_TYPE (field),
4689 byte_position(field),
4690 empty_base_offsets,
4691 /*is_data_member=*/true);
4692
4693 /* If a bit-field does not immediately follow another bit-field,
4694 and yet it starts in the middle of a byte, we have failed to
4695 comply with the ABI. */
4696 if (warn_abi
4697 && DECL_C_BIT_FIELD (field)
4698 /* The TREE_NO_WARNING flag gets set by Objective-C when
4699 laying out an Objective-C class. The ObjC ABI differs
4700 from the C++ ABI, and so we do not want a warning
4701 here. */
4702 && !TREE_NO_WARNING (field)
4703 && !last_field_was_bitfield
4704 && !integer_zerop (size_binop (TRUNC_MOD_EXPR,
4705 DECL_FIELD_BIT_OFFSET (field),
4706 bitsize_unit_node)))
4707 warning (0, "offset of %q+D is not ABI-compliant and may "
4708 "change in a future version of GCC", field);
4709
4710 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
4711 offset of the field. */
4712 if (warn_abi
4713 && !tree_int_cst_equal (DECL_FIELD_OFFSET (field),
4714 byte_position (field))
4715 && contains_empty_class_p (TREE_TYPE (field)))
4716 warning (0, "%q+D contains empty classes which may cause base "
4717 "classes to be placed at different locations in a "
4718 "future version of GCC", field);
4719
4720 /* If we needed additional padding after this field, add it
4721 now. */
4722 if (padding)
4723 {
4724 tree padding_field;
4725
4726 padding_field = build_decl (FIELD_DECL,
4727 NULL_TREE,
4728 char_type_node);
4729 DECL_BIT_FIELD (padding_field) = 1;
4730 DECL_SIZE (padding_field) = padding;
4731 DECL_CONTEXT (padding_field) = t;
4732 DECL_ARTIFICIAL (padding_field) = 1;
4733 DECL_IGNORED_P (padding_field) = 1;
4734 layout_nonempty_base_or_field (rli, padding_field,
4735 NULL_TREE,
4736 empty_base_offsets);
4737 }
4738
4739 last_field_was_bitfield = DECL_C_BIT_FIELD (field);
4740 }
4741
4742 if (abi_version_at_least (2) && !integer_zerop (rli->bitpos))
4743 {
4744 /* Make sure that we are on a byte boundary so that the size of
4745 the class without virtual bases will always be a round number
4746 of bytes. */
4747 rli->bitpos = round_up (rli->bitpos, BITS_PER_UNIT);
4748 normalize_rli (rli);
4749 }
4750
4751 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
4752 padding. */
4753 if (!abi_version_at_least (2))
4754 include_empty_classes(rli);
4755
4756 /* Delete all zero-width bit-fields from the list of fields. Now
4757 that the type is laid out they are no longer important. */
4758 remove_zero_width_bit_fields (t);
4759
4760 /* Create the version of T used for virtual bases. We do not use
4761 make_aggr_type for this version; this is an artificial type. For
4762 a POD type, we just reuse T. */
4763 if (CLASSTYPE_NON_POD_P (t) || CLASSTYPE_EMPTY_P (t))
4764 {
4765 base_t = make_node (TREE_CODE (t));
4766
4767 /* Set the size and alignment for the new type. In G++ 3.2, all
4768 empty classes were considered to have size zero when used as
4769 base classes. */
4770 if (!abi_version_at_least (2) && CLASSTYPE_EMPTY_P (t))
4771 {
4772 TYPE_SIZE (base_t) = bitsize_zero_node;
4773 TYPE_SIZE_UNIT (base_t) = size_zero_node;
4774 if (warn_abi && !integer_zerop (rli_size_unit_so_far (rli)))
4775 warning (0, "layout of classes derived from empty class %qT "
4776 "may change in a future version of GCC",
4777 t);
4778 }
4779 else
4780 {
4781 tree eoc;
4782
4783 /* If the ABI version is not at least two, and the last
4784 field was a bit-field, RLI may not be on a byte
4785 boundary. In particular, rli_size_unit_so_far might
4786 indicate the last complete byte, while rli_size_so_far
4787 indicates the total number of bits used. Therefore,
4788 rli_size_so_far, rather than rli_size_unit_so_far, is
4789 used to compute TYPE_SIZE_UNIT. */
4790 eoc = end_of_class (t, /*include_virtuals_p=*/0);
4791 TYPE_SIZE_UNIT (base_t)
4792 = size_binop (MAX_EXPR,
4793 convert (sizetype,
4794 size_binop (CEIL_DIV_EXPR,
4795 rli_size_so_far (rli),
4796 bitsize_int (BITS_PER_UNIT))),
4797 eoc);
4798 TYPE_SIZE (base_t)
4799 = size_binop (MAX_EXPR,
4800 rli_size_so_far (rli),
4801 size_binop (MULT_EXPR,
4802 convert (bitsizetype, eoc),
4803 bitsize_int (BITS_PER_UNIT)));
4804 }
4805 TYPE_ALIGN (base_t) = rli->record_align;
4806 TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t);
4807
4808 /* Copy the fields from T. */
4809 next_field = &TYPE_FIELDS (base_t);
4810 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
4811 if (TREE_CODE (field) == FIELD_DECL)
4812 {
4813 *next_field = build_decl (FIELD_DECL,
4814 DECL_NAME (field),
4815 TREE_TYPE (field));
4816 DECL_CONTEXT (*next_field) = base_t;
4817 DECL_FIELD_OFFSET (*next_field) = DECL_FIELD_OFFSET (field);
4818 DECL_FIELD_BIT_OFFSET (*next_field)
4819 = DECL_FIELD_BIT_OFFSET (field);
4820 DECL_SIZE (*next_field) = DECL_SIZE (field);
4821 DECL_MODE (*next_field) = DECL_MODE (field);
4822 next_field = &TREE_CHAIN (*next_field);
4823 }
4824
4825 /* Record the base version of the type. */
4826 CLASSTYPE_AS_BASE (t) = base_t;
4827 TYPE_CONTEXT (base_t) = t;
4828 }
4829 else
4830 CLASSTYPE_AS_BASE (t) = t;
4831
4832 /* Every empty class contains an empty class. */
4833 if (CLASSTYPE_EMPTY_P (t))
4834 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
4835
4836 /* Set the TYPE_DECL for this type to contain the right
4837 value for DECL_OFFSET, so that we can use it as part
4838 of a COMPONENT_REF for multiple inheritance. */
4839 layout_decl (TYPE_MAIN_DECL (t), 0);
4840
4841 /* Now fix up any virtual base class types that we left lying
4842 around. We must get these done before we try to lay out the
4843 virtual function table. As a side-effect, this will remove the
4844 base subobject fields. */
4845 layout_virtual_bases (rli, empty_base_offsets);
4846
4847 /* Make sure that empty classes are reflected in RLI at this
4848 point. */
4849 include_empty_classes(rli);
4850
4851 /* Make sure not to create any structures with zero size. */
4852 if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t))
4853 place_field (rli,
4854 build_decl (FIELD_DECL, NULL_TREE, char_type_node));
4855
4856 /* Let the back-end lay out the type. */
4857 finish_record_layout (rli, /*free_p=*/true);
4858
4859 /* Warn about bases that can't be talked about due to ambiguity. */
4860 warn_about_ambiguous_bases (t);
4861
4862 /* Now that we're done with layout, give the base fields the real types. */
4863 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
4864 if (DECL_ARTIFICIAL (field) && IS_FAKE_BASE_TYPE (TREE_TYPE (field)))
4865 TREE_TYPE (field) = TYPE_CONTEXT (TREE_TYPE (field));
4866
4867 /* Clean up. */
4868 splay_tree_delete (empty_base_offsets);
4869
4870 if (CLASSTYPE_EMPTY_P (t)
4871 && tree_int_cst_lt (sizeof_biggest_empty_class,
4872 TYPE_SIZE_UNIT (t)))
4873 sizeof_biggest_empty_class = TYPE_SIZE_UNIT (t);
4874 }
4875
4876 /* Determine the "key method" for the class type indicated by TYPE,
4877 and set CLASSTYPE_KEY_METHOD accordingly. */
4878
4879 void
4880 determine_key_method (tree type)
4881 {
4882 tree method;
4883
4884 if (TYPE_FOR_JAVA (type)
4885 || processing_template_decl
4886 || CLASSTYPE_TEMPLATE_INSTANTIATION (type)
4887 || CLASSTYPE_INTERFACE_KNOWN (type))
4888 return;
4889
4890 /* The key method is the first non-pure virtual function that is not
4891 inline at the point of class definition. On some targets the
4892 key function may not be inline; those targets should not call
4893 this function until the end of the translation unit. */
4894 for (method = TYPE_METHODS (type); method != NULL_TREE;
4895 method = TREE_CHAIN (method))
4896 if (DECL_VINDEX (method) != NULL_TREE
4897 && ! DECL_DECLARED_INLINE_P (method)
4898 && ! DECL_PURE_VIRTUAL_P (method))
4899 {
4900 CLASSTYPE_KEY_METHOD (type) = method;
4901 break;
4902 }
4903
4904 return;
4905 }
4906
4907 /* Perform processing required when the definition of T (a class type)
4908 is complete. */
4909
4910 void
4911 finish_struct_1 (tree t)
4912 {
4913 tree x;
4914 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
4915 tree virtuals = NULL_TREE;
4916 int n_fields = 0;
4917
4918 if (COMPLETE_TYPE_P (t))
4919 {
4920 gcc_assert (IS_AGGR_TYPE (t));
4921 error ("redefinition of %q#T", t);
4922 popclass ();
4923 return;
4924 }
4925
4926 /* If this type was previously laid out as a forward reference,
4927 make sure we lay it out again. */
4928 TYPE_SIZE (t) = NULL_TREE;
4929 CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE;
4930
4931 fixup_inline_methods (t);
4932
4933 /* Make assumptions about the class; we'll reset the flags if
4934 necessary. */
4935 CLASSTYPE_EMPTY_P (t) = 1;
4936 CLASSTYPE_NEARLY_EMPTY_P (t) = 1;
4937 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 0;
4938
4939 /* Do end-of-class semantic processing: checking the validity of the
4940 bases and members and add implicitly generated methods. */
4941 check_bases_and_members (t);
4942
4943 /* Find the key method. */
4944 if (TYPE_CONTAINS_VPTR_P (t))
4945 {
4946 /* The Itanium C++ ABI permits the key method to be chosen when
4947 the class is defined -- even though the key method so
4948 selected may later turn out to be an inline function. On
4949 some systems (such as ARM Symbian OS) the key method cannot
4950 be determined until the end of the translation unit. On such
4951 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
4952 will cause the class to be added to KEYED_CLASSES. Then, in
4953 finish_file we will determine the key method. */
4954 if (targetm.cxx.key_method_may_be_inline ())
4955 determine_key_method (t);
4956
4957 /* If a polymorphic class has no key method, we may emit the vtable
4958 in every translation unit where the class definition appears. */
4959 if (CLASSTYPE_KEY_METHOD (t) == NULL_TREE)
4960 keyed_classes = tree_cons (NULL_TREE, t, keyed_classes);
4961 }
4962
4963 /* Layout the class itself. */
4964 layout_class_type (t, &virtuals);
4965 if (CLASSTYPE_AS_BASE (t) != t)
4966 /* We use the base type for trivial assignments, and hence it
4967 needs a mode. */
4968 compute_record_mode (CLASSTYPE_AS_BASE (t));
4969
4970 virtuals = modify_all_vtables (t, nreverse (virtuals));
4971
4972 /* If necessary, create the primary vtable for this class. */
4973 if (virtuals || TYPE_CONTAINS_VPTR_P (t))
4974 {
4975 /* We must enter these virtuals into the table. */
4976 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
4977 build_primary_vtable (NULL_TREE, t);
4978 else if (! BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (t)))
4979 /* Here we know enough to change the type of our virtual
4980 function table, but we will wait until later this function. */
4981 build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t);
4982 }
4983
4984 if (TYPE_CONTAINS_VPTR_P (t))
4985 {
4986 int vindex;
4987 tree fn;
4988
4989 if (BINFO_VTABLE (TYPE_BINFO (t)))
4990 gcc_assert (DECL_VIRTUAL_P (BINFO_VTABLE (TYPE_BINFO (t))));
4991 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
4992 gcc_assert (BINFO_VIRTUALS (TYPE_BINFO (t)) == NULL_TREE);
4993
4994 /* Add entries for virtual functions introduced by this class. */
4995 BINFO_VIRTUALS (TYPE_BINFO (t))
4996 = chainon (BINFO_VIRTUALS (TYPE_BINFO (t)), virtuals);
4997
4998 /* Set DECL_VINDEX for all functions declared in this class. */
4999 for (vindex = 0, fn = BINFO_VIRTUALS (TYPE_BINFO (t));
5000 fn;
5001 fn = TREE_CHAIN (fn),
5002 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
5003 ? TARGET_VTABLE_USES_DESCRIPTORS : 1))
5004 {
5005 tree fndecl = BV_FN (fn);
5006
5007 if (DECL_THUNK_P (fndecl))
5008 /* A thunk. We should never be calling this entry directly
5009 from this vtable -- we'd use the entry for the non
5010 thunk base function. */
5011 DECL_VINDEX (fndecl) = NULL_TREE;
5012 else if (TREE_CODE (DECL_VINDEX (fndecl)) != INTEGER_CST)
5013 DECL_VINDEX (fndecl) = build_int_cst (NULL_TREE, vindex);
5014 }
5015 }
5016
5017 finish_struct_bits (t);
5018
5019 /* Complete the rtl for any static member objects of the type we're
5020 working on. */
5021 for (x = TYPE_FIELDS (t); x; x = TREE_CHAIN (x))
5022 if (TREE_CODE (x) == VAR_DECL && TREE_STATIC (x)
5023 && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t))
5024 DECL_MODE (x) = TYPE_MODE (t);
5025
5026 /* Done with FIELDS...now decide whether to sort these for
5027 faster lookups later.
5028
5029 We use a small number because most searches fail (succeeding
5030 ultimately as the search bores through the inheritance
5031 hierarchy), and we want this failure to occur quickly. */
5032
5033 n_fields = count_fields (TYPE_FIELDS (t));
5034 if (n_fields > 7)
5035 {
5036 struct sorted_fields_type *field_vec = GGC_NEWVAR
5037 (struct sorted_fields_type,
5038 sizeof (struct sorted_fields_type) + n_fields * sizeof (tree));
5039 field_vec->len = n_fields;
5040 add_fields_to_record_type (TYPE_FIELDS (t), field_vec, 0);
5041 qsort (field_vec->elts, n_fields, sizeof (tree),
5042 field_decl_cmp);
5043 if (! DECL_LANG_SPECIFIC (TYPE_MAIN_DECL (t)))
5044 retrofit_lang_decl (TYPE_MAIN_DECL (t));
5045 DECL_SORTED_FIELDS (TYPE_MAIN_DECL (t)) = field_vec;
5046 }
5047
5048 /* Make the rtl for any new vtables we have created, and unmark
5049 the base types we marked. */
5050 finish_vtbls (t);
5051
5052 /* Build the VTT for T. */
5053 build_vtt (t);
5054
5055 /* This warning does not make sense for Java classes, since they
5056 cannot have destructors. */
5057 if (!TYPE_FOR_JAVA (t) && warn_nonvdtor && TYPE_POLYMORPHIC_P (t))
5058 {
5059 tree dtor;
5060
5061 dtor = CLASSTYPE_DESTRUCTORS (t);
5062 /* Warn only if the dtor is non-private or the class has
5063 friends. */
5064 if (/* An implicitly declared destructor is always public. And,
5065 if it were virtual, we would have created it by now. */
5066 !dtor
5067 || (!DECL_VINDEX (dtor)
5068 && (!TREE_PRIVATE (dtor)
5069 || CLASSTYPE_FRIEND_CLASSES (t)
5070 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))))
5071 warning (0, "%q#T has virtual functions but non-virtual destructor",
5072 t);
5073 }
5074
5075 complete_vars (t);
5076
5077 if (warn_overloaded_virtual)
5078 warn_hidden (t);
5079
5080 /* Class layout, assignment of virtual table slots, etc., is now
5081 complete. Give the back end a chance to tweak the visibility of
5082 the class or perform any other required target modifications. */
5083 targetm.cxx.adjust_class_at_definition (t);
5084
5085 maybe_suppress_debug_info (t);
5086
5087 dump_class_hierarchy (t);
5088
5089 /* Finish debugging output for this type. */
5090 rest_of_type_compilation (t, ! LOCAL_CLASS_P (t));
5091 }
5092
5093 /* When T was built up, the member declarations were added in reverse
5094 order. Rearrange them to declaration order. */
5095
5096 void
5097 unreverse_member_declarations (tree t)
5098 {
5099 tree next;
5100 tree prev;
5101 tree x;
5102
5103 /* The following lists are all in reverse order. Put them in
5104 declaration order now. */
5105 TYPE_METHODS (t) = nreverse (TYPE_METHODS (t));
5106 CLASSTYPE_DECL_LIST (t) = nreverse (CLASSTYPE_DECL_LIST (t));
5107
5108 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5109 reverse order, so we can't just use nreverse. */
5110 prev = NULL_TREE;
5111 for (x = TYPE_FIELDS (t);
5112 x && TREE_CODE (x) != TYPE_DECL;
5113 x = next)
5114 {
5115 next = TREE_CHAIN (x);
5116 TREE_CHAIN (x) = prev;
5117 prev = x;
5118 }
5119 if (prev)
5120 {
5121 TREE_CHAIN (TYPE_FIELDS (t)) = x;
5122 if (prev)
5123 TYPE_FIELDS (t) = prev;
5124 }
5125 }
5126
5127 tree
5128 finish_struct (tree t, tree attributes)
5129 {
5130 location_t saved_loc = input_location;
5131
5132 /* Now that we've got all the field declarations, reverse everything
5133 as necessary. */
5134 unreverse_member_declarations (t);
5135
5136 cplus_decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
5137
5138 /* Nadger the current location so that diagnostics point to the start of
5139 the struct, not the end. */
5140 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (t));
5141
5142 if (processing_template_decl)
5143 {
5144 tree x;
5145
5146 finish_struct_methods (t);
5147 TYPE_SIZE (t) = bitsize_zero_node;
5148 TYPE_SIZE_UNIT (t) = size_zero_node;
5149
5150 /* We need to emit an error message if this type was used as a parameter
5151 and it is an abstract type, even if it is a template. We construct
5152 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
5153 account and we call complete_vars with this type, which will check
5154 the PARM_DECLS. Note that while the type is being defined,
5155 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
5156 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
5157 CLASSTYPE_PURE_VIRTUALS (t) = NULL;
5158 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
5159 if (DECL_PURE_VIRTUAL_P (x))
5160 VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x);
5161 complete_vars (t);
5162 }
5163 else
5164 finish_struct_1 (t);
5165
5166 input_location = saved_loc;
5167
5168 TYPE_BEING_DEFINED (t) = 0;
5169
5170 if (current_class_type)
5171 popclass ();
5172 else
5173 error ("trying to finish struct, but kicked out due to previous parse errors");
5174
5175 if (processing_template_decl && at_function_scope_p ())
5176 add_stmt (build_min (TAG_DEFN, t));
5177
5178 return t;
5179 }
5180 \f
5181 /* Return the dynamic type of INSTANCE, if known.
5182 Used to determine whether the virtual function table is needed
5183 or not.
5184
5185 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5186 of our knowledge of its type. *NONNULL should be initialized
5187 before this function is called. */
5188
5189 static tree
5190 fixed_type_or_null (tree instance, int* nonnull, int* cdtorp)
5191 {
5192 switch (TREE_CODE (instance))
5193 {
5194 case INDIRECT_REF:
5195 if (POINTER_TYPE_P (TREE_TYPE (instance)))
5196 return NULL_TREE;
5197 else
5198 return fixed_type_or_null (TREE_OPERAND (instance, 0),
5199 nonnull, cdtorp);
5200
5201 case CALL_EXPR:
5202 /* This is a call to a constructor, hence it's never zero. */
5203 if (TREE_HAS_CONSTRUCTOR (instance))
5204 {
5205 if (nonnull)
5206 *nonnull = 1;
5207 return TREE_TYPE (instance);
5208 }
5209 return NULL_TREE;
5210
5211 case SAVE_EXPR:
5212 /* This is a call to a constructor, hence it's never zero. */
5213 if (TREE_HAS_CONSTRUCTOR (instance))
5214 {
5215 if (nonnull)
5216 *nonnull = 1;
5217 return TREE_TYPE (instance);
5218 }
5219 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5220
5221 case PLUS_EXPR:
5222 case MINUS_EXPR:
5223 if (TREE_CODE (TREE_OPERAND (instance, 0)) == ADDR_EXPR)
5224 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5225 if (TREE_CODE (TREE_OPERAND (instance, 1)) == INTEGER_CST)
5226 /* Propagate nonnull. */
5227 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5228 return NULL_TREE;
5229
5230 case NOP_EXPR:
5231 case CONVERT_EXPR:
5232 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5233
5234 case ADDR_EXPR:
5235 instance = TREE_OPERAND (instance, 0);
5236 if (nonnull)
5237 {
5238 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
5239 with a real object -- given &p->f, p can still be null. */
5240 tree t = get_base_address (instance);
5241 /* ??? Probably should check DECL_WEAK here. */
5242 if (t && DECL_P (t))
5243 *nonnull = 1;
5244 }
5245 return fixed_type_or_null (instance, nonnull, cdtorp);
5246
5247 case COMPONENT_REF:
5248 /* If this component is really a base class reference, then the field
5249 itself isn't definitive. */
5250 if (DECL_FIELD_IS_BASE (TREE_OPERAND (instance, 1)))
5251 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5252 return fixed_type_or_null (TREE_OPERAND (instance, 1), nonnull, cdtorp);
5253
5254 case VAR_DECL:
5255 case FIELD_DECL:
5256 if (TREE_CODE (TREE_TYPE (instance)) == ARRAY_TYPE
5257 && IS_AGGR_TYPE (TREE_TYPE (TREE_TYPE (instance))))
5258 {
5259 if (nonnull)
5260 *nonnull = 1;
5261 return TREE_TYPE (TREE_TYPE (instance));
5262 }
5263 /* fall through... */
5264 case TARGET_EXPR:
5265 case PARM_DECL:
5266 case RESULT_DECL:
5267 if (IS_AGGR_TYPE (TREE_TYPE (instance)))
5268 {
5269 if (nonnull)
5270 *nonnull = 1;
5271 return TREE_TYPE (instance);
5272 }
5273 else if (instance == current_class_ptr)
5274 {
5275 if (nonnull)
5276 *nonnull = 1;
5277
5278 /* if we're in a ctor or dtor, we know our type. */
5279 if (DECL_LANG_SPECIFIC (current_function_decl)
5280 && (DECL_CONSTRUCTOR_P (current_function_decl)
5281 || DECL_DESTRUCTOR_P (current_function_decl)))
5282 {
5283 if (cdtorp)
5284 *cdtorp = 1;
5285 return TREE_TYPE (TREE_TYPE (instance));
5286 }
5287 }
5288 else if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE)
5289 {
5290 /* Reference variables should be references to objects. */
5291 if (nonnull)
5292 *nonnull = 1;
5293
5294 /* DECL_VAR_MARKED_P is used to prevent recursion; a
5295 variable's initializer may refer to the variable
5296 itself. */
5297 if (TREE_CODE (instance) == VAR_DECL
5298 && DECL_INITIAL (instance)
5299 && !DECL_VAR_MARKED_P (instance))
5300 {
5301 tree type;
5302 DECL_VAR_MARKED_P (instance) = 1;
5303 type = fixed_type_or_null (DECL_INITIAL (instance),
5304 nonnull, cdtorp);
5305 DECL_VAR_MARKED_P (instance) = 0;
5306 return type;
5307 }
5308 }
5309 return NULL_TREE;
5310
5311 default:
5312 return NULL_TREE;
5313 }
5314 }
5315
5316 /* Return nonzero if the dynamic type of INSTANCE is known, and
5317 equivalent to the static type. We also handle the case where
5318 INSTANCE is really a pointer. Return negative if this is a
5319 ctor/dtor. There the dynamic type is known, but this might not be
5320 the most derived base of the original object, and hence virtual
5321 bases may not be layed out according to this type.
5322
5323 Used to determine whether the virtual function table is needed
5324 or not.
5325
5326 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5327 of our knowledge of its type. *NONNULL should be initialized
5328 before this function is called. */
5329
5330 int
5331 resolves_to_fixed_type_p (tree instance, int* nonnull)
5332 {
5333 tree t = TREE_TYPE (instance);
5334 int cdtorp = 0;
5335
5336 tree fixed = fixed_type_or_null (instance, nonnull, &cdtorp);
5337 if (fixed == NULL_TREE)
5338 return 0;
5339 if (POINTER_TYPE_P (t))
5340 t = TREE_TYPE (t);
5341 if (!same_type_ignoring_top_level_qualifiers_p (t, fixed))
5342 return 0;
5343 return cdtorp ? -1 : 1;
5344 }
5345
5346 \f
5347 void
5348 init_class_processing (void)
5349 {
5350 current_class_depth = 0;
5351 current_class_stack_size = 10;
5352 current_class_stack
5353 = XNEWVEC (struct class_stack_node, current_class_stack_size);
5354 local_classes = VEC_alloc (tree, gc, 8);
5355 sizeof_biggest_empty_class = size_zero_node;
5356
5357 ridpointers[(int) RID_PUBLIC] = access_public_node;
5358 ridpointers[(int) RID_PRIVATE] = access_private_node;
5359 ridpointers[(int) RID_PROTECTED] = access_protected_node;
5360 }
5361
5362 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
5363
5364 static void
5365 restore_class_cache (void)
5366 {
5367 tree type;
5368
5369 /* We are re-entering the same class we just left, so we don't
5370 have to search the whole inheritance matrix to find all the
5371 decls to bind again. Instead, we install the cached
5372 class_shadowed list and walk through it binding names. */
5373 push_binding_level (previous_class_level);
5374 class_binding_level = previous_class_level;
5375 /* Restore IDENTIFIER_TYPE_VALUE. */
5376 for (type = class_binding_level->type_shadowed;
5377 type;
5378 type = TREE_CHAIN (type))
5379 SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (type), TREE_TYPE (type));
5380 }
5381
5382 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
5383 appropriate for TYPE.
5384
5385 So that we may avoid calls to lookup_name, we cache the _TYPE
5386 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5387
5388 For multiple inheritance, we perform a two-pass depth-first search
5389 of the type lattice. */
5390
5391 void
5392 pushclass (tree type)
5393 {
5394 class_stack_node_t csn;
5395
5396 type = TYPE_MAIN_VARIANT (type);
5397
5398 /* Make sure there is enough room for the new entry on the stack. */
5399 if (current_class_depth + 1 >= current_class_stack_size)
5400 {
5401 current_class_stack_size *= 2;
5402 current_class_stack
5403 = XRESIZEVEC (struct class_stack_node, current_class_stack,
5404 current_class_stack_size);
5405 }
5406
5407 /* Insert a new entry on the class stack. */
5408 csn = current_class_stack + current_class_depth;
5409 csn->name = current_class_name;
5410 csn->type = current_class_type;
5411 csn->access = current_access_specifier;
5412 csn->names_used = 0;
5413 csn->hidden = 0;
5414 current_class_depth++;
5415
5416 /* Now set up the new type. */
5417 current_class_name = TYPE_NAME (type);
5418 if (TREE_CODE (current_class_name) == TYPE_DECL)
5419 current_class_name = DECL_NAME (current_class_name);
5420 current_class_type = type;
5421
5422 /* By default, things in classes are private, while things in
5423 structures or unions are public. */
5424 current_access_specifier = (CLASSTYPE_DECLARED_CLASS (type)
5425 ? access_private_node
5426 : access_public_node);
5427
5428 if (previous_class_level
5429 && type != previous_class_level->this_entity
5430 && current_class_depth == 1)
5431 {
5432 /* Forcibly remove any old class remnants. */
5433 invalidate_class_lookup_cache ();
5434 }
5435
5436 if (!previous_class_level
5437 || type != previous_class_level->this_entity
5438 || current_class_depth > 1)
5439 pushlevel_class ();
5440 else
5441 restore_class_cache ();
5442 }
5443
5444 /* When we exit a toplevel class scope, we save its binding level so
5445 that we can restore it quickly. Here, we've entered some other
5446 class, so we must invalidate our cache. */
5447
5448 void
5449 invalidate_class_lookup_cache (void)
5450 {
5451 previous_class_level = NULL;
5452 }
5453
5454 /* Get out of the current class scope. If we were in a class scope
5455 previously, that is the one popped to. */
5456
5457 void
5458 popclass (void)
5459 {
5460 poplevel_class ();
5461
5462 current_class_depth--;
5463 current_class_name = current_class_stack[current_class_depth].name;
5464 current_class_type = current_class_stack[current_class_depth].type;
5465 current_access_specifier = current_class_stack[current_class_depth].access;
5466 if (current_class_stack[current_class_depth].names_used)
5467 splay_tree_delete (current_class_stack[current_class_depth].names_used);
5468 }
5469
5470 /* Mark the top of the class stack as hidden. */
5471
5472 void
5473 push_class_stack (void)
5474 {
5475 if (current_class_depth)
5476 ++current_class_stack[current_class_depth - 1].hidden;
5477 }
5478
5479 /* Mark the top of the class stack as un-hidden. */
5480
5481 void
5482 pop_class_stack (void)
5483 {
5484 if (current_class_depth)
5485 --current_class_stack[current_class_depth - 1].hidden;
5486 }
5487
5488 /* Returns 1 if current_class_type is either T or a nested type of T.
5489 We start looking from 1 because entry 0 is from global scope, and has
5490 no type. */
5491
5492 int
5493 currently_open_class (tree t)
5494 {
5495 int i;
5496 if (current_class_type && same_type_p (t, current_class_type))
5497 return 1;
5498 for (i = current_class_depth - 1; i > 0; --i)
5499 {
5500 if (current_class_stack[i].hidden)
5501 break;
5502 if (current_class_stack[i].type
5503 && same_type_p (current_class_stack [i].type, t))
5504 return 1;
5505 }
5506 return 0;
5507 }
5508
5509 /* If either current_class_type or one of its enclosing classes are derived
5510 from T, return the appropriate type. Used to determine how we found
5511 something via unqualified lookup. */
5512
5513 tree
5514 currently_open_derived_class (tree t)
5515 {
5516 int i;
5517
5518 /* The bases of a dependent type are unknown. */
5519 if (dependent_type_p (t))
5520 return NULL_TREE;
5521
5522 if (!current_class_type)
5523 return NULL_TREE;
5524
5525 if (DERIVED_FROM_P (t, current_class_type))
5526 return current_class_type;
5527
5528 for (i = current_class_depth - 1; i > 0; --i)
5529 {
5530 if (current_class_stack[i].hidden)
5531 break;
5532 if (DERIVED_FROM_P (t, current_class_stack[i].type))
5533 return current_class_stack[i].type;
5534 }
5535
5536 return NULL_TREE;
5537 }
5538
5539 /* When entering a class scope, all enclosing class scopes' names with
5540 static meaning (static variables, static functions, types and
5541 enumerators) have to be visible. This recursive function calls
5542 pushclass for all enclosing class contexts until global or a local
5543 scope is reached. TYPE is the enclosed class. */
5544
5545 void
5546 push_nested_class (tree type)
5547 {
5548 tree context;
5549
5550 /* A namespace might be passed in error cases, like A::B:C. */
5551 if (type == NULL_TREE
5552 || type == error_mark_node
5553 || TREE_CODE (type) == NAMESPACE_DECL
5554 || ! IS_AGGR_TYPE (type)
5555 || TREE_CODE (type) == TEMPLATE_TYPE_PARM
5556 || TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
5557 return;
5558
5559 context = DECL_CONTEXT (TYPE_MAIN_DECL (type));
5560
5561 if (context && CLASS_TYPE_P (context))
5562 push_nested_class (context);
5563 pushclass (type);
5564 }
5565
5566 /* Undoes a push_nested_class call. */
5567
5568 void
5569 pop_nested_class (void)
5570 {
5571 tree context = DECL_CONTEXT (TYPE_MAIN_DECL (current_class_type));
5572
5573 popclass ();
5574 if (context && CLASS_TYPE_P (context))
5575 pop_nested_class ();
5576 }
5577
5578 /* Returns the number of extern "LANG" blocks we are nested within. */
5579
5580 int
5581 current_lang_depth (void)
5582 {
5583 return VEC_length (tree, current_lang_base);
5584 }
5585
5586 /* Set global variables CURRENT_LANG_NAME to appropriate value
5587 so that behavior of name-mangling machinery is correct. */
5588
5589 void
5590 push_lang_context (tree name)
5591 {
5592 VEC_safe_push (tree, gc, current_lang_base, current_lang_name);
5593
5594 if (name == lang_name_cplusplus)
5595 {
5596 current_lang_name = name;
5597 }
5598 else if (name == lang_name_java)
5599 {
5600 current_lang_name = name;
5601 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5602 (See record_builtin_java_type in decl.c.) However, that causes
5603 incorrect debug entries if these types are actually used.
5604 So we re-enable debug output after extern "Java". */
5605 DECL_IGNORED_P (TYPE_NAME (java_byte_type_node)) = 0;
5606 DECL_IGNORED_P (TYPE_NAME (java_short_type_node)) = 0;
5607 DECL_IGNORED_P (TYPE_NAME (java_int_type_node)) = 0;
5608 DECL_IGNORED_P (TYPE_NAME (java_long_type_node)) = 0;
5609 DECL_IGNORED_P (TYPE_NAME (java_float_type_node)) = 0;
5610 DECL_IGNORED_P (TYPE_NAME (java_double_type_node)) = 0;
5611 DECL_IGNORED_P (TYPE_NAME (java_char_type_node)) = 0;
5612 DECL_IGNORED_P (TYPE_NAME (java_boolean_type_node)) = 0;
5613 }
5614 else if (name == lang_name_c)
5615 {
5616 current_lang_name = name;
5617 }
5618 else
5619 error ("language string %<\"%E\"%> not recognized", name);
5620 }
5621
5622 /* Get out of the current language scope. */
5623
5624 void
5625 pop_lang_context (void)
5626 {
5627 current_lang_name = VEC_pop (tree, current_lang_base);
5628 }
5629 \f
5630 /* Type instantiation routines. */
5631
5632 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
5633 matches the TARGET_TYPE. If there is no satisfactory match, return
5634 error_mark_node, and issue an error & warning messages under control
5635 of FLAGS. Permit pointers to member function if FLAGS permits. If
5636 TEMPLATE_ONLY, the name of the overloaded function was a
5637 template-id, and EXPLICIT_TARGS are the explicitly provided
5638 template arguments. */
5639
5640 static tree
5641 resolve_address_of_overloaded_function (tree target_type,
5642 tree overload,
5643 tsubst_flags_t flags,
5644 bool template_only,
5645 tree explicit_targs)
5646 {
5647 /* Here's what the standard says:
5648
5649 [over.over]
5650
5651 If the name is a function template, template argument deduction
5652 is done, and if the argument deduction succeeds, the deduced
5653 arguments are used to generate a single template function, which
5654 is added to the set of overloaded functions considered.
5655
5656 Non-member functions and static member functions match targets of
5657 type "pointer-to-function" or "reference-to-function." Nonstatic
5658 member functions match targets of type "pointer-to-member
5659 function;" the function type of the pointer to member is used to
5660 select the member function from the set of overloaded member
5661 functions. If a nonstatic member function is selected, the
5662 reference to the overloaded function name is required to have the
5663 form of a pointer to member as described in 5.3.1.
5664
5665 If more than one function is selected, any template functions in
5666 the set are eliminated if the set also contains a non-template
5667 function, and any given template function is eliminated if the
5668 set contains a second template function that is more specialized
5669 than the first according to the partial ordering rules 14.5.5.2.
5670 After such eliminations, if any, there shall remain exactly one
5671 selected function. */
5672
5673 int is_ptrmem = 0;
5674 int is_reference = 0;
5675 /* We store the matches in a TREE_LIST rooted here. The functions
5676 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
5677 interoperability with most_specialized_instantiation. */
5678 tree matches = NULL_TREE;
5679 tree fn;
5680
5681 /* By the time we get here, we should be seeing only real
5682 pointer-to-member types, not the internal POINTER_TYPE to
5683 METHOD_TYPE representation. */
5684 gcc_assert (TREE_CODE (target_type) != POINTER_TYPE
5685 || TREE_CODE (TREE_TYPE (target_type)) != METHOD_TYPE);
5686
5687 gcc_assert (is_overloaded_fn (overload));
5688
5689 /* Check that the TARGET_TYPE is reasonable. */
5690 if (TYPE_PTRFN_P (target_type))
5691 /* This is OK. */;
5692 else if (TYPE_PTRMEMFUNC_P (target_type))
5693 /* This is OK, too. */
5694 is_ptrmem = 1;
5695 else if (TREE_CODE (target_type) == FUNCTION_TYPE)
5696 {
5697 /* This is OK, too. This comes from a conversion to reference
5698 type. */
5699 target_type = build_reference_type (target_type);
5700 is_reference = 1;
5701 }
5702 else
5703 {
5704 if (flags & tf_error)
5705 error ("cannot resolve overloaded function %qD based on"
5706 " conversion to type %qT",
5707 DECL_NAME (OVL_FUNCTION (overload)), target_type);
5708 return error_mark_node;
5709 }
5710
5711 /* If we can find a non-template function that matches, we can just
5712 use it. There's no point in generating template instantiations
5713 if we're just going to throw them out anyhow. But, of course, we
5714 can only do this when we don't *need* a template function. */
5715 if (!template_only)
5716 {
5717 tree fns;
5718
5719 for (fns = overload; fns; fns = OVL_NEXT (fns))
5720 {
5721 tree fn = OVL_CURRENT (fns);
5722 tree fntype;
5723
5724 if (TREE_CODE (fn) == TEMPLATE_DECL)
5725 /* We're not looking for templates just yet. */
5726 continue;
5727
5728 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
5729 != is_ptrmem)
5730 /* We're looking for a non-static member, and this isn't
5731 one, or vice versa. */
5732 continue;
5733
5734 /* Ignore functions which haven't been explicitly
5735 declared. */
5736 if (DECL_ANTICIPATED (fn))
5737 continue;
5738
5739 /* See if there's a match. */
5740 fntype = TREE_TYPE (fn);
5741 if (is_ptrmem)
5742 fntype = build_ptrmemfunc_type (build_pointer_type (fntype));
5743 else if (!is_reference)
5744 fntype = build_pointer_type (fntype);
5745
5746 if (can_convert_arg (target_type, fntype, fn, LOOKUP_NORMAL))
5747 matches = tree_cons (fn, NULL_TREE, matches);
5748 }
5749 }
5750
5751 /* Now, if we've already got a match (or matches), there's no need
5752 to proceed to the template functions. But, if we don't have a
5753 match we need to look at them, too. */
5754 if (!matches)
5755 {
5756 tree target_fn_type;
5757 tree target_arg_types;
5758 tree target_ret_type;
5759 tree fns;
5760
5761 if (is_ptrmem)
5762 target_fn_type
5763 = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (target_type));
5764 else
5765 target_fn_type = TREE_TYPE (target_type);
5766 target_arg_types = TYPE_ARG_TYPES (target_fn_type);
5767 target_ret_type = TREE_TYPE (target_fn_type);
5768
5769 /* Never do unification on the 'this' parameter. */
5770 if (TREE_CODE (target_fn_type) == METHOD_TYPE)
5771 target_arg_types = TREE_CHAIN (target_arg_types);
5772
5773 for (fns = overload; fns; fns = OVL_NEXT (fns))
5774 {
5775 tree fn = OVL_CURRENT (fns);
5776 tree instantiation;
5777 tree instantiation_type;
5778 tree targs;
5779
5780 if (TREE_CODE (fn) != TEMPLATE_DECL)
5781 /* We're only looking for templates. */
5782 continue;
5783
5784 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
5785 != is_ptrmem)
5786 /* We're not looking for a non-static member, and this is
5787 one, or vice versa. */
5788 continue;
5789
5790 /* Try to do argument deduction. */
5791 targs = make_tree_vec (DECL_NTPARMS (fn));
5792 if (fn_type_unification (fn, explicit_targs, targs,
5793 target_arg_types, target_ret_type,
5794 DEDUCE_EXACT, LOOKUP_NORMAL))
5795 /* Argument deduction failed. */
5796 continue;
5797
5798 /* Instantiate the template. */
5799 instantiation = instantiate_template (fn, targs, flags);
5800 if (instantiation == error_mark_node)
5801 /* Instantiation failed. */
5802 continue;
5803
5804 /* See if there's a match. */
5805 instantiation_type = TREE_TYPE (instantiation);
5806 if (is_ptrmem)
5807 instantiation_type =
5808 build_ptrmemfunc_type (build_pointer_type (instantiation_type));
5809 else if (!is_reference)
5810 instantiation_type = build_pointer_type (instantiation_type);
5811 if (can_convert_arg (target_type, instantiation_type, instantiation,
5812 LOOKUP_NORMAL))
5813 matches = tree_cons (instantiation, fn, matches);
5814 }
5815
5816 /* Now, remove all but the most specialized of the matches. */
5817 if (matches)
5818 {
5819 tree match = most_specialized_instantiation (matches);
5820
5821 if (match != error_mark_node)
5822 matches = tree_cons (match, NULL_TREE, NULL_TREE);
5823 }
5824 }
5825
5826 /* Now we should have exactly one function in MATCHES. */
5827 if (matches == NULL_TREE)
5828 {
5829 /* There were *no* matches. */
5830 if (flags & tf_error)
5831 {
5832 error ("no matches converting function %qD to type %q#T",
5833 DECL_NAME (OVL_FUNCTION (overload)),
5834 target_type);
5835
5836 /* print_candidates expects a chain with the functions in
5837 TREE_VALUE slots, so we cons one up here (we're losing anyway,
5838 so why be clever?). */
5839 for (; overload; overload = OVL_NEXT (overload))
5840 matches = tree_cons (NULL_TREE, OVL_CURRENT (overload),
5841 matches);
5842
5843 print_candidates (matches);
5844 }
5845 return error_mark_node;
5846 }
5847 else if (TREE_CHAIN (matches))
5848 {
5849 /* There were too many matches. */
5850
5851 if (flags & tf_error)
5852 {
5853 tree match;
5854
5855 error ("converting overloaded function %qD to type %q#T is ambiguous",
5856 DECL_NAME (OVL_FUNCTION (overload)),
5857 target_type);
5858
5859 /* Since print_candidates expects the functions in the
5860 TREE_VALUE slot, we flip them here. */
5861 for (match = matches; match; match = TREE_CHAIN (match))
5862 TREE_VALUE (match) = TREE_PURPOSE (match);
5863
5864 print_candidates (matches);
5865 }
5866
5867 return error_mark_node;
5868 }
5869
5870 /* Good, exactly one match. Now, convert it to the correct type. */
5871 fn = TREE_PURPOSE (matches);
5872
5873 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
5874 && !(flags & tf_ptrmem_ok) && !flag_ms_extensions)
5875 {
5876 static int explained;
5877
5878 if (!(flags & tf_error))
5879 return error_mark_node;
5880
5881 pedwarn ("assuming pointer to member %qD", fn);
5882 if (!explained)
5883 {
5884 pedwarn ("(a pointer to member can only be formed with %<&%E%>)", fn);
5885 explained = 1;
5886 }
5887 }
5888
5889 /* If we're doing overload resolution purely for the purpose of
5890 determining conversion sequences, we should not consider the
5891 function used. If this conversion sequence is selected, the
5892 function will be marked as used at this point. */
5893 if (!(flags & tf_conv))
5894 mark_used (fn);
5895
5896 if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type))
5897 return build_unary_op (ADDR_EXPR, fn, 0);
5898 else
5899 {
5900 /* The target must be a REFERENCE_TYPE. Above, build_unary_op
5901 will mark the function as addressed, but here we must do it
5902 explicitly. */
5903 cxx_mark_addressable (fn);
5904
5905 return fn;
5906 }
5907 }
5908
5909 /* This function will instantiate the type of the expression given in
5910 RHS to match the type of LHSTYPE. If errors exist, then return
5911 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
5912 we complain on errors. If we are not complaining, never modify rhs,
5913 as overload resolution wants to try many possible instantiations, in
5914 the hope that at least one will work.
5915
5916 For non-recursive calls, LHSTYPE should be a function, pointer to
5917 function, or a pointer to member function. */
5918
5919 tree
5920 instantiate_type (tree lhstype, tree rhs, tsubst_flags_t flags)
5921 {
5922 tsubst_flags_t flags_in = flags;
5923
5924 flags &= ~tf_ptrmem_ok;
5925
5926 if (TREE_CODE (lhstype) == UNKNOWN_TYPE)
5927 {
5928 if (flags & tf_error)
5929 error ("not enough type information");
5930 return error_mark_node;
5931 }
5932
5933 if (TREE_TYPE (rhs) != NULL_TREE && ! (type_unknown_p (rhs)))
5934 {
5935 if (same_type_p (lhstype, TREE_TYPE (rhs)))
5936 return rhs;
5937 if (flag_ms_extensions
5938 && TYPE_PTRMEMFUNC_P (lhstype)
5939 && !TYPE_PTRMEMFUNC_P (TREE_TYPE (rhs)))
5940 /* Microsoft allows `A::f' to be resolved to a
5941 pointer-to-member. */
5942 ;
5943 else
5944 {
5945 if (flags & tf_error)
5946 error ("argument of type %qT does not match %qT",
5947 TREE_TYPE (rhs), lhstype);
5948 return error_mark_node;
5949 }
5950 }
5951
5952 if (TREE_CODE (rhs) == BASELINK)
5953 rhs = BASELINK_FUNCTIONS (rhs);
5954
5955 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
5956 deduce any type information. */
5957 if (TREE_CODE (rhs) == NON_DEPENDENT_EXPR)
5958 {
5959 if (flags & tf_error)
5960 error ("not enough type information");
5961 return error_mark_node;
5962 }
5963
5964 /* We don't overwrite rhs if it is an overloaded function.
5965 Copying it would destroy the tree link. */
5966 if (TREE_CODE (rhs) != OVERLOAD)
5967 rhs = copy_node (rhs);
5968
5969 /* This should really only be used when attempting to distinguish
5970 what sort of a pointer to function we have. For now, any
5971 arithmetic operation which is not supported on pointers
5972 is rejected as an error. */
5973
5974 switch (TREE_CODE (rhs))
5975 {
5976 case TYPE_EXPR:
5977 case CONVERT_EXPR:
5978 case SAVE_EXPR:
5979 case CONSTRUCTOR:
5980 gcc_unreachable ();
5981
5982 case INDIRECT_REF:
5983 case ARRAY_REF:
5984 {
5985 tree new_rhs;
5986
5987 new_rhs = instantiate_type (build_pointer_type (lhstype),
5988 TREE_OPERAND (rhs, 0), flags);
5989 if (new_rhs == error_mark_node)
5990 return error_mark_node;
5991
5992 TREE_TYPE (rhs) = lhstype;
5993 TREE_OPERAND (rhs, 0) = new_rhs;
5994 return rhs;
5995 }
5996
5997 case NOP_EXPR:
5998 rhs = copy_node (TREE_OPERAND (rhs, 0));
5999 TREE_TYPE (rhs) = unknown_type_node;
6000 return instantiate_type (lhstype, rhs, flags);
6001
6002 case COMPONENT_REF:
6003 {
6004 tree member = TREE_OPERAND (rhs, 1);
6005
6006 member = instantiate_type (lhstype, member, flags);
6007 if (member != error_mark_node
6008 && TREE_SIDE_EFFECTS (TREE_OPERAND (rhs, 0)))
6009 /* Do not lose object's side effects. */
6010 return build2 (COMPOUND_EXPR, TREE_TYPE (member),
6011 TREE_OPERAND (rhs, 0), member);
6012 return member;
6013 }
6014
6015 case OFFSET_REF:
6016 rhs = TREE_OPERAND (rhs, 1);
6017 if (BASELINK_P (rhs))
6018 return instantiate_type (lhstype, BASELINK_FUNCTIONS (rhs), flags_in);
6019
6020 /* This can happen if we are forming a pointer-to-member for a
6021 member template. */
6022 gcc_assert (TREE_CODE (rhs) == TEMPLATE_ID_EXPR);
6023
6024 /* Fall through. */
6025
6026 case TEMPLATE_ID_EXPR:
6027 {
6028 tree fns = TREE_OPERAND (rhs, 0);
6029 tree args = TREE_OPERAND (rhs, 1);
6030
6031 return
6032 resolve_address_of_overloaded_function (lhstype, fns, flags_in,
6033 /*template_only=*/true,
6034 args);
6035 }
6036
6037 case OVERLOAD:
6038 case FUNCTION_DECL:
6039 return
6040 resolve_address_of_overloaded_function (lhstype, rhs, flags_in,
6041 /*template_only=*/false,
6042 /*explicit_targs=*/NULL_TREE);
6043
6044 case CALL_EXPR:
6045 /* This is too hard for now. */
6046 gcc_unreachable ();
6047
6048 case PLUS_EXPR:
6049 case MINUS_EXPR:
6050 case COMPOUND_EXPR:
6051 TREE_OPERAND (rhs, 0)
6052 = instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
6053 if (TREE_OPERAND (rhs, 0) == error_mark_node)
6054 return error_mark_node;
6055 TREE_OPERAND (rhs, 1)
6056 = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
6057 if (TREE_OPERAND (rhs, 1) == error_mark_node)
6058 return error_mark_node;
6059
6060 TREE_TYPE (rhs) = lhstype;
6061 return rhs;
6062
6063 case MULT_EXPR:
6064 case TRUNC_DIV_EXPR:
6065 case FLOOR_DIV_EXPR:
6066 case CEIL_DIV_EXPR:
6067 case ROUND_DIV_EXPR:
6068 case RDIV_EXPR:
6069 case TRUNC_MOD_EXPR:
6070 case FLOOR_MOD_EXPR:
6071 case CEIL_MOD_EXPR:
6072 case ROUND_MOD_EXPR:
6073 case FIX_ROUND_EXPR:
6074 case FIX_FLOOR_EXPR:
6075 case FIX_CEIL_EXPR:
6076 case FIX_TRUNC_EXPR:
6077 case FLOAT_EXPR:
6078 case NEGATE_EXPR:
6079 case ABS_EXPR:
6080 case MAX_EXPR:
6081 case MIN_EXPR:
6082
6083 case BIT_AND_EXPR:
6084 case BIT_IOR_EXPR:
6085 case BIT_XOR_EXPR:
6086 case LSHIFT_EXPR:
6087 case RSHIFT_EXPR:
6088 case LROTATE_EXPR:
6089 case RROTATE_EXPR:
6090
6091 case PREINCREMENT_EXPR:
6092 case PREDECREMENT_EXPR:
6093 case POSTINCREMENT_EXPR:
6094 case POSTDECREMENT_EXPR:
6095 if (flags & tf_error)
6096 error ("invalid operation on uninstantiated type");
6097 return error_mark_node;
6098
6099 case TRUTH_AND_EXPR:
6100 case TRUTH_OR_EXPR:
6101 case TRUTH_XOR_EXPR:
6102 case LT_EXPR:
6103 case LE_EXPR:
6104 case GT_EXPR:
6105 case GE_EXPR:
6106 case EQ_EXPR:
6107 case NE_EXPR:
6108 case TRUTH_ANDIF_EXPR:
6109 case TRUTH_ORIF_EXPR:
6110 case TRUTH_NOT_EXPR:
6111 if (flags & tf_error)
6112 error ("not enough type information");
6113 return error_mark_node;
6114
6115 case COND_EXPR:
6116 if (type_unknown_p (TREE_OPERAND (rhs, 0)))
6117 {
6118 if (flags & tf_error)
6119 error ("not enough type information");
6120 return error_mark_node;
6121 }
6122 TREE_OPERAND (rhs, 1)
6123 = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
6124 if (TREE_OPERAND (rhs, 1) == error_mark_node)
6125 return error_mark_node;
6126 TREE_OPERAND (rhs, 2)
6127 = instantiate_type (lhstype, TREE_OPERAND (rhs, 2), flags);
6128 if (TREE_OPERAND (rhs, 2) == error_mark_node)
6129 return error_mark_node;
6130
6131 TREE_TYPE (rhs) = lhstype;
6132 return rhs;
6133
6134 case MODIFY_EXPR:
6135 TREE_OPERAND (rhs, 1)
6136 = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
6137 if (TREE_OPERAND (rhs, 1) == error_mark_node)
6138 return error_mark_node;
6139
6140 TREE_TYPE (rhs) = lhstype;
6141 return rhs;
6142
6143 case ADDR_EXPR:
6144 {
6145 if (PTRMEM_OK_P (rhs))
6146 flags |= tf_ptrmem_ok;
6147
6148 return instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
6149 }
6150
6151 case ERROR_MARK:
6152 return error_mark_node;
6153
6154 default:
6155 gcc_unreachable ();
6156 }
6157 return error_mark_node;
6158 }
6159 \f
6160 /* Return the name of the virtual function pointer field
6161 (as an IDENTIFIER_NODE) for the given TYPE. Note that
6162 this may have to look back through base types to find the
6163 ultimate field name. (For single inheritance, these could
6164 all be the same name. Who knows for multiple inheritance). */
6165
6166 static tree
6167 get_vfield_name (tree type)
6168 {
6169 tree binfo, base_binfo;
6170 char *buf;
6171
6172 for (binfo = TYPE_BINFO (type);
6173 BINFO_N_BASE_BINFOS (binfo);
6174 binfo = base_binfo)
6175 {
6176 base_binfo = BINFO_BASE_BINFO (binfo, 0);
6177
6178 if (BINFO_VIRTUAL_P (base_binfo)
6179 || !TYPE_CONTAINS_VPTR_P (BINFO_TYPE (base_binfo)))
6180 break;
6181 }
6182
6183 type = BINFO_TYPE (binfo);
6184 buf = alloca (sizeof (VFIELD_NAME_FORMAT) + TYPE_NAME_LENGTH (type) + 2);
6185 sprintf (buf, VFIELD_NAME_FORMAT,
6186 IDENTIFIER_POINTER (constructor_name (type)));
6187 return get_identifier (buf);
6188 }
6189
6190 void
6191 print_class_statistics (void)
6192 {
6193 #ifdef GATHER_STATISTICS
6194 fprintf (stderr, "convert_harshness = %d\n", n_convert_harshness);
6195 fprintf (stderr, "compute_conversion_costs = %d\n", n_compute_conversion_costs);
6196 if (n_vtables)
6197 {
6198 fprintf (stderr, "vtables = %d; vtable searches = %d\n",
6199 n_vtables, n_vtable_searches);
6200 fprintf (stderr, "vtable entries = %d; vtable elems = %d\n",
6201 n_vtable_entries, n_vtable_elems);
6202 }
6203 #endif
6204 }
6205
6206 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6207 according to [class]:
6208 The class-name is also inserted
6209 into the scope of the class itself. For purposes of access checking,
6210 the inserted class name is treated as if it were a public member name. */
6211
6212 void
6213 build_self_reference (void)
6214 {
6215 tree name = constructor_name (current_class_type);
6216 tree value = build_lang_decl (TYPE_DECL, name, current_class_type);
6217 tree saved_cas;
6218
6219 DECL_NONLOCAL (value) = 1;
6220 DECL_CONTEXT (value) = current_class_type;
6221 DECL_ARTIFICIAL (value) = 1;
6222 SET_DECL_SELF_REFERENCE_P (value);
6223
6224 if (processing_template_decl)
6225 value = push_template_decl (value);
6226
6227 saved_cas = current_access_specifier;
6228 current_access_specifier = access_public_node;
6229 finish_member_declaration (value);
6230 current_access_specifier = saved_cas;
6231 }
6232
6233 /* Returns 1 if TYPE contains only padding bytes. */
6234
6235 int
6236 is_empty_class (tree type)
6237 {
6238 if (type == error_mark_node)
6239 return 0;
6240
6241 if (! IS_AGGR_TYPE (type))
6242 return 0;
6243
6244 /* In G++ 3.2, whether or not a class was empty was determined by
6245 looking at its size. */
6246 if (abi_version_at_least (2))
6247 return CLASSTYPE_EMPTY_P (type);
6248 else
6249 return integer_zerop (CLASSTYPE_SIZE (type));
6250 }
6251
6252 /* Returns true if TYPE contains an empty class. */
6253
6254 static bool
6255 contains_empty_class_p (tree type)
6256 {
6257 if (is_empty_class (type))
6258 return true;
6259 if (CLASS_TYPE_P (type))
6260 {
6261 tree field;
6262 tree binfo;
6263 tree base_binfo;
6264 int i;
6265
6266 for (binfo = TYPE_BINFO (type), i = 0;
6267 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
6268 if (contains_empty_class_p (BINFO_TYPE (base_binfo)))
6269 return true;
6270 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
6271 if (TREE_CODE (field) == FIELD_DECL
6272 && !DECL_ARTIFICIAL (field)
6273 && is_empty_class (TREE_TYPE (field)))
6274 return true;
6275 }
6276 else if (TREE_CODE (type) == ARRAY_TYPE)
6277 return contains_empty_class_p (TREE_TYPE (type));
6278 return false;
6279 }
6280
6281 /* Note that NAME was looked up while the current class was being
6282 defined and that the result of that lookup was DECL. */
6283
6284 void
6285 maybe_note_name_used_in_class (tree name, tree decl)
6286 {
6287 splay_tree names_used;
6288
6289 /* If we're not defining a class, there's nothing to do. */
6290 if (!(innermost_scope_kind() == sk_class
6291 && TYPE_BEING_DEFINED (current_class_type)))
6292 return;
6293
6294 /* If there's already a binding for this NAME, then we don't have
6295 anything to worry about. */
6296 if (lookup_member (current_class_type, name,
6297 /*protect=*/0, /*want_type=*/false))
6298 return;
6299
6300 if (!current_class_stack[current_class_depth - 1].names_used)
6301 current_class_stack[current_class_depth - 1].names_used
6302 = splay_tree_new (splay_tree_compare_pointers, 0, 0);
6303 names_used = current_class_stack[current_class_depth - 1].names_used;
6304
6305 splay_tree_insert (names_used,
6306 (splay_tree_key) name,
6307 (splay_tree_value) decl);
6308 }
6309
6310 /* Note that NAME was declared (as DECL) in the current class. Check
6311 to see that the declaration is valid. */
6312
6313 void
6314 note_name_declared_in_class (tree name, tree decl)
6315 {
6316 splay_tree names_used;
6317 splay_tree_node n;
6318
6319 /* Look to see if we ever used this name. */
6320 names_used
6321 = current_class_stack[current_class_depth - 1].names_used;
6322 if (!names_used)
6323 return;
6324
6325 n = splay_tree_lookup (names_used, (splay_tree_key) name);
6326 if (n)
6327 {
6328 /* [basic.scope.class]
6329
6330 A name N used in a class S shall refer to the same declaration
6331 in its context and when re-evaluated in the completed scope of
6332 S. */
6333 error ("declaration of %q#D", decl);
6334 error ("changes meaning of %qD from %q+#D",
6335 DECL_NAME (OVL_CURRENT (decl)), (tree) n->value);
6336 }
6337 }
6338
6339 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6340 Secondary vtables are merged with primary vtables; this function
6341 will return the VAR_DECL for the primary vtable. */
6342
6343 tree
6344 get_vtbl_decl_for_binfo (tree binfo)
6345 {
6346 tree decl;
6347
6348 decl = BINFO_VTABLE (binfo);
6349 if (decl && TREE_CODE (decl) == PLUS_EXPR)
6350 {
6351 gcc_assert (TREE_CODE (TREE_OPERAND (decl, 0)) == ADDR_EXPR);
6352 decl = TREE_OPERAND (TREE_OPERAND (decl, 0), 0);
6353 }
6354 if (decl)
6355 gcc_assert (TREE_CODE (decl) == VAR_DECL);
6356 return decl;
6357 }
6358
6359
6360 /* Returns the binfo for the primary base of BINFO. If the resulting
6361 BINFO is a virtual base, and it is inherited elsewhere in the
6362 hierarchy, then the returned binfo might not be the primary base of
6363 BINFO in the complete object. Check BINFO_PRIMARY_P or
6364 BINFO_LOST_PRIMARY_P to be sure. */
6365
6366 static tree
6367 get_primary_binfo (tree binfo)
6368 {
6369 tree primary_base;
6370
6371 primary_base = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (binfo));
6372 if (!primary_base)
6373 return NULL_TREE;
6374
6375 return copied_binfo (primary_base, binfo);
6376 }
6377
6378 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
6379
6380 static int
6381 maybe_indent_hierarchy (FILE * stream, int indent, int indented_p)
6382 {
6383 if (!indented_p)
6384 fprintf (stream, "%*s", indent, "");
6385 return 1;
6386 }
6387
6388 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
6389 INDENT should be zero when called from the top level; it is
6390 incremented recursively. IGO indicates the next expected BINFO in
6391 inheritance graph ordering. */
6392
6393 static tree
6394 dump_class_hierarchy_r (FILE *stream,
6395 int flags,
6396 tree binfo,
6397 tree igo,
6398 int indent)
6399 {
6400 int indented = 0;
6401 tree base_binfo;
6402 int i;
6403
6404 indented = maybe_indent_hierarchy (stream, indent, 0);
6405 fprintf (stream, "%s (0x%lx) ",
6406 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER),
6407 (unsigned long) binfo);
6408 if (binfo != igo)
6409 {
6410 fprintf (stream, "alternative-path\n");
6411 return igo;
6412 }
6413 igo = TREE_CHAIN (binfo);
6414
6415 fprintf (stream, HOST_WIDE_INT_PRINT_DEC,
6416 tree_low_cst (BINFO_OFFSET (binfo), 0));
6417 if (is_empty_class (BINFO_TYPE (binfo)))
6418 fprintf (stream, " empty");
6419 else if (CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (binfo)))
6420 fprintf (stream, " nearly-empty");
6421 if (BINFO_VIRTUAL_P (binfo))
6422 fprintf (stream, " virtual");
6423 fprintf (stream, "\n");
6424
6425 indented = 0;
6426 if (BINFO_PRIMARY_P (binfo))
6427 {
6428 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6429 fprintf (stream, " primary-for %s (0x%lx)",
6430 type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)),
6431 TFF_PLAIN_IDENTIFIER),
6432 (unsigned long)BINFO_INHERITANCE_CHAIN (binfo));
6433 }
6434 if (BINFO_LOST_PRIMARY_P (binfo))
6435 {
6436 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6437 fprintf (stream, " lost-primary");
6438 }
6439 if (indented)
6440 fprintf (stream, "\n");
6441
6442 if (!(flags & TDF_SLIM))
6443 {
6444 int indented = 0;
6445
6446 if (BINFO_SUBVTT_INDEX (binfo))
6447 {
6448 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6449 fprintf (stream, " subvttidx=%s",
6450 expr_as_string (BINFO_SUBVTT_INDEX (binfo),
6451 TFF_PLAIN_IDENTIFIER));
6452 }
6453 if (BINFO_VPTR_INDEX (binfo))
6454 {
6455 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6456 fprintf (stream, " vptridx=%s",
6457 expr_as_string (BINFO_VPTR_INDEX (binfo),
6458 TFF_PLAIN_IDENTIFIER));
6459 }
6460 if (BINFO_VPTR_FIELD (binfo))
6461 {
6462 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6463 fprintf (stream, " vbaseoffset=%s",
6464 expr_as_string (BINFO_VPTR_FIELD (binfo),
6465 TFF_PLAIN_IDENTIFIER));
6466 }
6467 if (BINFO_VTABLE (binfo))
6468 {
6469 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6470 fprintf (stream, " vptr=%s",
6471 expr_as_string (BINFO_VTABLE (binfo),
6472 TFF_PLAIN_IDENTIFIER));
6473 }
6474
6475 if (indented)
6476 fprintf (stream, "\n");
6477 }
6478
6479 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
6480 igo = dump_class_hierarchy_r (stream, flags, base_binfo, igo, indent + 2);
6481
6482 return igo;
6483 }
6484
6485 /* Dump the BINFO hierarchy for T. */
6486
6487 static void
6488 dump_class_hierarchy_1 (FILE *stream, int flags, tree t)
6489 {
6490 fprintf (stream, "Class %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6491 fprintf (stream, " size=%lu align=%lu\n",
6492 (unsigned long)(tree_low_cst (TYPE_SIZE (t), 0) / BITS_PER_UNIT),
6493 (unsigned long)(TYPE_ALIGN (t) / BITS_PER_UNIT));
6494 fprintf (stream, " base size=%lu base align=%lu\n",
6495 (unsigned long)(tree_low_cst (TYPE_SIZE (CLASSTYPE_AS_BASE (t)), 0)
6496 / BITS_PER_UNIT),
6497 (unsigned long)(TYPE_ALIGN (CLASSTYPE_AS_BASE (t))
6498 / BITS_PER_UNIT));
6499 dump_class_hierarchy_r (stream, flags, TYPE_BINFO (t), TYPE_BINFO (t), 0);
6500 fprintf (stream, "\n");
6501 }
6502
6503 /* Debug interface to hierarchy dumping. */
6504
6505 extern void
6506 debug_class (tree t)
6507 {
6508 dump_class_hierarchy_1 (stderr, TDF_SLIM, t);
6509 }
6510
6511 static void
6512 dump_class_hierarchy (tree t)
6513 {
6514 int flags;
6515 FILE *stream = dump_begin (TDI_class, &flags);
6516
6517 if (stream)
6518 {
6519 dump_class_hierarchy_1 (stream, flags, t);
6520 dump_end (TDI_class, stream);
6521 }
6522 }
6523
6524 static void
6525 dump_array (FILE * stream, tree decl)
6526 {
6527 tree value;
6528 unsigned HOST_WIDE_INT ix;
6529 HOST_WIDE_INT elt;
6530 tree size = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (decl)));
6531
6532 elt = (tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl))), 0)
6533 / BITS_PER_UNIT);
6534 fprintf (stream, "%s:", decl_as_string (decl, TFF_PLAIN_IDENTIFIER));
6535 fprintf (stream, " %s entries",
6536 expr_as_string (size_binop (PLUS_EXPR, size, size_one_node),
6537 TFF_PLAIN_IDENTIFIER));
6538 fprintf (stream, "\n");
6539
6540 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (DECL_INITIAL (decl)),
6541 ix, value)
6542 fprintf (stream, "%-4ld %s\n", (long)(ix * elt),
6543 expr_as_string (value, TFF_PLAIN_IDENTIFIER));
6544 }
6545
6546 static void
6547 dump_vtable (tree t, tree binfo, tree vtable)
6548 {
6549 int flags;
6550 FILE *stream = dump_begin (TDI_class, &flags);
6551
6552 if (!stream)
6553 return;
6554
6555 if (!(flags & TDF_SLIM))
6556 {
6557 int ctor_vtbl_p = TYPE_BINFO (t) != binfo;
6558
6559 fprintf (stream, "%s for %s",
6560 ctor_vtbl_p ? "Construction vtable" : "Vtable",
6561 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER));
6562 if (ctor_vtbl_p)
6563 {
6564 if (!BINFO_VIRTUAL_P (binfo))
6565 fprintf (stream, " (0x%lx instance)", (unsigned long)binfo);
6566 fprintf (stream, " in %s", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6567 }
6568 fprintf (stream, "\n");
6569 dump_array (stream, vtable);
6570 fprintf (stream, "\n");
6571 }
6572
6573 dump_end (TDI_class, stream);
6574 }
6575
6576 static void
6577 dump_vtt (tree t, tree vtt)
6578 {
6579 int flags;
6580 FILE *stream = dump_begin (TDI_class, &flags);
6581
6582 if (!stream)
6583 return;
6584
6585 if (!(flags & TDF_SLIM))
6586 {
6587 fprintf (stream, "VTT for %s\n",
6588 type_as_string (t, TFF_PLAIN_IDENTIFIER));
6589 dump_array (stream, vtt);
6590 fprintf (stream, "\n");
6591 }
6592
6593 dump_end (TDI_class, stream);
6594 }
6595
6596 /* Dump a function or thunk and its thunkees. */
6597
6598 static void
6599 dump_thunk (FILE *stream, int indent, tree thunk)
6600 {
6601 static const char spaces[] = " ";
6602 tree name = DECL_NAME (thunk);
6603 tree thunks;
6604
6605 fprintf (stream, "%.*s%p %s %s", indent, spaces,
6606 (void *)thunk,
6607 !DECL_THUNK_P (thunk) ? "function"
6608 : DECL_THIS_THUNK_P (thunk) ? "this-thunk" : "covariant-thunk",
6609 name ? IDENTIFIER_POINTER (name) : "<unset>");
6610 if (DECL_THUNK_P (thunk))
6611 {
6612 HOST_WIDE_INT fixed_adjust = THUNK_FIXED_OFFSET (thunk);
6613 tree virtual_adjust = THUNK_VIRTUAL_OFFSET (thunk);
6614
6615 fprintf (stream, " fixed=" HOST_WIDE_INT_PRINT_DEC, fixed_adjust);
6616 if (!virtual_adjust)
6617 /*NOP*/;
6618 else if (DECL_THIS_THUNK_P (thunk))
6619 fprintf (stream, " vcall=" HOST_WIDE_INT_PRINT_DEC,
6620 tree_low_cst (virtual_adjust, 0));
6621 else
6622 fprintf (stream, " vbase=" HOST_WIDE_INT_PRINT_DEC "(%s)",
6623 tree_low_cst (BINFO_VPTR_FIELD (virtual_adjust), 0),
6624 type_as_string (BINFO_TYPE (virtual_adjust), TFF_SCOPE));
6625 if (THUNK_ALIAS (thunk))
6626 fprintf (stream, " alias to %p", (void *)THUNK_ALIAS (thunk));
6627 }
6628 fprintf (stream, "\n");
6629 for (thunks = DECL_THUNKS (thunk); thunks; thunks = TREE_CHAIN (thunks))
6630 dump_thunk (stream, indent + 2, thunks);
6631 }
6632
6633 /* Dump the thunks for FN. */
6634
6635 extern void
6636 debug_thunks (tree fn)
6637 {
6638 dump_thunk (stderr, 0, fn);
6639 }
6640
6641 /* Virtual function table initialization. */
6642
6643 /* Create all the necessary vtables for T and its base classes. */
6644
6645 static void
6646 finish_vtbls (tree t)
6647 {
6648 tree list;
6649 tree vbase;
6650
6651 /* We lay out the primary and secondary vtables in one contiguous
6652 vtable. The primary vtable is first, followed by the non-virtual
6653 secondary vtables in inheritance graph order. */
6654 list = build_tree_list (BINFO_VTABLE (TYPE_BINFO (t)), NULL_TREE);
6655 accumulate_vtbl_inits (TYPE_BINFO (t), TYPE_BINFO (t),
6656 TYPE_BINFO (t), t, list);
6657
6658 /* Then come the virtual bases, also in inheritance graph order. */
6659 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
6660 {
6661 if (!BINFO_VIRTUAL_P (vbase))
6662 continue;
6663 accumulate_vtbl_inits (vbase, vbase, TYPE_BINFO (t), t, list);
6664 }
6665
6666 if (BINFO_VTABLE (TYPE_BINFO (t)))
6667 initialize_vtable (TYPE_BINFO (t), TREE_VALUE (list));
6668 }
6669
6670 /* Initialize the vtable for BINFO with the INITS. */
6671
6672 static void
6673 initialize_vtable (tree binfo, tree inits)
6674 {
6675 tree decl;
6676
6677 layout_vtable_decl (binfo, list_length (inits));
6678 decl = get_vtbl_decl_for_binfo (binfo);
6679 initialize_artificial_var (decl, inits);
6680 dump_vtable (BINFO_TYPE (binfo), binfo, decl);
6681 }
6682
6683 /* Build the VTT (virtual table table) for T.
6684 A class requires a VTT if it has virtual bases.
6685
6686 This holds
6687 1 - primary virtual pointer for complete object T
6688 2 - secondary VTTs for each direct non-virtual base of T which requires a
6689 VTT
6690 3 - secondary virtual pointers for each direct or indirect base of T which
6691 has virtual bases or is reachable via a virtual path from T.
6692 4 - secondary VTTs for each direct or indirect virtual base of T.
6693
6694 Secondary VTTs look like complete object VTTs without part 4. */
6695
6696 static void
6697 build_vtt (tree t)
6698 {
6699 tree inits;
6700 tree type;
6701 tree vtt;
6702 tree index;
6703
6704 /* Build up the initializers for the VTT. */
6705 inits = NULL_TREE;
6706 index = size_zero_node;
6707 build_vtt_inits (TYPE_BINFO (t), t, &inits, &index);
6708
6709 /* If we didn't need a VTT, we're done. */
6710 if (!inits)
6711 return;
6712
6713 /* Figure out the type of the VTT. */
6714 type = build_index_type (size_int (list_length (inits) - 1));
6715 type = build_cplus_array_type (const_ptr_type_node, type);
6716
6717 /* Now, build the VTT object itself. */
6718 vtt = build_vtable (t, mangle_vtt_for_type (t), type);
6719 initialize_artificial_var (vtt, inits);
6720 /* Add the VTT to the vtables list. */
6721 TREE_CHAIN (vtt) = TREE_CHAIN (CLASSTYPE_VTABLES (t));
6722 TREE_CHAIN (CLASSTYPE_VTABLES (t)) = vtt;
6723
6724 dump_vtt (t, vtt);
6725 }
6726
6727 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
6728 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
6729 and CHAIN the vtable pointer for this binfo after construction is
6730 complete. VALUE can also be another BINFO, in which case we recurse. */
6731
6732 static tree
6733 binfo_ctor_vtable (tree binfo)
6734 {
6735 tree vt;
6736
6737 while (1)
6738 {
6739 vt = BINFO_VTABLE (binfo);
6740 if (TREE_CODE (vt) == TREE_LIST)
6741 vt = TREE_VALUE (vt);
6742 if (TREE_CODE (vt) == TREE_BINFO)
6743 binfo = vt;
6744 else
6745 break;
6746 }
6747
6748 return vt;
6749 }
6750
6751 /* Data for secondary VTT initialization. */
6752 typedef struct secondary_vptr_vtt_init_data_s
6753 {
6754 /* Is this the primary VTT? */
6755 bool top_level_p;
6756
6757 /* Current index into the VTT. */
6758 tree index;
6759
6760 /* TREE_LIST of initializers built up. */
6761 tree inits;
6762
6763 /* The type being constructed by this secondary VTT. */
6764 tree type_being_constructed;
6765 } secondary_vptr_vtt_init_data;
6766
6767 /* Recursively build the VTT-initializer for BINFO (which is in the
6768 hierarchy dominated by T). INITS points to the end of the initializer
6769 list to date. INDEX is the VTT index where the next element will be
6770 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
6771 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
6772 for virtual bases of T. When it is not so, we build the constructor
6773 vtables for the BINFO-in-T variant. */
6774
6775 static tree *
6776 build_vtt_inits (tree binfo, tree t, tree *inits, tree *index)
6777 {
6778 int i;
6779 tree b;
6780 tree init;
6781 tree secondary_vptrs;
6782 secondary_vptr_vtt_init_data data;
6783 int top_level_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
6784
6785 /* We only need VTTs for subobjects with virtual bases. */
6786 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
6787 return inits;
6788
6789 /* We need to use a construction vtable if this is not the primary
6790 VTT. */
6791 if (!top_level_p)
6792 {
6793 build_ctor_vtbl_group (binfo, t);
6794
6795 /* Record the offset in the VTT where this sub-VTT can be found. */
6796 BINFO_SUBVTT_INDEX (binfo) = *index;
6797 }
6798
6799 /* Add the address of the primary vtable for the complete object. */
6800 init = binfo_ctor_vtable (binfo);
6801 *inits = build_tree_list (NULL_TREE, init);
6802 inits = &TREE_CHAIN (*inits);
6803 if (top_level_p)
6804 {
6805 gcc_assert (!BINFO_VPTR_INDEX (binfo));
6806 BINFO_VPTR_INDEX (binfo) = *index;
6807 }
6808 *index = size_binop (PLUS_EXPR, *index, TYPE_SIZE_UNIT (ptr_type_node));
6809
6810 /* Recursively add the secondary VTTs for non-virtual bases. */
6811 for (i = 0; BINFO_BASE_ITERATE (binfo, i, b); ++i)
6812 if (!BINFO_VIRTUAL_P (b))
6813 inits = build_vtt_inits (b, t, inits, index);
6814
6815 /* Add secondary virtual pointers for all subobjects of BINFO with
6816 either virtual bases or reachable along a virtual path, except
6817 subobjects that are non-virtual primary bases. */
6818 data.top_level_p = top_level_p;
6819 data.index = *index;
6820 data.inits = NULL;
6821 data.type_being_constructed = BINFO_TYPE (binfo);
6822
6823 dfs_walk_once (binfo, dfs_build_secondary_vptr_vtt_inits, NULL, &data);
6824
6825 *index = data.index;
6826
6827 /* The secondary vptrs come back in reverse order. After we reverse
6828 them, and add the INITS, the last init will be the first element
6829 of the chain. */
6830 secondary_vptrs = data.inits;
6831 if (secondary_vptrs)
6832 {
6833 *inits = nreverse (secondary_vptrs);
6834 inits = &TREE_CHAIN (secondary_vptrs);
6835 gcc_assert (*inits == NULL_TREE);
6836 }
6837
6838 if (top_level_p)
6839 /* Add the secondary VTTs for virtual bases in inheritance graph
6840 order. */
6841 for (b = TYPE_BINFO (BINFO_TYPE (binfo)); b; b = TREE_CHAIN (b))
6842 {
6843 if (!BINFO_VIRTUAL_P (b))
6844 continue;
6845
6846 inits = build_vtt_inits (b, t, inits, index);
6847 }
6848 else
6849 /* Remove the ctor vtables we created. */
6850 dfs_walk_all (binfo, dfs_fixup_binfo_vtbls, NULL, binfo);
6851
6852 return inits;
6853 }
6854
6855 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
6856 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
6857
6858 static tree
6859 dfs_build_secondary_vptr_vtt_inits (tree binfo, void *data_)
6860 {
6861 secondary_vptr_vtt_init_data *data = (secondary_vptr_vtt_init_data *)data_;
6862
6863 /* We don't care about bases that don't have vtables. */
6864 if (!TYPE_VFIELD (BINFO_TYPE (binfo)))
6865 return dfs_skip_bases;
6866
6867 /* We're only interested in proper subobjects of the type being
6868 constructed. */
6869 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->type_being_constructed))
6870 return NULL_TREE;
6871
6872 /* We're only interested in bases with virtual bases or reachable
6873 via a virtual path from the type being constructed. */
6874 if (!(CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
6875 || binfo_via_virtual (binfo, data->type_being_constructed)))
6876 return dfs_skip_bases;
6877
6878 /* We're not interested in non-virtual primary bases. */
6879 if (!BINFO_VIRTUAL_P (binfo) && BINFO_PRIMARY_P (binfo))
6880 return NULL_TREE;
6881
6882 /* Record the index where this secondary vptr can be found. */
6883 if (data->top_level_p)
6884 {
6885 gcc_assert (!BINFO_VPTR_INDEX (binfo));
6886 BINFO_VPTR_INDEX (binfo) = data->index;
6887
6888 if (BINFO_VIRTUAL_P (binfo))
6889 {
6890 /* It's a primary virtual base, and this is not a
6891 construction vtable. Find the base this is primary of in
6892 the inheritance graph, and use that base's vtable
6893 now. */
6894 while (BINFO_PRIMARY_P (binfo))
6895 binfo = BINFO_INHERITANCE_CHAIN (binfo);
6896 }
6897 }
6898
6899 /* Add the initializer for the secondary vptr itself. */
6900 data->inits = tree_cons (NULL_TREE, binfo_ctor_vtable (binfo), data->inits);
6901
6902 /* Advance the vtt index. */
6903 data->index = size_binop (PLUS_EXPR, data->index,
6904 TYPE_SIZE_UNIT (ptr_type_node));
6905
6906 return NULL_TREE;
6907 }
6908
6909 /* Called from build_vtt_inits via dfs_walk. After building
6910 constructor vtables and generating the sub-vtt from them, we need
6911 to restore the BINFO_VTABLES that were scribbled on. DATA is the
6912 binfo of the base whose sub vtt was generated. */
6913
6914 static tree
6915 dfs_fixup_binfo_vtbls (tree binfo, void* data)
6916 {
6917 tree vtable = BINFO_VTABLE (binfo);
6918
6919 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
6920 /* If this class has no vtable, none of its bases do. */
6921 return dfs_skip_bases;
6922
6923 if (!vtable)
6924 /* This might be a primary base, so have no vtable in this
6925 hierarchy. */
6926 return NULL_TREE;
6927
6928 /* If we scribbled the construction vtable vptr into BINFO, clear it
6929 out now. */
6930 if (TREE_CODE (vtable) == TREE_LIST
6931 && (TREE_PURPOSE (vtable) == (tree) data))
6932 BINFO_VTABLE (binfo) = TREE_CHAIN (vtable);
6933
6934 return NULL_TREE;
6935 }
6936
6937 /* Build the construction vtable group for BINFO which is in the
6938 hierarchy dominated by T. */
6939
6940 static void
6941 build_ctor_vtbl_group (tree binfo, tree t)
6942 {
6943 tree list;
6944 tree type;
6945 tree vtbl;
6946 tree inits;
6947 tree id;
6948 tree vbase;
6949
6950 /* See if we've already created this construction vtable group. */
6951 id = mangle_ctor_vtbl_for_type (t, binfo);
6952 if (IDENTIFIER_GLOBAL_VALUE (id))
6953 return;
6954
6955 gcc_assert (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t));
6956 /* Build a version of VTBL (with the wrong type) for use in
6957 constructing the addresses of secondary vtables in the
6958 construction vtable group. */
6959 vtbl = build_vtable (t, id, ptr_type_node);
6960 DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1;
6961 list = build_tree_list (vtbl, NULL_TREE);
6962 accumulate_vtbl_inits (binfo, TYPE_BINFO (TREE_TYPE (binfo)),
6963 binfo, t, list);
6964
6965 /* Add the vtables for each of our virtual bases using the vbase in T
6966 binfo. */
6967 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
6968 vbase;
6969 vbase = TREE_CHAIN (vbase))
6970 {
6971 tree b;
6972
6973 if (!BINFO_VIRTUAL_P (vbase))
6974 continue;
6975 b = copied_binfo (vbase, binfo);
6976
6977 accumulate_vtbl_inits (b, vbase, binfo, t, list);
6978 }
6979 inits = TREE_VALUE (list);
6980
6981 /* Figure out the type of the construction vtable. */
6982 type = build_index_type (size_int (list_length (inits) - 1));
6983 type = build_cplus_array_type (vtable_entry_type, type);
6984 TREE_TYPE (vtbl) = type;
6985
6986 /* Initialize the construction vtable. */
6987 CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl);
6988 initialize_artificial_var (vtbl, inits);
6989 dump_vtable (t, binfo, vtbl);
6990 }
6991
6992 /* Add the vtbl initializers for BINFO (and its bases other than
6993 non-virtual primaries) to the list of INITS. BINFO is in the
6994 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
6995 the constructor the vtbl inits should be accumulated for. (If this
6996 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
6997 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
6998 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
6999 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
7000 but are not necessarily the same in terms of layout. */
7001
7002 static void
7003 accumulate_vtbl_inits (tree binfo,
7004 tree orig_binfo,
7005 tree rtti_binfo,
7006 tree t,
7007 tree inits)
7008 {
7009 int i;
7010 tree base_binfo;
7011 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7012
7013 gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (orig_binfo)));
7014
7015 /* If it doesn't have a vptr, we don't do anything. */
7016 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
7017 return;
7018
7019 /* If we're building a construction vtable, we're not interested in
7020 subobjects that don't require construction vtables. */
7021 if (ctor_vtbl_p
7022 && !CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
7023 && !binfo_via_virtual (orig_binfo, BINFO_TYPE (rtti_binfo)))
7024 return;
7025
7026 /* Build the initializers for the BINFO-in-T vtable. */
7027 TREE_VALUE (inits)
7028 = chainon (TREE_VALUE (inits),
7029 dfs_accumulate_vtbl_inits (binfo, orig_binfo,
7030 rtti_binfo, t, inits));
7031
7032 /* Walk the BINFO and its bases. We walk in preorder so that as we
7033 initialize each vtable we can figure out at what offset the
7034 secondary vtable lies from the primary vtable. We can't use
7035 dfs_walk here because we need to iterate through bases of BINFO
7036 and RTTI_BINFO simultaneously. */
7037 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7038 {
7039 /* Skip virtual bases. */
7040 if (BINFO_VIRTUAL_P (base_binfo))
7041 continue;
7042 accumulate_vtbl_inits (base_binfo,
7043 BINFO_BASE_BINFO (orig_binfo, i),
7044 rtti_binfo, t,
7045 inits);
7046 }
7047 }
7048
7049 /* Called from accumulate_vtbl_inits. Returns the initializers for
7050 the BINFO vtable. */
7051
7052 static tree
7053 dfs_accumulate_vtbl_inits (tree binfo,
7054 tree orig_binfo,
7055 tree rtti_binfo,
7056 tree t,
7057 tree l)
7058 {
7059 tree inits = NULL_TREE;
7060 tree vtbl = NULL_TREE;
7061 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7062
7063 if (ctor_vtbl_p
7064 && BINFO_VIRTUAL_P (orig_binfo) && BINFO_PRIMARY_P (orig_binfo))
7065 {
7066 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7067 primary virtual base. If it is not the same primary in
7068 the hierarchy of T, we'll need to generate a ctor vtable
7069 for it, to place at its location in T. If it is the same
7070 primary, we still need a VTT entry for the vtable, but it
7071 should point to the ctor vtable for the base it is a
7072 primary for within the sub-hierarchy of RTTI_BINFO.
7073
7074 There are three possible cases:
7075
7076 1) We are in the same place.
7077 2) We are a primary base within a lost primary virtual base of
7078 RTTI_BINFO.
7079 3) We are primary to something not a base of RTTI_BINFO. */
7080
7081 tree b;
7082 tree last = NULL_TREE;
7083
7084 /* First, look through the bases we are primary to for RTTI_BINFO
7085 or a virtual base. */
7086 b = binfo;
7087 while (BINFO_PRIMARY_P (b))
7088 {
7089 b = BINFO_INHERITANCE_CHAIN (b);
7090 last = b;
7091 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7092 goto found;
7093 }
7094 /* If we run out of primary links, keep looking down our
7095 inheritance chain; we might be an indirect primary. */
7096 for (b = last; b; b = BINFO_INHERITANCE_CHAIN (b))
7097 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7098 break;
7099 found:
7100
7101 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
7102 base B and it is a base of RTTI_BINFO, this is case 2. In
7103 either case, we share our vtable with LAST, i.e. the
7104 derived-most base within B of which we are a primary. */
7105 if (b == rtti_binfo
7106 || (b && binfo_for_vbase (BINFO_TYPE (b), BINFO_TYPE (rtti_binfo))))
7107 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7108 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
7109 binfo_ctor_vtable after everything's been set up. */
7110 vtbl = last;
7111
7112 /* Otherwise, this is case 3 and we get our own. */
7113 }
7114 else if (!BINFO_NEW_VTABLE_MARKED (orig_binfo))
7115 return inits;
7116
7117 if (!vtbl)
7118 {
7119 tree index;
7120 int non_fn_entries;
7121
7122 /* Compute the initializer for this vtable. */
7123 inits = build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo,
7124 &non_fn_entries);
7125
7126 /* Figure out the position to which the VPTR should point. */
7127 vtbl = TREE_PURPOSE (l);
7128 vtbl = build1 (ADDR_EXPR, vtbl_ptr_type_node, vtbl);
7129 index = size_binop (PLUS_EXPR,
7130 size_int (non_fn_entries),
7131 size_int (list_length (TREE_VALUE (l))));
7132 index = size_binop (MULT_EXPR,
7133 TYPE_SIZE_UNIT (vtable_entry_type),
7134 index);
7135 vtbl = build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, index);
7136 }
7137
7138 if (ctor_vtbl_p)
7139 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7140 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
7141 straighten this out. */
7142 BINFO_VTABLE (binfo) = tree_cons (rtti_binfo, vtbl, BINFO_VTABLE (binfo));
7143 else if (BINFO_PRIMARY_P (binfo) && BINFO_VIRTUAL_P (binfo))
7144 inits = NULL_TREE;
7145 else
7146 /* For an ordinary vtable, set BINFO_VTABLE. */
7147 BINFO_VTABLE (binfo) = vtbl;
7148
7149 return inits;
7150 }
7151
7152 static GTY(()) tree abort_fndecl_addr;
7153
7154 /* Construct the initializer for BINFO's virtual function table. BINFO
7155 is part of the hierarchy dominated by T. If we're building a
7156 construction vtable, the ORIG_BINFO is the binfo we should use to
7157 find the actual function pointers to put in the vtable - but they
7158 can be overridden on the path to most-derived in the graph that
7159 ORIG_BINFO belongs. Otherwise,
7160 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
7161 BINFO that should be indicated by the RTTI information in the
7162 vtable; it will be a base class of T, rather than T itself, if we
7163 are building a construction vtable.
7164
7165 The value returned is a TREE_LIST suitable for wrapping in a
7166 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
7167 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7168 number of non-function entries in the vtable.
7169
7170 It might seem that this function should never be called with a
7171 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7172 base is always subsumed by a derived class vtable. However, when
7173 we are building construction vtables, we do build vtables for
7174 primary bases; we need these while the primary base is being
7175 constructed. */
7176
7177 static tree
7178 build_vtbl_initializer (tree binfo,
7179 tree orig_binfo,
7180 tree t,
7181 tree rtti_binfo,
7182 int* non_fn_entries_p)
7183 {
7184 tree v, b;
7185 tree vfun_inits;
7186 vtbl_init_data vid;
7187 unsigned ix;
7188 tree vbinfo;
7189 VEC(tree,gc) *vbases;
7190
7191 /* Initialize VID. */
7192 memset (&vid, 0, sizeof (vid));
7193 vid.binfo = binfo;
7194 vid.derived = t;
7195 vid.rtti_binfo = rtti_binfo;
7196 vid.last_init = &vid.inits;
7197 vid.primary_vtbl_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
7198 vid.ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7199 vid.generate_vcall_entries = true;
7200 /* The first vbase or vcall offset is at index -3 in the vtable. */
7201 vid.index = ssize_int(-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE);
7202
7203 /* Add entries to the vtable for RTTI. */
7204 build_rtti_vtbl_entries (binfo, &vid);
7205
7206 /* Create an array for keeping track of the functions we've
7207 processed. When we see multiple functions with the same
7208 signature, we share the vcall offsets. */
7209 vid.fns = VEC_alloc (tree, gc, 32);
7210 /* Add the vcall and vbase offset entries. */
7211 build_vcall_and_vbase_vtbl_entries (binfo, &vid);
7212
7213 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7214 build_vbase_offset_vtbl_entries. */
7215 for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0;
7216 VEC_iterate (tree, vbases, ix, vbinfo); ix++)
7217 BINFO_VTABLE_PATH_MARKED (vbinfo) = 0;
7218
7219 /* If the target requires padding between data entries, add that now. */
7220 if (TARGET_VTABLE_DATA_ENTRY_DISTANCE > 1)
7221 {
7222 tree cur, *prev;
7223
7224 for (prev = &vid.inits; (cur = *prev); prev = &TREE_CHAIN (cur))
7225 {
7226 tree add = cur;
7227 int i;
7228
7229 for (i = 1; i < TARGET_VTABLE_DATA_ENTRY_DISTANCE; ++i)
7230 add = tree_cons (NULL_TREE,
7231 build1 (NOP_EXPR, vtable_entry_type,
7232 null_pointer_node),
7233 add);
7234 *prev = add;
7235 }
7236 }
7237
7238 if (non_fn_entries_p)
7239 *non_fn_entries_p = list_length (vid.inits);
7240
7241 /* Go through all the ordinary virtual functions, building up
7242 initializers. */
7243 vfun_inits = NULL_TREE;
7244 for (v = BINFO_VIRTUALS (orig_binfo); v; v = TREE_CHAIN (v))
7245 {
7246 tree delta;
7247 tree vcall_index;
7248 tree fn, fn_original;
7249 tree init = NULL_TREE;
7250
7251 fn = BV_FN (v);
7252 fn_original = fn;
7253 if (DECL_THUNK_P (fn))
7254 {
7255 if (!DECL_NAME (fn))
7256 finish_thunk (fn);
7257 if (THUNK_ALIAS (fn))
7258 {
7259 fn = THUNK_ALIAS (fn);
7260 BV_FN (v) = fn;
7261 }
7262 fn_original = THUNK_TARGET (fn);
7263 }
7264
7265 /* If the only definition of this function signature along our
7266 primary base chain is from a lost primary, this vtable slot will
7267 never be used, so just zero it out. This is important to avoid
7268 requiring extra thunks which cannot be generated with the function.
7269
7270 We first check this in update_vtable_entry_for_fn, so we handle
7271 restored primary bases properly; we also need to do it here so we
7272 zero out unused slots in ctor vtables, rather than filling themff
7273 with erroneous values (though harmless, apart from relocation
7274 costs). */
7275 for (b = binfo; ; b = get_primary_binfo (b))
7276 {
7277 /* We found a defn before a lost primary; go ahead as normal. */
7278 if (look_for_overrides_here (BINFO_TYPE (b), fn_original))
7279 break;
7280
7281 /* The nearest definition is from a lost primary; clear the
7282 slot. */
7283 if (BINFO_LOST_PRIMARY_P (b))
7284 {
7285 init = size_zero_node;
7286 break;
7287 }
7288 }
7289
7290 if (! init)
7291 {
7292 /* Pull the offset for `this', and the function to call, out of
7293 the list. */
7294 delta = BV_DELTA (v);
7295 vcall_index = BV_VCALL_INDEX (v);
7296
7297 gcc_assert (TREE_CODE (delta) == INTEGER_CST);
7298 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
7299
7300 /* You can't call an abstract virtual function; it's abstract.
7301 So, we replace these functions with __pure_virtual. */
7302 if (DECL_PURE_VIRTUAL_P (fn_original))
7303 {
7304 fn = abort_fndecl;
7305 if (abort_fndecl_addr == NULL)
7306 abort_fndecl_addr = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7307 init = abort_fndecl_addr;
7308 }
7309 else
7310 {
7311 if (!integer_zerop (delta) || vcall_index)
7312 {
7313 fn = make_thunk (fn, /*this_adjusting=*/1, delta, vcall_index);
7314 if (!DECL_NAME (fn))
7315 finish_thunk (fn);
7316 }
7317 /* Take the address of the function, considering it to be of an
7318 appropriate generic type. */
7319 init = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7320 }
7321 }
7322
7323 /* And add it to the chain of initializers. */
7324 if (TARGET_VTABLE_USES_DESCRIPTORS)
7325 {
7326 int i;
7327 if (init == size_zero_node)
7328 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7329 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7330 else
7331 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7332 {
7333 tree fdesc = build2 (FDESC_EXPR, vfunc_ptr_type_node,
7334 TREE_OPERAND (init, 0),
7335 build_int_cst (NULL_TREE, i));
7336 TREE_CONSTANT (fdesc) = 1;
7337 TREE_INVARIANT (fdesc) = 1;
7338
7339 vfun_inits = tree_cons (NULL_TREE, fdesc, vfun_inits);
7340 }
7341 }
7342 else
7343 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7344 }
7345
7346 /* The initializers for virtual functions were built up in reverse
7347 order; straighten them out now. */
7348 vfun_inits = nreverse (vfun_inits);
7349
7350 /* The negative offset initializers are also in reverse order. */
7351 vid.inits = nreverse (vid.inits);
7352
7353 /* Chain the two together. */
7354 return chainon (vid.inits, vfun_inits);
7355 }
7356
7357 /* Adds to vid->inits the initializers for the vbase and vcall
7358 offsets in BINFO, which is in the hierarchy dominated by T. */
7359
7360 static void
7361 build_vcall_and_vbase_vtbl_entries (tree binfo, vtbl_init_data* vid)
7362 {
7363 tree b;
7364
7365 /* If this is a derived class, we must first create entries
7366 corresponding to the primary base class. */
7367 b = get_primary_binfo (binfo);
7368 if (b)
7369 build_vcall_and_vbase_vtbl_entries (b, vid);
7370
7371 /* Add the vbase entries for this base. */
7372 build_vbase_offset_vtbl_entries (binfo, vid);
7373 /* Add the vcall entries for this base. */
7374 build_vcall_offset_vtbl_entries (binfo, vid);
7375 }
7376
7377 /* Returns the initializers for the vbase offset entries in the vtable
7378 for BINFO (which is part of the class hierarchy dominated by T), in
7379 reverse order. VBASE_OFFSET_INDEX gives the vtable index
7380 where the next vbase offset will go. */
7381
7382 static void
7383 build_vbase_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7384 {
7385 tree vbase;
7386 tree t;
7387 tree non_primary_binfo;
7388
7389 /* If there are no virtual baseclasses, then there is nothing to
7390 do. */
7391 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
7392 return;
7393
7394 t = vid->derived;
7395
7396 /* We might be a primary base class. Go up the inheritance hierarchy
7397 until we find the most derived class of which we are a primary base:
7398 it is the offset of that which we need to use. */
7399 non_primary_binfo = binfo;
7400 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7401 {
7402 tree b;
7403
7404 /* If we have reached a virtual base, then it must be a primary
7405 base (possibly multi-level) of vid->binfo, or we wouldn't
7406 have called build_vcall_and_vbase_vtbl_entries for it. But it
7407 might be a lost primary, so just skip down to vid->binfo. */
7408 if (BINFO_VIRTUAL_P (non_primary_binfo))
7409 {
7410 non_primary_binfo = vid->binfo;
7411 break;
7412 }
7413
7414 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7415 if (get_primary_binfo (b) != non_primary_binfo)
7416 break;
7417 non_primary_binfo = b;
7418 }
7419
7420 /* Go through the virtual bases, adding the offsets. */
7421 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
7422 vbase;
7423 vbase = TREE_CHAIN (vbase))
7424 {
7425 tree b;
7426 tree delta;
7427
7428 if (!BINFO_VIRTUAL_P (vbase))
7429 continue;
7430
7431 /* Find the instance of this virtual base in the complete
7432 object. */
7433 b = copied_binfo (vbase, binfo);
7434
7435 /* If we've already got an offset for this virtual base, we
7436 don't need another one. */
7437 if (BINFO_VTABLE_PATH_MARKED (b))
7438 continue;
7439 BINFO_VTABLE_PATH_MARKED (b) = 1;
7440
7441 /* Figure out where we can find this vbase offset. */
7442 delta = size_binop (MULT_EXPR,
7443 vid->index,
7444 convert (ssizetype,
7445 TYPE_SIZE_UNIT (vtable_entry_type)));
7446 if (vid->primary_vtbl_p)
7447 BINFO_VPTR_FIELD (b) = delta;
7448
7449 if (binfo != TYPE_BINFO (t))
7450 /* The vbase offset had better be the same. */
7451 gcc_assert (tree_int_cst_equal (delta, BINFO_VPTR_FIELD (vbase)));
7452
7453 /* The next vbase will come at a more negative offset. */
7454 vid->index = size_binop (MINUS_EXPR, vid->index,
7455 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7456
7457 /* The initializer is the delta from BINFO to this virtual base.
7458 The vbase offsets go in reverse inheritance-graph order, and
7459 we are walking in inheritance graph order so these end up in
7460 the right order. */
7461 delta = size_diffop (BINFO_OFFSET (b), BINFO_OFFSET (non_primary_binfo));
7462
7463 *vid->last_init
7464 = build_tree_list (NULL_TREE,
7465 fold_build1 (NOP_EXPR,
7466 vtable_entry_type,
7467 delta));
7468 vid->last_init = &TREE_CHAIN (*vid->last_init);
7469 }
7470 }
7471
7472 /* Adds the initializers for the vcall offset entries in the vtable
7473 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7474 to VID->INITS. */
7475
7476 static void
7477 build_vcall_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7478 {
7479 /* We only need these entries if this base is a virtual base. We
7480 compute the indices -- but do not add to the vtable -- when
7481 building the main vtable for a class. */
7482 if (BINFO_VIRTUAL_P (binfo) || binfo == TYPE_BINFO (vid->derived))
7483 {
7484 /* We need a vcall offset for each of the virtual functions in this
7485 vtable. For example:
7486
7487 class A { virtual void f (); };
7488 class B1 : virtual public A { virtual void f (); };
7489 class B2 : virtual public A { virtual void f (); };
7490 class C: public B1, public B2 { virtual void f (); };
7491
7492 A C object has a primary base of B1, which has a primary base of A. A
7493 C also has a secondary base of B2, which no longer has a primary base
7494 of A. So the B2-in-C construction vtable needs a secondary vtable for
7495 A, which will adjust the A* to a B2* to call f. We have no way of
7496 knowing what (or even whether) this offset will be when we define B2,
7497 so we store this "vcall offset" in the A sub-vtable and look it up in
7498 a "virtual thunk" for B2::f.
7499
7500 We need entries for all the functions in our primary vtable and
7501 in our non-virtual bases' secondary vtables. */
7502 vid->vbase = binfo;
7503 /* If we are just computing the vcall indices -- but do not need
7504 the actual entries -- not that. */
7505 if (!BINFO_VIRTUAL_P (binfo))
7506 vid->generate_vcall_entries = false;
7507 /* Now, walk through the non-virtual bases, adding vcall offsets. */
7508 add_vcall_offset_vtbl_entries_r (binfo, vid);
7509 }
7510 }
7511
7512 /* Build vcall offsets, starting with those for BINFO. */
7513
7514 static void
7515 add_vcall_offset_vtbl_entries_r (tree binfo, vtbl_init_data* vid)
7516 {
7517 int i;
7518 tree primary_binfo;
7519 tree base_binfo;
7520
7521 /* Don't walk into virtual bases -- except, of course, for the
7522 virtual base for which we are building vcall offsets. Any
7523 primary virtual base will have already had its offsets generated
7524 through the recursion in build_vcall_and_vbase_vtbl_entries. */
7525 if (BINFO_VIRTUAL_P (binfo) && vid->vbase != binfo)
7526 return;
7527
7528 /* If BINFO has a primary base, process it first. */
7529 primary_binfo = get_primary_binfo (binfo);
7530 if (primary_binfo)
7531 add_vcall_offset_vtbl_entries_r (primary_binfo, vid);
7532
7533 /* Add BINFO itself to the list. */
7534 add_vcall_offset_vtbl_entries_1 (binfo, vid);
7535
7536 /* Scan the non-primary bases of BINFO. */
7537 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7538 if (base_binfo != primary_binfo)
7539 add_vcall_offset_vtbl_entries_r (base_binfo, vid);
7540 }
7541
7542 /* Called from build_vcall_offset_vtbl_entries_r. */
7543
7544 static void
7545 add_vcall_offset_vtbl_entries_1 (tree binfo, vtbl_init_data* vid)
7546 {
7547 /* Make entries for the rest of the virtuals. */
7548 if (abi_version_at_least (2))
7549 {
7550 tree orig_fn;
7551
7552 /* The ABI requires that the methods be processed in declaration
7553 order. G++ 3.2 used the order in the vtable. */
7554 for (orig_fn = TYPE_METHODS (BINFO_TYPE (binfo));
7555 orig_fn;
7556 orig_fn = TREE_CHAIN (orig_fn))
7557 if (DECL_VINDEX (orig_fn))
7558 add_vcall_offset (orig_fn, binfo, vid);
7559 }
7560 else
7561 {
7562 tree derived_virtuals;
7563 tree base_virtuals;
7564 tree orig_virtuals;
7565 /* If BINFO is a primary base, the most derived class which has
7566 BINFO as a primary base; otherwise, just BINFO. */
7567 tree non_primary_binfo;
7568
7569 /* We might be a primary base class. Go up the inheritance hierarchy
7570 until we find the most derived class of which we are a primary base:
7571 it is the BINFO_VIRTUALS there that we need to consider. */
7572 non_primary_binfo = binfo;
7573 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7574 {
7575 tree b;
7576
7577 /* If we have reached a virtual base, then it must be vid->vbase,
7578 because we ignore other virtual bases in
7579 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
7580 base (possibly multi-level) of vid->binfo, or we wouldn't
7581 have called build_vcall_and_vbase_vtbl_entries for it. But it
7582 might be a lost primary, so just skip down to vid->binfo. */
7583 if (BINFO_VIRTUAL_P (non_primary_binfo))
7584 {
7585 gcc_assert (non_primary_binfo == vid->vbase);
7586 non_primary_binfo = vid->binfo;
7587 break;
7588 }
7589
7590 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7591 if (get_primary_binfo (b) != non_primary_binfo)
7592 break;
7593 non_primary_binfo = b;
7594 }
7595
7596 if (vid->ctor_vtbl_p)
7597 /* For a ctor vtable we need the equivalent binfo within the hierarchy
7598 where rtti_binfo is the most derived type. */
7599 non_primary_binfo
7600 = original_binfo (non_primary_binfo, vid->rtti_binfo);
7601
7602 for (base_virtuals = BINFO_VIRTUALS (binfo),
7603 derived_virtuals = BINFO_VIRTUALS (non_primary_binfo),
7604 orig_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
7605 base_virtuals;
7606 base_virtuals = TREE_CHAIN (base_virtuals),
7607 derived_virtuals = TREE_CHAIN (derived_virtuals),
7608 orig_virtuals = TREE_CHAIN (orig_virtuals))
7609 {
7610 tree orig_fn;
7611
7612 /* Find the declaration that originally caused this function to
7613 be present in BINFO_TYPE (binfo). */
7614 orig_fn = BV_FN (orig_virtuals);
7615
7616 /* When processing BINFO, we only want to generate vcall slots for
7617 function slots introduced in BINFO. So don't try to generate
7618 one if the function isn't even defined in BINFO. */
7619 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), DECL_CONTEXT (orig_fn)))
7620 continue;
7621
7622 add_vcall_offset (orig_fn, binfo, vid);
7623 }
7624 }
7625 }
7626
7627 /* Add a vcall offset entry for ORIG_FN to the vtable. */
7628
7629 static void
7630 add_vcall_offset (tree orig_fn, tree binfo, vtbl_init_data *vid)
7631 {
7632 size_t i;
7633 tree vcall_offset;
7634 tree derived_entry;
7635
7636 /* If there is already an entry for a function with the same
7637 signature as FN, then we do not need a second vcall offset.
7638 Check the list of functions already present in the derived
7639 class vtable. */
7640 for (i = 0; VEC_iterate (tree, vid->fns, i, derived_entry); ++i)
7641 {
7642 if (same_signature_p (derived_entry, orig_fn)
7643 /* We only use one vcall offset for virtual destructors,
7644 even though there are two virtual table entries. */
7645 || (DECL_DESTRUCTOR_P (derived_entry)
7646 && DECL_DESTRUCTOR_P (orig_fn)))
7647 return;
7648 }
7649
7650 /* If we are building these vcall offsets as part of building
7651 the vtable for the most derived class, remember the vcall
7652 offset. */
7653 if (vid->binfo == TYPE_BINFO (vid->derived))
7654 {
7655 tree_pair_p elt = VEC_safe_push (tree_pair_s, gc,
7656 CLASSTYPE_VCALL_INDICES (vid->derived),
7657 NULL);
7658 elt->purpose = orig_fn;
7659 elt->value = vid->index;
7660 }
7661
7662 /* The next vcall offset will be found at a more negative
7663 offset. */
7664 vid->index = size_binop (MINUS_EXPR, vid->index,
7665 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7666
7667 /* Keep track of this function. */
7668 VEC_safe_push (tree, gc, vid->fns, orig_fn);
7669
7670 if (vid->generate_vcall_entries)
7671 {
7672 tree base;
7673 tree fn;
7674
7675 /* Find the overriding function. */
7676 fn = find_final_overrider (vid->rtti_binfo, binfo, orig_fn);
7677 if (fn == error_mark_node)
7678 vcall_offset = build1 (NOP_EXPR, vtable_entry_type,
7679 integer_zero_node);
7680 else
7681 {
7682 base = TREE_VALUE (fn);
7683
7684 /* The vbase we're working on is a primary base of
7685 vid->binfo. But it might be a lost primary, so its
7686 BINFO_OFFSET might be wrong, so we just use the
7687 BINFO_OFFSET from vid->binfo. */
7688 vcall_offset = size_diffop (BINFO_OFFSET (base),
7689 BINFO_OFFSET (vid->binfo));
7690 vcall_offset = fold_build1 (NOP_EXPR, vtable_entry_type,
7691 vcall_offset);
7692 }
7693 /* Add the initializer to the vtable. */
7694 *vid->last_init = build_tree_list (NULL_TREE, vcall_offset);
7695 vid->last_init = &TREE_CHAIN (*vid->last_init);
7696 }
7697 }
7698
7699 /* Return vtbl initializers for the RTTI entries corresponding to the
7700 BINFO's vtable. The RTTI entries should indicate the object given
7701 by VID->rtti_binfo. */
7702
7703 static void
7704 build_rtti_vtbl_entries (tree binfo, vtbl_init_data* vid)
7705 {
7706 tree b;
7707 tree t;
7708 tree basetype;
7709 tree offset;
7710 tree decl;
7711 tree init;
7712
7713 basetype = BINFO_TYPE (binfo);
7714 t = BINFO_TYPE (vid->rtti_binfo);
7715
7716 /* To find the complete object, we will first convert to our most
7717 primary base, and then add the offset in the vtbl to that value. */
7718 b = binfo;
7719 while (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (b))
7720 && !BINFO_LOST_PRIMARY_P (b))
7721 {
7722 tree primary_base;
7723
7724 primary_base = get_primary_binfo (b);
7725 gcc_assert (BINFO_PRIMARY_P (primary_base)
7726 && BINFO_INHERITANCE_CHAIN (primary_base) == b);
7727 b = primary_base;
7728 }
7729 offset = size_diffop (BINFO_OFFSET (vid->rtti_binfo), BINFO_OFFSET (b));
7730
7731 /* The second entry is the address of the typeinfo object. */
7732 if (flag_rtti)
7733 decl = build_address (get_tinfo_decl (t));
7734 else
7735 decl = integer_zero_node;
7736
7737 /* Convert the declaration to a type that can be stored in the
7738 vtable. */
7739 init = build_nop (vfunc_ptr_type_node, decl);
7740 *vid->last_init = build_tree_list (NULL_TREE, init);
7741 vid->last_init = &TREE_CHAIN (*vid->last_init);
7742
7743 /* Add the offset-to-top entry. It comes earlier in the vtable than
7744 the typeinfo entry. Convert the offset to look like a
7745 function pointer, so that we can put it in the vtable. */
7746 init = build_nop (vfunc_ptr_type_node, offset);
7747 *vid->last_init = build_tree_list (NULL_TREE, init);
7748 vid->last_init = &TREE_CHAIN (*vid->last_init);
7749 }
7750
7751 /* Fold a OBJ_TYPE_REF expression to the address of a function.
7752 KNOWN_TYPE carries the true type of OBJ_TYPE_REF_OBJECT(REF). */
7753
7754 tree
7755 cp_fold_obj_type_ref (tree ref, tree known_type)
7756 {
7757 HOST_WIDE_INT index = tree_low_cst (OBJ_TYPE_REF_TOKEN (ref), 1);
7758 HOST_WIDE_INT i = 0;
7759 tree v = BINFO_VIRTUALS (TYPE_BINFO (known_type));
7760 tree fndecl;
7761
7762 while (i != index)
7763 {
7764 i += (TARGET_VTABLE_USES_DESCRIPTORS
7765 ? TARGET_VTABLE_USES_DESCRIPTORS : 1);
7766 v = TREE_CHAIN (v);
7767 }
7768
7769 fndecl = BV_FN (v);
7770
7771 #ifdef ENABLE_CHECKING
7772 gcc_assert (tree_int_cst_equal (OBJ_TYPE_REF_TOKEN (ref),
7773 DECL_VINDEX (fndecl)));
7774 #endif
7775
7776 cgraph_node (fndecl)->local.vtable_method = true;
7777
7778 return build_address (fndecl);
7779 }
7780
7781 #include "gt-cp-class.h"