]> gcc.gnu.org Git - gcc.git/blob - gcc/cp/class.c
class.c (get_enclosing_class): Remove.
[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, 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
22
23
24 /* High-level class interface. */
25
26 #include "config.h"
27 #include "system.h"
28 #include "coretypes.h"
29 #include "tm.h"
30 #include "tree.h"
31 #include "cp-tree.h"
32 #include "flags.h"
33 #include "rtl.h"
34 #include "output.h"
35 #include "toplev.h"
36 #include "target.h"
37 #include "convert.h"
38
39 /* The number of nested classes being processed. If we are not in the
40 scope of any class, this is zero. */
41
42 int current_class_depth;
43
44 /* In order to deal with nested classes, we keep a stack of classes.
45 The topmost entry is the innermost class, and is the entry at index
46 CURRENT_CLASS_DEPTH */
47
48 typedef struct class_stack_node {
49 /* The name of the class. */
50 tree name;
51
52 /* The _TYPE node for the class. */
53 tree type;
54
55 /* The access specifier pending for new declarations in the scope of
56 this class. */
57 tree access;
58
59 /* If were defining TYPE, the names used in this class. */
60 splay_tree names_used;
61 }* class_stack_node_t;
62
63 typedef struct vtbl_init_data_s
64 {
65 /* The base for which we're building initializers. */
66 tree binfo;
67 /* The type of the most-derived type. */
68 tree derived;
69 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
70 unless ctor_vtbl_p is true. */
71 tree rtti_binfo;
72 /* The negative-index vtable initializers built up so far. These
73 are in order from least negative index to most negative index. */
74 tree inits;
75 /* The last (i.e., most negative) entry in INITS. */
76 tree* last_init;
77 /* The binfo for the virtual base for which we're building
78 vcall offset initializers. */
79 tree vbase;
80 /* The functions in vbase for which we have already provided vcall
81 offsets. */
82 varray_type fns;
83 /* The vtable index of the next vcall or vbase offset. */
84 tree index;
85 /* Nonzero if we are building the initializer for the primary
86 vtable. */
87 int primary_vtbl_p;
88 /* Nonzero if we are building the initializer for a construction
89 vtable. */
90 int ctor_vtbl_p;
91 /* True when adding vcall offset entries to the vtable. False when
92 merely computing the indices. */
93 bool generate_vcall_entries;
94 } vtbl_init_data;
95
96 /* The type of a function passed to walk_subobject_offsets. */
97 typedef int (*subobject_offset_fn) (tree, tree, splay_tree);
98
99 /* The stack itself. This is a dynamically resized array. The
100 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
101 static int current_class_stack_size;
102 static class_stack_node_t current_class_stack;
103
104 /* An array of all local classes present in this translation unit, in
105 declaration order. */
106 varray_type local_classes;
107
108 static tree get_vfield_name (tree);
109 static void finish_struct_anon (tree);
110 static tree get_vtable_name (tree);
111 static tree get_basefndecls (tree, tree);
112 static int build_primary_vtable (tree, tree);
113 static int build_secondary_vtable (tree);
114 static void finish_vtbls (tree);
115 static void modify_vtable_entry (tree, tree, tree, tree, tree *);
116 static void finish_struct_bits (tree);
117 static int alter_access (tree, tree, tree);
118 static void handle_using_decl (tree, tree);
119 static void check_for_override (tree, tree);
120 static tree dfs_modify_vtables (tree, void *);
121 static tree modify_all_vtables (tree, tree);
122 static void determine_primary_bases (tree);
123 static void finish_struct_methods (tree);
124 static void maybe_warn_about_overly_private_class (tree);
125 static int method_name_cmp (const void *, const void *);
126 static int resort_method_name_cmp (const void *, const void *);
127 static void add_implicitly_declared_members (tree, int, int, int);
128 static tree fixed_type_or_null (tree, int *, int *);
129 static tree resolve_address_of_overloaded_function (tree, tree, tsubst_flags_t,
130 bool, tree);
131 static tree build_simple_base_path (tree expr, tree binfo);
132 static tree build_vtbl_ref_1 (tree, tree);
133 static tree build_vtbl_initializer (tree, tree, tree, tree, int *);
134 static int count_fields (tree);
135 static int add_fields_to_record_type (tree, struct sorted_fields_type*, int);
136 static void check_bitfield_decl (tree);
137 static void check_field_decl (tree, tree, int *, int *, int *, int *);
138 static void check_field_decls (tree, tree *, int *, int *, int *);
139 static tree *build_base_field (record_layout_info, tree, splay_tree, tree *);
140 static void build_base_fields (record_layout_info, splay_tree, tree *);
141 static void check_methods (tree);
142 static void remove_zero_width_bit_fields (tree);
143 static void check_bases (tree, int *, int *, int *);
144 static void check_bases_and_members (tree);
145 static tree create_vtable_ptr (tree, tree *);
146 static void include_empty_classes (record_layout_info);
147 static void layout_class_type (tree, tree *);
148 static void fixup_pending_inline (tree);
149 static void fixup_inline_methods (tree);
150 static void propagate_binfo_offsets (tree, tree);
151 static void layout_virtual_bases (record_layout_info, splay_tree);
152 static void build_vbase_offset_vtbl_entries (tree, vtbl_init_data *);
153 static void add_vcall_offset_vtbl_entries_r (tree, vtbl_init_data *);
154 static void add_vcall_offset_vtbl_entries_1 (tree, vtbl_init_data *);
155 static void build_vcall_offset_vtbl_entries (tree, vtbl_init_data *);
156 static void add_vcall_offset (tree, tree, vtbl_init_data *);
157 static void layout_vtable_decl (tree, int);
158 static tree dfs_find_final_overrider_pre (tree, void *);
159 static tree dfs_find_final_overrider_post (tree, void *);
160 static tree find_final_overrider (tree, tree, tree);
161 static int make_new_vtable (tree, tree);
162 static int maybe_indent_hierarchy (FILE *, int, int);
163 static tree dump_class_hierarchy_r (FILE *, int, tree, tree, int);
164 static void dump_class_hierarchy (tree);
165 static void dump_class_hierarchy_1 (FILE *, int, tree);
166 static void dump_array (FILE *, tree);
167 static void dump_vtable (tree, tree, tree);
168 static void dump_vtt (tree, tree);
169 static void dump_thunk (FILE *, int, tree);
170 static tree build_vtable (tree, tree, tree);
171 static void initialize_vtable (tree, tree);
172 static void layout_nonempty_base_or_field (record_layout_info,
173 tree, tree, splay_tree);
174 static tree end_of_class (tree, int);
175 static bool layout_empty_base (tree, tree, splay_tree);
176 static void accumulate_vtbl_inits (tree, tree, tree, tree, tree);
177 static tree dfs_accumulate_vtbl_inits (tree, tree, tree, tree,
178 tree);
179 static void build_rtti_vtbl_entries (tree, vtbl_init_data *);
180 static void build_vcall_and_vbase_vtbl_entries (tree, vtbl_init_data *);
181 static void clone_constructors_and_destructors (tree);
182 static tree build_clone (tree, tree);
183 static void update_vtable_entry_for_fn (tree, tree, tree, tree *, unsigned);
184 static void build_ctor_vtbl_group (tree, tree);
185 static void build_vtt (tree);
186 static tree binfo_ctor_vtable (tree);
187 static tree *build_vtt_inits (tree, tree, tree *, tree *);
188 static tree dfs_build_secondary_vptr_vtt_inits (tree, void *);
189 static tree dfs_fixup_binfo_vtbls (tree, void *);
190 static int record_subobject_offset (tree, tree, splay_tree);
191 static int check_subobject_offset (tree, tree, splay_tree);
192 static int walk_subobject_offsets (tree, subobject_offset_fn,
193 tree, splay_tree, tree, int);
194 static void record_subobject_offsets (tree, tree, splay_tree, int);
195 static int layout_conflict_p (tree, tree, splay_tree, int);
196 static int splay_tree_compare_integer_csts (splay_tree_key k1,
197 splay_tree_key k2);
198 static void warn_about_ambiguous_bases (tree);
199 static bool type_requires_array_cookie (tree);
200 static bool contains_empty_class_p (tree);
201 static bool base_derived_from (tree, tree);
202 static int empty_base_at_nonzero_offset_p (tree, tree, splay_tree);
203 static tree end_of_base (tree);
204 static tree get_vcall_index (tree, tree);
205
206 /* Variables shared between class.c and call.c. */
207
208 #ifdef GATHER_STATISTICS
209 int n_vtables = 0;
210 int n_vtable_entries = 0;
211 int n_vtable_searches = 0;
212 int n_vtable_elems = 0;
213 int n_convert_harshness = 0;
214 int n_compute_conversion_costs = 0;
215 int n_inner_fields_searched = 0;
216 #endif
217
218 /* Convert to or from a base subobject. EXPR is an expression of type
219 `A' or `A*', an expression of type `B' or `B*' is returned. To
220 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
221 the B base instance within A. To convert base A to derived B, CODE
222 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
223 In this latter case, A must not be a morally virtual base of B.
224 NONNULL is true if EXPR is known to be non-NULL (this is only
225 needed when EXPR is of pointer type). CV qualifiers are preserved
226 from EXPR. */
227
228 tree
229 build_base_path (enum tree_code code,
230 tree expr,
231 tree binfo,
232 int nonnull)
233 {
234 tree v_binfo = NULL_TREE;
235 tree d_binfo = NULL_TREE;
236 tree probe;
237 tree offset;
238 tree target_type;
239 tree null_test = NULL;
240 tree ptr_target_type;
241 int fixed_type_p;
242 int want_pointer = TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE;
243 bool has_empty = false;
244 bool virtual_access;
245
246 if (expr == error_mark_node || binfo == error_mark_node || !binfo)
247 return error_mark_node;
248
249 for (probe = binfo; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
250 {
251 d_binfo = probe;
252 if (is_empty_class (BINFO_TYPE (probe)))
253 has_empty = true;
254 if (!v_binfo && BINFO_VIRTUAL_P (probe))
255 v_binfo = probe;
256 }
257
258 probe = TYPE_MAIN_VARIANT (TREE_TYPE (expr));
259 if (want_pointer)
260 probe = TYPE_MAIN_VARIANT (TREE_TYPE (probe));
261
262 gcc_assert ((code == MINUS_EXPR
263 && SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), probe))
264 || (code == PLUS_EXPR
265 && SAME_BINFO_TYPE_P (BINFO_TYPE (d_binfo), probe)));
266
267 if (binfo == d_binfo)
268 /* Nothing to do. */
269 return expr;
270
271 if (code == MINUS_EXPR && v_binfo)
272 {
273 error ("cannot convert from base %qT to derived type %qT via virtual base %qT",
274 BINFO_TYPE (binfo), BINFO_TYPE (d_binfo), BINFO_TYPE (v_binfo));
275 return error_mark_node;
276 }
277
278 if (!want_pointer)
279 /* This must happen before the call to save_expr. */
280 expr = build_unary_op (ADDR_EXPR, expr, 0);
281
282 offset = BINFO_OFFSET (binfo);
283 fixed_type_p = resolves_to_fixed_type_p (expr, &nonnull);
284
285 /* Do we need to look in the vtable for the real offset? */
286 virtual_access = (v_binfo && fixed_type_p <= 0);
287
288 /* Do we need to check for a null pointer? */
289 if (want_pointer && !nonnull && (virtual_access || !integer_zerop (offset)))
290 null_test = error_mark_node;
291
292 /* Protect against multiple evaluation if necessary. */
293 if (TREE_SIDE_EFFECTS (expr) && (null_test || virtual_access))
294 expr = save_expr (expr);
295
296 /* Now that we've saved expr, build the real null test. */
297 if (null_test)
298 {
299 tree zero = cp_convert (TREE_TYPE (expr), integer_zero_node);
300 null_test = fold (build2 (NE_EXPR, boolean_type_node,
301 expr, zero));
302 }
303
304 /* If this is a simple base reference, express it as a COMPONENT_REF. */
305 if (code == PLUS_EXPR && !virtual_access
306 /* We don't build base fields for empty bases, and they aren't very
307 interesting to the optimizers anyway. */
308 && !has_empty)
309 {
310 expr = build_indirect_ref (expr, NULL);
311 expr = build_simple_base_path (expr, binfo);
312 if (want_pointer)
313 expr = build_address (expr);
314 target_type = TREE_TYPE (expr);
315 goto out;
316 }
317
318 if (virtual_access)
319 {
320 /* Going via virtual base V_BINFO. We need the static offset
321 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
322 V_BINFO. That offset is an entry in D_BINFO's vtable. */
323 tree v_offset;
324
325 if (fixed_type_p < 0 && in_base_initializer)
326 {
327 /* In a base member initializer, we cannot rely on
328 the vtable being set up. We have to use the vtt_parm. */
329 tree derived = BINFO_INHERITANCE_CHAIN (v_binfo);
330 tree t;
331
332 t = TREE_TYPE (TYPE_VFIELD (BINFO_TYPE (derived)));
333 t = build_pointer_type (t);
334 v_offset = convert (t, current_vtt_parm);
335 v_offset = build2 (PLUS_EXPR, t, v_offset,
336 BINFO_VPTR_INDEX (derived));
337 v_offset = build_indirect_ref (v_offset, NULL);
338 }
339 else
340 v_offset = build_vfield_ref (build_indirect_ref (expr, NULL),
341 TREE_TYPE (TREE_TYPE (expr)));
342
343 v_offset = build2 (PLUS_EXPR, TREE_TYPE (v_offset),
344 v_offset, BINFO_VPTR_FIELD (v_binfo));
345 v_offset = build1 (NOP_EXPR,
346 build_pointer_type (ptrdiff_type_node),
347 v_offset);
348 v_offset = build_indirect_ref (v_offset, NULL);
349 TREE_CONSTANT (v_offset) = 1;
350 TREE_INVARIANT (v_offset) = 1;
351
352 offset = convert_to_integer (ptrdiff_type_node,
353 size_diffop (offset,
354 BINFO_OFFSET (v_binfo)));
355
356 if (!integer_zerop (offset))
357 v_offset = build2 (code, ptrdiff_type_node, v_offset, offset);
358
359 if (fixed_type_p < 0)
360 /* Negative fixed_type_p means this is a constructor or destructor;
361 virtual base layout is fixed in in-charge [cd]tors, but not in
362 base [cd]tors. */
363 offset = build3 (COND_EXPR, ptrdiff_type_node,
364 build2 (EQ_EXPR, boolean_type_node,
365 current_in_charge_parm, integer_zero_node),
366 v_offset,
367 BINFO_OFFSET (binfo));
368 else
369 offset = v_offset;
370 }
371
372 target_type = code == PLUS_EXPR ? BINFO_TYPE (binfo) : BINFO_TYPE (d_binfo);
373
374 target_type = cp_build_qualified_type
375 (target_type, cp_type_quals (TREE_TYPE (TREE_TYPE (expr))));
376 ptr_target_type = build_pointer_type (target_type);
377 if (want_pointer)
378 target_type = ptr_target_type;
379
380 expr = build1 (NOP_EXPR, ptr_target_type, expr);
381
382 if (!integer_zerop (offset))
383 expr = build2 (code, ptr_target_type, expr, offset);
384 else
385 null_test = NULL;
386
387 if (!want_pointer)
388 expr = build_indirect_ref (expr, NULL);
389
390 out:
391 if (null_test)
392 expr = fold (build3 (COND_EXPR, target_type, null_test, expr,
393 fold (build1 (NOP_EXPR, target_type,
394 integer_zero_node))));
395
396 return expr;
397 }
398
399 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
400 Perform a derived-to-base conversion by recursively building up a
401 sequence of COMPONENT_REFs to the appropriate base fields. */
402
403 static tree
404 build_simple_base_path (tree expr, tree binfo)
405 {
406 tree type = BINFO_TYPE (binfo);
407 tree d_binfo = BINFO_INHERITANCE_CHAIN (binfo);
408 tree field;
409
410 if (d_binfo == NULL_TREE)
411 {
412 gcc_assert (TYPE_MAIN_VARIANT (TREE_TYPE (expr)) == type);
413 return expr;
414 }
415
416 /* Recurse. */
417 expr = build_simple_base_path (expr, d_binfo);
418
419 for (field = TYPE_FIELDS (BINFO_TYPE (d_binfo));
420 field; field = TREE_CHAIN (field))
421 /* Is this the base field created by build_base_field? */
422 if (TREE_CODE (field) == FIELD_DECL
423 && DECL_FIELD_IS_BASE (field)
424 && TREE_TYPE (field) == type)
425 return build_class_member_access_expr (expr, field,
426 NULL_TREE, false);
427
428 /* Didn't find the base field?!? */
429 gcc_unreachable ();
430 }
431
432 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
433 type is a class type or a pointer to a class type. In the former
434 case, TYPE is also a class type; in the latter it is another
435 pointer type. If CHECK_ACCESS is true, an error message is emitted
436 if TYPE is inaccessible. If OBJECT has pointer type, the value is
437 assumed to be non-NULL. */
438
439 tree
440 convert_to_base (tree object, tree type, bool check_access, bool nonnull)
441 {
442 tree binfo;
443 tree object_type;
444
445 if (TYPE_PTR_P (TREE_TYPE (object)))
446 {
447 object_type = TREE_TYPE (TREE_TYPE (object));
448 type = TREE_TYPE (type);
449 }
450 else
451 object_type = TREE_TYPE (object);
452
453 binfo = lookup_base (object_type, type,
454 check_access ? ba_check : ba_unique,
455 NULL);
456 if (!binfo || binfo == error_mark_node)
457 return error_mark_node;
458
459 return build_base_path (PLUS_EXPR, object, binfo, nonnull);
460 }
461
462 /* EXPR is an expression with unqualified class type. BASE is a base
463 binfo of that class type. Returns EXPR, converted to the BASE
464 type. This function assumes that EXPR is the most derived class;
465 therefore virtual bases can be found at their static offsets. */
466
467 tree
468 convert_to_base_statically (tree expr, tree base)
469 {
470 tree expr_type;
471
472 expr_type = TREE_TYPE (expr);
473 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (base), expr_type))
474 {
475 tree pointer_type;
476
477 pointer_type = build_pointer_type (expr_type);
478 expr = build_unary_op (ADDR_EXPR, expr, /*noconvert=*/1);
479 if (!integer_zerop (BINFO_OFFSET (base)))
480 expr = build2 (PLUS_EXPR, pointer_type, expr,
481 build_nop (pointer_type, BINFO_OFFSET (base)));
482 expr = build_nop (build_pointer_type (BINFO_TYPE (base)), expr);
483 expr = build1 (INDIRECT_REF, BINFO_TYPE (base), expr);
484 }
485
486 return expr;
487 }
488
489 \f
490 tree
491 build_vfield_ref (tree datum, tree type)
492 {
493 tree vfield, vcontext;
494
495 if (datum == error_mark_node)
496 return error_mark_node;
497
498 /* First, convert to the requested type. */
499 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (datum), type))
500 datum = convert_to_base (datum, type, /*check_access=*/false,
501 /*nonnull=*/true);
502
503 /* Second, the requested type may not be the owner of its own vptr.
504 If not, convert to the base class that owns it. We cannot use
505 convert_to_base here, because VCONTEXT may appear more than once
506 in the inheritance hierarchy of TYPE, and thus direct conversion
507 between the types may be ambiguous. Following the path back up
508 one step at a time via primary bases avoids the problem. */
509 vfield = TYPE_VFIELD (type);
510 vcontext = DECL_CONTEXT (vfield);
511 while (!same_type_ignoring_top_level_qualifiers_p (vcontext, type))
512 {
513 datum = build_simple_base_path (datum, CLASSTYPE_PRIMARY_BINFO (type));
514 type = TREE_TYPE (datum);
515 }
516
517 return build3 (COMPONENT_REF, TREE_TYPE (vfield), datum, vfield, NULL_TREE);
518 }
519
520 /* Given an object INSTANCE, return an expression which yields the
521 vtable element corresponding to INDEX. There are many special
522 cases for INSTANCE which we take care of here, mainly to avoid
523 creating extra tree nodes when we don't have to. */
524
525 static tree
526 build_vtbl_ref_1 (tree instance, tree idx)
527 {
528 tree aref;
529 tree vtbl = NULL_TREE;
530
531 /* Try to figure out what a reference refers to, and
532 access its virtual function table directly. */
533
534 int cdtorp = 0;
535 tree fixed_type = fixed_type_or_null (instance, NULL, &cdtorp);
536
537 tree basetype = non_reference (TREE_TYPE (instance));
538
539 if (fixed_type && !cdtorp)
540 {
541 tree binfo = lookup_base (fixed_type, basetype,
542 ba_unique | ba_quiet, NULL);
543 if (binfo)
544 vtbl = unshare_expr (BINFO_VTABLE (binfo));
545 }
546
547 if (!vtbl)
548 vtbl = build_vfield_ref (instance, basetype);
549
550 assemble_external (vtbl);
551
552 aref = build_array_ref (vtbl, idx);
553 TREE_CONSTANT (aref) |= TREE_CONSTANT (vtbl) && TREE_CONSTANT (idx);
554 TREE_INVARIANT (aref) = TREE_CONSTANT (aref);
555
556 return aref;
557 }
558
559 tree
560 build_vtbl_ref (tree instance, tree idx)
561 {
562 tree aref = build_vtbl_ref_1 (instance, idx);
563
564 return aref;
565 }
566
567 /* Given a stable object pointer INSTANCE_PTR, return an expression which
568 yields a function pointer corresponding to vtable element INDEX. */
569
570 tree
571 build_vfn_ref (tree instance_ptr, tree idx)
572 {
573 tree aref;
574
575 aref = build_vtbl_ref_1 (build_indirect_ref (instance_ptr, 0), idx);
576
577 /* When using function descriptors, the address of the
578 vtable entry is treated as a function pointer. */
579 if (TARGET_VTABLE_USES_DESCRIPTORS)
580 aref = build1 (NOP_EXPR, TREE_TYPE (aref),
581 build_unary_op (ADDR_EXPR, aref, /*noconvert=*/1));
582
583 /* Remember this as a method reference, for later devirtualization. */
584 aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr, idx);
585
586 return aref;
587 }
588
589 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
590 for the given TYPE. */
591
592 static tree
593 get_vtable_name (tree type)
594 {
595 return mangle_vtbl_for_type (type);
596 }
597
598 /* Return an IDENTIFIER_NODE for the name of the virtual table table
599 for TYPE. */
600
601 tree
602 get_vtt_name (tree type)
603 {
604 return mangle_vtt_for_type (type);
605 }
606
607 /* DECL is an entity associated with TYPE, like a virtual table or an
608 implicitly generated constructor. Determine whether or not DECL
609 should have external or internal linkage at the object file
610 level. This routine does not deal with COMDAT linkage and other
611 similar complexities; it simply sets TREE_PUBLIC if it possible for
612 entities in other translation units to contain copies of DECL, in
613 the abstract. */
614
615 void
616 set_linkage_according_to_type (tree type, tree decl)
617 {
618 /* If TYPE involves a local class in a function with internal
619 linkage, then DECL should have internal linkage too. Other local
620 classes have no linkage -- but if their containing functions
621 have external linkage, it makes sense for DECL to have external
622 linkage too. That will allow template definitions to be merged,
623 for example. */
624 if (no_linkage_check (type, /*relaxed_p=*/true))
625 {
626 TREE_PUBLIC (decl) = 0;
627 DECL_INTERFACE_KNOWN (decl) = 1;
628 }
629 else
630 TREE_PUBLIC (decl) = 1;
631 }
632
633 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
634 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
635 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
636
637 static tree
638 build_vtable (tree class_type, tree name, tree vtable_type)
639 {
640 tree decl;
641
642 decl = build_lang_decl (VAR_DECL, name, vtable_type);
643 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
644 now to avoid confusion in mangle_decl. */
645 SET_DECL_ASSEMBLER_NAME (decl, name);
646 DECL_CONTEXT (decl) = class_type;
647 DECL_ARTIFICIAL (decl) = 1;
648 TREE_STATIC (decl) = 1;
649 TREE_READONLY (decl) = 1;
650 DECL_VIRTUAL_P (decl) = 1;
651 DECL_ALIGN (decl) = TARGET_VTABLE_ENTRY_ALIGN;
652 DECL_VTABLE_OR_VTT_P (decl) = 1;
653 /* At one time the vtable info was grabbed 2 words at a time. This
654 fails on sparc unless you have 8-byte alignment. (tiemann) */
655 DECL_ALIGN (decl) = MAX (TYPE_ALIGN (double_type_node),
656 DECL_ALIGN (decl));
657 set_linkage_according_to_type (class_type, decl);
658 /* The vtable has not been defined -- yet. */
659 DECL_EXTERNAL (decl) = 1;
660 DECL_NOT_REALLY_EXTERN (decl) = 1;
661
662 /* Mark the VAR_DECL node representing the vtable itself as a
663 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
664 is rather important that such things be ignored because any
665 effort to actually generate DWARF for them will run into
666 trouble when/if we encounter code like:
667
668 #pragma interface
669 struct S { virtual void member (); };
670
671 because the artificial declaration of the vtable itself (as
672 manufactured by the g++ front end) will say that the vtable is
673 a static member of `S' but only *after* the debug output for
674 the definition of `S' has already been output. This causes
675 grief because the DWARF entry for the definition of the vtable
676 will try to refer back to an earlier *declaration* of the
677 vtable as a static member of `S' and there won't be one. We
678 might be able to arrange to have the "vtable static member"
679 attached to the member list for `S' before the debug info for
680 `S' get written (which would solve the problem) but that would
681 require more intrusive changes to the g++ front end. */
682 DECL_IGNORED_P (decl) = 1;
683
684 return decl;
685 }
686
687 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
688 or even complete. If this does not exist, create it. If COMPLETE is
689 nonzero, then complete the definition of it -- that will render it
690 impossible to actually build the vtable, but is useful to get at those
691 which are known to exist in the runtime. */
692
693 tree
694 get_vtable_decl (tree type, int complete)
695 {
696 tree decl;
697
698 if (CLASSTYPE_VTABLES (type))
699 return CLASSTYPE_VTABLES (type);
700
701 decl = build_vtable (type, get_vtable_name (type), vtbl_type_node);
702 CLASSTYPE_VTABLES (type) = decl;
703
704 if (complete)
705 {
706 DECL_EXTERNAL (decl) = 1;
707 cp_finish_decl (decl, NULL_TREE, NULL_TREE, 0);
708 }
709
710 return decl;
711 }
712
713 /* Build the primary virtual function table for TYPE. If BINFO is
714 non-NULL, build the vtable starting with the initial approximation
715 that it is the same as the one which is the head of the association
716 list. Returns a nonzero value if a new vtable is actually
717 created. */
718
719 static int
720 build_primary_vtable (tree binfo, tree type)
721 {
722 tree decl;
723 tree virtuals;
724
725 decl = get_vtable_decl (type, /*complete=*/0);
726
727 if (binfo)
728 {
729 if (BINFO_NEW_VTABLE_MARKED (binfo))
730 /* We have already created a vtable for this base, so there's
731 no need to do it again. */
732 return 0;
733
734 virtuals = copy_list (BINFO_VIRTUALS (binfo));
735 TREE_TYPE (decl) = TREE_TYPE (get_vtbl_decl_for_binfo (binfo));
736 DECL_SIZE (decl) = TYPE_SIZE (TREE_TYPE (decl));
737 DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (TREE_TYPE (decl));
738 }
739 else
740 {
741 gcc_assert (TREE_TYPE (decl) == vtbl_type_node);
742 virtuals = NULL_TREE;
743 }
744
745 #ifdef GATHER_STATISTICS
746 n_vtables += 1;
747 n_vtable_elems += list_length (virtuals);
748 #endif
749
750 /* Initialize the association list for this type, based
751 on our first approximation. */
752 BINFO_VTABLE (TYPE_BINFO (type)) = decl;
753 BINFO_VIRTUALS (TYPE_BINFO (type)) = virtuals;
754 SET_BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (type));
755 return 1;
756 }
757
758 /* Give BINFO a new virtual function table which is initialized
759 with a skeleton-copy of its original initialization. The only
760 entry that changes is the `delta' entry, so we can really
761 share a lot of structure.
762
763 FOR_TYPE is the most derived type which caused this table to
764 be needed.
765
766 Returns nonzero if we haven't met BINFO before.
767
768 The order in which vtables are built (by calling this function) for
769 an object must remain the same, otherwise a binary incompatibility
770 can result. */
771
772 static int
773 build_secondary_vtable (tree binfo)
774 {
775 if (BINFO_NEW_VTABLE_MARKED (binfo))
776 /* We already created a vtable for this base. There's no need to
777 do it again. */
778 return 0;
779
780 /* Remember that we've created a vtable for this BINFO, so that we
781 don't try to do so again. */
782 SET_BINFO_NEW_VTABLE_MARKED (binfo);
783
784 /* Make fresh virtual list, so we can smash it later. */
785 BINFO_VIRTUALS (binfo) = copy_list (BINFO_VIRTUALS (binfo));
786
787 /* Secondary vtables are laid out as part of the same structure as
788 the primary vtable. */
789 BINFO_VTABLE (binfo) = NULL_TREE;
790 return 1;
791 }
792
793 /* Create a new vtable for BINFO which is the hierarchy dominated by
794 T. Return nonzero if we actually created a new vtable. */
795
796 static int
797 make_new_vtable (tree t, tree binfo)
798 {
799 if (binfo == TYPE_BINFO (t))
800 /* In this case, it is *type*'s vtable we are modifying. We start
801 with the approximation that its vtable is that of the
802 immediate base class. */
803 return build_primary_vtable (binfo, t);
804 else
805 /* This is our very own copy of `basetype' to play with. Later,
806 we will fill in all the virtual functions that override the
807 virtual functions in these base classes which are not defined
808 by the current type. */
809 return build_secondary_vtable (binfo);
810 }
811
812 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
813 (which is in the hierarchy dominated by T) list FNDECL as its
814 BV_FN. DELTA is the required constant adjustment from the `this'
815 pointer where the vtable entry appears to the `this' required when
816 the function is actually called. */
817
818 static void
819 modify_vtable_entry (tree t,
820 tree binfo,
821 tree fndecl,
822 tree delta,
823 tree *virtuals)
824 {
825 tree v;
826
827 v = *virtuals;
828
829 if (fndecl != BV_FN (v)
830 || !tree_int_cst_equal (delta, BV_DELTA (v)))
831 {
832 /* We need a new vtable for BINFO. */
833 if (make_new_vtable (t, binfo))
834 {
835 /* If we really did make a new vtable, we also made a copy
836 of the BINFO_VIRTUALS list. Now, we have to find the
837 corresponding entry in that list. */
838 *virtuals = BINFO_VIRTUALS (binfo);
839 while (BV_FN (*virtuals) != BV_FN (v))
840 *virtuals = TREE_CHAIN (*virtuals);
841 v = *virtuals;
842 }
843
844 BV_DELTA (v) = delta;
845 BV_VCALL_INDEX (v) = NULL_TREE;
846 BV_FN (v) = fndecl;
847 }
848 }
849
850 \f
851 /* Add method METHOD to class TYPE. */
852
853 void
854 add_method (tree type, tree method)
855 {
856 int using;
857 unsigned slot;
858 tree overload;
859 bool template_conv_p = false;
860 bool conv_p;
861 VEC(tree) *method_vec;
862 bool complete_p;
863 bool insert_p = false;
864 tree current_fns;
865
866 if (method == error_mark_node)
867 return;
868
869 complete_p = COMPLETE_TYPE_P (type);
870 using = (DECL_CONTEXT (method) != type);
871 conv_p = DECL_CONV_FN_P (method);
872 if (conv_p)
873 template_conv_p = (TREE_CODE (method) == TEMPLATE_DECL
874 && DECL_TEMPLATE_CONV_FN_P (method));
875
876 method_vec = CLASSTYPE_METHOD_VEC (type);
877 if (!method_vec)
878 {
879 /* Make a new method vector. We start with 8 entries. We must
880 allocate at least two (for constructors and destructors), and
881 we're going to end up with an assignment operator at some
882 point as well. */
883 method_vec = VEC_alloc (tree, 8);
884 /* Create slots for constructors and destructors. */
885 VEC_quick_push (tree, method_vec, NULL_TREE);
886 VEC_quick_push (tree, method_vec, NULL_TREE);
887 CLASSTYPE_METHOD_VEC (type) = method_vec;
888 }
889
890 /* Constructors and destructors go in special slots. */
891 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (method))
892 slot = CLASSTYPE_CONSTRUCTOR_SLOT;
893 else if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method))
894 {
895 slot = CLASSTYPE_DESTRUCTOR_SLOT;
896 TYPE_HAS_DESTRUCTOR (type) = 1;
897
898 if (TYPE_FOR_JAVA (type))
899 error (DECL_ARTIFICIAL (method)
900 ? "Java class %qT cannot have an implicit non-trivial destructor"
901 : "Java class %qT cannot have a destructor",
902 DECL_CONTEXT (method));
903 }
904 else
905 {
906 tree m;
907
908 insert_p = true;
909 /* See if we already have an entry with this name. */
910 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
911 VEC_iterate (tree, method_vec, slot, m);
912 ++slot)
913 {
914 m = OVL_CURRENT (m);
915 if (template_conv_p)
916 {
917 if (TREE_CODE (m) == TEMPLATE_DECL
918 && DECL_TEMPLATE_CONV_FN_P (m))
919 insert_p = false;
920 break;
921 }
922 if (conv_p && !DECL_CONV_FN_P (m))
923 break;
924 if (DECL_NAME (m) == DECL_NAME (method))
925 {
926 insert_p = false;
927 break;
928 }
929 if (complete_p
930 && !DECL_CONV_FN_P (m)
931 && DECL_NAME (m) > DECL_NAME (method))
932 break;
933 }
934 }
935 current_fns = insert_p ? NULL_TREE : VEC_index (tree, method_vec, slot);
936
937 if (processing_template_decl)
938 /* TYPE is a template class. Don't issue any errors now; wait
939 until instantiation time to complain. */
940 ;
941 else
942 {
943 tree fns;
944
945 /* Check to see if we've already got this method. */
946 for (fns = current_fns; fns; fns = OVL_NEXT (fns))
947 {
948 tree fn = OVL_CURRENT (fns);
949 tree parms1;
950 tree parms2;
951 bool same = 1;
952
953 if (TREE_CODE (fn) != TREE_CODE (method))
954 continue;
955
956 /* [over.load] Member function declarations with the
957 same name and the same parameter types cannot be
958 overloaded if any of them is a static member
959 function declaration.
960
961 [namespace.udecl] When a using-declaration brings names
962 from a base class into a derived class scope, member
963 functions in the derived class override and/or hide member
964 functions with the same name and parameter types in a base
965 class (rather than conflicting). */
966 parms1 = TYPE_ARG_TYPES (TREE_TYPE (fn));
967 parms2 = TYPE_ARG_TYPES (TREE_TYPE (method));
968
969 /* Compare the quals on the 'this' parm. Don't compare
970 the whole types, as used functions are treated as
971 coming from the using class in overload resolution. */
972 if (! DECL_STATIC_FUNCTION_P (fn)
973 && ! DECL_STATIC_FUNCTION_P (method)
974 && (TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms1)))
975 != TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms2)))))
976 same = 0;
977
978 /* For templates, the template parms must be identical. */
979 if (TREE_CODE (fn) == TEMPLATE_DECL
980 && !comp_template_parms (DECL_TEMPLATE_PARMS (fn),
981 DECL_TEMPLATE_PARMS (method)))
982 same = 0;
983
984 if (! DECL_STATIC_FUNCTION_P (fn))
985 parms1 = TREE_CHAIN (parms1);
986 if (! DECL_STATIC_FUNCTION_P (method))
987 parms2 = TREE_CHAIN (parms2);
988
989 if (same && compparms (parms1, parms2)
990 && (!DECL_CONV_FN_P (fn)
991 || same_type_p (TREE_TYPE (TREE_TYPE (fn)),
992 TREE_TYPE (TREE_TYPE (method)))))
993 {
994 if (using && DECL_CONTEXT (fn) == type)
995 /* Defer to the local function. */
996 return;
997 else
998 {
999 cp_error_at ("%q#D and %q#D cannot be overloaded",
1000 method, fn);
1001
1002 /* We don't call duplicate_decls here to merge
1003 the declarations because that will confuse
1004 things if the methods have inline
1005 definitions. In particular, we will crash
1006 while processing the definitions. */
1007 return;
1008 }
1009 }
1010 }
1011 }
1012
1013 /* Add the new binding. */
1014 overload = build_overload (method, current_fns);
1015
1016 if (!conv_p && slot >= CLASSTYPE_FIRST_CONVERSION_SLOT && !complete_p)
1017 push_class_level_binding (DECL_NAME (method), overload);
1018
1019 if (insert_p)
1020 {
1021 /* We only expect to add few methods in the COMPLETE_P case, so
1022 just make room for one more method in that case. */
1023 if (VEC_reserve (tree, method_vec, complete_p ? 1 : -1))
1024 CLASSTYPE_METHOD_VEC (type) = method_vec;
1025 if (slot == VEC_length (tree, method_vec))
1026 VEC_quick_push (tree, method_vec, overload);
1027 else
1028 VEC_quick_insert (tree, method_vec, slot, overload);
1029 }
1030 else
1031 /* Replace the current slot. */
1032 VEC_replace (tree, method_vec, slot, overload);
1033 }
1034
1035 /* Subroutines of finish_struct. */
1036
1037 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1038 legit, otherwise return 0. */
1039
1040 static int
1041 alter_access (tree t, tree fdecl, tree access)
1042 {
1043 tree elem;
1044
1045 if (!DECL_LANG_SPECIFIC (fdecl))
1046 retrofit_lang_decl (fdecl);
1047
1048 gcc_assert (!DECL_DISCRIMINATOR_P (fdecl));
1049
1050 elem = purpose_member (t, DECL_ACCESS (fdecl));
1051 if (elem)
1052 {
1053 if (TREE_VALUE (elem) != access)
1054 {
1055 if (TREE_CODE (TREE_TYPE (fdecl)) == FUNCTION_DECL)
1056 cp_error_at ("conflicting access specifications for method"
1057 " %qD, ignored", TREE_TYPE (fdecl));
1058 else
1059 error ("conflicting access specifications for field %qE, ignored",
1060 DECL_NAME (fdecl));
1061 }
1062 else
1063 {
1064 /* They're changing the access to the same thing they changed
1065 it to before. That's OK. */
1066 ;
1067 }
1068 }
1069 else
1070 {
1071 perform_or_defer_access_check (TYPE_BINFO (t), fdecl);
1072 DECL_ACCESS (fdecl) = tree_cons (t, access, DECL_ACCESS (fdecl));
1073 return 1;
1074 }
1075 return 0;
1076 }
1077
1078 /* Process the USING_DECL, which is a member of T. */
1079
1080 static void
1081 handle_using_decl (tree using_decl, tree t)
1082 {
1083 tree ctype = DECL_INITIAL (using_decl);
1084 tree name = DECL_NAME (using_decl);
1085 tree access
1086 = TREE_PRIVATE (using_decl) ? access_private_node
1087 : TREE_PROTECTED (using_decl) ? access_protected_node
1088 : access_public_node;
1089 tree fdecl, binfo;
1090 tree flist = NULL_TREE;
1091 tree old_value;
1092
1093 if (ctype == error_mark_node)
1094 return;
1095
1096 binfo = lookup_base (t, ctype, ba_any, NULL);
1097 if (! binfo)
1098 {
1099 location_t saved_loc = input_location;
1100
1101 input_location = DECL_SOURCE_LOCATION (using_decl);
1102 error_not_base_type (ctype, t);
1103 input_location = saved_loc;
1104 return;
1105 }
1106
1107 if (constructor_name_p (name, ctype))
1108 {
1109 cp_error_at ("%qD names constructor", using_decl);
1110 return;
1111 }
1112 if (constructor_name_p (name, t))
1113 {
1114 cp_error_at ("%qD invalid in %qT", using_decl, t);
1115 return;
1116 }
1117
1118 fdecl = lookup_member (binfo, name, 0, false);
1119
1120 if (!fdecl)
1121 {
1122 cp_error_at ("no members matching %qD in %q#T", using_decl, ctype);
1123 return;
1124 }
1125
1126 if (BASELINK_P (fdecl))
1127 /* Ignore base type this came from. */
1128 fdecl = BASELINK_FUNCTIONS (fdecl);
1129
1130 old_value = lookup_member (t, name, /*protect=*/0, /*want_type=*/false);
1131 if (old_value)
1132 {
1133 if (is_overloaded_fn (old_value))
1134 old_value = OVL_CURRENT (old_value);
1135
1136 if (DECL_P (old_value) && DECL_CONTEXT (old_value) == t)
1137 /* OK */;
1138 else
1139 old_value = NULL_TREE;
1140 }
1141
1142 if (is_overloaded_fn (fdecl))
1143 flist = fdecl;
1144
1145 if (! old_value)
1146 ;
1147 else if (is_overloaded_fn (old_value))
1148 {
1149 if (flist)
1150 /* It's OK to use functions from a base when there are functions with
1151 the same name already present in the current class. */;
1152 else
1153 {
1154 cp_error_at ("%qD invalid in %q#T", using_decl, t);
1155 cp_error_at (" because of local method %q#D with same name",
1156 OVL_CURRENT (old_value));
1157 return;
1158 }
1159 }
1160 else if (!DECL_ARTIFICIAL (old_value))
1161 {
1162 cp_error_at ("%qD invalid in %q#T", using_decl, t);
1163 cp_error_at (" because of local member %q#D with same name", old_value);
1164 return;
1165 }
1166
1167 /* Make type T see field decl FDECL with access ACCESS. */
1168 if (flist)
1169 for (; flist; flist = OVL_NEXT (flist))
1170 {
1171 add_method (t, OVL_CURRENT (flist));
1172 alter_access (t, OVL_CURRENT (flist), access);
1173 }
1174 else
1175 alter_access (t, fdecl, access);
1176 }
1177 \f
1178 /* Run through the base classes of T, updating
1179 CANT_HAVE_DEFAULT_CTOR_P, CANT_HAVE_CONST_CTOR_P, and
1180 NO_CONST_ASN_REF_P. Also set flag bits in T based on properties of
1181 the bases. */
1182
1183 static void
1184 check_bases (tree t,
1185 int* cant_have_default_ctor_p,
1186 int* cant_have_const_ctor_p,
1187 int* no_const_asn_ref_p)
1188 {
1189 int i;
1190 int seen_non_virtual_nearly_empty_base_p;
1191 tree base_binfo;
1192 tree binfo;
1193
1194 seen_non_virtual_nearly_empty_base_p = 0;
1195
1196 for (binfo = TYPE_BINFO (t), i = 0;
1197 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
1198 {
1199 tree basetype = TREE_TYPE (base_binfo);
1200
1201 gcc_assert (COMPLETE_TYPE_P (basetype));
1202
1203 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1204 here because the case of virtual functions but non-virtual
1205 dtor is handled in finish_struct_1. */
1206 if (warn_ecpp && ! TYPE_POLYMORPHIC_P (basetype)
1207 && TYPE_HAS_DESTRUCTOR (basetype))
1208 warning ("base class %q#T has a non-virtual destructor", basetype);
1209
1210 /* If the base class doesn't have copy constructors or
1211 assignment operators that take const references, then the
1212 derived class cannot have such a member automatically
1213 generated. */
1214 if (! TYPE_HAS_CONST_INIT_REF (basetype))
1215 *cant_have_const_ctor_p = 1;
1216 if (TYPE_HAS_ASSIGN_REF (basetype)
1217 && !TYPE_HAS_CONST_ASSIGN_REF (basetype))
1218 *no_const_asn_ref_p = 1;
1219 /* Similarly, if the base class doesn't have a default
1220 constructor, then the derived class won't have an
1221 automatically generated default constructor. */
1222 if (TYPE_HAS_CONSTRUCTOR (basetype)
1223 && ! TYPE_HAS_DEFAULT_CONSTRUCTOR (basetype))
1224 {
1225 *cant_have_default_ctor_p = 1;
1226 if (! TYPE_HAS_CONSTRUCTOR (t))
1227 pedwarn ("base %qT with only non-default constructor in class "
1228 "without a constructor",
1229 basetype);
1230 }
1231
1232 if (BINFO_VIRTUAL_P (base_binfo))
1233 /* A virtual base does not effect nearly emptiness. */
1234 ;
1235 else if (CLASSTYPE_NEARLY_EMPTY_P (basetype))
1236 {
1237 if (seen_non_virtual_nearly_empty_base_p)
1238 /* And if there is more than one nearly empty base, then the
1239 derived class is not nearly empty either. */
1240 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1241 else
1242 /* Remember we've seen one. */
1243 seen_non_virtual_nearly_empty_base_p = 1;
1244 }
1245 else if (!is_empty_class (basetype))
1246 /* If the base class is not empty or nearly empty, then this
1247 class cannot be nearly empty. */
1248 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1249
1250 /* A lot of properties from the bases also apply to the derived
1251 class. */
1252 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (basetype);
1253 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
1254 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype);
1255 TYPE_HAS_COMPLEX_ASSIGN_REF (t)
1256 |= TYPE_HAS_COMPLEX_ASSIGN_REF (basetype);
1257 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (basetype);
1258 TYPE_POLYMORPHIC_P (t) |= TYPE_POLYMORPHIC_P (basetype);
1259 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t)
1260 |= CLASSTYPE_CONTAINS_EMPTY_CLASS_P (basetype);
1261 }
1262 }
1263
1264 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1265 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1266 that have had a nearly-empty virtual primary base stolen by some
1267 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1268 T. */
1269
1270 static void
1271 determine_primary_bases (tree t)
1272 {
1273 unsigned i;
1274 tree primary = NULL_TREE;
1275 tree type_binfo = TYPE_BINFO (t);
1276 tree base_binfo;
1277
1278 /* Determine the primary bases of our bases. */
1279 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1280 base_binfo = TREE_CHAIN (base_binfo))
1281 {
1282 tree primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (base_binfo));
1283
1284 /* See if we're the non-virtual primary of our inheritance
1285 chain. */
1286 if (!BINFO_VIRTUAL_P (base_binfo))
1287 {
1288 tree parent = BINFO_INHERITANCE_CHAIN (base_binfo);
1289 tree parent_primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (parent));
1290
1291 if (parent_primary
1292 && SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo),
1293 BINFO_TYPE (parent_primary)))
1294 /* We are the primary binfo. */
1295 BINFO_PRIMARY_P (base_binfo) = 1;
1296 }
1297 /* Determine if we have a virtual primary base, and mark it so.
1298 */
1299 if (primary && BINFO_VIRTUAL_P (primary))
1300 {
1301 tree this_primary = copied_binfo (primary, base_binfo);
1302
1303 if (BINFO_PRIMARY_P (this_primary))
1304 /* Someone already claimed this base. */
1305 BINFO_LOST_PRIMARY_P (base_binfo) = 1;
1306 else
1307 {
1308 tree delta;
1309
1310 BINFO_PRIMARY_P (this_primary) = 1;
1311 BINFO_INHERITANCE_CHAIN (this_primary) = base_binfo;
1312
1313 /* A virtual binfo might have been copied from within
1314 another hierarchy. As we're about to use it as a
1315 primary base, make sure the offsets match. */
1316 delta = size_diffop (convert (ssizetype,
1317 BINFO_OFFSET (base_binfo)),
1318 convert (ssizetype,
1319 BINFO_OFFSET (this_primary)));
1320
1321 propagate_binfo_offsets (this_primary, delta);
1322 }
1323 }
1324 }
1325
1326 /* First look for a dynamic direct non-virtual base. */
1327 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, base_binfo); i++)
1328 {
1329 tree basetype = BINFO_TYPE (base_binfo);
1330
1331 if (TYPE_CONTAINS_VPTR_P (basetype) && !BINFO_VIRTUAL_P (base_binfo))
1332 {
1333 primary = base_binfo;
1334 goto found;
1335 }
1336 }
1337
1338 /* A "nearly-empty" virtual base class can be the primary base
1339 class, if no non-virtual polymorphic base can be found. Look for
1340 a nearly-empty virtual dynamic base that is not already a primary
1341 base of something in the hierarchy. If there is no such base,
1342 just pick the first nearly-empty virtual base. */
1343
1344 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1345 base_binfo = TREE_CHAIN (base_binfo))
1346 if (BINFO_VIRTUAL_P (base_binfo)
1347 && CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (base_binfo)))
1348 {
1349 if (!BINFO_PRIMARY_P (base_binfo))
1350 {
1351 /* Found one that is not primary. */
1352 primary = base_binfo;
1353 goto found;
1354 }
1355 else if (!primary)
1356 /* Remember the first candidate. */
1357 primary = base_binfo;
1358 }
1359
1360 found:
1361 /* If we've got a primary base, use it. */
1362 if (primary)
1363 {
1364 tree basetype = BINFO_TYPE (primary);
1365
1366 CLASSTYPE_PRIMARY_BINFO (t) = primary;
1367 if (BINFO_PRIMARY_P (primary))
1368 /* We are stealing a primary base. */
1369 BINFO_LOST_PRIMARY_P (BINFO_INHERITANCE_CHAIN (primary)) = 1;
1370 BINFO_PRIMARY_P (primary) = 1;
1371 if (BINFO_VIRTUAL_P (primary))
1372 {
1373 tree delta;
1374
1375 BINFO_INHERITANCE_CHAIN (primary) = type_binfo;
1376 /* A virtual binfo might have been copied from within
1377 another hierarchy. As we're about to use it as a primary
1378 base, make sure the offsets match. */
1379 delta = size_diffop (ssize_int (0),
1380 convert (ssizetype, BINFO_OFFSET (primary)));
1381
1382 propagate_binfo_offsets (primary, delta);
1383 }
1384
1385 primary = TYPE_BINFO (basetype);
1386
1387 TYPE_VFIELD (t) = TYPE_VFIELD (basetype);
1388 BINFO_VTABLE (type_binfo) = BINFO_VTABLE (primary);
1389 BINFO_VIRTUALS (type_binfo) = BINFO_VIRTUALS (primary);
1390 }
1391 }
1392 \f
1393 /* Set memoizing fields and bits of T (and its variants) for later
1394 use. */
1395
1396 static void
1397 finish_struct_bits (tree t)
1398 {
1399 tree variants;
1400
1401 /* Fix up variants (if any). */
1402 for (variants = TYPE_NEXT_VARIANT (t);
1403 variants;
1404 variants = TYPE_NEXT_VARIANT (variants))
1405 {
1406 /* These fields are in the _TYPE part of the node, not in
1407 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1408 TYPE_HAS_CONSTRUCTOR (variants) = TYPE_HAS_CONSTRUCTOR (t);
1409 TYPE_HAS_DESTRUCTOR (variants) = TYPE_HAS_DESTRUCTOR (t);
1410 TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t);
1411 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variants)
1412 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
1413
1414 TYPE_POLYMORPHIC_P (variants) = TYPE_POLYMORPHIC_P (t);
1415
1416 TYPE_BINFO (variants) = TYPE_BINFO (t);
1417
1418 /* Copy whatever these are holding today. */
1419 TYPE_VFIELD (variants) = TYPE_VFIELD (t);
1420 TYPE_METHODS (variants) = TYPE_METHODS (t);
1421 TYPE_FIELDS (variants) = TYPE_FIELDS (t);
1422 TYPE_SIZE (variants) = TYPE_SIZE (t);
1423 TYPE_SIZE_UNIT (variants) = TYPE_SIZE_UNIT (t);
1424 }
1425
1426 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) && TYPE_POLYMORPHIC_P (t))
1427 /* For a class w/o baseclasses, 'finish_struct' has set
1428 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1429 Similarly for a class whose base classes do not have vtables.
1430 When neither of these is true, we might have removed abstract
1431 virtuals (by providing a definition), added some (by declaring
1432 new ones), or redeclared ones from a base class. We need to
1433 recalculate what's really an abstract virtual at this point (by
1434 looking in the vtables). */
1435 get_pure_virtuals (t);
1436
1437 /* If this type has a copy constructor or a destructor, force its
1438 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1439 nonzero. This will cause it to be passed by invisible reference
1440 and prevent it from being returned in a register. */
1441 if (! TYPE_HAS_TRIVIAL_INIT_REF (t) || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
1442 {
1443 tree variants;
1444 DECL_MODE (TYPE_MAIN_DECL (t)) = BLKmode;
1445 for (variants = t; variants; variants = TYPE_NEXT_VARIANT (variants))
1446 {
1447 TYPE_MODE (variants) = BLKmode;
1448 TREE_ADDRESSABLE (variants) = 1;
1449 }
1450 }
1451 }
1452
1453 /* Issue warnings about T having private constructors, but no friends,
1454 and so forth.
1455
1456 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1457 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1458 non-private static member functions. */
1459
1460 static void
1461 maybe_warn_about_overly_private_class (tree t)
1462 {
1463 int has_member_fn = 0;
1464 int has_nonprivate_method = 0;
1465 tree fn;
1466
1467 if (!warn_ctor_dtor_privacy
1468 /* If the class has friends, those entities might create and
1469 access instances, so we should not warn. */
1470 || (CLASSTYPE_FRIEND_CLASSES (t)
1471 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))
1472 /* We will have warned when the template was declared; there's
1473 no need to warn on every instantiation. */
1474 || CLASSTYPE_TEMPLATE_INSTANTIATION (t))
1475 /* There's no reason to even consider warning about this
1476 class. */
1477 return;
1478
1479 /* We only issue one warning, if more than one applies, because
1480 otherwise, on code like:
1481
1482 class A {
1483 // Oops - forgot `public:'
1484 A();
1485 A(const A&);
1486 ~A();
1487 };
1488
1489 we warn several times about essentially the same problem. */
1490
1491 /* Check to see if all (non-constructor, non-destructor) member
1492 functions are private. (Since there are no friends or
1493 non-private statics, we can't ever call any of the private member
1494 functions.) */
1495 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
1496 /* We're not interested in compiler-generated methods; they don't
1497 provide any way to call private members. */
1498 if (!DECL_ARTIFICIAL (fn))
1499 {
1500 if (!TREE_PRIVATE (fn))
1501 {
1502 if (DECL_STATIC_FUNCTION_P (fn))
1503 /* A non-private static member function is just like a
1504 friend; it can create and invoke private member
1505 functions, and be accessed without a class
1506 instance. */
1507 return;
1508
1509 has_nonprivate_method = 1;
1510 /* Keep searching for a static member function. */
1511 }
1512 else if (!DECL_CONSTRUCTOR_P (fn) && !DECL_DESTRUCTOR_P (fn))
1513 has_member_fn = 1;
1514 }
1515
1516 if (!has_nonprivate_method && has_member_fn)
1517 {
1518 /* There are no non-private methods, and there's at least one
1519 private member function that isn't a constructor or
1520 destructor. (If all the private members are
1521 constructors/destructors we want to use the code below that
1522 issues error messages specifically referring to
1523 constructors/destructors.) */
1524 unsigned i;
1525 tree binfo = TYPE_BINFO (t);
1526
1527 for (i = 0; i != BINFO_N_BASE_BINFOS (binfo); i++)
1528 if (BINFO_BASE_ACCESS (binfo, i) != access_private_node)
1529 {
1530 has_nonprivate_method = 1;
1531 break;
1532 }
1533 if (!has_nonprivate_method)
1534 {
1535 warning ("all member functions in class %qT are private", t);
1536 return;
1537 }
1538 }
1539
1540 /* Even if some of the member functions are non-private, the class
1541 won't be useful for much if all the constructors or destructors
1542 are private: such an object can never be created or destroyed. */
1543 if (TYPE_HAS_DESTRUCTOR (t)
1544 && TREE_PRIVATE (CLASSTYPE_DESTRUCTORS (t)))
1545 {
1546 warning ("%q#T only defines a private destructor and has no friends",
1547 t);
1548 return;
1549 }
1550
1551 if (TYPE_HAS_CONSTRUCTOR (t))
1552 {
1553 int nonprivate_ctor = 0;
1554
1555 /* If a non-template class does not define a copy
1556 constructor, one is defined for it, enabling it to avoid
1557 this warning. For a template class, this does not
1558 happen, and so we would normally get a warning on:
1559
1560 template <class T> class C { private: C(); };
1561
1562 To avoid this asymmetry, we check TYPE_HAS_INIT_REF. All
1563 complete non-template or fully instantiated classes have this
1564 flag set. */
1565 if (!TYPE_HAS_INIT_REF (t))
1566 nonprivate_ctor = 1;
1567 else
1568 for (fn = CLASSTYPE_CONSTRUCTORS (t); fn; fn = OVL_NEXT (fn))
1569 {
1570 tree ctor = OVL_CURRENT (fn);
1571 /* Ideally, we wouldn't count copy constructors (or, in
1572 fact, any constructor that takes an argument of the
1573 class type as a parameter) because such things cannot
1574 be used to construct an instance of the class unless
1575 you already have one. But, for now at least, we're
1576 more generous. */
1577 if (! TREE_PRIVATE (ctor))
1578 {
1579 nonprivate_ctor = 1;
1580 break;
1581 }
1582 }
1583
1584 if (nonprivate_ctor == 0)
1585 {
1586 warning ("%q#T only defines private constructors and has no friends",
1587 t);
1588 return;
1589 }
1590 }
1591 }
1592
1593 static struct {
1594 gt_pointer_operator new_value;
1595 void *cookie;
1596 } resort_data;
1597
1598 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1599
1600 static int
1601 method_name_cmp (const void* m1_p, const void* m2_p)
1602 {
1603 const tree *const m1 = m1_p;
1604 const tree *const m2 = m2_p;
1605
1606 if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1607 return 0;
1608 if (*m1 == NULL_TREE)
1609 return -1;
1610 if (*m2 == NULL_TREE)
1611 return 1;
1612 if (DECL_NAME (OVL_CURRENT (*m1)) < DECL_NAME (OVL_CURRENT (*m2)))
1613 return -1;
1614 return 1;
1615 }
1616
1617 /* This routine compares two fields like method_name_cmp but using the
1618 pointer operator in resort_field_decl_data. */
1619
1620 static int
1621 resort_method_name_cmp (const void* m1_p, const void* m2_p)
1622 {
1623 const tree *const m1 = m1_p;
1624 const tree *const m2 = m2_p;
1625 if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1626 return 0;
1627 if (*m1 == NULL_TREE)
1628 return -1;
1629 if (*m2 == NULL_TREE)
1630 return 1;
1631 {
1632 tree d1 = DECL_NAME (OVL_CURRENT (*m1));
1633 tree d2 = DECL_NAME (OVL_CURRENT (*m2));
1634 resort_data.new_value (&d1, resort_data.cookie);
1635 resort_data.new_value (&d2, resort_data.cookie);
1636 if (d1 < d2)
1637 return -1;
1638 }
1639 return 1;
1640 }
1641
1642 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1643
1644 void
1645 resort_type_method_vec (void* obj,
1646 void* orig_obj ATTRIBUTE_UNUSED ,
1647 gt_pointer_operator new_value,
1648 void* cookie)
1649 {
1650 VEC(tree) *method_vec = (VEC(tree) *) obj;
1651 int len = VEC_length (tree, method_vec);
1652 size_t slot;
1653 tree fn;
1654
1655 /* The type conversion ops have to live at the front of the vec, so we
1656 can't sort them. */
1657 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1658 VEC_iterate (tree, method_vec, slot, fn);
1659 ++slot)
1660 if (!DECL_CONV_FN_P (OVL_CURRENT (fn)))
1661 break;
1662
1663 if (len - slot > 1)
1664 {
1665 resort_data.new_value = new_value;
1666 resort_data.cookie = cookie;
1667 qsort (VEC_address (tree, method_vec) + slot, len - slot, sizeof (tree),
1668 resort_method_name_cmp);
1669 }
1670 }
1671
1672 /* Warn about duplicate methods in fn_fields.
1673
1674 Sort methods that are not special (i.e., constructors, destructors,
1675 and type conversion operators) so that we can find them faster in
1676 search. */
1677
1678 static void
1679 finish_struct_methods (tree t)
1680 {
1681 tree fn_fields;
1682 VEC(tree) *method_vec;
1683 int slot, len;
1684
1685 method_vec = CLASSTYPE_METHOD_VEC (t);
1686 if (!method_vec)
1687 return;
1688
1689 len = VEC_length (tree, method_vec);
1690
1691 /* Clear DECL_IN_AGGR_P for all functions. */
1692 for (fn_fields = TYPE_METHODS (t); fn_fields;
1693 fn_fields = TREE_CHAIN (fn_fields))
1694 DECL_IN_AGGR_P (fn_fields) = 0;
1695
1696 if (TYPE_HAS_DESTRUCTOR (t) && !CLASSTYPE_DESTRUCTORS (t))
1697 /* We thought there was a destructor, but there wasn't. Some
1698 parse errors cause this anomalous situation. */
1699 TYPE_HAS_DESTRUCTOR (t) = 0;
1700
1701 /* Issue warnings about private constructors and such. If there are
1702 no methods, then some public defaults are generated. */
1703 maybe_warn_about_overly_private_class (t);
1704
1705 /* The type conversion ops have to live at the front of the vec, so we
1706 can't sort them. */
1707 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1708 VEC_iterate (tree, method_vec, slot, fn_fields);
1709 ++slot)
1710 if (!DECL_CONV_FN_P (OVL_CURRENT (fn_fields)))
1711 break;
1712 if (len - slot > 1)
1713 qsort (VEC_address (tree, method_vec) + slot,
1714 len-slot, sizeof (tree), method_name_cmp);
1715 }
1716
1717 /* Make BINFO's vtable have N entries, including RTTI entries,
1718 vbase and vcall offsets, etc. Set its type and call the backend
1719 to lay it out. */
1720
1721 static void
1722 layout_vtable_decl (tree binfo, int n)
1723 {
1724 tree atype;
1725 tree vtable;
1726
1727 atype = build_cplus_array_type (vtable_entry_type,
1728 build_index_type (size_int (n - 1)));
1729 layout_type (atype);
1730
1731 /* We may have to grow the vtable. */
1732 vtable = get_vtbl_decl_for_binfo (binfo);
1733 if (!same_type_p (TREE_TYPE (vtable), atype))
1734 {
1735 TREE_TYPE (vtable) = atype;
1736 DECL_SIZE (vtable) = DECL_SIZE_UNIT (vtable) = NULL_TREE;
1737 layout_decl (vtable, 0);
1738 }
1739 }
1740
1741 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1742 have the same signature. */
1743
1744 int
1745 same_signature_p (tree fndecl, tree base_fndecl)
1746 {
1747 /* One destructor overrides another if they are the same kind of
1748 destructor. */
1749 if (DECL_DESTRUCTOR_P (base_fndecl) && DECL_DESTRUCTOR_P (fndecl)
1750 && special_function_p (base_fndecl) == special_function_p (fndecl))
1751 return 1;
1752 /* But a non-destructor never overrides a destructor, nor vice
1753 versa, nor do different kinds of destructors override
1754 one-another. For example, a complete object destructor does not
1755 override a deleting destructor. */
1756 if (DECL_DESTRUCTOR_P (base_fndecl) || DECL_DESTRUCTOR_P (fndecl))
1757 return 0;
1758
1759 if (DECL_NAME (fndecl) == DECL_NAME (base_fndecl)
1760 || (DECL_CONV_FN_P (fndecl)
1761 && DECL_CONV_FN_P (base_fndecl)
1762 && same_type_p (DECL_CONV_FN_TYPE (fndecl),
1763 DECL_CONV_FN_TYPE (base_fndecl))))
1764 {
1765 tree types, base_types;
1766 types = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
1767 base_types = TYPE_ARG_TYPES (TREE_TYPE (base_fndecl));
1768 if ((TYPE_QUALS (TREE_TYPE (TREE_VALUE (base_types)))
1769 == TYPE_QUALS (TREE_TYPE (TREE_VALUE (types))))
1770 && compparms (TREE_CHAIN (base_types), TREE_CHAIN (types)))
1771 return 1;
1772 }
1773 return 0;
1774 }
1775
1776 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1777 subobject. */
1778
1779 static bool
1780 base_derived_from (tree derived, tree base)
1781 {
1782 tree probe;
1783
1784 for (probe = base; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
1785 {
1786 if (probe == derived)
1787 return true;
1788 else if (BINFO_VIRTUAL_P (probe))
1789 /* If we meet a virtual base, we can't follow the inheritance
1790 any more. See if the complete type of DERIVED contains
1791 such a virtual base. */
1792 return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (derived))
1793 != NULL_TREE);
1794 }
1795 return false;
1796 }
1797
1798 typedef struct find_final_overrider_data_s {
1799 /* The function for which we are trying to find a final overrider. */
1800 tree fn;
1801 /* The base class in which the function was declared. */
1802 tree declaring_base;
1803 /* The candidate overriders. */
1804 tree candidates;
1805 /* Path to most derived. */
1806 VEC (tree) *path;
1807 } find_final_overrider_data;
1808
1809 /* Add the overrider along the current path to FFOD->CANDIDATES.
1810 Returns true if an overrider was found; false otherwise. */
1811
1812 static bool
1813 dfs_find_final_overrider_1 (tree binfo,
1814 find_final_overrider_data *ffod,
1815 unsigned depth)
1816 {
1817 tree method;
1818
1819 /* If BINFO is not the most derived type, try a more derived class.
1820 A definition there will overrider a definition here. */
1821 if (depth)
1822 {
1823 depth--;
1824 if (dfs_find_final_overrider_1
1825 (VEC_index (tree, ffod->path, depth), ffod, depth))
1826 return true;
1827 }
1828
1829 method = look_for_overrides_here (BINFO_TYPE (binfo), ffod->fn);
1830 if (method)
1831 {
1832 tree *candidate = &ffod->candidates;
1833
1834 /* Remove any candidates overridden by this new function. */
1835 while (*candidate)
1836 {
1837 /* If *CANDIDATE overrides METHOD, then METHOD
1838 cannot override anything else on the list. */
1839 if (base_derived_from (TREE_VALUE (*candidate), binfo))
1840 return true;
1841 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
1842 if (base_derived_from (binfo, TREE_VALUE (*candidate)))
1843 *candidate = TREE_CHAIN (*candidate);
1844 else
1845 candidate = &TREE_CHAIN (*candidate);
1846 }
1847
1848 /* Add the new function. */
1849 ffod->candidates = tree_cons (method, binfo, ffod->candidates);
1850 return true;
1851 }
1852
1853 return false;
1854 }
1855
1856 /* Called from find_final_overrider via dfs_walk. */
1857
1858 static tree
1859 dfs_find_final_overrider_pre (tree binfo, void *data)
1860 {
1861 find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1862
1863 if (binfo == ffod->declaring_base)
1864 dfs_find_final_overrider_1 (binfo, ffod, VEC_length (tree, ffod->path));
1865 VEC_safe_push (tree, ffod->path, binfo);
1866
1867 return NULL_TREE;
1868 }
1869
1870 static tree
1871 dfs_find_final_overrider_post (tree binfo ATTRIBUTE_UNUSED, void *data)
1872 {
1873 find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1874 VEC_pop (tree, ffod->path);
1875
1876 return NULL_TREE;
1877 }
1878
1879 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
1880 FN and whose TREE_VALUE is the binfo for the base where the
1881 overriding occurs. BINFO (in the hierarchy dominated by the binfo
1882 DERIVED) is the base object in which FN is declared. */
1883
1884 static tree
1885 find_final_overrider (tree derived, tree binfo, tree fn)
1886 {
1887 find_final_overrider_data ffod;
1888
1889 /* Getting this right is a little tricky. This is valid:
1890
1891 struct S { virtual void f (); };
1892 struct T { virtual void f (); };
1893 struct U : public S, public T { };
1894
1895 even though calling `f' in `U' is ambiguous. But,
1896
1897 struct R { virtual void f(); };
1898 struct S : virtual public R { virtual void f (); };
1899 struct T : virtual public R { virtual void f (); };
1900 struct U : public S, public T { };
1901
1902 is not -- there's no way to decide whether to put `S::f' or
1903 `T::f' in the vtable for `R'.
1904
1905 The solution is to look at all paths to BINFO. If we find
1906 different overriders along any two, then there is a problem. */
1907 if (DECL_THUNK_P (fn))
1908 fn = THUNK_TARGET (fn);
1909
1910 /* Determine the depth of the hierarchy. */
1911 ffod.fn = fn;
1912 ffod.declaring_base = binfo;
1913 ffod.candidates = NULL_TREE;
1914 ffod.path = VEC_alloc (tree, 30);
1915
1916 dfs_walk_all (derived, dfs_find_final_overrider_pre,
1917 dfs_find_final_overrider_post, &ffod);
1918
1919 VEC_free (tree, ffod.path);
1920
1921 /* If there was no winner, issue an error message. */
1922 if (!ffod.candidates || TREE_CHAIN (ffod.candidates))
1923 {
1924 error ("no unique final overrider for %qD in %qT", fn,
1925 BINFO_TYPE (derived));
1926 return error_mark_node;
1927 }
1928
1929 return ffod.candidates;
1930 }
1931
1932 /* Return the index of the vcall offset for FN when TYPE is used as a
1933 virtual base. */
1934
1935 static tree
1936 get_vcall_index (tree fn, tree type)
1937 {
1938 VEC (tree_pair_s) *indices = CLASSTYPE_VCALL_INDICES (type);
1939 tree_pair_p p;
1940 unsigned ix;
1941
1942 for (ix = 0; VEC_iterate (tree_pair_s, indices, ix, p); ix++)
1943 if ((DECL_DESTRUCTOR_P (fn) && DECL_DESTRUCTOR_P (p->purpose))
1944 || same_signature_p (fn, p->purpose))
1945 return p->value;
1946
1947 /* There should always be an appropriate index. */
1948 gcc_unreachable ();
1949 }
1950
1951 /* Update an entry in the vtable for BINFO, which is in the hierarchy
1952 dominated by T. FN has been overridden in BINFO; VIRTUALS points to the
1953 corresponding position in the BINFO_VIRTUALS list. */
1954
1955 static void
1956 update_vtable_entry_for_fn (tree t, tree binfo, tree fn, tree* virtuals,
1957 unsigned ix)
1958 {
1959 tree b;
1960 tree overrider;
1961 tree delta;
1962 tree virtual_base;
1963 tree first_defn;
1964 tree overrider_fn, overrider_target;
1965 tree target_fn = DECL_THUNK_P (fn) ? THUNK_TARGET (fn) : fn;
1966 tree over_return, base_return;
1967 bool lost = false;
1968
1969 /* Find the nearest primary base (possibly binfo itself) which defines
1970 this function; this is the class the caller will convert to when
1971 calling FN through BINFO. */
1972 for (b = binfo; ; b = get_primary_binfo (b))
1973 {
1974 gcc_assert (b);
1975 if (look_for_overrides_here (BINFO_TYPE (b), target_fn))
1976 break;
1977
1978 /* The nearest definition is from a lost primary. */
1979 if (BINFO_LOST_PRIMARY_P (b))
1980 lost = true;
1981 }
1982 first_defn = b;
1983
1984 /* Find the final overrider. */
1985 overrider = find_final_overrider (TYPE_BINFO (t), b, target_fn);
1986 if (overrider == error_mark_node)
1987 return;
1988 overrider_target = overrider_fn = TREE_PURPOSE (overrider);
1989
1990 /* Check for adjusting covariant return types. */
1991 over_return = TREE_TYPE (TREE_TYPE (overrider_target));
1992 base_return = TREE_TYPE (TREE_TYPE (target_fn));
1993
1994 if (POINTER_TYPE_P (over_return)
1995 && TREE_CODE (over_return) == TREE_CODE (base_return)
1996 && CLASS_TYPE_P (TREE_TYPE (over_return))
1997 && CLASS_TYPE_P (TREE_TYPE (base_return)))
1998 {
1999 /* If FN is a covariant thunk, we must figure out the adjustment
2000 to the final base FN was converting to. As OVERRIDER_TARGET might
2001 also be converting to the return type of FN, we have to
2002 combine the two conversions here. */
2003 tree fixed_offset, virtual_offset;
2004
2005 if (DECL_THUNK_P (fn))
2006 {
2007 gcc_assert (DECL_RESULT_THUNK_P (fn));
2008 fixed_offset = ssize_int (THUNK_FIXED_OFFSET (fn));
2009 virtual_offset = THUNK_VIRTUAL_OFFSET (fn);
2010 }
2011 else
2012 fixed_offset = virtual_offset = NULL_TREE;
2013
2014 if (virtual_offset)
2015 /* Find the equivalent binfo within the return type of the
2016 overriding function. We will want the vbase offset from
2017 there. */
2018 virtual_offset = binfo_for_vbase (BINFO_TYPE (virtual_offset),
2019 TREE_TYPE (over_return));
2020 else if (!same_type_p (TREE_TYPE (over_return),
2021 TREE_TYPE (base_return)))
2022 {
2023 /* There was no existing virtual thunk (which takes
2024 precedence). */
2025 tree thunk_binfo;
2026 base_kind kind;
2027
2028 thunk_binfo = lookup_base (TREE_TYPE (over_return),
2029 TREE_TYPE (base_return),
2030 ba_check | ba_quiet, &kind);
2031
2032 if (thunk_binfo && (kind == bk_via_virtual
2033 || !BINFO_OFFSET_ZEROP (thunk_binfo)))
2034 {
2035 tree offset = convert (ssizetype, BINFO_OFFSET (thunk_binfo));
2036
2037 if (kind == bk_via_virtual)
2038 {
2039 /* We convert via virtual base. Find the virtual
2040 base and adjust the fixed offset to be from there. */
2041 while (!BINFO_VIRTUAL_P (thunk_binfo))
2042 thunk_binfo = BINFO_INHERITANCE_CHAIN (thunk_binfo);
2043
2044 virtual_offset = thunk_binfo;
2045 offset = size_diffop
2046 (offset, convert
2047 (ssizetype, BINFO_OFFSET (virtual_offset)));
2048 }
2049 if (fixed_offset)
2050 /* There was an existing fixed offset, this must be
2051 from the base just converted to, and the base the
2052 FN was thunking to. */
2053 fixed_offset = size_binop (PLUS_EXPR, fixed_offset, offset);
2054 else
2055 fixed_offset = offset;
2056 }
2057 }
2058
2059 if (fixed_offset || virtual_offset)
2060 /* Replace the overriding function with a covariant thunk. We
2061 will emit the overriding function in its own slot as
2062 well. */
2063 overrider_fn = make_thunk (overrider_target, /*this_adjusting=*/0,
2064 fixed_offset, virtual_offset);
2065 }
2066 else
2067 gcc_assert (!DECL_THUNK_P (fn));
2068
2069 /* Assume that we will produce a thunk that convert all the way to
2070 the final overrider, and not to an intermediate virtual base. */
2071 virtual_base = NULL_TREE;
2072
2073 /* See if we can convert to an intermediate virtual base first, and then
2074 use the vcall offset located there to finish the conversion. */
2075 for (; b; b = BINFO_INHERITANCE_CHAIN (b))
2076 {
2077 /* If we find the final overrider, then we can stop
2078 walking. */
2079 if (SAME_BINFO_TYPE_P (BINFO_TYPE (b),
2080 BINFO_TYPE (TREE_VALUE (overrider))))
2081 break;
2082
2083 /* If we find a virtual base, and we haven't yet found the
2084 overrider, then there is a virtual base between the
2085 declaring base (first_defn) and the final overrider. */
2086 if (BINFO_VIRTUAL_P (b))
2087 {
2088 virtual_base = b;
2089 break;
2090 }
2091 }
2092
2093 if (overrider_fn != overrider_target && !virtual_base)
2094 {
2095 /* The ABI specifies that a covariant thunk includes a mangling
2096 for a this pointer adjustment. This-adjusting thunks that
2097 override a function from a virtual base have a vcall
2098 adjustment. When the virtual base in question is a primary
2099 virtual base, we know the adjustments are zero, (and in the
2100 non-covariant case, we would not use the thunk).
2101 Unfortunately we didn't notice this could happen, when
2102 designing the ABI and so never mandated that such a covariant
2103 thunk should be emitted. Because we must use the ABI mandated
2104 name, we must continue searching from the binfo where we
2105 found the most recent definition of the function, towards the
2106 primary binfo which first introduced the function into the
2107 vtable. If that enters a virtual base, we must use a vcall
2108 this-adjusting thunk. Bleah! */
2109 tree probe = first_defn;
2110
2111 while ((probe = get_primary_binfo (probe))
2112 && (unsigned) list_length (BINFO_VIRTUALS (probe)) > ix)
2113 if (BINFO_VIRTUAL_P (probe))
2114 virtual_base = probe;
2115
2116 if (virtual_base)
2117 /* Even if we find a virtual base, the correct delta is
2118 between the overrider and the binfo we're building a vtable
2119 for. */
2120 goto virtual_covariant;
2121 }
2122
2123 /* Compute the constant adjustment to the `this' pointer. The
2124 `this' pointer, when this function is called, will point at BINFO
2125 (or one of its primary bases, which are at the same offset). */
2126 if (virtual_base)
2127 /* The `this' pointer needs to be adjusted from the declaration to
2128 the nearest virtual base. */
2129 delta = size_diffop (convert (ssizetype, BINFO_OFFSET (virtual_base)),
2130 convert (ssizetype, BINFO_OFFSET (first_defn)));
2131 else if (lost)
2132 /* If the nearest definition is in a lost primary, we don't need an
2133 entry in our vtable. Except possibly in a constructor vtable,
2134 if we happen to get our primary back. In that case, the offset
2135 will be zero, as it will be a primary base. */
2136 delta = size_zero_node;
2137 else
2138 /* The `this' pointer needs to be adjusted from pointing to
2139 BINFO to pointing at the base where the final overrider
2140 appears. */
2141 virtual_covariant:
2142 delta = size_diffop (convert (ssizetype,
2143 BINFO_OFFSET (TREE_VALUE (overrider))),
2144 convert (ssizetype, BINFO_OFFSET (binfo)));
2145
2146 modify_vtable_entry (t, binfo, overrider_fn, delta, virtuals);
2147
2148 if (virtual_base)
2149 BV_VCALL_INDEX (*virtuals)
2150 = get_vcall_index (overrider_target, BINFO_TYPE (virtual_base));
2151 else
2152 BV_VCALL_INDEX (*virtuals) = NULL_TREE;
2153 }
2154
2155 /* Called from modify_all_vtables via dfs_walk. */
2156
2157 static tree
2158 dfs_modify_vtables (tree binfo, void* data)
2159 {
2160 tree t = (tree) data;
2161 tree virtuals;
2162 tree old_virtuals;
2163 unsigned ix;
2164
2165 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
2166 /* A base without a vtable needs no modification, and its bases
2167 are uninteresting. */
2168 return dfs_skip_bases;
2169
2170 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t)
2171 && !CLASSTYPE_HAS_PRIMARY_BASE_P (t))
2172 /* Don't do the primary vtable, if it's new. */
2173 return NULL_TREE;
2174
2175 if (BINFO_PRIMARY_P (binfo) && !BINFO_VIRTUAL_P (binfo))
2176 /* There's no need to modify the vtable for a non-virtual primary
2177 base; we're not going to use that vtable anyhow. We do still
2178 need to do this for virtual primary bases, as they could become
2179 non-primary in a construction vtable. */
2180 return NULL_TREE;
2181
2182 make_new_vtable (t, binfo);
2183
2184 /* Now, go through each of the virtual functions in the virtual
2185 function table for BINFO. Find the final overrider, and update
2186 the BINFO_VIRTUALS list appropriately. */
2187 for (ix = 0, virtuals = BINFO_VIRTUALS (binfo),
2188 old_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
2189 virtuals;
2190 ix++, virtuals = TREE_CHAIN (virtuals),
2191 old_virtuals = TREE_CHAIN (old_virtuals))
2192 update_vtable_entry_for_fn (t,
2193 binfo,
2194 BV_FN (old_virtuals),
2195 &virtuals, ix);
2196
2197 return NULL_TREE;
2198 }
2199
2200 /* Update all of the primary and secondary vtables for T. Create new
2201 vtables as required, and initialize their RTTI information. Each
2202 of the functions in VIRTUALS is declared in T and may override a
2203 virtual function from a base class; find and modify the appropriate
2204 entries to point to the overriding functions. Returns a list, in
2205 declaration order, of the virtual functions that are declared in T,
2206 but do not appear in the primary base class vtable, and which
2207 should therefore be appended to the end of the vtable for T. */
2208
2209 static tree
2210 modify_all_vtables (tree t, tree virtuals)
2211 {
2212 tree binfo = TYPE_BINFO (t);
2213 tree *fnsp;
2214
2215 /* Update all of the vtables. */
2216 dfs_walk_once (binfo, dfs_modify_vtables, NULL, t);
2217
2218 /* Add virtual functions not already in our primary vtable. These
2219 will be both those introduced by this class, and those overridden
2220 from secondary bases. It does not include virtuals merely
2221 inherited from secondary bases. */
2222 for (fnsp = &virtuals; *fnsp; )
2223 {
2224 tree fn = TREE_VALUE (*fnsp);
2225
2226 if (!value_member (fn, BINFO_VIRTUALS (binfo))
2227 || DECL_VINDEX (fn) == error_mark_node)
2228 {
2229 /* We don't need to adjust the `this' pointer when
2230 calling this function. */
2231 BV_DELTA (*fnsp) = integer_zero_node;
2232 BV_VCALL_INDEX (*fnsp) = NULL_TREE;
2233
2234 /* This is a function not already in our vtable. Keep it. */
2235 fnsp = &TREE_CHAIN (*fnsp);
2236 }
2237 else
2238 /* We've already got an entry for this function. Skip it. */
2239 *fnsp = TREE_CHAIN (*fnsp);
2240 }
2241
2242 return virtuals;
2243 }
2244
2245 /* Get the base virtual function declarations in T that have the
2246 indicated NAME. */
2247
2248 static tree
2249 get_basefndecls (tree name, tree t)
2250 {
2251 tree methods;
2252 tree base_fndecls = NULL_TREE;
2253 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
2254 int i;
2255
2256 /* Find virtual functions in T with the indicated NAME. */
2257 i = lookup_fnfields_1 (t, name);
2258 if (i != -1)
2259 for (methods = VEC_index (tree, CLASSTYPE_METHOD_VEC (t), i);
2260 methods;
2261 methods = OVL_NEXT (methods))
2262 {
2263 tree method = OVL_CURRENT (methods);
2264
2265 if (TREE_CODE (method) == FUNCTION_DECL
2266 && DECL_VINDEX (method))
2267 base_fndecls = tree_cons (NULL_TREE, method, base_fndecls);
2268 }
2269
2270 if (base_fndecls)
2271 return base_fndecls;
2272
2273 for (i = 0; i < n_baseclasses; i++)
2274 {
2275 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (t), i));
2276 base_fndecls = chainon (get_basefndecls (name, basetype),
2277 base_fndecls);
2278 }
2279
2280 return base_fndecls;
2281 }
2282
2283 /* If this declaration supersedes the declaration of
2284 a method declared virtual in the base class, then
2285 mark this field as being virtual as well. */
2286
2287 static void
2288 check_for_override (tree decl, tree ctype)
2289 {
2290 if (TREE_CODE (decl) == TEMPLATE_DECL)
2291 /* In [temp.mem] we have:
2292
2293 A specialization of a member function template does not
2294 override a virtual function from a base class. */
2295 return;
2296 if ((DECL_DESTRUCTOR_P (decl)
2297 || IDENTIFIER_VIRTUAL_P (DECL_NAME (decl))
2298 || DECL_CONV_FN_P (decl))
2299 && look_for_overrides (ctype, decl)
2300 && !DECL_STATIC_FUNCTION_P (decl))
2301 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2302 the error_mark_node so that we know it is an overriding
2303 function. */
2304 DECL_VINDEX (decl) = decl;
2305
2306 if (DECL_VIRTUAL_P (decl))
2307 {
2308 if (!DECL_VINDEX (decl))
2309 DECL_VINDEX (decl) = error_mark_node;
2310 IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) = 1;
2311 }
2312 }
2313
2314 /* Warn about hidden virtual functions that are not overridden in t.
2315 We know that constructors and destructors don't apply. */
2316
2317 void
2318 warn_hidden (tree t)
2319 {
2320 VEC(tree) *method_vec = CLASSTYPE_METHOD_VEC (t);
2321 tree fns;
2322 size_t i;
2323
2324 /* We go through each separately named virtual function. */
2325 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
2326 VEC_iterate (tree, method_vec, i, fns);
2327 ++i)
2328 {
2329 tree fn;
2330 tree name;
2331 tree fndecl;
2332 tree base_fndecls;
2333 tree base_binfo;
2334 tree binfo;
2335 int j;
2336
2337 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2338 have the same name. Figure out what name that is. */
2339 name = DECL_NAME (OVL_CURRENT (fns));
2340 /* There are no possibly hidden functions yet. */
2341 base_fndecls = NULL_TREE;
2342 /* Iterate through all of the base classes looking for possibly
2343 hidden functions. */
2344 for (binfo = TYPE_BINFO (t), j = 0;
2345 BINFO_BASE_ITERATE (binfo, j, base_binfo); j++)
2346 {
2347 tree basetype = BINFO_TYPE (base_binfo);
2348 base_fndecls = chainon (get_basefndecls (name, basetype),
2349 base_fndecls);
2350 }
2351
2352 /* If there are no functions to hide, continue. */
2353 if (!base_fndecls)
2354 continue;
2355
2356 /* Remove any overridden functions. */
2357 for (fn = fns; fn; fn = OVL_NEXT (fn))
2358 {
2359 fndecl = OVL_CURRENT (fn);
2360 if (DECL_VINDEX (fndecl))
2361 {
2362 tree *prev = &base_fndecls;
2363
2364 while (*prev)
2365 /* If the method from the base class has the same
2366 signature as the method from the derived class, it
2367 has been overridden. */
2368 if (same_signature_p (fndecl, TREE_VALUE (*prev)))
2369 *prev = TREE_CHAIN (*prev);
2370 else
2371 prev = &TREE_CHAIN (*prev);
2372 }
2373 }
2374
2375 /* Now give a warning for all base functions without overriders,
2376 as they are hidden. */
2377 while (base_fndecls)
2378 {
2379 /* Here we know it is a hider, and no overrider exists. */
2380 cp_warning_at ("%qD was hidden", TREE_VALUE (base_fndecls));
2381 cp_warning_at (" by %qD", fns);
2382 base_fndecls = TREE_CHAIN (base_fndecls);
2383 }
2384 }
2385 }
2386
2387 /* Check for things that are invalid. There are probably plenty of other
2388 things we should check for also. */
2389
2390 static void
2391 finish_struct_anon (tree t)
2392 {
2393 tree field;
2394
2395 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
2396 {
2397 if (TREE_STATIC (field))
2398 continue;
2399 if (TREE_CODE (field) != FIELD_DECL)
2400 continue;
2401
2402 if (DECL_NAME (field) == NULL_TREE
2403 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
2404 {
2405 tree elt = TYPE_FIELDS (TREE_TYPE (field));
2406 for (; elt; elt = TREE_CHAIN (elt))
2407 {
2408 /* We're generally only interested in entities the user
2409 declared, but we also find nested classes by noticing
2410 the TYPE_DECL that we create implicitly. You're
2411 allowed to put one anonymous union inside another,
2412 though, so we explicitly tolerate that. We use
2413 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2414 we also allow unnamed types used for defining fields. */
2415 if (DECL_ARTIFICIAL (elt)
2416 && (!DECL_IMPLICIT_TYPEDEF_P (elt)
2417 || TYPE_ANONYMOUS_P (TREE_TYPE (elt))))
2418 continue;
2419
2420 if (TREE_CODE (elt) != FIELD_DECL)
2421 {
2422 cp_pedwarn_at ("%q#D invalid; an anonymous union can "
2423 "only have non-static data members",
2424 elt);
2425 continue;
2426 }
2427
2428 if (TREE_PRIVATE (elt))
2429 cp_pedwarn_at ("private member %q#D in anonymous union",
2430 elt);
2431 else if (TREE_PROTECTED (elt))
2432 cp_pedwarn_at ("protected member %q#D in anonymous union",
2433 elt);
2434
2435 TREE_PRIVATE (elt) = TREE_PRIVATE (field);
2436 TREE_PROTECTED (elt) = TREE_PROTECTED (field);
2437 }
2438 }
2439 }
2440 }
2441
2442 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2443 will be used later during class template instantiation.
2444 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2445 a non-static member data (FIELD_DECL), a member function
2446 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2447 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2448 When FRIEND_P is nonzero, T is either a friend class
2449 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2450 (FUNCTION_DECL, TEMPLATE_DECL). */
2451
2452 void
2453 maybe_add_class_template_decl_list (tree type, tree t, int friend_p)
2454 {
2455 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2456 if (CLASSTYPE_TEMPLATE_INFO (type))
2457 CLASSTYPE_DECL_LIST (type)
2458 = tree_cons (friend_p ? NULL_TREE : type,
2459 t, CLASSTYPE_DECL_LIST (type));
2460 }
2461
2462 /* Create default constructors, assignment operators, and so forth for
2463 the type indicated by T, if they are needed.
2464 CANT_HAVE_DEFAULT_CTOR, CANT_HAVE_CONST_CTOR, and
2465 CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason, the
2466 class cannot have a default constructor, copy constructor taking a
2467 const reference argument, or an assignment operator taking a const
2468 reference, respectively. If a virtual destructor is created, its
2469 DECL is returned; otherwise the return value is NULL_TREE. */
2470
2471 static void
2472 add_implicitly_declared_members (tree t,
2473 int cant_have_default_ctor,
2474 int cant_have_const_cctor,
2475 int cant_have_const_assignment)
2476 {
2477 tree default_fn;
2478 tree implicit_fns = NULL_TREE;
2479 tree virtual_dtor = NULL_TREE;
2480 tree *f;
2481
2482 /* Destructor. */
2483 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) && !TYPE_HAS_DESTRUCTOR (t))
2484 {
2485 default_fn = implicitly_declare_fn (sfk_destructor, t, /*const_p=*/0);
2486 check_for_override (default_fn, t);
2487
2488 TREE_CHAIN (default_fn) = implicit_fns;
2489 implicit_fns = default_fn;
2490
2491 if (DECL_VINDEX (default_fn))
2492 virtual_dtor = default_fn;
2493 }
2494 else
2495 /* Any non-implicit destructor is non-trivial. */
2496 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) |= TYPE_HAS_DESTRUCTOR (t);
2497
2498 /* Default constructor. */
2499 if (! TYPE_HAS_CONSTRUCTOR (t) && ! cant_have_default_ctor)
2500 {
2501 TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 1;
2502 CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 1;
2503 }
2504
2505 /* Copy constructor. */
2506 if (! TYPE_HAS_INIT_REF (t) && ! TYPE_FOR_JAVA (t))
2507 {
2508 TYPE_HAS_INIT_REF (t) = 1;
2509 TYPE_HAS_CONST_INIT_REF (t) = !cant_have_const_cctor;
2510 CLASSTYPE_LAZY_COPY_CTOR (t) = 1;
2511 TYPE_HAS_CONSTRUCTOR (t) = 1;
2512 }
2513
2514 /* If there is no assignment operator, one will be created if and
2515 when it is needed. For now, just record whether or not the type
2516 of the parameter to the assignment operator will be a const or
2517 non-const reference. */
2518 if (!TYPE_HAS_ASSIGN_REF (t) && !TYPE_FOR_JAVA (t))
2519 {
2520 TYPE_HAS_ASSIGN_REF (t) = 1;
2521 TYPE_HAS_CONST_ASSIGN_REF (t) = !cant_have_const_assignment;
2522 CLASSTYPE_LAZY_ASSIGNMENT_OP (t) = 1;
2523 }
2524
2525 /* Now, hook all of the new functions on to TYPE_METHODS,
2526 and add them to the CLASSTYPE_METHOD_VEC. */
2527 for (f = &implicit_fns; *f; f = &TREE_CHAIN (*f))
2528 {
2529 add_method (t, *f);
2530 maybe_add_class_template_decl_list (current_class_type, *f, /*friend_p=*/0);
2531 }
2532 if (abi_version_at_least (2))
2533 /* G++ 3.2 put the implicit destructor at the *beginning* of the
2534 list, which cause the destructor to be emitted in an incorrect
2535 location in the vtable. */
2536 TYPE_METHODS (t) = chainon (TYPE_METHODS (t), implicit_fns);
2537 else
2538 {
2539 if (warn_abi && virtual_dtor)
2540 warning ("vtable layout for class %qT may not be ABI-compliant "
2541 "and may change in a future version of GCC due to implicit "
2542 "virtual destructor",
2543 t);
2544 *f = TYPE_METHODS (t);
2545 TYPE_METHODS (t) = implicit_fns;
2546 }
2547 }
2548
2549 /* Subroutine of finish_struct_1. Recursively count the number of fields
2550 in TYPE, including anonymous union members. */
2551
2552 static int
2553 count_fields (tree fields)
2554 {
2555 tree x;
2556 int n_fields = 0;
2557 for (x = fields; x; x = TREE_CHAIN (x))
2558 {
2559 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2560 n_fields += count_fields (TYPE_FIELDS (TREE_TYPE (x)));
2561 else
2562 n_fields += 1;
2563 }
2564 return n_fields;
2565 }
2566
2567 /* Subroutine of finish_struct_1. Recursively add all the fields in the
2568 TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX. */
2569
2570 static int
2571 add_fields_to_record_type (tree fields, struct sorted_fields_type *field_vec, int idx)
2572 {
2573 tree x;
2574 for (x = fields; x; x = TREE_CHAIN (x))
2575 {
2576 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2577 idx = add_fields_to_record_type (TYPE_FIELDS (TREE_TYPE (x)), field_vec, idx);
2578 else
2579 field_vec->elts[idx++] = x;
2580 }
2581 return idx;
2582 }
2583
2584 /* FIELD is a bit-field. We are finishing the processing for its
2585 enclosing type. Issue any appropriate messages and set appropriate
2586 flags. */
2587
2588 static void
2589 check_bitfield_decl (tree field)
2590 {
2591 tree type = TREE_TYPE (field);
2592 tree w = NULL_TREE;
2593
2594 /* Detect invalid bit-field type. */
2595 if (DECL_INITIAL (field)
2596 && ! INTEGRAL_TYPE_P (TREE_TYPE (field)))
2597 {
2598 cp_error_at ("bit-field %q#D with non-integral type", field);
2599 w = error_mark_node;
2600 }
2601
2602 /* Detect and ignore out of range field width. */
2603 if (DECL_INITIAL (field))
2604 {
2605 w = DECL_INITIAL (field);
2606
2607 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2608 STRIP_NOPS (w);
2609
2610 /* detect invalid field size. */
2611 w = integral_constant_value (w);
2612
2613 if (TREE_CODE (w) != INTEGER_CST)
2614 {
2615 cp_error_at ("bit-field %qD width not an integer constant",
2616 field);
2617 w = error_mark_node;
2618 }
2619 else if (tree_int_cst_sgn (w) < 0)
2620 {
2621 cp_error_at ("negative width in bit-field %qD", field);
2622 w = error_mark_node;
2623 }
2624 else if (integer_zerop (w) && DECL_NAME (field) != 0)
2625 {
2626 cp_error_at ("zero width for bit-field %qD", field);
2627 w = error_mark_node;
2628 }
2629 else if (compare_tree_int (w, TYPE_PRECISION (type)) > 0
2630 && TREE_CODE (type) != ENUMERAL_TYPE
2631 && TREE_CODE (type) != BOOLEAN_TYPE)
2632 cp_warning_at ("width of %qD exceeds its type", field);
2633 else if (TREE_CODE (type) == ENUMERAL_TYPE
2634 && (0 > compare_tree_int (w,
2635 min_precision (TYPE_MIN_VALUE (type),
2636 TYPE_UNSIGNED (type)))
2637 || 0 > compare_tree_int (w,
2638 min_precision
2639 (TYPE_MAX_VALUE (type),
2640 TYPE_UNSIGNED (type)))))
2641 cp_warning_at ("%qD is too small to hold all values of %q#T",
2642 field, type);
2643 }
2644
2645 /* Remove the bit-field width indicator so that the rest of the
2646 compiler does not treat that value as an initializer. */
2647 DECL_INITIAL (field) = NULL_TREE;
2648
2649 if (w != error_mark_node)
2650 {
2651 DECL_SIZE (field) = convert (bitsizetype, w);
2652 DECL_BIT_FIELD (field) = 1;
2653 }
2654 else
2655 {
2656 /* Non-bit-fields are aligned for their type. */
2657 DECL_BIT_FIELD (field) = 0;
2658 CLEAR_DECL_C_BIT_FIELD (field);
2659 }
2660 }
2661
2662 /* FIELD is a non bit-field. We are finishing the processing for its
2663 enclosing type T. Issue any appropriate messages and set appropriate
2664 flags. */
2665
2666 static void
2667 check_field_decl (tree field,
2668 tree t,
2669 int* cant_have_const_ctor,
2670 int* cant_have_default_ctor,
2671 int* no_const_asn_ref,
2672 int* any_default_members)
2673 {
2674 tree type = strip_array_types (TREE_TYPE (field));
2675
2676 /* An anonymous union cannot contain any fields which would change
2677 the settings of CANT_HAVE_CONST_CTOR and friends. */
2678 if (ANON_UNION_TYPE_P (type))
2679 ;
2680 /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
2681 structs. So, we recurse through their fields here. */
2682 else if (ANON_AGGR_TYPE_P (type))
2683 {
2684 tree fields;
2685
2686 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2687 if (TREE_CODE (fields) == FIELD_DECL && !DECL_C_BIT_FIELD (field))
2688 check_field_decl (fields, t, cant_have_const_ctor,
2689 cant_have_default_ctor, no_const_asn_ref,
2690 any_default_members);
2691 }
2692 /* Check members with class type for constructors, destructors,
2693 etc. */
2694 else if (CLASS_TYPE_P (type))
2695 {
2696 /* Never let anything with uninheritable virtuals
2697 make it through without complaint. */
2698 abstract_virtuals_error (field, type);
2699
2700 if (TREE_CODE (t) == UNION_TYPE)
2701 {
2702 if (TYPE_NEEDS_CONSTRUCTING (type))
2703 cp_error_at ("member %q#D with constructor not allowed in union",
2704 field);
2705 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
2706 cp_error_at ("member %q#D with destructor not allowed in union",
2707 field);
2708 if (TYPE_HAS_COMPLEX_ASSIGN_REF (type))
2709 cp_error_at ("member %q#D with copy assignment operator not allowed in union",
2710 field);
2711 }
2712 else
2713 {
2714 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (type);
2715 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
2716 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type);
2717 TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_HAS_COMPLEX_ASSIGN_REF (type);
2718 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (type);
2719 }
2720
2721 if (!TYPE_HAS_CONST_INIT_REF (type))
2722 *cant_have_const_ctor = 1;
2723
2724 if (!TYPE_HAS_CONST_ASSIGN_REF (type))
2725 *no_const_asn_ref = 1;
2726
2727 if (TYPE_HAS_CONSTRUCTOR (type)
2728 && ! TYPE_HAS_DEFAULT_CONSTRUCTOR (type))
2729 *cant_have_default_ctor = 1;
2730 }
2731 if (DECL_INITIAL (field) != NULL_TREE)
2732 {
2733 /* `build_class_init_list' does not recognize
2734 non-FIELD_DECLs. */
2735 if (TREE_CODE (t) == UNION_TYPE && any_default_members != 0)
2736 error ("multiple fields in union %qT initialized", t);
2737 *any_default_members = 1;
2738 }
2739 }
2740
2741 /* Check the data members (both static and non-static), class-scoped
2742 typedefs, etc., appearing in the declaration of T. Issue
2743 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
2744 declaration order) of access declarations; each TREE_VALUE in this
2745 list is a USING_DECL.
2746
2747 In addition, set the following flags:
2748
2749 EMPTY_P
2750 The class is empty, i.e., contains no non-static data members.
2751
2752 CANT_HAVE_DEFAULT_CTOR_P
2753 This class cannot have an implicitly generated default
2754 constructor.
2755
2756 CANT_HAVE_CONST_CTOR_P
2757 This class cannot have an implicitly generated copy constructor
2758 taking a const reference.
2759
2760 CANT_HAVE_CONST_ASN_REF
2761 This class cannot have an implicitly generated assignment
2762 operator taking a const reference.
2763
2764 All of these flags should be initialized before calling this
2765 function.
2766
2767 Returns a pointer to the end of the TYPE_FIELDs chain; additional
2768 fields can be added by adding to this chain. */
2769
2770 static void
2771 check_field_decls (tree t, tree *access_decls,
2772 int *cant_have_default_ctor_p,
2773 int *cant_have_const_ctor_p,
2774 int *no_const_asn_ref_p)
2775 {
2776 tree *field;
2777 tree *next;
2778 bool has_pointers;
2779 int any_default_members;
2780
2781 /* Assume there are no access declarations. */
2782 *access_decls = NULL_TREE;
2783 /* Assume this class has no pointer members. */
2784 has_pointers = false;
2785 /* Assume none of the members of this class have default
2786 initializations. */
2787 any_default_members = 0;
2788
2789 for (field = &TYPE_FIELDS (t); *field; field = next)
2790 {
2791 tree x = *field;
2792 tree type = TREE_TYPE (x);
2793
2794 next = &TREE_CHAIN (x);
2795
2796 if (TREE_CODE (x) == FIELD_DECL)
2797 {
2798 if (TYPE_PACKED (t))
2799 {
2800 if (!pod_type_p (TREE_TYPE (x)) && !TYPE_PACKED (TREE_TYPE (x)))
2801 cp_warning_at
2802 ("ignoring packed attribute on unpacked non-POD field %q#D",
2803 x);
2804 else
2805 DECL_PACKED (x) = 1;
2806 }
2807
2808 if (DECL_C_BIT_FIELD (x) && integer_zerop (DECL_INITIAL (x)))
2809 /* We don't treat zero-width bitfields as making a class
2810 non-empty. */
2811 ;
2812 else
2813 {
2814 tree element_type;
2815
2816 /* The class is non-empty. */
2817 CLASSTYPE_EMPTY_P (t) = 0;
2818 /* The class is not even nearly empty. */
2819 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
2820 /* If one of the data members contains an empty class,
2821 so does T. */
2822 element_type = strip_array_types (type);
2823 if (CLASS_TYPE_P (element_type)
2824 && CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type))
2825 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
2826 }
2827 }
2828
2829 if (TREE_CODE (x) == USING_DECL)
2830 {
2831 /* Prune the access declaration from the list of fields. */
2832 *field = TREE_CHAIN (x);
2833
2834 /* Save the access declarations for our caller. */
2835 *access_decls = tree_cons (NULL_TREE, x, *access_decls);
2836
2837 /* Since we've reset *FIELD there's no reason to skip to the
2838 next field. */
2839 next = field;
2840 continue;
2841 }
2842
2843 if (TREE_CODE (x) == TYPE_DECL
2844 || TREE_CODE (x) == TEMPLATE_DECL)
2845 continue;
2846
2847 /* If we've gotten this far, it's a data member, possibly static,
2848 or an enumerator. */
2849 DECL_CONTEXT (x) = t;
2850
2851 /* When this goes into scope, it will be a non-local reference. */
2852 DECL_NONLOCAL (x) = 1;
2853
2854 if (TREE_CODE (t) == UNION_TYPE)
2855 {
2856 /* [class.union]
2857
2858 If a union contains a static data member, or a member of
2859 reference type, the program is ill-formed. */
2860 if (TREE_CODE (x) == VAR_DECL)
2861 {
2862 cp_error_at ("%qD may not be static because it is a member of a union", x);
2863 continue;
2864 }
2865 if (TREE_CODE (type) == REFERENCE_TYPE)
2866 {
2867 cp_error_at ("%qD may not have reference type %qT because"
2868 " it is a member of a union",
2869 x, type);
2870 continue;
2871 }
2872 }
2873
2874 /* ``A local class cannot have static data members.'' ARM 9.4 */
2875 if (current_function_decl && TREE_STATIC (x))
2876 cp_error_at ("field %qD in local class cannot be static", x);
2877
2878 /* Perform error checking that did not get done in
2879 grokdeclarator. */
2880 if (TREE_CODE (type) == FUNCTION_TYPE)
2881 {
2882 cp_error_at ("field %qD invalidly declared function type", x);
2883 type = build_pointer_type (type);
2884 TREE_TYPE (x) = type;
2885 }
2886 else if (TREE_CODE (type) == METHOD_TYPE)
2887 {
2888 cp_error_at ("field %qD invalidly declared method type", x);
2889 type = build_pointer_type (type);
2890 TREE_TYPE (x) = type;
2891 }
2892
2893 if (type == error_mark_node)
2894 continue;
2895
2896 if (TREE_CODE (x) == CONST_DECL || TREE_CODE (x) == VAR_DECL)
2897 continue;
2898
2899 /* Now it can only be a FIELD_DECL. */
2900
2901 if (TREE_PRIVATE (x) || TREE_PROTECTED (x))
2902 CLASSTYPE_NON_AGGREGATE (t) = 1;
2903
2904 /* If this is of reference type, check if it needs an init.
2905 Also do a little ANSI jig if necessary. */
2906 if (TREE_CODE (type) == REFERENCE_TYPE)
2907 {
2908 CLASSTYPE_NON_POD_P (t) = 1;
2909 if (DECL_INITIAL (x) == NULL_TREE)
2910 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
2911
2912 /* ARM $12.6.2: [A member initializer list] (or, for an
2913 aggregate, initialization by a brace-enclosed list) is the
2914 only way to initialize nonstatic const and reference
2915 members. */
2916 *cant_have_default_ctor_p = 1;
2917 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
2918
2919 if (! TYPE_HAS_CONSTRUCTOR (t) && CLASSTYPE_NON_AGGREGATE (t)
2920 && extra_warnings)
2921 cp_warning_at ("non-static reference %q#D in class without a constructor", x);
2922 }
2923
2924 type = strip_array_types (type);
2925
2926 /* This is used by -Weffc++ (see below). Warn only for pointers
2927 to members which might hold dynamic memory. So do not warn
2928 for pointers to functions or pointers to members. */
2929 if (TYPE_PTR_P (type)
2930 && !TYPE_PTRFN_P (type)
2931 && !TYPE_PTR_TO_MEMBER_P (type))
2932 has_pointers = true;
2933
2934 if (CLASS_TYPE_P (type))
2935 {
2936 if (CLASSTYPE_REF_FIELDS_NEED_INIT (type))
2937 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
2938 if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (type))
2939 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
2940 }
2941
2942 if (DECL_MUTABLE_P (x) || TYPE_HAS_MUTABLE_P (type))
2943 CLASSTYPE_HAS_MUTABLE (t) = 1;
2944
2945 if (! pod_type_p (type))
2946 /* DR 148 now allows pointers to members (which are POD themselves),
2947 to be allowed in POD structs. */
2948 CLASSTYPE_NON_POD_P (t) = 1;
2949
2950 if (! zero_init_p (type))
2951 CLASSTYPE_NON_ZERO_INIT_P (t) = 1;
2952
2953 /* If any field is const, the structure type is pseudo-const. */
2954 if (CP_TYPE_CONST_P (type))
2955 {
2956 C_TYPE_FIELDS_READONLY (t) = 1;
2957 if (DECL_INITIAL (x) == NULL_TREE)
2958 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
2959
2960 /* ARM $12.6.2: [A member initializer list] (or, for an
2961 aggregate, initialization by a brace-enclosed list) is the
2962 only way to initialize nonstatic const and reference
2963 members. */
2964 *cant_have_default_ctor_p = 1;
2965 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
2966
2967 if (! TYPE_HAS_CONSTRUCTOR (t) && CLASSTYPE_NON_AGGREGATE (t)
2968 && extra_warnings)
2969 cp_warning_at ("non-static const member %q#D in class without a constructor", x);
2970 }
2971 /* A field that is pseudo-const makes the structure likewise. */
2972 else if (CLASS_TYPE_P (type))
2973 {
2974 C_TYPE_FIELDS_READONLY (t) |= C_TYPE_FIELDS_READONLY (type);
2975 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t,
2976 CLASSTYPE_READONLY_FIELDS_NEED_INIT (t)
2977 | CLASSTYPE_READONLY_FIELDS_NEED_INIT (type));
2978 }
2979
2980 /* Core issue 80: A nonstatic data member is required to have a
2981 different name from the class iff the class has a
2982 user-defined constructor. */
2983 if (constructor_name_p (DECL_NAME (x), t) && TYPE_HAS_CONSTRUCTOR (t))
2984 cp_pedwarn_at ("field %q#D with same name as class", x);
2985
2986 /* We set DECL_C_BIT_FIELD in grokbitfield.
2987 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
2988 if (DECL_C_BIT_FIELD (x))
2989 check_bitfield_decl (x);
2990 else
2991 check_field_decl (x, t,
2992 cant_have_const_ctor_p,
2993 cant_have_default_ctor_p,
2994 no_const_asn_ref_p,
2995 &any_default_members);
2996 }
2997
2998 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
2999 it should also define a copy constructor and an assignment operator to
3000 implement the correct copy semantic (deep vs shallow, etc.). As it is
3001 not feasible to check whether the constructors do allocate dynamic memory
3002 and store it within members, we approximate the warning like this:
3003
3004 -- Warn only if there are members which are pointers
3005 -- Warn only if there is a non-trivial constructor (otherwise,
3006 there cannot be memory allocated).
3007 -- Warn only if there is a non-trivial destructor. We assume that the
3008 user at least implemented the cleanup correctly, and a destructor
3009 is needed to free dynamic memory.
3010
3011 This seems enough for practical purposes. */
3012 if (warn_ecpp
3013 && has_pointers
3014 && TYPE_HAS_CONSTRUCTOR (t)
3015 && TYPE_HAS_DESTRUCTOR (t)
3016 && !(TYPE_HAS_INIT_REF (t) && TYPE_HAS_ASSIGN_REF (t)))
3017 {
3018 warning ("%q#T has pointer data members", t);
3019
3020 if (! TYPE_HAS_INIT_REF (t))
3021 {
3022 warning (" but does not override %<%T(const %T&)%>", t, t);
3023 if (! TYPE_HAS_ASSIGN_REF (t))
3024 warning (" or %<operator=(const %T&)%>", t);
3025 }
3026 else if (! TYPE_HAS_ASSIGN_REF (t))
3027 warning (" but does not override %<operator=(const %T&)%>", t);
3028 }
3029
3030
3031 /* Check anonymous struct/anonymous union fields. */
3032 finish_struct_anon (t);
3033
3034 /* We've built up the list of access declarations in reverse order.
3035 Fix that now. */
3036 *access_decls = nreverse (*access_decls);
3037 }
3038
3039 /* If TYPE is an empty class type, records its OFFSET in the table of
3040 OFFSETS. */
3041
3042 static int
3043 record_subobject_offset (tree type, tree offset, splay_tree offsets)
3044 {
3045 splay_tree_node n;
3046
3047 if (!is_empty_class (type))
3048 return 0;
3049
3050 /* Record the location of this empty object in OFFSETS. */
3051 n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3052 if (!n)
3053 n = splay_tree_insert (offsets,
3054 (splay_tree_key) offset,
3055 (splay_tree_value) NULL_TREE);
3056 n->value = ((splay_tree_value)
3057 tree_cons (NULL_TREE,
3058 type,
3059 (tree) n->value));
3060
3061 return 0;
3062 }
3063
3064 /* Returns nonzero if TYPE is an empty class type and there is
3065 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3066
3067 static int
3068 check_subobject_offset (tree type, tree offset, splay_tree offsets)
3069 {
3070 splay_tree_node n;
3071 tree t;
3072
3073 if (!is_empty_class (type))
3074 return 0;
3075
3076 /* Record the location of this empty object in OFFSETS. */
3077 n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3078 if (!n)
3079 return 0;
3080
3081 for (t = (tree) n->value; t; t = TREE_CHAIN (t))
3082 if (same_type_p (TREE_VALUE (t), type))
3083 return 1;
3084
3085 return 0;
3086 }
3087
3088 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3089 F for every subobject, passing it the type, offset, and table of
3090 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3091 be traversed.
3092
3093 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3094 than MAX_OFFSET will not be walked.
3095
3096 If F returns a nonzero value, the traversal ceases, and that value
3097 is returned. Otherwise, returns zero. */
3098
3099 static int
3100 walk_subobject_offsets (tree type,
3101 subobject_offset_fn f,
3102 tree offset,
3103 splay_tree offsets,
3104 tree max_offset,
3105 int vbases_p)
3106 {
3107 int r = 0;
3108 tree type_binfo = NULL_TREE;
3109
3110 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3111 stop. */
3112 if (max_offset && INT_CST_LT (max_offset, offset))
3113 return 0;
3114
3115 if (!TYPE_P (type))
3116 {
3117 if (abi_version_at_least (2))
3118 type_binfo = type;
3119 type = BINFO_TYPE (type);
3120 }
3121
3122 if (CLASS_TYPE_P (type))
3123 {
3124 tree field;
3125 tree binfo;
3126 int i;
3127
3128 /* Avoid recursing into objects that are not interesting. */
3129 if (!CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type))
3130 return 0;
3131
3132 /* Record the location of TYPE. */
3133 r = (*f) (type, offset, offsets);
3134 if (r)
3135 return r;
3136
3137 /* Iterate through the direct base classes of TYPE. */
3138 if (!type_binfo)
3139 type_binfo = TYPE_BINFO (type);
3140 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, binfo); i++)
3141 {
3142 tree binfo_offset;
3143
3144 if (abi_version_at_least (2)
3145 && BINFO_VIRTUAL_P (binfo))
3146 continue;
3147
3148 if (!vbases_p
3149 && BINFO_VIRTUAL_P (binfo)
3150 && !BINFO_PRIMARY_P (binfo))
3151 continue;
3152
3153 if (!abi_version_at_least (2))
3154 binfo_offset = size_binop (PLUS_EXPR,
3155 offset,
3156 BINFO_OFFSET (binfo));
3157 else
3158 {
3159 tree orig_binfo;
3160 /* We cannot rely on BINFO_OFFSET being set for the base
3161 class yet, but the offsets for direct non-virtual
3162 bases can be calculated by going back to the TYPE. */
3163 orig_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), i);
3164 binfo_offset = size_binop (PLUS_EXPR,
3165 offset,
3166 BINFO_OFFSET (orig_binfo));
3167 }
3168
3169 r = walk_subobject_offsets (binfo,
3170 f,
3171 binfo_offset,
3172 offsets,
3173 max_offset,
3174 (abi_version_at_least (2)
3175 ? /*vbases_p=*/0 : vbases_p));
3176 if (r)
3177 return r;
3178 }
3179
3180 if (abi_version_at_least (2) && CLASSTYPE_VBASECLASSES (type))
3181 {
3182 unsigned ix;
3183 VEC (tree) *vbases;
3184
3185 /* Iterate through the virtual base classes of TYPE. In G++
3186 3.2, we included virtual bases in the direct base class
3187 loop above, which results in incorrect results; the
3188 correct offsets for virtual bases are only known when
3189 working with the most derived type. */
3190 if (vbases_p)
3191 for (vbases = CLASSTYPE_VBASECLASSES (type), ix = 0;
3192 VEC_iterate (tree, vbases, ix, binfo); ix++)
3193 {
3194 r = walk_subobject_offsets (binfo,
3195 f,
3196 size_binop (PLUS_EXPR,
3197 offset,
3198 BINFO_OFFSET (binfo)),
3199 offsets,
3200 max_offset,
3201 /*vbases_p=*/0);
3202 if (r)
3203 return r;
3204 }
3205 else
3206 {
3207 /* We still have to walk the primary base, if it is
3208 virtual. (If it is non-virtual, then it was walked
3209 above.) */
3210 tree vbase = get_primary_binfo (type_binfo);
3211
3212 if (vbase && BINFO_VIRTUAL_P (vbase)
3213 && BINFO_PRIMARY_P (vbase)
3214 && BINFO_INHERITANCE_CHAIN (vbase) == type_binfo)
3215 {
3216 r = (walk_subobject_offsets
3217 (vbase, f, offset,
3218 offsets, max_offset, /*vbases_p=*/0));
3219 if (r)
3220 return r;
3221 }
3222 }
3223 }
3224
3225 /* Iterate through the fields of TYPE. */
3226 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3227 if (TREE_CODE (field) == FIELD_DECL && !DECL_ARTIFICIAL (field))
3228 {
3229 tree field_offset;
3230
3231 if (abi_version_at_least (2))
3232 field_offset = byte_position (field);
3233 else
3234 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3235 field_offset = DECL_FIELD_OFFSET (field);
3236
3237 r = walk_subobject_offsets (TREE_TYPE (field),
3238 f,
3239 size_binop (PLUS_EXPR,
3240 offset,
3241 field_offset),
3242 offsets,
3243 max_offset,
3244 /*vbases_p=*/1);
3245 if (r)
3246 return r;
3247 }
3248 }
3249 else if (TREE_CODE (type) == ARRAY_TYPE)
3250 {
3251 tree element_type = strip_array_types (type);
3252 tree domain = TYPE_DOMAIN (type);
3253 tree index;
3254
3255 /* Avoid recursing into objects that are not interesting. */
3256 if (!CLASS_TYPE_P (element_type)
3257 || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type))
3258 return 0;
3259
3260 /* Step through each of the elements in the array. */
3261 for (index = size_zero_node;
3262 /* G++ 3.2 had an off-by-one error here. */
3263 (abi_version_at_least (2)
3264 ? !INT_CST_LT (TYPE_MAX_VALUE (domain), index)
3265 : INT_CST_LT (index, TYPE_MAX_VALUE (domain)));
3266 index = size_binop (PLUS_EXPR, index, size_one_node))
3267 {
3268 r = walk_subobject_offsets (TREE_TYPE (type),
3269 f,
3270 offset,
3271 offsets,
3272 max_offset,
3273 /*vbases_p=*/1);
3274 if (r)
3275 return r;
3276 offset = size_binop (PLUS_EXPR, offset,
3277 TYPE_SIZE_UNIT (TREE_TYPE (type)));
3278 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3279 there's no point in iterating through the remaining
3280 elements of the array. */
3281 if (max_offset && INT_CST_LT (max_offset, offset))
3282 break;
3283 }
3284 }
3285
3286 return 0;
3287 }
3288
3289 /* Record all of the empty subobjects of TYPE (located at OFFSET) in
3290 OFFSETS. If VBASES_P is nonzero, virtual bases of TYPE are
3291 examined. */
3292
3293 static void
3294 record_subobject_offsets (tree type,
3295 tree offset,
3296 splay_tree offsets,
3297 int vbases_p)
3298 {
3299 walk_subobject_offsets (type, record_subobject_offset, offset,
3300 offsets, /*max_offset=*/NULL_TREE, vbases_p);
3301 }
3302
3303 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3304 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3305 virtual bases of TYPE are examined. */
3306
3307 static int
3308 layout_conflict_p (tree type,
3309 tree offset,
3310 splay_tree offsets,
3311 int vbases_p)
3312 {
3313 splay_tree_node max_node;
3314
3315 /* Get the node in OFFSETS that indicates the maximum offset where
3316 an empty subobject is located. */
3317 max_node = splay_tree_max (offsets);
3318 /* If there aren't any empty subobjects, then there's no point in
3319 performing this check. */
3320 if (!max_node)
3321 return 0;
3322
3323 return walk_subobject_offsets (type, check_subobject_offset, offset,
3324 offsets, (tree) (max_node->key),
3325 vbases_p);
3326 }
3327
3328 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3329 non-static data member of the type indicated by RLI. BINFO is the
3330 binfo corresponding to the base subobject, OFFSETS maps offsets to
3331 types already located at those offsets. This function determines
3332 the position of the DECL. */
3333
3334 static void
3335 layout_nonempty_base_or_field (record_layout_info rli,
3336 tree decl,
3337 tree binfo,
3338 splay_tree offsets)
3339 {
3340 tree offset = NULL_TREE;
3341 bool field_p;
3342 tree type;
3343
3344 if (binfo)
3345 {
3346 /* For the purposes of determining layout conflicts, we want to
3347 use the class type of BINFO; TREE_TYPE (DECL) will be the
3348 CLASSTYPE_AS_BASE version, which does not contain entries for
3349 zero-sized bases. */
3350 type = TREE_TYPE (binfo);
3351 field_p = false;
3352 }
3353 else
3354 {
3355 type = TREE_TYPE (decl);
3356 field_p = true;
3357 }
3358
3359 /* Try to place the field. It may take more than one try if we have
3360 a hard time placing the field without putting two objects of the
3361 same type at the same address. */
3362 while (1)
3363 {
3364 struct record_layout_info_s old_rli = *rli;
3365
3366 /* Place this field. */
3367 place_field (rli, decl);
3368 offset = byte_position (decl);
3369
3370 /* We have to check to see whether or not there is already
3371 something of the same type at the offset we're about to use.
3372 For example, consider:
3373
3374 struct S {};
3375 struct T : public S { int i; };
3376 struct U : public S, public T {};
3377
3378 Here, we put S at offset zero in U. Then, we can't put T at
3379 offset zero -- its S component would be at the same address
3380 as the S we already allocated. So, we have to skip ahead.
3381 Since all data members, including those whose type is an
3382 empty class, have nonzero size, any overlap can happen only
3383 with a direct or indirect base-class -- it can't happen with
3384 a data member. */
3385 /* In a union, overlap is permitted; all members are placed at
3386 offset zero. */
3387 if (TREE_CODE (rli->t) == UNION_TYPE)
3388 break;
3389 /* G++ 3.2 did not check for overlaps when placing a non-empty
3390 virtual base. */
3391 if (!abi_version_at_least (2) && binfo && BINFO_VIRTUAL_P (binfo))
3392 break;
3393 if (layout_conflict_p (field_p ? type : binfo, offset,
3394 offsets, field_p))
3395 {
3396 /* Strip off the size allocated to this field. That puts us
3397 at the first place we could have put the field with
3398 proper alignment. */
3399 *rli = old_rli;
3400
3401 /* Bump up by the alignment required for the type. */
3402 rli->bitpos
3403 = size_binop (PLUS_EXPR, rli->bitpos,
3404 bitsize_int (binfo
3405 ? CLASSTYPE_ALIGN (type)
3406 : TYPE_ALIGN (type)));
3407 normalize_rli (rli);
3408 }
3409 else
3410 /* There was no conflict. We're done laying out this field. */
3411 break;
3412 }
3413
3414 /* Now that we know where it will be placed, update its
3415 BINFO_OFFSET. */
3416 if (binfo && CLASS_TYPE_P (BINFO_TYPE (binfo)))
3417 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3418 this point because their BINFO_OFFSET is copied from another
3419 hierarchy. Therefore, we may not need to add the entire
3420 OFFSET. */
3421 propagate_binfo_offsets (binfo,
3422 size_diffop (convert (ssizetype, offset),
3423 convert (ssizetype,
3424 BINFO_OFFSET (binfo))));
3425 }
3426
3427 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3428
3429 static int
3430 empty_base_at_nonzero_offset_p (tree type,
3431 tree offset,
3432 splay_tree offsets ATTRIBUTE_UNUSED)
3433 {
3434 return is_empty_class (type) && !integer_zerop (offset);
3435 }
3436
3437 /* Layout the empty base BINFO. EOC indicates the byte currently just
3438 past the end of the class, and should be correctly aligned for a
3439 class of the type indicated by BINFO; OFFSETS gives the offsets of
3440 the empty bases allocated so far. T is the most derived
3441 type. Return nonzero iff we added it at the end. */
3442
3443 static bool
3444 layout_empty_base (tree binfo, tree eoc, splay_tree offsets)
3445 {
3446 tree alignment;
3447 tree basetype = BINFO_TYPE (binfo);
3448 bool atend = false;
3449
3450 /* This routine should only be used for empty classes. */
3451 gcc_assert (is_empty_class (basetype));
3452 alignment = ssize_int (CLASSTYPE_ALIGN_UNIT (basetype));
3453
3454 if (!integer_zerop (BINFO_OFFSET (binfo)))
3455 {
3456 if (abi_version_at_least (2))
3457 propagate_binfo_offsets
3458 (binfo, size_diffop (size_zero_node, BINFO_OFFSET (binfo)));
3459 else if (warn_abi)
3460 warning ("offset of empty base %qT may not be ABI-compliant and may"
3461 "change in a future version of GCC",
3462 BINFO_TYPE (binfo));
3463 }
3464
3465 /* This is an empty base class. We first try to put it at offset
3466 zero. */
3467 if (layout_conflict_p (binfo,
3468 BINFO_OFFSET (binfo),
3469 offsets,
3470 /*vbases_p=*/0))
3471 {
3472 /* That didn't work. Now, we move forward from the next
3473 available spot in the class. */
3474 atend = true;
3475 propagate_binfo_offsets (binfo, convert (ssizetype, eoc));
3476 while (1)
3477 {
3478 if (!layout_conflict_p (binfo,
3479 BINFO_OFFSET (binfo),
3480 offsets,
3481 /*vbases_p=*/0))
3482 /* We finally found a spot where there's no overlap. */
3483 break;
3484
3485 /* There's overlap here, too. Bump along to the next spot. */
3486 propagate_binfo_offsets (binfo, alignment);
3487 }
3488 }
3489 return atend;
3490 }
3491
3492 /* Layout the the base given by BINFO in the class indicated by RLI.
3493 *BASE_ALIGN is a running maximum of the alignments of
3494 any base class. OFFSETS gives the location of empty base
3495 subobjects. T is the most derived type. Return nonzero if the new
3496 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3497 *NEXT_FIELD, unless BINFO is for an empty base class.
3498
3499 Returns the location at which the next field should be inserted. */
3500
3501 static tree *
3502 build_base_field (record_layout_info rli, tree binfo,
3503 splay_tree offsets, tree *next_field)
3504 {
3505 tree t = rli->t;
3506 tree basetype = BINFO_TYPE (binfo);
3507
3508 if (!COMPLETE_TYPE_P (basetype))
3509 /* This error is now reported in xref_tag, thus giving better
3510 location information. */
3511 return next_field;
3512
3513 /* Place the base class. */
3514 if (!is_empty_class (basetype))
3515 {
3516 tree decl;
3517
3518 /* The containing class is non-empty because it has a non-empty
3519 base class. */
3520 CLASSTYPE_EMPTY_P (t) = 0;
3521
3522 /* Create the FIELD_DECL. */
3523 decl = build_decl (FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype));
3524 DECL_ARTIFICIAL (decl) = 1;
3525 DECL_IGNORED_P (decl) = 1;
3526 DECL_FIELD_CONTEXT (decl) = t;
3527 DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype);
3528 DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype);
3529 DECL_ALIGN (decl) = CLASSTYPE_ALIGN (basetype);
3530 DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype);
3531 DECL_MODE (decl) = TYPE_MODE (basetype);
3532 DECL_FIELD_IS_BASE (decl) = 1;
3533
3534 /* Try to place the field. It may take more than one try if we
3535 have a hard time placing the field without putting two
3536 objects of the same type at the same address. */
3537 layout_nonempty_base_or_field (rli, decl, binfo, offsets);
3538 /* Add the new FIELD_DECL to the list of fields for T. */
3539 TREE_CHAIN (decl) = *next_field;
3540 *next_field = decl;
3541 next_field = &TREE_CHAIN (decl);
3542 }
3543 else
3544 {
3545 tree eoc;
3546 bool atend;
3547
3548 /* On some platforms (ARM), even empty classes will not be
3549 byte-aligned. */
3550 eoc = round_up (rli_size_unit_so_far (rli),
3551 CLASSTYPE_ALIGN_UNIT (basetype));
3552 atend = layout_empty_base (binfo, eoc, offsets);
3553 /* A nearly-empty class "has no proper base class that is empty,
3554 not morally virtual, and at an offset other than zero." */
3555 if (!BINFO_VIRTUAL_P (binfo) && CLASSTYPE_NEARLY_EMPTY_P (t))
3556 {
3557 if (atend)
3558 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3559 /* The check above (used in G++ 3.2) is insufficient because
3560 an empty class placed at offset zero might itself have an
3561 empty base at a nonzero offset. */
3562 else if (walk_subobject_offsets (basetype,
3563 empty_base_at_nonzero_offset_p,
3564 size_zero_node,
3565 /*offsets=*/NULL,
3566 /*max_offset=*/NULL_TREE,
3567 /*vbases_p=*/true))
3568 {
3569 if (abi_version_at_least (2))
3570 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3571 else if (warn_abi)
3572 warning ("class %qT will be considered nearly empty in a "
3573 "future version of GCC", t);
3574 }
3575 }
3576
3577 /* We do not create a FIELD_DECL for empty base classes because
3578 it might overlap some other field. We want to be able to
3579 create CONSTRUCTORs for the class by iterating over the
3580 FIELD_DECLs, and the back end does not handle overlapping
3581 FIELD_DECLs. */
3582
3583 /* An empty virtual base causes a class to be non-empty
3584 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3585 here because that was already done when the virtual table
3586 pointer was created. */
3587 }
3588
3589 /* Record the offsets of BINFO and its base subobjects. */
3590 record_subobject_offsets (binfo,
3591 BINFO_OFFSET (binfo),
3592 offsets,
3593 /*vbases_p=*/0);
3594
3595 return next_field;
3596 }
3597
3598 /* Layout all of the non-virtual base classes. Record empty
3599 subobjects in OFFSETS. T is the most derived type. Return nonzero
3600 if the type cannot be nearly empty. The fields created
3601 corresponding to the base classes will be inserted at
3602 *NEXT_FIELD. */
3603
3604 static void
3605 build_base_fields (record_layout_info rli,
3606 splay_tree offsets, tree *next_field)
3607 {
3608 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3609 subobjects. */
3610 tree t = rli->t;
3611 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
3612 int i;
3613
3614 /* The primary base class is always allocated first. */
3615 if (CLASSTYPE_HAS_PRIMARY_BASE_P (t))
3616 next_field = build_base_field (rli, CLASSTYPE_PRIMARY_BINFO (t),
3617 offsets, next_field);
3618
3619 /* Now allocate the rest of the bases. */
3620 for (i = 0; i < n_baseclasses; ++i)
3621 {
3622 tree base_binfo;
3623
3624 base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i);
3625
3626 /* The primary base was already allocated above, so we don't
3627 need to allocate it again here. */
3628 if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t))
3629 continue;
3630
3631 /* Virtual bases are added at the end (a primary virtual base
3632 will have already been added). */
3633 if (BINFO_VIRTUAL_P (base_binfo))
3634 continue;
3635
3636 next_field = build_base_field (rli, base_binfo,
3637 offsets, next_field);
3638 }
3639 }
3640
3641 /* Go through the TYPE_METHODS of T issuing any appropriate
3642 diagnostics, figuring out which methods override which other
3643 methods, and so forth. */
3644
3645 static void
3646 check_methods (tree t)
3647 {
3648 tree x;
3649
3650 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
3651 {
3652 check_for_override (x, t);
3653 if (DECL_PURE_VIRTUAL_P (x) && ! DECL_VINDEX (x))
3654 cp_error_at ("initializer specified for non-virtual method %qD", x);
3655 /* The name of the field is the original field name
3656 Save this in auxiliary field for later overloading. */
3657 if (DECL_VINDEX (x))
3658 {
3659 TYPE_POLYMORPHIC_P (t) = 1;
3660 if (DECL_PURE_VIRTUAL_P (x))
3661 VEC_safe_push (tree, CLASSTYPE_PURE_VIRTUALS (t), x);
3662 }
3663 }
3664 }
3665
3666 /* FN is a constructor or destructor. Clone the declaration to create
3667 a specialized in-charge or not-in-charge version, as indicated by
3668 NAME. */
3669
3670 static tree
3671 build_clone (tree fn, tree name)
3672 {
3673 tree parms;
3674 tree clone;
3675
3676 /* Copy the function. */
3677 clone = copy_decl (fn);
3678 /* Remember where this function came from. */
3679 DECL_CLONED_FUNCTION (clone) = fn;
3680 DECL_ABSTRACT_ORIGIN (clone) = fn;
3681 /* Reset the function name. */
3682 DECL_NAME (clone) = name;
3683 SET_DECL_ASSEMBLER_NAME (clone, NULL_TREE);
3684 /* There's no pending inline data for this function. */
3685 DECL_PENDING_INLINE_INFO (clone) = NULL;
3686 DECL_PENDING_INLINE_P (clone) = 0;
3687 /* And it hasn't yet been deferred. */
3688 DECL_DEFERRED_FN (clone) = 0;
3689
3690 /* The base-class destructor is not virtual. */
3691 if (name == base_dtor_identifier)
3692 {
3693 DECL_VIRTUAL_P (clone) = 0;
3694 if (TREE_CODE (clone) != TEMPLATE_DECL)
3695 DECL_VINDEX (clone) = NULL_TREE;
3696 }
3697
3698 /* If there was an in-charge parameter, drop it from the function
3699 type. */
3700 if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3701 {
3702 tree basetype;
3703 tree parmtypes;
3704 tree exceptions;
3705
3706 exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
3707 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
3708 parmtypes = TYPE_ARG_TYPES (TREE_TYPE (clone));
3709 /* Skip the `this' parameter. */
3710 parmtypes = TREE_CHAIN (parmtypes);
3711 /* Skip the in-charge parameter. */
3712 parmtypes = TREE_CHAIN (parmtypes);
3713 /* And the VTT parm, in a complete [cd]tor. */
3714 if (DECL_HAS_VTT_PARM_P (fn)
3715 && ! DECL_NEEDS_VTT_PARM_P (clone))
3716 parmtypes = TREE_CHAIN (parmtypes);
3717 /* If this is subobject constructor or destructor, add the vtt
3718 parameter. */
3719 TREE_TYPE (clone)
3720 = build_method_type_directly (basetype,
3721 TREE_TYPE (TREE_TYPE (clone)),
3722 parmtypes);
3723 if (exceptions)
3724 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone),
3725 exceptions);
3726 TREE_TYPE (clone)
3727 = cp_build_type_attribute_variant (TREE_TYPE (clone),
3728 TYPE_ATTRIBUTES (TREE_TYPE (fn)));
3729 }
3730
3731 /* Copy the function parameters. But, DECL_ARGUMENTS on a TEMPLATE_DECL
3732 aren't function parameters; those are the template parameters. */
3733 if (TREE_CODE (clone) != TEMPLATE_DECL)
3734 {
3735 DECL_ARGUMENTS (clone) = copy_list (DECL_ARGUMENTS (clone));
3736 /* Remove the in-charge parameter. */
3737 if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3738 {
3739 TREE_CHAIN (DECL_ARGUMENTS (clone))
3740 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3741 DECL_HAS_IN_CHARGE_PARM_P (clone) = 0;
3742 }
3743 /* And the VTT parm, in a complete [cd]tor. */
3744 if (DECL_HAS_VTT_PARM_P (fn))
3745 {
3746 if (DECL_NEEDS_VTT_PARM_P (clone))
3747 DECL_HAS_VTT_PARM_P (clone) = 1;
3748 else
3749 {
3750 TREE_CHAIN (DECL_ARGUMENTS (clone))
3751 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3752 DECL_HAS_VTT_PARM_P (clone) = 0;
3753 }
3754 }
3755
3756 for (parms = DECL_ARGUMENTS (clone); parms; parms = TREE_CHAIN (parms))
3757 {
3758 DECL_CONTEXT (parms) = clone;
3759 cxx_dup_lang_specific_decl (parms);
3760 }
3761 }
3762
3763 /* Create the RTL for this function. */
3764 SET_DECL_RTL (clone, NULL_RTX);
3765 rest_of_decl_compilation (clone, /*top_level=*/1, at_eof);
3766
3767 /* Make it easy to find the CLONE given the FN. */
3768 TREE_CHAIN (clone) = TREE_CHAIN (fn);
3769 TREE_CHAIN (fn) = clone;
3770
3771 /* If this is a template, handle the DECL_TEMPLATE_RESULT as well. */
3772 if (TREE_CODE (clone) == TEMPLATE_DECL)
3773 {
3774 tree result;
3775
3776 DECL_TEMPLATE_RESULT (clone)
3777 = build_clone (DECL_TEMPLATE_RESULT (clone), name);
3778 result = DECL_TEMPLATE_RESULT (clone);
3779 DECL_TEMPLATE_INFO (result) = copy_node (DECL_TEMPLATE_INFO (result));
3780 DECL_TI_TEMPLATE (result) = clone;
3781 }
3782 else if (pch_file)
3783 note_decl_for_pch (clone);
3784
3785 return clone;
3786 }
3787
3788 /* Produce declarations for all appropriate clones of FN. If
3789 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
3790 CLASTYPE_METHOD_VEC as well. */
3791
3792 void
3793 clone_function_decl (tree fn, int update_method_vec_p)
3794 {
3795 tree clone;
3796
3797 /* Avoid inappropriate cloning. */
3798 if (TREE_CHAIN (fn)
3799 && DECL_CLONED_FUNCTION (TREE_CHAIN (fn)))
3800 return;
3801
3802 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
3803 {
3804 /* For each constructor, we need two variants: an in-charge version
3805 and a not-in-charge version. */
3806 clone = build_clone (fn, complete_ctor_identifier);
3807 if (update_method_vec_p)
3808 add_method (DECL_CONTEXT (clone), clone);
3809 clone = build_clone (fn, base_ctor_identifier);
3810 if (update_method_vec_p)
3811 add_method (DECL_CONTEXT (clone), clone);
3812 }
3813 else
3814 {
3815 gcc_assert (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn));
3816
3817 /* For each destructor, we need three variants: an in-charge
3818 version, a not-in-charge version, and an in-charge deleting
3819 version. We clone the deleting version first because that
3820 means it will go second on the TYPE_METHODS list -- and that
3821 corresponds to the correct layout order in the virtual
3822 function table.
3823
3824 For a non-virtual destructor, we do not build a deleting
3825 destructor. */
3826 if (DECL_VIRTUAL_P (fn))
3827 {
3828 clone = build_clone (fn, deleting_dtor_identifier);
3829 if (update_method_vec_p)
3830 add_method (DECL_CONTEXT (clone), clone);
3831 }
3832 clone = build_clone (fn, complete_dtor_identifier);
3833 if (update_method_vec_p)
3834 add_method (DECL_CONTEXT (clone), clone);
3835 clone = build_clone (fn, base_dtor_identifier);
3836 if (update_method_vec_p)
3837 add_method (DECL_CONTEXT (clone), clone);
3838 }
3839
3840 /* Note that this is an abstract function that is never emitted. */
3841 DECL_ABSTRACT (fn) = 1;
3842 }
3843
3844 /* DECL is an in charge constructor, which is being defined. This will
3845 have had an in class declaration, from whence clones were
3846 declared. An out-of-class definition can specify additional default
3847 arguments. As it is the clones that are involved in overload
3848 resolution, we must propagate the information from the DECL to its
3849 clones. */
3850
3851 void
3852 adjust_clone_args (tree decl)
3853 {
3854 tree clone;
3855
3856 for (clone = TREE_CHAIN (decl); clone && DECL_CLONED_FUNCTION (clone);
3857 clone = TREE_CHAIN (clone))
3858 {
3859 tree orig_clone_parms = TYPE_ARG_TYPES (TREE_TYPE (clone));
3860 tree orig_decl_parms = TYPE_ARG_TYPES (TREE_TYPE (decl));
3861 tree decl_parms, clone_parms;
3862
3863 clone_parms = orig_clone_parms;
3864
3865 /* Skip the 'this' parameter. */
3866 orig_clone_parms = TREE_CHAIN (orig_clone_parms);
3867 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3868
3869 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
3870 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3871 if (DECL_HAS_VTT_PARM_P (decl))
3872 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3873
3874 clone_parms = orig_clone_parms;
3875 if (DECL_HAS_VTT_PARM_P (clone))
3876 clone_parms = TREE_CHAIN (clone_parms);
3877
3878 for (decl_parms = orig_decl_parms; decl_parms;
3879 decl_parms = TREE_CHAIN (decl_parms),
3880 clone_parms = TREE_CHAIN (clone_parms))
3881 {
3882 gcc_assert (same_type_p (TREE_TYPE (decl_parms),
3883 TREE_TYPE (clone_parms)));
3884
3885 if (TREE_PURPOSE (decl_parms) && !TREE_PURPOSE (clone_parms))
3886 {
3887 /* A default parameter has been added. Adjust the
3888 clone's parameters. */
3889 tree exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
3890 tree basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
3891 tree type;
3892
3893 clone_parms = orig_decl_parms;
3894
3895 if (DECL_HAS_VTT_PARM_P (clone))
3896 {
3897 clone_parms = tree_cons (TREE_PURPOSE (orig_clone_parms),
3898 TREE_VALUE (orig_clone_parms),
3899 clone_parms);
3900 TREE_TYPE (clone_parms) = TREE_TYPE (orig_clone_parms);
3901 }
3902 type = build_method_type_directly (basetype,
3903 TREE_TYPE (TREE_TYPE (clone)),
3904 clone_parms);
3905 if (exceptions)
3906 type = build_exception_variant (type, exceptions);
3907 TREE_TYPE (clone) = type;
3908
3909 clone_parms = NULL_TREE;
3910 break;
3911 }
3912 }
3913 gcc_assert (!clone_parms);
3914 }
3915 }
3916
3917 /* For each of the constructors and destructors in T, create an
3918 in-charge and not-in-charge variant. */
3919
3920 static void
3921 clone_constructors_and_destructors (tree t)
3922 {
3923 tree fns;
3924
3925 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
3926 out now. */
3927 if (!CLASSTYPE_METHOD_VEC (t))
3928 return;
3929
3930 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
3931 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
3932 for (fns = CLASSTYPE_DESTRUCTORS (t); fns; fns = OVL_NEXT (fns))
3933 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
3934 }
3935
3936 /* Remove all zero-width bit-fields from T. */
3937
3938 static void
3939 remove_zero_width_bit_fields (tree t)
3940 {
3941 tree *fieldsp;
3942
3943 fieldsp = &TYPE_FIELDS (t);
3944 while (*fieldsp)
3945 {
3946 if (TREE_CODE (*fieldsp) == FIELD_DECL
3947 && DECL_C_BIT_FIELD (*fieldsp)
3948 && DECL_INITIAL (*fieldsp))
3949 *fieldsp = TREE_CHAIN (*fieldsp);
3950 else
3951 fieldsp = &TREE_CHAIN (*fieldsp);
3952 }
3953 }
3954
3955 /* Returns TRUE iff we need a cookie when dynamically allocating an
3956 array whose elements have the indicated class TYPE. */
3957
3958 static bool
3959 type_requires_array_cookie (tree type)
3960 {
3961 tree fns;
3962 bool has_two_argument_delete_p = false;
3963
3964 gcc_assert (CLASS_TYPE_P (type));
3965
3966 /* If there's a non-trivial destructor, we need a cookie. In order
3967 to iterate through the array calling the destructor for each
3968 element, we'll have to know how many elements there are. */
3969 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
3970 return true;
3971
3972 /* If the usual deallocation function is a two-argument whose second
3973 argument is of type `size_t', then we have to pass the size of
3974 the array to the deallocation function, so we will need to store
3975 a cookie. */
3976 fns = lookup_fnfields (TYPE_BINFO (type),
3977 ansi_opname (VEC_DELETE_EXPR),
3978 /*protect=*/0);
3979 /* If there are no `operator []' members, or the lookup is
3980 ambiguous, then we don't need a cookie. */
3981 if (!fns || fns == error_mark_node)
3982 return false;
3983 /* Loop through all of the functions. */
3984 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
3985 {
3986 tree fn;
3987 tree second_parm;
3988
3989 /* Select the current function. */
3990 fn = OVL_CURRENT (fns);
3991 /* See if this function is a one-argument delete function. If
3992 it is, then it will be the usual deallocation function. */
3993 second_parm = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fn)));
3994 if (second_parm == void_list_node)
3995 return false;
3996 /* Otherwise, if we have a two-argument function and the second
3997 argument is `size_t', it will be the usual deallocation
3998 function -- unless there is one-argument function, too. */
3999 if (TREE_CHAIN (second_parm) == void_list_node
4000 && same_type_p (TREE_VALUE (second_parm), sizetype))
4001 has_two_argument_delete_p = true;
4002 }
4003
4004 return has_two_argument_delete_p;
4005 }
4006
4007 /* Check the validity of the bases and members declared in T. Add any
4008 implicitly-generated functions (like copy-constructors and
4009 assignment operators). Compute various flag bits (like
4010 CLASSTYPE_NON_POD_T) for T. This routine works purely at the C++
4011 level: i.e., independently of the ABI in use. */
4012
4013 static void
4014 check_bases_and_members (tree t)
4015 {
4016 /* Nonzero if we are not allowed to generate a default constructor
4017 for this case. */
4018 int cant_have_default_ctor;
4019 /* Nonzero if the implicitly generated copy constructor should take
4020 a non-const reference argument. */
4021 int cant_have_const_ctor;
4022 /* Nonzero if the the implicitly generated assignment operator
4023 should take a non-const reference argument. */
4024 int no_const_asn_ref;
4025 tree access_decls;
4026
4027 /* By default, we use const reference arguments and generate default
4028 constructors. */
4029 cant_have_default_ctor = 0;
4030 cant_have_const_ctor = 0;
4031 no_const_asn_ref = 0;
4032
4033 /* Check all the base-classes. */
4034 check_bases (t, &cant_have_default_ctor, &cant_have_const_ctor,
4035 &no_const_asn_ref);
4036
4037 /* Check all the data member declarations. */
4038 check_field_decls (t, &access_decls,
4039 &cant_have_default_ctor,
4040 &cant_have_const_ctor,
4041 &no_const_asn_ref);
4042
4043 /* Check all the method declarations. */
4044 check_methods (t);
4045
4046 /* A nearly-empty class has to be vptr-containing; a nearly empty
4047 class contains just a vptr. */
4048 if (!TYPE_CONTAINS_VPTR_P (t))
4049 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
4050
4051 /* Do some bookkeeping that will guide the generation of implicitly
4052 declared member functions. */
4053 TYPE_HAS_COMPLEX_INIT_REF (t)
4054 |= (TYPE_HAS_INIT_REF (t) || TYPE_CONTAINS_VPTR_P (t));
4055 TYPE_NEEDS_CONSTRUCTING (t)
4056 |= (TYPE_HAS_CONSTRUCTOR (t) || TYPE_CONTAINS_VPTR_P (t));
4057 CLASSTYPE_NON_AGGREGATE (t)
4058 |= (TYPE_HAS_CONSTRUCTOR (t) || TYPE_POLYMORPHIC_P (t));
4059 CLASSTYPE_NON_POD_P (t)
4060 |= (CLASSTYPE_NON_AGGREGATE (t) || TYPE_HAS_DESTRUCTOR (t)
4061 || TYPE_HAS_ASSIGN_REF (t));
4062 TYPE_HAS_COMPLEX_ASSIGN_REF (t)
4063 |= TYPE_HAS_ASSIGN_REF (t) || TYPE_CONTAINS_VPTR_P (t);
4064
4065 /* Synthesize any needed methods. */
4066 add_implicitly_declared_members (t, cant_have_default_ctor,
4067 cant_have_const_ctor,
4068 no_const_asn_ref);
4069
4070 /* Create the in-charge and not-in-charge variants of constructors
4071 and destructors. */
4072 clone_constructors_and_destructors (t);
4073
4074 /* Process the using-declarations. */
4075 for (; access_decls; access_decls = TREE_CHAIN (access_decls))
4076 handle_using_decl (TREE_VALUE (access_decls), t);
4077
4078 /* Build and sort the CLASSTYPE_METHOD_VEC. */
4079 finish_struct_methods (t);
4080
4081 /* Figure out whether or not we will need a cookie when dynamically
4082 allocating an array of this type. */
4083 TYPE_LANG_SPECIFIC (t)->u.c.vec_new_uses_cookie
4084 = type_requires_array_cookie (t);
4085 }
4086
4087 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4088 accordingly. If a new vfield was created (because T doesn't have a
4089 primary base class), then the newly created field is returned. It
4090 is not added to the TYPE_FIELDS list; it is the caller's
4091 responsibility to do that. Accumulate declared virtual functions
4092 on VIRTUALS_P. */
4093
4094 static tree
4095 create_vtable_ptr (tree t, tree* virtuals_p)
4096 {
4097 tree fn;
4098
4099 /* Collect the virtual functions declared in T. */
4100 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
4101 if (DECL_VINDEX (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)
4102 && TREE_CODE (DECL_VINDEX (fn)) != INTEGER_CST)
4103 {
4104 tree new_virtual = make_node (TREE_LIST);
4105
4106 BV_FN (new_virtual) = fn;
4107 BV_DELTA (new_virtual) = integer_zero_node;
4108 BV_VCALL_INDEX (new_virtual) = NULL_TREE;
4109
4110 TREE_CHAIN (new_virtual) = *virtuals_p;
4111 *virtuals_p = new_virtual;
4112 }
4113
4114 /* If we couldn't find an appropriate base class, create a new field
4115 here. Even if there weren't any new virtual functions, we might need a
4116 new virtual function table if we're supposed to include vptrs in
4117 all classes that need them. */
4118 if (!TYPE_VFIELD (t) && (*virtuals_p || TYPE_CONTAINS_VPTR_P (t)))
4119 {
4120 /* We build this decl with vtbl_ptr_type_node, which is a
4121 `vtable_entry_type*'. It might seem more precise to use
4122 `vtable_entry_type (*)[N]' where N is the number of virtual
4123 functions. However, that would require the vtable pointer in
4124 base classes to have a different type than the vtable pointer
4125 in derived classes. We could make that happen, but that
4126 still wouldn't solve all the problems. In particular, the
4127 type-based alias analysis code would decide that assignments
4128 to the base class vtable pointer can't alias assignments to
4129 the derived class vtable pointer, since they have different
4130 types. Thus, in a derived class destructor, where the base
4131 class constructor was inlined, we could generate bad code for
4132 setting up the vtable pointer.
4133
4134 Therefore, we use one type for all vtable pointers. We still
4135 use a type-correct type; it's just doesn't indicate the array
4136 bounds. That's better than using `void*' or some such; it's
4137 cleaner, and it let's the alias analysis code know that these
4138 stores cannot alias stores to void*! */
4139 tree field;
4140
4141 field = build_decl (FIELD_DECL, get_vfield_name (t), vtbl_ptr_type_node);
4142 SET_DECL_ASSEMBLER_NAME (field, get_identifier (VFIELD_BASE));
4143 DECL_VIRTUAL_P (field) = 1;
4144 DECL_ARTIFICIAL (field) = 1;
4145 DECL_FIELD_CONTEXT (field) = t;
4146 DECL_FCONTEXT (field) = t;
4147
4148 TYPE_VFIELD (t) = field;
4149
4150 /* This class is non-empty. */
4151 CLASSTYPE_EMPTY_P (t) = 0;
4152
4153 return field;
4154 }
4155
4156 return NULL_TREE;
4157 }
4158
4159 /* Fixup the inline function given by INFO now that the class is
4160 complete. */
4161
4162 static void
4163 fixup_pending_inline (tree fn)
4164 {
4165 if (DECL_PENDING_INLINE_INFO (fn))
4166 {
4167 tree args = DECL_ARGUMENTS (fn);
4168 while (args)
4169 {
4170 DECL_CONTEXT (args) = fn;
4171 args = TREE_CHAIN (args);
4172 }
4173 }
4174 }
4175
4176 /* Fixup the inline methods and friends in TYPE now that TYPE is
4177 complete. */
4178
4179 static void
4180 fixup_inline_methods (tree type)
4181 {
4182 tree method = TYPE_METHODS (type);
4183 VEC (tree) *friends;
4184 unsigned ix;
4185
4186 if (method && TREE_CODE (method) == TREE_VEC)
4187 {
4188 if (TREE_VEC_ELT (method, 1))
4189 method = TREE_VEC_ELT (method, 1);
4190 else if (TREE_VEC_ELT (method, 0))
4191 method = TREE_VEC_ELT (method, 0);
4192 else
4193 method = TREE_VEC_ELT (method, 2);
4194 }
4195
4196 /* Do inline member functions. */
4197 for (; method; method = TREE_CHAIN (method))
4198 fixup_pending_inline (method);
4199
4200 /* Do friends. */
4201 for (friends = CLASSTYPE_INLINE_FRIENDS (type), ix = 0;
4202 VEC_iterate (tree, friends, ix, method); ix++)
4203 fixup_pending_inline (method);
4204 CLASSTYPE_INLINE_FRIENDS (type) = NULL;
4205 }
4206
4207 /* Add OFFSET to all base types of BINFO which is a base in the
4208 hierarchy dominated by T.
4209
4210 OFFSET, which is a type offset, is number of bytes. */
4211
4212 static void
4213 propagate_binfo_offsets (tree binfo, tree offset)
4214 {
4215 int i;
4216 tree primary_binfo;
4217 tree base_binfo;
4218
4219 /* Update BINFO's offset. */
4220 BINFO_OFFSET (binfo)
4221 = convert (sizetype,
4222 size_binop (PLUS_EXPR,
4223 convert (ssizetype, BINFO_OFFSET (binfo)),
4224 offset));
4225
4226 /* Find the primary base class. */
4227 primary_binfo = get_primary_binfo (binfo);
4228
4229 if (primary_binfo && BINFO_INHERITANCE_CHAIN (primary_binfo) == binfo)
4230 propagate_binfo_offsets (primary_binfo, offset);
4231
4232 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4233 downwards. */
4234 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4235 {
4236 /* Don't do the primary base twice. */
4237 if (base_binfo == primary_binfo)
4238 continue;
4239
4240 if (BINFO_VIRTUAL_P (base_binfo))
4241 continue;
4242
4243 propagate_binfo_offsets (base_binfo, offset);
4244 }
4245 }
4246
4247 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
4248 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
4249 empty subobjects of T. */
4250
4251 static void
4252 layout_virtual_bases (record_layout_info rli, splay_tree offsets)
4253 {
4254 tree vbase;
4255 tree t = rli->t;
4256 bool first_vbase = true;
4257 tree *next_field;
4258
4259 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) == 0)
4260 return;
4261
4262 if (!abi_version_at_least(2))
4263 {
4264 /* In G++ 3.2, we incorrectly rounded the size before laying out
4265 the virtual bases. */
4266 finish_record_layout (rli, /*free_p=*/false);
4267 #ifdef STRUCTURE_SIZE_BOUNDARY
4268 /* Packed structures don't need to have minimum size. */
4269 if (! TYPE_PACKED (t))
4270 TYPE_ALIGN (t) = MAX (TYPE_ALIGN (t), (unsigned) STRUCTURE_SIZE_BOUNDARY);
4271 #endif
4272 rli->offset = TYPE_SIZE_UNIT (t);
4273 rli->bitpos = bitsize_zero_node;
4274 rli->record_align = TYPE_ALIGN (t);
4275 }
4276
4277 /* Find the last field. The artificial fields created for virtual
4278 bases will go after the last extant field to date. */
4279 next_field = &TYPE_FIELDS (t);
4280 while (*next_field)
4281 next_field = &TREE_CHAIN (*next_field);
4282
4283 /* Go through the virtual bases, allocating space for each virtual
4284 base that is not already a primary base class. These are
4285 allocated in inheritance graph order. */
4286 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
4287 {
4288 if (!BINFO_VIRTUAL_P (vbase))
4289 continue;
4290
4291 if (!BINFO_PRIMARY_P (vbase))
4292 {
4293 tree basetype = TREE_TYPE (vbase);
4294
4295 /* This virtual base is not a primary base of any class in the
4296 hierarchy, so we have to add space for it. */
4297 next_field = build_base_field (rli, vbase,
4298 offsets, next_field);
4299
4300 /* If the first virtual base might have been placed at a
4301 lower address, had we started from CLASSTYPE_SIZE, rather
4302 than TYPE_SIZE, issue a warning. There can be both false
4303 positives and false negatives from this warning in rare
4304 cases; to deal with all the possibilities would probably
4305 require performing both layout algorithms and comparing
4306 the results which is not particularly tractable. */
4307 if (warn_abi
4308 && first_vbase
4309 && (tree_int_cst_lt
4310 (size_binop (CEIL_DIV_EXPR,
4311 round_up (CLASSTYPE_SIZE (t),
4312 CLASSTYPE_ALIGN (basetype)),
4313 bitsize_unit_node),
4314 BINFO_OFFSET (vbase))))
4315 warning ("offset of virtual base %qT is not ABI-compliant and "
4316 "may change in a future version of GCC",
4317 basetype);
4318
4319 first_vbase = false;
4320 }
4321 }
4322 }
4323
4324 /* Returns the offset of the byte just past the end of the base class
4325 BINFO. */
4326
4327 static tree
4328 end_of_base (tree binfo)
4329 {
4330 tree size;
4331
4332 if (is_empty_class (BINFO_TYPE (binfo)))
4333 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4334 allocate some space for it. It cannot have virtual bases, so
4335 TYPE_SIZE_UNIT is fine. */
4336 size = TYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4337 else
4338 size = CLASSTYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4339
4340 return size_binop (PLUS_EXPR, BINFO_OFFSET (binfo), size);
4341 }
4342
4343 /* Returns the offset of the byte just past the end of the base class
4344 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
4345 only non-virtual bases are included. */
4346
4347 static tree
4348 end_of_class (tree t, int include_virtuals_p)
4349 {
4350 tree result = size_zero_node;
4351 VEC (tree) *vbases;
4352 tree binfo;
4353 tree base_binfo;
4354 tree offset;
4355 int i;
4356
4357 for (binfo = TYPE_BINFO (t), i = 0;
4358 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4359 {
4360 if (!include_virtuals_p
4361 && BINFO_VIRTUAL_P (base_binfo)
4362 && (!BINFO_PRIMARY_P (base_binfo)
4363 || BINFO_INHERITANCE_CHAIN (base_binfo) != TYPE_BINFO (t)))
4364 continue;
4365
4366 offset = end_of_base (base_binfo);
4367 if (INT_CST_LT_UNSIGNED (result, offset))
4368 result = offset;
4369 }
4370
4371 /* G++ 3.2 did not check indirect virtual bases. */
4372 if (abi_version_at_least (2) && include_virtuals_p)
4373 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4374 VEC_iterate (tree, vbases, i, base_binfo); i++)
4375 {
4376 offset = end_of_base (base_binfo);
4377 if (INT_CST_LT_UNSIGNED (result, offset))
4378 result = offset;
4379 }
4380
4381 return result;
4382 }
4383
4384 /* Warn about bases of T that are inaccessible because they are
4385 ambiguous. For example:
4386
4387 struct S {};
4388 struct T : public S {};
4389 struct U : public S, public T {};
4390
4391 Here, `(S*) new U' is not allowed because there are two `S'
4392 subobjects of U. */
4393
4394 static void
4395 warn_about_ambiguous_bases (tree t)
4396 {
4397 int i;
4398 VEC (tree) *vbases;
4399 tree basetype;
4400 tree binfo;
4401 tree base_binfo;
4402
4403 /* If there are no repeated bases, nothing can be ambiguous. */
4404 if (!CLASSTYPE_REPEATED_BASE_P (t))
4405 return;
4406
4407 /* Check direct bases. */
4408 for (binfo = TYPE_BINFO (t), i = 0;
4409 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4410 {
4411 basetype = BINFO_TYPE (base_binfo);
4412
4413 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4414 warning ("direct base %qT inaccessible in %qT due to ambiguity",
4415 basetype, t);
4416 }
4417
4418 /* Check for ambiguous virtual bases. */
4419 if (extra_warnings)
4420 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4421 VEC_iterate (tree, vbases, i, binfo); i++)
4422 {
4423 basetype = BINFO_TYPE (binfo);
4424
4425 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4426 warning ("virtual base %qT inaccessible in %qT due to ambiguity",
4427 basetype, t);
4428 }
4429 }
4430
4431 /* Compare two INTEGER_CSTs K1 and K2. */
4432
4433 static int
4434 splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2)
4435 {
4436 return tree_int_cst_compare ((tree) k1, (tree) k2);
4437 }
4438
4439 /* Increase the size indicated in RLI to account for empty classes
4440 that are "off the end" of the class. */
4441
4442 static void
4443 include_empty_classes (record_layout_info rli)
4444 {
4445 tree eoc;
4446 tree rli_size;
4447
4448 /* It might be the case that we grew the class to allocate a
4449 zero-sized base class. That won't be reflected in RLI, yet,
4450 because we are willing to overlay multiple bases at the same
4451 offset. However, now we need to make sure that RLI is big enough
4452 to reflect the entire class. */
4453 eoc = end_of_class (rli->t,
4454 CLASSTYPE_AS_BASE (rli->t) != NULL_TREE);
4455 rli_size = rli_size_unit_so_far (rli);
4456 if (TREE_CODE (rli_size) == INTEGER_CST
4457 && INT_CST_LT_UNSIGNED (rli_size, eoc))
4458 {
4459 if (!abi_version_at_least (2))
4460 /* In version 1 of the ABI, the size of a class that ends with
4461 a bitfield was not rounded up to a whole multiple of a
4462 byte. Because rli_size_unit_so_far returns only the number
4463 of fully allocated bytes, any extra bits were not included
4464 in the size. */
4465 rli->bitpos = round_down (rli->bitpos, BITS_PER_UNIT);
4466 else
4467 /* The size should have been rounded to a whole byte. */
4468 gcc_assert (tree_int_cst_equal
4469 (rli->bitpos, round_down (rli->bitpos, BITS_PER_UNIT)));
4470 rli->bitpos
4471 = size_binop (PLUS_EXPR,
4472 rli->bitpos,
4473 size_binop (MULT_EXPR,
4474 convert (bitsizetype,
4475 size_binop (MINUS_EXPR,
4476 eoc, rli_size)),
4477 bitsize_int (BITS_PER_UNIT)));
4478 normalize_rli (rli);
4479 }
4480 }
4481
4482 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
4483 BINFO_OFFSETs for all of the base-classes. Position the vtable
4484 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
4485
4486 static void
4487 layout_class_type (tree t, tree *virtuals_p)
4488 {
4489 tree non_static_data_members;
4490 tree field;
4491 tree vptr;
4492 record_layout_info rli;
4493 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4494 types that appear at that offset. */
4495 splay_tree empty_base_offsets;
4496 /* True if the last field layed out was a bit-field. */
4497 bool last_field_was_bitfield = false;
4498 /* The location at which the next field should be inserted. */
4499 tree *next_field;
4500 /* T, as a base class. */
4501 tree base_t;
4502
4503 /* Keep track of the first non-static data member. */
4504 non_static_data_members = TYPE_FIELDS (t);
4505
4506 /* Start laying out the record. */
4507 rli = start_record_layout (t);
4508
4509 /* Mark all the primary bases in the hierarchy. */
4510 determine_primary_bases (t);
4511
4512 /* Create a pointer to our virtual function table. */
4513 vptr = create_vtable_ptr (t, virtuals_p);
4514
4515 /* The vptr is always the first thing in the class. */
4516 if (vptr)
4517 {
4518 TREE_CHAIN (vptr) = TYPE_FIELDS (t);
4519 TYPE_FIELDS (t) = vptr;
4520 next_field = &TREE_CHAIN (vptr);
4521 place_field (rli, vptr);
4522 }
4523 else
4524 next_field = &TYPE_FIELDS (t);
4525
4526 /* Build FIELD_DECLs for all of the non-virtual base-types. */
4527 empty_base_offsets = splay_tree_new (splay_tree_compare_integer_csts,
4528 NULL, NULL);
4529 build_base_fields (rli, empty_base_offsets, next_field);
4530
4531 /* Layout the non-static data members. */
4532 for (field = non_static_data_members; field; field = TREE_CHAIN (field))
4533 {
4534 tree type;
4535 tree padding;
4536
4537 /* We still pass things that aren't non-static data members to
4538 the back-end, in case it wants to do something with them. */
4539 if (TREE_CODE (field) != FIELD_DECL)
4540 {
4541 place_field (rli, field);
4542 /* If the static data member has incomplete type, keep track
4543 of it so that it can be completed later. (The handling
4544 of pending statics in finish_record_layout is
4545 insufficient; consider:
4546
4547 struct S1;
4548 struct S2 { static S1 s1; };
4549
4550 At this point, finish_record_layout will be called, but
4551 S1 is still incomplete.) */
4552 if (TREE_CODE (field) == VAR_DECL)
4553 {
4554 maybe_register_incomplete_var (field);
4555 /* The visibility of static data members is determined
4556 at their point of declaration, not their point of
4557 definition. */
4558 determine_visibility (field);
4559 }
4560 continue;
4561 }
4562
4563 type = TREE_TYPE (field);
4564
4565 padding = NULL_TREE;
4566
4567 /* If this field is a bit-field whose width is greater than its
4568 type, then there are some special rules for allocating
4569 it. */
4570 if (DECL_C_BIT_FIELD (field)
4571 && INT_CST_LT (TYPE_SIZE (type), DECL_SIZE (field)))
4572 {
4573 integer_type_kind itk;
4574 tree integer_type;
4575 bool was_unnamed_p = false;
4576 /* We must allocate the bits as if suitably aligned for the
4577 longest integer type that fits in this many bits. type
4578 of the field. Then, we are supposed to use the left over
4579 bits as additional padding. */
4580 for (itk = itk_char; itk != itk_none; ++itk)
4581 if (INT_CST_LT (DECL_SIZE (field),
4582 TYPE_SIZE (integer_types[itk])))
4583 break;
4584
4585 /* ITK now indicates a type that is too large for the
4586 field. We have to back up by one to find the largest
4587 type that fits. */
4588 integer_type = integer_types[itk - 1];
4589
4590 /* Figure out how much additional padding is required. GCC
4591 3.2 always created a padding field, even if it had zero
4592 width. */
4593 if (!abi_version_at_least (2)
4594 || INT_CST_LT (TYPE_SIZE (integer_type), DECL_SIZE (field)))
4595 {
4596 if (abi_version_at_least (2) && TREE_CODE (t) == UNION_TYPE)
4597 /* In a union, the padding field must have the full width
4598 of the bit-field; all fields start at offset zero. */
4599 padding = DECL_SIZE (field);
4600 else
4601 {
4602 if (warn_abi && TREE_CODE (t) == UNION_TYPE)
4603 warning ("size assigned to %qT may not be "
4604 "ABI-compliant and may change in a future "
4605 "version of GCC",
4606 t);
4607 padding = size_binop (MINUS_EXPR, DECL_SIZE (field),
4608 TYPE_SIZE (integer_type));
4609 }
4610 }
4611 #ifdef PCC_BITFIELD_TYPE_MATTERS
4612 /* An unnamed bitfield does not normally affect the
4613 alignment of the containing class on a target where
4614 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
4615 make any exceptions for unnamed bitfields when the
4616 bitfields are longer than their types. Therefore, we
4617 temporarily give the field a name. */
4618 if (PCC_BITFIELD_TYPE_MATTERS && !DECL_NAME (field))
4619 {
4620 was_unnamed_p = true;
4621 DECL_NAME (field) = make_anon_name ();
4622 }
4623 #endif
4624 DECL_SIZE (field) = TYPE_SIZE (integer_type);
4625 DECL_ALIGN (field) = TYPE_ALIGN (integer_type);
4626 DECL_USER_ALIGN (field) = TYPE_USER_ALIGN (integer_type);
4627 layout_nonempty_base_or_field (rli, field, NULL_TREE,
4628 empty_base_offsets);
4629 if (was_unnamed_p)
4630 DECL_NAME (field) = NULL_TREE;
4631 /* Now that layout has been performed, set the size of the
4632 field to the size of its declared type; the rest of the
4633 field is effectively invisible. */
4634 DECL_SIZE (field) = TYPE_SIZE (type);
4635 /* We must also reset the DECL_MODE of the field. */
4636 if (abi_version_at_least (2))
4637 DECL_MODE (field) = TYPE_MODE (type);
4638 else if (warn_abi
4639 && DECL_MODE (field) != TYPE_MODE (type))
4640 /* Versions of G++ before G++ 3.4 did not reset the
4641 DECL_MODE. */
4642 warning ("the offset of %qD may not be ABI-compliant and may "
4643 "change in a future version of GCC", field);
4644 }
4645 else
4646 layout_nonempty_base_or_field (rli, field, NULL_TREE,
4647 empty_base_offsets);
4648
4649 /* Remember the location of any empty classes in FIELD. */
4650 if (abi_version_at_least (2))
4651 record_subobject_offsets (TREE_TYPE (field),
4652 byte_position(field),
4653 empty_base_offsets,
4654 /*vbases_p=*/1);
4655
4656 /* If a bit-field does not immediately follow another bit-field,
4657 and yet it starts in the middle of a byte, we have failed to
4658 comply with the ABI. */
4659 if (warn_abi
4660 && DECL_C_BIT_FIELD (field)
4661 && !last_field_was_bitfield
4662 && !integer_zerop (size_binop (TRUNC_MOD_EXPR,
4663 DECL_FIELD_BIT_OFFSET (field),
4664 bitsize_unit_node)))
4665 cp_warning_at ("offset of %qD is not ABI-compliant and may "
4666 "change in a future version of GCC",
4667 field);
4668
4669 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
4670 offset of the field. */
4671 if (warn_abi
4672 && !tree_int_cst_equal (DECL_FIELD_OFFSET (field),
4673 byte_position (field))
4674 && contains_empty_class_p (TREE_TYPE (field)))
4675 cp_warning_at ("%qD contains empty classes which may cause base "
4676 "classes to be placed at different locations in a "
4677 "future version of GCC",
4678 field);
4679
4680 /* If we needed additional padding after this field, add it
4681 now. */
4682 if (padding)
4683 {
4684 tree padding_field;
4685
4686 padding_field = build_decl (FIELD_DECL,
4687 NULL_TREE,
4688 char_type_node);
4689 DECL_BIT_FIELD (padding_field) = 1;
4690 DECL_SIZE (padding_field) = padding;
4691 DECL_CONTEXT (padding_field) = t;
4692 DECL_ARTIFICIAL (padding_field) = 1;
4693 DECL_IGNORED_P (padding_field) = 1;
4694 layout_nonempty_base_or_field (rli, padding_field,
4695 NULL_TREE,
4696 empty_base_offsets);
4697 }
4698
4699 last_field_was_bitfield = DECL_C_BIT_FIELD (field);
4700 }
4701
4702 if (abi_version_at_least (2) && !integer_zerop (rli->bitpos))
4703 {
4704 /* Make sure that we are on a byte boundary so that the size of
4705 the class without virtual bases will always be a round number
4706 of bytes. */
4707 rli->bitpos = round_up (rli->bitpos, BITS_PER_UNIT);
4708 normalize_rli (rli);
4709 }
4710
4711 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
4712 padding. */
4713 if (!abi_version_at_least (2))
4714 include_empty_classes(rli);
4715
4716 /* Delete all zero-width bit-fields from the list of fields. Now
4717 that the type is laid out they are no longer important. */
4718 remove_zero_width_bit_fields (t);
4719
4720 /* Create the version of T used for virtual bases. We do not use
4721 make_aggr_type for this version; this is an artificial type. For
4722 a POD type, we just reuse T. */
4723 if (CLASSTYPE_NON_POD_P (t) || CLASSTYPE_EMPTY_P (t))
4724 {
4725 base_t = make_node (TREE_CODE (t));
4726
4727 /* Set the size and alignment for the new type. In G++ 3.2, all
4728 empty classes were considered to have size zero when used as
4729 base classes. */
4730 if (!abi_version_at_least (2) && CLASSTYPE_EMPTY_P (t))
4731 {
4732 TYPE_SIZE (base_t) = bitsize_zero_node;
4733 TYPE_SIZE_UNIT (base_t) = size_zero_node;
4734 if (warn_abi && !integer_zerop (rli_size_unit_so_far (rli)))
4735 warning ("layout of classes derived from empty class %qT "
4736 "may change in a future version of GCC",
4737 t);
4738 }
4739 else
4740 {
4741 tree eoc;
4742
4743 /* If the ABI version is not at least two, and the last
4744 field was a bit-field, RLI may not be on a byte
4745 boundary. In particular, rli_size_unit_so_far might
4746 indicate the last complete byte, while rli_size_so_far
4747 indicates the total number of bits used. Therefore,
4748 rli_size_so_far, rather than rli_size_unit_so_far, is
4749 used to compute TYPE_SIZE_UNIT. */
4750 eoc = end_of_class (t, /*include_virtuals_p=*/0);
4751 TYPE_SIZE_UNIT (base_t)
4752 = size_binop (MAX_EXPR,
4753 convert (sizetype,
4754 size_binop (CEIL_DIV_EXPR,
4755 rli_size_so_far (rli),
4756 bitsize_int (BITS_PER_UNIT))),
4757 eoc);
4758 TYPE_SIZE (base_t)
4759 = size_binop (MAX_EXPR,
4760 rli_size_so_far (rli),
4761 size_binop (MULT_EXPR,
4762 convert (bitsizetype, eoc),
4763 bitsize_int (BITS_PER_UNIT)));
4764 }
4765 TYPE_ALIGN (base_t) = rli->record_align;
4766 TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t);
4767
4768 /* Copy the fields from T. */
4769 next_field = &TYPE_FIELDS (base_t);
4770 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
4771 if (TREE_CODE (field) == FIELD_DECL)
4772 {
4773 *next_field = build_decl (FIELD_DECL,
4774 DECL_NAME (field),
4775 TREE_TYPE (field));
4776 DECL_CONTEXT (*next_field) = base_t;
4777 DECL_FIELD_OFFSET (*next_field) = DECL_FIELD_OFFSET (field);
4778 DECL_FIELD_BIT_OFFSET (*next_field)
4779 = DECL_FIELD_BIT_OFFSET (field);
4780 DECL_SIZE (*next_field) = DECL_SIZE (field);
4781 DECL_MODE (*next_field) = DECL_MODE (field);
4782 next_field = &TREE_CHAIN (*next_field);
4783 }
4784
4785 /* Record the base version of the type. */
4786 CLASSTYPE_AS_BASE (t) = base_t;
4787 TYPE_CONTEXT (base_t) = t;
4788 }
4789 else
4790 CLASSTYPE_AS_BASE (t) = t;
4791
4792 /* Every empty class contains an empty class. */
4793 if (CLASSTYPE_EMPTY_P (t))
4794 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
4795
4796 /* Set the TYPE_DECL for this type to contain the right
4797 value for DECL_OFFSET, so that we can use it as part
4798 of a COMPONENT_REF for multiple inheritance. */
4799 layout_decl (TYPE_MAIN_DECL (t), 0);
4800
4801 /* Now fix up any virtual base class types that we left lying
4802 around. We must get these done before we try to lay out the
4803 virtual function table. As a side-effect, this will remove the
4804 base subobject fields. */
4805 layout_virtual_bases (rli, empty_base_offsets);
4806
4807 /* Make sure that empty classes are reflected in RLI at this
4808 point. */
4809 include_empty_classes(rli);
4810
4811 /* Make sure not to create any structures with zero size. */
4812 if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t))
4813 place_field (rli,
4814 build_decl (FIELD_DECL, NULL_TREE, char_type_node));
4815
4816 /* Let the back-end lay out the type. */
4817 finish_record_layout (rli, /*free_p=*/true);
4818
4819 /* Warn about bases that can't be talked about due to ambiguity. */
4820 warn_about_ambiguous_bases (t);
4821
4822 /* Now that we're done with layout, give the base fields the real types. */
4823 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
4824 if (DECL_ARTIFICIAL (field) && IS_FAKE_BASE_TYPE (TREE_TYPE (field)))
4825 TREE_TYPE (field) = TYPE_CONTEXT (TREE_TYPE (field));
4826
4827 /* Clean up. */
4828 splay_tree_delete (empty_base_offsets);
4829 }
4830
4831 /* Determine the "key method" for the class type indicated by TYPE,
4832 and set CLASSTYPE_KEY_METHOD accordingly. */
4833
4834 void
4835 determine_key_method (tree type)
4836 {
4837 tree method;
4838
4839 if (TYPE_FOR_JAVA (type)
4840 || processing_template_decl
4841 || CLASSTYPE_TEMPLATE_INSTANTIATION (type)
4842 || CLASSTYPE_INTERFACE_KNOWN (type))
4843 return;
4844
4845 /* The key method is the first non-pure virtual function that is not
4846 inline at the point of class definition. On some targets the
4847 key function may not be inline; those targets should not call
4848 this function until the end of the translation unit. */
4849 for (method = TYPE_METHODS (type); method != NULL_TREE;
4850 method = TREE_CHAIN (method))
4851 if (DECL_VINDEX (method) != NULL_TREE
4852 && ! DECL_DECLARED_INLINE_P (method)
4853 && ! DECL_PURE_VIRTUAL_P (method))
4854 {
4855 CLASSTYPE_KEY_METHOD (type) = method;
4856 break;
4857 }
4858
4859 return;
4860 }
4861
4862 /* Perform processing required when the definition of T (a class type)
4863 is complete. */
4864
4865 void
4866 finish_struct_1 (tree t)
4867 {
4868 tree x;
4869 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
4870 tree virtuals = NULL_TREE;
4871 int n_fields = 0;
4872
4873 if (COMPLETE_TYPE_P (t))
4874 {
4875 gcc_assert (IS_AGGR_TYPE (t));
4876 error ("redefinition of %q#T", t);
4877 popclass ();
4878 return;
4879 }
4880
4881 /* If this type was previously laid out as a forward reference,
4882 make sure we lay it out again. */
4883 TYPE_SIZE (t) = NULL_TREE;
4884 CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE;
4885
4886 fixup_inline_methods (t);
4887
4888 /* Make assumptions about the class; we'll reset the flags if
4889 necessary. */
4890 CLASSTYPE_EMPTY_P (t) = 1;
4891 CLASSTYPE_NEARLY_EMPTY_P (t) = 1;
4892 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 0;
4893
4894 /* Do end-of-class semantic processing: checking the validity of the
4895 bases and members and add implicitly generated methods. */
4896 check_bases_and_members (t);
4897
4898 /* Find the key method. */
4899 if (TYPE_CONTAINS_VPTR_P (t))
4900 {
4901 /* The Itanium C++ ABI permits the key method to be chosen when
4902 the class is defined -- even though the key method so
4903 selected may later turn out to be an inline function. On
4904 some systems (such as ARM Symbian OS) the key method cannot
4905 be determined until the end of the translation unit. On such
4906 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
4907 will cause the class to be added to KEYED_CLASSES. Then, in
4908 finish_file we will determine the key method. */
4909 if (targetm.cxx.key_method_may_be_inline ())
4910 determine_key_method (t);
4911
4912 /* If a polymorphic class has no key method, we may emit the vtable
4913 in every translation unit where the class definition appears. */
4914 if (CLASSTYPE_KEY_METHOD (t) == NULL_TREE)
4915 keyed_classes = tree_cons (NULL_TREE, t, keyed_classes);
4916 }
4917
4918 /* Layout the class itself. */
4919 layout_class_type (t, &virtuals);
4920 if (CLASSTYPE_AS_BASE (t) != t)
4921 /* We use the base type for trivial assignments, and hence it
4922 needs a mode. */
4923 compute_record_mode (CLASSTYPE_AS_BASE (t));
4924
4925 virtuals = modify_all_vtables (t, nreverse (virtuals));
4926
4927 /* If necessary, create the primary vtable for this class. */
4928 if (virtuals || TYPE_CONTAINS_VPTR_P (t))
4929 {
4930 /* We must enter these virtuals into the table. */
4931 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
4932 build_primary_vtable (NULL_TREE, t);
4933 else if (! BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (t)))
4934 /* Here we know enough to change the type of our virtual
4935 function table, but we will wait until later this function. */
4936 build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t);
4937 }
4938
4939 if (TYPE_CONTAINS_VPTR_P (t))
4940 {
4941 int vindex;
4942 tree fn;
4943
4944 if (BINFO_VTABLE (TYPE_BINFO (t)))
4945 gcc_assert (DECL_VIRTUAL_P (BINFO_VTABLE (TYPE_BINFO (t))));
4946 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
4947 gcc_assert (BINFO_VIRTUALS (TYPE_BINFO (t)) == NULL_TREE);
4948
4949 /* Add entries for virtual functions introduced by this class. */
4950 BINFO_VIRTUALS (TYPE_BINFO (t))
4951 = chainon (BINFO_VIRTUALS (TYPE_BINFO (t)), virtuals);
4952
4953 /* Set DECL_VINDEX for all functions declared in this class. */
4954 for (vindex = 0, fn = BINFO_VIRTUALS (TYPE_BINFO (t));
4955 fn;
4956 fn = TREE_CHAIN (fn),
4957 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
4958 ? TARGET_VTABLE_USES_DESCRIPTORS : 1))
4959 {
4960 tree fndecl = BV_FN (fn);
4961
4962 if (DECL_THUNK_P (fndecl))
4963 /* A thunk. We should never be calling this entry directly
4964 from this vtable -- we'd use the entry for the non
4965 thunk base function. */
4966 DECL_VINDEX (fndecl) = NULL_TREE;
4967 else if (TREE_CODE (DECL_VINDEX (fndecl)) != INTEGER_CST)
4968 DECL_VINDEX (fndecl) = build_int_cst (NULL_TREE, vindex);
4969 }
4970 }
4971
4972 finish_struct_bits (t);
4973
4974 /* Complete the rtl for any static member objects of the type we're
4975 working on. */
4976 for (x = TYPE_FIELDS (t); x; x = TREE_CHAIN (x))
4977 if (TREE_CODE (x) == VAR_DECL && TREE_STATIC (x)
4978 && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t))
4979 DECL_MODE (x) = TYPE_MODE (t);
4980
4981 /* Done with FIELDS...now decide whether to sort these for
4982 faster lookups later.
4983
4984 We use a small number because most searches fail (succeeding
4985 ultimately as the search bores through the inheritance
4986 hierarchy), and we want this failure to occur quickly. */
4987
4988 n_fields = count_fields (TYPE_FIELDS (t));
4989 if (n_fields > 7)
4990 {
4991 struct sorted_fields_type *field_vec = GGC_NEWVAR
4992 (struct sorted_fields_type,
4993 sizeof (struct sorted_fields_type) + n_fields * sizeof (tree));
4994 field_vec->len = n_fields;
4995 add_fields_to_record_type (TYPE_FIELDS (t), field_vec, 0);
4996 qsort (field_vec->elts, n_fields, sizeof (tree),
4997 field_decl_cmp);
4998 if (! DECL_LANG_SPECIFIC (TYPE_MAIN_DECL (t)))
4999 retrofit_lang_decl (TYPE_MAIN_DECL (t));
5000 DECL_SORTED_FIELDS (TYPE_MAIN_DECL (t)) = field_vec;
5001 }
5002
5003 /* Make the rtl for any new vtables we have created, and unmark
5004 the base types we marked. */
5005 finish_vtbls (t);
5006
5007 /* Build the VTT for T. */
5008 build_vtt (t);
5009
5010 if (warn_nonvdtor && TYPE_POLYMORPHIC_P (t) && TYPE_HAS_DESTRUCTOR (t)
5011 && !DECL_VINDEX (CLASSTYPE_DESTRUCTORS (t)))
5012
5013 {
5014 tree dtor = CLASSTYPE_DESTRUCTORS (t);
5015
5016 /* Warn only if the dtor is non-private or the class has friends */
5017 if (!TREE_PRIVATE (dtor) ||
5018 (CLASSTYPE_FRIEND_CLASSES (t) ||
5019 DECL_FRIENDLIST (TYPE_MAIN_DECL (t))))
5020 warning ("%q#T has virtual functions but non-virtual destructor", t);
5021 }
5022
5023 complete_vars (t);
5024
5025 if (warn_overloaded_virtual)
5026 warn_hidden (t);
5027
5028 maybe_suppress_debug_info (t);
5029
5030 dump_class_hierarchy (t);
5031
5032 /* Finish debugging output for this type. */
5033 rest_of_type_compilation (t, ! LOCAL_CLASS_P (t));
5034 }
5035
5036 /* When T was built up, the member declarations were added in reverse
5037 order. Rearrange them to declaration order. */
5038
5039 void
5040 unreverse_member_declarations (tree t)
5041 {
5042 tree next;
5043 tree prev;
5044 tree x;
5045
5046 /* The following lists are all in reverse order. Put them in
5047 declaration order now. */
5048 TYPE_METHODS (t) = nreverse (TYPE_METHODS (t));
5049 CLASSTYPE_DECL_LIST (t) = nreverse (CLASSTYPE_DECL_LIST (t));
5050
5051 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5052 reverse order, so we can't just use nreverse. */
5053 prev = NULL_TREE;
5054 for (x = TYPE_FIELDS (t);
5055 x && TREE_CODE (x) != TYPE_DECL;
5056 x = next)
5057 {
5058 next = TREE_CHAIN (x);
5059 TREE_CHAIN (x) = prev;
5060 prev = x;
5061 }
5062 if (prev)
5063 {
5064 TREE_CHAIN (TYPE_FIELDS (t)) = x;
5065 if (prev)
5066 TYPE_FIELDS (t) = prev;
5067 }
5068 }
5069
5070 tree
5071 finish_struct (tree t, tree attributes)
5072 {
5073 location_t saved_loc = input_location;
5074
5075 /* Now that we've got all the field declarations, reverse everything
5076 as necessary. */
5077 unreverse_member_declarations (t);
5078
5079 cplus_decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
5080
5081 /* Nadger the current location so that diagnostics point to the start of
5082 the struct, not the end. */
5083 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (t));
5084
5085 if (processing_template_decl)
5086 {
5087 tree x;
5088
5089 finish_struct_methods (t);
5090 TYPE_SIZE (t) = bitsize_zero_node;
5091
5092 /* We need to emit an error message if this type was used as a parameter
5093 and it is an abstract type, even if it is a template. We construct
5094 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
5095 account and we call complete_vars with this type, which will check
5096 the PARM_DECLS. Note that while the type is being defined,
5097 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
5098 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
5099 CLASSTYPE_PURE_VIRTUALS (t) = NULL;
5100 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
5101 if (DECL_PURE_VIRTUAL_P (x))
5102 VEC_safe_push (tree, CLASSTYPE_PURE_VIRTUALS (t), x);
5103 complete_vars (t);
5104 }
5105 else
5106 finish_struct_1 (t);
5107
5108 input_location = saved_loc;
5109
5110 TYPE_BEING_DEFINED (t) = 0;
5111
5112 if (current_class_type)
5113 popclass ();
5114 else
5115 error ("trying to finish struct, but kicked out due to previous parse errors");
5116
5117 if (processing_template_decl && at_function_scope_p ())
5118 add_stmt (build_min (TAG_DEFN, t));
5119
5120 return t;
5121 }
5122 \f
5123 /* Return the dynamic type of INSTANCE, if known.
5124 Used to determine whether the virtual function table is needed
5125 or not.
5126
5127 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5128 of our knowledge of its type. *NONNULL should be initialized
5129 before this function is called. */
5130
5131 static tree
5132 fixed_type_or_null (tree instance, int* nonnull, int* cdtorp)
5133 {
5134 switch (TREE_CODE (instance))
5135 {
5136 case INDIRECT_REF:
5137 if (POINTER_TYPE_P (TREE_TYPE (instance)))
5138 return NULL_TREE;
5139 else
5140 return fixed_type_or_null (TREE_OPERAND (instance, 0),
5141 nonnull, cdtorp);
5142
5143 case CALL_EXPR:
5144 /* This is a call to a constructor, hence it's never zero. */
5145 if (TREE_HAS_CONSTRUCTOR (instance))
5146 {
5147 if (nonnull)
5148 *nonnull = 1;
5149 return TREE_TYPE (instance);
5150 }
5151 return NULL_TREE;
5152
5153 case SAVE_EXPR:
5154 /* This is a call to a constructor, hence it's never zero. */
5155 if (TREE_HAS_CONSTRUCTOR (instance))
5156 {
5157 if (nonnull)
5158 *nonnull = 1;
5159 return TREE_TYPE (instance);
5160 }
5161 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5162
5163 case PLUS_EXPR:
5164 case MINUS_EXPR:
5165 if (TREE_CODE (TREE_OPERAND (instance, 0)) == ADDR_EXPR)
5166 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5167 if (TREE_CODE (TREE_OPERAND (instance, 1)) == INTEGER_CST)
5168 /* Propagate nonnull. */
5169 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5170 return NULL_TREE;
5171
5172 case NOP_EXPR:
5173 case CONVERT_EXPR:
5174 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5175
5176 case ADDR_EXPR:
5177 instance = TREE_OPERAND (instance, 0);
5178 if (nonnull)
5179 {
5180 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
5181 with a real object -- given &p->f, p can still be null. */
5182 tree t = get_base_address (instance);
5183 /* ??? Probably should check DECL_WEAK here. */
5184 if (t && DECL_P (t))
5185 *nonnull = 1;
5186 }
5187 return fixed_type_or_null (instance, nonnull, cdtorp);
5188
5189 case COMPONENT_REF:
5190 /* If this component is really a base class reference, then the field
5191 itself isn't definitive. */
5192 if (DECL_FIELD_IS_BASE (TREE_OPERAND (instance, 1)))
5193 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5194 return fixed_type_or_null (TREE_OPERAND (instance, 1), nonnull, cdtorp);
5195
5196 case VAR_DECL:
5197 case FIELD_DECL:
5198 if (TREE_CODE (TREE_TYPE (instance)) == ARRAY_TYPE
5199 && IS_AGGR_TYPE (TREE_TYPE (TREE_TYPE (instance))))
5200 {
5201 if (nonnull)
5202 *nonnull = 1;
5203 return TREE_TYPE (TREE_TYPE (instance));
5204 }
5205 /* fall through... */
5206 case TARGET_EXPR:
5207 case PARM_DECL:
5208 case RESULT_DECL:
5209 if (IS_AGGR_TYPE (TREE_TYPE (instance)))
5210 {
5211 if (nonnull)
5212 *nonnull = 1;
5213 return TREE_TYPE (instance);
5214 }
5215 else if (instance == current_class_ptr)
5216 {
5217 if (nonnull)
5218 *nonnull = 1;
5219
5220 /* if we're in a ctor or dtor, we know our type. */
5221 if (DECL_LANG_SPECIFIC (current_function_decl)
5222 && (DECL_CONSTRUCTOR_P (current_function_decl)
5223 || DECL_DESTRUCTOR_P (current_function_decl)))
5224 {
5225 if (cdtorp)
5226 *cdtorp = 1;
5227 return TREE_TYPE (TREE_TYPE (instance));
5228 }
5229 }
5230 else if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE)
5231 {
5232 /* Reference variables should be references to objects. */
5233 if (nonnull)
5234 *nonnull = 1;
5235
5236 /* DECL_VAR_MARKED_P is used to prevent recursion; a
5237 variable's initializer may refer to the variable
5238 itself. */
5239 if (TREE_CODE (instance) == VAR_DECL
5240 && DECL_INITIAL (instance)
5241 && !DECL_VAR_MARKED_P (instance))
5242 {
5243 tree type;
5244 DECL_VAR_MARKED_P (instance) = 1;
5245 type = fixed_type_or_null (DECL_INITIAL (instance),
5246 nonnull, cdtorp);
5247 DECL_VAR_MARKED_P (instance) = 0;
5248 return type;
5249 }
5250 }
5251 return NULL_TREE;
5252
5253 default:
5254 return NULL_TREE;
5255 }
5256 }
5257
5258 /* Return nonzero if the dynamic type of INSTANCE is known, and
5259 equivalent to the static type. We also handle the case where
5260 INSTANCE is really a pointer. Return negative if this is a
5261 ctor/dtor. There the dynamic type is known, but this might not be
5262 the most derived base of the original object, and hence virtual
5263 bases may not be layed out according to this type.
5264
5265 Used to determine whether the virtual function table is needed
5266 or not.
5267
5268 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5269 of our knowledge of its type. *NONNULL should be initialized
5270 before this function is called. */
5271
5272 int
5273 resolves_to_fixed_type_p (tree instance, int* nonnull)
5274 {
5275 tree t = TREE_TYPE (instance);
5276 int cdtorp = 0;
5277
5278 tree fixed = fixed_type_or_null (instance, nonnull, &cdtorp);
5279 if (fixed == NULL_TREE)
5280 return 0;
5281 if (POINTER_TYPE_P (t))
5282 t = TREE_TYPE (t);
5283 if (!same_type_ignoring_top_level_qualifiers_p (t, fixed))
5284 return 0;
5285 return cdtorp ? -1 : 1;
5286 }
5287
5288 \f
5289 void
5290 init_class_processing (void)
5291 {
5292 current_class_depth = 0;
5293 current_class_stack_size = 10;
5294 current_class_stack
5295 = xmalloc (current_class_stack_size * sizeof (struct class_stack_node));
5296 VARRAY_TREE_INIT (local_classes, 8, "local_classes");
5297
5298 ridpointers[(int) RID_PUBLIC] = access_public_node;
5299 ridpointers[(int) RID_PRIVATE] = access_private_node;
5300 ridpointers[(int) RID_PROTECTED] = access_protected_node;
5301 }
5302
5303 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
5304
5305 static void
5306 restore_class_cache (void)
5307 {
5308 tree type;
5309
5310 /* We are re-entering the same class we just left, so we don't
5311 have to search the whole inheritance matrix to find all the
5312 decls to bind again. Instead, we install the cached
5313 class_shadowed list and walk through it binding names. */
5314 push_binding_level (previous_class_level);
5315 class_binding_level = previous_class_level;
5316 /* Restore IDENTIFIER_TYPE_VALUE. */
5317 for (type = class_binding_level->type_shadowed;
5318 type;
5319 type = TREE_CHAIN (type))
5320 SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (type), TREE_TYPE (type));
5321 }
5322
5323 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
5324 appropriate for TYPE.
5325
5326 So that we may avoid calls to lookup_name, we cache the _TYPE
5327 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5328
5329 For multiple inheritance, we perform a two-pass depth-first search
5330 of the type lattice. */
5331
5332 void
5333 pushclass (tree type)
5334 {
5335 type = TYPE_MAIN_VARIANT (type);
5336
5337 /* Make sure there is enough room for the new entry on the stack. */
5338 if (current_class_depth + 1 >= current_class_stack_size)
5339 {
5340 current_class_stack_size *= 2;
5341 current_class_stack
5342 = xrealloc (current_class_stack,
5343 current_class_stack_size
5344 * sizeof (struct class_stack_node));
5345 }
5346
5347 /* Insert a new entry on the class stack. */
5348 current_class_stack[current_class_depth].name = current_class_name;
5349 current_class_stack[current_class_depth].type = current_class_type;
5350 current_class_stack[current_class_depth].access = current_access_specifier;
5351 current_class_stack[current_class_depth].names_used = 0;
5352 current_class_depth++;
5353
5354 /* Now set up the new type. */
5355 current_class_name = TYPE_NAME (type);
5356 if (TREE_CODE (current_class_name) == TYPE_DECL)
5357 current_class_name = DECL_NAME (current_class_name);
5358 current_class_type = type;
5359
5360 /* By default, things in classes are private, while things in
5361 structures or unions are public. */
5362 current_access_specifier = (CLASSTYPE_DECLARED_CLASS (type)
5363 ? access_private_node
5364 : access_public_node);
5365
5366 if (previous_class_level
5367 && type != previous_class_level->this_entity
5368 && current_class_depth == 1)
5369 {
5370 /* Forcibly remove any old class remnants. */
5371 invalidate_class_lookup_cache ();
5372 }
5373
5374 if (!previous_class_level
5375 || type != previous_class_level->this_entity
5376 || current_class_depth > 1)
5377 pushlevel_class ();
5378 else
5379 restore_class_cache ();
5380 }
5381
5382 /* When we exit a toplevel class scope, we save its binding level so
5383 that we can restore it quickly. Here, we've entered some other
5384 class, so we must invalidate our cache. */
5385
5386 void
5387 invalidate_class_lookup_cache (void)
5388 {
5389 previous_class_level = NULL;
5390 }
5391
5392 /* Get out of the current class scope. If we were in a class scope
5393 previously, that is the one popped to. */
5394
5395 void
5396 popclass (void)
5397 {
5398 poplevel_class ();
5399
5400 current_class_depth--;
5401 current_class_name = current_class_stack[current_class_depth].name;
5402 current_class_type = current_class_stack[current_class_depth].type;
5403 current_access_specifier = current_class_stack[current_class_depth].access;
5404 if (current_class_stack[current_class_depth].names_used)
5405 splay_tree_delete (current_class_stack[current_class_depth].names_used);
5406 }
5407
5408 /* Returns 1 if current_class_type is either T or a nested type of T.
5409 We start looking from 1 because entry 0 is from global scope, and has
5410 no type. */
5411
5412 int
5413 currently_open_class (tree t)
5414 {
5415 int i;
5416 if (current_class_type && same_type_p (t, current_class_type))
5417 return 1;
5418 for (i = 1; i < current_class_depth; ++i)
5419 if (current_class_stack[i].type
5420 && same_type_p (current_class_stack [i].type, t))
5421 return 1;
5422 return 0;
5423 }
5424
5425 /* If either current_class_type or one of its enclosing classes are derived
5426 from T, return the appropriate type. Used to determine how we found
5427 something via unqualified lookup. */
5428
5429 tree
5430 currently_open_derived_class (tree t)
5431 {
5432 int i;
5433
5434 /* The bases of a dependent type are unknown. */
5435 if (dependent_type_p (t))
5436 return NULL_TREE;
5437
5438 if (!current_class_type)
5439 return NULL_TREE;
5440
5441 if (DERIVED_FROM_P (t, current_class_type))
5442 return current_class_type;
5443
5444 for (i = current_class_depth - 1; i > 0; --i)
5445 if (DERIVED_FROM_P (t, current_class_stack[i].type))
5446 return current_class_stack[i].type;
5447
5448 return NULL_TREE;
5449 }
5450
5451 /* When entering a class scope, all enclosing class scopes' names with
5452 static meaning (static variables, static functions, types and
5453 enumerators) have to be visible. This recursive function calls
5454 pushclass for all enclosing class contexts until global or a local
5455 scope is reached. TYPE is the enclosed class. */
5456
5457 void
5458 push_nested_class (tree type)
5459 {
5460 tree context;
5461
5462 /* A namespace might be passed in error cases, like A::B:C. */
5463 if (type == NULL_TREE
5464 || type == error_mark_node
5465 || TREE_CODE (type) == NAMESPACE_DECL
5466 || ! IS_AGGR_TYPE (type)
5467 || TREE_CODE (type) == TEMPLATE_TYPE_PARM
5468 || TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
5469 return;
5470
5471 context = DECL_CONTEXT (TYPE_MAIN_DECL (type));
5472
5473 if (context && CLASS_TYPE_P (context))
5474 push_nested_class (context);
5475 pushclass (type);
5476 }
5477
5478 /* Undoes a push_nested_class call. */
5479
5480 void
5481 pop_nested_class (void)
5482 {
5483 tree context = DECL_CONTEXT (TYPE_MAIN_DECL (current_class_type));
5484
5485 popclass ();
5486 if (context && CLASS_TYPE_P (context))
5487 pop_nested_class ();
5488 }
5489
5490 /* Returns the number of extern "LANG" blocks we are nested within. */
5491
5492 int
5493 current_lang_depth (void)
5494 {
5495 return VARRAY_ACTIVE_SIZE (current_lang_base);
5496 }
5497
5498 /* Set global variables CURRENT_LANG_NAME to appropriate value
5499 so that behavior of name-mangling machinery is correct. */
5500
5501 void
5502 push_lang_context (tree name)
5503 {
5504 VARRAY_PUSH_TREE (current_lang_base, current_lang_name);
5505
5506 if (name == lang_name_cplusplus)
5507 {
5508 current_lang_name = name;
5509 }
5510 else if (name == lang_name_java)
5511 {
5512 current_lang_name = name;
5513 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5514 (See record_builtin_java_type in decl.c.) However, that causes
5515 incorrect debug entries if these types are actually used.
5516 So we re-enable debug output after extern "Java". */
5517 DECL_IGNORED_P (TYPE_NAME (java_byte_type_node)) = 0;
5518 DECL_IGNORED_P (TYPE_NAME (java_short_type_node)) = 0;
5519 DECL_IGNORED_P (TYPE_NAME (java_int_type_node)) = 0;
5520 DECL_IGNORED_P (TYPE_NAME (java_long_type_node)) = 0;
5521 DECL_IGNORED_P (TYPE_NAME (java_float_type_node)) = 0;
5522 DECL_IGNORED_P (TYPE_NAME (java_double_type_node)) = 0;
5523 DECL_IGNORED_P (TYPE_NAME (java_char_type_node)) = 0;
5524 DECL_IGNORED_P (TYPE_NAME (java_boolean_type_node)) = 0;
5525 }
5526 else if (name == lang_name_c)
5527 {
5528 current_lang_name = name;
5529 }
5530 else
5531 error ("language string %<\"%E\"%> not recognized", name);
5532 }
5533
5534 /* Get out of the current language scope. */
5535
5536 void
5537 pop_lang_context (void)
5538 {
5539 current_lang_name = VARRAY_TOP_TREE (current_lang_base);
5540 VARRAY_POP (current_lang_base);
5541 }
5542 \f
5543 /* Type instantiation routines. */
5544
5545 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
5546 matches the TARGET_TYPE. If there is no satisfactory match, return
5547 error_mark_node, and issue a error & warning messages under control
5548 of FLAGS. Permit pointers to member function if FLAGS permits. If
5549 TEMPLATE_ONLY, the name of the overloaded function was a
5550 template-id, and EXPLICIT_TARGS are the explicitly provided
5551 template arguments. */
5552
5553 static tree
5554 resolve_address_of_overloaded_function (tree target_type,
5555 tree overload,
5556 tsubst_flags_t flags,
5557 bool template_only,
5558 tree explicit_targs)
5559 {
5560 /* Here's what the standard says:
5561
5562 [over.over]
5563
5564 If the name is a function template, template argument deduction
5565 is done, and if the argument deduction succeeds, the deduced
5566 arguments are used to generate a single template function, which
5567 is added to the set of overloaded functions considered.
5568
5569 Non-member functions and static member functions match targets of
5570 type "pointer-to-function" or "reference-to-function." Nonstatic
5571 member functions match targets of type "pointer-to-member
5572 function;" the function type of the pointer to member is used to
5573 select the member function from the set of overloaded member
5574 functions. If a nonstatic member function is selected, the
5575 reference to the overloaded function name is required to have the
5576 form of a pointer to member as described in 5.3.1.
5577
5578 If more than one function is selected, any template functions in
5579 the set are eliminated if the set also contains a non-template
5580 function, and any given template function is eliminated if the
5581 set contains a second template function that is more specialized
5582 than the first according to the partial ordering rules 14.5.5.2.
5583 After such eliminations, if any, there shall remain exactly one
5584 selected function. */
5585
5586 int is_ptrmem = 0;
5587 int is_reference = 0;
5588 /* We store the matches in a TREE_LIST rooted here. The functions
5589 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
5590 interoperability with most_specialized_instantiation. */
5591 tree matches = NULL_TREE;
5592 tree fn;
5593
5594 /* By the time we get here, we should be seeing only real
5595 pointer-to-member types, not the internal POINTER_TYPE to
5596 METHOD_TYPE representation. */
5597 gcc_assert (TREE_CODE (target_type) != POINTER_TYPE
5598 || TREE_CODE (TREE_TYPE (target_type)) != METHOD_TYPE);
5599
5600 gcc_assert (is_overloaded_fn (overload));
5601
5602 /* Check that the TARGET_TYPE is reasonable. */
5603 if (TYPE_PTRFN_P (target_type))
5604 /* This is OK. */;
5605 else if (TYPE_PTRMEMFUNC_P (target_type))
5606 /* This is OK, too. */
5607 is_ptrmem = 1;
5608 else if (TREE_CODE (target_type) == FUNCTION_TYPE)
5609 {
5610 /* This is OK, too. This comes from a conversion to reference
5611 type. */
5612 target_type = build_reference_type (target_type);
5613 is_reference = 1;
5614 }
5615 else
5616 {
5617 if (flags & tf_error)
5618 error ("cannot resolve overloaded function %qD based on"
5619 " conversion to type %qT",
5620 DECL_NAME (OVL_FUNCTION (overload)), target_type);
5621 return error_mark_node;
5622 }
5623
5624 /* If we can find a non-template function that matches, we can just
5625 use it. There's no point in generating template instantiations
5626 if we're just going to throw them out anyhow. But, of course, we
5627 can only do this when we don't *need* a template function. */
5628 if (!template_only)
5629 {
5630 tree fns;
5631
5632 for (fns = overload; fns; fns = OVL_NEXT (fns))
5633 {
5634 tree fn = OVL_CURRENT (fns);
5635 tree fntype;
5636
5637 if (TREE_CODE (fn) == TEMPLATE_DECL)
5638 /* We're not looking for templates just yet. */
5639 continue;
5640
5641 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
5642 != is_ptrmem)
5643 /* We're looking for a non-static member, and this isn't
5644 one, or vice versa. */
5645 continue;
5646
5647 /* Ignore anticipated decls of undeclared builtins. */
5648 if (DECL_ANTICIPATED (fn))
5649 continue;
5650
5651 /* See if there's a match. */
5652 fntype = TREE_TYPE (fn);
5653 if (is_ptrmem)
5654 fntype = build_ptrmemfunc_type (build_pointer_type (fntype));
5655 else if (!is_reference)
5656 fntype = build_pointer_type (fntype);
5657
5658 if (can_convert_arg (target_type, fntype, fn))
5659 matches = tree_cons (fn, NULL_TREE, matches);
5660 }
5661 }
5662
5663 /* Now, if we've already got a match (or matches), there's no need
5664 to proceed to the template functions. But, if we don't have a
5665 match we need to look at them, too. */
5666 if (!matches)
5667 {
5668 tree target_fn_type;
5669 tree target_arg_types;
5670 tree target_ret_type;
5671 tree fns;
5672
5673 if (is_ptrmem)
5674 target_fn_type
5675 = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (target_type));
5676 else
5677 target_fn_type = TREE_TYPE (target_type);
5678 target_arg_types = TYPE_ARG_TYPES (target_fn_type);
5679 target_ret_type = TREE_TYPE (target_fn_type);
5680
5681 /* Never do unification on the 'this' parameter. */
5682 if (TREE_CODE (target_fn_type) == METHOD_TYPE)
5683 target_arg_types = TREE_CHAIN (target_arg_types);
5684
5685 for (fns = overload; fns; fns = OVL_NEXT (fns))
5686 {
5687 tree fn = OVL_CURRENT (fns);
5688 tree instantiation;
5689 tree instantiation_type;
5690 tree targs;
5691
5692 if (TREE_CODE (fn) != TEMPLATE_DECL)
5693 /* We're only looking for templates. */
5694 continue;
5695
5696 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
5697 != is_ptrmem)
5698 /* We're not looking for a non-static member, and this is
5699 one, or vice versa. */
5700 continue;
5701
5702 /* Try to do argument deduction. */
5703 targs = make_tree_vec (DECL_NTPARMS (fn));
5704 if (fn_type_unification (fn, explicit_targs, targs,
5705 target_arg_types, target_ret_type,
5706 DEDUCE_EXACT, -1) != 0)
5707 /* Argument deduction failed. */
5708 continue;
5709
5710 /* Instantiate the template. */
5711 instantiation = instantiate_template (fn, targs, flags);
5712 if (instantiation == error_mark_node)
5713 /* Instantiation failed. */
5714 continue;
5715
5716 /* See if there's a match. */
5717 instantiation_type = TREE_TYPE (instantiation);
5718 if (is_ptrmem)
5719 instantiation_type =
5720 build_ptrmemfunc_type (build_pointer_type (instantiation_type));
5721 else if (!is_reference)
5722 instantiation_type = build_pointer_type (instantiation_type);
5723 if (can_convert_arg (target_type, instantiation_type, instantiation))
5724 matches = tree_cons (instantiation, fn, matches);
5725 }
5726
5727 /* Now, remove all but the most specialized of the matches. */
5728 if (matches)
5729 {
5730 tree match = most_specialized_instantiation (matches);
5731
5732 if (match != error_mark_node)
5733 matches = tree_cons (match, NULL_TREE, NULL_TREE);
5734 }
5735 }
5736
5737 /* Now we should have exactly one function in MATCHES. */
5738 if (matches == NULL_TREE)
5739 {
5740 /* There were *no* matches. */
5741 if (flags & tf_error)
5742 {
5743 error ("no matches converting function %qD to type %q#T",
5744 DECL_NAME (OVL_FUNCTION (overload)),
5745 target_type);
5746
5747 /* print_candidates expects a chain with the functions in
5748 TREE_VALUE slots, so we cons one up here (we're losing anyway,
5749 so why be clever?). */
5750 for (; overload; overload = OVL_NEXT (overload))
5751 matches = tree_cons (NULL_TREE, OVL_CURRENT (overload),
5752 matches);
5753
5754 print_candidates (matches);
5755 }
5756 return error_mark_node;
5757 }
5758 else if (TREE_CHAIN (matches))
5759 {
5760 /* There were too many matches. */
5761
5762 if (flags & tf_error)
5763 {
5764 tree match;
5765
5766 error ("converting overloaded function %qD to type %q#T is ambiguous",
5767 DECL_NAME (OVL_FUNCTION (overload)),
5768 target_type);
5769
5770 /* Since print_candidates expects the functions in the
5771 TREE_VALUE slot, we flip them here. */
5772 for (match = matches; match; match = TREE_CHAIN (match))
5773 TREE_VALUE (match) = TREE_PURPOSE (match);
5774
5775 print_candidates (matches);
5776 }
5777
5778 return error_mark_node;
5779 }
5780
5781 /* Good, exactly one match. Now, convert it to the correct type. */
5782 fn = TREE_PURPOSE (matches);
5783
5784 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
5785 && !(flags & tf_ptrmem_ok) && !flag_ms_extensions)
5786 {
5787 static int explained;
5788
5789 if (!(flags & tf_error))
5790 return error_mark_node;
5791
5792 pedwarn ("assuming pointer to member %qD", fn);
5793 if (!explained)
5794 {
5795 pedwarn ("(a pointer to member can only be formed with %<&%E%>)", fn);
5796 explained = 1;
5797 }
5798 }
5799
5800 /* If we're doing overload resolution purely for the purpose of
5801 determining conversion sequences, we should not consider the
5802 function used. If this conversion sequence is selected, the
5803 function will be marked as used at this point. */
5804 if (!(flags & tf_conv))
5805 mark_used (fn);
5806
5807 if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type))
5808 return build_unary_op (ADDR_EXPR, fn, 0);
5809 else
5810 {
5811 /* The target must be a REFERENCE_TYPE. Above, build_unary_op
5812 will mark the function as addressed, but here we must do it
5813 explicitly. */
5814 cxx_mark_addressable (fn);
5815
5816 return fn;
5817 }
5818 }
5819
5820 /* This function will instantiate the type of the expression given in
5821 RHS to match the type of LHSTYPE. If errors exist, then return
5822 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
5823 we complain on errors. If we are not complaining, never modify rhs,
5824 as overload resolution wants to try many possible instantiations, in
5825 the hope that at least one will work.
5826
5827 For non-recursive calls, LHSTYPE should be a function, pointer to
5828 function, or a pointer to member function. */
5829
5830 tree
5831 instantiate_type (tree lhstype, tree rhs, tsubst_flags_t flags)
5832 {
5833 tsubst_flags_t flags_in = flags;
5834
5835 flags &= ~tf_ptrmem_ok;
5836
5837 if (TREE_CODE (lhstype) == UNKNOWN_TYPE)
5838 {
5839 if (flags & tf_error)
5840 error ("not enough type information");
5841 return error_mark_node;
5842 }
5843
5844 if (TREE_TYPE (rhs) != NULL_TREE && ! (type_unknown_p (rhs)))
5845 {
5846 if (same_type_p (lhstype, TREE_TYPE (rhs)))
5847 return rhs;
5848 if (flag_ms_extensions
5849 && TYPE_PTRMEMFUNC_P (lhstype)
5850 && !TYPE_PTRMEMFUNC_P (TREE_TYPE (rhs)))
5851 /* Microsoft allows `A::f' to be resolved to a
5852 pointer-to-member. */
5853 ;
5854 else
5855 {
5856 if (flags & tf_error)
5857 error ("argument of type %qT does not match %qT",
5858 TREE_TYPE (rhs), lhstype);
5859 return error_mark_node;
5860 }
5861 }
5862
5863 if (TREE_CODE (rhs) == BASELINK)
5864 rhs = BASELINK_FUNCTIONS (rhs);
5865
5866 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
5867 deduce any type information. */
5868 if (TREE_CODE (rhs) == NON_DEPENDENT_EXPR)
5869 {
5870 if (flags & tf_error)
5871 error ("not enough type information");
5872 return error_mark_node;
5873 }
5874
5875 /* We don't overwrite rhs if it is an overloaded function.
5876 Copying it would destroy the tree link. */
5877 if (TREE_CODE (rhs) != OVERLOAD)
5878 rhs = copy_node (rhs);
5879
5880 /* This should really only be used when attempting to distinguish
5881 what sort of a pointer to function we have. For now, any
5882 arithmetic operation which is not supported on pointers
5883 is rejected as an error. */
5884
5885 switch (TREE_CODE (rhs))
5886 {
5887 case TYPE_EXPR:
5888 case CONVERT_EXPR:
5889 case SAVE_EXPR:
5890 case CONSTRUCTOR:
5891 gcc_unreachable ();
5892
5893 case INDIRECT_REF:
5894 case ARRAY_REF:
5895 {
5896 tree new_rhs;
5897
5898 new_rhs = instantiate_type (build_pointer_type (lhstype),
5899 TREE_OPERAND (rhs, 0), flags);
5900 if (new_rhs == error_mark_node)
5901 return error_mark_node;
5902
5903 TREE_TYPE (rhs) = lhstype;
5904 TREE_OPERAND (rhs, 0) = new_rhs;
5905 return rhs;
5906 }
5907
5908 case NOP_EXPR:
5909 rhs = copy_node (TREE_OPERAND (rhs, 0));
5910 TREE_TYPE (rhs) = unknown_type_node;
5911 return instantiate_type (lhstype, rhs, flags);
5912
5913 case COMPONENT_REF:
5914 {
5915 tree member = TREE_OPERAND (rhs, 1);
5916
5917 member = instantiate_type (lhstype, member, flags);
5918 if (member != error_mark_node
5919 && TREE_SIDE_EFFECTS (TREE_OPERAND (rhs, 0)))
5920 /* Do not lose object's side effects. */
5921 return build2 (COMPOUND_EXPR, TREE_TYPE (member),
5922 TREE_OPERAND (rhs, 0), member);
5923 return member;
5924 }
5925
5926 case OFFSET_REF:
5927 rhs = TREE_OPERAND (rhs, 1);
5928 if (BASELINK_P (rhs))
5929 return instantiate_type (lhstype, BASELINK_FUNCTIONS (rhs), flags_in);
5930
5931 /* This can happen if we are forming a pointer-to-member for a
5932 member template. */
5933 gcc_assert (TREE_CODE (rhs) == TEMPLATE_ID_EXPR);
5934
5935 /* Fall through. */
5936
5937 case TEMPLATE_ID_EXPR:
5938 {
5939 tree fns = TREE_OPERAND (rhs, 0);
5940 tree args = TREE_OPERAND (rhs, 1);
5941
5942 return
5943 resolve_address_of_overloaded_function (lhstype, fns, flags_in,
5944 /*template_only=*/true,
5945 args);
5946 }
5947
5948 case OVERLOAD:
5949 case FUNCTION_DECL:
5950 return
5951 resolve_address_of_overloaded_function (lhstype, rhs, flags_in,
5952 /*template_only=*/false,
5953 /*explicit_targs=*/NULL_TREE);
5954
5955 case CALL_EXPR:
5956 /* This is too hard for now. */
5957 gcc_unreachable ();
5958
5959 case PLUS_EXPR:
5960 case MINUS_EXPR:
5961 case COMPOUND_EXPR:
5962 TREE_OPERAND (rhs, 0)
5963 = instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
5964 if (TREE_OPERAND (rhs, 0) == error_mark_node)
5965 return error_mark_node;
5966 TREE_OPERAND (rhs, 1)
5967 = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
5968 if (TREE_OPERAND (rhs, 1) == error_mark_node)
5969 return error_mark_node;
5970
5971 TREE_TYPE (rhs) = lhstype;
5972 return rhs;
5973
5974 case MULT_EXPR:
5975 case TRUNC_DIV_EXPR:
5976 case FLOOR_DIV_EXPR:
5977 case CEIL_DIV_EXPR:
5978 case ROUND_DIV_EXPR:
5979 case RDIV_EXPR:
5980 case TRUNC_MOD_EXPR:
5981 case FLOOR_MOD_EXPR:
5982 case CEIL_MOD_EXPR:
5983 case ROUND_MOD_EXPR:
5984 case FIX_ROUND_EXPR:
5985 case FIX_FLOOR_EXPR:
5986 case FIX_CEIL_EXPR:
5987 case FIX_TRUNC_EXPR:
5988 case FLOAT_EXPR:
5989 case NEGATE_EXPR:
5990 case ABS_EXPR:
5991 case MAX_EXPR:
5992 case MIN_EXPR:
5993
5994 case BIT_AND_EXPR:
5995 case BIT_IOR_EXPR:
5996 case BIT_XOR_EXPR:
5997 case LSHIFT_EXPR:
5998 case RSHIFT_EXPR:
5999 case LROTATE_EXPR:
6000 case RROTATE_EXPR:
6001
6002 case PREINCREMENT_EXPR:
6003 case PREDECREMENT_EXPR:
6004 case POSTINCREMENT_EXPR:
6005 case POSTDECREMENT_EXPR:
6006 if (flags & tf_error)
6007 error ("invalid operation on uninstantiated type");
6008 return error_mark_node;
6009
6010 case TRUTH_AND_EXPR:
6011 case TRUTH_OR_EXPR:
6012 case TRUTH_XOR_EXPR:
6013 case LT_EXPR:
6014 case LE_EXPR:
6015 case GT_EXPR:
6016 case GE_EXPR:
6017 case EQ_EXPR:
6018 case NE_EXPR:
6019 case TRUTH_ANDIF_EXPR:
6020 case TRUTH_ORIF_EXPR:
6021 case TRUTH_NOT_EXPR:
6022 if (flags & tf_error)
6023 error ("not enough type information");
6024 return error_mark_node;
6025
6026 case COND_EXPR:
6027 if (type_unknown_p (TREE_OPERAND (rhs, 0)))
6028 {
6029 if (flags & tf_error)
6030 error ("not enough type information");
6031 return error_mark_node;
6032 }
6033 TREE_OPERAND (rhs, 1)
6034 = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
6035 if (TREE_OPERAND (rhs, 1) == error_mark_node)
6036 return error_mark_node;
6037 TREE_OPERAND (rhs, 2)
6038 = instantiate_type (lhstype, TREE_OPERAND (rhs, 2), flags);
6039 if (TREE_OPERAND (rhs, 2) == error_mark_node)
6040 return error_mark_node;
6041
6042 TREE_TYPE (rhs) = lhstype;
6043 return rhs;
6044
6045 case MODIFY_EXPR:
6046 TREE_OPERAND (rhs, 1)
6047 = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
6048 if (TREE_OPERAND (rhs, 1) == error_mark_node)
6049 return error_mark_node;
6050
6051 TREE_TYPE (rhs) = lhstype;
6052 return rhs;
6053
6054 case ADDR_EXPR:
6055 {
6056 if (PTRMEM_OK_P (rhs))
6057 flags |= tf_ptrmem_ok;
6058
6059 return instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
6060 }
6061
6062 case ERROR_MARK:
6063 return error_mark_node;
6064
6065 default:
6066 gcc_unreachable ();
6067 }
6068 return error_mark_node;
6069 }
6070 \f
6071 /* Return the name of the virtual function pointer field
6072 (as an IDENTIFIER_NODE) for the given TYPE. Note that
6073 this may have to look back through base types to find the
6074 ultimate field name. (For single inheritance, these could
6075 all be the same name. Who knows for multiple inheritance). */
6076
6077 static tree
6078 get_vfield_name (tree type)
6079 {
6080 tree binfo, base_binfo;
6081 char *buf;
6082
6083 for (binfo = TYPE_BINFO (type);
6084 BINFO_N_BASE_BINFOS (binfo);
6085 binfo = base_binfo)
6086 {
6087 base_binfo = BINFO_BASE_BINFO (binfo, 0);
6088
6089 if (BINFO_VIRTUAL_P (base_binfo)
6090 || !TYPE_CONTAINS_VPTR_P (BINFO_TYPE (base_binfo)))
6091 break;
6092 }
6093
6094 type = BINFO_TYPE (binfo);
6095 buf = alloca (sizeof (VFIELD_NAME_FORMAT) + TYPE_NAME_LENGTH (type) + 2);
6096 sprintf (buf, VFIELD_NAME_FORMAT,
6097 IDENTIFIER_POINTER (constructor_name (type)));
6098 return get_identifier (buf);
6099 }
6100
6101 void
6102 print_class_statistics (void)
6103 {
6104 #ifdef GATHER_STATISTICS
6105 fprintf (stderr, "convert_harshness = %d\n", n_convert_harshness);
6106 fprintf (stderr, "compute_conversion_costs = %d\n", n_compute_conversion_costs);
6107 if (n_vtables)
6108 {
6109 fprintf (stderr, "vtables = %d; vtable searches = %d\n",
6110 n_vtables, n_vtable_searches);
6111 fprintf (stderr, "vtable entries = %d; vtable elems = %d\n",
6112 n_vtable_entries, n_vtable_elems);
6113 }
6114 #endif
6115 }
6116
6117 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6118 according to [class]:
6119 The class-name is also inserted
6120 into the scope of the class itself. For purposes of access checking,
6121 the inserted class name is treated as if it were a public member name. */
6122
6123 void
6124 build_self_reference (void)
6125 {
6126 tree name = constructor_name (current_class_type);
6127 tree value = build_lang_decl (TYPE_DECL, name, current_class_type);
6128 tree saved_cas;
6129
6130 DECL_NONLOCAL (value) = 1;
6131 DECL_CONTEXT (value) = current_class_type;
6132 DECL_ARTIFICIAL (value) = 1;
6133 SET_DECL_SELF_REFERENCE_P (value);
6134
6135 if (processing_template_decl)
6136 value = push_template_decl (value);
6137
6138 saved_cas = current_access_specifier;
6139 current_access_specifier = access_public_node;
6140 finish_member_declaration (value);
6141 current_access_specifier = saved_cas;
6142 }
6143
6144 /* Returns 1 if TYPE contains only padding bytes. */
6145
6146 int
6147 is_empty_class (tree type)
6148 {
6149 if (type == error_mark_node)
6150 return 0;
6151
6152 if (! IS_AGGR_TYPE (type))
6153 return 0;
6154
6155 /* In G++ 3.2, whether or not a class was empty was determined by
6156 looking at its size. */
6157 if (abi_version_at_least (2))
6158 return CLASSTYPE_EMPTY_P (type);
6159 else
6160 return integer_zerop (CLASSTYPE_SIZE (type));
6161 }
6162
6163 /* Returns true if TYPE contains an empty class. */
6164
6165 static bool
6166 contains_empty_class_p (tree type)
6167 {
6168 if (is_empty_class (type))
6169 return true;
6170 if (CLASS_TYPE_P (type))
6171 {
6172 tree field;
6173 tree binfo;
6174 tree base_binfo;
6175 int i;
6176
6177 for (binfo = TYPE_BINFO (type), i = 0;
6178 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
6179 if (contains_empty_class_p (BINFO_TYPE (base_binfo)))
6180 return true;
6181 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
6182 if (TREE_CODE (field) == FIELD_DECL
6183 && !DECL_ARTIFICIAL (field)
6184 && is_empty_class (TREE_TYPE (field)))
6185 return true;
6186 }
6187 else if (TREE_CODE (type) == ARRAY_TYPE)
6188 return contains_empty_class_p (TREE_TYPE (type));
6189 return false;
6190 }
6191
6192 /* Note that NAME was looked up while the current class was being
6193 defined and that the result of that lookup was DECL. */
6194
6195 void
6196 maybe_note_name_used_in_class (tree name, tree decl)
6197 {
6198 splay_tree names_used;
6199
6200 /* If we're not defining a class, there's nothing to do. */
6201 if (!(innermost_scope_kind() == sk_class
6202 && TYPE_BEING_DEFINED (current_class_type)))
6203 return;
6204
6205 /* If there's already a binding for this NAME, then we don't have
6206 anything to worry about. */
6207 if (lookup_member (current_class_type, name,
6208 /*protect=*/0, /*want_type=*/false))
6209 return;
6210
6211 if (!current_class_stack[current_class_depth - 1].names_used)
6212 current_class_stack[current_class_depth - 1].names_used
6213 = splay_tree_new (splay_tree_compare_pointers, 0, 0);
6214 names_used = current_class_stack[current_class_depth - 1].names_used;
6215
6216 splay_tree_insert (names_used,
6217 (splay_tree_key) name,
6218 (splay_tree_value) decl);
6219 }
6220
6221 /* Note that NAME was declared (as DECL) in the current class. Check
6222 to see that the declaration is valid. */
6223
6224 void
6225 note_name_declared_in_class (tree name, tree decl)
6226 {
6227 splay_tree names_used;
6228 splay_tree_node n;
6229
6230 /* Look to see if we ever used this name. */
6231 names_used
6232 = current_class_stack[current_class_depth - 1].names_used;
6233 if (!names_used)
6234 return;
6235
6236 n = splay_tree_lookup (names_used, (splay_tree_key) name);
6237 if (n)
6238 {
6239 /* [basic.scope.class]
6240
6241 A name N used in a class S shall refer to the same declaration
6242 in its context and when re-evaluated in the completed scope of
6243 S. */
6244 error ("declaration of %q#D", decl);
6245 cp_error_at ("changes meaning of %qD from %q+#D",
6246 DECL_NAME (OVL_CURRENT (decl)),
6247 (tree) n->value);
6248 }
6249 }
6250
6251 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6252 Secondary vtables are merged with primary vtables; this function
6253 will return the VAR_DECL for the primary vtable. */
6254
6255 tree
6256 get_vtbl_decl_for_binfo (tree binfo)
6257 {
6258 tree decl;
6259
6260 decl = BINFO_VTABLE (binfo);
6261 if (decl && TREE_CODE (decl) == PLUS_EXPR)
6262 {
6263 gcc_assert (TREE_CODE (TREE_OPERAND (decl, 0)) == ADDR_EXPR);
6264 decl = TREE_OPERAND (TREE_OPERAND (decl, 0), 0);
6265 }
6266 if (decl)
6267 gcc_assert (TREE_CODE (decl) == VAR_DECL);
6268 return decl;
6269 }
6270
6271
6272 /* Returns the binfo for the primary base of BINFO. If the resulting
6273 BINFO is a virtual base, and it is inherited elsewhere in the
6274 hierarchy, then the returned binfo might not be the primary base of
6275 BINFO in the complete object. Check BINFO_PRIMARY_P or
6276 BINFO_LOST_PRIMARY_P to be sure. */
6277
6278 tree
6279 get_primary_binfo (tree binfo)
6280 {
6281 tree primary_base;
6282 tree result;
6283
6284 primary_base = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (binfo));
6285 if (!primary_base)
6286 return NULL_TREE;
6287
6288 result = copied_binfo (primary_base, binfo);
6289 return result;
6290 }
6291
6292 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
6293
6294 static int
6295 maybe_indent_hierarchy (FILE * stream, int indent, int indented_p)
6296 {
6297 if (!indented_p)
6298 fprintf (stream, "%*s", indent, "");
6299 return 1;
6300 }
6301
6302 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
6303 INDENT should be zero when called from the top level; it is
6304 incremented recursively. IGO indicates the next expected BINFO in
6305 inheritance graph ordering. */
6306
6307 static tree
6308 dump_class_hierarchy_r (FILE *stream,
6309 int flags,
6310 tree binfo,
6311 tree igo,
6312 int indent)
6313 {
6314 int indented = 0;
6315 tree base_binfo;
6316 int i;
6317
6318 indented = maybe_indent_hierarchy (stream, indent, 0);
6319 fprintf (stream, "%s (0x%lx) ",
6320 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER),
6321 (unsigned long) binfo);
6322 if (binfo != igo)
6323 {
6324 fprintf (stream, "alternative-path\n");
6325 return igo;
6326 }
6327 igo = TREE_CHAIN (binfo);
6328
6329 fprintf (stream, HOST_WIDE_INT_PRINT_DEC,
6330 tree_low_cst (BINFO_OFFSET (binfo), 0));
6331 if (is_empty_class (BINFO_TYPE (binfo)))
6332 fprintf (stream, " empty");
6333 else if (CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (binfo)))
6334 fprintf (stream, " nearly-empty");
6335 if (BINFO_VIRTUAL_P (binfo))
6336 fprintf (stream, " virtual");
6337 fprintf (stream, "\n");
6338
6339 indented = 0;
6340 if (BINFO_PRIMARY_P (binfo))
6341 {
6342 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6343 fprintf (stream, " primary-for %s (0x%lx)",
6344 type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)),
6345 TFF_PLAIN_IDENTIFIER),
6346 (unsigned long)BINFO_INHERITANCE_CHAIN (binfo));
6347 }
6348 if (BINFO_LOST_PRIMARY_P (binfo))
6349 {
6350 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6351 fprintf (stream, " lost-primary");
6352 }
6353 if (indented)
6354 fprintf (stream, "\n");
6355
6356 if (!(flags & TDF_SLIM))
6357 {
6358 int indented = 0;
6359
6360 if (BINFO_SUBVTT_INDEX (binfo))
6361 {
6362 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6363 fprintf (stream, " subvttidx=%s",
6364 expr_as_string (BINFO_SUBVTT_INDEX (binfo),
6365 TFF_PLAIN_IDENTIFIER));
6366 }
6367 if (BINFO_VPTR_INDEX (binfo))
6368 {
6369 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6370 fprintf (stream, " vptridx=%s",
6371 expr_as_string (BINFO_VPTR_INDEX (binfo),
6372 TFF_PLAIN_IDENTIFIER));
6373 }
6374 if (BINFO_VPTR_FIELD (binfo))
6375 {
6376 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6377 fprintf (stream, " vbaseoffset=%s",
6378 expr_as_string (BINFO_VPTR_FIELD (binfo),
6379 TFF_PLAIN_IDENTIFIER));
6380 }
6381 if (BINFO_VTABLE (binfo))
6382 {
6383 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6384 fprintf (stream, " vptr=%s",
6385 expr_as_string (BINFO_VTABLE (binfo),
6386 TFF_PLAIN_IDENTIFIER));
6387 }
6388
6389 if (indented)
6390 fprintf (stream, "\n");
6391 }
6392
6393 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
6394 igo = dump_class_hierarchy_r (stream, flags, base_binfo, igo, indent + 2);
6395
6396 return igo;
6397 }
6398
6399 /* Dump the BINFO hierarchy for T. */
6400
6401 static void
6402 dump_class_hierarchy_1 (FILE *stream, int flags, tree t)
6403 {
6404 fprintf (stream, "Class %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6405 fprintf (stream, " size=%lu align=%lu\n",
6406 (unsigned long)(tree_low_cst (TYPE_SIZE (t), 0) / BITS_PER_UNIT),
6407 (unsigned long)(TYPE_ALIGN (t) / BITS_PER_UNIT));
6408 fprintf (stream, " base size=%lu base align=%lu\n",
6409 (unsigned long)(tree_low_cst (TYPE_SIZE (CLASSTYPE_AS_BASE (t)), 0)
6410 / BITS_PER_UNIT),
6411 (unsigned long)(TYPE_ALIGN (CLASSTYPE_AS_BASE (t))
6412 / BITS_PER_UNIT));
6413 dump_class_hierarchy_r (stream, flags, TYPE_BINFO (t), TYPE_BINFO (t), 0);
6414 fprintf (stream, "\n");
6415 }
6416
6417 /* Debug interface to hierarchy dumping. */
6418
6419 extern void
6420 debug_class (tree t)
6421 {
6422 dump_class_hierarchy_1 (stderr, TDF_SLIM, t);
6423 }
6424
6425 static void
6426 dump_class_hierarchy (tree t)
6427 {
6428 int flags;
6429 FILE *stream = dump_begin (TDI_class, &flags);
6430
6431 if (stream)
6432 {
6433 dump_class_hierarchy_1 (stream, flags, t);
6434 dump_end (TDI_class, stream);
6435 }
6436 }
6437
6438 static void
6439 dump_array (FILE * stream, tree decl)
6440 {
6441 tree inits;
6442 int ix;
6443 HOST_WIDE_INT elt;
6444 tree size = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (decl)));
6445
6446 elt = (tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl))), 0)
6447 / BITS_PER_UNIT);
6448 fprintf (stream, "%s:", decl_as_string (decl, TFF_PLAIN_IDENTIFIER));
6449 fprintf (stream, " %s entries",
6450 expr_as_string (size_binop (PLUS_EXPR, size, size_one_node),
6451 TFF_PLAIN_IDENTIFIER));
6452 fprintf (stream, "\n");
6453
6454 for (ix = 0, inits = CONSTRUCTOR_ELTS (DECL_INITIAL (decl));
6455 inits; ix++, inits = TREE_CHAIN (inits))
6456 fprintf (stream, "%-4ld %s\n", (long)(ix * elt),
6457 expr_as_string (TREE_VALUE (inits), TFF_PLAIN_IDENTIFIER));
6458 }
6459
6460 static void
6461 dump_vtable (tree t, tree binfo, tree vtable)
6462 {
6463 int flags;
6464 FILE *stream = dump_begin (TDI_class, &flags);
6465
6466 if (!stream)
6467 return;
6468
6469 if (!(flags & TDF_SLIM))
6470 {
6471 int ctor_vtbl_p = TYPE_BINFO (t) != binfo;
6472
6473 fprintf (stream, "%s for %s",
6474 ctor_vtbl_p ? "Construction vtable" : "Vtable",
6475 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER));
6476 if (ctor_vtbl_p)
6477 {
6478 if (!BINFO_VIRTUAL_P (binfo))
6479 fprintf (stream, " (0x%lx instance)", (unsigned long)binfo);
6480 fprintf (stream, " in %s", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6481 }
6482 fprintf (stream, "\n");
6483 dump_array (stream, vtable);
6484 fprintf (stream, "\n");
6485 }
6486
6487 dump_end (TDI_class, stream);
6488 }
6489
6490 static void
6491 dump_vtt (tree t, tree vtt)
6492 {
6493 int flags;
6494 FILE *stream = dump_begin (TDI_class, &flags);
6495
6496 if (!stream)
6497 return;
6498
6499 if (!(flags & TDF_SLIM))
6500 {
6501 fprintf (stream, "VTT for %s\n",
6502 type_as_string (t, TFF_PLAIN_IDENTIFIER));
6503 dump_array (stream, vtt);
6504 fprintf (stream, "\n");
6505 }
6506
6507 dump_end (TDI_class, stream);
6508 }
6509
6510 /* Dump a function or thunk and its thunkees. */
6511
6512 static void
6513 dump_thunk (FILE *stream, int indent, tree thunk)
6514 {
6515 static const char spaces[] = " ";
6516 tree name = DECL_NAME (thunk);
6517 tree thunks;
6518
6519 fprintf (stream, "%.*s%p %s %s", indent, spaces,
6520 (void *)thunk,
6521 !DECL_THUNK_P (thunk) ? "function"
6522 : DECL_THIS_THUNK_P (thunk) ? "this-thunk" : "covariant-thunk",
6523 name ? IDENTIFIER_POINTER (name) : "<unset>");
6524 if (DECL_THUNK_P (thunk))
6525 {
6526 HOST_WIDE_INT fixed_adjust = THUNK_FIXED_OFFSET (thunk);
6527 tree virtual_adjust = THUNK_VIRTUAL_OFFSET (thunk);
6528
6529 fprintf (stream, " fixed=" HOST_WIDE_INT_PRINT_DEC, fixed_adjust);
6530 if (!virtual_adjust)
6531 /*NOP*/;
6532 else if (DECL_THIS_THUNK_P (thunk))
6533 fprintf (stream, " vcall=" HOST_WIDE_INT_PRINT_DEC,
6534 tree_low_cst (virtual_adjust, 0));
6535 else
6536 fprintf (stream, " vbase=" HOST_WIDE_INT_PRINT_DEC "(%s)",
6537 tree_low_cst (BINFO_VPTR_FIELD (virtual_adjust), 0),
6538 type_as_string (BINFO_TYPE (virtual_adjust), TFF_SCOPE));
6539 if (THUNK_ALIAS (thunk))
6540 fprintf (stream, " alias to %p", (void *)THUNK_ALIAS (thunk));
6541 }
6542 fprintf (stream, "\n");
6543 for (thunks = DECL_THUNKS (thunk); thunks; thunks = TREE_CHAIN (thunks))
6544 dump_thunk (stream, indent + 2, thunks);
6545 }
6546
6547 /* Dump the thunks for FN. */
6548
6549 extern void
6550 debug_thunks (tree fn)
6551 {
6552 dump_thunk (stderr, 0, fn);
6553 }
6554
6555 /* Virtual function table initialization. */
6556
6557 /* Create all the necessary vtables for T and its base classes. */
6558
6559 static void
6560 finish_vtbls (tree t)
6561 {
6562 tree list;
6563 tree vbase;
6564
6565 /* We lay out the primary and secondary vtables in one contiguous
6566 vtable. The primary vtable is first, followed by the non-virtual
6567 secondary vtables in inheritance graph order. */
6568 list = build_tree_list (BINFO_VTABLE (TYPE_BINFO (t)), NULL_TREE);
6569 accumulate_vtbl_inits (TYPE_BINFO (t), TYPE_BINFO (t),
6570 TYPE_BINFO (t), t, list);
6571
6572 /* Then come the virtual bases, also in inheritance graph order. */
6573 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
6574 {
6575 if (!BINFO_VIRTUAL_P (vbase))
6576 continue;
6577 accumulate_vtbl_inits (vbase, vbase, TYPE_BINFO (t), t, list);
6578 }
6579
6580 if (BINFO_VTABLE (TYPE_BINFO (t)))
6581 initialize_vtable (TYPE_BINFO (t), TREE_VALUE (list));
6582 }
6583
6584 /* Initialize the vtable for BINFO with the INITS. */
6585
6586 static void
6587 initialize_vtable (tree binfo, tree inits)
6588 {
6589 tree decl;
6590
6591 layout_vtable_decl (binfo, list_length (inits));
6592 decl = get_vtbl_decl_for_binfo (binfo);
6593 initialize_artificial_var (decl, inits);
6594 dump_vtable (BINFO_TYPE (binfo), binfo, decl);
6595 }
6596
6597 /* Build the VTT (virtual table table) for T.
6598 A class requires a VTT if it has virtual bases.
6599
6600 This holds
6601 1 - primary virtual pointer for complete object T
6602 2 - secondary VTTs for each direct non-virtual base of T which requires a
6603 VTT
6604 3 - secondary virtual pointers for each direct or indirect base of T which
6605 has virtual bases or is reachable via a virtual path from T.
6606 4 - secondary VTTs for each direct or indirect virtual base of T.
6607
6608 Secondary VTTs look like complete object VTTs without part 4. */
6609
6610 static void
6611 build_vtt (tree t)
6612 {
6613 tree inits;
6614 tree type;
6615 tree vtt;
6616 tree index;
6617
6618 /* Build up the initializers for the VTT. */
6619 inits = NULL_TREE;
6620 index = size_zero_node;
6621 build_vtt_inits (TYPE_BINFO (t), t, &inits, &index);
6622
6623 /* If we didn't need a VTT, we're done. */
6624 if (!inits)
6625 return;
6626
6627 /* Figure out the type of the VTT. */
6628 type = build_index_type (size_int (list_length (inits) - 1));
6629 type = build_cplus_array_type (const_ptr_type_node, type);
6630
6631 /* Now, build the VTT object itself. */
6632 vtt = build_vtable (t, get_vtt_name (t), type);
6633 initialize_artificial_var (vtt, inits);
6634 /* Add the VTT to the vtables list. */
6635 TREE_CHAIN (vtt) = TREE_CHAIN (CLASSTYPE_VTABLES (t));
6636 TREE_CHAIN (CLASSTYPE_VTABLES (t)) = vtt;
6637
6638 dump_vtt (t, vtt);
6639 }
6640
6641 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
6642 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
6643 and CHAIN the vtable pointer for this binfo after construction is
6644 complete. VALUE can also be another BINFO, in which case we recurse. */
6645
6646 static tree
6647 binfo_ctor_vtable (tree binfo)
6648 {
6649 tree vt;
6650
6651 while (1)
6652 {
6653 vt = BINFO_VTABLE (binfo);
6654 if (TREE_CODE (vt) == TREE_LIST)
6655 vt = TREE_VALUE (vt);
6656 if (TREE_CODE (vt) == TREE_BINFO)
6657 binfo = vt;
6658 else
6659 break;
6660 }
6661
6662 return vt;
6663 }
6664
6665 /* Data for secondary VTT initialization. */
6666 typedef struct secondary_vptr_vtt_init_data_s
6667 {
6668 /* Is this the primary VTT? */
6669 bool top_level_p;
6670
6671 /* Current index into the VTT. */
6672 tree index;
6673
6674 /* TREE_LIST of initializers built up. */
6675 tree inits;
6676
6677 /* The type being constructed by this secondary VTT. */
6678 tree type_being_constructed;
6679 } secondary_vptr_vtt_init_data;
6680
6681 /* Recursively build the VTT-initializer for BINFO (which is in the
6682 hierarchy dominated by T). INITS points to the end of the initializer
6683 list to date. INDEX is the VTT index where the next element will be
6684 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
6685 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
6686 for virtual bases of T. When it is not so, we build the constructor
6687 vtables for the BINFO-in-T variant. */
6688
6689 static tree *
6690 build_vtt_inits (tree binfo, tree t, tree *inits, tree *index)
6691 {
6692 int i;
6693 tree b;
6694 tree init;
6695 tree secondary_vptrs;
6696 secondary_vptr_vtt_init_data data;
6697 int top_level_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
6698
6699 /* We only need VTTs for subobjects with virtual bases. */
6700 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
6701 return inits;
6702
6703 /* We need to use a construction vtable if this is not the primary
6704 VTT. */
6705 if (!top_level_p)
6706 {
6707 build_ctor_vtbl_group (binfo, t);
6708
6709 /* Record the offset in the VTT where this sub-VTT can be found. */
6710 BINFO_SUBVTT_INDEX (binfo) = *index;
6711 }
6712
6713 /* Add the address of the primary vtable for the complete object. */
6714 init = binfo_ctor_vtable (binfo);
6715 *inits = build_tree_list (NULL_TREE, init);
6716 inits = &TREE_CHAIN (*inits);
6717 if (top_level_p)
6718 {
6719 gcc_assert (!BINFO_VPTR_INDEX (binfo));
6720 BINFO_VPTR_INDEX (binfo) = *index;
6721 }
6722 *index = size_binop (PLUS_EXPR, *index, TYPE_SIZE_UNIT (ptr_type_node));
6723
6724 /* Recursively add the secondary VTTs for non-virtual bases. */
6725 for (i = 0; BINFO_BASE_ITERATE (binfo, i, b); ++i)
6726 if (!BINFO_VIRTUAL_P (b))
6727 inits = build_vtt_inits (b, t, inits, index);
6728
6729 /* Add secondary virtual pointers for all subobjects of BINFO with
6730 either virtual bases or reachable along a virtual path, except
6731 subobjects that are non-virtual primary bases. */
6732 data.top_level_p = top_level_p;
6733 data.index = *index;
6734 data.inits = NULL;
6735 data.type_being_constructed = BINFO_TYPE (binfo);
6736
6737 dfs_walk_once (binfo, dfs_build_secondary_vptr_vtt_inits, NULL, &data);
6738
6739 *index = data.index;
6740
6741 /* The secondary vptrs come back in reverse order. After we reverse
6742 them, and add the INITS, the last init will be the first element
6743 of the chain. */
6744 secondary_vptrs = data.inits;
6745 if (secondary_vptrs)
6746 {
6747 *inits = nreverse (secondary_vptrs);
6748 inits = &TREE_CHAIN (secondary_vptrs);
6749 gcc_assert (*inits == NULL_TREE);
6750 }
6751
6752 if (top_level_p)
6753 /* Add the secondary VTTs for virtual bases in inheritance graph
6754 order. */
6755 for (b = TYPE_BINFO (BINFO_TYPE (binfo)); b; b = TREE_CHAIN (b))
6756 {
6757 if (!BINFO_VIRTUAL_P (b))
6758 continue;
6759
6760 inits = build_vtt_inits (b, t, inits, index);
6761 }
6762 else
6763 /* Remove the ctor vtables we created. */
6764 dfs_walk_all (binfo, dfs_fixup_binfo_vtbls, NULL, binfo);
6765
6766 return inits;
6767 }
6768
6769 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
6770 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
6771
6772 static tree
6773 dfs_build_secondary_vptr_vtt_inits (tree binfo, void *data_)
6774 {
6775 secondary_vptr_vtt_init_data *data = (secondary_vptr_vtt_init_data *)data_;
6776
6777 /* We don't care about bases that don't have vtables. */
6778 if (!TYPE_VFIELD (BINFO_TYPE (binfo)))
6779 return dfs_skip_bases;
6780
6781 /* We're only interested in proper subobjects of the type being
6782 constructed. */
6783 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->type_being_constructed))
6784 return NULL_TREE;
6785
6786 /* We're only interested in bases with virtual bases or reachable
6787 via a virtual path from the type being constructed. */
6788 if (!(CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
6789 || binfo_via_virtual (binfo, data->type_being_constructed)))
6790 return dfs_skip_bases;
6791
6792 /* We're not interested in non-virtual primary bases. */
6793 if (!BINFO_VIRTUAL_P (binfo) && BINFO_PRIMARY_P (binfo))
6794 return NULL_TREE;
6795
6796 /* Record the index where this secondary vptr can be found. */
6797 if (data->top_level_p)
6798 {
6799 gcc_assert (!BINFO_VPTR_INDEX (binfo));
6800 BINFO_VPTR_INDEX (binfo) = data->index;
6801
6802 if (BINFO_VIRTUAL_P (binfo))
6803 {
6804 /* It's a primary virtual base, and this is not a
6805 construction vtable. Find the base this is primary of in
6806 the inheritance graph, and use that base's vtable
6807 now. */
6808 while (BINFO_PRIMARY_P (binfo))
6809 binfo = BINFO_INHERITANCE_CHAIN (binfo);
6810 }
6811 }
6812
6813 /* Add the initializer for the secondary vptr itself. */
6814 data->inits = tree_cons (NULL_TREE, binfo_ctor_vtable (binfo), data->inits);
6815
6816 /* Advance the vtt index. */
6817 data->index = size_binop (PLUS_EXPR, data->index,
6818 TYPE_SIZE_UNIT (ptr_type_node));
6819
6820 return NULL_TREE;
6821 }
6822
6823 /* Called from build_vtt_inits via dfs_walk. After building
6824 constructor vtables and generating the sub-vtt from them, we need
6825 to restore the BINFO_VTABLES that were scribbled on. DATA is the
6826 binfo of the base whose sub vtt was generated. */
6827
6828 static tree
6829 dfs_fixup_binfo_vtbls (tree binfo, void* data)
6830 {
6831 tree vtable = BINFO_VTABLE (binfo);
6832
6833 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
6834 /* If this class has no vtable, none of its bases do. */
6835 return dfs_skip_bases;
6836
6837 if (!vtable)
6838 /* This might be a primary base, so have no vtable in this
6839 hierarchy. */
6840 return NULL_TREE;
6841
6842 /* If we scribbled the construction vtable vptr into BINFO, clear it
6843 out now. */
6844 if (TREE_CODE (vtable) == TREE_LIST
6845 && (TREE_PURPOSE (vtable) == (tree) data))
6846 BINFO_VTABLE (binfo) = TREE_CHAIN (vtable);
6847
6848 return NULL_TREE;
6849 }
6850
6851 /* Build the construction vtable group for BINFO which is in the
6852 hierarchy dominated by T. */
6853
6854 static void
6855 build_ctor_vtbl_group (tree binfo, tree t)
6856 {
6857 tree list;
6858 tree type;
6859 tree vtbl;
6860 tree inits;
6861 tree id;
6862 tree vbase;
6863
6864 /* See if we've already created this construction vtable group. */
6865 id = mangle_ctor_vtbl_for_type (t, binfo);
6866 if (IDENTIFIER_GLOBAL_VALUE (id))
6867 return;
6868
6869 gcc_assert (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t));
6870 /* Build a version of VTBL (with the wrong type) for use in
6871 constructing the addresses of secondary vtables in the
6872 construction vtable group. */
6873 vtbl = build_vtable (t, id, ptr_type_node);
6874 DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1;
6875 list = build_tree_list (vtbl, NULL_TREE);
6876 accumulate_vtbl_inits (binfo, TYPE_BINFO (TREE_TYPE (binfo)),
6877 binfo, t, list);
6878
6879 /* Add the vtables for each of our virtual bases using the vbase in T
6880 binfo. */
6881 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
6882 vbase;
6883 vbase = TREE_CHAIN (vbase))
6884 {
6885 tree b;
6886
6887 if (!BINFO_VIRTUAL_P (vbase))
6888 continue;
6889 b = copied_binfo (vbase, binfo);
6890
6891 accumulate_vtbl_inits (b, vbase, binfo, t, list);
6892 }
6893 inits = TREE_VALUE (list);
6894
6895 /* Figure out the type of the construction vtable. */
6896 type = build_index_type (size_int (list_length (inits) - 1));
6897 type = build_cplus_array_type (vtable_entry_type, type);
6898 TREE_TYPE (vtbl) = type;
6899
6900 /* Initialize the construction vtable. */
6901 CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl);
6902 initialize_artificial_var (vtbl, inits);
6903 dump_vtable (t, binfo, vtbl);
6904 }
6905
6906 /* Add the vtbl initializers for BINFO (and its bases other than
6907 non-virtual primaries) to the list of INITS. BINFO is in the
6908 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
6909 the constructor the vtbl inits should be accumulated for. (If this
6910 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
6911 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
6912 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
6913 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
6914 but are not necessarily the same in terms of layout. */
6915
6916 static void
6917 accumulate_vtbl_inits (tree binfo,
6918 tree orig_binfo,
6919 tree rtti_binfo,
6920 tree t,
6921 tree inits)
6922 {
6923 int i;
6924 tree base_binfo;
6925 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
6926
6927 gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (orig_binfo)));
6928
6929 /* If it doesn't have a vptr, we don't do anything. */
6930 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
6931 return;
6932
6933 /* If we're building a construction vtable, we're not interested in
6934 subobjects that don't require construction vtables. */
6935 if (ctor_vtbl_p
6936 && !CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
6937 && !binfo_via_virtual (orig_binfo, BINFO_TYPE (rtti_binfo)))
6938 return;
6939
6940 /* Build the initializers for the BINFO-in-T vtable. */
6941 TREE_VALUE (inits)
6942 = chainon (TREE_VALUE (inits),
6943 dfs_accumulate_vtbl_inits (binfo, orig_binfo,
6944 rtti_binfo, t, inits));
6945
6946 /* Walk the BINFO and its bases. We walk in preorder so that as we
6947 initialize each vtable we can figure out at what offset the
6948 secondary vtable lies from the primary vtable. We can't use
6949 dfs_walk here because we need to iterate through bases of BINFO
6950 and RTTI_BINFO simultaneously. */
6951 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
6952 {
6953 /* Skip virtual bases. */
6954 if (BINFO_VIRTUAL_P (base_binfo))
6955 continue;
6956 accumulate_vtbl_inits (base_binfo,
6957 BINFO_BASE_BINFO (orig_binfo, i),
6958 rtti_binfo, t,
6959 inits);
6960 }
6961 }
6962
6963 /* Called from accumulate_vtbl_inits. Returns the initializers for
6964 the BINFO vtable. */
6965
6966 static tree
6967 dfs_accumulate_vtbl_inits (tree binfo,
6968 tree orig_binfo,
6969 tree rtti_binfo,
6970 tree t,
6971 tree l)
6972 {
6973 tree inits = NULL_TREE;
6974 tree vtbl = NULL_TREE;
6975 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
6976
6977 if (ctor_vtbl_p
6978 && BINFO_VIRTUAL_P (orig_binfo) && BINFO_PRIMARY_P (orig_binfo))
6979 {
6980 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
6981 primary virtual base. If it is not the same primary in
6982 the hierarchy of T, we'll need to generate a ctor vtable
6983 for it, to place at its location in T. If it is the same
6984 primary, we still need a VTT entry for the vtable, but it
6985 should point to the ctor vtable for the base it is a
6986 primary for within the sub-hierarchy of RTTI_BINFO.
6987
6988 There are three possible cases:
6989
6990 1) We are in the same place.
6991 2) We are a primary base within a lost primary virtual base of
6992 RTTI_BINFO.
6993 3) We are primary to something not a base of RTTI_BINFO. */
6994
6995 tree b;
6996 tree last = NULL_TREE;
6997
6998 /* First, look through the bases we are primary to for RTTI_BINFO
6999 or a virtual base. */
7000 b = binfo;
7001 while (BINFO_PRIMARY_P (b))
7002 {
7003 b = BINFO_INHERITANCE_CHAIN (b);
7004 last = b;
7005 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7006 goto found;
7007 }
7008 /* If we run out of primary links, keep looking down our
7009 inheritance chain; we might be an indirect primary. */
7010 for (b = last; b; b = BINFO_INHERITANCE_CHAIN (b))
7011 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7012 break;
7013 found:
7014
7015 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
7016 base B and it is a base of RTTI_BINFO, this is case 2. In
7017 either case, we share our vtable with LAST, i.e. the
7018 derived-most base within B of which we are a primary. */
7019 if (b == rtti_binfo
7020 || (b && binfo_for_vbase (BINFO_TYPE (b), BINFO_TYPE (rtti_binfo))))
7021 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7022 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
7023 binfo_ctor_vtable after everything's been set up. */
7024 vtbl = last;
7025
7026 /* Otherwise, this is case 3 and we get our own. */
7027 }
7028 else if (!BINFO_NEW_VTABLE_MARKED (orig_binfo))
7029 return inits;
7030
7031 if (!vtbl)
7032 {
7033 tree index;
7034 int non_fn_entries;
7035
7036 /* Compute the initializer for this vtable. */
7037 inits = build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo,
7038 &non_fn_entries);
7039
7040 /* Figure out the position to which the VPTR should point. */
7041 vtbl = TREE_PURPOSE (l);
7042 vtbl = build1 (ADDR_EXPR, vtbl_ptr_type_node, vtbl);
7043 index = size_binop (PLUS_EXPR,
7044 size_int (non_fn_entries),
7045 size_int (list_length (TREE_VALUE (l))));
7046 index = size_binop (MULT_EXPR,
7047 TYPE_SIZE_UNIT (vtable_entry_type),
7048 index);
7049 vtbl = build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, index);
7050 }
7051
7052 if (ctor_vtbl_p)
7053 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7054 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
7055 straighten this out. */
7056 BINFO_VTABLE (binfo) = tree_cons (rtti_binfo, vtbl, BINFO_VTABLE (binfo));
7057 else if (BINFO_PRIMARY_P (binfo) && BINFO_VIRTUAL_P (binfo))
7058 inits = NULL_TREE;
7059 else
7060 /* For an ordinary vtable, set BINFO_VTABLE. */
7061 BINFO_VTABLE (binfo) = vtbl;
7062
7063 return inits;
7064 }
7065
7066 /* Construct the initializer for BINFO's virtual function table. BINFO
7067 is part of the hierarchy dominated by T. If we're building a
7068 construction vtable, the ORIG_BINFO is the binfo we should use to
7069 find the actual function pointers to put in the vtable - but they
7070 can be overridden on the path to most-derived in the graph that
7071 ORIG_BINFO belongs. Otherwise,
7072 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
7073 BINFO that should be indicated by the RTTI information in the
7074 vtable; it will be a base class of T, rather than T itself, if we
7075 are building a construction vtable.
7076
7077 The value returned is a TREE_LIST suitable for wrapping in a
7078 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
7079 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7080 number of non-function entries in the vtable.
7081
7082 It might seem that this function should never be called with a
7083 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7084 base is always subsumed by a derived class vtable. However, when
7085 we are building construction vtables, we do build vtables for
7086 primary bases; we need these while the primary base is being
7087 constructed. */
7088
7089 static tree
7090 build_vtbl_initializer (tree binfo,
7091 tree orig_binfo,
7092 tree t,
7093 tree rtti_binfo,
7094 int* non_fn_entries_p)
7095 {
7096 tree v, b;
7097 tree vfun_inits;
7098 vtbl_init_data vid;
7099 unsigned ix;
7100 tree vbinfo;
7101 VEC (tree) *vbases;
7102
7103 /* Initialize VID. */
7104 memset (&vid, 0, sizeof (vid));
7105 vid.binfo = binfo;
7106 vid.derived = t;
7107 vid.rtti_binfo = rtti_binfo;
7108 vid.last_init = &vid.inits;
7109 vid.primary_vtbl_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
7110 vid.ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7111 vid.generate_vcall_entries = true;
7112 /* The first vbase or vcall offset is at index -3 in the vtable. */
7113 vid.index = ssize_int(-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE);
7114
7115 /* Add entries to the vtable for RTTI. */
7116 build_rtti_vtbl_entries (binfo, &vid);
7117
7118 /* Create an array for keeping track of the functions we've
7119 processed. When we see multiple functions with the same
7120 signature, we share the vcall offsets. */
7121 VARRAY_TREE_INIT (vid.fns, 32, "fns");
7122 /* Add the vcall and vbase offset entries. */
7123 build_vcall_and_vbase_vtbl_entries (binfo, &vid);
7124
7125 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7126 build_vbase_offset_vtbl_entries. */
7127 for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0;
7128 VEC_iterate (tree, vbases, ix, vbinfo); ix++)
7129 BINFO_VTABLE_PATH_MARKED (vbinfo) = 0;
7130
7131 /* If the target requires padding between data entries, add that now. */
7132 if (TARGET_VTABLE_DATA_ENTRY_DISTANCE > 1)
7133 {
7134 tree cur, *prev;
7135
7136 for (prev = &vid.inits; (cur = *prev); prev = &TREE_CHAIN (cur))
7137 {
7138 tree add = cur;
7139 int i;
7140
7141 for (i = 1; i < TARGET_VTABLE_DATA_ENTRY_DISTANCE; ++i)
7142 add = tree_cons (NULL_TREE,
7143 build1 (NOP_EXPR, vtable_entry_type,
7144 null_pointer_node),
7145 add);
7146 *prev = add;
7147 }
7148 }
7149
7150 if (non_fn_entries_p)
7151 *non_fn_entries_p = list_length (vid.inits);
7152
7153 /* Go through all the ordinary virtual functions, building up
7154 initializers. */
7155 vfun_inits = NULL_TREE;
7156 for (v = BINFO_VIRTUALS (orig_binfo); v; v = TREE_CHAIN (v))
7157 {
7158 tree delta;
7159 tree vcall_index;
7160 tree fn, fn_original;
7161 tree init = NULL_TREE;
7162
7163 fn = BV_FN (v);
7164 fn_original = fn;
7165 if (DECL_THUNK_P (fn))
7166 {
7167 if (!DECL_NAME (fn))
7168 finish_thunk (fn);
7169 if (THUNK_ALIAS (fn))
7170 {
7171 fn = THUNK_ALIAS (fn);
7172 BV_FN (v) = fn;
7173 }
7174 fn_original = THUNK_TARGET (fn);
7175 }
7176
7177 /* If the only definition of this function signature along our
7178 primary base chain is from a lost primary, this vtable slot will
7179 never be used, so just zero it out. This is important to avoid
7180 requiring extra thunks which cannot be generated with the function.
7181
7182 We first check this in update_vtable_entry_for_fn, so we handle
7183 restored primary bases properly; we also need to do it here so we
7184 zero out unused slots in ctor vtables, rather than filling themff
7185 with erroneous values (though harmless, apart from relocation
7186 costs). */
7187 for (b = binfo; ; b = get_primary_binfo (b))
7188 {
7189 /* We found a defn before a lost primary; go ahead as normal. */
7190 if (look_for_overrides_here (BINFO_TYPE (b), fn_original))
7191 break;
7192
7193 /* The nearest definition is from a lost primary; clear the
7194 slot. */
7195 if (BINFO_LOST_PRIMARY_P (b))
7196 {
7197 init = size_zero_node;
7198 break;
7199 }
7200 }
7201
7202 if (! init)
7203 {
7204 /* Pull the offset for `this', and the function to call, out of
7205 the list. */
7206 delta = BV_DELTA (v);
7207 vcall_index = BV_VCALL_INDEX (v);
7208
7209 gcc_assert (TREE_CODE (delta) == INTEGER_CST);
7210 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
7211
7212 /* You can't call an abstract virtual function; it's abstract.
7213 So, we replace these functions with __pure_virtual. */
7214 if (DECL_PURE_VIRTUAL_P (fn_original))
7215 fn = abort_fndecl;
7216 else if (!integer_zerop (delta) || vcall_index)
7217 {
7218 fn = make_thunk (fn, /*this_adjusting=*/1, delta, vcall_index);
7219 if (!DECL_NAME (fn))
7220 finish_thunk (fn);
7221 }
7222 /* Take the address of the function, considering it to be of an
7223 appropriate generic type. */
7224 init = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7225 }
7226
7227 /* And add it to the chain of initializers. */
7228 if (TARGET_VTABLE_USES_DESCRIPTORS)
7229 {
7230 int i;
7231 if (init == size_zero_node)
7232 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7233 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7234 else
7235 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7236 {
7237 tree fdesc = build2 (FDESC_EXPR, vfunc_ptr_type_node,
7238 TREE_OPERAND (init, 0),
7239 build_int_cst (NULL_TREE, i));
7240 TREE_CONSTANT (fdesc) = 1;
7241 TREE_INVARIANT (fdesc) = 1;
7242
7243 vfun_inits = tree_cons (NULL_TREE, fdesc, vfun_inits);
7244 }
7245 }
7246 else
7247 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7248 }
7249
7250 /* The initializers for virtual functions were built up in reverse
7251 order; straighten them out now. */
7252 vfun_inits = nreverse (vfun_inits);
7253
7254 /* The negative offset initializers are also in reverse order. */
7255 vid.inits = nreverse (vid.inits);
7256
7257 /* Chain the two together. */
7258 return chainon (vid.inits, vfun_inits);
7259 }
7260
7261 /* Adds to vid->inits the initializers for the vbase and vcall
7262 offsets in BINFO, which is in the hierarchy dominated by T. */
7263
7264 static void
7265 build_vcall_and_vbase_vtbl_entries (tree binfo, vtbl_init_data* vid)
7266 {
7267 tree b;
7268
7269 /* If this is a derived class, we must first create entries
7270 corresponding to the primary base class. */
7271 b = get_primary_binfo (binfo);
7272 if (b)
7273 build_vcall_and_vbase_vtbl_entries (b, vid);
7274
7275 /* Add the vbase entries for this base. */
7276 build_vbase_offset_vtbl_entries (binfo, vid);
7277 /* Add the vcall entries for this base. */
7278 build_vcall_offset_vtbl_entries (binfo, vid);
7279 }
7280
7281 /* Returns the initializers for the vbase offset entries in the vtable
7282 for BINFO (which is part of the class hierarchy dominated by T), in
7283 reverse order. VBASE_OFFSET_INDEX gives the vtable index
7284 where the next vbase offset will go. */
7285
7286 static void
7287 build_vbase_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7288 {
7289 tree vbase;
7290 tree t;
7291 tree non_primary_binfo;
7292
7293 /* If there are no virtual baseclasses, then there is nothing to
7294 do. */
7295 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
7296 return;
7297
7298 t = vid->derived;
7299
7300 /* We might be a primary base class. Go up the inheritance hierarchy
7301 until we find the most derived class of which we are a primary base:
7302 it is the offset of that which we need to use. */
7303 non_primary_binfo = binfo;
7304 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7305 {
7306 tree b;
7307
7308 /* If we have reached a virtual base, then it must be a primary
7309 base (possibly multi-level) of vid->binfo, or we wouldn't
7310 have called build_vcall_and_vbase_vtbl_entries for it. But it
7311 might be a lost primary, so just skip down to vid->binfo. */
7312 if (BINFO_VIRTUAL_P (non_primary_binfo))
7313 {
7314 non_primary_binfo = vid->binfo;
7315 break;
7316 }
7317
7318 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7319 if (get_primary_binfo (b) != non_primary_binfo)
7320 break;
7321 non_primary_binfo = b;
7322 }
7323
7324 /* Go through the virtual bases, adding the offsets. */
7325 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
7326 vbase;
7327 vbase = TREE_CHAIN (vbase))
7328 {
7329 tree b;
7330 tree delta;
7331
7332 if (!BINFO_VIRTUAL_P (vbase))
7333 continue;
7334
7335 /* Find the instance of this virtual base in the complete
7336 object. */
7337 b = copied_binfo (vbase, binfo);
7338
7339 /* If we've already got an offset for this virtual base, we
7340 don't need another one. */
7341 if (BINFO_VTABLE_PATH_MARKED (b))
7342 continue;
7343 BINFO_VTABLE_PATH_MARKED (b) = 1;
7344
7345 /* Figure out where we can find this vbase offset. */
7346 delta = size_binop (MULT_EXPR,
7347 vid->index,
7348 convert (ssizetype,
7349 TYPE_SIZE_UNIT (vtable_entry_type)));
7350 if (vid->primary_vtbl_p)
7351 BINFO_VPTR_FIELD (b) = delta;
7352
7353 if (binfo != TYPE_BINFO (t))
7354 /* The vbase offset had better be the same. */
7355 gcc_assert (tree_int_cst_equal (delta, BINFO_VPTR_FIELD (vbase)));
7356
7357 /* The next vbase will come at a more negative offset. */
7358 vid->index = size_binop (MINUS_EXPR, vid->index,
7359 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7360
7361 /* The initializer is the delta from BINFO to this virtual base.
7362 The vbase offsets go in reverse inheritance-graph order, and
7363 we are walking in inheritance graph order so these end up in
7364 the right order. */
7365 delta = size_diffop (BINFO_OFFSET (b), BINFO_OFFSET (non_primary_binfo));
7366
7367 *vid->last_init
7368 = build_tree_list (NULL_TREE,
7369 fold (build1 (NOP_EXPR,
7370 vtable_entry_type,
7371 delta)));
7372 vid->last_init = &TREE_CHAIN (*vid->last_init);
7373 }
7374 }
7375
7376 /* Adds the initializers for the vcall offset entries in the vtable
7377 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7378 to VID->INITS. */
7379
7380 static void
7381 build_vcall_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7382 {
7383 /* We only need these entries if this base is a virtual base. We
7384 compute the indices -- but do not add to the vtable -- when
7385 building the main vtable for a class. */
7386 if (BINFO_VIRTUAL_P (binfo) || binfo == TYPE_BINFO (vid->derived))
7387 {
7388 /* We need a vcall offset for each of the virtual functions in this
7389 vtable. For example:
7390
7391 class A { virtual void f (); };
7392 class B1 : virtual public A { virtual void f (); };
7393 class B2 : virtual public A { virtual void f (); };
7394 class C: public B1, public B2 { virtual void f (); };
7395
7396 A C object has a primary base of B1, which has a primary base of A. A
7397 C also has a secondary base of B2, which no longer has a primary base
7398 of A. So the B2-in-C construction vtable needs a secondary vtable for
7399 A, which will adjust the A* to a B2* to call f. We have no way of
7400 knowing what (or even whether) this offset will be when we define B2,
7401 so we store this "vcall offset" in the A sub-vtable and look it up in
7402 a "virtual thunk" for B2::f.
7403
7404 We need entries for all the functions in our primary vtable and
7405 in our non-virtual bases' secondary vtables. */
7406 vid->vbase = binfo;
7407 /* If we are just computing the vcall indices -- but do not need
7408 the actual entries -- not that. */
7409 if (!BINFO_VIRTUAL_P (binfo))
7410 vid->generate_vcall_entries = false;
7411 /* Now, walk through the non-virtual bases, adding vcall offsets. */
7412 add_vcall_offset_vtbl_entries_r (binfo, vid);
7413 }
7414 }
7415
7416 /* Build vcall offsets, starting with those for BINFO. */
7417
7418 static void
7419 add_vcall_offset_vtbl_entries_r (tree binfo, vtbl_init_data* vid)
7420 {
7421 int i;
7422 tree primary_binfo;
7423 tree base_binfo;
7424
7425 /* Don't walk into virtual bases -- except, of course, for the
7426 virtual base for which we are building vcall offsets. Any
7427 primary virtual base will have already had its offsets generated
7428 through the recursion in build_vcall_and_vbase_vtbl_entries. */
7429 if (BINFO_VIRTUAL_P (binfo) && vid->vbase != binfo)
7430 return;
7431
7432 /* If BINFO has a primary base, process it first. */
7433 primary_binfo = get_primary_binfo (binfo);
7434 if (primary_binfo)
7435 add_vcall_offset_vtbl_entries_r (primary_binfo, vid);
7436
7437 /* Add BINFO itself to the list. */
7438 add_vcall_offset_vtbl_entries_1 (binfo, vid);
7439
7440 /* Scan the non-primary bases of BINFO. */
7441 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7442 if (base_binfo != primary_binfo)
7443 add_vcall_offset_vtbl_entries_r (base_binfo, vid);
7444 }
7445
7446 /* Called from build_vcall_offset_vtbl_entries_r. */
7447
7448 static void
7449 add_vcall_offset_vtbl_entries_1 (tree binfo, vtbl_init_data* vid)
7450 {
7451 /* Make entries for the rest of the virtuals. */
7452 if (abi_version_at_least (2))
7453 {
7454 tree orig_fn;
7455
7456 /* The ABI requires that the methods be processed in declaration
7457 order. G++ 3.2 used the order in the vtable. */
7458 for (orig_fn = TYPE_METHODS (BINFO_TYPE (binfo));
7459 orig_fn;
7460 orig_fn = TREE_CHAIN (orig_fn))
7461 if (DECL_VINDEX (orig_fn))
7462 add_vcall_offset (orig_fn, binfo, vid);
7463 }
7464 else
7465 {
7466 tree derived_virtuals;
7467 tree base_virtuals;
7468 tree orig_virtuals;
7469 /* If BINFO is a primary base, the most derived class which has
7470 BINFO as a primary base; otherwise, just BINFO. */
7471 tree non_primary_binfo;
7472
7473 /* We might be a primary base class. Go up the inheritance hierarchy
7474 until we find the most derived class of which we are a primary base:
7475 it is the BINFO_VIRTUALS there that we need to consider. */
7476 non_primary_binfo = binfo;
7477 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7478 {
7479 tree b;
7480
7481 /* If we have reached a virtual base, then it must be vid->vbase,
7482 because we ignore other virtual bases in
7483 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
7484 base (possibly multi-level) of vid->binfo, or we wouldn't
7485 have called build_vcall_and_vbase_vtbl_entries for it. But it
7486 might be a lost primary, so just skip down to vid->binfo. */
7487 if (BINFO_VIRTUAL_P (non_primary_binfo))
7488 {
7489 gcc_assert (non_primary_binfo == vid->vbase);
7490 non_primary_binfo = vid->binfo;
7491 break;
7492 }
7493
7494 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7495 if (get_primary_binfo (b) != non_primary_binfo)
7496 break;
7497 non_primary_binfo = b;
7498 }
7499
7500 if (vid->ctor_vtbl_p)
7501 /* For a ctor vtable we need the equivalent binfo within the hierarchy
7502 where rtti_binfo is the most derived type. */
7503 non_primary_binfo
7504 = original_binfo (non_primary_binfo, vid->rtti_binfo);
7505
7506 for (base_virtuals = BINFO_VIRTUALS (binfo),
7507 derived_virtuals = BINFO_VIRTUALS (non_primary_binfo),
7508 orig_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
7509 base_virtuals;
7510 base_virtuals = TREE_CHAIN (base_virtuals),
7511 derived_virtuals = TREE_CHAIN (derived_virtuals),
7512 orig_virtuals = TREE_CHAIN (orig_virtuals))
7513 {
7514 tree orig_fn;
7515
7516 /* Find the declaration that originally caused this function to
7517 be present in BINFO_TYPE (binfo). */
7518 orig_fn = BV_FN (orig_virtuals);
7519
7520 /* When processing BINFO, we only want to generate vcall slots for
7521 function slots introduced in BINFO. So don't try to generate
7522 one if the function isn't even defined in BINFO. */
7523 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), DECL_CONTEXT (orig_fn)))
7524 continue;
7525
7526 add_vcall_offset (orig_fn, binfo, vid);
7527 }
7528 }
7529 }
7530
7531 /* Add a vcall offset entry for ORIG_FN to the vtable. */
7532
7533 static void
7534 add_vcall_offset (tree orig_fn, tree binfo, vtbl_init_data *vid)
7535 {
7536 size_t i;
7537 tree vcall_offset;
7538
7539 /* If there is already an entry for a function with the same
7540 signature as FN, then we do not need a second vcall offset.
7541 Check the list of functions already present in the derived
7542 class vtable. */
7543 for (i = 0; i < VARRAY_ACTIVE_SIZE (vid->fns); ++i)
7544 {
7545 tree derived_entry;
7546
7547 derived_entry = VARRAY_TREE (vid->fns, i);
7548 if (same_signature_p (derived_entry, orig_fn)
7549 /* We only use one vcall offset for virtual destructors,
7550 even though there are two virtual table entries. */
7551 || (DECL_DESTRUCTOR_P (derived_entry)
7552 && DECL_DESTRUCTOR_P (orig_fn)))
7553 return;
7554 }
7555
7556 /* If we are building these vcall offsets as part of building
7557 the vtable for the most derived class, remember the vcall
7558 offset. */
7559 if (vid->binfo == TYPE_BINFO (vid->derived))
7560 {
7561 tree_pair_p elt = VEC_safe_push (tree_pair_s,
7562 CLASSTYPE_VCALL_INDICES (vid->derived),
7563 NULL);
7564 elt->purpose = orig_fn;
7565 elt->value = vid->index;
7566 }
7567
7568 /* The next vcall offset will be found at a more negative
7569 offset. */
7570 vid->index = size_binop (MINUS_EXPR, vid->index,
7571 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7572
7573 /* Keep track of this function. */
7574 VARRAY_PUSH_TREE (vid->fns, orig_fn);
7575
7576 if (vid->generate_vcall_entries)
7577 {
7578 tree base;
7579 tree fn;
7580
7581 /* Find the overriding function. */
7582 fn = find_final_overrider (vid->rtti_binfo, binfo, orig_fn);
7583 if (fn == error_mark_node)
7584 vcall_offset = build1 (NOP_EXPR, vtable_entry_type,
7585 integer_zero_node);
7586 else
7587 {
7588 base = TREE_VALUE (fn);
7589
7590 /* The vbase we're working on is a primary base of
7591 vid->binfo. But it might be a lost primary, so its
7592 BINFO_OFFSET might be wrong, so we just use the
7593 BINFO_OFFSET from vid->binfo. */
7594 vcall_offset = size_diffop (BINFO_OFFSET (base),
7595 BINFO_OFFSET (vid->binfo));
7596 vcall_offset = fold (build1 (NOP_EXPR, vtable_entry_type,
7597 vcall_offset));
7598 }
7599 /* Add the initializer to the vtable. */
7600 *vid->last_init = build_tree_list (NULL_TREE, vcall_offset);
7601 vid->last_init = &TREE_CHAIN (*vid->last_init);
7602 }
7603 }
7604
7605 /* Return vtbl initializers for the RTTI entries corresponding to the
7606 BINFO's vtable. The RTTI entries should indicate the object given
7607 by VID->rtti_binfo. */
7608
7609 static void
7610 build_rtti_vtbl_entries (tree binfo, vtbl_init_data* vid)
7611 {
7612 tree b;
7613 tree t;
7614 tree basetype;
7615 tree offset;
7616 tree decl;
7617 tree init;
7618
7619 basetype = BINFO_TYPE (binfo);
7620 t = BINFO_TYPE (vid->rtti_binfo);
7621
7622 /* To find the complete object, we will first convert to our most
7623 primary base, and then add the offset in the vtbl to that value. */
7624 b = binfo;
7625 while (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (b))
7626 && !BINFO_LOST_PRIMARY_P (b))
7627 {
7628 tree primary_base;
7629
7630 primary_base = get_primary_binfo (b);
7631 gcc_assert (BINFO_PRIMARY_P (primary_base)
7632 && BINFO_INHERITANCE_CHAIN (primary_base) == b);
7633 b = primary_base;
7634 }
7635 offset = size_diffop (BINFO_OFFSET (vid->rtti_binfo), BINFO_OFFSET (b));
7636
7637 /* The second entry is the address of the typeinfo object. */
7638 if (flag_rtti)
7639 decl = build_address (get_tinfo_decl (t));
7640 else
7641 decl = integer_zero_node;
7642
7643 /* Convert the declaration to a type that can be stored in the
7644 vtable. */
7645 init = build_nop (vfunc_ptr_type_node, decl);
7646 *vid->last_init = build_tree_list (NULL_TREE, init);
7647 vid->last_init = &TREE_CHAIN (*vid->last_init);
7648
7649 /* Add the offset-to-top entry. It comes earlier in the vtable that
7650 the the typeinfo entry. Convert the offset to look like a
7651 function pointer, so that we can put it in the vtable. */
7652 init = build_nop (vfunc_ptr_type_node, offset);
7653 *vid->last_init = build_tree_list (NULL_TREE, init);
7654 vid->last_init = &TREE_CHAIN (*vid->last_init);
7655 }
7656
7657 /* Fold a OBJ_TYPE_REF expression to the address of a function.
7658 KNOWN_TYPE carries the true type of OBJ_TYPE_REF_OBJECT(REF). */
7659
7660 tree
7661 cp_fold_obj_type_ref (tree ref, tree known_type)
7662 {
7663 HOST_WIDE_INT index = tree_low_cst (OBJ_TYPE_REF_TOKEN (ref), 1);
7664 HOST_WIDE_INT i = 0;
7665 tree v = BINFO_VIRTUALS (TYPE_BINFO (known_type));
7666 tree fndecl;
7667
7668 while (i != index)
7669 {
7670 i += (TARGET_VTABLE_USES_DESCRIPTORS
7671 ? TARGET_VTABLE_USES_DESCRIPTORS : 1);
7672 v = TREE_CHAIN (v);
7673 }
7674
7675 fndecl = BV_FN (v);
7676
7677 #ifdef ENABLE_CHECKING
7678 gcc_assert (tree_int_cst_equal (OBJ_TYPE_REF_TOKEN (ref),
7679 DECL_VINDEX (fndecl)));
7680 #endif
7681
7682 return build_address (fndecl);
7683 }
7684
This page took 0.380457 seconds and 6 git commands to generate.