1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4 Contributed by Michael Tiemann (tiemann@cygnus.com)
5
6 This file is part of GCC.
7
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
11 any later version.
12
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to
20 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, USA. */
22
23
24 /* High-level class interface. */
25
26 #include "config.h"
27 #include "system.h"
28 #include "coretypes.h"
29 #include "tm.h"
30 #include "tree.h"
31 #include "cp-tree.h"
32 #include "flags.h"
33 #include "rtl.h"
34 #include "output.h"
35 #include "toplev.h"
36 #include "target.h"
37 #include "convert.h"
38 #include "cgraph.h"
39 #include "tree-dump.h"
40
41 /* The number of nested classes being processed. If we are not in the
42 scope of any class, this is zero. */
43
44 int current_class_depth;
45
46 /* In order to deal with nested classes, we keep a stack of classes.
47 The topmost entry is the innermost class, and is the entry at index
48 CURRENT_CLASS_DEPTH */
49
50 typedef struct class_stack_node {
51 /* The name of the class. */
52 tree name;
53
54 /* The _TYPE node for the class. */
55 tree type;
56
57 /* The access specifier pending for new declarations in the scope of
58 this class. */
59 tree access;
60
61 /* If were defining TYPE, the names used in this class. */
62 splay_tree names_used;
63
64 /* Nonzero if this class is no longer open, because of a call to
65 push_to_top_level. */
66 size_t hidden;
67 }* class_stack_node_t;
68
69 typedef struct vtbl_init_data_s
70 {
71 /* The base for which we're building initializers. */
72 tree binfo;
73 /* The type of the most-derived type. */
74 tree derived;
75 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
76 unless ctor_vtbl_p is true. */
77 tree rtti_binfo;
78 /* The negative-index vtable initializers built up so far. These
79 are in order from least negative index to most negative index. */
80 tree inits;
81 /* The last (i.e., most negative) entry in INITS. */
82 tree* last_init;
83 /* The binfo for the virtual base for which we're building
84 vcall offset initializers. */
85 tree vbase;
86 /* The functions in vbase for which we have already provided vcall
87 offsets. */
88 VEC(tree,gc) *fns;
89 /* The vtable index of the next vcall or vbase offset. */
90 tree index;
91 /* Nonzero if we are building the initializer for the primary
92 vtable. */
93 int primary_vtbl_p;
94 /* Nonzero if we are building the initializer for a construction
95 vtable. */
96 int ctor_vtbl_p;
97 /* True when adding vcall offset entries to the vtable. False when
98 merely computing the indices. */
99 bool generate_vcall_entries;
100 } vtbl_init_data;
101
102 /* The type of a function passed to walk_subobject_offsets. */
103 typedef int (*subobject_offset_fn) (tree, tree, splay_tree);
104
105 /* The stack itself. This is a dynamically resized array. The
106 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
107 static int current_class_stack_size;
108 static class_stack_node_t current_class_stack;
109
110 /* The size of the largest empty class seen in this translation unit. */
111 static GTY (()) tree sizeof_biggest_empty_class;
112
113 /* An array of all local classes present in this translation unit, in
114 declaration order. */
115 VEC(tree,gc) *local_classes;
116
117 static tree get_vfield_name (tree);
118 static void finish_struct_anon (tree);
119 static tree get_vtable_name (tree);
120 static tree get_basefndecls (tree, tree);
121 static int build_primary_vtable (tree, tree);
122 static int build_secondary_vtable (tree);
123 static void finish_vtbls (tree);
124 static void modify_vtable_entry (tree, tree, tree, tree, tree *);
125 static void finish_struct_bits (tree);
126 static int alter_access (tree, tree, tree);
127 static void handle_using_decl (tree, tree);
128 static tree dfs_modify_vtables (tree, void *);
129 static tree modify_all_vtables (tree, tree);
130 static void determine_primary_bases (tree);
131 static void finish_struct_methods (tree);
132 static void maybe_warn_about_overly_private_class (tree);
133 static int method_name_cmp (const void *, const void *);
134 static int resort_method_name_cmp (const void *, const void *);
135 static void add_implicitly_declared_members (tree, int, int);
136 static tree fixed_type_or_null (tree, int *, int *);
137 static tree build_simple_base_path (tree expr, tree binfo);
138 static tree build_vtbl_ref_1 (tree, tree);
139 static tree build_vtbl_initializer (tree, tree, tree, tree, int *);
140 static int count_fields (tree);
141 static int add_fields_to_record_type (tree, struct sorted_fields_type*, int);
142 static void check_bitfield_decl (tree);
143 static void check_field_decl (tree, tree, int *, int *, int *);
144 static void check_field_decls (tree, tree *, int *, int *);
145 static tree *build_base_field (record_layout_info, tree, splay_tree, tree *);
146 static void build_base_fields (record_layout_info, splay_tree, tree *);
147 static void check_methods (tree);
148 static void remove_zero_width_bit_fields (tree);
149 static void check_bases (tree, int *, int *);
150 static void check_bases_and_members (tree);
151 static tree create_vtable_ptr (tree, tree *);
152 static void include_empty_classes (record_layout_info);
153 static void layout_class_type (tree, tree *);
154 static void fixup_pending_inline (tree);
155 static void fixup_inline_methods (tree);
156 static void propagate_binfo_offsets (tree, tree);
157 static void layout_virtual_bases (record_layout_info, splay_tree);
158 static void build_vbase_offset_vtbl_entries (tree, vtbl_init_data *);
159 static void add_vcall_offset_vtbl_entries_r (tree, vtbl_init_data *);
160 static void add_vcall_offset_vtbl_entries_1 (tree, vtbl_init_data *);
161 static void build_vcall_offset_vtbl_entries (tree, vtbl_init_data *);
162 static void add_vcall_offset (tree, tree, vtbl_init_data *);
163 static void layout_vtable_decl (tree, int);
164 static tree dfs_find_final_overrider_pre (tree, void *);
165 static tree dfs_find_final_overrider_post (tree, void *);
166 static tree find_final_overrider (tree, tree, tree);
167 static int make_new_vtable (tree, tree);
168 static tree get_primary_binfo (tree);
169 static int maybe_indent_hierarchy (FILE *, int, int);
170 static tree dump_class_hierarchy_r (FILE *, int, tree, tree, int);
171 static void dump_class_hierarchy (tree);
172 static void dump_class_hierarchy_1 (FILE *, int, tree);
173 static void dump_array (FILE *, tree);
174 static void dump_vtable (tree, tree, tree);
175 static void dump_vtt (tree, tree);
176 static void dump_thunk (FILE *, int, tree);
177 static tree build_vtable (tree, tree, tree);
178 static void initialize_vtable (tree, tree);
179 static void layout_nonempty_base_or_field (record_layout_info,
180 tree, tree, splay_tree);
181 static tree end_of_class (tree, int);
182 static bool layout_empty_base (tree, tree, splay_tree);
183 static void accumulate_vtbl_inits (tree, tree, tree, tree, tree);
184 static tree dfs_accumulate_vtbl_inits (tree, tree, tree, tree,
185 tree);
186 static void build_rtti_vtbl_entries (tree, vtbl_init_data *);
187 static void build_vcall_and_vbase_vtbl_entries (tree, vtbl_init_data *);
188 static void clone_constructors_and_destructors (tree);
189 static tree build_clone (tree, tree);
190 static void update_vtable_entry_for_fn (tree, tree, tree, tree *, unsigned);
191 static void build_ctor_vtbl_group (tree, tree);
192 static void build_vtt (tree);
193 static tree binfo_ctor_vtable (tree);
194 static tree *build_vtt_inits (tree, tree, tree *, tree *);
195 static tree dfs_build_secondary_vptr_vtt_inits (tree, void *);
196 static tree dfs_fixup_binfo_vtbls (tree, void *);
197 static int record_subobject_offset (tree, tree, splay_tree);
198 static int check_subobject_offset (tree, tree, splay_tree);
199 static int walk_subobject_offsets (tree, subobject_offset_fn,
200 tree, splay_tree, tree, int);
201 static void record_subobject_offsets (tree, tree, splay_tree, bool);
202 static int layout_conflict_p (tree, tree, splay_tree, int);
203 static int splay_tree_compare_integer_csts (splay_tree_key k1,
204 splay_tree_key k2);
205 static void warn_about_ambiguous_bases (tree);
206 static bool type_requires_array_cookie (tree);
207 static bool contains_empty_class_p (tree);
208 static bool base_derived_from (tree, tree);
209 static int empty_base_at_nonzero_offset_p (tree, tree, splay_tree);
210 static tree end_of_base (tree);
211 static tree get_vcall_index (tree, tree);
212
213 /* Variables shared between class.c and call.c. */
214
215 #ifdef GATHER_STATISTICS
216 int n_vtables = 0;
217 int n_vtable_entries = 0;
218 int n_vtable_searches = 0;
219 int n_vtable_elems = 0;
220 int n_convert_harshness = 0;
221 int n_compute_conversion_costs = 0;
222 int n_inner_fields_searched = 0;
223 #endif
224
225 /* Convert to or from a base subobject. EXPR is an expression of type
226 `A' or `A*', an expression of type `B' or `B*' is returned. To
227 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
228 the B base instance within A. To convert base A to derived B, CODE
229 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
230 In this latter case, A must not be a morally virtual base of B.
231 NONNULL is true if EXPR is known to be non-NULL (this is only
232 needed when EXPR is of pointer type). CV qualifiers are preserved
233 from EXPR. */
234
235 tree
build_base_path(enum tree_code code,tree expr,tree binfo,int nonnull)236 build_base_path (enum tree_code code,
237 tree expr,
238 tree binfo,
239 int nonnull)
240 {
241 tree v_binfo = NULL_TREE;
242 tree d_binfo = NULL_TREE;
243 tree probe;
244 tree offset;
245 tree target_type;
246 tree null_test = NULL;
247 tree ptr_target_type;
248 int fixed_type_p;
249 int want_pointer = TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE;
250 bool has_empty = false;
251 bool virtual_access;
252
253 if (expr == error_mark_node || binfo == error_mark_node || !binfo)
254 return error_mark_node;
255
256 for (probe = binfo; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
257 {
258 d_binfo = probe;
259 if (is_empty_class (BINFO_TYPE (probe)))
260 has_empty = true;
261 if (!v_binfo && BINFO_VIRTUAL_P (probe))
262 v_binfo = probe;
263 }
264
265 probe = TYPE_MAIN_VARIANT (TREE_TYPE (expr));
266 if (want_pointer)
267 probe = TYPE_MAIN_VARIANT (TREE_TYPE (probe));
268
269 gcc_assert ((code == MINUS_EXPR
270 && SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), probe))
271 || (code == PLUS_EXPR
272 && SAME_BINFO_TYPE_P (BINFO_TYPE (d_binfo), probe)));
273
274 if (binfo == d_binfo)
275 /* Nothing to do. */
276 return expr;
277
278 if (code == MINUS_EXPR && v_binfo)
279 {
280 error ("cannot convert from base %qT to derived type %qT via virtual base %qT",
281 BINFO_TYPE (binfo), BINFO_TYPE (d_binfo), BINFO_TYPE (v_binfo));
282 return error_mark_node;
283 }
284
285 if (!want_pointer)
286 /* This must happen before the call to save_expr. */
287 expr = build_unary_op (ADDR_EXPR, expr, 0);
288
289 offset = BINFO_OFFSET (binfo);
290 fixed_type_p = resolves_to_fixed_type_p (expr, &nonnull);
291 target_type = code == PLUS_EXPR ? BINFO_TYPE (binfo) : BINFO_TYPE (d_binfo);
292
293 /* Do we need to look in the vtable for the real offset? */
294 virtual_access = (v_binfo && fixed_type_p <= 0);
295
296 /* Do we need to check for a null pointer? */
297 if (want_pointer && !nonnull)
298 {
299 /* If we know the conversion will not actually change the value
300 of EXPR, then we can avoid testing the expression for NULL.
301 We have to avoid generating a COMPONENT_REF for a base class
302 field, because other parts of the compiler know that such
303 expressions are always non-NULL. */
304 if (!virtual_access && integer_zerop (offset))
305 {
306 tree class_type;
307 /* TARGET_TYPE has been extracted from BINFO, and, is
308 therefore always cv-unqualified. Extract the
309 cv-qualifiers from EXPR so that the expression returned
310 matches the input. */
311 class_type = TREE_TYPE (TREE_TYPE (expr));
312 target_type
313 = cp_build_qualified_type (target_type,
314 cp_type_quals (class_type));
315 return build_nop (build_pointer_type (target_type), expr);
316 }
317 null_test = error_mark_node;
318 }
319
320 /* Protect against multiple evaluation if necessary. */
321 if (TREE_SIDE_EFFECTS (expr) && (null_test || virtual_access))
322 expr = save_expr (expr);
323
324 /* Now that we've saved expr, build the real null test. */
325 if (null_test)
326 {
327 tree zero = cp_convert (TREE_TYPE (expr), integer_zero_node);
328 null_test = fold_build2 (NE_EXPR, boolean_type_node,
329 expr, zero);
330 }
331
332 /* If this is a simple base reference, express it as a COMPONENT_REF. */
333 if (code == PLUS_EXPR && !virtual_access
334 /* We don't build base fields for empty bases, and they aren't very
335 interesting to the optimizers anyway. */
336 && !has_empty)
337 {
338 expr = build_indirect_ref (expr, NULL);
339 expr = build_simple_base_path (expr, binfo);
340 if (want_pointer)
341 expr = build_address (expr);
342 target_type = TREE_TYPE (expr);
343 goto out;
344 }
345
346 if (virtual_access)
347 {
348 /* Going via virtual base V_BINFO. We need the static offset
349 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
350 V_BINFO. That offset is an entry in D_BINFO's vtable. */
351 tree v_offset;
352
353 if (fixed_type_p < 0 && in_base_initializer)
354 {
355 /* In a base member initializer, we cannot rely on the
356 vtable being set up. We have to indirect via the
357 vtt_parm. */
358 tree t;
359
360 t = TREE_TYPE (TYPE_VFIELD (current_class_type));
361 t = build_pointer_type (t);
362 v_offset = convert (t, current_vtt_parm);
363 v_offset = build_indirect_ref (v_offset, NULL);
364 }
365 else
366 v_offset = build_vfield_ref (build_indirect_ref (expr, NULL),
367 TREE_TYPE (TREE_TYPE (expr)));
368
369 v_offset = build2 (PLUS_EXPR, TREE_TYPE (v_offset),
370 v_offset, BINFO_VPTR_FIELD (v_binfo));
371 v_offset = build1 (NOP_EXPR,
372 build_pointer_type (ptrdiff_type_node),
373 v_offset);
374 v_offset = build_indirect_ref (v_offset, NULL);
375 TREE_CONSTANT (v_offset) = 1;
376 TREE_INVARIANT (v_offset) = 1;
377
378 offset = convert_to_integer (ptrdiff_type_node,
379 size_diffop (offset,
380 BINFO_OFFSET (v_binfo)));
381
382 if (!integer_zerop (offset))
383 v_offset = build2 (code, ptrdiff_type_node, v_offset, offset);
384
385 if (fixed_type_p < 0)
386 /* Negative fixed_type_p means this is a constructor or destructor;
387 virtual base layout is fixed in in-charge [cd]tors, but not in
388 base [cd]tors. */
389 offset = build3 (COND_EXPR, ptrdiff_type_node,
390 build2 (EQ_EXPR, boolean_type_node,
391 current_in_charge_parm, integer_zero_node),
392 v_offset,
393 convert_to_integer (ptrdiff_type_node,
394 BINFO_OFFSET (binfo)));
395 else
396 offset = v_offset;
397 }
398
399 target_type = cp_build_qualified_type
400 (target_type, cp_type_quals (TREE_TYPE (TREE_TYPE (expr))));
401 ptr_target_type = build_pointer_type (target_type);
402 if (want_pointer)
403 target_type = ptr_target_type;
404
405 expr = build1 (NOP_EXPR, ptr_target_type, expr);
406
407 if (!integer_zerop (offset))
408 expr = build2 (code, ptr_target_type, expr, offset);
409 else
410 null_test = NULL;
411
412 if (!want_pointer)
413 expr = build_indirect_ref (expr, NULL);
414
415 out:
416 if (null_test)
417 expr = fold_build3 (COND_EXPR, target_type, null_test, expr,
418 fold_build1 (NOP_EXPR, target_type,
419 integer_zero_node));
420
421 return expr;
422 }
423
424 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
425 Perform a derived-to-base conversion by recursively building up a
426 sequence of COMPONENT_REFs to the appropriate base fields. */
427
428 static tree
build_simple_base_path(tree expr,tree binfo)429 build_simple_base_path (tree expr, tree binfo)
430 {
431 tree type = BINFO_TYPE (binfo);
432 tree d_binfo = BINFO_INHERITANCE_CHAIN (binfo);
433 tree field;
434
435 if (d_binfo == NULL_TREE)
436 {
437 tree temp;
438
439 gcc_assert (TYPE_MAIN_VARIANT (TREE_TYPE (expr)) == type);
440
441 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
442 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
443 an lvalue in the frontend; only _DECLs and _REFs are lvalues
444 in the backend. */
445 temp = unary_complex_lvalue (ADDR_EXPR, expr);
446 if (temp)
447 expr = build_indirect_ref (temp, NULL);
448
449 return expr;
450 }
451
452 /* Recurse. */
453 expr = build_simple_base_path (expr, d_binfo);
454
455 for (field = TYPE_FIELDS (BINFO_TYPE (d_binfo));
456 field; field = TREE_CHAIN (field))
457 /* Is this the base field created by build_base_field? */
458 if (TREE_CODE (field) == FIELD_DECL
459 && DECL_FIELD_IS_BASE (field)
460 && TREE_TYPE (field) == type)
461 {
462 /* We don't use build_class_member_access_expr here, as that
463 has unnecessary checks, and more importantly results in
464 recursive calls to dfs_walk_once. */
465 int type_quals = cp_type_quals (TREE_TYPE (expr));
466
467 expr = build3 (COMPONENT_REF,
468 cp_build_qualified_type (type, type_quals),
469 expr, field, NULL_TREE);
470 expr = fold_if_not_in_template (expr);
471
472 /* Mark the expression const or volatile, as appropriate.
473 Even though we've dealt with the type above, we still have
474 to mark the expression itself. */
475 if (type_quals & TYPE_QUAL_CONST)
476 TREE_READONLY (expr) = 1;
477 if (type_quals & TYPE_QUAL_VOLATILE)
478 TREE_THIS_VOLATILE (expr) = 1;
479
480 return expr;
481 }
482
483 /* Didn't find the base field?!? */
484 gcc_unreachable ();
485 }
486
487 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
488 type is a class type or a pointer to a class type. In the former
489 case, TYPE is also a class type; in the latter it is another
490 pointer type. If CHECK_ACCESS is true, an error message is emitted
491 if TYPE is inaccessible. If OBJECT has pointer type, the value is
492 assumed to be non-NULL. */
493
494 tree
convert_to_base(tree object,tree type,bool check_access,bool nonnull)495 convert_to_base (tree object, tree type, bool check_access, bool nonnull)
496 {
497 tree binfo;
498 tree object_type;
499
500 if (TYPE_PTR_P (TREE_TYPE (object)))
501 {
502 object_type = TREE_TYPE (TREE_TYPE (object));
503 type = TREE_TYPE (type);
504 }
505 else
506 object_type = TREE_TYPE (object);
507
508 binfo = lookup_base (object_type, type,
509 check_access ? ba_check : ba_unique,
510 NULL);
511 if (!binfo || binfo == error_mark_node)
512 return error_mark_node;
513
514 return build_base_path (PLUS_EXPR, object, binfo, nonnull);
515 }
516
517 /* EXPR is an expression with unqualified class type. BASE is a base
518 binfo of that class type. Returns EXPR, converted to the BASE
519 type. This function assumes that EXPR is the most derived class;
520 therefore virtual bases can be found at their static offsets. */
521
522 tree
convert_to_base_statically(tree expr,tree base)523 convert_to_base_statically (tree expr, tree base)
524 {
525 tree expr_type;
526
527 expr_type = TREE_TYPE (expr);
528 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (base), expr_type))
529 {
530 tree pointer_type;
531
532 pointer_type = build_pointer_type (expr_type);
533 expr = build_unary_op (ADDR_EXPR, expr, /*noconvert=*/1);
534 if (!integer_zerop (BINFO_OFFSET (base)))
535 expr = build2 (PLUS_EXPR, pointer_type, expr,
536 build_nop (pointer_type, BINFO_OFFSET (base)));
537 expr = build_nop (build_pointer_type (BINFO_TYPE (base)), expr);
538 expr = build1 (INDIRECT_REF, BINFO_TYPE (base), expr);
539 }
540
541 return expr;
542 }
543
544
545 tree
build_vfield_ref(tree datum,tree type)546 build_vfield_ref (tree datum, tree type)
547 {
548 tree vfield, vcontext;
549
550 if (datum == error_mark_node)
551 return error_mark_node;
552
553 /* First, convert to the requested type. */
554 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (datum), type))
555 datum = convert_to_base (datum, type, /*check_access=*/false,
556 /*nonnull=*/true);
557
558 /* Second, the requested type may not be the owner of its own vptr.
559 If not, convert to the base class that owns it. We cannot use
560 convert_to_base here, because VCONTEXT may appear more than once
561 in the inheritance hierarchy of TYPE, and thus direct conversion
562 between the types may be ambiguous. Following the path back up
563 one step at a time via primary bases avoids the problem. */
564 vfield = TYPE_VFIELD (type);
565 vcontext = DECL_CONTEXT (vfield);
566 while (!same_type_ignoring_top_level_qualifiers_p (vcontext, type))
567 {
568 datum = build_simple_base_path (datum, CLASSTYPE_PRIMARY_BINFO (type));
569 type = TREE_TYPE (datum);
570 }
571
572 return build3 (COMPONENT_REF, TREE_TYPE (vfield), datum, vfield, NULL_TREE);
573 }
574
575 /* Given an object INSTANCE, return an expression which yields the
576 vtable element corresponding to INDEX. There are many special
577 cases for INSTANCE which we take care of here, mainly to avoid
578 creating extra tree nodes when we don't have to. */
579
580 static tree
build_vtbl_ref_1(tree instance,tree idx)581 build_vtbl_ref_1 (tree instance, tree idx)
582 {
583 tree aref;
584 tree vtbl = NULL_TREE;
585
586 /* Try to figure out what a reference refers to, and
587 access its virtual function table directly. */
588
589 int cdtorp = 0;
590 tree fixed_type = fixed_type_or_null (instance, NULL, &cdtorp);
591
592 tree basetype = non_reference (TREE_TYPE (instance));
593
594 if (fixed_type && !cdtorp)
595 {
596 tree binfo = lookup_base (fixed_type, basetype,
597 ba_unique | ba_quiet, NULL);
598 if (binfo)
599 vtbl = unshare_expr (BINFO_VTABLE (binfo));
600 }
601
602 if (!vtbl)
603 vtbl = build_vfield_ref (instance, basetype);
604
605 assemble_external (vtbl);
606
607 aref = build_array_ref (vtbl, idx);
608 TREE_CONSTANT (aref) |= TREE_CONSTANT (vtbl) && TREE_CONSTANT (idx);
609 TREE_INVARIANT (aref) = TREE_CONSTANT (aref);
610
611 return aref;
612 }
613
614 tree
build_vtbl_ref(tree instance,tree idx)615 build_vtbl_ref (tree instance, tree idx)
616 {
617 tree aref = build_vtbl_ref_1 (instance, idx);
618
619 return aref;
620 }
621
622 /* Given a stable object pointer INSTANCE_PTR, return an expression which
623 yields a function pointer corresponding to vtable element INDEX. */
624
625 tree
build_vfn_ref(tree instance_ptr,tree idx)626 build_vfn_ref (tree instance_ptr, tree idx)
627 {
628 tree aref;
629
630 aref = build_vtbl_ref_1 (build_indirect_ref (instance_ptr, 0), idx);
631
632 /* When using function descriptors, the address of the
633 vtable entry is treated as a function pointer. */
634 if (TARGET_VTABLE_USES_DESCRIPTORS)
635 aref = build1 (NOP_EXPR, TREE_TYPE (aref),
636 build_unary_op (ADDR_EXPR, aref, /*noconvert=*/1));
637
638 /* Remember this as a method reference, for later devirtualization. */
639 aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr, idx);
640
641 return aref;
642 }
643
644 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
645 for the given TYPE. */
646
647 static tree
get_vtable_name(tree type)648 get_vtable_name (tree type)
649 {
650 return mangle_vtbl_for_type (type);
651 }
652
653 /* DECL is an entity associated with TYPE, like a virtual table or an
654 implicitly generated constructor. Determine whether or not DECL
655 should have external or internal linkage at the object file
656 level. This routine does not deal with COMDAT linkage and other
657 similar complexities; it simply sets TREE_PUBLIC if it possible for
658 entities in other translation units to contain copies of DECL, in
659 the abstract. */
660
661 void
set_linkage_according_to_type(tree type,tree decl)662 set_linkage_according_to_type (tree type, tree decl)
663 {
664 /* If TYPE involves a local class in a function with internal
665 linkage, then DECL should have internal linkage too. Other local
666 classes have no linkage -- but if their containing functions
667 have external linkage, it makes sense for DECL to have external
668 linkage too. That will allow template definitions to be merged,
669 for example. */
670 if (no_linkage_check (type, /*relaxed_p=*/true))
671 {
672 TREE_PUBLIC (decl) = 0;
673 DECL_INTERFACE_KNOWN (decl) = 1;
674 }
675 else
676 TREE_PUBLIC (decl) = 1;
677 }
678
679 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
680 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
681 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
682
683 static tree
build_vtable(tree class_type,tree name,tree vtable_type)684 build_vtable (tree class_type, tree name, tree vtable_type)
685 {
686 tree decl;
687
688 decl = build_lang_decl (VAR_DECL, name, vtable_type);
689 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
690 now to avoid confusion in mangle_decl. */
691 SET_DECL_ASSEMBLER_NAME (decl, name);
692 DECL_CONTEXT (decl) = class_type;
693 DECL_ARTIFICIAL (decl) = 1;
694 TREE_STATIC (decl) = 1;
695 TREE_READONLY (decl) = 1;
696 DECL_VIRTUAL_P (decl) = 1;
697 DECL_ALIGN (decl) = TARGET_VTABLE_ENTRY_ALIGN;
698 DECL_VTABLE_OR_VTT_P (decl) = 1;
699 /* At one time the vtable info was grabbed 2 words at a time. This
700 fails on sparc unless you have 8-byte alignment. (tiemann) */
701 DECL_ALIGN (decl) = MAX (TYPE_ALIGN (double_type_node),
702 DECL_ALIGN (decl));
703 set_linkage_according_to_type (class_type, decl);
704 /* The vtable has not been defined -- yet. */
705 DECL_EXTERNAL (decl) = 1;
706 DECL_NOT_REALLY_EXTERN (decl) = 1;
707
708 /* Mark the VAR_DECL node representing the vtable itself as a
709 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
710 is rather important that such things be ignored because any
711 effort to actually generate DWARF for them will run into
712 trouble when/if we encounter code like:
713
714 #pragma interface
715 struct S { virtual void member (); };
716
717 because the artificial declaration of the vtable itself (as
718 manufactured by the g++ front end) will say that the vtable is
719 a static member of `S' but only *after* the debug output for
720 the definition of `S' has already been output. This causes
721 grief because the DWARF entry for the definition of the vtable
722 will try to refer back to an earlier *declaration* of the
723 vtable as a static member of `S' and there won't be one. We
724 might be able to arrange to have the "vtable static member"
725 attached to the member list for `S' before the debug info for
726 `S' get written (which would solve the problem) but that would
727 require more intrusive changes to the g++ front end. */
728 DECL_IGNORED_P (decl) = 1;
729
730 return decl;
731 }
732
733 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
734 or even complete. If this does not exist, create it. If COMPLETE is
735 nonzero, then complete the definition of it -- that will render it
736 impossible to actually build the vtable, but is useful to get at those
737 which are known to exist in the runtime. */
738
739 tree
get_vtable_decl(tree type,int complete)740 get_vtable_decl (tree type, int complete)
741 {
742 tree decl;
743
744 if (CLASSTYPE_VTABLES (type))
745 return CLASSTYPE_VTABLES (type);
746
747 decl = build_vtable (type, get_vtable_name (type), vtbl_type_node);
748 CLASSTYPE_VTABLES (type) = decl;
749
750 if (complete)
751 {
752 DECL_EXTERNAL (decl) = 1;
753 finish_decl (decl, NULL_TREE, NULL_TREE);
754 }
755
756 return decl;
757 }
758
759 /* Build the primary virtual function table for TYPE. If BINFO is
760 non-NULL, build the vtable starting with the initial approximation
761 that it is the same as the one which is the head of the association
762 list. Returns a nonzero value if a new vtable is actually
763 created. */
764
765 static int
build_primary_vtable(tree binfo,tree type)766 build_primary_vtable (tree binfo, tree type)
767 {
768 tree decl;
769 tree virtuals;
770
771 decl = get_vtable_decl (type, /*complete=*/0);
772
773 if (binfo)
774 {
775 if (BINFO_NEW_VTABLE_MARKED (binfo))
776 /* We have already created a vtable for this base, so there's
777 no need to do it again. */
778 return 0;
779
780 virtuals = copy_list (BINFO_VIRTUALS (binfo));
781 TREE_TYPE (decl) = TREE_TYPE (get_vtbl_decl_for_binfo (binfo));
782 DECL_SIZE (decl) = TYPE_SIZE (TREE_TYPE (decl));
783 DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (TREE_TYPE (decl));
784 }
785 else
786 {
787 gcc_assert (TREE_TYPE (decl) == vtbl_type_node);
788 virtuals = NULL_TREE;
789 }
790
791 #ifdef GATHER_STATISTICS
792 n_vtables += 1;
793 n_vtable_elems += list_length (virtuals);
794 #endif
795
796 /* Initialize the association list for this type, based
797 on our first approximation. */
798 BINFO_VTABLE (TYPE_BINFO (type)) = decl;
799 BINFO_VIRTUALS (TYPE_BINFO (type)) = virtuals;
800 SET_BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (type));
801 return 1;
802 }
803
804 /* Give BINFO a new virtual function table which is initialized
805 with a skeleton-copy of its original initialization. The only
806 entry that changes is the `delta' entry, so we can really
807 share a lot of structure.
808
809 FOR_TYPE is the most derived type which caused this table to
810 be needed.
811
812 Returns nonzero if we haven't met BINFO before.
813
814 The order in which vtables are built (by calling this function) for
815 an object must remain the same, otherwise a binary incompatibility
816 can result. */
817
818 static int
build_secondary_vtable(tree binfo)819 build_secondary_vtable (tree binfo)
820 {
821 if (BINFO_NEW_VTABLE_MARKED (binfo))
822 /* We already created a vtable for this base. There's no need to
823 do it again. */
824 return 0;
825
826 /* Remember that we've created a vtable for this BINFO, so that we
827 don't try to do so again. */
828 SET_BINFO_NEW_VTABLE_MARKED (binfo);
829
830 /* Make fresh virtual list, so we can smash it later. */
831 BINFO_VIRTUALS (binfo) = copy_list (BINFO_VIRTUALS (binfo));
832
833 /* Secondary vtables are laid out as part of the same structure as
834 the primary vtable. */
835 BINFO_VTABLE (binfo) = NULL_TREE;
836 return 1;
837 }
838
839 /* Create a new vtable for BINFO which is the hierarchy dominated by
840 T. Return nonzero if we actually created a new vtable. */
841
842 static int
make_new_vtable(tree t,tree binfo)843 make_new_vtable (tree t, tree binfo)
844 {
845 if (binfo == TYPE_BINFO (t))
846 /* In this case, it is *type*'s vtable we are modifying. We start
847 with the approximation that its vtable is that of the
848 immediate base class. */
849 return build_primary_vtable (binfo, t);
850 else
851 /* This is our very own copy of `basetype' to play with. Later,
852 we will fill in all the virtual functions that override the
853 virtual functions in these base classes which are not defined
854 by the current type. */
855 return build_secondary_vtable (binfo);
856 }
857
858 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
859 (which is in the hierarchy dominated by T) list FNDECL as its
860 BV_FN. DELTA is the required constant adjustment from the `this'
861 pointer where the vtable entry appears to the `this' required when
862 the function is actually called. */
863
864 static void
modify_vtable_entry(tree t,tree binfo,tree fndecl,tree delta,tree * virtuals)865 modify_vtable_entry (tree t,
866 tree binfo,
867 tree fndecl,
868 tree delta,
869 tree *virtuals)
870 {
871 tree v;
872
873 v = *virtuals;
874
875 if (fndecl != BV_FN (v)
876 || !tree_int_cst_equal (delta, BV_DELTA (v)))
877 {
878 /* We need a new vtable for BINFO. */
879 if (make_new_vtable (t, binfo))
880 {
881 /* If we really did make a new vtable, we also made a copy
882 of the BINFO_VIRTUALS list. Now, we have to find the
883 corresponding entry in that list. */
884 *virtuals = BINFO_VIRTUALS (binfo);
885 while (BV_FN (*virtuals) != BV_FN (v))
886 *virtuals = TREE_CHAIN (*virtuals);
887 v = *virtuals;
888 }
889
890 BV_DELTA (v) = delta;
891 BV_VCALL_INDEX (v) = NULL_TREE;
892 BV_FN (v) = fndecl;
893 }
894 }
895
896
897 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
898 the USING_DECL naming METHOD. Returns true if the method could be
899 added to the method vec. */
900
901 bool
add_method(tree type,tree method,tree using_decl)902 add_method (tree type, tree method, tree using_decl)
903 {
904 unsigned slot;
905 tree overload;
906 bool template_conv_p = false;
907 bool conv_p;
908 VEC(tree,gc) *method_vec;
909 bool complete_p;
910 bool insert_p = false;
911 tree current_fns;
912
913 if (method == error_mark_node)
914 return false;
915
916 complete_p = COMPLETE_TYPE_P (type);
917 conv_p = DECL_CONV_FN_P (method);
918 if (conv_p)
919 template_conv_p = (TREE_CODE (method) == TEMPLATE_DECL
920 && DECL_TEMPLATE_CONV_FN_P (method));
921
922 method_vec = CLASSTYPE_METHOD_VEC (type);
923 if (!method_vec)
924 {
925 /* Make a new method vector. We start with 8 entries. We must
926 allocate at least two (for constructors and destructors), and
927 we're going to end up with an assignment operator at some
928 point as well. */
929 method_vec = VEC_alloc (tree, gc, 8);
930 /* Create slots for constructors and destructors. */
931 VEC_quick_push (tree, method_vec, NULL_TREE);
932 VEC_quick_push (tree, method_vec, NULL_TREE);
933 CLASSTYPE_METHOD_VEC (type) = method_vec;
934 }
935
936 /* Maintain TYPE_HAS_CONSTRUCTOR, etc. */
937 grok_special_member_properties (method);
938
939 /* Constructors and destructors go in special slots. */
940 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (method))
941 slot = CLASSTYPE_CONSTRUCTOR_SLOT;
942 else if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method))
943 {
944 slot = CLASSTYPE_DESTRUCTOR_SLOT;
945
946 if (TYPE_FOR_JAVA (type))
947 {
948 if (!DECL_ARTIFICIAL (method))
949 error ("Java class %qT cannot have a destructor", type);
950 else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
951 error ("Java class %qT cannot have an implicit non-trivial "
952 "destructor",
953 type);
954 }
955 }
956 else
957 {
958 tree m;
959
960 insert_p = true;
961 /* See if we already have an entry with this name. */
962 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
963 VEC_iterate (tree, method_vec, slot, m);
964 ++slot)
965 {
966 m = OVL_CURRENT (m);
967 if (template_conv_p)
968 {
969 if (TREE_CODE (m) == TEMPLATE_DECL
970 && DECL_TEMPLATE_CONV_FN_P (m))
971 insert_p = false;
972 break;
973 }
974 if (conv_p && !DECL_CONV_FN_P (m))
975 break;
976 if (DECL_NAME (m) == DECL_NAME (method))
977 {
978 insert_p = false;
979 break;
980 }
981 if (complete_p
982 && !DECL_CONV_FN_P (m)
983 && DECL_NAME (m) > DECL_NAME (method))
984 break;
985 }
986 }
987 current_fns = insert_p ? NULL_TREE : VEC_index (tree, method_vec, slot);
988
989 if (processing_template_decl)
990 /* TYPE is a template class. Don't issue any errors now; wait
991 until instantiation time to complain. */
992 ;
993 else
994 {
995 tree fns;
996
997 /* Check to see if we've already got this method. */
998 for (fns = current_fns; fns; fns = OVL_NEXT (fns))
999 {
1000 tree fn = OVL_CURRENT (fns);
1001 tree fn_type;
1002 tree method_type;
1003 tree parms1;
1004 tree parms2;
1005
1006 if (TREE_CODE (fn) != TREE_CODE (method))
1007 continue;
1008
1009 /* [over.load] Member function declarations with the
1010 same name and the same parameter types cannot be
1011 overloaded if any of them is a static member
1012 function declaration.
1013
1014 [namespace.udecl] When a using-declaration brings names
1015 from a base class into a derived class scope, member
1016 functions in the derived class override and/or hide member
1017 functions with the same name and parameter types in a base
1018 class (rather than conflicting). */
1019 fn_type = TREE_TYPE (fn);
1020 method_type = TREE_TYPE (method);
1021 parms1 = TYPE_ARG_TYPES (fn_type);
1022 parms2 = TYPE_ARG_TYPES (method_type);
1023
1024 /* Compare the quals on the 'this' parm. Don't compare
1025 the whole types, as used functions are treated as
1026 coming from the using class in overload resolution. */
1027 if (! DECL_STATIC_FUNCTION_P (fn)
1028 && ! DECL_STATIC_FUNCTION_P (method)
1029 && (TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms1)))
1030 != TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms2)))))
1031 continue;
1032
1033 /* For templates, the return type and template parameters
1034 must be identical. */
1035 if (TREE_CODE (fn) == TEMPLATE_DECL
1036 && (!same_type_p (TREE_TYPE (fn_type),
1037 TREE_TYPE (method_type))
1038 || !comp_template_parms (DECL_TEMPLATE_PARMS (fn),
1039 DECL_TEMPLATE_PARMS (method))))
1040 continue;
1041
1042 if (! DECL_STATIC_FUNCTION_P (fn))
1043 parms1 = TREE_CHAIN (parms1);
1044 if (! DECL_STATIC_FUNCTION_P (method))
1045 parms2 = TREE_CHAIN (parms2);
1046
1047 if (compparms (parms1, parms2)
1048 && (!DECL_CONV_FN_P (fn)
1049 || same_type_p (TREE_TYPE (fn_type),
1050 TREE_TYPE (method_type))))
1051 {
1052 if (using_decl)
1053 {
1054 if (DECL_CONTEXT (fn) == type)
1055 /* Defer to the local function. */
1056 return false;
1057 if (DECL_CONTEXT (fn) == DECL_CONTEXT (method))
1058 error ("repeated using declaration %q+D", using_decl);
1059 else
1060 error ("using declaration %q+D conflicts with a previous using declaration",
1061 using_decl);
1062 }
1063 else
1064 {
1065 error ("%q+#D cannot be overloaded", method);
1066 error ("with %q+#D", fn);
1067 }
1068
1069 /* We don't call duplicate_decls here to merge the
1070 declarations because that will confuse things if the
1071 methods have inline definitions. In particular, we
1072 will crash while processing the definitions. */
1073 return false;
1074 }
1075 }
1076 }
1077
1078 /* A class should never have more than one destructor. */
1079 if (current_fns && DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method))
1080 return false;
1081
1082 /* Add the new binding. */
1083 overload = build_overload (method, current_fns);
1084
1085 if (conv_p)
1086 TYPE_HAS_CONVERSION (type) = 1;
1087 else if (slot >= CLASSTYPE_FIRST_CONVERSION_SLOT && !complete_p)
1088 push_class_level_binding (DECL_NAME (method), overload);
1089
1090 if (insert_p)
1091 {
1092 bool reallocated;
1093
1094 /* We only expect to add few methods in the COMPLETE_P case, so
1095 just make room for one more method in that case. */
1096 if (complete_p)
1097 reallocated = VEC_reserve_exact (tree, gc, method_vec, 1);
1098 else
1099 reallocated = VEC_reserve (tree, gc, method_vec, 1);
1100 if (reallocated)
1101 CLASSTYPE_METHOD_VEC (type) = method_vec;
1102 if (slot == VEC_length (tree, method_vec))
1103 VEC_quick_push (tree, method_vec, overload);
1104 else
1105 VEC_quick_insert (tree, method_vec, slot, overload);
1106 }
1107 else
1108 /* Replace the current slot. */
1109 VEC_replace (tree, method_vec, slot, overload);
1110 return true;
1111 }
1112
1113 /* Subroutines of finish_struct. */
1114
1115 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1116 legit, otherwise return 0. */
1117
1118 static int
alter_access(tree t,tree fdecl,tree access)1119 alter_access (tree t, tree fdecl, tree access)
1120 {
1121 tree elem;
1122
1123 if (!DECL_LANG_SPECIFIC (fdecl))
1124 retrofit_lang_decl (fdecl);
1125
1126 gcc_assert (!DECL_DISCRIMINATOR_P (fdecl));
1127
1128 elem = purpose_member (t, DECL_ACCESS (fdecl));
1129 if (elem)
1130 {
1131 if (TREE_VALUE (elem) != access)
1132 {
1133 if (TREE_CODE (TREE_TYPE (fdecl)) == FUNCTION_DECL)
1134 error ("conflicting access specifications for method"
1135 " %q+D, ignored", TREE_TYPE (fdecl));
1136 else
1137 error ("conflicting access specifications for field %qE, ignored",
1138 DECL_NAME (fdecl));
1139 }
1140 else
1141 {
1142 /* They're changing the access to the same thing they changed
1143 it to before. That's OK. */
1144 ;
1145 }
1146 }
1147 else
1148 {
1149 perform_or_defer_access_check (TYPE_BINFO (t), fdecl, fdecl);
1150 DECL_ACCESS (fdecl) = tree_cons (t, access, DECL_ACCESS (fdecl));
1151 return 1;
1152 }
1153 return 0;
1154 }
1155
1156 /* Process the USING_DECL, which is a member of T. */
1157
1158 static void
handle_using_decl(tree using_decl,tree t)1159 handle_using_decl (tree using_decl, tree t)
1160 {
1161 tree decl = USING_DECL_DECLS (using_decl);
1162 tree name = DECL_NAME (using_decl);
1163 tree access
1164 = TREE_PRIVATE (using_decl) ? access_private_node
1165 : TREE_PROTECTED (using_decl) ? access_protected_node
1166 : access_public_node;
1167 tree flist = NULL_TREE;
1168 tree old_value;
1169
1170 gcc_assert (!processing_template_decl && decl);
1171
1172 old_value = lookup_member (t, name, /*protect=*/0, /*want_type=*/false);
1173 if (old_value)
1174 {
1175 if (is_overloaded_fn (old_value))
1176 old_value = OVL_CURRENT (old_value);
1177
1178 if (DECL_P (old_value) && DECL_CONTEXT (old_value) == t)
1179 /* OK */;
1180 else
1181 old_value = NULL_TREE;
1182 }
1183
1184 cp_emit_debug_info_for_using (decl, USING_DECL_SCOPE (using_decl));
1185
1186 if (is_overloaded_fn (decl))
1187 flist = decl;
1188
1189 if (! old_value)
1190 ;
1191 else if (is_overloaded_fn (old_value))
1192 {
1193 if (flist)
1194 /* It's OK to use functions from a base when there are functions with
1195 the same name already present in the current class. */;
1196 else
1197 {
1198 error ("%q+D invalid in %q#T", using_decl, t);
1199 error (" because of local method %q+#D with same name",
1200 OVL_CURRENT (old_value));
1201 return;
1202 }
1203 }
1204 else if (!DECL_ARTIFICIAL (old_value))
1205 {
1206 error ("%q+D invalid in %q#T", using_decl, t);
1207 error (" because of local member %q+#D with same name", old_value);
1208 return;
1209 }
1210
1211 /* Make type T see field decl FDECL with access ACCESS. */
1212 if (flist)
1213 for (; flist; flist = OVL_NEXT (flist))
1214 {
1215 add_method (t, OVL_CURRENT (flist), using_decl);
1216 alter_access (t, OVL_CURRENT (flist), access);
1217 }
1218 else
1219 alter_access (t, decl, access);
1220 }
1221
1222 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1223 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1224 properties of the bases. */
1225
1226 static void
check_bases(tree t,int * cant_have_const_ctor_p,int * no_const_asn_ref_p)1227 check_bases (tree t,
1228 int* cant_have_const_ctor_p,
1229 int* no_const_asn_ref_p)
1230 {
1231 int i;
1232 int seen_non_virtual_nearly_empty_base_p;
1233 tree base_binfo;
1234 tree binfo;
1235
1236 seen_non_virtual_nearly_empty_base_p = 0;
1237
1238 for (binfo = TYPE_BINFO (t), i = 0;
1239 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
1240 {
1241 tree basetype = TREE_TYPE (base_binfo);
1242
1243 gcc_assert (COMPLETE_TYPE_P (basetype));
1244
1245 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1246 here because the case of virtual functions but non-virtual
1247 dtor is handled in finish_struct_1. */
1248 if (!TYPE_POLYMORPHIC_P (basetype))
1249 warning (OPT_Weffc__,
1250 "base class %q#T has a non-virtual destructor", basetype);
1251
1252 /* If the base class doesn't have copy constructors or
1253 assignment operators that take const references, then the
1254 derived class cannot have such a member automatically
1255 generated. */
1256 if (! TYPE_HAS_CONST_INIT_REF (basetype))
1257 *cant_have_const_ctor_p = 1;
1258 if (TYPE_HAS_ASSIGN_REF (basetype)
1259 && !TYPE_HAS_CONST_ASSIGN_REF (basetype))
1260 *no_const_asn_ref_p = 1;
1261
1262 if (BINFO_VIRTUAL_P (base_binfo))
1263 /* A virtual base does not effect nearly emptiness. */
1264 ;
1265 else if (CLASSTYPE_NEARLY_EMPTY_P (basetype))
1266 {
1267 if (seen_non_virtual_nearly_empty_base_p)
1268 /* And if there is more than one nearly empty base, then the
1269 derived class is not nearly empty either. */
1270 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1271 else
1272 /* Remember we've seen one. */
1273 seen_non_virtual_nearly_empty_base_p = 1;
1274 }
1275 else if (!is_empty_class (basetype))
1276 /* If the base class is not empty or nearly empty, then this
1277 class cannot be nearly empty. */
1278 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1279
1280 /* A lot of properties from the bases also apply to the derived
1281 class. */
1282 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (basetype);
1283 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
1284 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype);
1285 TYPE_HAS_COMPLEX_ASSIGN_REF (t)
1286 |= TYPE_HAS_COMPLEX_ASSIGN_REF (basetype);
1287 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (basetype);
1288 TYPE_POLYMORPHIC_P (t) |= TYPE_POLYMORPHIC_P (basetype);
1289 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t)
1290 |= CLASSTYPE_CONTAINS_EMPTY_CLASS_P (basetype);
1291 }
1292 }
1293
1294 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1295 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1296 that have had a nearly-empty virtual primary base stolen by some
1297 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1298 T. */
1299
1300 static void
determine_primary_bases(tree t)1301 determine_primary_bases (tree t)
1302 {
1303 unsigned i;
1304 tree primary = NULL_TREE;
1305 tree type_binfo = TYPE_BINFO (t);
1306 tree base_binfo;
1307
1308 /* Determine the primary bases of our bases. */
1309 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1310 base_binfo = TREE_CHAIN (base_binfo))
1311 {
1312 tree primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (base_binfo));
1313
1314 /* See if we're the non-virtual primary of our inheritance
1315 chain. */
1316 if (!BINFO_VIRTUAL_P (base_binfo))
1317 {
1318 tree parent = BINFO_INHERITANCE_CHAIN (base_binfo);
1319 tree parent_primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (parent));
1320
1321 if (parent_primary
1322 && SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo),
1323 BINFO_TYPE (parent_primary)))
1324 /* We are the primary binfo. */
1325 BINFO_PRIMARY_P (base_binfo) = 1;
1326 }
1327 /* Determine if we have a virtual primary base, and mark it so.
1328 */
1329 if (primary && BINFO_VIRTUAL_P (primary))
1330 {
1331 tree this_primary = copied_binfo (primary, base_binfo);
1332
1333 if (BINFO_PRIMARY_P (this_primary))
1334 /* Someone already claimed this base. */
1335 BINFO_LOST_PRIMARY_P (base_binfo) = 1;
1336 else
1337 {
1338 tree delta;
1339
1340 BINFO_PRIMARY_P (this_primary) = 1;
1341 BINFO_INHERITANCE_CHAIN (this_primary) = base_binfo;
1342
1343 /* A virtual binfo might have been copied from within
1344 another hierarchy. As we're about to use it as a
1345 primary base, make sure the offsets match. */
1346 delta = size_diffop (convert (ssizetype,
1347 BINFO_OFFSET (base_binfo)),
1348 convert (ssizetype,
1349 BINFO_OFFSET (this_primary)));
1350
1351 propagate_binfo_offsets (this_primary, delta);
1352 }
1353 }
1354 }
1355
1356 /* First look for a dynamic direct non-virtual base. */
1357 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, base_binfo); i++)
1358 {
1359 tree basetype = BINFO_TYPE (base_binfo);
1360
1361 if (TYPE_CONTAINS_VPTR_P (basetype) && !BINFO_VIRTUAL_P (base_binfo))
1362 {
1363 primary = base_binfo;
1364 goto found;
1365 }
1366 }
1367
1368 /* A "nearly-empty" virtual base class can be the primary base
1369 class, if no non-virtual polymorphic base can be found. Look for
1370 a nearly-empty virtual dynamic base that is not already a primary
1371 base of something in the hierarchy. If there is no such base,
1372 just pick the first nearly-empty virtual base. */
1373
1374 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1375 base_binfo = TREE_CHAIN (base_binfo))
1376 if (BINFO_VIRTUAL_P (base_binfo)
1377 && CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (base_binfo)))
1378 {
1379 if (!BINFO_PRIMARY_P (base_binfo))
1380 {
1381 /* Found one that is not primary. */
1382 primary = base_binfo;
1383 goto found;
1384 }
1385 else if (!primary)
1386 /* Remember the first candidate. */
1387 primary = base_binfo;
1388 }
1389
1390 found:
1391 /* If we've got a primary base, use it. */
1392 if (primary)
1393 {
1394 tree basetype = BINFO_TYPE (primary);
1395
1396 CLASSTYPE_PRIMARY_BINFO (t) = primary;
1397 if (BINFO_PRIMARY_P (primary))
1398 /* We are stealing a primary base. */
1399 BINFO_LOST_PRIMARY_P (BINFO_INHERITANCE_CHAIN (primary)) = 1;
1400 BINFO_PRIMARY_P (primary) = 1;
1401 if (BINFO_VIRTUAL_P (primary))
1402 {
1403 tree delta;
1404
1405 BINFO_INHERITANCE_CHAIN (primary) = type_binfo;
1406 /* A virtual binfo might have been copied from within
1407 another hierarchy. As we're about to use it as a primary
1408 base, make sure the offsets match. */
1409 delta = size_diffop (ssize_int (0),
1410 convert (ssizetype, BINFO_OFFSET (primary)));
1411
1412 propagate_binfo_offsets (primary, delta);
1413 }
1414
1415 primary = TYPE_BINFO (basetype);
1416
1417 TYPE_VFIELD (t) = TYPE_VFIELD (basetype);
1418 BINFO_VTABLE (type_binfo) = BINFO_VTABLE (primary);
1419 BINFO_VIRTUALS (type_binfo) = BINFO_VIRTUALS (primary);
1420 }
1421 }
1422
1423 /* Set memoizing fields and bits of T (and its variants) for later
1424 use. */
1425
1426 static void
finish_struct_bits(tree t)1427 finish_struct_bits (tree t)
1428 {
1429 tree variants;
1430
1431 /* Fix up variants (if any). */
1432 for (variants = TYPE_NEXT_VARIANT (t);
1433 variants;
1434 variants = TYPE_NEXT_VARIANT (variants))
1435 {
1436 /* These fields are in the _TYPE part of the node, not in
1437 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1438 TYPE_HAS_CONSTRUCTOR (variants) = TYPE_HAS_CONSTRUCTOR (t);
1439 TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t);
1440 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variants)
1441 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
1442
1443 TYPE_POLYMORPHIC_P (variants) = TYPE_POLYMORPHIC_P (t);
1444
1445 TYPE_BINFO (variants) = TYPE_BINFO (t);
1446
1447 /* Copy whatever these are holding today. */
1448 TYPE_VFIELD (variants) = TYPE_VFIELD (t);
1449 TYPE_METHODS (variants) = TYPE_METHODS (t);
1450 TYPE_FIELDS (variants) = TYPE_FIELDS (t);
1451 }
1452
1453 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) && TYPE_POLYMORPHIC_P (t))
1454 /* For a class w/o baseclasses, 'finish_struct' has set
1455 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1456 Similarly for a class whose base classes do not have vtables.
1457 When neither of these is true, we might have removed abstract
1458 virtuals (by providing a definition), added some (by declaring
1459 new ones), or redeclared ones from a base class. We need to
1460 recalculate what's really an abstract virtual at this point (by
1461 looking in the vtables). */
1462 get_pure_virtuals (t);
1463
1464 /* If this type has a copy constructor or a destructor, force its
1465 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1466 nonzero. This will cause it to be passed by invisible reference
1467 and prevent it from being returned in a register. */
1468 if (! TYPE_HAS_TRIVIAL_INIT_REF (t) || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
1469 {
1470 tree variants;
1471 DECL_MODE (TYPE_MAIN_DECL (t)) = BLKmode;
1472 for (variants = t; variants; variants = TYPE_NEXT_VARIANT (variants))
1473 {
1474 TYPE_MODE (variants) = BLKmode;
1475 TREE_ADDRESSABLE (variants) = 1;
1476 }
1477 }
1478 }
1479
1480 /* Issue warnings about T having private constructors, but no friends,
1481 and so forth.
1482
1483 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1484 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1485 non-private static member functions. */
1486
1487 static void
maybe_warn_about_overly_private_class(tree t)1488 maybe_warn_about_overly_private_class (tree t)
1489 {
1490 int has_member_fn = 0;
1491 int has_nonprivate_method = 0;
1492 tree fn;
1493
1494 if (!warn_ctor_dtor_privacy
1495 /* If the class has friends, those entities might create and
1496 access instances, so we should not warn. */
1497 || (CLASSTYPE_FRIEND_CLASSES (t)
1498 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))
1499 /* We will have warned when the template was declared; there's
1500 no need to warn on every instantiation. */
1501 || CLASSTYPE_TEMPLATE_INSTANTIATION (t))
1502 /* There's no reason to even consider warning about this
1503 class. */
1504 return;
1505
1506 /* We only issue one warning, if more than one applies, because
1507 otherwise, on code like:
1508
1509 class A {
1510 // Oops - forgot `public:'
1511 A();
1512 A(const A&);
1513 ~A();
1514 };
1515
1516 we warn several times about essentially the same problem. */
1517
1518 /* Check to see if all (non-constructor, non-destructor) member
1519 functions are private. (Since there are no friends or
1520 non-private statics, we can't ever call any of the private member
1521 functions.) */
1522 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
1523 /* We're not interested in compiler-generated methods; they don't
1524 provide any way to call private members. */
1525 if (!DECL_ARTIFICIAL (fn))
1526 {
1527 if (!TREE_PRIVATE (fn))
1528 {
1529 if (DECL_STATIC_FUNCTION_P (fn))
1530 /* A non-private static member function is just like a
1531 friend; it can create and invoke private member
1532 functions, and be accessed without a class
1533 instance. */
1534 return;
1535
1536 has_nonprivate_method = 1;
1537 /* Keep searching for a static member function. */
1538 }
1539 else if (!DECL_CONSTRUCTOR_P (fn) && !DECL_DESTRUCTOR_P (fn))
1540 has_member_fn = 1;
1541 }
1542
1543 if (!has_nonprivate_method && has_member_fn)
1544 {
1545 /* There are no non-private methods, and there's at least one
1546 private member function that isn't a constructor or
1547 destructor. (If all the private members are
1548 constructors/destructors we want to use the code below that
1549 issues error messages specifically referring to
1550 constructors/destructors.) */
1551 unsigned i;
1552 tree binfo = TYPE_BINFO (t);
1553
1554 for (i = 0; i != BINFO_N_BASE_BINFOS (binfo); i++)
1555 if (BINFO_BASE_ACCESS (binfo, i) != access_private_node)
1556 {
1557 has_nonprivate_method = 1;
1558 break;
1559 }
1560 if (!has_nonprivate_method)
1561 {
1562 warning (OPT_Wctor_dtor_privacy,
1563 "all member functions in class %qT are private", t);
1564 return;
1565 }
1566 }
1567
1568 /* Even if some of the member functions are non-private, the class
1569 won't be useful for much if all the constructors or destructors
1570 are private: such an object can never be created or destroyed. */
1571 fn = CLASSTYPE_DESTRUCTORS (t);
1572 if (fn && TREE_PRIVATE (fn))
1573 {
1574 warning (OPT_Wctor_dtor_privacy,
1575 "%q#T only defines a private destructor and has no friends",
1576 t);
1577 return;
1578 }
1579
1580 if (TYPE_HAS_CONSTRUCTOR (t)
1581 /* Implicitly generated constructors are always public. */
1582 && (!CLASSTYPE_LAZY_DEFAULT_CTOR (t)
1583 || !CLASSTYPE_LAZY_COPY_CTOR (t)))
1584 {
1585 int nonprivate_ctor = 0;
1586
1587 /* If a non-template class does not define a copy
1588 constructor, one is defined for it, enabling it to avoid
1589 this warning. For a template class, this does not
1590 happen, and so we would normally get a warning on:
1591
1592 template <class T> class C { private: C(); };
1593
1594 To avoid this asymmetry, we check TYPE_HAS_INIT_REF. All
1595 complete non-template or fully instantiated classes have this
1596 flag set. */
1597 if (!TYPE_HAS_INIT_REF (t))
1598 nonprivate_ctor = 1;
1599 else
1600 for (fn = CLASSTYPE_CONSTRUCTORS (t); fn; fn = OVL_NEXT (fn))
1601 {
1602 tree ctor = OVL_CURRENT (fn);
1603 /* Ideally, we wouldn't count copy constructors (or, in
1604 fact, any constructor that takes an argument of the
1605 class type as a parameter) because such things cannot
1606 be used to construct an instance of the class unless
1607 you already have one. But, for now at least, we're
1608 more generous. */
1609 if (! TREE_PRIVATE (ctor))
1610 {
1611 nonprivate_ctor = 1;
1612 break;
1613 }
1614 }
1615
1616 if (nonprivate_ctor == 0)
1617 {
1618 warning (OPT_Wctor_dtor_privacy,
1619 "%q#T only defines private constructors and has no friends",
1620 t);
1621 return;
1622 }
1623 }
1624 }
1625
1626 static struct {
1627 gt_pointer_operator new_value;
1628 void *cookie;
1629 } resort_data;
1630
1631 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1632
1633 static int
method_name_cmp(const void * m1_p,const void * m2_p)1634 method_name_cmp (const void* m1_p, const void* m2_p)
1635 {
1636 const tree *const m1 = (const tree *) m1_p;
1637 const tree *const m2 = (const tree *) m2_p;
1638
1639 if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1640 return 0;
1641 if (*m1 == NULL_TREE)
1642 return -1;
1643 if (*m2 == NULL_TREE)
1644 return 1;
1645 if (DECL_NAME (OVL_CURRENT (*m1)) < DECL_NAME (OVL_CURRENT (*m2)))
1646 return -1;
1647 return 1;
1648 }
1649
1650 /* This routine compares two fields like method_name_cmp but using the
1651 pointer operator in resort_field_decl_data. */
1652
1653 static int
resort_method_name_cmp(const void * m1_p,const void * m2_p)1654 resort_method_name_cmp (const void* m1_p, const void* m2_p)
1655 {
1656 const tree *const m1 = (const tree *) m1_p;
1657 const tree *const m2 = (const tree *) m2_p;
1658 if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1659 return 0;
1660 if (*m1 == NULL_TREE)
1661 return -1;
1662 if (*m2 == NULL_TREE)
1663 return 1;
1664 {
1665 tree d1 = DECL_NAME (OVL_CURRENT (*m1));
1666 tree d2 = DECL_NAME (OVL_CURRENT (*m2));
1667 resort_data.new_value (&d1, resort_data.cookie);
1668 resort_data.new_value (&d2, resort_data.cookie);
1669 if (d1 < d2)
1670 return -1;
1671 }
1672 return 1;
1673 }
1674
1675 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1676
1677 void
resort_type_method_vec(void * obj,void * orig_obj ATTRIBUTE_UNUSED,gt_pointer_operator new_value,void * cookie)1678 resort_type_method_vec (void* obj,
1679 void* orig_obj ATTRIBUTE_UNUSED ,
1680 gt_pointer_operator new_value,
1681 void* cookie)
1682 {
1683 VEC(tree,gc) *method_vec = (VEC(tree,gc) *) obj;
1684 int len = VEC_length (tree, method_vec);
1685 size_t slot;
1686 tree fn;
1687
1688 /* The type conversion ops have to live at the front of the vec, so we
1689 can't sort them. */
1690 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1691 VEC_iterate (tree, method_vec, slot, fn);
1692 ++slot)
1693 if (!DECL_CONV_FN_P (OVL_CURRENT (fn)))
1694 break;
1695
1696 if (len - slot > 1)
1697 {
1698 resort_data.new_value = new_value;
1699 resort_data.cookie = cookie;
1700 qsort (VEC_address (tree, method_vec) + slot, len - slot, sizeof (tree),
1701 resort_method_name_cmp);
1702 }
1703 }
1704
1705 /* Warn about duplicate methods in fn_fields.
1706
1707 Sort methods that are not special (i.e., constructors, destructors,
1708 and type conversion operators) so that we can find them faster in
1709 search. */
1710
1711 static void
finish_struct_methods(tree t)1712 finish_struct_methods (tree t)
1713 {
1714 tree fn_fields;
1715 VEC(tree,gc) *method_vec;
1716 int slot, len;
1717
1718 method_vec = CLASSTYPE_METHOD_VEC (t);
1719 if (!method_vec)
1720 return;
1721
1722 len = VEC_length (tree, method_vec);
1723
1724 /* Clear DECL_IN_AGGR_P for all functions. */
1725 for (fn_fields = TYPE_METHODS (t); fn_fields;
1726 fn_fields = TREE_CHAIN (fn_fields))
1727 DECL_IN_AGGR_P (fn_fields) = 0;
1728
1729 /* Issue warnings about private constructors and such. If there are
1730 no methods, then some public defaults are generated. */
1731 maybe_warn_about_overly_private_class (t);
1732
1733 /* The type conversion ops have to live at the front of the vec, so we
1734 can't sort them. */
1735 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1736 VEC_iterate (tree, method_vec, slot, fn_fields);
1737 ++slot)
1738 if (!DECL_CONV_FN_P (OVL_CURRENT (fn_fields)))
1739 break;
1740 if (len - slot > 1)
1741 qsort (VEC_address (tree, method_vec) + slot,
1742 len-slot, sizeof (tree), method_name_cmp);
1743 }
1744
1745 /* Make BINFO's vtable have N entries, including RTTI entries,
1746 vbase and vcall offsets, etc. Set its type and call the backend
1747 to lay it out. */
1748
1749 static void
layout_vtable_decl(tree binfo,int n)1750 layout_vtable_decl (tree binfo, int n)
1751 {
1752 tree atype;
1753 tree vtable;
1754
1755 atype = build_cplus_array_type (vtable_entry_type,
1756 build_index_type (size_int (n - 1)));
1757 layout_type (atype);
1758
1759 /* We may have to grow the vtable. */
1760 vtable = get_vtbl_decl_for_binfo (binfo);
1761 if (!same_type_p (TREE_TYPE (vtable), atype))
1762 {
1763 TREE_TYPE (vtable) = atype;
1764 DECL_SIZE (vtable) = DECL_SIZE_UNIT (vtable) = NULL_TREE;
1765 layout_decl (vtable, 0);
1766 }
1767 }
1768
1769 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1770 have the same signature. */
1771
1772 int
same_signature_p(tree fndecl,tree base_fndecl)1773 same_signature_p (tree fndecl, tree base_fndecl)
1774 {
1775 /* One destructor overrides another if they are the same kind of
1776 destructor. */
1777 if (DECL_DESTRUCTOR_P (base_fndecl) && DECL_DESTRUCTOR_P (fndecl)
1778 && special_function_p (base_fndecl) == special_function_p (fndecl))
1779 return 1;
1780 /* But a non-destructor never overrides a destructor, nor vice
1781 versa, nor do different kinds of destructors override
1782 one-another. For example, a complete object destructor does not
1783 override a deleting destructor. */
1784 if (DECL_DESTRUCTOR_P (base_fndecl) || DECL_DESTRUCTOR_P (fndecl))
1785 return 0;
1786
1787 if (DECL_NAME (fndecl) == DECL_NAME (base_fndecl)
1788 || (DECL_CONV_FN_P (fndecl)
1789 && DECL_CONV_FN_P (base_fndecl)
1790 && same_type_p (DECL_CONV_FN_TYPE (fndecl),
1791 DECL_CONV_FN_TYPE (base_fndecl))))
1792 {
1793 tree types, base_types;
1794 types = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
1795 base_types = TYPE_ARG_TYPES (TREE_TYPE (base_fndecl));
1796 if ((TYPE_QUALS (TREE_TYPE (TREE_VALUE (base_types)))
1797 == TYPE_QUALS (TREE_TYPE (TREE_VALUE (types))))
1798 && compparms (TREE_CHAIN (base_types), TREE_CHAIN (types)))
1799 return 1;
1800 }
1801 return 0;
1802 }
1803
1804 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1805 subobject. */
1806
1807 static bool
base_derived_from(tree derived,tree base)1808 base_derived_from (tree derived, tree base)
1809 {
1810 tree probe;
1811
1812 for (probe = base; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
1813 {
1814 if (probe == derived)
1815 return true;
1816 else if (BINFO_VIRTUAL_P (probe))
1817 /* If we meet a virtual base, we can't follow the inheritance
1818 any more. See if the complete type of DERIVED contains
1819 such a virtual base. */
1820 return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (derived))
1821 != NULL_TREE);
1822 }
1823 return false;
1824 }
1825
1826 typedef struct find_final_overrider_data_s {
1827 /* The function for which we are trying to find a final overrider. */
1828 tree fn;
1829 /* The base class in which the function was declared. */
1830 tree declaring_base;
1831 /* The candidate overriders. */
1832 tree candidates;
1833 /* Path to most derived. */
1834 VEC(tree,heap) *path;
1835 } find_final_overrider_data;
1836
1837 /* Add the overrider along the current path to FFOD->CANDIDATES.
1838 Returns true if an overrider was found; false otherwise. */
1839
1840 static bool
dfs_find_final_overrider_1(tree binfo,find_final_overrider_data * ffod,unsigned depth)1841 dfs_find_final_overrider_1 (tree binfo,
1842 find_final_overrider_data *ffod,
1843 unsigned depth)
1844 {
1845 tree method;
1846
1847 /* If BINFO is not the most derived type, try a more derived class.
1848 A definition there will overrider a definition here. */
1849 if (depth)
1850 {
1851 depth--;
1852 if (dfs_find_final_overrider_1
1853 (VEC_index (tree, ffod->path, depth), ffod, depth))
1854 return true;
1855 }
1856
1857 method = look_for_overrides_here (BINFO_TYPE (binfo), ffod->fn);
1858 if (method)
1859 {
1860 tree *candidate = &ffod->candidates;
1861
1862 /* Remove any candidates overridden by this new function. */
1863 while (*candidate)
1864 {
1865 /* If *CANDIDATE overrides METHOD, then METHOD
1866 cannot override anything else on the list. */
1867 if (base_derived_from (TREE_VALUE (*candidate), binfo))
1868 return true;
1869 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
1870 if (base_derived_from (binfo, TREE_VALUE (*candidate)))
1871 *candidate = TREE_CHAIN (*candidate);
1872 else
1873 candidate = &TREE_CHAIN (*candidate);
1874 }
1875
1876 /* Add the new function. */
1877 ffod->candidates = tree_cons (method, binfo, ffod->candidates);
1878 return true;
1879 }
1880
1881 return false;
1882 }
1883
1884 /* Called from find_final_overrider via dfs_walk. */
1885
1886 static tree
dfs_find_final_overrider_pre(tree binfo,void * data)1887 dfs_find_final_overrider_pre (tree binfo, void *data)
1888 {
1889 find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1890
1891 if (binfo == ffod->declaring_base)
1892 dfs_find_final_overrider_1 (binfo, ffod, VEC_length (tree, ffod->path));
1893 VEC_safe_push (tree, heap, ffod->path, binfo);
1894
1895 return NULL_TREE;
1896 }
1897
1898 static tree
dfs_find_final_overrider_post(tree binfo ATTRIBUTE_UNUSED,void * data)1899 dfs_find_final_overrider_post (tree binfo ATTRIBUTE_UNUSED, void *data)
1900 {
1901 find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1902 VEC_pop (tree, ffod->path);
1903
1904 return NULL_TREE;
1905 }
1906
1907 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
1908 FN and whose TREE_VALUE is the binfo for the base where the
1909 overriding occurs. BINFO (in the hierarchy dominated by the binfo
1910 DERIVED) is the base object in which FN is declared. */
1911
1912 static tree
find_final_overrider(tree derived,tree binfo,tree fn)1913 find_final_overrider (tree derived, tree binfo, tree fn)
1914 {
1915 find_final_overrider_data ffod;
1916
1917 /* Getting this right is a little tricky. This is valid:
1918
1919 struct S { virtual void f (); };
1920 struct T { virtual void f (); };
1921 struct U : public S, public T { };
1922
1923 even though calling `f' in `U' is ambiguous. But,
1924
1925 struct R { virtual void f(); };
1926 struct S : virtual public R { virtual void f (); };
1927 struct T : virtual public R { virtual void f (); };
1928 struct U : public S, public T { };
1929
1930 is not -- there's no way to decide whether to put `S::f' or
1931 `T::f' in the vtable for `R'.
1932
1933 The solution is to look at all paths to BINFO. If we find
1934 different overriders along any two, then there is a problem. */
1935 if (DECL_THUNK_P (fn))
1936 fn = THUNK_TARGET (fn);
1937
1938 /* Determine the depth of the hierarchy. */
1939 ffod.fn = fn;
1940 ffod.declaring_base = binfo;
1941 ffod.candidates = NULL_TREE;
1942 ffod.path = VEC_alloc (tree, heap, 30);
1943
1944 dfs_walk_all (derived, dfs_find_final_overrider_pre,
1945 dfs_find_final_overrider_post, &ffod);
1946
1947 VEC_free (tree, heap, ffod.path);
1948
1949 /* If there was no winner, issue an error message. */
1950 if (!ffod.candidates || TREE_CHAIN (ffod.candidates))
1951 return error_mark_node;
1952
1953 return ffod.candidates;
1954 }
1955
1956 /* Return the index of the vcall offset for FN when TYPE is used as a
1957 virtual base. */
1958
1959 static tree
get_vcall_index(tree fn,tree type)1960 get_vcall_index (tree fn, tree type)
1961 {
1962 VEC(tree_pair_s,gc) *indices = CLASSTYPE_VCALL_INDICES (type);
1963 tree_pair_p p;
1964 unsigned ix;
1965
1966 for (ix = 0; VEC_iterate (tree_pair_s, indices, ix, p); ix++)
1967 if ((DECL_DESTRUCTOR_P (fn) && DECL_DESTRUCTOR_P (p->purpose))
1968 || same_signature_p (fn, p->purpose))
1969 return p->value;
1970
1971 /* There should always be an appropriate index. */
1972 gcc_unreachable ();
1973 }
1974
1975 /* Update an entry in the vtable for BINFO, which is in the hierarchy
1976 dominated by T. FN has been overridden in BINFO; VIRTUALS points to the
1977 corresponding position in the BINFO_VIRTUALS list. */
1978
1979 static void
update_vtable_entry_for_fn(tree t,tree binfo,tree fn,tree * virtuals,unsigned ix)1980 update_vtable_entry_for_fn (tree t, tree binfo, tree fn, tree* virtuals,
1981 unsigned ix)
1982 {
1983 tree b;
1984 tree overrider;
1985 tree delta;
1986 tree virtual_base;
1987 tree first_defn;
1988 tree overrider_fn, overrider_target;
1989 tree target_fn = DECL_THUNK_P (fn) ? THUNK_TARGET (fn) : fn;
1990 tree over_return, base_return;
1991 bool lost = false;
1992
1993 /* Find the nearest primary base (possibly binfo itself) which defines
1994 this function; this is the class the caller will convert to when
1995 calling FN through BINFO. */
1996 for (b = binfo; ; b = get_primary_binfo (b))
1997 {
1998 gcc_assert (b);
1999 if (look_for_overrides_here (BINFO_TYPE (b), target_fn))
2000 break;
2001
2002 /* The nearest definition is from a lost primary. */
2003 if (BINFO_LOST_PRIMARY_P (b))
2004 lost = true;
2005 }
2006 first_defn = b;
2007
2008 /* Find the final overrider. */
2009 overrider = find_final_overrider (TYPE_BINFO (t), b, target_fn);
2010 if (overrider == error_mark_node)
2011 {
2012 error ("no unique final overrider for %qD in %qT", target_fn, t);
2013 return;
2014 }
2015 overrider_target = overrider_fn = TREE_PURPOSE (overrider);
2016
2017 /* Check for adjusting covariant return types. */
2018 over_return = TREE_TYPE (TREE_TYPE (overrider_target));
2019 base_return = TREE_TYPE (TREE_TYPE (target_fn));
2020
2021 if (POINTER_TYPE_P (over_return)
2022 && TREE_CODE (over_return) == TREE_CODE (base_return)
2023 && CLASS_TYPE_P (TREE_TYPE (over_return))
2024 && CLASS_TYPE_P (TREE_TYPE (base_return))
2025 /* If the overrider is invalid, don't even try. */
2026 && !DECL_INVALID_OVERRIDER_P (overrider_target))
2027 {
2028 /* If FN is a covariant thunk, we must figure out the adjustment
2029 to the final base FN was converting to. As OVERRIDER_TARGET might
2030 also be converting to the return type of FN, we have to
2031 combine the two conversions here. */
2032 tree fixed_offset, virtual_offset;
2033
2034 over_return = TREE_TYPE (over_return);
2035 base_return = TREE_TYPE (base_return);
2036
2037 if (DECL_THUNK_P (fn))
2038 {
2039 gcc_assert (DECL_RESULT_THUNK_P (fn));
2040 fixed_offset = ssize_int (THUNK_FIXED_OFFSET (fn));
2041 virtual_offset = THUNK_VIRTUAL_OFFSET (fn);
2042 }
2043 else
2044 fixed_offset = virtual_offset = NULL_TREE;
2045
2046 if (virtual_offset)
2047 /* Find the equivalent binfo within the return type of the
2048 overriding function. We will want the vbase offset from
2049 there. */
2050 virtual_offset = binfo_for_vbase (BINFO_TYPE (virtual_offset),
2051 over_return);
2052 else if (!same_type_ignoring_top_level_qualifiers_p
2053 (over_return, base_return))
2054 {
2055 /* There was no existing virtual thunk (which takes
2056 precedence). So find the binfo of the base function's
2057 return type within the overriding function's return type.
2058 We cannot call lookup base here, because we're inside a
2059 dfs_walk, and will therefore clobber the BINFO_MARKED
2060 flags. Fortunately we know the covariancy is valid (it
2061 has already been checked), so we can just iterate along
2062 the binfos, which have been chained in inheritance graph
2063 order. Of course it is lame that we have to repeat the
2064 search here anyway -- we should really be caching pieces
2065 of the vtable and avoiding this repeated work. */
2066 tree thunk_binfo, base_binfo;
2067
2068 /* Find the base binfo within the overriding function's
2069 return type. We will always find a thunk_binfo, except
2070 when the covariancy is invalid (which we will have
2071 already diagnosed). */
2072 for (base_binfo = TYPE_BINFO (base_return),
2073 thunk_binfo = TYPE_BINFO (over_return);
2074 thunk_binfo;
2075 thunk_binfo = TREE_CHAIN (thunk_binfo))
2076 if (SAME_BINFO_TYPE_P (BINFO_TYPE (thunk_binfo),
2077 BINFO_TYPE (base_binfo)))
2078 break;
2079
2080 /* See if virtual inheritance is involved. */
2081 for (virtual_offset = thunk_binfo;
2082 virtual_offset;
2083 virtual_offset = BINFO_INHERITANCE_CHAIN (virtual_offset))
2084 if (BINFO_VIRTUAL_P (virtual_offset))
2085 break;
2086
2087 if (virtual_offset
2088 || (thunk_binfo && !BINFO_OFFSET_ZEROP (thunk_binfo)))
2089 {
2090 tree offset = convert (ssizetype, BINFO_OFFSET (thunk_binfo));
2091
2092 if (virtual_offset)
2093 {
2094 /* We convert via virtual base. Adjust the fixed
2095 offset to be from there. */
2096 offset = size_diffop
2097 (offset, convert
2098 (ssizetype, BINFO_OFFSET (virtual_offset)));
2099 }
2100 if (fixed_offset)
2101 /* There was an existing fixed offset, this must be
2102 from the base just converted to, and the base the
2103 FN was thunking to. */
2104 fixed_offset = size_binop (PLUS_EXPR, fixed_offset, offset);
2105 else
2106 fixed_offset = offset;
2107 }
2108 }
2109
2110 if (fixed_offset || virtual_offset)
2111 /* Replace the overriding function with a covariant thunk. We
2112 will emit the overriding function in its own slot as
2113 well. */
2114 overrider_fn = make_thunk (overrider_target, /*this_adjusting=*/0,
2115 fixed_offset, virtual_offset);
2116 }
2117 else
2118 gcc_assert (!DECL_THUNK_P (fn));
2119
2120 /* Assume that we will produce a thunk that convert all the way to
2121 the final overrider, and not to an intermediate virtual base. */
2122 virtual_base = NULL_TREE;
2123
2124 /* See if we can convert to an intermediate virtual base first, and then
2125 use the vcall offset located there to finish the conversion. */
2126 for (; b; b = BINFO_INHERITANCE_CHAIN (b))
2127 {
2128 /* If we find the final overrider, then we can stop
2129 walking. */
2130 if (SAME_BINFO_TYPE_P (BINFO_TYPE (b),
2131 BINFO_TYPE (TREE_VALUE (overrider))))
2132 break;
2133
2134 /* If we find a virtual base, and we haven't yet found the
2135 overrider, then there is a virtual base between the
2136 declaring base (first_defn) and the final overrider. */
2137 if (BINFO_VIRTUAL_P (b))
2138 {
2139 virtual_base = b;
2140 break;
2141 }
2142 }
2143
2144 if (overrider_fn != overrider_target && !virtual_base)
2145 {
2146 /* The ABI specifies that a covariant thunk includes a mangling
2147 for a this pointer adjustment. This-adjusting thunks that
2148 override a function from a virtual base have a vcall
2149 adjustment. When the virtual base in question is a primary
2150 virtual base, we know the adjustments are zero, (and in the
2151 non-covariant case, we would not use the thunk).
2152 Unfortunately we didn't notice this could happen, when
2153 designing the ABI and so never mandated that such a covariant
2154 thunk should be emitted. Because we must use the ABI mandated
2155 name, we must continue searching from the binfo where we
2156 found the most recent definition of the function, towards the
2157 primary binfo which first introduced the function into the
2158 vtable. If that enters a virtual base, we must use a vcall
2159 this-adjusting thunk. Bleah! */
2160 tree probe = first_defn;
2161
2162 while ((probe = get_primary_binfo (probe))
2163 && (unsigned) list_length (BINFO_VIRTUALS (probe)) > ix)
2164 if (BINFO_VIRTUAL_P (probe))
2165 virtual_base = probe;
2166
2167 if (virtual_base)
2168 /* Even if we find a virtual base, the correct delta is
2169 between the overrider and the binfo we're building a vtable
2170 for. */
2171 goto virtual_covariant;
2172 }
2173
2174 /* Compute the constant adjustment to the `this' pointer. The
2175 `this' pointer, when this function is called, will point at BINFO
2176 (or one of its primary bases, which are at the same offset). */
2177 if (virtual_base)
2178 /* The `this' pointer needs to be adjusted from the declaration to
2179 the nearest virtual base. */
2180 delta = size_diffop (convert (ssizetype, BINFO_OFFSET (virtual_base)),
2181 convert (ssizetype, BINFO_OFFSET (first_defn)));
2182 else if (lost)
2183 /* If the nearest definition is in a lost primary, we don't need an
2184 entry in our vtable. Except possibly in a constructor vtable,
2185 if we happen to get our primary back. In that case, the offset
2186 will be zero, as it will be a primary base. */
2187 delta = size_zero_node;
2188 else
2189 /* The `this' pointer needs to be adjusted from pointing to
2190 BINFO to pointing at the base where the final overrider
2191 appears. */
2192 virtual_covariant:
2193 delta = size_diffop (convert (ssizetype,
2194 BINFO_OFFSET (TREE_VALUE (overrider))),
2195 convert (ssizetype, BINFO_OFFSET (binfo)));
2196
2197 modify_vtable_entry (t, binfo, overrider_fn, delta, virtuals);
2198
2199 if (virtual_base)
2200 BV_VCALL_INDEX (*virtuals)
2201 = get_vcall_index (overrider_target, BINFO_TYPE (virtual_base));
2202 else
2203 BV_VCALL_INDEX (*virtuals) = NULL_TREE;
2204 }
2205
2206 /* Called from modify_all_vtables via dfs_walk. */
2207
2208 static tree
dfs_modify_vtables(tree binfo,void * data)2209 dfs_modify_vtables (tree binfo, void* data)
2210 {
2211 tree t = (tree) data;
2212 tree virtuals;
2213 tree old_virtuals;
2214 unsigned ix;
2215
2216 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
2217 /* A base without a vtable needs no modification, and its bases
2218 are uninteresting. */
2219 return dfs_skip_bases;
2220
2221 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t)
2222 && !CLASSTYPE_HAS_PRIMARY_BASE_P (t))
2223 /* Don't do the primary vtable, if it's new. */
2224 return NULL_TREE;
2225
2226 if (BINFO_PRIMARY_P (binfo) && !BINFO_VIRTUAL_P (binfo))
2227 /* There's no need to modify the vtable for a non-virtual primary
2228 base; we're not going to use that vtable anyhow. We do still
2229 need to do this for virtual primary bases, as they could become
2230 non-primary in a construction vtable. */
2231 return NULL_TREE;
2232
2233 make_new_vtable (t, binfo);
2234
2235 /* Now, go through each of the virtual functions in the virtual
2236 function table for BINFO. Find the final overrider, and update
2237 the BINFO_VIRTUALS list appropriately. */
2238 for (ix = 0, virtuals = BINFO_VIRTUALS (binfo),
2239 old_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
2240 virtuals;
2241 ix++, virtuals = TREE_CHAIN (virtuals),
2242 old_virtuals = TREE_CHAIN (old_virtuals))
2243 update_vtable_entry_for_fn (t,
2244 binfo,
2245 BV_FN (old_virtuals),
2246 &virtuals, ix);
2247
2248 return NULL_TREE;
2249 }
2250
2251 /* Update all of the primary and secondary vtables for T. Create new
2252 vtables as required, and initialize their RTTI information. Each
2253 of the functions in VIRTUALS is declared in T and may override a
2254 virtual function from a base class; find and modify the appropriate
2255 entries to point to the overriding functions. Returns a list, in
2256 declaration order, of the virtual functions that are declared in T,
2257 but do not appear in the primary base class vtable, and which
2258 should therefore be appended to the end of the vtable for T. */
2259
2260 static tree
modify_all_vtables(tree t,tree virtuals)2261 modify_all_vtables (tree t, tree virtuals)
2262 {
2263 tree binfo = TYPE_BINFO (t);
2264 tree *fnsp;
2265
2266 /* Update all of the vtables. */
2267 dfs_walk_once (binfo, dfs_modify_vtables, NULL, t);
2268
2269 /* Add virtual functions not already in our primary vtable. These
2270 will be both those introduced by this class, and those overridden
2271 from secondary bases. It does not include virtuals merely
2272 inherited from secondary bases. */
2273 for (fnsp = &virtuals; *fnsp; )
2274 {
2275 tree fn = TREE_VALUE (*fnsp);
2276
2277 if (!value_member (fn, BINFO_VIRTUALS (binfo))
2278 || DECL_VINDEX (fn) == error_mark_node)
2279 {
2280 /* We don't need to adjust the `this' pointer when
2281 calling this function. */
2282 BV_DELTA (*fnsp) = integer_zero_node;
2283 BV_VCALL_INDEX (*fnsp) = NULL_TREE;
2284
2285 /* This is a function not already in our vtable. Keep it. */
2286 fnsp = &TREE_CHAIN (*fnsp);
2287 }
2288 else
2289 /* We've already got an entry for this function. Skip it. */
2290 *fnsp = TREE_CHAIN (*fnsp);
2291 }
2292
2293 return virtuals;
2294 }
2295
2296 /* Get the base virtual function declarations in T that have the
2297 indicated NAME. */
2298
2299 static tree
get_basefndecls(tree name,tree t)2300 get_basefndecls (tree name, tree t)
2301 {
2302 tree methods;
2303 tree base_fndecls = NULL_TREE;
2304 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
2305 int i;
2306
2307 /* Find virtual functions in T with the indicated NAME. */
2308 i = lookup_fnfields_1 (t, name);
2309 if (i != -1)
2310 for (methods = VEC_index (tree, CLASSTYPE_METHOD_VEC (t), i);
2311 methods;
2312 methods = OVL_NEXT (methods))
2313 {
2314 tree method = OVL_CURRENT (methods);
2315
2316 if (TREE_CODE (method) == FUNCTION_DECL
2317 && DECL_VINDEX (method))
2318 base_fndecls = tree_cons (NULL_TREE, method, base_fndecls);
2319 }
2320
2321 if (base_fndecls)
2322 return base_fndecls;
2323
2324 for (i = 0; i < n_baseclasses; i++)
2325 {
2326 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (t), i));
2327 base_fndecls = chainon (get_basefndecls (name, basetype),
2328 base_fndecls);
2329 }
2330
2331 return base_fndecls;
2332 }
2333
2334 /* If this declaration supersedes the declaration of
2335 a method declared virtual in the base class, then
2336 mark this field as being virtual as well. */
2337
2338 void
check_for_override(tree decl,tree ctype)2339 check_for_override (tree decl, tree ctype)
2340 {
2341 if (TREE_CODE (decl) == TEMPLATE_DECL)
2342 /* In [temp.mem] we have:
2343
2344 A specialization of a member function template does not
2345 override a virtual function from a base class. */
2346 return;
2347 if ((DECL_DESTRUCTOR_P (decl)
2348 || IDENTIFIER_VIRTUAL_P (DECL_NAME (decl))
2349 || DECL_CONV_FN_P (decl))
2350 && look_for_overrides (ctype, decl)
2351 && !DECL_STATIC_FUNCTION_P (decl))
2352 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2353 the error_mark_node so that we know it is an overriding
2354 function. */
2355 DECL_VINDEX (decl) = decl;
2356
2357 if (DECL_VIRTUAL_P (decl))
2358 {
2359 if (!DECL_VINDEX (decl))
2360 DECL_VINDEX (decl) = error_mark_node;
2361 IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) = 1;
2362 if (DECL_DLLIMPORT_P (decl))
2363 {
2364 /* When we handled the dllimport attribute we may not have known
2365 that this function is virtual We can't use dllimport
2366 semantics for a virtual method because we need to initialize
2367 the vtable entry with a constant address. */
2368 DECL_DLLIMPORT_P (decl) = 0;
2369 DECL_ATTRIBUTES (decl)
2370 = remove_attribute ("dllimport", DECL_ATTRIBUTES (decl));
2371 }
2372 }
2373 }
2374
2375 /* Warn about hidden virtual functions that are not overridden in t.
2376 We know that constructors and destructors don't apply. */
2377
2378 static void
warn_hidden(tree t)2379 warn_hidden (tree t)
2380 {
2381 VEC(tree,gc) *method_vec = CLASSTYPE_METHOD_VEC (t);
2382 tree fns;
2383 size_t i;
2384
2385 /* We go through each separately named virtual function. */
2386 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
2387 VEC_iterate (tree, method_vec, i, fns);
2388 ++i)
2389 {
2390 tree fn;
2391 tree name;
2392 tree fndecl;
2393 tree base_fndecls;
2394 tree base_binfo;
2395 tree binfo;
2396 int j;
2397
2398 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2399 have the same name. Figure out what name that is. */
2400 name = DECL_NAME (OVL_CURRENT (fns));
2401 /* There are no possibly hidden functions yet. */
2402 base_fndecls = NULL_TREE;
2403 /* Iterate through all of the base classes looking for possibly
2404 hidden functions. */
2405 for (binfo = TYPE_BINFO (t), j = 0;
2406 BINFO_BASE_ITERATE (binfo, j, base_binfo); j++)
2407 {
2408 tree basetype = BINFO_TYPE (base_binfo);
2409 base_fndecls = chainon (get_basefndecls (name, basetype),
2410 base_fndecls);
2411 }
2412
2413 /* If there are no functions to hide, continue. */
2414 if (!base_fndecls)
2415 continue;
2416
2417 /* Remove any overridden functions. */
2418 for (fn = fns; fn; fn = OVL_NEXT (fn))
2419 {
2420 fndecl = OVL_CURRENT (fn);
2421 if (DECL_VINDEX (fndecl))
2422 {
2423 tree *prev = &base_fndecls;
2424
2425 while (*prev)
2426 /* If the method from the base class has the same
2427 signature as the method from the derived class, it
2428 has been overridden. */
2429 if (same_signature_p (fndecl, TREE_VALUE (*prev)))
2430 *prev = TREE_CHAIN (*prev);
2431 else
2432 prev = &TREE_CHAIN (*prev);
2433 }
2434 }
2435
2436 /* Now give a warning for all base functions without overriders,
2437 as they are hidden. */
2438 while (base_fndecls)
2439 {
2440 /* Here we know it is a hider, and no overrider exists. */
2441 warning (0, "%q+D was hidden", TREE_VALUE (base_fndecls));
2442 warning (0, " by %q+D", fns);
2443 base_fndecls = TREE_CHAIN (base_fndecls);
2444 }
2445 }
2446 }
2447
2448 /* Check for things that are invalid. There are probably plenty of other
2449 things we should check for also. */
2450
2451 static void
finish_struct_anon(tree t)2452 finish_struct_anon (tree t)
2453 {
2454 tree field;
2455
2456 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
2457 {
2458 if (TREE_STATIC (field))
2459 continue;
2460 if (TREE_CODE (field) != FIELD_DECL)
2461 continue;
2462
2463 if (DECL_NAME (field) == NULL_TREE
2464 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
2465 {
2466 tree elt = TYPE_FIELDS (TREE_TYPE (field));
2467 for (; elt; elt = TREE_CHAIN (elt))
2468 {
2469 /* We're generally only interested in entities the user
2470 declared, but we also find nested classes by noticing
2471 the TYPE_DECL that we create implicitly. You're
2472 allowed to put one anonymous union inside another,
2473 though, so we explicitly tolerate that. We use
2474 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2475 we also allow unnamed types used for defining fields. */
2476 if (DECL_ARTIFICIAL (elt)
2477 && (!DECL_IMPLICIT_TYPEDEF_P (elt)
2478 || TYPE_ANONYMOUS_P (TREE_TYPE (elt))))
2479 continue;
2480
2481 if (TREE_CODE (elt) != FIELD_DECL)
2482 {
2483 pedwarn ("%q+#D invalid; an anonymous union can "
2484 "only have non-static data members", elt);
2485 continue;
2486 }
2487
2488 if (TREE_PRIVATE (elt))
2489 pedwarn ("private member %q+#D in anonymous union", elt);
2490 else if (TREE_PROTECTED (elt))
2491 pedwarn ("protected member %q+#D in anonymous union", elt);
2492
2493 TREE_PRIVATE (elt) = TREE_PRIVATE (field);
2494 TREE_PROTECTED (elt) = TREE_PROTECTED (field);
2495 }
2496 }
2497 }
2498 }
2499
2500 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2501 will be used later during class template instantiation.
2502 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2503 a non-static member data (FIELD_DECL), a member function
2504 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2505 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2506 When FRIEND_P is nonzero, T is either a friend class
2507 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2508 (FUNCTION_DECL, TEMPLATE_DECL). */
2509
2510 void
maybe_add_class_template_decl_list(tree type,tree t,int friend_p)2511 maybe_add_class_template_decl_list (tree type, tree t, int friend_p)
2512 {
2513 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2514 if (CLASSTYPE_TEMPLATE_INFO (type))
2515 CLASSTYPE_DECL_LIST (type)
2516 = tree_cons (friend_p ? NULL_TREE : type,
2517 t, CLASSTYPE_DECL_LIST (type));
2518 }
2519
2520 /* Create default constructors, assignment operators, and so forth for
2521 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2522 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2523 the class cannot have a default constructor, copy constructor
2524 taking a const reference argument, or an assignment operator taking
2525 a const reference, respectively. */
2526
2527 static void
add_implicitly_declared_members(tree t,int cant_have_const_cctor,int cant_have_const_assignment)2528 add_implicitly_declared_members (tree t,
2529 int cant_have_const_cctor,
2530 int cant_have_const_assignment)
2531 {
2532 /* Destructor. */
2533 if (!CLASSTYPE_DESTRUCTORS (t))
2534 {
2535 /* In general, we create destructors lazily. */
2536 CLASSTYPE_LAZY_DESTRUCTOR (t) = 1;
2537 /* However, if the implicit destructor is non-trivial
2538 destructor, we sometimes have to create it at this point. */
2539 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
2540 {
2541 bool lazy_p = true;
2542
2543 if (TYPE_FOR_JAVA (t))
2544 /* If this a Java class, any non-trivial destructor is
2545 invalid, even if compiler-generated. Therefore, if the
2546 destructor is non-trivial we create it now. */
2547 lazy_p = false;
2548 else
2549 {
2550 tree binfo;
2551 tree base_binfo;
2552 int ix;
2553
2554 /* If the implicit destructor will be virtual, then we must
2555 generate it now because (unfortunately) we do not
2556 generate virtual tables lazily. */
2557 binfo = TYPE_BINFO (t);
2558 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
2559 {
2560 tree base_type;
2561 tree dtor;
2562
2563 base_type = BINFO_TYPE (base_binfo);
2564 dtor = CLASSTYPE_DESTRUCTORS (base_type);
2565 if (dtor && DECL_VIRTUAL_P (dtor))
2566 {
2567 lazy_p = false;
2568 break;
2569 }
2570 }
2571 }
2572
2573 /* If we can't get away with being lazy, generate the destructor
2574 now. */
2575 if (!lazy_p)
2576 lazily_declare_fn (sfk_destructor, t);
2577 }
2578 }
2579
2580 /* Default constructor. */
2581 if (! TYPE_HAS_CONSTRUCTOR (t))
2582 {
2583 TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 1;
2584 CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 1;
2585 }
2586
2587 /* Copy constructor. */
2588 if (! TYPE_HAS_INIT_REF (t) && ! TYPE_FOR_JAVA (t))
2589 {
2590 TYPE_HAS_INIT_REF (t) = 1;
2591 TYPE_HAS_CONST_INIT_REF (t) = !cant_have_const_cctor;
2592 CLASSTYPE_LAZY_COPY_CTOR (t) = 1;
2593 TYPE_HAS_CONSTRUCTOR (t) = 1;
2594 }
2595
2596 /* If there is no assignment operator, one will be created if and
2597 when it is needed. For now, just record whether or not the type
2598 of the parameter to the assignment operator will be a const or
2599 non-const reference. */
2600 if (!TYPE_HAS_ASSIGN_REF (t) && !TYPE_FOR_JAVA (t))
2601 {
2602 TYPE_HAS_ASSIGN_REF (t) = 1;
2603 TYPE_HAS_CONST_ASSIGN_REF (t) = !cant_have_const_assignment;
2604 CLASSTYPE_LAZY_ASSIGNMENT_OP (t) = 1;
2605 }
2606 }
2607
2608 /* Subroutine of finish_struct_1. Recursively count the number of fields
2609 in TYPE, including anonymous union members. */
2610
2611 static int
count_fields(tree fields)2612 count_fields (tree fields)
2613 {
2614 tree x;
2615 int n_fields = 0;
2616 for (x = fields; x; x = TREE_CHAIN (x))
2617 {
2618 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2619 n_fields += count_fields (TYPE_FIELDS (TREE_TYPE (x)));
2620 else
2621 n_fields += 1;
2622 }
2623 return n_fields;
2624 }
2625
2626 /* Subroutine of finish_struct_1. Recursively add all the fields in the
2627 TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX. */
2628
2629 static int
add_fields_to_record_type(tree fields,struct sorted_fields_type * field_vec,int idx)2630 add_fields_to_record_type (tree fields, struct sorted_fields_type *field_vec, int idx)
2631 {
2632 tree x;
2633 for (x = fields; x; x = TREE_CHAIN (x))
2634 {
2635 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2636 idx = add_fields_to_record_type (TYPE_FIELDS (TREE_TYPE (x)), field_vec, idx);
2637 else
2638 field_vec->elts[idx++] = x;
2639 }
2640 return idx;
2641 }
2642
2643 /* FIELD is a bit-field. We are finishing the processing for its
2644 enclosing type. Issue any appropriate messages and set appropriate
2645 flags. */
2646
2647 static void
check_bitfield_decl(tree field)2648 check_bitfield_decl (tree field)
2649 {
2650 tree type = TREE_TYPE (field);
2651 tree w;
2652
2653 /* Extract the declared width of the bitfield, which has been
2654 temporarily stashed in DECL_INITIAL. */
2655 w = DECL_INITIAL (field);
2656 gcc_assert (w != NULL_TREE);
2657 /* Remove the bit-field width indicator so that the rest of the
2658 compiler does not treat that value as an initializer. */
2659 DECL_INITIAL (field) = NULL_TREE;
2660
2661 /* Detect invalid bit-field type. */
2662 if (!INTEGRAL_TYPE_P (type))
2663 {
2664 error ("bit-field %q+#D with non-integral type", field);
2665 TREE_TYPE (field) = error_mark_node;
2666 w = error_mark_node;
2667 }
2668 else
2669 {
2670 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2671 STRIP_NOPS (w);
2672
2673 /* detect invalid field size. */
2674 w = integral_constant_value (w);
2675
2676 if (TREE_CODE (w) != INTEGER_CST)
2677 {
2678 error ("bit-field %q+D width not an integer constant", field);
2679 w = error_mark_node;
2680 }
2681 else if (tree_int_cst_sgn (w) < 0)
2682 {
2683 error ("negative width in bit-field %q+D", field);
2684 w = error_mark_node;
2685 }
2686 else if (integer_zerop (w) && DECL_NAME (field) != 0)
2687 {
2688 error ("zero width for bit-field %q+D", field);
2689 w = error_mark_node;
2690 }
2691 else if (compare_tree_int (w, TYPE_PRECISION (type)) > 0
2692 && TREE_CODE (type) != ENUMERAL_TYPE
2693 && TREE_CODE (type) != BOOLEAN_TYPE)
2694 warning (0, "width of %q+D exceeds its type", field);
2695 else if (TREE_CODE (type) == ENUMERAL_TYPE
2696 && (0 > compare_tree_int (w,
2697 min_precision (TYPE_MIN_VALUE (type),
2698 TYPE_UNSIGNED (type)))
2699 || 0 > compare_tree_int (w,
2700 min_precision
2701 (TYPE_MAX_VALUE (type),
2702 TYPE_UNSIGNED (type)))))
2703 warning (0, "%q+D is too small to hold all values of %q#T", field, type);
2704 }
2705
2706 if (w != error_mark_node)
2707 {
2708 DECL_SIZE (field) = convert (bitsizetype, w);
2709 DECL_BIT_FIELD (field) = 1;
2710 }
2711 else
2712 {
2713 /* Non-bit-fields are aligned for their type. */
2714 DECL_BIT_FIELD (field) = 0;
2715 CLEAR_DECL_C_BIT_FIELD (field);
2716 }
2717 }
2718
2719 /* FIELD is a non bit-field. We are finishing the processing for its
2720 enclosing type T. Issue any appropriate messages and set appropriate
2721 flags. */
2722
2723 static void
check_field_decl(tree field,tree t,int * cant_have_const_ctor,int * no_const_asn_ref,int * any_default_members)2724 check_field_decl (tree field,
2725 tree t,
2726 int* cant_have_const_ctor,
2727 int* no_const_asn_ref,
2728 int* any_default_members)
2729 {
2730 tree type = strip_array_types (TREE_TYPE (field));
2731
2732 /* An anonymous union cannot contain any fields which would change
2733 the settings of CANT_HAVE_CONST_CTOR and friends. */
2734 if (ANON_UNION_TYPE_P (type))
2735 ;
2736 /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
2737 structs. So, we recurse through their fields here. */
2738 else if (ANON_AGGR_TYPE_P (type))
2739 {
2740 tree fields;
2741
2742 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2743 if (TREE_CODE (fields) == FIELD_DECL && !DECL_C_BIT_FIELD (field))
2744 check_field_decl (fields, t, cant_have_const_ctor,
2745 no_const_asn_ref, any_default_members);
2746 }
2747 /* Check members with class type for constructors, destructors,
2748 etc. */
2749 else if (CLASS_TYPE_P (type))
2750 {
2751 /* Never let anything with uninheritable virtuals
2752 make it through without complaint. */
2753 abstract_virtuals_error (field, type);
2754
2755 if (TREE_CODE (t) == UNION_TYPE)
2756 {
2757 if (TYPE_NEEDS_CONSTRUCTING (type))
2758 error ("member %q+#D with constructor not allowed in union",
2759 field);
2760 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
2761 error ("member %q+#D with destructor not allowed in union", field);
2762 if (TYPE_HAS_COMPLEX_ASSIGN_REF (type))
2763 error ("member %q+#D with copy assignment operator not allowed in union",
2764 field);
2765 }
2766 else
2767 {
2768 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (type);
2769 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
2770 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type);
2771 TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_HAS_COMPLEX_ASSIGN_REF (type);
2772 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (type);
2773 }
2774
2775 if (!TYPE_HAS_CONST_INIT_REF (type))
2776 *cant_have_const_ctor = 1;
2777
2778 if (!TYPE_HAS_CONST_ASSIGN_REF (type))
2779 *no_const_asn_ref = 1;
2780 }
2781 if (DECL_INITIAL (field) != NULL_TREE)
2782 {
2783 /* `build_class_init_list' does not recognize
2784 non-FIELD_DECLs. */
2785 if (TREE_CODE (t) == UNION_TYPE && any_default_members != 0)
2786 error ("multiple fields in union %qT initialized", t);
2787 *any_default_members = 1;
2788 }
2789 }
2790
2791 /* Check the data members (both static and non-static), class-scoped
2792 typedefs, etc., appearing in the declaration of T. Issue
2793 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
2794 declaration order) of access declarations; each TREE_VALUE in this
2795 list is a USING_DECL.
2796
2797 In addition, set the following flags:
2798
2799 EMPTY_P
2800 The class is empty, i.e., contains no non-static data members.
2801
2802 CANT_HAVE_CONST_CTOR_P
2803 This class cannot have an implicitly generated copy constructor
2804 taking a const reference.
2805
2806 CANT_HAVE_CONST_ASN_REF
2807 This class cannot have an implicitly generated assignment
2808 operator taking a const reference.
2809
2810 All of these flags should be initialized before calling this
2811 function.
2812
2813 Returns a pointer to the end of the TYPE_FIELDs chain; additional
2814 fields can be added by adding to this chain. */
2815
2816 static void
check_field_decls(tree t,tree * access_decls,int * cant_have_const_ctor_p,int * no_const_asn_ref_p)2817 check_field_decls (tree t, tree *access_decls,
2818 int *cant_have_const_ctor_p,
2819 int *no_const_asn_ref_p)
2820 {
2821 tree *field;
2822 tree *next;
2823 bool has_pointers;
2824 int any_default_members;
2825 int cant_pack = 0;
2826
2827 /* Assume there are no access declarations. */
2828 *access_decls = NULL_TREE;
2829 /* Assume this class has no pointer members. */
2830 has_pointers = false;
2831 /* Assume none of the members of this class have default
2832 initializations. */
2833 any_default_members = 0;
2834
2835 for (field = &TYPE_FIELDS (t); *field; field = next)
2836 {
2837 tree x = *field;
2838 tree type = TREE_TYPE (x);
2839
2840 next = &TREE_CHAIN (x);
2841
2842 if (TREE_CODE (x) == USING_DECL)
2843 {
2844 /* Prune the access declaration from the list of fields. */
2845 *field = TREE_CHAIN (x);
2846
2847 /* Save the access declarations for our caller. */
2848 *access_decls = tree_cons (NULL_TREE, x, *access_decls);
2849
2850 /* Since we've reset *FIELD there's no reason to skip to the
2851 next field. */
2852 next = field;
2853 continue;
2854 }
2855
2856 if (TREE_CODE (x) == TYPE_DECL
2857 || TREE_CODE (x) == TEMPLATE_DECL)
2858 continue;
2859
2860 /* If we've gotten this far, it's a data member, possibly static,
2861 or an enumerator. */
2862 DECL_CONTEXT (x) = t;
2863
2864 /* When this goes into scope, it will be a non-local reference. */
2865 DECL_NONLOCAL (x) = 1;
2866
2867 if (TREE_CODE (t) == UNION_TYPE)
2868 {
2869 /* [class.union]
2870
2871 If a union contains a static data member, or a member of
2872 reference type, the program is ill-formed. */
2873 if (TREE_CODE (x) == VAR_DECL)
2874 {
2875 error ("%q+D may not be static because it is a member of a union", x);
2876 continue;
2877 }
2878 if (TREE_CODE (type) == REFERENCE_TYPE)
2879 {
2880 error ("%q+D may not have reference type %qT because"
2881 " it is a member of a union",
2882 x, type);
2883 continue;
2884 }
2885 }
2886
2887 /* Perform error checking that did not get done in
2888 grokdeclarator. */
2889 if (TREE_CODE (type) == FUNCTION_TYPE)
2890 {
2891 error ("field %q+D invalidly declared function type", x);
2892 type = build_pointer_type (type);
2893 TREE_TYPE (x) = type;
2894 }
2895 else if (TREE_CODE (type) == METHOD_TYPE)
2896 {
2897 error ("field %q+D invalidly declared method type", x);
2898 type = build_pointer_type (type);
2899 TREE_TYPE (x) = type;
2900 }
2901
2902 if (type == error_mark_node)
2903 continue;
2904
2905 if (TREE_CODE (x) == CONST_DECL || TREE_CODE (x) == VAR_DECL)
2906 continue;
2907
2908 /* Now it can only be a FIELD_DECL. */
2909
2910 if (TREE_PRIVATE (x) || TREE_PROTECTED (x))
2911 CLASSTYPE_NON_AGGREGATE (t) = 1;
2912
2913 /* If this is of reference type, check if it needs an init.
2914 Also do a little ANSI jig if necessary. */
2915 if (TREE_CODE (type) == REFERENCE_TYPE)
2916 {
2917 CLASSTYPE_NON_POD_P (t) = 1;
2918 if (DECL_INITIAL (x) == NULL_TREE)
2919 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
2920
2921 /* ARM $12.6.2: [A member initializer list] (or, for an
2922 aggregate, initialization by a brace-enclosed list) is the
2923 only way to initialize nonstatic const and reference
2924 members. */
2925 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
2926
2927 if (! TYPE_HAS_CONSTRUCTOR (t) && CLASSTYPE_NON_AGGREGATE (t)
2928 && extra_warnings)
2929 warning (OPT_Wextra, "non-static reference %q+#D in class without a constructor", x);
2930 }
2931
2932 type = strip_array_types (type);
2933
2934 if (TYPE_PACKED (t))
2935 {
2936 if (!pod_type_p (type) && !TYPE_PACKED (type))
2937 {
2938 warning
2939 (0,
2940 "ignoring packed attribute because of unpacked non-POD field %q+#D",
2941 x);
2942 cant_pack = 1;
2943 }
2944 else if (TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT)
2945 DECL_PACKED (x) = 1;
2946 }
2947
2948 if (DECL_C_BIT_FIELD (x) && integer_zerop (DECL_INITIAL (x)))
2949 /* We don't treat zero-width bitfields as making a class
2950 non-empty. */
2951 ;
2952 else
2953 {
2954 /* The class is non-empty. */
2955 CLASSTYPE_EMPTY_P (t) = 0;
2956 /* The class is not even nearly empty. */
2957 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
2958 /* If one of the data members contains an empty class,
2959 so does T. */
2960 if (CLASS_TYPE_P (type)
2961 && CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type))
2962 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
2963 }
2964
2965 /* This is used by -Weffc++ (see below). Warn only for pointers
2966 to members which might hold dynamic memory. So do not warn
2967 for pointers to functions or pointers to members. */
2968 if (TYPE_PTR_P (type)
2969 && !TYPE_PTRFN_P (type)
2970 && !TYPE_PTR_TO_MEMBER_P (type))
2971 has_pointers = true;
2972
2973 if (CLASS_TYPE_P (type))
2974 {
2975 if (CLASSTYPE_REF_FIELDS_NEED_INIT (type))
2976 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
2977 if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (type))
2978 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
2979 }
2980
2981 if (DECL_MUTABLE_P (x) || TYPE_HAS_MUTABLE_P (type))
2982 CLASSTYPE_HAS_MUTABLE (t) = 1;
2983
2984 if (! pod_type_p (type))
2985 /* DR 148 now allows pointers to members (which are POD themselves),
2986 to be allowed in POD structs. */
2987 CLASSTYPE_NON_POD_P (t) = 1;
2988
2989 if (! zero_init_p (type))
2990 CLASSTYPE_NON_ZERO_INIT_P (t) = 1;
2991
2992 /* If any field is const, the structure type is pseudo-const. */
2993 if (CP_TYPE_CONST_P (type))
2994 {
2995 C_TYPE_FIELDS_READONLY (t) = 1;
2996 if (DECL_INITIAL (x) == NULL_TREE)
2997 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
2998
2999 /* ARM $12.6.2: [A member initializer list] (or, for an
3000 aggregate, initialization by a brace-enclosed list) is the
3001 only way to initialize nonstatic const and reference
3002 members. */
3003 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
3004
3005 if (! TYPE_HAS_CONSTRUCTOR (t) && CLASSTYPE_NON_AGGREGATE (t)
3006 && extra_warnings)
3007 warning (OPT_Wextra, "non-static const member %q+#D in class without a constructor", x);
3008 }
3009 /* A field that is pseudo-const makes the structure likewise. */
3010 else if (CLASS_TYPE_P (type))
3011 {
3012 C_TYPE_FIELDS_READONLY (t) |= C_TYPE_FIELDS_READONLY (type);
3013 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t,
3014 CLASSTYPE_READONLY_FIELDS_NEED_INIT (t)
3015 | CLASSTYPE_READONLY_FIELDS_NEED_INIT (type));
3016 }
3017
3018 /* Core issue 80: A nonstatic data member is required to have a
3019 different name from the class iff the class has a
3020 user-defined constructor. */
3021 if (constructor_name_p (DECL_NAME (x), t) && TYPE_HAS_CONSTRUCTOR (t))
3022 pedwarn ("field %q+#D with same name as class", x);
3023
3024 /* We set DECL_C_BIT_FIELD in grokbitfield.
3025 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3026 if (DECL_C_BIT_FIELD (x))
3027 check_bitfield_decl (x);
3028 else
3029 check_field_decl (x, t,
3030 cant_have_const_ctor_p,
3031 no_const_asn_ref_p,
3032 &any_default_members);
3033 }
3034
3035 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3036 it should also define a copy constructor and an assignment operator to
3037 implement the correct copy semantic (deep vs shallow, etc.). As it is
3038 not feasible to check whether the constructors do allocate dynamic memory
3039 and store it within members, we approximate the warning like this:
3040
3041 -- Warn only if there are members which are pointers
3042 -- Warn only if there is a non-trivial constructor (otherwise,
3043 there cannot be memory allocated).
3044 -- Warn only if there is a non-trivial destructor. We assume that the
3045 user at least implemented the cleanup correctly, and a destructor
3046 is needed to free dynamic memory.
3047
3048 This seems enough for practical purposes. */
3049 if (warn_ecpp
3050 && has_pointers
3051 && TYPE_HAS_CONSTRUCTOR (t)
3052 && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
3053 && !(TYPE_HAS_INIT_REF (t) && TYPE_HAS_ASSIGN_REF (t)))
3054 {
3055 warning (OPT_Weffc__, "%q#T has pointer data members", t);
3056
3057 if (! TYPE_HAS_INIT_REF (t))
3058 {
3059 warning (OPT_Weffc__,
3060 " but does not override %<%T(const %T&)%>", t, t);
3061 if (!TYPE_HAS_ASSIGN_REF (t))
3062 warning (OPT_Weffc__, " or %<operator=(const %T&)%>", t);
3063 }
3064 else if (! TYPE_HAS_ASSIGN_REF (t))
3065 warning (OPT_Weffc__,
3066 " but does not override %<operator=(const %T&)%>", t);
3067 }
3068
3069 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3070 if (cant_pack)
3071 TYPE_PACKED (t) = 0;
3072
3073 /* Check anonymous struct/anonymous union fields. */
3074 finish_struct_anon (t);
3075
3076 /* We've built up the list of access declarations in reverse order.
3077 Fix that now. */
3078 *access_decls = nreverse (*access_decls);
3079 }
3080
3081 /* If TYPE is an empty class type, records its OFFSET in the table of
3082 OFFSETS. */
3083
3084 static int
record_subobject_offset(tree type,tree offset,splay_tree offsets)3085 record_subobject_offset (tree type, tree offset, splay_tree offsets)
3086 {
3087 splay_tree_node n;
3088
3089 if (!is_empty_class (type))
3090 return 0;
3091
3092 /* Record the location of this empty object in OFFSETS. */
3093 n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3094 if (!n)
3095 n = splay_tree_insert (offsets,
3096 (splay_tree_key) offset,
3097 (splay_tree_value) NULL_TREE);
3098 n->value = ((splay_tree_value)
3099 tree_cons (NULL_TREE,
3100 type,
3101 (tree) n->value));
3102
3103 return 0;
3104 }
3105
3106 /* Returns nonzero if TYPE is an empty class type and there is
3107 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3108
3109 static int
check_subobject_offset(tree type,tree offset,splay_tree offsets)3110 check_subobject_offset (tree type, tree offset, splay_tree offsets)
3111 {
3112 splay_tree_node n;
3113 tree t;
3114
3115 if (!is_empty_class (type))
3116 return 0;
3117
3118 /* Record the location of this empty object in OFFSETS. */
3119 n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3120 if (!n)
3121 return 0;
3122
3123 for (t = (tree) n->value; t; t = TREE_CHAIN (t))
3124 if (same_type_p (TREE_VALUE (t), type))
3125 return 1;
3126
3127 return 0;
3128 }
3129
3130 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3131 F for every subobject, passing it the type, offset, and table of
3132 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3133 be traversed.
3134
3135 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3136 than MAX_OFFSET will not be walked.
3137
3138 If F returns a nonzero value, the traversal ceases, and that value
3139 is returned. Otherwise, returns zero. */
3140
3141 static int
walk_subobject_offsets(tree type,subobject_offset_fn f,tree offset,splay_tree offsets,tree max_offset,int vbases_p)3142 walk_subobject_offsets (tree type,
3143 subobject_offset_fn f,
3144 tree offset,
3145 splay_tree offsets,
3146 tree max_offset,
3147 int vbases_p)
3148 {
3149 int r = 0;
3150 tree type_binfo = NULL_TREE;
3151
3152 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3153 stop. */
3154 if (max_offset && INT_CST_LT (max_offset, offset))
3155 return 0;
3156
3157 if (type == error_mark_node)
3158 return 0;
3159
3160 if (!TYPE_P (type))
3161 {
3162 if (abi_version_at_least (2))
3163 type_binfo = type;
3164 type = BINFO_TYPE (type);
3165 }
3166
3167 if (CLASS_TYPE_P (type))
3168 {
3169 tree field;
3170 tree binfo;
3171 int i;
3172
3173 /* Avoid recursing into objects that are not interesting. */
3174 if (!CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type))
3175 return 0;
3176
3177 /* Record the location of TYPE. */
3178 r = (*f) (type, offset, offsets);
3179 if (r)
3180 return r;
3181
3182 /* Iterate through the direct base classes of TYPE. */
3183 if (!type_binfo)
3184 type_binfo = TYPE_BINFO (type);
3185 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, binfo); i++)
3186 {
3187 tree binfo_offset;
3188
3189 if (abi_version_at_least (2)
3190 && BINFO_VIRTUAL_P (binfo))
3191 continue;
3192
3193 if (!vbases_p
3194 && BINFO_VIRTUAL_P (binfo)
3195 && !BINFO_PRIMARY_P (binfo))
3196 continue;
3197
3198 if (!abi_version_at_least (2))
3199 binfo_offset = size_binop (PLUS_EXPR,
3200 offset,
3201 BINFO_OFFSET (binfo));
3202 else
3203 {
3204 tree orig_binfo;
3205 /* We cannot rely on BINFO_OFFSET being set for the base
3206 class yet, but the offsets for direct non-virtual
3207 bases can be calculated by going back to the TYPE. */
3208 orig_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), i);
3209 binfo_offset = size_binop (PLUS_EXPR,
3210 offset,
3211 BINFO_OFFSET (orig_binfo));
3212 }
3213
3214 r = walk_subobject_offsets (binfo,
3215 f,
3216 binfo_offset,
3217 offsets,
3218 max_offset,
3219 (abi_version_at_least (2)
3220 ? /*vbases_p=*/0 : vbases_p));
3221 if (r)
3222 return r;
3223 }
3224
3225 if (abi_version_at_least (2) && CLASSTYPE_VBASECLASSES (type))
3226 {
3227 unsigned ix;
3228 VEC(tree,gc) *vbases;
3229
3230 /* Iterate through the virtual base classes of TYPE. In G++
3231 3.2, we included virtual bases in the direct base class
3232 loop above, which results in incorrect results; the
3233 correct offsets for virtual bases are only known when
3234 working with the most derived type. */
3235 if (vbases_p)
3236 for (vbases = CLASSTYPE_VBASECLASSES (type), ix = 0;
3237 VEC_iterate (tree, vbases, ix, binfo); ix++)
3238 {
3239 r = walk_subobject_offsets (binfo,
3240 f,
3241 size_binop (PLUS_EXPR,
3242 offset,
3243 BINFO_OFFSET (binfo)),
3244 offsets,
3245 max_offset,
3246 /*vbases_p=*/0);
3247 if (r)
3248 return r;
3249 }
3250 else
3251 {
3252 /* We still have to walk the primary base, if it is
3253 virtual. (If it is non-virtual, then it was walked
3254 above.) */
3255 tree vbase = get_primary_binfo (type_binfo);
3256
3257 if (vbase && BINFO_VIRTUAL_P (vbase)
3258 && BINFO_PRIMARY_P (vbase)
3259 && BINFO_INHERITANCE_CHAIN (vbase) == type_binfo)
3260 {
3261 r = (walk_subobject_offsets
3262 (vbase, f, offset,
3263 offsets, max_offset, /*vbases_p=*/0));
3264 if (r)
3265 return r;
3266 }
3267 }
3268 }
3269
3270 /* Iterate through the fields of TYPE. */
3271 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3272 if (TREE_CODE (field) == FIELD_DECL && !DECL_ARTIFICIAL (field))
3273 {
3274 tree field_offset;
3275
3276 if (abi_version_at_least (2))
3277 field_offset = byte_position (field);
3278 else
3279 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3280 field_offset = DECL_FIELD_OFFSET (field);
3281
3282 r = walk_subobject_offsets (TREE_TYPE (field),
3283 f,
3284 size_binop (PLUS_EXPR,
3285 offset,
3286 field_offset),
3287 offsets,
3288 max_offset,
3289 /*vbases_p=*/1);
3290 if (r)
3291 return r;
3292 }
3293 }
3294 else if (TREE_CODE (type) == ARRAY_TYPE)
3295 {
3296 tree element_type = strip_array_types (type);
3297 tree domain = TYPE_DOMAIN (type);
3298 tree index;
3299
3300 /* Avoid recursing into objects that are not interesting. */
3301 if (!CLASS_TYPE_P (element_type)
3302 || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type))
3303 return 0;
3304
3305 /* Step through each of the elements in the array. */
3306 for (index = size_zero_node;
3307 /* G++ 3.2 had an off-by-one error here. */
3308 (abi_version_at_least (2)
3309 ? !INT_CST_LT (TYPE_MAX_VALUE (domain), index)
3310 : INT_CST_LT (index, TYPE_MAX_VALUE (domain)));
3311 index = size_binop (PLUS_EXPR, index, size_one_node))
3312 {
3313 r = walk_subobject_offsets (TREE_TYPE (type),
3314 f,
3315 offset,
3316 offsets,
3317 max_offset,
3318 /*vbases_p=*/1);
3319 if (r)
3320 return r;
3321 offset = size_binop (PLUS_EXPR, offset,
3322 TYPE_SIZE_UNIT (TREE_TYPE (type)));
3323 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3324 there's no point in iterating through the remaining
3325 elements of the array. */
3326 if (max_offset && INT_CST_LT (max_offset, offset))
3327 break;
3328 }
3329 }
3330
3331 return 0;
3332 }
3333
3334 /* Record all of the empty subobjects of TYPE (either a type or a
3335 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3336 is being placed at OFFSET; otherwise, it is a base class that is
3337 being placed at OFFSET. */
3338
3339 static void
record_subobject_offsets(tree type,tree offset,splay_tree offsets,bool is_data_member)3340 record_subobject_offsets (tree type,
3341 tree offset,
3342 splay_tree offsets,
3343 bool is_data_member)
3344 {
3345 tree max_offset;
3346 /* If recording subobjects for a non-static data member or a
3347 non-empty base class , we do not need to record offsets beyond
3348 the size of the biggest empty class. Additional data members
3349 will go at the end of the class. Additional base classes will go
3350 either at offset zero (if empty, in which case they cannot
3351 overlap with offsets past the size of the biggest empty class) or
3352 at the end of the class.
3353
3354 However, if we are placing an empty base class, then we must record
3355 all offsets, as either the empty class is at offset zero (where
3356 other empty classes might later be placed) or at the end of the
3357 class (where other objects might then be placed, so other empty
3358 subobjects might later overlap). */
3359 if (is_data_member
3360 || !is_empty_class (BINFO_TYPE (type)))
3361 max_offset = sizeof_biggest_empty_class;
3362 else
3363 max_offset = NULL_TREE;
3364 walk_subobject_offsets (type, record_subobject_offset, offset,
3365 offsets, max_offset, is_data_member);
3366 }
3367
3368 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3369 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3370 virtual bases of TYPE are examined. */
3371
3372 static int
layout_conflict_p(tree type,tree offset,splay_tree offsets,int vbases_p)3373 layout_conflict_p (tree type,
3374 tree offset,
3375 splay_tree offsets,
3376 int vbases_p)
3377 {
3378 splay_tree_node max_node;
3379
3380 /* Get the node in OFFSETS that indicates the maximum offset where
3381 an empty subobject is located. */
3382 max_node = splay_tree_max (offsets);
3383 /* If there aren't any empty subobjects, then there's no point in
3384 performing this check. */
3385 if (!max_node)
3386 return 0;
3387
3388 return walk_subobject_offsets (type, check_subobject_offset, offset,
3389 offsets, (tree) (max_node->key),
3390 vbases_p);
3391 }
3392
3393 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3394 non-static data member of the type indicated by RLI. BINFO is the
3395 binfo corresponding to the base subobject, OFFSETS maps offsets to
3396 types already located at those offsets. This function determines
3397 the position of the DECL. */
3398
3399 static void
layout_nonempty_base_or_field(record_layout_info rli,tree decl,tree binfo,splay_tree offsets)3400 layout_nonempty_base_or_field (record_layout_info rli,
3401 tree decl,
3402 tree binfo,
3403 splay_tree offsets)
3404 {
3405 tree offset = NULL_TREE;
3406 bool field_p;
3407 tree type;
3408
3409 if (binfo)
3410 {
3411 /* For the purposes of determining layout conflicts, we want to
3412 use the class type of BINFO; TREE_TYPE (DECL) will be the
3413 CLASSTYPE_AS_BASE version, which does not contain entries for
3414 zero-sized bases. */
3415 type = TREE_TYPE (binfo);
3416 field_p = false;
3417 }
3418 else
3419 {
3420 type = TREE_TYPE (decl);
3421 field_p = true;
3422 }
3423
3424 /* Try to place the field. It may take more than one try if we have
3425 a hard time placing the field without putting two objects of the
3426 same type at the same address. */
3427 while (1)
3428 {
3429 struct record_layout_info_s old_rli = *rli;
3430
3431 /* Place this field. */
3432 place_field (rli, decl);
3433 offset = byte_position (decl);
3434
3435 /* We have to check to see whether or not there is already
3436 something of the same type at the offset we're about to use.
3437 For example, consider:
3438
3439 struct S {};
3440 struct T : public S { int i; };
3441 struct U : public S, public T {};
3442
3443 Here, we put S at offset zero in U. Then, we can't put T at
3444 offset zero -- its S component would be at the same address
3445 as the S we already allocated. So, we have to skip ahead.
3446 Since all data members, including those whose type is an
3447 empty class, have nonzero size, any overlap can happen only
3448 with a direct or indirect base-class -- it can't happen with
3449 a data member. */
3450 /* In a union, overlap is permitted; all members are placed at
3451 offset zero. */
3452 if (TREE_CODE (rli->t) == UNION_TYPE)
3453 break;
3454 /* G++ 3.2 did not check for overlaps when placing a non-empty
3455 virtual base. */
3456 if (!abi_version_at_least (2) && binfo && BINFO_VIRTUAL_P (binfo))
3457 break;
3458 if (layout_conflict_p (field_p ? type : binfo, offset,
3459 offsets, field_p))
3460 {
3461 /* Strip off the size allocated to this field. That puts us
3462 at the first place we could have put the field with
3463 proper alignment. */
3464 *rli = old_rli;
3465
3466 /* Bump up by the alignment required for the type. */
3467 rli->bitpos
3468 = size_binop (PLUS_EXPR, rli->bitpos,
3469 bitsize_int (binfo
3470 ? CLASSTYPE_ALIGN (type)
3471 : TYPE_ALIGN (type)));
3472 normalize_rli (rli);
3473 }
3474 else
3475 /* There was no conflict. We're done laying out this field. */
3476 break;
3477 }
3478
3479 /* Now that we know where it will be placed, update its
3480 BINFO_OFFSET. */
3481 if (binfo && CLASS_TYPE_P (BINFO_TYPE (binfo)))
3482 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3483 this point because their BINFO_OFFSET is copied from another
3484 hierarchy. Therefore, we may not need to add the entire
3485 OFFSET. */
3486 propagate_binfo_offsets (binfo,
3487 size_diffop (convert (ssizetype, offset),
3488 convert (ssizetype,
3489 BINFO_OFFSET (binfo))));
3490 }
3491
3492 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3493
3494 static int
empty_base_at_nonzero_offset_p(tree type,tree offset,splay_tree offsets ATTRIBUTE_UNUSED)3495 empty_base_at_nonzero_offset_p (tree type,
3496 tree offset,
3497 splay_tree offsets ATTRIBUTE_UNUSED)
3498 {
3499 return is_empty_class (type) && !integer_zerop (offset);
3500 }
3501
3502 /* Layout the empty base BINFO. EOC indicates the byte currently just
3503 past the end of the class, and should be correctly aligned for a
3504 class of the type indicated by BINFO; OFFSETS gives the offsets of
3505 the empty bases allocated so far. T is the most derived
3506 type. Return nonzero iff we added it at the end. */
3507
3508 static bool
layout_empty_base(tree binfo,tree eoc,splay_tree offsets)3509 layout_empty_base (tree binfo, tree eoc, splay_tree offsets)
3510 {
3511 tree alignment;
3512 tree basetype = BINFO_TYPE (binfo);
3513 bool atend = false;
3514
3515 /* This routine should only be used for empty classes. */
3516 gcc_assert (is_empty_class (basetype));
3517 alignment = ssize_int (CLASSTYPE_ALIGN_UNIT (basetype));
3518
3519 if (!integer_zerop (BINFO_OFFSET (binfo)))
3520 {
3521 if (abi_version_at_least (2))
3522 propagate_binfo_offsets
3523 (binfo, size_diffop (size_zero_node, BINFO_OFFSET (binfo)));
3524 else
3525 warning (OPT_Wabi,
3526 "offset of empty base %qT may not be ABI-compliant and may"
3527 "change in a future version of GCC",
3528 BINFO_TYPE (binfo));
3529 }
3530
3531 /* This is an empty base class. We first try to put it at offset
3532 zero. */
3533 if (layout_conflict_p (binfo,
3534 BINFO_OFFSET (binfo),
3535 offsets,
3536 /*vbases_p=*/0))
3537 {
3538 /* That didn't work. Now, we move forward from the next
3539 available spot in the class. */
3540 atend = true;
3541 propagate_binfo_offsets (binfo, convert (ssizetype, eoc));
3542 while (1)
3543 {
3544 if (!layout_conflict_p (binfo,
3545 BINFO_OFFSET (binfo),
3546 offsets,
3547 /*vbases_p=*/0))
3548 /* We finally found a spot where there's no overlap. */
3549 break;
3550
3551 /* There's overlap here, too. Bump along to the next spot. */
3552 propagate_binfo_offsets (binfo, alignment);
3553 }
3554 }
3555 return atend;
3556 }
3557
3558 /* Layout the base given by BINFO in the class indicated by RLI.
3559 *BASE_ALIGN is a running maximum of the alignments of
3560 any base class. OFFSETS gives the location of empty base
3561 subobjects. T is the most derived type. Return nonzero if the new
3562 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3563 *NEXT_FIELD, unless BINFO is for an empty base class.
3564
3565 Returns the location at which the next field should be inserted. */
3566
3567 static tree *
build_base_field(record_layout_info rli,tree binfo,splay_tree offsets,tree * next_field)3568 build_base_field (record_layout_info rli, tree binfo,
3569 splay_tree offsets, tree *next_field)
3570 {
3571 tree t = rli->t;
3572 tree basetype = BINFO_TYPE (binfo);
3573
3574 if (!COMPLETE_TYPE_P (basetype))
3575 /* This error is now reported in xref_tag, thus giving better
3576 location information. */
3577 return next_field;
3578
3579 /* Place the base class. */
3580 if (!is_empty_class (basetype))
3581 {
3582 tree decl;
3583
3584 /* The containing class is non-empty because it has a non-empty
3585 base class. */
3586 CLASSTYPE_EMPTY_P (t) = 0;
3587
3588 /* Create the FIELD_DECL. */
3589 decl = build_decl (FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype));
3590 DECL_ARTIFICIAL (decl) = 1;
3591 DECL_IGNORED_P (decl) = 1;
3592 DECL_FIELD_CONTEXT (decl) = t;
3593 DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype);
3594 DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype);
3595 DECL_ALIGN (decl) = CLASSTYPE_ALIGN (basetype);
3596 DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype);
3597 DECL_MODE (decl) = TYPE_MODE (basetype);
3598 DECL_FIELD_IS_BASE (decl) = 1;
3599
3600 /* Try to place the field. It may take more than one try if we
3601 have a hard time placing the field without putting two
3602 objects of the same type at the same address. */
3603 layout_nonempty_base_or_field (rli, decl, binfo, offsets);
3604 /* Add the new FIELD_DECL to the list of fields for T. */
3605 TREE_CHAIN (decl) = *next_field;
3606 *next_field = decl;
3607 next_field = &TREE_CHAIN (decl);
3608 }
3609 else
3610 {
3611 tree eoc;
3612 bool atend;
3613
3614 /* On some platforms (ARM), even empty classes will not be
3615 byte-aligned. */
3616 eoc = round_up (rli_size_unit_so_far (rli),
3617 CLASSTYPE_ALIGN_UNIT (basetype));
3618 atend = layout_empty_base (binfo, eoc, offsets);
3619 /* A nearly-empty class "has no proper base class that is empty,
3620 not morally virtual, and at an offset other than zero." */
3621 if (!BINFO_VIRTUAL_P (binfo) && CLASSTYPE_NEARLY_EMPTY_P (t))
3622 {
3623 if (atend)
3624 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3625 /* The check above (used in G++ 3.2) is insufficient because
3626 an empty class placed at offset zero might itself have an
3627 empty base at a nonzero offset. */
3628 else if (walk_subobject_offsets (basetype,
3629 empty_base_at_nonzero_offset_p,
3630 size_zero_node,
3631 /*offsets=*/NULL,
3632 /*max_offset=*/NULL_TREE,
3633 /*vbases_p=*/true))
3634 {
3635 if (abi_version_at_least (2))
3636 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3637 else
3638 warning (OPT_Wabi,
3639 "class %qT will be considered nearly empty in a "
3640 "future version of GCC", t);
3641 }
3642 }
3643
3644 /* We do not create a FIELD_DECL for empty base classes because
3645 it might overlap some other field. We want to be able to
3646 create CONSTRUCTORs for the class by iterating over the
3647 FIELD_DECLs, and the back end does not handle overlapping
3648 FIELD_DECLs. */
3649
3650 /* An empty virtual base causes a class to be non-empty
3651 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3652 here because that was already done when the virtual table
3653 pointer was created. */
3654 }
3655
3656 /* Record the offsets of BINFO and its base subobjects. */
3657 record_subobject_offsets (binfo,
3658 BINFO_OFFSET (binfo),
3659 offsets,
3660 /*is_data_member=*/false);
3661
3662 return next_field;
3663 }
3664
3665 /* Layout all of the non-virtual base classes. Record empty
3666 subobjects in OFFSETS. T is the most derived type. Return nonzero
3667 if the type cannot be nearly empty. The fields created
3668 corresponding to the base classes will be inserted at
3669 *NEXT_FIELD. */
3670
3671 static void
build_base_fields(record_layout_info rli,splay_tree offsets,tree * next_field)3672 build_base_fields (record_layout_info rli,
3673 splay_tree offsets, tree *next_field)
3674 {
3675 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3676 subobjects. */
3677 tree t = rli->t;
3678 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
3679 int i;
3680
3681 /* The primary base class is always allocated first. */
3682 if (CLASSTYPE_HAS_PRIMARY_BASE_P (t))
3683 next_field = build_base_field (rli, CLASSTYPE_PRIMARY_BINFO (t),
3684 offsets, next_field);
3685
3686 /* Now allocate the rest of the bases. */
3687 for (i = 0; i < n_baseclasses; ++i)
3688 {
3689 tree base_binfo;
3690
3691 base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i);
3692
3693 /* The primary base was already allocated above, so we don't
3694 need to allocate it again here. */
3695 if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t))
3696 continue;
3697
3698 /* Virtual bases are added at the end (a primary virtual base
3699 will have already been added). */
3700 if (BINFO_VIRTUAL_P (base_binfo))
3701 continue;
3702
3703 next_field = build_base_field (rli, base_binfo,
3704 offsets, next_field);
3705 }
3706 }
3707
3708 /* Go through the TYPE_METHODS of T issuing any appropriate
3709 diagnostics, figuring out which methods override which other
3710 methods, and so forth. */
3711
3712 static void
check_methods(tree t)3713 check_methods (tree t)
3714 {
3715 tree x;
3716
3717 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
3718 {
3719 check_for_override (x, t);
3720 if (DECL_PURE_VIRTUAL_P (x) && ! DECL_VINDEX (x))
3721 error ("initializer specified for non-virtual method %q+D", x);
3722 /* The name of the field is the original field name
3723 Save this in auxiliary field for later overloading. */
3724 if (DECL_VINDEX (x))
3725 {
3726 TYPE_POLYMORPHIC_P (t) = 1;
3727 if (DECL_PURE_VIRTUAL_P (x))
3728 VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x);
3729 }
3730 /* All user-declared destructors are non-trivial. */
3731 if (DECL_DESTRUCTOR_P (x))
3732 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = 1;
3733 }
3734 }
3735
3736 /* FN is a constructor or destructor. Clone the declaration to create
3737 a specialized in-charge or not-in-charge version, as indicated by
3738 NAME. */
3739
3740 static tree
build_clone(tree fn,tree name)3741 build_clone (tree fn, tree name)
3742 {
3743 tree parms;
3744 tree clone;
3745
3746 /* Copy the function. */
3747 clone = copy_decl (fn);
3748 /* Remember where this function came from. */
3749 DECL_CLONED_FUNCTION (clone) = fn;
3750 DECL_ABSTRACT_ORIGIN (clone) = fn;
3751 /* Reset the function name. */
3752 DECL_NAME (clone) = name;
3753 SET_DECL_ASSEMBLER_NAME (clone, NULL_TREE);
3754 /* There's no pending inline data for this function. */
3755 DECL_PENDING_INLINE_INFO (clone) = NULL;
3756 DECL_PENDING_INLINE_P (clone) = 0;
3757 /* And it hasn't yet been deferred. */
3758 DECL_DEFERRED_FN (clone) = 0;
3759
3760 /* The base-class destructor is not virtual. */
3761 if (name == base_dtor_identifier)
3762 {
3763 DECL_VIRTUAL_P (clone) = 0;
3764 if (TREE_CODE (clone) != TEMPLATE_DECL)
3765 DECL_VINDEX (clone) = NULL_TREE;
3766 }
3767
3768 /* If there was an in-charge parameter, drop it from the function
3769 type. */
3770 if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3771 {
3772 tree basetype;
3773 tree parmtypes;
3774 tree exceptions;
3775
3776 exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
3777 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
3778 parmtypes = TYPE_ARG_TYPES (TREE_TYPE (clone));
3779 /* Skip the `this' parameter. */
3780 parmtypes = TREE_CHAIN (parmtypes);
3781 /* Skip the in-charge parameter. */
3782 parmtypes = TREE_CHAIN (parmtypes);
3783 /* And the VTT parm, in a complete [cd]tor. */
3784 if (DECL_HAS_VTT_PARM_P (fn)
3785 && ! DECL_NEEDS_VTT_PARM_P (clone))
3786 parmtypes = TREE_CHAIN (parmtypes);
3787 /* If this is subobject constructor or destructor, add the vtt
3788 parameter. */
3789 TREE_TYPE (clone)
3790 = build_method_type_directly (basetype,
3791 TREE_TYPE (TREE_TYPE (clone)),
3792 parmtypes);
3793 if (exceptions)
3794 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone),
3795 exceptions);
3796 TREE_TYPE (clone)
3797 = cp_build_type_attribute_variant (TREE_TYPE (clone),
3798 TYPE_ATTRIBUTES (TREE_TYPE (fn)));
3799 }
3800
3801 /* Copy the function parameters. But, DECL_ARGUMENTS on a TEMPLATE_DECL
3802 aren't function parameters; those are the template parameters. */
3803 if (TREE_CODE (clone) != TEMPLATE_DECL)
3804 {
3805 DECL_ARGUMENTS (clone) = copy_list (DECL_ARGUMENTS (clone));
3806 /* Remove the in-charge parameter. */
3807 if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3808 {
3809 TREE_CHAIN (DECL_ARGUMENTS (clone))
3810 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3811 DECL_HAS_IN_CHARGE_PARM_P (clone) = 0;
3812 }
3813 /* And the VTT parm, in a complete [cd]tor. */
3814 if (DECL_HAS_VTT_PARM_P (fn))
3815 {
3816 if (DECL_NEEDS_VTT_PARM_P (clone))
3817 DECL_HAS_VTT_PARM_P (clone) = 1;
3818 else
3819 {
3820 TREE_CHAIN (DECL_ARGUMENTS (clone))
3821 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3822 DECL_HAS_VTT_PARM_P (clone) = 0;
3823 }
3824 }
3825
3826 for (parms = DECL_ARGUMENTS (clone); parms; parms = TREE_CHAIN (parms))
3827 {
3828 DECL_CONTEXT (parms) = clone;
3829 cxx_dup_lang_specific_decl (parms);
3830 }
3831 }
3832
3833 /* Create the RTL for this function. */
3834 SET_DECL_RTL (clone, NULL_RTX);
3835 rest_of_decl_compilation (clone, /*top_level=*/1, at_eof);
3836
3837 /* Make it easy to find the CLONE given the FN. */
3838 TREE_CHAIN (clone) = TREE_CHAIN (fn);
3839 TREE_CHAIN (fn) = clone;
3840
3841 /* If this is a template, handle the DECL_TEMPLATE_RESULT as well. */
3842 if (TREE_CODE (clone) == TEMPLATE_DECL)
3843 {
3844 tree result;
3845
3846 DECL_TEMPLATE_RESULT (clone)
3847 = build_clone (DECL_TEMPLATE_RESULT (clone), name);
3848 result = DECL_TEMPLATE_RESULT (clone);
3849 DECL_TEMPLATE_INFO (result) = copy_node (DECL_TEMPLATE_INFO (result));
3850 DECL_TI_TEMPLATE (result) = clone;
3851 }
3852 else if (pch_file)
3853 note_decl_for_pch (clone);
3854
3855 return clone;
3856 }
3857
3858 /* Produce declarations for all appropriate clones of FN. If
3859 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
3860 CLASTYPE_METHOD_VEC as well. */
3861
3862 void
clone_function_decl(tree fn,int update_method_vec_p)3863 clone_function_decl (tree fn, int update_method_vec_p)
3864 {
3865 tree clone;
3866
3867 /* Avoid inappropriate cloning. */
3868 if (TREE_CHAIN (fn)
3869 && DECL_CLONED_FUNCTION (TREE_CHAIN (fn)))
3870 return;
3871
3872 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
3873 {
3874 /* For each constructor, we need two variants: an in-charge version
3875 and a not-in-charge version. */
3876 clone = build_clone (fn, complete_ctor_identifier);
3877 if (update_method_vec_p)
3878 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3879 clone = build_clone (fn, base_ctor_identifier);
3880 if (update_method_vec_p)
3881 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3882 }
3883 else
3884 {
3885 gcc_assert (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn));
3886
3887 /* For each destructor, we need three variants: an in-charge
3888 version, a not-in-charge version, and an in-charge deleting
3889 version. We clone the deleting version first because that
3890 means it will go second on the TYPE_METHODS list -- and that
3891 corresponds to the correct layout order in the virtual
3892 function table.
3893
3894 For a non-virtual destructor, we do not build a deleting
3895 destructor. */
3896 if (DECL_VIRTUAL_P (fn))
3897 {
3898 clone = build_clone (fn, deleting_dtor_identifier);
3899 if (update_method_vec_p)
3900 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3901 }
3902 clone = build_clone (fn, complete_dtor_identifier);
3903 if (update_method_vec_p)
3904 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3905 clone = build_clone (fn, base_dtor_identifier);
3906 if (update_method_vec_p)
3907 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3908 }
3909
3910 /* Note that this is an abstract function that is never emitted. */
3911 DECL_ABSTRACT (fn) = 1;
3912 }
3913
3914 /* DECL is an in charge constructor, which is being defined. This will
3915 have had an in class declaration, from whence clones were
3916 declared. An out-of-class definition can specify additional default
3917 arguments. As it is the clones that are involved in overload
3918 resolution, we must propagate the information from the DECL to its
3919 clones. */
3920
3921 void
adjust_clone_args(tree decl)3922 adjust_clone_args (tree decl)
3923 {
3924 tree clone;
3925
3926 for (clone = TREE_CHAIN (decl); clone && DECL_CLONED_FUNCTION (clone);
3927 clone = TREE_CHAIN (clone))
3928 {
3929 tree orig_clone_parms = TYPE_ARG_TYPES (TREE_TYPE (clone));
3930 tree orig_decl_parms = TYPE_ARG_TYPES (TREE_TYPE (decl));
3931 tree decl_parms, clone_parms;
3932
3933 clone_parms = orig_clone_parms;
3934
3935 /* Skip the 'this' parameter. */
3936 orig_clone_parms = TREE_CHAIN (orig_clone_parms);
3937 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3938
3939 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
3940 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3941 if (DECL_HAS_VTT_PARM_P (decl))
3942 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3943
3944 clone_parms = orig_clone_parms;
3945 if (DECL_HAS_VTT_PARM_P (clone))
3946 clone_parms = TREE_CHAIN (clone_parms);
3947
3948 for (decl_parms = orig_decl_parms; decl_parms;
3949 decl_parms = TREE_CHAIN (decl_parms),
3950 clone_parms = TREE_CHAIN (clone_parms))
3951 {
3952 gcc_assert (same_type_p (TREE_TYPE (decl_parms),
3953 TREE_TYPE (clone_parms)));
3954
3955 if (TREE_PURPOSE (decl_parms) && !TREE_PURPOSE (clone_parms))
3956 {
3957 /* A default parameter has been added. Adjust the
3958 clone's parameters. */
3959 tree exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
3960 tree basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
3961 tree type;
3962
3963 clone_parms = orig_decl_parms;
3964
3965 if (DECL_HAS_VTT_PARM_P (clone))
3966 {
3967 clone_parms = tree_cons (TREE_PURPOSE (orig_clone_parms),
3968 TREE_VALUE (orig_clone_parms),
3969 clone_parms);
3970 TREE_TYPE (clone_parms) = TREE_TYPE (orig_clone_parms);
3971 }
3972 type = build_method_type_directly (basetype,
3973 TREE_TYPE (TREE_TYPE (clone)),
3974 clone_parms);
3975 if (exceptions)
3976 type = build_exception_variant (type, exceptions);
3977 TREE_TYPE (clone) = type;
3978
3979 clone_parms = NULL_TREE;
3980 break;
3981 }
3982 }
3983 gcc_assert (!clone_parms);
3984 }
3985 }
3986
3987 /* For each of the constructors and destructors in T, create an
3988 in-charge and not-in-charge variant. */
3989
3990 static void
clone_constructors_and_destructors(tree t)3991 clone_constructors_and_destructors (tree t)
3992 {
3993 tree fns;
3994
3995 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
3996 out now. */
3997 if (!CLASSTYPE_METHOD_VEC (t))
3998 return;
3999
4000 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4001 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
4002 for (fns = CLASSTYPE_DESTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4003 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
4004 }
4005
4006 /* Remove all zero-width bit-fields from T. */
4007
4008 static void
remove_zero_width_bit_fields(tree t)4009 remove_zero_width_bit_fields (tree t)
4010 {
4011 tree *fieldsp;
4012
4013 fieldsp = &TYPE_FIELDS (t);
4014 while (*fieldsp)
4015 {
4016 if (TREE_CODE (*fieldsp) == FIELD_DECL
4017 && DECL_C_BIT_FIELD (*fieldsp)
4018 && DECL_INITIAL (*fieldsp))
4019 *fieldsp = TREE_CHAIN (*fieldsp);
4020 else
4021 fieldsp = &TREE_CHAIN (*fieldsp);
4022 }
4023 }
4024
4025 /* Returns TRUE iff we need a cookie when dynamically allocating an
4026 array whose elements have the indicated class TYPE. */
4027
4028 static bool
type_requires_array_cookie(tree type)4029 type_requires_array_cookie (tree type)
4030 {
4031 tree fns;
4032 bool has_two_argument_delete_p = false;
4033
4034 gcc_assert (CLASS_TYPE_P (type));
4035
4036 /* If there's a non-trivial destructor, we need a cookie. In order
4037 to iterate through the array calling the destructor for each
4038 element, we'll have to know how many elements there are. */
4039 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
4040 return true;
4041
4042 /* If the usual deallocation function is a two-argument whose second
4043 argument is of type `size_t', then we have to pass the size of
4044 the array to the deallocation function, so we will need to store
4045 a cookie. */
4046 fns = lookup_fnfields (TYPE_BINFO (type),
4047 ansi_opname (VEC_DELETE_EXPR),
4048 /*protect=*/0);
4049 /* If there are no `operator []' members, or the lookup is
4050 ambiguous, then we don't need a cookie. */
4051 if (!fns || fns == error_mark_node)
4052 return false;
4053 /* Loop through all of the functions. */
4054 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
4055 {
4056 tree fn;
4057 tree second_parm;
4058
4059 /* Select the current function. */
4060 fn = OVL_CURRENT (fns);
4061 /* See if this function is a one-argument delete function. If
4062 it is, then it will be the usual deallocation function. */
4063 second_parm = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fn)));
4064 if (second_parm == void_list_node)
4065 return false;
4066 /* Otherwise, if we have a two-argument function and the second
4067 argument is `size_t', it will be the usual deallocation
4068 function -- unless there is one-argument function, too. */
4069 if (TREE_CHAIN (second_parm) == void_list_node
4070 && same_type_p (TREE_VALUE (second_parm), sizetype))
4071 has_two_argument_delete_p = true;
4072 }
4073
4074 return has_two_argument_delete_p;
4075 }
4076
4077 /* Check the validity of the bases and members declared in T. Add any
4078 implicitly-generated functions (like copy-constructors and
4079 assignment operators). Compute various flag bits (like
4080 CLASSTYPE_NON_POD_T) for T. This routine works purely at the C++
4081 level: i.e., independently of the ABI in use. */
4082
4083 static void
check_bases_and_members(tree t)4084 check_bases_and_members (tree t)
4085 {
4086 /* Nonzero if the implicitly generated copy constructor should take
4087 a non-const reference argument. */
4088 int cant_have_const_ctor;
4089 /* Nonzero if the implicitly generated assignment operator
4090 should take a non-const reference argument. */
4091 int no_const_asn_ref;
4092 tree access_decls;
4093
4094 /* By default, we use const reference arguments and generate default
4095 constructors. */
4096 cant_have_const_ctor = 0;
4097 no_const_asn_ref = 0;
4098
4099 /* Check all the base-classes. */
4100 check_bases (t, &cant_have_const_ctor,
4101 &no_const_asn_ref);
4102
4103 /* Check all the method declarations. */
4104 check_methods (t);
4105
4106 /* Check all the data member declarations. We cannot call
4107 check_field_decls until we have called check_bases check_methods,
4108 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
4109 being set appropriately. */
4110 check_field_decls (t, &access_decls,
4111 &cant_have_const_ctor,
4112 &no_const_asn_ref);
4113
4114 /* A nearly-empty class has to be vptr-containing; a nearly empty
4115 class contains just a vptr. */
4116 if (!TYPE_CONTAINS_VPTR_P (t))
4117 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
4118
4119 /* Do some bookkeeping that will guide the generation of implicitly
4120 declared member functions. */
4121 TYPE_HAS_COMPLEX_INIT_REF (t)
4122 |= (TYPE_HAS_INIT_REF (t) || TYPE_CONTAINS_VPTR_P (t));
4123 TYPE_NEEDS_CONSTRUCTING (t)
4124 |= (TYPE_HAS_CONSTRUCTOR (t) || TYPE_CONTAINS_VPTR_P (t));
4125 CLASSTYPE_NON_AGGREGATE (t)
4126 |= (TYPE_HAS_CONSTRUCTOR (t) || TYPE_POLYMORPHIC_P (t));
4127 CLASSTYPE_NON_POD_P (t)
4128 |= (CLASSTYPE_NON_AGGREGATE (t)
4129 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
4130 || TYPE_HAS_ASSIGN_REF (t));
4131 TYPE_HAS_COMPLEX_ASSIGN_REF (t)
4132 |= TYPE_HAS_ASSIGN_REF (t) || TYPE_CONTAINS_VPTR_P (t);
4133
4134 /* Synthesize any needed methods. */
4135 add_implicitly_declared_members (t,
4136 cant_have_const_ctor,
4137 no_const_asn_ref);
4138
4139 /* Create the in-charge and not-in-charge variants of constructors
4140 and destructors. */
4141 clone_constructors_and_destructors (t);
4142
4143 /* Process the using-declarations. */
4144 for (; access_decls; access_decls = TREE_CHAIN (access_decls))
4145 handle_using_decl (TREE_VALUE (access_decls), t);
4146
4147 /* Build and sort the CLASSTYPE_METHOD_VEC. */
4148 finish_struct_methods (t);
4149
4150 /* Figure out whether or not we will need a cookie when dynamically
4151 allocating an array of this type. */
4152 TYPE_LANG_SPECIFIC (t)->u.c.vec_new_uses_cookie
4153 = type_requires_array_cookie (t);
4154 }
4155
4156 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4157 accordingly. If a new vfield was created (because T doesn't have a
4158 primary base class), then the newly created field is returned. It
4159 is not added to the TYPE_FIELDS list; it is the caller's
4160 responsibility to do that. Accumulate declared virtual functions
4161 on VIRTUALS_P. */
4162
4163 static tree
create_vtable_ptr(tree t,tree * virtuals_p)4164 create_vtable_ptr (tree t, tree* virtuals_p)
4165 {
4166 tree fn;
4167
4168 /* Collect the virtual functions declared in T. */
4169 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
4170 if (DECL_VINDEX (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)
4171 && TREE_CODE (DECL_VINDEX (fn)) != INTEGER_CST)
4172 {
4173 tree new_virtual = make_node (TREE_LIST);
4174
4175 BV_FN (new_virtual) = fn;
4176 BV_DELTA (new_virtual) = integer_zero_node;
4177 BV_VCALL_INDEX (new_virtual) = NULL_TREE;
4178
4179 TREE_CHAIN (new_virtual) = *virtuals_p;
4180 *virtuals_p = new_virtual;
4181 }
4182
4183 /* If we couldn't find an appropriate base class, create a new field
4184 here. Even if there weren't any new virtual functions, we might need a
4185 new virtual function table if we're supposed to include vptrs in
4186 all classes that need them. */
4187 if (!TYPE_VFIELD (t) && (*virtuals_p || TYPE_CONTAINS_VPTR_P (t)))
4188 {
4189 /* We build this decl with vtbl_ptr_type_node, which is a
4190 `vtable_entry_type*'. It might seem more precise to use
4191 `vtable_entry_type (*)[N]' where N is the number of virtual
4192 functions. However, that would require the vtable pointer in
4193 base classes to have a different type than the vtable pointer
4194 in derived classes. We could make that happen, but that
4195 still wouldn't solve all the problems. In particular, the
4196 type-based alias analysis code would decide that assignments
4197 to the base class vtable pointer can't alias assignments to
4198 the derived class vtable pointer, since they have different
4199 types. Thus, in a derived class destructor, where the base
4200 class constructor was inlined, we could generate bad code for
4201 setting up the vtable pointer.
4202
4203 Therefore, we use one type for all vtable pointers. We still
4204 use a type-correct type; it's just doesn't indicate the array
4205 bounds. That's better than using `void*' or some such; it's
4206 cleaner, and it let's the alias analysis code know that these
4207 stores cannot alias stores to void*! */
4208 tree field;
4209
4210 field = build_decl (FIELD_DECL, get_vfield_name (t), vtbl_ptr_type_node);
4211 DECL_VIRTUAL_P (field) = 1;
4212 DECL_ARTIFICIAL (field) = 1;
4213 DECL_FIELD_CONTEXT (field) = t;
4214 DECL_FCONTEXT (field) = t;
4215
4216 TYPE_VFIELD (t) = field;
4217
4218 /* This class is non-empty. */
4219 CLASSTYPE_EMPTY_P (t) = 0;
4220
4221 return field;
4222 }
4223
4224 return NULL_TREE;
4225 }
4226
4227 /* Fixup the inline function given by INFO now that the class is
4228 complete. */
4229
4230 static void
fixup_pending_inline(tree fn)4231 fixup_pending_inline (tree fn)
4232 {
4233 if (DECL_PENDING_INLINE_INFO (fn))
4234 {
4235 tree args = DECL_ARGUMENTS (fn);
4236 while (args)
4237 {
4238 DECL_CONTEXT (args) = fn;
4239 args = TREE_CHAIN (args);
4240 }
4241 }
4242 }
4243
4244 /* Fixup the inline methods and friends in TYPE now that TYPE is
4245 complete. */
4246
4247 static void
fixup_inline_methods(tree type)4248 fixup_inline_methods (tree type)
4249 {
4250 tree method = TYPE_METHODS (type);
4251 VEC(tree,gc) *friends;
4252 unsigned ix;
4253
4254 if (method && TREE_CODE (method) == TREE_VEC)
4255 {
4256 if (TREE_VEC_ELT (method, 1))
4257 method = TREE_VEC_ELT (method, 1);
4258 else if (TREE_VEC_ELT (method, 0))
4259 method = TREE_VEC_ELT (method, 0);
4260 else
4261 method = TREE_VEC_ELT (method, 2);
4262 }
4263
4264 /* Do inline member functions. */
4265 for (; method; method = TREE_CHAIN (method))
4266 fixup_pending_inline (method);
4267
4268 /* Do friends. */
4269 for (friends = CLASSTYPE_INLINE_FRIENDS (type), ix = 0;
4270 VEC_iterate (tree, friends, ix, method); ix++)
4271 fixup_pending_inline (method);
4272 CLASSTYPE_INLINE_FRIENDS (type) = NULL;
4273 }
4274
4275 /* Add OFFSET to all base types of BINFO which is a base in the
4276 hierarchy dominated by T.
4277
4278 OFFSET, which is a type offset, is number of bytes. */
4279
4280 static void
propagate_binfo_offsets(tree binfo,tree offset)4281 propagate_binfo_offsets (tree binfo, tree offset)
4282 {
4283 int i;
4284 tree primary_binfo;
4285 tree base_binfo;
4286
4287 /* Update BINFO's offset. */
4288 BINFO_OFFSET (binfo)
4289 = convert (sizetype,
4290 size_binop (PLUS_EXPR,
4291 convert (ssizetype, BINFO_OFFSET (binfo)),
4292 offset));
4293
4294 /* Find the primary base class. */
4295 primary_binfo = get_primary_binfo (binfo);
4296
4297 if (primary_binfo && BINFO_INHERITANCE_CHAIN (primary_binfo) == binfo)
4298 propagate_binfo_offsets (primary_binfo, offset);
4299
4300 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4301 downwards. */
4302 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4303 {
4304 /* Don't do the primary base twice. */
4305 if (base_binfo == primary_binfo)
4306 continue;
4307
4308 if (BINFO_VIRTUAL_P (base_binfo))
4309 continue;
4310
4311 propagate_binfo_offsets (base_binfo, offset);
4312 }
4313 }
4314
4315 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
4316 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
4317 empty subobjects of T. */
4318
4319 static void
layout_virtual_bases(record_layout_info rli,splay_tree offsets)4320 layout_virtual_bases (record_layout_info rli, splay_tree offsets)
4321 {
4322 tree vbase;
4323 tree t = rli->t;
4324 bool first_vbase = true;
4325 tree *next_field;
4326
4327 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) == 0)
4328 return;
4329
4330 if (!abi_version_at_least(2))
4331 {
4332 /* In G++ 3.2, we incorrectly rounded the size before laying out
4333 the virtual bases. */
4334 finish_record_layout (rli, /*free_p=*/false);
4335 #ifdef STRUCTURE_SIZE_BOUNDARY
4336 /* Packed structures don't need to have minimum size. */
4337 if (! TYPE_PACKED (t))
4338 TYPE_ALIGN (t) = MAX (TYPE_ALIGN (t), (unsigned) STRUCTURE_SIZE_BOUNDARY);
4339 #endif
4340 rli->offset = TYPE_SIZE_UNIT (t);
4341 rli->bitpos = bitsize_zero_node;
4342 rli->record_align = TYPE_ALIGN (t);
4343 }
4344
4345 /* Find the last field. The artificial fields created for virtual
4346 bases will go after the last extant field to date. */
4347 next_field = &TYPE_FIELDS (t);
4348 while (*next_field)
4349 next_field = &TREE_CHAIN (*next_field);
4350
4351 /* Go through the virtual bases, allocating space for each virtual
4352 base that is not already a primary base class. These are
4353 allocated in inheritance graph order. */
4354 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
4355 {
4356 if (!BINFO_VIRTUAL_P (vbase))
4357 continue;
4358
4359 if (!BINFO_PRIMARY_P (vbase))
4360 {
4361 tree basetype = TREE_TYPE (vbase);
4362
4363 /* This virtual base is not a primary base of any class in the
4364 hierarchy, so we have to add space for it. */
4365 next_field = build_base_field (rli, vbase,
4366 offsets, next_field);
4367
4368 /* If the first virtual base might have been placed at a
4369 lower address, had we started from CLASSTYPE_SIZE, rather
4370 than TYPE_SIZE, issue a warning. There can be both false
4371 positives and false negatives from this warning in rare
4372 cases; to deal with all the possibilities would probably
4373 require performing both layout algorithms and comparing
4374 the results which is not particularly tractable. */
4375 if (warn_abi
4376 && first_vbase
4377 && (tree_int_cst_lt
4378 (size_binop (CEIL_DIV_EXPR,
4379 round_up (CLASSTYPE_SIZE (t),
4380 CLASSTYPE_ALIGN (basetype)),
4381 bitsize_unit_node),
4382 BINFO_OFFSET (vbase))))
4383 warning (OPT_Wabi,
4384 "offset of virtual base %qT is not ABI-compliant and "
4385 "may change in a future version of GCC",
4386 basetype);
4387
4388 first_vbase = false;
4389 }
4390 }
4391 }
4392
4393 /* Returns the offset of the byte just past the end of the base class
4394 BINFO. */
4395
4396 static tree
end_of_base(tree binfo)4397 end_of_base (tree binfo)
4398 {
4399 tree size;
4400
4401 if (is_empty_class (BINFO_TYPE (binfo)))
4402 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4403 allocate some space for it. It cannot have virtual bases, so
4404 TYPE_SIZE_UNIT is fine. */
4405 size = TYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4406 else
4407 size = CLASSTYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4408
4409 return size_binop (PLUS_EXPR, BINFO_OFFSET (binfo), size);
4410 }
4411
4412 /* Returns the offset of the byte just past the end of the base class
4413 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
4414 only non-virtual bases are included. */
4415
4416 static tree
end_of_class(tree t,int include_virtuals_p)4417 end_of_class (tree t, int include_virtuals_p)
4418 {
4419 tree result = size_zero_node;
4420 VEC(tree,gc) *vbases;
4421 tree binfo;
4422 tree base_binfo;
4423 tree offset;
4424 int i;
4425
4426 for (binfo = TYPE_BINFO (t), i = 0;
4427 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4428 {
4429 if (!include_virtuals_p
4430 && BINFO_VIRTUAL_P (base_binfo)
4431 && (!BINFO_PRIMARY_P (base_binfo)
4432 || BINFO_INHERITANCE_CHAIN (base_binfo) != TYPE_BINFO (t)))
4433 continue;
4434
4435 offset = end_of_base (base_binfo);
4436 if (INT_CST_LT_UNSIGNED (result, offset))
4437 result = offset;
4438 }
4439
4440 /* G++ 3.2 did not check indirect virtual bases. */
4441 if (abi_version_at_least (2) && include_virtuals_p)
4442 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4443 VEC_iterate (tree, vbases, i, base_binfo); i++)
4444 {
4445 offset = end_of_base (base_binfo);
4446 if (INT_CST_LT_UNSIGNED (result, offset))
4447 result = offset;
4448 }
4449
4450 return result;
4451 }
4452
4453 /* Warn about bases of T that are inaccessible because they are
4454 ambiguous. For example:
4455
4456 struct S {};
4457 struct T : public S {};
4458 struct U : public S, public T {};
4459
4460 Here, `(S*) new U' is not allowed because there are two `S'
4461 subobjects of U. */
4462
4463 static void
warn_about_ambiguous_bases(tree t)4464 warn_about_ambiguous_bases (tree t)
4465 {
4466 int i;
4467 VEC(tree,gc) *vbases;
4468 tree basetype;
4469 tree binfo;
4470 tree base_binfo;
4471
4472 /* If there are no repeated bases, nothing can be ambiguous. */
4473 if (!CLASSTYPE_REPEATED_BASE_P (t))
4474 return;
4475
4476 /* Check direct bases. */
4477 for (binfo = TYPE_BINFO (t), i = 0;
4478 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4479 {
4480 basetype = BINFO_TYPE (base_binfo);
4481
4482 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4483 warning (0, "direct base %qT inaccessible in %qT due to ambiguity",
4484 basetype, t);
4485 }
4486
4487 /* Check for ambiguous virtual bases. */
4488 if (extra_warnings)
4489 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4490 VEC_iterate (tree, vbases, i, binfo); i++)
4491 {
4492 basetype = BINFO_TYPE (binfo);
4493
4494 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4495 warning (OPT_Wextra, "virtual base %qT inaccessible in %qT due to ambiguity",
4496 basetype, t);
4497 }
4498 }
4499
4500 /* Compare two INTEGER_CSTs K1 and K2. */
4501
4502 static int
splay_tree_compare_integer_csts(splay_tree_key k1,splay_tree_key k2)4503 splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2)
4504 {
4505 return tree_int_cst_compare ((tree) k1, (tree) k2);
4506 }
4507
4508 /* Increase the size indicated in RLI to account for empty classes
4509 that are "off the end" of the class. */
4510
4511 static void
include_empty_classes(record_layout_info rli)4512 include_empty_classes (record_layout_info rli)
4513 {
4514 tree eoc;
4515 tree rli_size;
4516
4517 /* It might be the case that we grew the class to allocate a
4518 zero-sized base class. That won't be reflected in RLI, yet,
4519 because we are willing to overlay multiple bases at the same
4520 offset. However, now we need to make sure that RLI is big enough
4521 to reflect the entire class. */
4522 eoc = end_of_class (rli->t,
4523 CLASSTYPE_AS_BASE (rli->t) != NULL_TREE);
4524 rli_size = rli_size_unit_so_far (rli);
4525 if (TREE_CODE (rli_size) == INTEGER_CST
4526 && INT_CST_LT_UNSIGNED (rli_size, eoc))
4527 {
4528 if (!abi_version_at_least (2))
4529 /* In version 1 of the ABI, the size of a class that ends with
4530 a bitfield was not rounded up to a whole multiple of a
4531 byte. Because rli_size_unit_so_far returns only the number
4532 of fully allocated bytes, any extra bits were not included
4533 in the size. */
4534 rli->bitpos = round_down (rli->bitpos, BITS_PER_UNIT);
4535 else
4536 /* The size should have been rounded to a whole byte. */
4537 gcc_assert (tree_int_cst_equal
4538 (rli->bitpos, round_down (rli->bitpos, BITS_PER_UNIT)));
4539 rli->bitpos
4540 = size_binop (PLUS_EXPR,
4541 rli->bitpos,
4542 size_binop (MULT_EXPR,
4543 convert (bitsizetype,
4544 size_binop (MINUS_EXPR,
4545 eoc, rli_size)),
4546 bitsize_int (BITS_PER_UNIT)));
4547 normalize_rli (rli);
4548 }
4549 }
4550
4551 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
4552 BINFO_OFFSETs for all of the base-classes. Position the vtable
4553 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
4554
4555 static void
layout_class_type(tree t,tree * virtuals_p)4556 layout_class_type (tree t, tree *virtuals_p)
4557 {
4558 tree non_static_data_members;
4559 tree field;
4560 tree vptr;
4561 record_layout_info rli;
4562 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4563 types that appear at that offset. */
4564 splay_tree empty_base_offsets;
4565 /* True if the last field layed out was a bit-field. */
4566 bool last_field_was_bitfield = false;
4567 /* The location at which the next field should be inserted. */
4568 tree *next_field;
4569 /* T, as a base class. */
4570 tree base_t;
4571
4572 /* Keep track of the first non-static data member. */
4573 non_static_data_members = TYPE_FIELDS (t);
4574
4575 /* Start laying out the record. */
4576 rli = start_record_layout (t);
4577
4578 /* Mark all the primary bases in the hierarchy. */
4579 determine_primary_bases (t);
4580
4581 /* Create a pointer to our virtual function table. */
4582 vptr = create_vtable_ptr (t, virtuals_p);
4583
4584 /* The vptr is always the first thing in the class. */
4585 if (vptr)
4586 {
4587 TREE_CHAIN (vptr) = TYPE_FIELDS (t);
4588 TYPE_FIELDS (t) = vptr;
4589 next_field = &TREE_CHAIN (vptr);
4590 place_field (rli, vptr);
4591 }
4592 else
4593 next_field = &TYPE_FIELDS (t);
4594
4595 /* Build FIELD_DECLs for all of the non-virtual base-types. */
4596 empty_base_offsets = splay_tree_new (splay_tree_compare_integer_csts,
4597 NULL, NULL);
4598 build_base_fields (rli, empty_base_offsets, next_field);
4599
4600 /* Layout the non-static data members. */
4601 for (field = non_static_data_members; field; field = TREE_CHAIN (field))
4602 {
4603 tree type;
4604 tree padding;
4605
4606 /* We still pass things that aren't non-static data members to
4607 the back-end, in case it wants to do something with them. */
4608 if (TREE_CODE (field) != FIELD_DECL)
4609 {
4610 place_field (rli, field);
4611 /* If the static data member has incomplete type, keep track
4612 of it so that it can be completed later. (The handling
4613 of pending statics in finish_record_layout is
4614 insufficient; consider:
4615
4616 struct S1;
4617 struct S2 { static S1 s1; };
4618
4619 At this point, finish_record_layout will be called, but
4620 S1 is still incomplete.) */
4621 if (TREE_CODE (field) == VAR_DECL)
4622 {
4623 maybe_register_incomplete_var (field);
4624 /* The visibility of static data members is determined
4625 at their point of declaration, not their point of
4626 definition. */
4627 determine_visibility (field);
4628 }
4629 continue;
4630 }
4631
4632 type = TREE_TYPE (field);
4633 if (type == error_mark_node)
4634 continue;
4635
4636 padding = NULL_TREE;
4637
4638 /* If this field is a bit-field whose width is greater than its
4639 type, then there are some special rules for allocating
4640 it. */
4641 if (DECL_C_BIT_FIELD (field)
4642 && INT_CST_LT (TYPE_SIZE (type), DECL_SIZE (field)))
4643 {
4644 integer_type_kind itk;
4645 tree integer_type;
4646 bool was_unnamed_p = false;
4647 /* We must allocate the bits as if suitably aligned for the
4648 longest integer type that fits in this many bits. type
4649 of the field. Then, we are supposed to use the left over
4650 bits as additional padding. */
4651 for (itk = itk_char; itk != itk_none; ++itk)
4652 if (INT_CST_LT (DECL_SIZE (field),
4653 TYPE_SIZE (integer_types[itk])))
4654 break;
4655
4656 /* ITK now indicates a type that is too large for the
4657 field. We have to back up by one to find the largest
4658 type that fits. */
4659 integer_type = integer_types[itk - 1];
4660
4661 /* Figure out how much additional padding is required. GCC
4662 3.2 always created a padding field, even if it had zero
4663 width. */
4664 if (!abi_version_at_least (2)
4665 || INT_CST_LT (TYPE_SIZE (integer_type), DECL_SIZE (field)))
4666 {
4667 if (abi_version_at_least (2) && TREE_CODE (t) == UNION_TYPE)
4668 /* In a union, the padding field must have the full width
4669 of the bit-field; all fields start at offset zero. */
4670 padding = DECL_SIZE (field);
4671 else
4672 {
4673 if (TREE_CODE (t) == UNION_TYPE)
4674 warning (OPT_Wabi, "size assigned to %qT may not be "
4675 "ABI-compliant and may change in a future "
4676 "version of GCC",
4677 t);
4678 padding = size_binop (MINUS_EXPR, DECL_SIZE (field),
4679 TYPE_SIZE (integer_type));
4680 }
4681 }
4682 #ifdef PCC_BITFIELD_TYPE_MATTERS
4683 /* An unnamed bitfield does not normally affect the
4684 alignment of the containing class on a target where
4685 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
4686 make any exceptions for unnamed bitfields when the
4687 bitfields are longer than their types. Therefore, we
4688 temporarily give the field a name. */
4689 if (PCC_BITFIELD_TYPE_MATTERS && !DECL_NAME (field))
4690 {
4691 was_unnamed_p = true;
4692 DECL_NAME (field) = make_anon_name ();
4693 }
4694 #endif
4695 DECL_SIZE (field) = TYPE_SIZE (integer_type);
4696 DECL_ALIGN (field) = TYPE_ALIGN (integer_type);
4697 DECL_USER_ALIGN (field) = TYPE_USER_ALIGN (integer_type);
4698 layout_nonempty_base_or_field (rli, field, NULL_TREE,
4699 empty_base_offsets);
4700 if (was_unnamed_p)
4701 DECL_NAME (field) = NULL_TREE;
4702 /* Now that layout has been performed, set the size of the
4703 field to the size of its declared type; the rest of the
4704 field is effectively invisible. */
4705 DECL_SIZE (field) = TYPE_SIZE (type);
4706 /* We must also reset the DECL_MODE of the field. */
4707 if (abi_version_at_least (2))
4708 DECL_MODE (field) = TYPE_MODE (type);
4709 else if (warn_abi
4710 && DECL_MODE (field) != TYPE_MODE (type))
4711 /* Versions of G++ before G++ 3.4 did not reset the
4712 DECL_MODE. */
4713 warning (OPT_Wabi,
4714 "the offset of %qD may not be ABI-compliant and may "
4715 "change in a future version of GCC", field);
4716 }
4717 else
4718 layout_nonempty_base_or_field (rli, field, NULL_TREE,
4719 empty_base_offsets);
4720
4721 /* Remember the location of any empty classes in FIELD. */
4722 if (abi_version_at_least (2))
4723 record_subobject_offsets (TREE_TYPE (field),
4724 byte_position(field),
4725 empty_base_offsets,
4726 /*is_data_member=*/true);
4727
4728 /* If a bit-field does not immediately follow another bit-field,
4729 and yet it starts in the middle of a byte, we have failed to
4730 comply with the ABI. */
4731 if (warn_abi
4732 && DECL_C_BIT_FIELD (field)
4733 /* The TREE_NO_WARNING flag gets set by Objective-C when
4734 laying out an Objective-C class. The ObjC ABI differs
4735 from the C++ ABI, and so we do not want a warning
4736 here. */
4737 && !TREE_NO_WARNING (field)
4738 && !last_field_was_bitfield
4739 && !integer_zerop (size_binop (TRUNC_MOD_EXPR,
4740 DECL_FIELD_BIT_OFFSET (field),
4741 bitsize_unit_node)))
4742 warning (OPT_Wabi, "offset of %q+D is not ABI-compliant and may "
4743 "change in a future version of GCC", field);
4744
4745 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
4746 offset of the field. */
4747 if (warn_abi
4748 && !tree_int_cst_equal (DECL_FIELD_OFFSET (field),
4749 byte_position (field))
4750 && contains_empty_class_p (TREE_TYPE (field)))
4751 warning (OPT_Wabi, "%q+D contains empty classes which may cause base "
4752 "classes to be placed at different locations in a "
4753 "future version of GCC", field);
4754
4755 /* The middle end uses the type of expressions to determine the
4756 possible range of expression values. In order to optimize
4757 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
4758 must be made aware of the width of "i", via its type.
4759
4760 Because C++ does not have integer types of arbitrary width,
4761 we must (for the purposes of the front end) convert from the
4762 type assigned here to the declared type of the bitfield
4763 whenever a bitfield expression is used as an rvalue.
4764 Similarly, when assigning a value to a bitfield, the value
4765 must be converted to the type given the bitfield here. */
4766 if (DECL_C_BIT_FIELD (field))
4767 {
4768 tree ftype;
4769 unsigned HOST_WIDE_INT width;
4770 ftype = TREE_TYPE (field);
4771 width = tree_low_cst (DECL_SIZE (field), /*unsignedp=*/1);
4772 if (width != TYPE_PRECISION (ftype))
4773 TREE_TYPE (field)
4774 = c_build_bitfield_integer_type (width,
4775 TYPE_UNSIGNED (ftype));
4776 }
4777
4778 /* If we needed additional padding after this field, add it
4779 now. */
4780 if (padding)
4781 {
4782 tree padding_field;
4783
4784 padding_field = build_decl (FIELD_DECL,
4785 NULL_TREE,
4786 char_type_node);
4787 DECL_BIT_FIELD (padding_field) = 1;
4788 DECL_SIZE (padding_field) = padding;
4789 DECL_CONTEXT (padding_field) = t;
4790 DECL_ARTIFICIAL (padding_field) = 1;
4791 DECL_IGNORED_P (padding_field) = 1;
4792 layout_nonempty_base_or_field (rli, padding_field,
4793 NULL_TREE,
4794 empty_base_offsets);
4795 }
4796
4797 last_field_was_bitfield = DECL_C_BIT_FIELD (field);
4798 }
4799
4800 if (abi_version_at_least (2) && !integer_zerop (rli->bitpos))
4801 {
4802 /* Make sure that we are on a byte boundary so that the size of
4803 the class without virtual bases will always be a round number
4804 of bytes. */
4805 rli->bitpos = round_up (rli->bitpos, BITS_PER_UNIT);
4806 normalize_rli (rli);
4807 }
4808
4809 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
4810 padding. */
4811 if (!abi_version_at_least (2))
4812 include_empty_classes(rli);
4813
4814 /* Delete all zero-width bit-fields from the list of fields. Now
4815 that the type is laid out they are no longer important. */
4816 remove_zero_width_bit_fields (t);
4817
4818 /* Create the version of T used for virtual bases. We do not use
4819 make_aggr_type for this version; this is an artificial type. For
4820 a POD type, we just reuse T. */
4821 if (CLASSTYPE_NON_POD_P (t) || CLASSTYPE_EMPTY_P (t))
4822 {
4823 base_t = make_node (TREE_CODE (t));
4824
4825 /* Set the size and alignment for the new type. In G++ 3.2, all
4826 empty classes were considered to have size zero when used as
4827 base classes. */
4828 if (!abi_version_at_least (2) && CLASSTYPE_EMPTY_P (t))
4829 {
4830 TYPE_SIZE (base_t) = bitsize_zero_node;
4831 TYPE_SIZE_UNIT (base_t) = size_zero_node;
4832 if (warn_abi && !integer_zerop (rli_size_unit_so_far (rli)))
4833 warning (OPT_Wabi,
4834 "layout of classes derived from empty class %qT "
4835 "may change in a future version of GCC",
4836 t);
4837 }
4838 else
4839 {
4840 tree eoc;
4841
4842 /* If the ABI version is not at least two, and the last
4843 field was a bit-field, RLI may not be on a byte
4844 boundary. In particular, rli_size_unit_so_far might
4845 indicate the last complete byte, while rli_size_so_far
4846 indicates the total number of bits used. Therefore,
4847 rli_size_so_far, rather than rli_size_unit_so_far, is
4848 used to compute TYPE_SIZE_UNIT. */
4849 eoc = end_of_class (t, /*include_virtuals_p=*/0);
4850 TYPE_SIZE_UNIT (base_t)
4851 = size_binop (MAX_EXPR,
4852 convert (sizetype,
4853 size_binop (CEIL_DIV_EXPR,
4854 rli_size_so_far (rli),
4855 bitsize_int (BITS_PER_UNIT))),
4856 eoc);
4857 TYPE_SIZE (base_t)
4858 = size_binop (MAX_EXPR,
4859 rli_size_so_far (rli),
4860 size_binop (MULT_EXPR,
4861 convert (bitsizetype, eoc),
4862 bitsize_int (BITS_PER_UNIT)));
4863 }
4864 TYPE_ALIGN (base_t) = rli->record_align;
4865 TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t);
4866
4867 /* Copy the fields from T. */
4868 next_field = &TYPE_FIELDS (base_t);
4869 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
4870 if (TREE_CODE (field) == FIELD_DECL)
4871 {
4872 *next_field = build_decl (FIELD_DECL,
4873 DECL_NAME (field),
4874 TREE_TYPE (field));
4875 DECL_CONTEXT (*next_field) = base_t;
4876 DECL_FIELD_OFFSET (*next_field) = DECL_FIELD_OFFSET (field);
4877 DECL_FIELD_BIT_OFFSET (*next_field)
4878 = DECL_FIELD_BIT_OFFSET (field);
4879 DECL_SIZE (*next_field) = DECL_SIZE (field);
4880 DECL_MODE (*next_field) = DECL_MODE (field);
4881 next_field = &TREE_CHAIN (*next_field);
4882 }
4883
4884 /* Record the base version of the type. */
4885 CLASSTYPE_AS_BASE (t) = base_t;
4886 TYPE_CONTEXT (base_t) = t;
4887 }
4888 else
4889 CLASSTYPE_AS_BASE (t) = t;
4890
4891 /* Every empty class contains an empty class. */
4892 if (CLASSTYPE_EMPTY_P (t))
4893 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
4894
4895 /* Set the TYPE_DECL for this type to contain the right
4896 value for DECL_OFFSET, so that we can use it as part
4897 of a COMPONENT_REF for multiple inheritance. */
4898 layout_decl (TYPE_MAIN_DECL (t), 0);
4899
4900 /* Now fix up any virtual base class types that we left lying
4901 around. We must get these done before we try to lay out the
4902 virtual function table. As a side-effect, this will remove the
4903 base subobject fields. */
4904 layout_virtual_bases (rli, empty_base_offsets);
4905
4906 /* Make sure that empty classes are reflected in RLI at this
4907 point. */
4908 include_empty_classes(rli);
4909
4910 /* Make sure not to create any structures with zero size. */
4911 if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t))
4912 place_field (rli,
4913 build_decl (FIELD_DECL, NULL_TREE, char_type_node));
4914
4915 /* Let the back-end lay out the type. */
4916 finish_record_layout (rli, /*free_p=*/true);
4917
4918 /* Warn about bases that can't be talked about due to ambiguity. */
4919 warn_about_ambiguous_bases (t);
4920
4921 /* Now that we're done with layout, give the base fields the real types. */
4922 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
4923 if (DECL_ARTIFICIAL (field) && IS_FAKE_BASE_TYPE (TREE_TYPE (field)))
4924 TREE_TYPE (field) = TYPE_CONTEXT (TREE_TYPE (field));
4925
4926 /* Clean up. */
4927 splay_tree_delete (empty_base_offsets);
4928
4929 if (CLASSTYPE_EMPTY_P (t)
4930 && tree_int_cst_lt (sizeof_biggest_empty_class,
4931 TYPE_SIZE_UNIT (t)))
4932 sizeof_biggest_empty_class = TYPE_SIZE_UNIT (t);
4933 }
4934
4935 /* Determine the "key method" for the class type indicated by TYPE,
4936 and set CLASSTYPE_KEY_METHOD accordingly. */
4937
4938 void
determine_key_method(tree type)4939 determine_key_method (tree type)
4940 {
4941 tree method;
4942
4943 if (TYPE_FOR_JAVA (type)
4944 || processing_template_decl
4945 || CLASSTYPE_TEMPLATE_INSTANTIATION (type)
4946 || CLASSTYPE_INTERFACE_KNOWN (type))
4947 return;
4948
4949 /* The key method is the first non-pure virtual function that is not
4950 inline at the point of class definition. On some targets the
4951 key function may not be inline; those targets should not call
4952 this function until the end of the translation unit. */
4953 for (method = TYPE_METHODS (type); method != NULL_TREE;
4954 method = TREE_CHAIN (method))
4955 if (DECL_VINDEX (method) != NULL_TREE
4956 && ! DECL_DECLARED_INLINE_P (method)
4957 && ! DECL_PURE_VIRTUAL_P (method))
4958 {
4959 CLASSTYPE_KEY_METHOD (type) = method;
4960 break;
4961 }
4962
4963 return;
4964 }
4965
4966 /* Perform processing required when the definition of T (a class type)
4967 is complete. */
4968
4969 void
finish_struct_1(tree t)4970 finish_struct_1 (tree t)
4971 {
4972 tree x;
4973 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
4974 tree virtuals = NULL_TREE;
4975 int n_fields = 0;
4976
4977 if (COMPLETE_TYPE_P (t))
4978 {
4979 gcc_assert (IS_AGGR_TYPE (t));
4980 error ("redefinition of %q#T", t);
4981 popclass ();
4982 return;
4983 }
4984
4985 /* If this type was previously laid out as a forward reference,
4986 make sure we lay it out again. */
4987 TYPE_SIZE (t) = NULL_TREE;
4988 CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE;
4989
4990 fixup_inline_methods (t);
4991
4992 /* Make assumptions about the class; we'll reset the flags if
4993 necessary. */
4994 CLASSTYPE_EMPTY_P (t) = 1;
4995 CLASSTYPE_NEARLY_EMPTY_P (t) = 1;
4996 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 0;
4997
4998 /* Do end-of-class semantic processing: checking the validity of the
4999 bases and members and add implicitly generated methods. */
5000 check_bases_and_members (t);
5001
5002 /* Find the key method. */
5003 if (TYPE_CONTAINS_VPTR_P (t))
5004 {
5005 /* The Itanium C++ ABI permits the key method to be chosen when
5006 the class is defined -- even though the key method so
5007 selected may later turn out to be an inline function. On
5008 some systems (such as ARM Symbian OS) the key method cannot
5009 be determined until the end of the translation unit. On such
5010 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
5011 will cause the class to be added to KEYED_CLASSES. Then, in
5012 finish_file we will determine the key method. */
5013 if (targetm.cxx.key_method_may_be_inline ())
5014 determine_key_method (t);
5015
5016 /* If a polymorphic class has no key method, we may emit the vtable
5017 in every translation unit where the class definition appears. */
5018 if (CLASSTYPE_KEY_METHOD (t) == NULL_TREE)
5019 keyed_classes = tree_cons (NULL_TREE, t, keyed_classes);
5020 }
5021
5022 /* Layout the class itself. */
5023 layout_class_type (t, &virtuals);
5024 if (CLASSTYPE_AS_BASE (t) != t)
5025 /* We use the base type for trivial assignments, and hence it
5026 needs a mode. */
5027 compute_record_mode (CLASSTYPE_AS_BASE (t));
5028
5029 virtuals = modify_all_vtables (t, nreverse (virtuals));
5030
5031 /* If necessary, create the primary vtable for this class. */
5032 if (virtuals || TYPE_CONTAINS_VPTR_P (t))
5033 {
5034 /* We must enter these virtuals into the table. */
5035 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
5036 build_primary_vtable (NULL_TREE, t);
5037 else if (! BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (t)))
5038 /* Here we know enough to change the type of our virtual
5039 function table, but we will wait until later this function. */
5040 build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t);
5041 }
5042
5043 if (TYPE_CONTAINS_VPTR_P (t))
5044 {
5045 int vindex;
5046 tree fn;
5047
5048 if (BINFO_VTABLE (TYPE_BINFO (t)))
5049 gcc_assert (DECL_VIRTUAL_P (BINFO_VTABLE (TYPE_BINFO (t))));
5050 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
5051 gcc_assert (BINFO_VIRTUALS (TYPE_BINFO (t)) == NULL_TREE);
5052
5053 /* Add entries for virtual functions introduced by this class. */
5054 BINFO_VIRTUALS (TYPE_BINFO (t))
5055 = chainon (BINFO_VIRTUALS (TYPE_BINFO (t)), virtuals);
5056
5057 /* Set DECL_VINDEX for all functions declared in this class. */
5058 for (vindex = 0, fn = BINFO_VIRTUALS (TYPE_BINFO (t));
5059 fn;
5060 fn = TREE_CHAIN (fn),
5061 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
5062 ? TARGET_VTABLE_USES_DESCRIPTORS : 1))
5063 {
5064 tree fndecl = BV_FN (fn);
5065
5066 if (DECL_THUNK_P (fndecl))
5067 /* A thunk. We should never be calling this entry directly
5068 from this vtable -- we'd use the entry for the non
5069 thunk base function. */
5070 DECL_VINDEX (fndecl) = NULL_TREE;
5071 else if (TREE_CODE (DECL_VINDEX (fndecl)) != INTEGER_CST)
5072 DECL_VINDEX (fndecl) = build_int_cst (NULL_TREE, vindex);
5073 }
5074 }
5075
5076 finish_struct_bits (t);
5077
5078 /* Complete the rtl for any static member objects of the type we're
5079 working on. */
5080 for (x = TYPE_FIELDS (t); x; x = TREE_CHAIN (x))
5081 if (TREE_CODE (x) == VAR_DECL && TREE_STATIC (x)
5082 && TREE_TYPE (x) != error_mark_node
5083 && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t))
5084 DECL_MODE (x) = TYPE_MODE (t);
5085
5086 /* Done with FIELDS...now decide whether to sort these for
5087 faster lookups later.
5088
5089 We use a small number because most searches fail (succeeding
5090 ultimately as the search bores through the inheritance
5091 hierarchy), and we want this failure to occur quickly. */
5092
5093 n_fields = count_fields (TYPE_FIELDS (t));
5094 if (n_fields > 7)
5095 {
5096 struct sorted_fields_type *field_vec = GGC_NEWVAR
5097 (struct sorted_fields_type,
5098 sizeof (struct sorted_fields_type) + n_fields * sizeof (tree));
5099 field_vec->len = n_fields;
5100 add_fields_to_record_type (TYPE_FIELDS (t), field_vec, 0);
5101 qsort (field_vec->elts, n_fields, sizeof (tree),
5102 field_decl_cmp);
5103 if (! DECL_LANG_SPECIFIC (TYPE_MAIN_DECL (t)))
5104 retrofit_lang_decl (TYPE_MAIN_DECL (t));
5105 DECL_SORTED_FIELDS (TYPE_MAIN_DECL (t)) = field_vec;
5106 }
5107
5108 /* Complain if one of the field types requires lower visibility. */
5109 constrain_class_visibility (t);
5110
5111 /* Make the rtl for any new vtables we have created, and unmark
5112 the base types we marked. */
5113 finish_vtbls (t);
5114
5115 /* Build the VTT for T. */
5116 build_vtt (t);
5117
5118 /* This warning does not make sense for Java classes, since they
5119 cannot have destructors. */
5120 if (!TYPE_FOR_JAVA (t) && warn_nonvdtor && TYPE_POLYMORPHIC_P (t))
5121 {
5122 tree dtor;
5123
5124 dtor = CLASSTYPE_DESTRUCTORS (t);
5125 /* Warn only if the dtor is non-private or the class has
5126 friends. */
5127 if (/* An implicitly declared destructor is always public. And,
5128 if it were virtual, we would have created it by now. */
5129 !dtor
5130 || (!DECL_VINDEX (dtor)
5131 && (!TREE_PRIVATE (dtor)
5132 || CLASSTYPE_FRIEND_CLASSES (t)
5133 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))))
5134 warning (0, "%q#T has virtual functions but non-virtual destructor",
5135 t);
5136 }
5137
5138 complete_vars (t);
5139
5140 if (warn_overloaded_virtual)
5141 warn_hidden (t);
5142
5143 /* Class layout, assignment of virtual table slots, etc., is now
5144 complete. Give the back end a chance to tweak the visibility of
5145 the class or perform any other required target modifications. */
5146 targetm.cxx.adjust_class_at_definition (t);
5147
5148 maybe_suppress_debug_info (t);
5149
5150 dump_class_hierarchy (t);
5151
5152 /* Finish debugging output for this type. */
5153 rest_of_type_compilation (t, ! LOCAL_CLASS_P (t));
5154 }
5155
5156 /* When T was built up, the member declarations were added in reverse
5157 order. Rearrange them to declaration order. */
5158
5159 void
unreverse_member_declarations(tree t)5160 unreverse_member_declarations (tree t)
5161 {
5162 tree next;
5163 tree prev;
5164 tree x;
5165
5166 /* The following lists are all in reverse order. Put them in
5167 declaration order now. */
5168 TYPE_METHODS (t) = nreverse (TYPE_METHODS (t));
5169 CLASSTYPE_DECL_LIST (t) = nreverse (CLASSTYPE_DECL_LIST (t));
5170
5171 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5172 reverse order, so we can't just use nreverse. */
5173 prev = NULL_TREE;
5174 for (x = TYPE_FIELDS (t);
5175 x && TREE_CODE (x) != TYPE_DECL;
5176 x = next)
5177 {
5178 next = TREE_CHAIN (x);
5179 TREE_CHAIN (x) = prev;
5180 prev = x;
5181 }
5182 if (prev)
5183 {
5184 TREE_CHAIN (TYPE_FIELDS (t)) = x;
5185 if (prev)
5186 TYPE_FIELDS (t) = prev;
5187 }
5188 }
5189
5190 tree
finish_struct(tree t,tree attributes)5191 finish_struct (tree t, tree attributes)
5192 {
5193 location_t saved_loc = input_location;
5194
5195 /* Now that we've got all the field declarations, reverse everything
5196 as necessary. */
5197 unreverse_member_declarations (t);
5198
5199 cplus_decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
5200
5201 /* Nadger the current location so that diagnostics point to the start of
5202 the struct, not the end. */
5203 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (t));
5204
5205 if (processing_template_decl)
5206 {
5207 tree x;
5208
5209 finish_struct_methods (t);
5210 TYPE_SIZE (t) = bitsize_zero_node;
5211 TYPE_SIZE_UNIT (t) = size_zero_node;
5212
5213 /* We need to emit an error message if this type was used as a parameter
5214 and it is an abstract type, even if it is a template. We construct
5215 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
5216 account and we call complete_vars with this type, which will check
5217 the PARM_DECLS. Note that while the type is being defined,
5218 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
5219 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
5220 CLASSTYPE_PURE_VIRTUALS (t) = NULL;
5221 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
5222 if (DECL_PURE_VIRTUAL_P (x))
5223 VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x);
5224 complete_vars (t);
5225 }
5226 else
5227 finish_struct_1 (t);
5228
5229 input_location = saved_loc;
5230
5231 TYPE_BEING_DEFINED (t) = 0;
5232
5233 if (current_class_type)
5234 popclass ();
5235 else
5236 error ("trying to finish struct, but kicked out due to previous parse errors");
5237
5238 if (processing_template_decl && at_function_scope_p ())
5239 add_stmt (build_min (TAG_DEFN, t));
5240
5241 return t;
5242 }
5243
5244 /* Return the dynamic type of INSTANCE, if known.
5245 Used to determine whether the virtual function table is needed
5246 or not.
5247
5248 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5249 of our knowledge of its type. *NONNULL should be initialized
5250 before this function is called. */
5251
5252 static tree
fixed_type_or_null(tree instance,int * nonnull,int * cdtorp)5253 fixed_type_or_null (tree instance, int* nonnull, int* cdtorp)
5254 {
5255 switch (TREE_CODE (instance))
5256 {
5257 case INDIRECT_REF:
5258 if (POINTER_TYPE_P (TREE_TYPE (instance)))
5259 return NULL_TREE;
5260 else
5261 return fixed_type_or_null (TREE_OPERAND (instance, 0),
5262 nonnull, cdtorp);
5263
5264 case CALL_EXPR:
5265 /* This is a call to a constructor, hence it's never zero. */
5266 if (TREE_HAS_CONSTRUCTOR (instance))
5267 {
5268 if (nonnull)
5269 *nonnull = 1;
5270 return TREE_TYPE (instance);
5271 }
5272 return NULL_TREE;
5273
5274 case SAVE_EXPR:
5275 /* This is a call to a constructor, hence it's never zero. */
5276 if (TREE_HAS_CONSTRUCTOR (instance))
5277 {
5278 if (nonnull)
5279 *nonnull = 1;
5280 return TREE_TYPE (instance);
5281 }
5282 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5283
5284 case PLUS_EXPR:
5285 case MINUS_EXPR:
5286 if (TREE_CODE (TREE_OPERAND (instance, 0)) == ADDR_EXPR)
5287 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5288 if (TREE_CODE (TREE_OPERAND (instance, 1)) == INTEGER_CST)
5289 /* Propagate nonnull. */
5290 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5291 return NULL_TREE;
5292
5293 case NOP_EXPR:
5294 case CONVERT_EXPR:
5295 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5296
5297 case ADDR_EXPR:
5298 instance = TREE_OPERAND (instance, 0);
5299 if (nonnull)
5300 {
5301 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
5302 with a real object -- given &p->f, p can still be null. */
5303 tree t = get_base_address (instance);
5304 /* ??? Probably should check DECL_WEAK here. */
5305 if (t && DECL_P (t))
5306 *nonnull = 1;
5307 }
5308 return fixed_type_or_null (instance, nonnull, cdtorp);
5309
5310 case COMPONENT_REF:
5311 /* If this component is really a base class reference, then the field
5312 itself isn't definitive. */
5313 if (DECL_FIELD_IS_BASE (TREE_OPERAND (instance, 1)))
5314 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp);
5315 return fixed_type_or_null (TREE_OPERAND (instance, 1), nonnull, cdtorp);
5316
5317 case VAR_DECL:
5318 case FIELD_DECL:
5319 if (TREE_CODE (TREE_TYPE (instance)) == ARRAY_TYPE
5320 && IS_AGGR_TYPE (TREE_TYPE (TREE_TYPE (instance))))
5321 {
5322 if (nonnull)
5323 *nonnull = 1;
5324 return TREE_TYPE (TREE_TYPE (instance));
5325 }
5326 /* fall through... */
5327 case TARGET_EXPR:
5328 case PARM_DECL:
5329 case RESULT_DECL:
5330 if (IS_AGGR_TYPE (TREE_TYPE (instance)))
5331 {
5332 if (nonnull)
5333 *nonnull = 1;
5334 return TREE_TYPE (instance);
5335 }
5336 else if (instance == current_class_ptr)
5337 {
5338 if (nonnull)
5339 *nonnull = 1;
5340
5341 /* if we're in a ctor or dtor, we know our type. */
5342 if (DECL_LANG_SPECIFIC (current_function_decl)
5343 && (DECL_CONSTRUCTOR_P (current_function_decl)
5344 || DECL_DESTRUCTOR_P (current_function_decl)))
5345 {
5346 if (cdtorp)
5347 *cdtorp = 1;
5348 return TREE_TYPE (TREE_TYPE (instance));
5349 }
5350 }
5351 else if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE)
5352 {
5353 /* We only need one hash table because it is always left empty. */
5354 static htab_t ht;
5355 if (!ht)
5356 ht = htab_create (37,
5357 htab_hash_pointer,
5358 htab_eq_pointer,
5359 /*htab_del=*/NULL);
5360
5361 /* Reference variables should be references to objects. */
5362 if (nonnull)
5363 *nonnull = 1;
5364
5365 /* Enter the INSTANCE in a table to prevent recursion; a
5366 variable's initializer may refer to the variable
5367 itself. */
5368 if (TREE_CODE (instance) == VAR_DECL
5369 && DECL_INITIAL (instance)
5370 && !htab_find (ht, instance))
5371 {
5372 tree type;
5373 void **slot;
5374
5375 slot = htab_find_slot (ht, instance, INSERT);
5376 *slot = instance;
5377 type = fixed_type_or_null (DECL_INITIAL (instance),
5378 nonnull, cdtorp);
5379 htab_remove_elt (ht, instance);
5380
5381 return type;
5382 }
5383 }
5384 return NULL_TREE;
5385
5386 default:
5387 return NULL_TREE;
5388 }
5389 }
5390
5391 /* Return nonzero if the dynamic type of INSTANCE is known, and
5392 equivalent to the static type. We also handle the case where
5393 INSTANCE is really a pointer. Return negative if this is a
5394 ctor/dtor. There the dynamic type is known, but this might not be
5395 the most derived base of the original object, and hence virtual
5396 bases may not be layed out according to this type.
5397
5398 Used to determine whether the virtual function table is needed
5399 or not.
5400
5401 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5402 of our knowledge of its type. *NONNULL should be initialized
5403 before this function is called. */
5404
5405 int
resolves_to_fixed_type_p(tree instance,int * nonnull)5406 resolves_to_fixed_type_p (tree instance, int* nonnull)
5407 {
5408 tree t = TREE_TYPE (instance);
5409 int cdtorp = 0;
5410
5411 tree fixed = fixed_type_or_null (instance, nonnull, &cdtorp);
5412 if (fixed == NULL_TREE)
5413 return 0;
5414 if (POINTER_TYPE_P (t))
5415 t = TREE_TYPE (t);
5416 if (!same_type_ignoring_top_level_qualifiers_p (t, fixed))
5417 return 0;
5418 return cdtorp ? -1 : 1;
5419 }
5420
5421
5422 void
init_class_processing(void)5423 init_class_processing (void)
5424 {
5425 current_class_depth = 0;
5426 current_class_stack_size = 10;
5427 current_class_stack
5428 = XNEWVEC (struct class_stack_node, current_class_stack_size);
5429 local_classes = VEC_alloc (tree, gc, 8);
5430 sizeof_biggest_empty_class = size_zero_node;
5431
5432 ridpointers[(int) RID_PUBLIC] = access_public_node;
5433 ridpointers[(int) RID_PRIVATE] = access_private_node;
5434 ridpointers[(int) RID_PROTECTED] = access_protected_node;
5435 }
5436
5437 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
5438
5439 static void
restore_class_cache(void)5440 restore_class_cache (void)
5441 {
5442 tree type;
5443
5444 /* We are re-entering the same class we just left, so we don't
5445 have to search the whole inheritance matrix to find all the
5446 decls to bind again. Instead, we install the cached
5447 class_shadowed list and walk through it binding names. */
5448 push_binding_level (previous_class_level);
5449 class_binding_level = previous_class_level;
5450 /* Restore IDENTIFIER_TYPE_VALUE. */
5451 for (type = class_binding_level->type_shadowed;
5452 type;
5453 type = TREE_CHAIN (type))
5454 SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (type), TREE_TYPE (type));
5455 }
5456
5457 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
5458 appropriate for TYPE.
5459
5460 So that we may avoid calls to lookup_name, we cache the _TYPE
5461 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5462
5463 For multiple inheritance, we perform a two-pass depth-first search
5464 of the type lattice. */
5465
5466 void
pushclass(tree type)5467 pushclass (tree type)
5468 {
5469 class_stack_node_t csn;
5470
5471 type = TYPE_MAIN_VARIANT (type);
5472
5473 /* Make sure there is enough room for the new entry on the stack. */
5474 if (current_class_depth + 1 >= current_class_stack_size)
5475 {
5476 current_class_stack_size *= 2;
5477 current_class_stack
5478 = XRESIZEVEC (struct class_stack_node, current_class_stack,
5479 current_class_stack_size);
5480 }
5481
5482 /* Insert a new entry on the class stack. */
5483 csn = current_class_stack + current_class_depth;
5484 csn->name = current_class_name;
5485 csn->type = current_class_type;
5486 csn->access = current_access_specifier;
5487 csn->names_used = 0;
5488 csn->hidden = 0;
5489 current_class_depth++;
5490
5491 /* Now set up the new type. */
5492 current_class_name = TYPE_NAME (type);
5493 if (TREE_CODE (current_class_name) == TYPE_DECL)
5494 current_class_name = DECL_NAME (current_class_name);
5495 current_class_type = type;
5496
5497 /* By default, things in classes are private, while things in
5498 structures or unions are public. */
5499 current_access_specifier = (CLASSTYPE_DECLARED_CLASS (type)
5500 ? access_private_node
5501 : access_public_node);
5502
5503 if (previous_class_level
5504 && type != previous_class_level->this_entity
5505 && current_class_depth == 1)
5506 {
5507 /* Forcibly remove any old class remnants. */
5508 invalidate_class_lookup_cache ();
5509 }
5510
5511 if (!previous_class_level
5512 || type != previous_class_level->this_entity
5513 || current_class_depth > 1)
5514 pushlevel_class ();
5515 else
5516 restore_class_cache ();
5517 }
5518
5519 /* When we exit a toplevel class scope, we save its binding level so
5520 that we can restore it quickly. Here, we've entered some other
5521 class, so we must invalidate our cache. */
5522
5523 void
invalidate_class_lookup_cache(void)5524 invalidate_class_lookup_cache (void)
5525 {
5526 previous_class_level = NULL;
5527 }
5528
5529 /* Get out of the current class scope. If we were in a class scope
5530 previously, that is the one popped to. */
5531
5532 void
popclass(void)5533 popclass (void)
5534 {
5535 poplevel_class ();
5536
5537 current_class_depth--;
5538 current_class_name = current_class_stack[current_class_depth].name;
5539 current_class_type = current_class_stack[current_class_depth].type;
5540 current_access_specifier = current_class_stack[current_class_depth].access;
5541 if (current_class_stack[current_class_depth].names_used)
5542 splay_tree_delete (current_class_stack[current_class_depth].names_used);
5543 }
5544
5545 /* Mark the top of the class stack as hidden. */
5546
5547 void
push_class_stack(void)5548 push_class_stack (void)
5549 {
5550 if (current_class_depth)
5551 ++current_class_stack[current_class_depth - 1].hidden;
5552 }
5553
5554 /* Mark the top of the class stack as un-hidden. */
5555
5556 void
pop_class_stack(void)5557 pop_class_stack (void)
5558 {
5559 if (current_class_depth)
5560 --current_class_stack[current_class_depth - 1].hidden;
5561 }
5562
5563 /* Returns 1 if the class type currently being defined is either T or
5564 a nested type of T. */
5565
5566 bool
currently_open_class(tree t)5567 currently_open_class (tree t)
5568 {
5569 int i;
5570
5571 /* We start looking from 1 because entry 0 is from global scope,
5572 and has no type. */
5573 for (i = current_class_depth; i > 0; --i)
5574 {
5575 tree c;
5576 if (i == current_class_depth)
5577 c = current_class_type;
5578 else
5579 {
5580 if (current_class_stack[i].hidden)
5581 break;
5582 c = current_class_stack[i].type;
5583 }
5584 if (!c)
5585 continue;
5586 if (same_type_p (c, t))
5587 return true;
5588 }
5589 return false;
5590 }
5591
5592 /* If either current_class_type or one of its enclosing classes are derived
5593 from T, return the appropriate type. Used to determine how we found
5594 something via unqualified lookup. */
5595
5596 tree
currently_open_derived_class(tree t)5597 currently_open_derived_class (tree t)
5598 {
5599 int i;
5600
5601 /* The bases of a dependent type are unknown. */
5602 if (dependent_type_p (t))
5603 return NULL_TREE;
5604
5605 if (!current_class_type)
5606 return NULL_TREE;
5607
5608 if (DERIVED_FROM_P (t, current_class_type))
5609 return current_class_type;
5610
5611 for (i = current_class_depth - 1; i > 0; --i)
5612 {
5613 if (current_class_stack[i].hidden)
5614 break;
5615 if (DERIVED_FROM_P (t, current_class_stack[i].type))
5616 return current_class_stack[i].type;
5617 }
5618
5619 return NULL_TREE;
5620 }
5621
5622 /* When entering a class scope, all enclosing class scopes' names with
5623 static meaning (static variables, static functions, types and
5624 enumerators) have to be visible. This recursive function calls
5625 pushclass for all enclosing class contexts until global or a local
5626 scope is reached. TYPE is the enclosed class. */
5627
5628 void
push_nested_class(tree type)5629 push_nested_class (tree type)
5630 {
5631 tree context;
5632
5633 /* A namespace might be passed in error cases, like A::B:C. */
5634 if (type == NULL_TREE
5635 || type == error_mark_node
5636 || TREE_CODE (type) == NAMESPACE_DECL
5637 || ! IS_AGGR_TYPE (type)
5638 || TREE_CODE (type) == TEMPLATE_TYPE_PARM
5639 || TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
5640 return;
5641
5642 context = DECL_CONTEXT (TYPE_MAIN_DECL (type));
5643
5644 if (context && CLASS_TYPE_P (context))
5645 push_nested_class (context);
5646 pushclass (type);
5647 }
5648
5649 /* Undoes a push_nested_class call. */
5650
5651 void
pop_nested_class(void)5652 pop_nested_class (void)
5653 {
5654 tree context = DECL_CONTEXT (TYPE_MAIN_DECL (current_class_type));
5655
5656 popclass ();
5657 if (context && CLASS_TYPE_P (context))
5658 pop_nested_class ();
5659 }
5660
5661 /* Returns the number of extern "LANG" blocks we are nested within. */
5662
5663 int
current_lang_depth(void)5664 current_lang_depth (void)
5665 {
5666 return VEC_length (tree, current_lang_base);
5667 }
5668
5669 /* Set global variables CURRENT_LANG_NAME to appropriate value
5670 so that behavior of name-mangling machinery is correct. */
5671
5672 void
push_lang_context(tree name)5673 push_lang_context (tree name)
5674 {
5675 VEC_safe_push (tree, gc, current_lang_base, current_lang_name);
5676
5677 if (name == lang_name_cplusplus)
5678 {
5679 current_lang_name = name;
5680 }
5681 else if (name == lang_name_java)
5682 {
5683 current_lang_name = name;
5684 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5685 (See record_builtin_java_type in decl.c.) However, that causes
5686 incorrect debug entries if these types are actually used.
5687 So we re-enable debug output after extern "Java". */
5688 DECL_IGNORED_P (TYPE_NAME (java_byte_type_node)) = 0;
5689 DECL_IGNORED_P (TYPE_NAME (java_short_type_node)) = 0;
5690 DECL_IGNORED_P (TYPE_NAME (java_int_type_node)) = 0;
5691 DECL_IGNORED_P (TYPE_NAME (java_long_type_node)) = 0;
5692 DECL_IGNORED_P (TYPE_NAME (java_float_type_node)) = 0;
5693 DECL_IGNORED_P (TYPE_NAME (java_double_type_node)) = 0;
5694 DECL_IGNORED_P (TYPE_NAME (java_char_type_node)) = 0;
5695 DECL_IGNORED_P (TYPE_NAME (java_boolean_type_node)) = 0;
5696 }
5697 else if (name == lang_name_c)
5698 {
5699 current_lang_name = name;
5700 }
5701 else
5702 error ("language string %<\"%E\"%> not recognized", name);
5703 }
5704
5705 /* Get out of the current language scope. */
5706
5707 void
pop_lang_context(void)5708 pop_lang_context (void)
5709 {
5710 current_lang_name = VEC_pop (tree, current_lang_base);
5711 }
5712
5713 /* Type instantiation routines. */
5714
5715 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
5716 matches the TARGET_TYPE. If there is no satisfactory match, return
5717 error_mark_node, and issue an error & warning messages under
5718 control of FLAGS. Permit pointers to member function if FLAGS
5719 permits. If TEMPLATE_ONLY, the name of the overloaded function was
5720 a template-id, and EXPLICIT_TARGS are the explicitly provided
5721 template arguments. If OVERLOAD is for one or more member
5722 functions, then ACCESS_PATH is the base path used to reference
5723 those member functions. */
5724
5725 static tree
resolve_address_of_overloaded_function(tree target_type,tree overload,tsubst_flags_t flags,bool template_only,tree explicit_targs,tree access_path)5726 resolve_address_of_overloaded_function (tree target_type,
5727 tree overload,
5728 tsubst_flags_t flags,
5729 bool template_only,
5730 tree explicit_targs,
5731 tree access_path)
5732 {
5733 /* Here's what the standard says:
5734
5735 [over.over]
5736
5737 If the name is a function template, template argument deduction
5738 is done, and if the argument deduction succeeds, the deduced
5739 arguments are used to generate a single template function, which
5740 is added to the set of overloaded functions considered.
5741
5742 Non-member functions and static member functions match targets of
5743 type "pointer-to-function" or "reference-to-function." Nonstatic
5744 member functions match targets of type "pointer-to-member
5745 function;" the function type of the pointer to member is used to
5746 select the member function from the set of overloaded member
5747 functions. If a nonstatic member function is selected, the
5748 reference to the overloaded function name is required to have the
5749 form of a pointer to member as described in 5.3.1.
5750
5751 If more than one function is selected, any template functions in
5752 the set are eliminated if the set also contains a non-template
5753 function, and any given template function is eliminated if the
5754 set contains a second template function that is more specialized
5755 than the first according to the partial ordering rules 14.5.5.2.
5756 After such eliminations, if any, there shall remain exactly one
5757 selected function. */
5758
5759 int is_ptrmem = 0;
5760 int is_reference = 0;
5761 /* We store the matches in a TREE_LIST rooted here. The functions
5762 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
5763 interoperability with most_specialized_instantiation. */
5764 tree matches = NULL_TREE;
5765 tree fn;
5766
5767 /* By the time we get here, we should be seeing only real
5768 pointer-to-member types, not the internal POINTER_TYPE to
5769 METHOD_TYPE representation. */
5770 gcc_assert (TREE_CODE (target_type) != POINTER_TYPE
5771 || TREE_CODE (TREE_TYPE (target_type)) != METHOD_TYPE);
5772
5773 gcc_assert (is_overloaded_fn (overload));
5774
5775 /* Check that the TARGET_TYPE is reasonable. */
5776 if (TYPE_PTRFN_P (target_type))
5777 /* This is OK. */;
5778 else if (TYPE_PTRMEMFUNC_P (target_type))
5779 /* This is OK, too. */
5780 is_ptrmem = 1;
5781 else if (TREE_CODE (target_type) == FUNCTION_TYPE)
5782 {
5783 /* This is OK, too. This comes from a conversion to reference
5784 type. */
5785 target_type = build_reference_type (target_type);
5786 is_reference = 1;
5787 }
5788 else
5789 {
5790 if (flags & tf_error)
5791 error ("cannot resolve overloaded function %qD based on"
5792 " conversion to type %qT",
5793 DECL_NAME (OVL_FUNCTION (overload)), target_type);
5794 return error_mark_node;
5795 }
5796
5797 /* If we can find a non-template function that matches, we can just
5798 use it. There's no point in generating template instantiations
5799 if we're just going to throw them out anyhow. But, of course, we
5800 can only do this when we don't *need* a template function. */
5801 if (!template_only)
5802 {
5803 tree fns;
5804
5805 for (fns = overload; fns; fns = OVL_NEXT (fns))
5806 {
5807 tree fn = OVL_CURRENT (fns);
5808 tree fntype;
5809
5810 if (TREE_CODE (fn) == TEMPLATE_DECL)
5811 /* We're not looking for templates just yet. */
5812 continue;
5813
5814 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
5815 != is_ptrmem)
5816 /* We're looking for a non-static member, and this isn't
5817 one, or vice versa. */
5818 continue;
5819
5820 /* Ignore functions which haven't been explicitly
5821 declared. */
5822 if (DECL_ANTICIPATED (fn))
5823 continue;
5824
5825 /* See if there's a match. */
5826 fntype = TREE_TYPE (fn);
5827 if (is_ptrmem)
5828 fntype = build_ptrmemfunc_type (build_pointer_type (fntype));
5829 else if (!is_reference)
5830 fntype = build_pointer_type (fntype);
5831
5832 if (can_convert_arg (target_type, fntype, fn, LOOKUP_NORMAL))
5833 matches = tree_cons (fn, NULL_TREE, matches);
5834 }
5835 }
5836
5837 /* Now, if we've already got a match (or matches), there's no need
5838 to proceed to the template functions. But, if we don't have a
5839 match we need to look at them, too. */
5840 if (!matches)
5841 {
5842 tree target_fn_type;
5843 tree target_arg_types;
5844 tree target_ret_type;
5845 tree fns;
5846
5847 if (is_ptrmem)
5848 target_fn_type
5849 = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (target_type));
5850 else
5851 target_fn_type = TREE_TYPE (target_type);
5852 target_arg_types = TYPE_ARG_TYPES (target_fn_type);
5853 target_ret_type = TREE_TYPE (target_fn_type);
5854
5855 /* Never do unification on the 'this' parameter. */
5856 if (TREE_CODE (target_fn_type) == METHOD_TYPE)
5857 target_arg_types = TREE_CHAIN (target_arg_types);
5858
5859 for (fns = overload; fns; fns = OVL_NEXT (fns))
5860 {
5861 tree fn = OVL_CURRENT (fns);
5862 tree instantiation;
5863 tree instantiation_type;
5864 tree targs;
5865
5866 if (TREE_CODE (fn) != TEMPLATE_DECL)
5867 /* We're only looking for templates. */
5868 continue;
5869
5870 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
5871 != is_ptrmem)
5872 /* We're not looking for a non-static member, and this is
5873 one, or vice versa. */
5874 continue;
5875
5876 /* Try to do argument deduction. */
5877 targs = make_tree_vec (DECL_NTPARMS (fn));
5878 if (fn_type_unification (fn, explicit_targs, targs,
5879 target_arg_types, target_ret_type,
5880 DEDUCE_EXACT, LOOKUP_NORMAL))
5881 /* Argument deduction failed. */
5882 continue;
5883
5884 /* Instantiate the template. */
5885 instantiation = instantiate_template (fn, targs, flags);
5886 if (instantiation == error_mark_node)
5887 /* Instantiation failed. */
5888 continue;
5889
5890 /* See if there's a match. */
5891 instantiation_type = TREE_TYPE (instantiation);
5892 if (is_ptrmem)
5893 instantiation_type =
5894 build_ptrmemfunc_type (build_pointer_type (instantiation_type));
5895 else if (!is_reference)
5896 instantiation_type = build_pointer_type (instantiation_type);
5897 if (can_convert_arg (target_type, instantiation_type, instantiation,
5898 LOOKUP_NORMAL))
5899 matches = tree_cons (instantiation, fn, matches);
5900 }
5901
5902 /* Now, remove all but the most specialized of the matches. */
5903 if (matches)
5904 {
5905 tree match = most_specialized_instantiation (matches);
5906
5907 if (match != error_mark_node)
5908 matches = tree_cons (TREE_PURPOSE (match),
5909 NULL_TREE,
5910 NULL_TREE);
5911 }
5912 }
5913
5914 /* Now we should have exactly one function in MATCHES. */
5915 if (matches == NULL_TREE)
5916 {
5917 /* There were *no* matches. */
5918 if (flags & tf_error)
5919 {
5920 error ("no matches converting function %qD to type %q#T",
5921 DECL_NAME (OVL_FUNCTION (overload)),
5922 target_type);
5923
5924 /* print_candidates expects a chain with the functions in
5925 TREE_VALUE slots, so we cons one up here (we're losing anyway,
5926 so why be clever?). */
5927 for (; overload; overload = OVL_NEXT (overload))
5928 matches = tree_cons (NULL_TREE, OVL_CURRENT (overload),
5929 matches);
5930
5931 print_candidates (matches);
5932 }
5933 return error_mark_node;
5934 }
5935 else if (TREE_CHAIN (matches))
5936 {
5937 /* There were too many matches. */
5938
5939 if (flags & tf_error)
5940 {
5941 tree match;
5942
5943 error ("converting overloaded function %qD to type %q#T is ambiguous",
5944 DECL_NAME (OVL_FUNCTION (overload)),
5945 target_type);
5946
5947 /* Since print_candidates expects the functions in the
5948 TREE_VALUE slot, we flip them here. */
5949 for (match = matches; match; match = TREE_CHAIN (match))
5950 TREE_VALUE (match) = TREE_PURPOSE (match);
5951
5952 print_candidates (matches);
5953 }
5954
5955 return error_mark_node;
5956 }
5957
5958 /* Good, exactly one match. Now, convert it to the correct type. */
5959 fn = TREE_PURPOSE (matches);
5960
5961 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
5962 && !(flags & tf_ptrmem_ok) && !flag_ms_extensions)
5963 {
5964 static int explained;
5965
5966 if (!(flags & tf_error))
5967 return error_mark_node;
5968
5969 pedwarn ("assuming pointer to member %qD", fn);
5970 if (!explained)
5971 {
5972 pedwarn ("(a pointer to member can only be formed with %<&%E%>)", fn);
5973 explained = 1;
5974 }
5975 }
5976
5977 /* If we're doing overload resolution purely for the purpose of
5978 determining conversion sequences, we should not consider the
5979 function used. If this conversion sequence is selected, the
5980 function will be marked as used at this point. */
5981 if (!(flags & tf_conv))
5982 {
5983 mark_used (fn);
5984 /* We could not check access when this expression was originally
5985 created since we did not know at that time to which function
5986 the expression referred. */
5987 if (DECL_FUNCTION_MEMBER_P (fn))
5988 {
5989 gcc_assert (access_path);
5990 perform_or_defer_access_check (access_path, fn, fn);
5991 }
5992 }
5993
5994 if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type))
5995 return build_unary_op (ADDR_EXPR, fn, 0);
5996 else
5997 {
5998 /* The target must be a REFERENCE_TYPE. Above, build_unary_op
5999 will mark the function as addressed, but here we must do it
6000 explicitly. */
6001 cxx_mark_addressable (fn);
6002
6003 return fn;
6004 }
6005 }
6006
6007 /* This function will instantiate the type of the expression given in
6008 RHS to match the type of LHSTYPE. If errors exist, then return
6009 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
6010 we complain on errors. If we are not complaining, never modify rhs,
6011 as overload resolution wants to try many possible instantiations, in
6012 the hope that at least one will work.
6013
6014 For non-recursive calls, LHSTYPE should be a function, pointer to
6015 function, or a pointer to member function. */
6016
6017 tree
instantiate_type(tree lhstype,tree rhs,tsubst_flags_t flags)6018 instantiate_type (tree lhstype, tree rhs, tsubst_flags_t flags)
6019 {
6020 tsubst_flags_t flags_in = flags;
6021 tree access_path = NULL_TREE;
6022
6023 flags &= ~tf_ptrmem_ok;
6024
6025 if (TREE_CODE (lhstype) == UNKNOWN_TYPE)
6026 {
6027 if (flags & tf_error)
6028 error ("not enough type information");
6029 return error_mark_node;
6030 }
6031
6032 if (TREE_TYPE (rhs) != NULL_TREE && ! (type_unknown_p (rhs)))
6033 {
6034 if (same_type_p (lhstype, TREE_TYPE (rhs)))
6035 return rhs;
6036 if (flag_ms_extensions
6037 && TYPE_PTRMEMFUNC_P (lhstype)
6038 && !TYPE_PTRMEMFUNC_P (TREE_TYPE (rhs)))
6039 /* Microsoft allows `A::f' to be resolved to a
6040 pointer-to-member. */
6041 ;
6042 else
6043 {
6044 if (flags & tf_error)
6045 error ("argument of type %qT does not match %qT",
6046 TREE_TYPE (rhs), lhstype);
6047 return error_mark_node;
6048 }
6049 }
6050
6051 if (TREE_CODE (rhs) == BASELINK)
6052 {
6053 access_path = BASELINK_ACCESS_BINFO (rhs);
6054 rhs = BASELINK_FUNCTIONS (rhs);
6055 }
6056
6057 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
6058 deduce any type information. */
6059 if (TREE_CODE (rhs) == NON_DEPENDENT_EXPR)
6060 {
6061 if (flags & tf_error)
6062 error ("not enough type information");
6063 return error_mark_node;
6064 }
6065
6066 /* There only a few kinds of expressions that may have a type
6067 dependent on overload resolution. */
6068 gcc_assert (TREE_CODE (rhs) == ADDR_EXPR
6069 || TREE_CODE (rhs) == COMPONENT_REF
6070 || TREE_CODE (rhs) == COMPOUND_EXPR
6071 || really_overloaded_fn (rhs));
6072
6073 /* We don't overwrite rhs if it is an overloaded function.
6074 Copying it would destroy the tree link. */
6075 if (TREE_CODE (rhs) != OVERLOAD)
6076 rhs = copy_node (rhs);
6077
6078 /* This should really only be used when attempting to distinguish
6079 what sort of a pointer to function we have. For now, any
6080 arithmetic operation which is not supported on pointers
6081 is rejected as an error. */
6082
6083 switch (TREE_CODE (rhs))
6084 {
6085 case COMPONENT_REF:
6086 {
6087 tree member = TREE_OPERAND (rhs, 1);
6088
6089 member = instantiate_type (lhstype, member, flags);
6090 if (member != error_mark_node
6091 && TREE_SIDE_EFFECTS (TREE_OPERAND (rhs, 0)))
6092 /* Do not lose object's side effects. */
6093 return build2 (COMPOUND_EXPR, TREE_TYPE (member),
6094 TREE_OPERAND (rhs, 0), member);
6095 return member;
6096 }
6097
6098 case OFFSET_REF:
6099 rhs = TREE_OPERAND (rhs, 1);
6100 if (BASELINK_P (rhs))
6101 return instantiate_type (lhstype, rhs, flags_in);
6102
6103 /* This can happen if we are forming a pointer-to-member for a
6104 member template. */
6105 gcc_assert (TREE_CODE (rhs) == TEMPLATE_ID_EXPR);
6106
6107 /* Fall through. */
6108
6109 case TEMPLATE_ID_EXPR:
6110 {
6111 tree fns = TREE_OPERAND (rhs, 0);
6112 tree args = TREE_OPERAND (rhs, 1);
6113
6114 return
6115 resolve_address_of_overloaded_function (lhstype, fns, flags_in,
6116 /*template_only=*/true,
6117 args, access_path);
6118 }
6119
6120 case OVERLOAD:
6121 case FUNCTION_DECL:
6122 return
6123 resolve_address_of_overloaded_function (lhstype, rhs, flags_in,
6124 /*template_only=*/false,
6125 /*explicit_targs=*/NULL_TREE,
6126 access_path);
6127
6128 case COMPOUND_EXPR:
6129 TREE_OPERAND (rhs, 0)
6130 = instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
6131 if (TREE_OPERAND (rhs, 0) == error_mark_node)
6132 return error_mark_node;
6133 TREE_OPERAND (rhs, 1)
6134 = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
6135 if (TREE_OPERAND (rhs, 1) == error_mark_node)
6136 return error_mark_node;
6137
6138 TREE_TYPE (rhs) = lhstype;
6139 return rhs;
6140
6141 case ADDR_EXPR:
6142 {
6143 if (PTRMEM_OK_P (rhs))
6144 flags |= tf_ptrmem_ok;
6145
6146 return instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
6147 }
6148
6149 case ERROR_MARK:
6150 return error_mark_node;
6151
6152 default:
6153 gcc_unreachable ();
6154 }
6155 return error_mark_node;
6156 }
6157
6158 /* Return the name of the virtual function pointer field
6159 (as an IDENTIFIER_NODE) for the given TYPE. Note that
6160 this may have to look back through base types to find the
6161 ultimate field name. (For single inheritance, these could
6162 all be the same name. Who knows for multiple inheritance). */
6163
6164 static tree
get_vfield_name(tree type)6165 get_vfield_name (tree type)
6166 {
6167 tree binfo, base_binfo;
6168 char *buf;
6169
6170 for (binfo = TYPE_BINFO (type);
6171 BINFO_N_BASE_BINFOS (binfo);
6172 binfo = base_binfo)
6173 {
6174 base_binfo = BINFO_BASE_BINFO (binfo, 0);
6175
6176 if (BINFO_VIRTUAL_P (base_binfo)
6177 || !TYPE_CONTAINS_VPTR_P (BINFO_TYPE (base_binfo)))
6178 break;
6179 }
6180
6181 type = BINFO_TYPE (binfo);
6182 buf = (char *) alloca (sizeof (VFIELD_NAME_FORMAT)
6183 + TYPE_NAME_LENGTH (type) + 2);
6184 sprintf (buf, VFIELD_NAME_FORMAT,
6185 IDENTIFIER_POINTER (constructor_name (type)));
6186 return get_identifier (buf);
6187 }
6188
6189 void
print_class_statistics(void)6190 print_class_statistics (void)
6191 {
6192 #ifdef GATHER_STATISTICS
6193 fprintf (stderr, "convert_harshness = %d\n", n_convert_harshness);
6194 fprintf (stderr, "compute_conversion_costs = %d\n", n_compute_conversion_costs);
6195 if (n_vtables)
6196 {
6197 fprintf (stderr, "vtables = %d; vtable searches = %d\n",
6198 n_vtables, n_vtable_searches);
6199 fprintf (stderr, "vtable entries = %d; vtable elems = %d\n",
6200 n_vtable_entries, n_vtable_elems);
6201 }
6202 #endif
6203 }
6204
6205 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6206 according to [class]:
6207 The class-name is also inserted
6208 into the scope of the class itself. For purposes of access checking,
6209 the inserted class name is treated as if it were a public member name. */
6210
6211 void
build_self_reference(void)6212 build_self_reference (void)
6213 {
6214 tree name = constructor_name (current_class_type);
6215 tree value = build_lang_decl (TYPE_DECL, name, current_class_type);
6216 tree saved_cas;
6217
6218 DECL_NONLOCAL (value) = 1;
6219 DECL_CONTEXT (value) = current_class_type;
6220 DECL_ARTIFICIAL (value) = 1;
6221 SET_DECL_SELF_REFERENCE_P (value);
6222
6223 if (processing_template_decl)
6224 value = push_template_decl (value);
6225
6226 saved_cas = current_access_specifier;
6227 current_access_specifier = access_public_node;
6228 finish_member_declaration (value);
6229 current_access_specifier = saved_cas;
6230 }
6231
6232 /* Returns 1 if TYPE contains only padding bytes. */
6233
6234 int
is_empty_class(tree type)6235 is_empty_class (tree type)
6236 {
6237 if (type == error_mark_node)
6238 return 0;
6239
6240 if (! IS_AGGR_TYPE (type))
6241 return 0;
6242
6243 /* In G++ 3.2, whether or not a class was empty was determined by
6244 looking at its size. */
6245 if (abi_version_at_least (2))
6246 return CLASSTYPE_EMPTY_P (type);
6247 else
6248 return integer_zerop (CLASSTYPE_SIZE (type));
6249 }
6250
6251 /* Returns true if TYPE contains an empty class. */
6252
6253 static bool
contains_empty_class_p(tree type)6254 contains_empty_class_p (tree type)
6255 {
6256 if (is_empty_class (type))
6257 return true;
6258 if (CLASS_TYPE_P (type))
6259 {
6260 tree field;
6261 tree binfo;
6262 tree base_binfo;
6263 int i;
6264
6265 for (binfo = TYPE_BINFO (type), i = 0;
6266 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
6267 if (contains_empty_class_p (BINFO_TYPE (base_binfo)))
6268 return true;
6269 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
6270 if (TREE_CODE (field) == FIELD_DECL
6271 && !DECL_ARTIFICIAL (field)
6272 && is_empty_class (TREE_TYPE (field)))
6273 return true;
6274 }
6275 else if (TREE_CODE (type) == ARRAY_TYPE)
6276 return contains_empty_class_p (TREE_TYPE (type));
6277 return false;
6278 }
6279
6280 /* Note that NAME was looked up while the current class was being
6281 defined and that the result of that lookup was DECL. */
6282
6283 void
maybe_note_name_used_in_class(tree name,tree decl)6284 maybe_note_name_used_in_class (tree name, tree decl)
6285 {
6286 splay_tree names_used;
6287
6288 /* If we're not defining a class, there's nothing to do. */
6289 if (!(innermost_scope_kind() == sk_class
6290 && TYPE_BEING_DEFINED (current_class_type)))
6291 return;
6292
6293 /* If there's already a binding for this NAME, then we don't have
6294 anything to worry about. */
6295 if (lookup_member (current_class_type, name,
6296 /*protect=*/0, /*want_type=*/false))
6297 return;
6298
6299 if (!current_class_stack[current_class_depth - 1].names_used)
6300 current_class_stack[current_class_depth - 1].names_used
6301 = splay_tree_new (splay_tree_compare_pointers, 0, 0);
6302 names_used = current_class_stack[current_class_depth - 1].names_used;
6303
6304 splay_tree_insert (names_used,
6305 (splay_tree_key) name,
6306 (splay_tree_value) decl);
6307 }
6308
6309 /* Note that NAME was declared (as DECL) in the current class. Check
6310 to see that the declaration is valid. */
6311
6312 void
note_name_declared_in_class(tree name,tree decl)6313 note_name_declared_in_class (tree name, tree decl)
6314 {
6315 splay_tree names_used;
6316 splay_tree_node n;
6317
6318 /* Look to see if we ever used this name. */
6319 names_used
6320 = current_class_stack[current_class_depth - 1].names_used;
6321 if (!names_used)
6322 return;
6323
6324 n = splay_tree_lookup (names_used, (splay_tree_key) name);
6325 if (n)
6326 {
6327 /* [basic.scope.class]
6328
6329 A name N used in a class S shall refer to the same declaration
6330 in its context and when re-evaluated in the completed scope of
6331 S. */
6332 error ("declaration of %q#D", decl);
6333 error ("changes meaning of %qD from %q+#D",
6334 DECL_NAME (OVL_CURRENT (decl)), (tree) n->value);
6335 }
6336 }
6337
6338 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6339 Secondary vtables are merged with primary vtables; this function
6340 will return the VAR_DECL for the primary vtable. */
6341
6342 tree
get_vtbl_decl_for_binfo(tree binfo)6343 get_vtbl_decl_for_binfo (tree binfo)
6344 {
6345 tree decl;
6346
6347 decl = BINFO_VTABLE (binfo);
6348 if (decl && TREE_CODE (decl) == PLUS_EXPR)
6349 {
6350 gcc_assert (TREE_CODE (TREE_OPERAND (decl, 0)) == ADDR_EXPR);
6351 decl = TREE_OPERAND (TREE_OPERAND (decl, 0), 0);
6352 }
6353 if (decl)
6354 gcc_assert (TREE_CODE (decl) == VAR_DECL);
6355 return decl;
6356 }
6357
6358
6359 /* Returns the binfo for the primary base of BINFO. If the resulting
6360 BINFO is a virtual base, and it is inherited elsewhere in the
6361 hierarchy, then the returned binfo might not be the primary base of
6362 BINFO in the complete object. Check BINFO_PRIMARY_P or
6363 BINFO_LOST_PRIMARY_P to be sure. */
6364
6365 static tree
get_primary_binfo(tree binfo)6366 get_primary_binfo (tree binfo)
6367 {
6368 tree primary_base;
6369
6370 primary_base = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (binfo));
6371 if (!primary_base)
6372 return NULL_TREE;
6373
6374 return copied_binfo (primary_base, binfo);
6375 }
6376
6377 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
6378
6379 static int
maybe_indent_hierarchy(FILE * stream,int indent,int indented_p)6380 maybe_indent_hierarchy (FILE * stream, int indent, int indented_p)
6381 {
6382 if (!indented_p)
6383 fprintf (stream, "%*s", indent, "");
6384 return 1;
6385 }
6386
6387 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
6388 INDENT should be zero when called from the top level; it is
6389 incremented recursively. IGO indicates the next expected BINFO in
6390 inheritance graph ordering. */
6391
6392 static tree
dump_class_hierarchy_r(FILE * stream,int flags,tree binfo,tree igo,int indent)6393 dump_class_hierarchy_r (FILE *stream,
6394 int flags,
6395 tree binfo,
6396 tree igo,
6397 int indent)
6398 {
6399 int indented = 0;
6400 tree base_binfo;
6401 int i;
6402
6403 indented = maybe_indent_hierarchy (stream, indent, 0);
6404 fprintf (stream, "%s (0x%lx) ",
6405 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER),
6406 (unsigned long) binfo);
6407 if (binfo != igo)
6408 {
6409 fprintf (stream, "alternative-path\n");
6410 return igo;
6411 }
6412 igo = TREE_CHAIN (binfo);
6413
6414 fprintf (stream, HOST_WIDE_INT_PRINT_DEC,
6415 tree_low_cst (BINFO_OFFSET (binfo), 0));
6416 if (is_empty_class (BINFO_TYPE (binfo)))
6417 fprintf (stream, " empty");
6418 else if (CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (binfo)))
6419 fprintf (stream, " nearly-empty");
6420 if (BINFO_VIRTUAL_P (binfo))
6421 fprintf (stream, " virtual");
6422 fprintf (stream, "\n");
6423
6424 indented = 0;
6425 if (BINFO_PRIMARY_P (binfo))
6426 {
6427 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6428 fprintf (stream, " primary-for %s (0x%lx)",
6429 type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)),
6430 TFF_PLAIN_IDENTIFIER),
6431 (unsigned long)BINFO_INHERITANCE_CHAIN (binfo));
6432 }
6433 if (BINFO_LOST_PRIMARY_P (binfo))
6434 {
6435 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6436 fprintf (stream, " lost-primary");
6437 }
6438 if (indented)
6439 fprintf (stream, "\n");
6440
6441 if (!(flags & TDF_SLIM))
6442 {
6443 int indented = 0;
6444
6445 if (BINFO_SUBVTT_INDEX (binfo))
6446 {
6447 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6448 fprintf (stream, " subvttidx=%s",
6449 expr_as_string (BINFO_SUBVTT_INDEX (binfo),
6450 TFF_PLAIN_IDENTIFIER));
6451 }
6452 if (BINFO_VPTR_INDEX (binfo))
6453 {
6454 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6455 fprintf (stream, " vptridx=%s",
6456 expr_as_string (BINFO_VPTR_INDEX (binfo),
6457 TFF_PLAIN_IDENTIFIER));
6458 }
6459 if (BINFO_VPTR_FIELD (binfo))
6460 {
6461 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6462 fprintf (stream, " vbaseoffset=%s",
6463 expr_as_string (BINFO_VPTR_FIELD (binfo),
6464 TFF_PLAIN_IDENTIFIER));
6465 }
6466 if (BINFO_VTABLE (binfo))
6467 {
6468 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6469 fprintf (stream, " vptr=%s",
6470 expr_as_string (BINFO_VTABLE (binfo),
6471 TFF_PLAIN_IDENTIFIER));
6472 }
6473
6474 if (indented)
6475 fprintf (stream, "\n");
6476 }
6477
6478 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
6479 igo = dump_class_hierarchy_r (stream, flags, base_binfo, igo, indent + 2);
6480
6481 return igo;
6482 }
6483
6484 /* Dump the BINFO hierarchy for T. */
6485
6486 static void
dump_class_hierarchy_1(FILE * stream,int flags,tree t)6487 dump_class_hierarchy_1 (FILE *stream, int flags, tree t)
6488 {
6489 fprintf (stream, "Class %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6490 fprintf (stream, " size=%lu align=%lu\n",
6491 (unsigned long)(tree_low_cst (TYPE_SIZE (t), 0) / BITS_PER_UNIT),
6492 (unsigned long)(TYPE_ALIGN (t) / BITS_PER_UNIT));
6493 fprintf (stream, " base size=%lu base align=%lu\n",
6494 (unsigned long)(tree_low_cst (TYPE_SIZE (CLASSTYPE_AS_BASE (t)), 0)
6495 / BITS_PER_UNIT),
6496 (unsigned long)(TYPE_ALIGN (CLASSTYPE_AS_BASE (t))
6497 / BITS_PER_UNIT));
6498 dump_class_hierarchy_r (stream, flags, TYPE_BINFO (t), TYPE_BINFO (t), 0);
6499 fprintf (stream, "\n");
6500 }
6501
6502 /* Debug interface to hierarchy dumping. */
6503
6504 void
debug_class(tree t)6505 debug_class (tree t)
6506 {
6507 dump_class_hierarchy_1 (stderr, TDF_SLIM, t);
6508 }
6509
6510 static void
dump_class_hierarchy(tree t)6511 dump_class_hierarchy (tree t)
6512 {
6513 int flags;
6514 FILE *stream = dump_begin (TDI_class, &flags);
6515
6516 if (stream)
6517 {
6518 dump_class_hierarchy_1 (stream, flags, t);
6519 dump_end (TDI_class, stream);
6520 }
6521 }
6522
6523 static void
dump_array(FILE * stream,tree decl)6524 dump_array (FILE * stream, tree decl)
6525 {
6526 tree value;
6527 unsigned HOST_WIDE_INT ix;
6528 HOST_WIDE_INT elt;
6529 tree size = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (decl)));
6530
6531 elt = (tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl))), 0)
6532 / BITS_PER_UNIT);
6533 fprintf (stream, "%s:", decl_as_string (decl, TFF_PLAIN_IDENTIFIER));
6534 fprintf (stream, " %s entries",
6535 expr_as_string (size_binop (PLUS_EXPR, size, size_one_node),
6536 TFF_PLAIN_IDENTIFIER));
6537 fprintf (stream, "\n");
6538
6539 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (DECL_INITIAL (decl)),
6540 ix, value)
6541 fprintf (stream, "%-4ld %s\n", (long)(ix * elt),
6542 expr_as_string (value, TFF_PLAIN_IDENTIFIER));
6543 }
6544
6545 static void
dump_vtable(tree t,tree binfo,tree vtable)6546 dump_vtable (tree t, tree binfo, tree vtable)
6547 {
6548 int flags;
6549 FILE *stream = dump_begin (TDI_class, &flags);
6550
6551 if (!stream)
6552 return;
6553
6554 if (!(flags & TDF_SLIM))
6555 {
6556 int ctor_vtbl_p = TYPE_BINFO (t) != binfo;
6557
6558 fprintf (stream, "%s for %s",
6559 ctor_vtbl_p ? "Construction vtable" : "Vtable",
6560 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER));
6561 if (ctor_vtbl_p)
6562 {
6563 if (!BINFO_VIRTUAL_P (binfo))
6564 fprintf (stream, " (0x%lx instance)", (unsigned long)binfo);
6565 fprintf (stream, " in %s", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6566 }
6567 fprintf (stream, "\n");
6568 dump_array (stream, vtable);
6569 fprintf (stream, "\n");
6570 }
6571
6572 dump_end (TDI_class, stream);
6573 }
6574
6575 static void
dump_vtt(tree t,tree vtt)6576 dump_vtt (tree t, tree vtt)
6577 {
6578 int flags;
6579 FILE *stream = dump_begin (TDI_class, &flags);
6580
6581 if (!stream)
6582 return;
6583
6584 if (!(flags & TDF_SLIM))
6585 {
6586 fprintf (stream, "VTT for %s\n",
6587 type_as_string (t, TFF_PLAIN_IDENTIFIER));
6588 dump_array (stream, vtt);
6589 fprintf (stream, "\n");
6590 }
6591
6592 dump_end (TDI_class, stream);
6593 }
6594
6595 /* Dump a function or thunk and its thunkees. */
6596
6597 static void
dump_thunk(FILE * stream,int indent,tree thunk)6598 dump_thunk (FILE *stream, int indent, tree thunk)
6599 {
6600 static const char spaces[] = " ";
6601 tree name = DECL_NAME (thunk);
6602 tree thunks;
6603
6604 fprintf (stream, "%.*s%p %s %s", indent, spaces,
6605 (void *)thunk,
6606 !DECL_THUNK_P (thunk) ? "function"
6607 : DECL_THIS_THUNK_P (thunk) ? "this-thunk" : "covariant-thunk",
6608 name ? IDENTIFIER_POINTER (name) : "<unset>");
6609 if (DECL_THUNK_P (thunk))
6610 {
6611 HOST_WIDE_INT fixed_adjust = THUNK_FIXED_OFFSET (thunk);
6612 tree virtual_adjust = THUNK_VIRTUAL_OFFSET (thunk);
6613
6614 fprintf (stream, " fixed=" HOST_WIDE_INT_PRINT_DEC, fixed_adjust);
6615 if (!virtual_adjust)
6616 /*NOP*/;
6617 else if (DECL_THIS_THUNK_P (thunk))
6618 fprintf (stream, " vcall=" HOST_WIDE_INT_PRINT_DEC,
6619 tree_low_cst (virtual_adjust, 0));
6620 else
6621 fprintf (stream, " vbase=" HOST_WIDE_INT_PRINT_DEC "(%s)",
6622 tree_low_cst (BINFO_VPTR_FIELD (virtual_adjust), 0),
6623 type_as_string (BINFO_TYPE (virtual_adjust), TFF_SCOPE));
6624 if (THUNK_ALIAS (thunk))
6625 fprintf (stream, " alias to %p", (void *)THUNK_ALIAS (thunk));
6626 }
6627 fprintf (stream, "\n");
6628 for (thunks = DECL_THUNKS (thunk); thunks; thunks = TREE_CHAIN (thunks))
6629 dump_thunk (stream, indent + 2, thunks);
6630 }
6631
6632 /* Dump the thunks for FN. */
6633
6634 void
debug_thunks(tree fn)6635 debug_thunks (tree fn)
6636 {
6637 dump_thunk (stderr, 0, fn);
6638 }
6639
6640 /* Virtual function table initialization. */
6641
6642 /* Create all the necessary vtables for T and its base classes. */
6643
6644 static void
finish_vtbls(tree t)6645 finish_vtbls (tree t)
6646 {
6647 tree list;
6648 tree vbase;
6649
6650 /* We lay out the primary and secondary vtables in one contiguous
6651 vtable. The primary vtable is first, followed by the non-virtual
6652 secondary vtables in inheritance graph order. */
6653 list = build_tree_list (BINFO_VTABLE (TYPE_BINFO (t)), NULL_TREE);
6654 accumulate_vtbl_inits (TYPE_BINFO (t), TYPE_BINFO (t),
6655 TYPE_BINFO (t), t, list);
6656
6657 /* Then come the virtual bases, also in inheritance graph order. */
6658 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
6659 {
6660 if (!BINFO_VIRTUAL_P (vbase))
6661 continue;
6662 accumulate_vtbl_inits (vbase, vbase, TYPE_BINFO (t), t, list);
6663 }
6664
6665 if (BINFO_VTABLE (TYPE_BINFO (t)))
6666 initialize_vtable (TYPE_BINFO (t), TREE_VALUE (list));
6667 }
6668
6669 /* Initialize the vtable for BINFO with the INITS. */
6670
6671 static void
initialize_vtable(tree binfo,tree inits)6672 initialize_vtable (tree binfo, tree inits)
6673 {
6674 tree decl;
6675
6676 layout_vtable_decl (binfo, list_length (inits));
6677 decl = get_vtbl_decl_for_binfo (binfo);
6678 initialize_artificial_var (decl, inits);
6679 dump_vtable (BINFO_TYPE (binfo), binfo, decl);
6680 }
6681
6682 /* Build the VTT (virtual table table) for T.
6683 A class requires a VTT if it has virtual bases.
6684
6685 This holds
6686 1 - primary virtual pointer for complete object T
6687 2 - secondary VTTs for each direct non-virtual base of T which requires a
6688 VTT
6689 3 - secondary virtual pointers for each direct or indirect base of T which
6690 has virtual bases or is reachable via a virtual path from T.
6691 4 - secondary VTTs for each direct or indirect virtual base of T.
6692
6693 Secondary VTTs look like complete object VTTs without part 4. */
6694
6695 static void
build_vtt(tree t)6696 build_vtt (tree t)
6697 {
6698 tree inits;
6699 tree type;
6700 tree vtt;
6701 tree index;
6702
6703 /* Build up the initializers for the VTT. */
6704 inits = NULL_TREE;
6705 index = size_zero_node;
6706 build_vtt_inits (TYPE_BINFO (t), t, &inits, &index);
6707
6708 /* If we didn't need a VTT, we're done. */
6709 if (!inits)
6710 return;
6711
6712 /* Figure out the type of the VTT. */
6713 type = build_index_type (size_int (list_length (inits) - 1));
6714 type = build_cplus_array_type (const_ptr_type_node, type);
6715
6716 /* Now, build the VTT object itself. */
6717 vtt = build_vtable (t, mangle_vtt_for_type (t), type);
6718 initialize_artificial_var (vtt, inits);
6719 /* Add the VTT to the vtables list. */
6720 TREE_CHAIN (vtt) = TREE_CHAIN (CLASSTYPE_VTABLES (t));
6721 TREE_CHAIN (CLASSTYPE_VTABLES (t)) = vtt;
6722
6723 dump_vtt (t, vtt);
6724 }
6725
6726 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
6727 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
6728 and CHAIN the vtable pointer for this binfo after construction is
6729 complete. VALUE can also be another BINFO, in which case we recurse. */
6730
6731 static tree
binfo_ctor_vtable(tree binfo)6732 binfo_ctor_vtable (tree binfo)
6733 {
6734 tree vt;
6735
6736 while (1)
6737 {
6738 vt = BINFO_VTABLE (binfo);
6739 if (TREE_CODE (vt) == TREE_LIST)
6740 vt = TREE_VALUE (vt);
6741 if (TREE_CODE (vt) == TREE_BINFO)
6742 binfo = vt;
6743 else
6744 break;
6745 }
6746
6747 return vt;
6748 }
6749
6750 /* Data for secondary VTT initialization. */
6751 typedef struct secondary_vptr_vtt_init_data_s
6752 {
6753 /* Is this the primary VTT? */
6754 bool top_level_p;
6755
6756 /* Current index into the VTT. */
6757 tree index;
6758
6759 /* TREE_LIST of initializers built up. */
6760 tree inits;
6761
6762 /* The type being constructed by this secondary VTT. */
6763 tree type_being_constructed;
6764 } secondary_vptr_vtt_init_data;
6765
6766 /* Recursively build the VTT-initializer for BINFO (which is in the
6767 hierarchy dominated by T). INITS points to the end of the initializer
6768 list to date. INDEX is the VTT index where the next element will be
6769 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
6770 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
6771 for virtual bases of T. When it is not so, we build the constructor
6772 vtables for the BINFO-in-T variant. */
6773
6774 static tree *
build_vtt_inits(tree binfo,tree t,tree * inits,tree * index)6775 build_vtt_inits (tree binfo, tree t, tree *inits, tree *index)
6776 {
6777 int i;
6778 tree b;
6779 tree init;
6780 tree secondary_vptrs;
6781 secondary_vptr_vtt_init_data data;
6782 int top_level_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
6783
6784 /* We only need VTTs for subobjects with virtual bases. */
6785 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
6786 return inits;
6787
6788 /* We need to use a construction vtable if this is not the primary
6789 VTT. */
6790 if (!top_level_p)
6791 {
6792 build_ctor_vtbl_group (binfo, t);
6793
6794 /* Record the offset in the VTT where this sub-VTT can be found. */
6795 BINFO_SUBVTT_INDEX (binfo) = *index;
6796 }
6797
6798 /* Add the address of the primary vtable for the complete object. */
6799 init = binfo_ctor_vtable (binfo);
6800 *inits = build_tree_list (NULL_TREE, init);
6801 inits = &TREE_CHAIN (*inits);
6802 if (top_level_p)
6803 {
6804 gcc_assert (!BINFO_VPTR_INDEX (binfo));
6805 BINFO_VPTR_INDEX (binfo) = *index;
6806 }
6807 *index = size_binop (PLUS_EXPR, *index, TYPE_SIZE_UNIT (ptr_type_node));
6808
6809 /* Recursively add the secondary VTTs for non-virtual bases. */
6810 for (i = 0; BINFO_BASE_ITERATE (binfo, i, b); ++i)
6811 if (!BINFO_VIRTUAL_P (b))
6812 inits = build_vtt_inits (b, t, inits, index);
6813
6814 /* Add secondary virtual pointers for all subobjects of BINFO with
6815 either virtual bases or reachable along a virtual path, except
6816 subobjects that are non-virtual primary bases. */
6817 data.top_level_p = top_level_p;
6818 data.index = *index;
6819 data.inits = NULL;
6820 data.type_being_constructed = BINFO_TYPE (binfo);
6821
6822 dfs_walk_once (binfo, dfs_build_secondary_vptr_vtt_inits, NULL, &data);
6823
6824 *index = data.index;
6825
6826 /* The secondary vptrs come back in reverse order. After we reverse
6827 them, and add the INITS, the last init will be the first element
6828 of the chain. */
6829 secondary_vptrs = data.inits;
6830 if (secondary_vptrs)
6831 {
6832 *inits = nreverse (secondary_vptrs);
6833 inits = &TREE_CHAIN (secondary_vptrs);
6834 gcc_assert (*inits == NULL_TREE);
6835 }
6836
6837 if (top_level_p)
6838 /* Add the secondary VTTs for virtual bases in inheritance graph
6839 order. */
6840 for (b = TYPE_BINFO (BINFO_TYPE (binfo)); b; b = TREE_CHAIN (b))
6841 {
6842 if (!BINFO_VIRTUAL_P (b))
6843 continue;
6844
6845 inits = build_vtt_inits (b, t, inits, index);
6846 }
6847 else
6848 /* Remove the ctor vtables we created. */
6849 dfs_walk_all (binfo, dfs_fixup_binfo_vtbls, NULL, binfo);
6850
6851 return inits;
6852 }
6853
6854 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
6855 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
6856
6857 static tree
dfs_build_secondary_vptr_vtt_inits(tree binfo,void * data_)6858 dfs_build_secondary_vptr_vtt_inits (tree binfo, void *data_)
6859 {
6860 secondary_vptr_vtt_init_data *data = (secondary_vptr_vtt_init_data *)data_;
6861
6862 /* We don't care about bases that don't have vtables. */
6863 if (!TYPE_VFIELD (BINFO_TYPE (binfo)))
6864 return dfs_skip_bases;
6865
6866 /* We're only interested in proper subobjects of the type being
6867 constructed. */
6868 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->type_being_constructed))
6869 return NULL_TREE;
6870
6871 /* We're only interested in bases with virtual bases or reachable
6872 via a virtual path from the type being constructed. */
6873 if (!(CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
6874 || binfo_via_virtual (binfo, data->type_being_constructed)))
6875 return dfs_skip_bases;
6876
6877 /* We're not interested in non-virtual primary bases. */
6878 if (!BINFO_VIRTUAL_P (binfo) && BINFO_PRIMARY_P (binfo))
6879 return NULL_TREE;
6880
6881 /* Record the index where this secondary vptr can be found. */
6882 if (data->top_level_p)
6883 {
6884 gcc_assert (!BINFO_VPTR_INDEX (binfo));
6885 BINFO_VPTR_INDEX (binfo) = data->index;
6886
6887 if (BINFO_VIRTUAL_P (binfo))
6888 {
6889 /* It's a primary virtual base, and this is not a
6890 construction vtable. Find the base this is primary of in
6891 the inheritance graph, and use that base's vtable
6892 now. */
6893 while (BINFO_PRIMARY_P (binfo))
6894 binfo = BINFO_INHERITANCE_CHAIN (binfo);
6895 }
6896 }
6897
6898 /* Add the initializer for the secondary vptr itself. */
6899 data->inits = tree_cons (NULL_TREE, binfo_ctor_vtable (binfo), data->inits);
6900
6901 /* Advance the vtt index. */
6902 data->index = size_binop (PLUS_EXPR, data->index,
6903 TYPE_SIZE_UNIT (ptr_type_node));
6904
6905 return NULL_TREE;
6906 }
6907
6908 /* Called from build_vtt_inits via dfs_walk. After building
6909 constructor vtables and generating the sub-vtt from them, we need
6910 to restore the BINFO_VTABLES that were scribbled on. DATA is the
6911 binfo of the base whose sub vtt was generated. */
6912
6913 static tree
dfs_fixup_binfo_vtbls(tree binfo,void * data)6914 dfs_fixup_binfo_vtbls (tree binfo, void* data)
6915 {
6916 tree vtable = BINFO_VTABLE (binfo);
6917
6918 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
6919 /* If this class has no vtable, none of its bases do. */
6920 return dfs_skip_bases;
6921
6922 if (!vtable)
6923 /* This might be a primary base, so have no vtable in this
6924 hierarchy. */
6925 return NULL_TREE;
6926
6927 /* If we scribbled the construction vtable vptr into BINFO, clear it
6928 out now. */
6929 if (TREE_CODE (vtable) == TREE_LIST
6930 && (TREE_PURPOSE (vtable) == (tree) data))
6931 BINFO_VTABLE (binfo) = TREE_CHAIN (vtable);
6932
6933 return NULL_TREE;
6934 }
6935
6936 /* Build the construction vtable group for BINFO which is in the
6937 hierarchy dominated by T. */
6938
6939 static void
build_ctor_vtbl_group(tree binfo,tree t)6940 build_ctor_vtbl_group (tree binfo, tree t)
6941 {
6942 tree list;
6943 tree type;
6944 tree vtbl;
6945 tree inits;
6946 tree id;
6947 tree vbase;
6948
6949 /* See if we've already created this construction vtable group. */
6950 id = mangle_ctor_vtbl_for_type (t, binfo);
6951 if (IDENTIFIER_GLOBAL_VALUE (id))
6952 return;
6953
6954 gcc_assert (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t));
6955 /* Build a version of VTBL (with the wrong type) for use in
6956 constructing the addresses of secondary vtables in the
6957 construction vtable group. */
6958 vtbl = build_vtable (t, id, ptr_type_node);
6959 DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1;
6960 list = build_tree_list (vtbl, NULL_TREE);
6961 accumulate_vtbl_inits (binfo, TYPE_BINFO (TREE_TYPE (binfo)),
6962 binfo, t, list);
6963
6964 /* Add the vtables for each of our virtual bases using the vbase in T
6965 binfo. */
6966 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
6967 vbase;
6968 vbase = TREE_CHAIN (vbase))
6969 {
6970 tree b;
6971
6972 if (!BINFO_VIRTUAL_P (vbase))
6973 continue;
6974 b = copied_binfo (vbase, binfo);
6975
6976 accumulate_vtbl_inits (b, vbase, binfo, t, list);
6977 }
6978 inits = TREE_VALUE (list);
6979
6980 /* Figure out the type of the construction vtable. */
6981 type = build_index_type (size_int (list_length (inits) - 1));
6982 type = build_cplus_array_type (vtable_entry_type, type);
6983 TREE_TYPE (vtbl) = type;
6984
6985 /* Initialize the construction vtable. */
6986 CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl);
6987 initialize_artificial_var (vtbl, inits);
6988 dump_vtable (t, binfo, vtbl);
6989 }
6990
6991 /* Add the vtbl initializers for BINFO (and its bases other than
6992 non-virtual primaries) to the list of INITS. BINFO is in the
6993 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
6994 the constructor the vtbl inits should be accumulated for. (If this
6995 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
6996 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
6997 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
6998 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
6999 but are not necessarily the same in terms of layout. */
7000
7001 static void
accumulate_vtbl_inits(tree binfo,tree orig_binfo,tree rtti_binfo,tree t,tree inits)7002 accumulate_vtbl_inits (tree binfo,
7003 tree orig_binfo,
7004 tree rtti_binfo,
7005 tree t,
7006 tree inits)
7007 {
7008 int i;
7009 tree base_binfo;
7010 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7011
7012 gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (orig_binfo)));
7013
7014 /* If it doesn't have a vptr, we don't do anything. */
7015 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
7016 return;
7017
7018 /* If we're building a construction vtable, we're not interested in
7019 subobjects that don't require construction vtables. */
7020 if (ctor_vtbl_p
7021 && !CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
7022 && !binfo_via_virtual (orig_binfo, BINFO_TYPE (rtti_binfo)))
7023 return;
7024
7025 /* Build the initializers for the BINFO-in-T vtable. */
7026 TREE_VALUE (inits)
7027 = chainon (TREE_VALUE (inits),
7028 dfs_accumulate_vtbl_inits (binfo, orig_binfo,
7029 rtti_binfo, t, inits));
7030
7031 /* Walk the BINFO and its bases. We walk in preorder so that as we
7032 initialize each vtable we can figure out at what offset the
7033 secondary vtable lies from the primary vtable. We can't use
7034 dfs_walk here because we need to iterate through bases of BINFO
7035 and RTTI_BINFO simultaneously. */
7036 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7037 {
7038 /* Skip virtual bases. */
7039 if (BINFO_VIRTUAL_P (base_binfo))
7040 continue;
7041 accumulate_vtbl_inits (base_binfo,
7042 BINFO_BASE_BINFO (orig_binfo, i),
7043 rtti_binfo, t,
7044 inits);
7045 }
7046 }
7047
7048 /* Called from accumulate_vtbl_inits. Returns the initializers for
7049 the BINFO vtable. */
7050
7051 static tree
dfs_accumulate_vtbl_inits(tree binfo,tree orig_binfo,tree rtti_binfo,tree t,tree l)7052 dfs_accumulate_vtbl_inits (tree binfo,
7053 tree orig_binfo,
7054 tree rtti_binfo,
7055 tree t,
7056 tree l)
7057 {
7058 tree inits = NULL_TREE;
7059 tree vtbl = NULL_TREE;
7060 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7061
7062 if (ctor_vtbl_p
7063 && BINFO_VIRTUAL_P (orig_binfo) && BINFO_PRIMARY_P (orig_binfo))
7064 {
7065 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7066 primary virtual base. If it is not the same primary in
7067 the hierarchy of T, we'll need to generate a ctor vtable
7068 for it, to place at its location in T. If it is the same
7069 primary, we still need a VTT entry for the vtable, but it
7070 should point to the ctor vtable for the base it is a
7071 primary for within the sub-hierarchy of RTTI_BINFO.
7072
7073 There are three possible cases:
7074
7075 1) We are in the same place.
7076 2) We are a primary base within a lost primary virtual base of
7077 RTTI_BINFO.
7078 3) We are primary to something not a base of RTTI_BINFO. */
7079
7080 tree b;
7081 tree last = NULL_TREE;
7082
7083 /* First, look through the bases we are primary to for RTTI_BINFO
7084 or a virtual base. */
7085 b = binfo;
7086 while (BINFO_PRIMARY_P (b))
7087 {
7088 b = BINFO_INHERITANCE_CHAIN (b);
7089 last = b;
7090 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7091 goto found;
7092 }
7093 /* If we run out of primary links, keep looking down our
7094 inheritance chain; we might be an indirect primary. */
7095 for (b = last; b; b = BINFO_INHERITANCE_CHAIN (b))
7096 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7097 break;
7098 found:
7099
7100 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
7101 base B and it is a base of RTTI_BINFO, this is case 2. In
7102 either case, we share our vtable with LAST, i.e. the
7103 derived-most base within B of which we are a primary. */
7104 if (b == rtti_binfo
7105 || (b && binfo_for_vbase (BINFO_TYPE (b), BINFO_TYPE (rtti_binfo))))
7106 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7107 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
7108 binfo_ctor_vtable after everything's been set up. */
7109 vtbl = last;
7110
7111 /* Otherwise, this is case 3 and we get our own. */
7112 }
7113 else if (!BINFO_NEW_VTABLE_MARKED (orig_binfo))
7114 return inits;
7115
7116 if (!vtbl)
7117 {
7118 tree index;
7119 int non_fn_entries;
7120
7121 /* Compute the initializer for this vtable. */
7122 inits = build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo,
7123 &non_fn_entries);
7124
7125 /* Figure out the position to which the VPTR should point. */
7126 vtbl = TREE_PURPOSE (l);
7127 vtbl = build_address (vtbl);
7128 /* ??? We should call fold_convert to convert the address to
7129 vtbl_ptr_type_node, which is the type of elements in the
7130 vtable. However, the resulting NOP_EXPRs confuse other parts
7131 of the C++ front end. */
7132 gcc_assert (TREE_CODE (vtbl) == ADDR_EXPR);
7133 TREE_TYPE (vtbl) = vtbl_ptr_type_node;
7134 index = size_binop (PLUS_EXPR,
7135 size_int (non_fn_entries),
7136 size_int (list_length (TREE_VALUE (l))));
7137 index = size_binop (MULT_EXPR,
7138 TYPE_SIZE_UNIT (vtable_entry_type),
7139 index);
7140 vtbl = build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, index);
7141 }
7142
7143 if (ctor_vtbl_p)
7144 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7145 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
7146 straighten this out. */
7147 BINFO_VTABLE (binfo) = tree_cons (rtti_binfo, vtbl, BINFO_VTABLE (binfo));
7148 else if (BINFO_PRIMARY_P (binfo) && BINFO_VIRTUAL_P (binfo))
7149 inits = NULL_TREE;
7150 else
7151 /* For an ordinary vtable, set BINFO_VTABLE. */
7152 BINFO_VTABLE (binfo) = vtbl;
7153
7154 return inits;
7155 }
7156
7157 static GTY(()) tree abort_fndecl_addr;
7158
7159 /* Construct the initializer for BINFO's virtual function table. BINFO
7160 is part of the hierarchy dominated by T. If we're building a
7161 construction vtable, the ORIG_BINFO is the binfo we should use to
7162 find the actual function pointers to put in the vtable - but they
7163 can be overridden on the path to most-derived in the graph that
7164 ORIG_BINFO belongs. Otherwise,
7165 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
7166 BINFO that should be indicated by the RTTI information in the
7167 vtable; it will be a base class of T, rather than T itself, if we
7168 are building a construction vtable.
7169
7170 The value returned is a TREE_LIST suitable for wrapping in a
7171 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
7172 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7173 number of non-function entries in the vtable.
7174
7175 It might seem that this function should never be called with a
7176 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7177 base is always subsumed by a derived class vtable. However, when
7178 we are building construction vtables, we do build vtables for
7179 primary bases; we need these while the primary base is being
7180 constructed. */
7181
7182 static tree
build_vtbl_initializer(tree binfo,tree orig_binfo,tree t,tree rtti_binfo,int * non_fn_entries_p)7183 build_vtbl_initializer (tree binfo,
7184 tree orig_binfo,
7185 tree t,
7186 tree rtti_binfo,
7187 int* non_fn_entries_p)
7188 {
7189 tree v, b;
7190 tree vfun_inits;
7191 vtbl_init_data vid;
7192 unsigned ix;
7193 tree vbinfo;
7194 VEC(tree,gc) *vbases;
7195
7196 /* Initialize VID. */
7197 memset (&vid, 0, sizeof (vid));
7198 vid.binfo = binfo;
7199 vid.derived = t;
7200 vid.rtti_binfo = rtti_binfo;
7201 vid.last_init = &vid.inits;
7202 vid.primary_vtbl_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
7203 vid.ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7204 vid.generate_vcall_entries = true;
7205 /* The first vbase or vcall offset is at index -3 in the vtable. */
7206 vid.index = ssize_int(-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE);
7207
7208 /* Add entries to the vtable for RTTI. */
7209 build_rtti_vtbl_entries (binfo, &vid);
7210
7211 /* Create an array for keeping track of the functions we've
7212 processed. When we see multiple functions with the same
7213 signature, we share the vcall offsets. */
7214 vid.fns = VEC_alloc (tree, gc, 32);
7215 /* Add the vcall and vbase offset entries. */
7216 build_vcall_and_vbase_vtbl_entries (binfo, &vid);
7217
7218 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7219 build_vbase_offset_vtbl_entries. */
7220 for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0;
7221 VEC_iterate (tree, vbases, ix, vbinfo); ix++)
7222 BINFO_VTABLE_PATH_MARKED (vbinfo) = 0;
7223
7224 /* If the target requires padding between data entries, add that now. */
7225 if (TARGET_VTABLE_DATA_ENTRY_DISTANCE > 1)
7226 {
7227 tree cur, *prev;
7228
7229 for (prev = &vid.inits; (cur = *prev); prev = &TREE_CHAIN (cur))
7230 {
7231 tree add = cur;
7232 int i;
7233
7234 for (i = 1; i < TARGET_VTABLE_DATA_ENTRY_DISTANCE; ++i)
7235 add = tree_cons (NULL_TREE,
7236 build1 (NOP_EXPR, vtable_entry_type,
7237 null_pointer_node),
7238 add);
7239 *prev = add;
7240 }
7241 }
7242
7243 if (non_fn_entries_p)
7244 *non_fn_entries_p = list_length (vid.inits);
7245
7246 /* Go through all the ordinary virtual functions, building up
7247 initializers. */
7248 vfun_inits = NULL_TREE;
7249 for (v = BINFO_VIRTUALS (orig_binfo); v; v = TREE_CHAIN (v))
7250 {
7251 tree delta;
7252 tree vcall_index;
7253 tree fn, fn_original;
7254 tree init = NULL_TREE;
7255
7256 fn = BV_FN (v);
7257 fn_original = fn;
7258 if (DECL_THUNK_P (fn))
7259 {
7260 if (!DECL_NAME (fn))
7261 finish_thunk (fn);
7262 if (THUNK_ALIAS (fn))
7263 {
7264 fn = THUNK_ALIAS (fn);
7265 BV_FN (v) = fn;
7266 }
7267 fn_original = THUNK_TARGET (fn);
7268 }
7269
7270 /* If the only definition of this function signature along our
7271 primary base chain is from a lost primary, this vtable slot will
7272 never be used, so just zero it out. This is important to avoid
7273 requiring extra thunks which cannot be generated with the function.
7274
7275 We first check this in update_vtable_entry_for_fn, so we handle
7276 restored primary bases properly; we also need to do it here so we
7277 zero out unused slots in ctor vtables, rather than filling themff
7278 with erroneous values (though harmless, apart from relocation
7279 costs). */
7280 for (b = binfo; ; b = get_primary_binfo (b))
7281 {
7282 /* We found a defn before a lost primary; go ahead as normal. */
7283 if (look_for_overrides_here (BINFO_TYPE (b), fn_original))
7284 break;
7285
7286 /* The nearest definition is from a lost primary; clear the
7287 slot. */
7288 if (BINFO_LOST_PRIMARY_P (b))
7289 {
7290 init = size_zero_node;
7291 break;
7292 }
7293 }
7294
7295 if (! init)
7296 {
7297 /* Pull the offset for `this', and the function to call, out of
7298 the list. */
7299 delta = BV_DELTA (v);
7300 vcall_index = BV_VCALL_INDEX (v);
7301
7302 gcc_assert (TREE_CODE (delta) == INTEGER_CST);
7303 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
7304
7305 /* You can't call an abstract virtual function; it's abstract.
7306 So, we replace these functions with __pure_virtual. */
7307 if (DECL_PURE_VIRTUAL_P (fn_original))
7308 {
7309 fn = abort_fndecl;
7310 if (abort_fndecl_addr == NULL)
7311 abort_fndecl_addr = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7312 init = abort_fndecl_addr;
7313 }
7314 else
7315 {
7316 if (!integer_zerop (delta) || vcall_index)
7317 {
7318 fn = make_thunk (fn, /*this_adjusting=*/1, delta, vcall_index);
7319 if (!DECL_NAME (fn))
7320 finish_thunk (fn);
7321 }
7322 /* Take the address of the function, considering it to be of an
7323 appropriate generic type. */
7324 init = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7325 }
7326 }
7327
7328 /* And add it to the chain of initializers. */
7329 if (TARGET_VTABLE_USES_DESCRIPTORS)
7330 {
7331 int i;
7332 if (init == size_zero_node)
7333 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7334 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7335 else
7336 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7337 {
7338 tree fdesc = build2 (FDESC_EXPR, vfunc_ptr_type_node,
7339 TREE_OPERAND (init, 0),
7340 build_int_cst (NULL_TREE, i));
7341 TREE_CONSTANT (fdesc) = 1;
7342 TREE_INVARIANT (fdesc) = 1;
7343
7344 vfun_inits = tree_cons (NULL_TREE, fdesc, vfun_inits);
7345 }
7346 }
7347 else
7348 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7349 }
7350
7351 /* The initializers for virtual functions were built up in reverse
7352 order; straighten them out now. */
7353 vfun_inits = nreverse (vfun_inits);
7354
7355 /* The negative offset initializers are also in reverse order. */
7356 vid.inits = nreverse (vid.inits);
7357
7358 /* Chain the two together. */
7359 return chainon (vid.inits, vfun_inits);
7360 }
7361
7362 /* Adds to vid->inits the initializers for the vbase and vcall
7363 offsets in BINFO, which is in the hierarchy dominated by T. */
7364
7365 static void
build_vcall_and_vbase_vtbl_entries(tree binfo,vtbl_init_data * vid)7366 build_vcall_and_vbase_vtbl_entries (tree binfo, vtbl_init_data* vid)
7367 {
7368 tree b;
7369
7370 /* If this is a derived class, we must first create entries
7371 corresponding to the primary base class. */
7372 b = get_primary_binfo (binfo);
7373 if (b)
7374 build_vcall_and_vbase_vtbl_entries (b, vid);
7375
7376 /* Add the vbase entries for this base. */
7377 build_vbase_offset_vtbl_entries (binfo, vid);
7378 /* Add the vcall entries for this base. */
7379 build_vcall_offset_vtbl_entries (binfo, vid);
7380 }
7381
7382 /* Returns the initializers for the vbase offset entries in the vtable
7383 for BINFO (which is part of the class hierarchy dominated by T), in
7384 reverse order. VBASE_OFFSET_INDEX gives the vtable index
7385 where the next vbase offset will go. */
7386
7387 static void
build_vbase_offset_vtbl_entries(tree binfo,vtbl_init_data * vid)7388 build_vbase_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7389 {
7390 tree vbase;
7391 tree t;
7392 tree non_primary_binfo;
7393
7394 /* If there are no virtual baseclasses, then there is nothing to
7395 do. */
7396 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
7397 return;
7398
7399 t = vid->derived;
7400
7401 /* We might be a primary base class. Go up the inheritance hierarchy
7402 until we find the most derived class of which we are a primary base:
7403 it is the offset of that which we need to use. */
7404 non_primary_binfo = binfo;
7405 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7406 {
7407 tree b;
7408
7409 /* If we have reached a virtual base, then it must be a primary
7410 base (possibly multi-level) of vid->binfo, or we wouldn't
7411 have called build_vcall_and_vbase_vtbl_entries for it. But it
7412 might be a lost primary, so just skip down to vid->binfo. */
7413 if (BINFO_VIRTUAL_P (non_primary_binfo))
7414 {
7415 non_primary_binfo = vid->binfo;
7416 break;
7417 }
7418
7419 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7420 if (get_primary_binfo (b) != non_primary_binfo)
7421 break;
7422 non_primary_binfo = b;
7423 }
7424
7425 /* Go through the virtual bases, adding the offsets. */
7426 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
7427 vbase;
7428 vbase = TREE_CHAIN (vbase))
7429 {
7430 tree b;
7431 tree delta;
7432
7433 if (!BINFO_VIRTUAL_P (vbase))
7434 continue;
7435
7436 /* Find the instance of this virtual base in the complete
7437 object. */
7438 b = copied_binfo (vbase, binfo);
7439
7440 /* If we've already got an offset for this virtual base, we
7441 don't need another one. */
7442 if (BINFO_VTABLE_PATH_MARKED (b))
7443 continue;
7444 BINFO_VTABLE_PATH_MARKED (b) = 1;
7445
7446 /* Figure out where we can find this vbase offset. */
7447 delta = size_binop (MULT_EXPR,
7448 vid->index,
7449 convert (ssizetype,
7450 TYPE_SIZE_UNIT (vtable_entry_type)));
7451 if (vid->primary_vtbl_p)
7452 BINFO_VPTR_FIELD (b) = delta;
7453
7454 if (binfo != TYPE_BINFO (t))
7455 /* The vbase offset had better be the same. */
7456 gcc_assert (tree_int_cst_equal (delta, BINFO_VPTR_FIELD (vbase)));
7457
7458 /* The next vbase will come at a more negative offset. */
7459 vid->index = size_binop (MINUS_EXPR, vid->index,
7460 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7461
7462 /* The initializer is the delta from BINFO to this virtual base.
7463 The vbase offsets go in reverse inheritance-graph order, and
7464 we are walking in inheritance graph order so these end up in
7465 the right order. */
7466 delta = size_diffop (BINFO_OFFSET (b), BINFO_OFFSET (non_primary_binfo));
7467
7468 *vid->last_init
7469 = build_tree_list (NULL_TREE,
7470 fold_build1 (NOP_EXPR,
7471 vtable_entry_type,
7472 delta));
7473 vid->last_init = &TREE_CHAIN (*vid->last_init);
7474 }
7475 }
7476
7477 /* Adds the initializers for the vcall offset entries in the vtable
7478 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7479 to VID->INITS. */
7480
7481 static void
build_vcall_offset_vtbl_entries(tree binfo,vtbl_init_data * vid)7482 build_vcall_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7483 {
7484 /* We only need these entries if this base is a virtual base. We
7485 compute the indices -- but do not add to the vtable -- when
7486 building the main vtable for a class. */
7487 if (BINFO_VIRTUAL_P (binfo) || binfo == TYPE_BINFO (vid->derived))
7488 {
7489 /* We need a vcall offset for each of the virtual functions in this
7490 vtable. For example:
7491
7492 class A { virtual void f (); };
7493 class B1 : virtual public A { virtual void f (); };
7494 class B2 : virtual public A { virtual void f (); };
7495 class C: public B1, public B2 { virtual void f (); };
7496
7497 A C object has a primary base of B1, which has a primary base of A. A
7498 C also has a secondary base of B2, which no longer has a primary base
7499 of A. So the B2-in-C construction vtable needs a secondary vtable for
7500 A, which will adjust the A* to a B2* to call f. We have no way of
7501 knowing what (or even whether) this offset will be when we define B2,
7502 so we store this "vcall offset" in the A sub-vtable and look it up in
7503 a "virtual thunk" for B2::f.
7504
7505 We need entries for all the functions in our primary vtable and
7506 in our non-virtual bases' secondary vtables. */
7507 vid->vbase = binfo;
7508 /* If we are just computing the vcall indices -- but do not need
7509 the actual entries -- not that. */
7510 if (!BINFO_VIRTUAL_P (binfo))
7511 vid->generate_vcall_entries = false;
7512 /* Now, walk through the non-virtual bases, adding vcall offsets. */
7513 add_vcall_offset_vtbl_entries_r (binfo, vid);
7514 }
7515 }
7516
7517 /* Build vcall offsets, starting with those for BINFO. */
7518
7519 static void
add_vcall_offset_vtbl_entries_r(tree binfo,vtbl_init_data * vid)7520 add_vcall_offset_vtbl_entries_r (tree binfo, vtbl_init_data* vid)
7521 {
7522 int i;
7523 tree primary_binfo;
7524 tree base_binfo;
7525
7526 /* Don't walk into virtual bases -- except, of course, for the
7527 virtual base for which we are building vcall offsets. Any
7528 primary virtual base will have already had its offsets generated
7529 through the recursion in build_vcall_and_vbase_vtbl_entries. */
7530 if (BINFO_VIRTUAL_P (binfo) && vid->vbase != binfo)
7531 return;
7532
7533 /* If BINFO has a primary base, process it first. */
7534 primary_binfo = get_primary_binfo (binfo);
7535 if (primary_binfo)
7536 add_vcall_offset_vtbl_entries_r (primary_binfo, vid);
7537
7538 /* Add BINFO itself to the list. */
7539 add_vcall_offset_vtbl_entries_1 (binfo, vid);
7540
7541 /* Scan the non-primary bases of BINFO. */
7542 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7543 if (base_binfo != primary_binfo)
7544 add_vcall_offset_vtbl_entries_r (base_binfo, vid);
7545 }
7546
7547 /* Called from build_vcall_offset_vtbl_entries_r. */
7548
7549 static void
add_vcall_offset_vtbl_entries_1(tree binfo,vtbl_init_data * vid)7550 add_vcall_offset_vtbl_entries_1 (tree binfo, vtbl_init_data* vid)
7551 {
7552 /* Make entries for the rest of the virtuals. */
7553 if (abi_version_at_least (2))
7554 {
7555 tree orig_fn;
7556
7557 /* The ABI requires that the methods be processed in declaration
7558 order. G++ 3.2 used the order in the vtable. */
7559 for (orig_fn = TYPE_METHODS (BINFO_TYPE (binfo));
7560 orig_fn;
7561 orig_fn = TREE_CHAIN (orig_fn))
7562 if (DECL_VINDEX (orig_fn))
7563 add_vcall_offset (orig_fn, binfo, vid);
7564 }
7565 else
7566 {
7567 tree derived_virtuals;
7568 tree base_virtuals;
7569 tree orig_virtuals;
7570 /* If BINFO is a primary base, the most derived class which has
7571 BINFO as a primary base; otherwise, just BINFO. */
7572 tree non_primary_binfo;
7573
7574 /* We might be a primary base class. Go up the inheritance hierarchy
7575 until we find the most derived class of which we are a primary base:
7576 it is the BINFO_VIRTUALS there that we need to consider. */
7577 non_primary_binfo = binfo;
7578 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7579 {
7580 tree b;
7581
7582 /* If we have reached a virtual base, then it must be vid->vbase,
7583 because we ignore other virtual bases in
7584 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
7585 base (possibly multi-level) of vid->binfo, or we wouldn't
7586 have called build_vcall_and_vbase_vtbl_entries for it. But it
7587 might be a lost primary, so just skip down to vid->binfo. */
7588 if (BINFO_VIRTUAL_P (non_primary_binfo))
7589 {
7590 gcc_assert (non_primary_binfo == vid->vbase);
7591 non_primary_binfo = vid->binfo;
7592 break;
7593 }
7594
7595 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7596 if (get_primary_binfo (b) != non_primary_binfo)
7597 break;
7598 non_primary_binfo = b;
7599 }
7600
7601 if (vid->ctor_vtbl_p)
7602 /* For a ctor vtable we need the equivalent binfo within the hierarchy
7603 where rtti_binfo is the most derived type. */
7604 non_primary_binfo
7605 = original_binfo (non_primary_binfo, vid->rtti_binfo);
7606
7607 for (base_virtuals = BINFO_VIRTUALS (binfo),
7608 derived_virtuals = BINFO_VIRTUALS (non_primary_binfo),
7609 orig_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
7610 base_virtuals;
7611 base_virtuals = TREE_CHAIN (base_virtuals),
7612 derived_virtuals = TREE_CHAIN (derived_virtuals),
7613 orig_virtuals = TREE_CHAIN (orig_virtuals))
7614 {
7615 tree orig_fn;
7616
7617 /* Find the declaration that originally caused this function to
7618 be present in BINFO_TYPE (binfo). */
7619 orig_fn = BV_FN (orig_virtuals);
7620
7621 /* When processing BINFO, we only want to generate vcall slots for
7622 function slots introduced in BINFO. So don't try to generate
7623 one if the function isn't even defined in BINFO. */
7624 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), DECL_CONTEXT (orig_fn)))
7625 continue;
7626
7627 add_vcall_offset (orig_fn, binfo, vid);
7628 }
7629 }
7630 }
7631
7632 /* Add a vcall offset entry for ORIG_FN to the vtable. */
7633
7634 static void
add_vcall_offset(tree orig_fn,tree binfo,vtbl_init_data * vid)7635 add_vcall_offset (tree orig_fn, tree binfo, vtbl_init_data *vid)
7636 {
7637 size_t i;
7638 tree vcall_offset;
7639 tree derived_entry;
7640
7641 /* If there is already an entry for a function with the same
7642 signature as FN, then we do not need a second vcall offset.
7643 Check the list of functions already present in the derived
7644 class vtable. */
7645 for (i = 0; VEC_iterate (tree, vid->fns, i, derived_entry); ++i)
7646 {
7647 if (same_signature_p (derived_entry, orig_fn)
7648 /* We only use one vcall offset for virtual destructors,
7649 even though there are two virtual table entries. */
7650 || (DECL_DESTRUCTOR_P (derived_entry)
7651 && DECL_DESTRUCTOR_P (orig_fn)))
7652 return;
7653 }
7654
7655 /* If we are building these vcall offsets as part of building
7656 the vtable for the most derived class, remember the vcall
7657 offset. */
7658 if (vid->binfo == TYPE_BINFO (vid->derived))
7659 {
7660 tree_pair_p elt = VEC_safe_push (tree_pair_s, gc,
7661 CLASSTYPE_VCALL_INDICES (vid->derived),
7662 NULL);
7663 elt->purpose = orig_fn;
7664 elt->value = vid->index;
7665 }
7666
7667 /* The next vcall offset will be found at a more negative
7668 offset. */
7669 vid->index = size_binop (MINUS_EXPR, vid->index,
7670 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7671
7672 /* Keep track of this function. */
7673 VEC_safe_push (tree, gc, vid->fns, orig_fn);
7674
7675 if (vid->generate_vcall_entries)
7676 {
7677 tree base;
7678 tree fn;
7679
7680 /* Find the overriding function. */
7681 fn = find_final_overrider (vid->rtti_binfo, binfo, orig_fn);
7682 if (fn == error_mark_node)
7683 vcall_offset = build1 (NOP_EXPR, vtable_entry_type,
7684 integer_zero_node);
7685 else
7686 {
7687 base = TREE_VALUE (fn);
7688
7689 /* The vbase we're working on is a primary base of
7690 vid->binfo. But it might be a lost primary, so its
7691 BINFO_OFFSET might be wrong, so we just use the
7692 BINFO_OFFSET from vid->binfo. */
7693 vcall_offset = size_diffop (BINFO_OFFSET (base),
7694 BINFO_OFFSET (vid->binfo));
7695 vcall_offset = fold_build1 (NOP_EXPR, vtable_entry_type,
7696 vcall_offset);
7697 }
7698 /* Add the initializer to the vtable. */
7699 *vid->last_init = build_tree_list (NULL_TREE, vcall_offset);
7700 vid->last_init = &TREE_CHAIN (*vid->last_init);
7701 }
7702 }
7703
7704 /* Return vtbl initializers for the RTTI entries corresponding to the
7705 BINFO's vtable. The RTTI entries should indicate the object given
7706 by VID->rtti_binfo. */
7707
7708 static void
build_rtti_vtbl_entries(tree binfo,vtbl_init_data * vid)7709 build_rtti_vtbl_entries (tree binfo, vtbl_init_data* vid)
7710 {
7711 tree b;
7712 tree t;
7713 tree basetype;
7714 tree offset;
7715 tree decl;
7716 tree init;
7717
7718 basetype = BINFO_TYPE (binfo);
7719 t = BINFO_TYPE (vid->rtti_binfo);
7720
7721 /* To find the complete object, we will first convert to our most
7722 primary base, and then add the offset in the vtbl to that value. */
7723 b = binfo;
7724 while (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (b))
7725 && !BINFO_LOST_PRIMARY_P (b))
7726 {
7727 tree primary_base;
7728
7729 primary_base = get_primary_binfo (b);
7730 gcc_assert (BINFO_PRIMARY_P (primary_base)
7731 && BINFO_INHERITANCE_CHAIN (primary_base) == b);
7732 b = primary_base;
7733 }
7734 offset = size_diffop (BINFO_OFFSET (vid->rtti_binfo), BINFO_OFFSET (b));
7735
7736 /* The second entry is the address of the typeinfo object. */
7737 if (flag_rtti)
7738 decl = build_address (get_tinfo_decl (t));
7739 else
7740 decl = integer_zero_node;
7741
7742 /* Convert the declaration to a type that can be stored in the
7743 vtable. */
7744 init = build_nop (vfunc_ptr_type_node, decl);
7745 *vid->last_init = build_tree_list (NULL_TREE, init);
7746 vid->last_init = &TREE_CHAIN (*vid->last_init);
7747
7748 /* Add the offset-to-top entry. It comes earlier in the vtable than
7749 the typeinfo entry. Convert the offset to look like a
7750 function pointer, so that we can put it in the vtable. */
7751 init = build_nop (vfunc_ptr_type_node, offset);
7752 *vid->last_init = build_tree_list (NULL_TREE, init);
7753 vid->last_init = &TREE_CHAIN (*vid->last_init);
7754 }
7755
7756 /* Fold a OBJ_TYPE_REF expression to the address of a function.
7757 KNOWN_TYPE carries the true type of OBJ_TYPE_REF_OBJECT(REF). */
7758
7759 tree
cp_fold_obj_type_ref(tree ref,tree known_type)7760 cp_fold_obj_type_ref (tree ref, tree known_type)
7761 {
7762 HOST_WIDE_INT index = tree_low_cst (OBJ_TYPE_REF_TOKEN (ref), 1);
7763 HOST_WIDE_INT i = 0;
7764 tree v = BINFO_VIRTUALS (TYPE_BINFO (known_type));
7765 tree fndecl;
7766
7767 while (i != index)
7768 {
7769 i += (TARGET_VTABLE_USES_DESCRIPTORS
7770 ? TARGET_VTABLE_USES_DESCRIPTORS : 1);
7771 v = TREE_CHAIN (v);
7772 }
7773
7774 fndecl = BV_FN (v);
7775
7776 #ifdef ENABLE_CHECKING
7777 gcc_assert (tree_int_cst_equal (OBJ_TYPE_REF_TOKEN (ref),
7778 DECL_VINDEX (fndecl)));
7779 #endif
7780
7781 cgraph_node (fndecl)->local.vtable_method = true;
7782
7783 return build_address (fndecl);
7784 }
7785
7786 #include "gt-cp-class.h"
7787